The photocatalytic and cytotoxic effects of titanium dioxide particles used in sunscreen

NASA Astrophysics Data System (ADS)

Rampaul, Ashti

Titanium dioxide nanoparticles are used in sunscreens to reflect UV radiation from the skin. However, titanium dioxide as anatase and rutile crystal forms is a well-known photocatalyst. The nanoparticles are surface coated with inert inorganic oxides such as silica and alumina or organics such as organosilanes or silicone polymers and more recently, have been doped with manganese oxide. These modifications to the titanium dioxide particles are purported to prevent the production of harmful reactive oxygen species. A range of sunscreens was tested with crystal form and modification type identified via XRD, Raman Spectroscopy, XPS and SSNMR. The particle modification and crystal form determined whether the particles were inert or rapidly degraded methylene blue dye, and killed or protected cultured human epithelium cells. Novel solid state Electron Paramagnetic Resonance analysis showed that the greatest amount of superoxide anions was formed during UVA irradiation of the mixed anatase and rutile crystal forms coated with an organosilane. These particles also degraded methylene blue at a similar rate to Degussa P25, a standard uncoated titanium dioxide powder and produced an increase in UVA induced apoptosis of human keratinocytes. Double Stranded Breaks were observed extensively in cells exposed to UVA irradiated mixed anatase and rutile titanium dioxide with organosilane. A new apoptotic-like cell death mechanism may have been recognised during the UVA irradiation of animal and human cells in the presence of titanium dioxide. This research concludes that mixed anatase and rutile crystal forms of titanium dioxide coated with organosilane or dimethicone may not be safe to use in sunscreen lotions. A less harmful alternative for sunscreen formulations is the manganese doped rutile particles or the alumina coated rutile powders, both of which exhibited a protective effect on cultured epithelial cells.

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a...

Thermal oxidation of silicon in a residual oxygen atmosphere—the RESOX process—for self-limiting growth of thin silicon dioxide films

NASA Astrophysics Data System (ADS)

Wright, Jason T.; Carbaugh, Daniel J.; Haggerty, Morgan E.; Richard, Andrea L.; Ingram, David C.; Kaya, Savas; Jadwisienczak, Wojciech M.; Rahman, Faiz

2016-10-01

We describe in detail the growth procedures and properties of thermal silicon dioxide grown in a limited and dilute oxygen atmosphere. Thin thermal oxide films have become increasingly important in recent years due to the continuing down-scaling of ultra large scale integration metal oxide silicon field effect transistors. Such films are also of importance for organic transistors where back-gating is needed. The technique described here is novel and allows self-limited formation of high quality thin oxide films on silicon surfaces. This technique is easy to implement in both research laboratory and industrial settings. Growth conditions and their effects on film growth have been described. Properties of the resulting oxide films, relevant for microelectronic device applications, have also been investigated and reported here. Overall, our findings are that thin, high quality, dense silicon dioxide films of thicknesses up to 100 nm can be easily grown in a depleted oxygen environment at temperatures similar to that used for usual silicon dioxide thermal growth in flowing dry oxygen.

Advances on simultaneous desulfurization and denitrification using activated carbon irradiated by microwaves.

PubMed

Ma, Shuang-Chen; Gao, Li; Ma, Jing-Xiang; Jin, Xin; Yao, Juan-Juan; Zhao, Yi

2012-06-01

This paper describes the research background and chemistry of desulfurization and denitrification technology using microwave irradiation. Microwave-induced catalysis combined with activated carbon adsorption and reduction can reduce nitric oxide to nitrogen and sulfur dioxide to sulfur from flue gas effectively. This paper also highlights the main drawbacks of this technology and discusses future development trends. It is reported that the removal of sulfur dioxide and nitric oxide using microwave irradiation has broad prospects for development in the field of air pollution control.

NATIONAL PERFORMANCE AUDIT PROGRAM: 1979 PROFICIENCY SURVEYS FOR SULFUR DIOXIDE, NITROGEN DIOXIDE, CARBON MONOXIDE, SULFATE, NITRATE, LEAD AND HIGH VOLUME FLOW

EPA Science Inventory

The Quality Assurance Division of the Environmental Monitoring Systems Laboratory, Research Triangle Park, North Carolina, administers semiannual Surveys of Analytical Proficiency for sulfur dioxide, nitrogen dioxide, carbon monoxide, sulfate, nitrate and lead. Sample material, s...

Technical and economical evaluation of carbon dioxide capture and conversion to methanol process

NASA Astrophysics Data System (ADS)

Putra, Aditya Anugerah; Juwari, Handogo, Renanto

2017-05-01

Phenomenon of global warming, which is indicated by increasing of earth's surface temperature, is caused by high level of greenhouse gases level in the atmosphere. Carbon dioxide, which increases year by year because of high demand of energy, gives the largest contribution in greenhouse gases. One of the most applied solution to mitigate carbon dioxide level is post-combustion carbon capture technology. Although the technology can absorb up to 90% of carbon dioxide produced, some worries occur that captured carbon dioxide that is stored underground will be released over time. Utilizing captured carbon dioxide could be a promising solution. Captured carbon dioxide can be converted into more valuable material, such as methanol. This research will evaluate the conversion process of captured carbon dioxide to methanol, technically and economically. From the research, it is found that technically methanol can be made from captured carbon dioxide. Product gives 25.6905 kg/s flow with 99.69% purity of methanol. Economical evaluation of the whole conversion process shows that the process is economically feasible. The capture and conversion process needs 176,101,157.69 per year for total annual cost and can be overcome by revenue gained from methanol product sales.

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-20 Carbon dioxide storage. (a) Except as provided in...

Effect of drying environment on grain size of titanium dioxide nano-powder synthesized via sol-gel method

NASA Astrophysics Data System (ADS)

Zandi, Pegah; Hosseini, Elham; Rashchi, Fereshteh

2018-01-01

Titanium dioxide Nano powder has been synthesized from titanium isopropoxide (TTIP) in chloride media by sol-gel method. In this research, the effect of the drying environment, from air to oven drying at 100 °C, calcination time and temperature on nano TiO2 grain size was investigated. The synthesized powder was analyzed by x-ray diffraction and scanning electron microscope. Based on the results, the powder has been crystallized in anatase and rutile phases, due to different calcination temperatures. At temperatures above 600 °C, the Titanium dioxide nano powder has been crystallized as rutile. The crystalline structure of titanium dioxide nano powder changed because of the different calcination temperatures and time applied. The average particle size of the powder dried in air was larger than the powder dried in oven. The minimum particle size of the powder dried in air was 50 nm and in the oven was 9 nm, observed and calculated Williamson-Hall equation. All in all, with overall increasing of calcination time and temperature the grain size increased. Moreover, in the case of temperature, after a certain temperature, the grain size became constant and didn't change significantly.

Occurrence and attempted mitigation of carbon dioxide in a home constructed on reclaimed coal-mine spoil, Pike County, Indiana

USGS Publications Warehouse

Robinson, Bret A.

2010-01-01

In recent years carbon dioxide intrusion has become recognized as a potentially serious health threat where homes are constructed on or near reclaimed surface coal mines. When carbon dioxide invades the living space of a home, it can collect near the floor, displace the oxygen there, and produce an oxygen-deficient environment. In this investigation, several lines of inquiry were pursued to determine the environmental factors that most influence carbon dioxide intrusion at a Pike County, Ind., home where this phenomenon is known to occur. It was found that carbon dioxide intrusion events at the home are most closely tied to rapid drops in barometric pressure and rainfall. Other researchers have shown that windy conditions and periods of cold weather also can contribute to soil-gas intrusion to structures. From this, a conceptual model was developed to illustrate the influence of these four meteorological conditions. Additionally, three mitigation methods-block-wall depressurization, block-wall and sub-slab depressurization, and block-wall and sub-slab pressurization-were applied successively to the study-site home, and environmental data were collected to evaluate the effectiveness of each mitigation method. In each case, it was found that these methods did not ensure a safe environment when meteorological conditions were favorable for carbon dioxide intrusion.

Effects of temperature and modified atmospheres on diapausing 5th instar codling moth metabolism

USDA-ARS?s Scientific Manuscript database

Diapausing 5th instars of codling moth, Cydia pomonella, are serious quarantine pests of in-shell walnuts. Previous research indicates that heat treatments in combination with high concentrations of carbon dioxide and low concentrations of oxygen may be effective for controlling this pest in walnuts...

CHLORINE DIOXIDE CHEMISTRY, REACTIONS, AND DISINFECTION BY-PRODUCTS

EPA Science Inventory

This chapter contains two main sections-the first section describes the chemistry and reactions of chlorine dioxide, and the second describes the disinfection by-products (DBPs) of chlorine dioxide and their control. A short section on Research Needs completes this chapter. The...

Transition Organometallic Heterobimettalic Microns-Carbon Dioxide and Microns-Format Complexes in Homogeneous Carbon Dioxide Fixation

DTIC Science & Technology

1992-08-12

AD-A254 538 OFFICE OF NAVAL RESEARCH FINAL REPORT FCR Contract N00014-87-K-0465 R&T Code 413j006 "Transition Organometallic Heterobimetallic ix...ransition Organometallic Heterobimetallic P-Carbon Dioxide and p-FormateComplexes in Homogeneous Carbon Dioxide Fixation 12. PERSONAL AUTHOR(S) Alan R...J. L. Shibley, and A. R. Cutler, J. Organomet. Chem. 1989,378, 421.* "Characterization of the Heterobimetallic ±(r011-C: T12 -O,O’) Carbon Dioxide

Simulation of natural gas production from submarine gas hydrate deposits combined with carbon dioxide storage

NASA Astrophysics Data System (ADS)

Janicki, Georg; Schlüter, Stefan; Hennig, Torsten; Deerberg, Görge

2013-04-01

The recovery of methane from gas hydrate layers that have been detected in several submarine sediments and permafrost regions around the world so far is considered to be a promising measure to overcome future shortages in natural gas as fuel or raw material for chemical syntheses. Being aware that natural gas resources that can be exploited with conventional technologies are limited, research is going on to open up new sources and develop technologies to produce methane and other energy carriers. Thus various research programs have started since the early 1990s in Japan, USA, Canada, South Korea, India, China and Germany to investigate hydrate deposits and develop technologies to destabilize the hydrates and obtain the pure gas. In recent years, intensive research has focussed on the capture and storage of carbon dioxide from combustion processes to reduce climate change. While different natural or manmade reservoirs like deep aquifers, exhausted oil and gas deposits or other geological formations are considered to store gaseous or liquid carbon dioxide, the storage of carbon dioxide as hydrate in former methane hydrate fields is another promising alternative. Due to beneficial stability conditions, methane recovery may be well combined with CO2 storage in form of hydrates. This has been shown in several laboratory tests and simulations - technical field tests are still in preparation. Within the scope of the German research project »SUGAR«, different technological approaches are evaluated and compared by means of dynamic system simulations and analysis. Detailed mathematical models for the most relevant chemical and physical effects are developed. The basic mechanisms of gas hydrate formation/dissociation and heat and mass transport in porous media are considered and implemented into simulation programs like CMG STARS and COMSOL Multiphysics. New simulations based on field data have been carried out. The studies focus on the evaluation of the gas production potential from turbidites and their ability for carbon dioxide storage. The effects occurring during gas production and CO2 storage within a hydrate deposit are identified and described for various scenarios. The behaviour of relevant process parameters such as pressure, temperature and phase saturations is discussed and compared for different production strategies: depressurization, CO2 injection after depressurization and simultaneous methane production and CO2 injection.

Global Warming: How Much and Why?

ERIC Educational Resources Information Center

Lanouette, William

1990-01-01

Summarizes the history of the study of global warming and includes a discussion of the role of gases, like carbon dioxide, methane, and chlorofluorocarbon (CFC). Discusses modern research on the global warming, including computer modelling and the super-greenhouse effect. (YP)

Responses of invasive silver and bighead carp to a carbon dioxide barrier in outdoor ponds

USGS Publications Warehouse

Cupp, Aaron R.; Erickson, Richard A.; Fredricks, Kim T.; Swyers, Nicholas M.; Hatton, Tyson; Amberg, Jon J.

2017-01-01

Resource managers need for effective methods to prevent the movement of silver (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) from the Mississippi River basin into the Laurentian Great Lakes. In this study, we evaluated dissolved carbon dioxide (CO2) as a barrier and deterrent to silver (278 ± 30.5 mm) and bighead (212 ± 7.7 mm) carp movement in continuous-flow outdoor ponds. As a barrier, CO2 significantly reduced upstream movement but was not 100% effective at blocking fish passage. As a deterrent, we observed a significant shift away from areas of high CO2 relative to normal movement before and after injection. Carbon dioxide concentrations varied across the pond during injection and reached maximum concentrations of 74.5±1.9 mg/L CO2; 29 532 – 41 393 µatm at the site of injection during three independent trials. We conclude that CO2 altered silver and bighead carp movement in outdoor ponds and recommend further research to determine barrier effectiveness during field applications.

Material Compatibility for Historic Items Decontaminated with ...

EPA Pesticide Factsheets

Report This project continued research of the effects of decontamination methods for biological agents on materials identified as representative of types of irreplaceable objects or works of art found in museums and/or archive settings. In the previous research, surrogate materials were checked for compatibility with four decontamination methods: chlorine dioxide, hydrogen peroxide vapor, methyl bromide, and ethylene oxide gas. This project investigated the effects of gamma irradiation, which has also been shown to be an effective decontamination method for biological agents, on the surrogate test materials.

Chlorine Dioxide Induced Multiple Chemical Sensitivity: MMPI Validity Problems.

ERIC Educational Resources Information Center

Tentoni, Stuart C.

This paper discusses Minnesota Multiphasic Personality Inventory (MMPI) data obtained from individuals exposed to chlorine dioxide in the workplace who developed Multiple Chemical Sensitivity Syndrome. The paper explores current research on chlorine dioxide exposed persons who were misdiagnosed on the basis of MMPI interpretations. Difficulties…

Ambient intercomparison of direct and indirect methods for ambient nitrogen dioxide

EPA Science Inventory

AbstractRecent advances in measurement techniques for nitrogen dioxide (NO2), along with known interferences in the current Federal Reference Method (FRM) have created the need for NO2 measurement method research within EPA’s Office of Research and Development. Current meth...

[Effects of air pollution on human health and their importance in Mexico City].

PubMed

Vallejo, Maite; Jáuregui-Renaud, Kathrine; Hermosillo, Antonio G; Márquez, Manlio F; Cárdenas, Manuel

2003-01-01

The impact of air pollution on human health is a complicated problem. In this review, we describe the main health effects of exposure to ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide, lead and particulate matter. Geographical characteristics of the metropolitan area of Mexico City that favor pollutant persistence with adverse effects on the population are described; the use of the Indice Metropolitano de la Calidad del Aire (IMECA), current norms, and present programs to diminish this problem are discussed. Evidence shows that through these actions, air quality has improved. However, some pollutants such as ozone and particulate matter, still exceed the standard. To further improve air quality in the city, existing programs should continue and multidisciplinary research, both basic and applied, is required.

Hazardous Effects of Titanium Dioxide Nanoparticles in Ecosystem

PubMed Central

Hussain, Muzammal; Khan, Muzaffar

2017-01-01

Although nanoparticles (NPs) have made incredible progress in the field of nanotechnology and biomedical research and their applications are demanded throughout industrial world particularly over the past decades, little is known about the fate of nanoparticles in ecosystem. Concerning the biosafety of nanotechnology, nanotoxicity is going to be the second most priority of nanotechnology that needs to be properly addressed. This review covers the chemical as well as the biological concerns about nanoparticles particularly titanium dioxide (TiO2) NPs and emphasizes the toxicological profile of TiO2 at the molecular level in both in vitro and in vivo systems. In addition, the challenges and future prospects of nanotoxicology are discussed that may provide better understanding and new insights into ongoing and future research in this field. PMID:28373829

Indoor air pollution: Acute adverse health effects and host susceptibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zummo, S.M.; Karol, M.H.

1996-01-01

Increased awareness of the poor quality of indoor air compared with outdoor air has resulted in a significant amount of research on the adverse health effects and mechanisms of action of indoor air pollutants. Common indoor air agents are identified, along with resultant adverse health effects, mechanisms of action, and likely susceptible populations. Indoor air pollutants range from biological agents (such as dust mites) to chemical irritants (such as nitrogen dioxide, carbon monoxide, sulfur dioxide, formaldehyde, and isocyanates). These agents may exert their effects through allergic as well as nonallergic mechanisms. While the public does not generally perceive poor indoormore » air quality as a significant health risk, increasing reports of illness related to indoor air and an expanding base of knowledge on the health effects of indoor air pollution are likely to continue pushing the issue to the forefront.« less

Leaf Stomata as Bioindicators: Stimulating Student Research

ERIC Educational Resources Information Center

Case, Steven B.

2006-01-01

Stomata are the pores on leaves through which carbon dioxide, oxygen, and water vapor are exchanged with the atmosphere. Researchers have found that leaf stomatal densities change in response to several environmental variables, including humidity, light intensity, and atmospheric levels of carbon dioxide, a greenhouse gas (Van Der Burgh, Dilcher,…

NATIONAL PERFORMANCE AUDIT PROGRAM: 1980 PROFICIENCY SURVEY FOR SULFUR DIOXIDE, NITROGEN DIOXIDE, CARBON MONOXIDE, SULFATE, NITRATE, LEAD AND HIGH VOLUME FLOW

EPA Science Inventory

Based on authority granted by provisions of the Clean Air Act (42 U.S.C 7410, et seq.), the Quality Assurance Division of the Environmental Monitoring Systems Laboratory, Research Triangle Park, NC administers periodic surveys of analytical proficiency for sulfur dioxide, nitroge...

Plant physiological response of strawberry fruit to chlorine dioxide gas treatment during postharvest storage

USDA-ARS?s Scientific Manuscript database

Chlorine dioxide, a strong oxidizing and sanitizing agent, is used as a postharvest sanitizer for fruits and vegetables and generally applied on a packing line using a chlorine dioxide generator. The objective of this research was to study the physiological responses of strawberries to ClO2 when app...

46 CFR 196.37-8 - Carbon dioxide warning signs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a...

46 CFR 196.37-8 - Carbon dioxide warning signs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a...

46 CFR 196.37-8 - Carbon dioxide warning signs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide warning signs. 196.37-8 Section 196.37-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings for Fire and Emergency Equipment, etc. § 196.37-8 Carbon dioxide warning signs. Each entrance to a...

Effects of atmospheric CO2 enrichment on soil CO2 efflux in a young longleaf pine system

Treesearch

G. Brett Runion; John R. Butnor; S. A. Prior; R. J. Mitchell; H. H. Rogers

2012-01-01

The southeastern landscape is composed of agricultural and forest systems that can store carbon (C) in standing biomass and soil. Research is needed to quantify the effects of elevated atmospheric carbon dioxide (CO2) on terrestrial C dynamics including CO2 release back to the atmosphere and soil sequestration. Longleaf...

Experimental research on the effects of water application on greenhouse gas emissions from beef cattle feedlots

USDA-ARS?s Scientific Manuscript database

The effect of water application (e.g., through rainfall or sprinkler system) on emissions of greenhouse gases (GHGs), such as nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2), from pen surfaces of open-lot beef cattle feedlots was evaluated under controlled laboratory conditions. Soil/ma...

Triple-Pulse Integrated Path Differential Absorption Lidar for Carbon Dioxide Measurement - Novel Lidar Technologies and Techniques with Path to Space

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Refaat, Tamer F.; Petros, Mulugeta

2017-01-01

The societal benefits of understanding climate change through identification of global carbon dioxide sources and sinks led to the desired NASA's active sensing of carbon dioxide emissions over nights, days, and seasons (ASCENDS) space-based missions of global carbon dioxide measurements. For more than 15 years, NASA Langley Research Center (LaRC) have developed several carbon dioxide active remote sensors using the differential absorption lidar (DIAL) technique operating at the two-micron wavelength. Currently, an airborne two-micron triple-pulse integrated path differential absorption (IPDA) lidar is under development. This IPDA lidar measures carbon dioxide as well as water vapor, the dominant interfering molecule on carbon dioxide remote sensing. Advancement of this triple-pulse IPDA lidar development is presented.

Systematization of published research graphics characterizing weakly bound molecular complexes with carbon dioxide

NASA Astrophysics Data System (ADS)

Lavrentiev, N. A.; Rodimova, O. B.; Fazliev, A. Z.; Vigasin, A. A.

2017-11-01

An approach is suggested to the formation of applied ontologies in subject domains where results are represented in graphical form. An approach to systematization of research graphics is also given which contains information on weakly bound carbon dioxide complexes. The results of systematization of research plots and images that characterize the spectral properties of the CO2 complexes are presented.

Carbon dioxide laser for de-epithelialization of periodontal flaps.

PubMed

Centty, I G; Blank, L W; Levy, B A; Romberg, E; Barnes, D M

1997-08-01

Regeneration of mineralized and soft connective tissue components of the attachment apparatus is the main goal in the treatment of periodontal diseases. Often, apical migration of epithelium (long junctional epithelium) effectively prevents the formation of bone and connective tissue attachment after periodontal surgery. The purpose of the present study was to compare conventional periodontal surgery combined with carbon dioxide laser and conventional periodontal surgery alone with respect to epithelial elimination and degree of necrosis of mucoperiosteal flaps. After signing a consent form, five patients with at least two comparable bilateral periodontal defects needing pocket elimination surgery participated in this study. The investigators randomly divided each side into test and control sites. Each patient received oral hygiene instruction and initial therapy prior to surgery. At surgery, the test site received a sulcular incision and carbon dioxide laser de-epithelialization of the outer and inner aspects of the flap. The control group received reverse bevel incision only. The surgeon performed open flap debridement on all teeth. At the time of surgery, the surgeon did a biopsy of each site and submitted specimens for histologic evaluation. A matched pairs t-test was used to analyze the data. The results show significant differences between the carbon dioxide laser and reverse bevel incision with respect to sulcular (P < or = 0.025) and gingival (external) (P < or = 0.01) flap surface epithelial elimination and tissue necrosis (P < or = 0.005). These results should be replicated with a larger number of subjects. The carbon dioxide laser eliminated sulcular and gingival (external) epithelium without disturbing underlying connective tissue. This finding supports the concept that the carbon dioxide wavelength has little or no effect on tissues beyond the target. However, neither laser nor blade eliminated all the epithelium. Researchers observed chronic inflammation in the control and test sites, with a predominance of plasma cells. Lining the sulcular and gingival (external) lased areas, investigators found coagulation necrosis covered by fibrin and coagulated blood. The laser appears to effectively remove epithelium at the time of surgery; however, future long-term, well-controlled quantitative histologic studies are needed to evaluate the effect of repeated carbon dioxide laser de-epithelialization of the gingival (external) surface of mucoperiosteal flaps at intervals during the healing period.

[Plant responses to elevated atmospheric carbon dioxide and transmission to other trophic levels]. Progress report, May 1991, DOE Grant DE-FG09-84ER60255

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, D.E.

1991-05-01

Experiments were performed to determine the effects of carbon dioxide on plants and on the insects feeding on these plants. Current progress is reported for the following experiments: Response of a Specialist-Feeding Insect Herbivore to Carbon Dioxide Induced Changes in Its Hostplant; Growth and Reproduction of Grasshoppers Feeding on a C{sub 4} Grass Under Elevated Carbon Dioxide; Elevated Carbon Dioxide and Temperature Effects on Growth and Defense of Big Sagebrush; Sagebrush and Grasshopper Responses to Atmospheric Carbon Dioxide Concentration; Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide; and Sagebrush Carbon Allocation Patterns and Grasshopper Nutrition:more » The Influence of Carbon Dioxide Enrichment and Soil Mineral Limitation.« less

Comparison of commercial analytical techniques for measuring chlorine dioxide in urban desalinated drinking water.

PubMed

Ammar, T A; Abid, K Y; El-Bindary, A A; El-Sonbati, A Z

2015-12-01

Most drinking water industries are closely examining options to maintain a certain level of disinfectant residual through the entire distribution system. Chlorine dioxide is one of the promising disinfectants that is usually used as a secondary disinfectant, whereas the selection of the proper monitoring analytical technique to ensure disinfection and regulatory compliance has been debated within the industry. This research endeavored to objectively compare the performance of commercially available analytical techniques used for chlorine dioxide measurements (namely, chronoamperometry, DPD (N,N-diethyl-p-phenylenediamine), Lissamine Green B (LGB WET) and amperometric titration), to determine the superior technique. The commonly available commercial analytical techniques were evaluated over a wide range of chlorine dioxide concentrations. In reference to pre-defined criteria, the superior analytical technique was determined. To discern the effectiveness of such superior technique, various factors, such as sample temperature, high ionic strength, and other interferences that might influence the performance were examined. Among the four techniques, chronoamperometry technique indicates a significant level of accuracy and precision. Furthermore, the various influencing factors studied did not diminish the technique's performance where it was fairly adequate in all matrices. This study is a step towards proper disinfection monitoring and it confidently assists engineers with chlorine dioxide disinfection system planning and management.

KSC-96pc634

NASA Image and Video Library

1996-05-01

Researchers from the Smithsonian Institution hope their experiment in a local scrub oak community at KSC will yield new insights into the effects of increased carbon dioxide on natural vegetation. The experiment features a four-acre site just north of the Launch Complex 39 area. Increased amoounts of carbon dioxide are piped into 16 open-top chambers that house pristine Florida scrub vegetation, chosen because it is small and woody and fits in the chambers and can be controlled, yet has the attributes of much larger forests. Experts predict a doubling of the carbon dioxide in the Earth's atmosphere during the next century, and the three-year KSC project being conducted by the Smithsonian-led team hopes that by simulating the increase, they can determine how natural ecosystems and vegetation will respond. Also participating in the effort are KSC, academic and international organizations. The study is being funded by a Department of energy grant

KSC-96pc632

NASA Image and Video Library

1996-05-01

Researchers from the Smithsonian Institution hope their experiment in a local scrub oak community at KSC will yield new insights into the effects of increased carbon dioxide on natural vegetation. The experiment features a four-acre site just north of the Launch Complex 39 area. Increased amoounts of carbon dioxide are piped into 16 open-top chambers that house pristine Florida scrub vegetation, chosen because it is small and woody and fits in the chambers and can be controlled, yet has the attributes of much larger forests. Experts predict a doubling of the carbon dioxide in the Earth's atmosphere during the next century, and the three-year KSC project being conducted by the Smithsonian-led team hopes that by simulating the increase, they can determine how natural ecosystems and vegetation will respond. Also participating in the effort are KSC, academic and international organizations. The study is being funded by a Department of energy grant

KSC-96pc633

NASA Image and Video Library

1996-05-01

Researchers from the Smithsonian Institution hope their experiment in a local scrub oak community at KSC will yield new insights into the effects of increased carbon dioxide on natural vegetation. The experiment features a four-acre site just north of the Launch Complex 39 area. Increased amoounts of carbon dioxide are piped into 16 open-top chambers that house pristine Florida scrub vegetation, chosen because it is small and woody and fits in the chambers and can be controlled, yet has the attributes of much larger forests. Experts predict a doubling of the carbon dioxide in the Earth's atmosphere during the next century, and the three-year KSC project being conducted by the Smithsonian-led team hopes that by simulating the increase, they can determine how natural ecosystems and vegetation will respond. Also participating in the effort are KSC, academic and international organizations. The study is being funded by a Department of energy grant

KSC-96pc635

NASA Image and Video Library

1996-05-01

Researchers from the Smithsonian Institution hope their experiment in a local scrub oak community at KSC will yield new insights into the effects of increased carbon dioxide on natural vegetation. The experiment features a four-acre site just north of the Launch Complex 39 area. Increased amoounts of carbon dioxide are piped into 16 open-top chambers that house pristine Florida scrub vegetation, chosen because it is small and woody and fits in the chambers and can be controlled, yet has the attributes of much larger forests. Experts predict a doubling of the carbon dioxide in the Earth's atmosphere during the next century, and the three-year KSC project being conducted by the Smithsonian-led team hopes that by simulating the increase, they can determine how natural ecosystems and vegetation will respond. Also participating in the effort are KSC, academic and international organizations. The study is being funded by a Department of energy grant

An Alternative Mechanism for Accelerated Carbon Sequestration in Concrete

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haselbach, Liv M.; Thomle, Jonathan N.

The increased rate of carbon dioxide sequestration (carbonation) is desired in many primary and secondary life applications of concrete in order to make the life cycle of concrete structures more carbon neutral. Most carbonation rate studies have focused on concrete exposed to air under various conditions. An alternative mechanism for accelerated carbon sequestration in concrete was investigated in this research based on the pH change of waters in contact with pervious concrete which have been submerged in carbonate laden waters. The results indicate that the concrete exposed to high levels of carbonate species in water may carbonate faster than whenmore » exposed to ambient air, and that the rate is higher with higher concentrations. Validation of increased carbon dioxide sequestration was also performed via thermogravimetric analysis (TGA). It is theorized that the proposed alternative mechanism reduces a limiting rate effect of carbon dioxide dissolution in water in the micro pores of the concrete.« less

Using the 5E Learning Cycle Sequence with Carbon Dioxide

ERIC Educational Resources Information Center

Schlenker, Richard M.; Blanke, Regina; Mecca, Peter

2007-01-01

The authors used the 5E learning cycle (engage, explore, explain, extend, and evaluate) and a pulmonary carbon dioxide mystery to introduce eighth grade students to the study of chemistry. The activity engages students in measurement, data collection, data analysis, media and internet research, research design, and report writing as they search…

46 CFR 193.15-90 - Installations contracted for prior to March 1, 1968.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15... used in lieu of discharge nozzles for such systems. The number of pounds of carbon dioxide shall be... carbon dioxide required shall be equal to the gross volume of the space taken to the under side of the...

46 CFR 193.15-90 - Installations contracted for prior to March 1, 1968.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15... used in lieu of discharge nozzles for such systems. The number of pounds of carbon dioxide shall be... carbon dioxide required shall be equal to the gross volume of the space taken to the under side of the...

46 CFR 193.15-90 - Installations contracted for prior to March 1, 1968.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems... used in lieu of discharge nozzles for such systems. The number of pounds of carbon dioxide shall be... carbon dioxide required shall be equal to the gross volume of the space taken to the under side of the...

46 CFR 193.15-90 - Installations contracted for prior to March 1, 1968.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems... used in lieu of discharge nozzles for such systems. The number of pounds of carbon dioxide shall be... carbon dioxide required shall be equal to the gross volume of the space taken to the under side of the...

46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide and clean agent alarms. 196.37-9 Section 196.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide and clean agent alarms. Each extinguishing system using...

46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Carbon dioxide and clean agent alarms. 196.37-9 Section 196.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide and clean agent alarms. Each extinguishing system using...

46 CFR 196.37-9 - Carbon dioxide and clean agent alarms.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide and clean agent alarms. 196.37-9 Section 196.37-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide and clean agent alarms. Each extinguishing system using...

Effect of dissolved carbon dioxide on penicillin fermentations: mycelial growth and penicillin production. [Penicillium chrysogenum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, C.S.; Smith, M.D.

The effect of dissolved carbon dioxide on the specific growth rate and the penicillin production rate of Penicillium chrysogenum was examined experimentally. The dissolved carbon dioxide was found to inhibit the specific growth rate and the penicillin production rate when the aerated submerged penicillin fermentation was exposed to influent gases of 12.6 and 20% carbon dioxide, respectively. Upon exposure to influent gases of 3 and 5% carbon dioxide, no pronounced metabolic inhibition was noted.

Supercritical carbon dioxide-based sterilization of decellularized heart valves.

PubMed

Hennessy, Ryan S; Jana, Soumen; Tefft, Brandon J; Helder, Meghana R; Young, Melissa D; Hennessy, Rebecca R; Stoyles, Nicholas J; Lerman, Amir

2017-02-01

The goal of this research project encompasses finding the most efficient and effective method of decellularized tissue sterilization. Aortic tissue grafts have been utilized to repair damaged or diseased valves. Although, the tissues for grafting are collected aseptically, it does not eradicate the risk of contamination nor disease transfer. Thus, sterilization of grafts is mandatory. Several techniques have been applied to sterilize grafts; however, each technique shows drawbacks. In this study, we compared several sterilization techniques: supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide for impact on the sterility and mechanical integrity of porcine decellularized aortic valves. Valve sterility was characterized by histology, microbe culture, and electron microscopy. Uniaxial tensile testing was conducted on the valve cusps along their circumferential orientation to study these sterilization techniques on their integrity. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile. The tensile strength of supercritical carbon dioxide treated valves (4.28 ± 0.22 MPa) was higher to those valves treated with electrolyzed water, gamma radiation, ethanol-peracetic acid and hydrogen peroxide (1.02 ± 0.15, 1.25 ± 0.25, 3.53 ± 0.41 and 0.37 ± 0.04 MPa, respectively). Superior sterility and integrity were found in the decellularized porcine aortic valves with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile using histology, microbe culture and electron microscopy assays. The cusp tensile properties of supercritical carbon dioxide treated valves were higher compared to valves treated with other techniques. Superior sterility and integrity was found in the decellularized valves treated with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues.

Novel Technique and Technologies for Active Optical Remote Sensing of Greenhouse Gases

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Refaat, Tamer F.; Petros, Mulugeta

2017-01-01

The societal benefits of understanding climate change through identification of global carbon dioxide sources and sinks led to the desired NASA's active sensing of carbon dioxide emissions over nights, days, and seasons (ASCENDS) space-based missions of global carbon dioxide measurements. For more than 15 years, NASA Langley Research Center (LaRC) have developed several carbon dioxide active remote sensors using the differential absorption lidar (DIAL) technique operating at the two-micron wavelength. Currently, an airborne two-micron triple-pulse integrated path differential absorption (IPDA) lidar is under development. This IPDA lidar measures carbon dioxide as well as water vapor, the dominant interfering molecule on carbon dioxide remote sensing. Advancement of this triple-pulse IPDA lidar development is presented.

Effects of climatic variability and change

Treesearch

Michael G. Ryan; James M. Vose

2012-01-01

Climate profoundly shapes forests. Forest species composition, productivity, availability of goods and services, disturbance regimes, and location on the landscape are all regulated by climate. Much research attention has focused on the problem of projecting the response of forests to changing climate, elevated atmospheric carbon dioxide (CO2)...

Concerns--High Sea Levels and Temperatures Seen Next Century.

ERIC Educational Resources Information Center

Ryan, Paul R.

1984-01-01

A National Research Council committee recently concluded that atmospheric carbon dioxide levels will "most likely" double by late in the next century, causing an increase in the earth's average temperature. Effects of the increase on sea levels, global climate, and other parameters are discussed. (JN)

Hydrodynamic Controls on Carbon Dioxide Efflux from Inland Waters

NASA Astrophysics Data System (ADS)

Long, H. E.; Waldron, S.; Hoey, T.; Newton, J.; Quemin, S.

2013-12-01

Intensive research has been undertaken on carbon dioxide efflux from lakes, estuaries and oceans, but much less attention has been given to rivers and streams, especially lower order streams. River systems are often over-saturated with carbon dioxide and so tend to act as sources of carbon dioxide to the atmosphere. It has been thought that rivers act as pipes carrying this terrestrial carbon to the oceans. However, recent studies have shown that a significant amount of the carbon is reprocessed within the system in a series of transformations and losses. Fluvial evasion of carbon dioxide is now recognised to be a significant component of carbon cycles, however the factors controlling carbon dioxide efflux and its magnitude remain poorly understood and quantified. This research aims to quantify, and better understand the controls on, freshwater carbon dioxide evasion. Data are presented here from field measurements that commenced in Sept 2013 in two contrasting Scottish rivers: the River Kelvin which has a large (335 km.sq) part-urban catchment with predominantly non-peat soils and Drumtee Water, a small (9.6 km.sq) rural catchment of peat soils and agricultural land. Using a floating chamber with the headspace connected to an infrared gas analyser to measure changes in carbon dioxide concentration, efflux rates from 0.22 - 47.4 μmol CO2/m.sq/sec were measured, these close to the middle of the range of previously reported values. At one site on the River Kelvin in May 2013 an influx of -0.61 - -3.53 μmol CO2/m.sq/sec was recorded. Whereas previous research finds carbon dioxide efflux to increase with decreasing river size and a more organic-rich soil catchment, here the controls on carbon dioxide evasion are similar across the contrasting catchments. Carbon dioxide evasion shows seasonality, with maximum fluxes in the summer months being up to twice as high as the winter maxima. Linear regression demonstrates that evasion increases with increased flow velocity, water surface disturbance indicated by Froude number, and turbulent mixing indicated by Reynolds number. Similar relationships with season, flow velocity and turbulence have been reported previously, but there is little known about the mechanisms involved. When comparing spot carbon dioxide efflux measurements to river stage time series data, carbon dioxide efflux is more sensitive to an increase in stage at more turbulent measurement points. Further investigation of the mechanisms will be obtained by measurement of DIC concentration and isotopic composition to assess the controls of carbon source versus degassing, and the analysis of the interactions between hydraulic and seasonal controls and carbon dioxide fluxes extended.

EFFECTS OF OZONE, CHLORINE DIOXIDE, CHLORINE, AND MONOCHLORAMINE ON CRYTOSPORIDIUM PARVUM OOCYST VIABILITY

EPA Science Inventory

Purified Cryptosporiodium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were compareatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlor...

Carbon dioxide reduction through urban forestry: guidelines for professional and volunteer tree planters

Treesearch

E. Gregory McPherson; James R. Simpson

1999-01-01

Carbon dioxide reduction through urban forestry—Guidelines for professional and volunteer tree planters has been developed by the Pacific Southwest Research Station’s Western Center for Urban Forest Research and Education as a tool for utilities, urban foresters and arborists, municipalities, consultants, non-profit organizations and others to...

Numerically Simulating Carbonate Mineralization of Basalt with Injection of Carbon Dioxide into Deep Saline Formations

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, Mark D.; McGrail, B. Peter; Schaef, Herbert T.

2006-07-08

The principal mechanisms for the geologic sequestration of carbon dioxide in deep saline formations include geological structural trapping, hydrological entrapment of nonwetting fluids, aqueous phase dissolution and ionization, and geochemical sorption and mineralization. In sedimentary saline formations the dominant mechanisms are structural and dissolution trapping, with moderate to weak contributions from hydrological and geochemical trapping; where, hydrological trapping occurs during the imbibition of aqueous solution into pore spaces occupied by gaseous carbon dioxide, and geochemical trapping is controlled by generally slow reaction kinetics. In addition to being globally abundant and vast, deep basaltic lava formations offer mineralization kinetics that makemore » geochemical trapping a dominate mechanism for trapping carbon dioxide in these formations. For several decades the United States Department of Energy has been investigating Columbia River basalt in the Pacific Northwest as part of its environmental programs and options for natural gas storage. Recently this nonpotable and extensively characterized basalt formation is being reconsidered as a potential reservoir for geologic sequestration of carbon dioxide. The reservoir has an estimated storage capacity of 100 giga tonnes of carbon dioxide and comprises layered basalt flows with sublayering that generally alternates between low permeability massive and high permeability breccia. Chemical analysis of the formation shows 10 wt% Fe, primarily in the +2 valence. The mineralization reaction that makes basalt formations attractive for carbon dioxide sequestration is that of calcium, magnesium, and iron silicates reacting with dissolved carbon dioxide, producing carbonate minerals and amorphous quartz. Preliminary estimates of the kinetics of the silicate-to-carbonate reactions have been determined experimentally and this research is continuing to determine effects of temperature, pressure, rock composition and mineral assemblages on the reaction rates. This study numerically investigates the injection, migration and sequestration of supercritical carbon dioxide in deep Columbia River basalt formations using the multifluid subsurface flow and reactive transport simulator STOMP-CO2 with its ECKEChem module. Simulations are executed on high resolution multiple stochastic realizations of the layered basalt systems and demonstrate the migration behavior through layered basalt formations and the mineralization of dissolved carbon dioxide. Reported results include images of the migration behavior, distribution of carbonate formation, quantities of injected and sequestered carbon dioxide, and percentages of the carbon dioxide sequestered by different mechanisms over time.« less

The influence of deep-seabed CO2 sequestration on small metazoan (meiofaunal) viability and community structure: final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thistle, D

2008-09-30

Since the industrial revolution, the burning of fossil fuel has produced carbon dioxide at an increasing rate. Present atmospheric concentration is about ~1.5 times the preindustrial level and is rising. Because carbon dioxide is a greenhouse gas, its increased concentration in the atmosphere is thought to be a cause of global warming. If so, the rate of global warming could be slowed if industrial carbon dioxide were not released into the atmosphere. One suggestion has been to sequester it in the deep ocean, but theory predicts that deep-sea species will be intolerant of the increased concentrations of carbon dioxide andmore » the increased acidity it would cause. The aim of our research was to test for consequences of carbon dioxide sequestration on deep-sea, sediment-dwelling meiofauna. Recent technical advances allowed us to test for effects in situ at depths proposed for sequestration. The basic experimental unit was an open-topped container into which we pumped ~20 L of liquid carbon dioxide. The liquid carbon dioxide mixed with near-bottom sea water, which produced carbon dioxide-rich sea water that flowed out over the near-by seabed. We did 30-day experiments at several locations and with different numbers of carbon dioxide-filled containers. Harpacticoid copepods (Crustacea) were our test taxon. In an experiment we did during a previous grant period, we found that large numbers of individuals exposed to carbon dioxide-rich sea water had been killed (Thistle et al. 2004). During the present grant period, we analyzed the species-level data in greater detail and discovered that, although individuals of many species had been killed by exposure to carbon dioxide-rich sea water, individuals of some species had not (Thistle et al. 2005). This result suggests that seabed sequestration of carbon dioxide will not just reduce the abundance of the meiofauna but will change the composition of the community. In another experiment, we found that some harpacticoid species swim away from an advancing front of carbon dioxide-rich sea water (Thistle et al. 2007). This result demonstrates a second way that deep-sea meiofauna react negatively to carbon dioxide-rich sea water. In summary, we used in situ experiments to show that carbon dioxide-rich sea water triggers an escape response in some harpacticoid species. It kills most individuals of most harpacticoid species that do not flee, but a few species seem to be unaffected. Proposals to reduce global warming by sequestering industrial carbon dioxide in the deep ocean should take note of these environmental consequences when pros and cons are weighed.« less

Determining media and species effects on soil carbon dynamics in the landscape

USDA-ARS?s Scientific Manuscript database

Increased atmospheric carbon dioxide (CO2) concentration is an important factor in global change research. While agriculture is a major contributor to greenhouse gas (GHG) emissions, it has great potential to offset emissions by altering management practices. Much of the work on reducing GHG emissio...

Phloem function: A key to understanding and manipulating plant responses to rising atmospheric [CO2]?

USDA-ARS?s Scientific Manuscript database

Increasing atmospheric carbon dioxide concentration ([CO2]) directly stimulates photosynthesis and reduces stomatal conductance in C3 plants. Both of these physiological effects have the potential to alter phloem function at elevated [CO2]. Recent research has clearly established that photosynthetic...

Thinking like an Ecologist

ERIC Educational Resources Information Center

Carlson, Jenn

2008-01-01

This article presents a lesson in which students examine current field research on global change. In particular, students investigate the effect of carbon dioxide and tropospheric ozone on ecosystems by applying their knowledge of scientific inquiry and photosynthesis. The goal of the activity is for students to think like ecologists and draw…

Estimation of Aerosol Direct Radiative Effects from Satellite and In Situ Measurements

NASA Technical Reports Server (NTRS)

Bergstrom, Robert W.; Russell, Philip B.; Schmid, Beat; Redemann, Jens; McIntosh, Dawn

2000-01-01

Ames researchers have combined measurements from satellite, aircraft, and the surface to estimate the effect of airborne particles (aerosols) on the solar radiation over the North Atlantic region. These aerosols (which come from both natural and pollution sources) can reflect solar radiation, causing a cooling effect that opposes the warming caused by carbon dioxide. Recently, increased attention has been paid to aerosol effects to better understand the Earth climate system.

Semiconductor-Based Photoelectrochemical Conversion of Carbon Dioxide: Stepping Towards Artificial Photosynthesis.

PubMed

Pang, Hong; Masuda, Takuya; Ye, Jinhua

2018-01-18

The photoelectrochemical (PEC) carbon dioxide reduction process stands out as a promising avenue for the conversion of solar energy into chemical feedstocks, among various methods available for carbon dioxide mitigation. Semiconductors derived from cheap and abundant elements are interesting candidates for catalysis. Whether employed as intrinsic semiconductors or hybridized with metallic cocatalysts, biocatalysts, and metal molecular complexes, semiconductor photocathodes exhibit good performance and low overpotential during carbon dioxide reduction. Apart from focusing on carbon dioxide reduction materials and chemistry, PEC cells towards standalone devices that use photohybrid electrodes or solar cells have also been a hot topic in recent research. An overview of the state-of-the-art progress in PEC carbon dioxide reduction is presented and a deep understanding of the catalysts of carbon dioxide reduction is also given. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fischer-Tropsch synthesis in supercritical phase carbon dioxide: Recycle rates

NASA Astrophysics Data System (ADS)

Soti, Madhav

With increasing oil prices and attention towards the reduction of anthropogenic CO2, the use of supercritical carbon dioxide for Fischer Tropsch Synthesis (FTS) is showing promise in fulfilling the demand of clean liquid fuels. The evidence of consumption of carbon dioxide means that it need not to be removed from the syngas feed to the Fischer Tropsch reactor after the gasification process. Over the last five years, research at SIUC have shown that FTS in supercritical CO2reduces the selectivities for methane, enhances conversion, reduces the net CO2produces in the coal to liquid fuels process and increase the life of the catalyst. The research has already evaluated the impact of various operating and feed conditions on the FTS for the once through process. We believe that the integration of unreacted feed recycle would enhance conversion, increase the yield and throughput of liquid fuels for the same reactor size. The proposed research aims at evaluating the impact of recycle of the unreacted feed gas along with associated product gases on the performance of supercritical CO2FTS. The previously identified conditions will be utilized and various recycle ratios will be evaluated in this research once the recycle pump and associated fittings have been integrated to the supercritical CO2FTS. In this research two different catalysts (Fe-Zn-K, Fe-Co-Zn-K) were analyzed under SC-FTS in different recycle rate at 350oC and 1200 psi. The use of recycle was found to improve conversion from 80% to close to 100% with both catalysts. The experiment recycle rate at 4.32 and 4.91 was clearly surpassing theoretical recycle curve. The steady state reaction rate constant was increased to 0.65 and 0.8 min-1 for recycle rate of 4.32 and 4.91 respectively. Carbon dioxide selectivity was decreased for both catalyst as it was converting to carbon monoxide. Carbon dioxide consumption was increased from 0.014 to 0.034 mole fraction. This concluded that CO2is being used in the system and converting which created the concentration of the feed gas higher inside the reactor. The research has provided the best conditions for the enhanced conversion while minimizing CO2formation. Though this research was not able to provide the optimal recycle rate it have created the path for the future research to proceed in the right direction. This reduction and utilization of CO2will help to reduce the cost of carbon dioxide removal and saves the environment from carbon dioxide emission.

Development of a New X-Ray Polarization Detection Device

NASA Astrophysics Data System (ADS)

Thompson, Jahreem R.; Hill, Joanne E.; Jahoda, Keith; Black, Kevin; Querrard, Rodney

2018-01-01

The aim of this research is to confirm the functionality of a Gas Electron Multiplier made of stainless steel in a detection medium of carbon dioxide and nitromethane through a series of X-ray tests in a vacuum chamber. Utilizing the photoelectric effect with carbon dioxide and nitromethane, we can confirm polarization of X-rays emitted from the most extreme astronomical conditions. We chose to use CO2 because we can confirm that it works well with the stainless-steel detector based on previous tests and nitromethane because we suspect that the ionization electrons created by the photoelectron during the photoelectric effect will experience less diffusion if they are bonded to a large molecule such as nitromethane as they diffuse towards the drift plate. The development of these new X-ray polarimeters will help to further the study of gravitational fields near black holes, their effects on matter they encounter, and the magnetic fields of neutron stars.

Study of thickness and uniformity of oxide passivation with DI-O3 on silicon substrate for electronic and photonic applications

NASA Astrophysics Data System (ADS)

Sharma, Mamta; Hazra, Purnima; Singh, Satyendra Kumar

2018-05-01

Since the beginning of semiconductor fabrication technology evolution, clean and passivated substrate surface is one of the prime requirements for fabrication of Electronic and optoelectronic device fabrication. However, as the scale of silicon circuits and device architectures are continuously decreased from micrometer to nanometer (from VLSI to ULSI technology), the cleaning methods to achieve better wafer surface qualities has raised research interests. The development of controlled and uniform silicon dioxide is the most effective and reliable way to achieve better wafer surface quality for fabrication of electronic devices. On the other hand, in order to meet the requirement of high environment safety/regulatory standards, the innovation of cleaning technology is also in demand. The controlled silicon dioxide layer formed by oxidant de-ionized ozonated water has better uniformity. As the uniformity of the controlled silicon dioxide layer is improved on the substrate, it enhances the performance of the devices. We can increase the thickness of oxide layer, by increasing the ozone time treatment. We reported first time to measurement of thickness of controlled silicon dioxide layer and obtained the uniform layer for same ozone time.

Game Changing Development Program - Next Generation Life Support Project: Oxygen Recovery From Carbon Dioxide Using Ion Exchange Membrane Electrolysis Technology

NASA Technical Reports Server (NTRS)

Burke, Kenneth A.; Jiao, Feng

2016-01-01

This report summarizes the Phase I research and development work performed during the March 13, 2015 to July 13, 2016 period. The proposal for this work was submitted in response to NASA Research Announcement NNH14ZOA001N, "Space Technology Research, Development, Demonstration, and Infusion 2014 (SpaceTech-REDDI-2014)," Appendix 14GCD-C2 "Game Changing Development Program, Advanced Oxygen Recovery for Spacecraft Life Support Systems Appendix" The Task Agreement for this Phase I work is Document Control Number: GCDP-02-TA-15015. The objective of the Phase I project was to demonstrate in laboratories two Engineering Development Units (EDU) that perform critical functions of the low temperature carbon dioxide electrolysis and the catalytic conversion of carbon monoxide into carbon and carbon dioxide. The low temperature carbon dioxide electrolysis EDU was built by the University of Delaware with Dr. Feng Jiao as the principal investigator in charge of this EDU development (under NASA Contract NNC15CA04C). The carbon monoxide catalytic conversion EDU was built by the NASA Glenn Research Center with Kenneth Burke as the principal investigator and overall project leader for the development of both EDUs. Both EDUs were successfully developed and demonstrated the critical functions for each process. The carbon dioxide electrolysis EDU was delivered to the NASA Johnson Space Center and the carbon monoxide catalytic conversion EDU was delivered to the NASA Marshall Spaceflight Center.

Effects of drought and elevated atmospheric carbon dioxide on seed nutrition and 15N and 13C natural abundance isotopes in soybean cultivars under controlled environments

USDA-ARS?s Scientific Manuscript database

Climate change resulting from global warming is expected to affect crop production and seed quality. The objective of this research was to evaluate the response of soybean cultivars to the effect of drought and elevated temperature on seed composition and mineral nutrition. In a repeated growth cham...

The Health Effects of Chlorine Dioxide as a Disinfectant in Potable Water: A Literature Survey

ERIC Educational Resources Information Center

Calabrese, Edward J.; And Others

1978-01-01

The use of chlorine dioxide as a disinfectant in water is being considered by the EPA. This article presents a summary of the known published reports concerning health effects of chlorine dioxide on animal and human populations. (Author/MA)

Carbon Dioxide Insufflation Increases Colonoscopic Adenoma Detection Rate Compared With Air Insufflation.

PubMed

Mills, Christopher D; McCamley, Chere; Swan, Michael P

2018-03-07

To determine the effect of carbon dioxide insufflation on the most important outcome measure of colonoscopic quality: adenoma detection rate (ADR). Bowel cancer is the second most common cause of cancer deaths in males and females in Australia. Carbon dioxide has in recent times become the insufflation methodology of choice for screening colonoscopy for bowel cancer, as this has been shown to have significant advantages when compared with traditional air insufflation. Endoscopies performed over a period of 9 months immediately before and after the implementation of carbon dioxide insufflation at endoscopy centers were eligible for inclusion. The difference in ADR between the carbon dioxide and air insufflation methods was statistically significant, with an increased ADR in the carbon dioxide group. The superiority of carbon dioxide insufflation was sustained with a logistic regression model, which showed ADR was significantly impacted by insufflation method. Carbon dioxide insufflation is known to reduce abdominal pain, postprocedural duration of abdominal pain, abdominal distension, and analgesic requirements. This study represents for the first time the beneficial effect of carbon dioxide insufflation upon the key quality colonoscopy indicator of ADR.

Geotourism and volcanoes: health hazards facing tourists at volcanic and geothermal destinations.

PubMed

Heggie, Travis W

2009-09-01

Volcano tourism and tourism to geothermal destinations is increasingly popular. If such endeavors are to be a sustainable sector of the tourism industry, tourists must be made aware of the potential health hazards facing them in volcanic environments. With the aim of creating awareness amongst the tourism industry and practitioners of travel medicine, this paper reviews the potential influences and effects of volcanic gases such as carbon dioxide (CO(2)), hydrogen sulfide (H(2)S), sulfur dioxide (SO(2)), and hydrogen chloride/hydrochloric acid (HCl). It also reviews the negative health impacts of tephra and ash, lava flows, landslides, and mudflows. Finally, future research striving to quantify the health risks facing volcano tourists is recommended.

Emergency and Continuous Exposure Limits for Selected Airborne Contaminants. Volume 2

DTIC Science & Technology

1984-10-01

21, fluorocarbon 113, fluorocarbon 114, isopropyl alcohol, phosgene, sodium hydroxide, sulfur dioxide, vinylidene chloride . xylene. b. Identlflers/Open...fluorocarbon 114, isopropyl alcohol, phosgene, sodium hydroxide, sulfur dioxide, vinylidene chloride , xylene. c. COSATI Field/Group 1I. Availability Statement...Hydroxide 87 Sulfur Dioxide 95 Vinylidene Chloride 103 Xylene 113 -" , 0°. •. .. : V.•. ., , • .’’-.’ .’.’ INTRODUCTION The National Research Council’s

Greenhouse effect may not be all bad

DOE Office of Scientific and Technical Information (OSTI.GOV)

Senft, D.

1990-10-01

Evidence is presented that indicates US temperatures decreased by a fraction of a degree during the past 70 years contrary to the estimates of some researchers concerned with the greenhouse effect. There is general agreement that the carbon dioxide concentrations in the atmosphere will double by the late or mid 21st century. Experiments on cotton growth under increased temperature and carbon dioxide concentrations indicate sizeable gains in yield. This increased yield is exhibited by citrus trees and is projected for other crops. There is a concomitant need for more water and fertilizer. Increased populations of parasitic mites and insects alsomore » occur. Climatic changes are seen as being more gradual than previously thought. The possible increases in food production under these changes in climate are one positive element in the emerging scenario.« less

Strategic Research to Enable NASA's Exploration Missions Conference and Workshop: Poster Session. Volume 2

NASA Technical Reports Server (NTRS)

Nahra, Henry (Compiler)

2004-01-01

Reports are presented from volume 2 of the conference titled Strategic Research to Enable NASA's Exploration Missions, poster session. Topics included spacecraft fire suppression and fire extinguishing agents,materials flammability, various topics on the effects of microgravity including crystal growth, fluid mechanics, electric particulate suspension, melting and solidification, bubble formation, the sloshing of liquid fuels, biological studies, separation of carbon dioxide and carbon monoxide for Mars ISRU.

Swedish Defence Research Abstracts 82/83-2 (Froe Foersvars Forsknings Referat 82/83-2).

DTIC Science & Technology

1983-08-01

alarm (78) Carbon dioxide retention inside motorcycle helmets (79) Vibration and decompression gas bubbles (80) No effects of nootropic drugs on memory... nootropic drugs on memory and psychomotor performance during reduced air pressure (in English) S. Levander and others Report I from the Roche Clinical Unit

Characterization of information requirements for studies of CO/sub 2/ effects: water resources, agriculture, fisheries, forests and human health

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, M R

1985-12-01

The report discusses how climate change and vegetative response will affect selected areas of our way of life as a result of increased carbon dioxide concentrations. Needs for future research are identified. Separate abstracts have been prepared for individual chapters. (ACR)

Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU-Concepts

NASA Technical Reports Server (NTRS)

LeVan, M. Douglas; Finn, John E.; Sridhar, K. R.

