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Sample records for carbon monoxide nanotube

  1. Carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The document identifies the main sources of carbon monoxide (CO) in the general outdoor atmosphere, describes methods of measuring and monitoring its concentration levels in the United Kingdom, and discusses the effects of carbon monoxide on human health. Following its review, the Panel has put forward a recommendation for an air quality standard for carbon monoxide in the United Kingdom of 10 ppm, measured as a running 8-hour average. The document includes tables and graphs of emissions of CO, in total and by emission source, and on the increase in blood levels of carboxyhaemoglobin with continuing exposure to CO. 11 refs., 4 figs., 4 tabs.

  2. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Education Centers Carbon Monoxide Information Center Carbon Monoxide Information Center En Español The Invisible Killer Carbon monoxide, ... Install one and check its batteries regularly. View Information About CO Alarms Other CO Topics Safety Tips ...

  3. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Education Safety Education Centers Carbon Monoxide Information Center Carbon Monoxide Information Center En Español The Invisible Killer Carbon monoxide, also known as CO, is called the " ...

  4. Carbon Monoxide Safety

    Science.gov (United States)

    ... with the Media Fire Protection Technology Carbon monoxide safety outreach materials Keep your community informed about the ... KB | Spanish PDF 592 KB Handout: carbon monoxide safety Download this handout and add your organization's logo ...

  5. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... main content Languages 简体中文 English Bahasa Indonesia 한국어 Español ภาษาไทย Tiếng Việt Text Size: Decrease Font Increase ... Monoxide Information Center Carbon Monoxide Information Center En Español The Invisible Killer Carbon monoxide, also known as ...

  6. Carbon monoxide poisoning

    Science.gov (United States)

    ... Animals can also be poisoned by carbon monoxide. People who have pets at home may notice that their animals become ... or unresponsive from carbon monoxide exposure. Often the pets will ... these conditions. This can lead to a delay in getting help.

  7. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Unites States die every year from accidental non-fire related CO poisoning associated with consumer products, including ... CO Blogs Research & Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of ...

  8. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... On Safety Blogs: CO Safety More CO Blogs Research & Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide ... Related Links Recalls Safety Education Regulations, Laws & Standards Research & Statistics Business & Manufacturing Small Business Resources OnSafety Blogs ...

  9. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Community Outreach Resource Center Toy Recall Statistics CO Poster Contest Pool Safely Business & Manufacturing Business & Manufacturing Business ... Featured Resources CPSC announces winners of carbon monoxide poster contest Video View the blog Clues You Can ...

  10. Occult carbon monoxide poisoning.

    Science.gov (United States)

    Kirkpatrick, J N

    1987-01-01

    A syndrome of headache, fatigue, dizziness, paresthesias, chest pain, palpitations and visual disturbances was associated with chronic occult carbon monoxide exposure in 26 patients in a primary care setting. A causal association was supported by finding a source of carbon monoxide in a patient's home, workplace or vehicle; results of screening tests that ruled out other illnesses; an abnormally high carboxyhemoglobin level in 11 of 14 patients tested, and abatement or resolution of symptoms when the source of carbon monoxide was removed. Exposed household pets provided an important clue to the diagnosis in some cases. Recurrent occult carbon monoxide poisoning may be a frequently overlooked cause of persistent or recurrent headache, fatigue, dizziness, paresthesias, abdominal pain, diarrhea and unusual spells.

  11. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Import Surveillance International Recall Guidance Civil and Criminal Penalties Federal Court Orders & ... 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of Consumer Products 2012 ...

  12. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of Consumer Products 2012 Annual Estimates OCTOBER 13, 2015 Incidents, Deaths, and In-Depth Investigations Associated with Non-Fire ...

  13. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Safety Blogs: CO Safety More CO Blogs Research & Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths ... 2011 Annual Estimates View All CO-Related Injury Statistics and Technical Reports Related Links Recalls Safety Education ...

  14. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... CONSUMER PRODUCT SAFETY COMMISSION Search CPSC Search Menu Home Recalls Recall List CPSC Recall API Recall Lawsuits ... and Bans Report an Unsafe Product Consumers Businesses Home Safety Education Safety Education Centers Carbon Monoxide Information ...

  15. Carbon Monoxide Nonattainment Areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer identifies areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for Carbon Monoxide and have...

  16. Occult Carbon Monoxide Poisoning

    OpenAIRE

    Kirkpatrick, John N.

    1987-01-01

    A syndrome of headache, fatigue, dizziness, paresthesias, chest pain, palpitations and visual disturbances was associated with chronic occult carbon monoxide exposure in 26 patients in a primary care setting. A causal association was supported by finding a source of carbon monoxide in a patient's home, workplace or vehicle; results of screening tests that ruled out other illnesses; an abnormally high carboxyhemoglobin level in 11 of 14 patients tested, and abatement or resolution of symptoms ...

  17. Carbon Monoxide Poisoning

    Directory of Open Access Journals (Sweden)

    Kamal Mishra

    2016-01-01

    Full Text Available Introduction: Carbon monoxide is known as the silent killer, being colorless, odourless, and tasteless. Initially non-irritating, it is very difficult for people to detect Carbon monoxide is a product of incomplete combustion of organic matter due to insufficient oxygen supply that prevents complete oxidation of carbon to C02. During World War II, Nazis used gas vans to kill an estimated over 700,000 prisoners by carbon monoxide poisoning. This method was also used in the gas chambers ofseveral death camps. The true number of incidents of carbon monoxide poisoning is unknown, since many non-lethal exposures go undetected From the available data, carbon monoxide poisoning is the most common cause of injury and death due to poisoning worldwide. Clinical features and management: The signs of carbon monoxide poisoning vary with concentration and length of exposure. Subtle cardiovascular or neurobehavioural effects occur at low concentration. The onset of chronic poisoning is usually insidious and easily mistaken for viral prodrome, depression, or gastroenteritis in children. The classic sign of carbon monoxide poisoning which is actually more often seen in the dead than the living is appearing red-cheeked and healthy. Cherry pink colour develops in nails, skin and mucosa. In acute poisoning, common abnormalities of posture and tone are cogwheel rigidity, opisthotonus, spasticity or flaccidity and seizures. Retinal haemorrhages and the classic cherry red skin colour are seldom seen. Different people andpopulations may have different carbon monoxide tolerance levels. On average, exposures at 100ppm or greater is dangerous to human health. Treatment and prevention: The mainstay of treatment is 100% oxygen administration until the COHb level is normal When the patient is stable enough to be transported, hyperbaric oxygen (HBOT should be considered This treatment is safe and well tolerated Public education about the danger of carbon monoxide, with

  18. Carbon Monoxide Poisoning

    Directory of Open Access Journals (Sweden)

    Alisa Wray

    2016-07-01

    Full Text Available Audience: This oral boards case is appropriate for all emergency medicine learners (residents, interns, and medical students. Introduction: Carbon monoxide (CO is a colorless and odorless gas that typically results from combustion. It binds hemoglobin, dissociating oxygen, causing headache, weakness, confusion and possible seizure or coma. Pulse oxygen levels may be falsely elevated. Practitioners should maintain a high index of suspicion for carbon monoxide poisoning. If caught early CO poisoning is reversible with oxygen or hyperbaric oxygen therapy. Objectives: The learner will assess a patient with altered mental status and weakness, ultimately identifying that the patient has carbon monoxide poisoning. The learner will treat the patient with oxygen and admit/transfer the patient for hyperbaric oxygenation. Method: Oral boards case

  19. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Investigations Associated with Non-Fire Carbon Monoxide from Engine-Driven Generators and Other Engine-Driven Tools, 2004–2014 JANUARY 08, 2015 Non- ... outside of the Federal Government. CPSC does not control this external site or its privacy policy and ...

  20. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Español The Invisible Killer Carbon monoxide, also known as CO, is called the "Invisible Killer" because it's ... used or incorrectly-vented fuel-burning appliances such as furnaces, stoves, water heaters and fireplaces. Watch This ...

  1. Effect of multi-walled carbon nanotubes aspect ratio and temperature on the dielectric behavior of alternating alkene-carbon monoxide polyketone nanocomposites

    Science.gov (United States)

    Abu-Surrah, Adnan S.; Abdul Jawad, Saadi; Al-Ramahi, Esraa; Hallak, Awni B.; Khattari, Z.

    2015-04-01

    New alternating poly(propylene-alt-carbon monoxide/ethylene-alt-carbon monoxide) (PECO)/multiwalled carbon nanotubes (MWCNTs) composites have been prepared. Dielectric permittivity, electric modulus and ac conductivity of the isolated materials were investigated as a function of fiber aspect ratio, frequency and temperature. For aspect ratio of 30 and 200, a transition from insulator to semiconductor was observed at frequency 1×104. However, for high aspect ratio sample (660), no transition was observed and the conductivity is frequency independent in the measured frequency range of 10-106 Hz. The conductivity increases from about 1×10-4 for the sample that contain fibers of aspect ratio 30 and reaches 5×10-2 (Ω m)-1 for aspect ratio was 660. This behavior can be modeled by a circuit that consists of a contact resistance in series with a parallel combination of resistance (R) and capacitance (C). The calculated activation energy for sample filled with fibers having aspect ratio 30 is about 0.26 eV and decreases to about 0.16 eV when the aspect ratio is 660.

  2. Bacterium oxidizing carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Kistner, A

    1953-01-01

    Present-day knowledge of the microbiological oxidation of carbon monoxide is based on doubtful observations and imperfect experimental procedures. By making use of shake cultures in contact with gas mixtures containing high concentrations of CO and by employing liquid enrichment media with a low content of organic matter and solid media of the same composition with not more than 1.2% agar, it proved possible to isolate a co-oxidizing bacterium of the genus hydrogenomonas from sewage sludge. For the first time irrefutable proof has been given of the oxidation of carbon monoxide by a pure culture of a bacterium, both in growing cultures and in resting cell suspensions. 12 references.

  3. Method for producing carbon nanotubes

    Science.gov (United States)

    Phillips, Jonathan [Santa Fe, NM; Perry, William L [Jemez Springs, NM; Chen, Chun-Ku [Albuquerque, NM

    2006-02-14

    Method for producing carbon nanotubes. Carbon nanotubes were prepared using a low power, atmospheric pressure, microwave-generated plasma torch system. After generating carbon monoxide microwave plasma, a flow of carbon monoxide was directed first through a bed of metal particles/glass beads and then along the outer surface of a ceramic tube located in the plasma. As a flow of argon was introduced into the plasma through the ceramic tube, ropes of entangled carbon nanotubes, attached to the surface of the tube, were produced. Of these, longer ropes formed on the surface portion of the tube located in the center of the plasma. Transmission electron micrographs of individual nanotubes revealed that many were single-walled.

  4. Carbon nanotube composite materials

    Science.gov (United States)

    O'Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2015-03-24

    A material consisting essentially of a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes dissolved in a solvent. Un-functionalized carbon nanotube concentrations up to 30 wt % and hydroxylated carbon nanotube concentrations up to 40 wt % can be used with even small concentrations of each (less than 2 wt %) useful in producing enhanced conductivity properties of formed thin films.

  5. Effects of carbonyl bond, metal cluster dissociation, and evaporation rates on predictions of nanotube production in high-pressure carbon monoxide

    Science.gov (United States)

    Scott, Carl D.; Smalley, Richard E.

    2003-01-01

    The high-pressure carbon monoxide (HiPco) process for producing single-wall carbon nanotubes (SWNTs) uses iron pentacarbonyl as the source of iron for catalyzing the Boudouard reaction. Attempts using nickel tetracarbonyl led to no production of SWNTs. This paper discusses simulations at a constant condition of 1300 K and 30 atm in which the chemical rate equations are solved for different reaction schemes. A lumped cluster model is developed to limit the number of species in the models, yet it includes fairly large clusters. Reaction rate coefficients in these schemes are based on bond energies of iron and nickel species and on estimates of chemical rates for formation of SWNTs. SWNT growth is measured by the conformation of CO2. It is shown that the production of CO2 is significantly greater for FeCO because of its lower bond energy as compared with that of NiCO. It is also shown that the dissociation and evaporation rates of atoms from small metal clusters have a significant effect on CO2 production. A high rate of evaporation leads to a smaller number of metal clusters available to catalyze the Boudouard reaction. This suggests that if CO reacts with metal clusters and removes atoms from them by forming MeCO, this has the effect of enhancing the evaporation rate and reducing SWNT production. The study also investigates some other reactions in the model that have a less dramatic influence.

  6. Carbon nanotube nanoelectrode arrays

    Science.gov (United States)

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  7. Carbon monoxide, smoking, and atherosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Astrup, P

    1973-10-01

    Studies on the effects of carbon monoxide and smoking on atherosclerosis are reviewed. Nonsmokers do not run the risk of getting significantly elevated carboxyhemoglobin levels from automobile exhaust in the streets, however, they do run the risk of getting elevated carboxyhemoglobin levels from exposure to CO in closed areas such as garages and tunnels. Carboxyhemoglobin levels up to 20 percent may also be found in smokers. The central nervous system seems to be influenced by carboxyhemoglobin concentrations up to 20 percent. The myocardium may also be affected. Experimental work with rabbits exposed to carbon monoxide and cholesterol is described which proved that CO has a damaging effect on arterial walls, leading to increased permeability for various plasma components, to the formation of subendothelial edema, and to increased atheromatosis. The results indicate that the much higher risk of smokers of developing arterial disease in comparison to nonsmokers is mainly due to the inhaled CO in the tobacco smoke and not to nicotine. (Air Pollut. Abstr.)

  8. Catalytic hydrogenation of carbon monoxide

    International Nuclear Information System (INIS)

    Wayland, B.B.

    1993-12-01

    Focus of this project is on developing new approaches for hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. The strategies to accomplish CO reduction are based on favorable thermodynamics manifested by rhodium macrocycles for producing a series of intermediates implicated in the catalytic hydrogenation of CO. Metalloformyl complexes from reactions of H 2 and CO, and CO reductive coupling to form metallo α-diketone species provide alternate routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics are promising candidates for future development

  9. Delayed encephalopathy after acute carbon monoxide poisoning

    Directory of Open Access Journals (Sweden)

    Mehmet İbrahim Turan

    2014-03-01

    Full Text Available Carbon monoxide poisoning is a major cause of death following attempted suicide and accidental exposures. Although clinical presentation depends on the duration and the intensity of exposure, the assessment of the severity of intoxication is difficult. A small percentage of patients who show complete initial recovery may develop delayed neurological deficits. Delayed encephalopathy after acute carbon monoxide poisoning is a rare and poor prognosis neurologic disorders and there is no specific treatment. We present a case with early onset of delayed encephalopathy after acute carbon monoxide poisoning with typical cranial imaging findings in a child with atypical history and clinical presentation.

  10. Inhibition of photosynthesis by carbon monoxide and suspension of the carbon monoxide inhibition by light

    Energy Technology Data Exchange (ETDEWEB)

    Gewitz, H S; Voelker, W

    1963-08-01

    The experimental subject was the autotroph Chlorella pyrenoidosa. It was found that growth conditions determine whether the alga is inhibited by carbon monoxide or not. Respiration and photosynthesis are inhibited by carbon monoxide if the cells have grown rapidly under high light intensities. The inhibition of respiration and photosynthesis found in such cells is completely reversible. The inhibition depends not only on carbon monoxide pressure, but also on the oxygen pressure prevailing at the same time. 5 references, 1 figure, 3 tables.

  11. An unusual case of carbon monoxide poisoning.

    Science.gov (United States)

    Auger, P L; Levesque, B; Martel, R; Prud'homme, H; Bellemare, D; Barbeau, C; Lachance, P; Rhainds, M

    1999-01-01

    Carbon monoxide, a gas originating from incomplete combustion of carbon-based fuels, is an important cause of human deaths. In this paper, we describe an unusual carbon monoxide poisoning in a dwelling without obvious sources of combustion gases, for which two adults had to be treated in a hyperbaric chamber. Carbon monoxide readings were taken in the house and in the neighboring homes. Methane gas and nitrogen oxide levels were also monitored in the house air. Soil samples were collected around the house and tested for hydrocarbon residues. The investigation revealed the presence of a pocket of carbon monoxide under the foundation of the house. The first readings revealed carbon monoxide levels of 500 ppm in the basement. The contamination lasted for a week. The investigation indicated that the probable source of contamination was the use of explosives at a nearby rain sewer construction site. The use of explosives in a residential area can constitute a major source of carbon monoxide for the neighboring populations. This must be investigated, and public health authorities, primary-care physicians, governmental authorities, and users and manufacturers of explosives must be made aware of this problem. Images Figure 1 Figure 2 PMID:10379009

  12. An unusual case of carbon monoxide poisoning.

    Science.gov (United States)

    Auger, P L; Levesque, B; Martel, R; Prud'homme, H; Bellemare, D; Barbeau, C; Lachance, P; Rhainds, M

    1999-07-01

    Carbon monoxide, a gas originating from incomplete combustion of carbon-based fuels, is an important cause of human deaths. In this paper, we describe an unusual carbon monoxide poisoning in a dwelling without obvious sources of combustion gases, for which two adults had to be treated in a hyperbaric chamber. Carbon monoxide readings were taken in the house and in the neighboring homes. Methane gas and nitrogen oxide levels were also monitored in the house air. Soil samples were collected around the house and tested for hydrocarbon residues. The investigation revealed the presence of a pocket of carbon monoxide under the foundation of the house. The first readings revealed carbon monoxide levels of 500 ppm in the basement. The contamination lasted for a week. The investigation indicated that the probable source of contamination was the use of explosives at a nearby rain sewer construction site. The use of explosives in a residential area can constitute a major source of carbon monoxide for the neighboring populations. This must be investigated, and public health authorities, primary-care physicians, governmental authorities, and users and manufacturers of explosives must be made aware of this problem.

  13. Protect Yourself from Carbon Monoxide Poisoning

    Centers for Disease Control (CDC) Podcasts

    2007-11-20

    Learn about carbon monoxide - a colorless, odorless gas - and how to protect yourself and your family.  Created: 11/20/2007 by CDC National Center for Environmental Health.   Date Released: 12/4/2007.

  14. Polyketones as alternating copolymers of carbon monoxide

    International Nuclear Information System (INIS)

    Belov, Gennady P; Novikova, Elena V

    2004-01-01

    Characteristic features of the catalytic synthesis of alternating copolymers of carbon monoxide with various olefins, dienes, styrene and its derivatives are considered. The diversity of catalyst systems used for the copolymerisation of carbon monoxide is demonstrated and their influence on the structure and the molecular mass of the resulting copolymers is analysed. The data on the structure and physicochemical and mechanical properties of this new generation of functional copolymers are generalised and described systematically for the first time.

  15. Hearing Loss due to Carbon Monoxide Poisoning

    DEFF Research Database (Denmark)

    Mehrparvar, Amir Houshang; Davari, Mohammad Hossein; Mollasadeghi, Abolfazl

    2013-01-01

    Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker...... after an acute exposure to carbon monoxide. This complication was diagnosed by pure-tone audiometry and confirmed by transient evoked otoacoustic emissions. Hearing loss has not improved after 3 months of followup....

  16. Electrocatalytic oxidation of carbon monoxide

    Directory of Open Access Journals (Sweden)

    Manuel de Jesus Santiago Farias

    2009-01-01

    Full Text Available Este trabalho discute alguns aspectos importantes relacionados à reação de eletrooxidação do monóxido de carbono sobre monocristais de platina, em meio ácido. Aspectos mecanísticos são discutidos em termos da formação das estruturas compactas que o CO forma quando este é adsorvido. As principais idéias aqui apresentadas, levam em consideração as existências dessas estruturas. Os clássicos mecanismos Lagmuir-Hinshelwood e Eley-Rideal são aqui discutidos, especialmente o primeiro considerando a mobilidade do CO e também a nucleação e crescimento de ilhas formadas por espécies adsorvidas contendo oxigênio.////////// This work discusses some important aspects related to the carbon monoxide electrooxidation reaction on Pt single crystal electrodes in acidic media. The mechanistic aspects are discussed in terms of the formation of compact structures developed when CO is adsorbed. The main ideas presented here are focused on the mechanistic aspects that take into account the existence of such structures. The classical kinetic mechanisms of Lagmuir-Hinshelwood and Eley-Rideal are discussed considering the superficial mobility of CO or nucleation-growing of islands formed by oxygen-containing adsorbates.

  17. Recent development of carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Yamabe, Tokio [Div. of Molecular Engineering, Kyoto Univ. (Japan); [Inst. for Fundamental Chemistry, Kyoto (Japan)

    1995-03-15

    Recent developments of carbon nanotubes are reviewed. Analytical solutions for the electronic structure of carbon nanotube on the basis of thight-binding approximation are presented and interpreted using the concepts of crystal orbital. The electronic properties of actual carbon nanotubes are presented. The electronic structures of carbon nanotubes in the presence of magnetic fiels are also summerized. (orig.)

  18. Purification of carbon nanotubes via selective heating

    Science.gov (United States)

    Rogers, John A.; Wilson, William L.; Jin, Sung Hun; Dunham, Simon N.; Xie, Xu; Islam, Ahmad; Du, Frank; Huang, Yonggang; Song, Jizhou

    2017-11-21

    The present invention provides methods for purifying a layer of carbon nanotubes comprising providing a precursor layer of substantially aligned carbon nanotubes supported by a substrate, wherein the precursor layer comprises a mixture of first carbon nanotubes and second carbon nanotubes; selectively heating the first carbon nanotubes; and separating the first carbon nanotubes from the second carbon nanotubes, thereby generating a purified layer of carbon nanotubes. Devices benefiting from enhanced electrical properties enabled by the purified layer of carbon nanotubes are also described.

  19. Catalytic hydrogenation of carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Wayland, B.B.

    1992-12-01

    This project is focused on developing strategies to accomplish the reduction and hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. Our approaches to this issue are based on the recognition that rhodium macrocycles have unusually favorable thermodynamic values for producing a series of intermediate implicated in the catalytic hydrogenation of CO. Observations of metalloformyl complexes produced by reactions of H{sub 2} and CO, and reductive coupling of CO to form metallo {alpha}-diketone species have suggested a multiplicity of routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in constructing energy profiles for a variety of potential pathways, and these schemes are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Variation of the electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Emerging knowledge of the factors that contribute to M-H, M-C and M-O bond enthalpies is directing the search for ligand arrays that will expand the range of metal species that have favorable thermodynamic parameters to produce the primary intermediates for CO hydrogenation. Studies of rhodium complexes are being extended to non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics. Multifunctional catalyst systems designed to couple the ability of rhodium complexes to produce formyl and diketone intermediates with a second catalyst that hydrogenates these imtermediates are promising approaches to accomplish CO hydrogenation at mild conditions.

  20. Enzymic oxidation of carbon monoxide. II

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, T

    1959-01-01

    An enzyme which catalyzes the oxidation of carbon monoxide into carbon dioxide was obtained in a cell free state from Desulfovibrio desulfuricans. The enzyme activity was assayed manometrically by measuring the rate of gas uptake under the atmosphere of carbon monoxide in the presence of benzyl-viologen as an oxidant. The optimum pH range was 7 to 8. The activity was slightly suppressed by illumination. The enzyme was more stable than hydrogenase or formate dehydrogenase against the heat treatment, suggesting that it is a different entity from these enzymes. In the absence of an added oxidant, the enzyme preparation produced hydrogen gas under the atmosphere of carbon monoxide. The phenomenon can be explained assuming the reductive decomposition of water. 17 references, 4 figures, 2 tables.

  1. Conducting carbonized polyaniline nanotubes

    International Nuclear Information System (INIS)

    Mentus, Slavko; Ciric-Marjanovic, Gordana; Trchova, Miroslava; Stejskal, Jaroslav

    2009-01-01

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 deg. C min -1 up to a maximum temperature of 800 deg. C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 μm, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 μm, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm -1 , increased to 0.7 S cm -1 upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy.

  2. Conducting carbonized polyaniline nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mentus, Slavko; Ciric-Marjanovic, Gordana [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade (Serbia); Trchova, Miroslava; Stejskal, Jaroslav [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Square 2, 162 06 Prague 6 (Czech Republic)], E-mail: gordana@ffh.bg.ac.rs

    2009-06-17

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 deg. C min{sup -1} up to a maximum temperature of 800 deg. C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 {mu}m, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 {mu}m, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm{sup -1}, increased to 0.7 S cm{sup -1} upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy.

  3. CARBON MONOXIDE AND THE NERVOUS SYSTEM

    Science.gov (United States)

    Carbon monoxide (CO) is a colorless, tasteless, odorless, and non-irritating gas formed when carbon in fuel is not burned completely. It enters the bloodstream through the lungs and attaches to hemoglobin (Hb), the body's oxygen carrier, forming carboxyhemoglobin (COHb) and there...

  4. Effect of vegetation in reducing carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, J C

    1977-01-01

    Carbon monoxide is a product of incomplete combustion. Because almost all of this gas is produced by motor vehicles, it is considered to have a line rather than a stationary point source. Greatest concentrations of this lethal gas correspond to periods of peak traffic volume and congestion; therefore, there are two daily periods of maxima and minima. Carbon monoxide cannot be detected by sight or smell. For this reason, this gas is especially deadly. During the summer of 1975, a study involving carbon monoxide concentrations at selected sites in Sendai was undertaken in conjunction with an ongoing investigation of urban pollution under the directorship of Professor Toshio Noh of Tohoku University. This study was made possible by a grant from the Japan Society for the Promotion of Science. 5 references, 5 figures, 1 table.

  5. Pulmonary edema in acute carbon monoxide poisoning

    International Nuclear Information System (INIS)

    Kim, Kun Sang; Chang, Kee Hyun; Lee, Myung Uk

    1974-01-01

    Acute carbon monoxide poisoning has frequently occurred in Korean, because of the coal briquette being widely used as fuel in Korean residences. Carbon monoxide poisoning has been extensively studied, but it has been sparsely reported that pulmonary edema may develop in acute CO poisoning. We have noticed nine cases of pulmonary edema in acute CO poisoning last year. Other possible causes of pulmonary edema could be exclude in all cases but one. The purpose of this paper is to describe nine cases of pulmonary edema complicated in acute CO poisoning and discuss the pathogenesis and the prognosis

  6. Occupational medicine effects of carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, W.M. [South African Society of Occupational Medicine (South Africa)

    1998-10-01

    Carbon monoxide can affect the body if it is inhaled or if liquid carbon monoxide comes in contact with the eyes or skin. The effects of overexposure are discussed and a brief explanation of the toxicological effects of CO given. Methods of control of CO from common operations (exhaust fumes of internal combustion engines, the chemical industry and foundries, welding, mines or tunnels, fire damp explosions, industrial heating) are by local exhaust ventilation or use of a respiratory protective device. The South African hazardous chemical substance regulation NO. R. 1179 of 25 August 1995 stipulates maximum safe levels of CO concentration. 4 refs., 1 photo.

  7. Pulmonary edema in acute carbon monoxide poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kun Sang; Chang, Kee Hyun; Lee, Myung Uk [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1974-10-15

    Acute carbon monoxide poisoning has frequently occurred in Korean, because of the coal briquette being widely used as fuel in Korean residences. Carbon monoxide poisoning has been extensively studied, but it has been sparsely reported that pulmonary edema may develop in acute CO poisoning. We have noticed nine cases of pulmonary edema in acute CO poisoning last year. Other possible causes of pulmonary edema could be exclude in all cases but one. The purpose of this paper is to describe nine cases of pulmonary edema complicated in acute CO poisoning and discuss the pathogenesis and the prognosis.

  8. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-carbon monoxide copolymers. 177.1312... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1312 Ethylene-carbon monoxide copolymers. The ethylene-carbon monoxide copolymers identified in paragraph (a) of this section may be safely...

  9. Assessment of carbon monoxide values in smokers: a comparison of carbon monoxide in expired air and carboxyhaemoglobin in arterial blood

    DEFF Research Database (Denmark)

    Andersson, Mette F; Møller, Ann M

    2010-01-01

    Smoking increases perioperative complications. Carbon monoxide concentrations can estimate patients' smoking status and might be relevant in preoperative risk assessment. In smokers, we compared measurements of carbon monoxide in expired air (COexp) with measurements of carboxyhaemoglobin (COHb) ...

  10. Hearing Loss due to Carbon Monoxide Poisoning

    DEFF Research Database (Denmark)

    Mehrparvar, Amir Houshang; Davari, Mohammad Hossein; Mollasadeghi, Abolfazl

    2013-01-01

    Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker a...

  11. Carbon nanotube junctions and devices

    NARCIS (Netherlands)

    Postma, H.W.Ch.

    2001-01-01

    In this thesis Postma presents transport experiments performed on individual single-wall carbon nanotubes. Carbon nanotubes are molecules entirely made of carbon atoms. The electronic properties are determined by the exact symmetry of the nanotube lattice, resulting in either metallic or

  12. Carbon monoxide: The 21st century poison that goes unnoticed

    International Nuclear Information System (INIS)

    Hoskins, J.A.

    1999-01-01

    This editorial article describes the effects of carbon monoxide poisoning on human beings and the mechanisms involving carbon monoxide saturation of haemoglobin that are responsible for it. The initial research done in the mid-1800s by Claude Bernard is presented. Methods of treatment for persons poisoned by carbon monoxide are discussed and the experiments made by J.B.S. Haldane on himself by breathing in carbon monoxide are described. Acclimatisation effects observed by Haldane and his co-workers and concerning persons occupationally exposed to carbon monoxide emissions are described

  13. Carbon monoxide: The 21st century poison that goes unnoticed

    Energy Technology Data Exchange (ETDEWEB)

    Hoskins, J.A. [Reigate, Surrey (United Kingdom)

    1999-07-01

    This editorial article describes the effects of carbon monoxide poisoning on human beings and the mechanisms involving carbon monoxide saturation of haemoglobin that are responsible for it. The initial research done in the mid-1800s by Claude Bernard is presented. Methods of treatment for persons poisoned by carbon monoxide are discussed and the experiments made by J.B.S. Haldane on himself by breathing in carbon monoxide are described. Acclimatisation effects observed by Haldane and his co-workers and concerning persons occupationally exposed to carbon monoxide emissions are described.

  14. Electron diffraction from carbon nanotubes

    International Nuclear Information System (INIS)

    Qin, L-C

    2006-01-01

    The properties of a carbon nanotube are dependent on its atomic structure. The atomic structure of a carbon nanotube can be defined by specifying its chiral indices (u, v), that specify its perimeter vector (chiral vector), with which the diameter and helicity are also determined. The fine electron beam available in a modern transmission electron microscope (TEM) offers a unique probe to reveal the atomic structure of individual nanotubes. This review covers two aspects related to the use of the electron probe in the TEM for the study of carbon nanotubes: (a) to understand the electron diffraction phenomena for inter-pretation of the electron diffraction patterns of carbon nanotubes and (b) to obtain the chiral indices (u, v), of the carbon nanotubes from the electron diffraction patterns. For a nanotube of a given structure, the electron scattering amplitude from the carbon nanotube is first described analytically in closed form using the helical diffraction theory. From a known structure as given by the chiral indices (u, v), its electron diffraction pattern can be calculated and understood. The reverse problem, i.e. assignment of the chiral indices from an electron diffraction pattern of a carbon nanotube, is approached from the relationship between the electron scattering intensity distribution and the chiral indices (u, v). We show that electron diffraction patterns can provide an accurate and unambiguous assignment of the chiral indices of carbon nanotubes. The chiral indices (u, v) can be read indiscriminately with a high accuracy from the intensity distribution on the principal layer lines in an electron diffraction pattern. The symmetry properties of electron diffraction from carbon nanotubes and the electron diffraction from deformed carbon nanotubes are also discussed in detail. It is shown that 2mm symmetry is always preserved for single-walled carbon nanotubes, but it can break down for multiwalled carbon nanotubes under some special circumstances

  15. Carbon nanotube filters

    Science.gov (United States)

    Srivastava, A.; Srivastava, O. N.; Talapatra, S.; Vajtai, R.; Ajayan, P. M.

    2004-09-01

    Over the past decade of nanotube research, a variety of organized nanotube architectures have been fabricated using chemical vapour deposition. The idea of using nanotube structures in separation technology has been proposed, but building macroscopic structures that have controlled geometric shapes, density and dimensions for specific applications still remains a challenge. Here we report the fabrication of freestanding monolithic uniform macroscopic hollow cylinders having radially aligned carbon nanotube walls, with diameters and lengths up to several centimetres. These cylindrical membranes are used as filters to demonstrate their utility in two important settings: the elimination of multiple components of heavy hydrocarbons from petroleum-a crucial step in post-distillation of crude oil-with a single-step filtering process, and the filtration of bacterial contaminants such as Escherichia coli or the nanometre-sized poliovirus (~25 nm) from water. These macro filters can be cleaned for repeated filtration through ultrasonication and autoclaving. The exceptional thermal and mechanical stability of nanotubes, and the high surface area, ease and cost-effective fabrication of the nanotube membranes may allow them to compete with ceramic- and polymer-based separation membranes used commercially.

  16. Adhered Supported Carbon Nanotubes

    International Nuclear Information System (INIS)

    Johnson, Dale F.; Craft, Benjamin J.; Jaffe, Stephen M.

    2001-01-01

    Carbon nanotubes (NTs) in excess of 200 μm long are grown by catalytic pyrolysis of hydrocarbon vapors. The nanotubes grow continuously without the typical extinction due to catalyst encapsulation. A woven metal mesh supports the nanotubes creating a metal supported nanotube (MSNT) structure. The 140 μm wide mesh openings are completely filled by 70 nm diameter multiwalled nanotubes (MWNTs). The MWNTs are straight, uniform and highly crystalline. Their wall thickness is about 10 nm (30 graphite layers). The adherent NTs are not removed from the support in a Scotch tape pull test. A 12.5 cm 2 capacitor made from two MSNT structures immersed in 1 M KCl has a capacitance of 0.35 F and an equivalent series resistance of 0.18 Ω. Water flows through the MSNT at a flow velocity of 1 cm/min with a pressure drop of 15 inches of water. With the support removed, the MWNTs naturally form a carbon nanocomposite (CNC) paper with a specific area of 80 m 2 /gm, a bulk density of 0.21 g/cm 3 , an open pore fraction of 0.81, and a resistivity of 0.16 Ω-cm

  17. Sensorineural Hearing Loss following Carbon Monoxide Poisoning

    Directory of Open Access Journals (Sweden)

    Joseph P. Pillion

    2012-01-01

    Full Text Available A case study is presented of a 17-year-old male who sustained an anoxic brain injury and sensorineural hearing loss secondary to carbon monoxide poisoning. Audiological data is presented showing a slightly asymmetrical hearing loss of sensorineural origin and mild-to-severe degree for both ears. Word recognition performance was fair to poor bilaterally for speech presented at normal conversational levels in quiet. Management considerations of the hearing loss are discussed.

  18. Carbon Monoxide Exposure in Youth Ice Hockey.

    Science.gov (United States)

    Macnow, Theodore; Mannix, Rebekah; Meehan, William P

    2017-11-01

    To examine the effect of ice resurfacer type on carboxyhemoglobin levels in youth hockey players. We hypothesized that players in arenas with electric resurfacers would have normal, stable carboxyhemoglobin levels during games, whereas those in arenas with internal combustion engine (IC) resurfacers would have an increase in carboxyhemoglobin levels. Prospective cohort study. Enclosed ice arenas in the northeastern United States. Convenience sample of players aged 8 to 18 years old in 16 games at different arenas. Eight arenas (37 players) used an IC ice resurfacer and 8 arenas (36 players) an electric resurfacer. Carboxyhemoglobin levels (SpCO) were measured using a pulse CO-oximeter before and after the game. Arena air was tested for carbon monoxide (CO) using a metered gas detector. Players completed symptom questionnaires. The change in SpCO from pregame to postgame was compared between players at arenas with electric versus IC resurfacers. Carbon monoxide was present at 6 of 8 arenas using IC resurfacers, levels ranged from 4 to 42 parts per million. Carbon monoxide was not found at arenas with electric resurfacers. Players at arenas with IC resurfacers had higher median pregame SpCO levels compared with those at electric arenas (4.3% vs 1%, P carboxyhemoglobin during games and have elevated baseline carboxyhemoglobin levels compared with players at arenas with electric resurfacers. Electric resurfacers decrease the risk of CO exposure.

  19. Carbon nanotube plane fastener

    Directory of Open Access Journals (Sweden)

    Kaori Hirahara

    2011-12-01

    Full Text Available We report a feature of carbon nanotubes (CNTs that arises when the surfaces of two vertically-aligned CNT brushes are pressed together. Adhesion between the CNTs creates a plane fastener-like device. Observations from scanning electron microscopy and measurements of adhesion properties indicate a device-dependence on CNT density and shape near the tip region. Among other applications, such fasteners have the potential to attach small components onto micron-sized electronic devices.

  20. Carbon nanotube network varactor

    International Nuclear Information System (INIS)

    Generalov, A A; Anoshkin, I V; Lioubtchenko, D V; Räisänen, A V; Erdmanis, M; Ovchinnikov, V; Nasibulin, A G

    2015-01-01

    Microelectromechanical system (MEMS) varactors based on a freestanding layer of single-walled carbon nanotube (SWCNT) films were designed, fabricated and tested. The freestanding SWCNT film was employed as a movable upper patch in the parallel plate capacitor of the MEMS. The measurements of the SWCNT varactors show very high tunability, nearly 100%, of the capacitance with a low actuation voltage of 10 V. The functionality of the varactor is improved by implementing a flexible nanocellulose aerogel filling. (paper)

  1. Characteristics of exogenous carbon monoxide deliveries

    Directory of Open Access Journals (Sweden)

    Hui-jun Hu

    2016-01-01

    Full Text Available Carbon monoxide (CO has long been considered an environmental pollutant and a poison. Exogenous exposure to amounts of CO beyond the physiologic level of the body can result in a protective or adaptive response. However, as a gasotransmitter, endogenous CO is important for multiple physiologic functions. To date, at least seven distinct methods of delivering CO have been utilized in animal and clinical studies. In this mini-review, we summarize the exogenous CO delivery methods and compare their advantages and disadvantages.

  2. [Carbon monoxide poisoning by a heating system].

    Science.gov (United States)

    Dietz, Eric; Gehl, Axel; Friedrich, Peter; Kappus, Stefan; Petter, Franz; Maurer, Klaus; Püschel, Klaus

    2016-01-01

    A case of accidental carbon monoxide poisoning in several occupants of two neighboring residential buildings in Hamburg-Harburg (Germany) caused by a defective gas central heating system is described. Because of leaks in one of the residential buildings and the directly adjacent wall of the neighboring house, the gas could spread and accumulated in both residential buildings, which resulted in a highly dangerous situation. Exposure to the toxic gas caused mild to severe intoxication in 15 persons. Three victims died still at the site of the accident. Measures to protect the occupants were taken only with a great delay. As symptoms were unspecific, it was not realized that the various alarms given by persons involved in the accident were related to the same cause. In order to take appropriate measures in time it is indispensible to recognize, assess and check potential risks, which can be done by using carbon monoxide warning devices and performing immediate COHb measurements with special pulse oximeters on site. Moreover, the COHb content in the blood should be routinely determined in all patients admitted to an emergency department with unspecific symptoms.

  3. Cardiological aspects of carbon monoxide poisoning.

    Science.gov (United States)

    Marchewka, Jakub; Gawlik, Iwona; Dębski, Grzegorz; Popiołek, Lech; Marchewka, Wojciech; Hydzik, Piotr

    2017-01-01

    The aim of this study was to assess cardiological manifestations of carbon monoxide (CO) poisoning. Background/introduction: Carbon monoxide intoxication is one of the most important toxicological causes of morbidity and mortality worldwide. Early clinical manifestation of CO poisoning is cardiotoxicity. We enrolled 75 patients (34 males and 41 females, mean age 37.6 ± 17.7 y/o) hospitalized due to CO poisoning. Laboratory tests including troponin I, blood pressure measurements, HR and electrocardiograms (ECG) were collected. Pach's scale scoring and grading system was used to establish severity of poisoning. Grade of poisoning is positively correlated with troponin I levels and systolic blood pressure. Moreover, troponin levels are significantly correlated with exposition time, lactates and are higher in tachycardiac, hypertensive and positive ECG subpopulations. COHb levels are indicative of exposure but do not correlate with grade of poisoning. The main cause of CO poisoning were bathroom heaters - 83%, only 11% of examined intoxicated population were equipped with CO detectors. Complex cardiological screening covering troponin levels, ECG, blood pressure and heart rate measurements as well as complete blood count with particular attention to platelet parameters should be performed in each case where CO intoxication is suspected. More emphasis on education on CO poisoning is needed.

  4. 40 CFR 86.1322-84 - Carbon monoxide analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... be used. (2) Zero the carbon monoxide analyzer with either zero-grade air or zero-grade nitrogen. (3... columns is one form of corrective action which may be taken.) (b) Initial and periodic calibration. Prior... calibrated. (1) Adjust the analyzer to optimize performance. (2) Zero the carbon monoxide analyzer with...

  5. Carbon Nanotubes and Modern Nanoagriculture

    KAUST Repository

    Serag, Maged F.

    2015-01-27

    Since their discovery, carbon nanotubes have been prominent members of the nanomaterial family. Owing to their extraordinary physical, chemical, and mechanical properties, carbon nanotubes have been proven to be a useful tool in the field of plant science. They were frequently perceived to bring about valuable biotechnological and agricultural applications that still remain beyond experimental realization. An increasing number of studies have demonstrated the ability of carbon nanotubes to traverse different plant cell barriers. These studies, also, assessed the toxicity and environmental impacts of these nanomaterials. The knowledge provided by these studies is of practical and fundamental importance for diverse applications including intracellular labeling and imaging, genetic transformation, and for enhancing our knowledge of plant cell biology. Although different types of nanoparticles have been found to activate physiological processes in plants, carbon nanotubes received particular interest. Following addition to germination medium, carbon nanotubes enhanced root growth and elongation of some plants such as onion, cucumber and rye-grass. They, also, modulated the expression of some genes that are essential for cell division and plant development. In addition, multi-walled carbon nanotubes were evidenced to penetrate thick seed coats, stimulate germination, and to enhance growth of young tomato seedlings. Multi-walled carbon nanotubes can penetrate deeply into the root system and further distribute into the leaves and the fruits. In recent studies, carbon nanotubes were reported to be chemically entrapped into the structure of plant tracheary elements. This should activate studies in the fields of plant defense and wood engineering. Although, all of these effects on plant physiology and plant developmental biology have not been fully understood, the valuable findings promises more research activity in the near future toward complete scientific understanding of

  6. Search of medical literature for indoor carbon monoxide exposure

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, T.; Ivanovich, M.

    1995-12-01

    This report documents a literature search on carbon monoxide. The search was limited to the medical and toxicological databases at the National Library of Medicine (MEDLARS). The databases searched were Medline, Toxline and TOXNET. Searches were performed using a variety of strategies. Combinations of the following keywords were used: carbon, monoxide, accidental, residential, occult, diagnosis, misdiagnosis, heating, furnace, and indoor. The literature was searched from 1966 to the present. Over 1000 references were identified and summarized using the following abbreviations: The major findings of the search are: (1) Acute and subacute carbon monoxide exposures result in a large number of symptoms affecting the brain, kidneys, respiratory system, retina, and motor functions. (2) Acute and subacute carbon monoxide (CO) poisonings have been misdiagnosed on many occasions. (3) Very few systematic investigations have been made into the frequency and consequences of carbon monoxide poisonings.

  7. Continuous carbon nanotube reinforced composites.

    Science.gov (United States)

    Ci, L; Suhr, J; Pushparaj, V; Zhang, X; Ajayan, P M

    2008-09-01

    Carbon nanotubes are considered short fibers, and polymer composites with nanotube fillers are always analogues of random, short fiber composites. The real structural carbon fiber composites, on the other hand, always contain carbon fiber reinforcements where fibers run continuously through the composite matrix. With the recent optimization in aligned nanotube growth, samples of nanotubes in macroscopic lengths have become available, and this allows the creation of composites that are similar to the continuous fiber composites with individual nanotubes running continuously through the composite body. This allows the proper utilization of the extreme high modulus and strength predicted for nanotubes in structural composites. Here, we fabricate such continuous nanotube polymer composites with continuous nanotube reinforcements and report that under compressive loadings, the nanotube composites can generate more than an order of magnitude improvement in the longitudinal modulus (up to 3,300%) as well as damping capability (up to 2,100%). It is also observed that composites with a random distribution of nanotubes of same length and similar filler fraction provide three times less effective reinforcement in composites.

  8. Mechanical properties of carbon nanotubes

    Science.gov (United States)

    Salvetat, J.-P.; Bonard, J.-M.; Thomson, N. H.; Kulik, A. J.; Forró, L.; Benoit, W.; Zuppiroli, L.

    A variety of outstanding experimental results on the elucidation of the elastic properties of carbon nanotubes are fast appearing. These are based mainly on the techniques of high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM) to determine the Young's moduli of single-wall nanotube bundles and multi-walled nanotubes, prepared by a number of methods. These results are confirming the theoretical predictions that carbon nanotubes have high strength plus extraordinary flexibility and resilience. As well as summarising the most notable achievements of theory and experiment in the last few years, this paper explains the properties of nanotubes in the wider context of materials science and highlights the contribution of our research group in this rapidly expanding field. A deeper understanding of the relationship between the structural order of the nanotubes and their mechanical properties will be necessary for the development of carbon-nanotube-based composites. Our research to date illustrates a qualitative relationship between the Young's modulus of a nanotube and the amount of disorder in the atomic structure of the walls. Other exciting results indicate that composites will benefit from the exceptional mechanical properties of carbon nanotubes, but that the major outstanding problem of load transfer efficiency must be overcome before suitable engineering materials can be produced.

  9. Carbon nanotube based photocathodes

    International Nuclear Information System (INIS)

    Hudanski, Ludovic; Minoux, Eric; Schnell, Jean-Philippe; Xavier, Stephane; Pribat, Didier; Legagneux, Pierre; Gangloff, Laurent; Teo, Kenneth B K; Robertson, John; Milne, William I

    2008-01-01

    This paper describes a novel photocathode which is an array of vertically aligned multi-walled carbon nanotubes (MWCNTs), each MWCNT being associated with one p-i-n photodiode. Unlike conventional photocathodes, the functions of photon-electron conversion and subsequent electron emission are physically separated. Photon-electron conversion is achieved with p-i-n photodiodes and the electron emission occurs from the MWCNTs. The current modulation is highly efficient as it uses an optically controlled reconfiguration of the electric field at the MWCNT locations. Such devices are compatible with high frequency and very large bandwidth operation and could lead to their application in compact, light and efficient microwave amplifiers for satellite telecommunication. To demonstrate this new photocathode concept, we have fabricated the first carbon nanotube based photocathode using silicon p-i-n photodiodes and MWCNT bunches. Using a green laser, this photocathode delivers 0.5 mA with an internal quantum efficiency of 10% and an I ON /I OFF ratio of 30

  10. Carbon nanotube array actuators

    International Nuclear Information System (INIS)

    Geier, S; Mahrholz, T; Wierach, P; Sinapius, M

    2013-01-01

    Experimental investigations of highly vertically aligned carbon nanotubes (CNTs), also known as CNT-arrays, are the main focus of this paper. The free strain as result of an active material behavior is analyzed via a novel experimental setup. Previous test experiences of papers made of randomly oriented CNTs, also called Bucky-papers, reveal comparably low free strain. The anisotropy of aligned CNTs promises better performance. Via synthesis techniques like chemical vapor deposition (CVD) or plasma enhanced CVD (PECVD), highly aligned arrays of multi-walled carbon nanotubes (MWCNTs) are synthesized. Two different types of CNT-arrays are analyzed, morphologically first, and optically tested for their active characteristics afterwards. One type of the analyzed arrays features tube lengths of 750–2000 μm with a large variety of diameters between 20 and 50 nm and a wave-like CNT-shape. The second type features a maximum, almost uniform, length of 12 μm and a constant diameter of 50 nm. Different CNT-lengths and array types are tested due to their active behavior. As result of the presented tests, it is reported that the quality of orientation is the most decisive property for excellent active behavior. Due to their alignment, CNT-arrays feature the opportunity to clarify the actuation mechanism of architectures made of CNTs. (paper)

  11. Carbon nanotube biosensors

    Science.gov (United States)

    Tîlmaciu, Carmen-Mihaela; Morris, May C.

    2015-01-01

    Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular, carbon nanotubes (CNTs) can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical, and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites, or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we describe their structural and physical properties, functionalization and cellular uptake, biocompatibility, and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers. PMID:26579509

  12. Carbon Nanotube Biosensors

    Directory of Open Access Journals (Sweden)

    Carmen-Mihaela eTilmaciu

    2015-10-01

    Full Text Available Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular Carbon Nanotubes (CNTs can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we will describe their structural and physical properties, discuss functionalization and cellular uptake, biocompatibility and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers.

  13. Carbon monoxide and carbon dioxide interaction with tantalum

    International Nuclear Information System (INIS)

    Belov, V.D.; Ustinov, Yu.K.; Komar, A.P.

    1978-01-01

    The adsorption of carbon monoxide and carbon dioxide on tantalum and the dissolution of these gases in the adsorbent at T >= 300 K have been studied. The flash-filament method (FFM) in a monopole mass-spectrometer and a field emission microscopy was used in the same apparatus. Carbon monoxide and carbon dioxide dissociate on the tantalum surface, carbon monoxide being desorbed in both cases during the flash. The desorption curves of CO reveal three different binding states: two of them (α and β' 1 ) for the adsorbed particles whereas the high temperature desorption state relates to the adsorbate dissolved in the metal. For the β' 1 state of CO the activation energy, the pre-exponential factor and the kinetic order in the kinetic equation of desorption have been estimated. They turned out to be E = 110 kcal/mol, C = 3 X 10 12 sec -1 , and γ = 1. The activation energy of diffusion for CO in tantalum and the energy of outgassing for the metal were found to be 9.4 and 49 kcal/mole, respectively. (Auth.)

  14. Carbon monoxide and carbon dioxide interaction with tantalum

    Energy Technology Data Exchange (ETDEWEB)

    Belov, V D; USTINOV, YU K; KOMAR, A P [AN SSSR, LENINGRAD. FIZIKO-TEKHNICHESKIJ INST.

    1978-03-01

    The adsorption of carbon monoxide and carbon dioxide on tantalum and the dissolution of these gases in the adsorbent at T >= 300 K have been studied. The flash-filament method (FFM) in a monopole mass-spectrometer and a field emission microscopy was used in the same apparatus. Carbon monoxide and carbon dioxide dissociate on the tantalum surface, carbon monoxide being desorbed in both cases during the flash. The desorption curves of CO reveal three different binding states: two of them (..cap alpha.. and ..beta..'/sub 1/) for the adsorbed particles whereas the high temperature desorption state relates to the adsorbate dissolved in the metal. For the ..beta..'/sub 1/ state of CO the activation energy, the pre-exponential factor and the kinetic order in the kinetic equation of desorption have been estimated. They turned out to be E = 110 kcal/mol, C = 3 X 10/sup 12/ sec/sup -1/, and ..gamma.. = 1. The activation energy of diffusion for CO in tantalum and the energy of outgassing for the metal were found to be 9.4 and 49 kcal/mole, respectively.

  15. Residential indoor air quality guideline : carbon monoxide

    International Nuclear Information System (INIS)

    2010-01-01

    Carbon monoxide (CO) is a tasteless, odourless, and colourless gas that can be produced by both natural and anthropogenic processes, but is most often formed during the incomplete combustion of organic materials. In the indoor environment, CO occurs directly as a result of emissions from indoor sources or as a result of infiltration from outdoor air containing CO. Studies have shown that the use of specific sources can lead to increased concentrations of CO indoors. This residential indoor air quality guideline examined the factors influencing the introduction, dispersion and removal of CO indoors. The health effects of exposure to low and higher concentrations of CO were discussed. Residential maximum exposure limits for CO were presented. Sources and concentrations in indoor environments were also examined. 17 refs., 2 tabs.

  16. Recent changes in atmospheric carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, P.C.; Masarie, K.A. (Univ. of Colorado, Boulder, CO (United States)); Tans, P.P.; Lang, P.M. (National Oceanic and Atmospheric Administration, Boulder, CO (United States))

    1994-03-18

    Measurements of carbon monoxide (CO) in air samples collected from 27 locations between 71[degrees]N and 41[degrees]S show that atmospheric levels of this gas have decreased worldwide over the past 2 to 5 years. During this period, CO decreased at nearly a constant rate in the high northern latitudes. In contrast, in the tropics an abrupt decrease occurred beginning at the end of 1991. In the Northern Hemisphere, CO decreased at a spatially and temporally averaged rate of 7.3 ([+-]0.9) parts per billion per year (6.1 percent per year) from June 1990 to June 1993, whereas in the Southern Hemisphere, CO decreased 4.2 ([+-]0.5) parts per billion per year (7.0 percent per year). This recent change is opposite a long-term trend of a 1 to 2 percent per year increase inferred from measurements made in the Northern Hemisphere during the past 30 years.

  17. Carbon monoxide budget in the northern hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Bakwin, P.S.; Tans, P.P. (Climate Monitoring and Diagnostics Lab., Boulder, CO (United States)); Novelli, P.C. (Univ. of Colorado, Boulder, CO (United States))

    1994-03-15

    To improve urban air quality the major industrialized nations of the West took steps during the 1970s and 1980s to reduce carbon monoxide (CO) emissions from automobiles and other industrial sources. Overall, CO/CO[sub 2] emission ratios from the mix of fossil fuel combustion sources have been reduced by about half during 1976-1990. Also, the tropospheric abundance of hydroxyl radical (OH), which is the main sink for CO, is proposed to have increased globally by about 1.0 [+-] 0.8% yr[sup [minus]1]. The authors use a simple two-box model to examine the impact of shrinking emissions and increasing OH on the global abundance of CO. They find that these factors contribute about equally in reducing CO levels in the Northern Hemisphere troposphere by about 1.8 [+-] 0.8 ppb yr[sup [minus]1] on average. 19 refs., 1 fig.

  18. Health effects of carbon monoxide environmental pollution

    Energy Technology Data Exchange (ETDEWEB)

    1974-01-01

    Carbon monoxide's (CO) chronic effects on man, its sources, and measuring methods are reviewed, and guidelines to determine health criteria are considered. The European data exchange included CO measuring methods in air and blood and their use in survey and experimental work, atmospheric CO pollution and sampling methods in urban thoroughfares and road tunnels in the European countries, a population survey of carboxyhemoglobin levels from cigarette smoking and atmospheric exposure, and physiological kinetics (uptake, distribution, and elimination) of CO inhalation. Additional topics are CO and the central nervous system, effects of moderate CO exposure on the cardiovascular system and on fetal development, and the current views on existing air quality criteria for CO.

  19. Method for synthesizing carbon nanotubes

    Science.gov (United States)

    Fan, Hongyou

    2012-09-04

    A method for preparing a precursor solution for synthesis of carbon nanomaterials, where a polar solvent is added to at least one block copolymer and at least one carbohydrate compound, and the precursor solution is processed using a self-assembly process and subsequent heating to form nanoporous carbon films, porous carbon nanotubes, and porous carbon nanoparticles.

