Price-skid boosts propane sales

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

Ellis, P.

1979-02-05

Lower propane costs have prompted industrial users to switch from natural gas, although dealers are cautioning that they are gambling on an unstable price competition. Analysis of price and use trends indicates that the propane market is growing where users have relied on the interstate gas market, which will be experiencing incremental price increases. Those buying propane on the spot market will get the best prices because the propane market is now glutted as a result of conservation and large gas supplies. A further drop in propane price is not anticipated because producers would lack incentive to extract propane frommore » higher-priced natural gas unless it becomes justified by demand for unleaded gas, of which propane is a by-product.« less

Alternative Fuels Data Center: Propane Laws and Incentives

Science.gov Websites

Propane Printable Version Share this resource Send a link to Alternative Fuels Data Center: Propane Laws and Incentives to someone by E-mail Share Alternative Fuels Data Center: Propane Laws and and Incentives on Digg Find More places to share Alternative Fuels Data Center: Propane Laws and

Propane poisoning

MedlinePlus

Propane is a colorless and odorless flammable gas that can turn into liquid under very cold temperatures. This article discusses the harmful effects from breathing in or swallowing propane. Breathing in or swallowing propane can be ...

Analysis Of Condensate Samples In Support Of The Antifoam Degradation Study

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

Hay, M.; Martino, C.

2016-01-12

The degradation of Antifoam 747 to form flammable decomposition products has resulted in declaration of a Potential Inadequacy in the Safety Analysis (PISA) for the Defense Waste Processing Facility (DWPF). Savannah River National Laboratory (SRNL) testing with simulants showed that hexamethyldisiloxane (HMDSO), trimethylsilanol (TMS), and 1-propanal are formed in the offgas from the decomposition of the antifoam. A total of ten DWPF condensate samples from Batch 735 and 736 were analyzed by SRNL for three degradation products and additional analytes. All of the samples were analyzed to determine the concentrations of HMDSO, TMS, and propanal. The results of the organicmore » analysis found concentrations for propanal and HMDSO near or below the detection limits for the analysis. The TMS concentrations ranged from below detection to 11 mg/L. The samples from Batch 736 were also analyzed for formate and oxalate anions, total organic carbon, and aluminum, iron, manganese, and silicon. Most of the samples contained low levels of formate and therefore low levels of organic carbon. These two values for each sample show reasonable agreement in most cases. Low levels of all the metals (Al, Fe, Mn, and Si) were present in most of the samples.« less

ANALYSIS OF CONDENSATE SAMPLES IN SUPPORT OF THE ANTIFOAM DEGRADATION STUDY

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

Hay, M.; Martino, C.

2016-02-29

The degradation of Antifoam 747 to form flammable decomposition products has resulted in declaration of a Potential Inadequacy in the Safety Analysis (PISA) for the Defense Waste Processing Facility (DWPF). Savannah River National Laboratory (SRNL) testing with simulants showed that hexamethyldisiloxane (HMDSO), trimethylsilanol (TMS), and 1-propanal are formed in the offgas from the decomposition of the antifoam. A total of ten DWPF condensate samples from Batch 735 and 736 were analyzed by SRNL for three degradation products and additional analytes. All of the samples were analyzed to determine the concentrations of HMDSO, TMS, and propanal. The results of the organicmore » analysis found concentrations for propanal and HMDSO near or below the detection limits for the analysis. The TMS concentrations ranged from below detection to 11 mg/L. The samples from Batch 736 were also analyzed for formate and oxalate anions, total organic carbon, and aluminum, iron, manganese, and silicon. Most of the samples contained low levels of formate and therefore low levels of organic carbon. These two values for each sample show reasonable agreement in most cases. Low levels of all the metals (Al, Fe, Mn, and Si) were present in most of the samples.« less

77 FR 2293 - AmeriGas Propane, L.P., AmeriGas Propane, Inc., Energy Transfer Partners, L.P., and Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-17

... GP in which AmeriGas proposed to acquire ETP's Heritage Propane business through the approximately $2..., Titan Energy Partner, L.P., and Titan Energy GP, L.L.C. ETP's Heritage Propane business includes Heritage Propane Express, an entity that is engaged in the business of preparing, filling, distributing and...

Propane Update.

ERIC Educational Resources Information Center

Brantner, Max

1984-01-01

Reports on a northern Illinois school bus fleet converted to propane fuel in 1981 and 1982. Includes tables showing, first, total annual fuel costs before and after conversion and, second, fuel efficiency for 16 buses using propane and three using gasoline. Notes precautions for propane use. (MCG)

Alternative Fuels Data Center: Propane Vehicle Availability

Science.gov Websites

Availability to someone by E-mail Share Alternative Fuels Data Center: Propane Vehicle Availability on Facebook Tweet about Alternative Fuels Data Center: Propane Vehicle Availability on Twitter Bookmark Alternative Fuels Data Center: Propane Vehicle Availability on Google Bookmark Alternative Fuels

Alternative Fuels Data Center: Propane Vehicle Conversions

Science.gov Websites

Conversions to someone by E-mail Share Alternative Fuels Data Center: Propane Vehicle Conversions on Facebook Tweet about Alternative Fuels Data Center: Propane Vehicle Conversions on Twitter Bookmark Alternative Fuels Data Center: Propane Vehicle Conversions on Google Bookmark Alternative Fuels

Methane, Ethane, and Propane Sensor for Real-time Leak Detection and Diagnostics

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

Roscioli, Joseph R.; Herndon, Scott; Nelson, David D.

2017-03-24

The Phase I effort demonstrated the technical viability of a fast, sensitive, mobile hydrocarbon monitor. The instrument will enable the oil and gas industry, researchers, and regulators to rapidly identify and chemically profile leaks from facilities. This capability will allow operators to quickly narrow down and mitigate probable leaking equipment, minimizing product loss and penalties due to regulatory non-compliance. During the initial development phase, we demonstrated operation of a prototype monitor that is capable of measuring methane, ethane, and propane at sub-part-per-billion sensitivities in 1 second, using direct absorption infrared spectroscopy. To our knowledge, this is the first instrument capablemore » of fast propane measurements at atmospheric concentrations. In addition, the electrical requirements of the monitor have been reduced from the 1,200 W typical of a spectrometer, to <500 W, making it capable of being powered by a passenger vehicle, and easily deployed by the industry. The prototype monitor leverages recent advances in laser technology, using high-efficiency interband cascade lasers to access the 3 μm region of the mid-infrared, where the methane, ethane, and propane absorptions are strongest. Combined with established spectrometer technology, we have achieved precisions below 200 ppt for each compound. This allows the monitor to measure fast plumes from oil and gas facilities, as well as ambient background concentrations (typical ambient levels are 2 ppm, 1.5 ppb, and 0.7 ppb for methane, ethane and propane, respectively). Increases in instrument operating pressure were studied in order to allow for a smaller 125 W pump to be used, and passive cooling was explored to reduce the cooling load by almost 90% relative to active (refrigerated) cooling. In addition, the simulated infrared absorption profiles of ethane and propane were modified to minimize crosstalk between species, achieving <1% crosstalk between ethane and propane. Finally, a monitor was designed based upon the commercial compact mini-spectrometer capable of dual-laser operation. We intend to build and test this during phase II. Multiple opportunities for improvement were also identified. First, the reported ethane and propane concentrations are susceptible to external acceleration acting upon the instrument. During phase II we will address this “motion-sickness”. Second, significant software development will be needed operate the monitor at 1 second resolution in real time, and provide rapid, actionable data to a driver or passenger.« less

An adaptive self-healing ionic liquid nanocomposite membrane for olefin-paraffin separations.

PubMed

Pitsch, Fee; Krull, Florian F; Agel, Friederike; Schulz, Peter; Wasserscheid, Peter; Melin, Thomas; Wessling, Matthias

2012-08-16

An adaptive self-healing ionic liquid nanocomposite membrane comprising a multi-layer support structure hosting the ionic salt [Ag](+) [Tf(2) N](-) is used for the separation of the olefin propylene and the paraffin propane. The ionic salt renders liquid like upon complexation with propylene, resulting in facilitated transport of propylene over propane at benchmark-setting selectivity and permeance levels. The contacting with acetylene causes the ionic salt to liquefy without showing evidence of forming explosive silver acetylide. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Propane fear

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

Begley, R.

1992-02-12

A minor feature of a Congressional energy bill is causing consternation for a number of propane-consuming chemical companies. The firms are fighting the bill`s inclusion of liquefied petroleum gas (LPG) on a list of alternative fuels that can be used to meet its urban fleet vehicles requirements. The firms fear that this added use would drive up the price of propane-an LPG-for homeowners, farmers, and themselves. Speaking for the Propane Consumers Coalition, a Dow Chemical spokesman says 7.7 million households use propane, as does agriculture, and current demand is such that December saw a 23-year low in US inventories. Themore » US depends on imports of propane, he says, and about half the propane sold in the US is derived from the refining of oil, much of which is also imported. Adding demand for vehicle fuel would drive up imports and process, the spokesman says, thereby damaging all users, including the petrochemical industry.« less

. . . While Others Conserve Cash by Converting from Gasoline to Propane.

ERIC Educational Resources Information Center

Rasmussen, Scott A.

1988-01-01

Since 1983, when the David Douglas Public Schools (Portland, Oregon) converted 30 buses to propane fuel, the district has saved $75,000 in fuel and maintenance costs. Propane is priced consistently lower than gasoline and burns cleaner. Since propane engines do not require a carburetor, there are fewer maintenance problems. (MLH)

Alternative Fuels Data Center: Propane Buses Save Money for Virginia

Science.gov Websites

Schools Propane Buses Save Money for Virginia Schools to someone by E-mail Share Alternative Fuels Data Center: Propane Buses Save Money for Virginia Schools on Facebook Tweet about Alternative Fuels Data Center: Propane Buses Save Money for Virginia Schools on Twitter Bookmark Alternative Fuels

Alternative Fuels Data Center: Renzenberger Inc Saves Money With Propane

Science.gov Websites

Vans Renzenberger Inc Saves Money With Propane Vans to someone by E-mail Share Alternative Fuels Data Center: Renzenberger Inc Saves Money With Propane Vans on Facebook Tweet about Alternative Fuels Data Center: Renzenberger Inc Saves Money With Propane Vans on Twitter Bookmark Alternative Fuels

Alternative Fuels Data Center: Propane Production and Distribution

Science.gov Websites

produced from liquid components recovered during natural gas processing. These components include ethane & Incentives Propane Production and Distribution Propane is a by-product of natural gas processing distribution showing propane originating from three sources: 1) gas well and gas plant, 2) oil well and

Alternative Fuels Data Center: Michigan School Buses Get Rolling on Propane

Science.gov Websites

Michigan School Buses Get Rolling on Propane to someone by E-mail Share Alternative Fuels Data Center: Michigan School Buses Get Rolling on Propane on Facebook Tweet about Alternative Fuels Data Center: Michigan School Buses Get Rolling on Propane on Twitter Bookmark Alternative Fuels Data Center

An Inducible Propane Monooxygenase Is Responsible for N-Nitrosodimethylamine Degradation by Rhodococcus sp. Strain RHA1▿

PubMed Central

Sharp, Jonathan O.; Sales, Christopher M.; LeBlanc, Justin C.; Liu, Jie; Wood, Thomas K.; Eltis, Lindsay D.; Mohn, William W.; Alvarez-Cohen, Lisa

2007-01-01

Rhodococci are common soil heterotrophs that possess diverse functional enzymatic activities with economic and ecological significance. In this study, the correlation between gene expression and biological removal of the water contaminant N-nitrosodimethylamine (NDMA) is explored. NDMA is a hydrophilic, potent carcinogen that has gained recent notoriety due to its environmental persistence and emergence as a widespread micropollutant in the subsurface environment. In this study, we demonstrate that Rhodococcus sp. strain RHA1 can constitutively degrade NDMA and that activity toward this compound is enhanced by approximately 500-fold after growth on propane. Transcriptomic analysis of RHA1 and reverse transcriptase quantitative PCR assays demonstrate that growth on propane elicits the upregulation of gene clusters associated with (i) the oxidation of propane and (ii) the oxidation of substituted benzenes. Deletion mutagenesis of prmA, the gene encoding the large hydroxylase component of propane monooxygenase, abolished both growth on propane and removal of NDMA. These results demonstrate that propane monooxygenase is responsible for NDMA degradation by RHA1 and explain the enhanced cometabolic degradation of NDMA in the presence of propane. PMID:17873074

Microbial synthesis of propane by engineering valine pathway and aldehyde-deformylating oxygenase.

PubMed

Zhang, Lei; Liang, Yajing; Wu, Wei; Tan, Xiaoming; Lu, Xuefeng

2016-01-01

Propane, a major component of liquid petroleum gas (LPG) derived from fossil fuels, has widespread applications in vehicles, cooking, and ambient heating. Given the concerns about fossil fuel depletion and carbon emission, exploiting alternative and renewable source of propane have become attractive. In this study, we report the construction of a novel propane biosynthetic pathway in Escherichia coli. We constructed an aldehyde reductases (ALR)-deprived E. coli strain BW25113(DE3) Δ13 via genetic engineering, which produced sufficient isobutyraldehyde precursors and finally achieved de novo synthesis of propane (91 μg/L) by assembling the engineered valine pathway and cyanobacterial aldehyde-deformylating oxygenase (ADO). Additionally, after extensive screening of ADO mutants generated by engineering the active center to accommodate branched-chain isobutyraldehyde, we identified two ADO mutants (I127G, I127G/A48G) which exhibited higher catalytic activity for isobutyraldehyde and improved propane productivity by three times (267 μg/L). The propane biosynthetic pathway constructed here through the engineered valine pathway can produce abundant isobutyraldehyde for ADO and overcome the low availability of precursors in propane production. Furthermore, the rational design aiming at the ADO active center illustrates the plasticity and catalytic potential of ADO. These results together highlight the potential for developing a microbial biomanufacturing platform for propane.

Development of a 100 nmol mol(-1) propane-in-air SRM for automobile-exhaust testing for new low-emission requirements.

PubMed

Rhoderick, George C

2007-04-01

New US federal low-level automobile emission requirements, for example zero-level-emission vehicle (ZLEV), for hydrocarbons and other species, have resulted in the need by manufacturers for new certified reference materials. The new emission requirement for hydrocarbons requires the use, by automobile manufacturing testing facilities, of a 100 nmol mol(-1) propane in air gas standard. Emission-measurement instruments are required, by federal law, to be calibrated with National Institute of Standards and Technology (NIST) traceable reference materials. Because a NIST standard reference material (SRM) containing 100 nmol mol(-1) propane was not available, the US Environmental Protection Agency (EPA) and the Automobile Industry/Government Emissions Research Consortium (AIGER) requested that NIST develop such an SRM. A cylinder lot of 30 gas mixtures containing 100 nmol mol(-1) propane in air was prepared in 6-L aluminium gas cylinders by a specialty gas company and delivered to the Gas Metrology Group at NIST. Another mixture, contained in a 30-L aluminium cylinder and included in the lot, was used as a lot standard (LS). Using gas chromatography with flame-ionization detection all 30 samples were compared to the LS to obtain the average of six peak-area ratios to the LS for each sample with standard deviations of <0.31%. The average sample-to-LS ratio determinations resulted in a range of 0.9828 to 0.9888, a spread of 0.0060, which corresponds to a relative standard deviation of 0.15% of the average for all 30 samples. NIST developed its first set of five propane in air primary gravimetric standards covering a concentration range 91 to 103 nmol mol(-1) with relative uncertainties of 0.15%. This new suite of propane gravimetric standards was used to analyze and assign a concentration value to the SRM LS. On the basis of these data each SRM sample was individually certified, furnishing the desired relative expanded uncertainty of +/-0.5%. Because automobile companies use total hydrocarbons to make their measurements, it was also vital to assign a methane concentration to the SRM samples. Some of the SRM samples were analyzed and found to contain 1.2 nmol mol(-1) methane. Twenty-five of the samples were certified and released as SRM 2765.

Alternative Fuels Data Center: How Do Bi-fuel Propane Vehicles Work?

Science.gov Websites

Vehicles Work? Bi-fuel propane vehicles typically use a spark-ignited internal combustion engine. A bi-fuel stored on board and the driver can switch between the fuels. The vehicle is equipped with fuel tanks Propane vehicle image Key Components of a Bi-fuel Propane Vehicle Battery: The battery provides

Selective bio-oxidation of propane to acetone using methane-oxidizing Methylomonas sp. DH-1.

PubMed

Hur, Dong Hoon; Nguyen, Thu Thi; Kim, Donghyuk; Lee, Eun Yeol

2017-07-01

Propane is the major component of liquefied petroleum gas (LPG). Nowadays, the use of LPG is decreasing, and thus utilization of propane as a chemical feedstock is in need of development. An efficient biological conversion of propane to acetone using a methanotrophic whole cell as the biocatalyst was proposed and investigated. A bio-oxidation pathway of propane to acetone in Methylomonas sp. DH-1 was analyzed by gene expression profiling via RNA sequencing. Propane was oxidized to 2-propanol by particulate methane monooxygenase and subsequently to acetone by methanol dehydrogenases. Methylomonas sp. DH-1 was deficient in acetone-converting enzymes and thus accumulated acetone in the absence of any enzyme inhibition. The maximum accumulation, average productivity and specific productivity of acetone were 16.62 mM, 0.678 mM/h and 0.141 mmol/g cell/h, respectively, under the optimized conditions. Our study demonstrates a novel method for the bioconversion of propane to acetone using methanotrophs under mild reaction condition.

RMP Guidance for Propane Storage Facilities - Main Text

EPA Pesticide Factsheets

This document is intended as comprehensive Risk Management Program guidance for larger propane storage or distribution facilities who already comply with propane industry standards. Includes sample RMP, and release calculations.

Guidance for Facilities on Risk Management Programs (RMP)

EPA Pesticide Factsheets

Includes supplemental guidance specific to ammonia refrigeration, wastewater treatment, propane storage, warehouses, chemical distributors, offsite consequence analysis, retail agriculture, applicability of program levels, prevention, emergency response.

LPG Dependence after a Suicide Attempt

PubMed Central

Aldemir, Ebru; Akyel, Betül; Altıntoprak, A. Ender; Aydın, Rezzan; Coşkunol, Hakan

2015-01-01

Inhalant abuse is a problem that is getting more common all around the world. The increase in prevalence of inhalant abuse escalates morbidity and mortality rates. About 22% of people using inhalant have died at their first attempt. Particularly propane, butane, or propane-butane mixture has highest mortality rates. Sudden sniffing death syndrome, cardiomyopathy, central nervous system toxicity, hematological abnormalities, kidney toxicity, and hepatocellular toxicities are the major complications of inhalant abuse. Herein we present a patient with inhalant use disorder. At the age of 19, after a stressful life event he had unsuccessfully tried to suicide by inhaling LPG (liquefied petroleum gas, a mixture of butane and propane gases). After he realized that he had hallucinations and felt better during the inhalation, he started to abuse it. He was addicted to LPG for 10 years at the time of admission. Besides being dangerous for the society security, this intense level of LPG inhalation (12 liters a day) not giving any physical harm makes this case interesting. PMID:25664196

LPG Dependence after a Suicide Attempt.

PubMed

Aldemir, Ebru; Akyel, Betül; Altıntoprak, A Ender; Aydın, Rezzan; Coşkunol, Hakan

2015-01-01

Inhalant abuse is a problem that is getting more common all around the world. The increase in prevalence of inhalant abuse escalates morbidity and mortality rates. About 22% of people using inhalant have died at their first attempt. Particularly propane, butane, or propane-butane mixture has highest mortality rates. Sudden sniffing death syndrome, cardiomyopathy, central nervous system toxicity, hematological abnormalities, kidney toxicity, and hepatocellular toxicities are the major complications of inhalant abuse. Herein we present a patient with inhalant use disorder. At the age of 19, after a stressful life event he had unsuccessfully tried to suicide by inhaling LPG (liquefied petroleum gas, a mixture of butane and propane gases). After he realized that he had hallucinations and felt better during the inhalation, he started to abuse it. He was addicted to LPG for 10 years at the time of admission. Besides being dangerous for the society security, this intense level of LPG inhalation (12 liters a day) not giving any physical harm makes this case interesting.

Demonstration of a Fast, Precise Propane Measurement Using Infrared Spectroscopy

NASA Astrophysics Data System (ADS)

Zahniser, M. S.; Roscioli, J. R.; Nelson, D. D.; Herndon, S. C.

2016-12-01

Propane is one of the primary components of emissions from natural gas extraction and processing activities. In addition to being an air pollutant, its ratio to other hydrocarbons such as methane and ethane can serve as a "fingerprint" of a particular facility or process, aiding in identifying emission sources. Quantifying propane has typically required laboratory analysis of flask samples, resulting in low temporal resolution and making plume-based measurements infeasible. Here we demonstrate fast (1-second), high precision (<300 ppt) measurements of propane using high resolution mid-infrared spectroscopy at 2967 wavenumbers. In addition, we explore the impact of nearby water and ethane absorption lines on the accuracy and precision of the propane measurement. Finally, we discuss development of a dual-laser instrument capable of simultaneous measurements of methane, ethane, and propane (the C1-C3 compounds), all within a small spatial package that can be easily deployed aboard a mobile platform.

Enhancing aerobic biodegradation of 1,2-dibromoethane in groundwater using ethane or propane and inorganic nutrients.

PubMed

Hatzinger, Paul B; Streger, Sheryl H; Begley, James F

2015-01-01

1,2-Dibromoethane (ethylene dibromide; EDB) is a probable human carcinogen that was previously used as both a soil fumigant and a scavenger in leaded gasoline. EDB has been observed to persist in soils and groundwater, particularly under oxic conditions. The objective of this study was to evaluate options to enhance the aerobic degradation of EDB in groundwater, with a particular focus on possible in situ remediation strategies. Propane gas and ethane gas were observed to significantly stimulate the biodegradation of EDB in microcosms constructed with aquifer solids and groundwater from the FS-12 EDB plume at Joint Base Cape Cod (Cape Cod, MA), but only after inorganic nutrients were added. Ethene gas was also effective, but rates were appreciably slower than for ethane and propane. EDB was reduced to <0.02 μg/L, the Massachusetts state Maximum Contaminant Level (MCL), in microcosms that received ethane gas and inorganic nutrients. An enrichment culture (BE-3R) that grew on ethane or propane gas but not EDB was obtained from the site materials. The degradation of EDB by this culture was inhibited by acetylene gas, suggesting that degradation is catalyzed by a monooxygenase enzyme. The BE-3R culture was also observed to biodegrade 1,2-dichloroethane (DCA), a compound commonly used in conjunction with EDB as a lead scavenger in gasoline. The data suggest that addition of ethane or propane gas with inorganic nutrients may be a viable option to enhance degradation of EDB in groundwater aquifers to below current state or federal MCL values. Copyright © 2014 Elsevier B.V. All rights reserved.

Analysis of the site-specific carbon isotope composition of propane by gas source isotope ratio mass spectrometer

NASA Astrophysics Data System (ADS)

Piasecki, Alison; Sessions, Alex; Lawson, Michael; Ferreira, A. A.; Neto, E. V. Santos; Eiler, John M.

2016-09-01

Site-specific isotope ratio measurements potentially provide valuable information about the formation and degradation of complex molecules-information that is lost in conventional bulk isotopic measurements. Here we discuss the background and possible applications of such measurements, and present a technique for studying the site-specific carbon isotope composition of propane at natural abundance based on mass spectrometric analysis of the intact propane molecule and its fragment ions. We demonstrate the feasibility of this approach through measurements of mixtures of natural propane and propane synthesized with site-specific 13C enrichment, and we document the limits of precision of our technique. We show that mass balance calculations of the bulk δ13C of propane based on our site-specific measurements is generally consistent with independent constraints on bulk δ13C. We further demonstrate the accuracy of the technique, and illustrate one of its simpler applications by documenting the site-specific carbon isotope signature associated with gas phase diffusion of propane, confirming that our measurements conform to the predictions of the kinetic theory of gases. This method can be applied to propane samples of moderate size (tens of micromoles) isolated from natural gases. Thus, it provides a means of studying the site-specific stable isotope systematics of propane at natural isotope abundances on sample sizes that are readily recovered from many natural environments. This method may also serve as a model for future techniques that apply high-resolution mass spectrometry to study the site-specific isotopic distributions of larger organic molecules, with potential applications to biosynthesis, forensics and other geochemical subjects.

Alternative Fuels Data Center: How Do Propane Vehicles Work?

Science.gov Websites

gasoline vehicles with spark-ignited internal combustion engines. There are two types of propane fuel -injection systems available: vapor and liquid injection. In both types, propane is stored as a liquid in a

Site-Specific Hydrogen Isotope Composition of Propane: Mass spectrometric methods, equilibrium temperature dependence, and kinetics of exchange

NASA Astrophysics Data System (ADS)

Xie, H.; Ponton, C.; Kitchen, N.; Lloyd, M. K.; Lawson, M.; Formolo, M. J.; Eiler, J. M.

2016-12-01

Intramolecular isotope ordering can constrain temperatures of synthesis, mechanisms of formation, and/or source substrates of organic compounds. Here we explore site-specific hydrogen isotope variations of propane. Statistical thermodynamic models predict that at equilibrium methylene hydrogen (-CH2-) in propane will be 10's of per mil higher in D/H ratio than methyl hydrogen (-CH3) at geologically relevant temperatures, and that this difference is highly temperature dependent ( 0.5-1 ‰/°C). Chemical-kinetic controls on site-specific D/H in propane could constrain the mechanisms, conditions and extents of propane synthesis or destruction. We have developed a method for measuring the difference in D/H ratio between methylene and methyl hydrogen in propane by gas source mass spectrometry. The data were measured using the Thermo Fisher Double Focusing Sector high resolution mass spectrometer (DFS), and involve comparison of the D/H ratios of molecular ion (C3H8+) and the ethyl fragmental ion (C2H5+). We demonstrate the accuracy and precision of this method through analysis of D-labeled and independently analyzed propanes. In the exchange experiments, propane was heated (100-200 oC) either alone or in the presence of D-enriched water (δD=1,1419 ‰ SMOW), with or without one of several potentially catalytic substrates for hours to weeks. Propane was found to exchange hydrogen with water vigorously at 200 °C in the presence of metal catalysts. In the presence of Ni catalyst, methylene hydrogen exchanges 2.5 times faster than methyl hydrogen. Hydrogen exchange in the presence of Pd catalyst is more effective and can equilibrate hydrogen isotope distribution on propane on the order of 7 days. Isotopic exchange in the presence of natural materials have also been tested, but is only measurable in the methylene group at 200 °C. High catalytic activity of Pd permits attainment of a bracketed, time-invariant equilibrium state that we use to calibrate the site-specific thermometer; these experiments also provide a reference frame for reporting mass spectrometric data. Differential H-exchange rates of the two molecular sites in propane could be a new tool to constrain thermal history of sub-surface propane. Our experimental and mass spectrometric approaches should be generalizable to other hydrocarbon compounds.

Silane-propane ignitor/burner

DOEpatents

Hill, R.W.; Skinner, D.F. Jr.; Thorsness, C.B.

1983-05-26

A silane propane burner for an underground coal gasification process which is used to ignite the coal and to controllably retract the injection point by cutting the injection pipe. A narrow tube with a burner tip is positioned in the injection pipe through which an oxidant (oxygen or air) is flowed. A charge of silane followed by a supply of fuel, such as propane, is flowed through the tube. The silane spontaneously ignites on contact with oxygen and burns the propane fuel.

Silane-propane ignitor/burner

DOEpatents

Hill, Richard W.; Skinner, Dewey F.; Thorsness, Charles B.

1985-01-01

A silane propane burner for an underground coal gasification process which is used to ignite the coal and to controllably retract the injection point by cutting the injection pipe. A narrow tube with a burner tip is positioned in the injection pipe through which an oxidant (oxygen or air) is flowed. A charge of silane followed by a supply of fuel, such as propane, is flowed through the tube. The silane spontaneously ignites on contact with oxygen and burns the propane fuel.

Photodissociation dynamics of propanal and isobutanal: The Norrish Type I pathway

NASA Astrophysics Data System (ADS)

Harrison, Aaron W.; Kable, Scott H.

2018-04-01

The Norrish Type I photodissociation of two aliphatic aldehydes, propanal and isobutanal, has been investigated using velocity-map imaging. The HCO photoproduct of this reaction was probed using a 1+1 resonance-enhanced multiphoton ionization scheme via the 3p2Π Rydberg state. The velocity map images of HCO+ were collected across a range of photolysis energies for both species from 30 500 to 33 000 cm-1 (λ = 312-327 nm). The corresponding translational energy distributions show that the majority of the available energy goes into the translational motion of the products (55%-68%) with this fraction increasing as the T1 barrier is approached. Analysis of the translational energy distributions was also used to determine the aldehyde α C-C bond dissociation energies which were found to be 339.8 ± 2.5 and 331.2 ± 2.5 kJ/mol for propanal and isobutanal, respectively. These values were also found to be in good agreement with the computed dissociation energies using G4 and CCSD(T)/aug-cc-pVTZ//M062X/aug-cc-pVTZ levels of theory. Furthermore, these dissociation energies, combined with the known ΔfH (0 K) of the reaction products, provided the ΔfH (0 K) of propanal and isobutanal which were calculated to be -167.3 ± 2.5 and -184.0 ± 2.5 kJ/mol, respectively.

Reaction of propane with the ordered NiO/Rh(1 1 1) studied by XPS and LEISS

NASA Astrophysics Data System (ADS)

Zhang, Hong; Wang, Wenyi; Chen, Mingshu; Wan, Huilin

2018-05-01

Nickel oxide has been reported to be an efficient catalyst for oxidative dehydrogenation of propane (ODP) to propene at low temperature. In this paper, ultrathin NiO films with various thickness were prepared on a Rh(1 1 1) surface and characterized by X-ray photoemission spectroscopy (XPS) and Low-energy ion scattering spectroscopy (LEISS). Results show that NiO forms a two-dimensional (2D) network with a O-Ni-O structure at submonolayer coverages, and a bulk-like NiO at multilayer coverages. The submonolayer NiO films are less stable than the thick ones when annealed in ultra-high vacuum (UHV) due to the strong interaction with the Rh substrate. Propane was dosed onto the model surfaces at different temperatures to investigate the activation of propane and reactivity of NiO films with propane. The reactions of propane with the thin and thick NiO films are significantly different. Propane activates on the O defect sites for the thick NiO films, whereas activation occurs on the interface of nickel oxide and substrate for the thin films with a higher activity.

The Millimeter-Wave Spectrum of Propanal

NASA Astrophysics Data System (ADS)

Zingsheim, Oliver; Müller, Holger S. P.; Lewen, Frank; Schlemmer, Stephan

2017-06-01

The microwave spectrum of propanal, also known as propionaldehyde, CH_3CH_2CHO, has been investigated in the laboratory already since 1964^1 and has also been detected in space^2. Recently, propanal was detected with the Atacama Large Millimeter/submillimeter Array (ALMA), Protostellar Interferometric Line Survey (PILS)^3. The high sensitivity and resolution of ALMA indicated small discrepancies between observed and predicted rotational spectra of propanal. As higher accuracies are desired the spectrum of propanal was measured up to 500 GHz with the Cologne (Sub-)Millimeter spectrometer. Propanal has two stable conformers, syn and gauche, which differ mainly in the rotation of the aldehyd group with respect to the rigid C-atom framework of the molecule. We extensively studied both of them. The lower syn-conformer shows small splittings caused by the internal rotation of the methyl group, whereas the spectrum of gauche-propanal is complicated due to the tunneling rotation interaction from two stable degenerate conformers. Additionally, we analyzed vibrationally excited states. ^1 Butcher et al., J. Chem. Phys. 40 6 (1964) ^2 Hollis et al., Astrophys. J. 610 L21 (2004) ^3 Lykke et al., A&A 597 A53 (2017)

Emission measurements for a lean premixed propane/air system at pressures up to 30 atmospheres

NASA Technical Reports Server (NTRS)

Roffe, G.; Venkataramani, K. S.

1978-01-01

The emissions of a lean premixed system of propane/air were measured in a flametube apparatus. Tests were conducted at inlet temperatures of 600K and 800K and pressures of 10 atm and 30 atm over a range of equivalence ratios. The data obtained were combined with previous data taken in the same apparatus to correlate nitrogen oxide emissions with operating conditions. Sampling probe design was found to have a pronounced effect on measured CO levels but did not influence measurements. The most effective probe tested was one which combined thermal and pressure quenching of the gas sample.

School Districts Move to the Head of the Class with Propane

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

Propane has been a proven fuel for buses for decades. For the first time in 2007, Blue Bird rolled out a propane school bus using direct liquid injection, which was later followed by Thomas Built Buses and Navistar. Because this new technology is much more reliable than previous designs, it is essentially reintroducing propane buses to many school districts. During this same time period, vehicle emissions standards have tightened. To meet them, diesel engine manufacturers have added diesel particulate filters (DPF) and, more recently, selective catalytic reduction (SCR) systems. As an alternative to diesel buses with these systems, many schoolmore » districts have looked to other affordable, clean alternatives, and they've found that propane fits the bill.« less

Marine microbes rapidly adapt to consume ethane, propane, and butane within the dissolved hydrocarbon plume of a natural seep

NASA Astrophysics Data System (ADS)

Mendes, Stephanie D.; Redmond, Molly C.; Voigritter, Karl; Perez, Christian; Scarlett, Rachel; Valentine, David L.

2015-03-01

Simple hydrocarbon gases containing two to four carbons (ethane, propane, and butane) are among the most abundant compounds present in petroleum reservoirs, and are introduced into the ocean through natural seepage and industrial discharge. Yet little is known about the bacterial consumption of these compounds in ocean waters. To assess the timing by which microbes metabolize these gases, we conducted a three-phase study that tested and applied a radiotracer-based method to quantify the oxidation rates of ethane, propane, and butane in fresh seawater samples. Phase 1 involved the synthesis of tritiated ethane, propane, and butane using Grignard reagents and tritiated water. Phase 2 was a systematic assessment of experimental conditions, wherein the indigenous microbial community was found to rapidly oxidize ethane, propane, and butane. Phase 3 was the application of this tritium method near the Coal Oil Point seeps, offshore California. Spatial and temporal patterns of ethane, propane, and butane oxidation down current from the hydrocarbon seeps demonstrated that >99% of these gases are metabolized within 1.3 days following initial exposure. The oxidation of ethane outpaced oxidation of propane and butane with patterns indicating the microbial community responded to these gases by rapid adaptation or growth. Methane oxidation responded the slowest in plume waters. Estimates based on the observed metabolic rates and carbon mass balance suggest that ethane, propane, and butane-consuming microorganisms may transiently account for a majority of the total microbial community in these impacted waters.

Alternative Fuels Data Center

Science.gov Websites

Liquefied Petroleum Gas (Propane) Vehicle and Equipment Incentive - Propane Council of Texas fleets. New dedicated propane vehicles and aftermarket conversions are eligible for an incentive equal to the incremental cost, up to $7,500. Each fleet is limited to $20,000 in total incentive awards

PROGRAM TO DETERMINE PERFORMANCE OF FLUORINATED ETHERS AND FLUORINATED PROPANES IN A COMPRESSOR CALORIMETER

EPA Science Inventory

The paper discusses a program to determine the performance of fluorinated ethers and fluorinated propanes in a compressor calorimeter. These chlorine free ethers and propanes are being considered as potential long-term replacements for CFC-11, -12, -114, and -115. A standard comp...

THE ANGULAR DISTRIBUTION OF POSITRONS IN $pi$$sup +$-$mu$$sup +$-e$sup +$ DECAY IN PROPANE (in Russian)

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

Alikhanyan, A.I.; Kirillov-Ugryumov, V.G.; Kotenko, L.P.

1958-01-01

In consideration of the wide use of propane bubble cameras, investigations were made of the angular distribution of electrons from pi /sup +/ -- mu /sup +/--e/sup +/ decay in propane to determine the possibility of using propane in angular correlation measurements of processes simlar to mu --e decay. The scheme of the experiment made with a bubble chamber of (7.2 x 6.5 x 16)cm/ dmensions bombarded by a 175-Mev pi -meson beam from a phasotron is described. (R.V.J.)

Alternative Fuels Data Center: Alpha Baking Company Augments Its Fleet With

Science.gov Websites

Propane Delivery Trucks Alpha Baking Company Augments Its Fleet With Propane Delivery Trucks to someone by E-mail Share Alternative Fuels Data Center: Alpha Baking Company Augments Its Fleet With Propane Delivery Trucks on Facebook Tweet about Alternative Fuels Data Center: Alpha Baking Company

Alternative Fuels Data Center: Alabama Prisons Adopt Propane, Establish

Science.gov Websites

, Establish Fuel Savings for Years to Come on Facebook Tweet about Alternative Fuels Data Center: Alabama Prisons Adopt Propane, Establish Fuel Savings for Years to Come on Twitter Bookmark Alternative Fuels Data Center: Alabama Prisons Adopt Propane, Establish Fuel Savings for Years to Come on Google Bookmark

Epoxidation of Short-Chain Alkenes by Resting-Cell Suspensions of Propane-Grown Bacteria

PubMed Central

Hou, Ching T.; Patel, Ramesh; Laskin, Allen I.; Barnabe, Nancy; Barist, Irene

1983-01-01

Sixteen new cultures of propane-utilizing bacteria were isolated from lake water from Warinanco Park, Linden, N.J. and from lake and soil samples from Bayway Refinery, Linden, N.J. In addition, 19 known cultures obtained from culture collections were also found to be able to grow on propane as the sole carbon and energy source. In addition to their ability to oxidize n-alkanes, resting-cell suspensions of both new cultures and known cultures grown on propane oxidize short-chain alkenes to their corresponding 1,2-epoxides. Among the substrate alkenes, propylene was oxidized at the highest rate. In contrast to the case with methylotrophic bacteria, the product epoxides are further metabolized. Propane and other gaseous n-alkanes inhibit the epoxidation of propylene. The optimum conditions for in vivo epoxidation are described. Results from inhibition studies indicate that a propane monooxygenase system catalyzes both the epoxidation and hydroxylation reactions. Experiments with cell-free extracts show that both hydroxylation and epoxidation activities are located in the soluble fraction obtained after 80,000 × g centrifugation. PMID:16346338

Research on propane leak detection system and device based on mid infrared laser

NASA Astrophysics Data System (ADS)

Jiang, Meng; Wang, Xuefeng; Wang, Junlong; Wang, Yizhao; Li, Pan; Feng, Qiaoling

2017-10-01

Propane is a key component of liquefied petroleum gas (LPG) and crude oil volatile. This issue summarizes the recent progress of propane detection technology. Meanwhile, base on the development trend, our latest progress is also provided. We demonstrated a mid infrared propane sensor system, which is based on wavelength modulation spectroscopy (WMS) technique with a CW interband cascade laser (ICL) emitting at 3370.4nm. The ICL laser scanned over a sharp feature in the broader spectrum of propane, and harmonic signals are obtained by lock-in amplifier for gas concentration deduction. The surrounding gas is extracted into the fine optical absorption cell through the pump to realize online detection. The absorption cell is designed in mid infrared windows range. An example experimental setup is shown. The second harmonic signals 2f and first harmonic signals1f are obtained. We present the sensor performance test data including dynamic precision and temperature stability. The propane detection sensor system and device is portable can carried on the mobile inspection vehicle platforms or intelligent robot inspection platform to realize the leakage monitoring of whole oil gas tank area.

A surface flow visualisation technique for use in cryogenic wind tunnels

NASA Technical Reports Server (NTRS)

Kell, D. M.

1978-01-01

A method of surface flow visualization for use in cryogenic wind tunnels is described which requires injection of a cryogenic liquid onto the model while the tunnel is running. This necessitates the use of a substance that remains liquid over a large range of cryogenic wind tunnel operating temperatures. It is found that propane (C3H8) is a suitable substance. Experiments are conducted in a subsonic cryogenic wind tunnel to assess the practical application of liquid propane flow visualization. The propane is stored in a chamber cooled by liquid nitrogen and when required is pumped through pipes to a gallery inside the model and then out onto the surface through small holes. To color the liquid a suspension of pigment particles is used. Propane is supplied to the cooled chamber in gaseous form from a standard liquefied gas cylinder. The sequence of events is illustrated on a propane temperature-entropy diagram. The use of liquefied propane for flow visualization in a cryogenic tunnel operating at pressures up to 40 atm appears to be feasible. Illustrative examples are provided.

High rates of anaerobic oxidation of methane, ethane and propane coupled to thiosulphate reduction.

PubMed

Suarez-Zuluaga, Diego A; Weijma, Jan; Timmers, Peer H A; Buisman, Cees J N

2015-03-01

Anaerobic methane oxidation coupled to sulphate reduction and the use of ethane and propane as electron donors by sulphate-reducing bacteria represent new opportunities for the treatment of streams contaminated with sulphur oxyanions. However, growth of microbial sulphate-reducing populations with methane, propane or butane is extremely slow, which hampers research and development of bioprocesses based on these conversions. Thermodynamic calculations indicate that the growth rate with possible alternative terminal electron acceptors such as thiosulphate and elemental sulphur may be higher, which would facilitate future research. Here, we investigate the use of these electron acceptors for oxidation of methane, ethane and propane, with marine sediment as inoculum. Mixed marine sediments originating from Aarhus Bay (Denmark) and Eckernförde Bay (Germany) were cultivated anaerobically at a pH between 7.2 and 7.8 and a temperature of 15 °C in the presence of methane, ethane and propane and various sulphur electron acceptors. The sulphide production rates in the conditions with methane, ethane and propane with sulphate were respectively 2.3, 2.2 and 1.8 μmol S L(-1) day(-1). For sulphur, no reduction was demonstrated. For thiosulphate, the sulphide production rates were up to 50 times higher compared to those of sulphate, with 86.2, 90.7 and 108.1 μmol S L(-1) day(-1) for methane, ethane and propane respectively. This sulphide production was partly due to disproportionation, 50 % for ethane but only 7 and 14 % for methane and propane respectively. The oxidation of the alkanes in the presence of thiosulphate was confirmed by carbon dioxide production. This is, to our knowledge, the first report of thiosulphate use as electron acceptor with ethane and propane as electron donors. Additionally, these results indicate that thiosulphate is a promising electron acceptor to increase start-up rates for sulphate-reducing bioprocesses coupled to short-chain alkane oxidation.

Functional characterization of propane-enhanced N-nitrosodimethylamine degradation by two actinomycetales.

PubMed

Sharp, Jonathan O; Sales, Christopher M; Alvarez-Cohen, Lisa

2010-12-15

Propane-induced cometabolic degradation of n-nitrosodimethylamine (NDMA) by two propanotrophs is characterized through kinetic, gene presence, and expression studies. After growth on propane, resting cells of Rhodococcus sp. RR1 possessed a maximum transformation rate (v(max,n)) of 44 ± 5 µg NDMA (mg protein)(-1) h(-1); the rate for Mycobacterium vaccae (austroafricanum) JOB-5 was modestly lower with v(max,n) of 28 ± 3 µg NDMA (mg protein)(-1) h(-1). Both strains were capable of degrading environmentally relevant, trace quantities of NDMA to below the experimental limit of detection, calculated as 20 ng NDMA L(-1). However, a comparison of half saturation constants (K(s,n)) and NDMA degradation in the presence of propane revealed pronounced differences between the strains. The K(s,n) for strain RR1 was 36 ± 10 µg NDMA L(-1) while the propane concentration needed to inhibit NDMA rates by 50% (K(inh)) occurred at 7,700 µg propane L(-1) (R(2) = 0.9669). In contrast, strain JOB-5 had a markedly lower affinity for NDMA verses propane with a calculated K(s,n) of 2,200 ± 1,000 µg NDMA L(-1) and K(inh) of 120 µg propane L(-1) (R(2) = 0.9895). Genomic and transcriptional investigations indicated that the functional enzymes involved in NDMA degradation and propane metabolism are different for each strain. For Rhodococcus sp. RR1, a putative propane monooxygenase (PrMO) was identified and implicated in NDMA oxidation. In contrast, JOB-5 was not found to possess a PrMO homologue and two functionally analogous alkane monoxygenases (AlkMOs) were not induced by growth on propane. Differences between the PrMO in this Rhodococcus and the unidentified enzyme(s) in the Mycobacterium may explain differences in NDMA degradation and inhibition kinetics between these strains. © 2010 Wiley Periodicals, Inc.

Variation of the pressure limits of flame propagation with tube diameter for propane-air mixtures

NASA Technical Reports Server (NTRS)

Belles, Frank E; Simon, Dorothy M

1951-01-01

An investigation was made of the variation of the pressure limits of flame propagation with tube diameter for quiescent propane with tube diameter for quiescent propane-air mixtures. Pressure limits were measured in glass tubes of six different inside diameters, with a precise apparatus. Critical diameters for flame propagation were calculated and the effect of pressure was determined. The critical diameters depended on the pressure to the -0.97 power for stoichiometric mixtures. The pressure dependence decreased with decreasing propane concentration. Critical diameters were related to quenching distance, flame speeds, and minimum ignition energy.

Infrared absorption cross sections of propane broadened by hydrogen

NASA Astrophysics Data System (ADS)

Wong, A.; Hargreaves, R. J.; Billinghurst, B.; Bernath, P. F.

2017-09-01

Fourier transform infrared absorption cross-sections of pure propane (C3H8) and propane broadened with H2 have been calculated from transmittance spectra recorded at temperatures from 292 K to 205 K. Transmittance spectra were recorded at the Canadian Light Source (CLS) Far-Infrared beamline, utilizing both the synchrotron source and the internal glowbar source. The absorption cross-sections have been calibrated to Pacific Northwest National Laboratory (PNNL) reference cross-sections of propane and can be used to interpret astronomical observations of giant planets such as Jupiter and Saturn as well as exoplanets.

Novel Acetone Metabolism in a Propane-Utilizing Bacterium, Gordonia sp. Strain TY-5▿

PubMed Central

Kotani, Tetsuya; Yurimoto, Hiroya; Kato, Nobuo; Sakai, Yasuyoshi

2007-01-01

In the propane-utilizing bacterium Gordonia sp. strain TY-5, propane was shown to be oxidized to 2-propanol and then further oxidized to acetone. In this study, the subsequent metabolism of acetone was studied. Acetone-induced proteins were found in extracts of cells induced by acetone, and a gene cluster designated acmAB was cloned on the basis of the N-terminal amino acid sequences of acetone-induced proteins. The acmA and acmB genes encode a Baeyer-Villiger monooxygenase (BVMO) and esterase, respectively. The BVMO encoded by acmA was purified from acetone-induced cells of Gordonia sp. strain TY-5 and characterized. The BVMO exhibited NADPH-dependent oxidation activity for linear ketones (C3 to C10) and cyclic ketones (C4 to C8). Escherichia coli expressing the acmA gene oxidized acetone to methyl acetate, and E. coli expressing the acmB gene hydrolyzed methyl acetate. Northern blot analyses revealed that polycistronic transcription of the acmAB gene cluster was induced by propane, 2-propanol, and acetone. These results indicate that the acmAB gene products play an important role in the metabolism of acetone derived from propane oxidation and clarify the propane metabolism pathway of strain TY-5 (propane → 2-propanol → acetone → methyl acetate → acetic acid + methanol). This paper provides the first evidence for BVMO-dependent acetone metabolism. PMID:17071761

40 CFR 721.8145 - Propane,1,1,1,2,2,3,3-heptafluoro-3-methoxy-.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.8145 Propane,1,1,1,2,2,3,3-heptafluoro-3-methoxy-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as propane,1...

Deposit formation in hydrocarbon rocket fuels with an evaluation of a propane heat transfer correlation

NASA Technical Reports Server (NTRS)

Masters, P. A.; Aukerman, C. A.

1982-01-01

A high pressure fuel coking testing apparatus was designed and developed and was used to evaluate thermal decomposition limits and carbon decomposition rates in heated copper tubes for hydrocarbon fuels. A commercial propane (90% grade) and chemically pure (CP) propane were tested. Heat transfer to supercritical propane was evaluated at 136 atm, bulk fluid velocities of 6 to 30 m/s, and tube wall temperatures in the range of 422 to 811 K. A forced convection heat transfer correlation developed in a previous test effort verified a prediction of most of the experimental data within a + or - 30% range, with good agreement for the CP propane data. No significant differences were apparent in the predictions derived from the correlation when the carbon resistance was included with the film resistance. A post-test scanning electron microprobe analysis indicated occurrences of migration and interdiffusion of copper into the carbon deposit.

Alternative Fuels Data Center: Baton Rouge School District Adds Propane

Science.gov Websites

Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a school bus Michigan Transports Students Vehicles June 8, 2012 Natural Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Electric Trucks Alternative Fuels Oct. 16, 2010 Propane Buses Save Money for Virginia Schools Feb. 25, 2010 MedCorp Fuels

Alternative Fuels Data Center: Boston Public Schools Moves to Propane

Science.gov Websites

Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a school bus to Alternative Fuel Vehicles June 8, 2012 Natural Gas School Buses Help Kansas City Save Money Nov National Park Commits to Alternative Fuels Oct. 16, 2010 Propane Buses Save Money for Virginia Schools Feb

Alternative Fuels Data Center: Yellow Cab Converts Taxis to Propane in

Science.gov Websites

electric car. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a Columbus, OhioA> Yellow Cab Converts Taxis to Propane in Columbus, Ohio to someone by E-mail how Yellow Cab is overhauling their fleet in Columbus, Ohio, with propane power. For information about

Comparison of combustion characteristics of ASTM A-1, propane, and natural-gas fuels in an annular turbojet combustor

NASA Technical Reports Server (NTRS)

Wear, J. D.; Jones, R. E.

1973-01-01

The performance of an annular turbojet combustor using natural-gas fuel is compared with that obtained using ASTM A-1 and propane fuels. Propane gas was used to simulate operation with vaporized kerosene fuels. The results obtained at severe operating conditions and altitude relight conditions show that natural gas is inferior to both ASTM A-1 and propane fuels. Combustion efficiencies were significantly lower and combustor pressures for relight were higher with natural-gas fuel than with the other fuels. The inferior performance of natural gas is shown to be caused by the chemical stability of the methane molecule.

Evaluation of various models of propane-powered mosquito traps.