2000-01-01

Solid oxide electrolyzers, such as electrolysis cells utilizing yttria-stabilized zirconia, can produce oxygen from Mars atmospheric carbon dioxide and reject carbon monoxide and unreacted carbon dioxide in a separate stream. The oxygen-production process has been shown to be far more efficient if the high-pressure, unreacted carbon dioxide can be separated and recycled back into the feed stream. Additionally, the mass of the adsorption compressor can be reduced. Also, the carbon monoxide by-product is a valuable fuel for space exploration and habitation, with applications from fuel cells to production of hydrocarbons and plastics. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU. Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, respectively. In our research, we will design, construct, and test an innovative, robust, low mass, low power separation device that can recover carbon dioxide and carbon monoxide for Mars ISRU, Such fundamental process technology, involving gas-solid phase separation in a reduced gravitational environment, will help to enable Human Exploration and Development of Space. The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, The separation device will be scaled to operate with a CO2 sorption compressor and a zirconia electrolysis device built at the NASA Ames Research Center and the University of Arizona, Research needs for the design shown are as follows: (1) The best adsorbent for the process must be determined. (2) Adsorption isotherms must be measured, both for pure components and mixtures. (3) Mathematical modeling must be performed to provide a solid framework for design. (4) The separation system must be constructed and tested. (5) System integration must be studied.

Powdered Magnesium-Carbon Dioxide Rocket Combustion Technology for In Situ Mars Propulsion

NASA Technical Reports Server (NTRS)

Foote, J. P.; Litchford, R. J.

2007-01-01

Powdered magnesium (Mg) carbon dioxide (CO2) combustion is examined as a potential in situ propellant combination for Mars propulsion. Although this particular combination has relatively low performance in comparison to traditional bipropellants, it remains attractive as a potential basis for future martian mobility systems, since it could be partially or wholly manufactured from indigenous planetary resources. As a means of achieving high mobility during long-duration Mars exploration missions, the poorer performing in situ combination can, in fact, become a superior alternative to conventional storable propellants, which would need to be entirely transported from Earth. Thus, the engineering aspects of powdered metal combustion devices are discussed including transport/injection of compacted powder, ignition, combustion efficiency, combustion stability, dilution effects, lean burn limits, and slag formation issues. It is suggested that these technological issues could be effectively addressed through a multiphase research and development effort beginning with basic feasibility tests using an existing dump configured atmospheric pressure burner. Follow-on phases would involve the development and testing of a pressurized research combustor and technology demonstration tests of a prototypical rocket configuration.

"Powdered Magnesium: Carbon Dioxide Combustion for Mars Propulsion"

NASA Technical Reports Server (NTRS)

Foote, John P.; Litchford, Ron J.

2005-01-01

Powdered magnesium - carbon dioxide combustion is examined as a potential in-situ propellant combination for Mars propulsion. Although this particular combination has relatively low performance in comparison to traditional bi-propellants, it remains attractive as a potential basis for future Martian mobility systems since it could be partially or wholly manufactured from indigenous planetary resources. As a means of achieving high mobility during long-duration Mars exploration missions, the poorer performing in-situ combination can, in fact, become a superior alternative to conventional storable propellants, which would need to be entirely transported from earth. Thus, the engineering aspects of powdered metal combustion devices are discussed including transport/injection of compacted powder, ignition, combustion efficiency, combustion stability, dilution effects, lean burn limits, and slag formation issues. It is suggested that these technological issues could be effectively addressed through a multi-phase research and development effort beginning with basic feasibility tests using an existing dump configured atmospheric pressure burner. Follow-on phases would involve the development and testing of a pressurized research combustor and technology demonstration tests of a prototypical rocket configuration.

The preparation and the sustained release of titanium dioxide hollow particles encapsulating L-ascorbic acid

NASA Astrophysics Data System (ADS)

Tominaga, Yoko; Kadota, Kazunori; Shimosaka, Atsuko; Yoshida, Mikio; Oshima, Kotaro; Shirakawa, Yoshiyuki

2018-05-01

The preparation of the titanium dioxide hollow particles encapsulating L-ascorbic acid via sol-gel process using inkjet nozzle has been performed, and the sustained release and the effect protecting against degradation of L-ascorbic acid in the particles were investigated. The morphology of titanium dioxide particles was evaluated by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The sustained release and the effect protecting against degradation of L-ascorbic acid were estimated by dialysis bag method in phosphate buffer saline (PBS) (pH = 7.4) as release media. The prepared titanium dioxide particles exhibited spherical porous structures. The particle size distribution of the titanium dioxide particles was uniform. The hollow titanium dioxide particles encapsulating L-ascorbic acid showed the sustained release. It was also found that the degradation of L-ascorbic acid could be inhibited by encapsulating L-ascorbic acid in the titanium dioxide hollow particles.

The effect of environmental factors on selected mechanical properties of zirconium dioxide

NASA Astrophysics Data System (ADS)

Wirwicki, W.; Andrzejewska, A.; Andryszczyk, M.; Siemianowski, P.

2018-04-01

In many centers around the world, research studies are carried out on the mechanical strength of dental materials and glued joints. A literature review shows the variety of testing techniques related to analyzing the strength and durability of the material itself and the glued joints. In dental ceramics, zirconium dioxide is most often used as a base material, and chemically it consists of 97% ZrO2 and 3% Y2O3. This study was to determine the mechanical properties of zirconium dioxide under different environmental conditions. The material is used for the production of dental crowns and tooth bridges in the CAD/CAM technology. This medium is currently one of the most advanced-generation materials used for prosthetic and implant restorations. They were then subjected to a three-point bending test on the Instron ElektroPlus E3000 durability machine. Storage conditions and time have a positive influence on reducing variation in zirconium resistance for active forces and destructive stresses.

Modulation Doping of Silicon using Aluminium-induced Acceptor States in Silicon Dioxide

PubMed Central

König, Dirk; Hiller, Daniel; Gutsch, Sebastian; Zacharias, Margit; Smith, Sean

2017-01-01

All electronic, optoelectronic or photovoltaic applications of silicon depend on controlling majority charge carriers via doping with impurity atoms. Nanoscale silicon is omnipresent in fundamental research (quantum dots, nanowires) but also approached in future technology nodes of the microelectronics industry. In general, silicon nanovolumes, irrespective of their intended purpose, suffer from effects that impede conventional doping due to fundamental physical principles such as out-diffusion, statistics of small numbers, quantum- or dielectric confinement. In analogy to the concept of modulation doping, originally invented for III-V semiconductors, we demonstrate a heterostructure modulation doping method for silicon. Our approach utilizes a specific acceptor state of aluminium atoms in silicon dioxide to generate holes as majority carriers in adjacent silicon. By relocating the dopants from silicon to silicon dioxide, Si nanoscale doping problems are circumvented. In addition, the concept of aluminium-induced acceptor states for passivating hole selective tunnelling contacts as required for high-efficiency photovoltaics is presented and corroborated by first carrier lifetime and tunnelling current measurements. PMID:28425460

Supercritical carbon dioxide-based sterilization of decellularized heart valves

PubMed Central

Hennessy, Ryan S.; Jana, Soumen; Tefft, Brandon J.; Helder, Meghana R.; Young, Melissa D.; Hennessy, Rebecca R.; Stoyles, Nicholas J.; Lerman, Amir

2017-01-01

Objective The goal of this research project encompasses finding the most efficient and effective method of decellularized tissue sterilization. Background Aortic tissue grafts have been utilized to repair damaged or diseased valves. Although, the tissues for grafting are collected aseptically, it does not eradicate the risk of contamination nor disease transfer. Thus, sterilization of grafts is mandatory. Several techniques have been applied to sterilize grafts; however, each technique shows drawbacks. In this study, we compared several sterilization techniques: supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide for impact on the sterility and mechanical integrity of porcine decellularized aortic valves. Methods Valve sterility was characterized by histology, microbe culture, and electron microscopy. Uniaxial tensile testing was conducted on the valve cusps along their circumferential orientation to study these sterilization techniques on their integrity. Results Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile. The tensile strength of supercritical carbon dioxide treated valves (4.28 ± 0.22 MPa) was higher to those valves treated with electrolyzed water, gamma radiation, ethanol-peracetic acid and hydrogen peroxide (1.02 ± 0.15, 1.25 ± 0.25, 3.53 ± 0.41 and 0.37 ± 0.04 MPa, respectively). Conclusions Superior sterility and integrity were found in the decellularized porcine aortic valves with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Summary Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile using histology, microbe culture and electron microscopy assays. The cusp tensile properties of supercritical carbon dioxide treated valves were higher compared to valves treated with other techniques. Superior sterility and integrity was found in the decellularized valves treated with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. PMID:28337488

High Temperature Raman Spectroscopy Study of the Conversion of Formate into Oxalate: Search for the Elusive CO 2 2 - Intermediate

NASA Astrophysics Data System (ADS)

Ryan, Charles; Mead, Anna; Lakkaraju, Prasad; Kaczur, Jerry; Bennett, Christopher; Dobbins, Tabbetha

Research on conversion of carbon dioxide into chemicals and fuels has the potential to address three problems of global relevance. (a) By removing carbon dioxide from the atmosphere, we are able to reduce the amount of greenhouse gases in the atmosphere, (b) by converting carbon dioxide into fuels, we are providing pathways for renewable energy sources, (c) by converting carbon dioxide into C2 and higher order compounds, and we are able to generate valuable precursors for organic synthesis. Formate salts are formed by the electrochemical reduction of carbon dioxide in aqueous media. However, in order to increase the utilization of carbon dioxide, methods need to be developed for the conversion of formate into compounds containing two carbon atoms such as oxalate or oxalic acid. Recently, we examined the thermal conversion of sodium formate into sodium oxalate utilizing a hydride ion catalyst. The proposed mechanism for this reaction involves the carbon dioxide dianion. Currently at NASA Goddard Space Flight Center.

Evaluation of gaseous chlorine dioxide for the inactivation of tulane virus on blueberries

USDA-ARS?s Scientific Manuscript database

To determine the effectiveness of gaseous chlorine dioxide against a human norovirus surrogate on produce, chlorine dioxide was generated and applied to Tulane virus coated blueberries in a 240 ml treatment chamber. Chlorine dioxide was produced by acidifying sodium chlorite solution. Initial asse...

Potential effects of anthropogenic greenhouse gases on avian habitats and populations in the northern Great Plains

USGS Publications Warehouse

Larson, Diane L.

1994-01-01

Biotic response to the buildup of greenhouse gases in Earth's atmosphere is considerably more complex than an adjustment to changing temperature and precipitation. The fertilization effect carbon dioxide has on some plants, the impact UVB radiation has on health and productivity of organisms, and the resulting changes in competitive balance and trophic structure must also be considered. The intent of this paper is to review direct and indirect effects of anthropogenic greenhouse gases on wildlife, and to explore possible effects on populations of birds and their habitats in the northern Great Plains.Many of the potential effects of increasing greenhouse gases, such as declining plant nutritional value, changes in timing of insect emergence, and fewer and saltier wetlands, foreshadow a decline in avian populations on the Great Plains. However, other possible effects such as increased drought resistance and water use efficiency of vegetation, longer growing seasons, and greater overall plant biomass promise at least some mitigation. Effects of multiple simultaneous perturbations such as can be expected under doubled carbon dioxide scenarios will require substantial basic research to clarify.

EFFECTS OF FLY ASH TRANSITION METAL CONTENT AND FLUE GAS HCL/SO2 RATIO ON MERCURY SPECIATION IN WASTE COMBUSTION

EPA Science Inventory

The paper presents results of research on the effect of sulfur dioxide (SO2):HCI ratio on heterogeneous Hg0 oxidation. The addition of SO2 to moist flue gas at high SO2:HCI ratios (4:1 to 10:1) caused a decrease in oxidation of Hg0 relative to flur gas without SO2. This is attrib...

We Don't Need a "Geoengineering" Research Program

NASA Astrophysics Data System (ADS)

Caldeira, K.

2011-12-01

Most approaches commonly labeled as 'geoengineering' can be divided into two categories: approaches that attempt to reduce the change in atmospheric composition caused by anthropogenic emissions (commonly labeled CDR, for Carbon Dioxide Removal), and approaches that attempt to reduce the change in climate caused by changes in atmospheric composition (commonly labeled SRM, for Sunlight Reflection Methods or Solar Radiation Management). CDR is relatively uncontroversial (apart from ocean fertilization), and the primary issues are typically cost, effectiveness, local environmental consequences, and verification. In contrast, SRM has provoked much controversy, because large-scale SRM deployments necessarily would affect everyone on this planet. Several proposals have been tabled for SRM-specific or geoengineering-specific research and governance structures, treating SRM or geoengineering research as a thing apart. We should instead view CDR and SRM research as part of a broader continuum of activities aimed at understanding Earth system dynamics and reducing risks associated with climate change. The scope of existing research efforts should be broadened so that CDR and SRM approaches are, at this stage in development, treated as an extension of what we are already doing. What is 'geoengineering research'? A primary need at this time is for expansion of scope of and funding for existing climate-related research efforts. For examples: Scientists studying the role of aerosols in clouds or stratospheric processes can expand the domain of concern to consider effects of intentionally introduced aerosols (and not just natural aerosols and aerosols we introduce as a byproduct of civilization's normal functioning). Scientists studying effects of land-surface change on global and regional climates can expand the domain of concern beyond inadvertent effects to consider effects of land-surface changes undertaken with the intent to affect these climates. Research programs aimed at removing carbon dioxide from power plant flue gases can be broadened to consider industrial approaches to remove carbon dioxide that has already been released to the atmosphere. There appears to be little need for new overarching research structures or institutions at this time for activities for which there are no plans for deployment. Defining the scope of reference of 'geoengineering' and related terms (eg, 'geoengineering experiment') is a linguistic distraction and a waste of time. We should focus instead on substantive issues of primary concern. If our goal is to reduce risk from scientific experiments, then let's develop approaches aimed at governing risky experiments. Governance efforts can be aimed at eliminating unjustified risk independently of whether some people might want to apply labels like 'geoengineering' to those activities. We do not need 'a geoengineering research program'. We need to expand existing research programs to consider a broader range of activities and conditions. We do not need efforts to govern 'geoengineering experiments' although we may need efforts to govern scientific experiments that pose unjustified risks. Let's focus on gaining knowledge and managing risks, and not let our brains be addled by emotionally-charged language.

Effect of Carbon Dioxide on Testing of Susceptibilities of Respiratory Tract Pathogens to Macrolide and Azalide Antimicrobial Agents

PubMed Central

Johnson, M. M.; Hill, S. L.; Piddock, Laura J. V.

1999-01-01

The in vitro activities of erythromycin, azithromycin, and clarithromycin against 178 clinical isolates from the lower respiratory tract of patients with chronic obstructive pulmonary disease were determined by an agar dilution method. The plates were incubated in air alone or in 5% carbon dioxide. The MICs measured in air alone were lower for most isolates than those measured in 5% carbon dioxide, illustrating the “pH effect” of incubation in carbon dioxide. Testing of isolates in 5% carbon dioxide on pH-adjusted medium (pH 8.4) resulted in MICs of one or two doubling dilutions lower than those obtained on agar with a neutral pH. A bioassay of the three agents incubated in air and in 5% carbon dioxide resulted in a significant loss of activity of all three agents in the carbon dioxide-enriched atmosphere. However, this loss-of-activity effect was significantly reduced when the bioassay medium was adjusted to pH 8.4 prior to incubation in 5% carbon dioxide. PMID:10428903

The enhancing performance of (Ba{sub 0.85}Ca{sub 0.15}Ti{sub 0.90}Zr{sub 0.10})O{sub 3} ceramics by tuning anatase–rutile phase structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, Xiaolian, E-mail: chaoxl@snnu.edu.cn; Wang, Juanjuan; Wang, Zhongming

2016-04-15

Graphical abstract: Titanium dioxide (TiO{sub 2}) with different phase structure had interesting influence on the crystal structure, microstructure, the sintering temperature and electrical properties. - Highlights: • BCZT ceramics were prepared using either anatase or rutile structures as Ti source. • Orthorhombic and tetragonal mixture structure was exhibited by adjusting Ti source. • The optimal properties were observed in BCZT ceramics with rutile titanium dioxide. - Abstract: To research effect of raw materials TiO{sub 2} with the phase structures on the crystal structure, microstructure and electrical properties of lead-free (Ba{sub 0.85}Ca{sub 0.15})(Ti{sub 0.90}Zr{sub 0.10})O{sub 3} (BCZT) ceramics, BCZT ceramics usingmore » either anatase or rutile as Ti source were synthesized by solid-state reaction. Titanium dioxide (TiO{sub 2}) with anatase/rutile phase structures had interesting influence on the crystal structure, microstructure and the sintering temperature by the X-ray diffraction and SEM, which also played an important role in improved electrical properties. The BCZT ceramics with rutile titanium dioxide demonstrated optimal piezoelectric and dielectric properties: d{sub 33} = 590 pC/N, k{sub p} = 0.46, ε{sub r} = 2810, tanδ = 0.014 and T{sub c} = 91 °C, which was obviously superior to BCZT ceramics with anatase titanium dioxide.« less

Effects of acidic deposition on the erosion of carbonate stone — experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP)

NASA Astrophysics Data System (ADS)

Baedecker, Philip A.; Reddy, Michael M.; Reimann, Karl J.; Sciammarella, Cesar A.

One of the goals of NAPAP-sponsored research on the effects of acidic deposition on carbonate stone has been to quantify the incremental effects of wet and dry deposition of hydrogen ion, sulfur dioxide and nitrogen oxides on stone erosion. Test briquettes and slabs of freshly quarried Indiana limestone and Vermont marble have been exposed to ambient environmental conditions in a long-term exposure program. Physical measurements of the recession of test stones exposed to ambient conditions at an angle of 30° to horizontal at the five NAPAP materials exposure sites range from ˜ 15 to ˜ 30 μm yr -1 for marble, and from ˜ 25 to ˜ 45 μm yr -1 for limestone, and are approximately double the recession estimates based on the observed calcium content of run-off solutions from test slabs. The difference between the physical and chemical recession measurements is attributed to the loss of mineral grains from the stone surfaces that are not measured in the run-off experiments. The erosion due to grain loss does not appear to be influenced by rainfall acidity, however, preliminary evidence suggests that grain loss may be influenced by dry deposition of sulfur dioxide between rainfall events. Chemical analyses of the run-off solutions and associated rainfall blanks suggest that ˜ 30% of erosion by dissolution can be attributed to the wet deposition of hydrogen ion and the dry deposition of sulfur dioxide and nitric acid between rain events. The remaining ˜ 70% of erosion by dissolution is accounted for by the solubility of carbonate stone in rain that is in equilibrium with atmospheric carbon dioxide ("clean rain"). These results are for marble and limestone slabs exposed at an angle of 30° from horizontal. The relative contribution of sulfur dioxide to chemical erosion is significantly enhanced for stone slabs having an inclination of 60° or 85°. The dry deposition of alkaline particulate material has a mitigating effect at the two urban field exposure sites at Washington, DC, and Steubenville, OH.

Effects of acidic deposition on the erosion of carbonate stone - experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP)

USGS Publications Warehouse

Baedecker, P.A.; Reddy, M.M.; Reimann, K.J.; Sciammarella, C.A.

1992-01-01

One of the goals of NAPAP-sponsored research on the effects of acidic deposition on carbonate stone has been to quantify the incremental effects of wet and dry deposition of hydrogen ion, sulfur dioxide and nitrogen oxides on stone erosion. Test briquettes and slabs of freshly quarried Indiana limestone and Vermont marble have been exposed to ambient environmental conditions in a long-term exposure program. Physical measurements of the recession of test stones exposed to ambient conditions at an angle of 30?? to horizontal at the five NAPAP materials exposure sites range from ~15 to ~30?? ??m yr-1 for marble, and from ~25 to ~45 ??m yr -1 for limestone, and are approximately double the recession estimates based on the observed calcium content of run-off solutions from test slabs. The difference between the physical and chemical recession measurements is attributed to the loss of mineral grains from the stone surfaces that are not measured in the run-off experiments. The erosion due to grain loss does not appear to be influenced by rainfall acidity, however, preliminary evidence suggests that grain loss may be influenced by dry deposition of sulfur dioxide between rainfall events. Chemical analyses of the run-off solutions and associated rainfall blanks suggest that ~30% of erosion by dissolution can be attributed to the wet deposition of hydrogen ion and the dry deposition of sulfur dioxide and nitric acid between rain events. The remaining ~70% of erosion by dissolution is accounted for by the solubility of carbonate stone in rain that is in equilibrium with atmospheric carbon dioxide ('clean rain'). These results are for marble and limestone slabs exposed at an angle of 30?? from horizontal. The relative contribution of sulfur dioxide to chemical erosion is significantly enhanced for stone slabs having an inclination of 60?? or 85??. The dry deposition of alkaline particulate material has a mitigating effect at the two urban field exposure sites at Washington, DC, and Steubenville, OH.

Final Report: Fundamental Research on the Fractionation of Carbon Isotopes during Photosynthesis, New Interpretations of Terrestrial Organic Carbon within Geologic Substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jahren, A. Hope; Schubert, Brian A.

2017-08-02

The goal for the current grant period (2013 – 2016) was to quantify the effect of changing atmospheric carbon dioxide concentration (pCO2) on published terrestrial carbon isotope excursion events. This work supported four scientists across multiple career stages, and resulted in 5 published papers.

EFFECTS OF WATER VAPOR AND SULFUR DIOXIDE ON THE PERFORMANCE OF CE-AG-ZSM-5 FOR THE SCR OF NO WITH CH4. (R825430)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

EFFECTS OF CULTURE PARAMETERS ON DDT [1,1,1-TRICHLO- RO-2,2-BIS(4-CHLOROPHENYL) ETHANE] BIODEGRADATION BY PHANEROCHAETE CHRYSOSPORIUM

EPA Science Inventory

The lignin degrading system of the white rot fungus Phanerochaete chrysosporium is able to degrade a wide variety of structurally diverse organopollutants to carbon dioxide. Current research is focused on ways to increase or optimize rates of biodegradation in order to a...

The effect of sulphur dioxide and oxygen on the viability and culturability of a strain of Acetobacter pasteurianus and a strain of Brettanomyces bruxellensis isolated from wine.

PubMed

du Toit, W J; Pretorius, I S; Lonvaud-Funel, A

2005-01-01

The objective of this study was to investigate the effects of free molecular and bound forms of sulphur dioxide and oxygen on the viability and culturability of a selected strain of Acetobacter pasteurianus and a selected strain of Brettanomyces bruxellensis in wine. Acetic acid bacteria and Brettanomyces/Dekkera yeasts associated with wine spoilage were isolated from bottled commercial red wines. One bacterium, A. pasteurianus strain A8, and one yeast, B. bruxellensis strain B3a, were selected for further study. The resistance to sulphur dioxide and the effect of oxygen addition on these two selected strains were determined by using plating and epifluorescence techniques for monitoring cell viability in wine. Acetobacter pasteurianus A8 was more resistant to sulphur dioxide than B. bruxellensis B3a, with the latter being rapidly affected by a short exposure time to free molecular form of sulphur dioxide. As expected, neither of these microbial strains was affected by the bound form of sulphur dioxide. The addition of oxygen negated the difference observed between plate and epifluorescence counts for A. pasteurianus A8 during storage, while it stimulated growth of B. bruxellensis B3a. Acetobacter pasteurianus A8 can survive under anaerobic conditions in wine in the presence of sulphur dioxide. Brettanomyces bruxellensis B3a is more sensitive to sulphur dioxide than A. pasteurianus A8, but can grow in the presence of oxygen. Care should be taken to exclude oxygen from contact with wine when it is being transferred or moved. Wine spoilage can be avoided by preventing growth of undesirable acetic acid bacteria and Brettanomyces/Dekkera yeasts through the effective use of sulphur dioxide and the management of oxygen throughout the winemaking process.

Exposure to chlorine dioxide gas for 4 hours renders Syphacia ova nonviable.

PubMed

Czarra, Jane A; Adams, Joleen K; Carter, Christopher L; Hill, William A; Coan, Patricia N

2014-07-01

The purpose of our study was to evaluate the efficacy of chlorine dioxide gas for environmental decontamination of Syphacia spp. ova. We collected Syphacia ova by perianal cellophane tape impression of pinworm-infected mice. Tapes with attached ova were exposed to chlorine dioxide gas for 1, 2, 3, or 4 h. After gas exposure, ova were incubated in hatching medium for 6 h to promote hatching. For controls, tapes with attached ova were maintained at room temperature for 1, 2, 3, and 4 h without exposure to chlorine dioxide gas and similarly incubated in hatch medium for 6 h. Ova viability after incubation was assessed by microscopic examination. Exposure to chlorine dioxide gas for 4 h rendered 100% of Syphacia spp. ova nonviable. Conversely, only 17% of ova on the 4-h control slide were nonviable. Other times of exposure to chlorine dioxide gas resulted in variable effectiveness. These data suggest that exposure to chlorine dioxide gas for at least 4 h is effective for surface decontamination of Syphacia spp. ova.

Industrial air pollution is a threat to NY's grape industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jordan, T.D.

1977-01-01

Air pollution has become a serious problem for the grape industry in New York's Great Lakes region. Ozone is discussed in relation to crop damage. There are several by-products of coal-combustion and steel manufacture that may cause serious plant injury. They include: sulfur dioxide, hydrogen fluoride, nitrous oxide, and several of the heavy metals, such as arsenic, mercury, and lead. A leaf injury, called Brown Leaf, has been identified as oxidant stipple, which is caused by excessive ozone. It is evident that excessive soil moisture results in more oxidant stipple. In 1977, an expanded research effort has been undertaken tomore » determine the effects of other air pollutants, such as sulfur dioxide.« less

Extraction of Carbon Dioxide and Hydrogen from Seawater By an Electrolytic Cation Exchange Module (E-CEM) Part 5: E-CEM Effluent Discharge Composition as a Function of Electrode Water Composition

DTIC Science & Technology

2017-08-01

Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6360--17-9743 Extraction of Carbon Dioxide and Hydrogen from Seawater by an Electrolytic...Cation Exchange Module (E-CEM) Part V: E-CEM Effluent Discharge Composition as a Function of Electrode Water Composition August 1, 2017 Approved for...Office of Naval Research Arlington, Virginia Dennis r. HarDy Nova Research Inc. Alexandria, Virginia i REPORT DOCUMENTATION PAGE Form

NASA launches carbon dioxide research satellite

NASA Astrophysics Data System (ADS)

Wendel, JoAnna

2014-07-01

Last week NASA launched a new satellite to study atmospheric carbon dioxide (CO2). Once in orbit, the Orbiting Carbon Observatory-2 (OCO-2) satellite, launched from Vandenberg Air Force Base in California, will take more than 100,000 individual measurements of atmospheric CO2 per day.

An Impact of Mechanical Stress in Coal Briquettes on Sorption of Carbon Dioxide

NASA Astrophysics Data System (ADS)

Wierzbicki, Mirosław

2017-09-01

The presence of gases (methane or carbon dioxide) in hard coal is connected with numerous threats for miners employed in underground mining facilities. When analyzing the coal-methane system, it is necessary to determine the relationship between pressure and gas sorption. Such a relationship should be determined under conditions similar to the natural ones - when it comes to both temperature and pressure. The present paper discusses the results of research conducted with the use of coal briquettes under the state of mechanical stress. Carbon dioxide sorption isotherms were determined for different values of stress affecting the coal material. For five coal samples collected in different mines of the Upper Silesian Coal Basin, Langmuir's sorption isotherms were determined. The results point to significant impact that mechanical stress has upon the sorption process. It is about 1 percent of the value obtained for coal not subjected to stress per 1 MPa. The research results can also prove useful when analyzing hard coal seams from the perspective of their carbon dioxide sequestration abilities.

Trapping the Tiger: Efficacy of the Novel BG-Sentinel 2 With Several Attractants and Carbon Dioxide for Collecting Aedes albopictus (Diptera: Culicidae) in Southern France.

PubMed

Roiz, David; Duperier, Sandy; Roussel, Marion; Boussès, Philippe; Fontenille, Didier; Simard, Frédéric; Paupy, Christophe

2016-03-01

Targeted trapping of mosquito disease vectors plays an important role in the surveillance and control of mosquito-borne diseases. The Asian tiger mosquito, Aedes albopictus (Skuse), is an invasive species, which is spreading throughout the world, and is a potential vector of 24 arboviruses, particularly efficient in the transmission of chikungunya, dengue, and zika viruses. Using a 4 × 4 Latin square design, we assessed the efficacy of the new BG-Sentinel 2 mosquito trap using the attractants BG-lure and (R)-1-octen-3-ol cartridge, alone or in combination, and with and without carbon dioxide, for the field collection of Ae. albopictus mosquitoes.We found a synergistic effect of attractant and carbon dioxide that significantly increased twofold to fivefold the capture rate of Ae. albopictus. In combination with carbon dioxide, BG-lure cartridge is more effective than (R)-1-octen-3-ol in attracting females, while a combination of both attractants and carbon dioxide is the most effective for capturing males. In the absence of carbon dioxide, BG-lure cartridge alone did not increase the capture of males or females when compared with an unbaited trap. However, the synergistic effect of carbon dioxide and BG-lure makes this the most efficient combination in attracting Ae. albopictus.

Compendium of Dental Residents’ Research Projects and Literature Reviews for 1989

DTIC Science & Technology

1990-05-01

K. Krause, Major, USAF, DC The effectiveness of three immersion disinfectants: Chlorine dioxide, 2% glutaraldehyde, and 5.25% sodium hypochlorite was...5.25% sodium hypochlorite disinfectants also met the same standards of effectiveness at 10 and 5 minutes, respectively. 89 26 05 THE CLINICAL EFFECT...Solutions Time Temp Culture Culture Culture Sporicidin (Control) 10 min 240C 20 0 0 Sodium Hypochlorite 1 min 370C 20 0 0 Alcide Expore 2 min 370C 20 1

Designed amyloid fibers as materials for selective carbon dioxide capture

PubMed Central

Li, Dan; Furukawa, Hiroyasu; Deng, Hexiang; Liu, Cong; Yaghi, Omar M.; Eisenberg, David S.

2014-01-01

New materials capable of binding carbon dioxide are essential for addressing climate change. Here, we demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture. Solid-state NMR proves that amyloid fibers containing alkylamine groups reversibly bind carbon dioxide via carbamate formation. Thermodynamic and kinetic capture-and-release tests show the carbamate formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence of water, in both a natural amyloid and designed amyloids having increased carbon dioxide capacity. Heating to 100 °C regenerates the material. These results demonstrate the potential of amyloid fibers for environmental carbon dioxide capture. PMID:24367077

[Comparative study of nanosized and microsized silicon dioxide on spermatogenesis function of male rats].

PubMed

Fan, Yi-Ou; Zhang, Ying-Hua; Zhang, Xiao-Peng; Liu, Bing; Ma, Yi-xin; Jin, Yi-he

2006-09-01

To compare the effects of nanosized and microsized silicon dioxide on spermatogenesis function of male rats exposed by inhalation. 45 male rats were randomly divided into control group and four experimental groups which were exposed by 100 mg/m3 or 300 mg/m3 nanosized and microsized silicon dioxide in inhalation chambers 2 hours every other day. Age-matched rats were exposed to room air with the same condition and served as controls. 65 days later, the testicular and epididymal viscera coefficients, the quantity and quality of sperm were examined and the histopathological assessment was done. The changes in biochemical parameters in serum and testes were also measured. Nanosized silicon dioxide could induce histopathological changes of testes in rats, and the effect was higher than that of microsized particles at the same concentration. Nanosized silicon dioxide could reduce the sperm counts of rats and the testicular LDH-C4 activities, increase MDA levels in the testes and the effect was higher than that of microsized particles at the same concentration. Nanosized silicon dioxide could lead to the reduction of sperm motility, testicular LDH-C4 activities and 8-hydroxydeoxyguanosine (8-OHdG) concentration in serum elevation in particles-exposed rats compared with the control animals, but there are no significant difference compared with that of microsized particles at the same concentration. The present findings suggest a different effect of impairment of sperm production and maturation induced by inhalation of nanosized and microsized silicon dioxide, and nanosized silicon dioxide exerted more severe reaction.

Corona Preionization Technique for Carbon Dioxide TEA Lasers.

DTIC Science & Technology

1982-11-30

34’" " " " "- -. .. " "I~ 82R8O701-02 CORONA PREIONIZATION TECHNIQUE FOR CARBON DIOXIDE TEA LASERS W after R. Kamnki SUnited Technologiles Research Center C...TITLE (and Subtitle) S. TYPE OF REPORT a PERIOD COVERED CORONA PREIONIZATION TECHNIQUE FOR CARBON Final Report DIOXIDE TEA LASERS May 5, 1981...Preionization Laser UV Preionization Pulsed CO2 Laser Corona Preionization CO2 TEA Laser 10. ABSTRACT (Continue on reverse side If neceeeiny md Identify

Services to Operate and Maintain Walter Reed Army Institute of Research’s (WRAIR) Microwave Facility.

DTIC Science & Technology

1994-06-20

Sixty-four day old rats were euthanized individually in a polycarbonate cage with carbon dioxide from a 100 % carbon dioxide cylinder. Eyes were removed...grams were used. Rats were euthanized with carbon dioxide . A thermistor based temperature probe (Yellow Spring Instruments, YSI 423) was inserted 5 cm...gals). This has been a necessary procedure which evacuates carbon from the oil which in turn will build-up on the HV components and conductors in the

FACE: Free-Air CO{sub 2} Enrichment for plant research in the field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hendrey, G.R.

1992-08-01

Research programs concerning the effects of Carbon Dioxide(CO){sub 2} on cotton plants are described. Biological responses studied include foliage response to CO{sub 2} fluctuations; yield of cotton exposed to CO{sub 2} enrichment; responses of photosynthesis and stomatal conductance to elevated CO{sub 2} in field-grown cotton; cotton leaf and boll temperatures; root response to CO{sub 2} enrichment; and evaluations of cotton response to CO{sub 2} enrichment with canopy reflectance observations.

FACE: Free-Air CO[sub 2] Enrichment for plant research in the field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hendrey, G.R.

1992-08-01

Research programs concerning the effects of Carbon Dioxide(CO)[sub 2] on cotton plants are described. Biological responses studied include foliage response to CO[sub 2] fluctuations; yield of cotton exposed to CO[sub 2] enrichment; responses of photosynthesis and stomatal conductance to elevated CO[sub 2] in field-grown cotton; cotton leaf and boll temperatures; root response to CO[sub 2] enrichment; and evaluations of cotton response to CO[sub 2] enrichment with canopy reflectance observations.

Disinfecting capabilities of oxychlorine compounds.

PubMed Central

Noss, C I; Olivieri, V P

1985-01-01

The bacterial virus f2 was inactivated by chlorine dioxide at acidic, neutral, and alkaline pH values. The rate of inactivation increased with increasing pH. Chlorine dioxide disproportionation products, chlorite and chlorate, were not active disinfectants. As chlorine dioxide solutions were degraded under alkaline conditions, they displayed reduced viricidal effectiveness, thereby confirming the chlorine dioxide free radical as the active disinfecting species. PMID:3911893

CUORE: The Three Towers Test

NASA Astrophysics Data System (ADS)

Sparks, Laura; Goodsell, Alison

2009-11-01

Cryogenic Underground Observatory for Rare Events (CUORE) will be part of the next generation of detectors used to search for neutrinoless double beta decay (0vBB). Located in Assergi, Italy at the Gran Sasso National Laboratory (LNGS), CUORE will be a large cryogenic bolometer composed of 988 tellurium dioxide (TeO2) detectors with a total mass of 750 kg, and will search for 0vBB in 130Te. As the experiment will monitor the extremely rare event of 0vBB, all factors contributing to background need to be minimized to effectively increase the sensitivity. We assisted the LNGS researchers over the summer of 2008 by supporting Research and Development efforts to reduce the radioactive background of the experiment. Activities involved decontaminating the copper frame of radon daughters, and chemically etching and lapping the TeO2 crystals with nitric acid and silicon dioxide, respectively, to remove surface contaminants that contribute to background counts. This work was supported in part by NSF grant PHY-0653284 and the California State Faculty Support Grant.

Technology choice and development in Brazil: An assessment of Brazil's alternative fuel program and the agriculture, manufacturing, energy, and service sectors

NASA Astrophysics Data System (ADS)

Nolan, Lucy A.

Technology choice profoundly affects a country's development process because capital-intensive and labor-intensive technologies have different socioeconomic linkages within the economy. This research examines the impacts of technology choice through the use of a social accounting matrix (SAM) framework. SAM-based modeling determines the direct and indirect effects of technology choice on development, particularly poverty alleviation in Brazil. Brazil's alternative fuel program was analyzed as a special example of technology choice. Two ethanol production technologies and the gasoline sector were compared; to make the study more robust, labor and capital intensive technologies were evaluated in the production of agriculture, manufacturing, energy, and services. Growth in these economic sectors was examined to assess the effects on employment, factor and household income, energy intensity, and carbon dioxide costs. Poverty alleviation was a focus, so income to unskilled agriculture labor, unskilled non-agriculture labor, and income to rural and urban households in poverty was also analyzed. The major research finding is that overall, labor-intensive technologies generate more employment, factor and household income, environmental and energy benefits to Brazil's economy than capital-intensive technologies. In addition, labor-intensive technologies make a particular contribution to poverty alleviation. The results suggest that policies to encourage the adoption of these technologies, especially in the agriculture and renewable energy sectors, are important because of their intersectoral linkages within the economy. Many studies have shown that Brazil's fuel ethanol program has helped to realize multiple macroeconomic objectives. However, this is the first empirical study to quantify its household income effects. The ethanol industry generated the most household income of the energy sectors. The research confirms a key finding of the appropriate technology literature, namely that government policies are important to the implementation of labor-intensive technologies. Finally, this research makes two important contributions to the SAM methodology. It is one of the first SAM modeling exercises to quantify the costs of carbon dioxide emissions and the impact of alternative fuels on regional and human development. The addition of an environmental sector enables the planner to determine carbon dioxide effects resulting from growth in different socioeconomic sectors. This will have implications for greenhouse gas mitigation strategies.

Effect of doping on the photocatalytic, electronic and mechanical properties of sol-gel titanium dioxide films

NASA Astrophysics Data System (ADS)

Kurtoglu, Murat

Heterogeneous photocatalysis has been an active research area over the last decade as a promising solution for energy generation and environmental problems which has led to promising applications from air and water purification systems, self-cleaning and self-sterilizing surfaces to solar cells and hydrogen production from water dissociation reaction. Titanium dioxide (TiO2), an abundant material with a high photocatalytic efficiency and chemical stability, is undoubtedly the most widely studied and used among all photocatalytic materials. Although titanium dioxide has been used in powder form, its immobilized form (film) is necessary from practical application standpoint. However, there are several shortcomings of titanium dioxide films that need to be addressed to realize a wide range of successful applications: lack of visible light activity, poisoning of the catalytic performance by the substrate and the low surface area compared to powder forms. In addition, mechanical properties of such films have not been investigated thoroughly, which may be critical when abrasion and weathering resistance are necessary. To address each of these issues, a systematic experimental and theoretical investigation of doping titanium dioxide films with a variety of elements were conducted. Utilizing theoretical calculations to filter elements for experimental studies as well as interpretation of the experimental results, several dopant or dopant combinations were found to remedy some of the issues of photocatalytic titanium dioxide films. Doping with 32 metals, nitrogen and 11 metal-nitrogen combinations are investigated theoretically and the results are used as guideline for the experimental studies. Particular attention is given to certain metal dopants such as Cr, V, Mo, Ta and Ga not just because of their relatively modest cost but also their non-toxicity and wide availability of their compatible compounds for sol-gel synthesis. While metal-dopants improved the overall efficiency and mechanical properties of titanium dioxide films, visible light activity is only achieved with nitrogen and metal-nitrogen doping where some of the metal co-dopants significantly improved the overall photocatalytic efficiency compared to nitrogen-only doped films. In addition, majority of the experimental studies is accompanied by nanoindentation technique to study the effect of doping and calcination on the key mechanical properties of titanium dioxide films. It is shown that good mechanical properties---good photocatalytic activity combinations can be achieved by a choice of appropriate dopant---dopant combinations and coupled with appropriate calcination parameters. Results of the theoretical and experimental investigations led to the development of first commercial photocatalytic tableware glass items which can be utilized under indoor lighting conditions by carefully selecting metal-nitrogen couples for doping of titanium dioxide films.

Carbon dioxide in Arctic and subarctic regions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gosink, T. A.; Kelley, J. J.

1981-03-01

A three year research project was presented that would define the role of the Arctic ocean, sea ice, tundra, taiga, high latitude ponds and lakes and polar anthropogenic activity on the carbon dioxide content of the atmosphere. Due to the large physical and geographical differences between the two polar regions, a comparison of CO/sub 2/ source and sink strengths of the two areas was proposed. Research opportunities during the first year, particularly those aboard the Swedish icebreaker, YMER, provided additional confirmatory data about the natural source and sink strengths for carbon dioxide in the Arctic regions. As a result, themore » hypothesis that these natural sources and sinks are strong enough to significantly affect global atmospheric carbon dioxide levels is considerably strengthened. Based on the available data we calculate that the whole Arctic region is a net annual sink for about 1.1 x 10/sup 15/ g of CO/sub 2/, or the equivalent of about 5% of the annual anthropogenic input into the atmosphere. For the second year of this research effort, research on the seasonal sources and sinks of CO/sub 2/ in the Arctic will be continued. Particular attention will be paid to the seasonal sea ice zones during the freeze and thaw periods, and the tundra-taiga regions, also during the freeze and thaw periods.« less

Efficacy of chlorine dioxide mouthwash against halitosis

NASA Astrophysics Data System (ADS)

Bestari, M. D.; Sunarto, H.; Kemal, Y.

2017-08-01

To ascertain the effectiveness of using chlorine dioxide mouthwash in addressing halitosis. Forty people were divided equally into the test group (required to gargle with mouthwash containing chlorine dioxide) and the control group (required to gargle with aquadest). The volatile sulfur compound (VSC) and organoleptic scores were measured before gargling and 30 min, 2 h, 4 h, and 6 h after. The Wilcoxon test analysis showed a significant difference (p<0.05) in the mean value of VSC scores between the test group and the control group in four testing periods after gargling. Chlorine dioxide mouthwash is effective in addressing halitosis.

Elevated atmospheric carbon dioxide concentration affects interactions between Spodoptera exigua (Lepidoptera: Noctuidae) larvae and two host plant species outdoors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caulfield, F.; Bunce, J.A.

1994-08-01

Beet armyworm, Spodoptera exigua (Huebner), larvae were placed on sugarbeet (Beta vulgaris L.) and pigweed (Amaranthus hybridus L.) plants in outdoor chambers in which the plants were growing at either the ambient ([approximately] 350 [mu]l liter[sup [minus]1]) or ambient plus 350 [mu]l liter[sup [minus]1] ([approximately] 700 [mu]l liter[sup [minus]1]) carbon dioxide concentration. A series of experiments was performed to determine if larvae reduced plant growth differently at the two carbon dioxide concentrations in either species and if the insect growth or survival differed with carbon dioxide concentration. Leaf nitrogen, water, starch, and soluble carbohydrate contents were measured to assess carbonmore » dioxide concentration effects on leaf quality. Insect feeding significantly reduced plant growth in sugarbeet plants at 350 [mu]l liter[sup [minus]1] but not at 700 [mu]l liter[sup [minus]1] nor in pigweed at either carbon dioxide concentration. Larval survival was greater on sugarbeet plants at the elevated carbon dioxide concentration. Increased survival occurred only if the insects were at the elevated carbon dioxide concentration and consumed leaf material grown at the elevated concentration. Leaf quality was only marginally affected by growth at elevated carbon dioxide concentration in these experiments. The results indicate that in designing experiments to predict effects of elevated atmospheric carbon dioxide concentrations on plant-insect interactions, both plants and insects should be exposed to the experimental carbon dioxide concentrations, as well as to as realistic environmental conditions as possible.« less

Future Sulfur Dioxide Emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Steven J.; Pitcher, Hugh M.; Wigley, Tom M.

2005-12-01

The importance of sulfur dioxide emissions for climate change is now established, although substantial uncertainties remain. This paper presents projections for future sulfur dioxide emissions using the MiniCAM integrated assessment model. A new income-based parameterization for future sulfur dioxide emissions controls is developed based on purchasing power parity (PPP) income estimates and historical trends related to the implementation of sulfur emissions limitations. This parameterization is then used to produce sulfur dioxide emissions trajectories for the set of scenarios developed for the Special Report on Emission Scenarios (SRES). We use the SRES methodology to produce harmonized SRES scenarios using the latestmore » version of the MiniCAM model. The implications, and requirements, for IA modeling of sulfur dioxide emissions are discussed. We find that sulfur emissions eventually decline over the next century under a wide set of assumptions. These emission reductions result from a combination of emission controls, the adoption of advanced electric technologies, and a shift away from the direct end use of coal with increasing income levels. Only under a scenario where incomes in developing regions increase slowly do global emission levels remain at close to present levels over the next century. Under a climate policy that limits emissions of carbon dioxide, sulfur dioxide emissions fall in a relatively narrow range. In all cases, the relative climatic effect of sulfur dioxide emissions decreases dramatically to a point where sulfur dioxide is only a minor component of climate forcing by the end of the century. Ecological effects of sulfur dioxide, however, could be significant in some developing regions for many decades to come.« less

Final Technical Report: Fundamental Research on the Fractionation of Carbon Isotopes during Photosynthesis, New Interpretations of Terrestrial Organic Carbon within Geologic Substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schubert, Brian; Jahren, A. Hope

The goal for the current grant period (2013 – 2016) was to quantify the effect of changing atmospheric carbon dioxide concentration (pCO2) on published terrestrial carbon isotope excursion events. This work supported four scientists across multiple career stages, and resulted in 5 published papers.

Plant water relations and the effects of elevated CO2: a review and suggestions for future research

Treesearch

Melvin T. Tyree; John D. Alexander

1993-01-01

Increased ambient carbon dioxide (CO2) has been found to ameliorate water stress in the majority of species studied. The results of many studies indicate that lower evaporative flux density is associated with high CO2-induced stomatal closure. As a result of decreases in evaporative flux density and increases in net...

Arbuscular mycorrhizal fungi increase organic carbon decomposition under elevated carbon dioxide

USDA-ARS?s Scientific Manuscript database

A major goal of climate change research is to understand whether and how terrestrial ecosystems can sequester more carbon to mitigate rising atmospheric carbon dioxide (CO2) levels. The stimulation of arbuscular mycorrhizal fungi (AMF) by elevated atmospheric CO2 has been assumed to be a major mecha...

ASSESSMENT OF CROP LOSS FROM OZONE

EPA Science Inventory

Past research has shown that ozone (O3) alone or in combination with sulfur dioxide (SO2), and nitrogen dioxide (NO2) is responsible for up to 90% of the crop losses in the U.S. caused by air pollution. The National Crop Loss Assessment Network (NCLAN) was set up to determine mor...

Cedarwood: cross-over pressure research

USDA-ARS?s Scientific Manuscript database

A series of experiments were conducted to determine the cross-over pressure for cedarwood oil in carbon dioxide. A closed stirrer reactor with an in-line loop connected to the injector of a GC was used to measure the concentration of cedarwood oil in the carbon dioxide. Both neat cedarwood oil as ...

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE... storage. (a) Except as provided in paragraph (b) of this section, the cylinders shall be located outside...

46 CFR 193.15-20 - Carbon dioxide storage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Carbon dioxide storage. 193.15-20 Section 193.15-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE... storage. (a) Except as provided in paragraph (b) of this section, the cylinders shall be located outside...

Near-road measurements for nitrogen dioxide and its association with traffic exposure zones

EPA Science Inventory

Near-road measurements for nitrogen dioxide (NO₂) using passive air samplers were collected weekly in traffic exposure zones (TEZs) in the Research Triangle area of North Carolina (USA) during Fall 2014. Land use regression (LUR) analysis and pairwise comparisons of T...

Comparison of modeled traffic exposure zones using on-road air pollution measurements

EPA Science Inventory

Modeled traffic data were used to develop traffic exposure zones (TEZs) such as traffic delay, high volume, and transit routes in the Research Triangle area of North Carolina (USA). On-road air pollution measurements of nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxid...

“Artificial Leaf” Turns Carbon Dioxide Into Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Researchers at Argonne and the University of Illinois at Chicago have found a way to convert carbon dioxide into a usable energy source using sunlight. The process is similar to photosynthesis, the way plants make fuel from light, so the system is called the “artificial leaf.”

Aeroallergens, Allergic Disease, and Climate Change: Impacts and Adaptation

PubMed Central

Reid, Colleen E.

2009-01-01

Recent research has shown that there are many effects of climate change on aeroallergens and thus allergic diseases in humans. Increased atmospheric carbon dioxide concentration acts as a fertilizer for plant growth. The fertilizing effects of carbon dioxide, as well as increased temperatures from climate change, increase pollen production and the allergen content of pollen grains. In addition, higher temperatures are changing the timing and duration of the pollen season. As regional climates change, plants can move into new areas and changes in atmospheric circulation can blow pollen- and spore-containing dust to new areas, thus introducing people to allergens to which they have not been exposed previously. Climate change also influences the concentrations of airborne pollutants, which alone, and in conjunction with aeroallergens, can exacerbate asthma or other respiratory illnesses. The few epidemiological analyses of meteorological factors, aeroallergens, and allergic diseases demonstrate the pathways through which climate can exert its influence on aeroallergens and allergic diseases. In addition to the need for more research, there is the imperative to take preventive and adaptive actions to address the onset and exacerbation of allergic diseases associated with climate variability and change. PMID:19908096

Differences in energy expenditure during high-speed versus standard-speed yoga: A randomized sequence crossover trial.

PubMed

Potiaumpai, Melanie; Martins, Maria Carolina Massoni; Rodriguez, Roberto; Mooney, Kiersten; Signorile, Joseph F

2016-12-01

To compare energy expenditure and volume of oxygen consumption and carbon dioxide production during a high-speed yoga and a standard-speed yoga program. Randomized repeated measures controlled trial. A laboratory of neuromuscular research and active aging. Sun-Salutation B was performed, for eight minutes, at a high speed versus and a standard-speed separately while oxygen consumption was recorded. Caloric expenditure was calculated using volume of oxygen consumption and carbon dioxide production. Difference in energy expenditure (kcal) of HSY and SSY. Significant differences were observed in energy expenditure between yoga speeds with high-speed yoga producing significantly higher energy expenditure than standard-speed yoga (MD=18.55, SE=1.86, p<0.01). Significant differences were also seen between high-speed and standard-speed yoga for volume of oxygen consumed and carbon dioxide produced. High-speed yoga results in a significantly greater caloric expenditure than standard-speed yoga. High-speed yoga may be an effective alternative program for those targeting cardiometabolic markers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Angiotensin-converting Enzyme Inhibition Improves the Effectiveness of Transcutaneous Carbon Dioxide Treatment.

PubMed

Nemeth, Balazs; Kiss, Istvan; Jencsik, Timea; Peter, Ivan; Kreska, Zita; Koszegi, Tamas; Miseta, Attila; Kustan, Peter; Boncz, Imre; Laczo, Andrea; Ajtay, Zeno

2017-01-01

To study the effect of carbon dioxide (CO 2 ) therapy on the nitric oxide (NO) pathway by monitoring plasma asymmetric dimethylarginine (ADMA) concentrations. Forty-seven hypertensive patients who underwent transcutaneous CO 2 therapy were enrolled. Thirty healthy individuals were recruited for the control group. Blood samples were taken one hour before, as well as one hour, 24 hours and 3 weeks after the first CO 2 treatment. Controls did not undergo CO 2 treatment. Plasma ADMA levels were measured by ELISA. ADMA levels decreased significantly one hour after the first CO2 treatment compared to the baseline concentrations (p=0.003). Significantly greater reduction was found among patients in whom angiotensin converting enzyme inhibitors (ACEIs) were administered (p=0.019). The short- and long-term decrease of ADMA levels suggests that CO 2 is not only a vasodilator, but also has a beneficial effect on the NO pathway. ACE inhibition seems to enhance the effect of CO 2 treatment. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

The Effects of Toxic Particles in Human Lung Cells - Research Area 8. Life Sciences

DTIC Science & Technology

2016-01-05

Characterization of Metal Nanoparticles 2.1. Synthesis and Characterization of Nanoparticles We generated and tested a silver colloid solution with a mean... silver and gold nanoparticle -induced effects; and 6) Assess metal levels in whale skin biopsies in the Gulf of Mexico. The first five aims focused...We found that silver , gold and titanium dioxide nanoparticles were relatively non-toxic. Only silver 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND

Temperature effect on pyrene as a polarity probe for supercritical fluid and liquid solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, H.H.; McGuffin, V.L.

1994-05-01

The effect of temperature on the fluorescence spectrum of pyrene in supercritical and liquid carbon dioxide and liquid organic solvents is systematically studied. The Py parameter (intensity ratio of vibronic bands 1 and 3) is found to increase with the density of supercritical carbon dioxide in the range from 0.54 to 0.75 g/cm{sup 3}. This observation is consistent with the fact that dispersion forces which represent the major interaction between pyrene and carbon dioxide, depend inversely on the sixth power of distance. However, the Py parameter of both supercritical and liquid carbon dioxide is also found to decrease with temperaturemore » at constant density, which is not consistent with expectations for dispersion forces. Carbon dioxide, which is generally regarded as a nonpopular solvent, shows a temperature effect comparable to that for polar liquid solvents. The origin of this temperature effect is examined in this study by computer simulation using both semispherical molecular orbital and molecular mechanic methods. On the basis of these simulations, a strong electrostatic attraction arises between pyrene and carbon dioxide which is similiar in magnitude to that with polar solvents. The temperature dependence of the Py parameter can be qualitatively explained by these simulation results. 45 refs., 15 fig., 5 tab.« less

Carbon dioxide in the atmosphere. [and other research projects

NASA Technical Reports Server (NTRS)

Johnson, F. S.

1974-01-01

Research projects for the period ending September 15, 1973 are reported as follows: (1) the abundances of carbon dioxide in the atmosphere, and the processes by which it is released from carbonate deposits in the earth and then transferred to organic material by photosynthesis; the pathways for movement of carbon and oxygen through the atmosphere; (2) space science computation assistance by PDP computer; the performance characteristics and user instances; (3) OGO-6 data analysis studies of the variations of nighttime ion temperature in the upper atmosphere.

Science and Technology Review December 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blobaum, K M

This month's issue has the following articles: (1) More Insight to Better Understand Climate Change - Commentary by Tomas Diaz de la Rubia; (2) Strengthening Our Understanding of Climate Change - Researchers at the Center for Accelerator Mass Spectrometry are working to better understand climate variation and sharpen the accuracy of predictive models; (3) Precision Diagnostics Tell All - The National Ignition Facility relies on sophisticated diagnostic instruments for measuring the key physical processes that occur in high-energy-density experiments; (4) Quick Detection of Pathogens by the Thousands - Livermore scientists have developed a device that can simultaneously identify thousands ofmore » viruses and bacteria within 24 hours; and (5) Carbon Dioxide into the Briny Deep - A proposed technique for burying carbon dioxide underground could help mitigate the effects of this greenhouse gas while producing freshwater.« less

Trace gas emissions to the atmosphere by biomass burning in the west African savannas

NASA Technical Reports Server (NTRS)

Frouin, Robert J.; Iacobellis, Samuel F.; Razafimpanilo, Herisoa; Somerville, Richard C. J.

1994-01-01

Savanna fires and atmospheric carbon dioxide (CO2) detection and estimating burned area using Advanced Very High Resolution Radiometer_(AVHRR) reflectance data are investigated in this two part research project. The first part involves carbon dioxide flux estimates and a three-dimensional transport model to quantify the effect of north African savanna fires on atmospheric CO2 concentration, including CO2 spatial and temporal variability patterns and their significance to global emissions. The second article describes two methods used to determine burned area from AVHRR data. The article discusses the relationship between the percentage of burned area and AVHRR channel 2 reflectance (the linear method) and Normalized Difference Vegetation Index (NDVI) (the nonlinear method). A comparative performance analysis of each method is described.