  20. Electronics with carbon nanotubes

    International Nuclear Information System (INIS)

    Avouris, P.

    2007-01-01

    From mobile phones and laptops to Xboxes and iPods, it is difficult to think of any aspect of modern life that has not been touched by developments in electronics, computing and communications over the last few decades. Many of these technological advances have arisen from our ability to create ever smaller electronic devices, in particular silicon-based field effect transistors (FETs), which has led to denser, faster and less power-hungry circuits. The problem is that this device miniaturization, or 'scaling', cannot continue forever. Fundamental scientific and technological limitations exist that will make it impossible to build better performing silicon devices below a certain size. This potential show-stopper has inspired a worldwide effort to develop alternative device technologies based on 1D materials or those that exploit the spin, as well as the charge, of electrons. One promising and, in principle, simpler approach is to maintain the operating concept of today's silicon-based FETs but to replace a key component of the device - the semiconducting silicon channel - with 1D nanostructures that have much more versatile electrical-transport properties. Among the different 1D materials that have been developed, those with the most desirable properties are 'single-walled' carbon nanotubes, which were first created in 1993 by Sumio Ijima at the NEC Fundamental Research Laboratory in Tsukuba, Japan, and by Donald Bethune of IBM's Almaden Research Center in California. These materials are hollow tubes made from rolled up sheets of carbon just one atom thick, otherwise known as graphene. In the March issue of Physics World, Phaedon Avouris discusses some of the many properties and applications of carbon nanotubes, which he describes as an 'engineer's dream' because of their exceptionally high strength and heat conduction. (U.K.)

  1. Functionalization of Carbon Nanotubes

    Science.gov (United States)

    Khare, Bishun N. (Inventor); Meyyappan, Meyya (Inventor)

    2009-01-01

    Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H2 or F2 or CnHm) is irradiated to provide a cold plasma of selected target species particles, such as atomic H or F, in a first chamber. The target species particles are d irected toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target species particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec. *Discrimination against non-target species is provided by (i) use of a target species having a lifetime that is much greater than a lifetime of a non-target species and/or (2) use of an applied magnetic field to discriminate between charged particle trajectories for target species and for non-target species.

  2. Carbon Nanotube Electron Gun

    Science.gov (United States)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2013-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  3. Carbon Nanotube based Nanotechnolgy

    Science.gov (United States)

    Meyyappan, M.

    2000-10-01

    Carbon nanotube(CNT) was discovered in the early 1990s and is an off-spring of C60(the fullerene or buckyball). CNT, depending on chirality and diameter, can be metallic or semiconductor and thus allows formation of metal-semiconductor and semiconductor-semiconductor junctions. CNT exhibits extraordinary electrical and mechanical properties and offers remarkable potential for revolutionary applications in electronics devices, computing and data storage technology, sensors, composites, storage of hydrogen or lithium for battery development, nanoelectromechanical systems(NEMS), and as tip in scanning probe microscopy(SPM) for imaging and nanolithography. Thus the CNT synthesis, characterization and applications touch upon all disciplines of science and engineering. A common growth method now is based on CVD though surface catalysis is key to synthesis, in contrast to many CVD applications common in microelectronics. A plasma based variation is gaining some attention. This talk will provide an overview of CNT properties, growth methods, applications, and research challenges and opportunities ahead.

  4. Proposal of Carbon Nanotube Inductors

    National Research Council Canada - National Science Library

    Tsubaki, K; Nakajima, Y; Hanajiri, T; Yamaguchi, H

    2006-01-01

    The inductors made of carbon Nanotube (CNT) have been proposed. Though the fabrication of the proposed inductor is still challenging and has many problems, merits of the proposed inductor are following...

  5. Hydrogenation of carbon monoxide over supported palladium catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, K.; Hashimoto, H.; Kunugi, T.

    1978-03-01

    An alumina-supported 2% palladium catalyst had higher activity for carbon monoxide hydrogenation than a silica-supported 2% palladium catalyst, at 250/sup 0/-400/sup 0/C and 1 atm. The addition of lanthanum oxide or thorium oxide, but not of potassium oxide, to the silica-supported catalyst increased the conversion at 350/sup 0/C from 1.1% to 81.0% with a selectivity of 56.1% for methane, 1.4% for C/sub 2/ compounds, 0.1% for C/sub 3/ compounds, and 42.5% for carbon dioxide. Temperature-programed desorption of carbon monoxide in a hydrogen stream showed that of two desorption peaks observed for carbon monoxide, the one at higher temperature corresponded to the carbon monoxide species which hydrogenates to methane and that the area of this peak increased with increasing thorium content of the catalyst. Graphs, tables, and 12 references.

  6. Selective functionalization of carbon nanotubes

    Science.gov (United States)

    Strano, Michael S. (Inventor); Usrey, Monica (Inventor); Barone, Paul (Inventor); Dyke, Christopher A. (Inventor); Tour, James M. (Inventor); Kittrell, W. Carter (Inventor); Hauge, Robert H. (Inventor); Smalley, Richard E. (Inventor)

    2009-01-01

    The present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations.

  7. Carbon nanotubes for coherent spintronics

    DEFF Research Database (Denmark)

    Kuemmeth, Ferdinand; Churchill, H O H; Herring, P K

    2010-01-01

    Carbon nanotubes bridge the molecular and crystalline quantum worlds, and their extraordinary electronic, mechanical and optical properties have attracted enormous attention from a broad scientific community. We review the basic principles of fabricating spin-electronic devices based on individual......, electrically-gated carbon nanotubes, and present experimental efforts to understand their electronic and nuclear spin degrees of freedom, which in the future may enable quantum applications....

  8. Functional materials based on carbon nanotubes: Carbon nanotube actuators and noncovalent carbon nanotube modification

    Science.gov (United States)

    Fifield, Leonard S.

    Carbon nanotubes have attractive inherent properties that encourage the development of new functional materials and devices based on them. The use of single wall carbon nanotubes as electromechanical actuators takes advantage of the high mechanical strength, surface area and electrical conductivity intrinsic to these molecules. The work presented here investigates the mechanisms that have been discovered for actuation of carbon nanotube paper: electrostatic, quantum chemical charge injection, pneumatic and viscoelastic. A home-built apparatus for the measurement of actuation strain is developed and utilized in the investigation. An optical fiber switch, the first demonstrated macro-scale device based on the actuation of carbon nanotubes, is described and its performance evaluated. Also presented here is a new general process designed to modify the surface of carbon nanotubes in a non-covalent, non-destructive way. This method can be used to impart new functionalities to carbon nanotube samples for a variety of applications including sensing, solar energy conversion and chemical separation. The process described involves the achievement of large degrees of graphitic surface coverage with polycyclic aromatic hydrocarbons through the use of supercritical fluids. These molecules are bifunctional agents that anchor a desired chemical group to the aromatic surface of the carbon nanotubes without adversely disrupting the conjugated backbone that gives rise the attractive electronic and physical properties of the nanotubes. Both the nanotube functionalization work and the actuator work presented here emphasize how an understanding and control of nanoscale structure and phenomena can be of vital importance in achieving desired performance for active materials. Opportunities for new devices with improved function over current state-of-the-art can be envisioned and anticipated based on this understanding and control.

  9. Substitution reactions of carbon nanotube template

    Science.gov (United States)

    Li, Chi Pui; Chen, Ying; Gerald, John Fitz

    2006-05-01

    Substitution reactions between carbon nanotube (CNT) template and SiO with the formation of carbon rich silicon oxide nanowires (SiO-C-NWs) have been investigated using transmission electron microscopy and x-ray energy dispersive spectroscopy. The reaction was carried out by thermal annealing at 1200°C for 1h of a mixture of silicon monoxide (SiO) and iron (II) phthalocyanine, FeC32N8H16 (FePc) powders. Multiwalled CNTs were produced first via pyrolysis of FePc at a lower temperature (1000°C ). SiO vapors reacted with the CNTs at higher temperatures to produce amorphous SiO-C-NWs with a uniform diameter and a length in tens of micrometers. The special bamboolike structure of the CNTs allows the reaction to start from the external surface of the tubes and transform each CNT into a solid nanowire section by section.

  10. CT and clinical patterns in suicidal carbon monoxide

    International Nuclear Information System (INIS)

    Grobovschek, M.; Geretsegger, C.; Weinberger, R.; Fartacek, R.

    1988-01-01

    Cranial CT is important to exclude the presence of a mass in the cavum cranii in case of an unclear suicide attempt, particularly a traumatic mass. It can be helpful also in cases of carbon monoxide intoxications. (orig.) [de

  11. Atmospheric analyzer, carbon monoxide monitor and toluene diisocyanate monitor

    Science.gov (United States)

    Shannon, A. V.

    1977-01-01

    The purpose of the atmospheric analyzer and the carbon monoxide and toluene diisocyanate monitors is to analyze the atmospheric volatiles and to monitor carbon monoxide and toluene diisocyanate levels in the cabin atmosphere of Skylab. The carbon monoxide monitor was used on Skylab 2, 3, and 4 to detect any carbon monoxide levels above 25 ppm. Air samples were taken once each week. The toluene diisocyanate monitor was used only on Skylab 2. The loss of a micrometeoroid shield following the launch of Skylab 1 resulted in overheating of the interior walls of the Orbital Workshop. A potential hazard existed from outgassing of an isocyanate derivative resulting from heat-decomposition of the rigid polyurethane wall insulation. The toluene diisocyanate monitor was used to detect any polymer decomposition. The atmospheric analyzer was used on Skylab 4 because of a suspected leak in the Skylab cabin. An air sample was taken at the beginning, middle, and the end of the mission.

  12. Carbon Monoxide Hazards from Small Gasoline Powered Engines

    Science.gov (United States)

    ... DHHS (NIOSH) Publication No. 96-118 (1996) Describes health effects and current standards and guidelines relating to carbon monoxide, as well as recommendations for workers, employers, and manufacturers regarding small gasoline powered engine ...

  13. An interesting cause of pulmonary emboli: Acute carbon monoxide poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Sevinc, A.; Savli, H.; Atmaca, H. [Gaziantep University, Gaziantep (Turkey). School of Medicine

    2005-07-01

    Carbon monoxide poisoning, a public health problem of considerable significance, is a relatively frequent event today, resulting in thousands of hospitalizations annually. A 70-year-old lady was seen in the emergency department with a provisional diagnosis of carbon monoxide poisoning. The previous night, she slept in a tightly closed room heated with coal ember. She was found unconscious in the morning with poor ventilation. She had a rare presentation of popliteal vein thrombosis, pulmonary emboli, and possible tissue necrosis with carbon monoxide poisoning. Oxygen treatment with low-molecular-weight heparin (nadroparine) and warfarin therapy resulted in an improvement in both popliteal and pulmonary circulations. In conclusion, the presence of pulmonary emboli should be sought in patients with carbon monoxide poisoning.

  14. CT and clinical patterns in suicidal carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Grobovschek, M.; Geretsegger, C.; Weinberger, R.; Fartacek, R.

    1988-12-01

    Cranial CT is important to exclude the presence of a mass in the cavum cranii in case of an unclear suicide attempt, particularly a traumatic mass. It can be helpful also in cases of carbon monoxide intoxications.

  15. Carbon nanotube computer.

    Science.gov (United States)

    Shulaker, Max M; Hills, Gage; Patil, Nishant; Wei, Hai; Chen, Hong-Yu; Wong, H-S Philip; Mitra, Subhasish

    2013-09-26

    The miniaturization of electronic devices has been the principal driving force behind the semiconductor industry, and has brought about major improvements in computational power and energy efficiency. Although advances with silicon-based electronics continue to be made, alternative technologies are being explored. Digital circuits based on transistors fabricated from carbon nanotubes (CNTs) have the potential to outperform silicon by improving the energy-delay product, a metric of energy efficiency, by more than an order of magnitude. Hence, CNTs are an exciting complement to existing semiconductor technologies. Owing to substantial fundamental imperfections inherent in CNTs, however, only very basic circuit blocks have been demonstrated. Here we show how these imperfections can be overcome, and demonstrate the first computer built entirely using CNT-based transistors. The CNT computer runs an operating system that is capable of multitasking: as a demonstration, we perform counting and integer-sorting simultaneously. In addition, we implement 20 different instructions from the commercial MIPS instruction set to demonstrate the generality of our CNT computer. This experimental demonstration is the most complex carbon-based electronic system yet realized. It is a considerable advance because CNTs are prominent among a variety of emerging technologies that are being considered for the next generation of highly energy-efficient electronic systems.

  16. Catalytic Copolymerization of Ethene and Carbon Monoxide on Nickel Complexes.

    Science.gov (United States)

    Domhöver, Bernd; Kläui, Wolfgang; Kremer-Aach, Andreas; Bell, Ralf; Mootz, Dietrich

    1998-11-16

    Can palladium be replaced by nickel? For the industrial copolymerization of carbon monoxide and ethene a palladium catalyst is used which cannot be recovered-a cheaper procedure would be desirable. The presented complex 1 is the first structurally characterized nickel compound which does not polymerize ethene but a mixture from carbon monoxide and ethene unter mild conditions to give a perfectly alternating polyketone. © 1998 WILEY-VCH Verlag GmbH, Weinheim, Fed. Rep. of Germany.

  17. Carbon monoxide and coronary heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Scheidemandel, V

    1974-01-01

    Studies on the relationship between increased carboxyhemoglobin levels in the blood and coronary heart disease in smokers and city dwellers are reviewed. The evidence of myocardial infarction is significantly higher in smokers than in nonsmokers which is due, apart from nicotine which promotes coronary arteriosclerosis, to inhaled carbon monoxide which leads to increased carboxyhemoglobin levels and most likely plays a role in the risk of arteriosclerosis and the coronary heart disease. Apart from combining with hemoglobin, CO increases the circulation rate and the coronary blood flow, and reduces the coronary arteriovenous oxygen difference, which is indicative of a reduced rate of oxygen extraction by the myocardium against an increased myocardial oxygen demand. The reduction of the oxygen extraction correlates with the increased COHb level. Inhaled CO lowers the threshold of angina pectoris due to the reduced myocardial oxygen tension. Also, considerable reduction of the oxygen diffusion from the capillaries toward the mitochondria due to the combination of CO with myoglobin is observed. Chronically increased CO levels in the blood and tissues not only accelerate the development of arteriosclerosis, but also induce a process directly injurious to the myocardial metabolism. (Air Pollut. Abstr.)

  18. Carbon Monoxide Hydrogenation on Ice Surfaces.

    Science.gov (United States)

    Kuwahata, Kazuaki; Ohno, Kaoru

    2018-03-14

    We have performed density functional calculations to investigate the carbon monoxide hydrogenation reaction (H+CO→HCO), which is important in interstellar clouds. We found that the activation energy of the reaction on amorphous ice is lower than that on crystalline ice. In the course of this study, we demonstrated that it is roughly possible to use the excitation energy of the reactant molecule (CO) in place of the activation energy. This relationship holds also for small water clusters at the CCSD level of calculation and the two-layer-level ONIOM (CCSD : X3LYP) calculation. Generally, since it is computationally demanding to estimate activation energies of chemical reactions in a circumstance of many water molecules, this relationship enables one to determine the activation energy of this reaction on ice surfaces from the knowledge of the excitation energy of CO only. Incorporating quantum-tunneling effects, we discuss the reaction rate on ice surfaces. Our estimate that the reaction rate on amorphous ice is almost twice as large as that on crystalline ice is qualitatively consistent with the experimental evidence reported by Hidaka et al. [Chem. Phys. Lett., 2008, 456, 36.]. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Review: hemodynamic response to carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Penney, D.G.

    1988-04-01

    Historically, and at present, carbon monoxide is a major gaseous poison responsible for widespread morbidity and mortality. From threshold to maximal nonlethal levels, a variety of cardiovascular changes occur, both immediately and in the long term, whose homeostatic function it is to renormalize tissue oxygen delivery. However, notwithstanding numerous studies over the past century, the literature remains equivocal regarding the hemodynamic responses in animals and humans, although CO hypoxia is clearly different in several respects from hypoxic hypoxia. Factors complicating interpretation of experimental findings include species, CO dose level and rate, route of CO delivery, duration, level of exertion, state of consciousness, and anesthetic agent used. Augmented cardiac output usually observed with moderate COHb may be compromised in more sever poisoning for the same reasons, such that regional or global ischemia result. The hypotension usually seen in most animal studies is thought to be a primary cause of CNS damage resulting from acute CO poisoning, yet the exact mechanism(s) remains unproven in both animals and humans, as does the way in which CO produces hypotension. This review briefly summarizes the literature relevant to the short- and long-term hemodynamic responses reported in animals and humans. It concludes by presenting an overview using data from a single species in which the most complete work has been done to date.

  20. Carbon monoxide measurements at Mace Head, Ireland

    Science.gov (United States)

    Doddridge, Bruce G.; Dickerson, Russell R.; Spain, T. Gerard; Oltmans, Samuel J.; Novelli, Paul C.

    1994-01-01

    The North Atlantic Ocean is bordered by continents which may each, under the influence of seasonal weather patterns, act as sources of natural and anthropogenic trace gas and particulate species. Photochemically active species such as carbon monoxide (CO) react to form ozone (O3), a species of critical importance in global climate change. CO is sparingly soluble in water, and the relatively long lifetime of CO in the troposphere makes this species an ideal tracer of air masses with origin over land. We have measured CO using a nondispersive infrared gas filter correlation analyzer at Mace Head on the west coast of Ireland nearly continuously since August 9, 1991. Measurements of CO were acquired at 20-sec resolution and recorded as 60-sec averages. Daily, monthly, and diurnal variation data characteristics of CO mixing ratios observed at this site are reported. Depending on source regions of air parcels passing over this site, 60-min concentrations of CO range from clean air values of approximately 90 ppbv to values in excess of 300 ppbv. Data characterizing the correlation between 60-min CO and O3 mixing ratio data observed at this site are reported also.

  1. Residential carbon monoxide poisoning from motor vehicles.

    Science.gov (United States)

    Hampson, Neil B

    2011-01-01

    Although morbidity and mortality from accidental carbon monoxide (CO) poisoning are high in the United States, identification of common but poorly recognized sources should help prevention efforts. The study aimed to describe CO poisoning of home occupants due to a vehicle left running in an attached garage. News stories reporting incidents of US CO poisoning were collected daily from March 2007 to September 2009 via a news.Google.com search and data extracted. Patients were individuals reported in the media to have been poisoned with CO in their home by a vehicle running in the attached garage. Main outcome measures were frequency of occurrence, geographic distribution, patient demographics, and mortality. Of 837 CO poisoning incidents reported in US news media over 2 and a half years, 59 (8%) were the result of a vehicle left running in the garage. The elderly were disproportionately affected, with incidents most common in states with larger elderly populations and 29% of cases with age specified occurring in individuals older than 80 years. Among those older than 80 years, 15 of 17 were found dead at the scene. Residential CO poisoning from a vehicle running in the garage is common, disproportionately affects the elderly, has a high mortality rate, and should be preventable with a residential CO alarm. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Carbon Monoxide: An Essential Signalling Molecule

    Science.gov (United States)

    Mann, Brian E.

    Carbon monoxide (CO), like nitric oxide (NO), is an essential signalling molecule in humans. It is active in the cardiovascular system as a vasodilator. In addition, CO possesses anti-inflammatory, anti-apoptotic and anti-proliferative properties and protects tissues from hypoxia and reperfusion injury. Some of its applications in animal models include suppression of organ graft rejection and safeguarding the heart during reperfusion after cardiopulmonary bypass surgery. CO also suppresses arteriosclerotic lesions following angioplasty, reverses established pulmonary hypertension and mitigates the development of post-operative ileus in the murine small intestine and the development of cerebral malaria in mice as well as graft-induced intimal hyperplasia in pigs. There have been several clinical trials using air-CO mixtures for the treatment of lung-, heart-, kidney- and abdominal-related diseases. This review examines the research involving the development of classes of compounds (with particular emphasis on metal carbonyls) that release CO, which could be used in clinically relevant conditions. The review is drawn not only from published papers in the chemical literature but also from the extensive biological literature and patents on CO-releasing molecules (CO-RMs).

  3. Elevated carboxyhemoglobin: sources of carbon monoxide exposure.

    Science.gov (United States)

    Buchelli Ramirez, Herminia; Fernández Alvarez, Ramón; Rubinos Cuadrado, Gemma; Martinez Gonzalez, Cristina; Rodriguez Jerez, Francisco; Casan Clara, Pere

    2014-11-01

    Inhalation of carbon monoxide (CO) can result in poisoning, with symptoms ranging from mild and nonspecific to severe, or even death. CO poisoning is often underdiagnosed because exposure to low concentrations goes unnoticed, and threshold values for normal carboxyhemoglobin vary according to different authors. The aim of our study was to analyze carboxyhemoglobin (COHb) levels in an unselected population and detect sources of CO exposure In a cross-sectional descriptive study, we analyzed consecutive arterial blood gas levels processed in our laboratory. We selected those with COHb≥2.5% in nonsmokers and ≥5% in smokers. In these cases a structured telephone interview was conducted. Elevated levels of COHb were found in 64 (20%) of 306 initial determinations. Of these, data from 51 subjects aged 65±12 years, 31 (60%) of which were men, were obtained. Mean COHb was 4.0%. Forty patients (78%) were non-smokers with mean COHb of 3.2%, and 11 were smokers with COHb of 6.7%. In 45 patients (88.2%) we detected exposure to at least one source of ambient CO other than cigarette smoke. A significant proportion of individuals from an unselected sample had elevated levels of COHb. The main sources of CO exposure were probably the home, so this possibility should be explored. The population should be warned about the risks and encouraged to take preventive measures. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

  4. Solar cycle variations in mesospheric carbon monoxide

    Science.gov (United States)

    Lee, Jae N.; Wu, Dong L.; Ruzmaikin, Alexander; Fontenla, Juan

    2018-05-01

    As an extension of Lee et al. (2013), solar cycle variation of carbon monoxide (CO) is analyzed with MLS observation, which covers more than thirteen years (2004-2017) including maximum of solar cycle 24. Being produced primarily by the carbon dioxide (CO2) photolysis in the lower thermosphere, the variations of the mesospheric CO concentration are largely driven by the solar cycle modulated ultraviolet (UV) variation. This solar signal extends down to the lower altitudes by the dynamical descent in the winter polar vortex, showing a time lag that is consistent with the average descent velocity. To characterize a global distribution of the solar impact, MLS CO is correlated with the SORCE measured total solar irradiance (TSI) and UV. As high as 0.8 in most of the polar mesosphere, the linear correlation coefficients between CO and UV/TSI are more robust than those found in the previous work. The photochemical contribution explains most (68%) of the total variance of CO while the dynamical contribution accounts for 21% of the total variance at upper mesosphere. The photochemistry driven CO anomaly signal is extended in the tropics by vertical mixing. The solar cycle signal in CO is further examined with the Whole Atmosphere Community Climate Model (WACCM) 3.5 simulation by implementing two different modeled Spectral Solar Irradiances (SSIs): SRPM 2012 and NRLSSI. The model simulations underestimate the mean CO amount and solar cycle variations of CO, by a factor of 3, compared to those obtained from MLS observation. Different inputs of the solar spectrum have small impacts on CO variation.

  5. Assessment of carbon monoxide values in smokers: a comparison of carbon monoxide in expired air and carboxyhaemoglobin in arterial blood

    DEFF Research Database (Denmark)

    Andersson, Mette F; Møller, Ann M

    2010-01-01

    Smoking increases perioperative complications. Carbon monoxide concentrations can estimate patients' smoking status and might be relevant in preoperative risk assessment. In smokers, we compared measurements of carbon monoxide in expired air (COexp) with measurements of carboxyhaemoglobin (COHb) ......) in arterial blood. The objectives were to determine the level of correlation and to determine whether the methods showed agreement and evaluate them as diagnostic tests in discriminating between heavy and light smokers....

  6. Probing Photosensitization by Functionalized Carbon Nanotubes

    Science.gov (United States)

    Carbon nanotubes (CNTs) photosensitize the production of reactive oxygen species that can damage organisms by biomembrane oxidation or mediate CNTs' environmental transformations. The photosensitized nature of derivatized carbon nanotubes from various synthetic methods, and thus ...

  7. Quantum transport in carbon nanotubes

    DEFF Research Database (Denmark)

    Laird, Edward A.; Kuemmeth, Ferdinand; Steele, Gary A.

    2015-01-01

    Carbon nanotubes are a versatile material in which many aspects of condensed matter physics come together. Recent discoveries, enabled by sophisticated fabrication, have uncovered new phenomena that completely change our understanding of transport in these devices, especially the role of the spin...... blockade. This can be exploited to read out spin and valley qubits, and to measure the decay of these states through coupling to nuclear spins and phonons. A second unique property of carbon nanotubes is that the combination of valley freedom and electron-electron interactions in one dimension strongly...... and valley degrees of freedom. This review describes the modern understanding of transport through nanotube devices. Unlike conventional semiconductors, electrons in nanotubes have two angular momentum quantum numbers, arising from spin and from valley freedom. We focus on the interplay between the two...

  8. Carbon Nanotube Based Molecular Electronics

    Science.gov (United States)

    Srivastava, Deepak; Saini, Subhash; Menon, Madhu

    1998-01-01

    Carbon nanotubes and the nanotube heterojunctions have recently emerged as excellent candidates for nanoscale molecular electronic device components. Experimental measurements on the conductivity, rectifying behavior and conductivity-chirality correlation have also been made. While quasi-one dimensional simple heterojunctions between nanotubes with different electronic behavior can be generated by introduction of a pair of heptagon-pentagon defects in an otherwise all hexagon graphene sheet. Other complex 3- and 4-point junctions may require other mechanisms. Structural stability as well as local electronic density of states of various nanotube junctions are investigated using a generalized tight-binding molecular dynamics (GDBMD) scheme that incorporates non-orthogonality of the orbitals. The junctions investigated include straight and small angle heterojunctions of various chiralities and diameters; as well as more complex 'T' and 'Y' junctions which do not always obey the usual pentagon-heptagon pair rule. The study of local density of states (LDOS) reveal many interesting features, most prominent among them being the defect-induced states in the gap. The proposed three and four pointjunctions are one of the smallest possible tunnel junctions made entirely of carbon atoms. Furthermore the electronic behavior of the nanotube based device components can be taylored by doping with group III-V elements such as B and N, and BN nanotubes as a wide band gap semiconductor has also been realized in experiments. Structural properties of heteroatomic nanotubes comprising C, B and N will be discussed.

  9. Multiscale Modeling with Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, A

    2006-02-21

    Technologically important nanomaterials come in all shapes and sizes. They can range from small molecules to complex composites and mixtures. Depending upon the spatial dimensions of the system and properties under investigation computer modeling of such materials can range from equilibrium and nonequilibrium Quantum Mechanics, to force-field-based Molecular Mechanics and kinetic Monte Carlo, to Mesoscale simulation of evolving morphology, to Finite-Element computation of physical properties. This brief review illustrates some of the above modeling techniques through a number of recent applications with carbon nanotubes: nano electromechanical sensors (NEMS), chemical sensors, metal-nanotube contacts, and polymer-nanotube composites.

  10. EDITORIAL: Focus on Carbon Nanotubes

    Science.gov (United States)

    2003-09-01

    The study of carbon nanotubes, since their discovery by Iijima in 1991, has become a full research field with significant contributions from all areas of research in solid-state and molecular physics and also from chemistry. This Focus Issue in New Journal of Physics reflects this active research, and presents articles detailing significant advances in the production of carbon nanotubes, the study of their mechanical and vibrational properties, electronic properties and optical transitions, and electrical and transport properties. Fundamental research, both theoretical and experimental, represents part of this progress. The potential applications of nanotubes will rely on the progress made in understanding their fundamental physics and chemistry, as presented here. We believe this Focus Issue will be an excellent guide for both beginners and experts in the research field of carbon nanotubes. It has been a great pleasure to edit the many excellent contributions from Europe, Japan, and the US, as well from a number of other countries, and to witness the remarkable effort put into the manuscripts by the contributors. We thank all the authors and referees involved in the process. In particular, we would like to express our gratitude to Alexander Bradshaw, who invited us put together this Focus Issue, and to Tim Smith and the New Journal of Physics staff for their extremely efficient handling of the manuscripts. Focus on Carbon Nanotubes Contents Transport theory of carbon nanotube Y junctions R Egger, B Trauzettel, S Chen and F Siano The tubular conical helix of graphitic boron nitride F F Xu, Y Bando and D Golberg Formation pathways for single-wall carbon nanotube multiterminal junctions Inna Ponomareva, Leonid A Chernozatonskii, Antonis N Andriotis and Madhu Menon Synthesis and manipulation of carbon nanotubes J W Seo, E Couteau, P Umek, K Hernadi, P Marcoux, B Lukic, Cs Mikó, M Milas, R Gaál and L Forró Transitional behaviour in the transformation from active end

  11. Dispersions of Carbon nanotubes in Polymer Matrices

    Science.gov (United States)

    Wise, Kristopher Eric (Inventor); Park, Cheol (Inventor); Siochi, Emilie J. (Inventor); Harrison, Joycelyn S. (Inventor); Lillehei, Peter T. (Inventor); Lowther, Sharon E. (Inventor)

    2010-01-01

    Dispersions of carbon nanotubes exhibiting long term stability are based on a polymer matrix having moieties therein which are capable of a donor-acceptor complexation with carbon nanotubes. The carbon nanotubes are introduced into the polymer matrix and separated therein by standard means. Nanocomposites produced from these dispersions are useful in the fabrication of structures, e.g., lightweight aerospace structures.

  12. Synthesis of carbon nanotubes bridging metal electrodes

    International Nuclear Information System (INIS)

    Kotlar, M.; Vojs, M.; Marton, M.; Vesel, M.; Redhammer, R.

    2012-01-01

    In our work we demonstrate growth of carbon nanotubes that can conductively bridge the metal electrodes. The role of different catalysts was examined. Interdigitated metal electrodes are made from copper and we are using bimetal Al/Ni as catalyst for growth of carbon nanotubes. We are using this catalyst composition for growth of the single-walled carbon nanotube network. (authors)

  13. Carbon monoxide and COHb concentration in blood in various circumstances

    Energy Technology Data Exchange (ETDEWEB)

    Modic, J. [Faculty of Mechanical Engineering, University of Ljubljana, Ljubljana (Slovenia)

    2003-07-01

    On the basis of known medical experiments we find out the correlation between the concentration of carbon monoxide (CO) in inhaling air and the concentration of carboxihemoglobyne (COHb) in human blood. All internal combustion engines produce exhaust gases containing noxious compounds: carbon monoxide, nitrogen oxides (NO{sub x}), carbon oxides (CxHy) and smoke. In a living room is important the smoke of cigarettes, smoke of furnaces, improper ventilation. In tunnel is most dangerous the carbon monoxide if it exceeds an allowable level. In human blood the carbon monoxide causes increasing the concentration of carboxihemoglobyne and in this case the hypoxia of web. With help of mathematical model the concentrations of some dangerous substances at the end of tunnel were calculated. For this case a differential equation also was developed and it shows the correlation between concentration of carbon monoxide in the air and concentration of carboxihemoglobyne in the blood. The constructed mathematical model shows circumstances in the tunnel (velocity of air moving as effect of induction, concentration of noxious substances and criterial number). Also a corresponding computer program was developed, which makes possible a quick and simple calculation. All the results are proved by experiments. Finally the differential equation was done, which shows a temporal connection between both parameters as a function of tunnel characteristics. (author)

  14. Structural transformations of carbon chains inside nanotubes

    International Nuclear Information System (INIS)

    Warner, Jamie H.; Ruemmeli, Mark H.; Bachmatiuk, Alicja; Buechner, Bernd

    2010-01-01

    In situ aberration-corrected high-resolution transmission electron microscopy is used to examine the structural transformations of carbon chains that occur in the interior region of carbon nanotubes. We find electron-beam irradiation leads to the formation of two-dimensional carbon structures that are freely mobile inside the nanotube. The inner diameter of the nanotube influences the structural transformations of the carbon chains. As the diameter of the nanotube increases, electron-beam irradiation leads to curling of the chains and eventually the formation of closed looped structures. The closed looped structures evolve into spherical fullerenelike structures that exhibit translational motion inside the nanotubes and also coalesce to form larger nanotube structures. These results demonstrate the use of carbon nanotubes as test tubes for growing small carbon nanotubes within the interior by using only electron-beam irradiation at 80 kV.

  15. Carbon nanotube: the inside story.

    Science.gov (United States)

    Ando, Yoshinori

    2010-06-01

    Carbon nanotubes (CNTs) were serendipitously discovered as a byproduct of fullerenes by direct current (DC) arc discharge; and today this is the most-wanted material in the nanotechnology research. In this brief review, I begin with the history of the discovery of CNTs and focus on CNTs produced by arc discharge in hydrogen atmosphere, which is little explored outside my laboratory. DC arc discharge evaporation of pure graphite rod in pure hydrogen gas results in multi-walled carbon nanotubes (MWCNTs) of high crystallinity in the cathode deposit. As-grown MWCNTs have very narrow inner diameter. Raman spectra of these MWCNTs show high-intensity G-band, unusual high-frequency radial breathing mode at 570 cm(-1), and a new characteristic peak near 1850 cm(-1). Exciting carbon nanowires (CNWs), consisting of a linear carbon chain in the center of MWCNTs are also produced. Arc evaporation of graphite rod containing metal catalysts results in single-wall carbon nanotubes (SWCNTs) in the whole chamber like macroscopic webs. Two kinds of arc method have been developed to produce SWCNTs: Arc plasma jet (APJ) and Ferrum-Hydrogen (FH) arc methods. Some new purification methods for as-produced SWCNTs are reviewed. Finally, double-walled carbon nanotubes (DWCNTs) are also described.

  16. Photodetector based on carbon nanotubes

    Science.gov (United States)

    Pavlov, A.; Kitsyuk, E.; Ryazanov, R.; Timoshenkov, V.; Adamov, Y.

    2015-09-01

    Photodetector based on carbon nanotubes (CNT) was investigated. Sensors were done on quartz and silicon susbtrate. Samples of photodetectors sensors were produced by planar technology. This technology included deposition of first metal layer (Al), lithography for pads formation, etching, and formation of local catalyst area by inverse lithography. Vertically-aligned multi-wall carbon nanotubes were directly synthesized on substrate by PECVD method. I-V analysis and spectrum sensitivity of photodetector were investigated for 0.4 μm - 1.2 μm wavelength. Resistivity of CNT layers over temperature was detected in the range of -20°C to 100°C.

  17. CMOS Integrated Carbon Nanotube Sensor

    International Nuclear Information System (INIS)

    Perez, M. S.; Lerner, B.; Boselli, A.; Lamagna, A.; Obregon, P. D. Pareja; Julian, P. M.; Mandolesi, P. S.; Buffa, F. A.

    2009-01-01

    Recently carbon nanotubes (CNTs) have been gaining their importance as sensors for gases, temperature and chemicals. Advances in fabrication processes simplify the formation of CNT sensor on silicon substrate. We have integrated single wall carbon nanotubes (SWCNTs) with complementary metal oxide semiconductor process (CMOS) to produce a chip sensor system. The sensor prototype was designed and fabricated using a 0.30 um CMOS process. The main advantage is that the device has a voltage amplifier so the electrical measure can be taken and amplified inside the sensor. When the conductance of the SWCNTs varies in response to media changes, this is observed as a variation in the output tension accordingly.

  18. All carbon nanotubes are not created equal

    International Nuclear Information System (INIS)

    Geohegan, David B.; Puretzky, Alexander A.; Rouleau, Christopher M.

    2010-01-01

    This chapter presents the various factors that enter into consideration when choosing the source of carbon nanotubes for a specific application. Carbon nanotubes are giant molecules made of pure carbon. They have captured the imagination of the scientific community by the unique structure that provides superior physical, chemical, and electrical properties. However, a surprisingly wide disparity exists between the intrinsic properties determined under ideal conditions and the properties that carbon nanotubes exhibit in real world situations. The lack of uniformity in carbon nanotube properties is likely to be the main obstacle holding back the development of carbon nanotube applications. This tutorial addresses the nonuniformity of carbon nanotube properties from the synthesis standpoint. This synthesis-related nonuniformity is on top of the intrinsic chirality distribution that gives the ∼1:2 ratio of metallic to semiconducting nanotubes. From the standpoint of carbon bonding chemistry the variation in the quality and reproducibility of carbon nanotube materials is not unexpected. It is an intrinsic feature that is related to the metastability of carbon structures. The extent to which this effect is manifested in carbon nanotube formation is governed by the type and the kinetics of the carbon nanotube synthesis reaction. Addressing this variation is critical if nanotubes are to live up to the potential already demonstrated by their phenomenal physical properties.

  19. Carbon monoxide poisoning from waterpipe smoking: a retrospective cohort study.

    Science.gov (United States)

    Eichhorn, Lars; Michaelis, Dirk; Kemmerer, Michael; Jüttner, Björn; Tetzlaff, Kay

    2018-04-01

    Waterpipe smoking may increasingly account for unintentional carbon monoxide poisoning, a serious health hazard with high morbidity and mortality. We aimed at identifying waterpipe smoking as a cause for carbon monoxide poisoning in a large critical care database of a specialty care referral center. This retrospective cohort study included patients with a history of exposure to waterpipe smoking and carbon monoxide blood gas levels >10% or presence of clinical symptoms compatible with CO poisoning admitted between January 2013 and December 2016. Patients' initial symptoms and carbon monoxide blood levels were retrieved from records and neurologic status was assessed before and after hyperbaric oxygen treatment. Sixty-one subjects with carbon monoxide poisoning were included [41 males, 20 females; mean age 23 (SD ± 6) years; range 13-45] with an initial mean carboxyhemoglobin of 26.93% (SD ± 9.72). Most common symptoms included syncope, dizziness, headache, and nausea; 75% had temporary syncope. Symptoms were not closely associated with blood COHb levels. CO poisoning after waterpipe smoking may present in young adults with a wide variability of symptoms from none to unconsciousness. Therefore diagnosis should be suspected even in the absence of symptoms.

  20. Synthesis of carbon nanotubes and nanotube forests on copper catalyst

    International Nuclear Information System (INIS)

    Kruszka, Bartosz; Terzyk, Artur P; Wiśniewski, Marek; Gauden, Piotr A; Szybowicz, Mirosław

    2014-01-01

    The growth of carbon nanotubes on bulk copper is studied. We show for the first time, that super growth chemical vapor deposition method can be successfully applied for preparation of nanotubes on copper catalyst, and the presence of hydrogen is necessary. Next, different methods of copper surface activation are studied, to improve catalyst efficiency. Among them, applied for the first time for copper catalyst in nanotubes synthesis, sulfuric acid activation is the most promising. Among tested samples the surface modified for 10 min is the most active, causing the growth of vertically aligned carbon nanotube forests. Obtained results have potential importance in application of nanotubes and copper in electronic chips and nanodevices. (paper)

  1. Carbon nanotubes and methods of making carbon nanotubes

    KAUST Repository

    Basset, Jean-Marie; Zhou, Lu; Saih, Youssef

    2017-01-01

    Embodiments of the present disclosure provide for methods that can be used to produce carbon nanotubes (hereinafter CNT) having an inner diameter about 5-55 nm, methods of tuning the inner diameter of CNTs (e.g., by adjusting reaction pressure

  2. Carbon nanotubes and methods of making carbon nanotubes

    KAUST Repository

    Basset, Jean-Marie

    2017-04-27

    Embodiments of the present disclosure provide for methods that can be used to produce carbon nanotubes (hereinafter CNT) having an inner diameter about 5-55 nm, methods of tuning the inner diameter of CNTs (e.g., by adjusting reaction pressure), CNTs having an inner diameter of greater than 20 nm or more, and the like.

  3. Hydrogen storage in carbon nanotubes.

    Science.gov (United States)

    Hirscher, M; Becher, M

    2003-01-01

    The article gives a comprehensive overview of hydrogen storage in carbon nanostructures, including experimental results and theoretical calculations. Soon after the discovery of carbon nanotubes in 1991, different research groups succeeded in filling carbon nanotubes with some elements, and, therefore, the question arose of filling carbon nanotubes with hydrogen by possibly using new effects such as nano-capillarity. Subsequently, very promising experiments claiming high hydrogen storage capacities in different carbon nanostructures initiated enormous research activity. Hydrogen storage capacities have been reported that exceed the benchmark for automotive application of 6.5 wt% set by the U.S. Department of Energy. However, the experimental data obtained with different methods for various carbon nanostructures show an extreme scatter. Classical calculations based on physisorption of hydrogen molecules could not explain the high storage capacities measured at ambient temperature, and, assuming chemisorption of hydrogen atoms, hydrogen release requires temperatures too high for technical applications. Up to now, only a few calculations and experiments indicate the possibility of an intermediate binding energy. Recently, serious doubt has arisen in relation to several key experiments, causing considerable controversy. Furthermore, high hydrogen storage capacities measured for carbon nanofibers did not survive cross-checking in different laboratories. Therefore, in light of today's knowledge, it is becoming less likely that at moderate pressures around room temperature carbon nanostructures can store the amount of hydrogen required for automotive applications.

  4. Development of an enzymatic sensor for carbon monoxide

    International Nuclear Information System (INIS)

    Hurtado, Clara; Gomez, Diana; Larmat, Fernando; Torres, Walter; Cuervo, Raul; Bravo, Enrique; Benitez, Neyla

    2003-01-01

    The detection and the pursuit of gases that contribute in the increase of the atmospheric contamination are a necessity, for what the electrochemical sensors have potential industrial applications for the control of the quality of the air. The development of amperometric sensor based on enzymes offers advantages, since the use of the biological component provides him high selectivity due to the great specificity of the substrate of the enzyme. The monoxide of carbon (CO) it is a polluting, poisonous gas, taken place during the incomplete combustion of organic materials (natural gas, petroleum, gasoline, coal and vegetable material). The determination of monoxide of carbon (CO) it can be reached by electrochemical mediums using the methylene blue like the electronic mediator for the enzyme monoxide of carbon oxidase (COx)

  5. Quantum transport in carbon nanotubes

    NARCIS (Netherlands)

    Laird, E.A.; Kuemmeth, F.; Steele, G.A.; Grove-Rasmussen, K.; Nygard, J.; Flensberg, K.; Kouwenhoven, L.P.

    2015-01-01

    Carbon nanotubes are a versatile material in which many aspects of condensed matter physics come together. Recent discoveries have uncovered new phenomena that completely change our understanding of transport in these devices, especially the role of the spin and valley degrees of freedom. This

  6. Carbon nanotube-chalcogenide composite

    Czech Academy of Sciences Publication Activity Database

    Stehlík, Š.; Orava, J.; Kohoutek, T.; Wágner, T.; Frumar, M.; Zima, Vítězslav; Hara, T.; Matsui, Y.; Ueda, K.; Pumera, M.

    2010-01-01

    Roč. 183, č. 1 (2010), s. 144-149 ISSN 0022-4596 R&D Projects: GA ČR GA203/08/0208 Institutional research plan: CEZ:AV0Z40500505 Keywords : carbon nanotubes * chalcogenide glasses * composites Subject RIV: CA - Inorganic Chemistry Impact factor: 2.261, year: 2010

  7. Polyurethane compounds having carbon nanotubes

    NARCIS (Netherlands)

    2010-01-01

    The invention relates to semi-crystalline polyurethane (PUR) compositions filled with carbon nanotubes (CNT) and having improved electrical properties, which can be obtained on the basis of water-based polyurethane/CNT mixtures. The invention further relates to a method for producing polyurethane

  8. Functionalized carbon nanotubes containing isocyanate groups

    International Nuclear Information System (INIS)

    Zhao Chungui; Ji Lijun; Liu Huiju; Hu Guangjun; Zhang Shimin; Yang Mingshu; Yang Zhenzhong

    2004-01-01

    Functionalized carbon nanotubes containing isocyanate groups can extend the nanotube chemistry, and may promote their many potential applications such as in polymer composites and coatings. This paper describes a facile method to prepare functionalized carbon nanotubes containing highly reactive isocyanate groups on its surface via the reaction between toluene 2,4-diisocyanate and carboxylated carbon nanotubes. Fourier-transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed that reactive isocyanate groups were covalently attached to carbon nanotubes. The content of isocyanate groups were determined by chemical titration and thermogravimetric analysis (TGA)

  9. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    Science.gov (United States)

    Johnson, R.; Steinberg, M.

    This invention relates to high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280/sup 0/C and containing as little as 36 mo1% ethylene and about 41 to 51 mo1% sulfur dioxide, and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10 to 50/sup 0/C, and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  10. Modeling chemisorption kinetics of carbon monoxide on polycrystalline platinum

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, R.G.; Modell, M.; Baddour, R.F.

    1978-04-01

    Seven distinct desorption surface states of carbon monoxide on polycrystalline platinum were detected by deconvoluting temperature-programed desorption spectra of 4-100% carbon monoxide monolayer coverage. The adstates had fixed activation energies of desorption (22.5-32.6 kcal/mole) over the entire coverage range. Rates of formation and populations were derived. The chemisorption was modeled by a Hinshelwood-type expression which allowed for site creation and suggested that adsorbed molecules are sufficiently mobile during desorption heating to fill ordered states of minimum energy and that chemisorption into these states is noncompetitive and determined by the surface. Spectra, diagrams, graphs, tables, and 49 references.

  11. Microwave interaction with nonuniform hydrogen gas in carbon nanotubes

    International Nuclear Information System (INIS)

    Babaei, S.; Babaei, Sh.

    2009-01-01

    In this paper we study the reflection, absorption, and transmission of microwave from nonuniform hydrogen gas in carbon nanotubes, grown by iron-catalyzed high-pressure carbon monoxide disproportionate (HiPco) process. A discussion on the effect of various hydrogen gas parameters on the reflected power, absorbed power, and transmitted power is presented. The nonuniform hydrogen gas slab is modeled by a series of subslabs. The overall number density profile across the whole slab follows a parabolic function. The total reflected, absorbed, and transmitted powers are then deduced and their functional dependence on the number density, collision frequency, and angle of propagation is studied

  12. Theoretical properties of carbon nanotubes

    International Nuclear Information System (INIS)

    Palser, A.H.

    2000-01-01

    Carbon nanotubes are invariably terminated with hemi-fullerene caps. In order to investigate the effect of these caps on the electronic structure, a method is developed to enumerate every hemi-fullerene cap which is commensurate with a given nanotube body. This algorithm is then applied to nanotubes for which I + m ≤ 25. The results of this algorithm are then used to study the effects of caps with different symmetries on the electronic structure of metallic and semi-conducting nanotubes within the Hueckel model. It is found that caps can cause localised and resonance states, although the likelihood of localised states occurring in capped metallic nanotubes is shown to be small. In addition, caps induce a non-uniform charge distribution, in which negative charge tends to accumulate on pentagon vertices. The thesis ends by describing two new density matrix methods for performing linear-scaling electronic-structure calculations within the independent electron approximation. Example calculations demonstrate that these methods provide efficient and robust ways of performing linear-scaling calculations, either grand canonically (at a fixed chemical potential) or canonically (at a fixed electron count). (author)

  13. Optimization of Treatment Policy for Acute Carbon Monoxide Poisoning

    Directory of Open Access Journals (Sweden)

    R. N. Akalayev

    2012-01-01

    Full Text Available Objective: to evaluate the efficiency of combination use of hyperbaric oxygenation, succinate-containing solutions, and anti-edematous agents in patients with acute carbon monoxide poisoning. Subjects and methods. The results of treatment were analyzed in 32 patients admitted in 2009—2011 for severe acute carbon monoxide poisoning and a Glasgow coma score of 6—8. The patients were divided into 2 groups: 1 patients whose combination therapy involved hyperbaric oxygenation, Succinasol infusions, and L-lysine-aescinate injections; 2 those who received traditional therapy. All the patients underwent complex clinical, laboratory, and neurophysiologic examinations. Results. Just 24 hours after the combination use of Succinasol and L-lysine-aescinate, Group I patients were observed to have substantially reduced lactate, the content of the latter approached the normal value following 48 hours, which was much below the values in the control group. The similar pattern was observed when endogenous intoxication parameters were examined. During the performed therapy, the level of consciousness and that of intellect according to the MMSE and FAB scales were restored more rapidly in the study group patients than in Group 2. Conclusion. The combination use of hyperbaric oxygenation, the succinate-containing solution Succinasol, and the anti-edematous agent L-lysine-aescinate considerably enhances the efficiency of intensive therapy for acute carbon monoxide poisoning. Key words: carbon monoxide, toxic hypoxic encephalopathy, combination therapy, hyperbaric oxygenation, succinic acid, L-lysine-aescinate.

  14. Production of Ethylene and Carbon Monoxide by Microorganisms

    Science.gov (United States)

    T. H. Filer; L. R. Brown; S. Brown-Sarobot; S. Martin

    1984-01-01

    Various quantities of ethylene and carbon monoxide were produced on PDA by Fusicladium effusum, Pestilotia nucicola, Alternaria tenuis, and Fusarium oxysporum subcultured from diseased pecan shucks. Repeated subculturing of these fungi on potato dextrose broth supplemented with iron powder produced ethylene. The production of...

  15. Ethylene and Carbon Monoxide Production by Septoria musiva

    Science.gov (United States)

    S. Brown-Skrobot; L. R. Brown; T. H. Filer

    1984-01-01

    An investigation into the mechanism by which Septoria musiva causes the premature defoliation of cottonwood trees was undertaken. Gas-chromatograpic analysis of the atmosphere overlying the original culture indicated that this fungus produced significant quantities of ethylene and carbon monoxide. Subcultures failed to produce either gas on a variety...

  16. Poisoning by carbon monoxide in Morocco from 1991 to 2008.

    Science.gov (United States)

    Aghandous, Rachida; Chaoui, Hanane; Rhalem, Naima; Semllali, Ilham; Badri, Mohamed; Soulaymani, Abdelmajid; Ouammi, Lahcen; Soulaymani-Bencheikh, Rachida

    2012-04-01

    To describe the characteristics relating to the provenance of statements, patients and to evaluate the spatiotemporal evolution of carbon monoxide poisoning reported to Poison Control Center and Pharmacovigilance of Morocco (CAPM). This is a retrospective study over a period of 18 years from 1991 to 2008, for all cases of poisoning by carbon monoxide reported to CAPM. The epidemiological study focused on 12 976 cases of carbon monoxide poisoning reported to CAPM between 1991 and 2008. The average age of patients was 25.5 +/- 15.6 years, sex ratio was 0.5. The poisoning occurred by accident in 98.7% of cases, especially at home (96.7%) and in cold months. The urban population was the most affected (89.0%). The region of Meknes Tafilalt was the most concerned with 16.6% of cases. The symptomatology was characterized by the predominance of gastrointestinal tract diseases (37.1%). Deaths have reached a percentage of 0.9%. These qualitative and quantitative information is useful to highlight warnings and plan a strategy against carbon monoxide poisoning in Morocco.

  17. Pathways and bioenergetics of anaerobic carbon monoxide fermentation

    NARCIS (Netherlands)

    Diender, Martijn; Stams, Fons; Machado de Sousa, Diana

    2015-01-01

    Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the

  18. [Cerebellar Infarction After Carbon Monoxide Poisoning and Hyperbaric Oxygen Therapy].

    Science.gov (United States)

    Wick, Matthias; Schneiker, André; Bele, Sylvia; Pawlik, Michael; Meyringer, Helmut; Graf, Bernhard; Wendl, Christina; Kieninger, Martin

    2017-06-01

    We report on a patient who developed a space-occupying cerebellar infarction with occlusive hydrocephalus after a poisoning with carbon monoxide with the intention to commit suicide. A neurosurgical and intensive care therapy were needed. The patient's survival without severe neurological deficits could be secured due to the early detection of the intracerebral lesions. Georg Thieme Verlag KG Stuttgart · New York.

  19. Carbon Monoxide Poisoning in a Child: A Case Report | Asani ...

    African Journals Online (AJOL)

    The exact incidence of carbon monoxide (CO) poisoning in Nigeria is unknown. Globally, CO poisoning is frequently unrecognized and under-reported since the clinical presentation is relatively non-specific. The circumstances usually involve an unsuspected increase of CO in an enclosed environment. We present the ...

  20. Nitrotyrosine adsorption on carbon nanotube: a density functional theory study

    Science.gov (United States)

    Majidi, R.; Karami, A. R.

    2014-05-01

    We have studied the effect of nitrotyrosine on electronic properties of different single-wall carbon nanotubes by density functional theory. Optimal adsorption configurations of nitrotyrosine adsorbed on carbon nanotube have been determined by calculation of adsorption energy. Adsorption energies indicate that nitrotyrosine is chemisorbed on carbon nanotubes. It is found that the nitrotyrosine adsorption modifies the electronic properties of the semiconducting carbon nanotubes significantly and these nanotubes become n-type semiconductors, while the effect of nitrotyrosine on metallic carbon nanotubes is not considerable and these nanotubes remain metallic. Results clarify sensitivity of carbon nanotubes to nitrotyrosine adsorption and suggest the possibility of using carbon nanotubes as biosensor for nitrotyrosine detection.

  1. Vertically aligned carbon nanotube field-effect transistors

    KAUST Repository

    Li, Jingqi; Zhao, Chao; Wang, Qingxiao; Zhang, Qiang; Wang, Zhihong; Zhang, Xixiang; Abutaha, Anas I.; Alshareef, Husam N.

    2012-01-01

    Vertically aligned carbon nanotube field-effect transistors (CNTFETs) have been developed using pure semiconducting carbon nanotubes. The source and drain were vertically stacked, separated by a dielectric, and the carbon nanotubes were placed

  2. Torsional carbon nanotube artificial muscles.

    Science.gov (United States)

    Foroughi, Javad; Spinks, Geoffrey M; Wallace, Gordon G; Oh, Jiyoung; Kozlov, Mikhail E; Fang, Shaoli; Mirfakhrai, Tissaphern; Madden, John D W; Shin, Min Kyoon; Kim, Seon Jeong; Baughman, Ray H

    2011-10-28

    Rotary motors of conventional design can be rather complex and are therefore difficult to miniaturize; previous carbon nanotube artificial muscles provide contraction and bending, but not rotation. We show that an electrolyte-filled twist-spun carbon nanotube yarn, much thinner than a human hair, functions as a torsional artificial muscle in a simple three-electrode electrochemical system, providing a reversible 15,000° rotation and 590 revolutions per minute. A hydrostatic actuation mechanism, as seen in muscular hydrostats in nature, explains the simultaneous occurrence of lengthwise contraction and torsional rotation during the yarn volume increase caused by electrochemical double-layer charge injection. The use of a torsional yarn muscle as a mixer for a fluidic chip is demonstrated.