PubMed

Kline, Daniel L

2002-06-01

Large cage and field studies were conducted to determine the efficacy of various models of propane-powered mosquito traps. These traps utilized counterflow technology in conjunction with catalytic combustion to produce attractants (carbon dioxide, water vapor, and heat) and a thermoelectric generator that converted excess heat into electricity for stand-alone operation. The cage studies showed that large numbers of Aedes aegypti and Ochlerotatus taeniorhynchus were captured and that each progressive model resulted in increased trapping efficiency. In several field studies against natural populations of mosquitoes two different propane traps were compared against two other trap systems, the professional (PRO) and counterflow geometry (CFG) traps. In these studies the propane traps consistently caught more mosquitoes than the PRO trap and significantly fewer mosquitoes than the CFG traps. The difference in collection size between the CFG and propane traps was due mostly to Anopheles crucians. In spring 1997 the CFG trap captured 3.6X more An. crucians than the Portable Propane (PP) model and in spring 1998 it captured 6.3X more An. crucians than the Mosquito Magnet Beta-1 (MMB-1) trap. Both the PP and MMB-1 captured slightly more Culex spp. than the CFG trap.

Alternative Fuels Data Center: Glacier-Waterton Park Powers Buses With

Science.gov Websites

Photo of a truck Natural Gas Fuels School Buses and Refuse Trucks in Tulsa, Oklahoma Feb. 18, 2017 Photo of buses Baton Rouge School District Adds Propane Buses to Its Fleet Dec. 23, 2016 photo of a truck Buses to Its Fleet Nov. 11, 2016 photo of a propane school bus Propane Powers School Buses in Tuscaloosa

Cellular Lipids of a Nocardia Grown on Propane and n-Butane

PubMed Central

Davis, J. B.

1964-01-01

Lipid fractions of propane- and n-butane-grown nocardial cells each contain a chloroform-soluble, ether-insoluble polymer not observed previously in liquid n-alkane-grown cells. The polymer in propane-grown cells is poly-β-hydroxybutyrate. The polymer in n-butane-grown cells apparently contains unsaturation in the molecule, and is identified tentatively as a co-polymer of β-hydroxybutyric and β-hydroxybutenoic (specifically 3-hydroxy 2-butenoic) acids. The other major component of the lipid fraction consists of triglycerides containing principally palmitic and stearic acids. There seems to be little qualitative distinction in the glycerides of propane- or n-butane-grown cells. Oxidative assimilation of n-butane is described. PMID:14199017

Effect of temperature and pressure on the dynamics of nanoconfined propane

NASA Astrophysics Data System (ADS)

Gautam, Siddharth; Liu, Tingting; Rother, Gernot; Jalarvo, Niina; Mamontov, Eugene; Welch, Susan; Cole, David

2014-04-01

We report the effect of temperature and pressure on the dynamical properties of propane confined in nanoporous silica aerogel studied using quasielastic neutron scattering (QENS). Our results demonstrate that the effect of a change in the pressure dominates over the effect of temperature variation on the dynamics of propane nano-confined in silica aerogel. At low pressures, most of the propane molecules are strongly bound to the pore walls, only a small fraction is mobile. As the pressure is increased, the fraction of mobile molecules increases. A change in the mechanism of motion, from continuous diffusion at low pressures to jump diffusion at higher pressures has also been observed.

Supercritical CO(2) and subcritical propane extraction of pungent paprika and quantification of carotenoids, tocopherols, and capsaicinoids.

PubMed

Gnayfeed, M H; Daood, H G; Illés, V; Biacs, P A

2001-06-01

Ground paprika (Capsicum annuum L.) was extracted with supercritical carbon dioxide (SC-CO(2)) and subcritical propane at different conditions of pressure and temperature to estimate the yield and variation in carotenoid, tocopherol, and capsaicinoid contents and composition. The yield of paprika extract was found to be affected by the extraction conditions with SC-CO(2) but fairly constant at different conditions with subcritical propane. The maximum yields of oleoresin were 7.9 and 8.1% of ground paprika by SC-CO(2) and subcritical propane, respectively. The quantitative distribution of carotenoids, tocopherols, and capsaicinoids between paprika extract and powder was influenced by extraction conditions. SC-CO(2) was inefficient in the extraction of diesters of xanthophylls even at 400 bar and 55 degrees C, whereas tocopherols and capsaicinoids were easy to extract at these conditions. Under mild conditions subcritical propane was superior to SC-CO(2) in the extraction of carotenoids and tocopherols but less efficient in the extraction of capsaicinoids.

Design and Operation of the Synthesis Gas Generator System for Reformed Propane and Glycerin Combustion

NASA Astrophysics Data System (ADS)

Pickett, Derek Kyle

Due to an increased interest in sustainable energy, biodiesel has become much more widely used in the last several years. Glycerin, one major waste component in biodiesel production, can be converted into a hydrogen rich synthesis gas to be used in an engine generator to recover energy from the biodiesel production process. This thesis contains information detailing the production, testing, and analysis of a unique synthesis generator rig at the University of Kansas. Chapter 2 gives a complete background of all major components, as well as how they are operated. In addition to component descriptions, methods for operating the system on pure propane, reformed propane, reformed glycerin along with the methodology of data acquisition is described. This chapter will serve as a complete operating manual for future students to continue research on the project. Chapter 3 details the literature review that was completed to better understand fuel reforming of propane and glycerin. This chapter also describes the numerical model produced to estimate the species produced during reformation activities. The model was applied to propane reformation in a proof of concept and calibration test before moving to glycerin reformation and its subsequent combustion. Chapter 4 first describes the efforts to apply the numerical model to glycerin using the calibration tools from propane reformation. It then discusses catalytic material preparation and glycerin reformation tests. Gas chromatography analysis of the reformer effluent was completed to compare to theoretical values from the numerical model. Finally, combustion of reformed glycerin was completed for power generation. Tests were completed to compare emissions from syngas combustion and propane combustion.

Analysis of Ignition Behavior in a Turbocharged Direct Injection Dual Fuel Engine Using Propane and Methane as Primary Fuels

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

Polk, A. C.; Gibson, C. M.; Shoemaker, N. T.

2013-05-24

This paper presents experimental analyses of the ignition delay (ID) behavior for diesel-ignited propane and diesel-ignited methane dual fuel combustion. Two sets of experiments were performed at a constant speed (1800 rev/min) using a 4-cylinder direct injection diesel engine with the stock ECU and a wastegated turbocharger. First, the effects of fuel-air equivalence ratios (© pilot ¼ 0.2-0.6 and © overall ¼ 0.2-0.9) on IDs were quantified. Second, the effects of gaseous fuel percent energy substitution (PES) and brake mean effective pressure (BMEP) (from 2.5 to 10 bar) on IDs were investigated. With constant © pilot (> 0.5), increasing ©more » overall with propane initially decreased ID but eventually led to premature propane autoignition; however, the corresponding effects with methane were relatively minor. Cyclic variations in the start of combustion (SOC) increased with increasing © overall (at constant © pilot), more significantly for propane than for methane. With increasing PES at constant BMEP, the ID showed a nonlinear (initially increasing and later decreasing) trend at low BMEPs for propane but a linearly decreasing trend at high BMEPs. For methane, increasing PES only increased IDs at all BMEPs. At low BMEPs, increasing PES led to significantly higher cyclic SOC variations and SOC advancement for both propane and methane. Finally, the engine ignition delay (EID) was also shown to be a useful metric to understand the influence of ID on dual fuel combustion.« less

School Districts Move to the Head of the Class with Propane

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

None

School districts across the country are under pressure to reduce their cost of operations and ensure their budgets are spent wisely. School bus fleets operate more than 675,000 buses in the United States, and many school districts have found the answer to their budget woes in the form of propane, or liquefied petroleum gas (LPG). Propane is a reliable, domestic fuel, and it's used in approximately 2% of school buses nationwide.

Alternative Fuels Data Center: Propane Tank Overfill Safety Advisory

Science.gov Websites

rises above set safe levels. However, even if conditions result in a fuel release, an ignition source vehicle tanks are all equipped with PRDs to ensure safe levels of LPG pressure in the tanks, and we are practices for OPDs to ensure they work properly. The US DOE Clean Cities (DOE-CC) program is working with

Volatile compounds in whole meal bread crust: The effects of yeast level and fermentation temperature.

PubMed

Nor Qhairul Izzreen, M N; Hansen, Se S; Petersen, Mikael A

2016-11-01

The influence of fermentation temperatures (8°C, 16°C, and 32°C) and yeast levels (2%, 4%, and 6% of the flour) on the formation of volatile compounds in the crust of whole meal wheat bread was investigated. The fermentation times were regulated to optimum bread height for each treatment. The volatile compounds were extracted by dynamic headspace extraction and analyzed by gas chromatography-mass spectrometry. The results were evaluated using multivariate data analysis and ANOVA. In all crust samples 28 volatile compounds out of 58 compounds were identified and the other 30 compounds were tentatively identified. Higher fermentation temperatures promoted the formation of Maillard reaction products 3-methyl-1-butanol, pyrazine, 2-ethylpyrazine, 2-ethyl-3-methylpyrazine, 2-vinylpyrazine, 3-hydroxy-2-butanone, 3-(methylsulfanyl)-propanal, and 5-methyl-2-furancarboxaldehyde whereas at lower temperature (8°C) the formation of 2- and 3-methylbutanal was favored. Higher levels of yeast promoted the formation of 3-methyl-1-butanol, 2-methyl-1-propanol and 3-(methylsulfanyl)-propanal, whereas hexanal was promoted in the crust fermented with lower yeast level. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular dynamics simulations of propane in slit shaped silica nano-pores: direct comparison with quasielastic neutron scattering experiments.

PubMed

Gautam, Siddharth; Le, Thu; Striolo, Alberto; Cole, David

2017-12-13

Molecular motion under confinement has important implications for a variety of applications including gas recovery and catalysis. Propane confined in mesoporous silica aerogel as studied using quasielastic neutron scattering (QENS) showed anomalous pressure dependence in its diffusion coefficient (J. Phys. Chem. C, 2015, 119, 18188). Molecular dynamics (MD) simulations are often employed to complement the information obtained from QENS experiments. Here, we report an MD simulation study to probe the anomalous pressure dependence of propane diffusion in silica aerogel. Comparison is attempted based on the self-diffusion coefficients and on the time scales of the decay of the simulated intermediate scattering functions. While the self-diffusion coefficients obtained from the simulated mean squared displacement profiles do not exhibit the anomalous pressure dependence observed in the experiments, the time scales of the decay of the intermediate scattering functions calculated from the simulation data match the corresponding quantities obtained in the QENS experiment and thus confirm the anomalous pressure dependence of the diffusion coefficient. The origin of the anomaly in pressure dependence lies in the presence of an adsorbed layer of propane molecules that seems to dominate the confined propane dynamics at low pressure, thereby lowering the diffusion coefficient. Further, time scales for rotational motion obtained from the simulations explain the absence of rotational contribution to the QENS spectra in the experiments. In particular, the rotational motion of the simulated propane molecules is found to exhibit large angular jumps at lower pressure. The present MD simulation work thus reveals important new insights into the origin of anomalous pressure dependence of propane diffusivity in silica mesopores and supplements the information obtained experimentally by QENS data.

Catalytic properties of the VO x /Ce0.46Zr0.54O2 oxide system in the oxidative dehydrogenation of propane

NASA Astrophysics Data System (ADS)

Turakulova, A. O.; Kharlanov, A. N.; Levanov, A. V.; Isaikina, O. Ya.; Lunin, V. V.

2017-01-01

Ce0.46Zr0.54O2 solid solution prepared using a cellulose template was employed as a carrier for vanadium catalysts of the oxidative dehydrogenation of propane. The properties of VO x /Ce0.46Zr0.54O2 catalyst (5 wt % vanadium) are compared with the properties of the neat support. The carrier and catalyst are studied by means of BET, SEM, DTA, XRD, and Raman spectroscopy. It is shown that the CeVO4 phase responsible for the ODH process is formed upon interaction between vanadate ions and cerium ions on the surface of the solid solution. The catalytic properties of the catalyst and the support are studied in the propane oxidation reaction at temperatures of 450 and 500°C with pulse feeding of the reagent. It is found that the complete oxidation of propane occurs on the support with formation of CO2 and H2O. Three products (propene, CO2, and H2O) form in the presence of the vanadium catalyst. It is suggested that there are two types of catalytic centers on the catalyst's surface. It is concluded that the centers responsible for the complete oxidation of propane are concentrated mainly on the carrier, while the centers responsible for propane ODH are on the CeVO4.

Performance and emissions of a catalytic reactor with propane, diesel, and Jet A fuels

NASA Technical Reports Server (NTRS)

Anderson, D. N.

1977-01-01

Tests were made to determine the performance and emissions of a catalytic reactor operated with propane, No. 2 diesel, and Jet A fuels. A 12-cm diameter and 16-cm long catalytic reactor using a proprietary noble metal catalyst was operated at an inlet temperature of 800 K, a pressure of 300,000 Pa and reference velocities of 10 to 15 m/s. No significant differences between the performance of the three fuels were observed when 98.5 percent purity propane was used. The combustion efficiency for 99.8-percent purity propane tested later was significantly lower, however. The diesel fuel contained 135 ppm of bound nitrogen and consequently produced the highest NOx emissions of the three fuels. As much as 85 percent of the bound nitrogen was converted to NOx. Steady-state emissions goals based on half the most stringent proposed automotive standards were met when the reactor was operated at an adiabatic combustion temperature higher than 1350 K with all fuels except the 99.8-percent purity propane. With that fuel, a minimum temperature of 1480 K was required.

Hexagonal boron nitride catalyst in a fixed-bed reactor for exothermic propane oxidation dehydrogenation

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

Tian, Jinshu; Lin, Jinhan; Xu, Mingliang

Hexagonal boron nitride (h-BN) with high thermal conductivity is potentially an effective catalyst for highly exothermic propane oxidative dehydrogenation (ODH) reaction. Here, we report our experimental and theoretic studies of such a catalyst for propane ODH in a fixed-bed reactor. Based on the computational fluid dynamics calculation (CFD) results, the catalyst bed temperature increases by less than 1°C in the h-BN catalyst bed which is much smaller than that (8°C) in the VO x/γ-Al 2O 3 catalyst bed at a similar propane conversion (25%) using a micro-tubular reactor with a diameter of 6 mm. Even in an industrially relevant reactormore » with an inner diameter of 60 mm, a uniform temperature profile can still be maintained using the h-BN catalyst bed due to its excellent thermal conductivity as opposed to a temperature gradient of 47°C in the VO x/γ-Al 2O 3 catalyst bed. The results reported here provide useful information for potential application of h-BN catalyst in propane ODH.« less

Novel thermal management system using boiling cooling for high-powered lithium-ion battery packs for hybrid electric vehicles

NASA Astrophysics Data System (ADS)

Al-Zareer, Maan; Dincer, Ibrahim; Rosen, Marc A.

2017-09-01

A thermal management system is necessary to control the operating temperature of the lithium ion batteries in battery packs for electrical and hybrid electrical vehicles. This paper proposes a new battery thermal management system based on one type of phase change material for the battery packs in hybrid electrical vehicles and develops a three dimensional electrochemical thermal model. The temperature distributions of the batteries are investigated under various operating conditions for comparative evaluations. The proposed system boils liquid propane to remove the heat generated by the batteries, and the propane vapor is used to cool the part of the battery that is not covered with liquid propane. The effect on the thermal behavior of the battery pack of the height of the liquid propane inside the battery pack, relative to the height of the battery, is analyzed. The results show that the propane based thermal management system provides good cooling control of the temperature of the batteries under high and continuous charge and discharge cycles at 7.5C.

Hexagonal boron nitride catalyst in a fixed-bed reactor for exothermic propane oxidation dehydrogenation

DOE PAGES

Tian, Jinshu; Lin, Jinhan; Xu, Mingliang; ...

2018-04-17

Hexagonal boron nitride (h-BN) with high thermal conductivity is potentially an effective catalyst for highly exothermic propane oxidative dehydrogenation (ODH) reaction. Here, we report our experimental and theoretic studies of such a catalyst for propane ODH in a fixed-bed reactor. Based on the computational fluid dynamics calculation (CFD) results, the catalyst bed temperature increases by less than 1°C in the h-BN catalyst bed which is much smaller than that (8°C) in the VO x/γ-Al 2O 3 catalyst bed at a similar propane conversion (25%) using a micro-tubular reactor with a diameter of 6 mm. Even in an industrially relevant reactormore » with an inner diameter of 60 mm, a uniform temperature profile can still be maintained using the h-BN catalyst bed due to its excellent thermal conductivity as opposed to a temperature gradient of 47°C in the VO x/γ-Al 2O 3 catalyst bed. The results reported here provide useful information for potential application of h-BN catalyst in propane ODH.« less

An In-Situ XAS Study of the Structural Changes in a CuO-CeO2/Al2O3 Catalyst during Total Oxidation of Propane

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

Silversmith, Geert; Poelman, Hilde; Poelman, Dirk

2007-02-02

A CuOx-CeOx/Al2O3 catalyst was studied with in-situ transmission Cu K XAS for the total oxidation of propane as model reaction for the catalytic elimination of volatile organic compounds. The local Cu structure was determined for the catalyst as such, after pre-oxidation and after reduction with propane. The catalyst as such has a local CuO structure. No structural effect was observed upon heating in He up to 600 deg. C or after pre-oxidation at 150 deg. C. A full reduction of the Cu2+ towards metallic Cu0 occurred, when propane was fed to the catalyst. The change in local Cu structure duringmore » propane reduction was followed with a time resolution of 1 min. The {chi}(k) scans appeared as linear combinations of start and end spectra, CuO and Cu structure, respectively. However, careful examination of the XANES edge spectra indicates the presence of a small amount of additional Cu1+ species.« less

Adsorption of acrolein, propanal, and allyl alcohol on Pd(111): a combined infrared reflection–absorption spectroscopy and temperature programmed desorption study

PubMed Central

Dostert, Karl-Heinz; O'Brien, Casey P.; Mirabella, Francesca; Ivars-Barceló, Francisco

2016-01-01

Atomistic-level understanding of the interaction of α,β-unsaturated aldehydes and their derivatives with late transition metals is of fundamental importance for the rational design of new catalytic materials with the desired selectivity towards C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C vs. CO bond partial hydrogenation. In this study, we investigate the interaction of acrolein, and its partial hydrogenation products propanal and allyl alcohol, with Pd(111) as a prototypical system. A combination of infrared reflection–absorption spectroscopy (IRAS) and temperature programmed desorption (TPD) experiments was applied under well-defined ultrahigh vacuum (UHV) conditions to obtain detailed information on the adsorption geometries of acrolein, propanal, and allyl alcohol as a function of coverage. We compare the IR spectra obtained for multilayer coverages, reflecting the molecular structure of unperturbed molecules, with the spectra acquired for sub-monolayer coverages, at which the chemical bonds of the molecules are strongly distorted. Coverage-dependent IR spectra of acrolein on Pd(111) point to the strong changes in the adsorption geometry with increasing acrolein coverage. Acrolein adsorbs with the CC and CO bonds lying parallel to the surface in the low coverage regime and changes its geometry to a more upright orientation with increasing coverage. TPD studies indicate decomposition of the species adsorbed in the sub-monolayer regime upon heating. Similar strong coverage dependence of the IR spectra were found for propanal and allyl alcohol. For all investigated molecules a detailed assignment of vibrational bands is reported. PMID:27149902

Influence of The Metamorphism Grade and Porosity of Hard Coal on Sorption and Desorption of Propane / Wpływ Stopnia Metamorfizmu I Porowatości Węgli Kamiennych Na Sorpcję I Desorpcję Propanu

NASA Astrophysics Data System (ADS)

Dudzińska, Agnieszka; Żyła, Mieczysław; Cygankiewicz, Janusz

2013-09-01

In this paper results of investigations of sorption of hard coal samples collected from the extracted coal seams of Polish coal mines are presented. As sorbate propane was used. Examinations were carried out in the temperature of 298 K by means of volumetric assessment with the use of apparatus ASAP 2010 of Micromeritics. On the basis of conducted examinations it has been found out that the amount of sorbed propane depend on a type of coal, its metamorphism grade, content of oxygen element, moisture and porosity of these coals. The greatest amounts of propane are sorbed by low carbonized, high-porosity coals of high content of oxygen and moisture. Sorption of relatively high amounts of propane by these coals (ca. 10 cm3/g) is a result of the influence of polar surface of coals with molecules of propane and good availability of internal microporous structure of these coals for molecules of examined sorbate. Medium and high carbonized coals sorb insignificant amounts of propane. These coals have compact structure and non-polar character of their surface, their internal porous structure is to a minor degree available for propane molecules in conditions of carried out research. Sorption of propane in this case, takes place mainly in surface pores and on the surface of coals. Moreover, measurements of desorption isotherms of propane showing irreversible character of sorption were made. Desorption isotherms do not come together with sorption isotherms forming open hysteresis loop. Amounts of non-desorbing propane remaining in the coal depend on the type of examined coal. W pracy przedstawiono wyniki badań sorpcji próbek węgli kamiennych pobranych z eksploatowanych pokładów węglowych polskich kopalń. Jako sorbat zastosowano propan. Badania przeprowadzono w temperaturze 298 K metodą objętościową z wykorzystaniem aparatu ASAP 2010 firmy Micromeritics. Na podstawie przeprowadzonych badań stwierdzono, że ilości sorbowanego propanu są zależne od rodzaju węgla, jego stopnia metamorfizmu, zawartości pierwiastka tlenu, wilgoci i porowatości tych węgli. Największe ilości propanu sorbują węgle niskouwęglone, wysokoporowate o dużej zawartości tlenu i wilgoci. Sorpcja stosunkowo dużych ilości propanu tych węgli (ok. 10 cm3/g) jest wynikiem oddziaływania polarnej powierzchni węgli z cząsteczkami propanu oraz dobrej dostępności wewnętrznej mikroporowatej struktury tych węgli dla cząsteczek badanego sorbatu. Węgle średnio i wysokouwęglone sorbują niewielkie ilości propanu. Węgle te mają zwartą budowę oraz niepolarny charakter powierzchni, ich wewnętrzna struktura porowata jest w niewielkim stopniu dostępna dla cząsteczek propanu w warunkach przeprowadzanych badań. Sorpcja propanu w tym przypadku zachodzi głównie w powierzchniowych porach i na powierzchni węgli. Przeprowadzono również pomiary izoterm desorpcji propanu wykazując nieodwracalny charakter sorpcji. Izotermy desorpcji nie zbiegają się z izotermami sorpcji tworząc otwartą pętlę histerezy. Pozostające w węglu ilości nie desorbującego się propanu są zależne od rodzaju badanego węgla.

Detailed and reduced chemical-kinetic descriptions for hydrocarbon combustion

NASA Astrophysics Data System (ADS)

Petrova, Maria V.

Numerical and theoretical studies of autoignition processes of fuels such as propane are in need of realistic simplified chemical-kinetic descriptions that retain the essential features of the detailed descriptions. These descriptions should be computationally feasible and cost-effective. Such descriptions are useful for investigating ignition processes that occur, for example, in homogeneous-charge compression-ignition engines, for studying the structures and dynamics of detonations and in fields such as multi-dimensional Computational Fluid Dynamics (CFD). Reduced chemistry has previously been developed successfully for a number of other hydrocarbon fuels, however, propane has not been considered in this manner. This work focuses on the fuels of propane, as well propene, allene and propyne, for several reasons. The ignition properties of propane resemble those of other higher hydrocarbons but are different from those of the lower hydrocarbons (e.g. ethylene and acetylene). Propane, therefore, may be the smallest hydrocarbon that is representative of higher hydrocarbons in ignition and detonation processes. Since the overall activation energy and ignition times for propane are similar to those of other higher hydrocarbons, including liquid fuels that are suitable for many applications, propane has been used as a model fuel for several numerical and experimental studies. The reason for studying elementary chemistry of propene and C3H4 (allene or propyne) is that during the combustion process, propane breaks down to propene and C3H4 before proceeding to products. Similarly, propene combustion includes C3H4 chemistry. In studying propane combustion, it is therefore necessary to understand the underlying combustion chemistry of propene as well as C3H 4. The first part of this thesis focuses on obtaining and testing a detailed chemical-kinetic description for autoignition of propane, propene and C 3H4, by comparing predictions obtained with this detailed mechanism against numerous experimental data available from shock-tube studies and flame-speed measurements. To keep the detailed mechanism small, attention is restricted to pressures below about 100 atm, temperatures above about 1000 K and equivalence ratios less than about 3. Based on this detailed chemistry description, short (or skeletal) mechanisms are then obtained for each of the three fuels by eliminating reactions that are unimportant for the autoignition process under conditions presented above. This was achieved by utilizing tools such as sensitivity and reaction pathway analyses. Two distinct methodologies were then used in order to obtain a reduced mechanism for autoignition from the short mechanisms. A Systematic Reduction approach is first taken that involves introducing steady-state approximations to as many species as analytically possible. To avoid resorting to numerical methods, the analysis for obtaining ignition times for heptane, presented by Peters and co-workers is followed in order to obtain a rough estimate for an expression of propane ignition time. The results from this expression are then compared to the ignition times obtained computationally with the detailed mechanism. The second method is an Empirical Approach in which chemistry is not derived formally, but rather postulated empirically on the basis of experimental, computational and theoretical observations. As a result, generalized reduced mechanisms are proposed for autoignition of propane, propene and C3H 4. Expressions for ignition times obtained via this empirical approach are compared to the computational results obtained from the detailed mechanism.

Alternative Fuels Data Center

Science.gov Websites

Propane Vehicle and Mower Incentive - Louisiana Liquefied Petroleum Gas Commission Propane vehicle . Each recipient is limited to four incentive awards, up to $5,000, per year. Recipients must participate

Laboratory-Scale Demonstration Using Dilute Ammonia Gas-Induced Alkaline Hydrolysis of Soil Contaminants (Chlorinated Propanes and Explosives)

DTIC Science & Technology

2016-06-01

Hydrolysis of Soil Contaminants (Chlorinated Propanes and Explosives) En vi ro nm en ta l L ab or at or y Victor F. Medina, Scott A. Waisner, Charles...Using Dilute Ammonia Gas-Induced Alkaline Hydrolysis of Soil Contaminants (Chlorinated Propanes and Explosives) Victor F. Medina, Scott A. Waisner...hydrolysis. This project explored the use of ammonia gas to raise soil pH in order to stimulate alkaline hydrolysis. When ammonia gas dissolves in water

Mono-, di-, and tri- tert-butyl ethers of glycerol . A molecular spectroscopic study

NASA Astrophysics Data System (ADS)

Jamróz, Małgorzata E.; Jarosz, Małgorzata; Witowska-Jarosz, Janina; Bednarek, Elżbieta; Tęcza, Witold; Jamróz, Michał H.; Dobrowolski, Jan Cz.; Kijeński, Jacek

2007-07-01

MS, NMR, IR and Raman molecular spectroscopy techniques were applied to characterize 3- tert-butoxy-propane-1,2-diol, 1,3-di- tert-butoxy-propan-2-ol, and 1,2,3-tri- tert-butoxy-propane. These ethers are the main products of glycerol etherification reaction and are excellent oxygen additives for diesel fuel. Computational DFT/ B3LYP/6-31G ** studies were performed to support and rationalize both vibrational spectroscopy analysis and the isomer ratio.

Propane tank explosion (2 deaths, 7 injuries) at Herrig Brothers Feather Creek Farm, Albert City, Iowa, April 9, 1998. Investigation report

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

NONE

1999-09-01

This report explains the explosion/BLEVE that took place on April 9, 1998, at the Herrig Brothers Feather Creek Farm, located in Albert City, Iowa. Two volunteer fire fighters were killed and seven other emergency response personnel were injured. Safety issues covered in the report include protection of propane storage tanks and piping, state regulatory oversight of such installations, and fire fighter response to propane storage tank fires.

Heating Oil and Propane Update

EIA Publications

2017-01-01

Weekly residential, wholesale, and spot prices; and production, demand, and stocks of heating fuels. (Weekly heating oil and propane prices are only collected during the heating season which extends from October through March.)

Cu-Doped ZnO Thin Films Deposited by a Sol-Gel Process Using Two Copper Precursors: Gas-Sensing Performance in a Propane Atmosphere.

PubMed

Gómez-Pozos, Heberto; Arredondo, Emma Julia Luna; Maldonado Álvarez, Arturo; Biswal, Rajesh; Kudriavtsev, Yuriy; Pérez, Jaime Vega; Casallas-Moreno, Yenny Lucero; Olvera Amador, María de la Luz

2016-01-29

A study on the propane gas-sensing properties of Cu-doped ZnO thin films is presented in this work. The films were deposited on glass substrates by sol-gel and dip coating methods, using zinc acetate as a zinc precursor, copper acetate and copper chloride as precursors for doping. For higher sensitivity values, two film thickness values are controlled by the six and eight dippings, whereas for doping, three dippings were used, irrespective of the Cu precursor. The film structure was analyzed by X-ray diffractometry, and the analysis of the surface morphology and film composition was made through scanning electron microscopy (SEM) and secondary ion mass spectroscopy (SIMS), respectively. The sensing properties of Cu-doped ZnO thin films were then characterized in a propane atmosphere, C₃H₈, at different concentration levels and different operation temperatures of 100, 200 and 300 °C. Cu-doped ZnO films doped with copper chloride presented the highest sensitivity of approximately 6 × 10⁴, confirming a strong dependence on the dopant precursor type. The results obtained in this work show that the use of Cu as a dopant in ZnO films processed by sol-gel produces excellent catalysts for sensing C₃H₈ gas.

Alternative Fuels Data Center

Science.gov Websites

Propane and Natural Gas Safety The Railroad Commission of Texas regulates the safety of the natural gas and propane industries. (Reference Texas Statutes, Natural Resources Code 113.011 and 116.011

2. View of Liquified Propane Air Plant (New), former Exhaust ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. View of Liquified Propane Air Plant (New), former Exhaust and Compressor Building and former Purifying Plant in background. - Concord Gas Light Company, South Main Street, Concord, Merrimack County, NH

Characterization of Emissions from Liquid Fuel and Propane Open Burns.

PubMed

Aurell, Johanna; Hubble, David; Gullett, Brian K; Holder, Amara; Washburn, Ephraim; Tabor, Dennis

2017-11-07

The effect of accidental fires are simulated to understand the response of items such as vehicles, fuel tanks, and military ordnance and to remediate the effects through re-design of the items or changes in operational procedures. The comparative combustion emissions of using jet propellant (JP-5) liquid fuel pools or a propane manifold grid to simulate the effects of accidental fires was investigated. A helium-filled tethered aerostat was used to maneuver an instrument package into the open fire plumes to measure CO, CO 2 , fine particulate matter (PM 2.5 ), polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and elemental/organic/total carbon (EC/OC/TC). The results showed that all emissions except CO 2 were significantly higher from JP-5 burns than from propane. The major portion of the PM mass from fires of both fuels was less than 1 μm in diameter and differed in carbon content. The PM 2.5 emission factor from JP-5 burns (129 ± 23 g/kg Fuel c ) was approximately 150 times higher than the PM 2.5 emission factor from propane burns (0.89 ± 0.21 g/kg Fuel c ). The PAH emissions as well as some VOCs were more than one hundred times higher for the JP-5 burns than the propane burns. Using the propane test method to study flammability responses, the environmental impact of PM 2.5 , PAHs, and VOCs would be reduced by 2300, 700, and 100 times per test, respectively.

NMR Spin-Lock Induced Crossing (SLIC) Dispersion and Long-Lived Spin States of Gaseous Propane at Low Magnetic Field (0.05 T)

PubMed Central

Barskiy, Danila A.; Salnikov, Oleg G.; Romanov, Alexey S.; Feldman, Matthew A.; Coffey, Aaron M.; Kovtunov, Kirill V.; Koptyug, Igor V.; Chekmenev, Eduard Y.

2017-01-01

When parahydrogen reacts with propylene in low magnetic fields (e.g., 0.05 T), the reaction product propane develops an overpopulation of pseudo-singlet nuclear spin states. We studied how the spin-lock induced crossing (SLIC) technique can be used to convert these pseudo-singlet spin states of hyperpolarized gaseous propane into observable magnetization and to detect 1H NMR signal directly at 0.05 T. The theoretical simulation and experimental study of the NMR signal dependence on B1 power (SLIC amplitude) exhibits a well-resolved dispersion, which is induced by the spin-spin couplings in the eight-proton spin system of propane. We also measured the exponential decay time constants (TLLSS or TS) of these pseudo-singlet long-lived spin states (LLSS) by varying the time between hyperpolarized propane production and SLIC detection. We have found that, on average, TS is approximately 3 times longer than the corresponding T1 value under the same conditions in the range of pressures studied (up to 7.6 atm). Moreover, TS may exceed 13 seconds at pressures above 7 atm in the gas phase. These results are in agreement with the previous reports, and they corroborate a great potential of long-lived hyperpolarized propane as an inhalable gaseous contrast agent for lung imaging and as a molecular tracer to study porous media using low-field NMR and MRI. PMID:28152435

NMR Spin-Lock Induced Crossing (SLIC) dispersion and long-lived spin states of gaseous propane at low magnetic field (0.05 T)

NASA Astrophysics Data System (ADS)

Barskiy, Danila A.; Salnikov, Oleg G.; Romanov, Alexey S.; Feldman, Matthew A.; Coffey, Aaron M.; Kovtunov, Kirill V.; Koptyug, Igor V.; Chekmenev, Eduard Y.

2017-03-01

When parahydrogen reacts with propylene in low magnetic fields (e.g., 0.05 T), the reaction product propane develops an overpopulation of pseudo-singlet nuclear spin states. We studied how the Spin-Lock Induced Crossing (SLIC) technique can be used to convert these pseudo-singlet spin states of hyperpolarized gaseous propane into observable magnetization and to detect 1H NMR signal directly at 0.05 T. The theoretical simulation and experimental study of the NMR signal dependence on B1 power (SLIC amplitude) exhibits a well-resolved dispersion, which is induced by the spin-spin couplings in the eight-proton spin system of propane. We also measured the exponential decay time constants (TLLSS or TS) of these pseudo-singlet long-lived spin states (LLSS) by varying the time between hyperpolarized propane production and SLIC detection. We have found that, on average, TS is approximately 3 times longer than the corresponding T1 value under the same conditions in the range of pressures studied (up to 7.6 atm). Moreover, TS may exceed 13 s at pressures above 7 atm in the gas phase. These results are in agreement with the previous reports, and they corroborate a great potential of long-lived hyperpolarized propane as an inhalable gaseous contrast agent for lung imaging and as a molecular tracer to study porous media using low-field NMR and MRI.

Recovery Act: Demonstration of a SOFC Generator Fueled by Propane to Provide Electrical Power to Real World Applications

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

Bessette, Norman

The objective of this project provided with funds through the American Recovery and Reinvestment Act of 2009 (ARRA) was to demonstrate a Solid Oxide Fuel Cell (SOFC) generator capable of operation on propane fuel to improve efficiency and reduce emissions over commercially available portable generators. The key objectives can be summarized as: Development of two portable electrical generators in the 1-3kW range utilizing Solid Oxide Fuel Cells and propane fuel; The development and demonstration of a proof-of-concept electro-mechanical propane fuel interface that provides a user friendly capability for managing propane fuel; The deployment and use of the fuel cell portablemore » generators to power media production equipment over the course of several months at multiple NASCAR automobile racing events; The deployment and use of the fuel cell portable generators at scheduled events by first responders (police, fire) of the City of Folsom California; and Capturing data with regard to the systems’ ability to meet Department of Energy (DOE) Technical Targets and evaluating the ease of use and potential barriers to further adoption of the systems.« less

Case Study - Propane School Bus Fleets

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

Laughlin, M; Burnham, A.

As part of the U.S. Department of Energy’s (DOE’s) effort to deploy transportation technologies that reduce U.S. dependence on imported petroleum, this study examines five school districts, one in Virginia and four in Texas, successful use of propane school buses. These school districts used school buses equipped with the newly developed liquid propane injection system that improves vehicle performance. Some of the school districts in this study saved nearly 50% on a cost per mile basis for fuel and maintenance relative to diesel. Using Argonne National Laboratory’s Alternative Fuel Life-Cycle Environmental and Economic Transportation (AFLEET) Tool developed for the DOE’smore » Clean Cities program to help Clean Cities stakeholders estimate petroleum use, greenhouse gas (GHG) emissions, air pollutant emissions and cost of ownership of light-duty and heavy-duty vehicles, the results showed payback period ranges from 3—8 years, recouping the incremental cost of the vehicles and infrastructure. Overall, fuel economy for these propane vehicles is close to that of displaced diesel vehicles, on an energy-equivalent basis. In addition, the 110 propane buses examined demonstrated petroleum displacement, 212,000 diesel gallon equivalents per year, and GHG benefits of 770 tons per year.« less

Alternative Fuels Data Center

Science.gov Websites

Compressed Natural Gas (CNG) and Propane Tax Retail sales for CNG and liquefied petroleum gas (propane) used to operate vehicles are subject to a modified tax based on energy content. CNG is taxed per

Alternative Fuels Data Center: Propane Vehicles

Science.gov Websites

dedicated and bi-fuel vehicles is also comparable. Extra storage tanks can increase range, but the tank size propane or gasoline vehicles have. Likewise, larger storage tanks can increase range, but the additional

Short-Term Energy Outlook Model Documentation: Regional Residential Propane Price Model

EIA Publications

2009-01-01

The regional residential propane price module of the Short-Term Energy Outlook (STEO) model is designed to provide residential retail price forecasts for the 4 Census regions: Northeast, South, Midwest, and West.

Physicochemical Properties of Flaxseed Fortified Extruded Bean Snack.

PubMed

Vadukapuram, Naveen; Hall, Clifford; Tulbek, Mehmet; Niehaus, Mary

2014-01-01

Milled flaxseed was incorporated (0-20%) into a combination of bean-corn flours and extruded in a twin screw extruder using corn curl method. Physicochemical parameters such as water activity, color, expansion ratio, bulk density, lipid content, and peroxide values of extruded snack were analyzed. Scanning electron micrographs were taken. Peroxide values and propanal contents were measured over four months of storage. Rancidity scores of extruded snack were measured using a trained panel. As expected, omega-3 fatty acids and bulk density increased with increasing flaxseed fortification levels. Extrudates with more flaxseed had decreased lightness values and expansion ratios. However, only the 15 and 20% flaxseed containing extrudates had expansion ratios that were significantly (P ≤ 0.05) different from the control. In general, no significant difference (P > 0.05) in water activity values was observed in the flaxseed fortified extrudates, except in the navy-corn based extrudates. Peroxide values increased with increased flaxseed levels and over a storage period. However, propanal values did not change significantly in the 5-10% flaxseed fortified extrudates but increased in extrudates with higher levels of flaxseed. Rancidity scores were correlated with peroxide values and did not increase significantly during storage under nitrogen flushed conditions.

Physicochemical Properties of Flaxseed Fortified Extruded Bean Snack

PubMed Central

Vadukapuram, Naveen; Hall, Clifford

2014-01-01

Milled flaxseed was incorporated (0–20%) into a combination of bean-corn flours and extruded in a twin screw extruder using corn curl method. Physicochemical parameters such as water activity, color, expansion ratio, bulk density, lipid content, and peroxide values of extruded snack were analyzed. Scanning electron micrographs were taken. Peroxide values and propanal contents were measured over four months of storage. Rancidity scores of extruded snack were measured using a trained panel. As expected, omega-3 fatty acids and bulk density increased with increasing flaxseed fortification levels. Extrudates with more flaxseed had decreased lightness values and expansion ratios. However, only the 15 and 20% flaxseed containing extrudates had expansion ratios that were significantly (P ≤ 0.05) different from the control. In general, no significant difference (P > 0.05) in water activity values was observed in the flaxseed fortified extrudates, except in the navy-corn based extrudates. Peroxide values increased with increased flaxseed levels and over a storage period. However, propanal values did not change significantly in the 5–10% flaxseed fortified extrudates but increased in extrudates with higher levels of flaxseed. Rancidity scores were correlated with peroxide values and did not increase significantly during storage under nitrogen flushed conditions. PMID:26904633

Accumulation of hydroxyl lipids and 4-hydroxy-2-hexenal in live fish infected with fish diseases.

PubMed

Tanaka, Ryusuke; Shigeta, Kazuhiro; Sugiura, Yoshimasa; Hatate, Hideo; Matsushita, Teruo

2014-04-01

Hydroxy lipids (L-OH) and 4-hydroxy-2-hexenal (HHE) levels as well as other parameters such as lipid level, lipid class, fatty acid composition, and other aldehydes levels in the liver of diseased fish were investigated. Although significant differences in lipid level, lipid class, fatty acid composition, and other aldehyde levels were not always observed between normal and diseased fish, L-OH and HHE levels were significantly higher in the liver of the diseased fish than in that of the normal fish cultured with the same feeds under the same conditions. In the liver of puffer fish (Fugu rubripes) infected with Trichodina, L-OH and HHE levels significantly increased from 25.29±5.04 to 47.70 ± 5.27 nmol/mg lipid and from 299.79±25.25 to 1,184.40±60.27 nmol/g tissue, respectively. When the levels of HHE and other aldehydes in the liver of the normal and diseased puffer fish were plotted, a linear relationship with a high correlation coefficient was observed between HHE and propanal (r2=0.9447). Increased L-OH and HHE levels in the liver of the diseased fish and a high correlation between HHE and propanal in the liver of the normal and diseased fish were also observed in flat fish (Paralichthys olivaceus) infected with streptococcus, yellowtail (Seriola quinqueradiata) infected with jaundice, and amberjack (S. purpurascens) infected with Photobacterium damselae subsp. piscicida.

Alternative Fuels Data Center: Propane Vans Keep Kansas City Transportation

Science.gov Websites

anxiety. More recently, the company has been exploring dedicated-propane vehicles in Kansas City to ensure technologies and petroleum-use reduction strategies, then deployed bi-fuel vans; currently exploring dedicated

Alternative Fuels Data Center

Science.gov Websites

Compressed Natural Gas (CNG) and Propane Tax CNG and propane used in motor vehicles is subject to a state motor fuel tax rate of $0.26 per gasoline gallon equivalent (GGE). For taxation purposes, one GGE

Alternative Fuels Data Center: Propane Fueling Station Locations

Science.gov Websites

petroleum gas (propane) fueling stations near an address or ZIP code or along a route in the United States Location Map a Route Laws & Incentives Search Federal State Key Legislation Data & Tools Widgets

Experimental and analytical study of nitric oxide formation during combustion of propane in a jet-stirred combustor

NASA Technical Reports Server (NTRS)

Wakelyn, N. T.; Jachimowski, C. J.; Wilson, C. H.

1978-01-01

A jet-stirred combustor, constructed of castable zirconia and with an Inconel injector, was used to study nitric oxide formation in propane-air combustion with residence times in the range from 3.2 to 3.3 msec and equivalence ratios varying from 0.7 to 1.4. Measurements were made of combustor operating temperature and of nitric oxide concentration. Maximum nitric oxide concentrations of the order of 55 ppm were found in the range of equivalence ratio from 1.0 to 1.1. A finite-rate chemical kinetic mechanism for propane combustion and nitric oxide formation was assembled by coupling an existing propane oxidation mechanism with the Zeldovich reactions and reactions of molecular nitrogen with hydrocarbon fragments. Analytical studies using this mechanism in a computer simulation of the experimental conditions revealed that the hydrocarbon-fragment-nitrogen reactions play a significant role in nitric oxide formation during fuel-rich combustion.

Propane-Fueled Jet Engine

NASA Astrophysics Data System (ADS)

Farwell, D. A.; Svenson, A. J.; Ramsier, R. D.

2001-04-01

We present our recent efforts to design, construct, and test a gas turbine, or jet, engine. Our design utilizes a turbocharger and ignition system from an automobile, and a flame tube/reaction chamber unit fabricated by hand from stainless steel. Once the engine is running, it is completely self-sustaining as long as there is a fuel supply, which in our case is propane. Air is forced into the intake where it is compressed and then injected into the combustion chamber where it is mixed with propane. The spark plugs ignite the air-propane mixture which burns to produce thrust at the exhaust. We have performed operational tests under different environmental conditions and with several turbochargers. We are currently working on adding a lubrication system to the engine, and will discuss our plan to experiment with the reaction chamber and flame tube design in an effort to improve performance and efficiency. *Corresponding author: rex@uakron.edu

Number 2 heating oil/propane program. Final report, 1991/92

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

McBrien, J.

1992-06-01

During the 1991--92 heating season, the Massachusetts Division of Energy Resources (DOER) participated in a joint data collection program between several state energy offices and the federal Department of Energy`s (DOE) Energy Information Administration (EIA). The purpose of the program was to collect and monitor retail and wholesale heating oil and propane prices and inventories from October, 1991 through March, 1992. This final report begins with an overview of the unique events which had an impact on the reporting period. Next, the report summarizes the results from the residential heating oil and propane price surveys conducted by DOER over themore » 1991--1992 heating season. The report also incorporates the wholesale heating oil and propane prices and inventories collected by the EIA and distributed to the states. Finally, the report outlines DOER`s use of the data and responses to the events which unfolded during the 1991--1992 heating season.« less

Alternative Fuels Data Center: Illinois Transportation Data for Alternative

Science.gov Websites

Version More Illinois Videos on YouTube Video thumbnail for Alpha Baking Company Augments Its Fleet With Propane Delivery Trucks Alpha Baking Company Augments Its Fleet With Propane Delivery Trucks Nov. 2, 2013

75 FR 14131 - Effect on Propane Consumers of the Propane Education and Research Council's Operations, Market...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

... Education and Research Council (PERC), in conjunction with the cumulative effects of market changes and... the Secretary of Energy a report examining whether operation of the Council, in conjunction with the...

Developing synthesis techniques for zeolitic-imidazolate framework membranes for high resolution propylene/propane separation

NASA Astrophysics Data System (ADS)

Kwon, Hyuk Taek

Propylene/propane separation is one of the most challenging separations, currently achieved by energy-intensive cryogenic distillation. Despite the great potentials for energy-efficient membrane-based propylene/propane separation processes, no commercial membranes are available due to the limitations (i.e., low selectivity) of current polymeric materials. Zeolitic imidazolate frameworks (ZIFs) are promising membrane materials primarily due to their well-defined ultra-micropores with controllable surface chemistry along with their relatively high thermal/chemical stabilities. In particular, ZIF-8 with the effective aperture size of ~ 4.0 A has been shown very promising for propylene/propane separation. Despite the extensive research on ZIF-8 membranes, only a few of ZIF-8 membranes have displayed good propylene/propane separation performances presumably due to the challenges of controlling the microstructures of polycrystalline membranes. Since the membrane microstructures are greatly influenced by processing techniques, it is critically important to develop new techniques. In this dissertation, three state-of-the-art ZIF membrane synthesis techniques are developed. The first is a one-step in-situ synthesis technique based on the concept of counter diffusion. The technique enabled us to obtain highly propylene selective ZIF-8 membranes in less than a couple of hours with exceptional mechanical strength. Most importantly, due to the nature of the counter-diffusion concept, the new method offered unique opportunities such as healing defective membranes (i.e., poorly-intergrown) as well as significantly reducing the consumption of costly ligands and organic solvents. The second is a microwave-assisted seeding technique. Using this new seeding technique, we were able to prepare seeded supports with a high packing density in a couple of minutes, which subsequently grown into highly propylene-selective ZIF-8 membranes with an average propylene/propane selectivity of ~40. The last is a heteroepitaxial growth technique. The first well-intergrown membranes of ZIF-67 (Co-substituted ZIF-8) by heteroepitaxially growing ZIF-67 on ZIF-8 seed layers were reported. The ZIF-67 membranes exhibited impressively high propylene/propane separation capabilities. The presence of a methanol co-solvent in the growth solution was critically important to reproducibly prepare high quality ZIF-67 membranes. Furthermore, when the tertiary growth of ZIF-8 layers was applied to the ZIF-67 membranes, the membranes exhibited unprecedentedly high propylene/propane separation factors of ~ 200 possibly due to enhanced grain boundary structure.

PROPANE BUBBLE CHAMBER (in Italian)

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

Loria, A.; Mittner, P.; Scotoni, I.

1959-03-01

A propane bubble chamber of about two liters volume is described: details concerning the membrane expansion mechanism, the structure of the windows and the illuminating system are given. Some features of the use of it, recently made at the CERN synchrocyclotron, are indicated. (auth)

40 CFR 721.8140 - Substituted propane (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

....8140 Section 721.8140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.8140 Substituted propane (generic). (a) Chemical substance and significant new uses subject...

Alternative Fuels Data Center: Clean Cities Helps the National Mall Cut

Science.gov Websites

Transit Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a Yellowstone National Park Commits to Alternative Fuels Oct. 16, 2010 Propane Buses Save Money for Virginia

PHYSICAL PROPERTIES OF FLUORINATED PROPANE AND BUTANE DERIVATIVES AS ALTERNATIVE REFRIGERANTS

EPA Science Inventory

Physical property measurements are presented for 24 fluorinated propane and butane derivatives and one fluorinated ether. These measurements include melting point, boiling point, vapor pressure below the boiling point, heat of vaporization at the boiling point, critical propertie...

Anaerobic degradation of propane and butane by sulfate-reducing bacteria enriched from marine hydrocarbon cold seeps.

PubMed

Jaekel, Ulrike; Musat, Niculina; Adam, Birgit; Kuypers, Marcel; Grundmann, Olav; Musat, Florin

2013-05-01

The short-chain, non-methane hydrocarbons propane and butane can contribute significantly to the carbon and sulfur cycles in marine environments affected by oil or natural gas seepage. In the present study, we enriched and identified novel propane and butane-degrading sulfate reducers from marine oil and gas cold seeps in the Gulf of Mexico and Hydrate Ridge. The enrichment cultures obtained were able to degrade simultaneously propane and butane, but not other gaseous alkanes. They were cold-adapted, showing highest sulfate-reduction rates between 16 and 20 °C. Analysis of 16S rRNA gene libraries, followed by whole-cell hybridizations with sequence-specific oligonucleotide probes showed that each enrichment culture was dominated by a unique phylotype affiliated with the Desulfosarcina-Desulfococcus cluster within the Deltaproteobacteria. These phylotypes formed a distinct phylogenetic cluster of propane and butane degraders, including sequences from environments associated with hydrocarbon seeps. Incubations with (13)C-labeled substrates, hybridizations with sequence-specific probes and nanoSIMS analyses showed that cells of the dominant phylotypes were the first to become enriched in (13)C, demonstrating that they were directly involved in hydrocarbon degradation. Furthermore, using the nanoSIMS data, carbon assimilation rates were calculated for the dominant cells in each enrichment culture.