Effects of fuel and forest conservation on future levels of atmospheric carbon dioxide.

PubMed

Walker, J C; Kasting, J F

1992-01-01

We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomass reservoir. The simulation includes the rock cycle, distinguishing between shelf carbonate and pelagic carbonate precipitation, with distinct lysocline depths in the three deep ocean reservoirs. Dissolution of pelagic carbonates in response to decrease in lysocline depth is included. The simulation is tuned to reproduce the observed radiocarbon record resulting from atomic weapon testing. It is tuned also to reproduce the distribution of dissolved phosphate and total dissolved carbon between the ocean reservoirs as well as the carbon isotope ratios for both 13C and 14C in ocean and atmosphere. The simulation reproduces reasonably well the historical record of carbon dioxide partial pressure as well as the atmospheric isotope ratios for 13C and 14C over the last 200 yr as these have changed in response to fossil fuel burning and land use changes, principally forest clearance. The agreements between observation and calculation involves the assumption of a carbon dioxide fertilization effect in which the rate of production of biomass increases with increasing carbon dioxide partial pressure. At present the fertilization effect of increased carbon dioxide outweighs the effects of forest clearance, so the biota comprises an overall sink of atmospheric carbon dioxide sufficiently large to bring the budget approximately into balance. This simulation is used to examine the future evolution of carbon dioxide and its sensitivity to assumptions about the rate of fossil fuel burning and of forest clearance. Over times extending up to thousands of years, the results are insensitive to the formulation of the rock cycle and to the dissolution of deep sea carbonate sediments. Atmospheric carbon dioxide continues to increase as long fossil fuel is burned at a significant rate, because the rate of fossil fuel production of carbon dioxide far exceeds the rates at which geochemical processes can remove carbon dioxide from the atmosphere. The maximum concentration of carbon dioxide achieved in the atmosphere depends on the total amount of fossil fuel burned, but only weakly on the rate of burning. The future course of atmospheric carbon dioxide is, however, very sensitive to the fate of the forests in this simulation because of the important role assigned to carbon dioxide fertilization of plant growth rate. Forest clearance drives up atmospheric carbon dioxide not only by converting biomass into atmospheric carbon dioxide but more importantly by reducing the capacity of the biota to sequester fossil fuel carbon dioxide. In this simulation, atmospheric carbon dioxide levels could be sustained indefinitely below 500 parts per million (ppm) if fossil fuel combustion rates were immediately cut from their present value of 5 x 10(14) m/y to 0.2 x 10(14) m/y (a factor of 25 reduction) and if further forest clearance were halted. If neither of these conditions is met and if we consume most of the world's fossil fuel reserves, peak carbon dioxide concentrations of 1000-2000 ppm are probable within the next few centuries.

46 CFR 193.15-35 - Enclosure openings.

Code of Federal Regulations, 2014 CFR

2014-10-01

... EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces which are protected by carbon dioxide extinguishing... carbon dioxide extinguishing system, provisions shall be made for easily and effectively closing off the...

46 CFR 193.15-35 - Enclosure openings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces which are protected by carbon dioxide extinguishing... carbon dioxide extinguishing system, provisions shall be made for easily and effectively closing off the...

Development of a prototype regenerable carbon dioxide absorber

NASA Technical Reports Server (NTRS)

Onischak, M.

1976-01-01

Design information was obtained for a new, regenerable carbon dioxide control system for extravehicular activity life support systems. Solid potassium carbonate was supported in a thin porous sheet form and fabricated into carbon dioxide absorber units. Carbon dioxide and water in the life support system atmosphere react with the potassium carbonate and form potassium bicarbonate. The bicarbonate easily reverts to the carbonate by heating to 150 deg C. The methods of effectively packing the sorbent material into EVA-sized units and the effects of inlet concentrations, flowrate, and temperature upon performance were investigated. The cycle life of the sorbent upon the repeated thermal regenerations was demonstrated through 90 cycles.

Dramatic reduction of sulfur dioxide emission in Northeastern China in the last decade

NASA Astrophysics Data System (ADS)

Yuan, J.

2017-12-01

Analysis of spatial and temporal variations of sulfur dioxide concentration in planetary boundary layer were conducted. The data were generated by NASA satellite daily from October of 2004 and were obtained through NASA Giovanni. The global monthly mean spatial distribution of sulfur dioxide showed several hot spots including: several spots on some islands in the Pacific Ocean, several spots in central America, and central Africa. Most of these hot spots of sulfur dioxide are related to known active volcanos. The biggest hot spot of sulfur dioxide were observed in Northeastern China. While high concentration sulfur dioxide was still observed in Northeastern China in 2017. The area averaged concentration of sulfur dioxide declined dramatically since its peak in 2008. This temporal trend indicates that sulfur reduction effort has been effective in the last decade or post 2008 financial crisis recovery lead an industry less sulfur dioxide emission.

Method of immobilizing carbon dioxide from gas streams

DOEpatents

Holladay, David W.; Haag, Gary L.

1979-01-01

This invention is a method for rapidly and continuously immobilizing carbon dioxide contained in various industrial off-gas streams, the carbon dioxide being immobilized as dry, stable, and substantially water-insoluble particulates. Briefly, the method comprises passing the gas stream through a fixed or fluidized bed of hydrated barium hydroxide to remove and immobilize the carbon dioxide by converting the bed to barium carbonate. The method has several important advantages: it can be conducted effectively at ambient temperature; it provides a very rapid reaction rate over a wide range of carbon dioxide concentrations; it provides high decontamination factors; and it has a high capacity for carbon dioxide. The invention is especially well suited for the removal of radioactive carbon dioxide from off-gases generated by nuclear-fuel reprocessing facilities and nuclear power plants.

Fertilizer and tillage management impacts on non-carbon-dioxide greenhouse gas emissions

USDA-ARS?s Scientific Manuscript database

Recent efforts have been placed on trying to establish emission estimates for greenhouse gases (GHG) from agricultural soils in the United States. This research was conducted to assess the influence of cropping systems management on nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) emissio...

Detecting the unexpected: a research framework for ocean acidification.

PubMed

Pfister, Catherine A; Esbaugh, Andrew J; Frieder, Christina A; Baumann, Hannes; Bockmon, Emily E; White, Meredith M; Carter, Brendan R; Benway, Heather M; Blanchette, Carol A; Carrington, Emily; McClintock, James B; McCorkle, Daniel C; McGillis, Wade R; Mooney, T Aran; Ziveri, Patrizia

2014-09-02

The threat that ocean acidification (OA) poses to marine ecosystems is now recognized and U.S. funding agencies have designated specific funding for the study of OA. We present a research framework for studying OA that describes it as a biogeochemical event that impacts individual species and ecosystems in potentially unexpected ways. We draw upon specific lessons learned about ecosystem responses from research on acid rain, carbon dioxide enrichment in terrestrial plant communities, and nitrogen deposition. We further characterize the links between carbon chemistry changes and effects on individuals and ecosystems, and enumerate key hypotheses for testing. Finally, we quantify how U.S. research funding has been distributed among these linkages, concluding that there is an urgent need for research programs designed to anticipate how the effects of OA will reverberate throughout assemblages of species.

Evaluation of the impact of SO₂ and NO₂ emissions on the ambient air-quality in the Çan-Bayramiç region of northwest Turkey during 2007-2008.

PubMed

Ozkurt, Nesimi; Sari, Deniz; Akalin, Nuray; Hilmioglu, Bilgin

2013-07-01

The characterization and assessment of air-quality in this region are essential steps for the implementation of the "Clean Air Action Plan" as this is set by the Turkish Regulation on Ambient Air-Quality Assessment and Management. This study area intends to shed a light on use of modeling tools as an alternative method for the assessment of local atmospheric pollution and the determination of the importance of local emissions. This modeling approach can be also used for the consistent geographic representation of air-quality concentration as well as for assessing the future air-quality condition after the implementation of emission reduction measures in a certain area. With this article we evaluate the impact of sulfur dioxide and nitrogen dioxide emissions on the ambient air-quality in the Çan-Bayramiç region of Turkey. The emission rates of sulfur dioxide and nitrogen dioxide were calculated by using the CALPUFF model. The concentration of these pollutants had also been monitored at ten air-quality locations during 2007-2008 in the research area. The measured data were also utilized for testing the model performance. Results showed that the air-quality in this important rural region of Turkey can be evaluated effectively by using the current numerical modeling system. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Ambient air concentration of sulfur dioxide affects flight activity in bees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ginevan, M.E.; Lane, D.D.; Greenberg, L.

Three long-term (16 to 29 days) low-level (0.14 to 0.28 ppM) sulfur dioxide fumigations showed that exposure tothis gas has deleterious effects on male sweat bees (Lasioglossum zephrum). Although effects on mortality were equivocal, flight activity was definitely reduced. Because flight is necessary for successful mating behavior, the results suggest that sulfur dioxide air pollution could adversely affect this and doubtless other terrestrial insects.

Endoscopic Carbon Dioxide Laser Photocoagulation Of Bleeding Canine Gastric Ulcers

NASA Astrophysics Data System (ADS)

Gal, Dov; Ron, Nimrod; Orgad, Uri; Katzir, Abraham

1987-04-01

This is the first report which describes carbon dioxide laser photocoagulation of upper gastrointestinal bleeding via a flexible endoscope, using an infrared transmitting siver nalide fiber. Various laser parameters were checked to determine the optimal conditions for hemostasis. Both the acute effects of laser irradiation on tissue and the chronic effects on healing process were examined. Preliminary results indicate that carbon dioxide laser beam can successfully photocoagulate moderately bleeding ulcers.

46 CFR 95.15-35 - Enclosure openings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces other than cargo and similar spaces which are protected by a carbon dioxide... protected by a carbon dioxide extinguishing system, provisions shall be made for easily and effectively...

46 CFR 76.15-35 - Enclosure openings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces other than cargo and similar spaces which are protected by a carbon dioxide... protected by a carbon dioxide extinguishing system, provisions shall be made for easily and effectively...

46 CFR 95.15-35 - Enclosure openings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces other than cargo and similar spaces which are protected by a carbon dioxide... protected by a carbon dioxide extinguishing system, provisions shall be made for easily and effectively...

46 CFR 76.15-35 - Enclosure openings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces other than cargo and similar spaces which are protected by a carbon dioxide... protected by a carbon dioxide extinguishing system, provisions shall be made for easily and effectively...

46 CFR 76.15-35 - Enclosure openings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces other than cargo and similar spaces which are protected by a carbon dioxide... protected by a carbon dioxide extinguishing system, provisions shall be made for easily and effectively...

46 CFR 95.15-35 - Enclosure openings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces other than cargo and similar spaces which are protected by a carbon dioxide... protected by a carbon dioxide extinguishing system, provisions shall be made for easily and effectively...

46 CFR 76.15-35 - Enclosure openings.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces other than cargo and similar spaces which are protected by a carbon dioxide... protected by a carbon dioxide extinguishing system, provisions shall be made for easily and effectively...

46 CFR 76.15-35 - Enclosure openings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Carbon Dioxide Extinguishing Systems, Details § 76.15-35 Enclosure openings. (a) Where mechanical ventilation is provided for spaces other than cargo and similar spaces which are protected by a carbon dioxide... protected by a carbon dioxide extinguishing system, provisions shall be made for easily and effectively...

Investigation of the Sensitivity, Selectivity, and Reversibility of the Chemically-Sensitive Field-Effect Transistor (CHEMFET) to Detect Nitrogen Dioxide, Dimethyl Methylphosphonate, and Boron Trifluoride

DTIC Science & Technology

1993-09-01

SENSITIVE FIELD- EFFECT TRANSISTOR (CHEMFET) TO DETECT NITROGEN DIOXIDE, DIMETHYL METHYLPHOSPHONATE, AND BORON TRIFLUORIDE CHAPTER 1 1 Introduction Our rapidly...AND REVERSIBILITY OF THE CHEMICALLY-SENSITIVE FIELD- EFFECT TRANSISTOR (CHEMFET) TO DETECT NITROGEN 3 E I1• DIOXIDE, DIMETHYL METHYLPHOSPHONATE, ELECTE...AND BORON TRIFLUORIDE Neal Terence Hauschild Second Lieutenant, USAF AFIT/GE/ENG/9 3S-10 93-23815I II11l11l11 l gll I 1i 1111 11 I DEPARTMENT OF THE

Effects of nutrient and organic matter manipulation on carbon pools and fluxes in a young loblolly pine varietal stand on the lower coastal plain of South Carolina

Treesearch

Michael Tyree; John Seiler; Chris Maier

2010-01-01

Manipulation of site organic matter and nutrients, in addition to planting of superior genotypes will likely influence carbon fluxes from intensively managed forests. The objective of this research is to monitor total soil carbon dioxide (CO2) efflux (FS), microbial respiration (RH), and leaf gas...

Projecting the climatic effects of increasing carbon dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacCracken, M C; Luther, F M

This report presents the current knowns, unknowns, and uncertainties regarding the projected climate changes that might occur as a result of an increasing atmospheric CO/sub 2/ concentration. Further, the volume describes what research is required to estimate the magnitude and rate of a CO/sub 2/-induced clamate change with regional and seasonal resolution. Separate abstracts have been prepared for the individual papers. (ACR)

Effect of Six Days of Staging on Physiologic Adjustments and Acute Mountain Sickness During Ascent to 4300 Meters

DTIC Science & Technology

2009-01-01

respiratory alkalosis due to hyperventilation that was partially compensated for by increased excretion of HCO3 to maintain a normal pH following...carbon dioxide; RER, respiratory exchange quotient; Sao2, arterial oxygen saturation; Paco2, partial pressure of capillary-arterialized carbon dioxide...dioxide production; E=O2, ventilatory equivalent for oxygen; E=CO2, ventilatory equivalent for carbon dioxide; RER, respiratory exchange quotient

Annual soil CO_{2} production in Moscow Botanical Garden (Russia).

NASA Astrophysics Data System (ADS)

Udovenko, Maria; Goncharova, Olga; Matyshak, Georgy

2017-04-01

Soil respiration is an essential component of the carbon cycle, determining 25-40 % of carbon dioxide in the atmosphere. Urban soils are subject to significant anthropogenic influences. Anthropogenic impact affects both the plants and the soil microbiota. So, soil CO2 efflux and soil profile CO2 concentration probably differ in urban and natural soils. Influence of abiotic factors on soil carbon dioxide production is explored insufficiently. The research of their impact on soil carbon dioxide production is necessary to predict soil response to anthropogenic climate change. The aim of this study was estimation of annual soil CO2 production and the impact of climatic factors on it. The research took place in Moscow State University Botanical Garden Arboretum (southern taiga). Investigations were carried out at two sites: the areas planted with Picea obovata and Carpinus betulus. The study was conducted with 1-2 weeks intervals between November 2014 and December 2015. Emission measurement were carried out by closed chamber technique, profile concentration were measured by soil air sampling tubes method. Annual carbon dioxide soil surface efflux of soil planted with Picea obovata was 1370 gCO2/(m2 * year), soil planted with Carpinus betulus - 1590 gCO2/(m2 * year). Soil CO2 concentration increased with depth in average of 3300 to 12000 ppm (at 80 cm depth). Maximum concentration values are confined to the end of vegetation period (high biological activity) and to beginning of spring (spring ice cover of soil prevents CO2 emission). Soil CO2 efflux depends on soil temperature at 10 cm depth (R = 0.89; p <0.05), in a less degree it correlate with soil surface temperature and with soil temperature at 20 cm depth (r=0.88; p<0.05). Soil moisture has a little effect on CO2 efflux in the annual cycle (r=-0.16; p<0.05). However in vegetation period efflux of carbon dioxide largely depends on soil moisture, due to the fact, that soil moisture is limiting factor for soil microbiota activity and plant respiration.

Effects of Water Vapor on the Data Quality of the Stable Oxygen Isotopic Ratio of Atmospheric Carbon Dioxide

NASA Astrophysics Data System (ADS)

Evans, C. U.; White, J. W.; Vaughn, B.; Tans, P. P.; Pardo, L.

2007-12-01

The stable oxygen isotopic ratio of carbon dioxide can potentially track fundamental indicators of environmental change such as the balance between photosynthesis and respiration on regional to global scales. The Stable Isotope Laboratory (SIL) at the Institute of Arctic and Alpine Research (INSTAAR), University of Colorado at Boulder, has measured the stable isotopes of atmospheric carbon dioxide from more than 60 NOAA/Earth System Research Laboratory (ESRL) air flask-sampling sites since the early 1990s. If air is sampled without drying, oxygen can exchange between carbon dioxide and water in the flasks, entirely masking the desired signal. An attempt to investigate how water vapor is affecting the δ18O signal is accomplished by comparing the SIL measurements with specific humidity, calculated from the National Climatic Data Center (NCDC) global integrated surface hourly temperature and dew point database, at the time of sampling. Analysis of sites where samples have been collected initially without drying, and subsequently with a drying kit, in conjunction with the humidity data, has led to several conclusions. Samples that initially appear isotopically unaltered, in that their δ18O values are within the expected range, are being subtly influenced by the water vapor in the air. At Bermuda and other tropical to semi-tropical sites, the 'wet' sampling values have a seasonal cycle that is strongly anti-correlated to the specific humidity, while the 'dry' values have a seasonal cycle that is shifted earlier than the specific humidity cycle by 1-2 months. The latter phasing is expected given the seasonal phasing between climate over the ocean and land, while the former is consistent with a small, but measurable isotope exchange in the flasks. In addition, we note that there is a strong (r > 0.96) correlation between the average specific humidity and the percent of rejected samples for 'wet' sampling. This presents an opportunity for determining a threshold of specific humidity, below which air flask samples can be trusted. This approach may allow segregation of suspect and trusted data, and thus provide an improved record of oxygen isotopic ratios of carbon dioxide over the past two decades.

Electrochemical reduction of carbon dioxide. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaConti, A.B.; Molter, T.M.; Zagaja, J.A.

1986-05-01

Many researchers have studied the electrochemical reduction of carbon dioxide and related organic species to form concentrated liquid/gaseous products in laboratory-scale hardware. Hamilton Standard has developed a high pressure SPE electrolysis cell capable of reducing carbon dioxide streams to form pure, concentrated alcohols, carboxylic acids, and other hydrocarbons. The process is unique in that the byproducts of reaction include oxygen and, under some test conditions water. In addition, a relatively simple test system was designed and constructed permitting both batch and semibatch type electrochemical reduction studies. In this study, cathode materials were developed which 1) had a characteristic high hydrogenmore » overvoltage, and 2) possessed the intrinsic affinity for electrochemical reduction of the carbon dioxide species. In addition, suitable anode electrocatalyst materials were identified. Studies involving the electrochemical reduction of carbon dioxide required the ability to identify and quantify reaction products obtained during cell evaluation. Gas chromatographic techniques were developed along with the establishment of ion chromatographic methods permitting the analysis of organic reaction products. Hamilton Standard has evaluated electrochemical carbon dioxide reduction cells under a variety of test conditions.« less

77 FR 14167 - Approval Tests and Standards for Closed-Circuit Escape Respirators

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-08

... Dioxide 3. Oxygen 4. Peak Breathing Pressures 5. Wet-Bulb Temperature L. Section 84.304 Capacity Test... oxygen storage or chemical carbon dioxide scrubber can be altered by impact or any other effect must... inhaled carbon dioxide, average inhaled oxygen, peak breathing pressures, and wet-bulb temperature...

Promising flame retardant textile in supercritical carbon dioxide

USDA-ARS?s Scientific Manuscript database

Since carbon dioxide is non-toxic, non-flammable and cost-effective, supercritical carbon dioxide (scCO2) is widely used in textile dyeing applications. Due to its environmentally benign character, scCO2 is considered in green chemistry as a substitute for organic solvents in chemical reactions. O...

The Greenhouse Effect in a Vial.

ERIC Educational Resources Information Center

Golden, Richard; Sneider, Cary

1989-01-01

Presents an example of a greenhouse-effect experiment from the Climate Protection Institute. Analyzes the amount of carbon dioxide in ambient air, human exhalation, automobile exhaust, and nearly pure carbon dioxide by titrating with ammonia and bromthymol blue. (MVL)

Effects of low sulfur dioxide concentrations on bioactive compounds and antioxidant properties of Aglianico red wine.

PubMed

Gabriele, Morena; Gerardi, Chiara; Lucejko, Jeannette J; Longo, Vincenzo; Pucci, Laura; Domenici, Valentina

2018-04-15

This study analyzed the effect of low sulfur dioxide concentrations on the chromatic properties, phytochemical composition and antioxidant activity of Aglianico red wines with respect to wines produced from conventional winemaking. We determined the phytochemical composition by spectrophotometric methods and HPLC-DAD analysis and the in vitro antioxidant activity of different wine samples by the ORAC assay. The main important classes of fluorophore molecules in red wine were identified by Front-Face fluorescence spectroscopy, and the emission intensity trend was investigated at various sulfur dioxide concentrations. Lastly, we tested the effects of both conventional and low sulfite wines on ex vivo human erythrocytes under oxidative stimulus by the cellular antioxidant activity (CAA) assay and the hemolysis test. The addition of sulfur dioxide, which has well-known side effects, increased the content of certain bioactive components but did not raise the erythrocyte antioxidant capacity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Federal research, development, and demonstration priorities for carbon dioxide removal in the United States

NASA Astrophysics Data System (ADS)

Sanchez, Daniel L.; Amador, Giana; Funk, Jason; Mach, Katharine J.

2018-01-01

Atmospheric carbon dioxide removal (CDR) technologies may be critical to achieving deep decarbonization. Yet a lack of technical and commercial maturity of CDR technologies hinders potential deployment. Needs for commercialization span research, development, and demonstration (RD&D) activities, including development of new materials, reactors, and processes, and rigorous monitoring of a portfolio of demonstration projects. As a world leader in supporting science and engineering, the United States (US) can play an important role in reducing costs and clarifying the sustainable scale of CDR. To date, federal agencies have focused on voluntary or piecemeal CDR programs. Here, we present a synthesis of research and developement needs, relevant agency authority, barriers to coordination, and interventions to enhance RD&D across the federal government of the US. On the basis of agency authority and expertise, the Department of Energy, Department of Agriculture, Department of the Interior, National Oceanic and Atmospheric Administration, and National Science Foundation are most central to conducting research, funding projects, monitoring effects, and promulgating regulations. Key enablers for successful programs include embracing technological diversity and administrative efficiency, fostering agency buy-in, and achieving commercial deployment. Based on these criteria, the executive branch could effectively coordinate RD&D strategy through two complementary pathways: (1) renewing intra-agency commitment to CDR in five primary agencies, including both research and demonstration, and (2) coordinating research prioritization and outcomes across agencies, led by the Office of Science and Technology Policy and loosely based on the National Nanotechnology Initiative. Both pathways can be stimulated by executive order or Congressional mandate. Executive branch implementation can begin at any time; future Farm and Energy Bills provide legislative vehicles for enhancing programs.

Developmental and hematological responses to low level continuous exposure of nitrogen dioxide in mice

NASA Technical Reports Server (NTRS)

Singh, J.

1977-01-01

Young healthy mice were continuously exposed to 0ppm, 0.5ppm, 1.0ppm and 5ppm nitrogen dioxide gas for eight weeks. Nitrogen dioxide exposure for eight weeks decreased the average weight of mice, increased the average weight of lungs, heart, and brain and decreased the average weight of liver. Nitrogen dioxide exposure did not have any effects on the WBC and RBC in mice blood but it increased the HCT and HGB in mice blood. Nitrogen dioxide exposure increased the MCV and decreased the MCH and MCHC in mice blood.

Evaluation of CO2 and CO dopants in hydrogen to reduce hydrogen permeation in the Stirling engine heater head tube alloy CG-27

NASA Technical Reports Server (NTRS)

Misencik, J. A.

1983-01-01

Tubes of CG-27 alloy, filled with hydrogen doped with various amounts of carbon dioxide and carbon monoxide, were heated in a diesel fuel fired Stirling engine simulator materials test rig for 100 hours at 820 C and at a gas pressure of 15 MPa to determine the effectiveness of the dopants in reducing hydrogen permeation through the hot tube wall. This was done for clean as-heat treated tubes and also for tubes that had previously been exposed for 100 hours to hydrogen doped with 1.0 volume percent carbon dioxide to determine if the lower levels of dopant could maintain a low hydrogen permeation through the hot tube wall. Carbon dioxide, as a dopant in hydrogen, was most effective in reducing hydrogen permeation through clean tubes and in maintaining low hydrogen permeation after prior exposure to 1.0 volume percent carbon dioxide. Only the lowest level of carbon dioxide (0.05 volume percent) was not as effective in the clean or prior exposed tubes. Carbon monoxide as a dopant in hydrogen was less effective than carbon dioxide at a given concentration level. Of the four dopant levels studied; 1.0, 0.5, 0.2, and 0.05 volume percent carbon monoxide, only the 1.0 and 0.5 volume percent were effective in reducing and maintaining low hydrogen permeation through the CG-27.

Randomized Study Comparing the Effect of Carbon Dioxide Insufflation on Veins Using 2 Types of Endoscopic and Open Vein Harvesting.

PubMed

Krishnamoorthy, Bhuvaneswari; Critchley, William R; Nair, Janesh; Malagon, Ignacio; Carey, John; Barnard, James B; Waterworth, Paul D; Venkateswaran, Rajamiyer V; Fildes, James E; Caress, Ann L; Yonan, Nizar

The aim of the study was to assess whether the use of carbon dioxide insufflation has any impact on integrity of long saphenous vein comparing 2 types of endoscopic vein harvesting and traditional open vein harvesting. A total of 301 patients were prospectively randomized into 3 groups. Group 1 control arm of open vein harvesting (n = 101), group 2 closed tunnel (carbon dioxide) endoscopic vein harvesting (n = 100) and Group 3 open tunnel (carbon dioxide) endoscopic vein harvesting (open tunnel endoscopic vein harvesting) (n = 100). Each group was assessed to determine the systemic level of partial arterial carbon dioxide, end-tidal carbon dioxide, and pH. Three blood samples were obtained at baseline, 10 minutes after start of endoscopic vein harvesting, and 10 minutes after the vein was retrieved. Vein samples were taken immediately after vein harvesting without further surgical handling to measure the histological level of endothelial damage. A modified validated endothelial scoring system was used to compare the extent of endothelial stretching and detachment. The level of end-tidal carbon dioxide was maintained in the open tunnel endoscopic vein harvesting and open vein harvesting groups but increased significantly in the closed tunnel endoscopic vein harvesting group (P = 0.451, P = 0.385, and P < 0.001). Interestingly, partial arterial carbon dioxide also did not differ over time in the open tunnel endoscopic vein harvesting group (P = 0.241), whereas partial arterial carbon dioxide reduced significantly over time in the open vein harvesting group (P = 0.001). A profound increase in partial arterial carbon dioxide was observed in the closed tunnel endoscopic vein harvesting group (P < 0.001). Consistent with these patterns, only the closed tunnel endoscopic vein harvesting group demonstrated a sudden drop in pH over time (P < 0.001), whereas pH remained stable for both open tunnel endoscopic vein harvesting and open vein harvesting groups (P = 0.105 and P = 0.869, respectively). Endothelial integrity was better preserved in the open vein harvesting group compared with open tunnel endoscopic vein harvesting or closed tunnel endoscopic vein harvesting groups (P = 0.012) and was not affected by changes in carbon dioxide or low pH. Significantly greater stretching of the endothelium was observed in the open tunnel endoscopic open tunnel endoscopic vein harvesting group compared with the other groups (P = 0.003). This study demonstrated that the different vein harvesting techniques impact on endothelial integrity; however, this does not seem to be related to the increase in systemic absorption of carbon dioxide or to the pressurized endoscopic tunnel. The open tunnel endoscopic harvesting technique vein had more endothelial stretching compared with the closed tunnel endoscopic technique; this may be due to manual dissection of the vein. Further research is required to evaluate the long-term clinical outcome of these vein grafts.

Ultra-rapid photocatalytic activity of Azadirachta indica engineered colloidal titanium dioxide nanoparticles

NASA Astrophysics Data System (ADS)

Sankar, Renu; Rizwana, Kadarmohideen; Shivashangari, Kanchi Subramanian; Ravikumar, Vilwanathan

2015-08-01

Titanium dioxide nanoparticles were effectively synthesized from aqueous leaf extract of Azadirachta indica under pH and temperature-dependent condition. 5 mM titanium isopropoxide solution worked as a primary source for the synthesis of titanium dioxide nanoparticles. The green synthesized titanium dioxide nanoparticles were confirmed by UV-Vis spectroscopy. Fourier transform infrared spectrum of synthesized titanium dioxide nanoparticles authorized the presence of bioactive compounds in the leaf extract, which may play a role as capping and reducing agent. The high-resolution scanning electron microscopy and dynamic light scattering analyses results showed the interconnected spherical in shape titanium dioxide nanoparticles having a mean particle size of 124 nm and a zeta potential of -24 mV. Besides, the colloidal titanium dioxide nanoparticles energetically degrade the industrially harmful methyl red dye under bright sunlight.

Growth behaviors and biocidal properties of titanium dioxide films depending on nucleation duration in liquid phase deposition

NASA Astrophysics Data System (ADS)

Park, Sohyeon; Park, Joohee; Heo, Jiwoong; Hong, Bo Young; Hong, Jinkee

2017-12-01

Liquid phase deposition (LPD), which is a method to directly form a titanium dioxide (TiO2) film on a substrate, is the most practical method for applying TiO2 films to medical devices because it is performed at lower temperatures than other methods. The TiO2 films to be applied to medical devices should offer excellent antibacterial effect, but should be stable to normal cells and have appropriate strength. In this research, we observed that the size, shape, and density of TiO2 particles varied with the nucleation duration in LPD and confirmed that these results caused changes in several properties including the mechanical properties, cytotoxicity and antibacterial effect of TiO2 films. From the analysis of these results, we established the conditions for the preparation of TiO2 films that are suitable for medical devices and suggest a new approach to the study of TiO2 films prepared by LPD.

Modeling effects of traffic and landscape characteristics on ambient nitrogen dioxide levels in Connecticut

NASA Astrophysics Data System (ADS)

Skene, Katherine J.; Gent, Janneane F.; McKay, Lisa A.; Belanger, Kathleen; Leaderer, Brian P.; Holford, Theodore R.

2010-12-01

An integrated exposure model was developed that estimates nitrogen dioxide (NO 2) concentration at residences using geographic information systems (GIS) and variables derived within residential buffers representing traffic volume and landscape characteristics including land use, population density and elevation. Multiple measurements of NO 2 taken outside of 985 residences in Connecticut were used to develop the model. A second set of 120 outdoor NO 2 measurements as well as cross-validation were used to validate the model. The model suggests that approximately 67% of the variation in NO 2 levels can be explained by: traffic and land use primarily within 2 km of a residence; population density; elevation; and time of year. Potential benefits of this model for health effects research include improved spatial estimations of traffic-related pollutant exposure and reduced need for extensive pollutant measurements. The model, which could be calibrated and applied in areas other than Connecticut, has importance as a tool for exposure estimation in epidemiological studies of traffic-related air pollution.

Testing the role of fiscal policy in the environmental degradation: the case of Turkey.

PubMed

Katircioglu, Salih; Katircioglu, Setareh

2018-02-01

This study introduces a new research topic that investigates the relationship between fiscal development and carbon emissions in Turkey through testing Environmental Kuznets Curve (EKC) hypothesis. Annual data covering the period, 1960-2013, has been used and in addition to gross domestic product and energy consumption, fiscal policy variables have been regressed on the level of carbon emissions in Turkey. Results reveal that fiscal policies and carbon emissions are in long-term equilibrium relationship in Turkey; carbon dioxide emission level converges towards long-term paths as contributed by fiscal policy. The effects of fiscal aggregates on the level of carbon dioxide emissions are negatively significant revealing that growth in fiscal aggregates leads to declines on the levels of carbon emissions. This proves that as far as environmental effects are concerned, fiscal policies regarding energy sector is successful in Turkey. Thus, the major finding of this study confirmed the validity of the fiscal policy-induced EKC hypothesis in the case of Turkey.

Evaluating measurements of carbon dioxide emissions using a precision source--A natural gas burner.

PubMed

Bryant, Rodney; Bundy, Matthew; Zong, Ruowen

2015-07-01

A natural gas burner has been used as a precise and accurate source for generating large quantities of carbon dioxide (CO2) to evaluate emissions measurements at near-industrial scale. Two methods for determining carbon dioxide emissions from stationary sources are considered here: predicting emissions based on fuel consumption measurements-predicted emissions measurements, and direct measurement of emissions quantities in the flue gas-direct emissions measurements. Uncertainty for the predicted emissions measurement was estimated at less than 1%. Uncertainty estimates for the direct emissions measurement of carbon dioxide were on the order of ±4%. The relative difference between the direct emissions measurements and the predicted emissions measurements was within the range of the measurement uncertainty, therefore demonstrating good agreement. The study demonstrates how independent methods are used to validate source emissions measurements, while also demonstrating how a fire research facility can be used as a precision test-bed to evaluate and improve carbon dioxide emissions measurements from stationary sources. Fossil-fuel-consuming stationary sources such as electric power plants and industrial facilities account for more than half of the CO2 emissions in the United States. Therefore, accurate emissions measurements from these sources are critical for evaluating efforts to reduce greenhouse gas emissions. This study demonstrates how a surrogate for a stationary source, a fire research facility, can be used to evaluate the accuracy of measurements of CO2 emissions.

Plants Can't Do without Carbon Dioxide.

ERIC Educational Resources Information Center

Hershey, David R.

1992-01-01

Describes an experiment to induce carbon dioxide deficiency to demonstrate its effects on plant growth. Suggests further studies to examine respiration by soil microbes and the effects of relative humidity, other gases, and air pollution on plant growth. (MDH)

Tested Demonstrations: Visualization of Buffer Action and the Acidifying Effect of Carbon Dioxide.

ERIC Educational Resources Information Center

Gilbert, George L., Ed.

1985-01-01

Presents a buffer demonstration which features visualization of the effects of carbon dioxide on pH. Background information, list of materials needed, procedures used, and a discussion of results obtained are included. (JN)

Carbon dioxide inhalation treatments of neurotic anxiety. An overview.

PubMed

Wolpe, J

1987-03-01

A lucky chance more than 30 years ago revealed the remarkable efficacy of single inhalations of high concentrations of carbon dioxide in eliminating or markedly reducing free-floating anxiety. The reduction of anxiety lasts for days, weeks, or longer--well beyond the persistence of carbon dioxide in the body. The effects are explicable on the hypothesis that free-floating anxiety is anxiety conditioned to continuously present sources of stimulation, such as background noise or the awareness of space or time, and that the anxiety response habit is weakened when the anxiety is inhibited by the competition of responses that carbon dioxide induces. More recently, it has become apparent that inhalations of carbon dioxide, applied in a different manner, are effective in overcoming maladaptive anxiety responses to specific stimuli, e.g., social stimuli. The substance is also proving to be a valuable resource in the treatment of the common variety of panic attacks.

Effects of ozone, chlorine dioxide, chlorine, and monochloramine on Cryptosporidium parvum oocyst viability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korich, D.G.; Mead, J.R.; Madore, M.S.

1990-05-01

Purified Cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. Excystation and mouse infectivity were comparatively evaluated to assess oocyst viability. Ozone and chlorine dioxide more effectively inactivated oocysts than chlorine and monochloramine did. Greater than 90% inactivation as measured by infectivity was achieved by treating oocysts with 1 ppm of ozone (1 mg/liter) for 5 min. Exposure to 1.3 ppm of chlorine dioxide yielded 90% inactivation after 1 h, while 80 ppm of chlorine and 80 ppm of monochloramine required approximately 90 min for 90% inactivation. The data indicate that C. parvum oocysts are 30 timesmore » more resistant to ozone and 14 times more resistant to chlorine dioxide than Giardia cysts exposed to these disinfectants under the same conditions. With the possible exception of ozone, the use of disinfectants alone should not be expected to inactivate C. parvum oocysts in drinking water.« less

Sun protection enhancement of titanium dioxide crystals by the use of carnauba wax nanoparticles: the synergistic interaction between organic and inorganic sunscreens at nanoscale.

PubMed

Villalobos-Hernández, J R; Müller-Goymann, C C

2006-09-28

Carnauba wax is partially composed of cinnamates. The rational combination of cinnamates and titanium dioxide has shown a synergistic effect to improve the sun protection factor (SPF) of cosmetic preparations. However, the mechanism of this interaction has not been fully understood. In this study, an ethanolic extract of the carnauba wax and an ethanolic solution of a typical cinnamate derivative, ethylcinnamate, were prepared and their UV absorption and SPF either alone or in the presence of titanium dioxide were compared. The titanium dioxide crystals and the cinnamates solutions were also distributed into a matrix composed of saturated fatty acids to emulate the structure of the crystallized carnauba wax. SPF, differential scanning calorimetry (DSC) and X-ray studies of these matrices were performed. Additionally, carnauba wax nanosuspensions containing titanium dioxide either in the lipid phase or in the aqueous phase were prepared to evaluate their SPFs and their physical structure. Strong UV absorption was observed in diluted suspensions of titanium dioxide after the addition of cinnamates. The saturated fatty acid matrices probably favored the adsorption of the cinnamates at the surface of titanium dioxide crystals, which was reflected by an increase in the SPF. No modification of the crystal structure of the fatty acid matrices was observed after the addition of cinnamates or titanium dioxide. The distribution of the titanium dioxide inside the lipid phase of the nanosuspensions was more effective to reach higher SPFs than that at the aqueous phase. The close contact between the carnauba wax and the titanium dioxide crystals after the high-pressure homogenization process was confirmed by transmission electron microscopy (TEM).

Conversion of Carbon Dioxide into Ethanol by Electrochemical Synthesis Method Using Cu-Zn Electrode

NASA Astrophysics Data System (ADS)

Riyanto; Ramadan, S.; Fariduddin, S.; Aminudin, A. R.; Hayatri, A. K.

2018-01-01

Research on conversion of carbon dioxide into ethanol has been done. The conversion process is carried out in a sodium bicarbonate electrolyte solution in an electrochemical synthesis reactor. As cathode was used Cu-Zn, while as anode carbon was utilized. Variations of voltage, concentration of sodium bicarbonate electrolyte solution and time of electrolysis were performed to determine the optimum conditions to convert carbon dioxide into ethanol. Sample of the electrochemical synthesis process was analyzed by gas chromatography. From the result, it is found that the optimum conditions of the electrochemical synthesis process of carbon dioxide conversion into ethanol are voltage, concentration of sodium bicarbonate electrolyte solution and time of electrolysis are 3 volts, 0.4 M and 90 minutes with the ethanol concentration of 10.44%.

Chlorine dioxide-induced and Congo red-inhibited Marangoni effect on the chlorite-trithionate reaction front

NASA Astrophysics Data System (ADS)

Liu, Yang; Ren, Xingfeng; Pan, Changwei; Zheng, Ting; Yuan, Ling; Zheng, Juhua; Gao, Qingyu

2017-10-01

Hydrodynamic flows can exert multiple effects on an exothermal autocatalytic reaction, such as buoyancy and the Marangoni convection, which can change the structure and velocity of chemical waves. Here we report that in the chlorite-trithionate reaction, the production and consumption of chlorine dioxide can induce and inhibit Marangoni flow, respectively, leading to different chemo-hydrodynamic patterns. The horizontal propagation of a reaction-diffusion-convection front was investigated with the upper surface open to the air. The Marangoni convection, induced by gaseous chlorine dioxide on the surface, produced from chlorite disproportionation after the proton autocatalysis, has the same effect as the heat convection. When the Marangoni effect is removed by the reaction of chlorine dioxide with the Congo red (CR) indicator, an oscillatory propagation of the front tip is observed under suitable conditions. Replacing CR with bromophenol blue (BPB) distinctly enhanced the floating, resulting in multiple vortexes, owing to the coexistence between BPB and chlorine dioxide. Using the incompressible Navier-Stokes equations coupled with reaction-diffusion and heat conduction equations, we numerically obtain various experimental scenarios of front instability for the exothermic autocatalytic reaction coupled with buoyancy-driven convection and Marangoni convection.

Effects of carbon dioxide variations in the unsaturated zone on water chemistry in a glacial-outwash aquifer

USGS Publications Warehouse

Lee, R.W.

1997-01-01

The research site at Otis Air Base, Cape Cod, Massachusetts, has been developed for hydrogeological and geochemical studies of sewage-effluent contaminated groundwater since 1982. Research of hydrologic properties, transport, and chemical and biological processes is ongoing, but the origin of background water chemistry has not been determined. The principal geochemical process giving rise to the observed background water chemistry is CO2-controlled hydrolysis of Na feldspar. Geochemical modeling demonstrated that CO2 sources could vary over the project area. Analyses of unsaturated zone gases showed variations in CO2 which were dependent on land use and vegetative cover in the area of groundwater recharge. Measurements of CO2 in unsaturated-zone gases showed that concentrations of total inorganic C in recharge water should range from about 0.035 to 1.0 mmoles/L in the vicinity of Otis Air Base. Flux of CO2 from the unsaturated zone varied for a principal land uses, ranging from 86 gC/m2/yr for low vegetated areas to 1630 gC/m2/yr for a golf course. Carbon dioxide flux from woodlands was 220 gC/m2/yr, lower than reported fluxes of 500 to 600 gC/m2/yr for woodlands in a similar climate. Carbon dioxide flux from grassy areas was 540 gC/m2/yr, higher than reported fluxes of 230 to 490 gC/m2/yr for grasslands in a similar climate.

Reducing the environmental impact of trials: a comparison of the carbon footprint of the CRASH-1 and CRASH-2 clinical trials.

PubMed

Subaiya, Saleena; Hogg, Euan; Roberts, Ian

2011-02-03

All sectors of the economy, including the health research sector, must reduce their carbon emissions. The UK National Institute for Health Research has recently prepared guidelines on how to minimize the carbon footprint of research. We compare the carbon emissions from two international clinical trials in order to identify where emissions reductions can be made. We conducted a carbon audit of two clinical trials (the CRASH-1 and CRASH-2 trials), quantifying the carbon dioxide emissions produced over a one-year audit period. Carbon emissions arising from the coordination centre, freight delivery, trial-related travel and commuting were calculated and compared. The total emissions in carbon dioxide equivalents during the one-year audit period were 181.3 tonnes for CRASH-1 and 108.2 tonnes for CRASH-2. In total, CRASH-1 emitted 924.6 tonnes of carbon dioxide equivalents compared with 508.5 tonnes for CRASH-2. The CRASH-1 trial recruited 10,008 patients over 5.1 years, corresponding to 92 kg of carbon dioxide per randomized patient. The CRASH-2 trial recruited 20,211 patients over 4.7 years, corresponding to 25 kg of carbon dioxide per randomized patient. The largest contributor to emissions in CRASH-1 was freight delivery of trial materials (86.0 tonnes, 48% of total emissions), whereas the largest contributor in CRASH-2 was energy use by the trial coordination centre (54.6 tonnes, 30% of total emissions). Faster patient recruitment in the CRASH-2 trial largely accounted for its greatly increased carbon efficiency in terms of emissions per randomized patient. Lighter trial materials and web-based data entry also contributed to the overall lower carbon emissions in CRASH-2 as compared to CRASH-1. CRASH-1: ISRCTN74459797CRASH-2: ISRCTN86750102.

Carbon Dioxide and Global Warming: A Failed Experiment

ERIC Educational Resources Information Center

Ribeiro, Carla

2014-01-01

Global warming is a current environmental issue that has been linked to an increase in anthropogenic carbon dioxide in the atmosphere. To raise awareness of the problem, various simple experiments have been proposed to demonstrate the effect of carbon dioxide on the planet's temperature. This article describes a similar experiment, which…

Measurement of Chlorine Dioxide in Water by DPD Colorimetric Method

NASA Astrophysics Data System (ADS)

Song, Min; Yan, Panping; Yao, Jun

2018-01-01

In order to solve the problems of chlorine dioxide in water by DPD colorimetric method, this paper discusses the effects of the formulation, temperature, color development time and amount of color reagent on the measurement process, improving the on-line instrument for domestic and drinking water in chlorine dioxide measurement precision and accuracy.

Carbon Dioxide and the Greenhouse Effect: A Problem Evaluation Activity.

ERIC Educational Resources Information Center

Brewer, Carol A.; Beiswenger, Jane M.

1993-01-01

Describes exercises to examine the global carbon cycle. Students are asked to predict consequences of increased carbon dioxide emissions into the atmosphere and to suggest ways to mitigate problems associated with these higher levels of atmospheric carbon dioxide. A comparison modeling exercise examines some of the variables related to the success…

Natural deep eutectic solvents (NADES) as green solvents for carbon dioxide capture

NASA Astrophysics Data System (ADS)

Mulia, Kamarza; Putri, Sylvania; Krisanti, Elsa; Nasruddin

2017-03-01

This study was conducted to determine the effectiveness of Natural Deep Eutectic Solvent (NADES), consisting of choline chloride and a hydrogen bonding donor (HBD) compound, in terms of carbon dioxide absorption. Solubility of carbon dioxide in NADES was found to be influenced HBD compound used and choline chloride to HBD ratio, carbon dioxide pressure, and contact time. HBD and choline/HBD ratios used were 1,2-propanediol (1:2), glycerol (1:2), and malic acid (1:1). The carbon dioxide absorption measurement was conducted using an apparatus that utilizes the volumetric method. Absorption curves were obtained up to pressures of 30 bar, showing a linear relationship between the amount absorbed and the final pressure of carbon dioxide. The choline and 1,2-propanediol eutectic mixture absorbs the highest amount of carbon dioxide, approaching 0.1 mole-fraction at 3.0 MPa and 50°C. We found that NADES ability to absorb carbon dioxide correlates with its polarity as tested using Nile Red as a solvatochromic probe.

The effects of rising atmospheric carbon dioxide on shoot-root nitrogen and water signaling.

PubMed

Easlon, Hsien Ming; Bloom, Arnold J

2013-01-01

Terrestrial higher plants are composed of roots and shoots, distinct organs that conduct complementary functions in dissimilar environments. For example, roots are responsible for acquiring water and nutrients such as inorganic nitrogen from the soil, yet shoots consume the majority of these resources. The success of such a relationship depends on excellent root-shoot communications. Increased net photosynthesis and decreased shoot nitrogen and water use at elevated CO2 fundamentally alter these source-sink relations. Lower than predicted productivity gains at elevated CO2 under nitrogen or water stress may indicate shoot-root signaling lacks plasticity to respond to rising atmospheric CO2 concentrations. The following presents recent research results on shoot-root nitrogen and water signaling, emphasizing the influence that rising atmospheric carbon dioxide levels are having on these source-sink interactions.

Trace gas emissions to the atmosphere by biomass burning in the west African savannas. Final report, 1 October 1991-31 March 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frouin, R.J.; Iacobellis, S.F.; Razafimpanilo, H.

1994-08-01

Savanna fires and atmospheric carbon dioxide (CO2) detection and estimating burned area using Advanced Very High Resolution Radiometer (AVHRR) reflectance data are investigated in this two part research project. The first part involves carbon dioxide flux estimates and a three-dimensional transport model to quantify the effect of North African savanna fires on atmospheric CO2 concentration, including CO2 spatial and temporal variability patterns and their significance to global emissions. The second article describes two methods used to determine burned area from AVHRR data. The article discusses the relationship between the percentage of burned area and AVHRR channel 2 reflectance (the linearmore » method) and Normalized Difference Vegetation Index (NDVI) (the nonlinear method). A comparative performance analysis of each method is described.« less

FETC Programs for Reducing Greenhouse Gas Emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruether, J.A.

1998-02-01

Mark Twain once quipped that everyone talks about the weather but no one does anything about it. With interest in global climate change on the rise, researchers in the fossil-energy sector are feeling the heat to provide new technology to permit continued use of fossil fuels but with reduced emissions of so-called `greenhouse gases.` Three important greenhouse gases, carbon dioxide, methane, and nitrous oxide, are released to the atmosphere in the course of recovering and combusting fossil fuels. Their importance for trapping radiation, called forcing, is in the order given. In this report, we briefly review how greenhouse gases causemore » forcing and why this has a warming effect on the Earth`s atmosphere. Then we discuss programs underway at FETC that are aimed at reducing emissions of methane and carbon dioxide.« less

Clinical study on 71 anorectal cases treated by carbon dioxide laser

NASA Astrophysics Data System (ADS)

Li, Gui-hua

1993-03-01

This paper describes the effective result of carbon dioxide laser on type I and II internal hemorrhoids, mixed hemorrhoids, anal fissure or fistula, etc. At present, simple hemorrhoidectomy is less acceptable to patients for its excessive bleeding and severe pain during and after the operation. Therefore, the results of 71 anorectal cases of hemorrhoidectomy using carbon dioxide laser have been observed in our hospital. The rates of effective treatment and cure were 100% and 94.3%, respectively.

Controle des proprietes des couches optiques par bombardement ionique

NASA Astrophysics Data System (ADS)

Marushka, Viktor

The manufacture of optical coatings presents many challenges such as the control over the film properties and microstructure, the optimization for the production of thin films with high quality, and the research on new materials. Ion-assisted evaporation is one of the principal methods used for the fabrication of optical coatings as a response to these challenges. It allows for good process control, and it permits us to predict and put on an industrial scale the deposition process by considering the direct and quantitative relation between the energies of the incident ions, and the performance of the deposited materials. This work is devoted to the study of the effect of ion bombardment on the microstructure and properties of optical thin films of silicon dioxide and titanium dioxide, which are widely used in optical interference filters, in particular with the use of a Hall effect ion source. These studies include a systematic evaluation of the mechanical and optical properties and of the density of thin films using different complementary techniques - the Quartz Crystal Microbalance, Rutherford Backscattering Spectroscopy, and Infrared Variable Angle Spectroscopic Ellipsometry among others. Different approaches (Spectroscopic Ellipsometry and Infrared Ellipsometry, the measurement of mechanical stress) have been used to evaluate the amount of water in thin films. The results on the density of films and the presence of water in the films obtained by the different methods are in good agreement. It was found that the critical energy values giving rise to dense and stable optical coatings of silicon dioxide and titanium dioxide are 25 eV/atom and 45 eV/atom, respectively. Moreover, this work presents the methodology developed to determine the ion current density distribution on the surface of a substrate holder of a dome shape for different positions relative to the ion source. The proposed analysis can be used as an effective tool for the construction of an industrial reactor and for its appropriate optimization.

Effects of the biosynthesis and signaling pathway of ecdysterone on silkworm (Bombyx mori) following exposure to titanium dioxide nanoparticles.

PubMed

Li, Fanchi; Gu, Zhiya; Wang, Binbin; Xie, Yi; Ma, Lie; Xu, Kaizun; Ni, Min; Zhang, Hua; Shen, Weide; Li, Bing

2014-08-01

Silkworm (Bombyx mori), a model Lepidoptera insect, is economically important. Its growth and development are regulated by endogenous hormones. During the process of transition from larvae to pupae, 20-hydroxyecdysone (20E) plays an important role. The recent surge in consumer products and applications using metallic nanoparticles has increased the possibility of human or ecosystem exposure due to their unintentional release into the environment. We investigated the effects of exposure to titanium dioxide nanoparticles (TiO2 NPs) on the action of 20E in B. mori. Titanium dioxide nanoparticle treatment shortened the molting duration by 8 hr and prolonged the molting peak period by 10 %. Solexa sequencing profiled the changes in gene expression in the brain of fifth-instar B. mori in response to TiO2NPS exposure for 72 hr, to address the effects on hormone metabolism and regulation. Thirty one genes were differentially expressed. The transcriptional levels of pi3k and P70S6K, which are involved in the target of the rapamycin (TOR) signaling pathway, were up-regulated. Transcriptional levels of four cytochrome P450 genes, which are involved in 20E biosynthesis, at different developmental stages (48, 96, 144, and 192 hr) at 5th instars of all displayed trends of increasing expression. Simultaneously, the ecdysterone receptors, also displayed increasing trends. The 20E titers at four developmental stages during the 5th instar were 1.26, 1.23, 1.72, and 2.16 fold higher, respectively, than the control group. These results indicate that feeding B. mori with TiO2 NPs stimulates 20E biosynthesis, shortens the developmental progression, and reduces the duration of molting. Thus, application of TiO2 NPs is of high significance for saving the labor force in sericulture, and our research provides a reference for the ecological problems in the field of Lepidoptera exposured to titanium dioxide nanoparticles.

A strategic decision-making model considering the social costs of carbon dioxide emissions for sustainable supply chain management.

PubMed

Tseng, Shih-Chang; Hung, Shiu-Wan

2014-01-15

Incorporating sustainability into supply chain management has become a critical issue driven by pressures from governments, customers, and various stakeholder groups over the past decade. This study proposes a strategic decision-making model considering both the operational costs and social costs caused by the carbon dioxide emissions from operating such a supply chain network for sustainable supply chain management. This model was used to evaluate carbon dioxide emissions and operational costs under different scenarios in an apparel manufacturing supply chain network. The results showed that the higher the social cost rate of carbon dioxide emissions, the lower the amount of the emission of carbon dioxide. The results also suggested that a legislation that forces the enterprises to bear the social costs of carbon dioxide emissions resulting from their economic activities is an effective approach to reducing carbon dioxide emissions. Copyright © 2013 Elsevier Ltd. All rights reserved.

5% Carbon Dioxide is safe but of limited efficacy as a treatment for paediatric non-convulsive status epilepticus: An open label observational study.

PubMed

Forsyth, Rob; Martland, Tim; Lai, Ming; Vadlamani, Gayatri; Hogan, Vanessa

2016-07-01

To establish the efficacy and tolerability of inhaled 5% carbon dioxide/95% oxygen as a treatment for paediatric non-convulsive status epilepticus (NCSE). In an open label clinical trial, children in NCSE were given high flow inhaled 5% carbon dioxide/95% oxygen by face mask for 120 s under EEG control. Six children (five male; ages 3-13; all with severe underlying epilepsy and disability) were recruited. Inhalation was well tolerated in all cases. Capillary blood gasses showed no significant derangements at the end of the inhalation. Effects on EEG normalisation were limited and transient, and no clinical improvements were noted. No adverse effects occurred. Inhaled 5% carbon dioxide/95% oxygen has been suggested as a potent, well tolerated anticonvulsant. An anticonvulsant without sedating and respiration-depressing effects would be particularly welcome in the management of NCSE where the justification for aggressive anticonvulsant therapy is often uncertain, however it appears that 5% carbon dioxide is of limited efficacy in this context. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Stratospheric nitrogen dioxide in the vicinity of soufriere, st. Vincent.

PubMed

Romick, G J; Murcray, D G; Williams, W J

1982-06-04

In April 1979, measurements of nitrogen dioxide in the upper atmosphere were made near Soufriere Volcano by twilight optical-absorption techniques. The derived value of 5 x 10(15) molecules per square centimeter column implies an enhancement of 25 percent over earlier abundances measured in the same latitudinal regions. This enhancement may represent the normal stratospheric variability of nitrogen dioxide in the equatorial region but in any case may be considered an upper limit to the volcano's effect on the total nitrogen dioxide abundance.

Communication: Photoinduced carbon dioxide binding with surface-functionalized silicon quantum dots.

PubMed

Douglas-Gallardo, Oscar A; Sánchez, Cristián Gabriel; Vöhringer-Martinez, Esteban

2018-04-14

Nowadays, the search for efficient methods able to reduce the high atmospheric carbon dioxide concentration has turned into a very dynamic research area. Several environmental problems have been closely associated with the high atmospheric level of this greenhouse gas. Here, a novel system based on the use of surface-functionalized silicon quantum dots (sf-SiQDs) is theoretically proposed as a versatile device to bind carbon dioxide. Within this approach, carbon dioxide trapping is modulated by a photoinduced charge redistribution between the capping molecule and the silicon quantum dots (SiQDs). The chemical and electronic properties of the proposed SiQDs have been studied with a Density Functional Theory and Density Functional Tight-Binding (DFTB) approach along with a time-dependent model based on the DFTB framework. To the best of our knowledge, this is the first report that proposes and explores the potential application of a versatile and friendly device based on the use of sf-SiQDs for photochemically activated carbon dioxide fixation.