  3. Carbon Nanotubes: Molecular Electronic Components

    Science.gov (United States)

    Srivastava, Deepak; Saini, Subhash; Menon, Madhu

    1997-01-01

    The carbon Nanotube junctions have recently emerged as excellent candidates for use as the building blocks in the formation of nanoscale molecular electronic networks. While the simple joint of two dissimilar tubes can be generated by the introduction of a pair of heptagon-pentagon defects in an otherwise perfect hexagonal graphene sheet, more complex joints require other mechanisms. In this work we explore structural characteristics of complex 3-point junctions of carbon nanotubes using a generalized tight-binding molecular-dynamics scheme. The study of pi-electron local densities of states (LDOS) of these junctions reveal many interesting features, most prominent among them being the defect-induced states in the gap.

  4. 1/f noise in carbon nanotubes

    International Nuclear Information System (INIS)

    Collins, Philip G.; Fuhrer, M. S.; Zettl, A.

    2000-01-01

    The electrical noise characteristics of single-walled carbon nanotubes have been investigated. For all three cases of individual isolated nanotubes, thin films of interconnected nanotubes, and bulk nanotube mats, anomalously large bias-dependent 1/f noise is found. The noise magnitude greatly exceeds that commonly observed in metal films, carbon resistors, or even carbon fibers with comparable resistances. A single empirical expression describes the noise for all nanotube samples, suggesting a common noise-generating mechanism proportional only to the number of nanotubes in the conductor. We consider likely sources of the fluctuations, and consequences for electronic applications of nanotubes if the excessive noise cannot be suppressed. (c) 2000 American Institute of Physics

  5. Carbon nanotubes for biological and biomedical applications

    International Nuclear Information System (INIS)

    Yang Wenrong; Thordarson, Pall; Gooding, J Justin; Ringer, Simon P; Braet, Filip

    2007-01-01

    Ever since the discovery of carbon nanotubes, researchers have been exploring their potential in biological and biomedical applications. The recent expansion and availability of chemical modification and bio-functionalization methods have made it possible to generate a new class of bioactive carbon nanotubes which are conjugated with proteins, carbohydrates, or nucleic acids. The modification of a carbon nanotube on a molecular level using biological molecules is essentially an example of the 'bottom-up' fabrication principle of bionanotechnology. The availability of these biomodified carbon nanotube constructs opens up an entire new and exciting research direction in the field of chemical biology, finally aiming to target and to alter the cell's behaviour at the subcellular or molecular level. This review covers the latest advances of bio-functionalized carbon nanotubes with an emphasis on the development of functional biological nano-interfaces. Topics that are discussed herewith include methods for biomodification of carbon nanotubes, the development of hybrid systems of carbon nanotubes and biomolecules for bioelectronics, and carbon nanotubes as transporters for a specific delivery of peptides and/or genetic material to cells. All of these current research topics aim at translating these biotechnology modified nanotubes into potential novel therapeutic approaches. (topical review)

  6. Improvements in Production of Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Balzano, Leandro; Resasco, Daniel E.

    2009-01-01

    A continuing program of research and development has been directed toward improvement of a prior batch process in which single-walled carbon nanotubes are formed by catalytic disproportionation of carbon monoxide in a fluidized-bed reactor. The overall effect of the improvements has been to make progress toward converting the process from a batch mode to a continuous mode and to scaling of production to larger quantities. Efforts have also been made to optimize associated purification and dispersion post processes to make them effective at large scales and to investigate means of incorporating the purified products into composite materials. The ultimate purpose of the program is to enable the production of high-quality single-walled carbon nanotubes in quantities large enough and at costs low enough to foster the further development of practical applications. The fluidized bed used in this process contains mixed-metal catalyst particles. The choice of the catalyst and the operating conditions is such that the yield of single-walled carbon nanotubes, relative to all forms of carbon (including carbon fibers, multi-walled carbon nanotubes, and graphite) produced in the disproportionation reaction is more than 90 weight percent. After the reaction, the nanotubes are dispersed in various solvents in preparation for end use, which typically involves blending into a plastic, ceramic, or other matrix to form a composite material. Notwithstanding the batch nature of the unmodified prior fluidized-bed process, the fluidized-bed reactor operates in a continuous mode during the process. The operation is almost entirely automated, utilizing mass flow controllers, a control computer running software specific to the process, and other equipment. Moreover, an important inherent advantage of fluidized- bed reactors in general is that solid particles can be added to and removed from fluidized beds during operation. For these reasons, the process and equipment were amenable to

  7. Selected constituents in the smokes of foreign commercial cigaretts: tar, nicotine, carbon monoxide, and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    The tar, nicotine, carbon monoxide, and carbon dioxide contents of the smokes of 220 brands of foreign commercial cigarettes are reported. In some instances, filter cigarettes of certain brands were found to deliver as much or more smoke constituents than their nonfilter counterparts. Also, data indicated that there can be a great variation in the tar, nicotine, or carbon monoxide content of the smoke of samples of a given brand of cigarettes, depending on the nation in which they are purchased. 24 tables.

  8. Mechanics of filled carbon nanotubes

    KAUST Repository

    Monteiro, A.O.; Cachim, P.B.; Da Costa, Pedro M. F. J.

    2014-01-01

    The benefits of filling carbon nanotubes (CNTs) with assorted molecular and crystalline substances have been investigated for the past two decades. Amongst the study of new structural phases, defects, chemical reactions and varied types of host-guest interactions, there is one fundamental characterisation aspect of these systems that continues to be overlooked: the mechanical behaviour of filled CNTs. In contrast to their empty counterparts, the mechanics of filled CNTs is a subject where reports appear far and apart, this despite being key to the application of these materials in technological devices. In the following paragraphs, we review the work that has been carried out up to the present on the mechanics of filled CNTs. The studies discussed range from experimental resonant frequency essays performed within electron microscopes to modelling, via molecular dynamics, of three-point bending of nanotubes filled with gases. (C) 2014 Elsevier B.V. All rights reserved.

  9. Mechanics of filled carbon nanotubes

    KAUST Repository

    Monteiro, A.O.

    2014-04-01

    The benefits of filling carbon nanotubes (CNTs) with assorted molecular and crystalline substances have been investigated for the past two decades. Amongst the study of new structural phases, defects, chemical reactions and varied types of host-guest interactions, there is one fundamental characterisation aspect of these systems that continues to be overlooked: the mechanical behaviour of filled CNTs. In contrast to their empty counterparts, the mechanics of filled CNTs is a subject where reports appear far and apart, this despite being key to the application of these materials in technological devices. In the following paragraphs, we review the work that has been carried out up to the present on the mechanics of filled CNTs. The studies discussed range from experimental resonant frequency essays performed within electron microscopes to modelling, via molecular dynamics, of three-point bending of nanotubes filled with gases. (C) 2014 Elsevier B.V. All rights reserved.

  10. Discovery of carbon nanotubes. Sara ni carbon nanotube e

    Energy Technology Data Exchange (ETDEWEB)

    Iijima, S

    1994-01-20

    This paper describes the following matters on carbon nanotubes (CNt): CNt is discovered in carbon deposits generated in the tip of a negative electrode during DC arc discharge between carbon electrodes. CNt has a construction in which cylinders made of normally several layers are superposed, based on cylindrical crystals in a single layer with six-member rings of carbon atoms laid out. Spiral arrangement of carbon six-member rings has been discovered in the single-layered crystals. Five-member rings exist in a location where the CNt tip is closed, and seven-member rings in a location where the CNt presents a saddle-like curve, without exceptions. It is introduced theoretically that the electronic structure of the single-layered CNt depends on the cylinder diameter and spiral pitch. Replacing part of the carbon negative electrode with iron, and vaporizing iron and carbon simultaneously through arc discharge can result in a single-layered CNt with a diameter of 1 nm. Heating the CNt deposited with metallic lead in an oxygen atmosphere can form CNt containing lead compounds. 19 refs., 9 figs.

  11. Interaction of multiwalled carbon nanotube produces structural ...

    African Journals Online (AJOL)

    Abstract. Multiwalled carbon nanotube (MWCNT) has been found to produce structural changes in Calf Thymus-DNA (CT-DNA). The interaction or binding of the multi-walled carbon nanotubes (MWCNT) was investigated in order to discover if it brings about any significant changes of the DNA double helix using CD spectra ...

  12. Kinetics of heterogeneous catalysis oxidation of carbon monoxide

    International Nuclear Information System (INIS)

    Khawaja, Y.; Sadiq, A.

    1987-10-01

    An irreversible kinetic surface-reaction model, based upon the reaction of carbon monoxide nd oxygen on a catalyst surface is investigated by means of Monte Carlo simulation. The adsorbed molecules/atoms on the surface undergo both first and second order kinetic phase transitions. The first order transition is found to occur at x/sub/co=x/sub/2=0.5255 with an error bar of 0.0003, where x/sub/co is the concentration of carbon monoxide in the gas phase. The time evolution of this catalytic reaction is studied both analytically and by computer simulation. Slightly above x/sub/2, the oxygen coverage relaxation time for the oxygen is found to diverage as the inverse of 3.54 times the absolute of the difference of x/sub/2 and x/sub/co. (orig./A.B.)

  13. Composite catalyst for carbon monoxide and hydrocarbon oxidation

    Science.gov (United States)

    Liu, Wei; Flytzani-Stephanopoulos, Maria

    1996-01-01

    A method and composition for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdnum, copper, cobalt, maganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

  14. Digit and letter alexia in carbon monoxide poisoning

    Institute of Scientific and Technical Information of China (English)

    Qingyu Shen; Xiaoming Rong; Rui Pan; Ying Peng; Wei Peng; Yamei Tang

    2012-01-01

    This study examined a 24-year-old patient with delayed encephalopathy, who was admitted to hospital with complaints of headache and visual impairment 1 week after acute carbon monoxide poisoning. The results of a visual field assessment, electroencephalography and head magnetic resonance imaging indicated damage to the cerebral cortex. After a 2-week treatment period, the patient had recovered from the visual impairment, but exhibited digit- and letter-reading difficulty. The Chinese aphasia battery and the number and letter battery supplement were conducted. The results revealed that the patient exhibited digit and letter alexia, while the ability to read Chinese characters was preserved. In contrast, the patient exhibited a deficit in Chinese character writing, while number and letter writing remained intact. Following treatment, reading and writing ability was improved and electroencephalographic abnormalities were ameliorated. Overall, our experimental findings demonstrated that delayed encephalopathy following acute carbon monoxide poisoning was characterized by digit and letter alexia.

  15. Interactions of carbon monoxide and hemoglobin at high altitude

    Energy Technology Data Exchange (ETDEWEB)

    Collier, C.R. (Univ. of Southern California Medical Center, Los Angeles); Goldsmith, J.R.

    1983-01-01

    The health risks to U.S. populations who are exposed to ambient carbon monoxide and live at altitudes (such as Denver, Salt Lake City, and Albuquerque) were evaluated using a set of mathematical models. The assumption that a given increase in carboxyhemoglobin would require a more stringent volumetric air quality standard was tested. The results using the model predict that the 8-h or 1-h standards adopted for sea level condition need not be altered to protect individuals against health risks at altitude, if the standards are in volumetric terms. They would need to be reduced if the standards are left in gravimetric terms. If the guideline is to be based on a given decrement of oxygen tension, many other variables must be specified, but expected differences in ambient carbon monoxide have a small impact compared to the effect of altitude itself.

  16. Pathways and bioenergetics of anaerobic carbon monoxide fermentation.

    OpenAIRE

    Martijn eDiender; Alfons J.M. Stams; Alfons J.M. Stams; Diana Z. Sousa

    2015-01-01

    Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the potential of converting CO rich gas, such as synthesis gas, into bio-based products. Three main types of fermentative CO metabolism can be distinguished: hydrogenogenesis, methanogenesis and acetogenesis, ...

  17. Carbon Monoxide Poisoning: Death on Mount McKinley,

    Science.gov (United States)

    1987-05-08

    Additionally, studies by Astrup(5) and Thomas(6) have reported decreased erythrocytic 2, 3- diphosphoglycerate (2, 3-DPG) concentrations with acute...Halebian, et al found no significant difference in measured 02 consumption or extraction between dogs subjected to CO poisoning vs nitrogen anoxia .(9...Astrup P: Intraerythrocytic 2,3- diphosphoglycerate and carbon monoxide exposure. Ann NY Acad Sci 1970;174:252-254. 6. Thomas MF, Penny DG: Hematologic

  18. Diffusion-weighted MR imaging findings in carbon monoxide poisoning

    International Nuclear Information System (INIS)

    Teksam, M.; Casey, S.O.; Michel, E.; Liu, H.; Truwit, C.L.

    2002-01-01

    Diffusion-weighted MR imaging (DWI) of two patients with carbon monoxide (CO) poisoning demonstrated white matter and cortical hyperintensities. In one patient, the changes on the FLAIR sequence were more subtle than those on DWI. The DWI abnormality in this patient represented true restriction. In the second patient, repeated exposure to CO caused restricted diffusion. DWI may be helpful for earlier identification of the changes of acute CO poisoning. (orig.)

  19. Liquid surface model for carbon nanotube energetics

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Mathew, Maneesh; Solov'yov, Andrey V.

    2008-01-01

    an important insight in the energetics and stability of nanotubes of different chirality and might be important for the understanding of nanotube growth process. For the computations we use empirical Brenner and Tersoff potentials and discuss their applicability to the study of carbon nanotubes. From......In the present paper we developed a model for calculating the energy of single-wall carbon nanotubes of arbitrary chirality. This model, which we call as the liquid surface model, predicts the energy of a nanotube with relative error less than 1% once its chirality and the total number of atoms...... the calculated energies we determine the elastic properties of the single-wall carbon nanotubes (Young modulus, curvature constant) and perform a comparison with available experimental measurements and earlier theoretical predictions....

  20. Carbon Nanotube Supercapacitors

    OpenAIRE

    Lu, Wen; Dai, Liming

    2010-01-01

    In summary, CNTs have been explored as a new type of electrode materials for supercapacitors. Both randomly entangled and highly aligned CNTs have been investigated. The former is relatively easier to fabricate while the latter has a better capacitor performance. Combining the unique properties of CNTs with the high surface area of activated carbons or the additional pseduocapacitance of redox materials (electroactive polymers and metal oxides), high-capacitance and high-rate nanocomposites a...

  1. Optical properties of carbon nanotubes

    Science.gov (United States)

    Chen, Gugang

    This thesis addresses the optical properties of novel carbon filamentary nanomaterials: single-walled carbon nanotubes (SWNTs), double-walled carbon nanotubes (DWNTs), and SWNTs with interior C60 molecules ("peapods"). Optical reflectance spectra of bundled SWNTs are discussed in terms of their electronic energy band structure. An Effective Medium Model for a composite material was found to provide a reasonable description of the spectra. Furthermore, we have learned from optical absorption studies of DWNTs and C60-peapods that the host tube and the encapsulant interact weakly; small shifts in interband absorption structure were observed. Resonant Raman scattering studies on SWNTs synthesized via the HiPCO process show that the "zone-folding" approximation for phonons and electrons works reasonably well, even for small diameter (d effect, rather than the vdW interaction. Finally, we studied the chemical doping of DWNTs, where the dopant (Br anions) is chemically bound to the outside of the outer tube. The doped DWNT system is a model for a cylindrical molecular capacitor. We found experimentally that 90% of the positive charge resides on the outer tube, so that most of electric field on the inner tube is screened, i.e., we have observed a molecular Faraday cage effect. A self-consistent theoretical model in the tight-binding approximation with a classical electrostatic energy term is in good agreement with our experimental results.

  2. Coated carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng [Newton, MA; Wen, Jian [Newton, MA; Chen, Jinghua [Chestnut Hill, MA; Huang, Zhongping [Belmont, MA; Wang, Dezhi [Wellesley, MA

    2008-10-28

    The present invention provides conductive carbon nanotube (CNT) electrode materials comprising aligned CNT substrates coated with an electrically conducting polymer, and the fabrication of electrodes for use in high performance electrical energy storage devices. In particular, the present invention provides conductive CNTs electrode material whose electrical properties render them especially suitable for use in high efficiency rechargeable batteries. The present invention also provides methods for obtaining surface modified conductive CNT electrode materials comprising an array of individual linear, aligned CNTs having a uniform surface coating of an electrically conductive polymer such as polypyrrole, and their use in electrical energy storage devices.

  3. Structural properties of water around uncharged and charged carbon nanotubes

    International Nuclear Information System (INIS)

    Dezfoli, Amir Reza Ansari; Mehrabian, Mozaffar Ali; Rafsanjani, Hassan Hashemipour

    2013-01-01

    Studying the structural properties of water molecules around the carbon nanotubes is very important in a wide variety of carbon nanotubes applications. We studied the number of hydrogen bonds, oxygen and hydrogen density distributions, and water orientation around carbon nanotubes. The water density distribution for all carbon nanotubes was observed to have the same feature. In water-carbon nanotubes interface, a high-density region of water molecules exists around carbon nanotubes. The results reveal that the water orientation around carbon nanotubes is roughly dependent on carbon nanotubes surface charge. The water molecules in close distances to carbon nanotubes were found to make an HOH plane nearly perpendicular to the water-carbon nanotubes interface for carbon nanotubes with negative surface charge. For uncharged carbon nanotubes and carbon nanotubes with positive surface charge, the HOH plane was in tangential orientation with water-carbon nanotubes interface. There was also a significant reduction in hydrogen bond of water region around carbon nanotubes as compared with hydrogen bond in bulk water. This reduction was very obvious for carbon nanotubes with positive surface charge. In addition, the calculation of dynamic properties of water molecules in water-CNT interface revealed that there is a direct relation between the number of Hbonds and self-diffusion coefficient of water molecules

  4. Mobile Carbon Monoxide Monitoring System Based on Arduino-Matlab for Environmental Monitoring Application

    Science.gov (United States)

    Azieda Mohd Bakri, Nur; Junid, Syed Abdul Mutalib Al; Razak, Abdul Hadi Abdul; Idros, Mohd Faizul Md; Karimi Halim, Abdul

    2015-11-01

    Nowadays, the increasing level of carbon monoxide globally has become a serious environmental issue which has been highlighted in most of the country globally. The monitoring of carbon monoxide content is one of the approaches to identify the level of carbon monoxide pollution towards providing the solution for control the level of carbon monoxide produced. Thus, this paper proposed a mobile carbon monoxide monitoring system for measuring the carbon monoxide content based on Arduino-Matlab General User Interface (GUI). The objective of this project is to design, develop and implement the real-time mobile carbon monoxide sensor system and interfacing for measuring the level of carbon monoxide contamination in real environment. Four phases or stages of work have been carried out for the accomplishment of the project, which classified as sensor development, controlling and integrating sensor, data collection and data analysis. As a result, a complete design and developed system has been verified with the handheld industrial standard carbon monoxide sensor for calibrating the sensor sensitivity and measurement in the laboratory. Moreover, the system has been tested in real environments by measuring the level of carbon monoxide in three different lands used location; industrial area; residential area and main road (commercial area). In this real environment test, the industrial area recorded the highest reading with 71.23 ppm and 82.59 ppm for sensor 1 and sensor 2 respectively. As a conclusion, the mobile realtime carbon monoxide system based on the Arduino-Matlab is the best approach to measure the carbon monoxide concentration in different land-used since it does not require a manual data collection and reduce the complexity of the existing carbon monoxide level concentration measurement practise at the same time with a complete data analysis facilities.

  5. Review of carbon nanotube nanoelectronics and macroelectronics

    International Nuclear Information System (INIS)

    Che, Yuchi; Chen, Haitian; Gui, Hui; Liu, Jia; Liu, Bilu; Zhou, Chongwu

    2014-01-01

    Carbon nanotubes have the potential to spur future development in electronics due to their unequalled electrical properties. In this article, we present a review on carbon nanotube-based circuits in terms of their electrical performance in two major directions: nanoelectronics and macroelectronics. In the nanoelectronics direction, we direct our discussion to the performance of aligned carbon nanotubes for digital circuits and circuits designed for radio-frequency applications. In the macroelectronics direction, we focus our attention on the performance of thin films of carbon nanotube random networks in digital circuits, display applications, and printed electronics. In the last part, we discuss the existing challenges and future directions of nanotube-based nano- and microelectronics. (invited review)

  6. Carbon monoxide poisoning - Immediate diagnosis and treatment are crucial to avoid complications.

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, L.D. [Case Western Reserve University, Cleveland, OH (United States)

    2006-03-15

    Carbon monoxide is an odorless, colorless, tasteless gas produced by the incomplete combustion of carbon-containing fuels (oil, kerosene, coal, wood) or the inadequate ventilation of natural gas. When carbon monoxide is introduced into the bloodstream, it binds to hemoglobin, reducing the number of binding sites available for oxygen. Carbon monoxide also changes the structure of the hemoglobin molecule, which makes it even more difficult for oxygen that has attached to be released into tissues. The resulting tissue ischemia can lead to organ failure, permanent changes in cognition, or death. Carbon monoxide poisoning is the leading cause of death by poisoning in industrialized countries.

  7. Carbon nanotube woven textile photodetector

    Science.gov (United States)

    Zubair, Ahmed; Wang, Xuan; Mirri, Francesca; Tsentalovich, Dmitri E.; Fujimura, Naoki; Suzuki, Daichi; Soundarapandian, Karuppasamy P.; Kawano, Yukio; Pasquali, Matteo; Kono, Junichiro

    2018-01-01

    The increasing interest in mobile and wearable technology demands the enhancement of functionality of clothing through incorporation of sophisticated architectures of multifunctional materials. Flexible electronic and photonic devices based on organic materials have made impressive progress over the past decade, but higher performance, simpler fabrication, and most importantly, compatibility with woven technology are desired. Here we report on the development of a weaved, substrateless, and polarization-sensitive photodetector based on doping-engineered fibers of highly aligned carbon nanotubes. This room-temperature-operating, self-powered detector responds to radiation in an ultrabroad spectral range, from the ultraviolet to the terahertz, through the photothermoelectric effect, with a low noise-equivalent power (a few nW/Hz 1 /2) throughout the range and with a Z T -factor value that is twice as large as that of previously reported carbon nanotube-based photothermoelectric photodetectors. Particularly, we fabricated a ˜1 -m-long device consisting of tens of p+-p- junctions and weaved it into a shirt. This device demonstrated a collective photoresponse of the series-connected junctions under global illumination. The performance of the device did not show any sign of deterioration through 200 bending tests with a bending radius smaller than 100 μ m as well as standard washing and ironing cycles. This unconventional photodetector will find applications in wearable technology that require detection of electromagnetic radiation.

  8. Structure of Carbon Nanotube-dendrimer composite

    OpenAIRE

    Vasumathi, V.; Pramanik, Debabrata; Sood, A. K.; Maiti, Prabal K

    2012-01-01

    Using all atomistic molecular dynamics (MD) simulations we report the microscopic picture of the nanotube-dendrimer complex for PAMAM dendrimer of generation 2 to 4 and carbon nanotube of chirality (6,5). We find compact wrapping conformations of dendrimer onto the nanotube surface for all the three generations of PAMAM dendrimer. The degree of wrapping is more for non-protonated dendrimer compared to the protonated dendrimer. For comparison we also study the interaction of another dendrimer,...

  9. Carbon nanotubes as heat dissipaters in microelectronics

    DEFF Research Database (Denmark)

    Pérez Paz, Alejandro; García-Lastra, Juan María; Markussen, Troels

    2013-01-01

    We review our recent modelling work of carbon nanotubes as potential candidates for heat dissipation in microelectronics cooling. In the first part, we analyze the impact of nanotube defects on their thermal transport properties. In the second part, we investigate the loss of thermal properties...... of nanotubes in presence of an interface with various substances, including air and water. Comparison with previous works is established whenever is possible....

  10. Alternating copolymerization of fluoroalkenes with carbon monoxide.

    Science.gov (United States)

    Fujita, Tomoyuki; Nakano, Koji; Yamashita, Makoto; Nozaki, Kyoko

    2006-02-15

    The palladium-catalyzed alternating copolymerization of fluoroalkenes, represented as CH(2)=CH-CH(2)-C(n)F(2n+1), with CO was performed using (R,S)-BINAPHOS (2e) as a ligand. The CH(2)-C(n)F(2n+1) group is the most electronegative substituent ever reported for the copolymerization (Taft's sigma value of 0.90 for CH(2)CF(3)). The copolymer obtained from CH(2)=CH-CH(2)-C(8)F(17) (1a) existed as a mixture of polyspiroketal and polyketone, while that from CH(2)=CH-CH(2)-C(4)F(9) (1b) was a pure polyspiroketal, as was revealed by infrared and (13)C-CP/MAS NMR spectroscopies. The terminal structure of the polymer from 1b was confirmed by MALDI-TOF MS spectrometry. Detailed NMR studies suggested that the much higher reactivity with (R,S)-BINAPHOS (2e) than that with the conventional ligand DPPP (2a) can be attributed to the unique 1,2-insertion of the fluoroalkene into acylpalladium species. The existence of an electronegative substituent on the alpha-carbon of the palladium center is successfully avoided in the 1,2-insertion mechanism.

  11. Dielectrophoretic assembly of carbon nanotube devices

    DEFF Research Database (Denmark)

    Dimaki, Maria

    The purpose of this project has been to assemble single-walled carbon nanotubes on electrodes at the tip of a biocompatible cantilever and use these for chemical species sensing in air and liquid, for example in order to measure the local activity from ion channels in the cell membrane....... The electrical resistance of carbon nanotubes has been shown to be extremely sensitive to gas molecules. Dielectrophoresis is a method capable of quickly attracting nanotubes on microelectrodes by using an electric field, thus enabling nanotube integration in microsystems. Dielectrophoresis offers also....... A model for the dielectrophoretic assembly of carbon nanotubes on microelectrodes was developed and several simulations were conducted using values from the available literature for the various key parameters. The model can give qualitative results regarding the parameters dominating the dielectrophoretic...

  12. A Retrospective Analysis of Pediatric Patients Admitted to the Pediatric Emergency Service for Carbon Monoxide Intoxication

    OpenAIRE

    Metin Uysalol; Ezgi Paslı Uysalol; Gamze Varol Saraçoğlu; Semra Kayaoğlu

    2011-01-01

    Objective: The aim of the study is to analyze the general aspects of cases with carbon monoxide intoxication in order to improve the approach to future patients. Material and Methods: The hospital records of 84 children (mean age 4.71±2.64 years; 48 male, 36 female) who had been admitted to Paediatric Emergency Department for carbon monoxide intoxication between October 2007 and February 2009, were retrospectively evaluated in a descriptive analysis.Results: The source of carbon monoxide into...

  13. Carbon nanotube fiber spun from wetted ribbon

    Science.gov (United States)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  14. Methods for producing reinforced carbon nanotubes

    Science.gov (United States)

    Ren, Zhifen [Newton, MA; Wen, Jian Guo [Newton, MA; Lao, Jing Y [Chestnut Hill, MA; Li, Wenzhi [Brookline, MA

    2008-10-28

    Methods for producing reinforced carbon nanotubes having a plurality of microparticulate carbide or oxide materials formed substantially on the surface of such reinforced carbon nanotubes composite materials are disclosed. In particular, the present invention provides reinforced carbon nanotubes (CNTs) having a plurality of boron carbide nanolumps formed substantially on a surface of the reinforced CNTs that provide a reinforcing effect on CNTs, enabling their use as effective reinforcing fillers for matrix materials to give high-strength composites. The present invention also provides methods for producing such carbide reinforced CNTs.

  15. Carbon Nanotubes as Optical Sensors in Biomedicine.

    Science.gov (United States)

    Farrera, Consol; Torres Andón, Fernando; Feliu, Neus

    2017-11-28

    Single-walled carbon nanotubes (SWCNTs) have become potential candidates for a wide range of medical applications including sensing, imaging, and drug delivery. Their photophysical properties (i.e., the capacity to emit in the near-infrared), excellent photostability, and fluorescence, which is highly sensitive to the local environment, make SWCNTs promising optical probes in biomedicine. In this Perspective, we discuss the existing strategies for and challenges of using carbon nanotubes for medical diagnosis based on intracellular sensing as well as discuss also their biocompatibility and degradability. Finally, we highlight the potential improvements of this nanotechnology and future directions in the field of carbon nanotubes for biomedical applications.

  16. Carbon nanotubes : from molecular to macroscopic sensors

    NARCIS (Netherlands)

    Wood, J.R.; Zhao, Qing; Frogley, M.D.; Meurs, E.R.; Prins, A.D.; Peijs, A.A.J.M.; Dunstan, D.J.; Wagner, H.D.

    2000-01-01

    The components that contribute to Raman spectral shifts of single-wall carbon nanotubes (SWNT’s) embedded in polymer systems have been identified. The temperature dependence of the Raman shift can be separated into the temperature dependence of the nanotubes, the cohesive energy density of the

  17. XPS study on the surface reaction of uranium metal with carbon monoxide at 200 degree C

    International Nuclear Information System (INIS)

    Wang Xiaoling; Fu Yibei; Xie Renshou; Huang Ruiliang

    1996-12-01

    The surface reaction of uranium metal with carbon monoxide at 200 degree C has been studied by X-ray photoelectron spectroscopy (XPS). The carbon monoxide adsorption on the surface oxide layer resulted in U4f peak shifting to the lower binding energy and the content of oxygen in the oxide is decreased. O/U radio decreases with increasing the exposure of carbon monoxide to the surface layer. The investigation indicated the surface layer of uranium metal was further reduced in the atmosphere of carbon monoxide at high temperature. (3 refs., 5 figs.)

  18. Study on the surface oxidation resistance of uranium metal in the atmosphere of carbon monoxide

    International Nuclear Information System (INIS)

    Wang Xiaolin; Fu Yibei; Xie Renshou

    1999-01-01

    The surface reactions of different layers on uranium metal with carbon monoxide at 25, 80 and 200 degree C are studied by X-ray photoelectron spectroscopy (XPS). The experimental results show that the carbon monoxide is adsorbed on the surface oxide layer of uranium and interacted each other. The content of oxygen in the surface oxide and O/U ratio are decreased with increasing the exposure of carbon monoxide to the surface layer. The effect of reduction on the metal surface is more obviously with a higher temperature and increasing of layer thickness. The investigation indicates the uranium metal has resistance to further oxidation in the atmosphere of carbon monoxide

  19. Quantum conductance of carbon nanotube peapods

    International Nuclear Information System (INIS)

    Yoon, Young-Gui; Mazzoni, Mario S.C.; Louie, Steven G.

    2003-01-01

    We present a first-principles study of the quantum conductance of hybrid nanotube systems consisting of single-walled carbon nanotubes (SWCNTs) encapsulating either an isolated single C60 molecule or a chain of C60 molecules (nanotube peapods). The calculations show a rather weak bonding interaction between the fullerenes and the SWCNTs. The conductance of a (10,10) SWCNT with a single C60 molecule is virtually unaffected at the Fermi level, but exhibits quantized resonant reductions at the molecular levels. The nanotube peapod arrangement gives rise to high density of states for the fullerene highest occupied molecular orbital and lowest unoccupied molecular orbital bands

  20. Glucose oxidase immobilization onto carbon nanotube networking

    International Nuclear Information System (INIS)

    Karachevtsev, V.A.; Glamazda, A.Yu.; Zarudnev, E.S.; Karachevtsev, M.V.; Leontiev, V.S.; Linnik, A.S.; Plokhotnichenko, A.M.; Stepanian, S.G.; Lytvyn, O.S.

    2012-01-01

    The efficient immobilization of GOX onto a carbon nanotube network through the molecular interface formed by PSE is carried out. This conclusion is based on the analysis of AFM images of the network with the adsorbed enzyme, whose globules locate mainly along a nanotube. The band corresponding to the high-frequency component of the G mode in the RR spectrum of the nanotube with adsorbed PSE is downshifted by 0.7 cm -1 relative to this band in the spectrum of pristine nanotubes. The analysis of the intensities of bands assigned to the RBM of nanotubes with adsorbed PSE in comparison with the spectrum of pristine SWNTs revealed the intensity transformation, which can be explained by a change of the resonance condition with variation of the laser energy. Thus, we concluded that PSE molecules create nanohybrids with SWNTs, which ensures the further enzyme immobilization. As the RR spectrum of an SWNT:PSE:GOX film does not essentially differ from SWNT:PSE ones, this indicates that the molecular interface (PSE) isolates the enzyme from nanotubes strongly enough. Our studies on the conductive properties of a single walled carbon nanotube network sprayed onto a quartz substrate from a solution of nanotubes in dichlorobenzene demonstrated that the I(U) dependence has nonlinear character. Most likely, the nonlinearity is related to Schottky barriers, which originate on the contact between nanotubes and the gold electrode, as well as between nanotubes with different conductivities. The deposition of bioorganic compounds (PSE and GOX) on the carbon nanotube network is accompanied by a decrease of their conductivity. Most probably, such a decrease is caused by adsorbed PSE molecules, which induce the appearance of scattering centers for charge carriers on the nanotube surface. The following GOX adsorption has practically no effect on the conductivity of the nanotube network that evidences the reliable isolation of the nanotube surface from the enzyme by means of the molecular

  1. Multiwall carbon nanotube microcavity arrays

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Rajib; Butt, Haider, E-mail: h.butt@bham.ac.uk [Nanotechnology Laboratory, School of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT (United Kingdom); Rifat, Ahmmed A. [Integrated Lightwave Research Group, Department of Electrical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603 (Malaysia); Yetisen, Ali K.; Yun, Seok Hyun [Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, Massachusetts 02139 (United States); Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Dai, Qing [National Center for Nanoscience and Technology, Beijing 100190 (China)

    2016-03-21

    Periodic highly dense multi-wall carbon nanotube (MWCNT) arrays can act as photonic materials exhibiting band gaps in the visible regime and beyond terahertz range. MWCNT arrays in square arrangement for nanoscale lattice constants can be configured as a microcavity with predictable resonance frequencies. Here, computational analyses of compact square microcavities (≈0.8 × 0.8 μm{sup 2}) in MWCNT arrays were demonstrated to obtain enhanced quality factors (≈170–180) and narrow-band resonance peaks. Cavity resonances were rationally designed and optimized (nanotube geometry and cavity size) with finite element method. Series (1 × 2 and 1 × 3) and parallel (2 × 1 and 3 × 1) combinations of microcavities were modeled and resonance modes were analyzed. Higher order MWCNT microcavities showed enhanced resonance modes, which were red shifted with increasing Q-factors. Parallel microcavity geometries were also optimized to obtain narrow-band tunable filtering in low-loss communication windows (810, 1336, and 1558 nm). Compact series and parallel MWCNT microcavity arrays may have applications in optical filters and miniaturized optical communication devices.

  2. Mixing ratios of carbon monoxide in the troposphere

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, P.C.; Steele, L.P. (Univ. of Colorado, Boulder (United States)); Tans, P.P. (NOAA, Boulder, CO (United States))

    1992-12-20

    Carbon monoxide (CO) mixing ratios were measured in air samples collected weekly at eight locations. The air was collected as part of the CMDL/NOAA cooperative flask sampling program (Climate Monitoring and Diagnostics Laboratory, formerly Geophysical Monitoring for Climatic Change, Air Resources Laboratory/National Oceanic and Atmospheric Administration) at Point Barrow, Alaska, Niwot Ridge, Colorado, Mauna Loa and Cape Kumakahi, Hawaii, Guam, Marianas Islands, Christmas Island, Ascension Island and American Samoa. Half-liter or 3-L glass flasks fitted with glass piston stopcocks holding teflon O rings were used for sample collection. CO levels were determined within several weeks of collection using gas chromatography followed by mercuric oxide reduction detection, and mixing ratios were referenced against the CMDL/NOAA carbon monoxide standard scale. During the period of study (mid-1988 through December 1990) CO levels were greatest in the high latitudes of the northern hemisphere (mean mixing ratio from January 1989 to December 1990 at Point Barrow was approximately 154 ppb) and decreased towards the south (mean mixing ratio at Samoa over a similar period was 65 ppb). Mixing ratios varied seasonally, the amplitude of the seasonal cycle was greatest in the north and decreased to the south. Carbon monoxide levels were affected by both local and regional scale processes. The difference in CO levels between northern and southern latitudes also varied seasonally. The greatest difference in CO mixing ratios between Barrow and Samoa was observed during the northern winter (about 150 ppb). The smallest difference, 40 ppb, occurred during the austral winter. The annually averaged CO difference between 71[degrees]N and 14[degrees]S was approximately 90 ppb in both 1989 and 1990; the annually averaged interhemispheric gradient from 71[degrees]N to 41[degrees]S is estimated as approximately 95 ppb. 66 refs., 5 figs., 5 tabs.

  3. Pathology of carbon monoxide poisoning in two cats.

    Science.gov (United States)

    Sobhakumari, Arya; Poppenga, Robert H; Pesavento, J Brad; Uzal, Francisco A

    2018-03-05

    Carbon monoxide (CO), a common cause of poisoning in human beings has also been implicated in the death of animals. Though there are multiple studies on CO poisoning and relevant lethal blood COHb concentrations in humans, there are no reliable reports of diagnostic lethal carboxyhemoglobin percentage of saturation (COHb%) in cats. Additionally, due to shared housing environments, exposures to companion animals can be a surrogate for lethal exposures in human beings and provide valuable information in concurrent forensic investigations. Two adult Singapura brown ticked cats were submitted to the California Animal Health and Food Safety Laboratory (CAHFS) for necropsy and diagnostic work-up. These animals were found dead along with their two deceased owners. Similar lesions were observed in both cats. At necropsy, gross lesions consisted of multifocal, large, irregular, bright red spots on the skin of the abdomen and the inner surface of ear pinnae, bright red muscles and blood. The carcasses, and tissues fixed in formalin retained the bright red discoloration for up to two weeks. Microscopic lesions included diffuse pulmonary congestion and edema, and multifocal intense basophilia of cardiomyocytes mostly affecting whole fibers or occasionally a portion of the fiber. Based on the clinical history,gross and microscopic changes, cyanide or carbon monoxide poisoning was suspected. Blood samples analyzed for carbon monoxide showed 57 and 41% carboxyhemoglobin COHb%. Muscle samples were negative for cyanide. There are no established reference values for lethal COHb concentration in cats. The COHb % values detected in this case which fell within the lethal range reported for other species, along with the gross lesions and unique histological findings in the heart suggest a helpful criteria for diagnosis of CO intoxication associated death in cats. This case demonstrates that since pets share the same environment as human beings and often are a part of their activities

  4. Filled and empty states of carbon nanotubes in water: Dependence ...

    Indian Academy of Sciences (India)

    WINTEC

    We have carried out a series of molecular dynamics simulations of water containing a narrow carbon nanotube ..... tant system containing the nanotube is re-equilibrated for each ... quent production phase of the simulation run, the nanotube is ...

  5. Functionalization of carbon nanotubes with silver clusters

    International Nuclear Information System (INIS)

    Cveticanin, Jelena; Krkljes, Aleksandra; Kacarevic-Popovic, Zorica; Mitric, Miodrag; Rakocevic, Zlatko; Trpkov, Djordje; Neskovic, Olivera

    2010-01-01

    In this paper, an advanced method of one-step functionalization of single and multi walled carbon nanotubes (SWCNTs and MWCNTs) using γ-irradiation was described. Two synthesis procedures, related with different reduction species, were employed. For the first time, poly(vinyl alcohol) PVA is successfully utilized as a source to reduce silver (Ag) metal ions without having any additional reducing agents to obtain Ag nanoparticles on CNTs. The decoration of carbon nanotubes with Ag nanoparticles takes place through anchoring of (PVA) on nanotube's surface. Optical properties of as-prepared samples and mechanism responsible for the functionalization of carbon nanotubes were investigated using UV-vis and FTIR spectroscopy, respectively. Decorated carbon nanotubes were visualized using microscopic techniques: transmission electron microscopy and scanning tunneling microscopy. Also, the presence of Ag on the nanotubes was confirmed using energy dispersive X-ray spectroscopy. This simple and effective method of making a carbon nanotube type of composites is of interest not only for an application in various areas of technology and biology, but for investigation of the potential of radiation technology for nanoengineering of materials.

  6. Chlorination of niobium oxide in the presence of carbon monoxide

    International Nuclear Information System (INIS)

    Freitas, L.R. de

    1984-01-01

    The chlorination kinetics of niobium pentoxide in the presence of carbon monoxide between 500-800 0 C of temperature is studied. The following variable that influences on the reaction rate are analysed: gas flow, geometry and volume of the Nb 2 O 5 samples, reaction temperature and composition of the chlorinated mixture. At the same time, two other materials were studied: the CaO.Nb 2 O 5 (synthetized in laboratory) and pyrochlorine concentrates. The three materials are compared for the chlorination method used. (M.A.C.) [pt

  7. Thermodynamic properties of liquid mixtures of carbon monoxide and methane

    Energy Technology Data Exchange (ETDEWEB)

    Calado, J.C.G.; Guedes, H.J.R.; Nunes da Ponte, M.; Streett, W.B.

    1984-04-01

    Researchers conducted pressure-volume-temperature measurements of liquid methane at -230/sup 0/F and of six liquid mixtures of carbon monoxide and methane at -250/sup 0/, -240/sup 0/, and -230/sup 0/F from just above the saturation vapor pressure to the freezing pressure of methane. The excess volume proved to be large and negative at low pressures but less negative as the pressure increased, being almost zero at the highest pressure. Of the thermodynamic functions, excess enthalpy and excess entropy were much more sensitive to pressure than excess Gibbs energy. Conformal solution theory in the van der Waals one-fluid form reproduced the experimental results very successfully.

  8. Pathways and bioenergetics of anaerobic carbon monoxide fermentation.

    Directory of Open Access Journals (Sweden)

    Martijn eDiender

    2015-11-01

    Full Text Available Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the potential of converting CO rich gas, such as synthesis gas, into bio-based products. Three main types of fermentative CO metabolism can be distinguished: hydrogenogenesis, methanogenesis and acetogenesis, generating hydrogen, methane and acetate, respectively. Here, we review the current knowledge on these three variants of microbial CO metabolism with an emphasis on the potential enzymatic routes and bio-energetics involved.

  9. Pathways and Bioenergetics of Anaerobic Carbon Monoxide Fermentation.

    Science.gov (United States)

    Diender, Martijn; Stams, Alfons J M; Sousa, Diana Z

    2015-01-01

    Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the potential of converting CO-rich gas, such as synthesis gas, into bio-based products. Three main types of fermentative CO metabolism can be distinguished: hydrogenogenesis, methanogenesis, and acetogenesis, generating hydrogen, methane and acetate, respectively. Here, we review the current knowledge on these three variants of microbial CO metabolism with an emphasis on the potential enzymatic routes and bio-energetics involved.

  10. Raman spectra of filled carbon nanotubes

    International Nuclear Information System (INIS)

    Bose, S.M.; Behera, S.N.; Sarangi, S.N.; Entel, P.

    2004-01-01

    The Raman spectra of a metallic carbon nanotube filled with atoms or molecules have been investigated theoretically. It is found that there will be a three way splitting of the main Raman lines due to the interaction of the nanotube phonon with the collective excitations (plasmons) of the conduction electrons of the nanotube as well as its coupling with the phonon of the filling material. The positions and relative strengths of these Raman peaks depend on the strength of the electron-phonon interaction, phonon frequency of the filling atom and the strength of interaction of the nanotube phonon and the phonon of the filling atoms. Careful experimental studies of the Raman spectra of filled nanotubes should show these three peaks. It is also shown that in a semiconducting nanotube the Raman line will split into two and should be observed experimentally

  11. Functionalized carbon nanotubes: biomedical applications

    Science.gov (United States)

    Vardharajula, Sandhya; Ali, Sk Z; Tiwari, Pooja M; Eroğlu, Erdal; Vig, Komal; Dennis, Vida A; Singh, Shree R

    2012-01-01

    Carbon nanotubes (CNTs) are emerging as novel nanomaterials for various biomedical applications. CNTs can be used to deliver a variety of therapeutic agents, including biomolecules, to the target disease sites. In addition, their unparalleled optical and electrical properties make them excellent candidates for bioimaging and other biomedical applications. However, the high cytotoxicity of CNTs limits their use in humans and many biological systems. The biocompatibility and low cytotoxicity of CNTs are attributed to size, dose, duration, testing systems, and surface functionalization. The functionalization of CNTs improves their solubility and biocompatibility and alters their cellular interaction pathways, resulting in much-reduced cytotoxic effects. Functionalized CNTs are promising novel materials for a variety of biomedical applications. These potential applications are particularly enhanced by their ability to penetrate biological membranes with relatively low cytotoxicity. This review is directed towards the overview of CNTs and their functionalization for biomedical applications with minimal cytotoxicity. PMID:23091380

  12. Carbon nanotubes based vacuum gauge

    Science.gov (United States)

    Rudyk, N. N.; Il'in, O. I.; Il'ina, M. V.; Fedotov, A. A.; Klimin, V. S.; Ageev, O. A.

    2017-11-01

    We have created an ionization type Vacuum gauge with sensor element based on an array of vertically aligned carbon nanotubes. Obtained asymmetrical current-voltage characteristics at different voltage polarity on the electrode with the CNTs. It was found that when applying a negative potential on an electrode with the CNTs, the current in the gap is higher than at a positive potential. In the pressure range of 1 ÷ 103 Torr vacuum gauge sensitivity was 6 mV/Torr (at a current of 4.5·10-5 A) and in the range of 10-5 ÷ 1 Torr was 10 mV/Torr (at a current of 1.3·10-5 A). It is shown that the energy efficiency of vacuum gauge can be increased in the case where electrode with CNT operates as an emitter of electrons.

  13. Carbon Nanotube Tape Vibrating Gyroscope

    Science.gov (United States)

    Tucker, Dennis Stephen (Inventor)

    2016-01-01

    A vibrating gyroscope includes a piezoelectric strip having length and width dimensions. The piezoelectric strip includes a piezoelectric material and carbon nanotubes (CNTs) substantially aligned and polled along the strip's length dimension. A spindle having an axis of rotation is coupled to the piezoelectric strip. The axis of rotation is parallel to the strip's width dimension. A first capacitance sensor is mechanically coupled to the spindle for rotation therewith. The first capacitance sensor is positioned at one of the strip's opposing ends and is spaced apart from one of the strip's opposing faces. A second capacitance sensor is mechanically coupled to the spindle for rotation therewith. The second capacitance sensor is positioned at another of the strip's opposing ends and is spaced apart from another of the strip's opposing faces. A voltage source applies an AC voltage to the piezoelectric strip.

  14. Enhanced Carbon Nanotube Ultracapacitors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation utilizes carbon nanotubes (CNTs) coated with pseudo-capacitive MnO2 material as nano-composite electrode and ionic electrolyte for the...

  15. Nanoscratch technique for aligning multiwalled carbon nanotubes ...

    Indian Academy of Sciences (India)

    Carbon nanotube; arc discharge; characterization; alignment; nanoscratch. 1. Introduction ... During arc discharge, when the gap between the electrodes is ∼ 1 mm, ..... increase in the D band intensity in the aligned region may not be possibly ...

  16. Carbon Nanotube Infused Launch Vehicle Structures

    Data.gov (United States)

    National Aeronautics and Space Administration — For the past 5 years Orbital ATK has been investing in, prototyping, and testing carbon nanotube infused composite structures to evaluate their impact on launch...

  17. Thermophoresis of water droplets inside carbon nanotubes

    DEFF Research Database (Denmark)

    Zambrano, Harvey; Walther, Jens Honore; Oyarzua, Elton

    2016-01-01

    Carbon Nanotubes(CNTs) offer unique possibilities as fluid conduits with applications ranging from lab on a chip devices to encapsulation media for drug delivery. CNTs feature high mechanical strength, chemical and thermalstability and biocompatibility therefore they are promising candidates...

  18. Carbon Nano-Tube (CNT) Reinforced COPV

    Data.gov (United States)

    National Aeronautics and Space Administration — Reduce the structural mass of future aerospace vehicles through the development of ultra lightweight materials and structures through the use of: Carbon nanotube...

  19. Synthesis and characterization of carbon nanotubes

    Science.gov (United States)

    Ritschel, Manfred; Bartsch, Karl; Leonhardt, Albrecht; Graff, Andreas; Täschner, Christine; Fink, Jörg

    2001-11-01

    The catalytic chemical vapor deposition (CCVD) is a very promising process with respect to large scale production of different kinds of carbon nanostructures. By modifying the deposition temperature, the catalyst material and the hydrocarbon nanofibers with herringbone structure, multi-walled nanotubes with tubular structure and single-walled nanotubes were deposited. Furthermore, layers of aligned multi-walled nanotubes could be obtained on oxidized silicon substrates coated with thin sputtered metal layers (Co, permalloy) as well as onto WC-Co hardmetals by using the microwave assisted plasma CVD process (MWCVD). The obtained carbon modifications were characterized by scanning (SEM) and transmission (TEM) electron microscopy. The hydrogen storage capability of the nanofibers and nanotubes and the electron field emission of the nanotube layers was investigated.

  20. Carbon nanotube temperature and pressure sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Ilia N.; Geohegan, David B.

    2017-09-12

    The present invention, in one embodiment, provides a method of measuring pressure or temperature using a sensor including a sensor element composed of a plurality of carbon nanotubes. In one example, the resistance of the plurality of carbon nanotubes is measured in response to the application of temperature or pressure. The changes in resistance are then recorded and correlated to temperature or pressure. In one embodiment, the present invention provides for independent measurement of pressure or temperature using the sensors disclosed herein.

  1. Carbon nanotube temperature and pressure sensors

    Science.gov (United States)

    Ivanov, Ilia N; Geohegan, David Bruce

    2013-10-29

    The present invention, in one embodiment, provides a method of measuring pressure or temperature using a sensor including a sensor element composed of a plurality of carbon nanotubes. In one example, the resistance of the plurality of carbon nanotubes is measured in response to the application of temperature or pressure. The changes in resistance are then recorded and correlated to temperature or pressure. In one embodiment, the present invention provides for independent measurement of pressure or temperature using the sensors disclosed herein.

  2. Controlled Deposition and Alignment of Carbon Nanotubes

    Science.gov (United States)

    Smits, Jan M. (Inventor); Wincheski, Russell A. (Inventor); Patry, JoAnne L. (Inventor); Watkins, Anthony Neal (Inventor); Jordan, Jeffrey D. (Inventor)

    2012-01-01

    A carbon nanotube (CNT) attraction material is deposited on a substrate in the gap region between two electrodes on the substrate. An electric potential is applied to the two electrodes. The CNT attraction material is wetted with a solution defined by a carrier liquid having carbon nanotubes (CNTs) suspended therein. A portion of the CNTs align with the electric field and adhere to the CNT attraction material. The carrier liquid and any CNTs not adhered to the CNT attraction material are then removed.

  3. Solution-phase synthesis of chromium-functionalized single-walled carbon nanotubes

    KAUST Repository

    Kalinina, Irina V.

    2015-03-01

    The solution phase reactions of single-walled carbon nanotubes (SWNTs) with Cr(CO)6 and benzene-Cr(CO)3 can lead to the formation of small chromium clusters. The cluster size can be varied from less than 1 nm to about 4 nm by increasing the reaction time. TEM images suggest that the clusters are deposited predominantly on the exterior walls of the nanotubes. TGA analysis was used to obtain the Cr content and carbon to chromium ratio in the Cr-complexed SWNTs. It is suggested that the carbon nanotube benzenoid structure templates the condensation of chromium atoms and facilitates the loss of carbon monoxide leading to well defined metal clusters.

  4. Solution-phase synthesis of chromium-functionalized single-walled carbon nanotubes

    KAUST Repository

    Kalinina, Irina V.; Al-Hadeethi, Yas Fadel; Bekyarova, Elena; Zhao, Chao; Wang, Qingxiao; Zhang, Xixiang; Al-Zahrani, Ali; Al-Agel, Faisal Abdulaziz M; Al-Marzouki, Fahad M.; Haddon, Robert C.

    2015-01-01

    The solution phase reactions of single-walled carbon nanotubes (SWNTs) with Cr(CO)6 and benzene-Cr(CO)3 can lead to the formation of small chromium clusters. The cluster size can be varied from less than 1 nm to about 4 nm by increasing the reaction time. TEM images suggest that the clusters are deposited predominantly on the exterior walls of the nanotubes. TGA analysis was used to obtain the Cr content and carbon to chromium ratio in the Cr-complexed SWNTs. It is suggested that the carbon nanotube benzenoid structure templates the condensation of chromium atoms and facilitates the loss of carbon monoxide leading to well defined metal clusters.

  5. Ballistic resistance capacity of carbon nanotubes

    International Nuclear Information System (INIS)

    Mylvaganam, Kausala; Zhang, L C

    2007-01-01

    Carbon nanotubes have high strength, light weight and excellent energy absorption capacity and therefore have great potential applications in making antiballistic materials. By examining the ballistic impact and bouncing-back processes on carbon nanotubes, this investigation shows that nanotubes with large radii withstand higher bullet speeds and the ballistic resistance is the highest when the bullet hits the centre of the CNT; the ballistic resistance of CNTs will remain the same on subsequent bullet strikes if the impact is after a small time interval

  6. Method for nano-pumping using carbon nanotubes

    Science.gov (United States)

    Insepov, Zeke [Darien, IL; Hassanein, Ahmed [Bolingbrook, IL

    2009-12-15

    The present invention relates generally to the field of nanotechnology, carbon nanotubes and, more specifically, to a method and system for nano-pumping media through carbon nanotubes. One preferred embodiment of the invention generally comprises: method for nano-pumping, comprising the following steps: providing one or more media; providing one or more carbon nanotubes, the one or more nanotubes having a first end and a second end, wherein said first end of one or more nanotubes is in contact with the media; and creating surface waves on the carbon nanotubes, wherein at least a portion of the media is pumped through the nanotube.

  7. The Future of Carbon Monoxide Measurements from Space

    Science.gov (United States)

    Drummond, J.

    It is now over 20 years since the Measurements of Air Pollution from Space MAPS instrument made the first measurements of tropospheric carbon monoxide from the shuttle Since that time a number of instruments have flown including the Measurements Of Pollution In The Troposphere MOPITT Tropospheric Emission Spectrometer TES and SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY SCIAMCHY to name only three of many Each of these instruments has a unique observing method and unique mission characteristics It is accepted that measurements of carbon monoxide provide a useful proxy of the pollution of the troposphere and contribute significantly to studies of various phenomena in the atmosphere and atmosphere-surface interactions These measurements should therefore be continued -- but in what form Technology has progresses significantly since the current generation of instruments was designed and our ability to interpret the data from such instrumentation has likewise expanded It is therefore fruitful to consider what is the best set of measurements that can be made which parameters should be emphasized and which compromised on the way to the next generation of sensors The Measurements of Air Pollution Levels in the Environment MAPLE instrument is a study financed by the Canadian Space Agency to design a next-generation instrument and since instrument spacecraft and mission are now intimately linked a consideration of the whole mission is appropriate This talk will outline some potential developments in the hardware

  8. A carbon monoxide passive sampler: Research and development needs

    Energy Technology Data Exchange (ETDEWEB)

    Traynor, G.W.; Apte, M.G.; Diamond, R.C.; Woods, A.L.