Study of the potential for improving the economics of hydrogen liquefaction through the use of centrifugal compressors and the addition of a heavy water plant

NASA Technical Reports Server (NTRS)

Baker, C. R.

1977-01-01

An approach to the liquefaction of hydrogen was developed which permits the application of standard centrifugal compressors in place of reciprocating machines. A second fluid, such as propane, is added to the hydrogen prior to compression to form a mixture having a molecular weight much greater than that of hydrogen alone, so that a standard centrifugal compressor can be used. After compression, the mixture is cooled to cryogenic temperature levels where the propane condenses out of the mixture and is separated as a liquid. Since a small amount of deuterium is produced during hydrogen liquefaction, the potential of recovering deuterium and selling it as a co-product was investigated. Deuterium, in the form of heavy water, can be used in certain nuclear reactors as a neutron moderator to reduce the neutron velocity and enhance the probability of neutron collision with uranium nucleii.

Assessment of the effect of gaseous fuel delivery mode on thermal efficiency and fuel losses during the valve overlap period in a dual-fuel compression ignition engine

NASA Astrophysics Data System (ADS)

Skrzek, T.

2016-09-01

The paper describes the effect of dual fuelling of single cylinder AVL test CI engine with the use of two ways of gas delivery to the engine manifold. The engine was fuelled diesel oil and propane. For all the tests, gas consumption was maintained at the same level. In the first mode the gas was delivered by injector located under inlet valve. In the second method, there was used a mixer fitted to the intake manifold. The paper compares the results of thermal efficiency and emissions of propane in the exhaust for both fuelling modes. Research clearly show how important it is to synchronize the injector opening time of the intake stroke. This is especially important for supercharged engines in which there is a valve overlap.

Exhaust gas measurements in a propane fueled swirl stabilized combustor

NASA Technical Reports Server (NTRS)

Aanad, M. S.

1982-01-01

Exhaust gas temperature, velocity, and composition are measured and combustor efficiencies are calculated in a lean premixed swirl stabilized laboratory combustor. The radial profiles of the data between the co- and the counter swirl cases show significant differences. Co-swirl cases show evidence of poor turbulent mixing across the combustor in comparison to the counter-swirl cases. NO sub x levels are low in the combustor but substantial amounts of CO are present. Combustion efficiencies are low and surprisingly constant with varying outer swirl in contradiction to previous results under a slightly different inner swirl condition. This difference in the efficiency trends is expected to be a result of the high sensitivity of the combustor to changes in the inner swirl. Combustor operation is found to be the same for propane and methane fuels. A mechanism is proposed to explain the combustor operation and a few important characteristics determining combustor efficiency are identified.

Cu-Doped ZnO Thin Films Deposited by a Sol-Gel Process Using Two Copper Precursors: Gas-Sensing Performance in a Propane Atmosphere

PubMed Central

Gómez-Pozos, Heberto; Arredondo, Emma Julia Luna; Maldonado Álvarez, Arturo; Biswal, Rajesh; Kudriavtsev, Yuriy; Pérez, Jaime Vega; Casallas-Moreno, Yenny Lucero; Olvera Amador, María de la Luz

2016-01-01

A study on the propane gas-sensing properties of Cu-doped ZnO thin films is presented in this work. The films were deposited on glass substrates by sol-gel and dip coating methods, using zinc acetate as a zinc precursor, copper acetate and copper chloride as precursors for doping. For higher sensitivity values, two film thickness values are controlled by the six and eight dippings, whereas for doping, three dippings were used, irrespective of the Cu precursor. The film structure was analyzed by X-ray diffractometry, and the analysis of the surface morphology and film composition was made through scanning electron microscopy (SEM) and secondary ion mass spectroscopy (SIMS), respectively. The sensing properties of Cu-doped ZnO thin films were then characterized in a propane atmosphere, C3H8, at different concentration levels and different operation temperatures of 100, 200 and 300 °C. Cu-doped ZnO films doped with copper chloride presented the highest sensitivity of approximately 6 × 104, confirming a strong dependence on the dopant precursor type. The results obtained in this work show that the use of Cu as a dopant in ZnO films processed by sol-gel produces excellent catalysts for sensing C3H8 gas. PMID:28787885

Metal–organic framework supported cobalt catalysts for the oxidative dehydrogenation of propane at low temperature

DOE PAGES

Li, Zhanyong; Peters, Aaron W.; Bernales, Varinia; ...

2016-11-30

Here, Zr-based metal–organic frameworks (MOFs) have been shown to be excellent catalyst supports in heterogeneous catalysis due to their exceptional stability. Additionally, their crystalline nature affords the opportunity for molecular level characterization of both the support and the catalytically active site, facilitating mechanistic investigations of the catalytic process. We describe herein the installation of Co(II) ions to the Zr 6 nodes of the mesoporous MOF, NU-1000, via two distinct routes, namely, solvothermal deposition in a MOF (SIM) and atomic layer deposition in a MOF (AIM), denoted as Co-SIM+NU-1000 and Co-AIM+NU-1000, respectively. The location of the deposited Co species in themore » two materials is determined via difference envelope density (DED) analysis. Upon activation in a flow of O 2 at 230 °C, both materials catalyze the oxidative dehydrogenation (ODH) of propane to propene under mild conditions. Catalytic activity as well as propene selectivity of these two catalysts, however, is different under the same experimental conditions due to differences in the Co species generated in these two materials upon activation as observed by in situ X-ray absorption spectroscopy. A potential reaction mechanism for the propane ODH process catalyzed by Co-SIM+NU-1000 is proposed, yielding a low activation energy barrier which is in accord with the observed catalytic activity at low temperature.« less

Future perspectives of using hollow fibers as structured packings in light hydrocarbon distillation

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

Yang, Dali; Orler, Bruce; Tornga, Stephanie

2011-01-26

Olefin and paraffin are the largest chemical commodities. Furthermore, they are major building blocks for the petrochemical industry. Each year, petroleum refining, consumes 4,500 TBtu/yr in separation energy, making it one of the most energy-intensive industries in the United States). Just considering liquefied petroleum gas (ethane/propane/butane) and olefins (ethylene and propylene) alone, the distillation energy consumption is about 400 TBtu/yr in the US. Since petroleum distillation is a mature technology, incremental improvements in column/tray design will only provide a few percent improvements in the performance. However, each percent saving in net energy use amounts to savings of 10 TBtu/yr andmore » reduces CO{sub 2} emissions by 0.2 MTon/yr. In practice, distillation columns require 100 to 200 trays to achieve the desired separation. The height of a transfer unit (HTU) of conventional packings is typical in the range of 36-60 inch. Since 2006, we had explored using several non-selective membranes as the structured packings to replace the conventional packing materials used in propane and propylene distillation. We obtained the lowest HTU of < 8 inch for the hollow fiber column, which was >5 times shorter than that of the conventional packing materials. In 2008, we also investigated this type of packing materials in iso-/n-butane distillation. Because of a slightly larger relative volatility of iso-/n-butane than that of propane/propylene, a wider and a more stable operational range was obtained for the iso-/n-butane pair. However, all of the experiments were conducted on a small scale with flowrate of < 25 gram/min. Recently, we demonstrated this technology on a larger scale (<250 gram/min). Within the loading range of F-factor < 2.2 Pa{sup 0.5}, a pressure drop on the vapor side is below 50 mbar/m, which suggests that the pressure drop of hollow fibers packings is not an engineering barrier for the applications in distillations. The thermal stability study suggests that polypropylene hollow fibers are stable after a long time exposure to C{sub 2} - C{sub 4} mixtures. The effects of packing density on the separation efficiency will be discussed.« less

Theoretical insights into the sites and mechanisms for base catalyzed esterification and aldol condensation reactions over Cu.

PubMed

Neurock, Matthew; Tao, Zhiyuan; Chemburkar, Ashwin; Hibbitts, David D; Iglesia, Enrique

2017-04-28

Condensation and esterification are important catalytic routes in the conversion of polyols and oxygenates derived from biomass to fuels and chemical intermediates. Previous experimental studies show that alkanal, alkanol and hydrogen mixtures equilibrate over Cu/SiO 2 and form surface alkoxides and alkanals that subsequently promote condensation and esterification reactions. First-principle density functional theory (DFT) calculations were carried out herein to elucidate the elementary paths and the corresponding energetics for the interconversion of propanal + H 2 to propanol and the subsequent C-C and C-O bond formation paths involved in aldol condensation and esterification of these mixtures over model Cu surfaces. Propanal and hydrogen readily equilibrate with propanol via C-H and O-H addition steps to form surface propoxide intermediates and equilibrated propanal/propanol mixtures. Surface propoxides readily form via low energy paths involving a hydrogen addition to the electrophilic carbon center of the carbonyl of propanal or via a proton transfer from an adsorbed propanol to a vicinal propanal. The resulting propoxide withdraws electron density from the surface and behaves as a base catalyzing the activation of propanal and subsequent esterification and condensation reactions. These basic propoxides can readily abstract the acidic C α -H of propanal to produce the CH 3 CH (-) CH 2 O* enolate, thus initiating aldol condensation. The enolate can subsequently react with a second adsorbed propanal to form a C-C bond and a β-alkoxide alkanal intermediate. The β-alkoxide alkanal can subsequently undergo facile hydride transfer to form the 2-formyl-3-pentanone intermediate that decarbonylates to give the 3-pentanone product. Cu is unique in that it rapidly catalyzes the decarbonylation of the C 2n intermediates to form C 2n-1 3-pentanone as the major product with very small yields of C 2n products. This is likely due to the absence of Brønsted acid sites, present on metal oxide catalysts, that rapidly catalyze dehydration of the hemiacetal or hemiacetalate over decarbonylation. The basic surface propoxide that forms on Cu can also attack the carbonyl of a surface propanal to form propyl propionate. Theoretical results indicate that the rates for both aldol condensation and esterification are controlled by reactions between surface propoxide and propanal intermediates. In the condensation reaction, the alkoxide abstracts the weakly acidic hydrogen of the C α -H of the adsorbed alkanal to form the surface enolate whereas in the esterification reaction the alkoxide nucleophilically attacks the carbonyl group of a vicinal bound alkanal. As both condensation and esterification involve reactions between the same two species in the rate-limiting step, they result in the same rate expression which is consistent with experimental results. The theoretical results indicate that the barriers between condensation and esterification are within 3 kJ mol -1 of one another with esterification being slightly more favored. Experimental results also report small differences in the activation barriers but suggest that condensation is slightly preferred.

THERMODYNAMIC EVALUATION OF FLUORINATED ETHERS, ETHANES, AND PROPANES AS ALTERNATIVE REFRIGERANTS

EPA Science Inventory

The visuals, part of a thermodynamic evaluation of fluorinated ethers, ethanes, and propanes as alternative refrigerants, are a useful tool in comparing new chemicals to existing refrigerants in vapor compression cycles. hey present the required suction superheat and the performa...

Alternative Fuels Data Center: Kansas Transportation Data for Alternative

Science.gov Websites

Renzenberger Inc Saves Money With Propane Vans Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Save Money Natural Gas School Buses Help Kansas City Save Money Nov. 12, 2011 https://www.youtube.com

Phytochemical profile, antioxidant and antimicrobial activity of extracts obtained from erva-mate (Ilex paraguariensis) fruit using compressed propane and supercritical CO2.

PubMed

Fernandes, Ciro E F; Scapinello, Jaqueline; Bohn, Aline; Boligon, Aline A; Athayde, Margareth L; Magro, Jacir Dall; Palliga, Marshall; Oliveira, J Vladimir; Tres, Marcus V

2017-01-01

Traditionally, Ilex paraguariensis leaves are consumed in tea form or as typical drinks like mate and terere, while the fruits are discarded processing and has no commercial value. The aim of this work to evaluate phytochemical properties, total phenolic compounds, antioxidant and antimicrobial activity of extracts of Ilex paraguariensis fruits obtained from supercritical CO 2 and compressed propane extraction. The extraction with compressed propane yielded 2.72 wt%, whereas with supercritical CO 2 1.51 wt% was obtained. The compound extracted in larger amount by the two extraction solvents was caffeine, 163.28 and 54.17 mg/g by supercritical CO 2 and pressurized propane, respectively. The antioxidant activity was more pronounced for the supercritical CO 2 extract, with no difference found in terms of minimum inhibitory concentration for Staphylococcus aureus for the two extracts and better results observed for Escherichia coli when using supercritical CO 2 .

An experimental study of adsorption interference in binary mixtures flowing through activated carbon

NASA Technical Reports Server (NTRS)

Madey, R.; Photinos, P. J.

1983-01-01

The isothermal transmission through activated carbon adsorber beds at 25 C of acetaldehyde-propane and acetylene-ethane mixtures in a helium carrier gas was measured. The inlet concentration of each component was in the range between 10 ppm and 500 ppm. The constant inlet volumetric flow rate was controlled at 200 cc (STP)/min in the acetaldehyde-propane experiments and at 50 cc (STP)/min in the acetaldehyde-ethane experiments. Comparison of experimental results with the corresponding single-component experiments under similar conditions reveals interference phenomena between the components of the mixtures as evidenced by changes in both the adsorption capacity and the dispersion number. Propane was found to displace acetaldehyde from the adsorbed state. The outlet concentration profiles of propane in the binary mixtures tend to become more diffuse than the corresponding concentration profiles of the one-component experiments. Similar features were observed with mixtures of acetylene and ethane; however, the displacement of acetylene by ethane is less pronounced.

Millimeter and submillimeter wave spectroscopy of propanal

NASA Astrophysics Data System (ADS)

Zingsheim, Oliver; Müller, Holger S. P.; Lewen, Frank; Jørgensen, Jes K.; Schlemmer, Stephan

2017-12-01

The rotational spectra of the two stable conformers syn- and gauche-propanal (CH3CH2CHO) were studied in the millimeter and submillimeter wave regions from 75 to 500 GHz with the Cologne (Sub-)Millimeter wave Spectrometer. Furthermore, the first excited states associated with the aldehyde torsion and with the methyl torsion, respectively, of the syn-conformer were analyzed. The newly obtained spectroscopic parameters yield better predictions, thus fulfill sensitivity and resolution requirements in new astronomical observations in order to unambiguously assign pure rotational transitions of propanal. This is demonstrated on a radio astronomical spectrum from the Atacama Large Millimeter/submillimeter Array Protostellar Interferometric Line Survey (ALMA-PILS). In particular, an accurate description of observed splittings, caused by internal rotation of the methyl group in the syn-conformer and by tunneling rotation interaction from two stable degenerate gauche-conformers, is reported. The rotational spectrum of propanal is of additional interest because of its two large amplitude motions pertaining to the methyl and the aldehyde group, respectively.

Camping Burner-Based Flame Emission Spectrometer for Classroom Demonstrations

ERIC Educational Resources Information Center

Ne´el, Bastien; Crespo, Gasto´n A.; Perret, Didier; Cherubini, Thomas; Bakker, Eric

2014-01-01

A flame emission spectrometer was built in-house for the purpose of introducing this analytical technique to students at the high school level. The aqueous sample is sprayed through a homemade nebulizer into the air inlet of a consumer-grade propane camping burner. The resulting flame is analyzed by a commercial array spectrometer for the visible…

Alternative Fuels for Washington's School Buses: A Report to the Washington State Legislature.

ERIC Educational Resources Information Center

Lyons, John Kim; McCoy, Gilbert A.

This document presents findings of a study that evaluated the use of both propane and compressed natural gas as alternative fuels for Washington State school buses. It discusses air quality improvement actions by state- and federal-level regulators and summarizes vehicle design, development, and commercialization activities by all major engine,…

Complex chemical composition of colored surface films formed from reactions of propanal in sulfuric acid at upper troposphere/lower stratosphere aerosol acidities.

PubMed

Van Wyngarden, A L; Pérez-Montaño, S; Bui, J V H; Li, E S W; Nelson, T E; Ha, K T; Leong, L; Iraci, L T

Particles in the upper troposphere and lower stratosphere (UT/LS) consist mostly of concentrated sulfuric acid (40-80 wt %) in water. However, airborne measurements have shown that these particles also contain a significant fraction of organic compounds of unknown chemical composition. Acid-catalyzed reactions of carbonyl species are believed to be responsible for significant transfer of gas phase organic species into tropospheric aerosols and are potentially more important at the high acidities characteristic of UT/LS particles. In this study, experiments combining sulfuric acid (H 2 SO 4 ) with propanal and with mixtures of propanal with glyoxal and/or methylglyoxal at acidities typical of UT/LS aerosols produced highly colored surface films (and solutions) that may have implications for aerosol properties. In order to identify the chemical processes responsible for the formation of the surface films, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and 1 H nuclear magnetic resonance (NMR) spectroscopies were used to analyze the chemical composition of the films. Films formed from propanal were a complex mixture of aldol condensation products, acetals and propanal itself. The major aldol condensation products were the dimer (2-methyl-2-pentenal) and 1,3,5-trimethylbenzene that was formed by cyclization of the linear aldol condensation trimer. Additionally, the strong visible absorption of the films indicates that higher-order aldol condensation products must also be present as minor species. The major acetal species were 2,4,6-triethyl-1,3,5-trioxane and longer-chain linear polyacetals which are likely to separate from the aqueous phase. Films formed on mixtures of propanal with glyoxal and/or methylglyoxal also showed evidence of products of cross-reactions. Since cross-reactions would be more likely than self-reactions under atmospheric conditions, similar reactions of aldehydes like propanal with common aerosol organic species like glyoxal and methylglyoxal have the potential to produce significant organic aerosol mass and therefore could potentially impact chemical, optical and/or cloud-forming properties of aerosols, especially if the products partition to the aerosol surface.

Complex chemical composition of colored surface films formed from reactions of propanal in sulfuric acid at upper troposphere/lower stratosphere aerosol acidities

PubMed Central

Van Wyngarden, A. L.; Pérez-Montaño, S.; Bui, J. V. H.; Li, E. S. W.; Nelson, T. E.; Ha, K. T.; Leong, L.; Iraci, L. T.

2016-01-01

Particles in the upper troposphere and lower stratosphere (UT/LS) consist mostly of concentrated sulfuric acid (40–80 wt %) in water. However, airborne measurements have shown that these particles also contain a significant fraction of organic compounds of unknown chemical composition. Acid-catalyzed reactions of carbonyl species are believed to be responsible for significant transfer of gas phase organic species into tropospheric aerosols and are potentially more important at the high acidities characteristic of UT/LS particles. In this study, experiments combining sulfuric acid (H2SO4) with propanal and with mixtures of propanal with glyoxal and/or methylglyoxal at acidities typical of UT/LS aerosols produced highly colored surface films (and solutions) that may have implications for aerosol properties. In order to identify the chemical processes responsible for the formation of the surface films, attenuated total reflectance–Fourier transform infrared (ATR-FTIR) and 1H nuclear magnetic resonance (NMR) spectroscopies were used to analyze the chemical composition of the films. Films formed from propanal were a complex mixture of aldol condensation products, acetals and propanal itself. The major aldol condensation products were the dimer (2-methyl-2-pentenal) and 1,3,5-trimethylbenzene that was formed by cyclization of the linear aldol condensation trimer. Additionally, the strong visible absorption of the films indicates that higher-order aldol condensation products must also be present as minor species. The major acetal species were 2,4,6-triethyl-1,3,5-trioxane and longer-chain linear polyacetals which are likely to separate from the aqueous phase. Films formed on mixtures of propanal with glyoxal and/or methylglyoxal also showed evidence of products of cross-reactions. Since cross-reactions would be more likely than self-reactions under atmospheric conditions, similar reactions of aldehydes like propanal with common aerosol organic species like glyoxal and methylglyoxal have the potential to produce significant organic aerosol mass and therefore could potentially impact chemical, optical and/or cloud-forming properties of aerosols, especially if the products partition to the aerosol surface. PMID:27212937

21 CFR 184.1655 - Propane.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Propane. 184.1655 Section 184.1655 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific...

Characterization of Emissions from Liquid Fuel and Propane Open Burns

EPA Science Inventory

The comparative combustion emissions of using jet propellant (JP-5) liquid fuel pools or a propane manifold grid to simulate the effects of accidental fires was investigated. A helium-filled tethered aerostat was used to maneuver an instrument package into the open fire plumes ...

Alternative Fuels Data Center: Virginia Transportation Data for Alternative

Science.gov Websites

://www.youtube.com/embed/1S7JJHQpc1w Video thumbnail for Propane Buses Save Money for Virginia Schools Propane Buses Save Money for Virginia Schools Feb. 25, 2010 https://www.youtube.com/embed/enxaQ_QooWE Chart Data

Alternative Fuels Data Center

Science.gov Websites

), propane, electricity, and renewable diesel. For taxation purposes, one GGE of CNG is equal to 5.66 pounds (lbs.), one DGE of LNG is equal to 6.06 lbs., one GGE of propane is equal to 1.35 gallons, and one GGE

Alternative Fuels Data Center

Science.gov Websites

Natural Gas and Propane Vehicle Grant Program The Tennessee Department of Environment and Conservation's Office of Energy Programs administers the Natural Gas and Propane Vehicle Grant Program (Program and must intend to operate vehicles in Tennessee for a minimum of six years. Grant applications are

RETENTION OF HALOCARBONS ON A HEXAFLUOROPROPYLENE EPOXIDE-MODIFIED GRAPHITIZED CARBON BLACK - IV. PROPANE- BASED COMPOUNDS

EPA Science Inventory

The retention characteristics of 25 propane-based bromofluorocarbon, chlorocarbon, chlorofluorocarbon, and fluorocarbon fluids have been studied as a function of temperature on a stationary phase consisting of a 5% (m/m) coating of a low-molecular-mass polymer of hexafluoropropyl...

Numerical study of influences of crosswind and additional steam on the flow field and temperature of propane non-premixed turbulence flame

NASA Astrophysics Data System (ADS)

Wusnah; Bindar, Y.; Yunardi; Nur, F. M.; Syam, A. M.

2018-03-01

This paper presents results the process of combustion propane using computational fluid dynamics (CFD) to simulate the turbulent non-premixed flame under the influences of crosswinds and the ratio of fuel (propane) to steam, S. Configuration, discretization and boundary conditions of the flame are described using GambitTM software and integrated with FluentTM software for calculations of flow and reactive fields. This work focuses on the influence of various crosswind speeds (0–10 m/s) and values of S (0.14–2.35) while the velocity of fuel issued from the nozzle was kept constant at 20 m/s. A turbulence model, k-ɛ standard and combustion model, Eddy Dissipation model were employed for the calculation of velocity and temperature fields, respectively. The results are displayed in the form of predictive terrain profile of the propane flame at different crosswind speeds. The results of the propane flame profile demonstrated that the crosswind significantly affect the structure velocity and position of the flame which was off-center moving towards the direction of crosswind, eventually affect the temperature along the flame. As the values of S is increasing, the flame contour temperature decreases, until the flame was extinguished at S equals to 2.35. The combustion efficiency for a variety of crosswind speeds decreases with increasing values of S.

Pd-Ag Membrane Coupled to a Two-Zone Fluidized Bed Reactor (TZFBR) for Propane Dehydrogenation on a Pt-Sn/MgAl2O4 Catalyst

PubMed Central

Medrano, José-Antonio; Julián, Ignacio; Herguido, Javier; Menéndez, Miguel

2013-01-01

Several reactor configurations have been tested for catalytic propane dehydrogenation employing Pt-Sn/MgAl2O4 as a catalyst. Pd-Ag alloy membranes coupled to the multifunctional Two-Zone Fluidized Bed Reactor (TZFBR) provide an improvement in propane conversion by hydrogen removal from the reaction bed through the inorganic membrane in addition to in situ catalyst regeneration. Twofold process intensification is thereby achieved when compared to the use of traditional fluidized bed reactors (FBR), where coke formation and thermodynamic equilibrium represent important process limitations. Experiments were carried out at 500–575 °C and with catalyst mass to molar flow of fed propane ratios between 15.1 and 35.2 g min mmol−1, employing three different reactor configurations: FBR, TZFBR and TZFBR + Membrane (TZFBR + MB). The results in the FBR showed catalyst deactivation, which was faster at high temperatures. In contrast, by employing the TZFBR with the optimum regenerative agent flow (diluted oxygen), the process activity was sustained throughout the time on stream. The TZFBR + MB showed promising results in catalytic propane dehydrogenation, displacing the reaction towards higher propylene production and giving the best results among the different reactor configurations studied. Furthermore, the results obtained in this study were better than those reported on conventional reactors. PMID:24958620

Bio-Oil Separation and Stabilization by Near-Critical Propane Fractionation

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

Ginosar, Daniel M.; Petkovic, Lucia M.; Agblevor, Foster A.

Bio-oils produced by thermal process are promising sources of sustainable, low greenhouse gas alternative fuels. These thermal processes are also well suited to decentralized energy production due to low capital and operating costs. Algae feedstocks for bio-oil production are of particular interest, due in part to their high-energy growth yields. Further, algae can be grown in non-arable areas in fresh, brackish, salt water, or even waste water. Unfortunately, bio-oils produced by thermal processes present significant stability challenges. These oils have complex chemical compositions, are viscous, reactive, and thermally unstable. Further, the components within the oils are difficult to separate bymore » fractional distillation. By far, the most effective separation and stabilization method has been solvent extraction. However, liquid phase extraction processes pose two main obstacles to commercialization; they require a significant amount of energy to remove and recover the solvent from the product, and they have a propensity for the solvent to become contaminated with minerals from the char and ash present in the original bio-oil. Separation and fractionation of thermally produced bio-oils using supercritical fluids (SCF) offers the advantages of liquid solvent extraction while drastically reducing energy demands and the predisposition to carry over solids into the extracted phase. SCFs are dense fluids with liquid-like solvent properties and gas-like transport properties. Further, SCF density and solvent strength can be tuned with minor adjustments in pressure, co-solvent addition, or gas anti-solvent addition. Catalytic pyrolysis oils were produced from Scenedesmus dimorphus algae using a fluid catalytic cracking catalyst. Bio-oil produced from catalytic fast pyrolysis (CFP) was separated using critical fluids. Propane extraction was performed at 65 °C at a fluid reduced pressure of 2.0 (85 bar) using an eight to one solvent to feed ratio by weight. Extraction of catalytic fast pyrolysis oil with near critical propane produced an oil extract that was physically and chemically different from and more stable than the original oil. The propane extract displayed lower viscosity and lower average molecular weight. The species present in the propane extract were likely the less polar that would be expected from using a non-polar solvent (propane). Carbonyl containing species in the extract were likely ketones and esters. The raffinate contained a higher amnount of OH bonded species along with the more polar more polar acids, amides, and alcohols. The higher concentration of nitrogen in the raffinate may confirm the presence of amides. Viscosity of the propane extract increased only half as much as that of the CFP bio-oil. Further, In situ NMR aging studies showed that the propane extract was more stable than the raw oil. In conclusion, propane extraction is a promising method to decrease the nitrogen content of bio-oils and to improve the stability of bio-oils obtained by the catalytic pyrolysis of algae based biomass.« less

Light absorption properties and radiative effects of primary organic aerosol emissions

DOE PAGES

Lu, Zifeng; Streets, David G.; Winijkul, Ekbordin; ...

2015-03-26

Organic aerosols (OAs) in the atmosphere affect Earth’s energy budget by not only scattering but also absorbing solar radiation due to the presence of the so-called “brown carbon” (BrC) component. However, the absorptivities of OAs are not represented or are poorly represented in current climate and chemical transport models. In this study, we provide a method to constrain the BrC absorptivity at the emission inventory level using recent laboratory and field observations. We review available measurements of the light-absorbing primary OA (POA), and quantify the wavelength-dependent imaginary refractive indices (k OA, the fundamental optical parameter determining the particle’s absorptivity) andmore » their uncertainties for the bulk POA emitted from biomass/biofuel, lignite, propane, and oil combustion sources. In particular, we parametrize the k OA of biomass/biofuel combustion sources as a function of the black carbon (BC)-to-OA ratio, indicating that the absorptive properties of POA depend strongly on burning conditions. The derived fuel-type-based k OA profiles are incorporated into a global carbonaceous aerosol emission inventory, and the integrated k OA values of sectoral and total POA emissions are presented. The results of a simple radiative transfer model show that the POA absorptivity warms the atmosphere significantly and leads to ~27% reduction in the amount of the net global average POA cooling compared to results from the nonabsorbing assumption.« less

Alternative Fuels Data Center: Minnesota School District Finds Cost

Science.gov Websites

Savings, Cold-Weather Reliability with Propane Buses Minnesota School District Finds Cost Center: Minnesota School District Finds Cost Savings, Cold-Weather Reliability with Propane Buses on Facebook Tweet about Alternative Fuels Data Center: Minnesota School District Finds Cost Savings, Cold

Alternative Fuels Data Center: Mesa Unified School District Reaps Economic

Science.gov Websites

and Environmental Benefits with Propane Buses Mesa Unified School District Reaps Economic and School District Reaps Economic and Environmental Benefits with Propane Buses on Facebook Tweet about Alternative Fuels Data Center: Mesa Unified School District Reaps Economic and Environmental Benefits with

40 CFR 721.533 - Propane, 1,1,1,3,3-pentachloro-.

Code of Federal Regulations, 2010 CFR

2010-07-01

....533 Section 721.533 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.533 Propane, 1,1,1,3,3-pentachloro-. (a) Chemical substance and significant new uses subject...

Analysis of U.S. Propane Markets Winter 1996-97, An

EIA Publications

1997-01-01

This study constitutes an examination of propane supply, demand, and price developments and trends. The Energy Information Administration's approach focused on identifying the underlying reasons for the tight supply/demand balance in the fall of 1996, and on examining the potential for a recurrence of these events next year.

Zeolitic imidazolate frameworks for kinetic separation of propane and propene

DOEpatents

Li, Jing; Li, Kunhao; Olson, David H.

2014-08-05

Zeolitic Imidazolate Frameworks (ZIFs) characterized by organic ligands consisting of imidazole ligands that are either essentially all 2-chloroimidazole ligands or essentially all 2-bromoimidazole ligands are disclosed. Methods for separating propane and propene with the ZIFs of the present invention, as well as other ZIFs, are also disclosed.

Evaluation of Propane Combustion Traps for the Collection of Phlebotomus papatasi (Scopoli) in Southern Israel

DTIC Science & Technology

2011-03-01

traps for the consumer market , which utilize the combustion of propane to produce carbon dioxide (CO2) and other attractants. While these...Z. Abramsky, B.P. Kotler , R.S. Ostfeld, I.Yarom, and A.Warburg. 2003a. Anthropogenic disturbances enhance occurrence of cutaneous

Rapid analysis of perchlorate in drinking water at parts per billion levels using microchip electrophoresis.

PubMed

Gertsch, Jana C; Noblitt, Scott D; Cropek, Donald M; Henry, Charles S

2010-05-01

A microchip capillary electrophoresis (MCE) system has been developed for the determination of perchlorate in drinking water. The United States Environmental Protection Agency (USEPA) recently proposed a health advisory limit for perchlorate in drinking water of 15 parts per billion (ppb), a level requiring large, sophisticated instrumentation, such as ion chromatography coupled with mass spectrometry (IC-MS), for detection. An inexpensive, portable system is desired for routine online monitoring applications of perchlorate in drinking water. Here, we present an MCE method using contact conductivity detection for perchlorate determination. The method has several advantages, including reduced analysis times relative to IC, inherent portability, high selectivity, and minimal sample pretreatment. Resolution of perchlorate from more abundant ions was achieved using zwitterionic, sulfobetaine surfactants, N-hexadecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (HDAPS) and N-tetradecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (TDAPS). The system performance and the optimization of the separation chemistry, including the use of these surfactants to resolve perchlorate from other anions, are discussed in this work. The system is capable of detection limits of 3.4 +/- 1.8 ppb (n = 6) in standards and 5.6 +/- 1.7 ppb (n = 6) in drinking water.

International comparison CCQM-K111—propane in nitrogen

NASA Astrophysics Data System (ADS)

van der Veen, Adriaan M. H.; Wouter van der Hout, J.; Ziel, Paul R.; Oudwater, Rutger J.; Fioravante, Andreia L.; Augusto, Cristiane R.; Coutinho Brum, Mariana; Uehara, Shinji; Akima, Dai; Bae, Hyun Kil; Kang, Namgoo; Woo, Jin-Chun; Liaskos, Christina E.; Rhoderick, George C.; Jozela, Mudalo; Tshilongo, James; Ntsasa, Napo G.; Botha, Angelique; Brewer, Paul J.; Brown, Andrew S.; Bartlett, Sam; Downey, Michael L.; Konopelko, L. A.; Kolobova, A. V.; Pankov, A. A.; Orshanskaya, A. A.; Efremova, O. V.

2017-01-01

This key comparison aims to assess the core capabilities of the participants in gas analysis. Such competences include, among others, the capabilities to prepare primary standard gas Mixtures (PSMs), perform the necessary purity analysis on the materials used in the gas mixture preparation, the verification of the composition of newly prepared PSMs against existing ones, and the capability of calibrating the composition of a gas mixture. According to the Strategy for Key Comparisons of the Gas Analysis Working Group, this key comparison is classified as a track A key comparison, which means that the results of this key comparison can be used to underpin calibration and measurement capabilities using the flexible scheme, and for propane under the default scheme. The artefacts were binary mixtures of propane in nitrogen at a nominal amount-of-substance fraction level of 1000 μmol/mol. The values and uncertainties from the gravimetric gas mixture preparation were used as key comparison reference values (KCRVs). Each transfer standard had its own KCRV. The results are generally good. All results but one are within +/- 0.2 % of the KCRV. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

International comparison CCQM-K111.1—propane in nitrogen

NASA Astrophysics Data System (ADS)

van der Veen, Adriaan M. H.; Wouter van der Hout, J.; Ziel, Paul R.; Jozela, Mudalo; Tshilongo, James; Ntsasa, Napo G.; Botha, Angelique

2017-01-01

This key comparison aims to assess the core capabilities of the participants in gas analysis. Such competences include, among others, the capability of preparing Primary Standard gas Mixtures (PSMs), performing the necessary purity analysis on the materials used in the gas mixture preparation, the verification of the composition of newly prepared PSMs against existing ones, and the capability of calibrating the composition of a gas mixture. According to the Strategy for Key Comparisons of the Gas Analysis Working Group, this subsequent key comparison is classified as a track B key comparison, which means that the results of this key comparison can be used to underpin calibration and measurement capabilities for propane under the default scheme. The artefact was a binary mixture of propane in nitrogen at a nominal amount-of-substance fraction level of 1000 μmol/mol. The values and uncertainties from the gravimetric gas mixture preparation were used as key comparison reference values (KCRVs). Each transfer standard had its own KCRV. The result of the participating laboratory is consistent with the key comparison reference value within the respective expanded uncertainties and deviates less than 0.1 %. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Unearthing a Well-Defined Highly Active Bimetallic W/Ti Precatalyst Anchored on a Single Silica Surface for Metathesis of Propane.

PubMed

Samantaray, Manoja K; Kavitake, Santosh; Morlanés, Natalia; Abou-Hamad, Edy; Hamieh, Ali; Dey, Raju; Basset, Jean-Marie

2017-03-08

Two compatible organometallic complexes, W(Me) 6 (1) and TiNp 4 (2), were successively anchored on a highly dehydroxylated single silica support (SiO 2-700 ) to synthesize the well-defined bimetallic precatalyst [(≡Si-O-)W(Me) 5 (≡Si-O-)Ti(Np) 3 ] (4). Precatalyst 4 was characterized at the molecular level using advanced surface organometallic chemistry (SOMC) characterization techniques. The strong autocorrelation observed between methyl of W and Ti in 1 H- 1 H multiple-quantum NMR spectra demonstrates that W and Ti species are in close proximity to each other. The bimetallic precatalyst 4, with a turnover number (TON) of 9784, proved to be significantly more efficient than the silica-supported monometallic catalyst [(≡Si-O-)W(Me) 5 ] (3), with a TON of 98, for propane metathesis at 150 °C in a flow reactor. The dramatic improvement in the activity signifies the cooperativity between Ti and W and indicates that the key step of alkane metathesis (C-H bond activation followed by β-H elimination) occurs on Ti, followed by olefin metathesis, which occurs on W. We have demonstrated the influence and importance of proximity of Ti to W for achieving such a significantly high activity. This is the first report demonstrating the considerably high activity (TON = 9784) in propane metathesis at moderate temperature (150 °C) using a well-defined bimetallic system prepared via the SOMC approach.

Forensic medical evaluation of deaths resulting from inhalation of cigarette lighter refill fuel in Turkey.

PubMed

Özdemir, Erdinç; Eş, Hüseyin; Demir, Muhammet; Üzün, İbrahim

2017-01-01

Voluntary inhalation/abuse of volatile substances is an important public health problem which especially affects adolescent and young populations worldwide and may be encountered in all socioeconomic and cultural levels. Lighter gas abuse-related death is still an important health problem in Turkey. In this study, 25,265 case files and final reports submitted to the Institute of Forensic Medicine of the First Specialization Board between January 2011 and December 2015 were evaluated retrospectively. In 56 of these cases, lighter gas inhalation (n-butane, propane, isobutane) was recorded as the cause of death. All subjects were male with a mean age of 16.8years. According to eyewitness and crime scene investigation reports, in 48 (85.7%) of the cases, a lighter refill container was found at the scene. It was determined that 21.4% of the cases used a plastic bag to increase the effects of lighter gas and 76.8% inhaled the lighter gas via their mouth and nose. The toxicological analysis of the samples taken while hospitalized showed no lighter refill components (n-butane, propane, isobutane) in 66% of the cases, n-butane in 32.1% of the cases, and n-butane+propane+isobutane in 1.9% of the cases. The importance of lighter gas inhalation-related deaths in Turkey has been increasing. Strict measures against the abuse of these very dangerous substances should be undertaken by the mutual efforts of medical specialists and legislators. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The toxicological properties of petroleum gases.

PubMed

McKee, Richard H; Herron, Deborah; Saperstein, Mark; Podhasky, Paula; Hoffman, Gary M; Roberts, Linda

2014-01-01

To characterize the toxicological hazards of petroleum gases, 90-day inhalation toxicity (Organization for Economic Cooperation and Development [OECD] 413) and developmental toxicity (OECD 414) tests were conducted with liquefied propane gas (LPG) at concentrations of 1000, 5000, or 10,000 ppm. A micronucleus test (OECD 474) of LPG was also conducted. No systemic or developmental effects were observed; the overall no observed adverse effect concentration (NOAEC) was 10,000 ppm. Further, there was no effect of LPG exposure at levels up to 10,000 ppm on micronucleus induction and no evidence of bone marrow toxicity. Other alkane gases (ethane, propane, n-butane, and isobutane) were then evaluated in combined repeated exposure studies with reproduction/development toxicity screening tests (OECD 422). There were no toxicologically important changes in parameters relating to systemic toxicity or neurotoxicity for any of these gases at concentrations ranging from 9000 to 16,000 ppm. There was no evidence of effects on developmental or reproductive toxicity in the studies of ethane, propane, or n-butane at the highest concentrations tested. However, there was a reduction in mating in the high-exposure group (9000 ppm) of the isobutane study, which although not significantly different was outside the range previously observed in the testing laboratory. Assuming the reduction in mating to have been toxicologically significant, the NOAEC for the isobutane reproductive toxicity screening test was 3000 ppm (7125 mg/m(3)). A method is proposed by which the toxicity of any of the 106 complex petroleum gas streams can be estimated from its composition.

Method to obtain carbon nano-onions by pyrolisys of propane

NASA Astrophysics Data System (ADS)

Garcia-Martin, Tomas; Rincon-Arevalo, Pedro; Campos-Martin, Gemma

2013-11-01

We present a new and simple method for carbon nano-onions (CNOs) production which is based on the pyrolysis of Propane. CNOs are originated in a laminar premixed Propane/Oxygen flame of approximately 1.8 of stoichiometric coefficient. The stream of gasses resulting from the combustion drives the carbon particles towards the aluminium surface on which nano-onions are deposited and collected. The structure and size of the deposited carbon onion on the metal wall are characterized by High Resolution Transmission Electron Microscopy technique (HRTEM). The experimental images show the presence of two different types of CNOs. The first particles have diameters in the range of 18-25 nm and the second ones around 10 nm.

41 CFR 102-74.280 - Are privately owned vehicles converted for propane carburetion permitted in underground parking...

Code of Federal Regulations, 2010 CFR

2010-07-01

... (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 74-FACILITY MANAGEMENT Facility Management Parking... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Are privately owned vehicles converted for propane carburetion permitted in underground parking facilities? 102-74.280 Section...

Alternative Fuels Data Center: Alternative Fuels Help Ensure America's

Science.gov Websites

key players from the start. For example, a strategic partnership with Black Bear Solar Institute led is replacing its fleet vehicles with efficient and alternative fuel vehicles. For example, in recent deploying seven propane mowers, thanks to a donation from the Propane Education & Research Council (PERC

Alternative Fuels Data Center: Propane Vehicle Emissions

Science.gov Websites

compared to conventional gasoline and diesel fuel. When used as a vehicle fuel, propane can offer life , processing, manufacturing, distribution, use, and disposal or recycling. When comparing fuels, a life cycle GREET model estimates the life cycle petroleum use and GHG emissions for multiple fuels. When this model

THE HEAT CAPACITY OF FLUORINATED PROPANE AND BUTANE DERIVATIVES BY DIFFERENTIAL SCANNING CALORIMETRY

EPA Science Inventory

The paper gives results of the measurement (to 3% accuracy) of the constant-pressure liquid-phase heat capacities of 21 hydrogen-containing fluorinated propane and butane derivatives and one fluorinated ether (CF3OCF2H) with boiling points ranging from -34.6 to 76.7 C, using diff...

APMP.QM-K111—propane in nitrogen

NASA Astrophysics Data System (ADS)

Lin, Tsai-Yin; Liu, Hsin-Wang; Huang, Chiung-Kun; Kang, Namgoo; Bae, Hyun Kil; Woo, Jin Chun; Bi, Zhe; Zhou, Zeyi; Sinweeruthai, Ratirat; Wongjuk, Arnuttachai; Li, Hou; Beng Keat, Teo; Hui, Liu; Wu, Thomas; Hock Ann, Chua; Smeulders, Damian; Briton McCallum, John; Tendai Satumba, Raymond; Shimosaka, Takuya; Matsumoto, Nobuhiro; Kadir, Haslina Abdul; Fauzi Ahmad, Mohamad; Nasir, Noor Hidaya Abdul; Nishino, Tomoe; Akima, Dai; Uehara, Shinji

2018-01-01

This document describes the result of a key comparison for propane in nitrogen. The nominal amount-of-substance fraction of propane is 1000 μmol/mol. The comparison aimed to assess the measurement capability of participants in gas analysis. Nine NMIs or DIs participated in the comparison. CERI participated in a key comparison CCQM-K111—propane in nitrogen, and coordinated this key comparison. Therefore, every participants' results of this comparison are linking to the CCQM-K111. Gravimetric values of the samples were used as key comparison reference values (KCRVs). Measured values of eight participants were within +/- 0.25 % of the KCRVs. Many participants reported purity or impurity analysis of materials. These results are also able to assess the participants' capability of the analysis. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Gas Phase UTE MRI of Propane and Propene

PubMed Central

Kovtunov, Kirill V.; Romanov, Alexey S.; Salnikov, Oleg G.; Barskiy, Danila A.; Chekmenev, Eduard Y.; Koptyug, Igor V.

2016-01-01

1H MRI of gases can potentially enable functional lung imaging to probe gas ventilation and other functions. In this work, 1H MR images of hyperpolarized and thermally polarized propane gas were obtained using UTE (ultrashort echo time) pulse sequence. A 2D image of thermally polarized propane gas with ~0.9×0.9 mm2 spatial resolution was obtained in less than 2 seconds, demonstrating that even non-hyperpolarized hydrocarbon gases can be successfully utilized for conventional proton MRI. The experiments were also performed with hyperpolarized propane gas and demonstrated acquisition of high-resolution multi-slice FLASH 2D images in ca. 510 s and non slice-selective 2D UTE MRI images in ca. 2 s. The UTE approach adopted in this study can be potentially used for medical lung imaging. Furthermore, the possibility to combine UTE with selective suppression of 1H signals from one of the two gases in a mixture is demonstrated in this MRI study. The latter can be useful for visualizing industrially important processes where several gases may be present, e.g., gas-solid catalytic reactions. PMID:27478870

Thermocatalytic Destruction of Gas-Phase Perchloroethylene Using Propane as a Hydrogen Source

PubMed Central

Willinger, Marty; Rupp, Erik; Barbaris, Brian; Gao, Song; Arnolda, Robert; Betterton, Eric; Sáez, A. Eduardo

2009-01-01

The use of propane in combination with oxygen to promote the destruction of perchloroethylene (PCE) over a platinum (Pt)/rhodium (Rh) catalyst on a cerium/zirconium oxide washcoat supported on an alumina monolith was explored. Conversions of PCE were measured in a continuous flow reactor with residence times less than 0.5 s and temperatures ranging from 200 to 600°C. The presence of propane was shown to increase significantly the conversion of PCE over oxygen-only conditions. Conversions close to 100% were observed at temperatures lower than 450°C with 20% oxygen and 2% propane in the feed, which makes this process attractive from a practical standpoint. In the absence of oxygen, PCE conversion is even higher, but the catalyst suffers significant deactivation in less than an hour. Even though results show that oxygen competes with reactants for active sites on the catalyst, the long-term stability that oxygen confers to the catalyst makes the process an efficient alternative to PCE oxidation. A Langmuir-Hinshelwood competitive adsorption model is proposed to quantify PCE conversion. PMID:19217713

Kinetics of Hydrogen Oxidation Downstream of Lean Propane and Hydrogen Flames

NASA Technical Reports Server (NTRS)

Fine, Burton

1961-01-01

The decay of hydrogen was measured downstream of lean, flat, premixed hydrogen and propane-air flames seated on cooled porous burners. Experimental variables included temperature, pressure, initial equivalence ratio and diluent. Sampling of burned gas was done through uncooled quartz orifice probes, and the analysis was based on gas chromatography. An approximate treatment of the data in which diffusion was neglected led to the following rate expression for the zone downstream of hydrogen flames d[H (sub 2)] divided by (d times t) equals 1.7 times 10 (sup 10) [H (sub 2)] (sup 3) divided by (sub 2) [O (sub 2)]e (sup (-8100 divided by RT)) moles per liters per second. On the basis of a rate expression of this form, the specific rate constant for the reaction downstream of hydrogen flames was about three times as great as that determined downstream of propane flames. This result was explained on the basis of the existence of a steady state between hydrogen and carbon monoxide in the burned gas downstream of propane flames.

Comparative assessment of local tolerance of alcohols commonly used in alcohol-based hand rubs for hand hygiene.

PubMed

Manche, Monique; Foligné, Benoît; Sauty, Mathieu; Platel, Anne; Vercauteren, Eric; Rauwel, Gaétan; Catoire, Sophie; Ficheux, Hervé; Criquelion, Jacques; Nesslany, Fabrice

2017-10-01

Hand hygiene plays a key role in nosocomial infection prevention. To achieve users' adherence, products' dermal tolerance is essential. We aimed at making a comparative assessment of skin irritation and phototoxicity of the 3 alcohols commonly used in alcohol-based hand rubs (Ethanol, Propan-2-ol, Propan-1-ol) at 60, 70, 80 or 85% w/w in water or with co-formulates (hydrating, emollient and skin protective agents). In vitro validated OECD methods 439 and 432 were used. For irritation, EpiSkin™ Small Model was the chosen Reconstructed Human Epidermis (RhE). For phototoxicity, co-formulates alone or in mixture with and without alcohol were tested using BALB/c 3T3 cell cultures. Whilst Ethanol and Propan-2-ol could not be differentiated and displayed good skin tolerance profiles, Propan-1-ol based products lead to significant viability impairments of RhE at 60, 70 or 80% and at 60% in the presence of co-formulates. However, these results could not be reproduced in another RhE model. Taking also into account bibliographic data on Propan-1-ol, this suggests that our results are probably related to a lack of specificity of the used RhE. Therefore, it can be relevant in case of significant results to use two different RhE models before performing any classification and/or performing any complementary tests. Copyright © 2017 Elsevier Ltd. All rights reserved.

Booster propulsion/vehicle impact study, 2

NASA Technical Reports Server (NTRS)

Johnson, P.; Satterthwaite, S.; Carson, C.; Schnackel, J.

1988-01-01

This is the final report in a study examining the impact of launch vehicles for various boost propulsion design options. These options included: differing boost phase engines using different combinations of fuels and coolants to include RP-1, methane, propane (subcooled and normal boiling point), and hydrogen; variable and high mixture ratio hydrogen engines; translating nozzles on boost phase engines; and cross feeding propellants from the booster to second stage. Vehicles examined included a fully reusable two stage cargo vehicle and a single stage to orbit vehicle. The use of subcooled propane as a fuel generated vehicles with the lowest total vehicle dry mass. Engines with hydrogen cooling generated only slight mass reductions from the reference, all-hydrogen vehicle. Cross feeding propellants generated the most significant mass reductions from the reference two stage vehicle. The use of high mixture ratio or variable mixture ratio hydrogen engines in the boost phase of flight resulted in vehicles with total dry mass 20 percent greater than the reference hydrogen vehicle. Translating nozzles for boost phase engines generated a heavier vehicle. Also examined were the design impacts on the vehicle and ground support subsystems when subcooled propane is used as a fuel. The most significant cost difference between facilities to handle normal boiling point versus subcooled propane is 5 million dollars. Vehicle cost differences were negligible. A significant technical challenge exists for properly conditioning the vehicle propellant on the ground and in flight when subcooled propane is used as fuel.

Engineering a Promiscuous Tautomerase into a More Efficient Aldolase for Self-Condensations of Linear Aliphatic Aldehydes.