Communication: Photoinduced carbon dioxide binding with surface-functionalized silicon quantum dots

NASA Astrophysics Data System (ADS)

Douglas-Gallardo, Oscar A.; Sánchez, Cristián Gabriel; Vöhringer-Martinez, Esteban

2018-04-01

Nowadays, the search for efficient methods able to reduce the high atmospheric carbon dioxide concentration has turned into a very dynamic research area. Several environmental problems have been closely associated with the high atmospheric level of this greenhouse gas. Here, a novel system based on the use of surface-functionalized silicon quantum dots (sf-SiQDs) is theoretically proposed as a versatile device to bind carbon dioxide. Within this approach, carbon dioxide trapping is modulated by a photoinduced charge redistribution between the capping molecule and the silicon quantum dots (SiQDs). The chemical and electronic properties of the proposed SiQDs have been studied with a Density Functional Theory and Density Functional Tight-Binding (DFTB) approach along with a time-dependent model based on the DFTB framework. To the best of our knowledge, this is the first report that proposes and explores the potential application of a versatile and friendly device based on the use of sf-SiQDs for photochemically activated carbon dioxide fixation.

Effect of Ethanol, Sulfur Dioxide and Glucose on the Growth of Wine Spoilage Yeasts Using Response Surface Methodology

PubMed Central

Chandra, Mahesh; Oro, Inês; Ferreira-Dias, Suzana; Malfeito-Ferreira, Manuel

2015-01-01

Response surface methodology (RSM) was used to study the effect of three factors, sulfur dioxide, ethanol and glucose, on the growth of wine spoilage yeast species, Zygosaccharomyces bailii, Schizosaccharomyces pombe, Saccharomycodes ludwigii and Saccharomyces cerevisiae. Seventeen central composite rotatable design (CCRD) trials were designed for each test yeast using realistic concentrations of the factors (variables) in premium red wine. Polynomial regression equations were fitted to experimental data points, and the growth inhibitory conditions of these three variables were determined. The overall results showed Sa. ludwigii as the most resistant species growing under high ethanol/free sulfur dioxide concentrations, i.e., 15% (v/v)/20 mg L-1, 14% (v/v)/32 mg L-1 and 12.5% (v/v)/40 mg L-1, whereas other yeasts did not survive under the same levels of ethanol/free sulfur dioxide concentrations. The inhibitory effect of ethanol was primarily observed during longer incubation periods, compared with sulfur dioxide, which showed an immediate effect. In some CCRD trials, Sa. ludwigii and S. cerevisiae showed growth recovery after a short death period under the exposure of 20–32 mg L-1 sulfur dioxide in the presence of 11% (v/v) or more ethanol. However, Sc. pombe and Z. bailii did not show such growth recovery under similar conditions. Up to 10 g L-1 of glucose did not prevent cell death under the sulfur dioxide or ethanol stress. This observation demonstrates that the sugar levels commonly used in wine to sweeten the mouthfeel do not increase wine susceptibility to spoilage yeasts, contrary to the anecdotal evidence. PMID:26107389

INSIDE EPA RESEARCH

EPA Science Inventory

The article discusses air pollution research at the U.S. EPA, and particularly AEERL's role in that research which, in some areas, predates the Agency's. EPA's engineering research programs are shifting from an initial focus on sulfur dioxide and nitrogen oxide pollution control ...

[CHEMICAL AIR POLLUTION OF THE OCCUPATIONAL ENVIRONMENT AS A FACTOR FOR PROFESSIONAL RISK FOR WORKERS OF MAIN OCCUPATIONS IN THE COPPER AND NICKEL METALLURGY].

PubMed

Lipatov, G Ia; Adrianovskiĭ, V I; Gogoleva, O I

2015-01-01

There are presented the results of hygienic researches of the harmful substances content in the air of the working area ofthe copper and nickel metallurgy. Sulfur-containing gases (primarily sulfur dioxide), to the effects of which there are exposed workers of drying, smelting, converter conversion, are shown to play a leading role among professional factors.

Effects of Vaporized Decontamination Systems on Selected Building Interior Materials: Chlorine Dioxide

DTIC Science & Technology

2009-02-01

Chemical Biological Center (ECBC) to take advantage of ECBC’s extensive expertise and specialized research facilities for the decontamination of surfaces...Agency (EPA) established an Interagency Agreement with the U.S. Army Edgewood Chemical Biological Center (ECBC) to take advantage of ECBC’s extensive...Detector (Waters Corporation, Milford, MA). Conductivity suppression was carried out using an ERIS 1000HP Autosuppressor ( Alltech Corporation, Deerfield

Progress on High-Energy 2-micron Solid State Laser for NASA Space-Based Wind and Carbon Dioxide Measurements

NASA Technical Reports Server (NTRS)

Singh, Upendra N.

2011-01-01

Sustained research efforts at NASA Langley Research Center during last fifteen years have resulted in significant advancement of a 2-micron diode-pumped, solid-state laser transmitter for wind and carbon dioxide measurements from ground, air and space-borne platforms. Solid-state 2-micron laser is a key subsystem for a coherent Doppler lidar that measures the horizontal and vertical wind velocities with high precision and resolution. The same laser, after a few modifications, can also be used in a Differential Absorption Lidar system for measuring atmospheric CO2 concentration profiles. Researchers at NASA Langley Research Center have developed a compact, flight capable, high energy, injection seeded, 2-micron laser transmitter for ground and airborne wind and carbon dioxide measurements. It is capable of producing 250 mJ at 10 Hz by an oscillator and one amplifier. This compact laser transmitter was integrated into a mobile trailer based coherent Doppler wind and CO2 DIAL system and was deployed during field measurement campaigns. This paper will give an overview of 2-micron solid-state laser technology development and discuss results from recent ground-based field measurements.

The Bohr Effect Is Not a Likely Promoter of Renal Preglomerular Oxygen Shunting

PubMed Central

Olgac, Ufuk; Kurtcuoglu, Vartan

2016-01-01

The aim of this study was to evaluate whether possible preglomerular arterial-to-venous oxygen shunting is affected by the interaction between renal preglomerular carbon dioxide and oxygen transport. We hypothesized that a reverse (venous-to-arterial) shunting of carbon dioxide will increase partial pressure of carbon dioxide and decrease pH in the arteries and thereby lead to increased oxygen offloading and consequent oxygen shunting. To test this hypothesis, we employed a segment-wise three-dimensional computational model of coupled renal oxygen and carbon dioxide transport, wherein coupling is achieved by shifting the oxygen-hemoglobin dissociation curve in dependence of local changes in partial pressure of carbon dioxide and pH. The model suggests that primarily due to the high buffering capacity of blood, there is only marginally increased acidity in the preglomerular vasculature compared to systemic arterial blood caused by carbon dioxide shunting. Furthermore, effects of carbon dioxide transport do not promote but rather impair preglomerular oxygen shunting, as the increase in acidity is higher in the veins compared to that in the arteries. We conclude that while substantial arterial-to-venous oxygen shunting might take place in the postglomerular vasculature, the net amount of oxygen shunted at the preglomerular vasculature appears to be marginal. PMID:27833564

Why do we conduct energy research in Alabama?

NASA Astrophysics Data System (ADS)

Hills, D. J.

2017-12-01

The purpose of the Energy Investigations Program (EIP) at the Geological Survey of Alabama is to research all geological topics related to energy that would affect the state. The state of Alabama has a rich history of coal, oil, and natural gas production. These traditional fuels are still a necessary part of power production, even as other energy sources are being developed. EIP helps assess the remaining reserves of these hydrocarbons, both from areas that have had extensive production as well as new regions that have yet to have viable production. Our research helps people decide how (or even if) they want to develop the resource. Even so, the research in EIP is not all about fossil fuels. We also investigate how carbon dioxide produced from burning these traditional fuels might be captured and then either used or stored permanently. The same types of geology that are good for producing oil and gas are also often good for geologic storage of carbon dioxide permanently. Carbon dioxide can also be used to produce more oil and gas from an older, less productive field, as it can be used to push more of the hydrocarbon out of the rock. This type of research can lead to job development and economic stability or growth within the state.

The association between exposure to the oil and gas industry and beef calf mortality in Western Canada.

PubMed

Waldner, Cheryl L

2008-01-01

Researchers assessed the association between exposure to emissions from oil and gas field facilities and newborn calf survival and health status by determining the risks of calf mortality and treatment reported for 27,511 beef calves born to cows in 203 herds, which were followed from the beginning of the 2001 breeding season through the 2002 calving season. They prospectively measured exposures to sulfur dioxide, hydrogen sulfide, and volatile organic compounds (VOCs) by using data from passive air monitors. They also used the density of oil and gas well sites surrounding each pasture as an additional measure of exposure. The researchers found that well-site density as well as exposures to hydrogen sulfide and VOCs measured as benzene or toluene were not associated with the odds of calf mortality in the first 3 months of life. After adjusting for cow-and herd-level risk factors, they found that exposure to sulfur dioxide near the time of calving was associated with an increased risk of calf mortality during this period. Exposure to sulfur dioxide in the 3-month period before calving was most suggestive of a causal exposure-response relationship (the odds ratio for every 1 ppb increase in sulfur dioxide=1.32; 95% confidence interval=1.13-1.54; p=0004). Exposure to sulfur dioxide, hydrogen sulfide, and VOCs measured as benzene or toluene during gestation was not associated with the odds of calf treatment in the first 3 months of life. However, exposure to sulfur dioxide, hydrogen sulfide, and VOCs measured as benzene or toluene, and sulfur dioxide in the first month after calving, was associated with a small increase in the odds of calf treatment after the first month of life when risk was compared across quartiles for exposure; only the association between hydrogen sulfide exposure and the odds of treatment was consistent with a causal exposure.

Counter-current carbon dioxide extraction of fat from soy skim

USDA-ARS?s Scientific Manuscript database

This research aims to investigate the use of counter-current carbon dioxide extraction method as a means to reduce residual fat in soy skim after the enzyme-assisted aqueous extraction of soybeans. Extractions with liquid CO2 at 25°C and 10.34 MPa and supercritical CO2 at 50°C and 25.16 MPa are comp...

The Increase of Energy Consumption and Carbon Dioxide (CO2) Emission in Indonesia

NASA Astrophysics Data System (ADS)

Sasana, Hadi; Putri, Annisa Eka

2018-02-01

In the last decade, the increase of energy consumption that has multiplied carbondioxide emissions becomes world problems, especially in the developing countries undergoing industrialization to be developed ones like Indonesia. This aim of this study was to analyze the effect of fossil energy consumption, population growth, and consumption of renewable energy on carbon dioxide emission. The method used was multiple linear regression analysis with Ordinary Least Square approach using time series in the period of 1990 - 2014. The result showed that fossil energy consumption and population growth have a positive influence on carbon dioxide emission in Indonesia. Meanwhile, the consumption variable of renewable energy has a negative effect on the level of carbon dioxide emissions produced.

Effect of helium ion beam treatment on wet etching of silicon dioxide

NASA Astrophysics Data System (ADS)

Petrov, Yu. V.; Grigoryev, E. A.; Sharov, T. V.; Baraban, A. P.

2018-03-01

We investigated the effect of helium ion beam treatment on the etching rate of silicon dioxide in a water based solution of hydrofluoric acid. A 460-nm-thick silicon dioxide film on silicon was irradiated with helium ions having energies of 20 keV and 30 keV with ion fluences ranging from 1014 cm-2 to 1017 cm-2. The dependence of the etching rate on depth was obtained and compared with the depth distribution of ion-induced defects, which was obtained from numerical simulation. Irradiation with helium ions results in an increase of the etching rate of silicon dioxide. The dependence of the etching rate on the calculated concentration of ion-induced defects is described.

Observed changes in soyabean growth and seed yield from Albutilon theophrasti competition as a function of carbon dioxide concentration

USDA-ARS?s Scientific Manuscript database

Soybean (Glycine max) was grown at ambient and at projected levels of atmospheric carbon dioxide (+250 µmol mol-1 above ambient) with and without the presence of a weed (velvetleaf, Albutilon theophrasti Medic.) to quantify the potential effect of rising atmospheric carbon dioxide concentration [CO2...

Modelling effects of geoengineering options in response to climate change and global warming: implications for coral reefs.

PubMed

Crabbe, M J C

2009-12-01

Climate change will have serious effects on the planet and on its ecosystems. Currently, mitigation efforts are proving ineffectual in reducing anthropogenic CO2 emissions. Coral reefs are the most sensitive ecosystems on the planet to climate change, and here we review modelling a number of geoengineering options, and their potential influence on coral reefs. There are two categories of geoengineering, shortwave solar radiation management and longwave carbon dioxide removal. The first set of techniques only reduce some, but not all, effects of climate change, while possibly creating other problems. They also do not affect CO2 levels and therefore fail to address the wider effects of rising CO2, including ocean acidification, important for coral reefs. Solar radiation is important to coral growth and survival, and solar radiation management is not in general appropriate for this ecosystem. Longwave carbon dioxide removal techniques address the root cause of climate change, rising CO2 concentrations, they have relatively low uncertainties and risks. They are worthy of further research and potential implementation, particularly carbon capture and storage, biochar, and afforestation methods, alongside increased mitigation of atmospheric CO2 concentrations.

Titanium dioxide thin films by atomic layer deposition: a review

NASA Astrophysics Data System (ADS)

Niemelä, Janne-Petteri; Marin, Giovanni; Karppinen, Maarit

2017-09-01

Within its rich phase diagram titanium dioxide is a truly multifunctional material with a property palette that has been shown to span from dielectric to transparent-conducting characteristics, in addition to the well-known catalytic properties. At the same time down-scaling of microelectronic devices has led to an explosive growth in research on atomic layer deposition (ALD) of a wide variety of frontier thin-film materials, among which TiO2 is one of the most popular ones. In this topical review we summarize the advances in research of ALD of titanium dioxide starting from the chemistries of the over 50 different deposition routes developed for TiO2 and the resultant structural characteristics of the films. We then continue with the doped ALD-TiO2 thin films from the perspective of dielectric, transparent-conductor and photocatalytic applications. Moreover, in order to cover the latest trends in the research field, both the variously constructed TiO2 nanostructures enabled by ALD and the Ti-based hybrid inorganic-organic films grown by the emerging ALD/MLD (combined atomic/molecular layer deposition) technique are discussed.

Association of indoor nitrogen dioxide with respiratory symptoms and pulmonary function in children

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neas, L.M.; Dockery, D.W.; Ware, J.H.

1991-07-15

The effect of indoor nitrogen dioxide on the cumulative incidence of respiratory symptoms and pulmonary function level was studied in a cohort of 1,567 white children aged 7-11 years examined in six US cities from 1983 through 1988. Week-long measurements of nitrogen dioxide were obtained at three indoor locations over 2 consecutive weeks in both the winter and the summer months. The household annual average nitrogen dioxide concentration was modeled as a continuous variable and as four ordered categories. Multiple logistic regression analysis of symptom reports from a questionnaire administered after indoor monitoring showed that a 15-ppb increase in themore » household annual nitrogen dioxide mean was associated with an increased cumulative incidence of lower respiratory symptoms (odds ratio (OR) = 1.4, 95% confidence interval (95% Cl) 1.1-1.7). The response variable indicated the report of one or more of the following symptoms: attacks of shortness of breath with wheeze, chronic wheeze, chronic cough, chronic phlegm, or bronchitis. Girls showed a stronger association (OR = 1.7, 95% Cl 1.3-2.2) than did boys (OR = 1.2, 95% Cl 0.9-1.5). An analysis of pulmonary function measurements showed no consistent effect of nitrogen dioxide. These results are consistent with earlier reports based on categorical indicators of household nitrogen dioxide sources and provide a more specific association with nitrogen dioxide as measured in children's homes.« less

Synergistic action of tropospheric ozone and carbon dioxide on yield and nutritional quality of Indian mustard (Brassica juncea (L.) Czern.).

PubMed

Singh, Satyavan; Bhatia, Arti; Tomer, Ritu; Kumar, Vinod; Singh, B; Singh, S D

2013-08-01

Field experiments were conducted in open top chamber during rabi seasons of 2009-10 and 2010-11 at the research farm of the Indian Agricultural Research Institute, New Delhi to study the effect of tropospheric ozone (O3) and carbon dioxide (CO2) interaction on yield and nutritional quality of Indian mustard (Brassica juncea (L.) Czern.). Mustard plants were grown from emergence to maturity under different treatments: charcoal-filtered air (CF, 80-85 % less O3 than ambient O3 and ambient CO2), nonfiltered air (NF, 5-10 % less O3 than ambient O3 and ambient CO2 ), nonfiltered air with elevated carbon dioxide (NF + CO2, NF air and 550 ± 50 ppm CO2), elevated ozone (EO, NF air and 25-35 ppb elevated O3), elevated ozone along with elevated carbon dioxide (EO + CO2, NF air, 25-35 ppb O3 and 550 ± 50 ppm CO2), and ambient chamber less control (AC, ambient O3 and CO2). Elevated O3 exposure led to reduced photosynthesis and leaf area index resulting in decreased seed yield of mustard. Elevated ozone significantly decreased the oil and micronutrient content in mustard. Thirteen to 17 ppm hour O3 exposure (accumulated over threshold of 40 ppm, AOT 40) reduced the oil content by 18-20 %. Elevated CO2 (500 ± 50 ppm) along with EO was able to counter the decline in oil content in the seed, and it increased by 11 to 13 % over EO alone. Elevated CO2, however, decreased protein, calcium, zinc, iron, magnesium, and sulfur content in seed as compared to the nonfiltered control, whereas removal of O3 from air in the charcoal-filtered treatment resulted in a significant increase in the same.

REMOTE SENSING OF SULFUR DIOXIDE EFFECTS ON VEGETATION: SPECTRORADIOMETRY

EPA Science Inventory

Remote measurements of spectral reflectance were made in a laboratory to study sulfur dioxide (SO2) effects on the foliage of soybean (Glycine max (L.) Merr.) and winter wheat (Triticum aestivum) plants. The relationship between spectral reflectance and foliar injury from SO2 was...

Mitigation of Alicyclobacillus spp. spores on food contact surfaces with aqueous chlorine dioxide and hypochlorite.

PubMed

Friedrich, Loretta M; Goodrich-Schneider, Renee; Parish, Mickey E; Danyluk, Michelle D

2009-12-01

The prevalence of Alicyclobacillus spp. and other spore-forming spoilage organisms in food handling and processing environments presents a sanitation challenge to manufacturers of products such as juices and beverages. The objectives of this study were to determine the efficacy of chlorine dioxide and sodium hypochlorite in killing Alicyclobacillus spores in situ and to evaluate the efficacy of various chlorine dioxide and hypochlorite sanitizing regimes on Alicyclobacillus spp. spores on stainless steel, wood, and rubber conveyor material. Five or two log CFU/ml spore concentrations were left in aqueous solution or inoculated onto stainless steel, rubber, or wood coupons and challenged with sanitizer for varied time intervals. After treatment, the coupons were placed in sterile sample bags, massaged with neutralizing buffer, and enumerated on Ali agar. Surfaces were also examined before and after treatment by scanning electron microscopy to confirm destruction or removal of the spores. For both five and two log CFU/ml spore concentrations, treatments of 50 and 100 ppm of chlorine dioxide and 1000 and 2000 ppm of hypochlorite, respectively, were the most effective. Of the range of chlorine dioxide concentrations and contact time regimes evaluated for all surfaces, the most effective concentration/time regime applied was 100 ppm for 10 min. Reductions ranged from 0 to 4.5 log CFU/coupon. Chlorine dioxide was least effective when applied to wood. Hypochlorite was not efficient at eliminating Alicyclobacillus spores from any of the food contact surfaces at any time and concentration combinations tested. Chlorine dioxide is an alternative treatment to kill spores of Alicyclobacillus spp. in the processing environment.

Molecular Simulations of Carbon Dioxide and Water: Cation Solvation and Wettability

NASA Astrophysics Data System (ADS)

Criscenti, L. J.; Bracco, J.; Cygan, R. T.

2010-12-01

Proposed carbon dioxide sequestration scenarios in sedimentary basins require investigation into the interaction between supercritical carbon dioxide, brines, and the mineral phases found in the basin and overlying caprock. Classical molecular dynamics (MD) simulations can be used to investigate some of these interactions such as the partitioning of metal cations between aqueous solutions and supercritical carbon dioxide, and the relative wettability of basin and caprock minerals with different fluid phases including water, carbon dioxide, and oil. Initial research has lead to the development of a new flexible carbon dioxide force field that successfully reproduces the vibrational properties of carbon dioxide, and a methodology for extracting contact angle information from large-scale MD simulations. Molecular simulations were performed to compare the solvation of alkali and alkaline metal cations in water and liquid carbon dioxide at 300K, using a flexible simple point charge (SPC) model for water and the new carbon dioxide force field. Solvation energies for Na+, Cs+, Mg2+, and Ba2+ are larger in water than in carbon dioxide, suggesting that these cations will partition preferentially into water. In both solutions, the solvation energy for the cations decreases with ion size and increases with ion charge. However, changes in solvation energy with increasing ionic radii are smaller in carbon dioxide than in water. Therefore, the overall partitioning of cations into carbon dioxide is predicted to increase with ion size. Molecular dynamics simulations are also useful to examine the relative wettability of minerals with different fluid phases. Large-scale MD simulations involving between 100,000 and 200,000 atoms have been conducted to establish a dynamic equilibrium between a drop of liquid water, water vapor, and kaolinite surfaces. The water drops consisted of at least 1700 molecules. Simulations were performed for five nanoseconds. The contact angle calculated for the siloxane surface of kaolinite is approximately 110°, and compares well with calculated contact angles for silica reported in the literature. The contact angle determined for the gibbsite surface of kaolinite is approximately 13° and compares favorably to reported experimental results. As expected, the siloxane surface is calculated to be hydrophobic and the gibbsite surface hydrophilic. This technique should prove useful to investigate the relative wettability of different minerals with subsurface fluids including supercritical CO2. This material is based upon work partially supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Catalog of databases and reports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burtis, M.D.

1997-04-01

This catalog provides information about the many reports and materials made available by the US Department of Energy`s (DOE`s) Global Change Research Program (GCRP) and the Carbon Dioxide Information Analysis Center (CDIAC). The catalog is divided into nine sections plus the author and title indexes: Section A--US Department of Energy Global Change Research Program Research Plans and Summaries; Section B--US Department of Energy Global Change Research Program Technical Reports; Section C--US Department of Energy Atmospheric Radiation Measurement (ARM) Program Reports; Section D--Other US Department of Energy Reports; Section E--CDIAC Reports; Section F--CDIAC Numeric Data and Computer Model Distribution; Section G--Othermore » Databases Distributed by CDIAC; Section H--US Department of Agriculture Reports on Response of Vegetation to Carbon Dioxide; and Section I--Other Publications.« less

Are renewable energy policies upsetting carbon dioxide emissions? The case of Latin America countries.

PubMed

Fuinhas, José Alberto; Marques, António Cardoso; Koengkan, Matheus

2017-06-01

The impact of renewable energy policies in carbon dioxide emissions was analysed for a panel of ten Latin American countries, for the period from 1991 to 2012. Panel autoregressive distributed lag methodology was used to decompose the total effect of renewable energy policies on carbon dioxide emissions in its short- and long-run components. There is evidence for the presence of cross-sectional dependence, confirming that Latin American countries share spatial patterns. Heteroskedasticity, contemporaneous correlation, and first-order autocorrelation cross-sectional dependence are also present. To cope with these phenomena, the robust dynamic Driscoll-Kraay estimator, with fixed effects, was used. It was confirmed that the primary energy consumption per capita, in both the short- and long-run, contributes to an increase in carbon dioxide emissions, and also that renewable energy policies in the long-run, and renewable electricity generation per capita both in the short- and long-run, help to mitigate per capita carbon dioxide emissions.

The oxygen and carbon dioxide balance in the earth's atmosphere

NASA Technical Reports Server (NTRS)

Johnson, F. S.

1975-01-01

The oxygen-carbon dioxide cycle is described in detail, and steps which are sensitive to perturbation or instability are identified. About half of the carbon dioxide consumption each year in photosynthesis occurs in the oceans. Phytoplankton, which are the primary producers, have been shown to assimilate insecticides and herbicides. The impact of such materials on phytoplankton photosynthesis, both direct and as the indirect result of detrimental effects higher up in the food chain, cannot be assessed. Net oxygen production is very small in comparison with the total production and occurs almost exclusively in a few ocean areas with anoxic bottom conditions and in peat-forming marshes which are sensitive to anthropogenic disturbances. The carbon dioxide content of the atmosphere is increasing at a relatively rapid rate as the result of fossil fuel combustion. Increases in photosynthesis as the result of the hothouse effect may in turn reduce the carbon dioxide content of the atmosphere, leading to global cooling.

Double-Pulse Two-Micron IPDA Lidar Simulation for Airborne Carbon Dioxide Measurements

NASA Technical Reports Server (NTRS)

Refaat, Tamer F.; Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta

2015-01-01

An advanced double-pulsed 2-micron integrated path differential absorption lidar has been developed at NASA Langley Research Center for measuring atmospheric carbon dioxide. The instrument utilizes a state-of-the-art 2-micron laser transmitter with tunable on-line wavelength and advanced receiver. Instrument modeling and airborne simulations are presented in this paper. Focusing on random errors, results demonstrate instrument capabilities of performing precise carbon dioxide differential optical depth measurement with less than 3% random error for single-shot operation from up to 11 km altitude. This study is useful for defining CO2 measurement weighting, instrument setting, validation and sensitivity trade-offs.

Stratospheric nitrogen dioxide in the vicinity of Soufriere, St. Vincent

NASA Technical Reports Server (NTRS)

Romick, G. J.; Murcray, D. G.; Williams, W. J.

1982-01-01

In April 1979, measurements of nitrogen dioxide in the upper atmosphere were made near Soufriere Volcano by twilight optical-absorption techniques. The derived value of 5 x 10 to the 15th molecules per square centimeter column implies an enhancement of 25 percent over earlier abundances measured in the same latitudinal regions. This enhancement may represent the normal stratospheric variability of nitrogen dioxide in the equatorial region, but in any case may be considered an upper limit to the volcano's effect on the total nitrogen dioxide abundance.

Capacitance‐Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation

PubMed Central

Lamb, Katie J.; Dowsett, Mark R.; Chatzipanagis, Konstantinos; Scullion, Zhan Wei; Kröger, Roland; Lee, James D.

2017-01-01

Abstract An electrochemical cell comprising a novel dual‐component graphite and Earth‐crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero‐carbon energy source. PMID:29171724

The role of carbon dioxide in chemoselective hydrogenation of halonitroaromatics over supported noble metal catalysts in supercritical carbon dioxide.

PubMed

Ichikawa, Shinichiro; Tada, Mizuki; Iwasawa, Yasuhiro; Ikariya, Takao

2005-02-21

Chemoselective hydrogenation of halogenated nitrobenzenes over Pt/C catalysts proceeds effectively in supercritical carbon dioxide (scCO2) to produce halogenated anilines with excellent selectivity; the rate of the hydrogenation of nitro groups is markedly enhanced in scCO2 compared to the neat reaction, and the dehalogenation reaction is significantly suppressed.

Effects of surface-active organic matter on carbon dioxide nucleation in atmospheric wet aerosols: a molecular dynamics study.

PubMed

Daskalakis, Vangelis; Charalambous, Fevronia; Panagiotou, Fostira; Nearchou, Irene

2014-11-21

Organic matter (OM) uptake in cloud droplets produces water-soluble secondary organic aerosols (SOA) via aqueous chemistry. These play a significant role in aerosol properties. We report the effects of OM uptake in wet aerosols, in terms of the dissolved-to-gas carbon dioxide nucleation using molecular dynamics (MD) simulations. Carbon dioxide has been implicated in the natural rainwater as well as seawater acidity. Variability of the cloud and raindrop pH is assumed in space and time, as regional emissions, local human activities and geophysical characteristics differ. Rain scavenging of inorganic SOx, NOx and NH3 plays a major role in rain acidity in terms of acid-base activity, however carbon dioxide solubility also remains a key parameter. Based on the MD simulations we propose that the presence of surface-active OM promotes the dissolved-to-gas carbon dioxide nucleation in wet aerosols, even at low temperatures, strongly decreasing carbon dioxide solubility. A discussion is made on the role of OM in controlling the pH of a cloud or raindrop, as a consequence, without involving OM ionization equilibrium. The results are compared with experimental and computational studies in the literature.

Preparation of Heat Treated Titanium Dioxide (TiO2) Nanoparticles for Water Purification

NASA Astrophysics Data System (ADS)

Araoyinbo, A. O.; Abdullah, M. M. A. B.; Rahmat, A.; Azmi, A. I.; Vizureanu, P.; Rahim, W. M. F. Wan Abd

2018-06-01

Photocatalysis using the semiconductor titanium dioxide (TiO2) has proven to be a successful technology for waste water purification. The photocatalytic treatment is an alternative method for the removal of soluble organic compounds in waste water. In this research, titanium dioxide nanoparticles were synthesized by sol-gel method using titanium tetraisopropoxide (TTIP) as a precursor. The sol was dried in the oven at 120°C after aging for 24 hours. The dried powder was then calcined at 400°C and 700°C with a heating rate of 10°C/min. The phase transformation of the heat treated titanium dioxide nanoparticles were characterized by X-Ray Diffraction (XRD, and the surface morphology by Scanning Electron Microscopy (SEM). The photocatalytic activity of the heat treated titanium dioxide nanoparticles in the degradation of methyl orange (MO) dye under ultraviolet (UV) light irradiation has been studied. At calcination temperature of 400°C, only anatase phase was observed, as the calcination temperature increases to 700°C, the rutile phase was present. The SEM images show the irregular shape of titanium dioxide particles and the agglomeration which tends to be more significant at calcined temperature of 700°C. Degradation of methyl orange by 5 mg heat treated titanium dioxide nanoparticles gives the highest percentage of degradation after irradiation by UV lamp for 4 hours.

Regional Disparities in the Beneficial Effects of Rising CO2 Emissions on Crop Water Productivity

NASA Technical Reports Server (NTRS)

Deryng, Delphine; Elliott, Joshua; Folberth, Christian; Meuller, Christoph; Pugh, Thomas A. M.; Boote, Kenneth J.; Conway, Declan; Ruane, Alex C.; Gerten, Dieter; Jones, James W.;

Chemical Demilitarization - Assembled Chemical Weapons Assessment (ACWA): Root Cause Analysis

DTIC Science & Technology

2011-07-01

BGCAPP, supercritical water oxidation (SCWO) will subject the hydrolysate to very high temperatures and pressures, breaking it down into carbon dioxide ...ANS. The resulting hydrolysates from both the chemical and energetic process are then broken down into carbon dioxide , water and salts in the SCWO...Cutter Machine RDT&E Research, Development, Test and Evaluation RSM Rocket Shear Machine SAR Selected Acquisition Report SCWO Supercritical Water

Joint Center for Artificial Photosynthesis

ScienceCinema

Koval, Carl; Lee, Kenny; Houle, Frances; Lewis, Na

2018-05-30

The Joint Center for Artificial Photosynthesis (JCAP) is the nation's largest research program dedicated to the development of an artificial solar-fuel generation technology. Established in 2010 as a U.S. Department of Energy (DOE) Energy Innovation Hub, JCAP aims to find a cost-effective method to produce fuels using only sunlight, water, and carbon dioxide as inputs. JCAP brings together more than 140 top scientists and researchers from the California Institute of Technology and its lead partner, Berkeley Lab, along with collaborators from the SLAC National Accelerator Laboratory, and the University of California campuses at Irvine and San Diego.

Proceedings of the Chemical Research and Development Center’s Scientific Conference on Obscuration and Aerosol Research (1984) Held on 25-29 June 1984 at Aberdeen Proving Ground, Maryland.

DTIC Science & Technology

1985-06-01

early enough in the expansion to effect cluster growth. The gas-phase heat of dinerisation of sulfur dioxide is determined to be 4.3 t 0.3 kcal/mole...tubing and a roundbottom flask; the total volume is approximately one liter; heating is performed resistively. The temperature in the chamber is...noszles were used in the experiments ranging frou 100 to 300 us in diameter. These A vere convergent glass tubes that incorporated an annular heating

Joint Center for Artificial Photosynthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koval, Carl; Lee, Kenny; Houle, Frances

2013-12-10

The Joint Center for Artificial Photosynthesis (JCAP) is the nation's largest research program dedicated to the development of an artificial solar-fuel generation technology. Established in 2010 as a U.S. Department of Energy (DOE) Energy Innovation Hub, JCAP aims to find a cost-effective method to produce fuels using only sunlight, water, and carbon dioxide as inputs. JCAP brings together more than 140 top scientists and researchers from the California Institute of Technology and its lead partner, Berkeley Lab, along with collaborators from the SLAC National Accelerator Laboratory, and the University of California campuses at Irvine and San Diego.

Epoxide-functionalization of polyethyleneimine for synthesis of stable carbon dioxide adsorbent in temperature swing adsorption

PubMed Central

Choi, Woosung; Min, Kyungmin; Kim, Chaehoon; Ko, Young Soo; Jeon, Jae Wan; Seo, Hwimin; Park, Yong-Ki; Choi, Minkee

2016-01-01

Amine-containing adsorbents have been extensively investigated for post-combustion carbon dioxide capture due to their ability to chemisorb low-concentration carbon dioxide from a wet flue gas. However, earlier studies have focused primarily on the carbon dioxide uptake of adsorbents, and have not demonstrated effective adsorbent regeneration and long-term stability under such conditions. Here, we report the versatile and scalable synthesis of a functionalized-polyethyleneimine (PEI)/silica adsorbent which simultaneously exhibits a large working capacity (2.2 mmol g−1) and long-term stability in a practical temperature swing adsorption process (regeneration under 100% carbon dioxide at 120 °C), enabling the separation of concentrated carbon dioxide. We demonstrate that the functionalization of PEI with 1,2-epoxybutane reduces the heat of adsorption and facilitates carbon dioxide desorption (>99%) during regeneration compared with unmodified PEI (76%). Moreover, the functionalization significantly improves long-term adsorbent stability over repeated temperature swing adsorption cycles due to the suppression of urea formation and oxidative amine degradation. PMID:27572662

Determination of the wine preservative sulphur dioxide with cyclic voltammetry using inkjet printed electrodes.

PubMed

Schneider, Marion; Türke, Alexander; Fischer, Wolf-Joachim; Kilmartin, Paul A

2014-09-15

During winemaking sulphur dioxide is added to prevent undesirable reactions. However, concerns over the harmful effects of sulphites have led to legal limits being placed upon such additives. There is thus a need for simple and selective determinations of sulphur dioxide in wine, especially during winemaking. The simultaneous detection of polyphenols and sulphur dioxide, using cyclic voltammetry at inert electrodes is challenging due to close oxidation potentials. In the present study, inkjet printed electrodes were developed with a suitable voltammetric signal on which the polyphenol oxidation is suppressed and the oxidation peak height for sulphur dioxide corresponds linearly to the concentration. Different types of working electrodes were printed. Electrodes consisting of gold nanoparticles mixed with silver showed the highest sensitivity towards sulphur dioxide. Low cost production of the sensor elements and ultra fast determination of sulphur dioxide by cyclic voltammetry makes this technique very promising for the wine industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Separation of Carbon Monoxide and Carbon Dioxide for Mars ISRU

NASA Technical Reports Server (NTRS)

Walton, Krista S.; LeVan, M. Douglas

2004-01-01

The atmosphere of Mars has many resources that can be processed to produce things such as oxygen, fuel, buffer gas, and water for support of human exploration missions. Successful manipulation of these resources is crucial for safe, cost-effective, and self-sufficient long-term human exploration of Mars. In our research, we are developing enabling technologies that require fundamental knowledge of adsorptive gas storage and separation processes. In particular, we are designing and constructing an innovative, low mass, low power separation device to recover carbon dioxide and carbon monoxide for Mars ISRU (in-situ resource utilization). The technology has broad implications for gas storage and separations for gas-solid systems that are ideally suited for reduced gravitational environments. This paper describes our separation process design and experimental procedures and reports results for the separation of CO2 and CO by a four-step adsorption cycle.

Outdoor air pollution and asthma

PubMed Central

Guarnieri, Michael; Balmes, John R.

2015-01-01

Traffic and power generation are the main sources of urban air pollution. The idea that outdoor air pollution can cause exacerbations of pre-existing asthma is supported by an evidence base that has been accumulating for several decades, with several studies suggesting a contribution to new-onset asthma as well. In this Series paper, we discuss the effects of particulate matter (PM), gaseous pollutants (ozone, nitrogen dioxide, and sulphur dioxide), and mixed traffic-related air pollution. We focus on clinical studies, both epidemiological and experimental, published in the previous 5 years. From a mechanistic perspective, air pollutants probably cause oxidative injury to the airways, leading to inflammation, remodelling, and increased risk of sensitisation. Although several pollutants have been linked to new-onset asthma, the strength of the evidence is variable. We also discuss clinical implications, policy issues, and research gaps relevant to air pollution and asthma. PMID:24792855

Effects of a silica-based feed supplement on performance, health, and litter quality of growing turkeys.

PubMed

Tran, S T; Bowman, M E; Smith, T K

2015-08-01

Poor litter quality is a potential challenge to footpad health as well as the primary cause of ammonia volatilization. High ambient ammonia concentration is one of the most significant factors negatively affecting poultry production today. Some minerals have been reported to reduce ammonia release from poultry litter. Silicon dioxide, a highly pure and natural mineral, shows promise in decreasing ammonia volatilization and improving litter quality. The objective of the current study was to investigate the effects of feed-borne silicon dioxide on litter quality and how this impacts bird performance, general health and footpad health throughout a 12-wk posthatching turkey study. Supplementing the diet with silicon dioxide was found to significantly improve turkey BW gain and the efficiency of feed conversion. The severity of footpad dermatitis was monitored throughout the experimental period but no significant effect of diet was seen. The feeding of silicon dioxide reduced litter pH which decreased the conversion of NH4⁺ to NH3 thereby reducing nitrogen losses from litter. It was concluded that, under our study conditions, the feeding of 0.02% silicon dioxide offers potential economic benefits to turkey producers. © 2015 Poultry Science Association Inc.

Synergistic effects of exposure to concentrated ambient fine pollution particles and nitrogen dioxide in humans

EPA Science Inventory

Exposure to single pollutants such as ambient particulate matter (PM) is associated with adverse health effects. It is unclear, however, if simultaneous exposure to multiple air pollutants (e.g. PM and ozone or nitrogen dioxide), a more real world scenario, results in non-additiv...

Non-thermal inactivation of Noroviruses in food

NASA Astrophysics Data System (ADS)

Velebit, B.; Petronijević, R.; Bošković, T.

2017-09-01

An increased incidence of foodborne illnesses caused by Norovirus and consumer demand for fresh, convenient, and safe foods have prompted research into alternative antiviral processing technologies. Chlorine dioxide, UV treatment and thermal processing are standard antinoroviral technologies that have been employed for a while; however, they tend to be non-effective in modern processing due to residue concerns (ClO2), shadowing effects (UV) and low-energy efficiency (heat treatment). Alternative technologies have been validated such as ozone treatment, high pressure processing and pulse electric fields. Although these techniques are promising, none of them individually can deem food free of Norovirus. Further research on the effects on Norovirus in various food matrices is required. Good manufacturing practices and proper sanitation procedures remain the “gold” safety tools in food business.

The effect of doping titanium dioxide nanoparticles on phase transformation, photocatalytic activity and anti-bacterial properties

NASA Astrophysics Data System (ADS)

Buzby, Scott Edward

Nanosized titanium dioxide has a variety of important applications in everyday life including a photocatalyst for pollution remediation, photovoltaic devices, sunscreen, etc. This study focuses on the various properties of titanium dioxide nanoparticles doped with various cation and anion species. Samples were produced by various methods including metalorganic chemical vapor deposition (MOCVD), plasma assisted metalorganic chemical vapor deposition (PA-MOCVD) and sol-gel. Numerous techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron microscopy both scanning (SEM) and transmission (TEM) were used for physical characterization. Photocatalytic properties were determined by the oxidation of methylene blue dye and 2-chlorophenol in water as well as gaseous formic acid with results analyzed by high performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and ultra violet - visible spectroscopy (UV-VIS). For the purpose of enhancement of the photocatalytic activity of titanium dioxide nanoparticles, the effect of anion doping and the anatase-rutile phase ratio were studied. Although anatase, rutile and mixed crystallite phases all show some degree of activity in photocatalytic reactions, these results show that anatase is better suited for the degradation of organic compounds in an aqueous medium any advantage in photocatalytic activity gained through the enhancement in optical response from the smaller band gap by addition of rutile was overcome by the negatives associated with the rutile phase. Furthermore substitutional nitrogen doping showed significant improvement in UV photocatalysis as well as allowing for visible light activation of the catalyst. Further studies on the phase transitions in titanium dioxide nanoparticles were carried out by synthesizing various cation doped samples by sol-gel. Analysis of the phases by XRD showed an inverse relationship between dopant size and rutile percentage. Dopant ions with larger radii than titanium stress the crystal lattice promoting anatase formation, since it has a larger c/a ratio than rutile does. The cation dopants were also found to decrease the average particle size of the titanium dioxide nanoparticles. The defect sites caused by the doping prevent the nucleation and retard particle growth of titanium dioxide particles. Cation doping of titanium dioxide nanoparticles affect other properties of the nanoparticles besides the phase transitions. For example titanium dioxide doped with magnetic materials such as Fe, Ni, Co or Cr has been shown to display room temperature ferromagnetism which are currently being studied for use in spintronic devices. The antibacterial studies of silver doped titanium dioxide nanoparticles were carried out against Escherichia coli, both in nutrient solution and on agar-plates. Both studies show that while pure titanium dioxide has no antibacterial effect, when doped with as little as 0.72 atomic % silver becomes more effective than pure silver nanoparticles of similar size. It has been observed that with concentrations as low as 25mug/cm 2 of silver doped titanium dioxide, completely antibacterial surfaces may be synthesized.

Detecting the global and regional effects of sulphate aerosol geoengineering

NASA Astrophysics Data System (ADS)

Lo, Eunice; Charlton-Perez, Andrew; Highwood, Ellie

2017-04-01

Climate warming is unequivocal. In addition to carbon dioxide emission mitigation, some geoengineering ideas have been proposed to reduce future surface temperature rise. One of these proposals involves injecting sulphate aerosols into the stratosphere to increase the planet's albedo. Monitoring the effectiveness of sulphate aerosol injection (SAI) would require us to be able to distinguish and detect its cooling effect from the climate system's internal variability and other externally forced temperature changes. This research uses optimal fingerprinting techniques together with simulations from the GeoMIP data base to estimate the number of years of observations that would be needed to detect SAI's cooling signal in near-surface air temperature, should 5 Tg of sulphur dioxide be injected into the stratosphere per year on top of RCP4.5 from 2020-2070. The first part of the research compares the application of two detection methods that have different null hypotheses to SAI detection in global mean near-surface temperature. The first method assumes climate noise to be dominated by unforced climate variability and attempts to detect the SAI cooling signal and greenhouse gas driven warming signal in the "observations" simultaneously against this noise. The second method considers greenhouse gas driven warming to be a non-stationary background climate and attempts to detect the net cooling effect of SAI against this background. Results from this part of the research show that the conventional multi-variate detection method that has been extensively used to attribute climate warming to anthropogenic sources could also be applied for geoengineering detection. The second part of the research investigates detection of geoengineering effects on the regional scale. The globe is divided into various sub-continental scale regions and the cooling effect of SAI is looked for in the temperature time series in each of these regions using total least squares multi-variate detection. Results show that surface temperature observations would be most useful for SAI detection in the Northern Hemisphere mid-latitudes, especially in East Asia. This can be used to indicate the optimal observational network for monitoring the effectiveness of SAI in the future, should that be needed.

A new method of applying a controlled soil water stress, and its effect on the growth of cotton and soybean seedlings at ambient and elevated carbon dioxide

USDA-ARS?s Scientific Manuscript database

While numerous studies have shown that elevated carbon dioxide can delay soil water depletion by causing partial stomatal closure, few studies have compared responses of plant growth to the same soil water deficits imposed at ambient and elevated carbon dioxide. We applied a vacuum to ceramic cups ...

Volcanic CO2 abundance of Kilauea plume retrieved by means of AVIRIS data

NASA Technical Reports Server (NTRS)

Pieri, David; Spinetti, C.; Carrere, V.; Buongiorno, M. F.

2004-01-01

Absorbing the electromagnetic radiation in several regions of the solar spectrum, C02 plays an important role in the Earth radiation budget since it produces the greenhouse effect. Many natural processes in the Earth's system add and remove carbon dioxide. Overall, measurements of atmospheric carbon dioxide at different sites around the world show an increased carbon dioxide concentration in the atmosphere.

Spacecraft cabin environment effects on the growth and behavior of Chlorella vulgaris for life support applications

NASA Astrophysics Data System (ADS)

Niederwieser, Tobias; Kociolek, Patrick; Klaus, David

2018-02-01

An Environmental Control and Life Support System (ECLSS) is necessary for humans to survive in the hostile environment of space. As future missions move beyond Earth orbit for extended durations, reclaiming human metabolic waste streams for recycled use becomes increasingly important. Historically, these functions have been accomplished using a variety of physical and chemical processes with limited recycling capabilities. In contrast, biological systems can also be incorporated into a spacecraft to essentially mimic the balance of photosynthesis and respiration that occurs in Earth's ecosystem, along with increasing the reuse of biomass throughout the food chain. In particular, algal photobioreactors that use Chlorella vulgaris have been identified as potential multifunctional components for use as part of such a bioregenerative life support system (BLSS). However, a connection between the biological research examining C. vulgaris behavior and the engineered spacecraft cabin environmental conditions has not yet been thoroughly established. This review article characterizes the ranges of prior and expected cabin parameters (e.g. temperature, lighting, carbon dioxide, pH, oxygen, pressure, growth media, contamination, gravity, and radiation) and reviews algal metabolic response (e.g. growth rate, composition, carbon dioxide fixation rates, and oxygen evolution rates) to changes in those parameters that have been reported in prior space research and from related Earth-based experimental observations. Based on our findings, it appears that C. vulgaris offers many promising advantages for use in a BLSS. Typical atmospheric conditions found in spacecraft such as elevated carbon dioxide levels are, in fact, beneficial for algal cultivation. Other spacecraft cabin parameters, however, introduce unique environmental factors, such as reduced total pressure with elevated oxygen concentration, increased radiation, and altered gravity, whose effects on the biological responses of C. vulgaris are not yet well understood. A summary of optimum growth parameter ranges for C. vulgaris is presented in this article as a guideline for designing and integrating an algal photobioreactor into a spacecraft life support system. Additional research challenges for evaluating as of yet uncharacterized parameters are also identified in this article that have the potential for improving spaceflight applications as well as terrestrial aquatic algal cultivation systems.

Capacitance-Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation.

PubMed

Lamb, Katie J; Dowsett, Mark R; Chatzipanagis, Konstantinos; Scullion, Zhan Wei; Kröger, Roland; Lee, James D; Aguiar, Pedro M; North, Michael; Parkin, Alison

2018-01-10

An electrochemical cell comprising a novel dual-component graphite and Earth-crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero-carbon energy source. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Acute exposure of symptomatic steelworkers to sulphur dioxide and carbon dust: effects on mucociliary transport, pulmonary function, and bronchial reactivity.

PubMed Central

Wolff, R K; Obminski, G; Newhouse, M T

1984-01-01

Nine steel workers participated in controlled exposures to sulphur dioxide alone and sulphur dioxide plus carbon dust (5 ppm and 10 mg/m3, respectively). All were experiencing work related respiratory difficulties. Bronchial clearance was measured using radioaerosol inhalations and external detection. Results were variable and no statistically significant changes were observed. One asthmatic showed a complete cessation of clearance during exposure to sulphur dioxide and carbon dust. Bronchial reactivity was found to be significantly raised after exposure to sulphur dioxide but equivocal results were found after exposure to sulphur dioxide and carbon dust. Pronounced changes in pulmonary function were seen only in the two asthmatic subjects. They could not tolerate the levels, indicating that these threshold limit values are too high, at least for these individuals who showed much greater sensitivity to the pollutants than the others. PMID:6498113

Effect of Novel Quercetin Titanium Dioxide-Decorated Multi-Walled Carbon Nanotubes Nanocomposite on Bacillus subtilis Biofilm Development

PubMed Central

Raie, Diana S.; Mhatre, Eisha; El-Desouki, Doaa S.; Labena, Ahmed; El-Ghannam, Gamal; Farahat, Laila A.; Youssef, Tareq; Fritzsche, Wolfgang; Kovács, Ákos T.

2018-01-01

The present work was targeted to design a surface against cell seeding and adhering of bacteria, Bacillus subtilis. A multi-walled carbon nanotube/titanium dioxide nano-power was produced via simple mixing of carbon nanotube and titanium dioxide nanoparticles during the sol-gel process followed by heat treatment. Successfully, quercetin was immobilized on the nanocomposite via physical adsorption to form a quercetin/multi-walled carbon nanotube/titanium dioxide nanocomposite. The adhesion of bacteria on the coated-slides was verified after 24 h using confocal laser-scanning microscopy. Results indicated that the quercetin/multi-walled carbon nanotube/titanium dioxide nanocomposite had more negativity and higher recovery by glass surfaces than its counterpart. Moreover, coating surfaces with the quercetin-modified nanocomposite lowered both hydrophilicity and surface-attached bacteria compared to surfaces coated with the multi-walled carbon nanotubes/titanium dioxide nanocomposite. PMID:29346268

Ozone and carbon dioxide fluxes in a subalpine spruce-fir forest ecosystem

Treesearch

Karl Zeller

1995-01-01

RMFRES RWU 4452 has made several ozone (O3) and carbon dioxide (CO2) trace gas flux measurements in the Snowy Range, WY GLEES research area over the past few years. These measurements were made using the micrometeorological eddy correlation technique at two sites: one 6 m above tree canopy height on the Brooklyn tower (ozone only); and the other below canopy height, 1-...

Carbon dioxide/brine wettability of porous sandstone versus solid quartz: An experimental and theoretical investigation.

PubMed

Alnili, Firas; Al-Yaseri, Ahmed; Roshan, Hamid; Rahman, Taufiq; Verall, Michael; Lebedev, Maxim; Sarmadivaleh, Mohammad; Iglauer, Stefan; Barifcani, Ahmed

2018-08-15

Wettability plays an important role in underground geological storage of carbon dioxide because the fluid flow and distribution mechanism within porous media is controlled by this phenomenon. CO 2 pressure, temperature, brine composition, and mineral type have significant effects on wettability. Despite past research on this subject, the factors that control the wettability variation for CO 2 /water/minerals, particularly the effects of pores in the porous substrate on the contact angle at different pressures, temperatures, and salinities, as well as the physical processes involved are not fully understood. We measured the contact angle of deionised water and brine/CO 2 /porous sandstone samples at different pressures, temperatures, and salinities. Then, we compared the results with those of pure quartz. Finally, we developed a physical model to explain the observed phenomena. The measured contact angle of sandstone was systematically greater than that of pure quartz because of the pores present in sandstone. Moreover, the effect of pressure and temperature on the contact angle of sandstone was similar to that of pure quartz. The results showed that the contact angle increases with increase in temperature and pressure and decreases with increase in salinity. Copyright © 2018 Elsevier Inc. All rights reserved.

The use of chlorine dioxide for the inactivation of copepod zooplankton in drinking water treatment.

PubMed

Lin, Tao; Chen, Wei; Cai, Bo

2014-01-01

The presence of zooplankton in drinking water treatment system may cause a negative effect on the aesthetic value of drinking water and may also increase the threat to human health due to they being the carriers of bacteria. Very little research has been done on the effects of copepod inactivation and the mechanisms involved in this process. In a series of bench-scale experiments we used a response surface method to assess the sensitivity of copepod to inactivation when chlorine dioxide (ClO₂) was used as a disinfectant. We also assessed the effects of the ClO₂dosage, exposure time, organic matter concentration and temperature. Results indicated that the inactivation rate improved with increasing dosage, exposure time and temperature, whereas it decreased with increasing organic matter concentration. Copepod inactivation was more sensitive to the ClO₂dose than that to the exposure time, while being maintained at the same Ct-value conditions. The activation energy at different temperatures revealed that the inactivation of copepods with ClO₂was temperature-dependent. The presence of organic matter resulted in a lower available dose as well as a shorter available exposure time, which resulted in a decrease in inactivation efficiency.

Carbon dioxide warming of the early Earth

NASA Technical Reports Server (NTRS)

Arrhenius, G.

1997-01-01

Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure.

Carbon dioxide warming of the early Earth.

PubMed

Arrhenius, G

1997-02-01

Svante Arrhenius' research in atmospheric physics extended beyond the recent past and the near future states of the Earth, which today are at the center of sociopolitical attention. His plan encompassed all of the physical phenomena known at the time to relate to the formation and evolution of stars and planets. His two-volume textbook on cosmic physics is a comprehensive synopsis of the field. The inquiry into the possible cause of the ice ages and the theory of selective wavelength filter control led Arrhenius to consider the surface states of the other terrestrial planets, and of the ancient Earth before it had been modified by the emergence of life. The rapid escape of hydrogen and the equilibration with igneous rocks required that carbon in the early atmosphere prevailed mainly in oxidized form as carbon dioxide, together with other photoactive gases exerting a greenhouse effect orders of magnitude larger than in our present atmosphere. This effect, together with the ensuing chemical processes, would have set the conditions for life to evolve on our planet, seeded from spores spreading through an infinite Universe, and propelled, as Arrhenius thought, by stellar radiation pressure.

Effect of Same-day Sequential Exposure to Nitrogen Dioxide and Ozone on Cardiac and Ventilatory Function in Mice

EPA Science Inventory

This study examines the cardiac and ventilatory effects of sequential exposure to nitrogen dioxide and then ozone. The data show that mice exposed to both gases have increased arrhythmia and breathing changes not observed in the other groups. Although the mechanisms underlying ai...

Air Pollution and Its Effects on an Individual's Health and Exercise Performance.

ERIC Educational Resources Information Center

Singh, A. I. Clifford

1988-01-01

Air Pollution is a common environmental stressor affecting the training and competitive performance of athletes, commonly irritating the eyes, nose, and throat. The health and exercise effects of such primary and secondary air pollutants as carbon monoxide, sulfur dioxide, air particulates, ozone, and nitrogen dioxide are discussed. (CB)

The effectiveness of closed-circulation gaseous chlorine dioxide or ozone treatment against bacterial pathogens on produce food control

USDA-ARS?s Scientific Manuscript database

The objective of this study was to compare the effectiveness of gaseous chlorine dioxide (ClO2) and ozone (O3) treatment against Shiga toxin-producing Escherichia coli (STEC), Salmonella enterica serovars, and Listeria monocytogenes on baby-cut carrots, lowbush blueberries, and beefsteak tomatoes us...

Cerebral blood flow response to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in children

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kern, F.H.; Ungerleider, R.M.; Quill, T.J.

1991-04-01

We examined the relationship of changes in partial pressure of carbon dioxide on cerebral blood flow responsiveness in 20 pediatric patients undergoing hypothermic cardiopulmonary bypass. Cerebral blood flow was measured during steady-state hypothermic cardiopulmonary bypass with the use of xenon 133 clearance methodology at two different arterial carbon dioxide tensions. During these measurements there was no significant change in mean arterial pressure, nasopharyngeal temperature, pump flow rate, or hematocrit value. Cerebral blood flow was found to be significantly greater at higher arterial carbon dioxide tensions (p less than 0.01), so that for every millimeter of mercury rise in arterial carbonmore » dioxide tension there was a 1.2 ml.100 gm-1.min-1 increase in cerebral blood flow. Two factors, deep hypothermia (18 degrees to 22 degrees C) and reduced age (less than 1 year), diminished the effect carbon dioxide had on cerebral blood flow responsiveness but did not eliminate it. We conclude that cerebral blood flow remains responsive to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in infants and children; that is, increasing arterial carbon dioxide tension will independently increase cerebral blood flow.« less

Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinert, R.A.; Sanders, J.S.