    1991-11-01

    In rare instances, carbon monoxide (CO) levels in houses can reach dangerously high concentrations, causing adverse health effects ranging from mild headaches to, under extreme conditions, death. Hundreds of fatal accidental carbon monoxide poisonings occur each year primarily due to the indoor operation of motor vehicles, the indoor use of charcoal for cooking, the operation of malfunctioning vented and unvented combustion appliances, and the misuse combustion appliances. Because there is a lack of simple, inexpensive, and accurate field sampling instrumentation, it is difficult for gas utilities and researchers to conduct field research studies designed to quantify the concentrations of CO in residences. Determining the concentration of CO in residences is the first step towards identifying the high risk appliances and high-CO environments which pose health risks. Thus, there exists an urgent need to develop and field-validate a CO-quantifying technique suitable for affordable field research. A CO passive sampler, if developed, could fulfill these requirements. Existing CO monitoring techniques are discussed as well as three potential CO-detection methods for use in a CO passive sampler. Laboratory and field research needed for the development and validation of an effective and cost-efficient CO passive sampler are also discussed.

  9. Cumulative exposure to carbon monoxide during the day

    Energy Technology Data Exchange (ETDEWEB)

    Joumard, R. (INRETS, 69 - Bron (FR))

    The carbon monoxide, CO, has the advantage of being very easily and accurately measured under various conditions. In addition, it allows the translation of CO concentrations into their biological effects. The cumulative CO exposure should be considered according to current environment conditions during a given period of life, e.g. the day. In addition, the translation of concentrations and exposure times of CO fixed on blood haemoglobine (carboxyhaemoglobine) depends on physiological factors such as age, size, sex, or physical activity. This paper gives some examples of CO exposure translated into curves of carboxyhaemoglobine: case of 92 persons whose schedule was studied in details, of customs officers whose exposure was measured during one week, or other theoretical cases. In all the cases studied, smoking is by far the first factor of pollution by carbon monoxide. If not considering this case, the CO contents observed are preoccupying for sensitive subjects (in particular children) only in very rare cases. Furthermore, this approach allows the assessment of maximal allowable concentrations during specific exposures (work, e.g. in a tunnel) by integrating them into normal life conditions and population current exposure.

  10. Amorphous molecular junctions produced by ion irradiation on carbon nanotubes

    International Nuclear Information System (INIS)

    Wang Zhenxia; Yu Liping; Zhang Wei; Ding Yinfeng; Li Yulan; Han Jiaguang; Zhu Zhiyuan; Xu Hongjie; He Guowei; Chen Yi; Hu Gang

    2004-01-01

    Experiments and molecular dynamics have demonstrated that electron irradiation could create molecular junctions between crossed single-wall carbon nanotubes. Recently molecular dynamics computation predicted that ion irradiation could also join single-walled carbon nanotubes. Employing carbon ion irradiation on multi-walled carbon nanotubes, we find that these nanotubes evolve into amorphous carbon nanowires, more importantly, during the process of which various molecular junctions of amorphous nanowires are formed by welding from crossed carbon nanotubes. It demonstrates that ion-beam irradiation could be an effective way not only for the welding of nanotubes but also for the formation of nanowire junctions

  11. Functionalization of vertically aligned carbon nanotubes.

    Science.gov (United States)

    Van Hooijdonk, Eloise; Bittencourt, Carla; Snyders, Rony; Colomer, Jean-François

    2013-01-01

    This review focuses and summarizes recent studies on the functionalization of carbon nanotubes oriented perpendicularly to their substrate, so-called vertically aligned carbon nanotubes (VA-CNTs). The intrinsic properties of individual nanotubes make the VA-CNTs ideal candidates for integration in a wide range of devices, and many potential applications have been envisaged. These applications can benefit from the unidirectional alignment of the nanotubes, the large surface area, the high carbon purity, the outstanding electrical conductivity, and the uniformly long length. However, practical uses of VA-CNTs are limited by their surface characteristics, which must be often modified in order to meet the specificity of each particular application. The proposed approaches are based on the chemical modifications of the surface by functionalization (grafting of functional chemical groups, decoration with metal particles or wrapping of polymers) to bring new properties or to improve the interactions between the VA-CNTs and their environment while maintaining the alignment of CNTs.

  12. An Unusual Cause of Supraventricular Tachycardia: Acute Carbon Monoxide Poisoning

    Directory of Open Access Journals (Sweden)

    Suat Zengin

    2014-03-01

    Full Text Available      Carbon monoxide (CO is a toxic gas produced by the incomplete combustion of carbon-containing compounds. Exposure to high concentrations of CO can be letha and is the most common cause of death from poisoning worldwide. Cardiac manifestations after exposure to CO, including myocardial ischemia, heart failure, and arrhythmias, have been reported. A 28-year-old a patient was admitted to our emergency department with altered consciousness as a consequence of acute domestic exposure to CO from a stove. His carboxyhemoglobin level was 39%. The oxygen treatment was started promptly, and therapeutic red cell exchange was performed. An electrocardiogram revealed supraventricular tachycardia (SVT, and an echocardiographic examination demonstrated normal cardiac functions. To the best of our knowledge, this study is the second to report a case of SVT attack due to acute CO intoxication. This paper discusses the management of this complication in patients poisoned with CO.

  13. Carbon nanotube stationary phases for microchip electrochromatography

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; Bøggild, Peter; Kutter, Jörg Peter

    , microfluidic devices with microfabricated carbon nanotube columns for electrochromatographic separations will be presented. The electrically conductive carbon nanotube layer has been patterned into hexoganol micropillars in order to support electroosmotic flow without forming gas bubbles from electrolysis......The use of nanomaterials in separation science has increased rapidly in the last decade. The reason for this is to take advantage of the unique properties of these materials, such as a very high surface-to-volume ratio and favourable sorbent behaviour. Carbon nanostructures, such as carbon...

  14. Polymerization initated at sidewalls of carbon nanotubes

    Science.gov (United States)

    Tour, James M. (Inventor); Hudson, Jared L. (Inventor); Krishnamoorti, Ramanan (Inventor); Yurekli, Koray (Inventor); Mitchell, Cynthia A. (Inventor)

    2011-01-01

    The present invention is directed to aryl halide (such as aryl bromide) functionalized carbon nanotubes that can be utilized in anionic polymerization processes to form polymer-carbon nanotube materials with improved dispersion ability in polymer matrices. In this process the aryl halide is reacted with an alkyllithium species or is reacted with a metal to replace the aryl-bromine bond with an aryl-lithium or aryl-metal bond, respectively. It has further been discovered that other functionalized carbon nanotubes, after deprotonation with a deprotonation agent, can similarly be utilized in anionic polymerization processes to form polymer-carbon nanotube materials. Additionally or alternatively, a ring opening polymerization process can be performed. The resultant materials can be used by themselves due to their enhanced strength and reinforcement ability when compared to their unbound polymer analogs. Additionally, these materials can also be blended with pre-formed polymers to establish compatibility and enhanced dispersion of nanotubes in otherwise hard to disperse matrices resulting in significantly improved material properties. The resultant polymer-carbon nanotube materials can also be used in drug delivery processes due to their improved dispersion ability and biodegradability, and can also be used for scaffolding to promote cellular growth of tissue.

  15. 40 CFR 51.241 - Nonattainment areas for carbon monoxide and ozone.

    Science.gov (United States)

    2010-07-01

    ... Intergovernmental Consultation Agency Designation § 51.241 Nonattainment areas for carbon monoxide and ozone. (a... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Nonattainment areas for carbon monoxide and ozone. 51.241 Section 51.241 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

  16. Carbon monoxide may be an important molecule in migraine and other headaches

    DEFF Research Database (Denmark)

    Arngrim, Nanna; Schytz, Henrik W; Hauge, Mette K

    2014-01-01

    INTRODUCTION: Carbon monoxide was previously considered to just be a toxic gas. A wealth of recent information has, however, shown that it is also an important endogenously produced signalling molecule involved in multiple biological processes. Endogenously produced carbon monoxide may thus play...

  17. Carbon Nanotube Templated Microfabrication of Porous Silicon-Carbon Materials

    Science.gov (United States)

    Song, Jun; Jensen, David; Dadson, Andrew; Vail, Michael; Linford, Matthew; Vanfleet, Richard; Davis, Robert

    2010-10-01

    Carbon nanotube templated microfabrication (CNT-M) of porous materials is demonstrated. Partial chemical infiltration of three dimensional carbon nanotube structures with silicon resulted in a mechanically robust material, precisely structured from the 10 nm scale to the 100 micron scale. Nanoscale dimensions are determined by the diameter and spacing of the resulting silicon/carbon nanotubes while the microscale dimensions are controlled by lithographic patterning of the CNT growth catalyst. We demonstrate the utility of this hierarchical structuring approach by using CNT-M to fabricate thin layer chromatography (TLC) separations media with precise microscale channels for fluid flow control and nanoscale porosity for high analyte capacity.

  18. Carbon Nanotube-Based Synthetic Gecko Tapes

    Science.gov (United States)

    Dhinojwala, Ali

    2008-03-01

    Wall-climbing geckos have unique ability to attach to different surfaces without the use of any viscoelastic glues. On coming in contact with any surface, the micron-size gecko foot-hairs deform, enabling molecular contact over large areas, thus translating weak van der Waals (vdW) interactions into enormous shear forces. We will present our recent results on the development of synthetic gecko tape using aligned carbon nanotubes to mimic the keratin hairs found on gecko feet. The patterned carbon nanotube-based gecko tape can support a shear stress (36 N/cm^2) nearly four times higher than the gecko foot and sticks to a variety of surfaces, including Teflon. Both the micron-size setae (replicated by nanotube bundles) and nanometer-size spatulas (individual nanotubes) are necessary to achieve macroscopic shear adhesion and to translate the weak vdW interactions into high shear forces. The carbon nanotube based tape offers an excellent synthetic option as a dry conductive reversible adhesive in microelectronics, robotics and space applications. The mechanism behind these large shear forces and self-cleaning properties of these carbon nanotube based synthetic gecko tapes will be discussed. This work was performed in collaboration with graduate students Liehui Ge, and Sunny Sethi, and collaborators from RPI; Lijie Ci and Professor Pulickel Ajayan.

  19. Physical removal of metallic carbon nanotubes from nanotube network devices using a thermal and fluidic process

    International Nuclear Information System (INIS)

    Ford, Alexandra C; Shaughnessy, Michael; Wong, Bryan M; Kane, Alexander A; Krafcik, Karen L; Léonard, François; Kuznetsov, Oleksandr V; Billups, W Edward; Hauge, Robert H

    2013-01-01

    Electronic and optoelectronic devices based on thin films of carbon nanotubes are currently limited by the presence of metallic nanotubes. Here we present a novel approach based on nanotube alkyl functionalization to physically remove the metallic nanotubes from such network devices. The process relies on preferential thermal desorption of the alkyls from the semiconducting nanotubes and the subsequent dissolution and selective removal of the metallic nanotubes in chloroform. The approach is versatile and is applied to devices post-fabrication. (paper)

  20. Four-electron deoxygenative reductive coupling of carbon monoxide at a single metal site

    Science.gov (United States)

    Buss, Joshua A.; Agapie, Theodor

    2016-01-01

    Carbon dioxide is the ultimate source of the fossil fuels that are both central to modern life and problematic: their use increases atmospheric levels of greenhouse gases, and their availability is geopolitically constrained. Using carbon dioxide as a feedstock to produce synthetic fuels might, in principle, alleviate these concerns. Although many homogeneous and heterogeneous catalysts convert carbon dioxide to carbon monoxide, further deoxygenative coupling of carbon monoxide to generate useful multicarbon products is challenging. Molybdenum and vanadium nitrogenases are capable of converting carbon monoxide into hydrocarbons under mild conditions, using discrete electron and proton sources. Electrocatalytic reduction of carbon monoxide on copper catalysts also uses a combination of electrons and protons, while the industrial Fischer-Tropsch process uses dihydrogen as a combined source of electrons and electrophiles for carbon monoxide coupling at high temperatures and pressures. However, these enzymatic and heterogeneous systems are difficult to probe mechanistically. Molecular catalysts have been studied extensively to investigate the elementary steps by which carbon monoxide is deoxygenated and coupled, but a single metal site that can efficiently induce the required scission of carbon-oxygen bonds and generate carbon-carbon bonds has not yet been documented. Here we describe a molybdenum compound, supported by a terphenyl-diphosphine ligand, that activates and cleaves the strong carbon-oxygen bond of carbon monoxide, enacts carbon-carbon coupling, and spontaneously dissociates the resulting fragment. This complex four-electron transformation is enabled by the terphenyl-diphosphine ligand, which acts as an electron reservoir and exhibits the coordinative flexibility needed to stabilize the different intermediates involved in the overall reaction sequence. We anticipate that these design elements might help in the development of efficient catalysts for

  1. Synthesis and Characterization Carbon Nanotubes Doped Carbon Aerogels

    Science.gov (United States)

    Xu, Yuelong; Yan, Meifang; Liu, Zhenfa

    2017-12-01

    Polycondensation of phloroglucinol, resorcinol and formaldehyde with carbon nanotube (CNT) as the additives, using sodium carbonate as the catalyst, leads to the formation of CNT - doped carbon aerogels. The structure of carbon aerogels (CAs) with carbon nanotubes (CNTs) were characterized by X-ray diffraction and scanning electron microscopy. The specific surface area, pore size distribution and pore volume were measured by surface area analyzer. The results show that when the optimum doping dosage is 5%, the specific surface area of CNT - doped carbon aerogel is up to 665 m2 g-1 and exhibit plentiful mesoporous.

  2. Utility of the Measurement of Carboxyhemoglobin Level at the Site of Acute Carbon Monoxide Poisoning in Rural Areas

    OpenAIRE

    Onodera, Makoto; Fujino, Yasuhisa; Kikuchi, Satoshi; Sato, Masayuki; Mori, Kiyofumi; Beppu, Takaaki; Inoue, Yoshihiro

    2016-01-01

    Objective. This study examined the hypothesis that correlations exist between the carbon monoxide exposure time and the carboxyhemoglobin concentration at the site of carbon monoxide poisoning, using a pulse carbon monoxide oximeter in rural areas or the carboxyhemoglobin concentration measured at a given medical institution. Background. In previous studies, no definitive relationships between the arterial blood carboxyhemoglobin level and the severity of carbon monoxide poisoning have been o...

  3. Selective Functionalization of Carbon Nanotubes: Part II

    Science.gov (United States)

    Meyyappan, Meyya; Khare, Bishun

    2010-01-01

    An alternative method of low-temperature plasma functionalization of carbon nanotubes provides for the simultaneous attachment of molecular groups of multiple (typically two or three) different species or different mixtures of species to carbon nanotubes at different locations within the same apparatus. This method is based on similar principles, and involves the use of mostly the same basic apparatus, as those of the methods described in "Low-Temperature Plasma Functionalization of Carbon Nanotubes" (ARC-14661-1), NASA Tech Briefs, Vol. 28, No. 5 (May 2004), page 45. The figure schematically depicts the basic apparatus used in the aforementioned method, with emphasis on features that distinguish the present alternative method from the other. In this method, one exploits the fact that the composition of the deposition plasma changes as the plasma flows from its source in the precursor chamber toward the nanotubes in the target chamber. As a result, carbon nanotubes mounted in the target chamber at different flow distances (d1, d2, d3 . . .) from the precursor chamber become functionalized with different species or different mixtures of species. In one series of experiments to demonstrate this method, N2 was used as the precursor gas. After the functionalization process, the carbon nanotubes from three different positions in the target chamber were examined by Fourier-transform infrared spectroscopy to identify the molecular groups that had become attached. On carbon nanotubes from d1 = 1 cm, the attached molecular groups were found to be predominantly C-N and C=N. On carbon nanotubes from d2 = 2.5 cm, the attached molecular groups were found to be predominantly C-(NH)2 and/or C=NH2. (The H2 was believed to originate as residual hydrogen present in the nanotubes.) On carbon nanotubes from d3 = 7 cm no functionalization could be detected - perhaps, it was conjectured, because this distance is downstream of the plasma source, all of the free ions and free radicals of

  4. A Review: Carbon Nanotube-Based Piezoresistive Strain Sensors

    Directory of Open Access Journals (Sweden)

    Waris Obitayo

    2012-01-01

    Full Text Available The use of carbon nanotubes for piezoresistive strain sensors has acquired significant attention due to its unique electromechanical properties. In this comprehensive review paper, we discussed some important aspects of carbon nanotubes for strain sensing at both the nanoscale and macroscale. Carbon nanotubes undergo changes in their band structures when subjected to mechanical deformations. This phenomenon makes them applicable for strain sensing applications. This paper signifies the type of carbon nanotubes best suitable for piezoresistive strain sensors. The electrical resistivities of carbon nanotube thin film increase linearly with strain, making it an ideal material for a piezoresistive strain sensor. Carbon nanotube composite films, which are usually fabricated by mixing small amounts of single-walled or multiwalled carbon nanotubes with selected polymers, have shown promising characteristics of piezoresistive strain sensors. Studies also show that carbon nanotubes display a stable and predictable voltage response as a function of temperature.

  5. Phonon assisted thermophoretic motion of gold nanoparticles inside carbon nanotubes

    DEFF Research Database (Denmark)

    Schoen, Philipp A.E.; Walther, Jens Honore; Poulikakos, Dimos

    2007-01-01

    The authors investigate the thermally driven mass transport of gold nanoparticles confined inside carbon nanotubes using molecular dynamics simulations. The observed thermophoretic motion of the gold nanoparticles correlates with the phonon dispersion exhibited by a standard carbon nanotube and...

  6. Methods for Gas Sensing with Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Kaul, Anupama B. (Inventor)

    2013-01-01

    Methods for gas sensing with single-walled carbon nanotubes are described. The methods comprise biasing at least one carbon nanotube and exposing to a gas environment to detect variation in temperature as an electrical response.

  7. Carbon nanotubes : their synthesis and integration into nanofabricated structures

    NARCIS (Netherlands)

    Druzhinina, Tamara

    2011-01-01

    The field of nanotechnology has experienced constantly increasing interest over the past decades both from industry and academy. Commonly used nanomaterials include: nanoparticles, nanowires, quantum dots, fullerenes, and carbon nanotubes. Carbon nanotubes, in particular, are promising building

  8. Thermal conductivity and thermal rectification in unzipped carbon nanotubes

    International Nuclear Information System (INIS)

    Ni Xiaoxi; Li Baowen; Zhang Gang

    2011-01-01

    We study the thermal transport in completely unzipped carbon nanotubes, which are called graphene nanoribbons, partially unzipped carbon nanotubes, which can be seen as carbon-nanotube-graphene-nanoribbon junctions, and carbon nanotubes by using molecular dynamics simulations. It is found that the thermal conductivity of a graphene nanoribbon is much less than that of its perfect carbon nanotube counterparts because of the localized phonon modes at the boundary. A partially unzipped carbon nanotube has the lowest thermal conductivity due to additional localized modes at the junction region. More strikingly, a significant thermal rectification effect is observed in both partially unzipped armchair and zigzag carbon nanotubes. Our results suggest that carbon-nanotube-graphene-nanoribbon junctions can be used in thermal energy control.

  9. Release characteristics of selected carbon nanotube polymer composites

    Science.gov (United States)

    Multi-walled carbon nanotubes (MWCNTs) are commonly used in polymer formulations to improve strength, conductivity, and other attributes. A developing concern is the potential for carbon nanotube polymer nanocomposites to release nanoparticles into the environment as the polymer ...

  10. Electrical conductivity of metal–carbon nanotube structures: Effect of ...

    Indian Academy of Sciences (India)

    Administrator

    The electrical properties of asymmetric metal–carbon nanotube (CNT) structures have been studied using ... The models with asymmetric metal contacts and carbon nanotube bear resemblance to experimental ... ordinary mechanical strength.

  11. Liquid crystalline order of carbon nanotubes

    Science.gov (United States)

    Georgiev, Georgi; Ahlawat, Aditya; Mulkern, Brian; Doyle, Robert; Mongeau, Jennifer; Ogilvie, Alex

    2007-03-01

    Topological defects formed during phase transitions in liquid crystals provide a direct proof of the standard Cosmological model and are direct links to the Early Universe. On the other hand in Nanotechnology, carbon nanotubes can be manipulated and oriented directly by changing the liquid crystalline state of the nanotubes, in combination with organic liquid crystals. Currently there are no nano-assemblers, which makes the liquid crystal state of the nanotubes, one of the few ways of controlling them. We show the design of a fast and efficient polarized light ellipsometric system (a new modification of previous optical systems) that can provide fast quantitative real time measurements in two dimensions of the formation of topological defects in liquid crystals during phase transitions in lab settings. Our aim is to provide fundamental information about the formation of optically anisotropic structures in liquid crystals and the orientation of carbon nanotubes in electric field.

  12. Carbon Nanotubes and Chronic Granulomatous Disease

    Directory of Open Access Journals (Sweden)

    Barbara P. Barna

    2014-06-01

    Full Text Available Use of nanomaterials in manufactured consumer products is a rapidly expanding industry and potential toxicities are just beginning to be explored. Combustion-generated multiwall carbon nanotubes (MWCNT or nanoparticles are ubiquitous in non-manufacturing environments and detectable in vapors from diesel fuel, methane, propane, and natural gas. In experimental animal models, carbon nanotubes have been shown to induce granulomas or other inflammatory changes. Evidence suggesting potential involvement of carbon nanomaterials in human granulomatous disease, has been gathered from analyses of dusts generated in the World Trade Center disaster combined with epidemiological data showing a subsequent increase in granulomatous disease of first responders. In this review we will discuss evidence for similarities in the pathophysiology of carbon nanotube-induced pulmonary disease in experimental animals with that of the human granulomatous disease, sarcoidosis.

  13. 40 CFR 415.330 - Applicability; description of the carbon monoxide and by-product hydrogen production subcategory.

    Science.gov (United States)

    2010-07-01

    ... carbon monoxide and by-product hydrogen production subcategory. 415.330 Section 415.330 Protection of... MANUFACTURING POINT SOURCE CATEGORY Carbon Monoxide and By-Product Hydrogen Production Subcategory § 415.330 Applicability; description of the carbon monoxide and by-product hydrogen production subcategory. The provisions...

  14. 40 CFR 89.112 - Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission standards.

    Science.gov (United States)

    2010-07-01

    ....112 Oxides of nitrogen, carbon monoxide, hydrocarbon, and particulate matter exhaust emission... emissions of oxides of nitrogen, carbon monoxide, hydrocarbon, and nonmethane hydrocarbon are measured using... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Oxides of nitrogen, carbon monoxide...

  15. Elastomer Reinforced with Carbon Nanotubes

    Science.gov (United States)

    Hudson, Jared L.; Krishnamoorti, Ramanan

    2009-01-01

    Elastomers are reinforced with functionalized, single-walled carbon nanotubes (SWNTs) giving them high-breaking strain levels and low densities. Cross-linked elastomers are prepared using amine-terminated, poly(dimethylsiloxane) (PDMS), with an average molecular weight of 5,000 daltons, and a functionalized SWNT. Cross-link densities, estimated on the basis of swelling data in toluene (a dispersing solvent) indicated that the polymer underwent cross-linking at the ends of the chains. This thermally initiated cross-linking was found to occur only in the presence of the aryl alcohol functionalized SWNTs. The cross-link could have been via a hydrogen-bonding mechanism between the amine and the free hydroxyl group, or via attack of the amine on the ester linage to form an amide. Tensile properties examined at room temperature indicate a three-fold increase in the tensile modulus of the elastomer, with rupture and failure of the elastomer occurring at a strain of 6.5.

  16. Carbon nanotube fiber terahertz polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Zubair, Ahmed [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Tsentalovich, Dmitri E.; Young, Colin C. [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Heimbeck, Martin S. [Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Everitt, Henry O. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Charles M. Bowden Laboratory, Aviation & Missile Research, Development, and Engineering Center (AMRDEC), Redstone Arsenal, Alabama 35898 (United States); Pasquali, Matteo [Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005 (United States); Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

    2016-04-04

    Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ∼−30 dB with a low insertion loss (<0.5 dB) throughout a frequency range of 0.2–1.1 THz. In addition, we used a THz ellipsometer to measure the Müller matrix of the CNT-fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

  17. Vibrationally Excited Carbon Monoxide Produced via a Chemical Reaction Between Carbon Vapor and Oxygen

    Science.gov (United States)

    Jans, Elijah R.; Eckert, Zakari; Frederickson, Kraig; Rich, Bill; Adamovich, Igor V.

    2017-06-01

    Measurements of the vibrational distribution function of carbon monoxide produced via a reaction between carbon vapor and molecular oxygen has shown a total population inversion on vibrational levels 4-7. Carbon vapor, produced using an arc discharge to sublimate graphite, is mixed with an argon oxygen flow. The excited carbon monoxide is vibrationally populated up to level v=14, at low temperatures, T=400-450 K, in a collision-dominated environment, 15-20 Torr, with total population inversions between v=4-7. The average vibrational energy per CO molecule formed by the reaction is 0.6-1.2 eV/molecule, which corresponds to 10-20% of the reaction enthalpy. Kinetic modeling of the flow reactor, including state specific vibrational processes, was performed to infer the vibrational distribution of the products of the reaction. The results show viability of developing of a new chemical CO laser from the reaction of carbon vapor and oxygen.

  18. Carbon Nanotube Underwater Acoustic Thermophone

    Science.gov (United States)

    2016-09-23

    nanotubes (unless encapsulated or housed) are quite fragile and are susceptible to disintegration especially if the nanotubes are touched or moved too...The acoustic impedance (defined as the product of material density and sound speed) of the top shell 12 should match the Attorney Docket No. 300009

  19. Chemical reactions confined within carbon nanotubes.

    Science.gov (United States)

    Miners, Scott A; Rance, Graham A; Khlobystov, Andrei N

    2016-08-22

    In this critical review, we survey the wide range of chemical reactions that have been confined within carbon nanotubes, particularly emphasising how the pairwise interactions between the catalysts, reactants, transition states and products of a particular molecular transformation with the host nanotube can be used to control the yields and distributions of products of chemical reactions. We demonstrate that nanoscale confinement within carbon nanotubes enables the control of catalyst activity, morphology and stability, influences the local concentration of reactants and products thus affecting equilibria, rates and selectivity, pre-arranges the reactants for desired reactions and alters the relative stability of isomeric products. We critically evaluate the relative advantages and disadvantages of the confinement of chemical reactions inside carbon nanotubes from a chemical perspective and describe how further developments in the controlled synthesis of carbon nanotubes and the incorporation of multifunctionality are essential for the development of this ever-expanding field, ultimately leading to the effective control of the pathways of chemical reactions through the rational design of multi-functional carbon nanoreactors.

  20. Lethal carbon monoxide toxicity in a concrete shower unit.

    Science.gov (United States)

    Heath, Karen; Byard, Roger W

    2018-05-23

    A 47-year-old previously-well woman was found dead on the floor of a shower cubicle on a property in rural South Australia. The impression of the attending doctor and police was of collapse due to natural disease. Although there was significant stenosing coronary artery atherosclerosis found at autopsy, cherry pink discoloration of tissues prompted measurement of the blood carboxyhemoglobin level which was found to be 55%. The source of the gas was a poorly-maintained hot water heater that was mounted on the inside wall of the shower. Construction of the shower using an impermeable concrete rain water tank had caused gas accumulation when the water heater malfunctioned. Had lethal carbon monoxide exposure not been identified others using the same shower unit would also have been at risk.

  1. The effect of carbon monoxide on planetary haze formation

    Energy Technology Data Exchange (ETDEWEB)

    Hörst, S. M.; Tolbert, M. A, E-mail: sarah.horst@colorado.edu [Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO (United States)

    2014-01-20

    Organic haze plays a key role in many planetary processes ranging from influencing the radiation budget of an atmosphere to serving as a source of prebiotic molecules on the surface. Numerous experiments have investigated the aerosols produced by exposing mixtures of N{sub 2}/CH{sub 4} to a variety of energy sources. However, many N{sub 2}/CH{sub 4} atmospheres in both our solar system and extrasolar planetary systems also contain carbon monoxide (CO). We have conducted a series of atmosphere simulation experiments to investigate the effect of CO on the formation and particle size of planetary haze analogues for a range of CO mixing ratios using two different energy sources, spark discharge and UV. We find that CO strongly affects both number density and particle size of the aerosols produced in our experiments and indicates that CO may play an important, previously unexplored, role in aerosol chemistry in planetary atmospheres.

  2. Carbon monoxide (CO) intoxication: Computerized tomography and magnetic resonance

    International Nuclear Information System (INIS)

    Benitez Gomez, S.; Aguilera Navarro, J.M.; Gonzalez Garcia, A.; Gonzalez Marcos, J.R.; Fernandez Cruz, J.

    1993-01-01

    We present a case of acute carbon monoxide (CO) intoxication in a previously healthy 13-year-old girl, who was found in the bathroom, unconscious and with the gas-burning hot water thank operating. The neuroradiological study showed bilateral, symmetrical cortical and subcortical parietooccipital and temporal lesions as well as damage to the basal lymph nodes. These lesions were related to the anoxic situation induced by this type of intoxication. Clinicoradiological follow-up included CT and MR sequences over a period of 10 months. In this cases, we stress the greater sensitivity of MR in the early detection of the characteristic lesions in this situation and we analyze the evolution of the process. (Author)

  3. Investigation of Carbon Monoxide Adsorption on Cationic Gold- Palladium Clusters

    Science.gov (United States)

    Chen, Yang-Mei; Kuang, Xiao-Yu; Sheng, Xiao-Wei; Wang, Huai-Qian; Shao, Peng; Zhong, Min-Ming

    2013-11-01

    Density functional calculations have been performed for the carbon monoxide molecule adsorption on AunPd+m(n+m ≤ 6) clusters. In the process of CO adsorption, small Au clusters and Pd clusters tend to be an Au atom and three Pd atoms adsorption, respectively. For the mixed Au-Pd clusters, an Au atom, a Pd atom, two atoms consisted of an Au atom and a Pd atom, two Pd atoms, and three Pd atoms adsorption structures are displayed. The highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps and natural bond orbital charge population are calculated. Moreover, CO adsorption energy, CO stretching frequency, and CO bond length (upon adsorption) are also analysed in detail. The results predict that the adsorption strength of Au clusters with CO and the C-O vibration strength is enhanced and reduced after doping of Pd in the AunPdmCO+ complexes, respectively

  4. Reactivity of niobium cluster anions with nitrogen and carbon monoxide

    Science.gov (United States)

    Mwakapumba, Joseph; Ervin, Kent M.

    1997-02-01

    Reactions of small niobium cluster anions, Nbn-(n = 2-7), with CO and N2 are investigated using a flow tube reactor (flowing afterglow) apparatus. Carbon monoxide chemisorption on niobium cluster anions occurs with faster reaction rates than nitrogen chemisorption on corresponding cluster sizes. N2 addition to niobium cluster anions is much more size-selective than is CO addition. These general trends follow those reported in the literature for reactions of neutral and cationic niobium clusters with CO and N2. Extensive fragmentation of the clusters is observed upon chemisorption. A small fraction of the larger clusters survive and sequentially add multiple CO or N2 units without fragmentation. However, chemisorption saturation is not reached at the experimentally accessible pressure and reagent concentration ranges. The thermochemistry of the adsorption processes and the nature of the adsorbed species, molecular or dissociated, are discussed.

  5. UV-induced carbon monoxide emission from living vegetation

    DEFF Research Database (Denmark)

    Bruhn, Dan; Albert, Kristian Rost; Mikkelsen, Teis Nørgaard

    2013-01-01

    The global burden of carbon monoxide (CO) is rather uncertain. In this paper we address the potential for UV-induced CO emission by living terrestrial vegetation surfaces. Real-time measurements of CO concentrations were made with a cavity enhanced laser spectrometer connected in closed loop...... to either an ecosystem chamber or a plant-leaf scale chamber. Leaves of all examined plant species exhibited emission of CO in response to artificial UV-radiation as well as the UV-component of natural solar radiation. The UV-induced rate of CO emission exhibited a rather low dependence on temperature......, indicating an abiotic process. The emission of CO in response to the UV-component of natural solar radiation was also evident at the ecosystem scale....

  6. Four deaths due to carbon monoxide poisoning in car washes.

    Science.gov (United States)

    Carson, H J; Stephens, P J

    1999-09-01

    In a period of 13 months, three separate incidents of lethal carbon monoxide (CO) poisoning in closed car wash bays resulted in the deaths of 4 white men aged 20 to 36 years. Each man appears to have been intoxicated with mind-altering substances, which may impair judgment, perception of outside conditions, and self-awareness. All four died in winter months. For three men, the deaths were ruled accidental, and for the remaining man, the previous deaths appear to have provided a model for suicide. Warning signs may not be effective to prevent future CO deaths in car washes because of the possible role of intoxication. Mechanical or electronic methods to prevent a bay door from closing completely may be preferable.

  7. [Etiology of combined inhalational hydrocyanic acid and carbon monoxide poisoning].

    Science.gov (United States)

    Sigrist, T; Dirnhofer, R

    1979-01-01

    A young man was found dead in a kitchen, that was partly burnt. Autopsy revealed, as cause of death, a combined intoxication following inhalation of carbon monoxide and hydrocyanic acid. Own investigations on the pyrolysis of pieces of furniture found in the kitchen (plastic plates containing melamine and plates containing formaldehyde) showed, that hydrocyanic acid was liberated through combustion of such substances and inhaled by the victim. The poisoning picture is discussed, and discussion includes especially considerations on the peculiar sensitivity of the brain toward the action of hydrocyanic acid and the relative insensitivity of the heart muscle. It is thought that the cause of such sensitivity difference lies in the physiological differences of the intracellular energy production. Finally the dangers of combustion gases developing from burning plastic materials are reemphasized.

  8. Study on the influence of carbon monoxide to the surface oxide layer of uranium metal

    International Nuclear Information System (INIS)

    Wang Xiaolin; Duan Rongliang; Fu Yibei; Xie Renshou; Zuo Changming; Zhao Chunpei; Chen Hong

    1997-01-01

    The influence of carbon monoxide to the surface oxide layer of uranium metal has been studied by X-ray photoelectron spectroscopy (XPS) and gas chromatography (GC). Carbon monoxide adsorption on the oxide layer resulted in U4f peak shifting to the lower binding energy. The content of oxygen in the oxide is decreased and the atomic ratio (O/U) is decreased by 7.2%. The amount of carbon dioxide in the atmosphere after the surface reaction is increased by 11.0%. The investigation indicates that the surface layer can prevent the further oxidation uranium metal in the atmosphere of carbon monoxide

  9. Bulk Cutting of Carbon Nanotubes Using Electron Beam Irradiation

    Science.gov (United States)

    Ziegler, Kirk J. (Inventor); Rauwald, Urs (Inventor); Hauge, Robert H. (Inventor); Schmidt, Howard K. (Inventor); Smalley, Richard E. (Inventor); Kittrell, W. Carter (Inventor); Gu, Zhenning (Inventor)

    2013-01-01

    According to some embodiments, the present invention provides a method for attaining short carbon nanotubes utilizing electron beam irradiation, for example, of a carbon nanotube sample. The sample may be pretreated, for example by oxonation. The pretreatment may introduce defects to the sidewalls of the nanotubes. The method is shown to produces nanotubes with a distribution of lengths, with the majority of lengths shorter than 100 tun. Further, the median length of the nanotubes is between about 20 nm and about 100 nm.

  10. Graphene-carbon nanotube hybrid materials and use as electrodes

    Science.gov (United States)

    Tour, James M.; Zhu, Yu; Li, Lei; Yan, Zheng; Lin, Jian

    2016-09-27

    Provided are methods of making graphene-carbon nanotube hybrid materials. Such methods generally include: (1) associating a graphene film with a substrate; (2) applying a catalyst and a carbon source to the graphene film; and (3) growing carbon nanotubes on the graphene film. The grown carbon nanotubes become covalently linked to the graphene film through carbon-carbon bonds that are located at one or more junctions between the carbon nanotubes and the graphene film. In addition, the grown carbon nanotubes are in ohmic contact with the graphene film through the carbon-carbon bonds at the one or more junctions. The one or more junctions may include seven-membered carbon rings. Also provided are the formed graphene-carbon nanotube hybrid materials.

  11. Carbon nanotubes in neuroregeneration and repair.

    Science.gov (United States)

    Fabbro, Alessandra; Prato, Maurizio; Ballerini, Laura

    2013-12-01

    In the last decade, we have experienced an increasing interest and an improved understanding of the application of nanotechnology to the nervous system. The aim of such studies is that of developing future strategies for tissue repair to promote functional recovery after brain damage. In this framework, carbon nanotube based technologies are emerging as particularly innovative tools due to the outstanding physical properties of these nanomaterials together with their recently documented ability to interface neuronal circuits, synapses and membranes. This review will discuss the state of the art in carbon nanotube technology applied to the development of devices able to drive nerve tissue repair; we will highlight the most exciting findings addressing the impact of carbon nanotubes in nerve tissue engineering, focusing in particular on neuronal differentiation, growth and network reconstruction. © 2013.

  12. Carbon Nanotube Bolometer for Absolute FTIR Spectroscopy

    Science.gov (United States)

    Woods, Solomon; Neira, Jorge; Tomlin, Nathan; Lehman, John

    We have developed and calibrated planar electrical-substitution bolometers which employ absorbers made from vertically-aligned carbon nanotube arrays. The nearly complete absorption of light by the carbon nanotubes from the visible range to the far-infrared can be exploited to enable a device with read-out in native units equivalent to optical power. Operated at cryogenic temperatures near 4 K, these infrared detectors are designed to have time constant near 10 ms and a noise floor of about 10 pW. Built upon a micro-machined silicon platform, each device has an integrated heater and thermometer, either a carbon nanotube thermistor or superconducting transition edge sensor, for temperature control. We are optimizing temperature-controlled measurement techniques to enable high resolution spectral calibrations using these devices with a Fourier-transform spectrometer.

  13. High frequency conductivity in carbon nanotubes

    Directory of Open Access Journals (Sweden)

    S. S. Abukari

    2012-12-01

    Full Text Available We report on theoretical analysis of high frequency conductivity in carbon nanotubes. Using the kinetic equation with constant relaxation time, an analytical expression for the complex conductivity is obtained. The real part of the complex conductivity is initially negative at zero frequency and become more negative with increasing frequency, until it reaches a resonance minimum at ω ∼ ωB for metallic zigzag CNs and ω < ωB for armchair CNs. This resonance enhancement is indicative for terahertz gain without the formation of current instabilities induced by negative dc conductivity. We noted that due to the high density of states of conduction electrons in metallic zigzag carbon nanotubes and the specific dispersion law inherent in hexagonal crystalline structure result in a uniquely high frequency conductivity than the corresponding values for metallic armchair carbon nanotubes. We suggest that this phenomenon can be used to suppress current instabilities that are normally associated with a negative dc differential conductivity.

  14. Detection of gas atoms with carbon nanotubes

    Science.gov (United States)

    Arash, B.; Wang, Q.

    2013-01-01

    Owning to their unparalleled sensitivity resolution, nanomechanical resonators have excellent capabilities in design of nano-sensors for gas detection. The current challenge is to develop new designs of the resonators for differentiating distinct gas atoms with a recognizably high sensitivity. In this work, the characteristics of impulse wave propagation in carbon nanotube-based sensors are investigated using molecular dynamics simulations to provide a new method for detection of noble gases. A sensitivity index based on wave velocity shifts in a single-walled carbon nanotube, induced by surrounding gas atoms, is defined to explore the efficiency of the nano-sensor. The simulation results indicate that the nano-sensor is able to differentiate distinct noble gases at the same environmental temperature and pressure. The inertia and the strengthening effects by the gases on wave characteristics of carbon nanotubes are particularly discussed, and a continuum mechanics shell model is developed to interpret the effects.

  15. Campaign to prevent carbon monoxide poisoning : fall-winter 2007-2008

    International Nuclear Information System (INIS)

    Lefebvre, B.; Chabot, L.; Gratton, J.; Lacoursiere, D.

    2009-01-01

    Quebec launched a public health campaign for the Montreal region to prevent carbon monoxide poisoning. The objectives of the campaign were to communicate the dangers of carbon monoxide poisoning, its potential sources, its effects on public health, and the means to prevent poisoning. Its purpose was to inform the public of the risks and strategies to be used in case of carbon monoxide poisoning and to lay out the merits of household carbon monoxide alarms. The communication was done by way of the media, in cooperation with community organizations and school boards. Other tools used in the campaign included the Internet, flyers and press releases. A poll taken in 2008 showed that 59 per cent of the respondents had one or more sources for carbon monoxide in their homes, including fireplaces, and that 28 per cent had a functioning alarm for carbon monoxide detection. A future survey will be held to follow-up on the evolution of the campaign. The development of various activities will help decrease the risk of carbon monoxide poisoning. tabs., figs.

  16. Content of carbon monoxide in the tissues of rats intoxicated with carbon monoxide in various conditions of acute exposure

    Energy Technology Data Exchange (ETDEWEB)

    Sokal, J.A.; Majka, J.; Palus, J.

    1984-12-01

    Tissue carbon monoxide (CO) content was investigated in rats severely intoxicated with CO under various exposure conditions: 1% CO for 4 min, 0.4% CO for 40 min and 0.12% CO for 12 h. Extravascular CO was determined in the heart and skeletal muscles immediately after termination of exposure, and carboxymyoglobin (MbCO) percent saturation was calculated. Total brain CO was estimated immediately after termination of exposure and after the time periods of restitution. After the same exposure conditions, MbCO percent saturation was higher in the heart than in skeletal muscle. In both types of muscle, saturation on myoglobin (Mb) with CO depended on blood carboxyhemoglobin (HbCO) level and not on the duration of exposure. The time course of CO elimination was the same for blood and brain, irrespective of CO exposure conditions. The results obtained showed that acute CO intoxication induced by long duration exposures did not involve CO accumulation in the tissues.

  17. Influence of cation size and surface coverage upon the infrared spectrum of carbon monoxide

    OpenAIRE

    Huang, Jimin

    1991-01-01

    Adsorbed carbon monoxide is utilized as a double layer probe molecule because of its strong absorption in infrared region and because of the high sensitivity of the carbon-oxygen bond to changes in the environment local to the electrode surface. Potential Difference Infrared Spectroscopy was used to investigate the structural behavior of CO adsorbed on a platinum electrode. Carbon monoxide was found to be exclusively linear-bonded on platinum electrode in the presence of tetran...

  18. A carbon nanotube optical rectenna

    Science.gov (United States)

    Sharma, Asha; Singh, Virendra; Bougher, Thomas L.; Cola, Baratunde A.

    2015-12-01

    An optical rectenna—a device that directly converts free-propagating electromagnetic waves at optical frequencies to direct current—was first proposed over 40 years ago, yet this concept has not been demonstrated experimentally due to fabrication challenges at the nanoscale. Realizing an optical rectenna requires that an antenna be coupled to a diode that operates on the order of 1 PHz (switching speed on the order of 1 fs). Diodes operating at these frequencies are feasible if their capacitance is on the order of a few attofarads, but they remain extremely difficult to fabricate and to reliably couple to a nanoscale antenna. Here we demonstrate an optical rectenna by engineering metal-insulator-metal tunnel diodes, with a junction capacitance of ˜2 aF, at the tip of vertically aligned multiwalled carbon nanotubes (˜10 nm in diameter), which act as the antenna. Upon irradiation with visible and infrared light, we measure a d.c. open-circuit voltage and a short-circuit current that appear to be due to a rectification process (we account for a very small but quantifiable contribution from thermal effects). In contrast to recent reports of photodetection based on hot electron decay in a plasmonic nanoscale antenna, a coherent optical antenna field appears to be rectified directly in our devices, consistent with rectenna theory. Finally, power rectification is observed under simulated solar illumination, and there is no detectable change in diode performance after numerous current-voltage scans between 5 and 77 °C, indicating a potential for robust operation.

  19. Nitrogen in highly crystalline carbon nanotubes

    International Nuclear Information System (INIS)

    Ducati, C; Koziol, K; Stavrinadis, A; Friedrichs, S; Windle, A H; Midgley, P A

    2006-01-01

    Multiwall carbon nanotubes (MWCNTs) with an unprecedented degree of internal order were synthesised by chemical vapour deposition (CVD) adding a nitrogen-containing compound to the hydrocarbon feedstock. Ferrocene was used as the metal catalyst precursor. The remarkable crystallinity of these nanotubes lies both in the isochirality and in the crystallographic register of their walls, as demonstrated by electron diffraction and high resolution electron microscopy experiments. High resolution transmission electron microscopy analysis shows that the walls of the nanotubes consist of truncated stacked cones, instead of perfect cylinders, with a range of apex angles that appears to be related to the nitrogen concentration in the synthesis process. The structure of armchair, zigzag and chiral nanotubes is modelled and discussed in terms of density of topological defects, providing an interesting comparison with our microscopy experiments. A growth mechanism based on the interplay of base- and tip-growth is proposed to account for our experimental observations

  20. Topological phase diagram of superconducting carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Milz, Lars; Marganska-Lyzniak, Magdalena; Grifoni, Milena [Institut I - Theoretische Physik Universitaet Regensburg (Germany)

    2016-07-01

    The topological superconducting phase diagram of superconducting carbon nanotubes is discussed. Under the assumption of a short-ranged pairing potential, there are two spin-singlet states: an s-wave and an exotic p + ip-wave that are possible because of the special structure of the honeycomb lattice. The consequences for the possible presence of Majorana edge states in carbon nanotubes are addressed. In particular, regions in the magnetic field-chemical potential plane possibly hosting localized Majorana modes are discussed.

  1. Carbon nanotubes as anti-bacterial agents.

    Science.gov (United States)

    Mocan, Teodora; Matea, Cristian T; Pop, Teodora; Mosteanu, Ofelia; Buzoianu, Anca Dana; Suciu, Soimita; Puia, Cosmin; Zdrehus, Claudiu; Iancu, Cornel; Mocan, Lucian

    2017-10-01

    Multidrug-resistant bacterial infections that have evolved via natural selection have increased alarmingly at a global level. Thus, there is a strong need for the development of novel antibiotics for the treatment of these infections. Functionalized carbon nanotubes through their unique properties hold great promise in the fight against multidrug-resistant bacterial infections. This new family of nanovectors for therapeutic delivery proved to be innovative and efficient for the transport and cellular translocation of therapeutic molecules. The current review examines the latest progress in the antibacterial activity of carbon nanotubes and their composites.

  2. Laser ablative synthesis of carbon nanotubes

    Science.gov (United States)

    Smith, Michael W.; Jordan, Kevin; Park, Cheol

    2010-03-02

    An improved method for the production of single walled carbon nanotubes that utilizes an RF-induction heated side-pumped synthesis chamber for the production of such. Such a method, while capable of producing large volumes of carbon nanotubes, concurrently permits the use of a simplified apparatus that allows for greatly reduced heat up and cool down times and flexible flowpaths that can be readily modified for production efficiency optimization. The method of the present invention utilizes a free electron laser operating at high average and peak fluence to illuminate a rotating and translating graphite/catalyst target to obtain high yields of SWNTs without the use of a vacuum chamber.

  3. Underwater Acoustic Carbon Nanotube Thermophone

    Science.gov (United States)

    2016-09-23

    decreases rapidly as the distance from the conductor increases. Based on the rapid production of these temperature waves; the net effect is to produce a...fragile and are susceptible to disintegration especially if the nanotube fibers are touched or moved too quickly. A bare nanotube configuration also has...impedance (defined as the product of material density and sound speed) of the top shell 42 should match the radiation medium for higher efficiency

  4. Influence of carbon monoxide to the surface layer of uranium metal and its oxides

    International Nuclear Information System (INIS)

    Wang Xiaoling; Fu Yibei; Xie Renshou; Huang Ruiliang

    1996-09-01

    The surface structures of uranium metal and triuranium octaoxide (U 3 O 8 ) and the influence of carbon monoxide to the surface layers have been studied by X-ray photoelectron spectroscopy (XPS). After exposure to carbon monoxide, contents of oxygen in the surface oxides of uranium metal and U 3 O 8 are decreased and O/U ratios decrease 7.2%, 8.0% respectively. The investigation indicated the surface layers of uranium metal and its oxides were forbidden to further oxidation in the atmosphere of carbon monoxide. (11 refs., 9 figs., 2 tabs.)

  5. Geckolike high shear strength by carbon nanotube fiber adhesives

    Science.gov (United States)

    Maeno, Y.; Nakayama, Y.

    2009-01-01

    Carbon nanotube adhesives can adhere strongly to surfaces as a gecko does. The number of carbon nanotube layers is an important determinant of the contact area for adhesion. Balancing the catalyst ratio and buffer layer used for chemical vapor deposition processing controls the number of carbon nanotube layers and their distribution. The features of carbon nanotubes determine the shear strength of adhesion. Carbon nanotubes with a broad distribution of layers exhibit enhanced shear strength with equivalent adhesive capability to that of a natural Tokay Gecko (Gekko gecko)

  6. Cobalt Oxide Nanosheet and CNT Micro Carbon Monoxide Sensor Integrated with Readout Circuit on Chip

    Directory of Open Access Journals (Sweden)

    Ching-Liang Dai

    2010-03-01

    Full Text Available The study presents a micro carbon monoxide (CO sensor integrated with a readout circuit-on-a-chip manufactured by the commercial 0.35 μm complementary metal oxide semiconductor (CMOS process and a post-process. The sensing film of the sensor is a composite cobalt oxide nanosheet and carbon nanotube (CoOOH/CNT film that is prepared by a precipitation-oxidation method. The structure of the CO sensor is composed of a polysilicon resistor and a sensing film. The sensor, which is of a resistive type, changes its resistance when the sensing film adsorbs or desorbs CO gas. The readout circuit is used to convert the sensor resistance into the voltage output. The post-processing of the sensor includes etching the sacrificial layers and coating the sensing film. The advantages of the sensor include room temperature operation, short response/recovery times and easy post-processing. Experimental results show that the sensitivity of the CO sensor is about 0.19 mV/ppm, and the response and recovery times are 23 s and 34 s for 200 ppm CO, respectively.

  7. Bio-Inspired Carbon Monoxide Sensors with Voltage-Activated Sensitivity

    KAUST Repository

    Savagatrup, Suchol

    2017-09-27

    Carbon monoxide (CO) outcompetes oxygen when binding to the iron center of hemeproteins, leading to a reduction in blood oxygen level and acute poisoning. Harvesting the strong specific interaction between CO and the iron porphyrin provides a highly selective and customizable sensor. We report the development of chemiresistive sensors with voltage-activated sensitivity for the detection of CO comprising iron porphyrin and functionalized single-walled carbon nanotubes (F-SWCNTs). Modulation of the gate voltage offers a predicted extra dimension for sensing. Specifically, the sensors show a significant increase in sensitivity toward CO when negative gate voltage is applied. The dosimetric sensors are selective to ppm levels of CO and functional in air. UV/Vis spectroscopy, differential pulse voltammetry, and density functional theory reveal that the in situ reduction of FeIII to FeII enhances the interaction between the F-SWCNTs and CO. Our results illustrate a new mode of sensors wherein redox active recognition units are voltage-activated to give enhanced and highly specific responses.

  8. Carbon nanotube and graphene nanoribbon interconnects

    CERN Document Server

    Das, Debaprasad

    2014-01-01

    "The book, Caron Nanotube and Graphene Nanoribbon Interconnects, authored by Drs. Debapraad Das and Hafizur Rahaman serves as a good source of material on CNT and GNR interconnects for readers who wish to get into this area and also for practicing engineers who would like to be updated in advances of this field."-Prof. Ashok Srivastava, Louisiana State University, Baton Rouge, USA"Mathematical analysis included in each and every chapter is the main strength of the materials. ... The book is very precise and useful for those who are working in this area. ... highly focused, very compact, and easy to apply. ... This book depicts a detailed analysis and modelling of carbon nanotube and graphene nanoribbon interconnects. The book also covers the electrical circuit modelling of carbon nanotubes and graphene nanoribbons."-Prof. Chandan Kumar Sarkar, Jadavpur University, Kolkata, India.

  9. Cyclic process for producing methane from carbon monoxide with heat removal

    Science.gov (United States)

    Frost, Albert C.; Yang, Chang-lee

    1982-01-01

    Carbon monoxide-containing gas streams are converted to methane by a cyclic, essentially two-step process in which said carbon monoxide is disproportionated to form carbon dioxide and active surface carbon deposited on the surface of a catalyst, and said carbon is reacted with steam to form product methane and by-product carbon dioxide. The exothermic heat of reaction generated in each step is effectively removed during each complete cycle so as to avoid a build up of heat from cycle-to-cycle, with particularly advantageous techniques being employed for fixed bed, tubular and fluidized bed reactor operations.

  10. Application of Nanoparticles/Nanowires and Carbon Nanotubes for Breast Cancer Research

    National Research Council Canada - National Science Library

    Panchapakesan, Balaji

    2005-01-01

    .... Variety of techniques such as fabrication of single wall carbon nanotubes, functionalization of nanotubes with antibodies, interaction of cells with antibodies on nanotube surfaces, and finally cell...

  11. Immobilization of redox mediators on functionalized carbon nanotube

    Indian Academy of Sciences (India)

    Chemical functionalization of single-walled carbon nanotubes with redox mediators, namely, toluidine blue and thionin have been carried out and the performance of graphite electrode modified with functionalized carbon nanotubes is described. Mechanical immobilization of functionalized single-walled nanotube (SWNT) ...

  12. Black silicon maskless templates for carbon nanotube forests

    DEFF Research Database (Denmark)

    Wierzbicki, Rafal; Schmidt, Michael Stenbæk; Boisen, Anja

    2013-01-01

    allows maskless definition of carbon nanotube forests with control of their density, nanotube diameter and height. Four nanograss reactive ion etching recipes are investigated and their wafer-to-wafer repeatability, wafer uniformity, and density control is discussed. Evaluation of carbon nanotube forests...

  13. Nanotubes on Display: How Carbon Nanotubes Can Be Integrated into Electronic Displays

    KAUST Repository

    Opatkiewicz, Justin; LeMieux, Melburne C.; Bao, Zhenan

    2010-01-01

    Random networks of single-walled carbon nanotubes show promise for use in the field of flexible electronics. Nanotube networks have been difficult to utilize because of the mixture of electronic types synthesized when grown. A variety of separation

  14. Electrochemical Metal Deposition on Carbon Nanotubes

    Czech Academy of Sciences Publication Activity Database

    Dunsch, L.; Janda, Pavel; Mukhopadhyay, K.; Shinohara, H.

    2001-01-01

    Roč. 11, č. 6 (2001), s. 427-435 ISSN 1344-9931 Institutional research plan: CEZ:AV0Z4040901 Keywords : carbon nanotubes * electrodeposition * cyclic voltammetry Subject RIV: CG - Electrochemistry Impact factor: 0.800, year: 2001

  15. A New Resistance Formulation for Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Ji-Huan He

    2008-01-01

    Full Text Available A new resistance formulation for carbon nanotubes is suggested using fractal approach. The new formulation is also valid for other nonmetal conductors including nerve fibers, conductive polymers, and molecular wires. Our theoretical prediction agrees well with experimental observation.

  16. Carbon nanotubes for high-performance logic

    NARCIS (Netherlands)

    Chen, Zhihong; Philip Wong, H.-S.; Mitra, S.; Bol, A.A.; Peng, Lianmao; Hills, Gage; Thissen, N.F.W.