PubMed

Rahimi, Mehran; van der Meer, Jan-Ytzen; Geertsema, Edzard M; Poelarends, Gerrit J

2017-07-18

The enzyme 4-oxalocrotonate tautomerase (4-OT) from Pseudomonas putida mt-2 takes part in a catabolic pathway for aromatic hydrocarbons, where it catalyzes the conversion of 2hydroxyhexa-2,4-dienedioate into 2-oxohexa-3-enedioate. This tautomerase can also promiscuously catalyze carbon-carbon bond-forming reactions, including various types of aldol reactions, by using its amino-terminal proline as a key catalytic residue. Here, we used systematic mutagenesis to identify two hotspots in 4-OT (Met45 and Phe50) at which single mutations give marked improvements in aldolase activity for the self-condensation of propanal. Activity screening of a focused library in which these two hotspots were varied led to the discovery of a 4-OT variant (M45Y/F50V) with strongly enhanced aldolase activity in the self-condensation of linear aliphatic aldehydes, such as acetaldehyde, propanal, and butanal, to yield α,β-unsaturated aldehydes. With both propanal and benzaldehyde, this double mutant, unlike the previously constructed single mutant F50A, mainly catalyzes the self-condensation of propanal rather than the cross-condensation of propanal and benzaldehyde, thus indicating that it indeed has altered substrate specificity. This variant could serve as a template to create new biocatalysts that lack dehydration activity and possess further enhanced aldolase activity, thus enabling the efficient enzymatic self-coupling of aliphatic aldehydes. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Position-specific 13C distributions within propane from experiments and natural gas samples

NASA Astrophysics Data System (ADS)

Piasecki, Alison; Sessions, Alex; Lawson, Michael; Ferreira, A. A.; Santos Neto, E. V.; Ellis, Geoffrey S.; Lewan, Michael D.; Eiler, John M.

2018-01-01

Site-specific carbon isotope measurements of organic compounds potentially recover information that is lost in a conventional, 'bulk' isotopic analysis. Such measurements are useful because isotopically fractionating processes may have distinct effects at different molecular sites, and thermodynamically equilibrated populations of molecules tend to concentrate heavy isotopes in one molecular site versus another. Most recent studies of site-specific 13C in organics use specialized Nuclear Magnetic Resonance (NMR) techniques or complex chemical degradations prior to mass spectrometric measurements. Herein we present the first application of a new mass spectrometric technique that reconstructs the site-specific carbon isotope composition of propane based on measurements of the 13C/12C ratios of two or more fragment ions that sample different proportions of the terminal and central carbon sites. We apply this method to propane from laboratory experiments and natural gas samples to explore the relationships between site-specific carbon isotope composition, full-molecular δ13C, thermal maturity, and variation in organic matter precursors. Our goal is to advance the understanding of the sources and histories of short-chain alkanes within geologic systems. Our findings suggest that propane varies in its site-specific carbon isotope structure, which is correlated with increasing thermal maturity, first increasing in terminal position δ13C and then increasing in both center and terminal position δ13C. This pattern is observed in both experimental and natural samples, and is plausibly explained by a combination of site-specific, temperature-dependent isotope effects associated with conversion of different precursor molecules (kerogen, bitumen, and/or oil) to propane, differences in site-specific isotopic contents of those precursors, and possibly distillation of reactive components of those precursors with increasing maturity. We hypothesize that the largest changes in site-specific isotopic content of propane occur when bitumen and/or oil replace kerogen as the dominant precursors. If correct, this phenomenon could have significant utility for understanding gas generation in thermogenic petroleum systems.

Position-specific 13C distributions within propane from experiments and natural gas samples

USGS Publications Warehouse

Piasecki, Alison; Sessions, Alex L.; Lawson, Michael; Ferreira, A.A.; Santos Neto, E. V.; Ellis, Geoffrey S.; Lewan, Michael; Eilers, J.M.

2018-01-01

Site-specific carbon isotope measurements of organic compounds potentially recover information that is lost in a conventional, ‘bulk’ isotopic analysis. Such measurements are useful because isotopically fractionating processes may have distinct effects at different molecular sites, and thermodynamically equilibrated populations of molecules tend to concentrate heavy isotopes in one molecular site versus another. Most recent studies of site-specific 13C in organics use specialized Nuclear Magnetic Resonance (NMR) techniques or complex chemical degradations prior to mass spectrometric measurements. Herein we present the first application of a new mass spectrometric technique that reconstructs the site-specific carbon isotope composition of propane based on measurements of the 13C/12C ratios of two or more fragment ions that sample different proportions of the terminal and central carbon sites. We apply this method to propane from laboratory experiments and natural gas samples to explore the relationships between site-specific carbon isotope composition, full-molecular δ13C, thermal maturity, and variation in organic matter precursors. Our goal is to advance the understanding of the sources and histories of short-chain alkanes within geologic systems. Our findings suggest that propane varies in its site-specific carbon isotope structure, which is correlated with increasing thermal maturity, first increasing in terminal position δ13C and then increasing in both center and terminal position δ13C. This pattern is observed in both experimental and natural samples, and is plausibly explained by a combination of site-specific, temperature-dependent isotope effects associated with conversion of different precursor molecules (kerogen, bitumen, and/or oil) to propane, differences in site-specific isotopic contents of those precursors, and possibly distillation of reactive components of those precursors with increasing maturity. We hypothesize that the largest changes in site-specific isotopic content of propane occur when bitumen and/or oil replace kerogen as the dominant precursors. If correct, this phenomenon could have significant utility for understanding gas generation in thermogenic petroleum systems.

Energetic Level Scheme of the Stable S=-2 Dihyperon

NASA Astrophysics Data System (ADS)

Aslanyan, P. Z.; Shahbazian, B. A.

2001-11-01

The quark and soliton Skyrme-type models predict the two different sets of S=-2 stable dibaryon states. The lowest state of the quark model set is an I=0, Jπ = 0+, MH0 < 2MΛ isosinglet dibaryon, whereas that of solyton Skyrme-type model set is an I=1,Jπ = 0, MH-,H0,H+ ≈ 2370 MeV/c2 isotriplet dibaryon. On photographs of the JINR LHE 2m propane bubble chamber exposed to 10 GeV/c proton beam two groups of events interpreted as S=-2 stable dibaryons were observed [1-7]. Quasi-diffractive process plays the decisive role in dihyperon production. The average life for weak decay of stable dihyperons exceeds 3.3 10-10 s. Several Ξ- hyperons have been registrated in these collisions with an effective cross section of 1300-600 nb. The formally estimated effective cross section for H dibaryon production in propane at a momentum of 10 GeV/c is 100 nb.

Case Study - Propane Bakery Delivery Step Vans

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

Laughlin, M.; Burnham, A.

2016-04-01

A switch to propane from diesel by a major Midwest bakery fleet showed promising results, including a significant displacement of petroleum, a drop in greenhouse gases and a fuel cost savings of seven cents per mile, according to a study recently completed by the U.S. Department of Energy's Argonne National Laboratory for the Clean Cities program.

Regioselective preparation of 5-hydroxypropranolol and 4´-hydroxydiclofenac with a fungal peroxygenase

Treesearch

Matthias Kinne; Marzena Poraj-Kobielska; Elisabet Aranda; Rene Ullrich; Kenneth E. Hammel; Katrin Scheibner; Martin Hofrichter

2009-01-01

An extracellular peroxygenase of Agrocybe aegerita catalyzed the H2O2-dependent hydroxylation of the multi-function beta-adrenergic blocker propranolol (1-naphthalen-1-yloxy-3-(propan-2-ylamino)-propan-2-ol) and the non-steroidal anti-inflammatory drug diclofenac (2-[2-[(2,6-dichloro-phenyl)amino]phenyl]acetic acid) to give...

75 FR 13123 - Energy Conservation Program for Consumer Products: Representative Average Unit Costs of Energy

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-18

... electricity, natural gas, No. 2 heating oil, propane, and kerosene. DATES: The representative average unit... after-tax costs for electricity, natural gas, No. 2 heating oil, and propane are based on simulations... million Btu As required by test Type of energy \\1\\ In commonly used terms procedure Electricity $33.70 11...

76 FR 13168 - Energy Conservation Program for Consumer Products: Representative Average Unit Costs of Energy

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-10

... electricity, natural gas, No. 2 heating oil, propane, and kerosene. DATES: The representative average unit... after-tax costs for electricity, natural gas, No. 2 heating oil, and propane are based on simulations... million As required by Type of energy Btu \\1\\ In commonly used terms test procedure Electricity $34.14 11...

77 FR 24940 - Energy Conservation Program for Consumer Products: Representative Average Unit Costs of Energy

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-26

... electricity, natural gas, No. 2 heating oil, propane, and kerosene. DATES: The representative average unit... unit after-tax costs for electricity, natural gas, No. 2 heating oil, and propane are based on...\\ In commonly used terms As required by test procedure Electricity $34.70 11.84[cent]/kWh 2 3...

Alternative Fuels Data Center: Propane Buses Shuttle Visitors in Maine

Science.gov Websites

Florida Feb. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of an electric School Buses Help Kansas City Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels Vehicles Relies on Natural Gas Fueling Stations July 1, 2010 Hybrid Electric Shuttle Buses Offer Free Rides in

Alternative Fuels Data Center: Hydrogen Powers Fuel Cell Vehicles in

Science.gov Websites

. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of an electric vehicle at Natural Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels Gas Street Sweepers Improve Air Quality in New York March 11, 2010 Propane Buses Save Money for

Alternative Fuels Data Center: Metropolitan Utilities District Fuels

Science.gov Websites

Go Electric in Florida Feb. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Help Kansas City Save Money Nov. 12, 2011 Electric Trucks Deliver at Kansas City Schools Sept. 17, 2011 Quality in New York March 11, 2010 Propane Buses Save Money for Virginia Schools Feb. 25, 2010 Michigan

Alternative Fuels Data Center: Michigan Converts Vehicles to Propane,

Science.gov Websites

, Reducing Emissions Learn how Detroit reduces emissions and saves money by converting vehicles to run on , 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of an electric vehicle at a Natural Gas Fueling Stations July 1, 2010 Hybrid Electric Shuttle Buses Offer Free Rides in Maryland June

Alternative Fuels Data Center: South Florida Fleet Fuels with Propane

Science.gov Websites

Alternative Fuel Use and Public Transit Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Electric Vehicles March 31, 2012 Natural Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Free Rides in Maryland June 18, 2010 Fisher Coachworks Develops Plug-In Electric Bus in Michigan June 3

Alternative Fuels Data Center: Virginia Converts Vehicles to Propane in

Science.gov Websites

. 15, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of an electric vehicle at School Buses Help Kansas City Save Money Nov. 12, 2011 Metropolitan Utilities District Fuels Vehicles Electric Shuttle Buses Offer Free Rides in Maryland June 18, 2010 Texas Taxis Go Hybrid May 6, 2010

Evaluation of propane combustion traps for collection of Phlebotomus papatasi (Scopoli) in southern Israel.

USDA-ARS?s Scientific Manuscript database

Traps used for mosquitoes can possibly used to capture phlebotomine sand flies as well, but little testing has been done. Traps powered by propane could be extremely useful because most produce their own carbon dioxide (CO2), which can increase the number of sand flies captured. Scientists at the US...

40 CFR 63.1205 - What are the standards for hazardous waste burning lightweight aggregate kilns that are effective...

Code of Federal Regulations, 2012 CFR

2012-07-01

... rolling average, dry basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid... hydrochloric acid equivalents, dry basis and corrected to 7 percent oxygen; and (7) Particulate matter in... average, dry basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid and...

40 CFR 63.1205 - What are the standards for hazardous waste burning lightweight aggregate kilns that are effective...

Code of Federal Regulations, 2010 CFR

2010-07-01

... rolling average, dry basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid... hydrochloric acid equivalents, dry basis and corrected to 7 percent oxygen; and (7) Particulate matter in... average, dry basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid and...

40 CFR 63.1203 - What are the standards for hazardous waste incinerators that are effective until compliance with...

Code of Federal Regulations, 2013 CFR

2013-07-01

... as propane; (6) Hydrochloric acid and chlorine gas in excess of 77 parts per million by volume, combined emissions, expressed as hydrochloric acid equivalents, dry basis and corrected to 7 percent oxygen... basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid and chlorine gas in...

40 CFR 63.1205 - What are the standards for hazardous waste burning lightweight aggregate kilns that are effective...

Code of Federal Regulations, 2011 CFR

2011-07-01

... rolling average, dry basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid... hydrochloric acid equivalents, dry basis and corrected to 7 percent oxygen; and (7) Particulate matter in... average, dry basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid and...

40 CFR 63.1203 - What are the standards for hazardous waste incinerators that are effective until compliance with...

Code of Federal Regulations, 2014 CFR

2014-07-01

... as propane; (6) Hydrochloric acid and chlorine gas in excess of 77 parts per million by volume, combined emissions, expressed as hydrochloric acid equivalents, dry basis and corrected to 7 percent oxygen... basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid and chlorine gas in...

40 CFR 98.408 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GREENHOUSE GAS REPORTING Suppliers of Natural Gas and Natural Gas Liquids § 98.408 Definitions. All terms...) Natural Gas 1.027 MMBtu/Mscf 53.02 Propane 3.836 MMBtu/bbl 63.02 Normal butane 4.326 MMBtu/bbl 64.93... Unit Default CO2 emission value(MT CO2/Unit) Natural Gas Mscf 0.054452 Propane Barrel 0.241745 Normal...

Phase behavior and crystal structure of 3-(1-naphthyloxy)- and 3-(4-indolyloxy)-propane-1,2-diol, synthetic precursors of chiral drugs propranolol and pindolol

NASA Astrophysics Data System (ADS)

Bredikhin, Alexander A.; Gubaidullin, Aidar T.; Bredikhina, Zemfira A.; Fayzullin, Robert R.; Samigullina, Aida I.; Zakharychev, Dmitry V.

2013-08-01

Valuable precursors of popular chiral drugs propranolol and pindolol, 3-(1-naphthyloxy)-propane-1,2-diol 3 and 3-(4-indolyloxy)-propane-1,2-diol 4 were investigated by IR spectroscopy, DSC, and X-ray diffraction methods. Both compounds, crystallizing from enantiopure feed material, form "guaifenesin-like" crystal packing in which the classic H-bonded bilayers, framed in both sides by hydrophobic fragments of the molecules, acts as the basic crystal-forming motif. Diol 4 prone to spontaneous resolution and conserves its packing pattern crystallizing from racemate. Under the same conditions, diol 3 forms weakly stable solid racemic compound. Some reasons for such a behavior are identified and discussed.

Improvement of gas hydrate preservation by increasing compression pressure to simple hydrates of methane, ethane, and propane

NASA Astrophysics Data System (ADS)

Kida, Masato; Jin, Yusuke; Watanabe, Mizuho; Murayama, Tetsuro; Nagao, Jiro

2017-09-01

In this report, we describe the dissociation behavior of gas hydrate grains pressed at 1 and 6 MPa. Certain simple gas hydrates in powder form show anomalous preservation phenomenon under their thermodynamic unstable condition. Investigation of simple hydrates of methane, ethane, and propane reveals that high pressure applied to the gas hydrate particles enhances their preservation effects. Application of high pressure increases the dissociation temperature of methane hydrate and has a restrictive effect against the dissociation of ethane and propane hydrate grains. These improvements of gas hydrate preservation by increasing pressure to the initial gas hydrate particles imply that appropriate pressure applied to gas hydrate particles enhances gas hydrate preservation effects.

Experimental study on transmission of an overdriven detonation wave from propane/oxygen to propane/air

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

Li, J.; Lai, W.H.; Chung, K.

2008-08-15

Two sets of experiments were performed to achieve a strong overdriven state in a weaker mixture by propagating an overdriven detonation wave via a deflagration-to-detonation transition (DDT) process. First, preliminary experiments with a propane/oxygen mixture were used to evaluate the attenuation of the overdriven detonation wave in the DDT process. Next, experiments were performed wherein a propane/oxygen mixture was separated from a propane/air mixture by a thin diaphragm to observe the transmission of an overdriven detonation wave. Based on the characteristic relations, a simple wave intersection model was used to calculate the state of the transmitted detonation wave. The resultsmore » showed that a rarefaction effect must be included to ensure that there is no overestimate of the post-transmission wave properties when the incident detonation wave is overdriven. The strength of the incident overdriven detonation wave plays an important role in the wave transmission process. The experimental results showed that a transmitted overdriven detonation wave occurs instantaneously with a strong incident overdriven detonation wave. The near-CJ state of the incident wave leads to a transmitted shock wave, and then the transition to the overdriven detonation wave occurs downstream. The attenuation process for the overdriven detonation wave decaying to a near-CJ state occurs in all tests. After the attenuation process, an unstable detonation wave was observed in most tests. This may be attributed to the increase in the cell width in the attenuation process that exceeds the detonability cell width limit. (author)« less

Alternative Fuels Data Center

Science.gov Websites

Natural Gas and Propane Tax Effective January 1, 2019, propane, compressed natural gas (CNG), and liquefied natural gas (LNG) will be subject to an excise tax at a rate of $0.04 per gasoline gallon equivalent (GGE), plus a $0.01 ninth-cent fuel tax, a $0.01 local option fuel tax, and an additional variable

78 FR 17648 - Energy Conservation Program for Consumer Products: Representative Average Unit Costs of Energy

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-22

... electricity, natural gas, No. 2 heating oil, propane, and kerosene. DATES: The representative average unit... for electricity, natural gas, No. 2 heating oil, and propane are based on simulations used to produce... required by test procedure Electricity $35.46 12.1[cent]/kWh 2 3..... $0.121/kWh Natural Gas 10.87 $1.087...

Aerobic microorganism for the degradation of chlorinated aliphatic hydrocarbons

DOEpatents

Fliermans, Carl B.

1989-01-01

A chlorinated aliphatic hydrocarbon-degrading microorganism, having American Type Culture Collection accession numbers ATCC 53570 and 53571, in a biologically pure culture aseptically collected from a deep subsurface habitat and enhanced, mineralizes trichloroethylene and tetrachloroethylene to HCl, H.sub.2 O and Co.sub.2 under aerobic conditions stimulated by methane, acetate, methanol, tryptone-yeast extract, propane and propane-methane.

Alternative Fuels Data Center: Rio Rico Fire District Turns Grease Into

Science.gov Websites

Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a school bus Michigan Transports Students March 31, 2012 Natural Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Electric Trucks Natural Gas Street Sweepers Improve Air Quality in New York March 11, 2010 Propane Buses Save Money for

Alternative Fuels Data Center: Propane Powers School Buses in Tuscaloosa,

Science.gov Websites

Efficiency March 8, 2014 Renzenberger Inc Saves Money With Propane Vans Feb. 1, 2014 Photo of a school bus and Plug-In Electric Vehicles March 31, 2012 Natural Gas School Buses Help Kansas City Save Money Nov Electric Shuttle Buses Offer Free Rides in Maryland June 18, 2010 Electric Trolley Boosts Business in

Alternative Fuels Data Center: Tennessee Reduces Pollution With Propane

Science.gov Websites

Money With Propane Vans Feb. 1, 2014 Photo of an electric vehicle at a charging station Companies Power Natural Gas School Buses Help Kansas City Save Money Nov. 12, 2011 Electric Trucks Deliver at Kansas City Free Rides in Maryland June 18, 2010 Fisher Coachworks Develops Plug-In Electric Bus in Michigan June 3

Alternative Fuels Data Center: MedCorp Fuels Emergency Vehicles With

Science.gov Websites

. College Students Engineer Efficient Vehicles in EcoCAR 2 Competition Aug. 2, 2014 Photo of a police Propane in OhioA> MedCorp Fuels Emergency Vehicles With Propane in Ohio to someone by E-mail Television Related Videos Photo of a car Hydrogen Powers Fuel Cell Vehicles in California Nov. 18, 2017 Photo

40 CFR 63.1203 - What are the standards for hazardous waste incinerators that are effective until compliance with...

Code of Federal Regulations, 2010 CFR

2010-07-01

... monitoring system), dry basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid... hydrochloric acid equivalents, dry basis and corrected to 7 percent oxygen; and (7) Particulate matter in... oxygen, and reported as propane; (6) Hydrochloric acid and chlorine gas in excess of 21 parts per million...

40 CFR 63.1203 - What are the standards for hazardous waste incinerators that are effective until compliance with...

Code of Federal Regulations, 2011 CFR

2011-07-01

... monitoring system), dry basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid... hydrochloric acid equivalents, dry basis and corrected to 7 percent oxygen; and (7) Particulate matter in... oxygen, and reported as propane; (6) Hydrochloric acid and chlorine gas in excess of 21 parts per million...

40 CFR 63.1203 - What are the standards for hazardous waste incinerators that are effective until compliance with...

Code of Federal Regulations, 2012 CFR

2012-07-01

... monitoring system), dry basis, corrected to 7 percent oxygen, and reported as propane; (6) Hydrochloric acid... hydrochloric acid equivalents, dry basis and corrected to 7 percent oxygen; and (7) Particulate matter in... oxygen, and reported as propane; (6) Hydrochloric acid and chlorine gas in excess of 21 parts per million...

Alternative Fuels Data Center: Propane Buses Help Minnesota Schools Carve

Science.gov Websites

information about this project, contact Twin Cities Clean Cities Coalition. Download QuickTime Video QuickTime videos provided by Clean Cities TV and FuelEconomy.gov. MotorWeek - Television's Original Automotive Propane Aug. 22, 2015 A photo of two national parks buses parked in front of Redwood trees. Clean Cities

Alternative Fuels Data Center: School Buses Go Green in Virginia

Science.gov Websites

Gloucester County Public Schools put five Blue Bird propane school buses on the road. Funds from EPA and VDEQ October 2009 to November 2010, the five buses saved almost $7,000 in fuel and maintenance costs and could see, touch, and ride propane buses. And now, Gloucester's success is helping to make the case for

An automatic flow system for NIR screening analysis of liquefied petroleum gas with respect to propane content.

PubMed

Dantas, Hebertty V; Barbosa, Mayara F; Nascimento, Elaine C L; Moreira, Pablo N T; Galvão, Roberto K H; Araújo, Mário C U

2013-03-15

This paper proposes a NIR spectrometric method for screening analysis of liquefied petroleum gas (LPG) samples. The proposed method is aimed at discriminating samples with low and high propane content, which can be useful for the adjustment of burn settings in industrial applications. A gas flow system was developed to introduce the LPG sample into a NIR flow cell at constant pressure. In addition, a gas chromatographer was employed to determine the propane content of the sample for reference purposes. The results of a principal component analysis, as well as a classification study using SIMCA (soft independent modeling of class analogies), revealed that the samples can be successfully discriminated with respect to propane content by using the NIR spectrum in the range 8100-8800 cm(-1). In addition, by using SPA-LDA (linear discriminant analysis with variables selected by the successive projections algorithm), it was found that perfect discrimination can also be achieved by using only two wavenumbers (8215 and 8324 cm(-1)). This finding may be of value for the design of a dedicated, low-cost instrument for routine analyses. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis of fructooligosaccharides from Aspergillus niger commercial inulinase immobilized in montmorillonite pretreated in pressurized propane and LPG.

PubMed

de Oliveira Kuhn, Graciele; Rosa, Clarissa Dalla; Silva, Marceli Fernandes; Treichel, Helen; de Oliveira, Débora; Oliveira, J Vladimir

2013-02-01

Commercial inulinase from Aspergillus niger was immobilized in montmorillonite and then treated in pressurized propane and liquefied petroleum gas (LPG). Firstly, the effects of system pressure, exposure time, and depressurization rate, using propane and LPG, on enzymatic activity were evaluated through central composite design 2³. Residual activities of 145.1 and 148.5% were observed for LPG (30 bar, 6 h, and depressurization rate of 20 bar min⁻¹) and propane (270 bar, 1 h, and depressurization rate of 100 bar min⁻¹), respectively. The catalysts treated at these conditions in both fluids were then used for the production of fructooligosaccharides (FOS) using sucrose and inulin as substrates in aqueous and organic systems. The main objective of this step was to evaluate the yield and productivity in FOS, using alternatives for enhancing enzyme activity by means of pressurized fluids and also using low-cost supports for enzyme immobilization, aiming at obtaining a stable biocatalyst to be used for synthesis reactions. Yields of 18% were achieved using sucrose as substrate in aqueous medium, showing the potential of this procedure, hence suggesting a further optimization step to increase the process yield.

Biological formation of ethane and propane in the deep marine subsurface.

PubMed

Hinrichs, Kai-Uwe; Hayes, John M; Bach, Wolfgang; Spivack, Arthur J; Hmelo, Laura R; Holm, Nils G; Johnson, Carl G; Sylva, Sean P

2006-10-03

Concentrations and isotopic compositions of ethane and propane in cold, deeply buried sediments from the southeastern Pacific are best explained by microbial production of these gases in situ. Reduction of acetate to ethane provides one feasible mechanism. Propane is enriched in (13)C relative to ethane. The amount is consistent with derivation of the third C from inorganic carbon dissolved in sedimentary pore waters. At typical sedimentary conditions, the reactions yield free energy sufficient for growth. Relationships with competing processes are governed mainly by the abundance of H(2). Production of C(2) and C(3) hydrocarbons in this way provides a sink for acetate and hydrogen but upsets the general belief that hydrocarbons larger than methane derive only from thermal degradation of fossil organic material.

Biological formation of ethane and propane in the deep marine subsurface

PubMed Central

Hinrichs, Kai-Uwe; Hayes, John M.; Bach, Wolfgang; Spivack, Arthur J.; Hmelo, Laura R.; Holm, Nils G.; Johnson, Carl G.; Sylva, Sean P.

2006-01-01

Concentrations and isotopic compositions of ethane and propane in cold, deeply buried sediments from the southeastern Pacific are best explained by microbial production of these gases in situ. Reduction of acetate to ethane provides one feasible mechanism. Propane is enriched in 13C relative to ethane. The amount is consistent with derivation of the third C from inorganic carbon dissolved in sedimentary pore waters. At typical sedimentary conditions, the reactions yield free energy sufficient for growth. Relationships with competing processes are governed mainly by the abundance of H2. Production of C2 and C3 hydrocarbons in this way provides a sink for acetate and hydrogen but upsets the general belief that hydrocarbons larger than methane derive only from thermal degradation of fossil organic material. PMID:16990430

Kinetics of hydrogen peroxide decomposition by catalase: hydroxylic solvent effects.

PubMed

Raducan, Adina; Cantemir, Anca Ruxandra; Puiu, Mihaela; Oancea, Dumitru

2012-11-01

The effect of water-alcohol (methanol, ethanol, propan-1-ol, propan-2-ol, ethane-1,2-diol and propane-1,2,3-triol) binary mixtures on the kinetics of hydrogen peroxide decomposition in the presence of bovine liver catalase is investigated. In all solvents, the activity of catalase is smaller than in water. The results are discussed on the basis of a simple kinetic model. The kinetic constants for product formation through enzyme-substrate complex decomposition and for inactivation of catalase are estimated. The organic solvents are characterized by several physical properties: dielectric constant (D), hydrophobicity (log P), concentration of hydroxyl groups ([OH]), polarizability (α), Kamlet-Taft parameter (β) and Kosower parameter (Z). The relationships between the initial rate, kinetic constants and medium properties are analyzed by linear and multiple linear regression.

Site-Specific Carbon Isotopes in Organics

NASA Astrophysics Data System (ADS)

Piasecki, A.; Eiler, J. M.

2012-12-01

Natural organic molecules exhibit a wide range of internal site-specific isotope variation (i.e., molecules with same isotopic substitution type but different site). Such variations are generally unconstrained by bulk isotopic measurements. If known, site-specific variations might constrain temperatures of equilibrium, mechanisms of formation or consumption reactions, and possibly other details. For example, lipids can exhibit carbon isotope differences of up to 30‰ between adjacent carbon sites as a result of fractionations arising during decarboxylation of pyruvate and other steps in lipid biosynthesis(1). We present a method for site-specific carbon isotope analysis of propane, based on high-resolution, multi-collector gas source mass spectrometry, using a novel prototype instrument - the Thermo MAT 253 Ultra. This machine has an inlet system and electron bombardment ion source resembling those in conventional stable isotope gas source mass spectrometers, and the energy filter, magnet, and detector array resembling those in multi-collector ICPMS and TIMS. The detector array has 7 detector positions, 6 of which are movable, and each of which can collect ions with either a faraday cup (read through amplifiers ranging from 107-1012 ohms) or an SEM. High mass resolving power (up to 27,000, MRP = M/dM definition) is achieved through a narrow entrance slit, adjustable from 250 to 5 μm. Such resolution can cleanly separate isobaric interferences between isotopologues of organic molecules having the same cardinal mass (e.g., 13CH3 and 12CH2D). We use this technology to analyze the isotopologues and fragments of propane, and use such data to solve for the site-specific carbon isotope fractionation. By measuring isotopologues of both the one-carbon (13CH3) and the two-carbon (13C12CH4) fragment ion, we can solve for both bulk δ13C and the difference in δ13C between the terminal and central carbon position. We tested this method by analyzing mixtures between natural propane and labeled propane (13CH3-12CH2-12CH3). Results are consistent with the expected relative fractionations between the two fragments, indicating limited 'scrambling' of carbon positions of less than 2% in the source. The limits of precision of this method are currently ~0.5 ‰, sufficient to resolve known or suspected position-specific isotope effects in propane. We have explored the expected temperature-dependent equilibrium isotopic distributions of propane using density functional theory and quantum mechanical models of vibrational isotope effects. These models predict the homogeneous isotope exchange equilibria among the various isotopologues of propane, which include several of a wide range of effects that should be measurable by our methods. At 300 K we predict that the central carbon site is 15‰ higher in δ13C and 95 ‰ higher in δD than the terminal carbon site; similarly the molecule containing both a 13C and D in the central site is enriched by ~120 ‰ relative to a random isotopic distribution at 300 K. These predictions present targets for future experimental and empirical studies of the temperature dependence of isotopic ordering in propane. More generally, the methods we are developing for the study of intramolecular isotopic distributions in propane will serve as a model for future study of similar effects in other organic compounds. [1]DeNiro, Epstein (1977) Science Volume 197, 261-263.

Design and Development of a Salbutamol Intake Detector for Low Respiratory Treatment

NASA Astrophysics Data System (ADS)

Vui Hin, Tsen; Ilyani Ramli, Nur

2017-08-01

This paper proposed a new salbutamol intake detector design using asthma spacer and gas sensor. The device enable real time monitoring of propellant level inhaled by the infant which will decrease the recovery time of the asthma attack. Microcontroller Arduino UNO is program to control the input and output of the system. MQ6 gas sensor detecting the propellant Hydrofluoroalkane from the metered dose inhaler (MDI) canister and demonstrated the level of propellant inhaled on the LCD in real time. MQ6 gas sensor suitable used to detect concentration of propellant inside the asthma spacer due to it is low sensitive to natural gas where include the carbon dioxide exhaled by the infant. Besides this, MQ6 gas sensor also highly sensitive to propane and the preview aerosol inventor mentioned propane as propellant which used for MDI to push the salbutamol out from MDI canister. Therefore, MQ6 gas sensor is suitable to detect propellant inside asthma spacer. The output voltage of MQ6 in initial state where no propellant inside asthma spacer is between 0.55V and 0.65V. Furthermore, when the MDI canister is been pressed, the concentration of propellant is increased and the output voltage of MQ6 gas sensor also increased in ranged between 1.1V and 1.2V.

Alternative Fuels Data Center: Florida Schools First in State to Power up

Science.gov Websites

Indian River County School District became the first in the state to adopt propane-powered school buses Oil Powers Biodiesel Vehicles in Vermont March 4, 2017 Photo of a truck Natural Gas Fuels School Buses Natural Gas Jan. 14, 2017 Photo of buses Baton Rouge School District Adds Propane Buses to Its Fleet Dec

New insights into low-temperature oxidation of propane from synchrotron photoionization mass spectrometry and multi-scale informatics modeling

DOE PAGES

Welz, Oliver; Burke, Michael P.; Antonov, Ivan O.; ...

2015-04-10

We studied low-temperature propane oxidation at P = 4 Torr and T = 530, 600, and 670 K by time-resolved multiplexed photoionization mass spectrometry (MPIMS), which probes the reactants, intermediates, and products with isomeric selectivity using tunable synchrotron vacuum UV ionizing radiation. The oxidation is initiated by pulsed laser photolysis of oxalyl chloride, (COCl) 2, at 248 nm, which rapidly generates a ~1:1 mixture of 1-propyl (n-propyl) and 2-propyl (i-propyl) radicals via the fast Cl + propane reaction. At all three temperatures, the major stable product species is propene, formed in the propyl + O 2 reactions by direct HOmore » 2 elimination from both n- and i-propyl peroxy radicals. The experimentally derived propene yields relative to the initial concentration of Cl atoms are (20 ± 4)% at 530 K, (55 ± 11)% at 600 K, and (86 ± 17)% at 670 K at a reaction time of 20 ms. The lower yield of propene at low temperature reflects substantial formation of propyl peroxy radicals, which do not completely decompose on the experimental time scale. In addition, C 3H 6O isomers methyloxirane, oxetane, acetone, and propanal are detected as minor products. Our measured yields of oxetane and methyloxirane, which are coproducts of OH radicals, suggest a revision of the OH formation pathways in models of low-temperature propane oxidation. The experimental results are modeled and interpreted using a multiscale informatics approach, presented in detail in a separate publication (Burke, M. P.; Goldsmith, C. F.; Klippenstein, S. J.; Welz, O.; Huang H.; Antonov I. O.; Savee J. D.; Osborn D. L.; Zádor, J.; Taatjes, C. A.; Sheps, L. Multiscale Informatics for Low-Temperature Propane Oxidation: Further Complexities in Studies of Complex Reactions. J. Phys. Chem A. 2015, DOI: 10.1021/acs.jpca.5b01003). Additionally, we found that the model predicts the time profiles and yields of the experimentally observed primary products well, and shows satisfactory agreement for products formed mostly via secondary radical–radical reactions.« less

New Insights into Low-Temperature Oxidation of Propane from Synchrotron Photoionization Mass Spectrometry and Multiscale Informatics Modeling

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

Welz, Oliver; Burke, Michael P.; Antonov, Ivan O.

2015-07-16

We investigated the low-temperature oxidation of propane at 4 Torr and temperatures of 530, 600, and 670 K. The oxidation is initiated by pulsed laser photolysis of oxalyl chloride, (COCl)2, at 248 nm, which rapidly generates a ~1:1 mixture of 1-propyl (n-propyl) and 2-propyl (i-propyl) radicals via the fast Cl + propane reaction. Reactants, intermediates and products are probed with isomeric selectivity by time-resolved multiplexed photoionization mass spectrometry (MPIMS) with tunable synchrotron vacuum UV radiation as the ionization source. At all three temperatures, the major stable product species is propene, formed in the C3H7 + O2 reactions by direct HO2-eliminationmore » from both n- and i-propyl peroxy radicals. The experimentally derived propene yields relative to the initial concentration of Cl atoms are (20 ± 4)% at 530 K, (55 ± 11)% at 600 K, and (86 ± 17)% at 670 K at a reaction time of 20 ms. The lower yield of propene at low temperature reflects substantial formation of propyl peroxy radicals, which do not completely decompose on the experimental time scale. In addition, we detect the C3H6O isomers methyloxirane, oxetane, acetone and propanal as minor products. Our measured yields of oxetane and methyloxirane, which are co-products of OH radicals, suggest a revision of the OH formation pathways in models of low-temperature propane oxidation. The experimental results are modeled and interpreted using a multi-scale informatics approach that is presented in detail in a separate publication (Burke, M. P.; Goldsmith, C. F.; Klippenstein, S. J.; Welz, O.; Huang H.; Antonov I. O.; Savee J. D.; Osborn D. L.; Zádor, J.; Taatjes, C. A.; Sheps, L., Multi-Scale Informatics for Low-Temperature Propane Oxidation: Further Complexities in Studies of Complex Rections, submitted, 2015). The model predicts the time profiles and yields of the experimentally observed primary products well, and shows satisfactory agreement for products formed mostly via secondary radical-radical reactions.« less

Identification of Novel Methane-, Ethane-, and Propane-Oxidizing Bacteria at Marine Hydrocarbon Seeps by Stable Isotope Probing ▿ †

PubMed Central

Redmond, Molly C.; Valentine, David L.; Sessions, Alex L.

2010-01-01

Marine hydrocarbon seeps supply oil and gas to microorganisms in sediments and overlying water. We used stable isotope probing (SIP) to identify aerobic bacteria oxidizing gaseous hydrocarbons in surface sediment from the Coal Oil Point seep field located offshore of Santa Barbara, California. After incubating sediment with 13C-labeled methane, ethane, or propane, we confirmed the incorporation of 13C into fatty acids and DNA. Terminal restriction fragment length polymorphism (T-RFLP) analysis and sequencing of the 16S rRNA and particulate methane monooxygenase (pmoA) genes in 13C-DNA revealed groups of microbes not previously thought to contribute to methane, ethane, or propane oxidation. First, 13C methane was primarily assimilated by Gammaproteobacteria species from the family Methylococcaceae, Gammaproteobacteria related to Methylophaga, and Betaproteobacteria from the family Methylophilaceae. Species of the latter two genera have not been previously shown to oxidize methane and may have been cross-feeding on methanol, but species of both genera were heavily labeled after just 3 days. pmoA sequences were affiliated with species of Methylococcaceae, but most were not closely related to cultured methanotrophs. Second, 13C ethane was consumed by members of a novel group of Methylococcaceae. Growth with ethane as the major carbon source has not previously been observed in members of the Methylococcaceae; a highly divergent pmoA-like gene detected in the 13C-labeled DNA may encode an ethane monooxygenase. Third, 13C propane was consumed by members of a group of unclassified Gammaproteobacteria species not previously linked to propane oxidation. This study identifies several bacterial lineages as participants in the oxidation of gaseous hydrocarbons in marine seeps and supports the idea of an alternate function for some pmoA-like genes. PMID:20675448

Identification of novel methane-, ethane-, and propane-oxidizing bacteria at marine hydrocarbon seeps by stable isotope probing.

PubMed

Redmond, Molly C; Valentine, David L; Sessions, Alex L

2010-10-01

Marine hydrocarbon seeps supply oil and gas to microorganisms in sediments and overlying water. We used stable isotope probing (SIP) to identify aerobic bacteria oxidizing gaseous hydrocarbons in surface sediment from the Coal Oil Point seep field located offshore of Santa Barbara, California. After incubating sediment with (13)C-labeled methane, ethane, or propane, we confirmed the incorporation of (13)C into fatty acids and DNA. Terminal restriction fragment length polymorphism (T-RFLP) analysis and sequencing of the 16S rRNA and particulate methane monooxygenase (pmoA) genes in (13)C-DNA revealed groups of microbes not previously thought to contribute to methane, ethane, or propane oxidation. First, (13)C methane was primarily assimilated by Gammaproteobacteria species from the family Methylococcaceae, Gammaproteobacteria related to Methylophaga, and Betaproteobacteria from the family Methylophilaceae. Species of the latter two genera have not been previously shown to oxidize methane and may have been cross-feeding on methanol, but species of both genera were heavily labeled after just 3 days. pmoA sequences were affiliated with species of Methylococcaceae, but most were not closely related to cultured methanotrophs. Second, (13)C ethane was consumed by members of a novel group of Methylococcaceae. Growth with ethane as the major carbon source has not previously been observed in members of the Methylococcaceae; a highly divergent pmoA-like gene detected in the (13)C-labeled DNA may encode an ethane monooxygenase. Third, (13)C propane was consumed by members of a group of unclassified Gammaproteobacteria species not previously linked to propane oxidation. This study identifies several bacterial lineages as participants in the oxidation of gaseous hydrocarbons in marine seeps and supports the idea of an alternate function for some pmoA-like genes.

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

Sun, Pingping; Siddiqi, Georges; Vining, William C.

Catalysts for the dehydrogenation of light alkanes were prepared by dispersing Pt on the surface of a calcined hydrotalcite-like support containing indium, Mg(In)(Al)O. Upon reduction in H{sub 2} at temperatures above 673 K, bimetallic particles of PtIn are observed by TEM, which have an average diameter of 1 nm. Analysis of Pt LIII-edge extended X-ray absorption fine structure (EXAFS) data shows that the In content of the bimetallic particles increases with increasing bulk In/Pt ratio and reduction temperature. Pt LIII-edge X-ray absorption near edge structure (XANES) indicates that an increasing donation of electronic charge from In to Pt occurs withmore » increasing In content in the PtIn particles. The activity and selectivity of the Pt/Mg(In)(Al)O catalysts for ethane and propane dehydrogenation reactions are strongly dependent on the bulk In/Pt ratio. For both reactants, maximum activity was achieved for a bulk In/Pt ratio of 0.48, and at this In/Pt ratio, the selectivity to alkene was nearly 100%. Coke deposition was observed after catalyst use for either ethane or propane dehydrogenation, and it was observed that the alloying of Pt with In greatly reduced the amount of coke deposited. Characterization of the deposit by Raman spectroscopy indicates that the coke is present as highly disordered graphite particles <30 nm in diameter. While the amount of coke deposited during ethane and propane dehydrogenation are comparable, the effects on activity are dependent on reactant composition. Coke deposition had no effect on ethane dehydrogenation activity, but caused a loss in propane dehydrogenation activity. This difference is attributed to the greater ease with which coke produced on the surface of PtIn nanoparticles migrates to the support during ethane dehydrogenation versus propane dehydrogenation.« less

Fundamental studies on kinetic isotope effect (KIE) of hydrogen isotope fractionation in natural gas systems

USGS Publications Warehouse

Ni, Y.; Ma, Q.; Ellis, G.S.; Dai, J.; Katz, B.; Zhang, S.; Tang, Y.

2011-01-01

Based on quantum chemistry calculations for normal octane homolytic cracking, a kinetic hydrogen isotope fractionation model for methane, ethane, and propane formation is proposed. The activation energy differences between D-substitute and non-substituted methane, ethane, and propane are 318.6, 281.7, and 280.2cal/mol, respectively. In order to determine the effect of the entropy contribution for hydrogen isotopic substitution, a transition state for ethane bond rupture was determined based on density function theory (DFT) calculations. The kinetic isotope effect (KIE) associated with bond rupture in D and H substituted ethane results in a frequency factor ratio of 1.07. Based on the proposed mathematical model of hydrogen isotope fractionation, one can potentially quantify natural gas thermal maturity from measured hydrogen isotope values. Calculated gas maturity values determined by the proposed mathematical model using ??D values in ethane from several basins in the world are in close agreement with similar predictions based on the ??13C composition of ethane. However, gas maturity values calculated from field data of methane and propane using both hydrogen and carbon kinetic isotopic models do not agree as closely. It is possible that ??D values in methane may be affected by microbial mixing and that propane values might be more susceptible to hydrogen exchange with water or to analytical errors. Although the model used in this study is quite preliminary, the results demonstrate that kinetic isotope fractionation effects in hydrogen may be useful in quantitative models of natural gas generation, and that ??D values in ethane might be more suitable for modeling than comparable values in methane and propane. ?? 2011 Elsevier Ltd.

Alternative Fuels Data Center: Propane Rolls on as Reliable Fleet Fuel

Science.gov Websites

AddThis.com... March 6, 2015 Propane Rolls on as Reliable Fleet Fuel " If we can save the district money alternative fuels program for our buses as a way to save money and clean up the air and environment for our can save the district money and prevent pollution for our kids' sake in the process, I don't see a

Neutrophil autophagy and extracellular DNA traps contribute to airway inflammation in severe asthma.

PubMed

Pham, D L; Ban, G-Y; Kim, S-H; Shin, Y S; Ye, Y-M; Chwae, Y-J; Park, H-S

2017-01-01

Autophagy and neutrophil extracellular DNA traps (NETs) are implicated in asthma; however, their roles in asthma pathogenesis have not been elucidated. We compared autophagy and NET production levels from peripheral blood neutrophils (PBNs) of patients with severe asthma (SA) and non-severe asthma (NSA). Additionally, we investigated the inflammatory effects of NETs on human airway epithelial cells (AECs) and peripheral blood eosinophils (PBEs). Peripheral blood neutrophils from patients with SA (n = 30) and NSA (n = 38) were treated with interleukin (IL)-8 (100 ng/mL). Autophagy (light chain 3-II expression) and NET production levels were evaluated by Western blot, immunofluorescence microscopy, and PicoGreen assay. The effects of NETs on AECs were assessed by investigating cell death, cell detachment, expression of occludin and claudin-1, and IL-8 production; the effects of NETs on PBEs were examined by investigating the activation and release of eosinophil cationic protein (ECP) and eosinophil-derived neurotoxin (EDN). Untreated and IL-8-treated PBNs from the SA group produced higher autophagy and NET levels compared with those from the NSA group (P < 0.01). IL-8 increased autophagy and NET levels in PBNs from the SA group, but not from the NSA group. NET levels were correlated with autophagy levels in PBNs (P < 0.001). IL-8-induced NET production levels negatively were correlated with FEV1/FVC (r = -0.700, P = 0.016). NETs induced cell death, detachment, degradation of occludin and claudin-1, and IL-8 production from AECs. Higher levels of NET-induced ECP and EDN were released from PBEs in SA compared with NSA groups. Neutrophil autophagy and NETs could enhance asthma severity by damaging airway epithelium and triggering inflammatory responses of AECs and PBEs. Modulating neutrophil autophagy and NET production may be a new target therapy for SA. © 2016 John Wiley & Sons Ltd.

Nicotine Levels and Presence of Selected Tobacco-Derived Toxins in Tobacco Flavoured Electronic Cigarette Refill Liquids

PubMed Central

Farsalinos, Konstantinos E.; Gillman, I. Gene; Melvin, Matt S.; Paolantonio, Amelia R.; Gardow, Wendy J.; Humphries, Kathy E.; Brown, Sherri E.; Poulas, Konstantinos; Voudris, Vassilis

2015-01-01

Background. Some electronic cigarette (EC) liquids of tobacco flavour contain extracts of cured tobacco leaves produced by a process of solvent extraction and steeping. These are commonly called Natural Extract of Tobacco (NET) liquids. The purpose of the study was to evaluate nicotine levels and the presence of tobacco-derived toxins in tobacco-flavoured conventional and NET liquids. Methods. Twenty-one samples (10 conventional and 11 NET liquids) were obtained from the US and Greek market. Nicotine levels were measured and compared with labelled values. The levels of tobacco-derived chemicals were compared with literature data on tobacco products. Results. Twelve samples had nicotine levels within 10% of the labelled value. Inconsistency ranged from −21% to 22.1%, with no difference observed between conventional and NET liquids. Tobacco-specific nitrosamines (TSNAs) were present in all samples at ng/mL levels. Nitrates were present almost exclusively in NET liquids. Acetaldehyde was present predominantly in conventional liquids while formaldehyde was detected in almost all EC liquids at trace levels. Phenols were present in trace amounts, mostly in NET liquids. Total TSNAs and nitrate, which are derived from the tobacco plant, were present at levels 200–300 times lower in 1 mL of NET liquids compared to 1 gram of tobacco products. Conclusions. NET liquids contained higher levels of phenols and nitrates, but lower levels of acetaldehyde compared to conventional EC liquids. The lower levels of tobacco-derived toxins found in NET liquids compared to tobacco products indicate that the extraction process used to make these products did not transfer a significant amount of toxins to the NET. Overall, all EC liquids contained far lower (by 2–3 orders of magnitude) levels of the tobacco-derived toxins compared to tobacco products. PMID:25811768

Nicotine levels and presence of selected tobacco-derived toxins in tobacco flavoured electronic cigarette refill liquids.

PubMed

Farsalinos, Konstantinos E; Gillman, I Gene; Melvin, Matt S; Paolantonio, Amelia R; Gardow, Wendy J; Humphries, Kathy E; Brown, Sherri E; Poulas, Konstantinos; Voudris, Vassilis

2015-03-24

Some electronic cigarette (EC) liquids of tobacco flavour contain extracts of cured tobacco leaves produced by a process of solvent extraction and steeping. These are commonly called Natural Extract of Tobacco (NET) liquids. The purpose of the study was to evaluate nicotine levels and the presence of tobacco-derived toxins in tobacco-flavoured conventional and NET liquids. Twenty-one samples (10 conventional and 11 NET liquids) were obtained from the US and Greek market. Nicotine levels were measured and compared with labelled values. The levels of tobacco-derived chemicals were compared with literature data on tobacco products. Twelve samples had nicotine levels within 10% of the labelled value. Inconsistency ranged from -21% to 22.1%, with no difference observed between conventional and NET liquids. Tobacco-specific nitrosamines (TSNAs) were present in all samples at ng/mL levels. Nitrates were present almost exclusively in NET liquids. Acetaldehyde was present predominantly in conventional liquids while formaldehyde was detected in almost all EC liquids at trace levels. Phenols were present in trace amounts, mostly in NET liquids. Total TSNAs and nitrate, which are derived from the tobacco plant, were present at levels 200-300 times lower in 1 mL of NET liquids compared to 1 gram of tobacco products. NET liquids contained higher levels of phenols and nitrates, but lower levels of acetaldehyde compared to conventional EC liquids. The lower levels of tobacco-derived toxins found in NET liquids compared to tobacco products indicate that the extraction process used to make these products did not transfer a significant amount of toxins to the NET. Overall, all EC liquids contained far lower (by 2-3 orders of magnitude) levels of the tobacco-derived toxins compared to tobacco products.

Chemical kinetic models for combustion of hydrocarbons and formation of nitric oxide

NASA Technical Reports Server (NTRS)

Jachimowski, C. J.; Wilson, C. H.

1980-01-01

The formation of nitrogen oxides NOx during combustion of methane, propane, and a jet fuel, JP-4, was investigated in a jet stirred combustor. The results of the experiments were interpreted using reaction models in which the nitric oxide (NO) forming reactions were coupled to the appropriate hydrocarbon combustion reaction mechanisms. Comparison between the experimental data and the model predictions reveals that the CH + N2 reaction process has a significant effect on NO formation especially in stoichiometric and fuel rich mixtures. Reaction models were assembled that predicted nitric oxide levels that were in reasonable agreement with the jet stirred combustor data and with data obtained from a high pressure (5.9 atm (0.6 MPa)), prevaporized, premixed, flame tube type combustor. The results also suggested that the behavior of hydrocarbon mixtures, like JP-4, may not be significantly different from that of pure hydrocarbons. Application of the propane combustion and nitric oxide formation model to the analysis of NOx emission data reported for various aircraft gas turbines showed the contribution of the various nitric oxide forming processes to the total NOx formed.