Radish and marigold plants were exposed to 0.3 ppm of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and/or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in the presencemore » of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 3/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present.« less

Inactivation of Salmonella on Eggshells by Chlorine Dioxide Gas

PubMed Central

Yum, Bora; Yoon, Sung-Sik; Song, Kyoung-Ju; Kim, Jong-Rak

2016-01-01

Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO2 gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO2 each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry. PMID:27499670

Portable Unit for Metabolic Analysis

NASA Technical Reports Server (NTRS)

Dietrich, Daniel L.; Pitch, Nancy D.; Lewis, Mark E.; Juergens, Jeffrey R.; Lichter, Michael J.; Stuk, Peter M.; Diedrick, Dale M.; Valentine, Russell W.; Pettegrew, Richard D.

2007-01-01

The Portable Unit for Metabolic Analysis (PUMA) is an instrument that measures several quantities indicative of human metabolic function. Specifically, this instrument makes time-resolved measurements of temperature, pressure, flow, and the partial pressures of oxygen and carbon dioxide in breath during both inhalation and exhalation. Portable instruments for measuring these quantities have been commercially available, but the response times of those instruments are too long to enable temporal resolution of phenomena on the time scales of human respiration cycles. In contrast, the response time of the PUMA is significantly shorter than characteristic times of human respiration phenomena, making it possible to analyze varying metabolic parameters, not only on sequential breath cycles but also at successive phases of inhalation and exhalation within the same breath cycle. In operation, the PUMA is positioned to sample breath near the subject s mouth. Commercial off-the-shelf sensors are used for three of the measurements: a miniature pressure transducer for pressure, a thermistor for temperature, and an ultrasonic sensor for flow. Sensors developed at Glenn Research Center are used for measuring the partial pressures of oxygen and carbon dioxide: The carbon dioxide sensor exploits the relatively strong absorption of infrared light by carbon dioxide. Light from an infrared source passes through the stream of inhaled or exhaled gas and is focused on an infrared- sensitive photodetector. The oxygen sensor exploits the effect of oxygen in quenching the fluorescence of ruthenium-doped organic molecules in a dye on the tip of an optical fiber. A blue laser diode is used to excite the fluorescence, and the optical fiber carries the fluorescent light to a photodiode, the temporal variation of the output of which bears a known relationship with the rate of quenching of fluorescence and, hence, with the partial pressure of oxygen. The outputs of the sensors are digitized, preprocessed by a small onboard computer, and then sent wirelessly to a desktop computer, where the collected data are analyzed and displayed. In addition to the raw data on temperature, pressure, flow, and mole fractions of oxygen and carbon dioxide, the display can include volumetric oxygen consumption, volumetric carbon dioxide production, respiratory equivalent ratio, and volumetric flow rate of exhaled gas.

Reducing the environmental impact of trials: a comparison of the carbon footprint of the CRASH-1 and CRASH-2 clinical trials

PubMed Central

2011-01-01

Background All sectors of the economy, including the health research sector, must reduce their carbon emissions. The UK National Institute for Health Research has recently prepared guidelines on how to minimize the carbon footprint of research. We compare the carbon emissions from two international clinical trials in order to identify where emissions reductions can be made. Methods We conducted a carbon audit of two clinical trials (the CRASH-1 and CRASH-2 trials), quantifying the carbon dioxide emissions produced over a one-year audit period. Carbon emissions arising from the coordination centre, freight delivery, trial-related travel and commuting were calculated and compared. Results The total emissions in carbon dioxide equivalents during the one-year audit period were 181.3 tonnes for CRASH-1 and 108.2 tonnes for CRASH-2. In total, CRASH-1 emitted 924.6 tonnes of carbon dioxide equivalents compared with 508.5 tonnes for CRASH-2. The CRASH-1 trial recruited 10,008 patients over 5.1 years, corresponding to 92 kg of carbon dioxide per randomized patient. The CRASH-2 trial recruited 20,211 patients over 4.7 years, corresponding to 25 kg of carbon dioxide per randomized patient. The largest contributor to emissions in CRASH-1 was freight delivery of trial materials (86.0 tonnes, 48% of total emissions), whereas the largest contributor in CRASH-2 was energy use by the trial coordination centre (54.6 tonnes, 30% of total emissions). Conclusions Faster patient recruitment in the CRASH-2 trial largely accounted for its greatly increased carbon efficiency in terms of emissions per randomized patient. Lighter trial materials and web-based data entry also contributed to the overall lower carbon emissions in CRASH-2 as compared to CRASH-1. Trial Registration Numbers CRASH-1: ISRCTN74459797 CRASH-2: ISRCTN86750102 PMID:21291517

Effects of chronic and acute exposure to sulphur dioxide on the growth of hybrid poplar cuttings

Treesearch

Leon S. Dochinger; Keith F. Jensen

1975-01-01

Hybrid poplar clones were fumigated in controlled-environment chambers with either 5 ppm sulphur dioxide for 1½, 3, and 6 h or with 0.25 ppm sulphur dioxide for six weeks. Multivariate analyses were made from shoot-growth data before and after treatment and on the foliar injury induced by S02. Both short- and long-term fumigation produced similar...

Toxic Hazards Research Unit

NASA Technical Reports Server (NTRS)

Macewen, J. D.; Vernot, E. H.

1971-01-01

The activities of the Toxic Hazards Research Unit (THRU) for the period of June 1970 through May 1971 reviewed. Modification of the animal exposure facilities primarily for improved human safety but also for experimental integrity and continuity are discussed. Acute toxicity experiments were conducted on hydrogen fluoride (HF), hydrogen chloride (HCl), nitrogen dioxide (NO2), and hydrogen cyanide (HCN) both singly and in combination with carbon dioxide (CO). Additional acute toxicity experiments were conducted on oxygen difluoride (OF2) and chlorine pentafluoride (ClF5). Subacute toxicity studies were conducted on methylisobutylketone and dichloromethane (methylene dichloride). The interim results of further chronic toxicity experiments on monomethylhydrazine (MMH) are also described.

Effects of Carbon Dioxide and Oxygen Levels on Auditory Sensitivity and Frequency Tuning as Measured by the Stimulus Frequency Otoacoustic Emission Test

DTIC Science & Technology

2009-09-14

support of this project in arranging diver schedules so they could serve as study participants. The authors also wish to thank staff at Mimosa Acoustics...however, has now been implemented in a commercial unit, the Mimosa Acoustics SFOAE system. SFOAEs potentially provide more frequency-specific...Medical Research Laboratory, Massachusetts Eye and Ear Infirmary, and Mimosa Acoustics, Inc. (Lapsley Miller, Boege, Marshall, Shera, and Jeng, 2004

Fire suppression in human-crew spacecraft

NASA Technical Reports Server (NTRS)

Friedman, Robert; Dietrich, Daniel L.

1991-01-01

Fire extinguishment agents range from water and foam in early-design spacecraft (Halon 1301 in the present Shuttle) to carbon dioxide proposed for the Space Station Freedom. The major challenge to spacecraft fire extinguishment design and operations is from the micro-gravity environment, which minimizes natural convection and profoundly influences combustion and extinguishing agent effectiveness, dispersal, and post-fire cleanup. Discussed here are extinguishment in microgravity, fire-suppression problems anticipated in future spacecraft, and research needs and opportunities.

Boundary Layer Study. Experimental Validation Test Plan. Phase 4

DTIC Science & Technology

1990-11-01

34 Ph.D. Thesis. 2. "The Importance of Soot Particles and Nitrous Acid in Oxidizing 802 in Atmospheric Aqueous Droplets," with S.G. Chang and T. Novakov ...4. "Lifetime of Aerosol Droplets in Ambient Air: Consideration of the Effects of Surfactants and Chemical Reaction," with T. Novakov Atmgsoheric...California, 1975. 6. "Sulfur Dioxide Oxidation in a Dispersing Plumse," with S.G. Chang and T. Novakov , Atmosnherlic Aerosol Research Annual Report

Theoretical-Experimental Analysis of the Effects of Grain Boundaries on the Electrical Properties of SOI (Silicon-on-Insulator) MOSFETS.

DTIC Science & Technology

1983-11-01

work on recrystallization of polycrystalline silicon ( polysilicon ) films deposited on silicon-dioxide has demonstrated remarkable improvement in film...quality, and thus has identified another possibly viable 1SO technology for ICs. The polysilicon -on-S10 2 technology not only has the advantages alluded...and consequently higher areal device densities. Virtually all the research to date on polysilicon -on-SiO 2 has concentrated on the

Detecting the climatic effects of increasing carbon dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacCracken, M C; Luther, F M

1985-12-01

This report documents what is known about detecting the CO2-induced changes in climate, and describes the uncertainties and unknowns associated with this monitoring and analysis effort. The various approaches for detecting CO2-induced climate changes are discussed first, followed by a review of applications of these strategies to the various climatic variables that are expected to be changing. Recommendations are presented for research and analysis activities. Separate abstracts have been prepared for the individual papers. (ACR)

Utilization of heat from High Temperature Reactors (HTR) for dry reforming of methane

NASA Astrophysics Data System (ADS)

Jastrząb, Krzysztof

2018-01-01

One of the methods for utilization of waste carbon dioxide consists in reaction of methane with carbon dioxide, referred to as dry reforming of methane. It is an intensely endothermic catalytic process that takes place at the temperature above 700°C. Reaction of methane with carbon dioxide leads to formation of synthesis gas (syngas) that is a valuable chemical raw material. The energy that is necessary for the process to take place can be sourced from High Temperature Nuclear Reactors (HTR). The completed studies comprises a series of thermodynamic calculations and made it possible to establish optimum conditions for the process and demand for energy from HTR units. The dry reforming of methane needs also a catalytic agent with appropriate activity, therefore the hydrotalcite catalyser with admixture of cerium and nickel, developed at AGH University of Technology seems to be a promising solution. Thus, the researchers from the Institute for Chemical Processing of Coal (IChPW) in Zabrze have developed a methodology for production of the powdery hydrotalcite catalyser and investigated catalytic properties of the granulate obtained. The completed experiments confirmed that the new catalyser demonstrated high activity and is suitable for the process of methane dry reforming. In addition, optimum parameters of the were process (800°C, CO2:CH4 = 3:1) were established as well. Implementation of the technology in question into industrial practice, combined with utilization of HTR heat can be a promising method for management of waste carbon dioxide and may eventually lead to mitigation of the greenhouse effect.

Estimates of Fossil Fuel Carbon Dioxide Emissions From Mexico at Monthly Time Intervals

NASA Astrophysics Data System (ADS)

Losey, L. M.; Andres, R. J.

2003-12-01

Human consumption of fossil fuels has greatly contributed to the rise of carbon dioxide in the Earth's atmosphere. To better understand the global carbon cycle, it is important to identify the major sources of these fossil fuels. Mexico is among the top fifteen nations in the world for producing fossil fuel carbon dioxide emissions. Based on this information and that emissions from Mexico are a focus of the North American Carbon Program, Mexico was selected for this study. Mexican monthly inland sales volumes for January 1988-May 2003 were collected on natural gas and liquid fuels from the Energy Information Agency in the United States Department of Energy. These sales figures represent a major portion of the total fossil fuel consumption in Mexico. The fraction of a particular fossil fuel consumed in a given month was determined by dividing the monthly sales volumes by the annual sum of monthly sales volumes for a given year. This fraction was then multiplied by the annual carbon dioxide values reported by the Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL) to estimate the monthly carbon dioxide emissions from the respective fuels. The advantages of this methodology are: 1) monthly fluxes are consistent with the annual flux as determined by the widely-accepted CDIAC values, and 2) its general application can be easily adapted to other nations for determining their sub-annual time scale emissions. The major disadvantage of this methodology is the proxy nature inherent to it. Only a fraction of the total emissions are used as an estimate in determining the seasonal cycle. The error inherent in this approach increases as the fraction of total emissions represented by the proxy decreases. These data are part of a long-term project between researchers at the University of North Dakota and ORNL which attempts to identify and understand the source(s) of seasonal variations of global, fossil-fuel derived, carbon dioxide emissions. Better knowledge of the temporal variation of the annual fossil fuel flux will lead to a better understanding of the global carbon cycle. This research will be archived at CDIAC for public access.

Sodium hypochlorite-, chlorine dioxide- and peracetic acid-induced genotoxicity detected by the Comet assay and Saccharomyces cerevisiae D7 tests.

PubMed

Buschini, Annamaria; Carboni, Pamela; Furlini, Mariangela; Poli, Paola; Rossi, Carlo

2004-03-01

Mutagenicity of drinking water is due not only to industrial, agricultural and urban pollution but also to chlorine disinfection by-products. Furthermore, residual disinfection is used to provide a partial safeguard against low level contamination and bacterial re-growth within the distribution system. The aims of this study were to further evaluate the genotoxic potential of the world wide used disinfectants sodium hypochlorite and chlorine dioxide in human leukocytes by the Comet assay and in Saccharomyces cerevisiae strain D7 (mitotic gene conversion, point mutation and mitochondrial DNA mutability, with and without endogenous metabolic activation) and to compare their effects with those of peracetic acid, proposed as an alternative disinfectant. All three disinfectants are weakly genotoxic in human leukocytes (lowest effective dose 0.2 p.p.m. for chlorine dioxide, 0.5 p.p.m. for sodium hypochlorite and peracetic acid). The results in S.cerevisiae show a genotoxic response on the end-points considered with an effect only at doses higher (5- to 10-fold) than the concentration normally used for water disinfection; sodium hypochlorite and peracetic acid are able to induce genotoxic effects without endogenous metabolic activation (in stationary phase cells) whereas chlorine dioxide is effective in growing cells. The Comet assay was more sensitive than the yeast tests, with effective doses in the range normally used for water disinfection processes. The biological effectiveness of the three disinfectants on S.cerevisiae proved to be strictly dependent on cell-specific physiological/biochemical conditions. All the compounds appear to act on the DNA and peracetic acid shows effectiveness similar to sodium hypochlorite and chlorine dioxide.

Revisiting the Scattering Greenhouse Effect of CO2 Ice Clouds

NASA Astrophysics Data System (ADS)

Kitzmann, D.

2016-02-01

Carbon dioxide ice clouds are thought to play an important role for cold terrestrial planets with thick CO2 dominated atmospheres. Various previous studies showed that a scattering greenhouse effect by carbon dioxide ice clouds could result in a massive warming of the planetary surface. However, all of these studies only employed simplified two-stream radiative transfer schemes to describe the anisotropic scattering. Using accurate radiative transfer models with a general discrete ordinate method, this study revisits this important effect and shows that the positive climatic impact of carbon dioxide clouds was strongly overestimated in the past. The revised scattering greenhouse effect can have important implications for the early Mars, but also for planets like the early Earth or the position of the outer boundary of the habitable zone.

International Collaboration on Air Pollution and Pregnancy Outcomes (ICAPPO)

PubMed Central

Woodruff, Tracey J.; Parker, Jennifer D.; Adams, Kate; Bell, Michelle L.; Gehring, Ulrike; Glinianaia, Svetlana; Ha, Eun-Hee; Jalaludin, Bin; Slama, Rémy

2010-01-01

Reviews find a likely adverse effect of air pollution on perinatal outcomes, but variation of findings hinders the ability to incorporate the research into policy. The International Collaboration on Air Pollution and Pregnancy Outcomes (ICAPPO) was formed to better understand relationships between air pollution and adverse birth outcomes through standardized parallel analyses in datasets from different countries. A planning group with 10 members from 6 countries was formed to coordinate the project. Collaboration participants have datasets with air pollution values and birth outcomes. Eighteen research groups with data for approximately 20 locations in Asia, Australia, Europe, North America, and South America are participating, with most participating in an initial pilot study. Datasets generally cover the 1990s. Number of births is generally in the hundreds of thousands, but ranges from around 1,000 to about one million. Almost all participants have some measure of particulate matter, and most have ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide. Strong enthusiasm for participating and a geographically-diverse range of participants should lead to understanding uncertainties about the role of air pollution in perinatal outcomes and provide decision-makers with better tools to account for pregnancy outcomes in air pollution policies. PMID:20644693

Tiny and Hidden but Changing Your World: The Importance of Soil Microbes to Climate Change

NASA Astrophysics Data System (ADS)

Waldo, N.; Neumann, R. B.

2017-12-01

When most people think about global climate change they think about massive power plants billowing smoke and expansive glaciers melting to nothingness. What the public often overlooks is how natural processes invisible to the naked eye can be changed by the climate, and the fact that the natural response to those changes can further alter the climate. Scientists call these reactions "feedback cycles", and understanding them is crucial to predicting the true impact of human activities. In our research, we study one particular feedback cycle: the effect of increased plant productivity on methane emissions from wetlands. Globally, wetlands account for about a third of annual emissions of methane, the second most important greenhouse gas after carbon dioxide. This heat-trapping gas is generated in the soil of wetlands by microscopic organisms that consume, among other things, proteins and sugars released by the roots of plants. As the atmosphere becomes warmer and richer in carbon dioxide, these plants will grow larger and faster, releasing more of this microbe food into the soil. Our current research seeks to understand how that will affect the microbial ecosystem, and through it the emissions of methane gas.

The Formation of Ethane from Carbon Dioxide under Cold Plasma

NASA Astrophysics Data System (ADS)

Zhang, Xiu-ling; Zhang, Lin; Dai, Bin; Gong, Wei-min; Liu, Chang-hou

2001-04-01

Pulsed-corona plasma has been used as a new method for ethane dehydrogenation at low temperature and normal pressure using carbon dioxide as an oxidant in this paper. The effect of carbon dioxide content in the feed, power input, and flow rate of the reactants on the ethane dehydrogenation has been investigated. The experimental results show that the conversion of ethane increases with the increase in the amount of carbon dioxide in the feed. The yield of ethylene and acetylene decreases with the increase in the yield of carbon monoxide, indicating that the increased carbon dioxide leads to the part of ethylene and acetylene being oxidized to carbon monoxide. Power input is primarily an electrical parameter in pulsed-corona plasma, which plays an important role in reactant conversion and product formation. When the power input reaches 16 W, ethane conversion is 41.0% and carbon dioxide conversion is 26.3%. The total yield of ethylene and acetylene is 15.6%. The reduced flow rate of feed improves the conversion of ethane, carbon dioxide and the yield of acetylene, and induces carbon deposit as well.

Variation in Baiting Intensity Among CO2-Baited Traps Used to Collect Hematophagous Arthropods

PubMed Central

Springer, Yuri P.; Taylor, Jeffrey R.; Travers, Patrick D.

2015-01-01

Hematophagous arthropods transmit the etiological agents of numerous diseases and as a result are frequently the targets of sampling to characterize vector and pathogen populations. Arguably, the most commonly used sampling approach involves traps baited with carbon dioxide. We report results of a laboratory study in which the performance of carbon dioxide-baited traps was evaluated using measures of baiting intensity, the amount of carbon dioxide released per unit time during trap deployment. We evaluated the effects of trap design, carbon dioxide source, and wind speed on baiting intensity and documented significant effects of these factors on the length of sampling (time to baiting intensity = 0), maximum baiting intensity, and variation in baiting intensity during experimental trials. Among the three dry ice-baited trap types evaluated, traps utilizing insulated beverage coolers as dry ice containers sampled for the longest period of time, had the lowest maximum but most consistent baiting intensity within trials and were least sensitive to effects of wind speed and dry ice form (block vs. pellet) on baiting intensity. Results of trials involving traps baited with carbon dioxide released from pressurized cylinders suggested that this trap type had performance comparable to dry ice-baited insulated cooler traps but at considerably higher cost. PMID:26160803

Chlorine dioxide reactions with indoor materials during building disinfection: surface uptake.

PubMed

Hubbard, Heidi; Poppendieck, Dustin; Corsi, Richard L

2009-03-01

Chlorine dioxide received attention as a building disinfectant in the wake of Bacillus anthracis contamination of several large buildings in the fall of 2001. It is increasingly used for the disinfection of homes and other indoor environments afflicted by mold. However, little is known regarding the interaction of chlorine dioxide and indoor materials, particularly as related to the removal of chlorine dioxide from air. Such removal may be undesirable with respect to the subsequent formation of localized zones of depleted disinfectant concentrations and potential reductions in disinfection effectiveness in a building. The focus of this paper is on chlorine dioxide removal from air to each of 24 different indoor materials. Experiments were completed with materials housed in flow-through 48-L stainless steel chambers under standard conditions of 700 ppm chlorine dioxide inlet concentration, 75% relative humidity, 24 degrees C, and 0.5 h(-1) air changes. Chlorine dioxide concentration profiles, deposition velocities, and reaction probabilities are described in this paper. Deposition velocities and reaction probabilities varied over approximately 2 orders of magnitude across all materials. For most materials, deposition velocity decreased significantly over a 16-h disinfection period; that is, materials became smaller sinks for chlorine dioxide with time. Four materials (office partition, ceiling tile, medium density fiberboard, and gypsum wallboard) accounted for the most short- and long-term consumption of chlorine dioxide. Deposition velocity was observed to be a strong function of chlorine dioxide inlet concentration, suggesting the potential importance of chemical reactions on or within test materials.

Research on silicon microchannel array oxidation insulation technology and stress issues

NASA Astrophysics Data System (ADS)

Chai, Jin; Li, Mo; Liang, Yong-zhao; Yang, Ji-kai; Wang, Guo-zheng; Duanmu, Qing-duo

2013-08-01

Microchannel plate is widely used in the field of low light level night vision, photomultiplier, tubes, X-ray enhancer and so on. In order to meet the requirement of microchannel plate electron multiplier, we used the method of thermal oxidation to produce a thin film of silicon dioxide which could play a role in electric insulation. Silicon dioxide film has a high breakdown voltage, it can satisfy the high breakdown voltage requirements of electron multiplier. We should find the reasonable parameter values and preparation process in the oxidation so that the thickness and uniformity of the silicon dioxide layer would meet requirement. This article has been focused on researching and analyzing of the problem of oxide insulation and thermal stress in the process of production of silicon dioxide film. In this experiment, dry oxygen and wet oxygen were carried out respectively for 8 hours. The thickness of dry oxygen silicon dioxide films was 458 nm and wet oxygen silicon dioxide films was 1.4 μm. Under these conditions, the silicon microchannel is uniformity and neat, meanwhile the insulating layer's breakdown voltage was measured at 450 V after the wet oxygen oxidation. By using ANSYS finite element software, we analyze the thermal stress, which came from the microchannel oxygen processes, under the conditions of which ambient temperature was 27 ℃ and porosity was 64%, we simulated the thermal stress in the temperature of 1200 ℃ and 1000 ℃, finally we got the maximum equivalent thermal stress of 472 MPa and 403 MPa respectively. The higher thermal stress area was spread over Si-SiO2 interface, by simulate conditions 50% porosity silicon microchannel sample was selected for simulation analysis at 1100 ℃, we got the maximum equivalent thermal stress of 472 MPa, Thermal stress is the minimum value of 410 MPa.

A quantitative study on the absorption of gaseous chlorine dioxide onto lettuce leaf

USDA-ARS?s Scientific Manuscript database

Chlorine dioxide (ClO2) is an effective surface disinfectant and it is gaining interest in the food and pharmaceutical industries, due to its bacteriocide effects. One of the most promising applications of gaseous ClO2 is to be included in the headspace of food packaging systems for vapor-phase deco...

Serendipitous Policy Implications from Class-Size-Initiated Inquiry: IAQ?

ERIC Educational Resources Information Center

Achilles, C. M.; Prout, Jean; Finn, J. D.; Bobbett, Gordon C.

The level of carbon dioxide in a classroom can have a significant negative effect on teaching and learning. Carbon dioxide (CO2) level is affected by class size and time of day. Six urban schools were studied to characterize the effects of these three factors on different class sizes. Carbon monoxide, CO2, temperature, and relative humidity…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kitzmann, D., E-mail: daniel.kitzmann@csh.unibe.ch

Carbon dioxide ice clouds are thought to play an important role for cold terrestrial planets with thick CO{sub 2} dominated atmospheres. Various previous studies showed that a scattering greenhouse effect by carbon dioxide ice clouds could result in a massive warming of the planetary surface. However, all of these studies only employed simplified two-stream radiative transfer schemes to describe the anisotropic scattering. Using accurate radiative transfer models with a general discrete ordinate method, this study revisits this important effect and shows that the positive climatic impact of carbon dioxide clouds was strongly overestimated in the past. The revised scattering greenhousemore » effect can have important implications for the early Mars, but also for planets like the early Earth or the position of the outer boundary of the habitable zone.« less

Atmospheric Carbon Dioxide and Aerosols: Effects of Large Increases on Global Climate

ERIC Educational Resources Information Center

Science, 1971

1971-01-01

Mathematical models indicate increasing atmospheric carbon dioxide causes an increase in surface temperature at a decreasing rate, and the rate of temperature decrease caused by increasing aerosols increases with aerosol concentration. (AL)

Viscosity effects on the thermal decomposition of bis(perfluoro-2-N-propoxypropionyl) peroxide in dense carbon dioxide and fluorinated solvents.

PubMed

Bunyard, W C; Kadla, J F; DeYoung, J; DeSimone, J M

2001-08-01

The thermal decomposition of the free-radical initiator bis(perfluoro-2-N-propoxyprionyl) peroxide (BPPP) was studied in dense carbon dioxide and a series of fluorinated solvents. For the fluorinated solvents, the observed first-order decomposition rate constants, k(obs), increased with decreasing solvent viscosity, suggesting a single-bond decomposition mechanism. The k(obs) values are comparatively larger in dense carbon dioxide and similar to the "zero-viscosity" rate constants extrapolated from the decomposition kinetics in the fluorinated solvents. The decomposition activation parameters demonstrate a compensation behavior of the activation enthalpy with the activation entropy upon change in solvent viscosity. Comparison of the change in activation parameter values upon change in solvent viscosity for BPPP with two additional initiators, acetyl peroxide (AP) and trifluoroacetyl peroxide (TFAP), further suggests that carbon dioxide exerts a very minimal influence on the decomposition mechanism of these initiators through solvent-cage effects.

Development of a prototype regenerable carbon dioxide absorber for portable life support systems. [for astronaut EVA

NASA Technical Reports Server (NTRS)

Onischak, M.; Baker, B.

1977-01-01

The design and development of a prototype carbon dioxide absorber using potassium carbonate (K2CO3) is described. Absorbers are constructed of thin, porous sheets of supported K2CO3 that are spirally wound to form a cylindrical reactor. Axial gas passages are formed between the porous sheets by corrugated screen material. Carbon dioxide and water in an enclosed life support system atmosphere react with potassium carbonate to form potassium bicarbonate. The potassium carbonate is regenerated by heating the potassium bicarbonate to 150 C at ambient pressure. The extravehicular mission design conditions are for one man for 8 h. Results are shown for a subunit test module investigating the effects of heat release, length-to-diameter ratio, and active cooling upon performance. The most important effect upon carbon dioxide removal is the temperature of the potassium carbonate.

The use of lasers for periodontal debridement: marketing tool or proven therapy?

PubMed

Chanthaboury, Rachel; Irinakis, Tassos

2005-10-01

The use of lasers in dentistry has recently received much attention, in both clinical practice and research; their unique properties produce favourable clinical results in some cases and encourage patient acceptance. Various types of lasers have been investigated as an adjunct to periodontal therapy; these include carbon dioxide (CO₂), diode, neodymium:yttrium-aluminium-garnet (Nd:YAG) and erbium:yttrium-aluminium-garnet (Er:YAG) lasers.However, adverse results have been associated with each type, including thermal damage to root surfaces, increases in pulpal temperature and the production of toxic by-products. The Er:YAG laser has produced the most promising results, as it can ablate effectively with minimal adverse effects. More research is needed to determine the ideal settings and methods for using the laser safely and effectively in clinical practice.

A new procedure to analyze the effect of air changes in building energy consumption

PubMed Central

2014-01-01

Background Today, the International Energy Agency is working under good practice guides that integrate appropriate and cost effective technologies. In this paper a new procedure to define building energy consumption in accordance with the ISO 13790 standard was performed and tested based on real data from a Spanish region. Results Results showed that the effect of air changes on building energy consumption can be defined using the Weibull peak function model. Furthermore, the effect of climate change on building energy consumption under several different air changes was nearly nil during the summer season. Conclusions The procedure obtained could be the much sought-after solution to the problem stated by researchers in the past and future research works relating to this new methodology could help us define the optimal improvement in real buildings to reduce energy consumption, and its related carbon dioxide emissions, at minimal economical cost. PMID:24456655

The impact of energy, transport, and trade on air pollution in China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poon, J.P.H.; Casas, I.; He, C.F.

2006-09-15

A team of U.S.- and China-based geographers examines the relationship between China's economic development and its environment by modeling the effects of energy, transport, and trade on local air pollution emissions (sulfur dioxide and soot particulates) using the Environmental Kuznets model. Specifically, the latter model is investigated using spatial econometrics that take into account potential regional spillover effects from high-polluting neighbors. The analysis finds an inverted-U relationship for sulfur dioxide but a U-shaped curve for soot particulates. This suggests that soot particulates such as black carbon may pose a more serious environmental problem in China than sulfur dioxide.

Overview of Nitrogen Dioxide Effects on the Lung with Emphasis on Military Relevance

DTIC Science & Technology

1994-01-01

toxicity in humans is supportive therapy directed at hypoxemia, ventilatory failure, infection and any other complica- tions. Steroids, N - acetylcysteine ...bI.Irk) 2 AEPOqi OATI! I R(PO’lT fYPI AND) OA iT COV~iM)( A u g u s t 1 9 9 /4 [ ’ tJ, , t j, N __ I 4. Ti[t{ AND SUSTr I 5 4u4ING NUM8[PS Overview ot i...Respiratory Research (SGRI)-JWII-lE) Division of Medicine N /A Walter Reed Army Institute of Research Washington, DC 20307-5100 I-I I. SUP"LEMENTARY NOTES

Managing global change

USDA-ARS?s Scientific Manuscript database

Researchers at the US Department of Agriculture-Agricultural Research Service are exploring the environmental impact of agricultural waste management and rising levels of atmospheric carbon dioxide. This interview presents an overview of work being conducted at the National Soil Dynamics Laboratory ...

CO2 Injection Into CH4 Hydrate Reservoirs: Quantifying Controls of Micro-Scale Processes

NASA Astrophysics Data System (ADS)

Bigalke, N. K.; Deusner, C.; Kossel, E.; Haeckel, M.

2014-12-01

The exchangeability of methane for carbon dioxide in gas hydrates opens the possibility of producing emission-neutral hydrocarbon energy. Recent field tests have shown that the production of natural gas from gas hydrates is feasible via injection of carbon dioxide into sandy, methane-hydrate-bearing sediment strata. Industrial-scale application of this method requires identification of thermo- and fluid-dynamic as well as kinetic controls on methane yield from and carbon dioxide retention within the reservoir. Extraction of gas via injection of carbon dioxide into the hydrate reservoir triggers a number of macroscopic effects, which are revealed for example by changes of the hydraulic conductivity and geomechanical stability. Thus far, due to analytical limitations, localized reactions and fluid-flow phenomena held responsible for these effects remain unresolved on the microscale (1 µm - 1 mm) and at near-natural reservoir conditions. We address this deficit by showing results from high-resolution, two-dimensional Raman spectroscopy mappings of an artificial hydrate reservoir during carbon dioxide injection under realistic reservoir conditions. The experiments allow us to resolve hydrate conversion rate and efficiency as well as activation of fluid pathways in space and time and their effect on methane yield, carbon-dioxide retention and hydraulic conductivity of the reservoir. We hypothesize that the conversion of single hydrate grains is a diffusion-controlled process which starts at the grain surface before continuing into the grain interior and show that the conversion can be modeled simply by using published permeation coefficients for CO2 and CH4 in hydrate and grain size as only input parameters.

The effect of carbon dioxide on the twinkling artifact in ultrasound imaging of kidney stones: A pilot study

PubMed Central

Simon, Julianna C.; Wang, Yak-Nam; Cunitz, Bryan W.; Thiel, Jeffrey; Starr, Frank; Liu, Ziyue; Bailey, Michael R.

2016-01-01

Bone demineralization, dehydration, and stasis put astronauts at an increased risk of forming kidney stones in space. The color-Doppler ultrasound “twinkling artifact”, which highlights kidney stones with color, can make stones readily detectable with ultrasound; however our previous results suggest twinkling is caused by microbubbles on the stone surface which could be affected by the elevated levels of carbon dioxide found on space vehicles. Four pigs were implanted with kidney stones and imaged with ultrasound while the anesthetic carrier gas oscillated between oxygen and air containing 0.8% carbon dioxide. Upon exposing pigs to 0.8% carbon dioxide, twinkling was significantly reduced after 9–25 minutes and recovered when the carrier gas returned to oxygen. These trends repeated when pigs were again exposed to 0.8% carbon dioxide followed by oxygen. The reduction of twinkling from exposure to elevated carbon dioxide may make kidney stone detection with twinkling difficult in current space vehicles. PMID:28190622

Study on encapsulation of chlorine dioxide in gelatin microsphere for reducing release rate

PubMed Central

Ci, Ying; Wang, Lin; Guo, Yanchuan; Sun, Ruixue; Wang, Xijie; Li, Jinyou

2015-01-01

Objective: This study aims to explore the effects of encapsulation of chlorine dioxide in a hydrophilic biodegradable polymer gelatin to reduce its release rate. Methods: An emulsification-coacervation method was adopted. The characterizations of chlorine dioxide-gelatin microspheres were described. Using UV-vis spectrophotometer the λmax of chlorine dioxide was observed at 358 nm. The particle size and distribution of chlorine oxide-gelatin microspheres was measured by a dynamic light scattering (DLS) method, the diameter was (1400~1900) nm. The entrapment of chlorine dioxide-gelatin microspheres was confirmed by IR. The surface morphology, size, and shape of chlorine dioxide-gelatin microspheres were analyzed using Scanning electron microscope (SEM). Results: It showed that the encapsulated microspheres size was around 2000 nm with uniform distribution. The percentage entrapment of chlorine dioxide in the encapsulated samples was about 80~85%. A slow release study of chlorine dioxide from the encapsulated biopolymer (gelatin) in air was also carried out, which showed continuous release up to ten days. Conclusions: It can be concluded that it is possible to make a slow release formulation of ClO2 by entrapped in a hydrophilic biodegradable polymer gelatin. ClO2-gelatin microspheres can stable release low concentration ClO2 gas over an extended period. PMID:26550151

75 FR 18575 - Mandatory Reporting of Greenhouse Gases: Injection and Geologic Sequestration of Carbon Dioxide

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-12

... perfluorocarbon QA/QC quality assurance/quality control R&D research and development RFA Regulatory Flexibility... Climate Change.'' Joint Global Change Research Institute, Battelle Pacific Northwest Division. PNWD-3602... research, demonstration, and deployment programs throughout the world, are building confidence that...

Efficacy of autologous platelet-rich plasma combined with fractional ablative carbon dioxide resurfacing laser in treatment of facial atrophic acne scars: A split-face randomized clinical trial.

PubMed

Faghihi, Gita; Keyvan, Shima; Asilian, Ali; Nouraei, Saeid; Behfar, Shadi; Nilforoushzadeh, Mohamad Ali

2016-01-01

Autologous platelet-rich plasma has recently attracted significant attention throughout the medical field for its wound-healing ability. This study was conducted to investigate the potential of platelet-rich plasma combined with fractional laser therapy in the treatment of acne scarring. Sixteen patients (12 women and 4 men) who underwent split-face therapy were analyzed in this study. They received ablative fractional carbon dioxide laser combined with intradermal platelet-rich plasma treatment on one half of their face and ablative fractional carbon dioxide laser with intradermal normal saline on the other half. The injections were administered immediately after laser therapy. The treatment sessions were repeated after an interval of one month. The clinical response was assessed based on patient satisfaction and the objective evaluation of serial photographs by two blinded dermatologists at baseline, 1 month after the first treatment session and 4 months after the second. The adverse effects including erythema and edema were scored by participants on days 0, 2, 4, 6, 8, 15 and 30 after each session. Overall clinical improvement of acne scars was higher on the platelet-rich plasma-fractional carbon dioxide laser treated side but the difference was not statistically significant either 1 month after the first treatment session (P = 0.15) or 4 months after the second (P = 0.23). In addition, adverse effects (erythema and edema) on the platelet-rich plasma-fractional carbon dioxide laser-treated side were more severe and of longer duration. Small sample size, absence of all skin phototypes within the study group and lack of objective methods for the evaluation of response to treatment and adverse effects were the limitations. This study demonstrated that adding platelet-rich plasma to fractional carbon dioxide laser treatment did not produce any statistically significant synergistic effects and also resulted in more severe side effects and longer downtime.

Effect of purity on adsorption capacities of a Mars-like clay mineral at different pressures

NASA Technical Reports Server (NTRS)

Jenkins, Traci; Mcdoniel, Bridgett; Bustin, Roberta; Allton, Judith H.

1992-01-01

There has been considerable interest in adsorption of carbon dioxide on Marslike clay minerals. Some estimates of the carbon dioxide reservoir capacity of the martian regolith were calculated from the amount of carbon dioxide adsorbed on the ironrich smectite nontronite under martian conditions. The adsorption capacity of pure nontronite could place upper limits on the regolith carbon dioxide reservoir, both at present martian atmospheric pressure and at the postulated higher pressures required to permit liquid water on the surface. Adsorption of carbon dioxide on a Clay Mineral Society standard containing nontronite was studied over a wide range of pressures in the absence of water. Similar experiments were conducted on the pure nontronite extracted from the natural sample. Heating curves were obtained to help characterize and determine the purity of the clay sample.

Convective Heat Transfer in Internal Gas Flows with Temperature-Dependent Properties.

DTIC Science & Technology

1982-06-30

and carbon dioxide in order to examine the effects of physica’, properties differing from those of air. Helium was chosen to reore- sent the behavior of...monatomic gases and carbon dioxide because the temper- azure dependencies of its transoort oroperties differs mar’ ed-v frorn those of air. He...conditions cor- responding to pure forced convection and to significant buoyancy forces in the thermal entry region. For carbon dioxide only temperatures

Greening the Mixture: An Evaluation of the Department of Defense’s Alternative Aviation Fuel Strategy

DTIC Science & Technology

2012-06-08

process begins with gasification of feedstocks such as coal, natural gas, or biomass towards the production of alternative fuels. With adequate carbon...Barrels per day CBTL Coal and Biomass to Liquid CCS Carbon Dioxide Capture and Sequestration CTL Coal to Liquid DARPA Defense Advanced Research...sequestration. Captured carbon dioxide from coal-to-liquid (CTL) or coal and biomass -to-liquid (CBTL) production could be readily injected into the

Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch.

PubMed

Kwak, Hyoung S; Uhm, Han S; Hong, Yong C; Choi, Eun H

2015-12-17

A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10(-3), nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10(-7), nO2/nN = 5.39 × 10(-5), where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch.

Ordering effects of conjugate thermal fields in simulations of molecular liquids: Carbon dioxide and water

NASA Astrophysics Data System (ADS)

Dittmar, Harro R.; Kusalik, Peter G.

2016-10-01

As shown previously, it is possible to apply configurational and kinetic thermostats simultaneously in order to induce a steady thermal flux in molecular dynamics simulations of many-particle systems. This flux appears to promote motion along potential gradients and can be utilized to enhance the sampling of ordered arrangements, i.e., it can facilitate the formation of a critical nucleus. Here we demonstrate that the same approach can be applied to molecular systems, and report a significant enhancement of the homogeneous crystal nucleation of a carbon dioxide (EPM2 model) system. Quantitative ordering effects and reduction of the particle mobilities were observed in water (TIP4P-2005 model) and carbon dioxide systems. The enhancement of the crystal nucleation of carbon dioxide was achieved with relatively small conjugate thermal fields. The effect is many orders of magnitude bigger at milder supercooling, where the forward flux sampling method was employed, than at a lower temperature that enabled brute force simulations of nucleation events. The behaviour exhibited implies that the effective free energy barrier of nucleation must have been reduced by the conjugate thermal field in line with our interpretation of previous results for atomic systems.

The use of renewable energy in the form of methane via electrolytic hydrogen generation using carbon dioxide as the feedstock

NASA Astrophysics Data System (ADS)

Hashimoto, Koji; Kumagai, Naokazu; Izumiya, Koichi; Takano, Hiroyuki; Shinomiya, Hiroyuki; Sasaki, Yusuke; Yoshida, Tetsuya; Kato, Zenta

2016-12-01

The history reveals the continuous increase in world energy consumption and carbon emissions. For prevention of intolerable global warming and complete exhaustion of fossil fuels we need complete conversion from fossil fuel consumption to renewable energy. We have been performing the research and development of global carbon dioxide recycling for more than 25 years to supply renewable energy to the world in the form of methane produced by the reaction of carbon dioxide captured from chimney with hydrogen generated electrolytically using electricity generated by renewable energy. We created the cathode and anode for electrolytic hydrogen generation and the catalyst for carbon dioxide methanation by the reaction with hydrogen. The methane formation from renewable energy will be the most convenient and efficient key technology for the use of renewable energy by storage of intermittent and fluctuating electricity generated from renewable energy and by regeneration of stable electricity. Domestic and international cooperation of companies for industrialization is in progress.

Simulation and experimental verification of silicon dioxide deposition by PECVD

NASA Astrophysics Data System (ADS)

Xu, Qing; Li, Yu-Xing; Li, Xiao-Ning; Wang, Jia-Bin; Yang, Fan; Yang, Yi; Ren, Tian-Ling

2017-02-01

Deposition of silicon dioxide in high-density plasma is an important process in integrated circuit manufacturing. A software named CFD-ACE was used to simulate the mechanism of plasma in the chamber of plasma enhanced chemical vapor deposition (PECVD) system, and the evolution of the feature profile was simulated based on CFD-TOPO. Simulation and experiment of silicon dioxide that deposited in SiH4/N2O mixture by PECVD system was researched. The particle density, energy and angular distribution in the chamber were simulated and discussed. We also studied how the depth/width ratio affected the step coverage of the trench and analyzed the deposition rate of silicon dioxide on the feature scale. X-ray photoelectron spectroscopy (XPS) was used to analyze the elemental composition of thin films. Images of the feature profiles were taken by scanning electron microscope (SEM). The simulation results were in good agreement with experimental, which could guide the semiconductor device manufacture.

Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinert, R.A.; Sanders, J.S.

Radish and marigold plants were exposed to 0.3 ppM of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and /or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/ and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in themore » presence of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 2/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present. 8 references, 2 tables.« less

The antibacterial effects of silver, titanium dioxide and silica dioxide nanoparticles compared to the dental disinfectant chlorhexidine on Streptococcus mutans using a suite of bioassays

PubMed Central

Besinis, Alexandros; De Peralta, Tracy

2014-01-01

Metal-containing nanomaterials have the potential to be used in dentistry for infection control, but little is known about their antibacterial properties. This study investigated the toxicity of silver (Ag), titanium dioxide and silica nanoparticles (NPs) against the oral pathogenic species of Streptococcus mutans, compared to the routine disinfectant, chlorhexidine. The bacteria were assessed using the minimum inhibitory concentration assay for growth, fluorescent staining for live/dead cells, and measurements of lactate. All the assays showed that Ag NPs had the strongest antibacterial activity of the NPs tested, with bacterial growth also being 25-fold lower than that in chlorhexidine. The survival rate of bacteria under the effect of 100 mg l−1 Ag NPs in the media was 2% compared to 60% with chlorhexidine, while the lactate concentration was 0.6 and 4.0 mM, respectively. Silica and titanium dioxide NPs had limited effects. Dialysis experiments showed negligible silver dissolution. Overall, Ag NPs were the best disinfectant and performed better than chlorhexidine. Improvements to the MIC assay are suggested. PMID:23092443

Bench Remarks: Carbon Dioxide.

ERIC Educational Resources Information Center

Bent, Henry A.

1987-01-01

Discusses the properties of carbon dioxide in its solid "dry ice" stage. Suggests several demonstrations and experiments that use dry ice to illustrate Avogadro's Law, Boyle's Law, Kinetic-Molecular Theory, and the effects of dry ice in basic solution, in limewater, and in acetone. (TW)

IDENTIFICATION OF CHLORINE DIOXIDE AND CHLORAMINE DRINKING WATER DISINFECTION BY-PRODUCTS

EPA Science Inventory

Due to concern over the potential adverse health effects of trihalomethanes (THMs) and other chlorinated by-products in chlorinated drinking water, alternative disinfection methods are being explored. Chlorine dioxide and chloramine are two popular alternative disinfectants, with...

Light pollution and solid-state lighting: reducing the carbon dioxide footprint is not enough

NASA Astrophysics Data System (ADS)

Bará, Salvador

2013-11-01

Public and private lighting account for a relevant share of the overall electric power consumption worldwide. The pressing need of reducing the carbon dioxide emissions as well as of lowering the lumen•hour price tag has fostered the search for alternative lighting technologies to substitute for the incandescent and gas-discharge based lamps. The most successful approach to date, solid-state lighting, is already finding its way into the public lighting market, very often helped by substantial public investments and support. LED-based sources have distinct advantages: under controlled coditions their efficacy equals or surpasses that of conventional solutions, their small source size allows for an efficient collimation of the lightbeam (delivering the photons where they are actually needed and reducing lightspill on the surrounding areas), and they can be switched and/or dimmed on demand at very high rates, thus allowing for a taylored schedule of lighting. However, energy savings and carbon dioxide reduction are not the only crucial issues faced by present day lighting. A growing body of research has shown the significance of the spectral composition of light when it comes to assess the detrimental effects of artificial light-at-night (ALAN). The potential ALAN blueshift associated to the deployment of LED-based lighting systems has raised sensible concerns about its scientific, cultural, ecological and public health consequences, which can be further amplified if an increased light consumption is produced due to the rebound effect. This contribution addresses some of the challenges that these issues pose to the Optics and Photonics community.

The Effect of Varying Atmospheric Pressure upon Habitability and Biosignatures of Earth-like Planets.

PubMed

Keles, Engin; Grenfell, John Lee; Godolt, Mareike; Stracke, Barbara; Rauer, Heike

2018-02-01

Understanding the possible climatic conditions on rocky extrasolar planets, and thereby their potential habitability, is one of the major subjects of exoplanet research. Determining how the climate, as well as potential atmospheric biosignatures, changes under different conditions is a key aspect when studying Earth-like exoplanets. One important property is the atmospheric mass, hence pressure and its influence on the climatic conditions. Therefore, the aim of the present study is to understand the influence of atmospheric mass on climate, hence habitability, and the spectral appearance of planets with Earth-like, that is, N 2 -O 2 dominated, atmospheres orbiting the Sun at 1 AU. This work utilizes a 1D coupled, cloud-free, climate-photochemical atmospheric column model; varies atmospheric surface pressure from 0.5 to 30 bar; and investigates temperature and key species profiles, as well as emission and brightness temperature spectra in a range between 2 and 20 μm. Increasing the surface pressure up to 4 bar leads to an increase in the surface temperature due to increased greenhouse warming. Above this point, Rayleigh scattering dominates, and the surface temperature decreases, reaching surface temperatures below 273 K (approximately at ∼34 bar surface pressure). For ozone, nitrous oxide, water, methane, and carbon dioxide, the spectral response either increases with surface temperature or pressure depending on the species. Masking effects occur, for example, for the bands of the biosignatures ozone and nitrous oxide by carbon dioxide, which could be visible in low carbon dioxide atmospheres. Key Words: Planetary habitability and biosignatures-Atmospheres-Radiative transfer. Astrobiology 18, 116-132.

Nanoparticles in paints: A new strategy to protect façades and surfaces?

NASA Astrophysics Data System (ADS)

Kaiser, J.-P.; Diener, L.; Wick, P.

2013-04-01

The paint and lacquer industries consider the use of nanosilver, photocatalytic active nanotitanium dioxide or nanosilica dioxide as additives for the protection of surfaces, against microbial, physical and chemical deterioration, as alternative to conventional organic based additives. Nowadays it is not clear, if nanoparticles in paints will achieve the proposed effects, since there are no long time studies available. Another fact is that the potential risks of nanoparticles for the environment and the human health is still controversial discussed. The most sensitive entry port for nanomaterials is the lung. However other human organs/systems may also be affected by nanoparticles. Therefore the aim of the study was to assess the potential hazard effects of the three most interesting particles for paints on the gastro-intestinal tract and the immune system in vitro. In our study we could show that: i) Nanosilver (TEM size 25 nm) was far less toxic than silver ions of comparable concentrations tested with cells representing the gastro-intestinal tract (CaCo-2) and immune cells (Jurkat, T-lymphocytes). A significant amount of necrotic cells could be observed after exposure of CaCo-2 cells to 27 μg/ml nanosilver for 48 h. ii) Nanotitanium dioxide can adsorb UV-light and in the presence of water hydroxyl radicals are generated photocatalytically. The exposure of CaCo-2 cells and Jurkat cells to photocatalytically active nanotitanium dioxide (Hombikat UV 100, TEM-size 15 nm) under dark conditions, didn't affected the cells significantly. However, the cells were able to incorporate nanotitanium dioxide, especially when cells were exposed to higher concentrations. iii) Nanosilica dioxide improves the properties of the paints by increasing the water repellence. When cells were exposed to 243 μg/ml nanosilica dioxide (TEM-size 19 nm) for up to 48 h no cytotoxic effect could be observed.

Analysis on carbon dioxide emission reduction during the anaerobic synergetic digestion technology of sludge and kitchen waste: Taking kitchen waste synergetic digestion project in Zhenjiang as an example.

PubMed

Guo, Qia; Dai, Xiaohu

2017-11-01

With the popularization of municipal sewage treatment facilities, the improvement of sewage treatment efficiency and the deepening degree of sewage treatment, the sludge production of sewage plant has been sharply increased. Carbon emission during the process of municipal sewage treatment and disposal has become one of the important sources of greenhouse gases that cause greenhouse effect. How to reduce carbon dioxide emissions during sewage treatment and disposal process is of great significance for reducing air pollution. Kitchen waste and excess sludge, as two important organic wastes, once uses anaerobic synergetic digestion technology in the treatment process can on the one hand, avoid instability of sludge individual anaerobic digestion, improve sludge degradation rate and marsh gas production rate, and on the other hand, help increase the reduction of carbon dioxide emissions to a great extent. The paper uses material balance method, analyzes and calculates the carbon dioxide emissions from kitchen waste and sludge disposed by the anaerobic synergetic digestion technology, compares the anaerobic synergetic digestion technology with traditional sludge sanitary landfill technology and works out the carbon dioxide emission reductions after synergetic digestion. It takes the kitchen waste and sludge synergetic digestion engineering project of Zhenjiang city in Jiangsu province as an example, makes material balance analysis using concrete data and works out the carbon dioxide daily emission reductions. The paper analyzes the actual situation of emission reduction by comparing the data, and found that the synergetic digestion of kitchen waste and sludge can effectively reduce the carbon dioxide emission, and the reduction is obvious especially compared with that of sludge sanitary landfill, which has a certain effect on whether to promote the use of the technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nanomaterials for Advanced Life Support in Advanced Life Support in Space systems

NASA Technical Reports Server (NTRS)

Allada, Rama Kumar; Moloney, Padraig; Yowell, Leonard

2006-01-01

A viewgraph presentation describing nanomaterial research at NASA Johnson Space Center with a focus on advanced life support in space systems is shown. The topics include: 1) Introduction; 2) Research and accomplishments in Carbon Dioxide Removal; 3) Research and Accomplishments in Water Purification; and 4) Next Steps

Toxicity and Fate Comparison between Several Brass and Titanium Dioxide Powders

DTIC Science & Technology

1993-07-01

the entire gut without showing any apparent effects . 14. UBJET TEMS1I. NUMBER OF PAGES 27 Daphnia Algae EC50 Aquatic toxicity 11T.PRICE CODE 9...levels of soluble copper and zinc in solution. 3. RESULTS The titanium dioxide ( TiO2 ) materials did not show any apparent toxic effects to daphnia up to...The extended exposure did not show any apparent toxic effects . Long term effects on aquatic org.rnisms exposed to TiO2 are not known. It is apparent

Methanol Droplet Extinction in Carbon-Dioxide-Enriched Environments in Microgravity

NASA Technical Reports Server (NTRS)

Hicks, Michael C.; Nayagam, Vedha; Williams, Forman A.

2010-01-01

Diffusive extinction of methanol droplets with initial diameters between 1.25 mm and 1.72 mm, burning in a quiescent microgravity environment at one atmosphere pressure, was obtained experimentally for varying levels of ambient carbon-dioxide concentrations with a fixed oxygen concentration of 21% and a balance of nitrogen. These experiments serve as precursors to those which are beginning to be performed on the International Space Station and are motivated by the need to understand the effectiveness of carbon-dioxide as a fire suppressant in low-gravity environments. In these experiments, the flame standoff distance, droplet diameter, and flame radiation are measured as functions of time. The results show that the droplet extinction diameter depends on both the initial droplet diameter and the ambient concentration of carbon dioxide. Increasing the initial droplet diameter leads to an increased extinction diameter, while increasing the carbon-dioxide concentration leads to a slight decrease in the extinction diameter. These results are interpreted using a critical Damk hler number for extinction as predicted by an earlier theory, which is extended here to be applicable in the presence of effects of heat conduction along the droplet support fibers and of the volume occupied by the support beads

Seasonal analyses of carbon dioxide and energy fluxes above an oil palm plantation using the eddy covariance method

NASA Astrophysics Data System (ADS)

Ibrahim, Anis; Haniff Harun, Mohd; Yusup, Yusri

2017-04-01

A study presents the measurements of carbon dioxide and latent and sensible heat fluxes above a mature oil palm plantation on mineral soil in Keratong, Pahang, Peninsular Malaysia. The sampling campaign was conducted over an 25-month period, from September 2013 to February 2015 and May 2016 to November 2016, using the eddy covariance method. The main aim of this work is to assess carbon dioxide and energy fluxes over this plantation at different time scales, seasonal and diurnal, and determine the effects of season and relevant meteorological parameters on the latter fluxes. Energy balance closure analyses gave a slope between latent and sensible heat fluxes and total incoming energy to be 0.69 with an R2 value of 0.86 and energy balance ratio of 0.80. The averaged net radiation was 108 W m-2. The results show that at the diurnal scale, carbon dioxide, latent and sensible heat fluxes exhibited a clear diurnal trend where carbon dioxide flux was at its minimum - 3.59 μmol m-2 s-1 in the mid-afternoon and maximum in the morning while latent and sensible behaved conversely to the carbon dioxide flux. The average carbon dioxide flux was - 0.37 μmol m-2 s-1. At the seasonal timescale, carbon dioxide fluxes did not show any apparent trend except during the Northeast Monsoon where the highest variability of the monthly means of carbon dioxide occurred.

Variation in Baiting Intensity Among CO2-Baited Traps Used to Collect Hematophagous Arthropods.

PubMed

Springer, Yuri P; Taylor, Jeffrey R; Travers, Patrick D

2015-01-01

Hematophagous arthropods transmit the etiological agents of numerous diseases and as a result are frequently the targets of sampling to characterize vector and pathogen populations. Arguably, the most commonly used sampling approach involves traps baited with carbon dioxide. We report results of a laboratory study in which the performance of carbon dioxide-baited traps was evaluated using measures of baiting intensity, the amount of carbon dioxide released per unit time during trap deployment. We evaluated the effects of trap design, carbon dioxide source, and wind speed on baiting intensity and documented significant effects of these factors on the length of sampling (time to baiting intensity = 0), maximum baiting intensity, and variation in baiting intensity during experimental trials. Among the three dry ice-baited trap types evaluated, traps utilizing insulated beverage coolers as dry ice containers sampled for the longest period of time, had the lowest maximum but most consistent baiting intensity within trials and were least sensitive to effects of wind speed and dry ice form (block vs. pellet) on baiting intensity. Results of trials involving traps baited with carbon dioxide released from pressurized cylinders suggested that this trap type had performance comparable to dry ice-baited insulated cooler traps but at considerably higher cost. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Review of carbon dioxide research staffing and academic support

NASA Astrophysics Data System (ADS)

Clark, S. B.; Howard, L.; Stevenson, W.; Trice, J.