    2014-01-01

    Single-wall carbon nanotubes (CNTs) were discovered in 1993 and have been an area of intense research since then. They offer the right dimensions to explore material science and physical chemistry at the nanoscale and are the perfect system to study low-dimensional physics and transport. In the past

  17. Chemistry of Carbon Nanotubes for Everyone

    Science.gov (United States)

    Basu-Dutt, Sharmistha; Minus, Marilyn L.; Jain, Rahul; Nepal, Dhriti; Kumar, Satish

    2012-01-01

    Carbon nanotubes (CNTs) have the extraordinary potential to change our lives by improving existing products and enabling new ones. Current and future research and industrial workforce professionals are very likely to encounter some aspects of nanotechnology including CNT science and technology in their education or profession. The simple structure…

  18. New approach to synthesis of carbon nanotubes

    International Nuclear Information System (INIS)

    Ha, Jong Keun; Choi, Kyo Hong; Cho, Kwon Koo; Kim, Ki Won; Nam, Tae Hyun; Ahn, Hyo Jun; Ahn, Jou Hyun; Cho, Gyu Bong

    2007-01-01

    Carbon nanotubes (CNTs) have been synthesized through chemical vapor deposition in argon gas atmosphere using Fe-2.5%Mo alloyed nanoparticles as a catalyst and H 2 /CH 4 gas mixture as a reaction gas. Fe-2.5 wt.%Mo alloyed nanoparticles with average diameter of 7, 20, 45 and 85 nm are prepared by the chemical vapor condensation process using the pyrolysis of iron pentacarbonyl (Fe(CO) 5 ) and molybdenum hexacarbonyl (Mo(CO) 6 ). The morphologies of the CNTs are controlled by adjusting the nanoparticle size, reaction gas ratio and reaction temperature. With decreasing nanoparticle size under the same experimental conditions, the degree of crystalline perfection increases gradually and the morphologies of the carbon nanotubes vary from multi wall carbon nanotubes to single wall carbon nanotubes. Also, the ratio of reaction gas has an effect on the morphology and the degree of crystallinity of CNTs. In this work, it is suggested that morphology, diameter and degree of crystallinity of CNTs could be controlled by adjusting the reaction gas ratio, reaction temperature and catalyst size

  19. Synthesis of Carbon Nanotube (CNT Composite Membranes

    Directory of Open Access Journals (Sweden)

    Dusan Losic

    2010-12-01

    Full Text Available Carbon nanotubes are attractive approach for designing of new membranes for advanced molecular separation because of their unique transport properties and ability to mimic biological protein channels. In this work the synthetic approach for fabrication of carbon nanotubes (CNTs composite membranes is presented. The method is based on growth of multi walled carbon nanotubes (MWCNT using chemical vapour deposition (CVD on the template of nanoporous alumina (PA membranes. The influence of experimental conditions including carbon precursor, temperature, deposition time, and PA template on CNT growth process and quality of fabricated membranes was investigated. The synthesis of CNT/PA composites with controllable nanotube dimensions such as diameters (30–150 nm, and thickness (5–100 µm, was demonstrated. The chemical composition and morphological characteristics of fabricated CNT/PA composite membranes were investigated by various characterisation techniques including scanning electron microscopy (SEM, energy-dispersive x-ray spectroscopy (EDXS, high resolution transmission electron microscopy (HRTEM and x-ray diffraction (XRD. Transport properties of prepared membranes were explored by diffusion of dye (Rose Bengal used as model of hydrophilic transport molecule.

  20. Carbon Nanotubes as Thermally Induced Water Pumps

    DEFF Research Database (Denmark)

    Oyarzua, Elton; Walther, Jens Honore; Megaridis, Constantine M

    2017-01-01

    Thermal Brownian motors (TBMs) are nanoscale machines that exploit thermal fluctuations to provide useful work. We introduce a TBM-based nanopump which enables continuous water flow through a carbon nanotube (CNT) by imposing an axial thermal gradient along its surface. We impose spatial asymmetry...

  1. Effective models for excitons in carbon nanotubes

    DEFF Research Database (Denmark)

    Cornean, Horia; Duclos, Pierre; Ricaud, Benjamin

    We analyse the low lying spectrum of a model of excitons in carbon nanotubes. Consider two particles with a Coulomb self-interaction, placed on an infinitely long cylinder. If the cylinder radius becomes small, the low lying spectrum is well described by a one-dimensional effective Hamiltonian...

  2. Effective models for excitons in carbon nanotubes

    DEFF Research Database (Denmark)

    Cornean, Horia; Duclos, Pierre; Ricaud, Benjamin

    2007-01-01

    We analyse the low lying spectrum of a model of excitons in carbon nanotubes. Consider two particles with opposite charges and a Coulomb self-interaction, placed on an infinitely long cylinder. If the cylinder radius becomes small, the low lying spectrum of their relative motion is well described...

  3. Bioaccumulation and ecotoxicity of carbon nanotubes

    DEFF Research Database (Denmark)

    Jackson, Petra; Jacobsen, Nicklas Raun; Baun, Anders

    2013-01-01

    Carbon nanotubes (CNT) have numerous industrial applications and may be released to the environment. In the aquatic environment, pristine or functionalized CNT have different dispersion behavior, potentially leading to different risks of exposure along the water column. Data included in this review...

  4. Biodistribution of Carbon Nanotubes in Animal Models

    DEFF Research Database (Denmark)

    Jacobsen, Nicklas Raun; Møller, Peter Horn; Clausen, Per Axel

    2017-01-01

    The many interesting physical and chemical properties of carbon nanotubes (CNT) make it one of the most commercially attractive materials in the era of nanotechnology. Here, we review the recent publications on in vivo biodistribution of pristine and functionalized forms of single-walled and multi...

  5. Chemical vapor deposition of carbon nanotube forests

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, J.; Zhong, G.; Esconjauregui, S.; Zhang, C.; Fouquet, M.; Hofmann, S. [Engineering Department, Cambridge University, Cambridge CB2 1PZ (United Kingdom)

    2012-12-15

    We review the growth mechanisms of vertically aligned carbon nanotube forests, in terms of what controls the growth rate and control of the catalyst lifetime. We also review the production of very high-density forests, in terms of increasing the catalyst particle density. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Chemical vapor deposition of carbon nanotube forests

    International Nuclear Information System (INIS)

    Robertson, J.; Zhong, G.; Esconjauregui, S.; Zhang, C.; Fouquet, M.; Hofmann, S.

    2012-01-01

    We review the growth mechanisms of vertically aligned carbon nanotube forests, in terms of what controls the growth rate and control of the catalyst lifetime. We also review the production of very high-density forests, in terms of increasing the catalyst particle density. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Carbon Nanotubes in Drug and Gene Delivery

    Science.gov (United States)

    Karimi, Mahdi; Ghasemi, Amir; Mirkiani, Soroush; Moosavi Basri, Seyed Masoud; Hamblin, Michael R.

    2017-10-01

    Recent important discoveries and developments in nanotechnology have had a remarkable and ever-increasing impact on many industries, especially materials science, pharmaceuticals, and biotechnology. Within this book, the authors describe different features of carbon nanotubes, survey the properties of both the multi-walled and single-walled varieties, and cover their applications in drug and gene delivery.

  8. In-line manufacture of carbon nanotubes

    Science.gov (United States)

    Brambilla, Nicol Michele; Signorelli, Riccardo; Martini, Fabrizio; Corripio Luna, Oscar Enrique

    2015-04-28

    Mass production of carbon nanotubes (CNT) are facilitated by methods and apparatus disclosed herein. Advantageously, the methods and apparatus make use of a single production unit, and therefore provide for uninterrupted progress in a fabrication process. Embodiments of control systems for a variety of CNT production apparatus are included.

  9. Analysis of ionic conductance of carbon nanotubes

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Bazant, M.Z.

    2016-01-01

    We use space-charge (SC) theory (also called the capillary pore model) to describe the ionic conductance, G, of charged carbon nanotubes (CNTs). Based on the reversible adsorption of hydroxyl ions to CNT pore walls, we use a Langmuir isotherm for surface ionization and make calculations as a

  10. Autumn photoproduction of carbon monoxide in Jiaozhou Bay, China

    Science.gov (United States)

    Ren, Chunyan; Yang, Guipeng; Lu, Xiaolan

    2014-06-01

    Carbon monoxide (CO) plays a significant role in global warming and atmospheric chemistry. Global oceans are net natural sources of atmospheric CO. CO at surface ocean is primarily produced from the photochemical degradation of chromophoric dissolved organic matter (CDOM). In this study, the effects of photobleaching, temperature and the origin (terrestrial or marine) of CDOM on the apparent quantum yields (AQY) of CO were studied for seawater samples collected from Jiaozhou Bay. Our results demonstrat that photobleaching, temperature and the origin of CDOM strongly affected the efficiency of CO photoproduction. The concentration, absorbance and fluorescence of CDOM exponentially decreased with increasing light dose. Terrestrial riverine organic matter could be more prone to photodegradation than the marine algae-derived one. The relationships between CO AQY and the dissolved organic carbon-specific absorption coefficient at 254 nm for the photobleaching study were nonlinear, whereas those of the original samples were strongly linear. This suggests that: 1) terrestrial riverine CDOM was more efficient than marine algae-derived CDOM for CO photoproduction; 2) aromatic and olefinic moieties of the CDOM pool were affected more strongly by degradation processes than by aliphatic ones. Water temperature and the origin of CDOM strongly affected the efficiency of CO photoproduction. The photoproduction rate of CO in autumn was estimated to be 31.98 μmol m-2 d-1 and the total DOC photomineralization was equivalent to 3.25%-6.35% of primary production in Jiaozhou Bay. Our results indicate that CO photochemistry in coastal areas is important for oceanic carbon cycle.

  11. Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Inui, Y. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)]. E-mail: inui@eee.tut.ac.jp; Urata, A. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Ito, N. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Nakajima, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Tanaka, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)

    2006-08-15

    The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide.

  12. Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

    International Nuclear Information System (INIS)

    Inui, Y.; Urata, A.; Ito, N.; Nakajima, T.; Tanaka, T.

    2006-01-01

    The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide

  13. Mechanism of obtaining carbon monoxide and hydrogen during brown coal radiolysis. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rustamov, V R; Kurbanov, M A; Dzantiev, B T; Kerimov, V K; Musaeva, P F

    1982-05-01

    This article analyzes effects of gamma radiation on the yield of products of coal gasification: hydrogen and carbon monoxide. Samples of brown coal from the Kansk-Achins basin were treated by gamma radiation with cobalt 60 radiation source. Analyses show that accumulation of hydrogen and carbon monoxide in brown coal under influence of gamma radiation is characterized by a constant rate. Yields of carbon monoxide and hydrogen amount to 0.16 molecule/100 electro volt and 0.21 molecule/electro volt respectively. Reducing radiation dose from 2.5 to 0.7 millirad/h reduces yields of hydrogen and carbon monoxide. Increasing temperature of vacuum brown coal pyrolysis from 200 to 600 C causes decrease of hydrogen yield. Hydrogen yield decrease during temperature increase is caused by a high content of aromatic nuclei in the samples used in the radiolysis. (5 refs.)

  14. Carbon monoxide toxicity. (Latest citations from the Life Sciences Collection database). NewSearch

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    The bibliography contains citations concerning the mechanism and clinical manifestations of carbon monoxide (CO) exposure, including the effects on the liver, cardiovascular, and nervous systems. Topics include studies of the carbon monoxide binding affinity with hemoglobin, measurement of carboxyhemoglobin in humans and various animal species, carbon monoxide levels resulting from tobacco and marijuana smoke, occupational exposure and the NIOSH (National Institute for Occupational Safety and Health) biological exposure index, symptomology and percent of blood CO, and intrauterine exposure. Air pollution, tobacco smoking, and occupational exposure are discussed as primary sources of carbon monoxide exposure. The effects of cigarette smoking on fetal development and health are excluded and examined in a separate bibliography. (Contains a minimum of 137 citations and includes a subject term index and title list.)

  15. Carbon monoxide toxicity. (Latest citations from the Life Sciences Collection database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    The bibliography contains citations concerning the mechanism and clinical manifestations of carbon monoxide (CO) exposure, including the effects on the liver, cardiovascular, and nervous systems. Topics include studies of the carbon monoxide binding affinity with hemoglobin, measurement of carboxyhemoglobin in humans and various animal species, carbon monoxide levels resulting from tobacco and marijuana smoke, occupational exposure and the NIOSH (National Institute for Occupational Safety and Health) biological exposure index, symptomology and percent of blood CO, and intrauterine exposure. Air pollution, tobacco smoking, and occupational exposure are discussed as primary sources of carbon monoxide exposure. The effects of cigarette smoking on fetal development and health are excluded and examined in a separate bibliography.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Carbon monoxide toxicity. (Latest citations from the Life Sciences Collection database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    The bibliography contains citations concerning the mechanism and clinical manifestations of carbon monoxide (CO) exposure, including the effects on the liver, cardiovascular, and nervous systems. Topics include studies of the carbon monoxide binding affinity with hemoglobin, measurement of carboxyhemoglobin in humans and various animal species, carbon monoxide levels resulting from tobacco and marijuana smoke, occupational exposure and the NIOSH (National Institute for Occupational Safety and Health) biological exposure index, symptomology and percent of blood CO, and intrauterine exposure. Air pollution, tobacco smoking, and occupational exposure are discussed as primary sources of carbon monoxide exposure. The effects of cigarette smoking on fetal development and health are excluded and examined in a separate bibliography. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  17. Carbon monoxide toxicity. (Latest citations from the Life Sciences Collection data base). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    The bibliography contains citations concerning the mechanism and clinical manifestations of carbon monoxide (CO) exposure, including the effects on the liver, cardiovascular, and nervous systems. Topics include studies of the carbon monoxide binding affinity with hemoglobin, measurement of carboxyhemoglobin in humans and various animal species, carbon monoxide levels resulting from tobacco and marijuana smoke, occupational exposure and the NIOSH (National Institute for Occupational Safety and Health) biological exposure index, symptomology and percent of blood CO, and intrauterine exposure. Air pollution, tobacco smoking, and occupational exposure are discussed as primary sources of carbon monoxide exposure. The effects of cigarette smoking on fetal development and health are excluded and examined in a separate bibliography. (Contains a minimum of 172 citations and includes a subject term index and title list.)

  18. Environmental variables and levels of exhaled carbon monoxide and carboxyhemoglobin in elderly people taking exercise.

    Science.gov (United States)

    Salicio, Marcos Adriano; Mana, Viviane Aparecida Martins; Fett, Waléria Christiane Rezende; Gomes, Luciano Teixeira; Botelho, Clovis

    2016-04-01

    This article aims to analyze levels of exhaled carbon monoxide, carboxyhemoglobinand cardiopulmonary variables in old people practicing exercise in external environments, and correlate them with climate and pollution factors. Temporal ecological study with118 active elderly people in the city of Cuiabá, in the state of Mato Grosso, Brazil. Data were obtained on use of medication, smoking, anthropometric measurements, spirometry, peak flow, oxygen saturation, heart rate, exhaled carbon monoxide, carboxyhemoglobin, climate, number of farm fires and pollution. Correlations were found between on the one hand environmental temperature, relative humidity of the air and number of farmers' fires, and on the other hand levels of carbon monoxide exhaled and carboxyhemoglobin (p carboxyhemoglobin and heart rate. There is thus a need for these to be monitored during exercise. The use of a carbon monoxide monitor to evaluate exposure to pollutants is suggested.

  19. Fluorescently labeled bionanotransporters of nucleic acid based on carbon nanotubes

    International Nuclear Information System (INIS)

    Novopashina, D.S.; Apartsin, E.K.; Venyaminova, A.G.

    2012-01-01

    We propose an approach to the design of a new type of hybrids of oligonucleotides with fluorescein-functionalized single-walled carbon nanotubes. The approach is based on stacking interactions of functionalized nanotubes with pyrene residues in conjugates of oligonucleotides. The amino- and fluorescein-modified single walled carbon nanotubes are obtained, and their physico-chemical properties are investigated. The effect of the functionalization type of carbon nanotubes on the efficacy of the sorption of pyrene conjugates of oligonucleotides was examined. The proposed noncovalent hybrids of fluorescein-labeled carbon nanotubes with oligonucleotides may be used for the intracellular transport of functional nucleic acids.

  20. Degradation of multiwall carbon nanotubes by bacteria

    International Nuclear Information System (INIS)

    Zhang, Liwen; Petersen, Elijah J.; Habteselassie, Mussie Y.; Mao, Liang; Huang, Qingguo

    2013-01-01

    Understanding the environmental transformation of multiwall carbon nanotubes (MWCNTs) is important to their life cycle assessment and potential environmental impacts. We report that a bacterial community is capable of degrading 14 C-labeled MWCNTs into 14 CO 2 in the presence of an external carbon source via co-metabolism. Multiple intermediate products were detected, and genotypic characterization revealed three possible microbial degraders: Burkholderia kururiensis, Delftia acidovorans, and Stenotrophomonas maltophilia. This result suggests that microbe/MWCNTs interaction may impact the long-term fate of MWCNTs. Highlights: •Mineralization of MWCNTs by a bacterial community was observed. •The mineralization required an external carbon source. •Multiple intermediate products were identified in the MWCNT degrading culture. •Three bacterial species were found likely responsible for MWCNT degradation. -- The 14 C-labeled multiwall carbon nanotubes can be degraded to 14 CO 2 and other byproducts by a bacteria community under natural conditions

  1. Exploring the Immunotoxicity of Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Yu Yanmei

    2008-01-01

    Full Text Available Abstract Mass production of carbon nanotubes (CNTs and their applications in nanomedicine lead to the increased exposure risk of nanomaterials to human beings. Although reports on toxicity of nanomaterials are rapidly growing, there is still a lack of knowledge on the potential toxicity of such materials to immune systems. This article reviews some existing studies assessing carbon nanotubes’ toxicity to immune system and provides the potential mechanistic explanation.

  2. Exploring the Immunotoxicity of Carbon Nanotubes

    Science.gov (United States)

    Yu, Yanmei; Zhang, Qiu; Mu, Qingxin; Zhang, Bin; Yan, Bing

    2008-08-01

    Mass production of carbon nanotubes (CNTs) and their applications in nanomedicine lead to the increased exposure risk of nanomaterials to human beings. Although reports on toxicity of nanomaterials are rapidly growing, there is still a lack of knowledge on the potential toxicity of such materials to immune systems. This article reviews some existing studies assessing carbon nanotubes’ toxicity to immune system and provides the potential mechanistic explanation.

  3. Defect complexes in carbon and boron nitride nanotubes

    CSIR Research Space (South Africa)

    Mashapa, MG

    2012-05-01

    Full Text Available The effect of defect complexes on the stability, structural and electronic properties of single-walled carbon nanotubes and boron nitride nanotubes is investigated using the ab initio pseudopotential density functional method implemented...

  4. Decoration of Multi-walled Carbon Nanotubes by Metal ...

    African Journals Online (AJOL)

    NICO

    tures inside the nanotubes to increase the available surface for catalysis6 or in ... most common method to decorate CNTs by metal nanoparticles and metal oxides due .... 2.6 Characterization of Carbon Nanotubes, Metal Nano- particles and ...

  5. Contributions of distinct gold species to catalytic reactivity for carbon monoxide oxidation

    Science.gov (United States)

    Guo, Li-Wen; Du, Pei-Pei; Fu, Xin-Pu; Ma, Chao; Zeng, Jie; Si, Rui; Huang, Yu-Ying; Jia, Chun-Jiang; Zhang, Ya-Wen; Yan, Chun-Hua

    2016-11-01

    Small-size (carbon monoxide at room temperature, by the aid of in situ X-ray absorption fine structure analysis and in situ diffuse reflectance infrared Fourier transform spectroscopy. We find that the metallic gold component in clusters or particles plays a much more critical role as the active site than the cationic single-atom gold species for the room-temperature carbon monoxide oxidation reaction.

  6. Intrinsic Chirality Origination in Carbon Nanotubes.

    Science.gov (United States)

    Pierce, Neal; Chen, Gugang; P Rajukumar, Lakshmy; Chou, Nam Hawn; Koh, Ai Leen; Sinclair, Robert; Maruyama, Shigeo; Terrones, Mauricio; Harutyunyan, Avetik R

    2017-10-24

    Elucidating the origin of carbon nanotube chirality is key for realizing their untapped potential. Currently, prevalent theories suggest that catalyst structure originates chirality via an epitaxial relationship. Here we studied chirality abundances of carbon nanotubes grown on floating liquid Ga droplets, which excludes the influence of catalyst features, and compared them with abundances grown on solid Ru nanoparticles. Results of growth on liquid droplets bolsters the intrinsic preference of carbon nuclei toward certain chiralities. Specifically, the abundance of the (11,1)/χ = 4.31° tube can reach up to 95% relative to (9,4)/χ = 17.48°, although they have exactly the same diameter, (9.156 Å). However, the comparative abundances for the pair, (19,3)/χ = 7.2° and (17,6)/χ = 14.5°, with bigger diameter, (16.405 Å), fluctuate depending on synthesis temperature. The abundances of the same pairs of tubes grown on floating solid polyhedral Ru nanoparticles show completely different trends. Analysis of abundances in relation to nucleation probability, represented by a product of the Zeldovich factor and the deviation interval of a growing nuclei from equilibrium critical size, explain the findings. We suggest that the chirality in the nanotube in general is a result of interplay between intrinsic preference of carbon cluster and induction by catalyst structure. This finding can help to build the comprehensive theory of nanotube growth and offers a prospect for chirality-preferential synthesis of carbon nanotubes by the exploitation of liquid catalyst droplets.

  7. Review on properties, dispersion and toxicology of carbon nanotubes

    International Nuclear Information System (INIS)

    Saeed, K.

    2010-01-01

    Carbon nanotubes (CNTs) have the most intensely studied nano structures because of their unique properties. There are two types of carbon nanotubes CNTs, single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs), prepared by chemical-vapour deposition (CVD), plasma enhanced chemical-vapour deposition, thermal chemical vapour deposition, Vapour phase growth, Arc discharge and Lasser ablation. Both single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) possess high mechanical and electrical conductivity, ultra-light weight, high aspect ratio and have excellent chemical and thermal stabilities. They also possess semi- and metallic-conductive properties depending upon their chirality. This review focuses on progress toward functionalization (not only dispersed nano tube but also dramatically improve their solubility), preparation and purification, composites and the toxicity of the carbon nanotubes (CNTs). The functional groups attached to carbon nanotubes (CNTs) should react with polymers and improve the mechanical properties of the nano composites. Carbon nanotubes (CNTs) has significant application in pharmaceutical field such as drug delivery and nano medicine, but the available literature also suggests that carbon nanotubes (CNTs) may have unusual toxicity and have more adverse effects than the same mass of nano size carbon and quartz. (author)

  8. Carbon Monoxide Epidemic Among Immigrant Populations: King County, Washington, 2006

    Science.gov (United States)

    Kwan-Gett, Tao; Hampson, Neil B.; Baer, Atar; Shusterman, Dennis; Shandro, Jamie R.; Duchin, Jeffrey S.

    2009-01-01

    Objectives. We investigated an outbreak of carbon monoxide (CO) poisoning after a power outage to determine its extent, identify risk factors, and develop prevention measures. Methods. We reviewed medical records and medical examiner reports of patients with CO poisoning or related symptoms during December 15 to 24, 2006. We grouped patients into households exposed concurrently to a single source of CO. Results. Among 259 patients with CO poisoning, 204 cases were laboratory confirmed, 37 were probable, 10 were suspected, and 8 were fatal. Of 86 households studied, 58% (n = 50) were immigrant households from Africa (n = 21), Asia (n = 15), Latin America (n = 10), and the Middle East (n = 4); 34% (n = 29) were US-born households. One percent of households was European (n = 1), and the origin for 7% (n = 6) was unknown. Charcoal was the most common fuel source used among immigrant households (82%), whereas liquid fuel was predominant among US-born households (34%). Conclusions. Educational campaigns to prevent CO poisoning should consider immigrants’ cultural practices and languages and specifically warn against burning charcoal indoors and incorrect ventilation of gasoline- or propane-powered electric generators. PMID:19608962

  9. The neurotoxicology of carbon monoxide - Historical perspective and review.

    Science.gov (United States)

    Sykes, Oliver T; Walker, Edward

    2016-01-01

    Carbon monoxide (CO) has been recognized as a poison for centuries, and remains one of the most common causes of both accidental and deliberate poisoning worldwide. Despite this, there are widespread misconceptions with regards to the mechanisms, diagnosis and outcomes of CO induced poisoning such as the idea that CO poisoning is rare; that carboxyhaemoglobin levels above 20% and loss of consciousness are required before nervous system damage ensues; and that the binding of CO to haemoglobin is the only mechanism of toxicity. Prevention and diagnosis of CO poisoning is hampered by the lack of awareness of CO as a cause of illness, among both the general public and healthcare professionals. To complicate matters further there is no standardized definition of CO poisoning. Carboxyhaemoglobin levels are often used as a marker of CO poisoning, yet plasma levels rapidly reduce upon removal of the source and are therefore an unreliable biomarker of exposure and tissue damage. Adverse neuropsychiatric outcomes after CO poisoning are difficult to define, especially as they fluctuate, mimic other non-specific complaints, and are not present in all survivors. This paper challenges a number of misconceptions about CO poisoning which can result in misdiagnosis, and consequently in mismanagement. We illustrate how recent developments in the understanding of CO toxicology explain the particular susceptibility of the central nervous system to the effects of CO exposure. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  10. Composition of amino acid using carbon monoxide. Amide carbonylation reaction

    Energy Technology Data Exchange (ETDEWEB)

    Izawa, Kunisuke (Ajinomoto Co., Inc., Tokyo (Japan))

    1989-02-01

    Amide carbonylation reaction is a method to compose N-acyl-{alpha}-amino acid from aldehyde, carboxylic acid amide, and carbon monoxide in a phase and with high yield. Unlike the conventional Strecker reaction, this method does not use HCN which is in question on public pollution and does not require hydrolysis. This amide carbonylation reaction was discovered by Wakamatsu and others of Ajinomoto Co.,Ltd. Present application examples of this method are the composition of N-acetyl amino acid from the aldehyde class, the composition of N-Acyl amino acid from olefin, the composition of N-acyl or acetyl amino acid from the raw material of alcohol and the halide class, the composition of N-acyl or acetyl amino acid via the isomerization of epoxide and allyl alcohol, the composition of amino dicarboxylic acid, applying deoxidation of ring acid anhydride, the composition of N-acyl amino acid from the raw material of the amine class, the stereoselective composition of -substitution ring-{alpha}-amino acid, and the composition of amino aldehyde. 24 refs., 2 figs., 2 tabs.

  11. Carbon monoxide: from toxin to endogenous modulator of cardiovascular functions

    Directory of Open Access Journals (Sweden)

    R.A. Johnson

    1999-01-01

    Full Text Available Carbon monoxide (CO is a pollutant commonly recognized for its toxicological attributes, including CNS and cardiovascular effects. But CO is also formed endogenously in mammalian tissues. Endogenously formed CO normally arises from heme degradation in a reaction catalyzed by heme oxygenase. While inhibitors of endogenous CO production can raise arterial pressure, heme loading can enhance CO production and lead to vasodepression. Both central and peripheral tissues possess heme oxygenases and generate CO from heme, but the inability of heme substrate to cross the blood brain barrier suggests the CNS heme-heme oxygenase-CO system may be independent of the periphery. In the CNS, CO apparently acts in the nucleus tractus solitarii (NTS promoting changes in glutamatergic neurotransmission and lowering blood pressure. At the periphery, the heme-heme oxygenase-CO system can affect cardiovascular functions in a two-fold manner; specifically: 1 heme-derived CO generated within vascular smooth muscle (VSM can promote vasodilation, but 2 its actions on the endothelium apparently can promote vasoconstriction. Thus, it seems reasonable that the CNS-, VSM- and endothelial-dependent actions of the heme-heme oxygenase-CO system may all affect cardiac output and vascular resistance, and subsequently blood pressure.

  12. The Role of Oxygen Therapies in Carbon Monoxide Poisoning

    Directory of Open Access Journals (Sweden)

    Suleyman Metin

    2011-08-01

    Full Text Available Due to climate and socio-economic issues in Turkey, the incidence of carbon monoxide (CO poisoning is high, especially in winter. Clinical manifestations may vary depending on the type of CO source, concentration and duration of exposure. The symptoms of CO poisoning predominantly manifest in lots of organs and systems with high oxygen utilization, especially the brain and the heart. The primary aim in oxygen therapy is to eliminate CO and to reduce its toxic effects. In this context, normobaric and hyperbaric oxygen therapy are used to achieve these goals. Normobaric oxygen (NBO treatment is an easily accessible and relatively not expensive modality, where hyperbaric oxygen (HBO therapy requires specific equipment, certified staff and is available only in some centers. Additionally, HBO treatment has several additional advantages over NBO treatment. Despite its benefits, it is compulsory to search for some criteria in selecting patients to be treated because of the limited availability and access of hyperbaric facilities. For an effective evaluation and an optimal treatment, advanced education of the healthcare professionals on the use of oxygen delivery modalities in the management of CO poisoning is imperative. In this review, it has been aimed to outline the significance of oxygen treatment modalities and to determine patient selection criteria for HBO treatment in the management of CO poisoning which continues to be an important threat to community health care. [TAF Prev Med Bull 2011; 10(4.000: 487-494

  13. Risk and protective behaviours for residential carbon monoxide poisoning.

    Science.gov (United States)

    Rupert, Douglas J; Poehlman, Jon A; Damon, Scott A; Williams, Peyton N

    2013-04-01

    Unintentional, non-fire-related carbon monoxide (CO) poisoning is a leading cause of poisoning death and injury in the USA. Residential poisonings caused by faulty furnaces are the most common type of CO exposure. However, these poisonings are largely preventable with annual furnace inspections and CO alarm installation. This study aimed to identify the knowledge, attitudes and beliefs that might lead consumers to adopt these protective behaviours. In August 2009, four focus groups (n=29) were conducted with homeowners in Chicago, Illinois, USA, to identify the knowledge, attitudes and beliefs that lead consumers to adopt risk and protective behaviours. Discussions were transcribed and the findings were analysed using an ordered meta-matrix. Focus group participants were aware of CO poisoning and supported the idea of regular furnace inspections. However, few participants consistently scheduled professional inspections for fear of costly repairs and unscrupulous contractors. Participants often owned CO alarms, but many did not locate them properly, nor maintain them. Some participants confused CO and natural gas and were unsure how to react if a CO alarm sounds. Participants stated that incentives, such as discounts and inspector selection tips, would make them more likely to schedule furnace inspections. Participants also identified trustworthy sources for CO education, including realtors, fire departments, home insurance agents and local media outlets. Participants' residential CO risk behaviours are not random but driven by underlying knowledge, attitudes and beliefs. Correcting misperceptions, providing incentives and partnering with trustworthy sources might encourage greater consumer adoption of protective behaviours.

  14. Variability in hyperbaric oxygen treatment for acute carbon monoxide poisoning.

    Science.gov (United States)

    Byrne, Brendan T; Lu, Jenny J; Valento, Matthew; Bryant, Sean M

    2012-01-01

    In patients with acute carbon monoxide (CO) poisoning, we have noted wide clinical variability in both criteria for hyperbaric oxygen (HBO2) treatment as well as HBO2 treatment regimens. Our aim was to survey Midwest hyperbaric centers for insight into specific criteria and protocols for treating acute CO toxicity with HBO2. Hyperbaric centers were identified from the published list of the Undersea and Hyperbaric Medical Society. Ninety-three centers from nine Midwestern states were contacted via telephone. A standard script was used to minimize surveyor bias. Thirty centers that treat CO poisonings were identified. One did not participate in the study. Nineteen reported a specific level of carboxyhemoglobin (COHb) that served as an independent indication for initiation of HBO2 treatment. Four centers used the COHb level as the exclusive indication for HBO2 treatment. Ten centers relied solely on reported symptoms, while the remaining centers used a combination of symptoms plus COHb levels. There were 19 separate treatment protocols. No uniform practice for either the initiation or implementation of HBO2 therapy for CO poisoning exists among U.S. Midwest hyperbaric centers responding to a survey. We see opportunity for specific targeted educational programs as well as further study.

  15. A Wireless and Batteryless Intelligent Carbon Monoxide Sensor.

    Science.gov (United States)

    Chen, Chen-Chia; Sung, Gang-Neng; Chen, Wen-Ching; Kuo, Chih-Ting; Chue, Jin-Ju; Wu, Chieh-Ming; Huang, Chun-Ming

    2016-09-23

    Carbon monoxide (CO) poisoning from natural gas water heaters is a common household accident in Taiwan. We propose a wireless and batteryless intelligent CO sensor for improving the safety of operating natural gas water heaters. A micro-hydropower generator supplies power to a CO sensor without battery (COSWOB) (2.5 W at a flow rate of 4.2 L/min), and the power consumption of the COSWOB is only ~13 mW. The COSWOB monitors the CO concentration in ambient conditions around natural gas water heaters and transmits it to an intelligent gateway. When the CO level reaches a dangerous level, the COSWOB alarm sounds loudly. Meanwhile, the intelligent gateway also sends a trigger to activate Wi-Fi alarms and sends notifications to the mobile device through the Internet. Our strategy can warn people indoors and outdoors, thereby reducing CO poisoning accidents. We also believe that our technique not only can be used for home security but also can be used in industrial applications (for example, to monitor leak occurrence in a pipeline).

  16. The immunomodulatory role of carbon monoxide during transplantation

    Directory of Open Access Journals (Sweden)

    Amano Mariane

    2013-01-01

    Full Text Available Abstract The number of organ and tissue transplants has increased worldwide in recent decades. However, graft rejection, infections due to the use of immunosuppressive drugs and a shortage of graft donors remain major concerns. Carbon monoxide (CO had long been regarded solely as a poisonous gas. Ultimately, physiological studies unveiled the endogenous production of CO, particularly by the heme oxygenase (HO-1 enzyme, recognizing CO as a beneficial gas when used at therapeutic doses. The protective properties of CO led researchers to develop uses for it, resulting in devices and molecules that can deliver CO in vitro and in vivo. The resulting interest in clinical investigations was immediate. Studies regarding the CO/HO-1 modulation of immune responses and their effects on various immune disorders gave rise to transplantation research, where CO was shown to be essential in the protection against organ rejection in animal models. This review provides a perspective of how CO modulates the immune system to improve transplantation and suggests its use as a therapy in the field.

  17. Carbon Monoxide Poisoning Cases Autopsied in South Marmara Region

    Directory of Open Access Journals (Sweden)

    Filiz Eren

    2014-10-01

    Full Text Available Carbonmonoxide (CO related deaths, which are generally preventable accidents that include accidents due to the coal stoves and water heaters in bath at home, the mining accidents, and other accidents. CO accept as the most common cause of poisoning cases in many countries and its prominent feature is being a colorless, odorless and nonirritant gas. In the period from 2007 until the end of 2011, the autopsy records of the ........ of Turkey were reviewed. Over a period of 5 years a total of 5782 autopsies were done of which 218 involved CO poisoning, constituting 3,8 % of total cases. Information regarding age, sex, month, year, and as well as various aspects were examined. Study data were encoded with computer and Statistical analysis was performed using SPSS for windows program. Of the cases 76 were (34,9% female, 142 were (65,1% male and male/female ratio was 1,9. Of the cases average age was 46.8, range between 1 and 90 years. 57,8% of deaths were in winter markedly. The highest carboxyhemoglobin saturation was 92% in the blood. Poisoning due to CO leaks from coal heaters is an important problem in our country and surrounding regions. The mining accidents should be reduced by increasing safety in the workplace. We must more expend efforts to educate the public and prevent CO poisoning. Key words: Carbon monoxide, poisoning, autopsy.

  18. Carbon monoxide poisoning at motels, hotels, and resorts.

    Science.gov (United States)

    Weaver, Lindell K; Deru, Kayla

    2007-07-01

    Each year, more than 200 people in the United States die from carbon monoxide (CO) poisoning. Poisoning has occurred at motels, hotels, and resorts. Congressional mandate requires smoke alarms in all guest rooms; however, smoke alarms do not detect CO. Data on patients poisoned at hotels, motels, and resorts were evaluated at a hyperbaric medicine service. In 2005, legal databases and online news databanks were searched to discover additional incidents. Only victims evaluated in hospitals or declared dead at the scene were included. Cases of intentional poisoning and poisoning from fires were excluded. Between 1989 and 2004, 68 incidents of CO poisoning occurring at hotels, motels, and resorts were identified, resulting in 772 accidentally poisoned: 711 guests, 41 employees or owners, and 20 rescue personnel. Of those poisoned, 27 died, 66 had confirmed sequelae, and 6 had sequelae resulting in a jury verdict. Lodging-operated, faulty room heating caused 45 incidents, pool/spa boilers 16, CO entrained from outdoors 5, and unreported sources caused 2 incidents. Public verdicts have averaged $4.8 million per incident (range, $1 million to $17.5 million). Poisoning occurred at hotels of all classes. Despite these incidents, most properties did not install CO alarms, and requirements for CO alarms at hotels, motels, and resorts are rare. Guests of motels, hotels, and resorts remain at risk for injury or death from CO poisoning. Measures to prevent CO poisoning of guests and employees of the lodging industry should be evaluated.

  19. Retrieval of tropospheric carbon monoxide for the MOPITT experiment

    Science.gov (United States)

    Pan, Liwen; Gille, John C.; Edwards, David P.; Bailey, Paul L.; Rodgers, Clive D.

    1998-12-01

    A retrieval method for deriving the tropospheric carbon monoxide (CO) profile and column amount under clear sky conditions has been developed for the Measurements of Pollution In The Troposphere (MOPITT) instrument, scheduled for launch in 1998 onboard the EOS-AM1 satellite. This paper presents a description of the method along with analyses of retrieval information content. These analyses characterize the forward measurement sensitivity, the contribution of a priori information, and the retrieval vertical resolution. Ensembles of tropospheric CO profiles were compiled both from aircraft in situ measurements and from chemical model results and were used in retrieval experiments to characterize the method and to study the sensitivity to different parameters. Linear error analyses were carried out in parallel with the ensemble experiments. Results of these experiments and analyses indicate that MOPITT CO column measurements will have better than 10% precision, and CO profile measurement will have approximately three pieces of independent information that will resolve 3-5 tropospheric layers to approximately 10% precision. These analyses are important for understanding MOPITT data, both for application of data in tropospheric chemistry studies and for comparison with in situ measurements.

  20. General circulation model study of atmospheric carbon monoxide

    International Nuclear Information System (INIS)

    Pinto, J.P.; Yung, Y.L.; Rind, D.; Russell, G.L.; Lerner, J.A.; Hansen, J.E.; Hameed, S.

    1983-01-01

    The carbon monoxide cycle is studied by incorporating the known and hypothetical sources and sinks in a tracer model that uses the winds generated by a general circulation model. Photochemical production and loss terms, which depend on OH radical concentrations, are calculated in an interactive fashion. The computed global distribution and seasonal variations of CO are compared with observations to obtain constraints on the distribution and magnitude of the sources and sinks of CO, and on the tropospheric abundance of OH. The simplest model that accounts for available observations requires a low latitude plant source of about 1.3 x 10 15 g yr -1 , in addition to sources from incomplete combustion of fossil fuels and oxidation of methane. The globally averaged OH concentration calculated in the model is 7 x 10 5 cm -3 . Models that calculate globally averaged OH concentrations much lower than our nominal value are not consistent with the observed variability of CO. Such models are also inconsistent with measurements of CO isotopic abundances, which imply the existence of plant sources

  1. CT of the brain in acute carbon monoxide poisoning

    International Nuclear Information System (INIS)

    Ohno, Masato; Uchino, Akira; Hayashi, Kazuji; Nakata, Hajime.

    1988-01-01

    Cerebral computed tomographic (CT) findings of acute carbon monoxide (Co) poisoning were analized in thirty-six cases treated with hyperbraric oxygen therapy and their relationship with prognosis was evaluated. The cases were classified into there groups, early stage, interval form, and non-interval form groups. In all groups, the initial abnormality was low density areas presumably due to edema, demyelination and/or softening. It was seen in the globus pallidus and/or white matter. Following these initial changes, cerebral hemorrhage, ventricular dilatation, and cerebral atrophy developed in a few cases. The frequency of abnormal CT findings was higher in the interval form group (85 %) or non-interval group (83 %) than the early stage group (41 %). The prognosis was good in most cases with normal CT findings. The possibility of recovery diminished in the patients with abnormal CT findings. The prognosis was particularly poor in cases showing abnormality both in globus pallidus and white matter. We conclude that CT is useful not only for detecting the pathologic change but also for predicting the prognosis of the patient with acute Co poisoning. (author)

  2. Brain CT scan in acute carbon monoxide poisoning

    International Nuclear Information System (INIS)

    We, En-Huei

    1986-01-01

    The brain CT findings in 19 patients with acute carbon monoxide poisoning was analysed and the emphasis was placed on the relationship between CT findings and prognosis. Five had a normal manifestation in CT ; eight had the findings of ovoid or patchy low density area in globus pallidus, bilateral or unlateral, during the second day to fifth week after poisoning, and the low density areas were decreasing and blurring in edge in follow up and at last disappeared during 3 - 14 weeks in three cases of them ; nine showed the appearance of diffuse low density of white matter and of globus pallidus in some of them ; two had an appearance of brain atrophy. The pathology of CT findings mentioned above may be brain edema, necrosis, malacia and degeneration in gray matter and globus pallidus. The result suggested the cases with normal CT manifestation, cerebral edema and decreasing and disappearing low density area had a good prognosis, in contrary, the cases with persistant low density in globus pallidus had a poorer prognosis. (author)

  3. Heme oxygenase and carbon monoxide protect from muscle dystrophy.

    Science.gov (United States)

    Chan, Mun Chun; Ziegler, Olivia; Liu, Laura; Rowe, Glenn C; Das, Saumya; Otterbein, Leo E; Arany, Zoltan

    2016-11-28

    Duchenne muscle dystrophy (DMD) is one of the most common lethal genetic diseases of children worldwide and is 100% fatal. Steroids, the only therapy currently available, are marred by poor efficacy and a high side-effect profile. New therapeutic approaches are urgently needed. Here, we leverage PGC-1α, a powerful transcriptional coactivator known to protect against dystrophy in the mdx murine model of DMD, to search for novel mechanisms of protection against dystrophy. We identify heme oxygenase-1 (HO-1) as a potential novel target for the treatment of DMD. Expression of HO-1 is blunted in the muscles from the mdx murine model of DMD, and further reduction of HO-1 by genetic haploinsufficiency worsens muscle damage in mdx mice. Conversely, induction of HO-1 pharmacologically protects against muscle damage. Mechanistically, HO-1 degrades heme into biliverdin, releasing in the process ferrous iron and carbon monoxide (CO). We show that exposure to a safe low dose of CO protects against muscle damage in mdx mice, as does pharmacological treatment with CO-releasing molecules. These data identify HO-1 and CO as novel therapeutic agents for the treatment of DMD. Safety profiles and clinical testing of inhaled CO already exist, underscoring the translational potential of these observations.

  4. Gene expression in rat striatum following carbon monoxide poisoning

    Directory of Open Access Journals (Sweden)

    Shuichi Hara

    2017-06-01

    Full Text Available Carbon monoxide (CO poisoning causes brain damage, which is attenuated by treatment with hydrogen [1,2], a scavenger selective to hydroxyl radical (·≡OH [3]. This suggests a role of ·≡OH in brain damage due to CO poisoning. Studies have shown strong enhancement of ·≡OH production in rat striatum by severe CO poisoning with a blood carboxyhemoglobin (COHb level >70% due to 3000 ppm CO, but not less severe CO poisoning with a blood COHb level at approximately 50% due to 1000 ppm CO [4]. Interestingly, 5% O2 causes hypoxia comparable with that by 3000 ppm CO and produces much less •OH than 3000 ppm CO does [4]. In addition, cAMP production in parallel with ·≡OH production [5] might contribute to ·≡OH production [6]. It is likely that mechanisms other than hypoxia contribute to brain damage due to CO poisoning [7]. To search for the mechanisms, we examined the effects of 1000 ppm CO, 3000 ppm CO and 5% O2 on gene expression in rat striatum. All array data have been deposited in the Gene Expression Omnibus (GEO database under accession number GSE94780.

  5. Experimental and clinical study of chronic poisoning by carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Thiele, H.; Gohlke, R.; Rothe, R.

    1973-01-01

    Animal and clinical tests on carbon monoxide-exposed subjects are described in an attempt to demonstrate the specific chronic action of CO. Rabbits exposed to 802 ppM and 284 ppM CO for 103 and 112 days, respectively, for 5 days a week showed carboxyhemoglobin values in the respective ranges of 2.5 to 11.9% and 2.5 to 8.3%. The macroscopic findings and gain in weight were normal, except for an increase by 20% and 14% in the weight of the liver. Dose-dependent increases in the hemoglobin and hematocrit levels, significant increases in the pyruvate level of the first group, and significant reductions of the cholinesterase, inorganic phosphate levels, hepatic lipase, phosphate, phosphatase, and cytochrome-C oxidase were observed. An increased cholinesterase level was found in brain homogenates. Inhibition of the glucose-6-phosphatase was observed. There is a specific damage due to CO in addition to merely the hypoxic effect. Clinical tests in humans with and without acute, subacute, or chronic exposure to CO revealed that acute and subacute poisoning have no additional pathogenic effect in chronic exposure, i.e., indicate the existence of primary chronic poisoning with CO.

  6. Subclinical carbon monoxide poisoning in our health area

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo, I.G.; Testa, A.F.; Sangrador, C.O.; Garcia, M.T.A.; Berrocal, J.L.S.; Pastor, N.R.; Martin, J.M.; Garcia, L.S.; Garcia, M.C.F.; Maire-Richard, E.G. [Hospital of Virgen Concha, Zamora (Spain)

    2003-08-01

    We present an observation study on the relationship between high levels of carboxyhemoglobin (COHB) and subclinical poisoning by carbon monoxide (CO) in our health area. The study was carried out in February and March 2000 in 228 over 18-year-old patients of both sexes who went to the Emergency Room for various reasons. After an informed consent was conceded, a venous blood sample was obtained in order to determine the level of COHB; later, we collected the anthropometric data, the data relative to the tobacco use, and the data of the type of heating at home. The values limit of the COHB obtained were the following: in non smokers, 1.9%; in 1-10 cigarettes/day smokers, 5.2%; in 11-20 cigarettes/day smokers, 6.9%; in {gt}20 cigarettes/day smokers, 9.6%. A COHB high level was observed in 25% of the patients regardless of the smoking habits, being the coal-dust slack brazier the source of most frequent exposure to CO.

  7. Magnetic resonance imaging of carbon monoxide poisoning in chronic stage

    International Nuclear Information System (INIS)

    Kojima, Shigeyuki; Kawamura, Mitsuru; Shibata, Noriyuki; Takahashi, Nobuyoshi; Hirayama, Keizo

    1986-01-01

    Magnetic resonance imaging (MRI) was evaluated in three patients with carbon monoxide (CO) poisoning in chronic stage by comparison with serial X-ray computed tomography (CT). In Case 1 and 3, no pallidal lesions believed to be the most common lesion of the gray matter in CO poisoning were found in the serial X-ray CT scans. In the other case (Case 2), the typical initial bilateral symmetrical low density areas in the globus pallidus were found to have decreased markedly in size and finally disappeared in the latter X-ray CT scan. But MRI using inversion recovery (IR) or spin echo (SE) pulse sequence clearly showed bilateral symmetrical decreased or increased signal intensity areas in the globus pallidus in all three cases. In Case 3, chronic CO poisoning was confirmed by the bilateral symmetrical pallidal lesions on MRI, although differential diagnosis was difficult. Furthermore, in Case 2, with pure alexia, MRI using IR or SE pulse sequence demonstrated a patchy decreased or increased signal intensity area in the subcortical white matter at the left angular gyrus, although X-ray CT scan showed no abnormal findings. MRI is useful in the diagnosis of CO poisoning, especially chronic CO poisoning, because necrosis, cavitation, demyelination, gliosis and so on due to hypoxia of CO poisoning were sensitively detected from changes in the proton density and the T1 or T2 relaxation time value on MRI. (J.P.N.)

  8. Optimization of mass flow rate in RGTT200K coolant purification for Carbon Monoxide conversion process

    International Nuclear Information System (INIS)

    Sumijanto; Sriyono

    2016-01-01

    Carbon monoxide is a species that is difficult to be separated from the reactor coolant helium because it has a relatively small molecular size. So it needs a process of conversion from carbon monoxide to carbondioxide. The rate of conversion of carbon monoxide in the purification system is influenced by several parameters including concentration, temperature and mass flow rate. In this research, optimization of the mass flow rate in coolant purification of RGTT200K for carbon monoxide conversion process was done. Optimization is carried out by using software Super Pro Designer. The rate of reduction of reactant species, the growth rate between the species and the species products in the conversion reactions equilibrium were analyzed to derive the mass flow rate optimization of purification for carbon monoxide conversion process. The purpose of this study is to find the mass flow rate of purification for the preparation of the basic design of the RGTT200K coolant helium purification system. The analysis showed that the helium mass flow rate of 0.6 kg/second resulted in an un optimal conversion process. The optimal conversion process was reached at a mass flow rate of 1.2 kg/second. A flow rate of 3.6 kg/second – 12 kg/second resulted in an ineffective process. For supporting the basic design of the RGTT200K helium purification system, the mass flow rate for carbon monoxide conversion process is suggested to be 1.2 kg/second. (author)

  9. Carbon monoxide exposure in households in Ciudad Juárez, México.

    Science.gov (United States)

    Montoya, Teresa; Gurian, Patrick L; Velázquez-Angulo, Gilberto; Corella-Barud, Verónica; Rojo, Analila; Graham, Jay P

    2008-03-01

    This study assessed exposure to carbon monoxide from gas and wood heater emissions in a sample of 64 households in peri-urban residential areas in Ciudad Juárez, Chihuahua, México. Indoor and outdoor carbon monoxide concentrations and temperatures were monitored for a continuous period of 1 week at 1 and 6-min intervals, respectively. The moving average carbon monoxide concentrations were compared to the World Health Organization (WHO) standards for carbon monoxide. Sixty-seven percent of households with gas heaters and 60% of households with wood heaters exceeded a health-based standard at some point during the monitoring. The difference between indoor and outdoor temperatures was modestly correlated with average carbon monoxide exposure (r=0.35, p-value h standard of 9ppm (odds ratio=5.1, p-value=0.031). These results highlight the need for further efforts to identify and mitigate potentially hazardous carbon monoxide exposures, particularly in moderate-income countries with cooler climates.

  10. Lithium storage properties of multiwall carbon nanotubes prepared by CVD

    International Nuclear Information System (INIS)

    Ahn, J.-O.; Andong National University,; Wang, G.X.; Liu, H.K.; Dou, S.X.

    2003-01-01

    Full text: Multiwall carbon nanotubes (MWCNTs) were synthesised by chemical vapour deposition (CVD) method using acetylene gas. The XRD pattern of as prepared carbon nanotubes showed that the d 002 value is 3.44 Angstroms. The morphology and microstructure of carbon nanotubes were characterized by HRTEM. Most of carbon nanotubes are entangled together to form bundles or ropes. The diameter of the carbon nanotubes is in the range of 10 ∼ 20 nm. There is a small amount of amorphous carbon particles presented in the sample. However, the yield of carbon nanotubes is more than 95%. Electrochemical properties of carbon nanotubes were characterised via a variety of electrochemical testing techniques. The result of CV test showed that the Li insertion potential is quite low, which is very close to O V versus Li + /Li reference electrode, whereas the potential for Li de-intercalation is in the range of 0.2-0.4 V. There exists a slight voltage hysteresis between Li intercalation and Li de-intercalation, which is similar to the other carbonaceous materials. The intensity of redox peaks of carbon nanotubes decrease with scanning cycle, indicating that the reversible Li insertion capacity gradually decreases. The carbon nanotubes electrode demonstrated a reversible lithium storage capacity of 340 mAh/g with good cyclability at moderate current density. Further improvement of Li storage capacity is possible by opening the end of carbon nanotubes to allow lithium insertion into inner graphene sheet of carbon nanotubes. The kinetic properties of lithium insertion in carbon nanotube electrodes were characterised by a.c. impedance measurements. It was found that the lithium diffusion coefficient d Li decreases with an increase of Li ion concentration in carbon nanotube host

  11. Nicotine adsorption on single wall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Girao, Eduardo C. [Departamento de Fisica, Universidade Federal do Ceara, Caixa Postal 6030, Campus do Pici, 60455-900 Fortaleza, Ceara (Brazil); Fagan, Solange B.; Zanella, Ivana [Area de Ciencias Tecnologicas, Centro Universitario Franciscano - UNIFRA, 97010-032 Santa Maria, RS (Brazil); Filho, Antonio G. Souza, E-mail: agsf@fisica.ufc.br [Departamento de Fisica, Universidade Federal do Ceara, Caixa Postal 6030, Campus do Pici, 60455-900 Fortaleza, Ceara (Brazil)

    2010-12-15

    This work reports a theoretical study of nicotine molecules interacting with single wall carbon nanotubes (SWCNTs) through ab initio calculations within the framework of density functional theory (DFT). Different adsorption sites for nicotine on the surface of pristine and defective (8,0) SWCNTs were analyzed and the total energy curves, as a function of molecular position relative to the SWCNT surface, were evaluated. The nicotine adsorption process is found to be energetically favorable and the molecule-nanotube interaction is intermediated by the tri-coordinated nitrogen atom from the nicotine. It is also predicted the possibility of a chemical bonding between nicotine and SWCNT through the di-coordinated nitrogen.

  12. Energy structure of fullerenes and carbon nanotubes

    International Nuclear Information System (INIS)

    Byszewski, P.; Kowalska, E.

    1997-01-01

    The absorption spectrum of C 60 can be reasonably well reproduced theoretically with the use of the quantum chemistry calculation methods. It allows investigation of the influence of a deformation of C 60 on the absorption spectrum. The deformation of the electronic density on C 60 can occur under the influence of molecules of good solvent. Similar calculations of the energetic structure of carbon nanotubes does not support the idea that their chirality may strongly influence the energy levels distribution, in particular that it may open the energy gap of nanotubes. (author). 40 refs, 13 figs, 1 tab

  13. Aligned carbon nanotubes patterned photolithographically by silver

    Science.gov (United States)

    Huang, Shaoming; Mau, Albert H. W.

    2003-02-01

    Selective growth of aligned carbon nanotubes (CNTs) by pyrolysis of iron (II) phthalocyanine (FePc) on quartz substrate patterned photolithographically by metallic silver has been demonstrated. Micro/nanopattern of aligned CNTs can be achieved by using a photomask with features on a microscale. With convenient use of simple high-contract black and white films as a photomask, aligned nanotubes patterned with 20 μm resolution in large scale can be fabricated. This practical fabrication of aligned CNTs on patterned conducting substrate could be applied to various device applications of CNTs.