Study of the Low Temperature Oxidation of Propane

PubMed Central

Cord, Maximilien; Husson, Benoit; Huerta, Juan Carlos Lizardo; Herbinet, Olivier; Glaude, Pierre-Alexandre; Fournet, René; Sirjean, Baptiste; Battin-Leclerc, Frédérique; Ruiz-Lopez, Manuel; Wang, Zhandong; Xie, Mingfeng; Cheng, Zhanjun; Qi, Fei

2013-01-01

The low-temperature oxidation of propane was investigated using a jet-stirred reactor at atmospheric pressure and two methods of analysis: gas chromatography and synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) with direct sampling through a molecular jet. The second method allowed the identification of products, such as molecules with hydroperoxy functions, which are not stable enough to be detected by gas chromatography. Mole fractions of the reactants and reaction products were measured as a function of the temperature (530-730 K), with a particular attention to reaction products involved in the low temperature oxidation, such as cyclic ethers, aldehydes, alcohols, ketones, and hydroperoxides. A new model has been obtained from an automatically generated one, which was used as a starting point, with a large number of re-estimated thermochemical and kinetic data. The kinetic data of the most sensitive reactions, i.e., isomerizations of alkylperoxy radicals and the subsequent decompositions, have been calculated at the CBS-QB3 level of theory. The model allows a satisfactory prediction of the experimental data. A flow rate analysis has allowed highlighting the important reaction channels. PMID:23181456

Correlation of smoke development in room tests with cone calorimeter data for wood products

Treesearch

Mark A. Dietenberger; Ondrej Grexa

2000-01-01

A direct proportionality has been found between the smoke extinction area (SEA) for smoke of room linings and the SEA as measured in the cone calorimeter (ISO5660). The room test scenario (ISO9705) considered was the propane ignition burner at the corner with a 100/300 kW program and the specimen lined on the walls only. The mixing of smoke from propane and lining...

Fuel Cell Power Plants Renewable and Waste Fuels

DTIC Science & Technology

2011-01-13

of FuelCell Energy, Inc. Fuels Resources for DFC • Natural Gas and LNG • Propane • Biogas (by Anaerobicnaerobic Digestion) - Municipal Waste...FUEL RESOURCES z NATURAL GAS z PROPANE z DFC H2 (50-60%) z ETHANOL zWASTE METHANE z BIOGAS z COAL GAS Diversity of Fuels plus High Efficiency...trademarks (®) of FuelCell Energy, Inc. DFC Advantages for Biogas • More power for given amount of biogas : Higher efficiency than

Flame behaviors of propane/air premixed flame propagation in a closed rectangular duct with a 90-deg bend

NASA Astrophysics Data System (ADS)

He, Xuechao; Sun, Jinhua; Yuen, K. K.; Ding, Yibin; Chen, Sining

2008-11-01

Experiments of flame propagation in a small, closed rectangular duct with a 90° bend were performed for a propane-air mixture. The high speed camera and Schlieren techniques were used to record images of flame propagation process in the combustion pipe. Meanwhile, the fine thermocouples and ion current probes were applied to measure the temperature distribution and reaction intensity of combustion. The characteristics of propane-air flame and its microstructure were analyzed in detail by the experimental results. In the test, the special tulip flame formation was observed. Around the bend, the flame tip proceeded more quickly at the lower side with the flame front elongated toward the axial direction. And transition to turbulent flame occurred. It was suggested that fluctuations of velocity, ion current and temperature were mainly due to the comprehensive effects of multi-wave and the intense of turbulent combustion.

Effect of primary-zone water injection on pollutants from a combustor burning liquid ASTM A-1 and vaporized propane fuels

NASA Technical Reports Server (NTRS)

Ingebo, R. D.; Norgren, C. T.

1973-01-01

A combustor segment 0.457 meter (18 in.) long with a maximum cross section of 0.153 by 0.305 meter (6 by 12 in.) was operated at inlet-air temperatures of 590 and 700 K, inlet-air pressures of 4 and 10 atmospheres, and fuel-air ratios of 0.014 and 0.018 to determine the effect of primary-zone water injection on pollutants from burning either propane or ASTM A-1 fuel. At a simulated takeoff condition of 10 atmospheres and 700 K, multiple-orifice nozzles used to inject water at 1 percent of the airflow rate reduced nitrogen oxides 75 percent with propane and 65 percent with ASTM A-1 fuel. Although carbon monoxide and unburned hydrocarbons increased with water injection, they remained relatively low; and smoke numbers were well below the visibility limit.

Computational fluid dynamic on the temperature simulation of air preheat effect combustion in propane turbulent flame

NASA Astrophysics Data System (ADS)

Elwina; Yunardi; Bindar, Yazid

2018-04-01

this paper presents results obtained from the application of a computational fluid dynamics (CFD) code Fluent 6.3 to modelling of temperature in propane flames with and without air preheat. The study focuses to investigate the effect of air preheat temperature on the temperature of the flame. A standard k-ε model and Eddy Dissipation model are utilized to represent the flow field and combustion of the flame being investigated, respectively. The results of calculations are compared with experimental data of propane flame taken from literature. The results of the study show that a combination of the standard k-ε turbulence model and eddy dissipation model is capable of producing reasonable predictions of temperature, particularly in axial profile of all three flames. Both experimental works and numerical simulation showed that increasing the temperature of the combustion air significantly increases the flame temperature.

Hydrogen Safety Issues Compared to Safety Issues with Methane and Propane

NASA Astrophysics Data System (ADS)

Green, M. A.

2006-04-01

The hydrogen economy is not possible if the safety standards currently applied to liquid hydrogen and hydrogen gas by many laboratories are applied to devices that use either liquid or gaseous hydrogen. Methane and propane are commonly used by ordinary people without the special training. This report asks, "How is hydrogen different from flammable gasses that are commonly being used all over the world?" This report compares the properties of hydrogen, methane and propane and how these properties may relate to safety when they are used in both the liquid and gaseous state. Through such an analysis, sensible safety standards for the large-scale (or even small-scale) use of liquid and gaseous hydrogen systems can be developed. This paper is meant to promote discussion of issues related to hydrogen safety so that engineers designing equipment can factor sensible safety standards into their designs.

Sprawling nursery unveils propane backup for natural gas boilers

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

Not Available

1991-02-01

First, take the most authoritative policy- making body in the pervasive problem area of Southern California air pollution (South Coast Air Quality Management District - SCAQMD). Then apply that organization's recently- enacted regulation prohibiting the use of diesel fuel in boilers to a well-known commercial establishment. The result is an alternative fuel story, that's too engaging to overlook. Monrovia Nursery, a 65-year-old, 500-acre wholesale growing facility in Azusa, Calif., has installed two 200-hp Dixon boilers, a 14 MMBtuh Sam Dick Industries vaporizer, and six 1150-gal. tanks on the property for the use of propane as a backup fuel. While themore » nursery ordinarily uses natural gas for water heating, there are times during the winter when the supply may be curtailed or interrupted. It is then that propane would be used to heat water to keep more than 1200 varieties of plants growing as they should.« less

Hydrogen Safety Issues Compared to Safety Issues with Methane andPropane

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

Green, Michael A.

The hydrogen economy is not possible if the safety standards currently applied to liquid hydrogen and hydrogen gas by many laboratories are applied to devices that use either liquid or gaseous hydrogen. Methane and propane are commonly used by ordinary people without the special training. This report asks, 'How is hydrogen different from flammable gasses that are commonly being used all over the world?' This report compares the properties of hydrogen, methane and propane and how these properties may relate to safety when they are used in both the liquid and gaseous state. Through such an analysis, sensible safety standardsmore » for the large-scale (or even small-scale) use of liquid and gaseous hydrogen systems can be developed. This paper is meant to promote discussion of issues related to hydrogen safety so that engineers designing equipment can factor sensible safety standards into their designs.« less

Two cases of acute propane/butane poisoning in prison.

PubMed

Rossi, Riccardo; Suadoni, Fabio; Pieroni, Ludovica; De-Giorgio, Fabio; Lancia, Massimo

2012-05-01

Hydrocarbon inhalation is seldom chosen as a means to commit suicide. This practice is exclusively a prerogative of the prison population; it is, however, only exceptionally found in this environment. The two cases of lethal inhalation of propane/butane gas observed by us over a very short time occurred in this context. Toxicologic analyses were performed by means of gas chromatography (head space) and revealed a propane/butane mixture in all specimens (heart blood, bile, and urine) except vitreous humor. Although fatal arrhythmia posthydrocarbon gas abuse is well known, the concentrations of the two hydrocarbons were sufficient to induce death by asphyxiation and were distributed (fairly) homogeneously in all biological fluids and organs examined, a parameter permitting one to assume that death occurred within a relatively short period of time. The absence of finding in vitreous humor and the trace amount in urine suggests that both men died very quickly. © 2011 American Academy of Forensic Sciences.

An adjusted bed net coverage indicator with estimations for 23 African countries

PubMed Central

2013-01-01

Background Many studies have assessed the level of bed net coverage in populations at risk of malaria infection. These revealed large variations in bed net use across countries, regions and social strata. Such studies are often aimed at identifying populations with low access to bed nets that should be prioritized in future interventions. However, often spatial differences in malaria endemicity are not taken into account. By ignoring variability in malaria endemicity, these studies prioritize populations with little access to bed nets, even if these happen to live in low endemicity areas. Conversely, populations living in regions with high malaria endemicity will receive a lower priority once a seizable proportion is protected by bed nets. Adequately assigning priorities requires accounting for both the current level of bed net coverage and the local malaria endemicity. Indeed, as shown here for 23 African countries, there is no correlation between the level of bed net coverage and the level of malaria endemicity in a region. Therefore, the need for future interventions can not be assessed based on current bed net coverage alone. This paper proposes the Adjusted Bed net Coverage (ABC) statistic as a measure taking into account both local malaria endemicity and the level of bed net coverage. The measure allows setting priorities for future interventions taking into account both local malaria endemicity and bed net coverage. Methods A mathematical formulation of the ABC as a weighted difference of bed net coverage and malaria endemicity is presented. The formulation is parameterized based on a model of malaria epidemiology (Smith et al. Trends Parasitol 25:511-516, 2009). By parameterizing the ABC based on this model, the ABC as used in this paper is proxy for the steady-state malaria burden given the current level of bed net coverage. Data on the bed net coverage in under five year olds and malaria endemicity in 23 Sub-Saharan countries is used to show that the ABC prioritizes different populations than the level of bed net coverage by itself. Data from the following countries was used: Angola, Burkina Faso, Burundi, Cameroon, Congo Democratic Republic, Ethiopia, Ghana, Guinea, Kenya, Liberia, Madagascar, Malawi, Mali, Mozambique, Namibia, Nigeria, Rwanda, Senegal, Sierra Leone, Tanzania, Uganda, Zambia and Zimbabwe. The priority order given by the ABC and the bed net coverage are compared at the countries’ level, the first level administrative divisions and for five different wealth quintiles. Results Both at national level and at the level of the administrative divisions the ABC suggests a different priority order for selecting countries and divisions for future interventions. When taking into account malaria endemicity, measures assessing equality in access to bed nets across wealth quintiles, such as slopes of inequality, are prone to change. This suggests that when assessing inequality in access to bed nets one should take into account the local malaria endemicity for populations from different wealth quintiles. Conclusion Accounting for malaria endemicity highlights different countries, regions and socio-economic strata for future intervention than the bed net coverage by itself. Therefore, care should be taken to factor out any effects of local malaria endemicity in assessing bed net coverage and in prioritizing populations for further scale-up of bed net coverage. The ABC is proposed as a simple means to do this that is derived from an existing model of malaria epidemiology. PMID:24359227

Propulsion and Power Rapid Response Research and Development Support: Delivery Order: Fundamental Science Investigations for Propulsion and Power Systems

DTIC Science & Technology

2009-01-01

propane/air flame (φ = 1.1, flow speed = 1.3 m/s). A small DC current causes a laminar flame to go unsteady and decrease somewhat in height due to...three-level model which is used for inert gases. The three-level model describes the build-up of electrons in the system as they go through the...Produced MWCNT 94 96 98 100 102 W ei gh t ( % ) 0 200 400 600 800 1000 Temperature (°C) Universal V4.2E TA Instruments Figure 7. TGA Analysis of

Enzyme-catalyzed hydrolysis of dentin adhesives containing a new urethane-based trimethacrylate monomer

PubMed Central

Park, Jong-Gu; Ye, Qiang; Topp, Elizabeth M.; Spencer, Paulette

2009-01-01

A new trimethacrylate monomer with urethane-linked groups, 1,1,1-tri-[4-(methacryloxyethylamino-carbonyloxy)-phenyl]ethane (MPE), was synthesized, characterized, and used as a co-monomer in dentin adhesives. Dentin adhesives containing 2-hydroxyethyl methacrylate (HEMA, 45% w/w) and 2,2-bis[4(2-hydroxy-3-methacryloyloxy-propyloxy)-phenyl] propane (BisGMA, 30% w/w) in addition to MPE (25% w/w) were formulated with H2O at 0 (MPE0), 8 (MPE8) and 16 wt % water (MPE16) to simulate the wet demineralized dentin matrix and compared with controls [HEMA/BisGMA, 45/55 w/w, at 0 (C0), 8 (C8) and 16 wt% water (C16)]. The new adhesive showed a degree of double bond conversion and mechanical properties comparable with control, with good penetration into the dentin surface and a uniform adhesive/dentin interface. On exposure to porcine liver esterase, the net cumulative methacrylic acid (MAA) release from the new adhesives was dramatically (P < 0.05) decreased relative to the control, suggesting that the new monomer improves esterase resistance. PMID:19582843

Fluorescent temperature sensor

DOEpatents

Baker, Gary A [Los Alamos, NM; Baker, Sheila N [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM

2009-03-03

The present invention is a fluorescent temperature sensor or optical thermometer. The sensor includes a solution of 1,3-bis(1-pyrenyl)propane within a 1-butyl-1-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid solvent. The 1,3-bis(1-pyrenyl)propane remains unassociated when in the ground state while in solution. When subjected to UV light, an excited state is produced that exists in equilibrium with an excimer. The position of the equilibrium between the two excited states is temperature dependent.

Mechanosensitivity below Ground: Touch-Sensitive Smell-Producing Roots in the Shy Plant Mimosa pudica1[OPEN

PubMed Central

Musah, Rabi A.; Lesiak, Ashton D.; Maron, Max J.; Edwards, David; Fowble, Kristen L.; Long, Michael C.

2016-01-01

The roots of the shy plant Mimosa pudica emit a cocktail of small organic and inorganic sulfur compounds and reactive intermediates into the environment, including SO2, methanesulfinic acid, pyruvic acid, lactic acid, ethanesulfinic acid, propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, phenothiazine, and thioformaldehyde, an elusive and highly unstable compound that, to our knowledge, has never before been reported to be emitted by a plant. When soil around the roots is dislodged or when seedling roots are touched, an odor is detected. The perceived odor corresponds to the emission of higher amounts of propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, and phenothiazine. The mechanosensitivity response is selective. Whereas touching the roots with soil or human skin resulted in odor detection, agitating the roots with other materials such as glass did not induce a similar response. Light and electron microscopy studies of the roots revealed the presence of microscopic sac-like root protuberances. Elemental analysis of these projections by energy-dispersive x-ray spectroscopy revealed them to contain higher levels of K+ and Cl− compared with the surrounding tissue. Exposing the protuberances to stimuli that caused odor emission resulted in reductions in the levels of K+ and Cl− in the touched area. The mechanistic implications of the variety of sulfur compounds observed vis-à-vis the pathways for their formation are discussed. PMID:26661932

Vibrational spectroscopy (FT-IR and Laser-Raman) investigation, and computational (M06-2X and B3LYP) analysis on the structure of 4-(3-fluorophenyl)-1-(propan-2-ylidene)-thiosemicarbazone.

PubMed

Sert, Yusuf; Miroslaw, Barbara; Çırak, Çağrı; Doğan, Hatice; Szulczyk, Daniel; Struga, Marta

2014-07-15

In this study, the experimental and theoretical vibrational spectral analysis of 4-(3-fluorophenyl)-1-(propan-2-ylidene)-thiosemicarbazone have been carried out. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) have been recorded for the solid state samples. The theoretical vibrational frequencies and the optimized geometric parameters (bond lengths and angles) have been calculated for gas phase using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and M06-2X (the highly parametrized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set. The diversity in molecular geometry of fluorophenyl substituted thiosemicarbazones has been discussed based on the X-ray crystal structure reports and theoretical calculation results from the literature. The assignments of the vibrational frequencies have been done on the basis of potential energy distribution (PED) analysis by using VEDA4 software. A good correlation was found between the computed and experimental geometric and vibrational data. In addition, the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbital energy levels and other related molecular energy values of the compound have been determined using the same level of theoretical calculations. Copyright © 2014 Elsevier B.V. All rights reserved.

Contact allergy to epoxy (meth)acrylates.

PubMed

Aalto-Korte, Kristiina; Jungewelter, Soile; Henriks-Eckerman, Maj-Len; Kuuliala, Outi; Jolanki, Riitta

2009-07-01

Contact allergy to epoxy (meth)acrylates, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA), 2,2-bis[4-(2-hydroxy-3-acryloxypropoxy)phenyl]-propane (bis-GA), 2,2-bis[4-(methacryl-oxyethoxy)phenyl] propane (bis-EMA), 2,2-bis[4-(methacryloxy)phenyl]-propane (bis-MA), and glycidyl methacrylate (GMA) is often manifested together with contact allergy to diglycidyl ether of bisphenol A (DGEBA) epoxy resin. To analyse patterns of concomitant allergic reactions to the five epoxy (meth)acrylates in relation to exposure. We reviewed the 1994-2008 patch test files at the Finnish Institute of Occupational Health (FIOH) for reactions to the five epoxy (meth)acrylates, and examined the patients' medical records for exposure. Twenty-four patients had an allergic reaction to at least one of the studied epoxy (meth)acrylates, but specific exposure was found only in five patients: two bis-GMA allergies from dental products, two bis-GA allergies from UV-curable printing inks, and one bis-GA allergy from an anaerobic glue. Only 25% of the patients were negative to DGEBA epoxy resin. The great majority of allergic patch test reactions to bis-GMA, bis-GA, GMA and bis-EMA were not associated with specific exposure, and cross-allergy to DGEBA epoxy resin remained a probable explanation. However, independent reactions to bis-GA indicated specific exposure. Anaerobic sealants may induce sensitization not only to aliphatic (meth)acrylates but also to aromatic bis-GA.

Natural gas and temperature structured a microbial community response to the Deepwater Horizon oil spill.

PubMed

Redmond, Molly C; Valentine, David L

2012-12-11

Microbial communities present in the Gulf of Mexico rapidly responded to the Deepwater Horizon oil spill. In deep water plumes, these communities were initially dominated by members of Oceanospirillales, Colwellia, and Cycloclasticus. None of these groups were abundant in surface oil slick samples, and Colwellia was much more abundant in oil-degrading enrichment cultures incubated at 4 °C than at room temperature, suggesting that the colder temperatures at plume depth favored the development of these communities. These groups decreased in abundance after the well was capped in July, but the addition of hydrocarbons in laboratory incubations of deep waters from the Gulf of Mexico stimulated Colwellia's growth. Colwellia was the primary organism that incorporated (13)C from ethane and propane in stable isotope probing experiments, and given its abundance in environmental samples at the time that ethane and propane oxidation rates were high, it is likely that Colwellia was active in ethane and propane oxidation in situ. Colwellia also incorporated (13)C benzene, and Colwellia's abundance in crude oil enrichments without natural gas suggests that it has the ability to consume a wide range of hydrocarbon compounds or their degradation products. However, the fact that ethane and propane alone were capable of stimulating the growth of Colwellia, and to a lesser extent, Oceanospirillales, suggests that high natural gas content of this spill may have provided an advantage to these organisms.

Deposit formation and heat transfer in hydrocarbon rocket fuels

NASA Technical Reports Server (NTRS)

Giovanetti, A. J.; Spadaccini, L. J.; Szetela, E. J.

1983-01-01

An experimental research program was undertaken to investigate the thermal stability and heat transfer characteristics of several hydrocarbon fuels under conditions that simulate high-pressure, rocket engine cooling systems. The rates of carbon deposition in heated copper and nickel-plated copper tubes were determined for RP-1, propane, and natural gas using a continuous flow test apparatus which permitted independent variation and evaluation of the effect on deposit formation of wall temperature, fuel pressure, and fuel velocity. In addition, the effects of fuel additives and contaminants, cryogenic fuel temperatures, and extended duration testing with intermittent operation were examined. Parametric tests to map the thermal stability characteristics of RP-1, commercial-grade propane, and natural gas were conducted at pressures of 6.9 to 13.8 MPa, bulk fuel velocities of 30 to 90 m/s, and tube wall temperatures in the range of 230 to 810 K. Also, tests were run in which propane and natural gas fuels were chilled to 230 and 160 K, respectively. Corrosion of the copper tube surface was detected for all fuels tested. Plating the inside of the copper tubes with nickel reduced deposit formation and eliminated tube corrosion in most cases. The lowest rates of carbon deposition were obtained for natural gas, and the highest rates were obtained for propane. For all fuels tested, the forced-convection heat transfer film coefficients were satisfactorily correlated using a Nusselt-Reynolds-Prandtl number equation.

A Experimental Study of the Growth of Laser Spark and Electric Spark Ignited Flame Kernels.

NASA Astrophysics Data System (ADS)

Ho, Chi Ming

1995-01-01

Better ignition sources are constantly in demand for enhancing the spark ignition in practical applications such as automotive and liquid rocket engines. In response to this practical challenge, the present experimental study was conducted with the major objective to obtain a better understanding on how spark formation and hence spark characteristics affect the flame kernel growth. Two laser sparks and one electric spark were studied in air, propane-air, propane -air-nitrogen, methane-air, and methane-oxygen mixtures that were initially at ambient pressure and temperature. The growth of the kernels was monitored by imaging the kernels with shadowgraph systems, and by imaging the planar laser -induced fluorescence of the hydroxyl radicals inside the kernels. Characteristic dimensions and kernel structures were obtained from these images. Since different energy transfer mechanisms are involved in the formation of a laser spark as compared to that of an electric spark; a laser spark is insensitive to changes in mixture ratio and mixture type, while an electric spark is sensitive to changes in both. The detailed structures of the kernels in air and propane-air mixtures primarily depend on the spark characteristics. But the combustion heat released rapidly in methane-oxygen mixtures significantly modifies the kernel structure. Uneven spark energy distribution causes remarkably asymmetric kernel structure. The breakdown energy of a spark creates a blast wave that shows good agreement with the numerical point blast solution, and a succeeding complex spark-induced flow that agrees reasonably well with a simple puff model. The transient growth rates of the propane-air, propane-air -nitrogen, and methane-air flame kernels can be interpreted in terms of spark effects, flame stretch, and preferential diffusion. For a given mixture, a spark with higher breakdown energy produces a greater and longer-lasting enhancing effect on the kernel growth rate. By comparing the growth rates of the appropriate mixtures, the positive and negative effects of preferential diffusion and flame stretch on the developing flame are clearly demonstrated.

Mechanisms for the dehydrogenation of alkanes on platinum: insights gained from the reactivity of gaseous cluster cations, Ptn + n=1-21.

PubMed

Adlhart, Christian; Uggerud, Einar

2007-01-01

Rates for the dihydrogen elimination of methane, ethane, and propane with cationic platinum clusters, Pt(n) (+) (1

Specific, Measureable, Attainable, Relevant, and Timely (SMART) Documents: Utilized in Assessing Socioeconomic Impacts of Cascading Infrastructure Disruptions

DTIC Science & Technology

2017-02-01

wind turbines . The following questions focus on determining how a local population uses the available electrical network, and what aspects of normal...panels, wind turbines , propane tanks, or gas tanks visible in pictures? • Direct Observation – What equipment is used to generate power? • Local...the grid may not be a high priority. Data Collection: • Remote Sensing – Are solar panels, wind turbines , propane tanks, or gas tanks visible in

Platinum-Promoted Ga/Al2O3 as Highly Active, Selective, and Stable Catalyst for the Dehydrogenation of Propane**

PubMed Central

Sattler, Jesper J H B; Gonzalez-Jimenez, Ines D; Luo, Lin; Stears, Brien A; Malek, Andrzej; Barton, David G; Kilos, Beata A; Kaminsky, Mark P; Verhoeven, Tiny W G M; Koers, Eline J; Baldus, Marc; Weckhuysen, Bert M

2014-01-01

A novel catalyst material for the selective dehydrogenation of propane is presented. The catalyst consists of 1000 ppm Pt, 3 wt % Ga, and 0.25 wt % K supported on alumina. We observed a synergy between Ga and Pt, resulting in a highly active and stable catalyst. Additionally, we propose a bifunctional active phase, in which coordinately unsaturated Ga3+ species are the active species and where Pt functions as a promoter. PMID:24989975

Severe Sunburn After a Hot Air Balloon Ride: A Case Report and Literature Review.

PubMed

Ozturk, Sinan; Karagoz, Huseyin

2015-01-01

Hot air balloon tours are very popular among travelers worldwide. Preventable burn injuries associated with hot air balloon rides have been reported during crashes into power lines, in propane burner explosions, and following contact with the propane burner tanks. We present a case of severe repeated sunburn, which poses another risk of preventable injury during hot air balloon rides, and briefly discuss the injury epidemiology of hot air balloon rides. © 2015 International Society of Travel Medicine.

Extreme toxicity from combustion products of a fire-retarded polyurethane foam.

PubMed

Petajan, J H; Voorhees, K J; Packham, S C; Baldwin, R C; Einhorn, I N; Grunnet, M L; Dinger, B G; Birky, M M

1975-02-28

The products from nonflaming combustion of wood and a trimethylol-propane-based rigid-urethane foam that was not fire-retarded produced elevated carboxyhemoglobin levels but no abnormal neurological effects. However, when this type of foam contained a reactive phosphate fire retardant, the combustion products caused grand mal seizures and death in rats. The toxic combustion product responsible for the seizures has been identified as 4-ethyl-1-phospha-2,6,7-trioxabicyclo(2.2.2.)octane-1-oxide.

Facile radiosynthesis of fluorine-18 labeled beta-blockers. Synthesis, radiolabeling, and ex vivo biodistribution of [18F]-(2S and 2R)-1-(1-fluoropropan-2-ylamino)-3-(m-tolyloxy)propan-2-ol.

PubMed

Stephenson, Karin A; Wilson, Alan A; Meyer, Jeffrey H; Houle, Sylvain; Vasdev, Neil

2008-08-28

An efficient and general method has been developed for fluorine-18 labeling of beta-blockers that possess the propanolamine moiety. A new synthetically versatile intermediate, 3-(1-(benzyloxy)propan-2-yl)-2-oxooxazolidin-5-yl)methyl 4-methylbenzenesulfonate (13), was prepared and can be conjugated to any phenoxy core. To demonstrate the synthetic methodology, fluorinated derivatives of toliprolol were prepared, namely, [(18)F]-(2S and 2R)-1-(1-fluoropropan-2-ylamino)-3-(m-tolyloxy)propan-2-ol ((2S and 2R)-[(18)F]1). The radiosyntheses were accomplished in <1 h, with 20-24% (uncorrected for decay, n = 7) radiochemical yields, >96% radiochemical and >99% enantiomeric purities, with specific activities of 0.9-1.1 Ci/micromol (EOS). Ex vivo biodistribution studies with the radiotracers demonstrated excessively rapid washout that may limit their use for cerebral PET imaging.

Influence of propane additives on the detonation characteristics of H2-air mixtures

NASA Astrophysics Data System (ADS)

Cheng, Guanbing; Bauer, Pascal; Zitoun, Ratiba

2014-03-01

Hydrogen is more and more considered as a potential fuel for propulsion applications. However, due to its low ignition energy and wide flammability limits, H2-air mixtures raise a concern in terms of safety. This aspect can be partly solved by adding an alkane to these mixtures, which plays the role of an inhibitor. The present paper provides data on such binary fuel-air mixtures where various amounts of propane are added to hydrogen. The behavior of the corresponding mixtures, in terms of detonation characteristics and other fundamental properties, such as the cell size of the detonation front and induction delay, are presented and discussed for a series of equivalence ratios and propane addition. The experimental detonation velocity is in good agreement with calculated theoretical Chapman-Jouguet values. Based on soot tracks records, the cell size λ is measured, whereas the induction length L i is derived from data using a GRI-Mech kinetic mechanism. These data allow providing a value of the coefficient K = λ/L i .

Selective deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) surfaces

NASA Astrophysics Data System (ADS)

Xiong, Ke; Yu, Weiting; Chen, Jingguang G.

2014-12-01

The selective deoxygenation of aldehydes and alcohols without cleaving the Csbnd C bond is crucial for upgrading bio-oil and other biomass-derived molecules to useful fuels and chemicals. In this work, propanal, 1-propanol, furfural and furfuryl alcohol were selected as probe molecules to study the deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) prepared over a Mo(1 1 0) surface. The reaction pathways were investigated using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The deoxygenation of propanal and 1-propanol went through a similar intermediate (propoxide or η2(C,O)-propanal) to produce propene. The deoxygenation of furfural and furfuryl alcohol produced a surface intermediate similar to adsorbed 2-methylfuran. The comparison of these results revealed the promising deoxygenation performance of Mo2C, as well as the effect of the furan ring on the selective deoxygenation of the Cdbnd O and Csbnd OH bonds.

Effect of an alternating electric field on the polluting emission from propane flame.

NASA Astrophysics Data System (ADS)

Ukradiga, I.; Turlajs, D.; Purmals, M.; Barmina, I.; Zake, M.

2001-12-01

The experimental investigations of the AC field effect on the propane combustion and processes that cause the formation of polluting emissions (NO_x, CO, CO_2) are performed. The AC-enhanced variations of the temperature and composition of polluting emissions are studied for the fuel-rich and fuel-lean conditions of the flame core. The results show that the AC field-enhanced mixing of the fuel-rich core with the surrounding air coflow enhances the propane combustion with increase in the mass fraction of NO_x and CO_2 in the products. The reverse field effect on the composition of polluting emissions is observed under the fuel-lean conditions in the flame core. The field-enhanced CO_2 destruction is registered when the applied voltage increase. The destruction of CO_2 leads to a correlating increase in the mass fraction of CO in the products and enhances the process of NO_x formation within the limit of the fuel lean and low temperature combustion. Figs 11, Refs 18.

Use of propane as a quench gas in argon-filled proportional counters and comparison with other quench gases

NASA Technical Reports Server (NTRS)

Agrawal, P. C.; Ramsey, B. D.

1988-01-01

An experimental investigation of propane and six other quench gases was carried out in argon-filled proportional counters. The objective of the study was to find the best gas mixture for optimizing the gas gain and the energy resolution as well as to understand the role of the ionization potential of quench gases in determining these parameters. It was found that the best gas gains and energy resolutions are obtained with propane, ethane, and isobutane in that order. The ionization potentials of these three lie below the argon metastable potentials and have the lowest value of resonance defect compared to the other quench gases. The better results obtained with these mixtures can be explained by an increased ionization yield resulting from the Penning effect. Propylene and trans-2-butene give inferior performance compared to the above three gases. Methane and carbon dioxide, the most commonly used quench gases in the argon-filled detectors, provide the worst results.

Synthesis of ZnMn₂O₄ Nanoparticles by a Microwave-Assisted Colloidal Method and their Evaluation as a Gas Sensor of Propane and Carbon Monoxide.

PubMed

Morán-Lázaro, Juan Pablo; Guillen-López, Erwin Said; López-Urias, Florentino; Muñoz-Sandoval, Emilio; Blanco-Alonso, Oscar; Guillén-Bonilla, Héctor; Guillén-Bonilla, Alex; Rodríguez-Betancourtt, Verónica María; Sanchez-Tizapa, Marciano; Olvera-Amador, María de la Luz

2018-02-27

Spinel-type ZnMn₂O₄ nanoparticles were synthesized via a simple and inexpensive microwave-assisted colloidal route. Structural studies by X-ray diffraction showed that a spinel crystal phase of ZnMn₂O₄ was obtained at a calcination temperature of 500 °C, which was confirmed by Raman and UV-vis characterizations. Spinel-type ZnMn₂O₄ nanoparticles with a size of 41 nm were identified by transmission electron microscopy. Pellet-type sensors were fabricated using ZnMn₂O₄ nanoparticles as sensing material. Sensing measurements were performed by exposing the sensor to different concentrations of propane or carbon monoxide at temperatures in the range from 100 to 300 °C. Measurements performed at an operating temperature of 300 °C revealed a good response to 500 ppm of propane and 300 ppm of carbon monoxide. Hence, ZnMn₂O₄ nanoparticles possess a promising potential in the gas sensors field.

Combustion performance and heat transfer characterization of LOX/hydrocarbon type propellants

NASA Technical Reports Server (NTRS)

Michel, R. W.

1983-01-01

An evaluation liquid oxygen (LOX) and various hydrocarbon fuels as low cost alternative propellants suitable for future space transportation system applications was done. The emphasis was directed toward low earth orbit maneuvering engine and reaction control engine systems. The feasibility of regeneratively cooling an orbit maneuvering thruster was analytically determined over a range of operating conditions from 100 to 1000 psia chamber pressure and 1000 to 10,000-1bF thrust, and specific design points were analyzed in detail for propane, methane, RP-1, ammonia, and ethanol; similar design point studies were performed for a film-cooled reaction control thruster. Heat transfer characteristics of propane were experimentally evaluated in heated tube tests. Forced convection heat transfer coefficients were determined. Seventy-seven hot firing tests were conducted with LOX/propane and LOX/ethanol, for a total duration of nearly 1400 seconds, using both heat sink and water-cooled calorimetric chambers. Combustion performance and stability and gas-side heat transfer characteristics were evaluated.

Enhanced Hydrate Nucleation Near the Limit of Stability.

PubMed

Jimenez-Angeles, Felipe; Firoozabadi, Abbas

2015-03-30

Clathrate hydrates are crystalline structures composed of small guest molecules trapped into cages formed by hydrogen-bonded water molecules. In hydrate nucleation, water and the guest molecules may stay in a metastable fluid mixture for a long period. Metastability is broken if the concentration of the guest is above certain limit. We perform molecular dynamics (MD) simulations of supersaturated water-propane solutions close to the limit of stability. We show that hydrate nucleation can be very fast in a very narrow range of composition at moderate temperatures. Propane density fluctuations near the fluid-fluid demixing are coupled with crystallization producing en- hanced nucleation rates. This is the first report of propane-hydrate nucleation by MD simulations. We observe motifs of the crystalline structure II in line with experiments and new hydrate cages not reported in the literature. Our study relates nucleation to the fluid-fluid spinodal decomposition and demonstration that the enhanced nucleation phenomenon is more general than short range attractive interactions as suggested in nucleation of proteins.

Effect of Initial Mixture Temperature on Flame Speed of Methane-Air, Propane-Air, and Ethylene-Air Mixtures

NASA Technical Reports Server (NTRS)

Dugger, Gordon L

1952-01-01

Flame speeds based on the outer edge of the shadow cast by the laminar Bunsen cone were determined as functions of composition for methane-air mixtures at initial mixture temperatures ranging from -132 degrees to 342 degrees c and for propane-air and ethylene-air mixtures at initial mixture temperatures ranging from -73 degrees to 344 degrees c. The data showed that maximum flame speed increased with temperature at an increasing rate. The percentage change in flame speed with change in initial temperature for the three fuels followed the decreasing order, methane, propane, and ethylene. Empirical equations were determined for maximum flame speed as a function of initial temperature over the temperature range covered for each fuel. The observed effect of temperature on flame speed for each of the fuels was reasonably well predicted by either the thermal theory as presented by Semenov or the square-root law of Tanford and Pease.

Powering the Future

NASA Technical Reports Server (NTRS)

2002-01-01

Stirling Technology Company (STC) developed the RG-350 convertor using components from separate Goddard Space Center and U.S. Army Natick SBIR contracts. Based on the RG-350, STC commercialized a product line of Stirling cycle generator sets, known as RemoteGen(TM), with power levels ranging from 10We to 3kWe. Under SBIR agreements with Glenn Research Center, the company refined and extended the capabilities of the RemoteGen convertors. They can provide power in remote locations by efficiently producing electricity from multiple-fuel sources, such as propane, alcohol, gasoline, diesel, coal, solar energy, or wood pellets. Utilizing any fuel source that can create heat, RemoteGen enables the choice of the most appropriate fuel source available. The engines operate without friction, wear, or maintenance. These abilities pave the way for self-powered appliances, such as refrigerators and furnaces. Numerous applications for RemoteGen include quiet, pollution-free generators for RVs and yachts, power for cell phone towers remote from the grid, and off-grid residential power variously using propane, ethanol, and solid biomass fuels. One utility and the National Renewable Energy Laboratory are evaluating a solar dish concentrator version with excellent potential for powering remote irrigation pumps.

Design of a Vehicle-Based Intervention System to Prevent Ozone Loss

NASA Technical Reports Server (NTRS)

Mason, William H.; Kirchbaum, Nathan; Kay, Jacob; Benoliel, Alexander M.; Lynn, Sean R.; Bunker, Deborah; Hesbach, Thomas D., Jr.; Howerton, Everett B.; Hreinsson, Gudbjoern; Mistr, E. Kirk

1993-01-01

Reduced quantities of ozone in the atmosphere allow greater levels of ultraviolet (UV) radiation to reach the earth's surface. The 1992/1993 project goals for the Virginia Tech Senior Design Team were to 1) understand the processes which contribute to stratospheric ozone loss, 2) examine ways to prevent ozone loss, and 3) define the requirements for an implementation vehicle to carry out the prevention scheme. A scheme proposed by R.J. Cicerone, el al late in 1991 was selected because of its supporting research and economic feasibility. This scheme uses hydrocarbon injected into the Antarctic ozone hole to form stable compounds with free chlorine, thus reducing ozone depletion. A study of the hydrocarbon injection requirements determined that 130 aircraft traveling Mach 2.4 at a maximum altitude of 66,000 ft. would provide the most economic approach to preventing ozone loss. Each aircraft would require an 8,000 nm. range and be able to carry 35,000 lbs. of propane. The propane would be stored in a three-tank high pressure system. Modularity and multi-role functionality were selected to be key design features. Missions originate from airports located in South America and Australia.

Evaluation of propane combustion traps for the collection of Phlebotomus papatasi (Scopoli) in southern Israel.

PubMed

Kline, Daniel L; Müller, Günter C; Hogsette, Jerome A

2011-03-01

In this study, we evaluated the efficacy of eleven commercial models of propane combustion traps for catching male and female Phlebotomus papatasi. The traps differed in physical appearance, amount of carbon dioxide produced and released, type and location of capturing device, and the method by which the trap suction fans were powered. The traps tested were the Mosquito Magnet™(MM)-Pro, MM-Liberty, MM-Liberty Plus, MM-Defender, SkeeterVac®(SV)-35, SV-27, Mosquito Deleto™(MD)-2200, MD-2500, MT150-Power Trap, and two models of The Guardian Mosquito Traps (MK-01 and MK-12). All trap models except the SV-35, the SV-27, the MD-2500, and the MK-12 attracted significantly more females than males. The SV-35 was the most efficient trap, catching significantly more females than all the other models. The MD-2200 and MK-12 models were the least effective in catching either female or male sand flies. These data indicate that several models of propane combustion traps might be suitable substitutes for either CO(2) -baited or unbaited light traps for adult sand fly surveillance tools. One advantageous feature is the traps' ability to remain operational 24/7 for ca. 20 days on a single tank of propane. Additionally, the models that produce their own electricity to power the trap's fans have an important logistical advantage in field operations over light traps, which require daily battery exchange and charging. © 2011 The Society for Vector Ecology.

Quantitative determination of n-propane, iso-butane, and n-butane by headspace GC-MS in intoxications by inhalation of lighter fluid.

PubMed

Bouche, Marie-Paule L A; Lambert, Willy E; Van Bocxlaer, Jan F P; Piette, Michel H; De Leenheer, André P

2002-01-01

This report describes a fully elaborated and validated method for quantitation of the hydrocarbons n-propane, iso-butane, and n-butane in blood samples. The newly developed analytical procedure is suitable for both emergency cases and forensic medicine investigations. Its practical applicability is illustrated with a forensic blood sample after acute inhalative intoxication with lighter fluid; case history and toxicological findings are included. Identification and quantitation of the analytes were performed using static headspace extraction combined with gas chromatography-mass spectrometry. In order to reconcile the large gas volumes injected (0.5 mL) with the narrowbore capillary column and thus achieve preconcentration, cold trapping on a Tenax sorbent followed by flash desorption was applied. Adequate retention and separation were achieved isothermally at 35 degrees C on a thick-film capillary column. Sample preparation was kept to a strict minimum and involved simply adding 2.5 microL of a liquid solution of 1,1,2-trichlorotrifluoroethane in t-butyl-methylether as an internal standard to aliquots of blood in a capped vial. Standards were created by volumetric dilution departing from a gravimetrically prepared calibration gas mixture composed of 0.3% of n-propane, 0.7% of iso-butane, and 0.8% of n-butane in nitrogen. In the forensic blood sample, the following concentrations were measured: 90.0 microg/L for n-propane, 246 microg/L for iso-butane, and 846 microg/L for n-butane.

Exposure of flight attendants to pyrethroid insecticides on commercial flights: urinary metabolite levels and implications

PubMed Central

Wei, Binnian; Mohan, Krishnan R.; Weisel, Clifford P.

2011-01-01

Pyrethroid insecticides have been used for disinsection of commercial aircrafts. However, little is known about the pyrethroids exposure of flight attendants. The objective of the study was to assess pyrethroids exposure of flight attendants working on commercial aircrafts through monitoring the urinary pyrethroids metabolite levels. Eighty four urine samples were collected from 28 flight attendants, 18 – 65 years of age, with seventeen working on planes that were non-disinsected, and eleven working on planes that had been disinsected. Five urinary metabolites of pyrethroids were measured using gas chromatographic–mass spectrometric method: 3-phenoxybenzoic acid (3-PBA), cis-/trans-3-(2,2-Dichlorovinyl)-2,2-dimethylcyclo-propane carboxylic acid (cis-/trans-Cl2CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclo-propane-1-carboxylic acid (cis-Br2CA) and 4-fluoro-3-phenoxybenzoic acid (4F-3-PBA). Flight attendants working on disinsected planes had significantly higher urinary levels of 3-PBA, cis- and trans-Cl2CA in pre, post- and 24hr-post flight samples than those on planes which did not report having been disinsected. Urinary levels of cis-Br2CA and 4F-3-PBA did not show significant differences between the two groups. Flight attendants working on international flights connected to Australia had higher urinary levels of 3-PBA, cis- and trans-Cl2CA than those on either domestic and other international flights flying among Asia, Europe and North America. Post-disinsection duration (number of days from disinsection date to flight date) was the most significant factor affecting the urinary pyrethroid metabolites levels of 3-PBA, cis- and trans-Cl2CA of the group flying on disinsected aircraft. It was concluded that working on commercial aircrafts disinsected by pyrethroids resulted in elevated body burden of 3-PBA, cis- and trans-Cl2CA. PMID:21937269

Ethene/ethane and propene/propane separation via the olefin and paraffin selective metal-organic framework adsorbents CPO-27 and ZIF-8.

PubMed

Böhme, Ulrike; Barth, Benjamin; Paula, Carolin; Kuhnt, Andreas; Schwieger, Wilhelm; Mundstock, Alexander; Caro, Jürgen; Hartmann, Martin

2013-07-09

Two types of metal-organic frameworks (MOFs) have been synthesized and evaluated in the separation of C2 and C3 olefins and paraffins. Whereas Co2(dhtp) (=Co-CPO-27 = Co-MOF-74) and Mg2(dhtp) show an adsorption selectivity for the olefins ethene and propene over the paraffins ethane and propane, the zeolitic imidazolate framework ZIF-8 behaves in the opposite way and preferentially adsorbs the alkane. Consequently, in breakthrough experiments, the olefins or paraffins, respectively, can be separated.

Method for measuring surface temperature

DOEpatents

Baker, Gary A [Los Alamos, NM; Baker, Sheila N [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM

2009-07-28

The present invention relates to a method for measuring a surface temperature using is a fluorescent temperature sensor or optical thermometer. The sensor includes a solution of 1,3-bis(1-pyrenyl)propane within a 1-butyl-1-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid solvent. The 1,3-bis(1-pyrenyl)propane remains unassociated when in the ground state while in solution. When subjected to UV light, an excited state is produced that exists in equilibrium with an excimer. The position of the equilibrium between the two excited states is temperature dependent.

An Investigation of Slurry Fuel Combustion.

DTIC Science & Technology

1981-01-01

tit Lil’ sitas wtae f).4 mm ap.art. w w =Q L-1~ rAn Li w > 0 0- - q The propane gas flow rate was metered withi a Matlieson Model 604 rotameter and...controlled by a Harris Model 2515 pressure regulator with an output capacity of 0-0.69 MPa. The flow rate of the iydrog’en gas was metered with a...propane 3nd hydrogen flows were calibrated with a Precision Scientific Companv wet-test meter (2.83 ml/rev). The fuel drops were mounted with a

Cryosurgical treatment of warts: dimethyl ether and propane versus liquid nitrogen - case report and review of the literature.

PubMed

Nguyen, Nicholas V; Burkhart, Craig G

2011-10-01

For years, dermatologists have relied on cryotherapy with liquid nitrogen as a safe and effective treatment for warts. More recently, several over-the-counter (OTC) wart-freezing therapies have become available. Manufacturers have substituted liquid nitrogen with dimethyl ether and propane (DMEP), and marketed these new preparations to be safe and effective alternatives to in-office cryotherapy with liquid nitrogen. However, data from in vitro studies and comparative studies in humans refute manufacturers' claims that these products reproduce in-office cryotherapy.

Proceedings of the Air Force High Energy Density Materials Contractors Conference (2nd) Held in Newport Beach, CA, on 28 Feb-2 Mar 1988

DTIC Science & Technology

1988-05-27

expansion process is currently under investigation. 7 REFERENCES 1 . A. P. Marchand. " Synthesis and Chemistry of Novel Polynitropolycylic Cage...for example is 0.12 ± 0.01 for formation of 1 - chloropropane and 2- chloropropane from an equimolar mixture of propane and chlorine. Although the...that the product branching ratio (2-chloropropane:l- chloropropane ) is 5.6: 1 . When corrected for the fact that propane contains only one third as many

Synthesis, crystal structure, and spectroscopic characterization of trans-bis[(mu-1,3-bis(4-pyridyl)propane)(mu-(3-thiopheneacetate-O))(3-thiopheneacetate-O)]dicopper(II), [[Cu2(O2CCH2C4H3S)4mu-(BPP)2

PubMed

Marinho, Maria Vanda; Yoshida, Maria Irene; Guedes, Kassilio J; Krambrock, Klaus; Bortoluzzi, Adailton J; Hörner, Manfredo; Machado, Flávia C; Teles, Wagner M

2004-02-23

From the reaction between a dinuclear paddle-wheel carboxylate, namely [Cu2mu-(O2CCH2C4H3S)4] (1), and the flexible ligand 1,3-bis(4-pyridyl)propane (BPP) a neutral 2-D coordination polymer [[Cu2(O2CCH2C4H3S)4mu-(BPP)2

Spontaneous ignition characteristics of gaseous hydrocarbon-air mixtures

NASA Technical Reports Server (NTRS)

Freeman, G.; Lefebvre, A. H.

1984-01-01

Experiments are conducted to determine the spontaneous ignition delay times of gaseous propane, kerosine vapor, and n-heptane vapor in mixtures with air, and oxygen-enriched air, at atmospheric pressure. Over a range of equivalence ratios from 0.2 to 0.8 it is found that ignition delay times are sensibly independent of fuel concentration. However, the results indicate a strong dependence of delay times on oxygen concentration. The experimental data for kerosine and propane demonstrate very close agreement with the results obtained previously by Mullins and Lezberg respectively.

Development and Demonstration of Advanced Technologies for Direct Electrochemical Oxidation of Hydrocarbons (Methanol, Methane, Propane)

DTIC Science & Technology

1994-07-01

Propane) Final Report Prepared by: J.A. Kosek A.B. LaConti C.C. Cropley ŕ 1:July 1994 U.S. ARMY RESEARCH OFFICE Contract No. DAAL03-92-C-001 1 GINER, INC...LaConti, C.C. Cropley 7. PERFORMING ORGANIZATION NAME(S) AND AORESS(E5 U. PERFORMING ORGANIZATION GINER, INC. REPORT NUMBER 14 Spring Street Waltham...SCIENTIFIC PERSONNEL A.B. LaConti and J.A. Kosek - Principal Investigators; C.C. Cropley , G. Wilson, J. Unger, S. McCatty, A. Griffith, and M. Hamdan

Infrared Absorption Cross Sections of Cold Propane in the Low Frequency Region Between 600 - 1300 \\wn

NASA Astrophysics Data System (ADS)

Wong, Andy; Hargreaves, Robert J.; Billinghurst, Brant E.; Bernath, Peter F.

2017-06-01

Propane is one of several hydrocarbons present in the atmospheres of the Giant Planets, Jupiter and Saturn. In order to characterize the atmospheres of the Giant Planets, it is necessary to provide absorption cross sections which can be used to determine abundances. Absorption cross sections have been obtained from high resolution transmission spectra recorded at the Canadian Light Source Far Infrared beamline. The experimental conditions used mimic those of the atmospheres belonging to the Giant Planets using He and H_{2} as foreign broadeners.

Mechanosensitivity below Ground: Touch-Sensitive Smell-Producing Roots in the Shy Plant Mimosa pudica.

PubMed

Musah, Rabi A; Lesiak, Ashton D; Maron, Max J; Cody, Robert B; Edwards, David; Fowble, Kristen L; Dane, A John; Long, Michael C

2016-02-01

The roots of the shy plant Mimosa pudica emit a cocktail of small organic and inorganic sulfur compounds and reactive intermediates into the environment, including SO2, methanesulfinic acid, pyruvic acid, lactic acid, ethanesulfinic acid, propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, phenothiazine, and thioformaldehyde, an elusive and highly unstable compound that, to our knowledge, has never before been reported to be emitted by a plant. When soil around the roots is dislodged or when seedling roots are touched, an odor is detected. The perceived odor corresponds to the emission of higher amounts of propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, and phenothiazine. The mechanosensitivity response is selective. Whereas touching the roots with soil or human skin resulted in odor detection, agitating the roots with other materials such as glass did not induce a similar response. Light and electron microscopy studies of the roots revealed the presence of microscopic sac-like root protuberances. Elemental analysis of these projections by energy-dispersive x-ray spectroscopy revealed them to contain higher levels of K(+) and Cl(-) compared with the surrounding tissue. Exposing the protuberances to stimuli that caused odor emission resulted in reductions in the levels of K(+) and Cl(-) in the touched area. The mechanistic implications of the variety of sulfur compounds observed vis-à-vis the pathways for their formation are discussed. © 2016 American Society of Plant Biologists. All Rights Reserved.