1985-04-01

More than 60 percent of the staff on Carbon Dioxide Research Division (CDRD) projects were university affiliated, and over one third of project scientists and engineers also had university teaching responsibilities. Almost 20 percent of project staff were students. CO2 research is unlikely to affect the general labor market for scientists and engineers because it uses such a small portion of the total pool. On the other hand, anticipated tight labor markets in some disciplines important to CO2 research may make it advantageous for CDRD to expand its support of university faculty, students, and staff to ensure that competent, knowledgeable researchers and managers are available for eventual policy decisions on CO2 issues. Options for academic support that lend themselves readily to the diffuse nature of CO2 research, while providing flexibility in the identification and accomplishment of specific programmatic objectives, include modifying procurement procedures for research contracts to enhance academic involvement, sponsoring summer institutes tailored to specific participants and focused on issues of interest to CDRD, and supporting traveling lecture programs designed to bring information of concern to CDRD to technical and nontechnical audiences.

2011 Joint Science Education Project: Research Experience in Polar Science

NASA Astrophysics Data System (ADS)

Wilkening, J.; Ader, V.

2011-12-01

The Joint Science Education Project (JSEP), sponsored by the National Science Foundation, is a two-part program that brings together students and teachers from the United States, Greenland, and Denmark, for a unique cross-cultural, first-hand experience of the realities of polar science field research in Greenland. During JSEP, students experienced research being conducted on and near the Greenland ice sheet by attending researcher presentations, visiting NSF-funded field sites (including Summit and NEEM field stations, both located on the Greenland ice sheet), and designing and conducting research projects in international teams. The results of two of these projects will be highlighted. The atmospheric project investigated the differences in CO2, UVA, UVB, temperature, and albedo in different Arctic microenvironments, while also examining the interaction between the atmosphere and water present in the given environments. It was found that the carbon dioxide levels varied: glacial environments having the lowest levels, with an average concentration of 272.500 ppm, and non-vegetated, terrestrial environments having the highest, with an average concentration of 395.143 ppm. Following up on these results, it is planned to further investigate the interaction of the water and atmosphere, including water's role in the uptake of carbon dioxide. The ecology project investigated the occurrence of unusual large blooms of Nostoc cyanobacteria in Kangerlussuaq area lakes. The water chemistry of the lakes which contained the cyanobacteria and the lakes that did not were compared. The only noticeable difference was of the lakes' acidity, lakes containing the blooms had an average pH value of 8.58, whereas lakes without the blooms had an average pH value of 6.60. Further investigation of these results is needed to determine whether or not this was a cause or effect of the cyanobacteria blooms. As a next step, it is planned to attempt to grow the blooms to monitor their effects on different common ecosystems within the Kangerlussuaq area.

Ionic Liquid-Based Optical and Electrochemical Carbon Dioxide Sensors.

PubMed

Behera, Kamalakanta; Pandey, Shubha; Kadyan, Anu; Pandey, Siddharth

2015-12-04

Due to their unusual physicochemical properties (e.g., high thermal stability, low volatility, high intrinsic conductivity, wide electrochemical windows and good solvating ability), ionic liquids have shown immense application potential in many research areas. Applications of ionic liquid in developing various sensors, especially for the sensing of biomolecules, such as nucleic acids, proteins and enzymes, gas sensing and sensing of various important ions, among other chemosensing platforms, are currently being explored by researchers worldwide. The use of ionic liquids for the detection of carbon dioxide (CO₂) gas is currently a major topic of research due to the associated importance of this gas with daily human life. This review focuses on the application of ionic liquids in optical and electrochemical CO₂ sensors. The design, mechanism, sensitivity and detection limit of each type of sensor are highlighted in this review.

Ionic Liquid-Based Optical and Electrochemical Carbon Dioxide Sensors

PubMed Central

Behera, Kamalakanta; Pandey, Shubha; Kadyan, Anu; Pandey, Siddharth

2015-01-01

Due to their unusual physicochemical properties (e.g., high thermal stability, low volatility, high intrinsic conductivity, wide electrochemical windows and good solvating ability), ionic liquids have shown immense application potential in many research areas. Applications of ionic liquid in developing various sensors, especially for the sensing of biomolecules, such as nucleic acids, proteins and enzymes, gas sensing and sensing of various important ions, among other chemosensing platforms, are currently being explored by researchers worldwide. The use of ionic liquids for the detection of carbon dioxide (CO2) gas is currently a major topic of research due to the associated importance of this gas with daily human life. This review focuses on the application of ionic liquids in optical and electrochemical CO2 sensors. The design, mechanism, sensitivity and detection limit of each type of sensor are highlighted in this review. PMID:26690155

Designing management strategies for carbon dioxide storage and utilization under uncertainty using inexact modelling

NASA Astrophysics Data System (ADS)

Wang, Yu; Fan, Jie; Xu, Ye; Sun, Wei; Chen, Dong

2017-06-01

Effective application of carbon capture, utilization and storage (CCUS) systems could help to alleviate the influence of climate change by reducing carbon dioxide (CO2) emissions. The research objective of this study is to develop an equilibrium chance-constrained programming model with bi-random variables (ECCP model) for supporting the CCUS management system under random circumstances. The major advantage of the ECCP model is that it tackles random variables as bi-random variables with a normal distribution, where the mean values follow a normal distribution. This could avoid irrational assumptions and oversimplifications in the process of parameter design and enrich the theory of stochastic optimization. The ECCP model is solved by an equilibrium change-constrained programming algorithm, which provides convenience for decision makers to rank the solution set using the natural order of real numbers. The ECCP model is applied to a CCUS management problem, and the solutions could be useful in helping managers to design and generate rational CO2-allocation patterns under complexities and uncertainties.

Carbon dioxide dynamics in an artificial ecosystem

NASA Astrophysics Data System (ADS)

Hu, Enzhu; Hu, Dawei; Tong, Ling; Li, Ming; Fu, Yuming; He, Wenting; Liu, Hong

An experimental artificial ecosystem was established as a tool to understand the behavior of closed ecosystem and to develop the technology for a future bioregenerative life support system for lunar or planetary exploration. Total effective volume of the system is 0.7 m3 . It consists of a higher plant chamber, an animal chamber and a photo-bioreactor which cultivated lettuce (Lactuca sativa L.), silkworm (Bombyx Mori L.) and microalgae (Chlorella), respectively. For uniform and sustained observations, lettuce and silkworms was cultivated using sequential cultivation method, and microalgae using continuous culture. Four researchers took turns breathing the system air through a tube for brief periods every few hours. A mathematic model, simulating the carbon dioxide dynamics was developed. The main biological parameters concerning photosynthesis of lettuce and microalgae, respiration of silkworms and human were validated by the experimental data. The model described the respiratory relationship between autotrophic and heterotrophic compartments. A control strategy was proposed as a tool for the atmosphere management of the artificial ecosystem.

Toxicity mechanism of titanium dioxide and zinc oxide nanoparticles against food pathogens.

PubMed

Venkatasubbu, G Devanand; Baskar, R; Anusuya, T; Seshan, C Arun; Chelliah, Ramachandran

2016-12-01

Food preservation is an important field of research. It extends the shelf life of major food products. Our current study is based on food preservation through TiO 2 and ZnO nanoparticles. TiO 2 and ZnO are biocompatible nanomaterial. The biocompatibility of the materials were established through toxicity studies on cell lines. Titanium dioxide and Zinc Oxide nanoparticle were synthesized by wet chemical process. They are characterized by X-Ray diffraction and TEM. The antibacterial activities of both the materials were analysed to ensure their effectiveness as food preservative against Salmonella typhi, Klebsiella pneumoniae and Shigella flexneri. The results indicates that TiO 2 and ZnO nanoparticle inhibits Salmonella, Klebsiella and Shigella. The mode of action is by the generation of ROS in cases of Salmonella, Klebsiella. Mode of action in Shigella is still unclear. It was also proved that TiO 2 and ZnO nanoparticle are biocompatible materials. Copyright © 2016 Elsevier B.V. All rights reserved.

SEPARATING PROTOACTINIUM WITH MANGANESE DIOXIDE

DOEpatents

Seaborg, G.T.; Gofman, J.W.; Stoughton, R.W.

1958-04-22

The preparation of U/sup 235/ and an improved method for isolating Pa/ sup 233/ from foreign products present in neutronirradiated thorium is described. The method comprises forming a solution of neutron-irradiated thorium together with a manganous salt, then adding potassium permanganate to precipitate the manganese as manganese dioxide whereby protoactinium is carried down with the nnanganese dioxide dissolving the precipitate, adding a soluble zirconium salt, and adding phosphate ion to precipitate zirconium phosphate whereby protoactinium is then carried down with the zirconium phosphate to effect a further concentration.

Iron-catalyzed hydrogenation of bicarbonates and carbon dioxide to formates.

PubMed

Zhu, Fengxiang; Zhu-Ge, Ling; Yang, Guangfu; Zhou, Shaolin

2015-02-01

The catalytic hydrogenation of carbon dioxide and bicarbonate to formate has been explored extensively. The vast majority of the known active catalyst systems are based on precious metals. Herein, we describe an effective, phosphine-free, air- and moisture-tolerant catalyst system based on Knölker's iron complex for the hydrogenation of bicarbonate and carbon dioxide to formate. The catalyst system can hydrogenate bicarbonate at remarkably low hydrogen pressures (1-5 bar). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of Attentional Focus on Emotional Responding to a Biological Challenge in Panic Disorder

DTIC Science & Technology

1996-08-26

Panic .5 1.4. Biological Challenges 6 1.4.1. Carbon dioxide 6 1.4.2. Sodium Lactate 7 1.4.3. Yohimbine 7 1.4.4. Caffeine 8 1.4.5. Hyperventilation 8...biological challenges (e.g., carbon dioxide, caffeine , lactate infusion) have been used to provoke somatic symptoms that are similar to those reported during...challenges utilized in the study of panic disorder. Examples of biological challenge agents include carbon dioxide, sodium lactate, yohimbine, caffeine

Titanium dioxide nanoparticles cause genotoxicity in human lung epithelial cells

EPA Science Inventory

The use of engineered nanoparticles in consumer products is steadily increasing. However, the health effects of exposure to these nanoparticles are not thoroughly understood. This study investigated the genotoxicity of six titanium dioxide and two cerium oxide nanoparticles of va...

Development of a tunable Fabry-Perot interferometer UV camera for monitoring sulfur dioxide emissions

NASA Astrophysics Data System (ADS)

Tamminen, J.; Kujanpää, J.; Ojanen, H.; Saari, H.; Näkki, I.; Tukiainen, S.; Kyrölä, E.

2017-12-01

We present a novel UV camera for sulfur dioxide emission monitoring.The camera is equipped with a piezo-actuated Fabry-Perot interferometer allowing thefilter transmission to be tuned to match the differential absorption features ofsulfur dioxide in the wavelength region 305-320 nm. The differential absorption structuresare exploited to reduce the interfering effects of weakly wavelength dependent absorbers, suchas aerosols and black carbon, present in the exhaust gas. A data processing algorithm basedon two air gaps of the filter is presented allowing collection of a sufficient signal-to-noise ratio fordetecting sulfur dioxide in the ship plumes even in the designated emission control areas, such as the Baltic Seawhere the sulfur content limit of fuel oil is 0.1 %. First field tests performed inLänsisatama harbour, Helsinki Finland, indicate that sulfur dioxide can be detectedin ship plumes. The camera is light-weight and can be mounted to a drone.

Carbon dioxide poisoning: a literature review of an often forgotten cause of intoxication in the emergency department.

PubMed

Permentier, Kris; Vercammen, Steven; Soetaert, Sylvia; Schellemans, Christian

2017-12-01

The goal of this article was to provide an overview of the literature available on carbon dioxide intoxication. Articles were included based on their focus on medical or physiological effects of carbon dioxide. Studies related to decompression sickness were excluded. Mechanisms of carbon dioxide poising (both as an asphyxiant and as a toxicant) were described. Our review suggested that precautions are needed when handling dry ice or while working in confined spaces. Pre-hospital responders also need to pay attention for the possible diagnosis of CO 2 intoxication for their own safety. When confronted with a victim, he/she should be removed from the dangerous area as fast as possible and oxygen should be administered. Without adequate treatment, victims may show acute reduced cognitive performance, respiratory failure, and circulatory arrest. Therefore, carbon dioxide poisoning is a rare but not to miss diagnosis in the emergency department.

Entrapment of carbon dioxide with chitosan-based core-shell particles containing changeable cores.

PubMed

Dong, Yanrui; Fu, Yinghao; Lin, Xia; Xiao, Congming

2016-08-01

Water-soluble chitosan-based core-shell particles that contained changeable cores were successfully applied to anchor carbon dioxide. The entrapment capacity of the particles for carbon dioxide (EC) depended on the cores. It was found that EC of the particles contained aqueous cores was higher than that of the beads with water-soluble chitosan gel cores, which was confirmed with thermogravimetric analysis. In addition, calcium ions and sodium hydroxide were introduced within the particles to examine their effect on the entrapment. EC of the particles was enhanced with sodium hydroxide when the cores were WSC gel. The incorporation of calcium ions was helpful for stabilizing carbon dioxide through the formation of calcium carbonate, which was verified with Fourier transform infrared spectra and scanning electron microscopy/energy-dispersive spectrometry. This phenomenon meant the role of calcium ions for fixating carbon dioxide was significant. Copyright © 2016 Elsevier B.V. All rights reserved.

Diffusion of gas mixtures in the sI hydrate structure

NASA Astrophysics Data System (ADS)

Waage, Magnus H.; Trinh, Thuat T.; van Erp, Titus S.

2018-06-01

Replacing methane with carbon dioxide in gas hydrates has been suggested as a way of harvesting methane, while at the same time storing carbon dioxide. Experimental evidence suggests that this process is facilitated if gas mixtures are used instead of pure carbon dioxide. We studied the free energy barriers for diffusion of methane, carbon dioxide, nitrogen, and hydrogen in the sI hydrate structure using molecular simulation techniques. Cage hops between neighboring cages were considered with and without a water vacancy and with a potential inclusion of an additional gas molecule in either the initial or final cage. Our results give little evidence for enhanced methane and carbon dioxide diffusion if nitrogen is present as well. However, the inclusion of hydrogen seems to have a substantial effect as it diffuses rapidly and can easily enter occupied cages, which reduces the barriers of diffusion for the gas molecules that co-occupy a cage with hydrogen.

Extended duration orbiter study: CO2 removal and water recovery

NASA Technical Reports Server (NTRS)

Marshall, R. D.; Ellis, G. S.; Schubert, F. H.; Wynveen, R. A.

1979-01-01

Two electrochemical depolarized carbon dioxide concentrator subsystems were evaluated against baseline lithium hydroxide for (1) the baseline orbiter when expanded to accommodate a crew of seven (mission option one), (2) an extended duration orbiter with a power extension package to reduce fuel cell expendables (mission option two), and (3) an extended duration orbiter with a full capability power module to eliminate fuel cell expendables (mission option three). The electrochemical depolarized carbon dioxide concentrator was also compared to the solid amine regenerable carbon dioxide removal concept. Water recovery is not required for Mission Option One since sufficient water is generated by the fuel cells. The vapor compression distillation subsystem was evaluated for mission option two and three only. Weight savings attainable using the vapor compression distillation subsystem for water recovery versus on-board water storage were determined. Combined carbon dioxide removal and water recovery was evaluated to determine the effect on regenerable carbon dioxide removal subsystem selection.

Effects of alprazolam and clonidine on carbon dioxide-induced increases in anxiety rating in healthy human subjects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woods, S.W.; Krystal, J.H.; Heninger, G.R.

1989-01-01

In order to investigate possible neurobiologic mechanisms underlying carbon dioxide-induced anxiety, the effects of oral alprazolam 0.75 mg and intravenous clonidine 2 mcg/kg on CO/sub 2/-induced increases in ratings of subjective anxiety, pulse rate, and ventilation were measured in healthy human subjects. Pretreatment with alprazolam but not with clonidine significantly reduced the CO/sub 2/-induced increases in ratings of anxiety. Neither drug altered CO/sub 2/-induced increases in pulse rate or ventilatory responses. Clonidine did produce potent sedative and hypotensive effects. The behavioral data suggest that the mechanisms through which CO/sub 2/ induces anxiety-like effects involve neural systems regulated by benzodiazepine receptorsmore » and, secondly, that they appear not to require normal functioning of noradrenergic systems. Carbon dioxide may provide a useful model system for identification of new drugs with anxiolytic properties.« less

Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario

PubMed Central

Keller, David P.; Feng, Ellias Y.; Oschlies, Andreas

2014-01-01

The realization that mitigation efforts to reduce carbon dioxide emissions have, until now, been relatively ineffective has led to an increasing interest in climate engineering as a possible means of preventing the potentially catastrophic consequences of climate change. While many studies have addressed the potential effectiveness of individual methods there have been few attempts to compare them. Here we use an Earth system model to compare the effectiveness and side effects of afforestation, artificial ocean upwelling, ocean iron fertilization, ocean alkalinization and solar radiation management during a high carbon dioxide-emission scenario. We find that even when applied continuously and at scales as large as currently deemed possible, all methods are, individually, either relatively ineffective with limited (<8%) warming reductions, or they have potentially severe side effects and cannot be stopped without causing rapid climate change. Our simulations suggest that the potential for these types of climate engineering to make up for failed mitigation may be very limited. PMID:24569320

Effect of forage to concentrate ratio in dairy cow diets on emission of methane, carbon dioxide and ammonia, lactation performance and manure excretion

USDA-ARS?s Scientific Manuscript database

Holstein cows housed in a modified tie-stall barn were used to determine the effect of feeding diets with different forage to concentrate ratios (F:C) on performance and emission of methane (CH4), carbon dioxide (CO2) and manure ammonia-nitrogen (NH3-N). Eight multiparous cows (means ± standard devi...

Surface Chemistry and Tribology of Copper Surfaces in Carbon Dioxide and Water Vapor Environments

DTIC Science & Technology

2011-02-23

state that the copper brushes in the superconducting homopolar motor experience wear at rates greater than 3X10" wear /distance traveled when biased...positively. It has been found the motor operates best in an atmosphere of carbon dioxide and water vapor. The objective of our research therefore is...possible to prepare different chemical states of the Cu, as those produced in the motor electrodes under positive and negative bias. In situ XAS

Air quality aerometric data for the city of Cleveland from 1967 to 1970 for sulphur dioxide, suspended particulates, and nitrogen dioxide

NASA Technical Reports Server (NTRS)

Neustadter, H. E.; King, R. B.; Fordyce, J. S.; Burr, J. C., Jr.

1972-01-01

The NASA Lewis Research Center is assisting the City of Cleveland, Ohio, in its effort to monitor its air pollution. This report describes the Cleveland program of the past 4 years and the supportive Lewis program currently being developed. The data accumulated by Cleveland over the past 4 years are presented together with some preliminary statistical analyses indicating in a semiquantitive manner the degree of air pollution existing within the boundaries of Cleveland.

Carbon Dioxide Tucked into Basalt Converts to Rock

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGrail, Pete

2016-11-18

Carbon Sequestration or storing carbon dioxide underground may be one approach to reducing atmospheric levels of the greenhouse gas. Storing it in basalt formations creates a chemical reaction in which the CO2 is transformed into a mineral similar to limestone enabling permanent storage underground. A field study by researchers at the Department of Energy’s Pacific Northwest National Laboratory shows that chemical happens quickly. Within two years, CO2 injected underground in Washington state had converted to the carbonate mineral ankerite.

Carbon Dioxide Tucked into Basalt Converts to Rock

ScienceCinema

McGrail, Pete

2018-06-13

Carbon Sequestration or storing carbon dioxide underground may be one approach to reducing atmospheric levels of the greenhouse gas. Storing it in basalt formations creates a chemical reaction in which the CO2 is transformed into a mineral similar to limestone enabling permanent storage underground. A field study by researchers at the Department of Energy’s Pacific Northwest National Laboratory shows that chemical happens quickly. Within two years, CO2 injected underground in Washington state had converted to the carbonate mineral ankerite.

Pollution Detection Devices

NASA Technical Reports Server (NTRS)

1980-01-01

Barringer Research, Inc.'s COSPEC IVB (correlation spectrometer) can sense from a considerable distance emissions from a volcanic eruption. Remote sensor is capable of measuring sulfur dioxide and nitrogen dioxide in the atmosphere. An associated product, GASPEC, a compression of Non-dispersive Gas Filter Spectrometer, is an infrared/ultraviolet gas analyzer which can be used as either a ground based detector or in aircraft/spacecraft applications. Extremely sensitive, it is useful in air pollution investigations for detecting a variety of trace elements, vapors, which exist in the atmosphere in small amounts.

Determination of diffusion coefficients of carbon dioxide in water between 268 and 473 K in a high-pressure capillary optical cell with in situ Raman spectroscopic measurements

USGS Publications Warehouse

Lu, Wanjun; Guo, Huirong; Chou, I.-Ming; Burruss, R.C.; Li, Lanlan

2013-01-01

Accurate values of diffusion coefficients for carbon dioxide in water and brine at reservoir conditions are essential to our understanding of transport behavior of carbon dioxide in subsurface pore space. However, the experimental data are limited to conditions at low temperatures and pressures. In this study, diffusive transfer of carbon dioxide in water at pressures up to 45 MPa and temperatures from 268 to 473 K was observed within an optical capillary cell via time-dependent Raman spectroscopy. Diffusion coefficients were estimated by the least-squares method for the measured variations in carbon dioxide concentration in the cell at various sample positions and time. At the constant pressure of 20 MPa, the measured diffusion coefficients of carbon dioxide in water increase with increasing temperature from 268 to 473 K. The relationship between diffusion coefficient of carbon dioxide in water [D(CO2) in m2/s] and temperature (T in K) was derived with Speedy–Angell power-law approach as: D(CO2)=D0[T/Ts-1]m where D0 = 13.942 × 10−9 m2/s, Ts = 227.0 K, and m = 1.7094. At constant temperature, diffusion coefficients of carbon dioxide in water decrease with pressure increase. However, this pressure effect is rather small (within a few percent).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, M.

Six months after Saddam Hussein's torching of more than 700 Kuwaiti oil wells, health officials, meteorologists, and environmental experts convened during mid-August in Cambridge, Massachusetts, to assess the impact of the fires. The soot cloud produced by the fires hasn't produced a nuclear winter, nor are the carbon dioxide and other gases released going to have an appreciable effect on global warming, although regional weather changes are possible. So far adverse health effects from the heavy pall of pollution caused by the fires have been surprisingly mild. This isn't to say that premature deaths will not occur, but many scientistsmore » had feared much worse. Nevertheless, all researchers concede that the data for this particular conclusion are still preliminary, and they expressed concerns that health problems may worsen in the coming months. Most of the health effects are expected in a region blanketed by a plume of smoke 800 to 1,000 kilometers long. The average concentrations of the primary pollutants it contains, carbon-based particles and sulfur dioxide, are similar to those in any large urban center. Still, the oil fires increase the pollution burden on Kuwait, which already had a problem with particulates in the air, and some epidemiologists expect that the extra pollutants will take their toll.« less

Chemical and physical pretreatments of fruits and vegetables: Effects on drying characteristics and quality attributes - a comprehensive review.

PubMed

Deng, Li-Zhen; Mujumdar, Arun S; Zhang, Qian; Yang, Xu-Hai; Wang, Jun; Zheng, Zhi-An; Gao, Zhen-Jiang; Xiao, Hong-Wei

2017-12-20

Pretreatment is widely used before drying of agro-products to inactivate enzymes, enhance drying process and improve quality of dried products. In current work, the influence of various pretreatments on drying characteristics and quality attributes of fruits and vegetables is summarized. They include chemical solution (hyperosmotic, alkali, sulfite and acid, etc.) and gas (sulfur dioxide, carbon dioxide and ozone) treatments, thermal blanching (hot water, steam, super heated steam impingement, ohmic and microwave heating, etc), and non-thermal process (ultrasound, freezing, pulsed electric field, and high hydrostatic pressure, etc). Chemical pretreatments effectively enhance drying kinetics, meanwhile, it causes soluble nutrients losing, trigger food safety issues by chemical residual. Conventional hot water blanching has significant effect on inactivating various undesirable enzymatic reactions, destroying microorganisms, and softening the texture, as well as facilitating drying rate. However, it induces undesirable quality of products, e.g., loss of texture, soluble nutrients, pigment and aroma. Novel blanching treatments, such as high-humidity hot air impingement blanching, microwave and ohmic heat blanching can reduce the nutrition loss and are more efficient. Non-thermal technologies can be a better alternative to thermal blanching to overcome these drawbacks, and more fundamental researches are needed for better design and scale up.

Current research and prospects for health effects of nanoparticles on offspring

NASA Astrophysics Data System (ADS)

Umezawa, Masakazu; Takeda, Ken

2011-10-01

Caution in handling ceramic nanoparticles is required by workers and consumers if they are to be used safely and profitably. The small size of nanoparticles can bestow high reactivity and unique translocational properties. Studies have shown that exposure to some types of nanoparticles affects the respiratory, cardiovascular and central nervous systems and various organs. When pregnant mice were exposed to nanoparticles, various organs of offspring are also affected. Our recent studies showed that prenatal exposure to nanoparticles (carbon black and titanium dioxide) causes long-term adverse effects on the reproductive, respiratory and central nervous systems of offspring. The effects of nanoparticles on fetuses and children and the possibility of them leading to the onset of diseases in adulthood are of concern. Thus, it is important to research the risk of unintentional exposure to nanoparticles, including ceramic nanoparticles, from the environment and to attempt to identify methods to protect against their toxicity.

Disintegration of Carbon Dioxide Molecules in a Microwave Plasma Torch

PubMed Central

Kwak, Hyoung S.; Uhm, Han S.; Hong, Yong C.; Choi, Eun H.

2015-01-01

A pure carbon dioxide torch is generated by making use of 2.45 GHz microwave. Carbon dioxide gas becomes the working gas and produces a stable carbon dioxide torch. The torch volume is almost linearly proportional to the microwave power. Temperature of the torch flame is measured by making use of optical spectroscopy and thermocouple. Two distinctive regions are exhibited, a bright, whitish region of high-temperature zone and a bluish, dimmer region of relatively low-temperature zone. Study of carbon dioxide disintegration and gas temperature effects on the molecular fraction characteristics in the carbon dioxide plasma of a microwave plasma torch under atmospheric pressure is carried out. An analytical investigation of carbon dioxide disintegration indicates that substantial fraction of carbon dioxide molecules disintegrate and form other compounds in the torch. For example, the normalized particle densities at center of plasma are given by nCO2/nN = 6.12 × 10−3, nCO/nN = 0.13, nC/nN = 0.24, nO/nN = 0.61, nC2/nN = 8.32 × 10−7, nO2/nN = 5.39 × 10−5, where nCO2, nCO, nC, nO, nC2, and nO2 are carbon dioxide, carbon monoxide, carbon and oxygen atom, carbon and oxygen molecule densities, respectively. nN is the neutral particle density. Emission profiles of the oxygen and carbon atom radicals and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. PMID:26674957

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waldhoff, Stephanie T.; Anthoff, David; Rose, Steven K.

We use FUND 3.8 to estimate the social cost of four greenhouse gases: carbon dioxide, methane, nitrous oxide, and sulphur hexafluoride emissions. The damage potential for each gas—the ratio of the social cost of the non-carbon dioxide greenhouse gas to the social cost of carbon dioxide—is also estimated. The damage potentials are compared to several metrics, focusing in particular on the global warming potentials, which are frequently used to measure the trade-off between gases in the form of carbon dioxide equivalents. We find that damage potentials could be significantly higher than global warming potentials. This finding implies that previous papersmore » have underestimated the relative importance of reducing non-carbon dioxide greenhouse gas emissions from an economic damage perspective. We show results for a range of sensitivity analyses: carbon dioxide fertilization on agriculture productivity, terrestrial feedbacks, climate sensitivity, discounting, equity weighting, and socioeconomic and emissions scenarios. The sensitivity of the results to carbon dioxide fertilization is a primary focus as it is an important element of climate change that has not been considered in much of the previous literature. We estimate that carbon dioxide fertilization has a large positive impact that reduces the social cost of carbon dioxide with a much smaller effect on the other greenhouse gases. As a result, our estimates of the damage potentials of methane and nitrous oxide are much higher compared to estimates that ignore carbon dioxide fertilization. As a result, our base estimates of the damage potential for methane and nitrous oxide that include carbon dioxide fertilization are twice their respective global warming potentials. Our base estimate of the damage potential of sulphur hexafluoride is similar to the one previous estimate, both almost three times the global warming potential.« less

Extracorporeal Carbon Dioxide Removal Enhanced by Lactic Acid Infusion in Spontaneously Breathing Conscious Sheep.

PubMed

Scaravilli, Vittorio; Kreyer, Stefan; Belenkiy, Slava; Linden, Katharina; Zanella, Alberto; Li, Yansong; Dubick, Michael A; Cancio, Leopoldo C; Pesenti, Antonio; Batchinsky, Andriy I

2016-03-01

The authors studied the effects on membrane lung carbon dioxide extraction (VCO2ML), spontaneous ventilation, and energy expenditure (EE) of an innovative extracorporeal carbon dioxide removal (ECCO2R) technique enhanced by acidification (acid load carbon dioxide removal [ALCO2R]) via lactic acid. Six spontaneously breathing healthy ewes were connected to an extracorporeal circuit with blood flow 250 ml/min and gas flow 10 l/min. Sheep underwent two randomly ordered experimental sequences, each consisting of two 12-h alternating phases of ALCO2R and ECCO2R. During ALCO2R, lactic acid (1.5 mEq/min) was infused before the membrane lung. Caloric intake was not controlled, and animals were freely fed. VCO2ML, natural lung carbon dioxide extraction, total carbon dioxide production, and minute ventilation were recorded. Oxygen consumption and EE were calculated. ALCO2R enhanced VCO2ML by 48% relative to ECCO2R (55.3 ± 3.1 vs. 37.2 ± 3.2 ml/min; P less than 0.001). During ALCO2R, minute ventilation and natural lung carbon dioxide extraction were not affected (7.88 ± 2.00 vs. 7.51 ± 1.89 l/min, P = 0.146; 167.9 ± 41.6 vs. 159.6 ± 51.8 ml/min, P = 0.063), whereas total carbon dioxide production, oxygen consumption, and EE rose by 12% each (223.53 ± 42.68 vs. 196.64 ± 50.92 ml/min, 215.3 ± 96.9 vs. 189.1 ± 89.0 ml/min, 67.5 ± 24.0 vs. 60.3 ± 20.1 kcal/h; P less than 0.001). ALCO2R was effective in enhancing VCO2ML. However, lactic acid caused a rise in EE that made ALCO2R no different from standard ECCO2R with respect to ventilation. The authors suggest coupling lactic acid-enhanced ALCO2R with active measures to control metabolism.

IDENTIFICATION OF NEW DRINKING WATER DISINFECTION BY-PRODUCTS FROM OZONE, CHLORINE DIOXIDE, CHLORAMINE, AND CHLORINE

EPA Science Inventory

Due to concern over the potential adverse health effects of trihalomethanes (THMs) and other chlorinated by-products in chlorinated drinking water, alternative disinfection methods are being explored. Ozone, chlorine dioxide, and chloramine are currently popular alternatives to ...

IDENTIFICATION OF CHLORINE DIOXIDE DRINKING WATER DISINFECTION BY-PRODUCTS FORMED AT HIGH BROMIDE LEVELS

EPA Science Inventory

Due to concern over the potential adverse health effects of trihalomethanes (THMs), haloacetic acids, and other chlorinated by-products in chlorinated drinking water, alternative disinfection methods are being explored. Chlorine dioxide is a popular alternative, with over 500 dri...

Genotoxic Effects of Titanium Dioxide and Cerium Dioxide Nanoparticles in Human Respiratory Epithelial Cells

EPA Science Inventory

The nanomaterial industry has recently seen rapid growth, therefore, the risk assessment of human exposure to nanomaterials in consumer products is of paramount importance. The genotoxicity of nanomaterials is a fundamental aspect of hazard identification and regulatory guidance....

Reduction of pollutants in painting operation and suggestion of an optimal technique for extracting titanium dioxide from paint sludge in car manufacturing industries--case study (SAIPA).

PubMed

Khezri, Seyed Mostafa; Shariat, Seyed Mahmood; Tabibian, Sahar

2012-06-01

Paint sludge of car manufacturing industries are not disposed in landfills, since they contain hazardous materials with a high concentration of chromium, aluminum, titanium, barium, copper, Iron, magnesium, strontium, and so on. Thus, it is essential to find solutions in order to neutralize them or suggest cost-effective techniques, which are also environmentally acceptable. Because, this sludge contains considerable amounts of Ti pigments and unbaked resins, recycling these pigments--which could be used in a variety of industries such as paint factories--is an appropriate subject for further research. In this article, with the aim of identification of main pollutants in order to eliminate them and suggest a cost-effective solution to recover the sludge, a large number of tests including X-ray fluorescence spectroscopy, X ray diffraction spectroscopy, and diffusion thermal analysis are conducted to determine types and concentration of elements, and combinations of paint sludge in car manufacturing industries. As titanium dioxide (TiO₂) is widely used as the main pigment of automobile paints, an optimal technique is suggested for extracting TiO₂ with high purity percentage through adopting scientific methods such as membrane and electrolysis.

Inactivation of the microbiota and effect on the quality attributes of pineapple juice using a continuous flow ultrasound-assisted supercritical carbon dioxide system.

PubMed

Paniagua-Martínez, I; Mulet, A; García-Alvarado, M A; Benedito, J

2018-01-01

Supercritical carbon dioxide inactivation technology represents a promising nonthermal processing method, as it causes minimum impact on the nutritional food properties. The aim of this study was to analyze the combined effect of supercritical carbon dioxide and high-power ultrasound on the inactivation of natural microbiota and the quality attributes of pineapple juice treated in a continuous flow system. Different juice residence times (3.06-4.6 min), at 100 bar and 31.5 ℃, were used. The results indicated that the microbiota inactivation was complete and the differences obtained in the quality attributes (2.2% for pH, 4.8% for °Brix, 2% for vitamin C) were minimal. During storage, microorganisms were not able to recover and the vitamin C decrease could be limited to 8.2% after four weeks. The results demonstrated that the supercritical carbon dioxide-high-power ultrasound technique could be an excellent alternative for the cold pasteurization of pineapple juice.

Chloroxyanion Residue on Seeds and Sprouts after Chlorine Dioxide Sanitation of Alfalfa Seed.

PubMed

Smith, David J; Herges, Grant R

2018-02-28

The effects of a 6-h chlorine dioxide sanitation of alfalfa seed (0, 50, 100, and 200 mg/kg seed) on total coliform bacteria, seed germination, and the presence of chlorate and perchlorate residues in seed rinse, seed soak, and alfalfa sprouts was determined. Chlorate residues in 20,000 mg/L calcium hypochlorite, commonly used to disinfect seed, were quantified. Chlorine dioxide treatment reduced (P < 0.05) total coliforms on seeds with no effect (P > 0.05) on germination. Dose-dependent sodium chlorate residues were present in seed rinse (4.1 to 31.2 μg/g seed) and soak (0.7 to 8.3 μg/g seed) waters, whereas chlorate residues were absent (LOQ 5 ng/g) in sprouts, except for 2 of 5 replicates from the high chlorine dioxide treatment. Copious chlorate residues were present (168 to 1260 mg/L) in freshly prepared 20,000 mg/L calcium hypochlorite solution, and storage at room temperature increased chlorate residues significantly (P < 0.01).

Antimicrobial polymers - The antibacterial effect of photoactivated nano titanium dioxide polymer composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huppmann, T., E-mail: teresa.huppmann@tum.de; Leonhardt, S., E-mail: stefan.leonhardt@mytum.de, E-mail: erhard.krampe@tum.de; Krampe, E., E-mail: stefan.leonhardt@mytum.de, E-mail: erhard.krampe@tum.de

To obtain a polymer with antimicrobial properties for medical and sanitary applications nanoscale titanium dioxide (TiO{sub 2}) particles have been incorporated into a medical grade polypropylene (PP) matrix with various filler contents (0 wt %, 2 wt %, 10 wt % and 15 wt %). The standard application of TiO{sub 2} for antimicrobial efficacy is to deposit a thin TiO{sub 2} coating on the surface. In contrast to the common way of applying a coating, TiO{sub 2} particles were applied into the bulk polymer. With this design we want to ensure antimicrobial properties even after application of impact effects thatmore » could lead to surface defects. The filler material (Aeroxide® TiO{sub 2} P25, Evonik) was applied via melt compounding and the compounding parameters were optimized with respect to nanoscale titanium dioxide. In a next step the effect of UV-irradiation on the compounds concerning their photocatalytic activity, which is related to the titanium dioxide amount, was investigated. The photocatalytic effect of TiO{sub 2}-PP-composites was analyzed by contact angle measurement, by methylene blue testing and by evaluation of inactivation potential for Escherichia coli (E.coli) bacteria. The dependence of antimicrobial activity on the filler content was evaluated, and on the basis of different titanium dioxide fractions adequate amounts of additives within the compounds were discussed. Specimens displayed a higher photocatalytic and also antimicrobial activity and lower contact angles with increasing titania content. The results suggest that the presence of titania embedded in the PP matrix leads to a surface change and a photocatalytic effect with bacteria killing result.« less

Effect of Carbon Dioxide on the Twinkling Artifact in Ultrasound Imaging of Kidney Stones: A Pilot Study.

PubMed

Simon, Julianna C; Wang, Yak-Nam; Cunitz, Bryan W; Thiel, Jeffrey; Starr, Frank; Liu, Ziyue; Bailey, Michael R

2017-05-01

Bone demineralization, dehydration and stasis put astronauts at increased risk of forming kidney stones in space. The color-Doppler ultrasound "twinkling artifact," which highlights kidney stones with color, can make stones readily detectable with ultrasound; however, our previous results suggest twinkling is caused by microbubbles on the stone surface which could be affected by the elevated levels of carbon dioxide found on space vehicles. Four pigs were implanted with kidney stones and imaged with ultrasound while the anesthetic carrier gas oscillated between oxygen and air containing 0.8% carbon dioxide. On exposure of the pigs to 0.8% carbon dioxide, twinkling was significantly reduced after 9-25 min and recovered when the carrier gas returned to oxygen. These trends repeated when pigs were again exposed to 0.8% carbon dioxide followed by oxygen. The reduction of twinkling caused by exposure to elevated carbon dioxide may make kidney stone detection with twinkling difficult in current space vehicles. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Predator-induced reduction of freshwater carbon dioxide emissions

NASA Astrophysics Data System (ADS)

Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

2013-03-01

Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

Chlorine dioxide against bacteria and yeasts from the alcoholic fermentation

PubMed Central

Meneghin, Silvana Perissatto; Reis, Fabricia Cristina; de Almeida, Paulo Garcia; Ceccato-Antonini, Sandra Regina

2008-01-01

The ethanol production in Brazil is carried out by fed-batch or continuous process with cell recycle, in such way that bacterial contaminants are also recycled and may be troublesome due to the substrate competition. Addition of sulphuric acid when inoculum cells are washed can control the bacterial growth or alternatively biocides are used. This work aimed to verify the effect of chlorine dioxide, a well-known biocide for bacterial decontamination of water and equipments, against contaminant bacteria (Bacillus subtilis, Lactobacillus plantarum, Lactobacillus fermentum and Leuconostoc mesenteroides) from alcoholic fermentation, through the method of minimum inhibitory concentration (MIC), as well as its effect on the industrial yeast inoculum. Lower MIC was found for B. subtilis (10 ppm) and Leuconostoc mesenteroides (50 ppm) than for Lactobacillus fermentum (75 ppm) and Lactobacillus plantarum (125 ppm). Additionally, these concentrations of chlorine dioxide had similar effects on bacteria as 3 ppm of Kamoran® (recommended dosage for fermentation tanks), exception for B. subtilis, which could not be controlled at this Kamoran® dosage. The growth of industrial yeasts was affected when the concentration of chlorine dioxide was higher than 50 ppm, but the effect was slightly dependent on the type of yeast strain. Smooth yeast colonies (dispersed cells) seemed to be more sensitive than wrinkled yeast colonies (clustered cells/pseudohyphal growth), both isolated from an alcohol-producing unit during the 2006/2007 sugar cane harvest. The main advantage in the usage of chlorine dioxide that it can replace antibiotics, avoiding the selection of resistant populations of microorganisms. PMID:24031227

Combination of super chilling and high carbon dioxide concentration techniques most effectively to preserve freshness of shell eggs during long-term storage.

PubMed

Yanagisawa, T; Ariizumi, M; Shigematsu, Y; Kobayashi, H; Hasegawa, M; Watanabe, K

2010-01-01

This study was made to examine the combined effects of stored temperature and carbon dioxide atmosphere on shell egg quality. The shell eggs were packed into polyethylene terephthalate/polyethylene (PET/PE) pouches and stored at 0 degrees C (super chilling), 10 degrees C, and 20 degrees C, respectively for 90 d. The atmospheric carbon dioxide concentration was controlled to obtain the 3 concentration levels of high (about 2.0%), medium (about 0.5%), and low (below 0.01%). Changes in Haugh unit (HU) values, weakening of vitelline membranes, and generation of volatiles were analyzed to evaluate the freshness of shell eggs. Results showed that, compared with the other combinations, the technique of super chilling and high carbon dioxide concentration enabled shell eggs to be most effectively stored for 90 d, based on estimations of the statistical significances of differences in HU values, and on maintaining the initial HU values during storage. In addition, the storage of shell eggs using this combination technique was found to significantly prevent the weakening of the vitelline membrane based on the estimations of numbers of eggs without vitelline membrane breakage when eggs broke, and significantly lowered the incidence of hexanal in the yolk from exposure to the gas chromatographic-mass spectrometric analyses of volatiles. Thus, these results confirmed that the combination of super chilling and high carbon dioxide concentration was the most effective technique for preserving shell eggs during a long term of 90 d compared with other combination techniques.

Exposure to nano-size titanium dioxide causes oxidative damages in human mesothelial cells: The crystal form rather than size of particle contributes to cytotoxicity.

PubMed

Hattori, Kenji; Nakadate, Kazuhiko; Morii, Akane; Noguchi, Takumi; Ogasawara, Yuki; Ishii, Kazuyuki

2017-10-14

Exposure to nanoparticles such as carbon nanotubes has been shown to cause pleural mesothelioma similar to that caused by asbestos, and has become an environmental health issue. Not only is the percutaneous absorption of nano-size titanium dioxide particles frequently considered problematic, but the possibility of absorption into the body through the pulmonary route is also a concern. Nevertheless, there are few reports of nano-size titanium dioxide particles on respiratory organ exposure and dynamics or on the mechanism of toxicity. In this study, we focused on the morphology as well as the size of titanium dioxide particles. In comparing the effects between nano-size anatase and rutile titanium dioxide on human-derived pleural mesothelial cells, the anatase form was shown to be actively absorbed into cells, producing reactive oxygen species and causing oxidative damage to DNA. In contrast, we showed for the first time that the rutile form is not easily absorbed by cells and, therefore, does not cause oxidative DNA damage and is significantly less damaging to cells. These results suggest that with respect to the toxicity of titanium dioxide particles on human-derived mesothelial cells, the crystal form rather than the particle size has a greater effect on cellular absorption. Also, it was indicated that the difference in absorption is the primary cause of the difference in the toxicity against mesothelial cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Carbon dioxide therapy and hyaluronic acid for cosmetic correction of the nasolabial folds.

PubMed

Nisi, Giuseppe; Cuomo, Roberto; Brandi, Cesare; Grimaldi, Luca; Sisti, Andrea; D'Aniello, Carlo

2016-06-01

The main application of hyaluronic acid filling, in esthetic medicine, is the augmentation of soft tissues. The carbon dioxide therapy, instead, improves quality and elasticity of the dermis and increases the oxygen release to the tissue through an enhancing of the Bohr's effect. The aim of the study was to compare the efficacy, tolerability, and effect duration of hyaluronic acid fillers and the use of carbon dioxide therapy plus hyaluronic acid in the cosmetic correction of nasolabial folds. Forty healthy female patients received a blinded and randomized treatment on nasolabial folds (hyaluronic acid in group A and hyaluronic acid plus subcutaneous injections of carbon dioxide in group B) for cosmetic correction of the nasolabial folds. The results were evaluated by two blinded plastic surgeons after the implant (1 week, 4 and 6 months) using a 1-5 graduated scale (GAIS), and at the same time, each patient was asked to express her opinion about the cosmetic result. Any long-term adverse reaction was reported. The blinded evaluation at 4 and 6 months from the implant shows in all patients a maintenance of a good cosmetic result higher for the side treated with carbon dioxide therapy plus hyaluronic acid. At the control visit, 6 months after the treatment, the patients treated with hyaluronic acid plus carbon dioxide therapy maintain a satisfactory esthetic result while the nasolabial fold treated only with hyaluronic acid shows, in almost all patients, a come back to pretreatment appearance. © 2016 Wiley Periodicals, Inc.

Business Travel | Climate Neutral Research Campuses | NREL

Science.gov Websites

evaluated for research campus climate action plans, and it can be surprisingly large. At Cornell University , for example, business air travel generated 27,000 tons of carbon dioxide in 2008, accounting for 8.5 campus. The following outlines resources and opportunities for research campuses to manage business

Mapping the Mineral Resource Base for Mineral Carbon-Dioxide Sequestration in the Conterminous United States

USGS Publications Warehouse

Krevor, S.C.; Graves, C.R.; Van Gosen, B. S.; McCafferty, A.E.

2009-01-01

This database provides information on the occurrence of ultramafic rocks in the conterminous United States that are suitable for sequestering captured carbon dioxide in mineral form, also known as mineral carbon-dioxide sequestration. Mineral carbon-dioxide sequestration is a proposed greenhouse gas mitigation technology whereby carbon dioxide (CO2) is disposed of by reacting it with calcium or magnesium silicate minerals to form a solid magnesium or calcium carbonate product. The technology offers a large capacity to permanently store CO2 in an environmentally benign form via a process that takes little effort to verify or monitor after disposal. These characteristics are unique among its peers in greenhouse gas disposal technologies. The 2005 Intergovernmental Panel on Climate Change report on Carbon Dioxide Capture and Storage suggested that a major gap in mineral CO2 sequestration is locating the magnesium-silicate bedrock available to sequester the carbon dioxide. It is generally known that silicate minerals with high concentrations of magnesium are suitable for mineral carbonation. However, no assessment has been made in the United States that details their geographical distribution and extent, nor has anyone evaluated their potential for use in mineral carbonation. Researchers at Columbia University and the U.S. Geological Survey have developed a digital geologic database of ultramafic rocks in the conterminous United States. Data were compiled from varied-scale geologic maps of magnesium-silicate ultramafic rocks. The focus of our national-scale map is entirely on ultramafic rock types, which typically consist primarily of olivine- and serpentine-rich rocks. These rock types are potentially suitable as source material for mineral CO2 sequestration.

A Bibliometric Analysis of Research on Supported Ionic Liquid Membranes during the 1995–2015 Period: Study of the Main Applications and Trending Topics

PubMed Central

Abejón, Ricardo; Pérez-Acebo, Heriberto; Garea, Aurora

2017-01-01

A bibliometric analysis based on Scopus database was performed to identify the global research trends related to Supported Ionic Liquid Membranes (SILMs) during the time period from 1995 to 2015. This work tries to improve the understanding of the most relevant research topics and applications. The results from the analysis reveal that only after 2005 the research efforts focused on SILMs became significant, since the references found before that year are scarce. The most important research works on the four main application groups for SILMs defined in this work (carbon dioxide separation, other gas phase separations, pervaporation and liquid phase separations) were summarized in this paper. Carbon dioxide separation appeared as the application that has received by far the most attention according to the research trends during the analysed period. Comments about other significant applications that are gaining attention, such as the employment of SILMs in analytical tasks or their consideration for the production of fuel cells, have been included. PMID:29112172

Influence of drinking water treatments on chlorine dioxide consumption and chlorite/chlorate formation.

PubMed

Sorlini, Sabrina; Gialdini, Francesca; Biasibetti, Michela; Collivignarelli, Carlo

2014-05-01

Disinfection is the last treatment stage of a Drinking Water Treatment Plant (DWTP) and is carried out to maintain a residual concentration of disinfectant in the water distribution system. Chlorine dioxide (ClO2) is a widely used chemical employed for this purpose. The aim of this work was to evaluate the influence of several treatments on chlorine dioxide consumption and on chlorite and chlorate formation in the final oxidation/disinfection stage. A number of tests was performed at laboratory scale employing water samples collected from the DWTP of Cremona (Italy). The following processes were studied: oxidation with potassium permanganate, chlorine dioxide and sodium hypochlorite, coagulation/flocculation with ferric chloride and aluminum sulfate, filtration and adsorption onto activated carbon. The results showed that the chlorine dioxide demand is high if sodium hypochlorite or potassium permanganate are employed in pre-oxidation. On the other hand, chlorine dioxide leads to the highest production of chlorite and chlorate. The coagulation/flocculation process after pre-oxidation shows that chlorine dioxide demand decreases if potassium permanganate is employed as an oxidant, both with ferric chloride and aluminum sulfate. Therefore, the combination of these processes leads to a lower production of chlorite and chlorate. Aluminum sulfate is preferable in terms of the chlorine dioxide demand reduction and minimization of the chlorite and chlorate formation. Activated carbon is the most effective solution as it reduced the chlorine dioxide consumption by about 50% and the DBP formation by about 20-40%. Copyright © 2014 Elsevier Ltd. All rights reserved.

Thirsty Walls: A New Paradigm for Air Revitalization in Life Support

NASA Technical Reports Server (NTRS)

Graf, John; Brennecke, Joan; Weislogel, Mark

2015-01-01

Carbon Dioxide removal systems on submarines are compact and reliable. They use solubility chemistry. They spray a Carbon Dioxide adsorbing chemical directly into the air stream, and allow the liquid to settle. Carbon Dioxide removal systems on ISS are large and need repair. They use adsorption chemistry. They force air through a bed packed with granular zeolite, and heat the bed to desorb the Carbon Dioxide. The thermal cycles cause the zeolite to dust. New advances in additive manufacturing, and a better understanding of uid behavior in microgravity make it possible to expose a liquid directly to air in a microgravity environment. It is now practical to use submarine style solubility chemistry for atmosphere revitalization in space. It is now possible to develop space systems that achieve submarine levels of reliability. New developments in Ionic Liquid research make it possible to match the solubility performance characteristics of MEA used on submarines - with Ionic Liquids that do not release chemical vapors into the air. "Thirsty Walls" provide gentle, passive contact between ventilation air and Air Revitalization functions of temperature control, relative humidity control, and Carbon Dioxide removal. "Thirsty Walls" eliminates the need of large blowers and compressors that need to force air at high velocities through restrictive Air Revitalization hardware.

Multivariate co-integration analysis of the Kaya factors in Ghana.

PubMed

Asumadu-Sarkodie, Samuel; Owusu, Phebe Asantewaa

2016-05-01

The fundamental goal of the Government of Ghana's development agenda as enshrined in the Growth and Poverty Reduction Strategy to grow the economy to a middle income status of US$1000 per capita by the end of 2015 could be met by increasing the labour force, increasing energy supplies and expanding the energy infrastructure in order to achieve the sustainable development targets. In this study, a multivariate co-integration analysis of the Kaya factors namely carbon dioxide, total primary energy consumption, population and GDP was investigated in Ghana using vector error correction model with data spanning from 1980 to 2012. Our research results show an existence of long-run causality running from population, GDP and total primary energy consumption to carbon dioxide emissions. However, there is evidence of short-run causality running from population to carbon dioxide emissions. There was a bi-directional causality running from carbon dioxide emissions to energy consumption and vice versa. In other words, decreasing the primary energy consumption in Ghana will directly reduce carbon dioxide emissions. In addition, a bi-directional causality running from GDP to energy consumption and vice versa exists in the multivariate model. It is plausible that access to energy has a relationship with increasing economic growth and productivity in Ghana.

Development and Application of Nonlinear Land-Use Regression Models

NASA Astrophysics Data System (ADS)

Champendal, Alexandre; Kanevski, Mikhail; Huguenot, Pierre-Emmanuel

2014-05-01

The problem of air pollution modelling in urban zones is of great importance both from scientific and applied points of view. At present there are several fundamental approaches either based on science-based modelling (air pollution dispersion) or on the application of space-time geostatistical methods (e.g. family of kriging models or conditional stochastic simulations). Recently, there were important developments in so-called Land Use Regression (LUR) models. These models take into account geospatial information (e.g. traffic network, sources of pollution, average traffic, population census, land use, etc.) at different scales, for example, using buffering operations. Usually the dimension of the input space (number of independent variables) is within the range of (10-100). It was shown that LUR models have some potential to model complex and highly variable patterns of air pollution in urban zones. Most of LUR models currently used are linear models. In the present research the nonlinear LUR models are developed and applied for Geneva city. Mainly two nonlinear data-driven models were elaborated: multilayer perceptron and random forest. An important part of the research deals also with a comprehensive exploratory data analysis using statistical, geostatistical and time series tools. Unsupervised self-organizing maps were applied to better understand space-time patterns of the pollution. The real data case study deals with spatial-temporal air pollution data of Geneva (2002-2011). Nitrogen dioxide (NO2) has caught our attention. It has effects on human health and on plants; NO2 contributes to the phenomenon of acid rain. The negative effects of nitrogen dioxides on plants are the reduction of the growth, production and pesticide resistance. And finally, the effects on materials: nitrogen dioxide increases the corrosion. The data used for this study consist of a set of 106 NO2 passive sensors. 80 were used to build the models and the remaining 36 have constituted the testing set. Missing data have been completed using multiple linear regression and annual average values of pollutant concentrations were computed. All sensors are dispersed homogeneously over the central urban area of Geneva. The main result of the study is that the nonlinear LUR models developed have demonstrated their efficiency in modelling complex phrenomena of air pollution in urban zones and significantly reduced the testing error in comparison with linear models. Further research deals with the development and application of other non-linear data-driven models (Kanevski et al. 2009). References Kanevski M., Pozdnoukhov A. and Timonin V. (2009). Machine Learning for Spatial Environmental Data. Theory, Applications and Software. EPLF Press, Lausanne.

Engineering self-assembled bioreactors from protein microcompartments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savage, David

2016-10-12

The goals of this research are to understand how organisms such as bacteria segregate certain metabolic processes inside of specific structures, or “microcompartments,” in the cell and apply this knowledge to develop novel engineered microcompartments for use in nanotechnology and metabolic engineering. For example, in some bacteria, self-assembling protein microcompartments called carboxysomes encapsulate the enzymes involved in carbon fixation, enabling the cell to utilize carbon dioxide more effectively than if the enzymes were free in the cell. The proposed research will determine how structures such as carboxysomes assemble and function in bacteria and develop a means for creating novel, syntheticmore » microcompartments for optimizing production of specific energy-rich compounds.« less

Supplement to the Second Addendum (1986) to Air Quality Criteria for Particulate Matter and Sulfur Oxides (1982): Assessment of New Findings on Sulfur Dioxide and Acute Exposure Health Effects in Asthmatic Individuals (1994)

EPA Science Inventory

The present Supplement to the Second Addendum (1986) to the document Air Quality Criteria for Particulate Matter and Sulfur Oxides (1982) focuses on evaluation of newly available controlled human exposure studies of acute (a\\1h) sulfur dioxide (SO2) exposure effects on pulmonary ...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poenkae, A.

The weekly changes in ambient sulfur dioxide, nitrogen dioxide, and temperature were compared with the figures for respiratory infection in children and adults and for absenteeism from day-care centers (DCC), schools, and workplaces during a 1-year period in Helsinki. The annual average level of sulfur dioxide was 21 micrograms/m3 and of nitrogen dioxide 47 micrograms/m3; the average temperature was +3.1 degrees C. The levels of these pollutants and the temperature were significantly correlated with the number of upper respiratory infections reported from health centers. Low temperature also correlated with increased frequency of acute tonsillitis, of lower respiratory tract infection amongmore » DCC children, and of absenteeism from day-care centers, schools and workplaces. Furthermore, a significant association was found between levels of sulfur dioxide and absenteeism. After statistical standardization for temperature, no other correlations were observed apart from that between high levels of sulfur dioxide and numbers of upper respiratory tract infections diagnosed at health centers (P = 0.04). When the concentrations of sulfur dioxide were above the mean, the frequency of the upper respiratory tract infections was 15% higher than that during the periods of low concentration. The relative importance of the effects of low-level air pollution and low temperature on health is difficult to assess.« less

Importance of carbon dioxide in the critical patient: Implications at the cellular and clinical levels.