  14. Vertically aligned multiwalled carbon nanotubes as electronic interconnects

    Science.gov (United States)

    Gopee, Vimal Chandra

    The drive for miniaturisation of electronic circuits provides new materials challenges for the electronics industry. Indeed, the continued downscaling of transistor dimensions, described by Moore’s Law, has led to a race to find suitable replacements for current interconnect materials to replace copper. Carbon nanotubes have been studied as a suitable replacement for copper due to its superior electrical, thermal and mechanical properties. One of the advantages of using carbon nanotubes is their high current carrying capacity which has been demonstrated to be three orders of magnitude greater than that of copper. Most approaches in the implementation of carbon nanotubes have so far focused on the growth in vias which limits their application. In this work, a process is described for the transfer of carbon nanotubes to substrates allowing their use for more varied applications. Arrays of vertically aligned multiwalled carbon nanotubes were synthesised by photo-thermal chemical vapour deposition with high growth rates. Raman spectroscopy was used to show that the synthesised carbon nanotubes were of high quality. The carbon nanotubes were exposed to an oxygen plasma and the nature of the functional groups present was determined using X-ray photoelectron spectroscopy. Functional groups, such as carboxyl, carbonyl and hydroxyl groups, were found to be present on the surface of the multiwalled carbon nanotubes after the functionalisation process. The multiwalled carbon nanotubes were metallised after the functionalisation process using magnetron sputtering. Two materials, solder and sintered silver, were chosen to bind carbon nanotubes to substrates so as to enable their transfer and also to make electrical contact. The wettability of solder to carbon nanotubes was investigated and it was demonstrated that both functionalisation and metallisation were required in order for solder to bond with the carbon nanotubes. Similarly, functionalisation followed by metallisation

  15. Functionalization of vertically aligned carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Eloise Van Hooijdonk

    2013-02-01

    Full Text Available This review focuses and summarizes recent studies on the functionalization of carbon nanotubes oriented perpendicularly to their substrate, so-called vertically aligned carbon nanotubes (VA-CNTs. The intrinsic properties of individual nanotubes make the VA-CNTs ideal candidates for integration in a wide range of devices, and many potential applications have been envisaged. These applications can benefit from the unidirectional alignment of the nanotubes, the large surface area, the high carbon purity, the outstanding electrical conductivity, and the uniformly long length. However, practical uses of VA-CNTs are limited by their surface characteristics, which must be often modified in order to meet the specificity of each particular application. The proposed approaches are based on the chemical modifications of the surface by functionalization (grafting of functional chemical groups, decoration with metal particles or wrapping of polymers to bring new properties or to improve the interactions between the VA-CNTs and their environment while maintaining the alignment of CNTs.

  16. Carbon monoxide and methane adsorption of crude oil refinery using activated carbon from palm shells as biosorbent

    Science.gov (United States)

    Yuliusman; Afdhol, M. K.; Sanal, Alristo

    2018-03-01

    Carbon monoxide and methane gas are widely present in oil refineries. Off-potential gas is used as raw material for the petrochemical industry. In order for this off-gas to be utilized, carbon monoxide and methane must be removed from off-gas. This study aims to adsorb carbon monoxide and methane using activated carbon of palm shells and commercial activated carbon simultaneously. This research was conducted in 2 stages: 1) Preparation and characterization of activated carbon, 2) Carbon monoxide and methane adsorption test. The activation experiments using carbon dioxide at a flow rate of 150 ml/min yielded a surface area of 978.29 m2/g, Nitrogen at flow rate 150 ml/min yielded surface area 1241.48 m2/g, and carbon dioxide and nitrogen at a flow rate 200 ml/min yielded a surface area 300.37 m2/g. Adsorption of carbon monoxide and methane on activated carbon of palm shell systems yielded results in the amount of 0.5485 mg/g and 0.0649 mg/g and using commercial activated carbon yielded results in the amount of 0.5480 mg/g and 0.0650 mg/g

  17. Optical trapping of carbon nanotubes and graphene

    Directory of Open Access Journals (Sweden)

    S. Vasi

    2011-09-01

    Full Text Available We study optical trapping of nanotubes and graphene. We extract the distribution of both centre-of-mass and angular fluctuations from three-dimensional tracking of these optically trapped carbon nanostructures. The optical force and torque constants are measured from auto and cross-correlation of the tracking signals. We demonstrate that nanotubes enable nanometer spatial, and femto-Newton force resolution in photonic force microscopy by accurately measuring the radiation pressure in a double frequency optical tweezers. Finally, we integrate optical trapping with Raman and photoluminescence spectroscopy demonstrating the use of a Raman and photoluminescence tweezers by investigating the spectroscopy of nanotubes and graphene flakes in solution. Experimental results are compared with calculations based on electromagnetic scattering theory.

  18. C{sub 60} fullerene decoration of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Demin, V. A., E-mail: victordemin88@gmail.com [Russian Academy of Sciences, Emanuel Institute of Biochemical Physics (Russian Federation); Blank, V. D.; Karaeva, A. R.; Kulnitskiy, B. A.; Mordkovich, V. Z. [Technological Institute for Superhard and Novel Carbon Materials (Russian Federation); Parkhomenko, Yu. N. [National University of Science and Technology MISiS (Russian Federation); Perezhogin, I. A.; Popov, M. Yu. [Technological Institute for Superhard and Novel Carbon Materials (Russian Federation); Skryleva, E. A. [National University of Science and Technology MISiS (Russian Federation); Urvanov, S. A. [Technological Institute for Superhard and Novel Carbon Materials (Russian Federation); Chernozatonskii, L. A. [Russian Academy of Sciences, Emanuel Institute of Biochemical Physics (Russian Federation)

    2016-12-15

    A new fully carbon nanocomposite material is synthesized by the immersion of carbon nanotubes in a fullerene solution in carbon disulfide. The presence of a dense layer of fullerene molecules on the outer nanotube surface is demonstrated by TEM and XPS. Fullerenes are redistributed on the nanotube surface during a long-term action of an electron beam, which points to the existence of a molecular bond between a nanotube and fullerenes. Theoretical calculations show that the formation of a fullerene shell begins with the attachment of one C{sub 60} molecule to a defect on the nanotube surface.

  19. Carbon nanotubes: Sensor properties. A review

    Directory of Open Access Journals (Sweden)

    Irina V. Zaporotskova

    2016-12-01

    Full Text Available Recent publications dealing with dealing with the fabrication of gas and electrochemical biosensors based on carbon nanotubes have been reviewed. Experimental and theoretical data on the working principles of nanotubes have been presented. The main regularities of the structure, energy parameters and sensor properties of modified semiconducting systems on the basis of cabon nanotubes have been studied by analyzing the mechanisms of nanotubule interaction with functional groups (including carboxyl and amino groups, metallic nanoparticles and polymers leading to the formation of chemically active sensors. The possibility of using boundary modified nanotubes for the identification of metals has been discussed. Simulation results have been reported for the interaction of nanotubes boundary modified by –СООН and –NH2 groups with atoms and ions of potassium, sodium and lithium. The simulation has been carried out using the molecular cluster model and the MNDO and DFT calculation methods. Sensors fabricated using this technology will find wide application for the detection of metallic atoms and their ions included in salts and alkali.

  20. Use of Functionalized Carbon Nanotubes for Covalent Attachment of Nanotubes to Silicon

    Science.gov (United States)

    Tour, James M.; Dyke, Christopher A.; Maya, Francisco; Stewart, Michael P.; Chen, Bo; Flatt, Austen K.

    2012-01-01

    The purpose of the invention is to covalently attach functionalized carbon nanotubes to silicon. This step allows for the introduction of carbon nanotubes onto all manner of silicon surfaces, and thereby introduction of carbon nano - tubes covalently into silicon-based devices, onto silicon particles, and onto silicon surfaces. Single-walled carbon nanotubes (SWNTs) dispersed as individuals in surfactant were functionalized. The nano - tube was first treated with 4-t-butylbenzenediazonium tetrafluoroborate to give increased solubility to the carbon nanotube; the second group attached to the sidewall of the nanotube has a silyl-protected terminal alkyne that is de-protected in situ. This gives a soluble carbon nanotube that has functional groups appended to the sidewall that can be attached covalently to silicon. This reaction was monitored by UV/vis/NJR to assure direct covalent functionalization.

  1. Carbon Micronymphaea: Graphene on Vertically Aligned Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Jong Won Choi

    2013-01-01

    Full Text Available This paper describes the morphology of carbon nanomaterials such as carbon nanotube (CNT, graphene, and their hybrid structure under various operating conditions during a one-step synthesis via plasma-enhanced chemical vapor deposition (PECVD. We focus on the synthetic aspects of carbon hybrid material composed of heteroepitaxially grown graphene on top of a vertical array of carbon nanotubes, called carbon micronymphaea. We characterize the structural features of this unique nanocomposite by uses of electron microscopy and micro-Raman spectroscopy. We observe carbon nanofibers, poorly aligned and well-aligned vertical arrays of CNT sequentially as the growth temperature increases, while we always discover the carbon hybrids, called carbon micronymphaea, at specific cooling rate of 15°C/s, which is optimal for the carbon precipitation from the Ni nanoparticles in this study. We expect one-pot synthesized graphene-on-nanotube hybrid structure poses great potential for applications that demand ultrahigh surface-to-volume ratios with intact graphitic nature and directional electronic and thermal transports.

  2. Optimization of the sintering atmosphere for high-density hydroxyapatite–carbon nanotube composites

    Science.gov (United States)

    White, Ashley A.; Kinloch, Ian A.; Windle, Alan H.; Best, Serena M.

    2010-01-01

    Hydroxyapatite–carbon nanotube (HA–CNT) composites have the potential for improved mechanical properties over HA for use in bone graft applications. Finding an appropriate sintering atmosphere for this composite presents a dilemma, as HA requires water in the sintering atmosphere to remain phase pure and well hydroxylated, yet CNTs oxidize at the high temperatures required for sintering. The purpose of this study was to optimize the atmosphere for sintering these composites. While the reaction between carbon and water to form carbon monoxide and hydrogen at high temperatures (known as the ‘water–gas reaction’) would seem to present a problem for sintering these composites, Le Chatelier's principle suggests this reaction can be suppressed by increasing the concentration of carbon monoxide and hydrogen relative to the concentration of carbon and water, so as to retain the CNTs and keep the HA's structure intact. Eight sintering atmospheres were investigated, including standard atmospheres (such as air and wet Ar), as well as atmospheres based on the water–gas reaction. It was found that sintering in an atmosphere of carbon monoxide and hydrogen, with a small amount of water added, resulted in an optimal combination of phase purity, hydroxylation, CNT retention and density. PMID:20573629

  3. Carbon nanotubes and graphene in analytical sciences

    International Nuclear Information System (INIS)

    Perez-Lopez, B.; Merkoci, A.

    2012-01-01

    Nanosized carbon materials are offering great opportunities in various areas of nanotechnology. Carbon nanotubes and graphene, due to their unique mechanical, electronic, chemical, optical and electrochemical properties, represent the most interesting building blocks in various applications where analytical chemistry is of special importance. The possibility of conjugating carbon nanomaterials with biomolecules has received particular attention with respect to the design of chemical sensors and biosensors. This review describes the trends in this field as reported in the last 6 years in (bio)analytical chemistry in general, and in biosensing in particular. (author)

  4. Carbon nanotube formation by laser direct writing

    International Nuclear Information System (INIS)

    Wu, Y.-T.; Su, H.-C.; Tsai, C.-M.; Liu, K.-L.; Chen, G.-D.; Huang, R.-H.; Yew, T.-R.

    2008-01-01

    This letter presents carbon nanotube (CNT) formation by laser direct writing using 248 nm KrF excimer pulsed laser in air at room temperature, which was applied to irradiate amorphous carbon (a-C) assisted by Ni catalysts underneath for the transformation of carbon species into CNTs. The CNTs were synthesized under appropriate combination of laser energy density and a-C thickness. The growth mechanism and key parameters to determine the success of CNT formation were also discussed. The demonstration of the CNT growth by laser direct writing in air at room temperature opens an opportunity of in-position CNT formation at low temperatures

  5. Remote Joule heating by a carbon nanotube.

    Science.gov (United States)

    Baloch, Kamal H; Voskanian, Norvik; Bronsgeest, Merijntje; Cumings, John

    2012-04-08

    Minimizing Joule heating remains an important goal in the design of electronic devices. The prevailing model of Joule heating relies on a simple semiclassical picture in which electrons collide with the atoms of a conductor, generating heat locally and only in regions of non-zero current density, and this model has been supported by most experiments. Recently, however, it has been predicted that electric currents in graphene and carbon nanotubes can couple to the vibrational modes of a neighbouring material, heating it remotely. Here, we use in situ electron thermal microscopy to detect the remote Joule heating of a silicon nitride substrate by a single multiwalled carbon nanotube. At least 84% of the electrical power supplied to the nanotube is dissipated directly into the substrate, rather than in the nanotube itself. Although it has different physical origins, this phenomenon is reminiscent of induction heating or microwave dielectric heating. Such an ability to dissipate waste energy remotely could lead to improved thermal management in electronic devices.

  6. Graphene nanoribbons production from flat carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Melo, W. S.; Guerini, S.; Diniz, E. M., E-mail: eduardo.diniz@ufma.br [Departamento de Física, Universidade Federal do Maranhão, São Luís - MA 65080-805 (Brazil)

    2015-11-14

    Graphene nanoribbons are of great interest for pure and applied sciences due to their unique properties which depend on the nanoribbon edges, as, for example, energy gap and antiferromagnetic coupling. Nevertheless, the synthesis of nanoribbons with well-defined edges remains a challenge. To collaborate with this subject, here we propose a new route for the production of graphene nanoribbons from flat carbon nanotubes filled with a one-dimensional chain of Fe atoms by first principles calculations based on density functional theory. Our results show that Fe-filled flat carbon nanotubes are energetically more stable than non flattened geometries. Also we find that by hydrogenation or oxygenation of the most curved region of the Fe-filled flat armchair carbon nanotube, it occurred a spontaneous production of zigzag graphene nanoribbons which have metallic or semiconducting behavior depending on the edge and size of the graphene nanoribbon. Such findings can be used to create a new method of synthesis of regular-edge carbon nanoribbons.

  7. Graphene nanoribbons production from flat carbon nanotubes

    International Nuclear Information System (INIS)

    Melo, W. S.; Guerini, S.; Diniz, E. M.

    2015-01-01

    Graphene nanoribbons are of great interest for pure and applied sciences due to their unique properties which depend on the nanoribbon edges, as, for example, energy gap and antiferromagnetic coupling. Nevertheless, the synthesis of nanoribbons with well-defined edges remains a challenge. To collaborate with this subject, here we propose a new route for the production of graphene nanoribbons from flat carbon nanotubes filled with a one-dimensional chain of Fe atoms by first principles calculations based on density functional theory. Our results show that Fe-filled flat carbon nanotubes are energetically more stable than non flattened geometries. Also we find that by hydrogenation or oxygenation of the most curved region of the Fe-filled flat armchair carbon nanotube, it occurred a spontaneous production of zigzag graphene nanoribbons which have metallic or semiconducting behavior depending on the edge and size of the graphene nanoribbon. Such findings can be used to create a new method of synthesis of regular-edge carbon nanoribbons

  8. Carbon nanotube based stationary phases for microchip chromatography

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; Kutter, Jörg Peter

    2012-01-01

    already been demonstrated in more classical formats, for improved separation performance in gas and liquid chromatography, and for unique applications in solid phase extraction. Carbon nanotubes are now also entering the field of microfluidics, where there is a large potential to be able to provide......The objective of this article is to provide an overview and critical evaluation of the use of carbon nanotubes and related carbon-based nanomaterials for microchip chromatography. The unique properties of carbon nanotubes, such as a very high surface area and intriguing adsorptive behaviour, have...... integrated, tailor-made nanotube columns by means of catalytic growth of the nanotubes inside the fluidic channels. An evaluation of the different implementations of carbon nanotubes and related carbon-based nanomaterials for microfluidic chromatography devices is given in terms of separation performance...

  9. The Mossbauer spectra of carbon nanotubes synthesize using ferrite catalyst

    International Nuclear Information System (INIS)

    Zhang Haiyan; Lin Jiapeng; Peng Zuxiong; Zeng Guoxun; Pang Jinshan; Chen Yiming

    2009-01-01

    The ferrite powder with honeycombed structure obtained by chemical combustion was used as catalyst to synthesize multi-walled carbon nanotubes by chemical vapor deposition. The magnetic components and characters of the the carbon nanotubes synthesized were investigated by X-ray diffraction (XRD), Mossbauer spectra and vibrating-sample magnetometer (VSM). The ferric components of the carbon nanotubes samples can be identified by Mossbauer spectra. The Mossbauer spectra of carbon nanotubes sample after purification contains two ferromagnetic sextet components corresponding to α-Fe species and Fe 3 C (cementite) species. While the Mossbauer spectra of the carbon nanotubes sample before purification contains three ferromagnetic sextet components corresponding to α-Fe species, Fe 3 C species and γ-Fe 2 O 3 . The saturation magnetization intensity Ms of carbon nanotubes sample after purification is decreased from 46.61 to 2.94 emu/g, but the coercive force increasd and reached 328Oe.

  10. Electrophoretic deposition and field emission properties of patterned carbon nanotubes

    International Nuclear Information System (INIS)

    Zhao Haifeng; Song Hang; Li Zhiming; Yuan Guang; Jin Yixin

    2005-01-01

    Patterned carbon nanotubes on silicon substrates were obtained using electrophoretic method. The carbon nanotubes migrated towards the patterned silicon electrode in the electrophoresis suspension under the applied voltage. The carbon nanotubes arrays adhered well on the silicon substrates. The surface images of carbon nanotubes were observed by scanning electron microscopy. The field emission properties of the patterned carbon nanotubes were tested in a diode structure under a vacuum pressure below 5 x 10 -4 Pa. The measured emission area was about 1.0 mm 2 . The emission current density up to 30 mA/cm 2 at an electric field of 8 V/μm has been obtained. The deposition of patterned carbon nanotubes by electrophoresis is an alternative method to prepare field emission arrays

  11. Ag-catalysed cutting of multi-walled carbon nanotubes

    International Nuclear Information System (INIS)

    La Torre, A; Rance, G A; Miners, S A; Lucas, C Herreros; Smith, E F; Giménez-López, M C; Khlobystov, A N; Fay, M W; Brown, P D; Zoberbier, T; Kaiser, U

    2016-01-01

    In this work, the cutting of carbon nanotubes is investigated using silver nanoparticles deposited on arc discharge multi-walled carbon nanotubes. The composite is subsequently heated in air to fabricate shortened multi-walled nanotubes. Complementary transmission electron microscopy and spectroscopy techniques shed light on the cutting mechanism. The nanotube cutting is catalysed by the fundamental mechanism based on the coordination of the silver atoms to the π-bonds of carbon nanotubes. As a result of the metal coordination, the strength of the carbon–carbon bond is reduced, promoting the oxidation of carbon at lower temperature when heated in air, or lowering the activation energy required for the removal of carbon atoms by electron beam irradiation, assuring in both cases the cutting of the nanotubes. (paper)

  12. The conversion of polyaniline nanotubes to nitrogen-containing carbon nanotubes and their comparison with multi-walled carbon nanotubes

    Czech Academy of Sciences Publication Activity Database

    Trchová, Miroslava; Konyushenko, Elena; Stejskal, Jaroslav; Kovářová, Jana; Ciric-Marjanovic, G.

    2009-01-01

    Roč. 94, č. 6 (2009), s. 929-938 ISSN 0141-3910 R&D Projects: GA ČR GA203/08/0686; GA AV ČR IAA400500905 Institutional research plan: CEZ:AV0Z40500505 Keywords : carbon nanotubes * carbonization * FTIR spectroscopy Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.154, year: 2009

  13. Conversion of carbon monoxide intensities tomolecular hydrogen abundances

    International Nuclear Information System (INIS)

    Kutner, M.L.; Leung, C.M.

    1985-01-01

    We present results of theoretical models (static spherical clouds with a microturbulent velocity field) to study the conversion of carbon monoxide (CO) line parameters into molecular hydrogen (H 2 ) column densities, N2. The three potential H 2 tracers that we investigate are the integrated 12 CO and 13 CO intensities, I 12 and I 13 , and the 13 CO LTE column density, N( 13 . We find that I 12 may be a reasonable tracer of N2 under conditions appropriate to the envelopes of giant molecular clouds and for studies involving cloud ensembles of different cloud sizes and velocity dispersions. However, it saturates under higher density conditions. It is important that empirical conversion factors be set using the types of objects to which they will be applied. For this reason, our analysis suggests that the conversion factor N2/I 12 for giant molecular clouds in the molecular ring of our galaxy may be a factor of 2 lower than the average used by many observers. This lower value is supported by some recent empirical determinations. The quantity I 13 is a good tracer of N2 over a wide range of densities but it is more sensitive to the actual 13 CO abundance. The quantity N( 13 is similar to I 13 as a good tracer of N2 except at low densities and temperatures. The ratio I 12 /I 13 may be used to delineate temperature and column density effects. Finally, we find a strong temperature dependence in the various conversion factors, with N2/I 12 scaling with gas temperature (T/sub k/ approximately as (T/sub k/)/sup -1.3/

  14. Magnetic Resonance Imaging Findings in Chronic Carbon Monoxide Intoxication

    Energy Technology Data Exchange (ETDEWEB)

    Durak, A. C.; Coskun, A.; Yikilmaz, A.; Erdogan, F.; Mavili, E.; Guven, M. [Hospital of Erciyes Univ., Kayseri (Turkey). Dept. of Radiology

    2005-05-01

    Purpose: To define the cranial magnetic resonance imaging (MRI) features of the chronic stage of carbon monoxide (CO) poisoning in patients with and without neuropsychiatric sequelae. Material and Methods: Eight patients who had neither symptoms nor neurological sequelae and eight patients with neuropsychiatric sequelae were included in the study. Patients aged between 9 to 57 (mean 32.2 years). All patients had been comatose at initial admittance and awoke after normobaric 100% oxygen therapy within 1-7 days. In this study, the patients were being examined with routine cranial MRI between 1 and 10 years (mean 3.4 years) after exposure to CO. Results: The most common finding was bilateral symmetric hyperintensity of the white matter, which was more significant in the centrum semiovale, with relative sparing of the temporal lobes and anterior parts of the frontal lobes on T2-weighted and FLAIR images in all patients. Cerebral cortical atrophy was seen in 10 patients; mild atrophy of cerebellar hemispheres in 8; and vermian atrophy in 11. Corpus callosum was atrophic in one patient. Bilateral globus pallidus lesions were seen in three patients. The lesions were hypointense on T1-weighted images and hyperintense on T2-weighted and FLAIR images. Conclusion: Patients with severe CO intoxication may develop persistent cerebral changes independently of their neuropsychiatric findings in the chronic stage. They may present with characteristic MRI findings as described here, even if asymptomatic. The history of CO exposure is therefore helpful for recognizing and interpreting the MRI findings of chronic stage CO intoxication.

  15. Erythropoietin in the treatment of carbon monoxide neurotoxicity in rat.

    Science.gov (United States)

    Moallem, Seyed Adel; Mohamadpour, Amir Hooshang; Abnous, Khalil; Sankian, Mojtaba; Sadeghnia, Hamid Reza; Tsatsakis, Aristidis; Shahsavand, Shabnam

    2015-12-01

    Erythropoietin (EPO) plays a critical role in the development of the nervous system. In this study, the effects of EPO in carbon monoxide (CO) neurotoxicity were examined. Rats were exposed to 3000 ppm CO for 1 h and then different doses of EPO were administrated intraperitoneally. After 24 h, glial fibrillary acidic protein (GFAP) levels in the serum were determined and water content of brain and the extravasation of a tracer (Evans blue) were measured. Brain lipid peroxidation, myeloperoxidase activity Myelin basic protein (MBP) and BAX/BcL2 protein relative expressions were determined. Cation exchange chromatography was used to evaluate MBP alterations. Seven days after exposure, pathological assessment was performed after Klüver-Barrera staining. EPO reduced malondialdehyde levels at all doses (2500, 5000 and 10,000 u/kg). Lower doses of EPO (625, 1250, 2500 u/kg) significantly decreased the elevated serum levels of GFAP. EPO could not reduce the water content of the edematous poisoned brains. However, at 5000 and 10,000 u/kg it protected the blood brain barrier against integrity loss as a result of CO. EPO could significantly decrease the MPO activity. CO-mediated oxidative stress caused chemical alterations in MBP and EPO could partially prevent these biochemical changes. Fewer vacuoles and demyelinated fibers were found in the EPO-treated animals. EPO (5000 u/kg) could restore the MBP density. CO increased brain BAX/Bcl-2 ratio 38.78%. EPO reduced it 38.86%. These results reveal that EPO could relatively prevent different pathways of neurotoxicity by CO poisoning and thus has the potential to be used as a novel approach to manage this poisoning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Carbon Monoxide in Meat and Fish Packaging: Advantages and Limits

    Science.gov (United States)

    Roncalés, Pedro

    2018-01-01

    Due to increased demands for greater expectation in relation to quality, convenience, safety and extended shelf-life, combined with growing demand from retailers for cost-effective extensions of fresh muscle foods’ shelf-life, the food packaging industry quickly developed to meet these expectations. During the last few decades, modified atmosphere packaging (MAP) of foods has been a promising area of research, but much remains to be known regarding the use of unconventional gases such carbon monoxide (CO). The use of CO for meat and seafood packaging is not allowed in most countries due to the potential toxic effect, and its use is controversial in some countries. The commercial application of CO in food packaging was not then considered feasible because of possible environmental hazards for workers. CO has previously been reported to mask muscle foods’ spoilage, and this was the primary concern raised for the prohibition, as this may mislead consumers. This review was undertaken to present the most comprehensive and current overview of the widely-available, scattered information about the use of CO in the preservation of muscle foods. The advantages of CO and its industrial limits are presented and discussed. The most recent literature on the consumer safety issues related to the use of CO and consumer acceptance of CO especially in meat packaging systems were also discussed. Recommendations and future prospects were addressed for food industries, consumers and regulators on what would be a “best practice” in the use of CO in food packaging. All this promotes high ethical standards in commercial communications by means of effective regulation, for the benefit of consumers and businesses in the world, and this implies that industrialized countries and members of their regulatory agencies must develop a coherent and robust systems of regulation and control that can respond effectively to new challenges. PMID:29360803

  17. Unusual way of suicide by carbon monoxide. Case Report.

    Science.gov (United States)

    Zelený, Michal; Pivnička, Jan; Šindler, Martin; Kukleta, Pavel

    2015-01-01

    Authors discuss the case of a suicide of a 29-year-old man caused by carbon monoxide (CO) intoxication. What the authors found interesting was the unusual way of committing suicide that required good technical skills and expert knowledge. The level of carboxyhemoglobin (COHb) in the blood of the deceased man was routinely determined by the modified method by Blackmoore (1970), using gas chromatography/thermal conductivity detection. The level of saturation of the hemoglobin by CO in the collected blood sample is determined relatively to the same sample saturated to 100%. In the blood sample of the deceased man the lethal concentration of COHb of 76.5% was determined. Within the following examinations the blood alcohol concentration of 0.05 g.kg(-1) was determined. Further analysis revealed traces of sertraline, its metabolite N-desmethylsertraline, omeprazole and caffeine in the liver tissue, traces of N-desmethylsertraline, ibuprofen and caffeine in urine sample, and only traces of caffeine in the stomach content and blood samples were proved. To commit suicide the man used a sophisticated double container-system equipped with a timer for controlled generation of CO based on the chemical reaction of concentrated sulphuric acid and formic acid. The used timer was set by an electromechanical timer switch that triggered the fatal reaction of the acids while the man was sleeping. The authors discuss an unusual case of suicide by CO intoxication rarely seen in the area of forensic medicine and toxicology that is specific due to its sophisticated way of execution.

  18. CROSS-CORRELATIONS AS A COSMOLOGICAL CARBON MONOXIDE DETECTOR

    International Nuclear Information System (INIS)

    Pullen, Anthony R.; Doré, Olivier; Chang, Tzu-Ching; Lidz, Adam

    2013-01-01

    We present a new procedure to measure the large-scale carbon monoxide (CO) emissions across cosmic history. As a tracer of large-scale structure (LSS), the CO gas content as a function of redshift can be quantified by its three-dimensional fluctuation power spectra. Furthermore, cross-correlating CO emission with other LSS tracers offers a way to measure the emission as a function of scale and redshift. Here we introduce the model relevant for such a cross-correlation measurement between CO and other LSS tracers, and between different CO rotational lines. We propose a novel use of cosmic microwave background (CMB) data and attempt to extract redshifted CO emissions embedded in the Wilkinson Microwave Anisotropy Probe (WMAP) data set. We cross-correlate the all-sky WMAP7 data with LSS data sets, namely, the photometric quasar sample and the luminous red galaxy sample from the Sloan Digital Sky Survey Data Releases 6 and 7, respectively. We are unable to detect a cross-correlation signal with either CO(1-0) or CO(2-1) lines, mainly due to the instrumental noise in the WMAP data. However, we are able to rule out models more than three times greater than our more optimistic model. We discuss the cross-correlation signal from the thermal Sunyaev-Zeldovich effect and dust as potential contaminants, and quantify their impact for our CO measurements. We discuss forecasts for current CMB experiments and a hypothetical future CO-focused experiment, and propose to cross-correlate CO temperature data with the Hobby-Eberly Telescope Dark Energy Experiment Lyα-emitter sample, for which a signal-to-noise ratio of 58 is possible.

  19. Carbon monoxide inhalation increases microparticles causing vascular and CNS dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jiajun; Yang, Ming [Department of Emergency Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 (United States); Kosterin, Paul [Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 (United States); Salzberg, Brian M. [Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 (United States); Milovanova, Tatyana N.; Bhopale, Veena M. [Department of Emergency Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 (United States); Thom, Stephen R., E-mail: sthom@smail.umaryland.edu [Department of Emergency Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 (United States)

    2013-12-01

    We hypothesized that circulating microparticles (MPs) play a role in pro-inflammatory effects associated with carbon monoxide (CO) inhalation. Mice exposed for 1 h to 100 ppm CO or more exhibit increases in circulating MPs derived from a variety of vascular cells as well as neutrophil activation. Tissue injury was quantified as 2000 kDa dextran leakage from vessels and as neutrophil sequestration in the brain and skeletal muscle; and central nervous system nerve dysfunction was documented as broadening of the neurohypophysial action potential (AP). Indices of injury occurred following exposures to 1000 ppm for 1 h or to 1000 ppm for 40 min followed by 3000 ppm for 20 min. MPs were implicated in causing injuries because infusing the surfactant MP lytic agent, polyethylene glycol telomere B (PEGtB) abrogated elevations in MPs, vascular leak, neutrophil sequestration and AP prolongation. These manifestations of tissue injury also did not occur in mice lacking myeloperoxidase. Vascular leakage and AP prolongation were produced in naïve mice infused with MPs that had been obtained from CO poisoned mice, but this did not occur with MPs obtained from control mice. We conclude that CO poisoning triggers elevations of MPs that activate neutrophils which subsequently cause tissue injuries. - Highlights: • Circulating microparticles (MPs) increase in mice exposed to 100 ppm CO or more. • MPs are lysed by infusing the surfactant polyethylene glycol telomere B. • CO-induced MPs cause neutrophil activation, vascular leak and CNS dysfunction. • Similar tissue injuries do not arise with MPs obtained from air-exposed, control mice.

  20. Selective carbon monoxide oxidation over Ag-based composite oxides

    Energy Technology Data Exchange (ETDEWEB)

    Guldur, C. [Gazi University, Ankara (Turkey). Chemical Engineering Department; Balikci, F. [Gazi University, Ankara (Turkey). Institute of Science and Technology, Environmental Science Department

    2002-02-01

    We report our results of the synthesis of 1 : 1 molar ratio of the silver cobalt and silver manganese composite oxide catalysts to remove carbon monoxide from hydrogen-rich fuels by the catalytic oxidation reaction. Catalysts were synthesized by the co-precipitation method. XRD, BET, TGA, catalytic activity and catalyst deactivation studies were used to identify active catalysts. Both CO oxidation and selective CO oxidation were carried out in a microreactor using a reaction gas mixture of 1 vol% CO in air and another gas mixture was prepared by mixing 1 vol% CO, 2 vol% O{sub 2}, 84 vol% H{sub 2}, the balance being He. 15 vol% CO{sub 2} was added to the reactant gas mixture in order to determine the effect of CO{sub 2}, reaction gases were passed through the humidifier to determine the effect of the water vapor on the oxidation reaction. It was demonstrated that metal oxide base was decomposed to the metallic phase and surface areas of the catalysts were decreased when the calcination temperature increased from 200{sup o}C to 500{sup o}C. Ag/Co composite oxide catalyst calcined at 200{sup o}C gave good activity at low temperatures and 90% of CO conversion at 180{sup o}C was obtained for the selective CO oxidation reaction. The addition of the impurities (CO{sub 2} or H{sub 2}O) decreased the activity of catalyst for selective CO oxidation in order to get highly rich hydrogen fuels. (author)

  1. Exhaled carbon monoxide in asthmatics: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Huang Mao

    2010-04-01

    Full Text Available Abstract Background The non-invasive assessment of airway inflammation is potentially advantageous in asthma management. Exhaled carbon monoxide (eCO measurement is cheap and has been proposed to reflect airway inflammation and oxidative stress but current data are conflicting. The purpose of this meta-analysis is to determine whether eCO is elevated in asthmatics, is regulated by steroid treatment and reflects disease severity and control. Methods A systematic search for English language articles published between 1997 and 2009 was performed using Medline, Embase and Cochrane databases. Observational studies comparing eCO in non-smoking asthmatics and healthy subjects or asthmatics before and after steroid treatment were included. Data were independently extracted by two investigators and analyzed to generate weighted mean differences using either a fixed or random effects meta-analysis depending upon the degree of heterogeneity. Results 18 studies were included in the meta-analysis. The eCO level was significantly higher in asthmatics as compared to healthy subjects and in intermittent asthma as compared to persistent asthma. However, eCO could not distinguish between steroid-treated asthmatics and steroid-free patients nor separate controlled and partly-controlled asthma from uncontrolled asthma in cross-sectional studies. In contrast, eCO was significantly reduced following a course of corticosteroid treatment. Conclusions eCO is elevated in asthmatics but levels only partially reflect disease severity and control. eCO might be a potentially useful non-invasive biomarker of airway inflammation and oxidative stress in nonsmoking asthmatics.

  2. Carbon Monoxide in Meat and Fish Packaging: Advantages and Limits

    Directory of Open Access Journals (Sweden)

    Djamel Djenane

    2018-01-01

    Full Text Available Due to increased demands for greater expectation in relation to quality, convenience, safety and extended shelf-life, combined with growing demand from retailers for cost-effective extensions of fresh muscle foods’ shelf-life, the food packaging industry quickly developed to meet these expectations. During the last few decades, modified atmosphere packaging (MAP of foods has been a promising area of research, but much remains to be known regarding the use of unconventional gases such carbon monoxide (CO. The use of CO for meat and seafood packaging is not allowed in most countries due to the potential toxic effect, and its use is controversial in some countries. The commercial application of CO in food packaging was not then considered feasible because of possible environmental hazards for workers. CO has previously been reported to mask muscle foods’ spoilage, and this was the primary concern raised for the prohibition, as this may mislead consumers. This review was undertaken to present the most comprehensive and current overview of the widely-available, scattered information about the use of CO in the preservation of muscle foods. The advantages of CO and its industrial limits are presented and discussed. The most recent literature on the consumer safety issues related to the use of CO and consumer acceptance of CO especially in meat packaging systems were also discussed. Recommendations and future prospects were addressed for food industries, consumers and regulators on what would be a “best practice” in the use of CO in food packaging. All this promotes high ethical standards in commercial communications by means of effective regulation, for the benefit of consumers and businesses in the world, and this implies that industrialized countries and members of their regulatory agencies must develop a coherent and robust systems of regulation and control that can respond effectively to new challenges.

  3. Evaluation of exposure to carbon monoxide associated with passive smoking

    International Nuclear Information System (INIS)

    Jo, W.-K.; Oh, J.-W.; Dong, J.-I.

    2004-01-01

    The current study measured breath carbon monoxide (CO) concentrations prior to and at prescribed time intervals after exposure to passive smoking under controlled conditions, along with the air CO concentration in the exposure room during the exposure periods. The postexposure breath CO levels were 1.4-2.7 times higher than the background breath CO levels after 30 min of exposure, yet only slightly higher after 10 min of exposure, thereby confirming that exposure to CO from passive smoking causes a significant body burden of CO. The air CO concentration gradually increased during the burning of a cigarette(s), regardless of the exposure duration, whereas it slightly decreased after burning. However, the pattern of breath CO decay was similar for the two different types of exposure (during and after a cigarette(s)) in each subject. The decrease in the postexposure alveolar CO concentrations was slow even in the early phase of the decay curves, indicating a monocompartment uptake and elimination model for the human body. The half-lives (78-277 min) estimated in the present study were comparable to those reported in previous studies associated with CO exposure from active smoking or other activities. The current study also evaluated the CO exposure of visitors and workers at three different types of recreation facility (bars, Internet cafes, and billiard halls) typically associated with passive smoking. The results confirmed that passive smoking is the major contributor to the CO exposure of nonsmoking visitors in a recreation environment. In addition, workplace exposure to CO from passive smoking was found to be the most important contributor to the daily CO exposure of nonsmoking recreation workers

  4. Computed Tomographic Findings of Acute Carbon Monoxide Posioning

    International Nuclear Information System (INIS)

    Park, Young Keun; Won, Hee Sun; Lee, Seung Ro; Hahm, Chang Kok

    1983-01-01

    Carbon monoxide (CO) is a kind of frequent toxic gas around our living lives, for common use of briquets as fuel, and its pathologic effect has been known due to mainly hypoxia and direct cytotoxicity in some part to almost all organs, especially to the brain and heart. Some authors have reported pathologic and anatomic changes of the acute of poisoning, although in a few cases, that bilaterally symmetrical lesions of the globs pallidus or cerebral white matter regarded as typical. After using computed tomography (CT), those findings have been discovered more easily and accurately. Authors analysed CT findings of 32 cases, who had a history of acute CO poisoning and performed CT at Hanyang University Hospital from May 1970 to June 1983. The results were as follows: 1. Of all 32 cases with CT scan, low density lesions were demonstrated in 28 cases (88%) and others were hemorrhage and calcified in 2(6%), respectively. 2. All lesions were seen as bilaterally symmetrical, except 2 cases of hemorrhage and 1 of low density. 3. Of all 28 cases of the low densities, 15 cases(53.6%) were located in the globs pallidus, 10(35.7%) in the cerebral white matter and 3(10.7%) in both of them. 4. Of all 113 cases of the low density lesions in the cerebral white matter, common locations were in the frontal and parietal lobes (65.6%), and more in frontal (40.6%). 5. Of all 113 cases of low density lesions in the cerebral white matter, cases of involving all of the lobes were found in only 4. 6. All of 2 cases of the calcified lesions were seen at both sides of the globs pallidus, symmetrically. 7. All of 2 cases of the hemorrhage were seen at thalamus, ventricles and head of caudate nucleus, and these locations were different from those of the low densities or calcifications.

  5. Process for derivatizing carbon nanotubes with diazonium species

    Science.gov (United States)

    Tour, James M. (Inventor); Bahr, Jeffrey L. (Inventor); Yang, Jiping (Inventor)

    2007-01-01

    The invention incorporates new processes for the chemical modification of carbon nanotubes. Such processes involve the derivatization of multi- and single-wall carbon nanotubes, including small diameter (ca. 0.7 nm) single-wall carbon nanotubes, with diazonium species. The method allows the chemical attachment of a variety of organic compounds to the side and ends of carbon nanotubes. These chemically modified nanotubes have applications in polymer composite materials, molecular electronic applications and sensor devices. The methods of derivatization include electrochemical induced reactions thermally induced reactions (via in-situ generation of diazonium compounds or pre-formed diazonium compounds), and photochemically induced reactions. The derivatization causes significant changes in the spectroscopic properties of the nanotubes. The estimated degree of functionality is ca. 1 out of every 20 to 30 carbons in a nanotube bearing a functionality moiety. Such electrochemical reduction processes can be adapted to apply site-selective chemical functionalization of nanotubes. Moreover, when modified with suitable chemical groups, the derivatized nanotubes are chemically compatible with a polymer matrix, allowing transfer of the properties of the nanotubes (such as, mechanical strength or electrical conductivity) to the properties of the composite material as a whole. Furthermore, when modified with suitable chemical groups, the groups can be polymerized to form a polymer that includes carbon nanotubes ##STR00001##.

  6. Oscillation of nested fullerenes (carbon onions) in carbon nanotubes

    International Nuclear Information System (INIS)

    Thamwattana, Ngamta; Hill, James M.

    2008-01-01

    Nested spherical fullerenes, which are sometimes referred to as carbon onions, of I h symmetries which have N(n) carbon atoms in the nth shell given by N(n) = 60n 2 are studied in this paper. The continuum approximation together with the Lennard-Jones potential is utilized to determine the resultant potential energy. High frequency nanoscale oscillators or gigahertz oscillators created from fullerenes and both single- and multi-walled carbon nanotubes have attracted much attention for a number of proposed applications, such as ultra-fast optical filters and ultra-sensitive nano-antennae that might impact on the development of computing and signalling nano-devices. Further, it is only at the nanoscale where such gigahertz frequencies can be achieved. This paper focuses on the interaction of nested fullerenes and the mechanics of such molecules oscillating in carbon nanotubes. Here we investigate such issues as the acceptance condition for nested fullerenes into carbon nanotubes, the total force and energy of the nested fullerenes, and the velocity and gigahertz frequency of the oscillating molecule. In particular, optimum nanotube radii are determined for which nested fullerenes oscillate at maximum velocity and frequency, which will be of considerable benefit for the design of future nano-oscillating devices

  7. Carbon monoxide poisoning-induced cardiomyopathy from charcoal at a barbecue restaurant: a case report.

    Science.gov (United States)

    Kim, Hyun-Jun; Chung, Yun Kyung; Kwak, Kyeong Min; Ahn, Se-Jin; Kim, Yong-Hyun; Ju, Young-Su; Kwon, Young-Jun; Kim, Eun-A

    2015-01-01

    Acute carbon monoxide poisoning has important clinical value because it can cause severe adverse cardiovascular effects and sudden death. Acute carbon monoxide poisoning due to charcoal is well reported worldwide, and increased use of charcoal in the restaurant industry raises concern for an increase in occupational health problems. We present a case of carbon monoxide poisoning induced cardiomyopathy in a 47-year-old restaurant worker. A male patient was brought to the emergency department to syncope and complained of left chest pain. Cardiac angiography and electrocardiography were performed to rule out acute ischemic heart disease, and cardiac markers were checked. After relief of the symptoms and stabilization of the cardiac markers, the patient was discharged without any complications. Electrocardiography was normal, but cardiac angiography showed up to a 40% midsegmental stenosis of the right coronary artery with thrombotic plaque. The level of cardiac markers was elevated at least 5 to 10 times higher than the normal value, and the carboxyhemoglobin concentration was 35% measured at one hour after syncope. Following the diagnosis of acute carbon monoxide poisoning induced cardiomyopathy, the patient's medical history and work exposure history were examined. He was found to have been exposed to burning charcoal constantly during his work hours. Severe exposure to carbon monoxide was evident in the patient because of high carboxyhemoglobin concentration and highly elevated cardiac enzymes. We concluded that this exposure led to subsequent cardiac injury. He was diagnosed with acute carbon monoxide poisoning-induced cardiomyopathy due to an unsafe working environment. According to the results, the risk of exposure to noxious chemicals such as carbon monoxide by workers in the food service industry is potentially high, and workers in this sector should be educated and monitored by the occupational health service to prevent adverse effects.

  8. Thermogravimetric Analysis of Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Arepalli, Sivram; Nikolaev, Pavel; Gorelik, Olga

    2010-01-01

    An improved protocol for thermogravimetric analysis (TGA) of samples of single-wall carbon nanotube (SWCNT) material has been developed to increase the degree of consistency among results so that meaningful comparisons can be made among different samples. This improved TGA protocol is suitable for incorporation into the protocol for characterization of carbon nanotube material. In most cases, TGA of carbon nanotube materials is performed in gas mixtures that contain oxygen at various concentrations. The improved protocol is summarized.

  9. Continuous Growth of Vertically Aligned Carbon Nanotubes Forests

    OpenAIRE

    Guzman de Villoria, Roberto; Wardle, Brian L.

    2011-01-01

    Vertically aligned carbon nanotubes are one of the most promising materials due their numerous applications in flexible electronic devices, biosensors and multifunctional aircraft materials, among others. However, the costly production of aligned carbon nanotubes, generally in a batch process, prevents their commercial use. For the first time, a controlled process to grow aligned carbon nanotubes in a continuous manner is presented. Uniform growth is achieved using 2D and 3D substrates. A sig...

  10. Chemically Functionalized Carbon Nanotubes as Substrates for Neuronal Growth

    Science.gov (United States)

    Hu, Hui; Ni, Yingchun; Montana, Vedrana; Haddon, Robert C.; Parpura, Vladimir

    2009-01-01

    We report the use of chemically modified carbon nanotubes as a substrate for cultured neurons. The morphological features of neurons that directly reflect their potential capability in synaptic transmission are characterized. The chemical properties of carbon nanotubes are systematically varied by attaching different functional groups that confer known characteristics to the substrate. By manipulating the charge carried by functionalized carbon nanotubes we are able to control the outgrowth and branching pattern of neuronal processes. PMID:21394241

  11. Carbon Nanotube Flexible and Stretchable Electronics.

    Science.gov (United States)

    Cai, Le; Wang, Chuan

    2015-12-01

    The low-cost and large-area manufacturing of flexible and stretchable electronics using printing processes could radically change people's perspectives on electronics and substantially expand the spectrum of potential applications. Examples range from personalized wearable electronics to large-area smart wallpapers and from interactive bio-inspired robots to implantable health/medical apparatus. Owing to its one-dimensional structure and superior electrical property, carbon nanotube is one of the most promising material platforms for flexible and stretchable electronics. Here in this paper, we review the recent progress in this field. Applications of single-wall carbon nanotube networks as channel semiconductor in flexible thin-film transistors and integrated circuits, as stretchable conductors in various sensors, and as channel material in stretchable transistors will be discussed. Lastly, state-of-the-art advancement on printing process, which is ideal for large-scale fabrication of flexible and stretchable electronics, will also be reviewed in detail.

  12. Density controlled carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng F [Newton, MA; Tu, Yi [Belmont, MA

    2008-12-16

    CNT materials comprising aligned carbon nanotubes (CNTs) with pre-determined site densities, catalyst substrate materials for obtaining them and methods for forming aligned CNTs with controllable densities on such catalyst substrate materials are described. The fabrication of films comprising site-density controlled vertically aligned CNT arrays of the invention with variable field emission characteristics, whereby the field emission properties of the films are controlled by independently varying the length of CNTs in the aligned array within the film or by independently varying inter-tubule spacing of the CNTs within the array (site density) are disclosed. The fabrication of microelectrode arrays (MEAs) formed utilizing the carbon nanotube material of the invention is also described.

  13. Molecular discriminators using single wall carbon nanotubes

    International Nuclear Information System (INIS)

    Bhattacharyya, Tamoghna; Dasgupta, Anjan Kr; Ray, Nihar Ranjan; Sarkar, Sabyasachi

    2012-01-01

    The interaction between single wall carbon nanotubes (SWNTs) and amphiphilic molecules has been studied in a solid phase. SWNTs are allowed to interact with different amphiphilic probes (e.g. lipids) in a narrow capillary interface. Contact between strong hydrophobic and amphiphilic interfaces leads to a molecular restructuring of the lipids at the interface. The geometry of the diffusion front and the rate and the extent of diffusion of the interface are dependent on the structure of the lipid at the interface. Lecithin having a linear tail showed greater mobility of the interface as compared to a branched tail lipid like dipalmitoyl phosphatidylcholine, indicating the hydrophobic interaction between single wall carbon nanotube core and the hydrophobic tail of the lipid. Solid phase interactions between SWNT and lipids can thus become a very simple but efficient means of discriminating amphiphilic molecules in general and lipids in particular. (paper)

  14. Electrostatic sensing and electrochemistry with single carbon nanotubes

    NARCIS (Netherlands)

    Heller, I.

    2009-01-01

    This thesis describes the experimental study of devices based on single carbon nanotubes in the context of (bio)sensing in aqueous solutions. Carbon nanotubes are cylindrical molecules of sp2- carbon, about one nanometer in diameter and typically several micrometers long, which have semiconducting

  15. A Carbon Nanotube Cable for a Space Elevator

    Science.gov (United States)

    Bochnícek, Zdenek

    2013-01-01

    In this paper the mechanical properties of carbon nanotubes are discussed in connection with the possibility to use them for the construction of a space elevator. From the fundamental information about the structure of a carbon nanotube and the chemical bond between carbon atoms, Young's modulus and the ultimate tensile strength are…

  16. Synthesis of PbI(2) single-layered inorganic nanotubes encapsulated within carbon nanotubes.

    Science.gov (United States)

    Cabana, Laura; Ballesteros, Belén; Batista, Eudar; Magén, César; Arenal, Raúl; Oró-Solé, Judith; Rurali, Riccardo; Tobias, Gerard

    2014-04-02

    The template assisted growth of single-layered inorganic nanotubes is reported. Single-crystalline lead iodide single-layered nanotubes have been prepared using the inner cavities of carbon nanotubes as hosting templates. The diameter of the resulting inorganic nanotubes is merely dependent on the diameter of the host. This facile method is highly versatile opening up new horizons in the preparation of single-layered nanostructures. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. A DFT study on the effect of supporting titania on silica graphene epoxy graphene and carbon nanotubes - Interfacial properties and optical response

    CSIR Research Space (South Africa)

    Kiarii, EM

    2017-08-01

    Full Text Available A first principles study of the Titania is done as used in photo-catalysis to generate charge carries. Models of titania, silica, graphene, epoxy graphene monoxide, single wall Carbon nanotubes and their respective layer were studied in order...

  18. Carbon Nanotubes as Future Energy Storage System

    OpenAIRE

    Vasu , V; Silambarasan , D

    2017-01-01

    International audience; Hydrogen is considered to be a clean energy carrier. At present the main drawback in using hydrogen as the fuel is the lack of proper hydrogen storage vehicle, thus ongoing research is focused on the development of advance hydrogen storage materials. Many alloys are able to store hydrogen reversibly, but the gravimetric storage density is too low for any practical applications. Theoretical studies have predicted that interaction of hydrogen with carbon nanotubes is by ...

  19. Aqueous solution dispersement of carbon nanotubes

    Science.gov (United States)

    Kim, Jae-Woo (Inventor); Park, Cheol (Inventor); Choi, Sang H. (Inventor); Lillehei, Peter T. (Inventor); Harrison, Joycelyn S. (Inventor)

    2011-01-01

    Carbon nanotubes (CNTs) are dispersed in an aqueous buffer solution consisting of at least 50 weight percent water and a remainder weight percent that includes a buffer material. The buffer material has a molecular structure defined by a first end, a second end, and a middle disposed between the first and second ends. The first end is a cyclic ring with nitrogen and oxygen heteroatomes, the middle is a hydrophobic alkyl chain, and the second end is a charged group.

  20. Passive Mode Carbon Nanotube Underwater Acoustic Transducer

    Science.gov (United States)

    2016-09-20

    Acoustical transducer arrays can reflect a sound signal in reverse to the sender which can be used for echo location devices. [0008] In Jiang...States Patent No. 8,494,187) a sound wave generator is disclosed which includes a carbon nanotube structure and an insulating reinforcement structure... acoustic device that includes an electrode layer and a sound wave generator. The sound wave generator is disposed on a surface of the electrode

  1. Carbon nanotubes: do they toughen brittle matrices?

    Czech Academy of Sciences Publication Activity Database

    Chao, J.; Inam, F.; Reece, M.J.; Chlup, Zdeněk; Dlouhý, Ivo; Shaffer, M.S.P.; Boccaccini, A. R.

    2011-01-01

    Roč. 46, č. 14 (2011), s. 4770-4779 ISSN 0022-2461 R&D Projects: GA ČR GA101/09/1821 Institutional research plan: CEZ:AV0Z20410507 Keywords : fracture toughness * carbon nanotube * silica glass Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.015, year: 2011 http://www.springerlink.com/content/74106l0458326n91/

  2. Carbon nanotube-based black coatings

    Science.gov (United States)

    Lehman, J.; Yung, C.; Tomlin, N.; Conklin, D.; Stephens, M.

    2018-03-01

    Coatings comprising carbon nanotubes are very black, that is, characterized by uniformly low reflectance over a broad range of wavelengths from the visible to far infrared. Arguably, there is no other material that is comparable. This is attributable to the intrinsic properties of graphitic material as well as the morphology (density, thickness, disorder, and tube size). We briefly describe a history of other coatings such as nickel phosphorous, gold black, and carbon-based paints and the comparable structural morphology that we associate with very black coatings. The need for black coatings is persistent for a variety of applications ranging from baffles and traps to blackbodies and thermal detectors. Applications for space-based instruments are of interest and we present a review of space qualification and the results of outgassing measurements. Questions of nanoparticle safety depend on the nanotube size and aspect ratio as well as the nature and route of exposure. We describe the growth of carbon nanotube forests along with the catalyst requirements and temperature limitations. We also describe coatings derived from carbon nanotubes and applied like paint. Building the measurement apparatus and determining the optical properties of something having negligible reflectance are challenging and we summarize the methods and means for such measurements. There exists information in the literature for effective media approximations to model the dielectric function of vertically aligned arrays. We summarize this along with the refractive index of graphite from the literature that is necessary for modeling the optical properties. In our experience, the scientific questions can be overshadowed by practical matters, so we provide an appendix of recipes for making as-grown and sprayed coatings along with an example of reflectance measurements.