Precision of channel catfish catch estimates using hoop nets in larger Oklahoma reservoirs

USGS Publications Warehouse

Stewart, David R.; Long, James M.

2012-01-01

Hoop nets are rapidly becoming the preferred gear type used to sample channel catfish Ictalurus punctatus, and many managers have reported that hoop nets effectively sample channel catfish in small impoundments (<200 ha). However, the utility and precision of this approach in larger impoundments have not been tested. We sought to determine how the number of tandem hoop net series affected the catch of channel catfish and the time involved in using 16 tandem hoop net series in larger impoundments (>200 ha). Hoop net series were fished once, set for 3 d; then we used Monte Carlo bootstrapping techniques that allowed us to estimate the number of net series required to achieve two levels of precision (relative standard errors [RSEs] of 15 and 25) at two levels of confidence (80% and 95%). Sixteen hoop net series were effective at obtaining an RSE of 25 with 80% and 95% confidence in all but one reservoir. Achieving an RSE of 15 was often less effective and required 18-96 hoop net series given the desired level of confidence. We estimated that an hour was needed, on average, to deploy and retrieve three hoop net series, which meant that 16 hoop net series per reservoir could be "set" and "retrieved" within a day, respectively. The estimated number of net series to achieve an RSE of 25 or 15 was positively associated with the coefficient of variation (CV) of the sample but not with reservoir surface area or relative abundance. Our results suggest that hoop nets are capable of providing reasonably precise estimates of channel catfish relative abundance and that the relationship with the CV of the sample reported herein can be used to determine the sampling effort for a desired level of precision.

Poly[4,4'-(propane-1,3-diyl)dipyridinium bis{tetraaquabis(μ2-5-carboxybenzene-1,2,4-tricarboxylato)bis[μ2-1,3-bis(4-pyridyl)propane]dicobalt(II)} pentahydrate].

PubMed

Atria, Ana María; Corsini, Gino; Garland, Maria Teresa; Baggio, Ricardo

2011-11-01

The title polymeric compound, {(C(13)H(16)N(2))[Co(C(10)H(3)O(8))(C(13)H(14)N(2))(H(2)O)(2)](2)·5H(2)O}(n), is an ionic structure comprising an anionic two-dimensional mesh characterized by a {[Co(Hbtc)(bpp)(H(2)O)(2)](-)}(2) motif [Hbtc is 5-carboxybenzene-1,2,4-tricarboxylate and bpp is 1,3-bis(4-pyridyl)propane], with interspersed 4,4'-(propane-1,3-diyl)dipyridinium cations, denoted (H(2)bpp)(2+), and water molecules providing the charge balance and structure stabilization. The reticular mesh consists of two independent types of [Co(H(2)O)(2)](2+) cationic nodes (lying on inversion centres), interconnected in the [101] direction by two independent sets of neutral bridging bpp ligands, both types of ligands being split by non-equivalent twofold axes. One set is formed by genuinely symmetric moieties, while those in the second set are only symmetric by disorder in the central propane bridge. These chains contain only one type of Co(II) centre and one type of bpp ligand; the metal cations therein are laterally bridged by Hbtc anions, thus forming transverse chains of alternating types of Co(II) cations. The elemental motif of the resulting grid is a highly distorted parallelogram, with metal-metal distances of 13.5242 (14) Å in the bpp direction and 9.105 (2) Å in the Hbtc direction, and a large internal angle of 138.42 (18)°. These two-dimensional structures have a profusion of hydrogen-bonding interactions with each other, either directly (with the aqua molecules as donors and the Hbtc anions as acceptors) or mediated by the unbound (H(2)bpp)(2+) cations and water molecules of hydration. These interactions generate a very complex hydrogen-bonding scheme involving all of the available N-H and O-H groups and which links these two-dimensional grids into a three-dimensional network.

First High Resolution IR Spectra of 1-^{13}C-PROPANE. the νb{9} B-Type Band Near 366.404 \\wn and the νb{26} C-Type Band Near 748.470 \\wn. Determination of Ground and Upper State Constants.

NASA Astrophysics Data System (ADS)

Daunt, S. J.; Grzywacz, Robert; Lafferty, Walter; Flaud, Jean-Marie; Billinghurst, Brant E.

2017-06-01

We report in this talk on the first high resolution IR spectra (Δν = 0.0009 \\wn) of the 1-^{13}C-Propane isotopologue. Spectra were taken on the Bruker FTS instrument on the Far-IR beamline at the Canadian National Synchrotron (CLS) located at the University of Saskatchewan. The νb{9} B-type band centered near 366.404 \\wn appears unperturbed and lines were assigned up to K = 17 and J = 50. Since the 1960 MW study of Lide only used 6 J lines of K = 0 we had to use GSCD analyses to determine a fuller set of molecular constants for this molecule. Since normal propane has been detected using the νb{26} C-type band in Titan and other astrophysical objects our main focus was on the analagous bands for the both the 1-^{13}C and 2-^{13}C isotopologues. Assigned lines up to K = 17, J = 50 in νb{26} were analyzed with GSCD to independently obtain ground state rotational constants. These were consistent with those obtained from the νb{9} analysis. Upper state constants were also determined that reproduce the vast majority of this band. As in the normal and 2-^{13}C species a Coriolis resonance with the 2νb{9} state causes lines of most K levels above 15 to be shifted. We did not have enough sample available at the time of these experiments to be able to record the 2νb{9} - νb{9} hot band transitions in the low frequency study of νb{9}. Lide, J. Chem. Phys. 33, p. 1514 ff. (1960) Flaud, Kwabia Tchana, Lafferty & Nixon, Mol. Phys. 108, p. 699 ff. (2010)

26 CFR 1.810-3 - Adjustment for change in computing reserves.

Code of Federal Regulations, 2010 CFR

2010-04-01

... restatement under section 818(c) 60 75 Strengthened reserves at 2-percent assumed rate and net level premium... preliminary term basis on January 1, 1960 ($50) and the reserves restated on the net level premium basis on... life insurance reserves on a preliminary term basis elects to revalue such reserves on a net level...

First High Resolution IR Spectra of 2-^{13}C-PROPANE. the νb{9} B-Type Band Near 366.767 \\wn and the νb{26} C-Type Band Near 746.615 \\wn. Determination of Ground and Upper State Constants.

NASA Astrophysics Data System (ADS)

Daunt, S. J.; Grzywacz, Robert; Lafferty, Walter; Flaud, Jean-Marie; Billinghurst, Brant E.

2017-06-01

This is the first report in a project to record high resolution IR data of the ^{13}C and D substituted isotopologues of propane. In this talk we will give details on the first high resolution (Δν = 0.0009 \\wn) IR investigation of 2-^{13}C-propane. Spectra of the CCC skeletal bending mode near 336.767 \\wn (B-type) and the wagging mode near 746.615 \\wn (C-type) were recorded using the FTS on the Far-IR beamline of the Canadian Light Source (CLS). The spectra were assigned both traditionally and with the aid of the PGOPHER program of Colin Western. The only available MW data on this molecule are the six K =0 J lines from Lide. We therefore had to use the present data to determine a new set of ground state constants that included centrifugal distortion terms for this molecule. We compare these experimentally determined values with the recent ab initio values of Villa, Senent & Carvajal. Upper state constants for both bands have been found that provide a good simulation of the spectra. The hope is that this data will be useful in identifying isotopic propane lines in Titan and other astrophysical objects. C. Western, J. Quant. Spectrosc. & Rad. Transf. 186, 221 ff. (2017). Lide, J.Chem. Phys. 33, p.1514ff. (1960). Villa, Senent & Carvajal, PCCP 15, 10258 (2013).

Structural and dynamic properties of propane coordinated to TpRh(CNR) from a confrontation between theory and experiment

PubMed Central

Clot, Eric; Eisenstein, Odile; Jones, William D.

2007-01-01

Density functional calculations with the B3PW91 functional have been carried out on the TpRh(CNMe) species [Tp = HB(pyrazolyl)3] as a model for Tp′Rh(CNCH2CMe3) [Tp′ = HB(3,5-dimethylpyrazolyl)3] in interaction with propane. Two σ complexes have been found as minima coordinated through either a methyl or a methylene CH bond, the former being more stable. The approach of the alkane to TpRh(CNMe) has been studied. Although no transition state could be located, study of this path reveals the key importance of the partial decoordination of one pyrazole ring. The full coordination of the alkane can only be achieved when the metal is essentially in a square pyramid coordination with one of the three pyrazole groups only weakly interacting with Rh. The main reaction of the methyl σ complex is oxidative addition, leading to the n-propyl hydride complex. In contrast, two reactions are found for the methylene σ complex: (i) oxidative addition to give the isopropyl complex and (ii) exchange between the secondary and primary CH bonds to convert the methylene complex of propane into a methyl complex of propane. This latter reaction has a much lower barrier than the oxidative addition at the methylene CH bond. The results account well for most of the experimental results obtained from kinetic studies. Steric factors are found to control the energy barriers between these various processes, disfavoring any process that brings the central carbon into close proximity to Rh. PMID:17412834

Effects of the state of Co species in Co/Al2O3 catalysts on the catalytic performance of propane dehydrogenation

NASA Astrophysics Data System (ADS)

Li, Xiuyi; Wang, Pengzhao; Wang, Haoren; Li, Chunyi

2018-05-01

In this paper, the Co/Al2O3 catalyst was prepared by incipient wetness impregnation method, and different post treatment methods were used to promote its dehydrogenation properties. Interestingly, we found that Co/Al2O3 catalysts with different post treatment protocols exhibited totally different catalytic behaviors in propane dehydrogenation. Fresh catalyst showed an induction period and was highly active for pyrolysis and coking at 10-30 min of reaction. The pre-reduction led to complete pyrolysis and coking at the beginning of reaction. However, the re-oxidation treatment gave a high selectivity (∼93.0%) to propylene at the whole process. XRD, H2-TPR, XPS, TEM and hydrogen chemisorption investigations showed that the post treatment has a great impact on the state of cobalt species and the performance of propane dehydrogenation over Co/Al2O3 catalysts. Specifically, the poorly dispersed metal Co led to pyrolysis and coking, while highly dispersed metal Co were responsible for the dehydrogenation of propane. The large Co3O4 particles (DFresh = 33.68 nm) result in the large metal Co grains (DPre-reduced = 24.90 nm) after the reduction or reaction process. While during the re-oxidization process, the surface metal Co was re-oxidized in a mild environment and got re-dispersion (DRe-oxidized = 6.07 nm). And the surface cobalt oxides layer is more readily to be reduced to metal Co during the reaction thus leading to the shortened induction period.

Deposit formation in hydrocarbon rocket fuels

NASA Technical Reports Server (NTRS)

Roback, R.; Szetela, E. J.; Spadaccini, L. J.

1981-01-01

An experimental program was conducted to study deposit formation in hydrocarbon fuels under flow conditions that exist in high-pressure, rocket engine cooling systems. A high pressure fuel coking test apparatus was designed and developed and was used to evaluate thermal decomposition (coking) limits and carbon deposition rates in heated copper tubes for two hydrocarbon rocket fuels, RP-1 and commercial-grade propane. Tests were also conducted using JP-7 and chemically-pure propane as being representative of more refined cuts of the baseline fuels. A parametric evaluation of fuel thermal stability was performed at pressures of 136 atm to 340 atm, bulk fuel velocities in the range 6 to 30 m/sec, and tube wall temperatures in the range 422 to 811 K. Results indicated that substantial deposit formation occurs with RP-1 fuel at wall temperatures between 600 and 800 K, with peak deposit formation occurring near 700 K. No improvements were obtained when deoxygenated JP-7 fuel was substituted for RP-1. The carbon deposition rates for the propane fuels were generally higher than those obtained for either of the kerosene fuels at any given wall temperature. There appeared to be little difference between commercial-grade and chemically-pure propane with regard to type and quantity of deposit. Results of tests conducted with RP-1 indicated that the rate of deposit formation increased slightly with pressure over the range 136 atm to 340 atm. Finally, lating the inside wall of the tubes with nickel was found to significantly reduce carbon deposition rates for RP-1 fuel.

Emission sources of non-methane volatile organic compounds (NMVOCs) and their contribution to photochemical ozone (O3) formation at an urban atmosphere in western India.

NASA Astrophysics Data System (ADS)

Yadav, R.; Sahu, L. K.; Tripathi, N.; Pal, D.

2017-12-01

Atmospheric non-methane volatile organic compounds (NMVOCs) were measured at a sampling site in Udaipur city of western India during 2015 to recognize their pollution levels, variation characteristics, sources and photochemical reactivity. The samples were analyzed for NMVOCs using a Gas Chromatograph equipped with Flame Ionization Detector (GC/FID) and Thermal Desorption (TD) system. The main focus on understand the sources responsible for NMVOC emissions, and evaluating the role of the identified sources towards ozone formation. Hourly variations of various NMVOC species indicate that VOCs mixing ratios were influenced by photochemical removal with OH radicals for reactive species, secondary formation for oxygenated VOCs. In general, higher mixing ratios were observed during winter/pre-monsoon and lower levels during the monsoon season due to the seasonal change in meteorological, transport path of air parcel and boundary layer conditions. The high levels of propane (C3H8) and butane (C4H10) show the dominance of LPG over the study location. The correlation coefficients of typical NMVOC pairs (ethylene/propylene, propylene/isoprene, and ethane/propane) depicted that vehicular emission and natural gas leakages were important sources for atmospheric hydrocarbons in Udaipur. Based on the annual data, PMF analysis suggest the source factors namely biomass burning/ bio-fuel, automobile exhaust, Industrial/ natural gas/power plant emissions, petrol/Diesel, gasoline evaporation, and use of liquid petroleum gas (LPG) contribute to NMVOCs loading. The propylene-equivalent and ozone formation potential of NMVOCs have also been calculated in order to find out their OH reactivity and contribution to the photochemical ozone formation.

Is College Affordable? Are Loans Manageable? What Do Colleges' Net Price Calculators Show? Policy Bulletin

ERIC Educational Resources Information Center

Advisory Committee on Student Financial Assistance, 2012

2012-01-01

A review of net price calculators--a financial aid tool mandated by the "Higher Education Opportunity Act" of 2008--reveals that students from low-, moderate-, and middle-income families face record-level net prices at 4-year public colleges today. These net prices will translate into levels of average total loan burden far in excess of…

Effect of fuel nitrogen and hydrogen content on emissions in hydrocarbon combustion

NASA Technical Reports Server (NTRS)

Bittker, D. A.; Wolfbrandt, G.

1981-01-01

How the emissions of nitrogen oxides and carbon monoxide are affected by: (1) the decreased hydrogen content and (2) the increased organic nitrogen content of coal derived fuels is investigated. Previous CRT experimental work in a two stage flame tube has shown the effectiveness of rich lean two stage combustion in reducing fuel nitrogen conversion to nitrogen oxides. Previous theoretical work gave preliminary indications that emissions trends from the flame tube experiment could be predicted by a two stage, well stirred reactor combustor model using a detailed chemical mechanism for propane oxidation and nitrogen oxide formation. Additional computations are reported and comparisons with experimental results for two additional fuels and a wide range of operating conditions are given. Fuels used in the modeling are pure propane, a propane toluene mixture and pure toluene. These give hydrogen contents 18, 11 and 9 percent by weight, respectively. Fuel bound nitrogen contents of 0.5 and 1.0 percent were used. Results are presented for oxides of nitrogen and also carbon monoxide concentrations as a function of primary equivalence ratio, hydrogen content and fuel bound nitrogen content.

Reduced chemical kinetics for propane combustion

NASA Technical Reports Server (NTRS)

Ying, Shuh-Jing; Nguyen, Hung Lee

1990-01-01

It is pointed out that a detailed chemical kinetics mechanism for the combustion of propane consists of 40 chemical species and 118 elementary chemical reactions. An attempt is made to reduce the number of chemical species and elementary chemical reactions so that the computer run times and storage requirements may be greatly reduced in three-dimensional gas turbine combustion flow calculations, while maintaining accurate predictions of the propane combustion and exhaust emissions. By way of a sensitivity analysis, the species of interest and chemical reactions are classified in descending order of importance. Nineteen species are chosen, and their pressure, temperature, and concentration profiles are presented for the reduced mechanisms, which are then compared with those from the full 118 reactions. It is found that 45 reactions involving 27 species have to be kept for comparable agreement. A comparison of the results obtained from the 45 reactions to that of the full 118 shows that the pressure and temperature profiles and concentrations of C3H8, O2, N2, H2O, CO, and CO2 are within 10 percent of maximum change.

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

Yuan Zhang; Jin-hu Wu; Dong-ke Zhang

The cracking of oil refinery off-gas, simulated with a gas mixture containing methane (51%), ethylene (21.4%), ethane (21.1%), and propane (6.5%), over a coal char, petroleum coke, and quartz, respectively, has been studied in a fixed bed reactor. The experiments were performed at temperatures between 850 and 1000{sup o}C and at atmospheric pressure. The results show that the conversions of all species considered increased with increasing temperature. Ethane and propane completely decomposed over all three bed materials in the temperature range investigated. However, the higher initial conversion rates of methane and ethylene cracking at all temperatures were observed only overmore » the coal char and not on the petroleum coke and quartz, indicating a significant catalytic effect of the coal char on methane and ethylene cracking. Methane and ethylene conversions decreased with reaction time due to deactivation of the coal char by carbon deposition on the char surface and, in the later stage of a cracking experiment, became negative, suggesting that methane and ethylene had been formed during the cracking of ethane and propane. 16 refs., 13 figs., 2 tabs.« less

Fluorometric detection of nitroaromatics by fluorescent lead complexes: A spectroscopic assessment of detection mechanism

NASA Astrophysics Data System (ADS)

Chattopadhyay, Tanmay; Chatterjee, Sourav; Majumder, Ishani; Ghosh, Soumen; Yoon, Sangee; Sim, Eunji

2018-04-01

Three Schiff base ligands such as 2-[(2-Hydroxy-3-methoxy-benzylidene)-amino]-2-hydroxymethyl-propane-1,3-diol (HL1), 2-[(2-Hydroxy-benzylidene)-amino]-2-hydroxymethyl-propane-1,3-diol (HL2), 2-[(3,5-Dichloro-2-hydroxy-benzylidene)-amino]-2-hydroxymethyl-propane-1,3-diol (HL3) have been synthesized by condensation of aldehydes (such as 3,5-Dichloro-2-hydroxy benzaldehyde, 2-Hydroxy-benzaldehyde, and 2-Hydroxy-3-methoxy-benzaldehyde) with Tris-(hydroxymethyl)amino methane and characterized by IR, UV-vis and 1H NMR spectroscopy. Then all these three ligands have been used to prepare Pb(II) complexes by reaction with lead(II) acetate tri-hydrate in methanol. In view of analytical and spectral (IR, UV-vis and Mass) studies, it has been concluded that, except HL2, other two ligands form 1:1 metal complexes (1 and 3) with lead. Between two complexes, complex 3 is highly fluorescent and this property has been used to identify the pollutant nitroaromatics. Finally, the quenching mechanism has been established by means of spectroscopic investigation.

Volatile Organic Compound (VOC) Emissions from Dairy Cows and Their Waste

NASA Astrophysics Data System (ADS)

Shaw, S.; Holzinger, R.; Mitloehner, F.; Goldstein, A.

2005-12-01

Biogenic VOCs are typically defined as those directly emitted from plants, but approximately 6% of global net primary production is consumed by cattle that carry out enteric fermentation and then emit VOCs that could also be considered biogenic. Current regulatory estimates suggest that dairy cattle in central California emit VOCs at rates comparable to those from passenger vehicles in the region, and thus contribute significantly to the extreme non-attainment of ozone standards there. We report PTR-MS measurements of ammonia and VOCs, and cavity-enhanced-absorption gas analyzer (Los Gatos Research, Inc.) measurements of CH4, emitted from dairy cattle in various stages of pregnancy/lactation and their waste. Experiments were conducted in chambers at UC Davis that simulate freestall cow housing conditions. CH4 fluxes ranged from 125-374 lb/cow/year. The compounds with the highest fluxes from '3 cows+waste' treatments were: ammonia (1-18), methanol (0-2.3), acetone+propanal (0.2-0.7), dimethylsulfide (0-0.4), and mass 109 (likely ID = p-cresol; 0-0.3) in lb/cow/year. Mass 60 (likely ID = trimethylamine) and acetic acid were also abundant. There were 10s of additional compounds with detectable, but small, emissions. A few compounds that were likely emitted (i.e. ethanol, formaldehyde, and dimethylamine) were not quantified by the PTR-MS. The total flux for all measured organic gases (TOG = CH4 + PTR-MS VOCs(including acetone+propanal)) averaged 246±45 lb/cow/year for '3 cows+waste' treatments, and was dominated by methane (>98%). TOG flux for 'waste only' treatments averaged 1.1±0.1 lb/cow/year, and was instead dominated by VOC (>84%). The PTR-MS VOCs as a percent of TOG (0.6±0.2%) emitted from '3 cows+waste' treatments in chamber conditions was a factor of 10 smaller than that currently estimated by the California Air Resources Board. In addition, the ozone forming potentials of the most abundant VOCs are only about 10% those of typical combustion or plant-derived VOCs, implying dairy cattle have a smaller effect on ozone formation than currently assumed by air districts in central California.

Exhaust Emissions from Gasoline- and LPG-Powered Vehicles Operating at the Altitude of Mexico City.

PubMed

Gamas, Erick D; Diaz, Luis; Rodriguez, René; López-Salinas, E; Schifter, Isaac; Ontiveros, Luis

1999-10-01

Unburned hydrocarbons (HCs), carbon monoxide (CO), and oxides of nitrogen (NO x ) are the compounds regulated as pollutants by an environmental standard in the Metropolitan Area of Mexico City (MAMC). The main fuel used in vehicular transportation is gasoline, and the use of liquefied petroleum gas (LPG) is now an alternative as low emission technology to decrease the environmental impact of transportation operations. The environmental impact of commercial gasoline consumption in the Valley of Mexico was estimated by on-road and FTP-75 testing of three formulations of gasoline (one leaded [octane 81] and two unleaded [one octane 87 and one octane 93]). A fleet of 30 vehicles was used: 10 were chosen that had pre-1990 technology, while 12 were 1991-1996 vehicles equipped with fuel injection, catalytic converters, and air/ fuel ratio control technology. The remaining eight vehicles were high-performance new model vehicles (1995-1996) equipped with the newest technology available for pollution control. Fifteen vehicles in the fleet were also tested for the effect of changing from leaded to unleaded gasoline. Three different LPG formulations were tested using three vehicles representative of the LPG-powered fleet in the MAMC. Two gasoline-to-LPG conversion certified commercial systems were evaluated following the BAR-90 and the HOT-505 procedures. Emissions corresponding to the high-octane (premium) gasoline showed a 15% higher contribution to HCs with a 6% lower reactivity than the 87 octane gasoline; the HCs in the exhaust for premium gasoline are mainly isoparaffins. When the vehicles were tested on the road at high speeds, an average 3% increase in mileage was obtained when vehicles were switched from leaded to unleaded gasoline, while a 5% increase in mileage was observed when vehicles were switched from 87 octane to premium gasoline. The tests of LPG formulations indicated that a change in composition from 60% vol of propane to 85.5% vol reduces levels of HCs and CO emissions; such is not the case for the NO x emissions. The higher the concentration of propane, the higher the levels of NO x that reached values above the maximum limits set by the environmental standard. A value of 70% vol of propane in the LPG mixture, with variations no greater than 4%, seems to be the best method for reducing pollutant emissions in Mexico City.

Regioselective alkane hydroxylation with a mutant AlkB enzyme

DOEpatents

Koch, Daniel J.; Arnold, Frances H.

2012-11-13

AlkB from Pseudomonas putida was engineered using in-vivo directed evolution to hydroxylate small chain alkanes. Mutant AlkB-BMO1 hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. Mutant AlkB-BMO2 similarly hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. These biocatalysts are highly active for small chain alkane substrates and their regioselectivity is retained in whole-cell biotransformations.

Remote fire stack igniter. [with solenoid-controlled valve

NASA Technical Reports Server (NTRS)

Ray, W. L. (Inventor)

1974-01-01

An igniter is described mounted on a vent stack with an upper, flame cage near the top of the stack to ignite emissions from the stack. The igniter is a tube with a lower, open, flared end having a spark plug near the lower end and a solenoid-controlled valve which supplies propane fuel from a supply tank. Propane from the tank is supplied at the top under control of a second, solenoid-controlled valve. The valve controlling the lower supply is closed after ignition at the flame cage. The igniter is economical, practical, and highly reliable.

Neutron powder diffraction studies as a function of temperature of structure II hydrate formed from propane

USGS Publications Warehouse

Rawn, C.J.; Rondinone, A.J.; Chakoumakos, B.C.; Circone, S.; Stern, L.A.; Kirby, S.H.; Ishii, Y.

2003-01-01

Neutron powder diffraction data confirm that hydrate samples synthesized with propane crystallize as structure type II hydrate. The structure has been modeled using rigid-body constraints to describe C3H8 molecules located in the eight larger polyhedral cavities of a deuterated host lattice. Data were collected at 12, 40, 100, 130, 160, 190, 220, and 250 K and used to calculate the thermal expansivity from the temperature dependence of the lattice parameters. The data collected allowed for full structural refinement of atomic coordinates and the atomic-displacement parameters.

Select Components and Finish System Design of a Window Air Conditioner with Propane

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

Shen, Bo; Abdelaziz, Omar

This report describes the technical targets for developing a high efficiency window air conditioner (WAC) using propane (R-290). The baseline unit selected for this activity is a GE R-410A WAC. We established collaboration with a Chinese rotary compressor manufacturer, to select an R-290 compressor. We first modelled and calibrated the WAC system model using R-410A. Next, we applied the calibrated system model to design the R-290 WAC, and decided the strategies to reduce the system charge below 260 grams and achieve the capacity and efficiency targets.

Experimental investigation of the phase equilibria in the carbon dioxide-propane-3 M MDEA system

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

Jou, F.Y.; Mather, A.E.; Otto, F.D.

1995-07-01

The treating of liquefied petroleum gas (LPG) to remove carbon dioxide and hydrogen sulfide using aqueous alkanolamine solutions is an important aspect of gas processing. One of the amines used in the natural gas industry is methyldiethanolamine (MDEA). Measurements of the phase equilibria in the carbon dioxide-propane-3 M MDEA system have been made at 25 and 40 C at pressures up to 15.5 MPa. Vapor-liquid, liquid-liquid, and vapor-liquid-liquid equilibria were determined. The vapor-liquid equilibrium data were compared with the model of Deshmukh and Mather.

Two LNG plants slated for Indonesia

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

Parker, R.F.; Phannenstiel, L.L.

1975-06-09

Two large LNG plants are in the planning stage for Indonesia. The Badak field in East Kalimantan, Borneo, will have a 450 million ft/sup 3//day plant with a projected 20-y life. Gas will be liquefied in a 2-train plant employing the propane-MCR process, then stored in double-wall tanks having a total capacity of 2.4 million bbl. Arun field in North Sumatra will have an LNG plant capable of liquefying 1.2 billion ft/sup 3//day of gas in 6 trains, also using the propane-MCR process. LNG storage capacity at Arun will total 3.2 million bbl.

Helium broadened propane absorption cross sections in the far-IR

NASA Astrophysics Data System (ADS)

Wong, A.; Billinghurst, B.; Bernath, P. F.

2017-09-01

Infrared absorption spectra for pure and He broadened propane have been recorded in the far-IR region (650-1300 cm-1) at the Canadian Light Source (CLS) facility using either the synchrotron or internal glowbar source depending on the required resolution. The measurements were made for 4 temperatures in the range 202-292 K and for 3 pressures of He broadening gas up to 100 Torr. Infrared absorption cross sections are derived from the spectra and the integrated cross sections are within 10 % of the corresponding values from the Pacific Northwest National Laboratory (PNNL) for all temperatures and pressures.

Evaluation of micron size carbon fibers released from burning graphite composites

NASA Technical Reports Server (NTRS)

Sussholz, B.

1980-01-01

Quantitative estimates were developed of micron carbon fibers released during the burning of graphite composites. Evidence was found of fibrillated particles which were the predominant source of the micron fiber data obtained from large pool fire tests. The fibrillation phenomena were attributed to fiber oxidation effects caused by the fire environment. Analysis of propane burn test records indicated that wind sources can cause considerable carbon fiber oxidation. Criteria estimates were determined for the number of micron carbon fibers released during an aircraft accident. An extreme case analysis indicated that the upper limit of the micron carbon fiber concentration level was only about half the permissible asbestos ceiling concentration level.

26 CFR 1.818-4 - Election with respect to life insurance reserves computed on preliminary term basis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... reserves for all such contracts had been computed on a net level premium basis (using the same mortality or... portion of such reserves during the taxable year by actually changing to a net level premium basis in... a net level premium basis for the purpose of determining the amount which may be taken into account...

International comparison Euramet.QM-K111—propane in nitrogen

NASA Astrophysics Data System (ADS)

Wouter van der Hout, J.; van der Veen, Adriaan M. H.; Ziel, Paul R.; Kipphardt, Heinrich; Tuma, Dirk; Maiwald, Michael; Fernández, Teresa E.; Gómez, Concepción; Cieciora, Dariusz; Ochman, Grzegorz; Dias, Florbela; Silvino, Victor; Macé, Tatiana; Sutour, Christophe; Marioni, Fabrice; Ackermann, Andreas; Niederhauser, Bernhard; Fükő, Judit; Büki, Tamás; Nagyné Szilágyi, Zsófia; Tarhan, Tanıl; Engin, Erinç

2017-01-01

This key comparison aims to assess the core capabilities of the participants in gas analysis. Such competences include, among others, the capabilities to prepare Primary Standard gas Mixtures (PSMs), perform the necessary purity analysis on the materials used in the gas mixture preparation, the verification of the composition of newly prepared PSMs against existing ones, and the capability of calibrating the composition of a gas mixture. According to the Strategy for Key Comparisons of the Gas Analysis Working Group, this key comparison is classified as an RMO track A key comparison. The artefacts were binary mixtures of propane in nitrogen at a nominal amount-of-substance fraction level of 1000 μmol/mol. The values and uncertainties from the gravimetric gas mixture preparation were used as key comparison reference values (KCRVs). Each transfer standard had its own KCRV. The results are generally good. All results are within +/- 1 % of the KCRV. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Circulating levels of carbamylated protein and neutrophil extracellular traps are associated with periodontitis severity in patients with rheumatoid arthritis: A pilot case-control study.

PubMed

Kaneko, Chihiro; Kobayashi, Tetsuo; Ito, Satoshi; Sugita, Noriko; Murasawa, Akira; Nakazono, Kiyoshi; Yoshie, Hiromasa

2018-01-01

An interrelationship between rheumatoid arthritis (RA) and periodontitis has been suggested due to their common pathogenic mechanisms. Protein carbamylation and neutrophil extracellular traps (NETs) formation have been shown to be related to autoimmune conditions, including RA, but their association with periodontitis has not been elucidated. Therefore, we assessed whether or not circulating levels of carbamylated protein (CarP) and NETs are associated with periodontitis severity and influenced by periodontal treatment. We conducted a retrospective case-control study that included 40 patients with RA and periodontitis, 30 patients with periodontitis, and 43 systemically and periodontally healthy controls to assess the circulating levels of CarP and NETs and rheumatologic and periodontal conditions. The same assessments were also performed in 22 patients with RA and periodontitis after 2 months of periodontal treatment, including oral hygiene instruction and full-mouth supragingival scaling. Patients with RA and periodontitis showed significantly higher serum levels of CarP and NETs than the control group (P = 0.04 and P < 0.001, respectively). The serum levels of CarP and NETs were significantly correlated positively with the mean values of probing depth (P = 0.01 and P = 0.007, respectively) and clinical attachment level (P = 0.007 and P = 0.001, respectively) in the 40 patients with RA and periodontitis. Multiple logistic regression analyses also revealed significantly positive associations between the serum levels of CarP and NETs and moderate to severe periodontitis (P = 0.03 and P = 0.001, respectively). Furthermore, periodontal treatment significantly decreased the serum levels of CarP and NETs in patients with RA and periodontitis (P = 0.03 and P = 0.02). The circulating levels of CarP and NETs are associated with periodontitis severity and influenced by periodontal treatment in patients with RA.

Circulating levels of carbamylated protein and neutrophil extracellular traps are associated with periodontitis severity in patients with rheumatoid arthritis: A pilot case-control study

PubMed Central

Kaneko, Chihiro; Ito, Satoshi; Sugita, Noriko; Murasawa, Akira; Nakazono, Kiyoshi; Yoshie, Hiromasa

2018-01-01

Objectives An interrelationship between rheumatoid arthritis (RA) and periodontitis has been suggested due to their common pathogenic mechanisms. Protein carbamylation and neutrophil extracellular traps (NETs) formation have been shown to be related to autoimmune conditions, including RA, but their association with periodontitis has not been elucidated. Therefore, we assessed whether or not circulating levels of carbamylated protein (CarP) and NETs are associated with periodontitis severity and influenced by periodontal treatment. Methods We conducted a retrospective case-control study that included 40 patients with RA and periodontitis, 30 patients with periodontitis, and 43 systemically and periodontally healthy controls to assess the circulating levels of CarP and NETs and rheumatologic and periodontal conditions. The same assessments were also performed in 22 patients with RA and periodontitis after 2 months of periodontal treatment, including oral hygiene instruction and full-mouth supragingival scaling. Results Patients with RA and periodontitis showed significantly higher serum levels of CarP and NETs than the control group (P = 0.04 and P < 0.001, respectively). The serum levels of CarP and NETs were significantly correlated positively with the mean values of probing depth (P = 0.01 and P = 0.007, respectively) and clinical attachment level (P = 0.007 and P = 0.001, respectively) in the 40 patients with RA and periodontitis. Multiple logistic regression analyses also revealed significantly positive associations between the serum levels of CarP and NETs and moderate to severe periodontitis (P = 0.03 and P = 0.001, respectively). Furthermore, periodontal treatment significantly decreased the serum levels of CarP and NETs in patients with RA and periodontitis (P = 0.03 and P = 0.02). Conclusion The circulating levels of CarP and NETs are associated with periodontitis severity and influenced by periodontal treatment in patients with RA. PMID:29394286

Planning long lasting insecticide treated net campaigns: should households’ existing nets be taken into account?

PubMed Central

2013-01-01

Background Mass distribution of long-lasting insecticide treated bed nets (LLINs) has led to large increases in LLIN coverage in many African countries. As LLIN ownership levels increase, planners of future mass distributions face the challenge of deciding whether to ignore the nets already owned by households or to take these into account and attempt to target individuals or households without nets. Taking existing nets into account would reduce commodity costs but require more sophisticated, and potentially more costly, distribution procedures. The decision may also have implications for the average age of nets in use and therefore on the maintenance of universal LLIN coverage over time. Methods A stochastic simulation model based on the NetCALC algorithm was used to determine the scenarios under which it would be cost saving to take existing nets into account, and the potential effects of doing so on the age profile of LLINs owned. The model accounted for variability in timing of distributions, concomitant use of continuous distribution systems, population growth, sampling error in pre-campaign coverage surveys, variable net ‘decay’ parameters and other factors including the feasibility and accuracy of identifying existing nets in the field. Results Results indicate that (i) where pre-campaign coverage is around 40% (of households owning at least 1 LLIN), accounting for existing nets in the campaign will have little effect on the mean age of the net population and (ii) even at pre-campaign coverage levels above 40%, an approach that reduces LLIN distribution requirements by taking existing nets into account may have only a small chance of being cost-saving overall, depending largely on the feasibility of identifying nets in the field. Based on existing literature the epidemiological implications of such a strategy is likely to vary by transmission setting, and the risks of leaving older nets in the field when accounting for existing nets must be considered. Conclusions Where pre-campaign coverage levels established by a household survey are below 40% we recommend that planners do not take such LLINs into account and instead plan a blanket mass distribution. At pre-campaign coverage levels above 40%, campaign planners should make explicit consideration of the cost and feasibility of accounting for existing LLINs before planning blanket mass distributions. Planners should also consider restricting the coverage estimates used for this decision to only include nets under two years of age in order to ensure that old and damaged nets do not compose too large a fraction of existing net coverage. PMID:23763773

Planning long lasting insecticide treated net campaigns: should households' existing nets be taken into account?

PubMed

Yukich, Joshua; Bennett, Adam; Keating, Joseph; Yukich, Rudy K; Lynch, Matt; Eisele, Thomas P; Kolaczinski, Kate

2013-06-14

Mass distribution of long-lasting insecticide treated bed nets (LLINs) has led to large increases in LLIN coverage in many African countries. As LLIN ownership levels increase, planners of future mass distributions face the challenge of deciding whether to ignore the nets already owned by households or to take these into account and attempt to target individuals or households without nets. Taking existing nets into account would reduce commodity costs but require more sophisticated, and potentially more costly, distribution procedures. The decision may also have implications for the average age of nets in use and therefore on the maintenance of universal LLIN coverage over time. A stochastic simulation model based on the NetCALC algorithm was used to determine the scenarios under which it would be cost saving to take existing nets into account, and the potential effects of doing so on the age profile of LLINs owned. The model accounted for variability in timing of distributions, concomitant use of continuous distribution systems, population growth, sampling error in pre-campaign coverage surveys, variable net 'decay' parameters and other factors including the feasibility and accuracy of identifying existing nets in the field. Results indicate that (i) where pre-campaign coverage is around 40% (of households owning at least 1 LLIN), accounting for existing nets in the campaign will have little effect on the mean age of the net population and (ii) even at pre-campaign coverage levels above 40%, an approach that reduces LLIN distribution requirements by taking existing nets into account may have only a small chance of being cost-saving overall, depending largely on the feasibility of identifying nets in the field. Based on existing literature the epidemiological implications of such a strategy is likely to vary by transmission setting, and the risks of leaving older nets in the field when accounting for existing nets must be considered. Where pre-campaign coverage levels established by a household survey are below 40% we recommend that planners do not take such LLINs into account and instead plan a blanket mass distribution. At pre-campaign coverage levels above 40%, campaign planners should make explicit consideration of the cost and feasibility of accounting for existing LLINs before planning blanket mass distributions. Planners should also consider restricting the coverage estimates used for this decision to only include nets under two years of age in order to ensure that old and damaged nets do not compose too large a fraction of existing net coverage.

Formation of C-C and C-O bonds and oxygen removal in reactions of alkanediols, alkanols, and alkanals on copper catalysts.

PubMed

Sad, María E; Neurock, Matthew; Iglesia, Enrique

2011-12-21

This study reports evidence for catalytic deoxygenation of alkanols, alkanals, and alkanediols on dispersed Cu clusters with minimal use of external H(2) and with the concurrent formation of new C-C and C-O bonds. These catalysts selectively remove O-atoms from these oxygenates as CO or CO(2) through decarbonylation or decarboxylation routes, respectively, that use C-atoms present within reactants or as H(2)O using H(2) added or formed in situ from CO/H(2)O mixtures via water-gas shift. Cu catalysts fully convert 1,3-propanediol to equilibrated propanol-propanal intermediates that subsequently form larger oxygenates via aldol-type condensation and esterification routes without detectable involvement of the oxide supports. Propanal-propanol-H(2) equilibration is mediated by their chemisorption and interconversion at surfaces via C-H and O-H activation and propoxide intermediates. The kinetic effects of H(2), propanal, and propanol pressures on turnover rates, taken together with measured selectivities and the established chemical events for base-catalyzed condensation and esterification reactions, indicate that both reactions involve kinetically relevant bimolecular steps in which propoxide species, acting as the base, abstract the α-hydrogen in adsorbed propanal (condensation) or attack the electrophilic C-atom at its carbonyl group (esterification). These weakly held basic alkoxides render Cu surfaces able to mediate C-C and C-O formation reactions typically catalyzed by basic sites inherent in the catalyst, instead of provided by coadsorbed organic moieties. Turnover rates for condensation and esterification reactions decrease with increasing Cu dispersion, because low-coordination corner and edge atoms prevalent on small clusters stabilize adsorbed intermediates and increase the activation barriers for the bimolecular kinetically relevant steps required for both reactions. © 2011 American Chemical Society

A practical grinding-assisted dry synthesis of nanocrystalline NiMoO{sub 4} polymorphs for oxidative dehydrogenation of propane

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

Chen Miao, E-mail: chenmiao@sinochem.com; Zhejiang Chemical Industry Research Institute, Hangzhou 310023; Wu Jialing

2011-12-15

A practical two-stage reactive grinding-assisted pathway waste-free and cost-effective for the synthesis of NiMoO{sub 4} has been successfully developed. It was demonstrated that proper design in synthetic strategy for grinding plays a crucial role in determining the ultimate polymorph of NiMoO{sub 4}. Specifically, direct grinding (DG) of MoO{sub 3} and NiO rendered {alpha}-NiMoO{sub 4} after annealing, whereas sequential grinding (SG) of the two independently pre-ground oxides followed by annealing generated {beta}-NiMoO{sub 4} solid solution. Characterizations in terms of Raman and X-ray diffraction suggest the creation of {beta}-NiMoO{sub 4} precursor in the latter alternative is the key aspect for the formationmore » of {beta}-NiMoO{sub 4}. The DG-derived {alpha}-NiMoO{sub 4} tested by oxidative dehydrogenation of propane exhibited superior activity in contrast to its analog synthesized via conventional coprecipitation. It is suggested that the favorable chemical composition facilely obtained via grinding in contrast to that by coprecipitation was essential for achieving a more selective production of propylene. - Graphical Abstract: Grinding-assisted synthesis of NiMoO{sub 4} offers higher and more reproducible activities in contrast to coprecipitation for oxidative dehydrogenation of propane, and both {alpha}- and {beta}-NiMoO{sub 4} can be synthesized. Highlights: Black-Right-Pointing-Pointer NiMoO{sub 4} was prepared through grinding-assisted pathway. Black-Right-Pointing-Pointer Direct/sequential grinding rendered {alpha}-, {beta}-NiMoO{sub 4}, respectively. Black-Right-Pointing-Pointer Grinding-derived {alpha}-NiMoO{sub 4} showed high and reproducible activity for oxidative dehydrogenation of propane.« less

Critical evaluation of Jet-A spray combustion using propane chemical kinetics in gas turbine combustion simulated by KIVA-2

NASA Technical Reports Server (NTRS)

Nguyen, H. L.; Ying, S.-J.

1990-01-01

Jet-A spray combustion has been evaluated in gas turbine combustion with the use of propane chemical kinetics as the first approximation for the chemical reactions. Here, the numerical solutions are obtained by using the KIVA-2 computer code. The KIVA-2 code is the most developed of the available multidimensional combustion computer programs for application of the in-cylinder combustion dynamics of internal combustion engines. The released version of KIVA-2 assumes that 12 chemical species are present; the code uses an Arrhenius kinetic-controlled combustion model governed by a four-step global chemical reaction and six equilibrium reactions. Researchers efforts involve the addition of Jet-A thermophysical properties and the implementation of detailed reaction mechanisms for propane oxidation. Three different detailed reaction mechanism models are considered. The first model consists of 131 reactions and 45 species. This is considered as the full mechanism which is developed through the study of chemical kinetics of propane combustion in an enclosed chamber. The full mechanism is evaluated by comparing calculated ignition delay times with available shock tube data. However, these detailed reactions occupy too much computer memory and CPU time for the computation. Therefore, it only serves as a benchmark case by which to evaluate other simplified models. Two possible simplified models were tested in the existing computer code KIVA-2 for the same conditions as used with the full mechanism. One model is obtained through a sensitivity analysis using LSENS, the general kinetics and sensitivity analysis program code of D. A. Bittker and K. Radhakrishnan. This model consists of 45 chemical reactions and 27 species. The other model is based on the work published by C. K. Westbrook and F. L. Dryer.

Carbon doped GaN buffer layer using propane for high electron mobility transistor applications: Growth and device results

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

Li, X.; Nilsson, D.; Danielsson, Ö.

2015-12-28

The creation of a semi insulating (SI) buffer layer in AlGaN/GaN High Electron Mobility Transistor (HEMT) devices is crucial for preventing a current path beneath the two-dimensional electron gas (2DEG). In this investigation, we evaluate the use of a gaseous carbon gas precursor, propane, for creating a SI GaN buffer layer in a HEMT structure. The carbon doped profile, using propane gas, is a two stepped profile with a high carbon doping (1.5 × 10{sup 18 }cm{sup −3}) epitaxial layer closest to the substrate and a lower doped layer (3 × 10{sup 16 }cm{sup −3}) closest to the 2DEG channel. Secondary Ion Mass Spectrometry measurement showsmore » a uniform incorporation versus depth, and no memory effect from carbon doping can be seen. The high carbon doping (1.5 × 10{sup 18 }cm{sup −3}) does not influence the surface morphology, and a roughness root-mean-square value of 0.43 nm is obtained from Atomic Force Microscopy. High resolution X-ray diffraction measurements show very sharp peaks and no structural degradation can be seen related to the heavy carbon doped layer. HEMTs are fabricated and show an extremely low drain induced barrier lowering value of 0.1 mV/V, demonstrating an excellent buffer isolation. The carbon doped GaN buffer layer using propane gas is compared to samples using carbon from the trimethylgallium molecule, showing equally low leakage currents, demonstrating the capability of growing highly resistive buffer layers using a gaseous carbon source.« less

Low-temperature superacid catalysis: Reactions of n - butane and propane catalyzed by iron- and manganese-promoted sulfated zirconia

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

Tsz-Keung, Cheung; d`Itri, J.L.; Lange, F.C.

1995-12-31

The primary goal of this project is to evaluate the potential value of solid superacid catalysts of the sulfated zirconia type for light hydrocarbon conversion. The key experiments catalytic testing of the performance of such catalysts in a flow reactor fed with streams containing, for example, n-butane or propane. Fe- and Mn-promoted sulfated zirconia was used to catalyze the conversion of n-butane at atmospheric pressure, 225-450{degrees}C, and n-butane partial pressures in the range of 0.0025-0.01 atm. At temperatures <225{degrees}C, these reactions were accompanied by cracking; at temperatures >350{degrees}C, cracking and isomerization occurred. Catalyst deactivation, resulting at least in part frommore » coke formation, was rapid. The primary cracking products were methane, ethane, ethylene, and propylene. The observation of these products along with an ethane/ethylene molar ratio of nearly 1 at 450{degrees}C is consistent with cracking occurring, at least in part, by the Haag-Dessau mechanism, whereby the strongly acidic catalyst protonates n-butane to give carbonium ions. The rate of methane formation from n-butane cracking catalyzed by Fe- and Mn-promoted sulfated zirconia at 450{degrees}C was about 3 x 10{sup -8} mol/(g of catalyst {center_dot}s). The observation of butanes, pentanes, and methane as products is consistent with Olah superacid chemistry, whereby propane is first protonated by a very strong acid to form a carbonium ion. The carbonium ion then decomposes into methane and an ethyl cation which undergoes oligocondensation reactions with propane to form higher molecular weight alkanes. The results are consistent with the identification of iron- and manganese-promoted sulfated zirconia as a superacid.« less

Update from the Analysis of High Resolution Propane Spectra and the Interpretation of Titan's Infrared Spectra

NASA Technical Reports Server (NTRS)

Klavans, V.; Nixon, C.; Hewagama, T.; Jennings, D. E.

2012-01-01

Titan has an extremely thick atmosphere dominated by nitrogen, but includes a range of trace species such as hydrocarbons and nitriles. One such hydrocarbon is propane (C3H8). Propane has 21 active IR bands covering broad regions of the mid-infrared. Therefore, its ubiquitous signature may potentially mask weaker signatures of other undetected species with important roles in Titan's chemistry. Cassini's Composite Infrared Spectrometer (CIRS) observations of Titan's atmosphere hint at the presence of such molecules. Unfortunately, C3H8 line atlases for the vibration bands V(sub 8), V(sub 21), V(sub 20), and V(sub 7) (869, 922, 1054, and 1157 per centimeter, respectively) are not currently available for subtracting the C3H8 signal to reveal, or constrain, the signature of underlying chemical species. Using spectra previously obtained by Jennings, D. E., et al. at the McMath-Pierce FTIR at Kitt Peak, AZ, as the source and automated analysis utilities developed for this application, we are compiling an atlas of spectroscopic parameters for propane that characterize the ro-vibrational transitions in the above bands. In this paper, we will discuss our efforts for inspecting and fitting the aforementioned bands, present updated results for spectroscopic parameters including absolute line intensities and transition frequencies in HITRAN and GEISA formats, and show how these optical constants will be used in searching for other trace chemical species in Titan's atmosphere. Our line atlas for the V(sub 21) band contains a total number of 2971 lines. The band integrated strength calculated for the V(sub 21) band is 1.003 per centimeter per (centimeter-atm).

Household economic modelsof gill net fishermen at Madura strait

NASA Astrophysics Data System (ADS)

Primyastanto, M.

2018-04-01

The purposes of this research was to analyze household economic models of gill net fishermen at Madura strait. 30 families of gillnet fishermenwere used for purposive sampling. Data analysis used descriptive qualitative and quantitative (regression analysis). Quantitative descriptive analysis was used to analyze research and compare to factors that affecting household economic models of gill net fishermen family. Research results showed tha thousehold economic models of gill net fishermen at Madura strait was production value level or fishermen revenue at sea was strongly influenced byp roduction asset production, education level, fuel, and work flow. Work flow rate of fishermen families affected by asset production, non fisheries workflow and number of male workforce. Non fishing income level was strongly influenced by non-fishery business assets, number of family members owned andnon-fishing work flow. Spending levels of gill net fishermen at Madura strait was affected by fishing income, non-fishing income, fishermen wife education and fishermen family members.

Whole-body cortisol response of zebrafish to acute net handling stress

USGS Publications Warehouse

Ramsay, J.M.; Feist, G.W.; Varga, Z.M.; Westerfield, M.; Kent, M.L.; Schreck, C.B.