PubMed

Morales Quinteros, Luis; Bringué Roque, Josep; Kaufman, David; Artigas Raventós, Antonio

2018-02-24

Important recent insights have emerged regarding the cellular and molecular role of carbon dioxide (CO 2 ) and the effects of hypercapnia. The latter may have beneficial effects in patients with acute lung injury, affording reductions in pulmonary inflammation, lessened oxidative alveolar damage, and the regulation of innate immunity and host defenses by inhibiting the expression of inflammatory cytokines. However, other studies suggest that CO 2 can have deleterious effects upon the lung, reducing alveolar wound repair in lung injury, decreasing the rate of reabsorption of alveolar fluid, and inhibiting alveolar cell proliferation. Clearly, hypercapnia has both beneficial and harmful consequences, and it is important to determine the net effect under specific conditions. The purpose of this review is to describe the immunological and physiological effects of carbon dioxide, considering their potential consequences in patients with acute respiratory failure. Copyright © 2018 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

The Effects of Voltage and Concentration of Sodium Bicarbonate on Electrochemical Synthesis of Ethanol from Carbon Dioxide Using Brass as Cathode

NASA Astrophysics Data System (ADS)

Ramadan, Septian; Fariduddin, Sholah; Rizki Aminudin, Afianti; Kurnia Hayatri, Antisa; Riyanto

2017-11-01

The effects of voltage and concentration of sodium bicarbonate were investigated to determine the optimum conditions of the electrochemical synthesis process to convert carbon dioxide into ethanol. The conversion process is carried out using a sodium bicarbonate electrolyte solution in an electrochemical synthesis reactor equipped with a cathode and anode. As the cathode was used brass, while as the anode carbon was utilized. Sample of the electrochemical synthesis process was analyzed by gas chromatography to determine the content of the compounds produced. The optimum electrochemical synthesis conditions to convert carbon dioxide into ethanol are voltage and concentration of sodium bicarbonate are 3 volts and 0.4 M with ethanol concentration of 1.33%.

An Evaluation of the Feasibility of Combining Carbon Dioxide Flooding Technologies with Microbial Enhanced Oil Recovery Technologies in Order To Sequester Carbon Dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Todd French; Lew Brown; Rafael Hernandez

2009-08-19

The need for more energy as our population grows results in an increase in the amount of CO2 introduced into the atmosphere. The effect of this introduction is currently debated intensely as to the severity of the effect of this. The bjective of this investigation was to determine if the production of more energy (i.e. petroleum) and the sequestration of CO2 could be coupled into one process. Carbon dioxide flooding is a well-established technique that introduces Compressed CO2 into a subsurface oil-bearing formation to aide in liquefying harder to extract petroleum and enhancing its mobility towards the production wells.

Further studies on the effect of nitrogen dioxide on mast cells: The effect of the metabolite, nitrite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujimaki, Hidekazu; Ozawa, Masashi; Bissonnette, E.

1993-05-01

To evaluate the relationship between atmospheric nitrogen dioxide exposure and the development of allergic diseases, the effects of nitrite as a chemical product of inhaled nitrogen dioxide on mast cell functions were investigated. We have studied nitride-induced histamine release from two functionally distinct mast cell populations, namely peritoneal mast cells (PMC) and intestinal mucosal mast cells (IMMC) of Nippostrongylus brasiliensis-infected rats. High concentrations of nitrite alone (10, 20, and 50 mM) induced histamine release from IMMC, but not from PMC. Moreover, histamine release from PMC and IMMC stimulated with sensitizing antigen was significantly enhanced by pretreatment with 50 mM nitritemore » or nitrate. No differences in histamine release from nitrite-treated and control PMC were seen below 1 mM. To investigate the effect of nitrite on tumor cell cytotoxic activity, PMC were incubated with various concentrations of nitrite. Pretreatment with 5 and 50 mM nitrite markedly depressed tumor necrosis factor (TNF)-[alpha]-dependent natural cytotoxicity of PMC for the tumor target WEHI-164. Thus, high concentrations of nitrite enhanced mast cell histamine release, but depressed TNF-[alpha]-dependent cytotoxicity. However, low concentrations of nitrite (<1 mM) that would normally be produced by short-term atmospheric exposure to nitrogen dioxide may have no significant effects on mast cell functions. 27 refs., 3 figs., 1 tab.« less

Effect of Porosity Parameters and Surface Chemistry on Carbon Dioxide Adsorption in Sulfur-Doped Porous Carbons.

PubMed

Wang, En-Jie; Sui, Zhu-Yin; Sun, Ya-Nan; Ma, Zhuang; Han, Bao-Hang

2018-05-22

In this work, a series of highly porous sulfur-doped carbons are prepared through physical activation methods by using polythiophene as a precursor. The morphology, structure, and physicochemical properties are revealed by a variety of characterization methods, such as scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and nitrogen sorption measurement. Their porosity parameters and chemical compositions can be well-tuned by changing the activating agents (steam and carbon dioxide) and reaction temperature. These sulfur-doped porous carbons possess specific surface area of 670-2210 m 2 g -1 , total pore volume of 0.31-1.26 cm 3 g -1 , and sulfur content of 0.6-4.9 atom %. The effect of porosity parameters and surface chemistry on carbon dioxide adsorption in sulfur-doped porous carbons is studied in detail. After a careful analysis of carbon dioxide uptake at different temperatures (273 and 293 K), pore volumes from small pore size (less than 1 nm) play an important role in carbon dioxide adsorption at 273 K, whereas surface chemistry is the key factor at a higher adsorption temperature or lower relative pressure. Furthermore, sulfur-doped porous carbons also possess good gas adsorption selectivity and excellent recyclability for regeneration.

Oil Contact Angles in a Water-Decane-Silicon Dioxide System: Effects of Surface Charge

NASA Astrophysics Data System (ADS)

Xu, Shijing; Wang, Jingyao; Wu, Jiazhong; Liu, Qingjie; Sun, Chengzhen; Bai, Bofeng

2018-04-01

Oil wettability in the water-oil-rock systems is very sensitive to the evolution of surface charges on the rock surfaces induced by the adsorption of ions and other chemical agents in water flooding. Through a set of large-scale molecular dynamics simulations, we reveal the effects of surface charge on the oil contact angles in an ideal water-decane-silicon dioxide system. The results show that the contact angles of oil nano-droplets have a great dependence on the surface charges. As the surface charge density exceeds a critical value of 0.992 e/nm2, the contact angle reaches up to 78.8° and the water-wet state is very apparent. The variation of contact angles can be confirmed from the number density distributions of oil molecules. With increasing the surface charge density, the adsorption of oil molecules weakens and the contact areas between nano-droplets and silicon dioxide surface are reduced. In addition, the number density distributions, RDF distributions, and molecular orientations indicate that the oil molecules are adsorbed on the silicon dioxide surface layer-by-layer with an orientation parallel to the surface. However, the layered structure of oil molecules near the silicon dioxide surface becomes more and more obscure at higher surface charge densities.

The ultrasonic-enhanced factor of mass-transfer coefficient in the supercritical carbon dioxide extraction

NASA Astrophysics Data System (ADS)

Luo, Benyi; Lu, Yigang

2008-10-01

Based on several hypotheses about the process of supercritical carbon dioxide extraction, the onflow around the solute granule is figured out by the Navier-Stocks equation. In combination with the Higbie’s solute infiltration model, the link between the mass-transfer coefficient and the velocity of flow is found. The mass-transfer coefficient with the ultrasonical effect is compared with that without the ultrasonical effect, and then a new parameter named the ultrasonic-enhanced factor of mass-transfer coefficient is brought forward, which describes the mathematical model of the supercritical carbon dioxide extraction process enhanced by ultrasonic. The model gives out the relationships among the ultrasonical power, the ultrasonical frequency, the radius of solute granule and the ultrasonic-enhanced factor of mass-transfer coefficient. The results calculated by this model fit well with the experimental data, including the extraction of Coix Lacryma-jobi Seed Oil (CLSO) and Coix Lacryma-jobi Seed Ester (CLSE) from coix seeds and the extraction of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) from the alga by means of the ultrasonic-enhanced supercritical carbon dioxide extraction (USFE) and the supercritical carbon dioxide extraction (SFE) respectively. This proves the rationality of the ultrasonic-enhanced factor model. The model provides a theoretical basis for the application of ultrasonic-enhanced supercritical fluid extraction technique.

Oil Contact Angles in a Water-Decane-Silicon Dioxide System: Effects of Surface Charge.

PubMed

Xu, Shijing; Wang, Jingyao; Wu, Jiazhong; Liu, Qingjie; Sun, Chengzhen; Bai, Bofeng

2018-04-19

Oil wettability in the water-oil-rock systems is very sensitive to the evolution of surface charges on the rock surfaces induced by the adsorption of ions and other chemical agents in water flooding. Through a set of large-scale molecular dynamics simulations, we reveal the effects of surface charge on the oil contact angles in an ideal water-decane-silicon dioxide system. The results show that the contact angles of oil nano-droplets have a great dependence on the surface charges. As the surface charge density exceeds a critical value of 0.992 e/nm 2 , the contact angle reaches up to 78.8° and the water-wet state is very apparent. The variation of contact angles can be confirmed from the number density distributions of oil molecules. With increasing the surface charge density, the adsorption of oil molecules weakens and the contact areas between nano-droplets and silicon dioxide surface are reduced. In addition, the number density distributions, RDF distributions, and molecular orientations indicate that the oil molecules are adsorbed on the silicon dioxide surface layer-by-layer with an orientation parallel to the surface. However, the layered structure of oil molecules near the silicon dioxide surface becomes more and more obscure at higher surface charge densities.

Hadfield with the Reassembled Amine Swingbed in the U.S. Lab

NASA Image and Video Library

2013-03-20

ISS035-E-006230 (20 March 2013) --- Expedition 35 Commander Chris Hadfield in Harmony Node 2 aboard the Earth-orbiting International Space Station examines his work after reassembling the amine swing bed into its locker chassis. This device examines whether a vacuum-regenerated amine system can effectively remove carbon dioxide from the space station atmosphere using a smaller, more efficient vacuum regeneration system. The goal is to recover carbon dioxide from the atmosphere, and separate the dioxide from the carbon, so that the oxygen molecules can be used for crew life support.

Toxicity of Nitrogen Dioxide: An Introduction

DTIC Science & Technology

1994-01-01

3- A q t 19794 ( Final. NIA 4. TITLE AND SUTCLEt1 5 9FUNDING NUM8(RS ’ Toxicity of nitrogen dioxide: an introduction SJ6. AUTHOR(S) NabilI M. Elsayed...limited interest in the toxicity of high-level exposures, and partly due to the public pressure and interest to study the effects of low...2e0-5500 Star’dara :orm 298 (Rev .-89) - - ’• - .•*" ,y ’ S~iO~COMS E L SEVIER Toxicology 89 (19;4) 161-174 Toxicity of nitrogen dioxide: an

Phenotypic and genomic responses to titanium dioxide and cerium oxide nanoparticles in Arabidopsis germinants

EPA Science Inventory

The effects of exposure to two nanoparticles (NPs) -titanium dioxide (nano-titania) and cerium oxide (nano-ceria) at 500 mg NPs L-1 on gene expression and growth in Arabidopsis thaliana germinants were studied using microarrays and phenotype studies. After 12 days post treatment,...

Fruit growing in areas of air pollution by sulfur dioxide (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guderian, R.

1969-01-01

A review is presented dealing with leaf injuries and reductions in growth, yield, and fruit quality in pome fruits, stone fruits, bush fruits, vines, strawberries, and walnuts caused by sulfur dioxide. References to varietal resistance and the effects of manuring on resistance are provided. 11 references.

Photosynthesis in tropical cover crop legumes influenced by irradiance, external carbon dioxide concentration and temperature

USDA-ARS?s Scientific Manuscript database

In plantation crops perennial tropical legumes are grown as understory plants, receive limited irradiance, and are subjected to elevated levels of CO2 and temperature. Independent short-term effects of photosynthetic photon flux density (PPFD), external carbon dioxide concentration [CO2] and temper...

ENHANCEMENT OF REACTIVITY IN SURFACTANT-MODIFIED SORBENTS FOR SULFUR DIOXIDE CONTROL

EPA Science Inventory

Injection of calcium-based sorbents into the postflame zone of utility boilers is capable of achieving sulfur dioxide (SO2) captures of 50-60% at a stoichiometry of 2. Calcium hydroxide [Ca(OH)2] appears to be the most effective commercially available sorbent. Recent attempts to ...

COMBINED EFFECT OF SULFUR DIOXIDE AND OZONE ON BEAN AND TOBACCO PLANTS

EPA Science Inventory

Plants of two cultivars of Phaseolus vulgaris and one cultivar of Nicotiana tabacum were exposed to a replicated series of concentrations of sulfur dioxide (SO2), ozone (03), and combinations of these two air pollutants for single four-hour periods. Experiments were performed in ...

75 FR 29534 - Inorganic Nitrates-Nitrite, Carbon and Carbon Dioxide, and Sulfur Registration Review; Draft...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-26

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0434; FRL-8826-6] Inorganic Nitrates-Nitrite... for the registration review of inorganic nitrates - nitrites, carbon and carbon dioxide, and gas... identifies those species for which exposure and effects may occur for all inorganic nitrates- nitrites...

Effect of chlorine dioxide gas on physical, thermal, mechanical, and barrier properties of p[olymeric packaging materials

USDA-ARS?s Scientific Manuscript database

In the first part of our study we determined permeability, diffusion, and solubility coefficients of gaseous chlorine dioxide (ClO2) through the following packaging material: biaxial-oriented polypropylene (BOPP); polyethylene terephthalate (PET); poly lactic acid (PLA); multilayer structure of ethy...

Effects of seasonal drought on net carbon dioxide exchange from a woody-plant-encroached semiarid grassland

USDA-ARS?s Scientific Manuscript database

The encroachment of woody plants into historical semiarid grasslands has important ecohydrological and socioeconomic consequences. In this paper, we document the biosphere-atmosphere exchange of water and carbon dioxide that occurred from 2004 through 2007 over a semiarid, warm-season savanna in sou...

Toxicity Assessment of Six Titanium Dioxide Nanoparticles in Human Epidermal Keratinocytes

EPA Science Inventory

Toxicity Assessment of Six Titanium Dioxide Nanoparticles in Human Epidermal Keratinocytes Nanoparticle uptake in cells may be an important determinant of their potential cytotoxic and inflammatory effects. Six commercial TiO2 NP (A=Alfa Aesar,10nm, A*=Alfa Aesar 32nm, B=P25 27...

Herbivore responses to plants grown in enriched carbon dioxide atmospheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, D.E.

1990-05-01

Our initial study of sagebrush and grasshopper responses to elevated and historical carbon dioxide atmospheres is complete and has been accepted for publication. The study on Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide has completed and the manuscript has been submitted for publication. We have completed the study of plant growth under two nutrient and carbon dioxide regimes and grasshopper feeding responses. The study of a specialist feeding caterpillar, the cabbage butterfly, and a mustard hostplant has recently been completed. We were able to identify the principal allelochemicals of the mustard plants, butenyl andmore » pentenyl isothiocyanates, by combined gas chromatography and mass spectrometry. Measurement of these chemicals has been a critical component of this study since these compounds contain nitrogen and sulphur and act as a feeding stimulant to the caterpillar. This insect responds to elevated carbon dioxide by consuming more leaves and we can now say that this is not due to a change in the feeding stimulants. Reduced leaf protein content is a critical factor for even specialist feeding insect herbivores under elevated carbon dioxide conditions. The study on Grasshopper Population Responses to Enriched Carbon Dioxide Concentration is currently in progress at the Duke University Phytotron. We have changed hostplant species in order to complement the investigations of carbon dioxide effects on tallgrass prairie. Specifically, we are using big bluestem, Andropogon geradii, as the host plant to feed to the grasshoppers. This experiment will be completed in July 1990.« less

Modeling carbon dioxide, pH, and un-ionized ammonia relationships in serial reuse systems

USGS Publications Warehouse

Colt, J.; Watten, B.; Rust, M.

2009-01-01

In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity-pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air-water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air-water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

Modeling Carbon Dioxide, pH and Un-Ionized Ammonia Relationships in Serial Reuse Systems

USGS Publications Warehouse

Watten, Barnaby J.; Rust, Michael; Colt, John

2009-01-01

In serial reuse systems, excretion of metabolic carbon dioxide has a significant impact on ambient pH, carbon dioxide, and un-ionized ammonia concentrations. This impact depends strongly on alkalinity, water flow rate, feeding rate, and loss of carbon dioxide to the atmosphere. A reduction in pH from metabolic carbon dioxide can significantly reduce the un-ionized ammonia concentration and increase the carbon dioxide concentrations compared to those parameters computed from influent pH. The ability to accurately predict pH in serial reuse systems is critical to their design and effective operation. A trial and error solution to the alkalinity–pH system was used to estimate important water quality parameters in serial reuse systems. Transfer of oxygen and carbon dioxide across the air–water interface, at overflow weirs, and impacts of substrate-attached algae and suspended bacteria were modeled. Gas transfer at the weirs was much greater than transfer across the air–water boundary. This simulation model can rapidly estimate influent and effluent concentrations of dissolved oxygen, carbon dioxide, and un-ionized ammonia as a function of water temperature, elevation, water flow, and weir type. The accuracy of the estimates strongly depends on assumed pollutional loading rates and gas transfer at the weirs. The current simulation model is based on mean daily loading rates; the impacts of daily variation loading rates are discussed. Copies of the source code and executable program are available free of charge.

The Gonzaga desulfurization flue gas process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelleher, R.L.; O'Leary, T.J.; Shirk, I.A.

1984-01-01

The Gonzaga desulfurization flue gas process removes sulfur dioxide from a flue by cold water scrubbing. Sulfur dioxide is significantly more soluable in cold water (35/sup 0/F to 60/sup 0/F) than in warm water (100/sup 0/F). Sulfur dioxide reacts in water similarly as carbon dioxide reacts in water, in that both gasses are released from the water as the temperature of the water increases. The researchers at the Gonzaga University developed this process from the observations and techniques used in studying the acid and aldehyde concentrations in flue gasses with varying of fuel to air ratios. The apparatus was fixedmore » to a stationary engine and a gas/oil fired boiler. The flue gas was cooled to the dew point temperature of the air entering the combustion chamber on the pre-air heater. The system is described in two parts: the energies required for cooling in the scrubbing section and the energies required in the treatment section. The cold flue gas is utilized in cooling the scrubber section.« less

Behavioral-Physiological Effects of Red Phosphorus Smoke Inhalation on Two Wildlife Species. Task 3. (RP/BR Aerosol Effects upon the Spontaneous Activity, Startle Response, Pulmonary Function and Blood Chemistry/Hematology of Black-Tailed Prairie Dogs (Cynomys ludovicianus) and Rock Doves (Columba livia)

DTIC Science & Technology

1989-09-01

physiological effects of multiple exposures~-to..a red phosphorus- butyl rubber (RP/BR) military smoke product in 2 wildlife species -- bhack-tailed...effects on any pulmonary function variable of prairie dogs. There was a significant Concentration X Day interaction effect for carbon dioxide production ...dioxide production (Vco 2), respiratory exchange ratio (RER), and metabolic rate (MR) of rock doves. The interactions were associated with responses of

Food contact surfaces coated with nitrogen-doped titanium dioxide: effect on Listeria monocytogenes survival under different light sources

NASA Astrophysics Data System (ADS)

Rodrigues, D.; Teixeira, P.; Tavares, C. J.; Azeredo, J.

2013-04-01

Improvement of food safety is a very important issue, and is on the basis of production and application of new/modified food contact surfaces. Titanium dioxide (TiO2) and, more recently, nitrogen-doped titanium dioxide (N-TiO2) coatings are among the possible forms to enhance food contact surfaces performance in terms of higher hygiene and easier sanitation. In this context, the present work aimed at evaluating the bactericidal activity of an N-TiO2 coating on glass and stainless steel under two different sources of visible light - fluorescent and incandescent - and ultraviolet (UV) irradiation. Listeria monocytogenes was chosen as representative of major foodborne pathogens and its survival was tested on N-TiO2 coated coupons. In terms of survival percentage, good results were obtained after exposure of coated surfaces to all light types since, apart from the value obtained after exposing glass to fluorescent light (56.3%), survival rates were always below 50%. However, no effective disinfection was obtained, given that for a disinfectant or sanitizing agent to be claimed as effective it needs to be able to promote at least a 3-log reduction of the microbial load, which was not observed for any of the experimental conditions assessed. Even so, UV irradiation was the most successful on eliminating cells on coated surfaces, since the amount of bacteria was reduced to 1.49 × 106 CFU/ml on glass and 2.37 × 107 on stainless steel. In contrast, both visible light sources had only slightly decreased the amount of viable cells, which remained in the range of 8 log CFU/ml. Hence, although some bactericidal effect was accomplished under visible light, UV was the most effective light source on promoting photocatalytic reactions on N-TiO2 coated coupons and none of the experimental conditions have reached a satisfactory disinfection level. Thus, this surface coating needs further research and improvement in order to become truly effective against foodborne pathogens and, ultimately, become a useful tool towards food safety in general.

Research and Development of Hazardous/Toxic Waste Analytical Screening Procedures. Available Field Methods for Rapid Screening of Hazardous Waste Materials at Waste Sites (Class A Poisons).

DTIC Science & Technology

1982-01-01

bromide is listed as a positive interference. Nitric oxide and nitrogen dioxide can be detected by using the Draeger nitrous fumes detector tube. A... fumes exhibit a delay from the time of exposure to the onset of symptoms. This time delay would not be conducive for a rapid field screening test. It...Dangerous when strongly heated, emits highly toxic fumes . THRESHOLD LIMIT VALUE: No information available PHYSIOLOGICAL EFFECTS: A. Intensely irritating to

Acute Exposure to Low-to-Moderate Carbon Dioxide Levels and Submariner Decision Making.

PubMed

Rodeheffer, Christopher D; Chabal, Sarah; Clarke, John M; Fothergill, David M

2018-06-01

Submarines routinely operate with higher levels of ambient carbon dioxide (CO2) (i.e., 2000 - 5000 ppm) than what is typically considered normal (i.e., 400 - 600 ppm). Although significant cognitive impairments are rarely reported at these elevated CO2 levels, recent studies using the Strategic Management Simulation (SMS) test have found impairments in decision-making performance during acute CO2 exposure at levels as low as 1000 ppm. This is a potential concern for submarine operations, as personnel regularly make mission-critical decisions that affect the safety and efficiency of the vessel and its crew while exposed to similar levels of CO2. The objective of this study was to determine if submariner decision-making performance is impacted by acute exposure to levels of CO2 routinely present in the submarine atmosphere during sea patrols. Using a subject-blinded balanced design, 36 submarine-qualified sailors were randomly assigned to receive 1 of 3 CO2 exposure conditions (600, 2500, or 15,000 ppm). After a 45-min atmospheric acclimation period, participants completed an 80-min computer-administered SMS test as a measure of decision making. There were no significant differences for any of the nine SMS measures of decision making between the CO2 exposure conditions. In contrast to recent research demonstrating cognitive deficits on the SMS test in students and professional-grade office workers, we were unable to replicate this effect in a submariner population-even with acute CO2 exposures more than an order of magnitude greater than those used in previous studies that demonstrated such effects.Rodeheffer CD, Chabal S, Clarke JM, Fothergill DM. Acute exposure to low-to-moderate carbon dioxide levels and submariner decision making. Aerosp Med Hum Perform. 2018; 89(6):520-525.

Gd, I-doped TiO2 thin films coated on solid waste material: synthesis, characterization, and photocatalytic activity under UV or visible light irradiation

NASA Astrophysics Data System (ADS)

Deng, Siwei; Yu, Jiang; Yang, Chun; Chang, Jiahua; Wang, Yizheng; Wang, Ping; Xie, Shiqian

2017-10-01

In this work, titanium dioxide thin films doped with different concentrations of gadolinium (Gd) and iodine (I) were synthesized using the sol-gel method and successfully coated on solid waste material (made in our lab) by dipping, resulting in the titanium dioxide thin-film-coated material (TiO2M). Then, the doped titanium dioxide thin films were characterized by X-ray diffraction (XRD), SEM, and UV-Vis spectroscopy; the optimum coating cycle was evaluated by removal rates of COD and ammonia nitrogen in raw wastewater and secondary effluent. Moreover, the photocatalytic activity was determined by degradation efficiency of methyl orange. The results showed that TiO2M had desirable reusability and the photocatalytic activity was attractive under ultraviolet light irradiation. Furthermore, it is found that the amount of dopant in TiO2 was a key parameter in increasing the photoactivity. 1% Gd-doped TiO2M exhibited the best photocatalytic activity for the degradation of methyl orange with the removal rate reaching 85.55%. The result was in good agreement with the observed smaller crystallite size and profitable crystal structure (anatase phase). Besides, the TiO2M (0.8% Gd-doped TiO2M, 1% Gd-doped TiO2M, 10% I-doped TiO2M, and 5% I-1% Gd-doped TiO2M) with desirable photocatalytic activity at ultraviolet light irradiation was selected for the visible light photocatalytic experiments with taking methyl orange as the target pollutants. The results showed that all of them exhibited the similar photocatalytic activity after 7 h of sunlight irradiation (around 90% removal effect). In general, this research developed a very effective and environmentally friendly photocatalyst for pollutant degradation.

Effects of long-term (10 years) exposure to elevated CO2 and O3 on trembling Aspen carbon and nitrogen metabolism at the aspen FACE (Free-Air Carbon Dioxide Enrichment) study site [Abstract

Treesearch

R. Minocha; S. Long; S. Minocha; P Marquardt; M. Kubiske

2010-01-01

The objective of the present study was to evaluate the long-term (10 years) effects of elevated CO2 and O3 on the carbon and nitrogen metabolism of aspen trees. The study was conducted at the Aspen Free-Air Carbon Dioxide Enrichment (FACE) experimental site, Rhinelander, WI, (USA).

Influences of Air, Oxygen, Nitrogen, and Carbon Dioxide Nanobubbles on Seed Germination and Plant Growth.

PubMed

Ahmed, Ahmed Khaled Abdella; Shi, Xiaonan; Hua, Likun; Manzueta, Leidy; Qing, Weihua; Marhaba, Taha; Zhang, Wen

2018-05-23

Nanobubbles (NBs) hold promise in green and sustainable engineering applications in diverse fields (e.g., water/wastewater treatment, food processing, medical applications, and agriculture). This study investigated the effects of four types of NBs on seed germination and plant growth. Air, oxygen, nitrogen, and carbon dioxide NBs were generated and dispersed in tap water. Different plants, including lettuce, carrot, fava bean, and tomato, were used in germination and growth tests. The seeds in water-containing NBs exhibited 6-25% higher germination rates. Especially, nitrogen NBs exhibited considerable effects in the seed germination, whereas air and carbon dioxide NBs did not significantly promote germination. The growth of stem length and diameter, leave number, and leave width were promoted by NBs (except air). Furthermore, the promotion effect was primarily ascribed to the generation of exogenous reactive oxygen species by NBs and higher efficiency of nutrient fixation or utilization.

A longitudinal study of mortality and air pollution for São Paulo, Brazil.

PubMed

Botter, Denise A; Jørgensen, Bent; Peres, Antonieta A Q

2002-09-01

We study the effects of various air-pollution variables on the daily death counts for people over 65 years in São Paulo, Brazil, from 1991 to 1993, controlling for meteorological variables. We use a state space model where the air-pollution variables enter via the latent process, and the meteorological variables via the observation equation. The latent process represents the potential mortality due to air pollution, and is estimated by Kalman filter techniques. The effect of air pollution on mortality is found to be a function of the variation in the sulphur dioxide level for the previous 3 days, whereas the other air-pollution variables (total suspended particulates, nitrogen dioxide, carbon monoxide, ozone) are not significant when sulphur dioxide is in the equation. There are significant effects of humidity and up to lag 3 of temperature, and a significant seasonal variation.

The effect of a lignosulphate type additive on the lead—acid battery positive plate reactions

NASA Astrophysics Data System (ADS)

Ovuru, S. E.; Harrison, J. A.

The electrochemical formation of lead dioxide has been investigated at a lead electrode in a 5 M sulphuric acid solution, and in the presence of phosphoric acid and lignosulphate-type additive. The formation of lead dioxide from lead sulphate, and the reverse reaction, have been investigated by the linear potential sweep method, by an impedance method in which the impedance was measured at the end of each pulse during a potential pulse train, and by a charging curve method in which the current and charge was measured during a similar potential pulse train. The charge measurements prove that the main effect of the additive is to decrease the accompanying oxygen evolution reaction. The impedance measurements, however, show that the additive has a small but significant effect on the structure of the solid lead sulphate and lead dioxide layers.

A ballistic investigation of the aerodynamic characteristics of a blunt vehicle at hypersonic speeds in carbon dioxide and air

NASA Technical Reports Server (NTRS)

Packard, James D.; Griffith, Wayland C.; Yates, Leslie A.; Strawa, Anthony W.

1992-01-01

Missions to Mars require the successful development of aerobraking technology, and therefore a blunt cone representative of aerobrake shapes is investigated. Ballistic tests of the Pioneer Venus configuration are conducted in carbon dioxide and air at Mach numbers from 7 to 20 and Reynolds numbers from 0.1 x 10 exp 5 to 4 x 10 exp 6. Experimental results show that for defined conditions aerodynamic research can be conducted in air rather than carbon dioxide, providing savings in time and money. In addition, the results offer a prediction of flight aerodynamics during entry into the Martian atmosphere. Also discussed is a comparison of results from two data-reduction techniques showing that a five-degree-of-freedom routine employing weighted least-squares with differential corrections analyzes ballistic data more accurately.

Superpulsed carbon dioxide laser: an update on cutaneous surgical applications

NASA Astrophysics Data System (ADS)

Wheeland, Ronald G.

1990-06-01

Superpulsing the carbon dioxide laser allows delivery of high energy pulses separated by short pauses during which tissue cooling can occur.1 This new technology can provide several important advantages in cutaneous surgery over similar procedures performed with conventional continuous discharge carbon dioxide laser systems. In the excisional mode, there is a two-thirds reduction in thermal necrosis of the wound edge.2 This should translate into more rapid healing3 and increased rate of gain in tensile strength. In the vaporizational mode, precise, superficial and bloodless ablation of multiple benign appendigeal tumors is possible with less thermal damage yielding excellent cosmetic results. The establishment through additional research of accurate laser parameters, pulse duration, peak energy levels, and frequency of pulses, will help improve the specificity of the laser-tissue interaction to provide even better surgical results.

Application of a Chemiluminescence Detector for the Measurement of Total Oxides of Nitrogen and Ammonia in the Atmosphere

NASA Technical Reports Server (NTRS)

Hodgeson, J. A.; Bell, J. P.; Rehme, K. A.; Krost, K. J.; Stevens, R. K.

1971-01-01

By means of the thermal conversion of nitrogen dioxide to the nitric oxide, the chemiluminescent nitric oxide monitor, based on the nitric oxide plus ozone reaction, may be used for monitoring nitrogen dioxide plus nitric oxide (NO(x)). Under conditions previously described, ammonia is also converted to nitric oxide and therefore interferes. A metal surface, gold wool or stainless steel, operated at two different temperatures has been used to convert only nitrogen dioxide or nitrogen dioxide plus ammonia. Quantitative conversion of nitrogen dioxide to nitric oxide has been obtained at temperatures as low as 200 C. Conversion of ammonia is effected at temperatures of 300 C or higher. By the addition of a converter the basic nitric oxide monitor may be used for measuring NO(x) or NO(x) plus ammonia. As an alternate mode, for a fixed high temperature, a specific scrubber is described for removing NH3 without affecting NO2 concentrations.

Imaging metal-like monoclinic phase stabilized by surface coordination effect in vanadium dioxide nanobeam

PubMed Central

Li, Zejun; Wu, Jiajing; Hu, Zhenpeng; Lin, Yue; Chen, Qi; Guo, Yuqiao; Liu, Yuhua; Zhao, Yingcheng; Peng, Jing; Chu, Wangsheng; Wu, Changzheng; Xie, Yi

2017-01-01

In correlated systems, intermediate states usually appear transiently across phase transitions even at the femtosecond scale. It therefore remains an open question how to determine these intermediate states—a critical issue for understanding the origin of their correlated behaviour. Here we report a surface coordination route to successfully stabilize and directly image an intermediate state in the metal-insulator transition of vanadium dioxide. As a prototype metal-insulator transition material, we capture an unusual metal-like monoclinic phase at room temperature that has long been predicted. Coordinate bonding of L-ascorbic acid molecules with vanadium dioxide nanobeams induces charge-carrier density reorganization and stabilizes metallic monoclinic vanadium dioxide, unravelling orbital-selective Mott correlation for gap opening of the vanadium dioxide metal–insulator transition. Our study contributes to completing phase-evolution pathways in the metal-insulator transition process, and we anticipate that coordination chemistry may be a powerful tool for engineering properties of low-dimensional correlated solids. PMID:28613281

Method of fabricating germanium and gallium arsenide devices

NASA Technical Reports Server (NTRS)

Jhabvala, Murzban (Inventor)

1990-01-01

A method of semiconductor diode fabrication is disclosed which relies on the epitaxial growth of a precisely doped thickness layer of gallium arsenide or germanium on a semi-insulating or intrinsic substrate, respectively, of gallium arsenide or germanium by either molecular beam epitaxy (MBE) or by metal-organic chemical vapor deposition (MOCVD). The method involves: depositing a layer of doped or undoped silicon dioxide on a germanium or gallium arsenide wafer or substrate, selectively removing the silicon dioxide layer to define one or more surface regions for a device to be fabricated thereon, growing a matched epitaxial layer of doped germanium or gallium arsenide of an appropriate thickness using MBE or MOCVD techniques on both the silicon dioxide layer and the defined one or more regions; and etching the silicon dioxide and the epitaxial material on top of the silicon dioxide to leave a matched epitaxial layer of germanium or gallium arsenide on the germanium or gallium arsenide substrate, respectively, and upon which a field effect device can thereafter be formed.

A comparative analysis of carbon dioxide displacement rates for euthanasia of the ferret.

PubMed

Fitzhugh, Dawn C; Parmer, Amanda; Shelton, Larry J; Sheets, James T

2008-02-01

Though carbon dioxide asphyxiation is a common method of euthanasia for laboratory animals, species-specific guidelines have not been established for this procedure in the domestic ferret (Mustela putorius furo). The authors investigated the efficacy and stress effects of carbon dioxide euthanasia in 24 ferrets that had participated in previous experimental protocols. They euthanized ferrets by placing them in cages that were either prefilled with carbon dioxide or gradually filled at a displacement rate of 10%, 20% or 50% of the cage volume per min. Blinded observers subjectively evaluated ferret distress. Prefilling the cage or filling it at a rate of 50% volume per min resulted in less time to recumbency and to last breath than did filling the cage at a slower displacement rate. Slower carbon dioxide displacement rates also caused an increase in ferret blood glucose concentrations, which may indicate distress. Overall, observers found that prefilling the euthanasia cage caused the least stress to ferrets.

Effects of local meteorology and aerosols on ozone and nitrogen dioxide retrievals from OMI and pandora spectrometers in Maryland, USA during DISCOVER-AQ 2011.

PubMed

Reed, Andra J; Thompson, Anne M; Kollonige, Debra E; Martins, Douglas K; Tzortziou, Maria A; Herman, Jay R; Berkoff, Timothy A; Abuhassan, Nader K; Cede, Alexander

An analysis is presented for both ground- and satellite-based retrievals of total column ozone and nitrogen dioxide levels from the Washington, D.C., and Baltimore, Maryland, metropolitan area during the NASA-sponsored July 2011 campaign of D eriving I nformation on S urface CO nditions from Column and VER tically Resolved Observations Relevant to A ir Q uality (DISCOVER-AQ). Satellite retrievals of total column ozone and nitrogen dioxide from the Ozone Monitoring Instrument (OMI) on the Aura satellite are used, while Pandora spectrometers provide total column ozone and nitrogen dioxide amounts from the ground. We found that OMI and Pandora agree well (residuals within ±25 % for nitrogen dioxide, and ±4.5 % for ozone) for a majority of coincident observations during July 2011. Comparisons with surface nitrogen dioxide from a Teledyne API 200 EU NO x Analyzer showed nitrogen dioxide diurnal variability that was consistent with measurements by Pandora. However, the wide OMI field of view, clouds, and aerosols affected retrievals on certain days, resulting in differences between Pandora and OMI of up to ±65 % for total column nitrogen dioxide, and ±23 % for total column ozone. As expected, significant cloud cover (cloud fraction >0.2) was the most important parameter affecting comparisons of ozone retrievals; however, small, passing cumulus clouds that do not coincide with a high (>0.2) cloud fraction, or low aerosol layers which cause significant backscatter near the ground affected the comparisons of total column nitrogen dioxide retrievals. Our results will impact post-processing satellite retrieval algorithms and quality control procedures.

Optimizing supercritical carbon dioxide in the inactivation of bacteria in clinical solid waste by using response surface methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hossain, Md. Sohrab; Nik Ab Rahman, Nik Norulaini; Balakrishnan, Venugopal

2015-04-15

Highlights: • Supercritical carbon dioxide sterilization of clinical solid waste. • Inactivation of bacteria in clinical solid waste using supercritical carbon dioxide. • Reduction of the hazardous exposure of clinical solid waste. • Optimization of the supercritical carbon dioxide experimental conditions. - Abstract: Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO{sub 2}) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis,more » and gram-negative Escherichia coli in CSW. The effects of SC-CO{sub 2} sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20 MPa, 60 °C, and 60 min. The SC-CO{sub 2}-treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO{sub 2} exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials.« less

An investigation of evapotranspiration rates within mid-western agricultural systems in response to elevated carbon dioxide and ozone concentrations and climate change

NASA Astrophysics Data System (ADS)

Abdullah, W. F.; Lombardozzi, D.; Levis, S.; Bonan, G. B.

2013-12-01

Warith Featherstone Abdullah, Danica Lombardozzi, Samuel Levis and Gordon Bonan Jackson State University Dept. of Physics, Atmospheric Sciences & Geosciences National Center for Atmospheric Research Climate & Global Dynamics Because the human population is expected to surpass 8 billion by the year 2050, food security is a pressing issue. In the face of elevated temperatures associated with climate change (CC), elevated carbon dioxide (CO2) and elevated ozone (O3) concentrations, food productivity is uncertain. Plant stomata must be open to gain carbon which simultaneously causes water loss. Research suggests rising temperatures, elevated CO2 and elevated O3 in the future may impact plant stomata and change the rate plants lose water and take up carbon, affecting plant productivity and crop yields. Evapotranspiration (ET), latent heat fluxes, leaf carbon and net primary productivity (NPP) were analyzed in U.S Mid-west where crop density is greatest. Four simulations were run using the National Center for Atmospheric Research (NCAR) Community Land Model version 4 (CLM4) component of the Community Earth System Model (CESM) with an extended carbon-nitrogen model (CN). Analyses were based on June-July-August seasonal averages through 2080-2100 to compare the individual effects of CC, elevated CO2 and O3, and combined effects of all drivers. Results from model projections show increased ET with CC and all drivers combined, but only small changes from O3 or CO2 alone. Further results show that NPP was reduced with CC and O3 alone, but increased with CO2 alone and only slightly reduced with interacting components. The combined driver simulation, which most accurately represents future global change, suggests deteriorating water usage efficiency, thus potentially decreasing carbon uptake and crop production. However, further research is needed for verification. Midwest seasonal summation estimates for net primary productivity calculated by CLM4CN model. Climate change, CO2 and O3 levels are predicted using IPCC RCP8.5 scenarios.

Volcanic versus anthropogenic carbon dioxide

USGS Publications Warehouse

Gerlach, T.

2011-01-01

Which emits more carbon dioxide (CO2): Earth's volcanoes or human activities? Research findings indicate unequivocally that the answer to this frequently asked question is human activities. However, most people, including some Earth scientists working in fields outside volcanology, are surprised by this answer. The climate change debate has revived and reinforced the belief, widespread among climate skeptics, that volcanoes emit more CO2 than human activities [Gerlach, 2010; Plimer, 2009]. In fact, present-day volcanoes emit relatively modest amounts of CO2, about as much annually as states like Florida, Michigan, and Ohio.

Safety hazards associated with the charging of lithium/sulfur dioxide cells

NASA Technical Reports Server (NTRS)

Frank, H.; Halpert, G.; Lawson, D. D.; Barnes, J. A.; Bis, R. F.

1986-01-01

A continuing research program to assess the responses of spirally wound, lithium/sulfur dioxide cells to charging as functions of charging current, temperature, and cell condition prior to charging is described. Partially discharged cells that are charged at currents greater than one ampere explode with the time to explosion inversely proportional to the charging current. Cells charged at currents of less than one ampere may fail in one of several modes. The data allows an empirical prediction of when certain cells will fail given a constant charging current.

Catalysts for CO2/epoxide ring-opening copolymerization

PubMed Central

Trott, G.; Saini, P. K.; Williams, C. K.

2016-01-01

This article summarizes and reviews recent progress in the development of catalysts for the ring-opening copolymerization of carbon dioxide and epoxides. The copolymerization is an interesting method to add value to carbon dioxide, including from waste sources, and to reduce pollution associated with commodity polymer manufacture. The selection of the catalyst is of critical importance to control the composition, properties and applications of the resultant polymers. This review highlights and exemplifies some key recent findings and hypotheses, in particular using examples drawn from our own research. PMID:26755758

Final Environmental Impact Statement/Environmental Impact Report for the California Acoustic Thermometry of Ocean Climate Project and its associated Marine Mammal Research Program. Volume 1

DTIC Science & Technology

1995-04-01

carbon dioxide, methane, and freons, are steadily increasing due to human activities. For example, carbon dioxide is produced by the burning of fossil ...shipping would remain approximately 35-45 km distant. It is so far offshore that only the incidental pleasurecraft or fishing boats traverse the area...the boat from which the source is deployed, and unless the boat can remain stationary for a long period of time prior to commencement of the

Greenhouse Gas Fluxes at the Tablelands, NL, Canada: A Site of Active Serpentinization

NASA Astrophysics Data System (ADS)

Morrill, P. L.; Morrissey, L. S.; Cumming, E.

2016-12-01

Active sites of serpentinization have been proposed as sites for carbon capture and storage (CCS) projects. However, in addition to their ability to convert carbon dioxide to carbonate rock, sites of serpentinization also have the potential release methane, which is a more power greenhouse gas than carbon dioxide. Very little is known about the natural flux of carbon dioxide sequestered and methane released into the atmosphere from active sites of serpentinization. In this study we measured carbon dioxide, methane, and nitrous oxide gas fluxes at a pool of ultra-basic water discharging from serpentinized rock in Winterhouse Canyon, Gros Morne, Newfoundland. We found that the flux of methane released was 4.6 x 10-7 mol/m2/min and the carbon dioxide sequestered was 1.9 x 10-5 mol/m2/min, while the concentrations of nitrous oxide showed little change. Based on these fluxes we calculated predictive climate change parameters such as net radiative forcing and global warming potential which predicted that despite the methane being released the site still had an overall long-term atmospheric cooling effect based on the natural rate of carbon dioxide sequestration.

Decontamination Efficacy and Skin Toxicity of Two Decontaminants against Bacillus anthracis

PubMed Central

Stratilo, Chad W.; Crichton, Melissa K. F.; Sawyer, Thomas W.

2015-01-01

Decontamination of bacterial endospores such as Bacillus anthracis has traditionally required the use of harsh or caustic chemicals. The aim of this study was to evaluate the efficacy of a chlorine dioxide decontaminant in killing Bacillus anthracis spores in solution and on a human skin simulant (porcine cadaver skin), compared to that of commonly used sodium hypochlorite or soapy water decontamination procedures. In addition, the relative toxicities of these decontaminants were compared in human skin keratinocyte primary cultures. The chlorine dioxide decontaminant was similarly effective to sodium hypochlorite in reducing spore numbers of Bacillus anthracis Ames in liquid suspension after a 10 minute exposure. After five minutes, the chlorine dioxide product was significantly more efficacious. Decontamination of isolated swine skin contaminated with Bacillus anthracis Sterne with the chlorine dioxide product resulted in no viable spores sampled. The toxicity of the chlorine dioxide decontaminant was up to two orders of magnitude less than that of sodium hypochlorite in human skin keratinocyte cultures. In summary, the chlorine dioxide based decontaminant efficiently killed Bacillus anthracis spores in liquid suspension, as well as on isolated swine skin, and was less toxic than sodium hypochlorite in cultures of human skin keratinocytes. PMID:26394165

Biomineralized diamond-like carbon films with incorporated titanium dioxide nanoparticles improved bioactivity properties and reduced biofilm formation.

PubMed

Lopes, F S; Oliveira, J R; Milani, J; Oliveira, L D; Machado, J P B; Trava-Airoldi, V J; Lobo, A O; Marciano, F R

2017-12-01

Recently, the development of coatings to protect biomedical alloys from oxidation, passivation and to reduce the ability for a bacterial biofilm to form after implantation has emerged. Diamond-like carbon films are commonly used for implanted medical due to their physical and chemical characteristics, showing good interactions with the biological environment. However, these properties can be significantly improved when titanium dioxide nanoparticles are included, especially to enhance the bactericidal properties of the films. So far, the deposition of hydroxyapatite on the film surface has been studied in order to improve biocompatibility and bioactive behavior. Herein, we developed a new route to obtain a homogeneous and crystalline apatite coating on diamond-like carbon films grown on 304 biomedical stainless steel and evaluated its antibacterial effect. For this purpose, films containing two different concentrations of titanium dioxide (0.1 and 0.3g/L) were obtained by chemical vapor deposition. To obtain the apatite layer, the samples were soaked in simulated body fluid solution for up to 21days. The antibacterial activity of the films was evaluated by bacterial eradication tests using Staphylococcus aureus biofilm. Scanning electron microscopy, X-ray diffraction, Raman scattering spectroscopy, and goniometry showed that homogeneous, crystalline, and hydrophilic apatite films were formed independently of the titanium dioxide concentration. Interestingly, the diamond-like films containing titanium dioxide and hydroxyapatite reduced the biofilm formation compared to controls. A synergism between hydroxyapatite and titanium dioxide that provided an antimicrobial effect against opportunistic pathogens was clearly observed. Copyright © 2017 Elsevier B.V. All rights reserved.

Nanoparticle–Cell Interactions: Relevance for Public Health

PubMed Central

2017-01-01

Nanoparticles, especially metal oxide nanoparticles, are used in a wide range of commercial and industrial applications that result in direct human contact, such as titanium dioxide nanoparticles in paints, food colorings, and cosmetics, or indirectly through release of nanoparticle-containing materials into the environment. Workers who process nanoparticles for downstream applications are exposed to especially high concentrations of nanoparticles. For physical chemists, nanoparticles present an interesting area of study as the small size of nanoparticles changes the properties from that of the bulk material, leading to novel properties and reactivity. For the public health community, this reduction in particle size means that exposure limits and outcomes that were determined from bulk material properties are not necessarily valid. Informed determination of exposure limits requires a fundamental understanding of how nanoparticles interact with cells. This Feature Article highlights the areas of intersection between physical chemistry and public health in understanding nanoparticle–cell interactions, with a focus on titanium dioxide nanoparticles. It provides an overview of recent research examining the interaction of titanium dioxide nanoparticles with cells in the absence of UV light and provides recommendations for additional nanoparticle–cell research in which physical chemistry expertise could help to inform the public health community. PMID:29111728

Nanoparticle-Cell Interactions: Relevance for Public Health.

PubMed

Runa, Sabiha; Hussey, Michael; Payne, Christine K

2018-01-25

Nanoparticles, especially metal oxide nanoparticles, are used in a wide range of commercial and industrial applications that result in direct human contact, such as titanium dioxide nanoparticles in paints, food colorings, and cosmetics, or indirectly through release of nanoparticle-containing materials into the environment. Workers who process nanoparticles for downstream applications are exposed to especially high concentrations of nanoparticles. For physical chemists, nanoparticles present an interesting area of study as the small size of nanoparticles changes the properties from that of the bulk material, leading to novel properties and reactivity. For the public health community, this reduction in particle size means that exposure limits and outcomes that were determined from bulk material properties are not necessarily valid. Informed determination of exposure limits requires a fundamental understanding of how nanoparticles interact with cells. This Feature Article highlights the areas of intersection between physical chemistry and public health in understanding nanoparticle-cell interactions, with a focus on titanium dioxide nanoparticles. It provides an overview of recent research examining the interaction of titanium dioxide nanoparticles with cells in the absence of UV light and provides recommendations for additional nanoparticle-cell research in which physical chemistry expertise could help to inform the public health community.

Risk of abortion and stillbirth in cow-calf herds exposed to the oil and gas industry in Western Canada.

PubMed

Waldner, Cheryl L

2009-01-01

To investigate the associations between emissions from oil and gas field facilities and fetal survival, researchers followed more than 28,000 beef cows from the beginning of the breeding season through calving. They prospectively measured exposure to sulfur dioxide, hydrogen sulfide, and volatile organic compounds and linked them to the location of individual cattle; they used the density of oil and gas well sites surrounding each pasture as an alternate measure of exposure. The researchers measured the risks of abortion and stillbirth in 203 cow-calf herds for the 2002 calving season, as well as animal and herd-management factors known or suspected to affect these parameters. Using mixed models to adjust for clustering by herd and after accounting for other known risk factors, they examined the associations between exposure to sulfur dioxide, volatile organic compounds measured as benzene and toluene, hydrogen sulfide, and well-site density, and the risks of abortion and stillbirth. There was no evidence across the measured range of exposures that emissions of sulfur dioxide, hydrogen sulfide, volatile organic compounds measured as benzene or toluene, or well-site density increased the risk of either abortion or stillbirth in these beef herds.

Decreased abundance of crustose coralline algae due to ocean acidification

USGS Publications Warehouse

Kuffner, Ilsa B.; Andersson, Andreas J; Jokiel, Paul L.; Rodgers, Ku'ulei S.; Mackenzie, Fred T.

2008-01-01

Owing to anthropogenic emissions, atmospheric concentrations of carbon dioxide could almost double between 2006 and 2100 according to business-as-usual carbon dioxide emission scenarios1. Because the ocean absorbs carbon dioxide from the atmosphere2, 3, 4, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states2, 5. As a consequence, it has been suggested that marine calcifying organisms, for example corals, coralline algae, molluscs and foraminifera, will have difficulties producing their skeletons and shells at current rates6, 7, with potentially severe implications for marine ecosystems, including coral reefs6, 8, 9, 10, 11. Here we report a seven-week experiment exploring the effects of ocean acidification on crustose coralline algae, a cosmopolitan group of calcifying algae that is ecologically important in most shallow-water habitats12, 13, 14. Six outdoor mesocosms were continuously supplied with sea water from the adjacent reef and manipulated to simulate conditions of either ambient or elevated seawater carbon dioxide concentrations. The recruitment rate and growth of crustose coralline algae were severely inhibited in the elevated carbon dioxide mesocosms. Our findings suggest that ocean acidification due to human activities could cause significant change to benthic community structure in shallow-warm-water carbonate ecosystems.

DEVELOPMENT AND VALIDATION OF A METHOD FOR MEASURING EXEMPT VOLATILE ORGANIC COMPOUNDS AND CARBON DIOXIDE IN CONSUMER PRODUCTS

EPA Science Inventory

The report describes the development and validation of a method for measuring exempt volatile organic compounds (VOCs) and carbon dioxide in consumer products. (NOTE: Ground-level ozone can cause a variety of adverse health effects as well as agricultural and ecological damage. C...

The effect of chlorine dioxide and chitosan/essential oil coatings on the safety and quality of fresh blueberries

USDA-ARS?s Scientific Manuscript database

Blueberries are high-value fruit with strong antioxidant capacity and other health-promoting benefits. Controlled release chlorine dioxide (ClO2) or chitosan coating plus different essential oils were applied to fresh blueberries to preserve their quality and safety during postharvest storage. In vi...

21 CFR 201.161 - Carbon dioxide and certain other gases.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Carbon dioxide and certain other gases. 201.161 Section 201.161 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... administration of (name of gas) and is familiar with the indications, effects, dosages, methods, and frequency...

Nasal continuous positive airway pressure: does bubbling improve gas exchange?

PubMed

Morley, C J; Lau, R; De Paoli, A; Davis, P G

2005-07-01

In a randomised crossover trial, 26 babies, treated with Hudson prong continuous positive airway pressure (CPAP) from a bubbling bottle, received vigorous, high amplitude, or slow bubbling for 30 minutes. Pulse oximetry, transcutaneous carbon dioxide, and respiratory rate were recorded. The bubbling rates had no effect on carbon dioxide, oxygenation, or respiratory rate.

Surface Chemistry and Structural Effects in the Stress Corrosion of Glass and Ceramic Materials.

DTIC Science & Technology

1986-03-31

capillary can be improved for (GC)2 by passing S sulfur dioxide or difluoroethane through the preform and capillary during the fabrication 27 . The...hydration resistance of the glass surface. In fact, it was recently shown that the combined use of sulfur dioxide and * difluoroethane could further

Effect of water activity, temperature, and carbon dioxide on the Aspergillus flavus transcriptome and aflatoxin B1 production

USDA-ARS?s Scientific Manuscript database

Aspergillus flavus is a opportunistic fungus that has the potential to colonize several crops, including maize, peanuts and cotton. A. flavus colonization may result in the secretion of mycotoxins, of which the most prominent is aflatoxin. Temperature, water availability and carbon dioxide levels ar...

Soil carbon dioxide partial pressure and dissolved inorganic carbonate chemistry under elevated carbon dioxide and ozone

Treesearch

N.J. Karberg; K.S. Pregitzer; J.S. King; A.L. Friend; J.R. Wood

2004-01-01

Global emissions of atmospheric CO2 and tropospheric O3 are rising and expected to impact large areas of the Earth's forests. While CO2 stimulates net primary production, O3 reduces photosynthesis, altering plant C allocation and reducing ecosystem C storage. The effects...

Effect of sulfur dioxide fumigation on survival of foodborne pathogens on table grapes under standard storage temperature

USDA-ARS?s Scientific Manuscript database

We examined the persistence of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica Thompson inoculated on freshly-harvested table grapes under standard cold storage with initial and weekly sulfur dioxide (SO2) fumigation. L. monocytogenes and S. enterica Thompson were much more...

Growth responses of Populus tremuloides clones to interacting elevated carbon dioxide and tropospheric ozone

Treesearch

J. G. Isebrands; E. P. McDonald; E. Kruger; G. Hendrey; K. Percy; K. Pregitzer; J. Sober; D. F. Karnosky

2001-01-01

The Intergovernmental Panel of Climate Change (IPCC) has concluded that the greenhouse gases carbon dioxide (CO2) and tropospheric ozone (O3) are increasing concomitantly globally. Little is known about the effect of these interacting gases on growth, survival, and productivity of forest ecosystems. In this study we assess...

Effects of Material Properties on Sedimentation and Aggregation of Titanium Dioxide Nanoparticles of Anatase and Rutile in the Aqueous Phase

EPA Science Inventory

This study investigated the sedimentation and aggregation kinetics of titanium dioxide (TiO2) nanoparticles with varying material properties (i.e., crystallinity, morphology, and chemical compositions). Used in the study were various types of commercially available TiO2 nanoparti...

Effect of Treatment Media on the Agglomeration of Titanium Dioxide Nanoparticles: Impact on Genotoxicity, Cellular Interaction, and Cell Cycle

EPA Science Inventory

ABSTRACT The widespread use of titanium dioxide (TiO2) nanoparticles in consumer products increases the probability of exposure to humans and the environment. Although TiO2 nanoparticles have been shown to induce DNA damage (comet assay) and chromosome damage (micronucleus ass...

Ty Neises | NREL

Science.gov Websites

analyzing the thermal fluid performance of concentrating solar power (CSP) systems and components. His recent work includes researching supercritical carbon dioxide (sCO2) systems for CSP applications and

Effect of substrate temperature on thermochromic vanadium dioxide thin films sputtered from vanadium target

NASA Astrophysics Data System (ADS)

Madiba, I. G.; Kotsedi, L.; Ngom, B. D.; Khanyile, B. S.; Maaza, M.