  3. New Insight into Carbon Nanotube Electronic Structure Selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Sumpter, Bobby G [ORNL; Meunier, Vincent [ORNL; Jiang, Deen [ORNL

    2009-01-01

    The fundamental role of aryl diazonium salts for post synthesis selectivity of carbon nanotubes is investigated using extensive electronic structure calculations. The resulting understanding for diazonium salt based selective separation of conducting and semiconducting carbon nanotubes shows how the primary contributions come from the interplay between the intrinsic electronic structure of the carbon nanotubes and that of the anion of the salt. We demonstrate how the electronic transport properties change upon the formation of charge transfer complexes and upon their conversion into covalently attached functional groups. Our results are found to correlate well with experiments and provide for the first time an atomistic description for diazonium salt based chemical separation of carbon nanotubes

  4. Conformational changes of fibrinogen in dispersed carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Park SJ

    2012-08-01

    Full Text Available Sung Jean Park,1 Dongwoo Khang21College of Pharmacy, Gachon University, Yeonsu-gu, Incheon, South Korea; 2School of Nano and Advanced Materials Science Engineering and Center for PRC and RIGET, Gyeongsang National University, Jinju, South KoreaAbstract: The conformational changes of plasma protein structures in response to carbon nanotubes are critical for determining the nanotoxicity and blood coagulation effects of carbon nanotubes. In this study, we identified that the functional intensity of carboxyl groups on carbon nanotubes, which correspond to the water dispersity or hydrophilicity of carbon nanotubes, can induce conformational changes in the fibrinogen domains. Also, elevation of carbon nanotube density can alter the secondary structures (ie, helices and beta sheets of fibrinogen. Furthermore, fibrinogen that had been in contact with the nanoparticle material demonstrated a different pattern of heat denaturation compared with free fibrinogen as a result of a variation in hydrophilicity and concentration of carbon nanotubes. Considering the importance of interactions between carbon nanotubes and plasma proteins in the drug delivery system, this study elucidated the correlation between nanoscale physiochemical material properties of carbon nanotubes and associated structural changes in fibrinogen.Keywords: carbon nanotubes, fibrinogen, nanotoxicity, conformational change, denaturation

  5. Carbon nanotubes from synthesis to in vivo biomedical applications.

    Science.gov (United States)

    Sajid, Muhammad Imran; Jamshaid, Usama; Jamshaid, Talha; Zafar, Nadiah; Fessi, H; Elaissari, Abdelhamid

    2016-03-30

    Owing to their unique and interesting properties, extensive research round the globe has been carried out on carbon nanotubes and carbon nanotubes based systems to investigate their practical usefulness in biomedical applications. The results from these studies demonstrate a great promise in their use in targeted drug delivery systems, diagnostic techniques and in bio-analytical applications. Although, carbon nanotubes possess quite interesting properties, which make them potential candidates in the biomedical science, but they also have some inherent properties which arise great concern regarding their biosafety. In this comprehensive review, we have discussed different aspects of carbon nanotubes and carbon nanotube based systems related to biomedical applications. In the beginning, a short historical account of these tiny yet powerful particles is given followed by discussion regarding their types, properties, methods of synthesis, large scale production method, purification techniques and characterization aspects of carbon nanotubes. In the second part of the review, the functionalization of carbon nanotubes is reviewed in detail, which is not only important to make them biocompatible and stable in biological systems but also render them a great property of loading various biomolecules, diagnostic and therapeutic moieties resulting in diversified applications. In the final part of the review, emphasis is given on the pharmacokinetic aspects of carbon nanotubes including administration routes, absorption mechanisms, distribution and elimination of carbon nanotubes based systems. Lastly, a comprehensive account about the potential biomedical applications has been given followed by insights into the future. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Simulation of the Band Structure of Graphene and Carbon Nanotube

    International Nuclear Information System (INIS)

    Mina, Aziz N; Awadallah, Attia A; Ahmed, Riham R; Phillips, Adel H

    2012-01-01

    Simulation technique has been performed to simulate the band structure of both graphene and carbon nanotube. Accordingly, the dispersion relations for graphene and carbon nanotube are deduced analytically, using the tight binding model and LCAO scheme. The results from the simulation of the dispersion relation of both graphene and carbon nanotube were found to be consistent with those in the literature which indicates the correctness of the process of simulation technique. The present research is very important for tailoring graphene and carbon nanotube with specific band structure, in order to satisfy the required electronic properties of them.

  7. Carbon nanotube materials for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, A.C.; Parilla, P.A.; Jones, K.M.; Riker, G.; Heben, M.J. [National Renewable Energy Lab., Golden, CO (United States)

    1998-08-01

    Carbon single-wall nanotubes (SWNTs) are essentially elongated pores of molecular dimensions and are capable of adsorbing hydrogen at relatively high temperatures and low pressures. This behavior is unique to these materials and indicates that SWNTs are the ideal building block for constructing safe, efficient, and high energy density adsorbents for hydrogen storage applications. In past work the authors developed methods for preparing and opening SWNTs, discovered the unique adsorption properties of these new materials, confirmed that hydrogen is stabilized by physical rather than chemical interactions, measured the strength of interaction to be {approximately} 5 times higher than for adsorption on planar graphite, and performed infrared absorption spectroscopy to determine the chemical nature of the surface terminations before, during, and after oxidation. This year the authors have made significant advances in synthesis and characterization of SWNT materials so that they can now prepare gram quantities of high-purity SWNT samples and measure and control the diameter distribution of the tubes by varying key parameters during synthesis. They have also developed methods which purify nanotubes and cut nanotubes into shorter segments. These capabilities provide a means for opening the tubes which were unreactive to the oxidation methods that successfully opened tubes, and offer a path towards organizing nanotube segments to enable high volumetric hydrogen storage densities. They also performed temperature programmed desorption spectroscopy on high purity carbon nanotube material obtained from collaborator Prof. Patrick Bernier and finished construction of a high precision Seivert`s apparatus which will allow the hydrogen pressure-temperature-composition phase diagrams to be evaluated for SWNT materials.

  8. Carbon Nanotube Paper-Based Electroanalytical Devices

    Directory of Open Access Journals (Sweden)

    Youngmi Koo

    2016-04-01

    Full Text Available Here, we report on carbon nanotube paper-based electroanalytical devices. A highly aligned-carbon nanotube (HA-CNT array, grown using chemical vapor deposition (CVD, was processed to form bi-layered paper with an integrated cellulose-based Origami-chip as the electroanalytical device. We used an inverse-ordered fabrication method from a thick carbon nanotube (CNT sheet to a thin CNT sheet. A 200-layered HA-CNT sheet and a 100-layered HA-CNT sheet are explored as a working electrode. The device was fabricated using the following methods: (1 cellulose-based paper was patterned using a wax printer, (2 electrical connection was made using a silver ink-based circuit printer, and (3 three electrodes were stacked on a 2D Origami cell. Electrochemical behavior was evaluated using electrochemical impedance spectroscopy (EIS and cyclic voltammetry (CV. We believe that this platform could attract a great deal of interest for use in various chemical and biomedical applications.

  9. Preparation of carbon nanotubes by MPECVD

    International Nuclear Information System (INIS)

    El-Shazly Duraia, M.A.; Mansorov, Z.A.; Tokmoldin, S.Zh.; Klimenov, V.V.; Nevmerzhitsky, I.S.; Dochshanov, A.M.

    2009-01-01

    Microwave plasma-enhanced chemical vapor deposition (MPECVD) method has been regarded as one of the most promising candidates for the synthesis of CNTs due to the vertical alignment, the large area growth, the lower growth temperature, uniform heat distribution and the good control of the different growth parameters. In this work we present our results about the preparation of carbon nanotube with different morphologies by using microwave plasma enhanced chemical vapor deposition MPECVD. Well aligned, curly and coiled carbon nanotubes have been prepared. We have investigated the effect of the different growth condition parameters such as type of the catalyst, pressure and the hydrogen to methane flow rate ratio on the morphology of the carbon nanotubes. The results were showed that there is a great dependence of the morphology of carbon nanotubes on these parameters. There is a linear relation between the growth rate and the methane to hydrogen ratio. We found that the growth rate has a great dependence on the amount of methane. For example the growth rate varied from the value 1,34 μm/min when the methane flow rate was 10 sccm to more than 14 μm/min when the methane flow rate was raised to 50 sccm. This growth rate is greater than that reported in the literature. The effect of the gas pressure on the CNTs was also studied. The Raman spectra (excitation wavelength 473 nm) of all samples show D-band peak at around 1300 cm -1 and G-band peak at around 1580 cm -1 , which indicate that our CNTs are multi wall CNTs (MWCNTs). The D-band and the G-band correspond to sp 2 and sp 3 carbon stretching modes relatively, and their intensity ratio is a measure of the amount of disorder in the CNTs. The D-band is known to be attributed to the carbonaceous particles, defects in the curved graphitic sheet and tube ends. It has been suggested that lower I g /I d ratios and narrower first and second order D and G bands are suggestive of well-aligned NNTs. The photoluminescence PL

  10. A population-based exposure assessment methodology for carbon monoxide: Development of a carbon monoxide passive sampler and occupational dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Apte, Michael G. [Univ. of California, Berkeley, CA (United States)

    1997-09-01

    Two devices, an occupational carbon monoxide (CO) dosimeter (LOCD), and an indoor air quality (IAQ) passive sampler were developed for use in population-based CO exposure assessment studies. CO exposure is a serious public health problem in the U.S., causing both morbidity and mortality (lifetime mortality risk approximately 10{sup -4}). Sparse data from population-based CO exposure assessments indicate that approximately 10% of the U.S. population is exposed to CO above the national ambient air quality standard. No CO exposure measurement technology is presently available for affordable population-based CO exposure assessment studies. The LOCD and IAQ Passive Sampler were tested in the laboratory and field. The palladium-molybdenum based CO sensor was designed into a compact diffusion tube sampler that can be worn. Time-weighted-average (TWA) CO exposure of the device is quantified by a simple spectrophotometric measurement. The LOCD and IAQ Passive Sampler were tested over an exposure range of 40 to 700 ppm-hours and 200 to 4200 ppm-hours, respectively. Both devices were capable of measuring precisely (relative standard deviation <20%), with low bias (<10%). The LOCD was screened for interferences by temperature, humidity, and organic and inorganic gases. Temperature effects were small in the range of 10°C to 30°C. Humidity effects were low between 20% and 90% RH. Ethylene (200 ppm) caused a positive interference and nitric oxide (50 ppm) caused a negative response without the presence of CO but not with CO.

  11. Carbon paste electrode incorporating multi-walled carbon nanotube ...

    Indian Academy of Sciences (India)

    The preparation and electrochemical performance of the carbon nanotube paste electrode modified with ferrocene (FCMCNPE) was investigated for electrocatalytic behaviour toward oxidation of -acetyl--cysteine (NAC) in the presence of tryptophan (Trp) using cyclic voltammetry (CV) and differential pulse voltammetry ...

  12. Carbon nanotube network-silicon oxide non-volatile switches.

    Science.gov (United States)

    Liao, Albert D; Araujo, Paulo T; Xu, Runjie; Dresselhaus, Mildred S

    2014-12-08

    The integration of carbon nanotubes with silicon is important for their incorporation into next-generation nano-electronics. Here we demonstrate a non-volatile switch that utilizes carbon nanotube networks to electrically contact a conductive nanocrystal silicon filament in silicon dioxide. We form this device by biasing a nanotube network until it physically breaks in vacuum, creating the conductive silicon filament connected across a small nano-gap. From Raman spectroscopy, we observe coalescence of nanotubes during breakdown, which stabilizes the system to form very small gaps in the network~15 nm. We report that carbon nanotubes themselves are involved in switching the device to a high resistive state. Calculations reveal that this switching event occurs at ~600 °C, the temperature associated with the oxidation of nanotubes. Therefore, we propose that, in switching to a resistive state, the nanotube oxidizes by extracting oxygen from the substrate.

  13. Preparation of carbon nanotubes from vacuum pyrolysis of polycarbosilane

    International Nuclear Information System (INIS)

    Jou, S.; Hsu, C.K.

    2004-01-01

    Carbon nanotubes (CNTs) were synthesized by vacuum pyrolysis of two types of polycarbosilane (PCS) with iron nano-particles between 800 and 1100 deg. C. Straight nanotubes were obtained from low molecular weight (990 g/mol) PCS whereas curled nanotubes were derived from medium molecular weight (1290 g/mol) PCS. Diameters of these straight and curled nanotubes were between 5 and 20 nm. The mechansim of condensed phase growth of carbon nanotubes was discussed. Electron emission capability of these carbon nanotubes increased with their pyrolyzing temperature. The electric fields required to emit a current density of 10 -2 A/cm 2 from the straight nanotubes being pyrolyzed at 800, 900, 1000, and 1100 deg. C were 1.17, 0.73, 0.67, and 0.33 V/μm, respectively

  14. Environmental tobacco smoke exposure among non-smoking waiters: measurement of expired carbon monoxide levels

    Directory of Open Access Journals (Sweden)

    Ronaldo Laranjeira

    2000-07-01

    Full Text Available CONTEXT: Exposure to environmental tobacco smoke is a health risk that is of concern to patrons and of particular concern to employees of restaurants and bars. OBJECTIVE: To assess environmental tobacco smoke exposure (using expired carbon monoxide levels in non-smoking waiters before and after a normal day's shift and to compare pre-exposure levels with non-smoking medical students. DESIGN: An observational study. SETTING: Restaurants with more than 50 tables or 100 places in São Paulo. SUBJECTS: 100 non-smoking restaurant waiters and 100 non-smoking medical students in São Paulo, Brazil. MAIN MEASUREMENTS: Levels of expired carbon monoxide, measured with a Smokerlyser (Bedfont EC 50 Scientific, before and after a normal day's work. RESULTS: Waiters' pre-exposure expired carbon monoxide levels were similar to those of medical students, but after a mean of 9 hours exposure in the workplace, median levels more than doubled (2.0 ppm vs. 5.0 ppm, P <0.001. Post-exposure carbon monoxide levels were correlated with the number of tables available for smokers (Kendall's tau = 0.2, P <0.0001. CONCLUSIONS: Exposure to environmental tobacco smoke is the most likely explanation for the increase in carbon monoxide levels among these non-smoking waiters. These findings can be used to inform the ongoing public health debate on passive smoking.

  15. [Protective effects of endogenous carbon monoxide against myocardial ischemia-reperfusion injury in rats].

    Science.gov (United States)

    Zhou, Zhen; Ma, Shuang; Liu, Jie; Ji, Qiao-Rong; Cao, Cheng-Zhu; Li, Xiao-Na; Tang, Feng; Zhang, Wei

    2018-04-25

    The present study is aimed to explore the effects of endogenous carbon monoxide on the ischemia-reperfusion in rats. Wistar rats were intraperitoneally injected with protoporphyrin cobalt chloride (CoPP, an endogenous carbon monoxide agonist, 5 mg/kg), zinc protoporphyrin (ZnPP, an endogenous carbon monoxide inhibitor, 5 mg/kg) or saline. Twenty-four hours after injection, the myocardial ischemia-reperfusion model was made by Langendorff isolated cardiac perfusion system, and cardiac function parameters were collected. Myocardial cGMP content was measured by ELISA, and the endogenous carbon monoxide in plasma and myocardial enzymes in perfusate at 10 min after reperfusion were measured by colorimetry. The results showed that before ischemia the cardiac functions of CoPP, ZnPP and control groups were stable, and there were no significant differences. After reperfusion, cardiac functions had significant differences among the three groups (P endogenous carbon monoxide can maintain cardiac function, shorten the time of cardiac function recovery, and play a protective role in cardiac ischemia-reperfusion.

  16. The Effect of Carbon Monoxide Poisoning on Platelet Volume in Children

    Directory of Open Access Journals (Sweden)

    Halise Akça

    2017-04-01

    Full Text Available Introduction: Carbon monoxide poisoning is one of the most important causes of morbidity and mortality. There is increasing evidence supporting the important role of mean platelet volume (MPV as a marker of hypoxia and inflammation. In this study, we aimed to determine changes in MPV values in pediatric patients with carbon monoxide poisoning. Methods: We retrospectively evaluated children who were diagnosed with carbon monoxide poisoning in our hospital between January 2005 and 2014. Results: We included 228 children with carbon monoxide poisoning (49% male in this retrospective, controlled study. The mean age of the patients was 88±56 months. Control group consisted of 200 age-matched healthy children. There was no statistically significant difference in MPV levels between the study and control groups (8.43±1.1 fL and 8.26±0.7 fL, respectively. No correlation of MPV and platelet count with carboxyhemoglobin (COHb was found. Conclusion: In our study, it was determined that MPV value was not a helpful parameter for predicting the diagnosis of acute carbon monoxide poisoning in childhood. The difference between the MPV values and the lack of significance and the absence of correlation between MPV value and COHb level led to the fact that MPV was not a guide indicating the clinical severity of the condition.

  17. Correlation of computed tomography, magnetic resonance imaging and clinical outcome in acute carbon monoxide poisoning.

    Science.gov (United States)

    Ozcan, Namik; Ozcam, Giray; Kosar, Pinar; Ozcan, Ayse; Basar, Hulya; Kaymak, Cetin

    2016-01-01

    Carbon monoxide is a toxic gas for humans and is still a silent killer in both developed and developing countries. The aim of this case series was to evaluate early radiological images as a predictor of subsequent neuropsychological sequelae, following carbon monoxide poisoning. After carbon monoxide exposure, early computed tomography scans and magnetic resonance imaging findings of a 52-year-old woman showed bilateral lesions in the globus pallidus. This patient was discharged and followed for 90 days. The patient recovered without any neurological sequela. In a 58-year-old woman exposed to carbon monoxide, computed tomography showed lesions in bilateral globus pallidus and periventricular white matter. Early magnetic resonance imaging revealed changes similar to that like in early tomography images. The patient recovered and was discharged from hospital. On the 27th day of exposure, the patient developed disorientation and memory impairment. Late magnetic resonance imaging showed diffuse hyperintensity in the cerebral white matter. White matter lesions which progress to demyelination and end up in neuropsychological sequelae cannot always be diagnosed by early computed tomography and magnetic resonance imaging in carbon monoxide poisoning. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  18. Efficient electrochemical degradation of multiwall carbon nanotubes.

    Science.gov (United States)

    Reipa, Vytas; Hanna, Shannon K; Urbas, Aaron; Sander, Lane; Elliott, John; Conny, Joseph; Petersen, Elijah J

    2018-07-15

    As the production mass of multiwall carbon nanotubes (MWCNT) increases, the potential for human and environmental exposure to MWCNTs may also increase. We have shown that exposing an aqueous suspension of pristine MWCNTs to an intense oxidative treatment in an electrochemical reactor, equipped with an efficient hydroxyl radical generating Boron Doped Diamond (BDD) anode, leads to their almost complete mineralization. Thermal optical transmittance analysis showed a total carbon mass loss of over two orders of magnitude due to the electrochemical treatment, a result consistent with measurements of the degraded MWCNT suspensions using UV-vis absorbance. Liquid chromatography data excludes substantial accumulation of the low molecular weight reaction products. Therefore, up to 99% of the initially suspended MWCNT mass is completely mineralized into gaseous products such as CO 2 and volatile organic carbon. Scanning electron microscopy (SEM) images show sporadic opaque carbon clusters suggesting the remaining nanotubes are transformed into structure-less carbon during their electrochemical mineralization. Environmental toxicity of pristine and degraded MWCNTs was assessed using Caenorhabditis elegans nematodes and revealed a major reduction in the MWCNT toxicity after treatment in the electrochemical flow-by reactor. Published by Elsevier B.V.

  19. Solubility of carbon monoxide in bio-oil compounds

    International Nuclear Information System (INIS)

    Qureshi, Muhammad Saad; Le Nedelec, Tom; Guerrero-Amaya, Hernando; Uusi-Kyyny, Petri; Richon, Dominique; Alopaeus, Ville

    2017-01-01

    Highlights: • CO solubility was measured in four bio-oil compounds using static-analytic VLE equipment. • A comparison on the performance of different EoS (PC-SAFT, SRK and PR) was made. • Modelling of polar compounds with Polar PC-SAFT was tested. • Polar PC-SAFT is not needed for weakly polar compounds (μ < 1.0 D). - Abstract: The solubility of carbon monoxide is measured in four different bio-oil compounds (furan, diacetyl, 2-methylfuran, and trans-crotonaldehyde) at temperatures (273.15, 283.15, 298.15, and 323.15 K) and pressures up to 8 MPa using a static-analytical VLE measurement method. The equipment was validated by measuring the solubility of CO 2 in methanol at 298.15 K and pressures (P = 2.9–5.7 MPa). The results were compared with the abundantly available literature values. PC-SAFT, Polar PC-SAFT (PPC-SAFT), and Cubic (SRK, PR) EoS, part of commercial process simulator Aspen Plus V. 8.6, are used here for modelling purpose. The pure component parameters needed for PC-SAFT and PPC-SAFT EoS models, are regressed using the experimental liquid density and vapour pressure data of the pure components. It was observed that furan, 2-methylfuran and diacetyl, having weak dipole moments (μ < 1.0 D), could be modelled reasonably well without the addition of polar contribution using conventional PC-SAFT, while it is recommended to use PPC-SAFT for the description of a polar compound like trans-crotonaldehyde (μ ∼ 3.67 D). It was observed that SRK and PR EoS have similar predictive ability in comparison to PC-SAFT for a mixture of CO with weakly polar compounds in this study. A comparison between the performances of EoS models was made in two ways: first by setting the binary interaction parameter k ij to zero, and second by adjusting a temperature-dependent binary interaction parameter (k ij ). All the models perform with comparable accuracy with adjusted binary interaction parameters. However, due to the large differences between the chemical and

  20. Neurological Effects of Acute Carbon Monoxide Poisoning in Children

    Directory of Open Access Journals (Sweden)

    Coskun YARAR

    2009-11-01

    Full Text Available Carbon monoxide poisoning (COP is one of the most common causes of mortality and morbidity due to poisoning in all over the world. Although the incidence of COP has not been known exactly in the childhood, almost one-third of CO exposures occurred in children. The data regarding COP in children are inconclusive. Children may be more vulnerable to CO exposure than adults as a result of their high respiration and metabolic rates, high oxygen metabolism, and immature central nervous system. Recent researches proposed new theories about neurological effects of CO toxicity. The clinical presentations associated acute COP may be various and nonspecific. Unrecognized CO exposure may lead to significant morbidity and mortality. CO exposed children often become symptomatic earlier, and recover more rapidly, than similarly CO exposed adults. Mild clinical signs and symptoms associated with COP are headache, dizziness, weakness, lethargy, and myalgia; however, severe signs and symptoms such as blurred vision, syncope, convulsion, coma, cardiopulmonary arrest and death can also accompany with COP. Neurologic manifestations can include altered mental status at different degrees, neck stiffness, tremor, ataxia, and positive Babinski's sign. Delayed neurologic sequels (DNS of COP might be seen in children like adults. DNS symptoms and signs in children include memory problems, mental retardation, mutism, fecal and urinary incontinence, motor deficits, facial palsy, psychosis, chronic headache, seizures, and epilepsy. After CO exposure children must be cared to detect and treat DNS. Although hyperbaric oxygen therapy (HBOT is reported to prevent development of DNS, its indications, application duration and procedures are controversial in both of the children and adults. Although their predictive values are limited, exposing to CO more than eight hours and suffering from CO-induced coma, cardiac arrest, lactic acidosis, high COHb levels, and pathologic findings

  1. Stable isotope composition of atmospheric carbon monoxide. A modelling study

    International Nuclear Information System (INIS)

    Gromov, Sergey S.

    2014-01-01

    This study aims at an improved understanding of the stable carbon and oxygen isotope composition of the carbon monoxide (CO) in the global atmosphere by means of numerical simulations. At first, a new kinetic chemistry tagging technique for the most complete parameterisation of isotope effects has been introduced into the Modular Earth Submodel System (MESSy) framework. Incorporated into the ECHAM/MESSy Atmospheric Chemistry (EMAC) general circulation model, an explicit treatment of the isotope effects on the global scale is now possible. The expanded model system has been applied to simulate the chemical system containing up to five isotopologues of all carbon- and oxygen-bearing species, which ultimately determine the δ 13 C, δ 18 O and Δ 17 O isotopic signatures of atmospheric CO. As model input, a new stable isotope-inclusive emission inventory for the relevant trace gases has been compiled. The uncertainties of the emission estimates and of the resulting simulated mixing and isotope ratios have been analysed. The simulated CO mixing and stable isotope ratios have been compared to in-situ measurements from ground-based observatories and from the civil-aircraft-mounted CARIBIC-1 measurement platform. The systematically underestimated 13 CO/ 12 CO ratios of earlier, simplified modelling studies can now be partly explained. The EMAC simulations do not support the inferences of those studies, which suggest for CO a reduced input of the highly depleted in 13 C methane oxidation source. In particular, a high average yield of 0.94 CO per reacted methane (CH 4 ) molecule is simulated in the troposphere, to a large extent due to the competition between the deposition and convective transport processes affecting the CH 4 to CO reaction chain intermediates. None of the other factors, assumed or disregarded in previous studies, however hypothesised to have the potential in enriching tropospheric CO in 13 C, were found significant when explicitly simulated. The

  2. Imaging active topological defects in carbon nanotubes

    Science.gov (United States)

    Suenaga, Kazu; Wakabayashi, Hideaki; Koshino, Masanori; Sato, Yuta; Urita, Koki; Iijima, Sumio

    2007-06-01

    A single-walled carbon nanotube (SWNT) is a wrapped single graphene layer, and its plastic deformation should require active topological defects-non-hexagonal carbon rings that can migrate along the nanotube wall. Although in situ transmission electron microscopy (TEM) has been used to examine the deformation of SWNTs, these studies deal only with diameter changes and no atomistic mechanism has been elucidated experimentally. Theory predicts that some topological defects can form through the Stone-Wales transformation in SWNTs under tension at 2,000 K, and could act as a dislocation core. We demonstrate here, by means of high-resolution (HR)-TEM with atomic sensitivity, the first direct imaging of pentagon-heptagon pair defects found in an SWNT that was heated at 2,273 K. Moreover, our in situ HR-TEM observation reveals an accumulation of topological defects near the kink of a deformed nanotube. This result suggests that dislocation motions or active topological defects are indeed responsible for the plastic deformation of SWNTs.

  3. Properties of single-walled carbon nanotube-based aerogels as a function of nanotube loading

    International Nuclear Information System (INIS)

    Worsley, Marcus A.; Pauzauskie, Peter J.; Kucheyev, Sergei O.; Zaug, Joseph M.; Hamza, Alex V.; Satcher, Joe H.; Baumann, Theodore F.

    2009-01-01

    Here, we present the synthesis and characterization of low-density single-walled carbon nanotube-based aerogels (SWNT-CA). Aerogels with varying nanotube loading (0-55 wt.%) and density (20-350 mg cm -3 ) were fabricated and characterized by four-probe method, electron microscopy, Raman spectroscopy and nitrogen porosimetry. Several properties of the SWNT-CAs were highly dependent upon nanotube loading. At nanotube loadings of 55 wt.%, shrinkage of the aerogel monoliths during carbonization and drying was almost completely eliminated. Electrical conductivities are improved by an order of magnitude for the SWNT-CA (55 wt.% nanotubes) compared to those of foams without nanotubes. Surface areas as high as 184 m 2 g -1 were achieved for SWNT-CAs with greater than 20 wt.% nanotube loading.

  4. Low-frequency plasmons in metallic carbon nanotubes

    International Nuclear Information System (INIS)

    Lin, M.F.; Chuu, D.S.; Shung, K.W.

    1997-01-01

    A metallic carbon nanotube could exhibit a low-frequency plasmon, while a semiconducting carbon nanotube or a graphite layer could not. This plasmon is due to the free carriers in the linear subbands intersecting at the Fermi level. The low-frequency plasmon, which corresponds to the vanishing transferred angular momentum, belongs to an acoustic plasmon. For a smaller metallic nanotube, it could exist at larger transferred momenta, and its frequency is higher. Such a plasmon behaves as that in a one-dimensional electron gas (EGS). However, it is very different from the π plasmons in all carbon nanotubes. Intertube Coulomb interactions in a metallic multishell nanotube and a metallic nanotube bundle have been included. They have a strong effect on the low-frequency plasmon. The intertube coupling among coaxial nanotubes markedly modifies the acoustic plasmons in separate metallic nanotubes. When metallic carbon nanotubes are packed in the bundle form, the low-frequency plasmon would change into an optical plasmon, and behave like that in a three-dimensional EGS. Experimental measurements could be used to distinguish metallic and semiconducting carbon nanotubes. copyright 1997 The American Physical Society

  5. Fullerenes, nanotubes, onions and related carbon structures

    Energy Technology Data Exchange (ETDEWEB)

    Rao, C N.R.; Seshadri, Ram; Govindaraj, A; Sen, Rahul [Solid State and Structural Chemistry Unit, CSIR Centre of Excellence in Chemistry and Materials Research Centre, Indian Institute of Science, Bangalore (India)

    1995-12-01

    Fullerenes, containing five- and six-membered carbon rings, of which C{sub 6}0 and C{sub 7}0 are the prominent members, exhibit phase transitions associated with orientational ordering. When C{sub 6}0 is suitably doped with electrons, it shows novel superconducting and magnetic properties. We review these and other properties of fullerenes in bulk or in film form along with the preparative and structural aspects. Carbon nanotubes and onions (hyperfullerenes) are the other forms of carbon whose material properties have aroused considerable interest. Besides discussing these new forms of carbon, we briefly introduce other possible forms, such as those involving five-, six- and seven-membered rings and hybrids between diamond and graphite

  6. Recent changes in carbon dioxide, carbon monoxide and methane and the implications for global climate change

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, P.C.; Conway, T.J.; Dlugokencky, E.J.; Tans, P.P. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Climate Monitoring and Diagnostics Lab.

    1995-01-01

    The article reviews figures for published data on recent changes of atmospheric levels of carbon dioxide, carbon monoxide and methane in terms of their sources and sinks. The largest source of CO{sub 2} is the combustion of fossil fuels, followed by emissions from deforestation and the oxidation of CO to CO{sub 2}. Carbon monoxide has an indirect influence on the earth`s radiative balance, as if levels of CO increase, levels of OH radicals decline which affects removal of other gases oxidised by this radical, notably CH{sub 4}. Major sources of CO are fossil fuel combustion, emissions from biomass, and oxidation of atmospheric CH{sub 4} and other non-methane hydrocarbons. The latest measurements suggest the depressed growth rates of CO{sub 2}, CO and CH{sub 4} have began to recover. Reasons for this are suggested. Future monitoring of atmospheric species in laboratories around the world, coupled with information on the isotopic signature of the trace gases, will improve our understanding of possible causes for trends in these gases. This will be invaluable in making policy decisions regarding future climate change. 34 refs., 4 figs.

  7. Magnetic properties of carbon nanotubes with and without catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Lipert, Kamil; Ritschel, Manfred; Leonhardt, Albrecht; Krupskaya, Yulia; Buechner, Bernd; Klingeler, Ruediger, E-mail: k.lipert@ifw-dresden.d [Leibniz Institute for Solid State and Materials Research (IFW) Dresden (Germany)

    2010-01-01

    In this paper we report on the magnetic properties of single- and multiwalled carbon nanotubes synthesized using different chemical vapour deposition methods and with variety of catalyst materials (ferromagnetic Fe, FeCo and diamagnetic Re). Different methods yield carbon nanotubes with different morphologies and different quantity of residual catalyst material. Catalyst particles are usually encapsulated in the nanotubes and influence the magnetic respond of the samples. Varying ferromagnetic properties depending on the shape, size and type of catalyst are discussed in detail. The data are compared with M(H) characteristics of carbon nanotubes without catalysts and with nonmagnetic rhenium, as a reference.

  8. Absorption of nicotine and carbon monoxide from passive smoking under natural conditions of exposure.

    Science.gov (United States)

    Jarvis, M J; Russell, M A; Feyerabend, C

    1983-01-01

    Seven non-smokers were exposed to tobacco smoke under natural conditions for two hours in a public house. Measures of nicotine and cotinine in plasma, saliva, and urine and expired air carbon monoxide all showed reliable increases. The concentrations of carbon monoxide and nicotine after exposure averaged 15.7% and 7.5% respectively of the values found in heavy smokers. Although the increase in expired air carbon monoxide of 5.9 ppm was similar to increases in smokers after a single cigarette, the amount of nicotine absorbed was between a tenth and a third of the amount taken in from one cigarette. Since this represented a relatively extreme acute natural exposure, any health risks of passive smoking probably depend less on quantitative factors than on qualitative differences between sidestream and mainstream smoke. PMID:6648864

  9. [Carboxyhemoglobin concentration in carbon monoxide poisoning. Critical appraisal of the predictive value].

    Science.gov (United States)

    Köthe, L; Radke, J

    2010-06-01

    In cases of unclear depression of conciousness, arrhythmia and symptoms of cardiac insufficiency inadvertent carbon monoxide intoxication should always be taken into consideration. Rapid diagnosis of acute carbon monoxide intoxication with mostly unspecific symptoms requires an immediate supply of high dose oxygen which enables a distinct reduction of mortality and long-term morbidity. Levels of carboxyhemoglobin, however, should not be used as a parameter to decide whether to supply normobaric or the more efficient hyperbaric oxygen. There is no sufficient coherence between carboxyhemoglobin blood levels and clinical symptoms. Increased carboxyhemoglobin concentrations help to diagnose acute carbon monoxide intoxication but do not allow conclusions to be drawn about possible long-term neuropsychiatric or cardiac consequences.

  10. A carbon nanotube-based pressure sensor

    International Nuclear Information System (INIS)

    Karimov, Kh S; Saleem, M; Khan, Adam; Qasuria, T A; Mateen, A; Karieva, Z M

    2011-01-01

    In this study, a carbon nanotube (CNT)-based Al/CNT/Al pressure sensor was designed, fabricated and investigated. The sensor was fabricated by depositing CNTs on an adhesive elastic polymer tape and placing this in an elastic casing. The diameter of multiwalled nanotubes varied between 10 and 30 nm. The nominal thickness of the CNT layers in the sensors was in the range ∼300-430 μm. The inter-electrode distance (length) and the width of the surface-type sensors were in the ranges 4-6 and 3-4 mm, respectively. The dc resistance of the sensors decreased 3-4 times as the pressure was increased up to 17 kN m -2 . The resistance-pressure relationships were simulated.

  11. A carbon nanotube immunosensor for Salmonella

    Science.gov (United States)

    Lerner, Mitchell B.; Goldsmith, Brett R.; McMillon, Ronald; Dailey, Jennifer; Pillai, Shreekumar; Singh, Shree R.; Johnson, A. T. Charlie

    2011-12-01

    Antibody-functionalized carbon nanotube devices have been suggested for use as bacterial detectors for monitoring of food purity in transit from the farm to the kitchen. Here we report progress towards that goal by demonstrating specific detection of Salmonella in complex nutrient broth solutions using nanotube transistors functionalized with covalently-bound anti-Salmonella antibodies. The small size of the active device region makes them compatible with integration in large-scale arrays. We find that the on-state current of the transistor is sensitive specifically to the Salmonella concentration and saturates at low concentration (Salmonella and other bacteria types, with no sign of saturation even at much larger concentrations (108 cfu/ml).

  12. Modeling of a carbon nanotube ultracapacitor.

    Science.gov (United States)

    Orphanou, Antonis; Yamada, Toshishige; Yang, Cary Y

    2012-03-09

    The modeling of carbon nanotube ultracapacitor (CNU) performance based on the simulation of electrolyte ion motion between the cathode and the anode is described. Using a molecular dynamics (MD) approach, the equilibrium positions of the electrode charges interacting through the Coulomb potential are determined, which in turn yield the equipotential surface and electric field associated with the capacitor. With an applied ac voltage, the current is computed based on the nanotube and electrolyte particle distribution and interaction, resulting in the frequency-dependent impedance Z(ω). From the current and impedance profiles, the Nyquist and cyclic voltammetry (CV) plots are then extracted. The results of these calculations compare well with existing experimental data. A lumped-element equivalent circuit for the CNU is proposed and the impedance computed from this circuit correlates well with the simulated and measured impedances.

  13. Batch fabrication of carbon nanotube bearings

    International Nuclear Information System (INIS)

    Subramanian, A; Dong, L X; Tharian, J; Sennhauser, U; Nelson, B J

    2007-01-01

    Relative displacements between the atomically smooth, nested shells in multiwalled carbon nanotubes (MWNTs) can be used as a robust nanoscale motion enabling mechanism. Here, we report on a novel method suited for structuring large arrays of MWNTs into such nanobearings in a parallel fashion. By creating MWNT nanostructures with nearly identical electrical circuit resistance and heat transport conditions, uniform Joule heating across the array is used to simultaneously engineer the shell geometry via electric breakdown. The biasing approach used optimizes process metrics such as yield and cycle-time. We also present the parallel and piecewise shell engineering at different segments of a single nanotube to construct multiple, but independent, high density bearings. We anticipate this method for constructing electromechanical building blocks to be a fundamental unit process for manufacturing future nanoelectromechanical systems (NEMS) with sophisticated architectures and to drive several nanoscale transduction applications such as GHz-oscillators, shuttles, memories, syringes and actuators

  14. Carbon nanotubes: from nano test tube to nano-reactor.

    Science.gov (United States)

    Khlobystov, Andrei N

    2011-12-27

    Confinement of molecules and atoms inside carbon nanotubes provides a powerful strategy for studying structures and chemical properties of individual molecules at the nanoscale. In this issue of ACS Nano, Allen et al. explore the nanotube as a template leading to the formation of unusual supramolecular and covalent structures. The potential of carbon nanotubes as reactors for synthesis on the nano- and macroscales is discussed in light of recent studies.

  15. Catalytic growth of carbon nanotubes with large inner diameters

    Directory of Open Access Journals (Sweden)

    WEI REN ZHONG

    2005-02-01

    Full Text Available Carbon nanotubes (2.4 g/g catalyst, with large inner diameters were successfully synthesized through pyrolysis of methane on a Ni–Cu–Al catalyst by adding sodium carbonate into the carbon nanotubes growth system. The inner diameter of the carbon nanotubes prepared by this method is about 20–60 nm, while their outer diameter is about 40–80 nm. Transmission electron microscopy and X-ray diffraction were employed to investigate the morphology and microstructures of the carbon nanotubes. The analyses showed that these carbon nanotubes have large inner diameters and good graphitization. The addition of sodium carbonate into the reaction system brings about a slight decrease in the methane conversion and the yield of carbon. The experimental results showed that sodium carbonate is a mildly toxic material which influenced the catalytic activity of the Ni–Cu–Al catalyst and resulted in the formation of carbon nanotubes with large inner diameters. The growth mechanism of the carbon nanotubes with large inner diameters is discussed in this paper.

  16. Carbon composites composites with carbon fibers, nanofibers, and nanotubes

    CERN Document Server

    Chung, Deborah D L

    2017-01-01

    Carbon Composites: Composites with Carbon Fibers, Nanofibers, and Nanotubes, Second Edition, provides the reader with information on a wide range of carbon fiber composites, including polymer-matrix, metal-matrix, carbon-matrix, ceramic-matrix and cement-matrix composites. In contrast to other books on composites, this work emphasizes materials rather than mechanics. This emphasis reflects the key role of materials science and engineering in the development of composite materials. The applications focus of the book covers both the developing range of structural applications for carbon fiber composites, including military and civil aircraft, automobiles and construction, and non-structural applications, including electromagnetic shielding, sensing/monitoring, vibration damping, energy storage, energy generation, and deicing. In addition to these new application areas, new material in this updated edition includes coverage of cement-matrix composites, carbon nanofibers, carbon matrix precursors, fiber surface ...

  17. Occupational carbon monoxide poisoning in the State of Washington, 1994-1999.

    Science.gov (United States)

    Lofgren, Don J

    2002-04-01

    Carbon monoxide poisonings continue to be significant and preventable for a number of work operations. This study assesses occupational carbon monoxide morbidity and mortality for the state of Washington based on a review of workers' compensation records for the years 1994-1999. The study characterizes sources, industries, and causative factors, and further attempts to identify work operations most at risk. Records were identified by both injury source and diagnostic codes. The study limits itself to non-fire-related carbon monoxide poisonings and primarily those from acute exposure. A decline in the number of claims was not evident, but the number of incidents per year showed a slight decline. Carbon monoxide poisonings were found to occur throughout all types of industries. The greatest number of claims was found in agriculture, followed by construction and wholesale trade, with these three accounting for more than half the claims and nearly half of the incidents. The more severe poisonings did not necessarily occur in industries with the greatest number of incidents. The major source for carbon monoxide poisoning was forklift trucks, followed by auto/truck/bus, portable saws, and more than 20 other sources. Fruit packing and storage had the highest number of incidents mostly due to fuel-powered forklift activity, with nearly half of the incidents occurring in cold rooms. Adverse health effects as measured by carboxyhemoglobin, hyperbaric oxygen treatment, unconsciousness, and number and cost of claims were indexed by source. Though several specific work operations were identified, the episodic nature of carbon monoxide poisonings, as well as the diverse industries and sources, and the opportunity for a severe poisoning in any number of operations, poses challenges for effective intervention.

  18. Assessment of exposure to carbon monoxide group of firefighters from fire fighting and rescue units

    Directory of Open Access Journals (Sweden)

    Jadwiga Lembas-Bogaczyk

    2011-03-01

    Full Text Available Firemen threat during fire burning of chemical substances indicated presence of carbon monoxide (CO in all cases. Carbon monoxide causes death of fire. Inhaled through respiratory system, links with hemoglobin, thus blocking transport and distribution of oxygen in the body. This leads to tissue anoxia, which is a direct threat to firefighters’ life. The purpose of this study was to assess the exposure to carbon monoxide of participating firefighters extinguishing fire. Estimation of carbon monoxide quantity absorbed by firefighters was isolated in a group of 40 firefighters from Fire Extinguishing and Rescue Unit of State Fire in Nysa. The study was conducted by measuring carbon monoxide in exhaled air. For measurement of carbon monoxide concentration in exhaled air Micro CO meter was used. Results were demonstrated separately for nonsmokers (n425 and smokers (n415. Mean COHb[%] levels in nonsmokers, measured prior the rescue action was 0,3950,3% and increased statistically significant after the action to 0,6150,34%, while in the group smokers, this level was 2,1750,64% before the action and increased insignificantly after the action to 2,3350,63%. The average COHb level in the same groups before and after exercise, was respectively: for nonsmokers prior to exercise was 0,4850,28% and after exercise decreased statistically significant to 0,3050,27%. In the group of smokers before exercise was 2,2350,61% and decreased statistically significant up to 1,5450,71%. It was no difference between the group of age and time of employment.

  19. Catalysts for Efficient Production of Carbon Nanotubes

    Science.gov (United States)

    Sun, Ted X.; Dong, Yi

    2009-01-01

    Several metal alloys have shown promise as improved catalysts for catalytic thermal decomposition of hydrocarbon gases to produce carbon nanotubes (CNTs). Heretofore almost every experiment on the production of carbon nanotubes by this method has involved the use of iron, nickel, or cobalt as the catalyst. However, the catalytic-conversion efficiencies of these metals have been observed to be limited. The identification of better catalysts is part of a continuing program to develop means of mass production of high-quality carbon nanotubes at costs lower than those achieved thus far (as much as $100/g for purified multi-wall CNTs or $1,000/g for single-wall CNTs in year 2002). The main effort thus far in this program has been the design and implementation of a process tailored specifically for high-throughput screening of alloys for catalyzing the growth of CNTs. The process includes an integral combination of (1) formulation of libraries of catalysts, (2) synthesis of CNTs from decomposition of ethylene on powders of the alloys in a pyrolytic chemical-vapor-decomposition reactor, and (3) scanning- electron-microscope screening of the CNTs thus synthesized to evaluate the catalytic efficiencies of the alloys. Information gained in this process is put into a database and analyzed to identify promising alloy compositions, which are to be subjected to further evaluation in a subsequent round of testing. Some of these alloys have been found to catalyze the formation of carbon nano tubes from ethylene at temperatures as low as 350 to 400 C. In contrast, the temperatures typically required for prior catalysts range from 550 to 750 C.

  20. Softening of the Radial Breathing Mode in Metallic Carbon Nanotubes

    Czech Academy of Sciences Publication Activity Database

    Farhat, H. (ed.); Sasaki, K.; Kalbáč, Martin; Hofmann, M.; Saito, R.; Dresselhaus, M. S.; Kong, J.

    2009-01-01

    Roč. 102, č. 12 (2009), 126804-1-126804-4 ISSN 0031-9007 Institutional research plan: CEZ:AV0Z40400503 Keywords : metallic carbon nanotubes * radial breathing mode * single waled carbon nanotubes Subject RIV: CG - Electrochemistry Impact factor: 7.328, year: 2009

  1. Apparatus for the laser ablative synthesis of carbon nanotubes

    Science.gov (United States)

    Smith, Michael W.; Jordan, Kevin

    2010-02-16

    An RF-induction heated side-pumped synthesis chamber for the production of carbon nanotubes. Such an apparatus, while capable of producing large volumes of carbon nanotubes, concurrently provides a simplified apparatus that allows for greatly reduced heat up and cool down times and flexible flowpaths that can be readily modified for production efficiency optimization.

  2. Anode Sheath Switching in a Carbon Nanotube Arc Plasma

    International Nuclear Information System (INIS)

    Fetterman, Abe; Raitses, Yevgeny; Keidar, Michael

    2008-01-01

    The anode ablation rate is investigated as a function of anode diameter for a carbon nanotube arc plasma. It is found that anomalously high ablation occurs for small anode diameters. This result is explained by the formation of a positive anode sheath. The increased ablation rate due to this positive anode sheath could imply greater production rate for carbon nanotubes.

  3. Very short functionalized carbon nanotubes for membrane applications

    NARCIS (Netherlands)

    Fonseca, A.; Reijerkerk, Sander; Potreck, Jens; Nijmeijer, Dorothea C.; Mekhalif, Z.; Delhalle, J.

    2010-01-01

    The cutting and functionalization of carbon nanotubes is described, applying a single-step ball-mill based process. Very short carbon nanotubes bearing primary amine functions were produced, characterized and incorporated in polymeric membranes. The gas separation performance of the composite

  4. Catalyst deposition for the preparation of carbon nanotubes

    DEFF Research Database (Denmark)

    2013-01-01

    patterned surface is configured to ensure that no more than a single island of catalyst is formed on each plateau, so that a sub sequent growth of carbon nanotubes from the deposited islands result in that no more than a single carbon nanotube is grown from each plateau....

  5. Nitrogen doped carbon nanotubes : synthesis, characterization and catalysis

    NARCIS (Netherlands)

    van Dommele, S.

    2008-01-01

    Nitrogen containing Carbon Nanotubes (NCNT) have altered physical- and chemical properties with respect to polarity, conductivity and reactivity as compared to conventional carbon nanotubes (CNT) and have potential for use in electronic applications or catalysis. In this thesis the incorporation of

  6. Synthesis of nano-carbon (nanotubes, nanofibres, graphene ...

    Indian Academy of Sciences (India)

    In the present study, we report the synthesis of carbon nanotubes (CNTs) using a new natural precursor: castor oil. The CNTs were synthesized by spray pyrolysis of castor oil–ferrocene solution at 850°C under an Ar atmosphere. We also report the synthesis of carbon nitrogen (C–N) nanotubes using castor ...

  7. Electrical conductivity of metal–carbon nanotube structures

    Indian Academy of Sciences (India)

    The electrical properties of asymmetric metal–carbon nanotube (CNT) structures have been studied using density functional theory and non-equilibrium Green's function method with Atomistix tool kit. The models with asymmetric metal contacts and carbon nanotube bear resemblance to experimental set-ups. The study ...

  8. A thermodynamic model for growth mechanisms of multiwall carbon nanotubes.

    Energy Technology Data Exchange (ETDEWEB)

    Kaatz, Forrest H.; Overmyer, Donald L.; Siegal, Michael P.

    2006-02-01

    Multiwall carbon nanotubes are grown via thermal chemical vapor deposition between temperatures of 630 and 830 C using acetylene in nitrogen as the carbon source. This process is modeled using classical thermodynamics to explain the total carbon deposition as a function of time and temperature. An activation energy of 1.60 eV is inferred for nanotube growth after considering the carbon solubility term. Scanning electron microscopy shows growth with diameters increasing linearly with time. Transmission electron microscopy and Raman spectroscopy show multiwall nanotubes surrounded by a glassy-carbon sheath, which grows with increasing wall thickness as growth temperatures and times rise.

  9. Thermodynamic model for growth mechanisms of multiwall carbon nanotubes

    Science.gov (United States)

    Kaatz, F. H.; Siegal, M. P.; Overmyer, D. L.; Provencio, P. P.; Tallant, D. R.

    2006-12-01

    Multiwall carbon nanotubes are grown via thermal chemical vapor deposition between temperatures of 630 and 830°C using acetylene in nitrogen as the carbon source. This process is modeled using classical thermodynamics to explain the total carbon deposition as a function of time and temperature. An activation energy of 1.60eV is inferred for nanotube growth after considering the carbon solubility term. Scanning electron microscopy shows growth with diameters increasing linearly with time. Transmission electron microscopy and Raman spectroscopy show multiwall nanotubes surrounded by a glassy-carbon sheath, which grows with increasing wall thickness as growth temperatures and times rise.

  10. Magnetoelectronic properties of chiral carbon nanotubes and tori

    International Nuclear Information System (INIS)

    Shyu, F L; Tsai, C C; Lee, C H; Lin, M F

    2006-01-01

    Magnetoelectronic properties of chiral carbon nanotubes and toroids are studied for any magnetic field. They are sensitive to the changes in the magnitude and the direction of the magnetic field, as well as the chirality. The important differences between chiral and achiral carbon nanotubes include band symmetry, band curvature, band crossing, band-edge state, state degeneracy, band spacing, energy gap, and semiconductor-metal transition. Carbon tori also exhibit the strong chirality dependence on the field modulation of discrete states. Chiral carbon tori might differ from chiral carbon nanotubes in energy-gap modulation, density of states, and state degeneracy

  11. Occupational carbon monoxide violations in the State of Washington, 1994-1999.

    Science.gov (United States)

    Lofgren, Don J

    2002-07-01

    Occupational exposure to carbon monoxide continues to cause a number of injuries and deaths. This study reviewed the State of Washington OSHA inspection records for occupational safety or health violations related to carbon monoxide for the time period 1994-1999 to assess the agency's efforts and further identify and characterize causative factors. Inspection data were also compared with carbon monoxide claims data from a companion study to determine if the agency was visiting the most at risk work operations. Inspections were identified by searching computerized violation texts for "carbon monoxide" or "CO." The study found 142 inspections with one or more carbon monoxide violations. Inspections were spread over 84 different 4-digit Standard Industrial Classification codes. Most inspections were initiated as a result of a complaint or other informant. Inspections were predominantly in construction and manufacturing, whereas carbon monoxide claims were mores evenly distributed between the major industries. Inspections also may have failed to find violations for some types of equipment responsible for carbon monoxide claims. Forklifts were the source of carbon monoxide most often associated with a violation, followed by compressors for respirators, auto/truck/bus, and temporary heating devices. Inspections in response to poisonings found common factors associated with lack of recognition and failure to use or maintain equipment and ventilation. Some work sites with one or more poisonings were not being inspected. Only 10 of the 51 incidents with industrial insurance claim reports of carboxyhemoglobin at or above 20 percent were inspected. Further, it was found more preventive efforts should be targeted at cold storage operations and certain warehouse and construction activities. It is proposed that more specific standards, both consensus and regulatory, would provide additional risk reduction. Reliance upon safe work practices as a primary method of control in the

  12. Accidental carbon monoxide poisoning during yagya for faith healing--a case report.

    Science.gov (United States)

    Behera, C; Millo, T M; Jaiswal, A; Dogra, T D

    2013-03-01

    A 20-year-old female and a 45-year-old male were found lying dead on the floor with frothand vomitus stain present over mouth, nose and face in a closed room. An earthen bowl with incomplete burnt woods, flowers, food materials, agarbati, etc, was also found lying near the body of the two deceased. The cause of death, established by autopsy and toxicological examination was carbon monoxide poisoning in both victims. The source of carbon monoxide was incomplete burnt woods used for yagya during puja (a faith healing practice) for bearing children.

  13. The Range of 1-3 keV Electrons in Solid Oxygen and Carbon Monoxide

    DEFF Research Database (Denmark)

    Oehlenschlæger, M.; Andersen, H.H.; Schou, Jørgen

    1985-01-01

    The range of 1-3 keV electrons in films of solid oxygen and carbon monoxide has been measured by a mirror substrate method. The technique used here is identical to the one previously used for range measurements in solid hydrogen and nitrogen. The range in oxygen is slightly shorter than that in n......The range of 1-3 keV electrons in films of solid oxygen and carbon monoxide has been measured by a mirror substrate method. The technique used here is identical to the one previously used for range measurements in solid hydrogen and nitrogen. The range in oxygen is slightly shorter than...

  14. Selected constituents in the smokes of U. S. commercial cigaretts: tar, nicotine, carbon monoxide and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    One hundred twenty-one brands of United States commercial cigarettes were analyzed for their deliveries of tar, nicotine, carbon monoxide, and carbon dioxide under standard analytical smoking conditions. The sample included both filter and nonfilter cigarettes. Comparisons of carbon monoxide deliveries over the range of observed tar deliveries indicated a very high correlation between CO and tar for filter cigarettes, but nonfilter cigarettes tended to produce much less CO than would have been predicted from their tar deliveries. Comparison of ORNL nicotine values for specific brands with those determined by the Federal Trade Commission yield no statistically significant differences between laboratories. 4 figures, 6 tables.

  15. Carbon nanotubes significance in Darcy-Forchheimer flow

    Science.gov (United States)

    Hayat, Tasawar; Rafique, Kiran; Muhammad, Taseer; Alsaedi, Ahmed; Ayub, Muhammad

    2018-03-01

    The present article examines Darcy-Forchheimer flow of water-based carbon nanotubes. Flow is induced due to a curved stretchable surface. Heat transfer mechanism is analyzed in presence of convective heating process. Xue model of nanofluid is employed to study the characteristics of both single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). Results for both single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) are achieved and compared. Appropriate transformations correspond to strong nonlinear ordinary differential system. Optimal homotopy analysis method (OHAM) is used for the solution development of the resulting system. The contributions of different sundry variables on the velocity and temperature are studied. Further the skin friction coefficient and local Nusselt number are analyzed graphically for both SWCNTs and MWCNTs cases.

  16. Layered growth of aligned carbon nanotube arrays by pyrolysis

    International Nuclear Information System (INIS)

    Zhang Hongrui; Liang Erjun; Ding Pei; Chao Mingju

    2003-01-01

    Based on the study of reaction temperature and duration of the growth of aligned carbon nanotube arrays, layered aligned multi-wall carbon nanotube (MWNT) films grown directly around a reaction quartz tube in an Ar/H 2 atmosphere by pyrolysis of ferrocene in xylene in a suitable reaction furnace with the help of cobalt powder. The scanning electron microscope and transmission electron microscope images indicated that the obtained arrays were composed of many separated layers with MWNTs. The reaction temperature significantly influenced the alignment of the MWNTs, and an appropriate reaction temperature range for growth was 800-900 deg. C. The diameter of the carbon nanotube increased from 46 to 75 nm with the growth temperature. Besides temperature, the reaction duration influenced the length of the well-aligned carbon nanotubes. There was no significant relation between the growth time and the diameter of the carbon nanotubes in the array

  17. Thermophoretic Motion of Water Nanodroplets confined inside Carbon Nanotubes

    DEFF Research Database (Denmark)

    Zambrano, Harvey A; Walther, Jens Honore; Koumoutsakos, Petros

    2009-01-01

    We study the thermophoretic motion of water nanodroplets confined inside carbon nanotubes using molecular dynamics simulations. We find that the nanodroplets move in the direction opposite the imposed thermal gradient with a terminal velocity that is linearly proportional to the gradient....... The translational motion is associated with a solid body rotation of the water nanodroplet coinciding with the helical symmetry of the carbon nanotube. The thermal diffusion displays a weak dependence on the wetting of the water-carbon nanotube interface. We introduce the use of the Moment Scaling Spectrum (MSS......) in order to determine the characteristics of the motion of the nanoparticles inside the carbon nanotube. The MSS indicates that affinity of the nanodroplet with the walls of the carbon nanotubes is important for the isothermal diffusion, and hence for the Soret coefficient of the system....