2009-01-01

Zebrafish, Danio rerio, are frequently handled during husbandry and experimental procedures in the laboratory, yet little is known about the physiological responses to such stressors. We measured the whole-body cortisol levels of adult zebrafish subjected to net stress and air exposure at intervals over a 24 h period; cortisol recovered to near control levels by about 1 h post-net-stress (PNS). We then measured cortisol at frequent intervals over a 1 h period. Cortisol levels were more than 2-fold higher in net stressed fish at 3 min PNS and continued to increase peaking at 15 min PNS, when cortisol levels were 6-fold greater than the control cortisol. Mean cortisol declined from 15 to 60 min PNS, and at 60 min, net-stressed cortisol was similar to control cortisol. Because the age of fish differed between studies, we examined resting cortisol levels of fish of different ages (3, 7, 13, and 19 months). The resting cortisol values among tanks with the same age fish differed significantly but there was no clear effect of age. Our study is the first to report the response and recovery of cortisol after net handling for laboratory-reared zebrafish. ?? 2009 Elsevier B.V.

Pelvic Rotation and Lower Extremity Motion with Two Different Front Foot Directions in the Tennis Backhand Groundstroke

PubMed Central

Iwamoto, Sayumi; Fukubayashi, Toru; Hume, Patria

2013-01-01

When a tennis player steps forward to hit a backhand groundstroke in closed stance, modifying the direction of the front foot relative to the net may reduce the risk of ankle injury and increase performance. This study evaluated the relationship between pelvic rotation and lower extremity movement during the backhand groundstroke when players stepped with toes parallel to the net (Level) or with toes pointed towards the net (Net). High school competitive tennis players (eleven males and seven females, 16.8 ± 0.8 years, all right- handed) performed tennis court tests comprising five maximum speed directional runs to the court intersection line to hit an imaginary ball with forehand or backhand swings. The final backhand groundstroke for each player at the backcourt baseline was analyzed. Pelvic rotation and lower extremity motion were quantified using 3D video analysis from frontal and sagittal plane camera views reconstructed to 3D using DLT methods. Plantar flexion of ankle and supination of the front foot were displayed for both Net and Level groups during the late phase of the front foot step. The timings of the peak pelvis rotational velocity and peak pelvis rotational acceleration showed different pattern for Net and Level groups. The peak timing of the pelvis rotational velocity of the Level group occurred during the late phase of the step, suggesting an increase in the risk of inversion ankle sprain and a decrease in stroke power compared to the Net group. Key Points Regarding the movement of the forefoot, the Net group and the Level group showed a pattern of supination-pronation-supination during the front stepping foot contact phase (FSFCP). However, the Level group showed only supination of various degrees during FSFCP. For the Net group, the maximum angular velocity of pelvis occurred in the early phase of FSFCP before impact; however, for the Level group, the maximum angular velocity of pelvis occurred in the latter phase of FSFCP after impact. The Level group players showed a potentially higher risk of inversion ankle sprain during the latter stage of FSFCP as pelvic rotation reached maximum angular velocity. The Net group may have a more effective kinetic chain during backhand groundstrokes, which ultimately enhances performance. PMID:24149814

Numerical study on the hydrodynamic characteristics of biofouled full-scale net cage

NASA Astrophysics Data System (ADS)

Bi, Chun-wei; Zhao, Yun-peng; Dong, Guo-hai

2015-06-01

The effect of biofouling on the hydrodynamic characteristics of the net cage is of particular interest as biofouled nettings can significantly reduce flow of well-oxygenated water reaching the stocked fish. For computational efficiency, the porous-media fluid model is proposed to simulate flow through the biofouled plane net and full-scale net cage. The porous coefficients of the porous-media fluid model can be determined from the quadratic-function relationship between the hydrodynamic forces on a plane net and the flow velocity using the least squares method. In this study, drag forces on and flow fields around five plane nets with different levels of biofouling are calculated by use of the proposed model. The numerical results are compared with the experimental data of Swift et al. (2006) and the effectiveness of the numerical model is presented. On that basis, flow through full-scale net cages with the same level of biofouling as the tested plane nets are modeled. The flow fields inside and around biofouled net cages are analyzed and the drag force acting on a net cage is estimated by a control volume analysis method. According to the numerical results, empirical formulas of reduction in flow velocity and load on a net cage are derived as function of drag coefficient of the corresponding biofouled netting.

Impact of Nurse Staffing Mandates on Safety-Net Hospitals: Lessons from California

PubMed Central

McHugh, Matthew D; Brooks Carthon, Margo; Sloane, Douglas M; Wu, Evan; Kelly, Lesly; Aiken, Linda H

2012-01-01

Context California is the first and only state to implement a patient-to-nurse ratio mandate for hospitals. Increasing nurse staffing is an important organizational intervention for improving patient outcomes. Evidence suggests that staffing improved in California hospitals after the mandate was enacted, but the outcome for hospitals bearing a disproportionate share of uncompensated care—safety-net hospitals—remains unclear. One concern was that California's mandate would burden safety-net hospitals without improving staffing or that hospitals would reduce their skill mix, that is, the proportion of registered nurses of all nursing staff. We examined the differential effect of California's staffing mandate on safety-net and non-safety-net hospitals. Methods We used a time-series design with Annual Hospital Disclosure data files from the California Office of Statewide Health Planning and Development (OSHPD) for the years 1998 to 2007 to assess differences in the effect of California's mandate on staffing outcomes in safety-net and non-safety-net hospitals. Findings The mandate resulted in significant staffing improvements, on average nearly a full patient per nurse fewer (−0.98) for all California hospitals. The greatest effect was in those hospitals with the lowest staffing levels at the outset, both safety-net and non-safety-net hospitals, as the legislation intended. The mandate led to significantly improved staffing levels for safety-net hospitals, although there was a small but significant difference in the effect on staffing levels of safety-net and non-safety-net hospitals. Regarding skill mix, a marginally higher proportion of registered nurses was seen in non-safety-net hospitals following the mandate, while the skill mix remained essentially unchanged for safety-net hospitals. The difference between the two groups of hospitals was not significant. Conclusions California's mandate improved staffing for all hospitals, including safety-net hospitals. Furthermore, improvement did not come at the cost of a reduced skill mix, as was feared. Alternative and more targeted designs, however, might yield further improvement for safety-net hospitals and reduce potential disparities in the staffing and skill mix of safety-net and non-safety-net hospitals. PMID:22428696

Influence of nanosecond repetitively pulsed discharges on the stability of a swirled propane/air burner representative of an aeronautical combustor

PubMed Central

Barbosa, S.; Pilla, G.; Lacoste, D. A.; Scouflaire, P.; Ducruix, S.; Laux, C. O.; Veynante, D.

2015-01-01

This paper reports on an experimental study of the influence of a nanosecond repetitively pulsed spark discharge on the stability domain of a propane/air flame. This flame is produced in a lean premixed swirled combustor representative of an aeronautical combustion chamber. The lean extinction limits of the flame produced without and with plasma are determined and compared. It appears that only a low mean discharge power is necessary to increase the flame stability domain. Lastly, the effects of several parameters (pulse repetition frequency, global flowrate, electrode location) are studied. PMID:26170424

[1,1′-Diphenyl-3,3′-(propane-1,3-diyldinitrilo)dibut-1-enolato]copper(II)

PubMed Central

Salehi, Mehdi; Meghdadi, Soraia; Amirnasr, Mehdi; Mereiter, Kurt

2009-01-01

The title compound, [Cu(C23H24N2O2)] or [Cu{(BA)2pn}], where (BA)2pn is 1,1′-diphenyl-3,3′-(propane-1,3-diyldinitrilo)dibut-1-enolate, is a mononuclear copper(II) complex, located on a twofold axis. The four-coordinate CuII atom is in a tetra­hedrally distorted square plane defined by the N and O atoms of the Schiff base ligand. In the tetra­dentate ligand, the two chelate rings are twisted relative to each other, making a dihedral angle of 36.57 (3)°. PMID:21581795

Supercritical convection, critical heat flux, and coking characteristics of propane

NASA Technical Reports Server (NTRS)

Rousar, D. C.; Gross, R. S.; Boyd, W. C.

1984-01-01

The heat transfer characteristics of propane at subcritical and supercritical pressure were experimentally evaluated using electrically heated Monel K-500 tubes. A design correlation for supercritical heat transfer coefficient was established using the approach previously applied to supercritical oxygen. Flow oscillations were observed and the onset of these oscillations at supercritical pressures was correlated with wall-to-bulk temperature ratio and velocity. The critical heat flux measured at subcritical pressure was correlated with the product of velocity and subcooling. Long duration tests at fixed heat flux conditions were conducted to evaluate coking on the coolant side tube wall and coking rates comparable to RP-1 were observed.

Investigation of light scattering as a technique for detecting discrete soot particles in a luminous flame

NASA Technical Reports Server (NTRS)

1978-01-01

The practicability of using a classical light-scattering technique, involving comparison of angular scattering intensity patterns with theoretically determined Mie and Rayleight patterns, to detect discrete soot particles (diameter less than 50 nm) in premixed propane/air and propane/oxygen-helium flames is considered. The experimental apparatus employed in this investigation included a laser light source, a flat-flame burner, specially coated optics, a cooled photomultiplier detector, and a lock-in voltmeter readout. Although large, agglomerated soot particles were detected and sized, it was not possible to detect small, discrete particles. The limiting factor appears to be background scattering by the system's optics.

Development of a Two-Stage Mars Ascent Vehicle Using In-Situ Propellant Production

NASA Technical Reports Server (NTRS)

Paxton, Laurel; Vaughan, David

2014-01-01

Mars Sample Return (MSR) and Mars In-Situ Resource Utilization (ISRU) present two main challenges for the advancement of Mars science. MSR would demonstrate Mars lift-off capability, while ISRU would test the ability to produce fuel and oxidizer using Martian resources, a crucial step for future human missions. A two-stage Mars Ascent Vehicle (MAV) concept was developed to support sample return as well as in-situ propellant production. The MAV would be powered by a solid rocket first stage and a LOX-propane second stage. A liquid second-stage provides higher orbit insertion reliability than a solid second stage as well as a degree of complexity eventually required for manned missions. Propane in particular offers comparable performance to methane without requiring cryogenic storage. The total MAV mass would be 119.9 kg to carry an 11 kg payload to orbit. The feasibility of in-situ fuel and oxidizer production was also examined. Two potential schemes were evaluated for production capability, size and power requirements. The schemes examined utilize CO2 and water as starting blocks to produce LOX and a propane blend. The infrastructure required to fuel and launch the MAV was also explored.

Mechanism studies of the conversion of 13C-labeled n-butane on zeolite H-ZSM-5 by using 13C magic angle spinning NMR spectroscopy and GC-MS analysis.

PubMed

Luzgin, Mikhail V; Stepanov, Alexander G; Arzumanov, Sergei S; Rogov, Vladimir A; Parmon, Valentin N; Wang, Wei; Hunger, Michael; Freude, Dieter

2005-12-23

By using 13C MAS NMR spectroscopy (MAS = magic angle spinning), the conversion of selectively 13C-labeled n-butane on zeolite H-ZSM-5 at 430-470 K has been demonstrated to proceed through two pathways: 1) scrambling of the selective 13C-label in the n-butane molecule, and 2) oligomerization-cracking and conjunct polymerization. The latter processes (2) produce isobutane and propane simultaneously with alkyl-substituted cyclopentenyl cations and condensed aromatic compounds. In situ 13C MAS NMR and complementary ex situ GC-MS data provided evidence for a monomolecular mechanism of the 13C-label scrambling, whereas both isobutane and propane are formed through intermolecular pathways. According to 13C MAS NMR kinetic measurements, both pathways proceed with nearly the same activation energies (E(a) = 75 kJ mol(-1) for the scrambling and 71 kJ mol(-1) for isobutane and propane formation). This can be rationalized by considering the intermolecular hydride transfer between a primarily initiated carbenium ion and n-butane as being the rate-determining stage of the n-butane conversion on zeolite H-ZSM-5.

Identification and analytical characterization of four synthetic cathinone derivatives iso-4-BMC, β-TH-naphyrone, mexedrone, and 4-MDMC.

PubMed

Qian, Zhenhua; Jia, Wei; Li, Tao; Liu, Cuimei; Hua, Zhendong

2017-02-01

New psychoactive substances (NPS) have gained much popularity on the global market over the last number of years. The synthetic cathinone family is one of the most prominent groups and this paper reports on the analytical properties of four synthetic cathinone derivatives: (1) 1-(4-bromophenyl)-1-(methylamino)propan-2-one (iso-4-BMC or iso-brephedrone), (2) 2-(pyrrolidin-1-yl)-1-(5,6,7,8-tetrahydronaphthalen-2-yl)pentan-1-one (β-TH-naphyrone), (3) 3-methoxy-2-(methylamino)-1-(4-methylphenyl)propan-1-one (mexedrone), and (4) 2-(dimethylamino)-1-(4-methylphenyl)propan-1-one (4-MDMC). These identifications were based on liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy. To our knowledge, no chemical or pharmacological data about compounds 1-3 have appeared until now, making this the first report on these compounds. The Raman and GC-MS data of 4 have been reported, but this study added the LC-MS and NMR data for additional characterization. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Low Temperature Propane Oxidation over Co 3O 4 based Nano-array Catalysts. Ni Dopant Effect, Reaction Mechanism and Structural Stability

DOE PAGES

Ren, Zheng; Wu, Zili; Gao, Puxian; ...

2015-06-09

Low temperature propane oxidation has been achieved by Co 3O 4-based nano-array catalysts featuring low catalytic materials loading. The Ni doping into the Co 3O 4 lattice has led to enhanced reaction kinetics at low temperature by promoting the surface lattice oxygen activity. In situ DRIFTS investigation in tandem with isotopic oxygen exchange reveals that the propane oxidation proceeds via Mars-van Krevelen mechanism where surface lattice oxygen acts as the active site whereas O 2 in the reaction feed does not directly participate in CO 2 formation. The Ni doping promotes the formation of less stable carbonates on the surfacemore » to facilitate the CO 2 desorption. The thermal stability of Ni doped Co 3O 4 decreases with increased Ni concentration while catalytic activity increases. A balance between enhanced activity and compromised thermal stability shall be considered in the Ni doped Co 3O 4 nano-array catalysts for low temperature hydrocarbon oxidation. This study provides useful and timely guidance for rational catalyst design toward low temperature catalytic oxidation.« less

Measurement of reaeration coefficients for selected Florida streams

USGS Publications Warehouse

Hampson, P.S.; Coffin, J.E.

1989-01-01

A total of 29 separate reaeration coefficient determinations were performed on 27 subreaches of 12 selected Florida streams between October 1981 and May 1985. Measurements performed prior to June 1984 were made using the peak and area methods with ethylene and propane as the tracer gases. Later measurements utilized the steady-state method with propane as the only tracer gas. The reaeration coefficients ranged from 1.07 to 45.9 days with a mean estimated probable error of +/16.7%. Ten predictive equations (compiled from the literature) were also evaluated using the measured coefficients. The most representative equation was one of the energy dissipation type with a standard error of 60.3%. Seven of the 10 predictive additional equations were modified using the measured coefficients and nonlinear regression techniques. The most accurate of the developed equations was also of the energy dissipation form and had a standard error of 54.9%. For 5 of the 13 subreaches in which both ethylene and propane were used, the ethylene data resulted in substantially larger reaeration coefficient values which were rejected. In these reaches, ethylene concentrations were probably significantly affected by one or more electrophilic addition reactions known to occur in aqueous media. (Author 's abstract)

Synthesis and antioxidant, anti-inflammatory and gastroprotector activities of anethole and related compounds.

PubMed

Freire, Rosemayre S; Morais, Selene M; Catunda-Junior, Francisco Eduardo A; Pinheiro, Diana C S N

2005-07-01

Some derivatives of trans-anethole [1-methoxy-4-(1-propenyl)-benzene] (1) were synthesized, by introducing hydroxyl groups in the double bond of the propenyl moiety. Two types of reactions were performed: (i) oxymercuration/demercuration that formed two products, the mono-hydroxyl derivative, 1-hydroxy-1-(4-methoxyphenyl)-propane (2) and in lesser extent the dihydroxyl derivative, 1,2-dihydroxy-1-(4-methoxyphenyl)-propane (3) and (ii) epoxidation with m-chloroperbenzoic acid that also led to the formation of two products, the dihydroxyl derivative (3) and the correspondent m-chloro-benzoic acid mono-ester, 1-hydroxy-1(4-methoxyphenyl)-2-m-chlorobenzoyl-propane (4). The structures of these compounds were confirmed mainly by mass, IR, 1H and 13C NMR spectral data. The activity of anethole and hydroxylated derivatives was evaluated using antioxidant, anti-inflammatory and gastroprotector tests. Compounds (2) and (3) were more active antioxidant agents than (1) and (4). In the anti-inflammatory assay, anethole showed lower activity than hydroxylated derivatives. Anethole and in lesser extent its derivatives 2 and 4 showed significant gastroprotector activity. All tested compounds do not alter significantly the total number of white blood cells.

Absorption Reveals and Hydrogen Addition Explains New Interstellar Aldehydes: Propenal and Propanal

NASA Technical Reports Server (NTRS)

Hollis, J. M.; Jewell, P. R.; Lovas, F. J.; Remijan, A.; Mollendal, H.

2004-01-01

New interstellar molecules propenal (CH2CHCHO) and propanal (CH3CH2CHO) have been detected largely in absorption toward the star-forming region Sagittarius B2(N) by means of rotational transitions observed with the 100-m Green Bank Telescope (GBT) operating in the range of 18 GHz (lambda approximately 1.7 cm) to 26 GHz (lambda approximately 1.2 cm). The GBT was also used to observe the previously reported interstellar aldehyde propynal (HC2CHO) in Sagittarius B2(N) which is known for large molecules believed to form on interstellar grains. The presence of these three interstellar aldehydes toward Sagittarius B2(N) strongly suggests that simple hydrogen addition on interstellar grains accounts for successively larger molecular species: from propynal to propenal and from propenal to propanal. Energy sources within Sagittarius B2(N) likely permit the hydrogen addition reactions on grain surfaces to proceed. This work demonstrates that successive hydrogen addition is probably an important chemistry route in the formation of a number of complex interstellar molecules. We also searched for but did not detect the three-carbon sugar glyceraldehyde (CH2OHCHOHCHO).

High Resolution Spectra of Carbon Monoxide, Propane and Ammonia for Atmospheric Remote Sensing

NASA Astrophysics Data System (ADS)

Beale, Christopher Andrew

Spectroscopy is a critical tool for analyzing atmospheric data. Identification of atmospheric parameters such as temperature, pressure and the existence and concentrations of constituent gases via remote sensing techniques are only possible with spectroscopic data. These form the basis of model atmospheres which may be compared to observations to determine such parameters. To this end, this dissertation explores the spectroscopy of three molecules: ammonia, propane and carbon monoxide. Infrared spectra have been recorded for ammonia in the region 2400-9000 cm-1. These spectra were recorded at elevated temperatures (from 293-973 K) using a Fourier Transform Spectrometer (FTS). Comparison between the spectra recorded at different temperatures yielded experimental lower state energies. These spectra resulted in the measurement of roughly 30000 lines and about 3000 quantum assignments. In addition spectra of propane were recorded at elevated temperatures (296-700 K) using an FTS. Atmospheres with high temperatures require molecular data at appropriate conditions. This dissertation describes collection of such data and the potential application to atmospheres in our solar system, such as auroral regions in Jupiter, to those of planets orbiting around other stars and cool sub-stellar objects known as brown dwarfs. The spectra of propane and ammonia provide the highest resolution and most complete experimental study of these gases in their respective spectral regions at elevated temperatures. Detection of ammonia in an exoplanet or detection of propane in the atmosphere of Jupiter will most likely rely on the work presented here. The best laboratory that we have to study atmospheres is our own planet. The same techniques that are applied to these alien atmospheres originated on Earth. As such it is appropriate to discuss remote sensing of our own atmosphere. This idea is explored through analysis of spectroscopic data recorded by an FTS on the Atmospheric Chemistry Experiment satellite of carbon monoxide. The effect of the atmosphere's chemistry and physics on this molecule is measured through its isotopologues, primarily 13CO (carbon-13 substituted carbon monoxide). Isotopic chemistry allows a key analysis of the atmosphere as it may be used as a tracer for chemical reactions and dynamical processes. The carbon monoxide fractionation results in Chapter IV present the first global measurements of isotopic fractionation of CO, showing significant fractionation in the upper atmosphere (60-80 km) as a result of the photolysis of carbon dioxide (CO2).

Trapping-mediated dissociative chemisorption of C3H8 and C3D8 on Ir(110)

NASA Astrophysics Data System (ADS)

Kelly, D.; Weinberg, W. H.

1996-07-01

We have employed molecular beam techniques to investigate the molecular trapping and trapping-mediated dissociative chemisorption of C3H8 and C3D8 on Ir(110) at low beam translational energies, Ei≤5 kcal/mol, and surface temperatures, Ts, from 85 to 1200 K. For Ts=85 K, C3H8 is molecularly adsorbed on Ir(110) with a trapping probability, ξ, equal to 0.94 at Ei=1.6 kcal/mol and ξ=0.86 at Ei=5 kcal/mol. At Ei=1.9 kcal/mol and Ts=85 K, ξ of C3D8 is equal to 0.93. From 150 K to approximately 700 K, the initial probabilities of dissociative chemisorption of propane decrease with increasing Ts. For Ts from 700 to 1200 K, however, the initial probability of dissociative chemisorption maintains the essentially constant value of 0.16. These observations are explained within the context of a kinetic model which includes both C-H (C-D) and C-C bond cleavage. Below 450 K propane chemisorption on Ir(110) arises essentially solely from C-H (C-D) bond cleavage, an unactivated mechanism (with respect to a gas-phase energy zero) for this system, which accounts for the decrease in initial probabilities of chemisorption with increasing Ts. With increasing Ts, however, C-C bond cleavage, the activation energy of which is greater than the desorption energy of physically adsorbed propane, increasingly contributes to the measured probability of dissociative chemisorption. The activation energies, referenced to the bottom of the physically adsorbed molecular well, for C-H and C-C bond cleavage for C3H8 on Ir(110) are found to be Er,CH=5.3±0.3 kcal/mol and Er,CC=9.9±0.6 kcal/mol, respectively. The activation energies for C-D and C-C bond cleavage for C3D8 on Ir(110) are 6.3±0.3 kcal/mol and 10.5±0.6 kcal/mol, respectively. The desorption activation energy of propane from Ir(110) is approximately 9.5 kcal/mol. These activation energies are compared to activation energies determined recently for ethane and propane adsorption on Ir(111), Ru(001), and Pt(110)-(1×2), and ethane activation on Ir(110).

Knowledge and perception towards net care and repair practice in Ethiopia.

PubMed

Zewde, Ayele; Irish, Seth; Woyessa, Adugna; Wuletaw, Yonas; Nahusenay, Honelgn; Abdelmenan, Semira; Demissie, Meaza; Gulema, Hanna; Dissanayake, Gunawardena; Chibsa, Sheleme; Solomon, Hiwot; Yenehun, Meseret A; Kebede, Amha; Lorenz, Lena M; Ponce-de-Leon, Gabriel; Keating, Joseph; Worku, Alemayehu; Berhane, Yemane

2017-10-02

Long-lasting insecticidal nets (LLINs) are a key malaria control intervention. Although LLINs are presumed to be effective for 3 years under field or programmatic conditions, net care and repair approaches by users influence the physical and chemical durability. Understanding how knowledge, perception and practices influence net care and repair practices could guide the development of targeted behavioural change communication interventions related to net care and repair in Ethiopia and elsewhere. This population-based, household survey was conducted in four regions of Ethiopia [Amhara, Oromia, Tigray, Southern Nations Nationalities Peoples Region (SNNPR)] in June 2015. A total of 1839 households were selected using multi-stage sampling procedures. The household respondents were the heads of households. A questionnaire was administered and the data were captured electronically. STATA software version 12 was used to analyse the data. Survey commands were used to account for the multi-stage sampling approach. Household descriptive statistics related to characteristics and levels of knowledge and perception on net care and repair are presented. Ordinal logistic regression was used to identify factors associated with net care and repair perceptions. Less than a quarter of the respondents (22.3%: 95% CI 20.4-24.3%) reported adequate knowledge of net care and repair; 24.6% (95% CI 22.7-26.5%) of the respondents reported receiving information on net care and repair in the previous 6 months. Thirty-five per cent of the respondents (35.1%: 95% CI 32.9-37.4%) reported positive perceptions towards net care and repair. Respondents with adequate knowledge on net care and repair (AOR 1.58: 95% CI 1.2-2.02), and those who discussed net care and repair with their family (AOR 1.47: 95% CI 1.14-1.89) had higher odds of having positive perceptions towards net care and repair. The low level of reported knowledge on net care and repair, as well as the low level of reported positive perception towards net repair need to be addressed. Targeted behavioural change communication campaigns could be used to target specific groups; increased net care and repair would lead to longer lasting nets.

Association of MAOA, 5-HTT, and NET promoter polymorphisms with gene expression and protein activity in human placentas

PubMed Central

Zhang, Huiping; Smith, Graeme N.; Liu, Xudong

2010-01-01

Monoamine oxidase A (MAOA) and the transporters for serotonin (5-HTT) and norepinephrine (NET) may play important roles in regulating maternal monoamine neurotransmitters transferred across the placenta to the fetus. We investigated whether promoter polymorphisms in MAOA (uVNTR), 5-HTT (5-HTTLPR), and NET (NETpPR AAGG4) could influence gene expression and protein activity in human placentas. Normal term human placentas (n = 73) were collected, and placental MAOA, 5-HTT, and NET mRNA levels and protein activity were determined. The mRNA levels or protein activities were compared between different genotype groups. Placentas hemizygous (male fetus) or homozygous (female fetus) for MAOA uVNTR 4-repeat allele had significantly higher MAOA mRNA levels than those hemizygous or homozygous for the 3-repeat allele (P = 0.001). However, no significant difference in MAOA enzyme activity was found for these two groups of genotypes (P = 0.161). Placentas with the 5-HTTLPR short (S)-allele (S/S+S/L) had significantly lower 5-HTT mRNA levels and serotonin uptake rate than those homozygous for the long (L)-allele (L/L) (mRNA: P < 0.001; serotonin transporting activity: P < 0.001). Placentas homozygous for the NET AAGG4 L4 allele had significantly higher NET mRNA levels, as well as dopamine and norepinephrine uptake rates, than those with the S4/L4 genotype (mRNA: P < 0.001; dopamine transporting activity: P = 0.012; norepinephrine transporting activity: P = 0.011). These findings suggest that the three promoter polymorphisms of MAOA, 5-HTT, and NET influence gene expression levels and protein activity of these genes in human placentas, potentially leading to different fetal levels of maternal monoamine neurotransmitters, which may have an impact on fetal neurodevelopment. PMID:20332182

Association of MAOA, 5-HTT, and NET promoter polymorphisms with gene expression and protein activity in human placentas.

PubMed

Zhang, Huiping; Smith, Graeme N; Liu, Xudong; Holden, Jeanette J A

2010-06-01

Monoamine oxidase A (MAOA) and the transporters for serotonin (5-HTT) and norepinephrine (NET) may play important roles in regulating maternal monoamine neurotransmitters transferred across the placenta to the fetus. We investigated whether promoter polymorphisms in MAOA (uVNTR), 5-HTT (5-HTTLPR), and NET (NETpPR AAGG(4)) could influence gene expression and protein activity in human placentas. Normal term human placentas (n = 73) were collected, and placental MAOA, 5-HTT, and NET mRNA levels and protein activity were determined. The mRNA levels or protein activities were compared between different genotype groups. Placentas hemizygous (male fetus) or homozygous (female fetus) for MAOA uVNTR 4-repeat allele had significantly higher MAOA mRNA levels than those hemizygous or homozygous for the 3-repeat allele (P = 0.001). However, no significant difference in MAOA enzyme activity was found for these two groups of genotypes (P = 0.161). Placentas with the 5-HTTLPR short (S)-allele (S/S+S/L) had significantly lower 5-HTT mRNA levels and serotonin uptake rate than those homozygous for the long (L)-allele (L/L) (mRNA: P < 0.001; serotonin transporting activity: P < 0.001). Placentas homozygous for the NET AAGG(4) L(4) allele had significantly higher NET mRNA levels, as well as dopamine and norepinephrine uptake rates, than those with the S(4)/L(4) genotype (mRNA: P < 0.001; dopamine transporting activity: P = 0.012; norepinephrine transporting activity: P = 0.011). These findings suggest that the three promoter polymorphisms of MAOA, 5-HTT, and NET influence gene expression levels and protein activity of these genes in human placentas, potentially leading to different fetal levels of maternal monoamine neurotransmitters, which may have an impact on fetal neurodevelopment.

50 CFR 403.02 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... largest supportable within the ecosystem to the population level that results in maximum net productivity. Maximum net productivity is the greatest net annual increment in population numbers or biomass resulting...

Factors associated with mosquito net use by individuals in households owning nets in Ethiopia

PubMed Central

2011-01-01

Background Ownership of insecticidal mosquito nets has dramatically increased in Ethiopia since 2006, but the proportion of persons with access to such nets who use them has declined. It is important to understand individual level net use factors in the context of the home to modify programmes so as to maximize net use. Methods Generalized linear latent and mixed models (GLLAMM) were used to investigate net use using individual level data from people living in net-owning households from two surveys in Ethiopia: baseline 2006 included 12,678 individuals from 2,468 households and a sub-sample of the Malaria Indicator Survey (MIS) in 2007 included 14,663 individuals from 3,353 households. Individual factors (age, sex, pregnancy); net factors (condition, age, net density); household factors (number of rooms [2006] or sleeping spaces [2007], IRS, women's knowledge and school attendance [2007 only], wealth, altitude); and cluster level factors (rural or urban) were investigated in univariate and multi-variable models for each survey. Results In 2006, increased net use was associated with: age 25-49 years (adjusted (a) OR = 1.4, 95% confidence interval (CI) 1.2-1.7) compared to children U5; female gender (aOR = 1.4; 95% CI 1.2-1.5); fewer nets with holes (Ptrend = 0.002); and increasing net density (Ptrend < 0.001). Reduced net use was associated with: age 5-24 years (aOR = 0.2; 95% CI 0.2-0.3). In 2007, increased net use was associated with: female gender (aOR = 1.3; 95% CI 1.1-1.6); fewer nets with holes (aOR [all nets in HH good] = 1.6; 95% CI 1.2-2.1); increasing net density (Ptrend < 0.001); increased women's malaria knowledge (Ptrend < 0.001); and urban clusters (aOR = 2.5; 95% CI 1.5-4.1). Reduced net use was associated with: age 5-24 years (aOR = 0.3; 95% CI 0.2-0.4); number of sleeping spaces (aOR [per additional space] = 0.6, 95% CI 0.5-0.7); more old nets (aOR [all nets in HH older than 12 months] = 0.5; 95% CI 0.3-0.7); and increasing household altitude (Ptrend < 0.001). Conclusion In both surveys, net use was more likely by women, if nets had fewer holes and were at higher net per person density within households. School-age children and young adults were much less likely to use a net. Increasing availability of nets within households (i.e. increasing net density), and improving net condition while focusing on education and promotion of net use, especially in school-age children and young adults in rural areas, are crucial areas for intervention to ensure maximum net use and consequent reduction of malaria transmission. PMID:22165821

Estimation of insecticide persistence, biological activity and mosquito resistance to PermaNet® 2 long-lasting insecticidal nets over three to 32 months of use in Ethiopia.

PubMed

Anshebo, Gedeon Yohannes; Graves, Patricia M; Smith, Stephen C; Wills, Aprielle B; Damte, Mesele; Endeshaw, Tekola; Shargie, Estifanos Biru; Gebre, Teshome; Mosher, Aryc W; Patterson, Amy E; Emerson, Paul M

2014-03-06

Information is needed on the expected durability of insecticidal nets under operational conditions. The persistence of insecticidal efficacy is important to estimate the median serviceable life of nets under field conditions and to plan for net replacement. Deltamethrin residue levels were evaluated by the proxy method of X-ray fluorescence spectrometry on 189 nets used for three to six months from nine sites, 220 nets used for 14-20 months from 11 sites, and 200 nets used for 26-32 months from ten sites in Ethiopia. A random sample of 16.5-20% of nets from each time period (total 112 of 609 nets) were tested by bioassay with susceptible mosquitoes, and nets used for 14-20 months and 26-32 months were also tested with wild caught mosquitoes. Mean insecticide levels estimated by X-ray fluorescence declined by 25.9% from baseline of 66.2 (SD 14.6) mg/m2 at three to six months to 44.1 (SD 21.2) mg/m2 at 14-20 months and by 30.8% to 41.1 (SD 18.9) mg/m2 at 26-32 months. More than 95% of nets retained greater than 10 mg/m2 of deltamethrin and over 79% had at least 25 mg/m2 at all time periods. By bioassay with susceptible Anopheles, mortality averaged 89.0% on 28 nets tested at three to six months, 93.3% on 44 nets at 14-20 months and 94.1% on 40 nets at 26-32 months. With wild caught mosquitoes, mortality averaged 85.4% (range 79.1 to 91.7%) at 14-20 months but had dropped significantly to 47.2% (39.8 to 54.7%) at 26-32 months. Insecticide residue level, as estimated by X-ray fluorescence, declined by about one third between three and six months and 14-20 months, but remained relatively stable and above minimum requirements thereafter up to 26-32 months. The insecticidal activity of PermaNet® 2.0 long-lasting insecticidal nets in the specified study area may be considered effective to susceptible mosquitoes at least for the duration indicated in this study (32 months). However, results indicated that resistance in the wild population is already rendering nets with optimum insecticide concentrations less effective in practice.

The importance of education to increase the use of bed nets in villages outside of Kinshasa, Democratic Republic of the Congo.

PubMed

Ndjinga, Julie K; Minakawa, Noboru

2010-10-12

Malaria is the most prominent disease in the Democratic Republic of the Congo (DRC), and long-lasting insecticide-treated nets (LLINs) have been distributed free of charge since 2006 to combat the disease. However, the success of this bed net campaign depends on sufficient bed net use in all age groups. This study was designed to examine the factors affecting bed net use in villages outside of Kinshasa. Two villages along the Congo River, totalling 142 households with 640 residents, were surveyed using a standard questionnaire. The interview determined the number, ages, and sexes of family members; the education level of the family head; the number, colour, and type of nets owned; and the number of nets used in the previous night. The size of house was also measured, and numbers of rooms and beds were recorded. These variables were examined to reveal important factors that affect bed net use. A total of 469 nets were counted, and nearly all nets were white LLINs. Of these nets, 229 (48.8%) nets were used by 284 (44.4%) residents. Bed nets were used by over 90% of children 5 to 15 years of age, whereas less than 50% of the residents in other age groups used bed nets. The important variables affecting bed net use were numbers of beds and rooms in the house and the education level of the family head of household. Education was the most important factor affecting bed net use in the villages outside Kinshasa. Development of an educational programme, particularly one directed toward parents, is necessary to reduce misconceptions and increase prevalence of bed net use among all age groups.

Primary emissions and secondary formation of volatile organic compounds from natural gas production in five major U.S. shale plays

NASA Astrophysics Data System (ADS)

Gilman, J.; Lerner, B. M.; Warneke, C.; Graus, M.; Lui, R.; Koss, A.; Yuan, B.; Murphy, S. M.; Alvarez, S. L.; Lefer, B. L.; Min, K. E.; Brown, S. S.; Roberts, J. M.; Osthoff, H. D.; Hatch, C. D.; Peischl, J.; Ryerson, T. B.; De Gouw, J. A.

2014-12-01

According to the U.S. Energy and Information Administration (EIA), domestic production of natural gas from shale formations is currently at the highest levels in U.S. history. Shale gas production may also result in the production of natural gas plant liquids (NGPLs) such as ethane and propane as well as natural gas condensate composed of a complex mixture of non-methane hydrocarbons containing more than ~5 carbon atoms (e.g., hexane, cyclohexane, and benzene). The amounts of natural gas liquids and condensate produced depends on the particular reservoir. The source signature of primary emissions of hydrocarbons to the atmosphere within each shale play will therefore depend on the composition of the raw natural gas as well as the industrial processes and equipment used to extract, separate, store, and transport the raw materials. Characterizing the primary emissions of VOCs from natural gas production is critical to assessing the local and regional atmospheric impacts such as the photochemical formation of ozone and secondary formation of organic aerosol. This study utilizes ground-based measurements of a full suite of volatile organic compounds (VOCs) in two western U.S. basins, the Uintah (2012-2014 winter measurements only) and Denver-Julesburg (winter 2011 and summer 2012), and airborne measurements over the Haynesville, Fayetteville, and Marcellus shale basins (summer 2013). By comparing the observed VOC to propane enhancement ratios, we show that each basin has a unique VOC source signature associated with oil and natural gas operations. Of the shale basins studied, the Uintah basin had the largest overall VOC to propane enhancement ratios while the Marcellus had the lowest. For the western basins, we will compare the composition of oxygenated VOCs produced from photochemical oxidation of VOC precursors and contrast the oxygenated VOC mixture to a "typical" summertime urban VOC mixture. The relative roles of alkanes, alkenes, aromatics, and cycloalkanes as precursors for C2-C6 aldehydes and ketones, and C3-C4 alkyl nitrates will be investigated.

Propane in nitrogen, 1000 μmol/mol

NASA Astrophysics Data System (ADS)

Konopelko, L. A.; Kustikov, Y. A.; Kolobova, A. V.; Pankratov, V. V.; Pankov, A. A.; Efremova, O. V.; Rozhnov, M. S.; Melnyk, D. M.; Petryshyn, P. V.; Levbarg, O. S.; Kisel, S. P.; Shpilnyi, S. A.; Yakubov, S. Ye; Bakovec, N. V.; Mironchik, A. M.; Aleksandrov, V. V.

2017-01-01

This article presents the report on the COOMET key comparison COOMET.QM-K111, which is linking to the appropriate CCQM comparison—CCQM-K111 'Propane in nitrogen 1000 μmol/mol'. CCQM-K111 was carried out in 2014-2016 and it was one of a series of key comparisons in the gas analysis area assessing core competences. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Preliminary results from screening tests of commercial catalysts with potential use in gas turbine combustors. Part 1: Furnace studies of catalyst activity

NASA Technical Reports Server (NTRS)

Anderson, D. N.

1976-01-01

Thirty commercially produced monolith and pellet catalysts were tested as part of a screening process to select catalysts suitable for use in a gas turbine combustor. The catalysts were contained in a 1.8 centimeter diameter quartz tube and heated to temperatures varying between 300 and 1,200 K while a mixture of propane and air passed through the bed at space velocities of 44,000 to 70,000/hour. The amount of propane oxidized was measured as a function of catalyst temperature. Of the samples tested, the most effective catalysts proved to be noble metal catalysts on monolith substrates.

catena-Poly[[aqua­(1,10-phenanthroline)cobalt(II)]-μ-4,4′-(propane-1,3-diyldi­oxy)dibenzoato

PubMed Central

Shen, Su-Mei

2009-01-01

In the title compound, [Co(C17H14O6)(C12H8N2)(H2O)]n, the CoII atom is coordinated by a monodentate 4,4′-(propane-1,3-diyldi­oxy)dibenzoate (cpp) dianion, a water mol­ecule and a chelating 1,10-phenanthroline (phen) ligand. A symmetry-generated cpp ligand completes the CoN2O3 trigonal-bipyramidal geometry for the metal ion, with the N atoms occupying both equatorial and axial sites. The bridging cpp ligands form chains propagating in [110] and O—H⋯O hydrogen bonds consolidate the packing. PMID:21577702

Theoretical study of interactions between 2,2-Bis (ethylferrocenyl) propane and ammonium perchlorate at low temperature

NASA Astrophysics Data System (ADS)

Zhou, Junhong; Zhang, Wei; Yang, Jun; Jiang, Benzheng; Chen, Weiming

2016-05-01

In order to explore the interaction mechanism between 2,2-Bis (ethylferrocenyl) propane (GFP) and ammonium perchlorate (AP) at low temperature (below 250 °C), all the possible intermolecular interactions between GFP and AP were calculated. The calculations were performed in single molecule, cluster and slab models. The calculation results show that the interactions between GFP and AP at low temperature mainly come from GFP:-H+ and GFP-NH4+ pair interactions. We speculate that the interaction mechanism between GFP and AP at low temperature is that GFP/H+ or GFP/NH4+ interactions cause GFP to be protonated, and then protonated GFP is to further oxidized.

Chemical kinetic modeling of propane oxidation behind shock waves

NASA Technical Reports Server (NTRS)

Mclain, A. G.; Jachimowski, C. J.

1977-01-01

The stoichiometric combustion of propane behind incident shock waves was studied experimentally and analytically over a temperature range from 1700 K to 2600 K and a pressure range from 1.2 to 1.9 atm. Measurements of the concentrations of carbon monoxide (CO) and carbon dioxide (CO2) and the product of the oxygen atom and carbon dioxide concentrations (O)(CO) were made after passage of the incident shock wave. A kinetic mechanism was developed which, when used in a computer program for a flowing, reacting gas behind an incident shock wave predicted experimentally measured results quite well. Ignition delay times from the literature were also predicted quite well. The kinetic mechanism consisted of 59 individual kinetic steps.

Synergy between hexavalent chromium ions and TiO2 nanoparticles inside TUD-1 in the photocatalytic oxidation of propane, a spectroscopic study

NASA Astrophysics Data System (ADS)

Hamdy, Mohamed S.

2016-02-01

Siliceous TUD-1 mesoporous material was bi-functionalized by titanium dioxide nanoparticles and hexavalent chromium ions. The synthesis was carried out by one-pot procedure based on sol-gel technique. The photocatalytic performance of the prepared material was evaluated in the oxidation of propane under the illumination of ultraviolet light (wavelength = 360 nm) and monitored by in situ Fourier transform infrared spectroscopy. The photocatalytic activity of the prepared material exhibited an extra-ordinary activity than the reference samples that contain either hexavalent chromium ions or titanium dioxide nanoparticles only, confirming the true synergy between hexavalent chromium and tetravalent titanium ions of titanium dioxide nanoparticles.

Infrared, Raman and density functional characterization and structural study of 2-Nitro-2-phenyl-propane-1,3-diol

NASA Astrophysics Data System (ADS)

Kaya, Mehmet Fatih; Bağlayan, Özge; Kaya, Esma Güneş; Alver, Özgür

2017-12-01

Nitro compound and nitro derivatives are industrially important to produce rubber and agricultural chemicals. In this study, one of the promising derivatives of nitro compound 2-Nitro-2-phenyl-propane-1,3-diol (2NPP) is examined in detail. FT-Infrared and dispersive Raman spectra of 2NPP (C9H11NO4) were respectively recorded in 4000-10 cm-1 and 4000-100 cm-1. The bond distances and angles, conformational distributions, vibrational frequencies and the assignment of each mode, some thermodynamic parameters and reactivity descriptors: total energy, hardness, chemical potential, electrophilicity index, electronegativity, frontier orbitals energy gap of 2NPP were investigated by using DFT/B3LYP method with 6-31++G (d,p) basis set. In order to locate the global minimum on the potential energy surface of 2NPP, a beforehand conformational examinations were carried out using Spartan 10 along with semi-emprical PM6 method. The results of conformational analyses showed that there are five possible conformations having energies under 2 kcal/mol. Comparison of the theoretical and experimental results clearly indicates that density functional hybrid B3LYP/6-31++G (d,p) level of theory can be used to predict vibrational frequencies and structural parameters of 2NPP. Further, C1 geometry is considered to be the global minimum conformation of 2NPP.

Compact hydrogen production systems for solid polymer fuel cells

NASA Astrophysics Data System (ADS)

Ledjeff-Hey, K.; Formanski, V.; Kalk, Th.; Roes, J.

Generally there are several ways to produce hydrogen gas from carbonaceous fuels like natural gas, oil or alcohols. Most of these processes are designed for large-scale industrial production and are not suitable for a compact hydrogen production system (CHYPS) in the power range of 1 kW. In order to supply solid polymer fuel cells (SPFC) with hydrogen, a compact fuel processor is required for mobile applications. The produced hydrogen-rich gas has to have a low level of harmful impurities; in particular the carbon monoxide content has to be lower than 20 ppmv. Integrating the reaction step, the gas purification and the heat supply leads to small-scale hydrogen production systems. The steam reforming of methanol is feasible at copper catalysts in a low temperature range of 200-350°C. The combination of a small-scale methanol reformer and a metal membrane as purification step forms a compact system producing high-purity hydrogen. The generation of a SPFC hydrogen fuel gas can also be performed by thermal or catalytic cracking of liquid hydrocarbons such as propane. At a temperature of 900°C the decomposition of propane into carbon and hydrogen takes place. A fuel processor based on this simple concept produces a gas stream with a hydrogen content of more than 90 vol.% and without CO and CO2.

RadNet Databases and Reports

EPA Pesticide Factsheets

EPA’s RadNet data are available for viewing in a searchable database or as PDF reports. Historical and current RadNet monitoring data are used to estimate long-term trends in environmental radiation levels.

Predicting the impact of insecticide-treated bed nets on malaria transmission: the devil is in the detail.

PubMed

Gu, Weidong; Novak, Robert J

2009-11-16

Insecticide-treated bed nets (ITNs), including long-lasting insecticidal nets (LLINs), play a primary role in global campaigns to roll back malaria in tropical Africa. Effectiveness of treated nets depends on direct impacts on individual mosquitoes including killing and excite-repellency, which vary considerably among vector species due to variations in host-seeking behaviours. While monitoring and evaluation programmes of ITNs have focuses on morbidity and all-cause mortality in humans, local entomological context receives little attention. Without knowing the dynamics of local vector species and their responses to treated nets, it is difficult to predict clinical outcomes when ITN applications are scaled up across African continent. Sound model frameworks incorporating intricate interactions between mosquitoes and treated nets are needed to develop the predictive capacity for scale-up applications of ITNs. An established agent-based model was extended to incorporate the direct outcomes, e.g. killing and avoidance, of individual mosquitoes exposing to ITNs in a hypothetical village setting with 50 houses and 90 aquatic habitats. Individual mosquitoes were tracked throughout the life cycle across the landscape. Four levels of coverage, i.e. 40, 60, 80 and 100%, were applied at the household level with treated houses having only one bed net. By using Latin hypercube sampling scheme, parameters governing killing, diverting and personal protection of net users were evaluated for their relative roles in containing mosquito populations, entomological inoculation rates (EIRs) and malaria incidence. There were substantial gaps in coverage between households and individual persons, and 100% household coverage resulted in circa 50% coverage of the population. The results show that applications of ITNs could give rise to varying impacts on population-level metrics depending on values of parameters governing interactions of mosquitoes and treated nets at the individual level. The most significant factor in determining effectiveness was killing capability of treated nets. Strong excito-repellent effect of impregnated nets might lead to higher risk exposure to non-bed net users. With variabilities of vector mosquitoes in host-seeking behaviours and the responses to treated nets, it is anticipated that scale-up applications of INTs might produce varying degrees of success dependent on local entomological and epidemiological contexts. This study highlights that increased ITN coverage led to significant reduction in risk exposure and malaria incidence only when treated nets yielded high killing effects. It is necessary to test efficacy of treated nets on local dominant vector mosquitoes, at least in laboratory, for monitoring and evaluation of ITN programmes.

A Genomic DNA Reporter Screen Identifies Squalene Synthase Inhibitors That Act Cooperatively with Statins to Upregulate the Low-Density Lipoprotein Receptor

PubMed Central

Kerr, Alastair G.; Tam, Lawrence C. S.; Hale, Ashley B.; Cioroch, Milena; Douglas, Gillian; Agkatsev, Sarina; Hibbitt, Olivia; Mason, Joseph; Holt-Martyn, James; Bataille, Carole J. R.; Wynne, Graham M.; Channon, Keith M.; Russell, Angela J.

2017-01-01

Hypercholesterolemia remains one of the leading risk factors for the development of cardiovascular disease. Many large double-blind studies have demonstrated that lowering low-density lipoprotein (LDL) cholesterol using a statin can reduce the risk of having a cardiovascular event by approximately 30%. However, despite the success of statins, some patient populations are unable to lower their LDL cholesterol to meet the targeted lipid levels, due to compliance or potency issues. This is especially true for patients with heterozygous familial hypercholesterolemia who may require additional upregulation of the low-density lipoprotein receptor (LDLR) to reduce LDL cholesterol levels below those achievable with maximal dosing of statins. Here we identify a series of small molecules from a genomic DNA reporter screen that upregulate the LDLR in mouse and human liver cell lines at nanomolar potencies (EC50 = 39 nM). Structure-activity relationship studies carried out on the lead compound, OX03771 [(E)-N,N-dimethyl-3-(4-styrylphenoxy)propan-1-amine], led to the identification of compound OX03050 [(E)-3-(4-styrylphenoxy)propan-1-ol], which had similar potency (EC50 = 26 nM) but a much-improved pharmacokinetic profile and showed in vivo efficacy. Compounds OX03050 and OX03771 were found to inhibit squalene synthase, the first committed step in cholesterol biosynthesis. These squalene synthase inhibitors were shown to act cooperatively with statins to increase LDLR expression in vitro. Overall, we demonstrated here a novel series of small molecules with the potential to be further developed to treat patients either alone or in combination with statins. PMID:28360334

Solubility of polyethers in hydrocarbons at low temperatures. A model for potential genetic backbones on warm titans.

PubMed

McLendon, Christopher; Opalko, F Jeffrey; Illangkoon, Heshan I; Benner, Steven A

2015-03-01

Ethers are proposed here as the repeating backbone linking units in linear genetic biopolymers that might support Darwinian evolution in hydrocarbon oceans. Hydrocarbon oceans are found in our own solar system as methane mixtures on Titan. They may be found as mixtures of higher alkanes (propane, for example) on warmer hydrocarbon-rich planets in exosolar systems ("warm Titans"). We report studies on the solubility of several short polyethers in propane over its liquid range (from 85 to 231 K, or -188 °C to -42 °C). These show that polyethers are reasonably soluble in propane at temperatures down to ca. 200 K. However, their solubilities drop dramatically at still lower temperatures and become immeasurably low below 170 K, still well above the ∼ 95 K in Titan's oceans. Assuming that a liquid phase is essential for any living system, and genetic biopolymers must dissolve in that biosolvent to support Darwinism, these data suggest that we must look elsewhere to identify linear biopolymers that might support genetics in Titan's surface oceans. However, genetic molecules with polyether backbones may be suitable to support life in hydrocarbon oceans on warm Titans, where abundant organics and environments lacking corrosive water might make it easier for life to originate.

Soft Argon-Propane Dielectric Barrier Discharge Ionization.