2018-05-01

Vanadium dioxide films have been known as the most promising thermochromic thin films for smart windows which self-control the solar radiation and heat transfer for energy saving, comfort in houses and automotives. Such an attractive technological application is due to the fact that vanadium dioxide crystals exhibit a fast semiconductor-to-metal phase transition at a transition temperature Tc of about 68 °C, together with sharp optical changes from high transmitive to high reflective coatings in the IR spectral region. The phase transition has been associated with the nature of the microstructure, stoichiometry and stresses related to the oxide. This study reports on the effect of the crystallographic quality controlled by the substrate temperature on the thermochromic properties of vanadium dioxide thin films synthesized by reactive radio frequency inverted cylindrical magnetron sputtering from vanadium target. The reports results are based on X-ray diffraction, Atomic force microscopy, and UV-Visible spectrophotometer. The average crystalline grain size of VO2 increases with the substrate temperature, inducing stress related phenomena within the films.

Importance of network density of nanotube: Effect on nitrogen dioxide gas sensing by solid state resistive sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Prabhash; Grachyova, D. V.; Moskalenko, A. S.

2016-04-13

Dispersion of single-walled carbon nanotubes (SWCNTs) is an established fact, however, its effect on toxic gas sensing for the development of solid state resistive sensor was not well reported. In this report, the dispersion quality of SWCNTs has been investigated and improved, and this well-dispersed SWCNTs network was used for sensor fabrication to monitor nitrogen dioxide gas. Ultraviolet (UV)-visible spectroscopic studies shows the strength of SWNTs dispersion and scanning electron microscopy (SEM) imaging provides the morphological properties of the sensor device. In this gas sensor device, two sets of resistive type sensors were fabricated that consisting of a pair ofmore » interdigitated electrodes (IDEs) using dielectrophoresis technique with different SWCNTs network density. With low-density SWCNTs networks, this fabricated sensor exhibits a high response for nitrogen dioxide sensing. The sensing of nitrogen dioxide is mainly due to charge transfer from absorbed molecules to sidewalls of nanotube and tube-tube screening acting a major role for the transport properties of charge carriers.« less

The NASA high power carbon dioxide laser: A versatile tool for laser applications

NASA Technical Reports Server (NTRS)

Lancashire, R. B.; Alger, D. L.; Manista, E. J.; Slaby, J. G.; Dunning, J. W.; Stubbs, R. M.

1976-01-01

A closed-cycle, continuous wave, carbon dioxide high power laser has been designed and fabricated to support research for the identification and evaluation of possible high power laser applications. The device is designed to generate up to 70 kW of laser power in annular shape beams from 1 to 9 cm in diameter. Electric discharge, either self sustained or electron beam sustained, is used for excitation. This laser facility provides a versatile tool on which research can be performed to advance the state-of-the-art technology of high power CO2 lasers in such areas as electric excitation, laser chemistry, and quality of output beams. The facility provides a well defined, continuous wave beam for various application experiments, such as propulsion, power conversion, and materials processing.

Removing oxygen from a solvent extractant in an uranium recovery process

DOEpatents

Hurst, Fred J.; Brown, Gilbert M.; Posey, Franz A.

1984-01-01

An improvement in effecting uranium recovery from phosphoric acid solutions is provided by sparging dissolved oxygen contained in solutions and solvents used in a reductive stripping stage with an effective volume of a nonoxidizing gas before the introduction of the solutions and solvents into the stage. Effective volumes of nonoxidizing gases, selected from the group consisting of argon, carbon dioxide, carbon monoxide, helium, hydrogen, nitrogen, sulfur dioxide, and mixtures thereof, displace oxygen from the solutions and solvents thereby reduce deleterious effects of oxygen such as excessive consumption of elemental or ferrous and accumulation of complex iron phosphates or cruds.

Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2)emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma USA

USDA-ARS?s Scientific Manuscript database

Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2) emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma, USA J.P.S. Neel USDA ARS, El Reno, OK A reduction in enteric CH4 production in ruminants is associated with improved production effic...

Demonstration of Improved Technologies for Rehabilitating Metal Roofing in Severely Corrosive Environments

DTIC Science & Technology

2012-03-01

heat and carbon dioxide. The reaction is not violent. Carbon dioxide, carbon monoxide and in high temperature (Boo· F) low oxygen atmospheres such as in... effectively than a full replacement. The projected return on investment (ROI) for these technologies ranged from 21.6 to 28.7 depending on as- sumptions...rapidly and cost- effectively rehabilitat- ing failed corroded metal roofs. One is a high-build polyurea-hybrid mem- brane-producing coating, and the other

High Rate Performance Nanocomposite Electrode of Mesoporous Manganese Dioxide/Silver Nanowires in KI Electrolytes.

PubMed

Jiang, Yanhua; Cui, Xiuguo; Zu, Lei; Hu, Zhongkai; Gan, Jing; Lian, Huiqin; Liu, Yang; Xing, Guangjian

2015-10-13

In recent years, manganese dioxide has become a research hotspot as an electrode material because of its low price. However, it has also become an obstacle to industrialization due to its low ratio of capacitance and the low rate performance which is caused by the poor electrical conductivity. In this study, a KI solution with electrochemical activity was innovatively applied to the electrolyte, and we systematically investigated the rate performance of the mesoporous manganese dioxide and the composite electrode with silver nanowires in supercapacitors. The results showed that when mesoporous manganese dioxide and mesoporous manganese dioxide/silver nanowires composite were used as electrodes, the strength of the current was amplified five times (from 0.1 to 0.5 A/g), the remaining rates of specific capacitance were 95% (from 205.5 down to 197.1 F/g) and 92% (from 208.1 down to 191.7 F/g) in the KI electrolyte, and the rate performance was much higher than which in an Na₂SO₄ electrolyte with a remaining rate of 25% (from 200.3 down to 49.1 F/g) and 60% (from 187.2 down to 113.1 F/g). The morphology and detail structure were investigated by Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry and Nitrogen adsorption-desorption isotherms. The electrochemical performance was assessed by cyclic voltammograms, galvanostatic charge/discharge and electrochemical impedance spectroscopy.

The Influence of Seal Properties on Pressure Buildup and Leakage of Carbon Dioxide from Sequestration Reservoirs (Invited)

NASA Astrophysics Data System (ADS)

Benson, S. M.; Chabora, E.

2009-12-01

The transport properties of seals, namely permeability, relative permeability, and capillary pressure control both migration of carbon dioxide and brine through the seal. Only recently has the the importance of brine migration emerged as key issue in the environmental performance of carbon dioxide sequestration projects. In this study we use numerical simulation to show that brine migration through the seal can be either advantageous or deleterious to the environmental performance of a carbon dioxide sequestration project. Brine migration through the seal can lower the pressure buildup in the storage reservoir, thereby reducing the risk of leakage or geomechanical stresses on the seal. On the other hand, if the seal is penetrated by a permeable fault it can lead to focused flow up a fault, which could lead to brine migration into drinking water aquifers. We also show that as the carbon dioxide plume grows, brine flow undergoes a complex evolution from upward flow to downward flows driven by countercurrent migration of carbon dioxide and brine in the seal and capillary pressure gradients at the base of the seal. Finally, we discuss desirable attributes seals, taking into account both carbon dioxide and brine migration through the seal. In particular, identifying seals that provide an effective capillary barrier to block the flow of carbon dioxide while allowing some brine migration through the seal can help to control pressure buildup and allow more efficient utilization of a sequestration reservoir. This could be particularly important in those settings that may be limited by the maximum allowable pressure buildup.

Studies on the effects of air pollution on limestone degradation in Great Britain

NASA Astrophysics Data System (ADS)

Webb, A. H.; Bawden, R. J.; Busby, A. K.; Hopkins, J. N.

The CEGB and the Cathedrals Advisory Commission for England formed a Joint Working Party in 1985 to promote a research programme aimed at improving the understanding of the relationships between stone decay, atmospheric pollution and other factors. The programme has included exposure of limestone samples at York Minster and eight other sites in England and Scotland selected to give a mix of urban, marine and rural locations. All of the sites have comprehensive air pollution and meteorological monitoring and measurement of rainfall chemistry. At two sites samples have been fumigated with controlled levels of sulphur dioxide. Over all sites, there was a significant trend to increased weight loss with increase in average sulphur dioxide concentration, but a negative trend with total nitrogen oxides and with nitrogen dioxide. For sample exposures longer than 200 days, the sulphur dioxide dependence at the inland Liphook fumigation site was about half that found near the coast at Littlehampton. There was no significant trend to increase weight loss with total rainfall amount for the complete data set, but the analysis was dominated by the very wet Scottish site, which experienced the lowest average concentrations of air pollutants. A theoretical model for the chemical dissolution of rainwashed limestone has been derived from consideration of the ion and mass balances between the incident rain water and run-off water. The model has been fitted to the measured loss rates from the stonework field trials. With the exception of the very wet Scottish site, the difference between the stone loss rate, calculated from the model, and the mean measured loss rate for any particular exposure was generally smaller than the variation between the triplicate samples. Variation in the dry deposition velocity between sites and exposure periods does not appear to have been a very significant factor, and no residual effect due to the concentrations of nitrogen oxides was found. The natural solubility of limestone in water was the dominant term in describing the stone loss, and neutralization of the rainfall acidity the least significant. The volume of the intercepted rainfall and the variation in the pH of the run-off water with rainfall intensity have been identified as the two most significant terms which require more precise quantification. The data from the inland fumigation site used in the model predict a stone loss due to sulphur dioxide in the air of less than 1 μm yr -1 surface recession per ppb SO 2.

Warming trends: Adapting to nonlinear change

DOE PAGES

Jonko, Alexandra K.

2015-01-28

As atmospheric carbon dioxide concentrations rise, some regions are expected to warm more than others. Research suggests that whether warming will intensify or slow down over time also depends on location.

Chlorine dioxide water disinfection: a prospective epidemiology study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael, G.E.; Miday, R.K.; Bercz, J.P.

An epidemiologic study of 198 persons exposed for 3 months to drinking water disinfected with chlorine dioxide was conducted in a rural village. A control population of 118 nonexposed persons was also studied. Pre-exposure hematologic and serum chemical parameters were compared with test results after 115 days of exposure. Chlorite ion levels in the water averaged approximately 5 ppM during the study period. Statistical analysis (ANOVA) of the data failed to identify any significant exposure-related effects. This study suggests that future evaluations of chlorine dioxide disinfection should be directed toward populations with potentially increased sensitivity to hemolytic agents.

Impact of Climate Change on Air Quality and Public Health in Urban Areas.

PubMed

Hassan, Noor Artika; Hashim, Zailina; Hashim, Jamal Hisham

2016-03-01

This review discusses how climate undergo changes and the effect of climate change on air quality as well as public health. It also covers the inter relationship between climate and air quality. The air quality discussed here are in relation to the 5 criteria pollutants; ozone (O3), carbon dioxide (CO2), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter (PM). Urban air pollution is the main concern due to higher anthropogenic activities in urban areas. The implications on health are also discussed. Mitigating measures are presented with the final conclusion. © 2015 APJPH.

The anaesthesia of fish by high carbon-dioxide concentrations

USGS Publications Warehouse

1942-01-01

A practical and economical method for anaesthetizing adult salmon and steelhead trout in the fish trucks used in the Grand Coulee fish salvage program is described. The method consists in generating a predetermined carbon-dioxide concentration in the 1000-gallon tanks of the trucks through the successive addition of predissolved sodium bicarbonate and dilute sulphuric acid in proper quantities. Carbon-dioxide anaesthesia effectively solved the acute problem of species segregation in the fish salvage program and, with minor modifications, could be used with equal success in certain hatchery operations necessitating the handling of large fish.

Acute effect of ambient air pollution on stroke mortality in the China air pollution and health effects study.

PubMed

Chen, Renjie; Zhang, Yuhao; Yang, Chunxue; Zhao, Zhuohui; Xu, Xiaohui; Kan, Haidong

2013-04-01

There have been no multicity studies on the acute effects of air pollution on stroke mortality in China. This study was undertaken to examine the associations between daily stroke mortality and outdoor air pollution (particulate matter <10 μm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide) in 8 Chinese cities. We used Poisson regression models with natural spline-smoothing functions to adjust for long-term and seasonal trends, as well as other time-varying covariates. We applied 2-stage Bayesian hierarchical statistical models to estimate city-specific and national average associations of air pollution with daily stroke mortality. Air pollution was associated with daily stroke mortality in 8 Chinese cities. In the combined analysis, an increase of 10 μg/m(3) of 2-day moving average concentrations of particulate matter <10 μm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide corresponded to 0.54% (95% posterior intervals, 0.28-0.81), 0.88% (95% posterior intervals, 0.54-1.22), and 1.47% (95% posterior intervals, 0.88-2.06) increase of stroke mortality, respectively. The concentration-response curves indicated linear nonthreshold associations between air pollution and risk of stroke mortality. To our knowledge, this is the first multicity study in China, or even in other developing countries, to report the acute effect of air pollution on stroke mortality. Our results contribute to very limited data on the effect of air pollution on stroke for high-exposure settings typical in developing countries.

Influence of Oxygenated Compounds on Reaction Products in a Microwave Plasma Methane Pyrolysis Assembly for Post-Processing of Sabatier Methane

NASA Technical Reports Server (NTRS)

Mansell, J. Matthew; Abney, Morgan B.; Miller, Lee A.

2011-01-01

The state-of-the-art Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS) in April 2010. The system is designed to accept carbon dioxide from the Carbon Dioxide Removal Assembly and hydrogen from the Oxygen Generation Assembly. The two gases are reacted in the CRA in a Sabatier reactor to produce water and methane. Venting of methane results in an oxygen resupply requirement of about 378 lbs per crew member per year. If the oxygen is supplied as water, the total weight for resupply is about 476 lb per crew member per year. For long-term missions beyond low Earth orbit, during which resupply capabilities will be further limited, recovery of hydrogen from methane is highly desirable. For this purpose, NASA is pursuing development of a Plasma Pyrolysis Assembly (PPA) capable of recovering hydrogen from methane. Under certain conditions, water vapor and carbon dioxide (nominally intended to be separated from the CRA outlet stream) may be present in the PPA feed stream. Thus, testing was conducted in 2010 to determine the effect of these "oxygenated" compounds on PPA performance, particularly the effect of inlet carbon dioxide and water variations on the PPA product stream. This paper discusses the test set-up, analysis, and results of this testing

Influence of Oxygenated Compounds on Reaction Products in a Microwave Plasma Methane Pyrolysis Assembly for Post-Processing of Sabatier Methane

NASA Technical Reports Server (NTRS)

Mansell, J. Matthew; Abney, Morgan B.

2012-01-01

The state-of-the-art Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS) in April 2010. The system is designed to accept carbon dioxide from the Carbon Dioxide Removal Assembly and hydrogen from the Oxygen Generation Assembly. The two gases are reacted in the CRA in a Sabatier reactor to produce water and methane. Venting of methane results in an oxygen resupply requirement of about 378 lbs per crew member per year. If the oxygen is supplied as water, the total weight for resupply is about 476 lb per crew member per year. For long-term missions beyond low Earth orbit, during which resupply capabilities will be further limited, recovery of hydrogen from methane is highly desirable. For this purpose, NASA is pursuing development of a Plasma Pyrolysis Assembly (PPA) capable of recovering hydrogen from methane. Under certain conditions, water vapor and carbon dioxide (nominally intended to be separated from the CRA outlet stream) may be present in the PPA feed stream. Thus, testing was conducted in 2010 to determine the effect of these oxygenated compounds on PPA performance, particularly the effect of inlet carbon dioxide and water variations on the PPA product stream. This paper discusses the test set-up, analysis, and results of this testing.

Respiratory health effects of the indoor environment in a population of Dutch children

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dijkstra, L.; Houthuijs, D.; Brunekreef, B.

1990-11-01

The effect of indoor exposure to nitrogen dioxide on respiratory health was studied over a period of 2 yr in a population of nonsmoking Dutch children 6 to 12 yr of age. Lung function was measured at the schools, and information on respiratory symptoms was collected from a self-administered questionnaire completed by the parents of the children. Nitrogen dioxide was measured in the homes of all children with Palmes' diffusion tubes. In addition, information on smoking and dampness in the home was collected by questionnaire. There was no relationship between exposure to nitrogen dioxide in the home and respiratory symptoms.more » Respiratory symptoms were found to be associated with exposure to tobacco smoke and home dampness. There was a weak, negative association between maximal midexpiratory flow (MMEF) and exposure to nitrogen dioxide. FEV1, peak expiratory flow, and MMEF were all negatively associated with exposure to tobacco smoke. Home dampness was not associated with pulmonary function. Lung function growth, measured over a period of 2 yr, was not consistently associated with any of the indoor exposure variables. The development of respiratory symptoms over time was not associated with indoor exposure to nitrogen dioxide. There was a significant association between exposure to environmental tobacco smoke in the home and the development of wheeze. There was also a significant association between home dampness and the development of cough.« less

Role of environmental pollutants in liver physiology: special references to peoples living in the oil drilling sites of Assam.

PubMed

Dey, Tapan; Gogoi, Kabita; Unni, Balagopalan; Bharadwaz, Moonmee; Kalita, Munmi; Ozah, Dibyajyoti; Kalita, Manoj; Kalita, Jatin; Baruah, Pranab Kumar; Bora, Thaneswar

2015-01-01

The populations residing near polluted sites are more prone to various types of diseases. The important causes of air pollution are the suspended particulate matter, respirable suspended particulate matter, sulfur dioxide and nitrogen dioxide. As limited information is available enumerating the effect of these pollutants on liver physiology of the population living near the polluted sites; in the present study, we tried to investigate their effect on liver of the population residing near the oil drilling sites since birth. In this study, a randomly selected 105 subjects (46 subjects from oil drilling site and 61 subjects from control site) aged above 30 years were taken under consideration. The particulate matter as well as the gaseous pollutants, sulfur dioxide and nitrogen dioxide, were analyzed through a respirable dust sampler. The level of alkaline phosphatase, alanine transaminase and aspartate transaminase enzymes in serum were measured by spectrophotometer. The generalized regression model studies suggests a higher concentration of respirable suspended particulate matter, suspended particulate matter and nitrogen dioxide lowers the alkaline phosphatase level (p<0.0001) by 3.5 times (95% CI 3.1-3.9), 1.5 times (95% CI 1.4-1.6) and 12 times (95% CI 10.74-13.804), respectively in the exposed group. The higher concentration of respirable suspended particulate matter and nitrogen dioxide in air was associated with increase in alanine transaminase level (p<0.0001) by 0.8 times (95% CI 0.589-1.049) and by 2.8 times (95% CI 2.067-3.681) respectively in the exposed group. The increase in nitrogen dioxide level was also associated with increase in aspartate transaminase level (p<0.0001) by 2.5 times (95% CI 1.862-3.313) in the exposed group as compared to control group. Thus, the study reveals that long-term exposure to the environmental pollutants may lead to liver abnormality or injury of populations living in polluted sites.

Role of Environmental Pollutants in Liver Physiology: Special References to Peoples Living in the Oil Drilling Sites of Assam

PubMed Central

Dey, Tapan; Gogoi, Kabita; Unni, Balagopalan; Bharadwaz, Moonmee; Kalita, Munmi; Ozah, Dibyajyoti; Kalita, Manoj; Kalita, Jatin; Baruah, Pranab Kumar; Bora, Thaneswar

2015-01-01

The populations residing near polluted sites are more prone to various types of diseases. The important causes of air pollution are the suspended particulate matter, respirable suspended particulate matter, sulfur dioxide and nitrogen dioxide. As limited information is available enumerating the effect of these pollutants on liver physiology of the population living near the polluted sites; in the present study, we tried to investigate their effect on liver of the population residing near the oil drilling sites since birth. In this study, a randomly selected 105 subjects (46 subjects from oil drilling site and 61 subjects from control site) aged above 30 years were taken under consideration. The particulate matter as well as the gaseous pollutants, sulfur dioxide and nitrogen dioxide, were analyzed through a respirable dust sampler. The level of alkaline phosphatase, alanine transaminase and aspartate transaminase enzymes in serum were measured by spectrophotometer. The generalized regression model studies suggests a higher concentration of respirable suspended particulate matter, suspended particulate matter and nitrogen dioxide lowers the alkaline phosphatase level (p<0.0001) by 3.5 times (95% CI 3.1-3.9), 1.5 times (95% CI 1.4 - 1.6) and 12 times (95% CI 10.74 -13.804), respectively in the exposed group. The higher concentration of respirable suspended particulate matter and nitrogen dioxide in air was associated with increase in alanine transaminase level (p<0.0001) by 0.8 times (95% CI 0.589-1.049) and by 2.8 times (95% CI 2.067-3.681) respectively in the exposed group. The increase in nitrogen dioxide level was also associated with increase in aspartate transaminase level (p<0.0001) by 2.5 times (95% CI 1.862 – 3.313) in the exposed group as compared to control group. Thus, the study reveals that long-term exposure to the environmental pollutants may lead to liver abnormality or injury of populations living in polluted sites. PMID:25874634

In-situ surface science studies of the interaction between sulfur dioxide and two-dimensional palladium loaded-cerium/zirconium mixed metal oxide model catalysts

NASA Astrophysics Data System (ADS)

Romano, Esteban Javier

2005-07-01

Cerium and zirconium oxides are important materials in industrial catalysis. Particularly, the great advances attained in the past 30 years in controlling levels of gaseous pollutants released from internal combustion engines can be attributed to the development of catalysts employing these materials. Unfortunately, oxides of sulfur are known threats to the longevity of many catalytic systems by irreversibly interacting with catalytic materials. In this work, polycrystalline cerium-zirconium mixed-metal-oxide (MMO) solid solutions were synthesized. High resolution x-ray photoelectron spectroscopy (XPS) spectral data was collected and examined for revelation of the surface species that form on these metal oxides after in-situ exposures to sulfur dioxide. The model catalysts were exposed to sulfur dioxide using a custom modified in-situ reaction cell and platen heater. The results of this study demonstrate the formation of sulfate and sulfite surface sulfur species. Temperature and compositional dependencies were displayed, with higher temperatures and ceria molar ratios displaying a larger propensity for forming surface sulfur species. In addition to analysis of sulfur photoemission, the photoemission regions of oxygen, zirconium, and cerium were examined for the materials used in this study before and after the aforementioned treatments with sulfur dioxide. The presence of surface hydroxyl groups was observed and metal oxidation state changes were probed to further enhance the understanding of sulfur dioxide adsorption on the synthesized materials. Palladium loaded mixed-metal oxides were synthesized using a unique solid-state methodology to probe the effect of palladium addition on sulfur dioxide adsorption. The addition of palladium to this model system is shown to have a strong effect on the magnitude of adsorption for sulfur dioxide on some material/exposure condition combinations. Ceria/zirconia sulfite and sulfate species are identified on the palladium-loaded MMO materials with adsorption sites located on the exposed oxide sites.

Methodological issues in studies of air pollution and reproductive health.

PubMed

Woodruff, Tracey J; Parker, Jennifer D; Darrow, Lyndsey A; Slama, Rémy; Bell, Michelle L; Choi, Hyunok; Glinianaia, Svetlana; Hoggatt, Katherine J; Karr, Catherine J; Lobdell, Danelle T; Wilhelm, Michelle

2009-04-01

In the past decade there have been an increasing number of scientific studies describing possible effects of air pollution on perinatal health. These papers have mostly focused on commonly monitored air pollutants, primarily ozone (O(3)), particulate matter (PM), sulfur dioxide (SO(2)), carbon monoxide (CO), and nitrogen dioxide (NO(2)), and various indices of perinatal health, including fetal growth, pregnancy duration, and infant mortality. While most published studies have found some marker of air pollution related to some types of perinatal outcomes, variability exists in the nature of the pollutants and outcomes associated. Synthesis of the findings has been difficult for various reasons, including differences in study design and analysis. A workshop was held in September 2007 to discuss methodological differences in the published studies as a basis for understanding differences in study findings and to identify priorities for future research, including novel approaches for existing data. Four broad topic areas were considered: confounding and effect modification, spatial and temporal exposure variations, vulnerable windows of exposure, and multiple pollutants. Here we present a synopsis of the methodological issues and challenges in each area and make recommendations for future study. Two key recommendations include: (1) parallel analyses of existing data sets using a standardized methodological approach to disentangle true differences in associations from methodological differences among studies; and (2) identification of animal studies to inform important mechanistic research gaps. This work is of critical public health importance because of widespread exposure and because perinatal outcomes are important markers of future child and adult health.

Evaluating the effect of sample type on American alligator ( Alligator mississippiensis) analyte values in a point-of-care blood analyser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamilton, Matthew T.; Finger, John W.; Winzeler, Megan E.

The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressuremore » of carbon dioxide (PCO 2), bicarbonate (HCO 3₋), total carbon dioxide (TCO 2), base excess (BE), partial pressure of oxygen (PO 2), oxygen saturation (sO 2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F 2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. In conclusion, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood.« less

Evaluating the effect of sample type on American alligator (Alligator mississippiensis) analyte values in a point-of-care blood analyser

PubMed Central

Hamilton, Matthew T.; Finger, John W.; Winzeler, Megan E.; Tuberville, Tracey D.

2016-01-01

The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressure of carbon dioxide (PCO2), bicarbonate (HCO3−), total carbon dioxide (TCO2), base excess (BE), partial pressure of oxygen (PO2), oxygen saturation (sO2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. Lastly, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood. PMID:27382469

Simultaneous gas chromatographic determination of four toxic gases generally present in combustion atmospheres.

PubMed

Endecott, B R; Sanders, D C; Chaturvedi, A K

1996-01-01

The measurement of combustion gases produced by burning aircraft cabin materials poses a continuing limitation for smoke toxicity research. Because toxic effects of gases depend on both their concentrations and the duration of exposure, frequent atmosphere sampling is necessary to define the gas concentration-exposure time curve. A gas chromatographic (GC) method was developed for the simultaneous analyses of carbon monoxide (CO), hydrogen sulfide (H2S), sulfur dioxide (SO2), and hydrogen cyanide (HCN). The method used an MTI M200 dual-column gas chromatograph equipped with 4-m molecular sieve-5A and 8-m PoraPlot-U wall-coated capillary columns and two low-volume, high-sensitivity thermal conductivity detectors. Detectability (in parts per million [ppm]) and retention times (in seconds) for the gases were as follows: CO, 100 ppm, 28 s; H2S, 50 ppm, 26 s; SO2, 125 ppm, 76 s; and HCN, 60 ppm, 108 s. The method was effective for determining these gases in mixtures and in the combustion atmospheres generated by burning wool (CO, HCN, and H2S) and modacrylic fabrics (CO and HCN). Common atmospheric gaseous or combustion products (oxygen, carbon dioxide, nitrogen, water vapor, and other volatiles) did not interfere with the analyses. However, filtration of the combustion atmospheres was necessary to prevent restriction of the GC sampling inlet by smoke particulates. The speed, sensitivity, and selectivity of this method make it suitable for smoke toxicity research and for evaluating performance of passenger protective breathing equipment. Also, this method can potentially be modified to analyze these gases when they are liberated from biosamples.

Evaluating the effect of sample type on American alligator ( Alligator mississippiensis) analyte values in a point-of-care blood analyser

DOE PAGES

Hamilton, Matthew T.; Finger, John W.; Winzeler, Megan E.; ...

2016-01-01

The assessment of wildlife health has been enhanced by the ability of point-of-care (POC) blood analysers to provide biochemical analyses of non-domesticated animals in the field. However, environmental limitations (e.g. temperature, atmospheric humidity and rain) and lack of reference values may inhibit researchers from using such a device with certain wildlife species. Evaluating the use of alternative sample types, such as plasma, in a POC device may afford researchers the opportunity to delay sample analysis and the ability to use banked samples. In this study, we examined fresh whole blood, fresh plasma and frozen plasma (sample type) pH, partial pressuremore » of carbon dioxide (PCO 2), bicarbonate (HCO 3₋), total carbon dioxide (TCO 2), base excess (BE), partial pressure of oxygen (PO 2), oxygen saturation (sO 2) and lactate concentrations in 23 juvenile American alligators (Alligator mississippiensis) using an i-STAT CG4+ cartridge. Our results indicate that sample type had no effect on lactate concentration values (F 2,65 = 0.37, P = 0.963), suggesting that the i-STAT analyser can be used reliably to quantify lactate concentrations in fresh and frozen plasma samples. In contrast, the other seven blood parameters measured by the CG4+ cartridge were significantly affected by sample type. In conclusion, we were able to collect blood samples from all alligators within 2 min of capture to establish preliminary reference ranges for juvenile alligators based on values obtained using fresh whole blood.« less

Response of Photosynthesis and Yield of Sweetpotato and Peanut to Super-optimal CO2 levels

NASA Astrophysics Data System (ADS)

Bonsi, C.; Bullard, J.; Hileman, D.; Mortley, D.; Hill, J.; Hill, W.; Morrris, C.

The fate of persons involved in long-term space travel and habitation will depend greatly on the ability to provide food and a livable environment for them In the National Aeronautics and Space Administration NASA Advanced Life Support ALS program photosynthesis of higher plants will be utilized to provide food and oxygen while removing carbon dioxide produced by humans and other heterotrophs as well as transpiring water that can be recycled for drinking This plant-mediated process is collectively referred to as Bioregenerative Life Support Carbon dioxide concentrations on board a space shuttle cabin atmosphere range between 4000 and 6000 mu mol mol -1 CO 2 but with large crews may exceed 10 000- mu mol mol -1 CO 2 Thus it is critical to evaluate the responses of candidate crops to super optimal levels of CO 2 Soybean and potato have been exposed to CO 2 concentrations up to 5000 and 10 000- mu mol mol -1 Very little research has been published about the effects of super-optimal CO 2 levels on sweetpotato and peanut growth and physiology thus indicating a need for extensive research on these plants The aim of this study was to evaluate the effects of super-optimal CO 2 enrichment on growth of TU-82-155 sweetpotato and Georgia Red peanut in a Microporous Tube Membrane MPT using Turface Media and Nutrient Film Technique NFT nutrient delivery systems Sweetpotato Ipomoea batatas L Lam and peanut Arachis hypogaea L were exposed to three CO 2 levels of 400

Unraveling the Role of Transport, Electrocatalysis, and Surface Science in the Solid Oxide Fuel Cell Cathode Oxygen Reduction Reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gopalan, Srikanth

2017-04-06

This final report for project FE0009656 covers the period from 10/01/2012 to 09/30/2015 and covers research accomplishments on the effects of carbon dioxide on the surface composition and structure of cathode materials for solid oxide fuel cells (SOFCs), specifically La1-xSrxFeyCo1- yO3-δ (LSCF). Epitaxially deposited thin films of LSCF on various single-crystal substrates have revealed the selective segregation of strontium to the surface thereby resulting in a surface enrichment of strontium. The near surface compositional profile in the films have been measured using total x-ray fluorescence (TXRF), and show that the kinetics of strontium segregation are higher at higher partial pressuresmore » of carbon dioxide. Once the strontium segregates to the surface, it leads to the formation of precipitates of SrO which convert to SrCO3 in the presence of even modest concentrations of carbon dioxide in the atmosphere. This has important implications for the performance of SOFCs which is discussed in this report. These experimental observations have also been verified by Density Functional Theory calculations (DFT) which predict the conditions under which SrO and SrCO3 can occur in LSCF. Furthermore, a few cathode compositions which have received attention in the literature as alternatives to LSCF cathodes have been studied in this work and shown to be thermodynamically unstable under the operating conditions of the SOFCs.« less

Correlation Between Foraminifera Phanerozoic Body Size Record versus Carbon Dioxide and Oxygen

NASA Astrophysics Data System (ADS)

Vo, N.; Seixas, G.; Payne, J.

2012-12-01

Body sizes are crucial in determining organisms' niches and their survival in the environment. Whether body sizes are affected by environmental and/or biological variables has been an intriguing question to many paleobiology researchers for decades. The environment of an ecosystem can greatly impact its organisms; therefore, in this study, I attempt to identify possible factors that affect the body sizes of foraminifera by comparing their test volumes with oxygen and carbon dioxide concentrations through time. To obtain data for my graphs, I measured the body sizes of foraminifera recorded in the Ellis and Messina catalogue of foraminifera. Visual analysis of my graphs indicates that there is a positive correlation between their body sizes and oxygen concentrations from 400 to 200 mya. From 200 mya onward, mean body size remains relatively constant while maximum body size increases with increases in oxygen concentration. Previous work has shown that benthic foraminifera require little oxygen to survive. My results support this discovery, and add to it by indicating that benthic foraminifera may survive with little oxygen, but flourish most when there are high concentrations of oxygen. My results also show that there is a complicated relationship between the body sizes of foraminifera and carbon dioxide. Oxygen is required for respiration, and high concentrations of oxygen create a better living environment for foraminifera. The effect of oxygen concentrations on foraminifera can be extended to other organisms that need oxygen for respiration.

Application of response surface methodology to optimise supercritical carbon dioxide extraction of volatile compounds from Crocus sativus.

PubMed

Shao, Qingsong; Huang, Yuqiu; Zhou, Aicun; Guo, Haipeng; Zhang, Ailian; Wang, Yong

2014-05-01

Crocus sativus has been used as a traditional Chinese medicine for a long time. The volatile compounds of C. sativus appear biologically active and may act as antioxidants as well as anticonvulsants, antidepressants and antitumour agents. In order to obtain the highest possible yield of essential oils from C. sativus, response surface methodology was employed to optimise the conditions of supercritical fluid carbon dioxide extraction of the volatile compounds from C. sativus. Four factorswere investigated: temperature, pressure, extraction time and carbon dioxide flow rate. Furthermore, the chemical compositions of the volatile compounds extracted by supercritical fluid extraction were compared with those obtained by hydro-distillation and Soxhlet extraction. The optimum extraction conditions were found to be: optimised temperature 44.9°C, pressure 34.9 MPa, extraction time 150.2 min and CO₂ flow rate 10.1 L h⁻¹. Under these conditions, the mean extraction yield was 10.94 g kg⁻¹. The volatile compounds extracted by supercritical fluid extraction and Soxhlet extraction contained a large amount of unsaturated fatty acids. Response surface methodology was successfully applied for supercritical fluid CO₂ extraction optimisation of the volatile compounds from C. sativus. The study showed that pressure and CO₂ flow rate had significant effect on volatile compounds yield produced by supercritical fluid extraction. This study is beneficial for the further research operating on a large scale. © 2013 Society of Chemical Industry.

Long-Term, Autonomous Measurement of Atmospheric Carbon Dioxide Using an Ormosil Nanocomposite-Based Optical Sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kisholoy Goswami

2005-10-11

The goal of this project is to construct a prototype carbon dioxide sensor that can be commercialized to offer a low-cost, autonomous instrument for long-term, unattended measurements. Currently, a cost-effective CO2 sensor system is not available that can perform cross-platform measurements (ground-based or airborne platforms such as balloon and unmanned aerial vehicle (UAV)) for understanding the carbon sequestration phenomenon. The CO2 sensor would support the research objectives of DOE-sponsored programs such as AmeriFlux and the North American Carbon Program (NACP). Global energy consumption is projected to rise 60% over the next 20 years and use of oil is projected tomore » increase by approximately 40%. The combustion of coal, oil, and natural gas has increased carbon emissions globally from 1.6 billion tons in 1950 to 6.3 billion tons in 2000. This figure is expected to reach 10 billon tons by 2020. It is important to understand the fate of this excess CO2 in the global carbon cycle. The overall goal of the project is to develop an accurate and reliable optical sensor for monitoring carbon dioxide autonomously at least for one year at a point remote from the actual CO2 release site. In Phase I of this project, InnoSense LLC (ISL) demonstrated the feasibility of an ormosil-monolith based Autonomous Sensor for Atmospheric CO2 (ASAC) device. All of the Phase I objectives were successfully met.« less

Pacific Northwest Laboratory annual report for 1990 to the DOE Office of Energy Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owczarski, E.L.

At the start of FY 1990, the atmospheric sciences and carbon dioxide research programs within the Office of Health and Environmental Research (OHER) were gathered into the new Atmospheric and Climate Research Division (ACRD). One of the central missions of this new division is to provide the Department of Energy with scientifically defensible information on the local, regional, and global distributions of energy-related pollutants and their effects on climate. This information is vital to the definition and implementation of a sound national energy strategy. Because much of the work done at PNL during FY 1990 falls under the umbrella ofmore » the new ACRD, we are including in this volume the progress and status reports for all OHER atmospheric and climate research projects at PNL. The description of ongoing atmospheric and climate research at PNL is organized along two broad research areas; atmospheric research and climate research. This report describes the progress in FY 1990 in each of these areas. A divider page summarizes the goals of each area and lists projects that support research activities.« less

Lighting the Way to the Stars

NASA Technical Reports Server (NTRS)

Stutte, Gary W.

2015-01-01

NASA has long recognized the importance of biological life-support systems to remove carbon dioxide, generate oxygen, purify water, and produce food for long-duration space missions. Experiments to understand the effects of the space environment on plant development have been performed since early days of the space program. In the late 1970s, NASA sponsored a series of workshops to identify issues associated with developing a sustainable, biological life-support system for long-duration space missions. Based on findings from these workshops, NASA's Controlled Ecological Life Support Systems (CELSS) program began funding research at university and field centers to systematically conduct the research identified in those workshops. Key issues were the necessity to reduce mass, power/energy requirements, and volume of all components.

An Enhanced Soft Vibrotactile Actuator Based on ePVC Gel with Silicon Dioxide Nanoparticles.

PubMed

Park, Won-Hyeong; Shin, Eun-Jae; Yun, Sungryul; Kim, Sang-Youn

2018-01-01

In this paper, we propose a soft vibrotactile actuator made by mixing silicon dioxide nanoparticles and plasticized PVC gel. The effect of the silicon dioxide nanoparticles in the plasticized PVC gel for the haptic performance is investigated in terms of electric, dielectric, and mechanical properties. Furthermore, eight soft vibrotactile actuators are prepared as a function of the content. Experiments are conducted to examine the haptic performance of the prepared eight soft vibrotactile actuators and to find the best weight ratio of the plasticized PVC gel to the nanoparticles. The experiments should show that the plasticized PVC gel with silicon dioxide nanoparticles improves the haptic performance of the plasticized PVC gel-based vibrotactile actuator, and the proposed vibrotactile actuator can create a variety of haptic sensations in a wide frequency range.

Carbon Dioxide Management on the International Space Station

NASA Technical Reports Server (NTRS)

Burlingame, Katie

2016-01-01

The International Space Station (ISS) is a manned laboratory operating in orbit around the Earth that was built and is currently operated by several countries across the world. The ISS is a platform for novel scientific research as well as a testbed for technologies that will be required for the next step in space exploration. In order for astronauts to live on ISS for an extended period of time, it is vital that on board systems consistently provide a clean atmosphere. One contaminant that must be removed from the atmosphere is carbon dioxide (CO2). CO2 levels on ISS are higher than those on Earth and can cause crew members to experience symptoms such as headaches, lethargy and mental slowness. A variety of systems exist on ISS to remove carbon dioxide, including adsorbent technologies which can be reused and testbed technologies for future space vehicles.

[The application of the multidimensional statistical methods in the evaluation of the influence of atmospheric pollution on the population's health].

PubMed

Surzhikov, V D; Surzhikov, D V

2014-01-01

The search and measurement of causal relationships between exposure to air pollution and health state of the population is based on the system analysis and risk assessment to improve the quality of research. With this purpose there is applied the modern statistical analysis with the use of criteria of independence, principal component analysis and discriminate function analysis. As a result of analysis out of all atmospheric pollutants there were separated four main components: for diseases of the circulatory system main principal component is implied with concentrations of suspended solids, nitrogen dioxide, carbon monoxide, hydrogen fluoride, for the respiratory diseases the main c principal component is closely associated with suspended solids, sulfur dioxide and nitrogen dioxide, charcoal black. The discriminant function was shown to be used as a measure of the level of air pollution.

Measurement of Trace Water Vapor in a Carbon Dioxide Removal Assembly Product Stream

NASA Technical Reports Server (NTRS)

Wormhoudt, Joda; Shorter, Joanne H.; McManus, J. Barry; Nelson, David D.; Zahniser, Mark S.; Freedman, Andrew; Campbell, Melissa; Chang, Clarence T.; Smith, Frederick D.

2004-01-01

The International Space Station Carbon Dioxide Removal Assembly (CDRA) uses regenerable adsorption technology to remove carbon dioxide (COP) from cabin air. Product water vapor measurements from a CDRA test bed at the NASA Marshall Space Flight Center were made using a tunable infrared diode laser differential absorption spectrometer (TILDAS) provided by NASA Glenn Research Center. The TILDAS instrument exceeded all the test specifications, including sensitivity, dynamic range, time response, and unattended operation. During the COP desorption phase, water vapor concentrations as low as 5 ppmv were observed near the peak of CO2 evolution, rising to levels of approx. 40 ppmv at the end of a cycle. Periods of high water concentration (>100 ppmv) were detected and shown to be caused by an experimental artifact. Measured values of total water vapor evolved during a single desorption cycle were as low as 1 mg.

Modeling and visual simulation of Microalgae photobioreactor

NASA Astrophysics Data System (ADS)

Zhao, Ming; Hou, Dapeng; Hu, Dawei

Microalgae is a kind of nutritious and high photosynthetic efficiency autotrophic plant, which is widely distributed in the land and the sea. It can be extensively used in medicine, food, aerospace, biotechnology, environmental protection and other fields. Photobioreactor which is important equipment is mainly used to cultivate massive and high-density microalgae. In this paper, based on the mathematical model of microalgae which grew under different light intensity, three-dimensional visualization model was built and implemented in 3ds max, Virtools and some other three dimensional software. Microalgae is photosynthetic organism, it can efficiently produce oxygen and absorb carbon dioxide. The goal of the visual simulation is to display its change and impacting on oxygen and carbon dioxide intuitively. In this paper, different temperatures and light intensities were selected to control the photobioreactor, and dynamic change of microalgal biomass, Oxygen and carbon dioxide was observed with the aim of providing visualization support for microalgal and photobioreactor research.

Design and development of a new generation of UV-visible-light-driven nanosized codoped titanium dioxide photocatalysts and biocides/sporocides, and environmental applications

NASA Astrophysics Data System (ADS)

Hamal, Dambar B.

For solar environmental remediation, a new generation of nanosized (< 10 nm) titanium dioxide photocatalysts codoped with metals and nonmetals, or metals only were prepared by the xero-gel and aero-gel methods. For silver or cobalt-based xero-gel titanium dioxide photocatalysts, photoactivities tests revealed that codoping of titanium dioxide with a metal (1% Ag or 2% Co) and nonmetals (carbon and sulfur) is necessary to achieve high-activities for acetaldehyde degradation under visible light (wavelength > 420 nm). It was concluded that high visible-light-activities for acetaldehyde degradation over codoped titanium dioxide were attributed to an interplay of anatase crystallinity, high-surface area, reduced band-gap (< 3.0 eV), uniform dispersion of doped metal ions, and suppressed recombination rate of photogenerated electronhole pairs. Moreover, the nature and amount of codoped metals play a significant role in visible-light-induced photocatalysis. Metals (Al, Ga, and In) doped/codoped titanium dioxide photocatalysts were prepared by the aero-gel method. The photocatalytic studies showed that activities of metal doped/codoped photocatalysts under UV light (wavelength < 400 nm) were found to be dependent on pollutants. Indium demonstrated beneficial effects in both textural and photocatalytic properties. Gallium and indium codoped titanium dioxide photocatalysts displayed even better performance in the CO oxidation reaction under UV light. Notably, titanium dioxide codoped with Ga, In, and Pt, exhibited unique photoactivities for the CO oxidation under both UV and visible light irradiation, indicating that this system could have promise for the water-gas shift reaction for hydrogen production. Silver-based nanostructured titanium dioxide samples were developed for killing human pathogens (Escherichia coli cells and Bacillus subtilis spores). Biocidal tests revealed that silver, carbon, and sulfur codoped titanium dioxide nanoparticles (< 10 nm) possess very strong antimicrobial actions on both E. coli (logarithmic kill > 8) and B. subtilis spores (logarithmic kill > 5) for 30 minute exposures in dark conditions compared with Degussa P25. It was believed that the carbon and sulfur codoped titanium dioxide support and Ag species acted synergistically during deactivation of both E. coli and B. subtilis spores. Thus, titanium dioxide codoped with silver, carbon, sulfur can serve as a multifunctional generic biocide and a visible-light-active photocatalyst.

Options for lowering U.S. carbon dioxide emissions

NASA Astrophysics Data System (ADS)

Bierbaum, Rosina M.; Friedman, Robert M.; Levenson, Howard; Rapoport, Richard D.; Sundt, Nick

1992-03-01

The United States can decrease its emissions of carbon dioxide (CO2) to as much as 35 percent below 1987 levels within the next 25 years by adopting an aggressive package of policies crossing all sectors of the economy. Such emissions reductions will be difficult to achieve and may be costly, but no major technological breakthroughs are needed. In this paper, we identify a ``Tough'' package of energy conservation, energy supply, and forest managment practices to accomplish this level of emissions reductions. We also present a package of cost-effective, ``Moderate'' technical options, which if adopted, would hold CO2 emissions to about 15-percent increase over 1987 levels by 2015. In constrast, if the United State takes not new actions to curb energy use, CO2 emissions will likely rise 50 percent during that time. A variety of Federal policy initiatives will be required to achieve large reductions in U.S. CO2 emissions. Such policy actions will have to include both regulatory ``push'' and market ``pull'' mechanisms--including performance standards, tax incentive programs, carbon-emission or energy taxes, labeling and efficiency ratings, and research, development, and demostration activities.

Role of Endogenous Sulfur Dioxide in Regulating Vascular Structural Remodeling in Hypertension

PubMed Central

Chen, Selena; Tang, Chaoshu

2016-01-01

Sulfur dioxide (SO2), an emerging gasotransmitter, was discovered to be endogenously generated in the cardiovascular system. Recently, the physiological effects of endogenous SO2 were confirmed. Vascular structural remodeling (VSR), an important pathological change in many cardiovascular diseases, plays a crucial role in the pathogenesis of the diseases. Here, the authors reviewed the research progress of endogenous SO2 in regulating VSR by searching the relevant data from PubMed and Medline. In spontaneously hypertensive rats (SHRs) and pulmonary hypertensive rats, SO2/aspartate aminotransferase (AAT) pathway was significantly altered. SO2 inhibited vascular smooth muscle cell (VSMC) proliferation, promoted apoptosis, inhibited the synthesis of extracellular collagen but promoted its degradation, and enhanced antioxidative capacity, thereby playing a significant role in attenuating VSR. However, the detailed mechanisms needed to be further explored. Further studies in this field would be important for the better understanding of the pathogenesis of systemic hypertension and pulmonary hypertension. Also, clinical trials are needed to demonstrate if SO2 would be a potential therapeutic target in cardiovascular diseases. PMID:27721913

Vertical nanopillars for highly localized fluorescence imaging

PubMed Central

Xie, Chong; Hanson, Lindsey; Cui, Yi; Cui, Bianxiao

2011-01-01

Observing individual molecules in a complex environment by fluorescence microscopy is becoming increasingly important in biological and medical research, for which critical reduction of observation volume is required. Here, we demonstrate the use of vertically aligned silicon dioxide nanopillars to achieve below-the-diffraction-limit observation volume in vitro and inside live cells. With a diameter much smaller than the wavelength of visible light, a transparent silicon dioxide nanopillar embedded in a nontransparent substrate restricts the propagation of light and affords evanescence wave excitation along its vertical surface. This effect creates highly confined illumination volume that selectively excites fluorescence molecules in the vicinity of the nanopillar. We show that this nanopillar illumination can be used for in vitro single-molecule detection at high fluorophore concentrations. In addition, we demonstrate that vertical nanopillars interface tightly with live cells and function as highly localized light sources inside the cell. Furthermore, specific chemical modification of the nanopillar surface makes it possible to locally recruit proteins of interest and simultaneously observe their behavior within the complex, crowded environment of the cell. PMID:21368157

Comparison and Analysis of Zinc and Cobalt-Based Systems as Catalytic Entities for the Hydration of Carbon Dioxide

PubMed Central

Lau, Edmond Y.; Wong, Sergio E.; Baker, Sarah E.; Bearinger, Jane P.; Koziol, Lucas; Valdez, Carlos A.; Satcher, Joseph H.; Aines, Roger D.; Lightstone, Felice C.

2013-01-01

In nature, the zinc metalloenzyme carbonic anhydrase II (CAII) efficiently catalyzes the conversion of carbon dioxide (CO2) to bicarbonate under physiological conditions. Many research efforts have been directed towards the development of small molecule mimetics that can facilitate this process and thus have a beneficial environmental impact, but these efforts have met very limited success. Herein, we undertook quantum mechanical calculations of four mimetics, 1,5,9-triazacyclododedacane, 1,4,7,10-tetraazacyclododedacane, tris(4,5-dimethyl-2-imidazolyl)phosphine, and tris(2-benzimidazolylmethyl)amine, in their complexed form either with the Zn2+ or the Co2+ ion and studied their reaction coordinate for CO2 hydration. These calculations demonstrated that the ability of the complex to maintain a tetrahedral geometry and bind bicarbonate in a unidentate manner were vital for the hydration reaction to proceed favorably. Furthermore, these calculations show that the catalytic activity of the examined zinc complexes was insensitive to coordination states for zinc, while coordination states above four were found to have an unfavorable effect on product release for the cobalt counterparts. PMID:23840420

[Evaluation of different oxygen therapies on therapeutic effects in rats with acute carbon dioxide poisoning].

PubMed

Niu, Ying-mei; Hao, Feng-tong; Xue, Chang-jiang; Xia, Yu-jing; Zhou, Shuo; Lu, Qing-sheng; Liu, Jian-zhong; Zhang, Peng

2011-03-01

To study therapeutic effects by using different oxygen therapies in rats with acute carbon dioxide poisoning, to select the best oxygen therapy technology for patients with acute carbon dioxide poisoning on the spot. Sixty healthy male Sprague-Dawley rats were randomized into normal control group, carbon dioxide exposure group, hyperbaric oxygen treatment group (pressure 2 ATA, FiO(2)100%), high concentration of atmospheric oxygen treatment group (FiO(2)50%), low concentration of atmospheric oxygen treatment group (FiO(2)33%). After treated with different oxygen in rats with acute carbon dioxide poisoning, arterial pH, PO2 and PCO2 of rats were detected, in addition observe pathological changes of lung tissue and brain tissue. The arterial pH (7.31 ± 0.06) and PO2 [(68.50 ± 15.02) mm Hg] of carbon dioxide exposure group were lower than those of control group [pH (7.42 ± 0.02) and PO2 (92.83 ± 8.27) mm Hg], PCO2 [(71.66 ± 12.10) mm Hg] was higher than that of control group [(48.25 ± 2.59) mm Hg] (P < 0.05); the arterial pH (hyperbaric oxygen treatment group 7.37 ± 0.02, high concentration of atmospheric oxygen treatment group 7.39 ± 0.03, low concentration of atmospheric oxygen treatment group 7.38 ± 0.02) and PO2 of oxygen treatment groups [hyperbaric oxygen treatment group, high concentration of atmospheric oxygen treatment group, low concentration of atmospheric oxygen treatment group were (82.25 ± 12.98), (84.75 ± 11.24), (83.75 ± 16.77) mm Hg, respectively] were higher than that of carbon dioxide exposure group, PCO2 [hyperbaric oxygen treatment group, high concentration of atmospheric oxygen treatment group, low concentration of atmospheric oxygen treatment group were (52.25 ± 4.95), (51.75 ± 4.82), (52.66 ± 5.61) mm Hg, respectively] was lower than that of carbon dioxide exposure group (P < 0.05); there was no significant difference of the arterial pH, PO2 and PCO2 between oxygen treatment groups and control group (P > 0.05); there was no significant difference of the arterial pH, PO2 and PCO2 among oxygen treatment groups (P > 0.05). There was large area of bleeding of lungs in rats with carbon dioxide poisoning, the bleeding of lungs in rats with high concentration of atmospheric oxygen treatment and low concentration of atmospheric oxygen treatment was better than the rats with carbon dioxide poisoning, there was no abnormal appearance of lungs in rats with hyperbaric oxygen treatment. The light microscope observation showed that there were diffuse bleeding and exudation of lungs in rats with carbon dioxide poisoning, the bleeding and exudation of lungs in rats with high concentration of atmospheric oxygen treatment and low concentration of atmospheric oxygen treatment were better than the rats with carbon dioxide poisoning, there were only minor bleeding and exudation of lungs in rats with hyperbaric oxygen treatment. There was no difference of brain in anatomy and microscopy among all groups, there were no significant bleeding, edema, cell degeneration and necrosis. Lung pathology in acute carbon dioxide poisoning rats with hyperbaric oxygen treatment is better than the rats with high concentration of atmospheric oxygen treatment and low concentration of atmospheric oxygen treatment, there is no significant difference of effect between high concentration of atmospheric oxygen treatment group and low concentration of atmospheric oxygen treatment group, however, the results of blood gas analysis and lung pathology than the exposure group improved, so qualified medical unit for hyperbaric oxygen therapy as soon as possible, hyperbaric oxygen treatment facilities in the absence of circumstances, the emergency treatment of early oxygen is also a good measure.

UTILIZATION OF A RESPONSE-SURFACE TECHNIQUE IN THE STUDY OF PLANT RESPONSES TO OZONE AND SULFUR DIOXIDE MIXTURES

EPA Science Inventory

A second order rotatable design was used to obtain polynomial equations describing the effects of combinations of sulfur dioxide (SO2) and ozone (O3) on foliar injury and plant growth. The response surfaces derived from these equations were displayed as contour or isometric (3-di...

The chronic response of yellow-poplar and eastern white pine to ozone and elevated carbon dioxide: three-year summary

Treesearch

Joanne Rebbeck

1996-01-01

The objective of this study was to determine the long-term effects of ozone (O3) and carbon dioxide (CO2) on the growth and physiology of eastern white pine (Pinus strobus) and yellow-poplar (Liriodendron tulipifera) under plantation conditions. Two separate plantations of each species...

MERCURY SPECIATION IN COMBUSTION SYSTEMS: STUDIES WITH SIMULATED FLUE GASES AND MODEL FLY ASHES

EPA Science Inventory

The paper gives results of a bench-scale study of the effects of flue gas and fly ash parameters on the oxidation of elemental mercury in simulated flue gases containing hydrogen chloride (HCl), nitric oxide (NO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and water vapor (H2O...

Designing and Demonstrating a Master Student Project to Explore Carbon Dioxide Capture Technology

ERIC Educational Resources Information Center

Asherman, Florine; Cabot, Gilles; Crua, Cyril; Estel, Lionel; Gagnepain, Charlotte; Lecerf, Thibault; Ledoux, Alain; Leveneur, Sebastien; Lucereau, Marie; Maucorps, Sarah; Ragot, Melanie; Syrykh, Julie; Vige, Manon

2016-01-01

The rise in carbon dioxide (CO[subscript 2]) concentration in the Earth's atmosphere, and the associated strengthening of the greenhouse effect, requires the development of low carbon technologies. New carbon capture processes are being developed to remove CO[subscript 2] that would otherwise be emitted from industrial processes and fossil fuel…

Enhancing the Effectiveness of Carbon Dioxide Flooding by Managing Asphaltene Precipitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deo, Milind D.

2002-02-21

This project was undertaken to understand fundamental aspects of carbon dioxide (CO2) induced asphaltene precipitation. Oil and asphaltene samples from the Rangely field in Colorado were used for most of the project. The project consisted of pure component and high-pressure, thermodynamic experiments, thermodynamic modeling, kinetic experiments and modeling, targeted corefloods and compositional modeling.

Carbon dioxide and water vapour exchange in a tropical dry forest as influenced by the North American Monsoon System (NAMS)

USDA-ARS?s Scientific Manuscript database

To better understand the effects and relationship between precipitation, net ecosystem carbon dioxide (NEE) and water vapor exchange (ET), we report a study conducted in the tropical dry forest (TDF) in the northwest of Mexico. Ecosystem gas exchange was measured using the eddy correlation technique...

A short-term carbon dioxide treatment inhibits the browning of fresh-cut burdock

USDA-ARS?s Scientific Manuscript database

Fresh-cut burdock is susceptible to browning. The effect of short term carbon dioxide (CO2) treatment on inhibiting browning of fresh-cut burdock during storage at 2~4' was investigated. The results showed that the burdock slices treated with CO2 for 4 h, 6 h and 8 h exhibited better visual quality ...