  18. Fabrication and characterization of nanocomposites reinforced by carbon nanotubes - (1) synthesis of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Hseuh Hsiangming; Tai Nyanhwa; Perng Tongping [Dept. of Material Science, National Tsing-Hwa Univ., TW (China); Chyou Sander [Taiwan Power Research Inst., Taiwan Power Co., Taipei (China)

    2003-07-01

    Multi-walled carbon nanotubes (MWCNTs) produced by floating catalyst method were used for reinforcing material in polymeric nanocomposites. Five different kinds of carbon sources (benzene, toluene, xylene, cyclo-hexane, n-hexane) were used as precursors in the thermal chemical vapor deposition process. The products were collected and examined by Raman, HRTEM, and FESEM. The differences in microstructure and morphologies among these products are analyzed and discussed. (orig.)

  19. 40 CFR Table 5 to Subpart Jjj of... - Carbon Monoxide Emission Limits for Existing Small Municipal Waste Combustion Units

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Carbon Monoxide Emission Limits for Existing Small Municipal Waste Combustion Units 5 Table 5 to Subpart JJJ of Part 62 Protection of... of Part 62—Carbon Monoxide Emission Limits for Existing Small Municipal Waste Combustion Units...

  20. 40 CFR Table 2 to Subpart Aaaa of... - Carbon Monoxide Emission Limits for New Small Municipal Waste Combustion Units

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Carbon Monoxide Emission Limits for New... Pt. 60, Subpt. AAAA, Table 2 Table 2 to Subpart AAAA of Part 60—Carbon Monoxide Emission Limits for.... Compliance is determined by continuous emission monitoring systems. b Block averages, arithmetic mean. See...

  1. Utility of the Measurement of Carboxyhemoglobin Level at the Site of Acute Carbon Monoxide Poisoning in Rural Areas

    Directory of Open Access Journals (Sweden)

    Makoto Onodera

    2016-01-01

    Full Text Available Objective. This study examined the hypothesis that correlations exist between the carbon monoxide exposure time and the carboxyhemoglobin concentration at the site of carbon monoxide poisoning, using a pulse carbon monoxide oximeter in rural areas or the carboxyhemoglobin concentration measured at a given medical institution. Background. In previous studies, no definitive relationships between the arterial blood carboxyhemoglobin level and the severity of carbon monoxide poisoning have been observed. Method. The subjects included patients treated for acute carbon monoxide poisoning in whom a medical emergency team was able to measure the carboxyhemoglobin level at the site of poisoning. We examined the relationship between the carboxyhemoglobin level at the site of poisoning and carbon monoxide exposure time and the relationships between the arterial blood carboxyhemoglobin level and carbon monoxide exposure time. Results. A total of 10 patients met the above criteria. The carboxyhemoglobin levels at the site of poisoning were significantly and positively correlated with the exposure time (rs = 0.710, p=0.021, but the arterial blood carboxyhemoglobin levels were not correlated with the exposure time. Conclusion. In rural areas, the carboxyhemoglobin level measured at the site of carbon monoxide poisoning correlated with the exposure time.

  2. Utility of the Measurement of Carboxyhemoglobin Level at the Site of Acute Carbon Monoxide Poisoning in Rural Areas.

    Science.gov (United States)

    Onodera, Makoto; Fujino, Yasuhisa; Kikuchi, Satoshi; Sato, Masayuki; Mori, Kiyofumi; Beppu, Takaaki; Inoue, Yoshihiro

    2016-01-01

    Objective. This study examined the hypothesis that correlations exist between the carbon monoxide exposure time and the carboxyhemoglobin concentration at the site of carbon monoxide poisoning, using a pulse carbon monoxide oximeter in rural areas or the carboxyhemoglobin concentration measured at a given medical institution. Background. In previous studies, no definitive relationships between the arterial blood carboxyhemoglobin level and the severity of carbon monoxide poisoning have been observed. Method. The subjects included patients treated for acute carbon monoxide poisoning in whom a medical emergency team was able to measure the carboxyhemoglobin level at the site of poisoning. We examined the relationship between the carboxyhemoglobin level at the site of poisoning and carbon monoxide exposure time and the relationships between the arterial blood carboxyhemoglobin level and carbon monoxide exposure time. Results. A total of 10 patients met the above criteria. The carboxyhemoglobin levels at the site of poisoning were significantly and positively correlated with the exposure time (rs = 0.710, p = 0.021), but the arterial blood carboxyhemoglobin levels were not correlated with the exposure time. Conclusion. In rural areas, the carboxyhemoglobin level measured at the site of carbon monoxide poisoning correlated with the exposure time.

  3. Carbon monoxide measurement by gas chromatography; Mesure du monoxyde de carbone par chromatographie en phase gazeuse

    Energy Technology Data Exchange (ETDEWEB)

    Gros, V.; Sarda-Esteve, R.; Bonsang, B.; Ramonet, M.

    1998-09-01

    Although carbon monoxide (CO) is present in trace quantities in the atmosphere (0.1 ppm -or parts per million in volume- on average), the study of this gas is important. Indeed, its impact on human can be dangerous at high level of concentration on the hand and it constitutes one of the main precursor of ozone in presence of concentration on the one hand and it constitutes one of the main precursor of ozone in presence of other pollutants on the other hand. Finally, CO affects the levels of several important greenhouse gases, through its reaction with hydroxyl radicals (OH). CO is measured in the atmosphere since the mid 60's by various methods. Among them, gas chromatography has the advantage to combine a low detection limit with a high precision. This report details the improvements made on the measurement analyser which allowed to perform automatic CO measurements in remote areas with low mixing ratios of carbon monoxide. This report describes some quality tests and the results of various applications. (authors)

  4. Towards self-assembled devices, a carbon nanotube approach

    OpenAIRE

    Del Rio Castillo, Antonio Esau

    2012-01-01

    2010/2011 In the last decade the nanostructured carbon materials, especially single walled carbon nanotubes (SWNTs), had emerged as probable substitutes for Silicon in the next generation of electronic devices. This is due to their unique physic and chemical properties. Likewise, scientists all around the world have made a huge effort to introduce carbon materials into the market. Despite this effort, commercial application for carbon nanotubes in electronic devices has not yet been achiev...

  5. Selective and efficient reduction of carbon dioxide to carbon monoxide on oxide-derived nanostructured silver electrocatalysts

    NARCIS (Netherlands)

    Ma, Ming; Trześniewski, Bartek J.; Xie, Jie; Smith, Wilson A.

    2016-01-01

    In this work, the selective electrocatalytic reduction of carbon dioxide to carbon monoxide on oxide-derived silver electrocatalysts is presented. By a simple synthesis technique, the overall high faradaic efficiency for CO production on the oxide-derived Ag was shifted by more than 400 mV towards a

  6. Influence of surface chemistry on inkjet printed carbon nanotube films

    International Nuclear Information System (INIS)

    Hopkins, Alan R.; Straw, David C.; Spurrell, Kathryn C.

    2011-01-01

    Carbon nanotube ink chemistry and the proper formulation are crucial for direct-write printing of nanotubes. Moreover, the correct surface chemistry of the self-assembled monolayers that assist the direct deposition of carbon nanotubes onto the substrate is equally important to preserve orientation of the printed carbon nanotubes. We report that the successful formulation of two single walled carbon nanotube (SWNT) inks yields a consistent, homogenous printing pattern possessing the requisite viscosities needed for flow through the microcapillary nozzles of the inkjet printer with fairly modest drying times. The addition of an aqueous sodium silicate allows for a reliable method for forming a uniform carbon nanotube network deposited directly onto unfunctionalized surfaces such as glass or quartz via inkjet deposition. Furthermore, this sodium silicate ingredient helps preserve applied orientation to the printed SWNT solution. Sheet resistivity of this carbon nanotube ink formula printed on quartz decreases as a function of passes and is independent of the substrate. SWNTs were successfully patterned on Au. This amine-based surface chemistry dramatically helps improve the isolation stabilization of the printed SWNTs as seen in the atomic force microscopy (AFM) image. Lastly, using our optimized SWNT ink formula and waveform parameters in the Fuji materials printer, we are able to directly write/print SWNTs into 2D patterns. Dried ink pattern expose and help orient roped carbon nanotubes that are suspended in ordered arrays across the cracks.

  7. Mechanochemical treatment of amorphous carbon from brown sphagnum moss for the preparation of carbon nanotubes

    International Nuclear Information System (INIS)

    Onishchenko, D.V.

    2013-01-01

    Under consideration is the mechanism of multiwalled nanotubes formation during mechanical activation of amorphous carbon synthesized by pyrolysis of sphagnum moss. The formation of nanotubes has been shown to take place in the array of carbon particles. A complex study of the sorption characteristics of carbon nanotubes has been carried out. The dependence of the sorption capacity of carbon nanotubes on their storage time, as well as the effect of the process parameters of nanotubes formation on their ability for oxidative modification, is represented. (authors)

  8. Surface plasmon observed for carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Bursill, L A; Stadelmann, P A [Ecole Polytechnique Federale, Lausanne (Switzerland); Peng, J L; Prawer, S [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1994-12-31

    This paper presents parallel electron energy loss spectra (PEELS) results, obtained for individual carbon nanotubes, using nanoprobe techniques (1-2 nm diameter electron beam), energy resolution 0.5 eV and collection times of 4-25 sec. The aim was to use a nanoprobe to compare PEELS spectra from different parts of a tube, in order to search for variations in sp{sup 2}/sp{sup 3} bonding ratios as well as to look for orientation dependent plasmon and core-loss phenomena. It also seemed interesting to compare results for nanotubes with those for other varieties of graphitized carbons. The most interesting result so far was the appearance of a 15 eV plasmon peak, which appeared only for tubes containing {<=} about 12 graphite-like layers. This peak did not shift significantly with tube size. A low-loss peaks at 6 eV of variable relative intensity was also observed this peak was relatively very weak for amorphous tubes; it appears to be characteristic of graphite-like layers, as found for nanotubes and, of course, graphite itself. This paper is restricted to discussion of the low-loss results. The experimental techniques are first described, including some details of the methods which may be used to disperse and support sooty carbons for high-resolution transmission electron microscopy. The results are then presented, followed by an interpretation of all the low-loss PEELS results, including those of the other authors. 14 refs., 2 figs.

  9. Conversion of carbon dioxide to carbon monoxide by pulse dielectric barrier discharge plasma

    Science.gov (United States)

    Wang, Taobo; Liu, Hongxia; Xiong, Xiang; Feng, Xinxin

    2017-01-01

    The conversion of carbon dioxide (CO2) to carbon monoxide (CO) was investigated in a non-thermal plasma dielectric barrier discharge (DBD) reactor, and the effects of different process conditions on the CO2 conversion were investigated. The results showed that the increase of input power could optimize the conversion of CO2 to CO. The CO2 conversion and CO yield were negatively correlated with the gas flow rate, but there was an optimum gas flow rate, that made the CO selectivity best. The carrier gas (N2, Ar) was conducive to the conversion of CO2, and the effect of N2 as carrier gas was better than Ar. The conversion of CO2 to CO was enhanced by addition of the catalyst (5A molecular sieve).

  10. Carbon nanotubes for high-performance logic

    OpenAIRE

    Chen, Zhihong; Wong, H.S. Phillip; Mitra, Subhasish; Bol, Aggeth; Peng, Lianmao; Hills, Gage; Thissen, Nick

    2014-01-01

    Single-wall carbon nanotubes (CNTs) were discovered in 1993 and have been an area of intense research since then. They offer the right dimensions to explore material science and physical chemistry at the nanoscale and are the perfect system to study low-dimensional physics and transport. In the past decade, more attention has been shifted toward making use of this unique nanomaterial in real-world applications. In this article, we focus on potential applications of CNTs in the high-performanc...

  11. Metallic Carbon Nanotubes and Ag Nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Brus, Louis E

    2014-03-04

    The goal of this DOE solar energy research was to understand how visible light interacts with matter, and how to make electric excitations evolve into separated electrons and holes in photovoltaic cells, especially in nanoparticles and nanowires. Our specific experiments focused on A) understanding plasmon enhanced spectroscopy and charge-transfer (metal-to-molecule) photochemistry on the surface of metallic particles and B) the spectroscopy and photochemistry of carbon nanotubes and graphene. I also worked closely with R. Friesner on theoretical studies of photo-excited electrons near surfaces of titanium dioxide nanoparticles; this process is relevant to the Gratzel photovoltaic cell.

  12. Carbon Nanotubes Filled with Ferromagnetic Materials

    Directory of Open Access Journals (Sweden)

    Albrecht Leonhardt

    2010-08-01

    Full Text Available Carbon nanotubes (CNT filled with ferromagnetic metals like iron, cobalt or nickel are new and very interesting nanostructured materials with a number of unique properties. In this paper we give an overview about different chemical vapor deposition (CVD methods for their synthesis and discuss the influence of selected growth parameters. In addition we evaluate possible growth mechanisms involved in their formation. Moreover we show their identified structural and magnetic properties. On the basis of these properties we present different application possibilities. Some selected examples reveal the high potential of these materials in the field of medicine and nanotechnology.

  13. Fibrous composites comprising carbon nanotubes and silica

    Science.gov (United States)

    Peng, Huisheng [Shanghai, CN; Zhu, Yuntian Theodore [Cary, NC; Peterson, Dean E [Los Alamos, NM; Jia, Quanxi [Los Alamos, NM

    2011-10-11

    Fibrous composite comprising a plurality of carbon nanotubes; and a silica-containing moiety having one of the structures: (SiO).sub.3Si--(CH.sub.2).sub.n--NR.sub.1R.sub.2) or (SiO).sub.3Si--(CH.sub.2).sub.n--NCO; where n is from 1 to 6, and R.sub.1 and R.sub.2 are each independently H, CH.sub.3, or C.sub.2H.sub.5.

  14. Biomineralization of superhydrophilic vertically aligned carbon nanotubes.

    Science.gov (United States)

    Marsi, Teresa Cristina O; Santos, Tiago G; Pacheco-Soares, Cristina; Corat, Evaldo J; Marciano, Fernanda R; Lobo, Anderson O

    2012-03-06

    Vertically aligned carbon nanotubes (VACNT) promise a great role for the study of tissue regeneration. In this paper, we introduce a new biomimetic mineralization routine employing superhydrophilic VACNT films as highly stable template materials. The biomineralization was obtained after VACNT soaking in simulated body fluid solution. Detailed structural analysis reveals that the polycrystalline biological apatites formed due to the -COOH terminations attached to VACNT tips after oxygen plasma etching. Our approach not only provides a novel route for nanostructured materials, but also suggests that COOH termination sites can play a significant role in biomimetic mineralization. These new nanocomposites are very promising as nanobiomaterials due to the excellent human osteoblast adhesion.

  15. Carbon Nanotubes Filled with Ferromagnetic Materials

    Science.gov (United States)

    Weissker, Uhland; Hampel, Silke; Leonhardt, Albrecht; Büchner, Bernd

    2010-01-01

    Carbon nanotubes (CNT) filled with ferromagnetic metals like iron, cobalt or nickel are new and very interesting nanostructured materials with a number of unique properties. In this paper we give an overview about different chemical vapor deposition (CVD) methods for their synthesis and discuss the influence of selected growth parameters. In addition we evaluate possible growth mechanisms involved in their formation. Moreover we show their identified structural and magnetic properties. On the basis of these properties we present different application possibilities. Some selected examples reveal the high potential of these materials in the field of medicine and nanotechnology. PMID:28883334

  16. Disorder, Pseudospins, and Backscattering in Carbon Nanotubes

    International Nuclear Information System (INIS)

    McEuen, Paul L.; Bockrath, Marc; Cobden, David H.; Yoon, Young-Gui; Louie, Steven G.

    1999-01-01

    We address the effects of disorder on the conducting properties of metal and semiconducting carbon nanotubes. Experimentally, the mean free path is found to be much larger in metallic tubes than in doped semiconducting tubes. We show that this result can be understood theoretically if the disorder potential is long ranged. The effects of a pseudospin index that describes the internal sublattice structure of the states lead to a suppression of scattering in metallic tubes, but not in semiconducting tubes. This conclusion is supported by tight-binding calculations. (c) 1999 The American Physical Society

  17. Carbon Nanotube Integration with a CMOS Process

    Science.gov (United States)

    Perez, Maximiliano S.; Lerner, Betiana; Resasco, Daniel E.; Pareja Obregon, Pablo D.; Julian, Pedro M.; Mandolesi, Pablo S.; Buffa, Fabian A.; Boselli, Alfredo; Lamagna, Alberto

    2010-01-01

    This work shows the integration of a sensor based on carbon nanotubes using CMOS technology. A chip sensor (CS) was designed and manufactured using a 0.30 μm CMOS process, leaving a free window on the passivation layer that allowed the deposition of SWCNTs over the electrodes. We successfully investigated with the CS the effect of humidity and temperature on the electrical transport properties of SWCNTs. The possibility of a large scale integration of SWCNTs with CMOS process opens a new route in the design of more efficient, low cost sensors with high reproducibility in their manufacture. PMID:22319330

  18. Superconductivity in single wall carbon nanotubes

    Directory of Open Access Journals (Sweden)

    H Yavari

    2009-08-01

    Full Text Available   By using Greens function method we first show that the effective interaction between two electrons mediated by plasmon exchange can become attractive which in turn can lead to superconductivity at a high critical temperature in a singl wall carbon nanotubes (SWCNT. The superconducting transition temperature Tc for the SWCNT (3,3 obtained by this mechanism agrees with the recent experimental result. We also show as the radius of SWCNT increases, plasmon frequency becomes lower and leads to lower Tc.

  19. Spin transport in ferromagnetically contacted carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, C.; Morgan, C.; Schneider, C.M. [Peter Gruenberg Institut, PGI-6, Forschungszentrum Juelich and JARA Juelich Aachen Research Alliance, 52425 Juelich (Germany)

    2011-11-15

    We present magnetoresistance (MR) measurements on carbon nanotubes (CNTs) with different ferromagnetic leads. A sample with permalloy (Ni{sub 80}Fe{sub 20}) contacts shows the expected tunneling-type MR effect. Measurements on devices with CoPd contacts show a larger change of resistance with magnetic field. However, only minor loops are observed, which is explained with domain wall pinning. This is supported by magnetic force microscopy (MFM) measurements, which reveal a complicated bubble and stripe domain pattern. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Chemical production from waste carbon monoxide: its potential for energy conservation

    Energy Technology Data Exchange (ETDEWEB)

    Rohrmann, C.A.; Schiefelbein, G.F.; Molton, P.M.; Li, C.T.; Elliott, D.C.; Baker, E.G.

    1977-11-01

    Results of a study of the potential for energy conservation by producing chemicals from by-product or waste carbon monoxide (CO) from industrial sources are summarized. Extensive compilations of both industrial sources and uses for carbon monoxide were developed and included. Reviews of carbon monoxide purification and concentration technology and preliminary economic evaluations of carbon monoxide concentration, pipeline transportation and utilization of CO in the synthesis of ammonia and methanol are included. Preliminary technical and economic feasibility studies were made of producing ammonia and methanol from the by-product CO produced by a typical elemental phosphorus plant. Methanol synthesis appears to be more attractive than ammonia synthesis when using CO feedstock because of reduced water gas shift and carbon dioxide removal requirements. The economic studies indicate that methanol synthesis from CO appears to be competitive with conventional technology when the price of natural gas exceeds $0.82/million Btu, while ammonia synthesis from CO is probably not competitive until the price of natural gas exceeds $1.90/million Btu. It is concluded that there appears to be considerable potential for energy conservation in the chemical industry, by collecting CO rather than flaring it, and using it to make major chemicals such as ammonia and methanol.

  1. Thermodynamics on Soluble Carbon Nanotubes: How Do DNA Molecules Replace Surfactants on Carbon Nanotubes?

    Science.gov (United States)

    Kato, Yuichi; Inoue, Ayaka; Niidome, Yasuro; Nakashima, Naotoshi

    2012-01-01

    Here we represent thermodynamics on soluble carbon nanotubes that enables deep understanding the interactions between single-walled carbon nanotubes (SWNTs) and molecules. We selected sodium cholate and single-stranded cytosine oligo-DNAs (dCn (n = 4, 5, 6, 7, 8, 10, 15, and 20)), both of which are typical SWNT solubilizers, and successfully determined thermodynamic properties (ΔG, ΔH and ΔS values) for the exchange reactions of sodium cholate on four different chiralities of SWNTs ((n,m) = (6,5), (7,5), (10,2), and (8,6)) for the DNAs. Typical results contain i) the dC5 exhibited an exothermic exchange, whereas the dC6, 8, 10, 15, and 20 materials exhibited endothermic exchanges, and ii) the energetics of the dC4 and dC7 exchanges depended on the associated chiral indices and could be endothermic or exothermic. The presented method is general and is applicable to any molecule that interacts with nanotubes. The study opens a way for science of carbon nanotube thermodynamics. PMID:23066502

  2. Tuning the conductance of carbon nanotubes with encapsulated molecules

    International Nuclear Information System (INIS)

    Meunier, Vincent; Sumpter, Bobby G

    2007-01-01

    It was recently shown that a molecule encapsulated inside a carbon nanotube can be used to devise a novel type of non-volatile memory element. At the heart of the mechanism for storing and reading information is the new concept of a molecular gate where the molecule acts as a passive gate that hinders the flow of electrons for a given position relative to the nanotube host. By systematically exploring the effects of encapsulation of an acceptor molecule in a series of carbon nanotubes, we show that the reliability of the memory mechanism is very sensitive to the interaction between the nanotube host and the molecule guest

  3. Nanotube bundle oscillators: Carbon and boron nitride nanostructures

    International Nuclear Information System (INIS)

    Thamwattana, Ngamta; Hill, James M.

    2009-01-01

    In this paper, we investigate the oscillation of a fullerene that is moving within the centre of a bundle of nanotubes. In particular, certain fullerene-nanotube bundle oscillators, namely C 60 -carbon nanotube bundle, C 60 -boron nitride nanotube bundle, B 36 N 36 -carbon nanotube bundle and B 36 N 36 -boron nitride nanotube bundle are studied using the Lennard-Jones potential and the continuum approach which assumes a uniform distribution of atoms on the surface of each molecule. We address issues regarding the maximal suction energies of the fullerenes which lead to the generation of the maximum oscillation frequency. Since bundles are also found to comprise double-walled nanotubes, this paper also examines the oscillation of a fullerene inside a double-walled nanotube bundle. Our results show that the frequencies obtained for the oscillation within double-walled nanotube bundles are slightly higher compared to those of single-walled nanotube bundle oscillators. Our primary purpose here is to extend a number of established results for carbon to the boron nitride nanostructures.

  4. Carbon Nanotubes Hybrid Hydrogels in Drug Delivery: A Perspective Review

    Science.gov (United States)

    Hampel, Silke; Spizzirri, Umile Gianfranco; Parisi, Ortensia Ilaria; Picci, Nevio; Iemma, Francesca

    2014-01-01

    The use of biologics, polymers, silicon materials, carbon materials, and metals has been proposed for the preparation of innovative drug delivery devices. One of the most promising materials in this field are the carbon-nanotubes composites and hybrid materials coupling the advantages of polymers (biocompatibility and biodegradability) with those of carbon nanotubes (cellular uptake, stability, electromagnatic, and magnetic behavior). The applicability of polymer-carbon nanotubes composites in drug delivery, with particular attention to the controlled release by composites hydrogel, is being extensively investigated in the present review. PMID:24587993

  5. Spontaneous and controlled-diameter synthesis of single-walled and few-walled carbon nanotubes

    Science.gov (United States)

    Inoue, Shuhei; Lojindarat, Supanat; Kawamoto, Takahiro; Matsumura, Yukihiko; Charinpanitkul, Tawatchai

    2018-05-01

    In this study, we explored the spontaneous and controlled-diameter growth of carbon nanotubes. We evaluated the effects of catalyst density, reduction time, and a number of catalyst coating on the substrate (for multi-walled carbon nanotubes) on the diameter of single-walled carbon nanotubes and the number of layers in few-walled carbon nanotubes. Increasing the catalyst density and reduction time increased the diameters of the carbon nanotubes, with the average diameter increasing from 1.05 nm to 1.86 nm for single-walled carbon nanotubes. Finally, we succeeded in synthesizing a significant double-walled carbon nanotube population of 24%.

  6. Carbon nanotube/carbon nanotube composite AFM probes prepared using ion flux molding

    Science.gov (United States)

    Chesmore, Grace; Roque, Carrollyn; Barber, Richard

    The performance of carbon nanotube-carbon nanotube composite (CNT/CNT composite) atomic force microscopy (AFM) probes is compared to that of conventional Si probes in AFM tapping mode. The ion flux molding (IFM) process, aiming an ion beam at the CNT probe, aligns the tip to a desired angle. The result is a relatively rigid tip that is oriented to offset the cantilever angle. Scans using these probes reveal an improvement in image accuracy over conventional tips, while allowing higher aspect ratio imaging of 3D surface features. Furthermore, the lifetimes of CNT-CNT composite tips are observed to be longer than both conventional tips and those claimed for other CNT technologies. Novel applications include the imaging of embiid silk. Supported by the Clare Boothe Luce Research Scholars Award and Carbon Design Innovations.

  7. Oxidation of Carbon Nanotubes in an Ionizing Environment.

    Science.gov (United States)

    Koh, Ai Leen; Gidcumb, Emily; Zhou, Otto; Sinclair, Robert

    2016-02-10

    In this work, we present systematic studies on how an illuminating electron beam which ionizes molecular gas species can influence the mechanism of carbon nanotube oxidation in an environmental transmission electron microscope (ETEM). We found that preferential attack of the nanotube tips is much more prevalent than for oxidation in a molecular gas environment. We establish the cumulative electron doses required to damage carbon nanotubes from 80 keV electron beam irradiation in gas versus in high vacuum. Our results provide guidelines for the electron doses required to study carbon nanotubes within or without a gas environment, to determine or ameliorate the influence of the imaging electron beam. This work has important implications for in situ studies as well as for the oxidation of carbon nanotubes in an ionizing environment such as that occurring during field emission.

  8. The synthesis and filling of single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Friedrichs, Steffi

    2002-01-01

    This thesis is concerned with the synthesis, properties and application of single-walled carbon nanotubes (SWNTs). The two main objectives of the work were the development of a continuous-flow synthesis of SWNTs, using chemical vapour deposition (CVD) techniques, and the application of the hollow SWNTs as moulds for the study of the crystallisation behaviour of inorganic materials in the confined space of their inner cavity. The latter study was mainly performed by interpreting high-resolution transmission electron microscopy (HRTEM) images of the filled SWNTs. A so-called focal series restoration approach, which enhances the resolution of the images and thereby increases the information content, was employed where possible. Chapter I reviews the previous work in the field of SWNTs and introduces their basic structure, symmetry, physical and mechanical properties and the common methods of SWNT synthesis. The chapter ends with an overview of the techniques used in the present work for the characterisation of carbon nanotube samples by giving a description of the high-resolution transmission electron microscopy (HRTEM) techniques and the digital image processing method. Other physical measurement techniques used, such as Raman spectroscopy and thermogravimetric analysis (TGA), are discussed with reference to their application for the characterisation of carbon nanotubes. Chapter II describes the development of an improved synthesis strategy for SWNTs. A continuous-flow chemical vapour deposition (CVD) method was explored using carbon monoxide or mixtures of methane and hydrogen as the carbon feedstock gas and introducing various volatile organometallic compounds to catalyse the formation of SWNTs. In this study, a special water-cooled copper nozzle was designed and built so as to prevent the premature decompositiont (disproportionation) of the reactants (the carbon monoxide gas) and to allow their direct introduction into the centre of the hot reaction zone. A

  9. Integrated Science Assessment (ISA) for Carbon Monoxide (Second External Review Draft, Sep 2009)

    Science.gov (United States)

    EPA announced that the Second External Review Draft of the Integrated Science Assessment (ISA) for Carbon Monoxide (CO) and related Annexes was made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evaluation of t...

  10. Catalytic Reduction of Nitrous Oxide with Carbon Monoxide over Calcined Co–Mn–Al Hydrotalcite

    Czech Academy of Sciences Publication Activity Database

    Pacultová, K.; Obalová, L.; Kovanda, F.; Jirátová, Květa

    2008-01-01

    Roč. 137, 2-4 (2008), s. 358-389 ISSN 0920-5861 R&D Projects: GA ČR(CZ) GA106/05/0366 Institutional research plan: CEZ:AV0Z40720504 Keywords : nitrous oxide * carbon monoxide * mixed oxide catalysts Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.004, year: 2008

  11. Multimodel simulations of carbon monoxide: Comparison with observations and projected near-future changes

    NARCIS (Netherlands)

    Shindell, D.T.; Faluvegi, G.; Stevenson, D.S.; Krol, M.C.; Emmons, L.K.; Lamarque, J.F.; Petron, G.; Dentener, F.J.; Ellingsen, K.; Schultz, M.G.; Wild, O.; Amann, M.; Atherton, C.S.; Bergmann, D.J.; Bey, I.; Butler, T.; Cofala, J.; Collins, W.J.; Derwent, R.G.; Doherty, R.M.; Drevet, J.; Eskes, H.J.; Fiore, A.M.; Gauss, M.; Hauglustaine, D.A.; Horowitz, L.W.; Isaksen, I.S.A.; Lawrence, M.G.; Montanaro, V.; Muller, J.F.; Pitari, G.; Prather, M.J.; Pyle, J.A.; Rast, S.; Rodriguez, J.M.; Sanderson, M.G.; Savage, N.H.; Strahan, S.E.; Sudo, K.; Szopa, S.; Unger, N.; Noije, van T.P.C.; Zeng, G.

    2006-01-01

    We analyze present-day and future carbon monoxide (CO) simulations in 26 state-of-the-art atmospheric chemistry models run to study future air quality and climate change. In comparison with near-global satellite observations from the MOPITT instrument and local surface measurements, the models show

  12. SEASONAL SOIL FLUXES OF CARBON MONOXIDE IN BURNED AND UNBURNED BRAZILIAN SAVANNAS

    Science.gov (United States)

    Soil-atmosphere fluxes of carbon monoxide (CO) were measured from September 1999 through November 2000 in savanna areas in central Brazil (Cerrado) under different fire regimes using transparent and opaque static chambers. Studies focused on two vegetation types, cerrado stricto...

  13. MODELLING OF CARBON MONOXIDE AIR POLLUTION IN LARG CITIES BY EVALUETION OF SPECTRAL LANDSAT8 IMAGES

    Directory of Open Access Journals (Sweden)

    M. Hamzelo

    2015-12-01

    Full Text Available Air pollution in large cities is one of the major problems that resolve and reduce it need multiple applications and environmental management. Of The main sources of this pollution is industrial activities, urban and transport that enter large amounts of contaminants into the air and reduces its quality. With Variety of pollutants and high volume manufacturing, local distribution of manufacturing centers, Testing and measuring emissions is difficult. Substances such as carbon monoxide, sulfur dioxide, and unburned hydrocarbons and lead compounds are substances that cause air pollution and carbon monoxide is most important. Today, data exchange systems, processing, analysis and modeling is of important pillars of management system and air quality control. In this study, using the spectral signature of carbon monoxide gas as the most efficient gas pollution LANDSAT8 images in order that have better spatial resolution than appropriate spectral bands and weather meters،SAM classification algorithm and Geographic Information System (GIS , spatial distribution of carbon monoxide gas in Tehran over a period of one year from the beginning of 2014 until the beginning of 2015 at 11 map have modeled and then to the model valuation ،created maps were compared with the map provided by the Tehran quality comparison air company. Compare involved plans did with the error matrix and results in 4 types of care; overall, producer, user and kappa coefficient was investigated. Results of average accuracy were about than 80%, which indicates the fit method and data used for modeling.

  14. Intra-pulse Cavity Enhanced Measurements of Carbon Monoxide in a Rapid Compression Machine

    KAUST Repository

    Nasir, Ehson Fawad; Farooq, Aamir

    2018-01-01

    A laser absorption sensor for carbon monoxide concentration was developed for combustion studies in a rapid compression machine using a pulsed quantum cascade laser near 4.89 μm. Cavity enhancement reduced minimum detection limit down to 2.4 ppm

  15. Carbon monoxide oxidation using Zn-Cu-Ti hydrotalcite-derived ...

    Indian Academy of Sciences (India)

    Multioxide catalysts of zinc, copper and titanium with different ratios obtained from layered double hydroxide (LDH) precursors were used in the oxidation of carbon monoxide. The catalysts were characterized by energy-dispersive X-ray spectrometry, X-ray diffraction, thermal analyses (TG, DTG and DTA) and scanning ...

  16. Room-temperature cold-welding of gold nanoparticles for enhancing the electrooxidation of carbon monoxide.

    Science.gov (United States)

    Liu, Cai; Li, Yong-Jun; Sun, Shi-Gang; Yeung, Edward S

    2011-04-21

    A cold-welding strategy is proposed to rapidly join together Au nanoparticles (AuNPs) into two-dimensional continuous structures for enhancing the electrooxidation of carbon monoxide by injecting a mixture of ethanol and tolulene into the bottom of a AuNP solution. © The Royal Society of Chemistry 2011

  17. Forensic aspects of carbon monoxide poisoning by charcoal burning in Denmark, 2008-2012

    DEFF Research Database (Denmark)

    Nielsen, Pia Rude; Gheorghe, Alexandra; Lynnerup, Niels

    2014-01-01

    Carbon monoxide (CO) inhalation is a well-known method of committing suicide. There has been a drastic increase in suicide by inhalation of CO, produced from burning charcoal, in some parts of Asia, and a few studies have reported an increased number of these deaths in Europe. CO-related deaths c...

  18. Evidence for long-range transport of carbon monoxide in the Southern Hemisphere from SCIAMACHY observations

    NARCIS (Netherlands)

    Gloudemans, A.M.S.; Krol, M.C.; Meirink, J.F.; de Laat, A.T.J.; van der Werf, G.R.; Schrijver, H.; van den Broek, M.M.P.; Aben, I.

    2006-01-01

    The SCIAMACHY satellite instrument shows enhanced carbon monoxide (CO) columns in the Southern Hemisphere during the local Spring. Chemistry-transport model simulations using the new GFEDv2 biomass-burning emission database show a similar temporal and spatial CO distribution, indicating that the

  19. An infrared spectroscopic study of the adsorption of carbon monoxide on silica-supported copper particles

    NARCIS (Netherlands)

    Jong, K.P. de; Geus, John W.; Joziasse, J.

    Infrared spectroscopy is used to study the adsorption of carbon monoxide (20°C; 0.1– 100 Torr) on copper-on-silica catalysts differently prepared and pretreated. As determined by electron microscopy and X-ray line broadening, the catalysts contain copper particles having sizes of 60 to 5000 Å

  20. 77 FR 8252 - Adequacy Status of the Anchorage, Alaska, Carbon Monoxide Maintenance Plan for Transportation...

    Science.gov (United States)

    2012-02-14

    ... a SIP means that transportation activities will not produce new air quality violations, worsen... Anchorage, Alaska, Carbon Monoxide Maintenance Plan for Transportation Conformity Purposes AGENCY... Transportation & Public Facilities, and the U.S. Department of Transportation will be required to use [[Page 8253...

  1. A Retrospective Analysis of Pediatric Patients Admitted to the Pediatric Emergency Service for Carbon Monoxide Intoxication

    Directory of Open Access Journals (Sweden)

    Metin Uysalol

    2011-09-01

    Full Text Available Objective: The aim of the study is to analyze the general aspects of cases with carbon monoxide intoxication in order to improve the approach to future patients. Material and Methods: The hospital records of 84 children (mean age 4.71±2.64 years; 48 male, 36 female who had been admitted to Paediatric Emergency Department for carbon monoxide intoxication between October 2007 and February 2009, were retrospectively evaluated in a descriptive analysis.Results: The source of carbon monoxide intoxication was heaters, waterheaters and fi re in 82.1%, 7.1% and 6% of cases, respectively. There was a statistically signifi cant difference between the carboxyhemoglobin levels of the patients according to the clinical classifi cation (p<0.05. The intoxication caused by heaters was observed signifi cantly in November, December and January (p<0.001, between 16:00-24:00 hours (p<0.001 and among more than one member of a family (p<0.001. A medium level correlation was detected between the treatment approach and clinical classifi cation (r=0.50, p<0.001. Conclusion: Carbon monoxide intoxication, in the presented series, was found to develop accidentally; mostly in the Winter season; during night hours when the family members gathered together. The carboxyhemoglobin levels were appropriate with the developing clinical findings. Carboxyhemoglobin level solely was not enough for achieving the diagnosis and planning the treatment.

  2. Carbon monoxide poisoning in Nigeria - it is time to pay attention ...

    African Journals Online (AJOL)

    Background: Carbon monoxide (CO) is a colourless, odourless gas and a cause of thousands of deaths across the world annually but its lethal consequences often go unrecognized, especially in developing countries. Aim: To discuss the subject of CO poisoning using local examples. Methods: Information was drawn from ...

  3. Multimodel simulations of carbon monoxide: comparison with observations and projected near-future changes

    NARCIS (Netherlands)

    Shindell, D.T.; Krol, M.C.

    2006-01-01

    We analyze present-day and future carbon monoxide (CO) simulations in 26 state-ofthe- art atmospheric chemistry models run to study future air quality and climate change. In comparison with near-global satellite observations from the MOPITT instrument and local surface measurements, the models show

  4. Carbon nanotubes enhanced the lead toxicity on the freshwater fish

    International Nuclear Information System (INIS)

    Martinez, D S T; Alves, O L; Barbieri, E

    2013-01-01

    Carbon nanotubes are promising nanostructures for many applications in materials industry and biotechnology. However, it is mandatory to evaluate their toxicity and environmental implications. We evaluated nitric acid treated multiwalled carbon nanotubes (HNO 3 -MWCNT) toxicity in Nile tilapia (Oreochromis niloticus) and also the lead (Pb) toxicity modulation after the nanotube interaction. Industrial grade multiwalled carbon nanotubes [Ctube 100, CNT Co. Ltd] were treated with 9M HNO 3 for 12h at 150°C to generate oxygenated groups on the nanotube surface, to improve water dispersion and heavy metal interaction. The HNO 3 -treated multiwalled carbon nanotubes were physico-chemically characterized by several techniques [e.g. TEM, FE-SEM, TGA, ζ-potential and Raman spectroscopy]. HNO 3 -MWCNT did not show toxicity on Nile tilapia when the concentration ranged from 0.1 to 3.0 mg/L, and the maximum exposure time was 96h. After 24, 48, 72 and 96h the LC50 values of Pb were 1.65, 1.32, 1.10 and 0.99 mg/L, respectively. To evaluate the Pb-nanotube interaction influence on the ecotoxicity, we submitted the Nile tilapia to different concentrations of Pb mixed with a non-toxic concentration of HNO 3 -MWCNT (1.0 mg/L). After 24, 48, 72, 96 h the LC50 values of Pb plus nanotubes were: 0.32, 0.25, 0.20, 0.18 mg/L, respectively. These values showed a synergistic effect after Pb-nanotube interaction since Pb toxicity increased over five times. X-ray energy dispersive spectroscopy (EDS) was used to confirm lead adsorption on the carbon nanotube oxidized surface. The exposure of Nile tilapia to Pb plus HNO 3 -MWCNT caused both oxygen consumption and ammonium excretion decrease, when compared to the control. Finally, our results show that carbon nanotubes interact with classical pollutants drawing attention to the environmental implications.

  5. Fermentation based carbon nanotube multifunctional bionic composites

    Science.gov (United States)

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-06-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal.

  6. Carbon nanotube-based ethanol sensors

    International Nuclear Information System (INIS)

    Brahim, Sean; Colbern, Steve; Gump, Robert; Moser, Alex; Grigorian, Leonid

    2009-01-01

    Sensors containing metal-carbon nanotube (CNT) hybrid materials as the active sensing layer were demonstrated for ethanol vapor detection at room temperature. The metal-CNT hybrid materials were synthesized by infiltrating single wall carbon nanotubes (SWNTs) with the transition metals Ti, Mn, Fe, Co, Ni, Pd or Pt. Each sensor was prepared by drop-casting dilute dispersions of a metal-CNT hybrid onto quartz substrate electrodes and the impedimetric responses to varying ethanol concentration were recorded. Upon exposure to ethanol vapor, the ac impedance (Z') of the sensors was found to decrease to different extents. The sensor containing pristine CNT material was virtually non-responsive at low ethanol concentrations (<50 ppm). In contrast, all metal-CNT hybrid sensors showed extremely high sensitivity to trace ethanol levels with 100-fold or more gains in sensitivity relative to the starting SWNT sensor. All hybrid sensors, with the exception of Ni filled CNT, exhibited significantly larger sensor responses to ethanol vapor up to 250 ppm compared to the starting SWNT sensor.

  7. Fabrication of mesoporous and high specific surface area lanthanum carbide-carbon nanotube composites

    International Nuclear Information System (INIS)

    Biasetto, L.; Carturan, S.; Maggioni, G.; Zanonato, P.; Bernardo, P. Di; Colombo, P.; Andrighetto, A.; Prete, G.

    2009-01-01

    Mesoporous lanthanum carbide-carbon nanotube composites were produced by means of carbothermal reaction of lanthanum oxide, graphite and multi-walled carbon nanotube mixtures under high vacuum. Residual gas analysis revealed the higher reactivity of lanthanum oxide towards carbon nanotubes compared to graphite. After sintering, the composites revealed a specific surface area increasing with the amount of carbon nanotubes introduced. The meso-porosity of carbon nanotubes was maintained after thermal treatment.

  8. Illuminating the future of silicon photonics: optical coupling of carbon nanotubes to microrings

    International Nuclear Information System (INIS)

    Kato, Y K

    2015-01-01

    Advances in carbon nanotube material quality and processing techniques have led to an increased interest in nanotube photonics. In particular, emission in the telecommunication wavelengths makes nanotubes compatible with silicon photonics. Noury et al (2014 Nanotechnology 25 215201) have reported on carbon nanotube photoluminescence coupled to silicon microring resonators, underscoring the advantage of combining carbon nanotube emitters with silicon photonics. Their results open up the possibility of using nanotubes in other waveguide-based devices, taking advantage of well-established technologies. (viewpoint)

  9. Hydrogen Oxidation on Gas Diffusion Electrodes for Phosphoric Acid Fuel Cells in the Presence of Carbon Monoxide and Oxygen

    DEFF Research Database (Denmark)

    Gang, Xiao; Li, Qingfeng; Hjuler, Hans Aage

    1995-01-01

    Hydrogen oxidation has been studied on a carbon-supported platinum gas diffusion electrode in a phosphoric acidelectrolyte in the presence of carbon monoxide and oxygen in the feed gas. The poisoning effect of carbon monoxide presentin the feed gas was measured in the temperature range from 80...... to 150°C. It was found that throughout the temperaturerange, the potential loss due to the CO poisoning can be reduced to a great extent by the injection of small amounts ofgaseous oxygen into the hydrogen gas containing carbon monoxide. By adding 5 volume percent (v/o) oxygen, an almost...

  10. Carbon Nanotube Microarrays Grown on Nanoflake Substrates

    Science.gov (United States)

    Schmidt, Howard K.; Hauge, Robert H.; Pint, Cary; Pheasant, Sean

    2013-01-01

    This innovation consists of a new composition of matter where single-walled carbon nanotubes (SWNTs) are grown in aligned arrays from nanostructured flakes that are coated in Fe catalyst. This method of growth of aligned SWNTs, which can yield well over 400 percent SWNT mass per unit substrate mass, exceeds current yields for entangled SWNT growth. In addition, processing can be performed with minimal wet etching treatments, leaving aligned SWNTs with superior properties over those that exist in entangled mats. The alignment of the nanotubes is similar to that achieved in vertically aligned nanotubes, which are called "carpets. " Because these flakes are grown in a state where they are airborne in a reactor, these flakes, after growing SWNTs, are termed "flying carpets. " These flakes are created in a roll-to-roll evaporator system, where three subsequent evaporations are performed on a 100-ft (approx. =30-m) roll of Mylar. The first layer is composed of a water-soluble "release layer, " which can be a material such as NaCl. After depositing NaCl, the second layer involves 40 nm of supporting layer material . either Al2O3 or MgO. The thickness of the layer can be tuned to synthesize flakes that are larger or smaller than those obtained with a 40-nm deposition. Finally, the third layer consists of a thin Fe catalyst layer with a thickness of 0.5 nm. The thickness of this layer ultimately determines the diameter of SWNT growth, and a layer that is too thick will result in the growth of multiwalled carbon nanotubes instead of single-wall nanotubes. However, between a thickness of 0.5 nm to 1 nm, single-walled carbon nanotubes are known to be the primary constituent. After this three-layer deposition process, the Mylar is rolled through a bath of water, which allows catalyst-coated flakes to detach from the Mylar. The flakes are then collected and dried. The method described here for making such flakes is analogous to that which is used to make birefringent ink that is

  11. Dephasing and hyperfine interaction in carbon nanotubes double quantum dots

    DEFF Research Database (Denmark)

    Reynoso, Andres Alejandro; Flensberg, Karsten

    2012-01-01

    We study theoretically the return probability experiment, which is used to measure the dephasing time T-2*, in a double quantum dot (DQD) in semiconducting carbon nanotubes with spin-orbit coupling and disorder-induced valley mixing. Dephasing is due to hyperfine interaction with the spins of the C...... with these for DQDs in clean nanotubes, whereas the disorder effect is always relevant when the magnetic field is perpendicular to the nanotube axis....

  12. Unique case of fatal carbon monoxide poisoning in the absence of a combustible fossil fuel.

    Science.gov (United States)

    Morgan, D R; Poon, P; Titley, J; Jagger, S F; Rutty, G N

    2001-09-01

    A 37-year-old man died as a result of exposure to carbon monoxide within an apartment. An investigation of the apartment showed no gas appliances or gas supply to the apartment and no evidence of any combustion event to any part of the apartment or roof space. Inhalation of dichloromethane was excluded. Heating to the apartment was found to be via an electrical storage heater, the examination of which revealed that the cast-iron core and insulating material showed evidence of heat damage with significant areas devoid of carbon. This electric storage heater is hypothesized to be the source of carbon for the fatal production of carbon monoxide within the apartment.

  13. Carbon nanotubes on carbon fibers: Synthesis, structures and properties

    Science.gov (United States)

    Zhang, Qiuhong

    The interface between carbon fibers (CFs) and the resin matrix in traditional high performance composites is characterized by a large discontinuity in mechanical, electrical, and thermal properties which can cause inefficient energy transfer. Due to the exceptional properties of carbon nanotubes (CNTs), their growth at the surface of carbon fibers is a promising approach to controlling interfacial interactions and achieving the enhanced bulk properties. However, the reactive conditions used to grow carbon nanotubes also have the potential to introduce defects that can degrade the mechanical properties of the carbon fiber (CF) substrate. In this study, using thermal chemical vapor deposition (CVD) method, high density multi-wall carbon nanotubes have been successfully synthesized directly on PAN-based CF surface without significantly compromising tensile properties. The influence of CVD growth conditions on the single CF tensile properties and carbon nanotube (CNT) morphology was investigated. The experimental results revealed that under high temperature growth conditions, the tensile strength of CF was greatly decreased at the beginning of CNT growth process with the largest decrease observed for sized CFs. However, the tensile strength of unsized CFs with CNT was approximately the same as the initial CF at lower growth temperature. The interfacial shear strength of CNT coated CF (CNT/CF) in epoxy was studied by means of the single-fiber fragmentation test. Results of the test indicate an improvement in interfacial shear strength with the addition of a CNT coating. This improvement can most likely be attributed to an increase in the interphase yield strength as well as an improvement in interfacial adhesion due to the presence of the nanotubes. CNT/CF also offers promise as stress and strain sensors in CF reinforced composite materials. This study investigates fundamental mechanical and electrical properties of CNT/CF using nanoindentation method by designed

  14. Local gate control in carbon nanotube quantum devices

    Science.gov (United States)

    Biercuk, Michael Jordan

    This thesis presents transport measurements of carbon nanotube electronic devices operated in the quantum regime. Nanotubes are contacted by source and drain electrodes, and multiple lithographically-patterned electrostatic gates are aligned to each device. Transport measurements of device conductance or current as a function of local gate voltages reveal that local gates couple primarily to the proximal section of the nanotube, hence providing spatially localized control over carrier density along the nanotube length. Further, using several different techniques we are able to produce local depletion regions along the length of a tube. This phenomenon is explored in detail for different contact metals to the nanotube. We utilize local gating techniques to study multiple quantum dots in carbon nanotubes produced both by naturally occurring defects, and by the controlled application of voltages to depletion gates. We study double quantum dots in detail, where transport measurements reveal honeycomb charge stability diagrams. We extract values of energy-level spacings, capacitances, and interaction energies for this system, and demonstrate independent control over all relevant tunneling rates. We report rf-reflectometry measurements of gate-defined carbon nanotube quantum dots with integrated charge sensors. Aluminum rf-SETs are electrostatically coupled to carbon nanotube devices and detect single electron charging phenomena in the Coulomb blockade regime. Simultaneous correlated measurements of single electron charging are made using reflected rf power from the nanotube itself and from the rf-SET on microsecond time scales. We map charge stability diagrams for the nanotube quantum dot via charge sensing, observing Coulomb charging diamonds beyond the first order. Conductance measurements of carbon nanotubes containing gated local depletion regions exhibit plateaus as a function of gate voltage, spaced by approximately 1e2/h, the quantum of conductance for a single

  15. Electrophoretic deposition of carbon nanotubes on a carbon fiber surface with different index graphitization

    International Nuclear Information System (INIS)

    Almeida, E.C.; Baldan, M.R.; Ferreira, N.G.; Edwards, E.R.

    2009-01-01

    Full text: The purpose of this work is to examine the electrophoretic deposition of carbon nanotubes powder on carbon fibers, produced at different heat treatments temperatures. Besides, a systematic study of the effects of graphitization index from substrate on the structure and morphology of CNTs has been available. Carbon fibers were produced from polyacrylonitrile at three different heat treatments temperatures, 1000, 1500 and 2000 deg C. The carbon fibers microstructure or its graphitization index may be controlled by the heat treatments temperatures. The electrophoretic deposition of carbon nanotubes was obtained with the powder of carbon nanotubes dispersed in water by ultrasonication to obtain dispersions of 0.05 mg/mL. The carbon fibers were immersed in the nanotube dispersion, and a positive potential of 10 V/cm was applied. Morphology and microstructure of carbon nanotubes on carbon fibers were obtained by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. (author)

  16. Rotational actuator of motor based on carbon nanotubes

    Science.gov (United States)

    Zettl, Alexander K.; Fennimore, Adam M.; Yuzvinsky, Thomas D.

    2008-11-18

    A rotational actuator/motor based on rotation of a carbon nanotube is disclosed. The carbon nanotube is provided with a rotor plate attached to an outer wall, which moves relative to an inner wall of the nanotube. After deposit of a nanotube on a silicon chip substrate, the entire structure may be fabricated by lithography using selected techniques adapted from silicon manufacturing technology. The structures to be fabricated may comprise a multiwall carbon nanotube (MWNT), two in plane stators S1, S2 and a gate stator S3 buried beneath the substrate surface. The MWNT is suspended between two anchor pads and comprises a rotator attached to an outer wall and arranged to move in response to electromagnetic inputs. The substrate is etched away to allow the rotor to freely rotate. Rotation may be either in a reciprocal or fully rotatable manner.

  17. Structural and electronic properties of carbon nanotubes under hydrostatic pressures

    International Nuclear Information System (INIS)

    Zhang Ying; Cao Juexian; Yang Wei

    2008-01-01

    We studied the structural and electronic properties of carbon nanotubes under hydrostatic pressures based on molecular dynamics simulations and first principles band structure calculations. It is found that carbon nanotubes experience a hard-to-soft transition as external pressure increases. The bulk modulus of soft phase is two orders of magnitude smaller than that of hard phase. The band structure calculations show that band gap of (10, 0) nanotube increases with the increase of pressure at low pressures. Above a critical pressure (5.70GPa), band gap of (10, 0) nanotube drops rapidly and becomes zero at 6.62GPa. Moreover, the calculated charge density shows that a large pressure can induce an sp 2 -to-sp 3 bonding transition, which is confirmed by recent experiments on deformed carbon nanotubes

  18. Fabrication of Carbon Nanotube Polymer Actuator Using Nanofiber Sheet

    Science.gov (United States)

    Kato, Hayato; Shimizu, Akikazu; Sato, Taiga; Kushida, Masahito

    2017-11-01

    Carbon nanotube polymer actuators were developed using composite nanofiber sheets fabricated by multi-walled carbon nanotubes(MWCNTs) and poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Nanofiber sheets were fabricated by electrospinning method. The effect of flow rate and polymer concentration on nanofiber formation were verified for optimum condition for fabricating nanofiber sheets. We examined the properties of MWCNT/PVDF-HFP nanofiber sheets, as follows. Electrical conductivity and mechanical strength increased as the MWCNT weight ratio increased. We fabricated carbon nanotube polymer actuators using MWCNT/PVDF-HFP nanofiber sheets and succeeded in operating of our actuators.

  19. Correlation and dimensional effects of trions in carbon nanotubes

    DEFF Research Database (Denmark)

    Rønnow, Troels Frimodt; Pedersen, Thomas Garm; Cornean, Horia

    2010-01-01

    We study the binding energies of singlet trions, i.e., charged excitons, in carbon nanotubes. The problem is modeled, through the effective-mass model, as a three-particle complex on the surface of a cylinder, which we investigate using both one- and two-dimensional expansions of the wave function...... are used to compute physical binding energies for a wide selection of carbon nanotubes. In addition, the dependence on dielectric screening is examined. Our findings indicate that trions are detectable at room temperature in carbon nanotubes with radius below 8 Å....

  20. Control of carbon nanotube growth using cobalt nanoparticles as catalyst

    International Nuclear Information System (INIS)

    Huh, Yoon; Green, Malcolm L.H.; Kim, Young Heon; Lee, Jeong Yong; Lee, Cheol Jin

    2005-01-01

    We have controllably grown carbon nanotubes using uniformly distributed cobalt nanoparticles as catalyst. Cobalt nanoparticles with a uniform size were synthesized by chemical reaction and colloidal solutions including the cobalt nanoparticles were prepared. The cobalt nanoparticles were uniformly distributed on silicon substrates by a spin-coating method. Carbon nanotubes with a uniform diameter were synthesized on the cobalt nanoparticles by thermal chemical vapor deposition of acetylene gas. The density and vertical alignment of carbon nanotubes could be controlled by adjusting the density of cobalt (Co) nanoparticles