PubMed

Schütz, Alexander; Lara-Ortega, Felipe J; Klute, Felix David; Brandt, Sebastian; Schilling, Michael; Michels, Antje; Veza, Damir; Horvatic, Vlasta; García-Reyes, Juan F; Franzke, Joachim

2018-03-06

Dielectric barrier discharges (DBDs) have been used as soft ionization sources (DBDI) for organic mass spectrometry (DBDI-MS) for approximately ten years. Helium-based DBDI is often used because of its good ionization efficiency, low ignition voltage, and homogeneous plasma conditions. Argon needs much higher ignition voltages than helium when the same discharge geometry is used. A filamentary plasma, which is not suitable for soft ionization, may be produced instead of a homogeneous plasma. This difference results in N 2 , present in helium and argon as an impurity, being Penning-ionized by helium but not by metastable argon atoms. In this study, a mixture of argon and propane (C 3 H 8 ) was used as an ignition aid to decrease the ignition and working voltages, because propane can be Penning-ionized by argon metastables. This approach leads to homogeneous argon-based DBDI. Furthermore, operating DBDI in an open environment assumes that many uncharged analyte molecules do not interact with the reactant ions. To overcome this disadvantage, we present a novel approach, where the analyte is introduced in an enclosed system through the discharge capillary itself. This nonambient DBDI-MS arrangement is presented and characterized and could advance the novel connection of DBDI with analytical separation techniques such as gas chromatography (GC) and high-pressure liquid chromatography (HPLC) in the near future.

A comparative study of fungal and bacterial biofiltration treating a VOC mixture.

PubMed

Estrada, José M; Hernández, Sergio; Muñoz, Raúl; Revah, Sergio

2013-04-15

Bacterial biofilters usually exhibit a high microbial diversity and robustness, while fungal biofilters have been claimed to better withstand low moisture contents and pH values, and to be more efficient coping with hydrophobic volatile organic compounds (VOCs). However, there are only few systematic evaluations of both biofiltration technologies. The present study compared fungal and bacterial biofiltration for the treatment of a VOC mixture (propanal, methyl isobutyl ketone-MIBK, toluene and hexanol) under the same operating conditions. Overall, fungal biofiltration supported lower elimination capacities than its bacterial counterpart (27.7 ± 8.9 vs 40.2 ± 5.4 gCm(-3) reactor h(-1)), which exhibited a final pressure drop 60% higher than that of the bacterial biofilter due to mycelial growth. The VOC mineralization ratio was also higher in the bacterial bed (≈ 63% vs ≈ 43%). However, the substrate biodegradation preference order was similar for both biofilters (propanal>hexanol>MIBK>toluene) with propanal partially inhibiting the consumption of the rest of the VOCs. Both systems supported an excellent robustness versus 24h VOC starvation episodes. The implementation of a fungal/bacterial coupled system did not significantly improve the VOC removal performance compared to the individual biofilter performances. Copyright © 2013 Elsevier B.V. All rights reserved.

Stability and Behaviors of Methane/Propane and Hydrogen Micro Flames

NASA Astrophysics Data System (ADS)

Yoshimoto, Takamitsu; Kinoshita, Koichiro; Kitamura, Hideki; Tanigawa, Ryoichi

The flame stability limits essentially define the fundamental operation of the combustion system. Recently the micro diffusion flame has been remarked. The critical conditions of the flame stability limit are highly dependent on nozzle diameter, species of fuel and so on. The micro diffusion flame of Methane/Propane and Hydrogen is formed by using the micro-scale nozzle of which inner diameter is less than 1mm. The configurations and behaviors of the flame are observed directly and visualized by the high speed video camera The criteria of stability limits are proposed for the micro diffusion flame. The objectives of the present study are to get further understanding of lifting/blow-off for the micro diffusion flame. The results obtained are as follows. (1) The behaviors of the flames are classified into some regions for each diffusion flame. (2) The micro diffusion flame of Methane/Propane cannot be sustained, when the nozzle diameter is less than 0.14 mm. (3) The diffusion flame cannot be sustained below the critical fuel flow rate. (4) The minimum flow which is formed does not depends on the average jet velocity, but on the fuel flow rate. (5) the micro flame is laminar. The flame length is decided by fuel flow rate.

SCATTERING OF SLOW NEUTRONS FROM PROPANE GAS

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

Strong, K.A.; Marshall, G.D.; Brugger, R.M.

1962-02-01

Measurements of the partial differential neutron scattering cross sections for room-temperature propane gas are reported. These measurements were made at incident energies of 0.0l01, 0.0254, 0.0736, and 0.102 ev at seven scattering angles between 16.3 and 84.7 deg using the Materials Testing Reactor phased chopper velocity selector. The data are convented to the scattering-law presentation and compared with three theoretical calculations: The ideal gas, using an effective mass obtained from an average of the mass tensors for the three types of H atoms in propane, gives poor agreement. The Krieger-Nelkin approximation, which includes the effect of zero-point vibrations, gives limitedmore » agreement for energy transfer less than 0.5 k/sub b/T at intermediate momentum transfers. At large momentum transfers where vibrational effects become important it underestimates the cross section. A modification of the Krieger- Nelkin theory that includes the effects of single-quantum transitions from the three lowest vibratlonal states gives better agreement. The discrepancies still present at large momentum and energy transfers are attributed to an uncertainty in the methylgroup barrier height for the three lowest energy modes, to the harmonlc oscillator approximation for these modes, and to the approximate molecular orientation averaging used in the calculation. (auth)« less

Microbial Oxidation of Natural Gas in a Plume Emanating from the Coal Oil Point Seep Field

NASA Astrophysics Data System (ADS)

Mendes, S. D.; Valentine, D. L.; Perez, C.; Scarlett, R.

2012-12-01

The hydrocarbon seep field at Coal Oil Point, off the coast of Santa Barbara, California, releases > 1010 g of thermogenic natural gas each year. Gases emitted from Coal Oil Point include methane, ethane, propane, and butane, which are atmospheric pollutants and greenhouse gases. Even though the seeps are at water depths of only 5-80 m, much of the gas dissolves and contributes to a plume that is transported by ocean currents. While hydrocarbons can support bacterial respiration, resulting in the removal of hydrocarbon gas from the plume, the time-scale for the bacterial respiratory response is unconstrained. To track hydrocarbon respiration 3H-ethane, propane, and butane were synthesized using Grignard reagents and tritiated water with yields of >70% and applied as tracers to samples up- and down-current from the seeps at Coal Oil Point. Validation experiments conducted in September 2011 aboard the R/V Atlantis show that 3H-labeled tracers are an order of magnitude more sensitive than previous methods using stable carbon isotopes (Valentine et. al 2010), making this technique preferable in natural systems. Application of the tracers concurrent with plume tracking in July-August 2012 show ethane, propane, and butane consumption are readily inducible on a timescale of days.

Temperature and pressure influence on maximum rates of pressure rise during explosions of propane-air mixtures in a spherical vessel.

PubMed

Razus, D; Brinzea, V; Mitu, M; Movileanu, C; Oancea, D

2011-06-15

The maximum rates of pressure rise during closed vessel explosions of propane-air mixtures are reported, for systems with various initial concentrations, pressures and temperatures ([C(3)H(8)]=2.50-6.20 vol.%, p(0)=0.3-1.3 bar; T(0)=298-423 K). Experiments were performed in a spherical vessel (Φ=10 cm) with central ignition. The deflagration (severity) index K(G), calculated from experimental values of maximum rates of pressure rise is examined against the adiabatic deflagration index, K(G, ad), computed from normal burning velocities and peak explosion pressures. At constant temperature and fuel/oxygen ratio, both the maximum rates of pressure rise and the deflagration indices are linear functions of total initial pressure, as reported for other fuel-air mixtures. At constant initial pressure and composition, the maximum rates of pressure rise and deflagration indices are slightly influenced by the initial temperature; some influence of the initial temperature on maximum rates of pressure rise is observed only for propane-air mixtures far from stoichiometric composition. The differentiated temperature influence on the normal burning velocities and the peak explosion pressures might explain this behaviour. Copyright © 2011 Elsevier B.V. All rights reserved.

Condensation in One-Dimensional Dead-End Nanochannels.

PubMed

Zhong, Junjie; Zandavi, Seyed Hadi; Li, Huawei; Bao, Bo; Persad, Aaron H; Mostowfi, Farshid; Sinton, David

2017-01-24

Phase change at the nanoscale is at the heart of many biological and geological phenomena. The recent emergence and global implications of unconventional oil and gas production from nanoporous shale further necessitate a higher understanding of phase behavior at these scales. Here, we directly observe condensation and condensate growth of a light hydrocarbon (propane) in discrete sub-100 nm (∼70 nm) channels. Two different condensation mechanisms at this nanoscale are distinguished, continuous growth and discontinuous growth due to liquid bridging ahead of the meniscus, both leading to similar net growth rates. The growth rates agree well with those predicted by a suitably defined thermofluid resistance model. In contrast to phase change at larger scales (∼220 and ∼1000 nm cases), the rate of liquid condensate growth in channels of sub-100 nm size is found to be limited mainly by vapor flow resistance (∼70% of the total resistance here), with interface resistance making up the difference. The condensation-induced vapor flow is in the transitional flow regime (Knudsen flow accounting for up to 13% of total resistance here). Collectively, these results demonstrate that with confinement at sub-100 nm scales, such as is commonly found in porous shale and other applications, condensation conditions deviate from the microscale and larger bulk conditions chiefly due to vapor flow and interface resistances.

Testing signal enhancement mechanisms in the dissolution NMR of acetone

NASA Astrophysics Data System (ADS)

Alonso-Valdesueiro, Javier; Elliott, Stuart J.; Bengs, Christian; Meier, Benno; Levitt, Malcolm H.

2018-01-01

In cryogenic dissolution NMR experiments, a substance of interest is allowed to rest in a strong magnetic field at cryogenic temperature, before dissolving the substance in a warm solvent, transferring it to a high-resolution NMR spectrometer, and observing the solution-state NMR spectrum. In some cases, negative enhancements of the 13C NMR signals are observed, which have been attributed to quantum-rotor-induced polarization. We show that in the case of acetone (propan-2-one) the negative signal enhancements of the methyl 13C sites may be understood by invoking conventional cross-relaxation within the methyl groups. The 1H nuclei acquire a relative large net polarization through thermal equilibration in a magnetic field at low temperature, facilitated by the methyl rotation which acts as a relaxation sink; after dissolution, the 1H magnetization slowly returns to thermal equilibrium at high temperature, in part by cross-relaxation processes, which induce a transient negative polarization of nearby 13C nuclei. We provide evidence for this mechanism experimentally and theoretically by saturating the 1H magnetization using a radiofrequency field pulse sequence before dissolution and comparing the 13 C magnetization evolution after dissolution with the results obtained from a conventional 1 H-13 C cross relaxation model of the CH3 moieties in acetone.

Studies of the kinetics and mechanisms of perfluoroether reactions on iron and oxidized iron surfaces

NASA Technical Reports Server (NTRS)

Napier, Mary E.; Stair, Peter C.

1992-01-01

Polymeric perfluoroalkylethers are being considered for use as lubricants in high temperature applications, but have been observed to catalytically decompose in the presence of metals. X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD) were used to explore the decomposition of three model fluorinated ethers on clean polycrystalline iron surfaces and iron surfaces chemically modified with oxygen. Low temperature adsorption of the model fluorinated ethers on the clean, oxygen modified and oxidized iron surfaces was molecular. Thermally activated defluorination of the three model compounds was observed on the clean iron surface at remarkably low temperatures, 155 K and below, with formation of iron fluoride. Preferential C-F bond scission occurred at the terminal fluoromethoxy, CF3O, of perfluoro-1-methoxy-2-ethoxy ethane and perfluoro-1-methoxy-2-ethoxy propane and at CF3/CF2O of perfluoro-1,3-diethoxy propane. The reactivity of the clean iron toward perfluoroalkylether decomposition when compared to other metals is due to the strength of the iron fluoride bond and the strong electron donating ability of the metallic iron. Chemisorption of an oxygen overlayer lowered the reactivity of the iron surface to the adsorption and decomposition of the three model fluorinated ethers by blocking active sites on the metal surface. Incomplete coverage of the iron surface with chemisorbed oxygen results in a reaction which resembles the defluorination reaction observed on the clean iron surface. Perfluoro-1-methoxy-2-ethoxy ethane reacts on the oxidized iron surface at 138 K, through a Lewis acid assisted cleavage of the carbon oxygen bond, with preferential attack at the terminal fluoromethoxy, CF3O. The oxidized iron surface did not passivate, but became more reactive with time. Perfluoro-1-methoxy-2-ethoxy propane and perfluoro-1,3-diethoxy propane desorbed prior to the observation of decomposition on the oxidized iron surface.

Multi-variants synthesis of Petri nets for FPGA devices

NASA Astrophysics Data System (ADS)

Bukowiec, Arkadiusz; Doligalski, Michał

2015-09-01

There is presented new method of synthesis of application specific logic controllers for FPGA devices. The specification of control algorithm is made with use of control interpreted Petri net (PT type). It allows specifying parallel processes in easy way. The Petri net is decomposed into state-machine type subnets. In this case, each subnet represents one parallel process. For this purpose there are applied algorithms of coloring of Petri nets. There are presented two approaches of such decomposition: with doublers of macroplaces or with one global wait place. Next, subnets are implemented into two-level logic circuit of the controller. The levels of logic circuit are obtained as a result of its architectural decomposition. The first level combinational circuit is responsible for generation of next places and second level decoder is responsible for generation output symbols. There are worked out two variants of such circuits: with one shared operational memory or with many flexible distributed memories as a decoder. Variants of Petri net decomposition and structures of logic circuits can be combined together without any restrictions. It leads to existence of four variants of multi-variants synthesis.

Identification of novel serum autoantibodies against EID3 in non-functional pancreatic neuroendocrine tumors

PubMed Central

Hontani, Koji; Tsuchikawa, Takahiro; Hiwasa, Takaki; Nakamura, Toru; Ueno, Takashi; Kushibiki, Toshihiro; Takahashi, Mizuna; Inoko, Kazuho; Takano, Hironobu; Takeuchi, Satoshi; Dosaka-Akita, Hirotoshi; Kuwatani, Masaki; Sakamoto, Naoya; Hatanaka, Yutaka; Mitsuhashi, Tomoko; Shimada, Hideaki; Shichinohe, Toshiaki; Hirano, Satoshi

2017-01-01

Pancreatic neuroendocrine tumors (pNETs) are relatively rare heterogenous tumors, comprising only 1–2% of all pancreatic neoplasms. The majority of pNETs are non-functional tumors (NF-pNETs) that do not produce hormones, and as such, do not cause any hormone-related symptoms. As a result, these tumors are often diagnosed at an advanced stage because patients do not present with specific symptoms. Although tumor markers are used to help diagnosis and predict some types of cancers, chromogranin A, a widely used tumor marker of pNETs, has significant limitations. To identify novel NF-pNET-associated antigens, we performed serological identification of antigens by recombinant cDNA expression cloning (SEREX) and identified five tumor antigens (phosphatase and tensin homolog, EP300-interacting inhibitor of differentiation 3 [EID3], EH domain-containing protein 1, galactoside-binding soluble 9, and BRCA1-associated protein). Further analysis using the AlphaLISA® immunoassay to compare serum antibody levels revealed that antibody levels against the EID3 antigen was significantly higher in the patient group than in the healthy donor group (n = 25, both groups). In addition, higher serum anti-EID3 antibody levels in NF-pNET patients correlated with shorter disease-free survival. The AUC calculated by ROC analysis was 0.784 with moderate diagnostic accuracy. In conclusion, serum anti-EID3 antibody levels may be useful as a tumor marker for prediction of tumor recurrence in NF-pNETs. PMID:29290942

Net returns, fiscal risks, and the optimal patient mix for a profit-maximizing hospital.

PubMed

Ozatalay, S; Broyles, R

1987-10-01

As is well recognized, the provisions of PL98-21 not only transfer financial risks from the Medicare program to the hospital but also induce institutions to adjust the diagnostic mix of Medicare beneficiaries so as to maximize net income or minimize the net loss. This paper employs variation in the set of net returns as the sole measure of financial risk and develops a model that identifies the mix of beneficiaries that maximizes net income, subject to a given level of risk. The results indicate that the provisions of PL98-21 induce the institution to deny admission to elderly patients presenting conditions for which the net return is relatively low and the variance in the cost per case is large. Further, the paper suggests that the treatment of beneficiaries at a level commensurate with previous periods or the preferences of physicians may jeopardize the viability and solvency of Medicare-dependent hospitals.

High temperature durable catalyst development

NASA Technical Reports Server (NTRS)

Snow, G. C.; Tong, H.

1981-01-01

A program has been carried out to develop a catalytic reactor capable of operation in environments representative of those anticipated for advanced automotive gas turbine engines. A reactor consisting of a graded cell honeycomb support with a combination of noble metal and metal oxide catalyst coatings was built and successfully operated for 1000 hr. At an air preheat temperature of 740 K and a propane/air ratio of 0.028 by mass, the adiabatic flame temperature was held at about 1700 K. The graded cell monolithic reaction measured 5 cm in diameter by 10.2 cm in length and was operated at a reference velocity of 14.0 m/s at 1 atm. Measured NOx levels remained below 5 ppm, while unburned hydrocarbon concentrations registered near zero and carbon monoxide levels were nominally below 20 ppm.

Organic History and Ice-Rock Decoupling on Enceladus

NASA Astrophysics Data System (ADS)

Zolotov, M. Y.

2007-12-01

The Cassini detection of methane, propane and acetylene in the Enceladus plume, and condensed organic compounds (OC) on the south polar region imply an organic-bearing interior of the moon. At least a few wt. % of C is expected in rocks from which Enceladus accreted. By analogy with carbonaceous chondrites, the majority of accreted OC was in a polymer in which polyaromatic groups are linked by O-, N-, and S-bearing aliphatic units. If accreted, cometary-type materials also delivered CO2, CO(?), methanol, ethane, ethene, acetylene, and condensed OC. Subsequent water ice melting and hydrothermal processes driven by decay of short-lived radionuclides led to dissolution of CO, CO2 and methanol in water and transformations of the polymer and cometary OC. CO converted to formic acid, carbonate species, methanol and methane. Hydrous pyrolysis and oxidation of the polymer partially liberated aromatic molecules and led to the formation of O-bearing OC (carboxylic and amino acids, alcohols). Increase in temperature favored oxidation of OC to carbonate species and N2, and led to graphitization of the polymer. Despite net oxidation of OC driven by H2 escape, mineral- catalyzed Fisher-Tropsch like synthesis of hydrocarbons and methane occurred in H2-rich niches. As a result, an array of aromatic, aliphatic, and N-, O-, S-bearing OC, and methane was delivered into a primordial water ocean in hydrothermal fluids. Highly soluble OC (acids, alcohols) made multiple passes through hydrothermal systems causing further oxidation of OC in rocks and solutions. In contrast, hydrocarbons exolved from cold oceanic water and formed an organic layer below the ice shell. Subsequent cooling of ocean-entering fluids and ocean freezing from above led to further separation and accumulation of OC. Some OC was trapped in ice, and methane formed clathrates. After freezing of salt eutectic brines, the light oil (a solution/mixture of ethane, propane, butane, ethene, acetylene, methanol, toluene etc.) remained unfrozen and decoupled the ice shell from underlying salt deposits and rocks. Even after oil solidification, if it occurred, the organic layer had a lower viscosity than salts and ice. An uneven pressure and/or topography at the ice-salt boundary could have led to preferential oil (and salt?) accumulation below the south polar region. Throughout history (and today), the uneven oil-rich layer could have favored tidal motions and heat generation at the bottom of the ice shell.

Global distribution of alkyl nitrates and their impacts on reactive nitrogen in remote regions constrained by aircraft observations and chemical transport modeling

NASA Astrophysics Data System (ADS)

Fisher, J. A.; Atlas, E. L.; Blake, D. R.; Barletta, B.; Thompson, C. R.; Peischl, J.; Tzompa Sosa, Z. A.; Ryerson, T. B.; Murray, L. T.

2017-12-01

Nitrogen oxides (NO + NO­2 = NOx) are precursors in the formation of tropospheric ozone, contribute to the formation of aerosols, and enhance nitrogen deposition to ecosystems. While direct emissions tend to be localised over continental source regions, a significant source of NOx to the remote troposphere comes from degradation of other forms of reactive nitrogen. Long-lived, small chain alkyl nitrates (RONO2) including methyl, ethyl and propyl nitrates may be particularly significant forms of reactive nitrogen in the remote atmosphere as they are emitted directly by the ocean in regions where reactive nitrogen is otherwise very low. They also act as NOx reservoir species, sequestering NO­x in source regions and releasing it far downwind—and through this process may become increasingly important reservoirs as methane, ethane, and propane emissions grow. However, small RONO2 are not consistently included in global atmospheric chemistry models, and their distributions and impacts remain poorly constrained. In this presentation, we will describe a new RONO2 simulation in the GEOS-Chem chemical transport model evaluated using a large ensemble of aircraft observations collected over a 20-year period. The observations are largely concentrated over the Pacific Ocean, beginning with PEM-Tropics in the late 1990s and continuing through the recent HIPPO and ATom campaigns. Both observations and model show enhanced RONO2 in the tropical Pacific boundary layer that is consistent with a photochemical source in seawater. The model reproduces a similarly large enhancement over the southern ocean by assuming a large pool of oceanic RONO2 here, but the source of the seawater enhancement in this environment remains uncertain. We find that including marine RONO2 in the simulation is necessary to correct a large underestimate in simulated reactive nitrogen throughout the Pacific marine boundary layer. We also find that the impacts on NOx export from continental source regions are limited as RONO2 formation competes with other NO­x reservoirs such as PAN, leading to re-partitioning of reactive nitrogen rather than a net reactive nitrogen source. Further implications for NOx and ozone, as well as the impacts of recent changes in the global distribution of methane, ethane, propane, and NOx emissions, will also be discussed.

Electric Power Monthly, June 1990

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

Not Available

1990-09-13

The EPM is prepared by the Electric Power Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, electricity sales, and average revenue per kilowatthour of electricity sold. Data on net generation are also displayed at the North American Electric Reliability Council (NERC) region level. Additionally, company and plant level information are published in the EPM on capability of new plants, net generation, fuel consumption, fuel stocks, quantity andmore » quality of fuel, and cost of fuel. Quantity, quality, and cost of fuel data lag the net generation, fuel consumption, fuel stocks, electricity sales, and average revenue per kilowatthour data by 1 month. This difference in reporting appears in the national, Census division, and State level tables. However, at the plant level, all statistics presented are for the earlier month for the purpose of comparison. 40 tabs.« less

Burnout, Perceived Stress, and Job Satisfaction Among Trauma Nurses at a Level I Safety-Net Trauma Center.

PubMed

Munnangi, Swapna; Dupiton, Lynore; Boutin, Anthony; Angus, L D George

Nurses are at the forefront of our health care delivery system and have been reported to exhibit a high level of burnout. Burnout and stress in trauma nurses at a safety-net hospital can negatively impact patient care. Safety-net hospitals are confronted with unique social, financial, as well as resource problems that can potentially make the work environment frustrating. The purpose of this study was to explore the levels of burnout, stress, and job satisfaction in nurses providing care to trauma patients at a Level I safety-net trauma center. A cross-sectional survey design was used to investigate principal factors including personal and professional demographics, burnout, perceived stress, and job satisfaction. Trauma nurses working at a Level I safety-net trauma center are stressed and exhibited moderate degree of burnout. The extent of emotional exhaustion experienced by the nurses varied with work location and was highest in surgical intensive care unit nurses. The level of job satisfaction in terms of opportunities for promotion differed significantly by race and the health status of the nurses. Satisfaction with coworkers was lowest in those nurses between the ages of 60-69 years. Female nurses were more satisfied with their coworkers than male nurses. In addition, the study revealed that significant relationships exist among perceived stress, burnout, and job satisfaction. Work environment significantly impacts burnout, job satisfaction, and perceived stress experienced by trauma nurses in a safety-net hospital. Nursing administration can make an effort to understand the levels of burnout and strategically improve work environment for trauma nurses in order to minimize stressors leading to attrition and enhance job satisfaction.

Enrichment of light hydrocarbon mixture

DOEpatents

Yang, Dali [Los Alamos, NM; Devlin, David [Santa Fe, NM; Barbero, Robert S [Santa Cruz, NM; Carrera, Martin E [Naperville, IL; Colling, Craig W [Warrenville, IL

2011-11-29

Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

Enrichment of light hydrocarbon mixture

DOEpatents

Yang,; Dali, [Los Alamos, NM; Devlin, David [Santa Fe, NM; Barbero, Robert S [Santa Cruz, NM; Carrera, Martin E [Naperville, IL; Colling, Craig W [Warrenville, IL

2010-08-10

Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

Combustion efficiency of a premixed continuous flow combustor

NASA Technical Reports Server (NTRS)

Anand, M. S.; Gouldin, F. C.

1985-01-01

Exhaust gas temperature, velocity, and composition measurements at various radial locations at the combustor exit are presented for a swirling-flow continuous combustor of a confined concentric jet configuration operating on premixed propane or methane and air. The main objective of the study is to determine the effect of fuel substitution and of changes in outer flow swirl conditions on the combustor performance. It is found that there is no difference in observed properties for propane and methane firing; the use of either of the fuels results in nearly the same exit temperature and velocity profiles and the same efficiency for a given operating condition. A mechanism for combustion is proposed which explains qualitatively the changes in efficiency and pollutant emissions observed with changing swirl.

Geothermal heating facilities for Frontier Inn, Susanville, California

NASA Astrophysics Data System (ADS)

1982-03-01

A 38 unit motel composed of six major sections (coffee shop, A frame units, apartments, back units, two story units and office) was built over a number of years and exhibits widely varying types of construction. Space heating is provided by primarily electric resistance equipment with some propane use. Domestic hot water is provided primarily by propane with some electric resistance. The coffee shop uses fuel oil for both space and domestic hot water heating. A geothermal district heating system is being installed. Although the motel site is not located in the area of construction activity, it is expected that the pipeline will be extended. The potential of retrofitting the existing heating facilities at the inn to geothermal is studied.

Occurrence of 3-chloro-propane-1,2-diol (3-MCPD) and related compounds in foods: a review.

PubMed

Hamlet, C G; Sadd, P A; Crews, C; Velísek, J; Baxter, D E

2002-07-01

A critical review of the occurrence of 3-chloro-propane-1,2-diol (3-MCPD) in foods not known to contain hydrolysed vegetable proteins is presented. The review covers the properties and chemistry of 3-MCPD and the current methods of analysis in foodstuffs. The results of UK surveys of 3-MCPD occurrence in both retail foods and commercial food ingredients are discussed with particular reference to cereal, meat and dairy products. The possible mechanisms for the formation and decay of 3-MCPD in foods are suggested. The review does not cover the detailed toxicology of 3-MCPD and its occurrence in hydrolysed vegetable proteins, which have been considered elsewhere, nor possible issues such as in-vivo formation.

A neural net based architecture for the segmentation of mixed gray-level and binary pictures

NASA Technical Reports Server (NTRS)

Tabatabai, Ali; Troudet, Terry P.

1991-01-01

A neural-net-based architecture is proposed to perform segmentation in real time for mixed gray-level and binary pictures. In this approach, the composite picture is divided into 16 x 16 pixel blocks, which are identified as character blocks or image blocks on the basis of a dichotomy measure computed by an adaptive 16 x 16 neural net. For compression purposes, each image block is further divided into 4 x 4 subblocks; a one-bit nonparametric quantizer is used to encode 16 x 16 character and 4 x 4 image blocks; and the binary map and quantizer levels are obtained through a neural net segmentor over each block. The efficiency of the neural segmentation in terms of computational speed, data compression, and quality of the compressed picture is demonstrated. The effect of weight quantization is also discussed. VLSI implementations of such adaptive neural nets in CMOS technology are described and simulated in real time for a maximum block size of 256 pixels.

Effect of insecticide-treated bed nets on house-entry by malaria mosquitoes: The flight response recorded in a semi-field study in Kenya.

PubMed

Spitzen, Jeroen; Koelewijn, Teun; Mukabana, W Richard; Takken, Willem

2017-08-01

Insecticide-treated nets are currently a major tool to reduce malaria transmission. Their level of repellency affects contact of the mosquito with the net, but may also influence the mosquito's entry into the house. The response of host-seeking malaria mosquitoes approaching the eave of an experimental house was recorded within a large screen house. We compared entry- and exit rates in relation to the presence in the house of different insecticide-treated bed nets (ITNs) with an untreated net. Mosquitoes were lured towards the house by dispensing a synthetic host-odour blend from within the net in the house. Complementary WHO bioassays revealed that the treated nets caused high knock-down- and mortality responses to the Anopheles gambiae sensu stricto strain tested. The proportion of mosquitoes that came into view of the cameras and subsequently entered the house did not differ between treated nets and the untreated net. Treated nets did not affect proportions of mosquitoes that exited the house and departed from view around the eave. However, the percentage of house-leaving and re-entering mosquitoes when an insecticide- treated net was present, was lower than in the presence of an untreated net. Our results indicated that there was no spatial repellent effect from pyrethroid-treated nets that influences house-entry at eave level. It is argued that the toxic effect of treated bed nets resulted in a reduced number of mosquitoes re-entering the house, which could thereby affect malaria transmission in neighbouring, unprotected houses. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Mathematical evaluation of community level impact of combining bed nets and indoor residual spraying upon malaria transmission in areas where the main vectors are Anopheles arabiensis mosquitoes.

PubMed

Okumu, Fredros O; Kiware, Samson S; Moore, Sarah J; Killeen, Gerry F

2013-01-16

Indoor residual insecticide spraying (IRS) and long-lasting insecticide treated nets (LLINs) are commonly used together even though evidence that such combinations confer greater protection against malaria than either method alone is inconsistent. A deterministic model of mosquito life cycle processes was adapted to allow parameterization with results from experimental hut trials of various combinations of untreated nets or LLINs (Olyset, PermaNet 2.0, Icon Life nets) with IRS (pirimiphos methyl, lambda cyhalothrin, DDT), in a setting where vector populations are dominated by Anopheles arabiensis, so that community level impact upon malaria transmission at high coverage could be predicted. Intact untreated nets alone provide equivalent personal protection to all three LLINs. Relative to IRS plus untreated nets, community level protection is slightly higher when Olyset or PermaNet 2.0 nets are added onto IRS with pirimiphos methyl or lambda cyhalothrin but not DDT, and when Icon Life nets supplement any of the IRS insecticides. Adding IRS onto any net modestly enhances communal protection when pirimiphos methyl is sprayed, while spraying lambda cyhalothrin enhances protection for untreated nets but not LLINs. Addition of DDT reduces communal protection when added to LLINs. Where transmission is mediated primarily by An. arabiensis, adding IRS to high LLIN coverage provides only modest incremental benefit (e.g. when an organophosphate like pirimiphos methyl is used), but can be redundant (e.g. when a pyrethroid like lambda cyhalothin is used) or even regressive (e.g. when DDT is used for the IRS). Relative to IRS plus untreated nets, supplementing IRS with LLINs will only modestly improve community protection. Beyond the physical protection that intact nets provide, additional protection against transmission by An. arabiensis conferred by insecticides will be remarkably small, regardless of whether they are delivered as LLINs or IRS. The insecticidal action of LLINs and IRS probably already approaches their absolute limit of potential impact upon this persistent vector so personal protection of nets should be enhanced by improving the physical integrity and durability. Combining LLINs and non-pyrethroid IRS in residual transmission systems may nevertheless be justified as a means to manage insecticide resistance and prevent potential rebound of not only An. arabiensis, but also more potent, vulnerable and historically important species such as Anopheles gambiae and Anopheles funestus.

Phenomenological and molecular-level Petri net modeling and simulation of long-term potentiation.

PubMed

Hardy, S; Robillard, P N

2005-10-01

Petri net-based modeling methods have been used in many research projects to represent biological systems. Among these, the hybrid functional Petri net (HFPN) was developed especially for biological modeling in order to provide biologists with a more intuitive Petri net-based method. In the literature, HFPNs are used to represent kinetic models at the molecular level. We present two models of long-term potentiation previously represented by differential equations which we have transformed into HFPN models: a phenomenological synapse model and a molecular-level model of the CaMKII regulation pathway. Through simulation, we obtained results similar to those of previous studies using these models. Our results open the way to a new type of modeling for systems biology where HFPNs are used to combine different levels of abstraction within one model. This approach can be useful in fully modeling a system at the molecular level when kinetic data is missing or when a full study of a system at the molecular level it is not within the scope of the research.

Alternative Fuels Data Center: Propane

Science.gov Websites

they work, and find information about vehicle availability, conversions, emissions, maintenance, and Fuel Prices Conserve Fuel Idle Reduction Parts & Equipment Maintenance Driving Behavior Fleet

Tyr115, gln165 and trp209 contribute to the 1, 2-epoxy-3-(p-nitrophenoxy)propane-conjugating activity of glutathione S-transferase cGSTM1-1.

PubMed

Chern, M K; Wu, T C; Hsieh, C H; Chou, C C; Liu, L F; Kuan, I C; Yeh, Y H; Hsiao, C D; Tam, M F

2000-07-28

We investigated the epoxidase activity of a class mu glutathione S-transferase (cGSTM1-1), using 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP) as substrate. Trp209 on the C-terminal tail, Arg107 on the alpha4 helix, Asp161 and Gln165 on the alpha6 helix of cGSTM1-1 were selected for mutagenesis and kinetic studies. A hydrophobic side-chain at residue 209 is needed for the epoxidase activity of cGSTM1-1. Replacing Trp209 with histidine, isoleucine or proline resulted in a fivefold to 28-fold decrease in the k(cat)(app) of the enzyme, while a modest 25 % decrease in the k(cat)(app) was observed for the W209F mutant. The rGSTM1-1 enzyme has serine at the correponding position. The k(cat)(app) of the S209W mutant is 2. 5-fold higher than that of the wild-type rGSTM1-1. A charged residue is needed at position 107 of cGSTM1-1. The K(m)(app)(GSH) of the R107L mutant is 38-fold lower than that of the wild-type enzyme. On the contrary, the R107E mutant has a K(m)(app)(GSH) and a k(cat)(app) that are 11-fold and 35 % lower than those of the wild-type cGSTM1-1. The substitutions of Gln165 with Glu or Leu have minimal effect on the affinity of the mutants towards GSH or EPNP. However, a discernible reduction in k(cat)(app) was observed. Asp161 is involved in maintaining the structural integrity of the enzyme. The K(m)(app)(GSH) of the D161L mutant is 616-fold higher than that of the wild-type enzyme. In the hydrogen/deuterium exchange experiments, this mutant has the highest level of deuteration among all the proteins tested. We also elucidated the structure of cGSTM1-1 co-crystallized with the glutathionyl-conjugated 1, 2-epoxy-3-(p-nitrophenoxy)propane (EPNP) at 2.8 A resolution. The product found in the active site was 1-hydroxy-2-(S-glutathionyl)-3-(p-nitrophenoxy)propane, instead of the conventional 2-hydroxy isomer. The EPNP moiety orients towards Arg107 and Gln165 in dimer AB, and protrudes into a hydrophobic region formed by the loop connecting beta1 and alpha1 and part of the C-terminal tail in dimer CD. The phenoxyl ring forms strong ring stacking with the Trp209 side-chain in dimer CD. We hypothesize that these two conformations represent the EPNP moiety close to the initial and final stages of the reaction mechanism, respectively. Copyright 2000 Academic Press.

Insecticide-treated nets and treatment service: a trial using public and private sector channels in rural United Republic of Tanzania.

PubMed Central

Fraser-Hurt, N.; Lyimo, E. O.

1998-01-01

The Rotary Net Initiative, implemented in Kilombero District, southern United Republic of Tanzania, allowed us to explore different sales channels for the distribution of insecticide-treated nets (ITNs) and the insecticide treatment service in a rural area of very high malaria transmission. Several types of ITNs were promoted and sold through different channels in the public and private sector, i.e. hospital pharmacy, mother and child health (MCH) clinic, net committee, village health workers and retail shops. The ITNs were sold for US$ 5.0-9.2, with profit margins of 9-16%. Net treatment cost US$ 0.33, with commission fees of 75%. Net transport and treatment were partially subsidized. Some outlets established their own fund by ITN sales. Sales of nets and treatments were seasonal, and certain net types were preferred. Demand for insecticide treatment was generally low. Changes in net coverage were assessed in two villages. A range of outlet features were compared qualitatively. Our experience supports suggestions that ITN technology should be delivered through MCH care services and demonstrates that specific promotion and innovation are necessary to achieve substantial net treatment levels. A large-scale ITN project in the same area and other ITN studies should lead to better understanding of ITN implementation at the population level. PMID:10191557

Petri net controllers for distributed robotic systems

NASA Technical Reports Server (NTRS)

Lefebvre, D. R.; Saridis, George N.

1992-01-01

Petri nets are a well established modelling technique for analyzing parallel systems. When coupled with an event-driven operating system, Petri nets can provide an effective means for integrating and controlling the functions of distributed robotic applications. Recent work has shown that Petri net graphs can also serve as remarkably intuitive operator interfaces. In this paper, the advantages of using Petri nets as high-level controllers to coordinate robotic functions are outlined, the considerations for designing Petri net controllers are discussed, and simple Petri net structures for implementing an interface for operator supervision are presented. A detailed example is presented which illustrates these concepts for a sensor-based assembly application.

Chronic desipramine treatment alters tyrosine hydroxylase but not norepinephrine transporter immunoreactivity in norepinephrine axons in the rat prefrontal cortex

PubMed Central

Erickson, Susan L.; Gandhi, Anjalika R.; Asafu-Adjei, Josephine K.; Sampson, Allan R.; Miner, LeeAnn; Blakely, Randy D.; Sesack, Susan R.

2011-01-01

Pharmacological blockade of norepinephrine (NE) reuptake is clinically effective in treating several mental disorders. Drugs that bind to the NE transporter (NET) alter both protein levels and activity of NET and also the catecholamine synthetic enzyme tyrosine hydroxylase (TH). We examined the rat prefrontal cortex (PFC) by electron microscopy to determine whether the density and subcellular distribution of immunolabeling for NET and colocalization of NET with TH within individual NE axons were altered by chronic treatment with the selective NE uptake inhibitor desipramine (DMI). Following DMI treatment (21 days, 15 mg/kg/day), NET-immunoreactive (-ir) axons were significantly less likely to colocalize TH. This finding is consistent with reports of reduced TH levels and activity in the locus coeruleus after chronic DMI and indicates a reduction of NE synthetic capacity in the PFC. Measures of NET expression and membrane localization, including the number of NET-ir profiles per tissue area sampled, the number of gold particles per NET-ir profile area, and the proportion of gold particles associated with the plasma membrane, were similar in DMI and vehicle treated rats. These findings were verified using two different antibodies directed against distinct epitopes of the NET protein. The results suggest that chronic DMI treatment does not reduce NET expression within individual NE axons in vivo or induce an overall translocation of NET protein away from the plasma membrane in the PFC as measured by ultrastructural immunogold labeling. Our findings encourage consideration of possible postranslational mechanisms for regulating NET activity in antidepressant-induced modulation of NE clearance. PMID:21208501

Effects of capture by trammel net on Colorado River native fishes

USGS Publications Warehouse

Hunt, Teresa A.; Ward, David L.; Propper, Catherine R.; Gibb, Alice C.

2012-01-01

Trammel nets are commonly used to sample rare fishes; however, little research has assessed delayed mortality associated with this capture technique. We conducted laboratory experiments to evaluate the effects of capture by trammel net on bonytail Gila elegans, razorback sucker Xyrauchen texanus, and roundtail chub Gila robusta, at 15, 20, and 25uC. Fish (139–288 mm total length) were entangled in a trammel net for 2 h or captured by seine net and then monitored for mortality for at least 14 d. Blood samples were collected immediately after capture, and plasma cortisol levels were quantified as an index of capture-related stress. The cortisol response varied by species, but mean cortisol levels were higher for fish captured by trammel netting (295.9 ng/mL) relative to fish captured by seine netting (215.8 ng/mL). Only one fish (of 550) died during capture and handling, but 42% of the trammel-netted fish and 11% of the seine-netted fish died within 14 d after capture. In general, mortality after capture by trammel net increased with increased water temperature and at 25uC was 88% for bonytail, 94% for razorback sucker, and 25% for roundtail chub. Delayed mortality of wild-caught fish captured by trammel net has the potential to be high, at least under some circumstances. We suggest that sampling frequency, timing of sampling (relative to reproductive cycles), and water temperature all be considered carefully when using trammel nets to sample diminished populations of imperiled native fishes.

Low Ozone in the Marine Boundary Layer of the Tropical Pacific Ocean

NASA Technical Reports Server (NTRS)

Singh, Hanwant B.; Gregory, G. L.; Andesrson, B.; Browell, E.; Sachse, G. W.; Davis, D. D.; Crawford, J.; Bradshaw, J. D.; Talbot, R.; Blake, D. R.;

Alternative Fuels

EPA Pesticide Factsheets

Alternative fuels include gaseous fuels such as hydrogen, natural gas, and propane; alcohols such as ethanol, methanol, and butanol; vegetable and waste-derived oils; and electricity. Overview of alternative fuels is here.

Sonolysis of hydrocarbons in aqueous solution

NASA Astrophysics Data System (ADS)

Hart, Edwin J.; Fischer, Christian-Herbert; Henglein, Arnim

Water was irradiated with 300 kHz ultrasound under an argon atmosphere containing various amounts of methane and ethane. Limited studies were also made on ethylene, acetylene, propane and butane. The methane and ethane irradiations were carried out over the hydrocarbon-argon range of 2-100%. Maximum decomposition occurs at 15% for methane and 10% for ethane. While hydrogen is a dominant product in both cases, acetylene, ethylene and ethane are prominent products, too. Propane, propene and propin form in lesser quantities. 2-methyl-propane, n-butane, l-butene, 2-methyl-butene, butadiene and n-butin have also been identified. These hydrocarbons are similar to those found in pyrolysis and in fuel rich combustion experiments. Carbon monoxide is an important product at hydrocarbon concentrations less than 40% establishing water was an oxygen delivering reactant under these conditions. In the case of methane, the ratio of ethylene plus acetylene to ethane is used to estimate the effective temperature in the cavitation bubble. A temperature of about 2800 K is obtained for bubbles containing argon (plus water vapor and 20% CH 4) and T = 2000 K for pure methane. The rate of decomposition for unsaturated hydrocarbons is substantially greater than for the saturated ones. Low molecular weight products are mainly formed from saturated hydrocarbons whereas polymerization products are mainly formed from the unsaturated hydrocarbons. The decomposition of acetylene in argon bubbles is one of the fastest sonolytic processes.

Rotational reorientation dynamics of Aerosol-OT reverse micelles formed in near-critical propane

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

Heitz, M.P.; Bright, F.V.

1996-06-01

The rotational reorientation kinetics of two fluorescent solutes (rhodamine 6G, R6G, and rhodamine 101, R101) have been determined in sodium bis(2-ethylhexyl) sulfosuccinate (Aerosol-OT, AOT) reverse micelles formed in liquid and near-critical propane. We show that the amount of water loading ([water]/[AOT], R), continuous phase density, and temperature all influence the solute rotational dynamics. In all cases, the decay of anisotropy data (i.e., frequency-dependent differential polarized phase angle and polarized modulation ratio) are well described by a bi-exponential decay law. We find that the faster rotational correlation times are similar to but slightly less than the values predicted for an individualmore » AOT reverse micelle rotating in propane. The recovered rotational correlation times range from 200 to 500 ps depending on experimental conditions. This faster rotational process is explained in terms of lateral diffusion of the fluorophore along the water/headgroup interfacial region within the reverse micelle. The recovered values for the slower rotational correlation times range from 7 to 18 ns. These larger rotational reorientation times are assigned to varying micelle-micelle (i.e., tail-tail) interactions in the low-density, highly compressible fluid region. We also quantify the contribution of the reverse micellar {open_quotes}aggregate{close_quotes} to the total decay of anisotropy. {copyright} {ital 1996} {ital Society for Applied Spectroscopy}« less

The mechanisms of flame holding in the wake of a bluff body

NASA Technical Reports Server (NTRS)

Strehlow, R. A.; Malik, S.

1985-01-01

The flame holding mechanism for lean methane- and lean propane-air flames is examined under conditions where the recirculation zone is absent. The main objective of this work is to study the holding process in detail in an attempt to determine the mechanism of flame holding and also the conditions where this mechanism is viable and when it fails and blow-off occurs. Inverted flames held in the wake of a flat strip were studied. Experiments with different sizes of flame holders were performed. The velocity flow field was determined using a laser Doppler velocimetry technique. Equation of continuity was used to calculate the flame temperature from the change in area of flow streamlines before and after the flame. Observations of the inverted flame itself were obtained using schlieren and direct photography. Results show that there are different mechanisms operative at the time of blow-off for lean propane and methane flames. Blow-off or extinction occurs for lean propane-air flame in spite of the reaction going to completion and the disparity between the heat loss and the gain in mass diffusion in the reaction zone i.e., Le 1.0 causes the flame to blow-off. For methane-air flame the controlling factor or blow-off is incomplete reaction due to higher blowing rate leading to reduced residence time in the reaction zone.

Crystal structure of bis­[trans-di­chlorido­bis(propane-1,3-di­amine-κ2 N,N′)chromium(III)] dichromate from synchrotron data

PubMed Central

Moon, Dohyun; Ryoo, Keon Sang; Choi, Jong-Ha

2016-01-01

The structure of the title compound, [CrCl2(tn)2]2[Cr2O7] (tn = propane-1,3-di­amine; C3H10N2), has been determined from synchrotron data. The asymmetric unit contains one CrIII complex cation and half a [Cr2O7]2− anion. In the complex cation, the CrIII ion is coordinated by the four N atoms of two propane-1,3-di­amine (tn) ligands in the equatorial plane and by two Cl atoms in a trans configuration, displaying a distorted octa­hedral coordination sphere. The two six-membered rings in the complex cation have an anti chair–chair conformation with respect to each other. The mean Cr—N(tn) and Cr—Cl bond lengths are 2.09 (1) and 2.320 (2) Å, respectively. The slightly bent dichromate anion is disordered over two sets of sites (occupancy ratio = 0.7:0.3) and has a staggered conformation. The crystal structure is stabilized by inter­molecular hydrogen bonds involving the NH2 groups of the tn ligands as donors and the O atoms of the [Cr2O7]2− anion and chlorido ligands as acceptors. PMID:27920920

MPL-Net data products available at co-located AERONET sites and field experiment locations

NASA Astrophysics Data System (ADS)

Welton, E. J.; Campbell, J. R.; Berkoff, T. A.

2002-05-01

Micro-pulse lidar (MPL) systems are small, eye-safe lidars capable of profiling the vertical distribution of aerosol and cloud layers. There are now over 20 MPL systems around the world, and they have been used in numerous field experiments. A new project was started at NASA Goddard Space Flight Center in 2000. The new project, MPL-Net, is a coordinated network of long-time MPL sites. The network also supports a limited number of field experiments each year. Most MPL-Net sites and field locations are co-located with AERONET sunphotometers. At these locations, the AERONET and MPL-Net data are combined together to provide both column and vertically resolved aerosol and cloud measurements. The MPL-Net project coordinates the maintenance and repair for all instruments in the network. In addition, data is archived and processed by the project using common, standardized algorithms that have been developed and utilized over the past 10 years. These procedures ensure that stable, calibrated MPL systems are operating at sites and that the data quality remains high. Rigorous uncertainty calculations are performed on all MPL-Net data products. Automated, real-time level 1.0 data processing algorithms have been developed and are operational. Level 1.0 algorithms are used to process the raw MPL data into the form of range corrected, uncalibrated lidar signals. Automated, real-time level 1.5 algorithms have also been developed and are now operational. Level 1.5 algorithms are used to calibrate the MPL systems, determine cloud and aerosol layer heights, and calculate the optical depth and extinction profile of the aerosol boundary layer. The co-located AERONET sunphotometer provides the aerosol optical depth, which is used as a constraint to solve for the extinction-to-backscatter ratio and the aerosol extinction profile. Browse images and data files are available on the MPL-Net web-site. An overview of the processing algorithms and initial results from selected sites and field experiments will be presented. The capability of the MPL-Net project to produce automated real-time (next day) profiles of aerosol extinction will be shown. Finally, early results from Level 2.0 and Level 3.0 algorithms currently under development will be presented. The level 3.0 data provide continuous (day/night) retrievals of multiple aerosol and cloud heights, and optical properties of each layer detected.

The Vorticity Budgets of North Atlantic Winter Marine Extratropical Cyclones Development

NASA Astrophysics Data System (ADS)

Azad, R.; Sorteberg, A.

2012-12-01

A partitioned form of the Zwack-Okossi (Z-O) tendency equation is employed to examine the composite role of dynamic and thermodynamic forcing mechanisms to the development of North Atlantic winter marine extratropical cyclones. The results provide a further insight into the budgets of near surface cyclonic geostrophic vorticity (CGV) and their evolution during the life cycle of mid-latitude low pressure systems. Of interest are the direct, indirect and net effects of the Z-O forcing mechanisms. The direct effect shows the contribution of each process to the near surface geostrophic vorticity tendency, while the indirect effect implies the contribution from the associated vertical motion and resulting adiabatic cooling or warming. The net effect is the sum of the direct and indirect effects.We found that the vorticity advection term is the largest net contributor to the development of the marine cyclones. The net positive effect of both the temperature advection and latent heating terms is smaller owing to the induced adiabatic cooling which reduces the positive direct contributions. The direct and indirect parts of ageostrophic tendency and friction terms support each other, resulting in significant net contributions at the low center.Comparisons of the composite contributions by the Z-O forcing terms at different pressure levels over the low center indicate that, in agreement with previous studies, the commencement of significant development is accompanied with the upper level cyclonic absolute vorticity advection, upper level warm advection and mid-to low level latent heating. However, during the end of the development, mid-tropospheric net contribution by vorticity advection term and low level warm advection controls the production of CGV. The former is due to both the presence of mid-level cyclonic vorticity advection and induced adiabatic warming over the composite low center.

First High Resolution IR Spectra of 2,2-D_{2}-PROPANE. the νb{15} (B_{1}) A-Type Band Near 954.709 \\wn. Determination of Ground and Upper State Constants.

NASA Astrophysics Data System (ADS)

Gjuraj, Daniel; Daunt, S. J.; Grzywacz, Robert; Lafferty, Walter; Flaud, Jean-Marie; Billinghurst, Brant E.

2017-06-01

As part of our project on the study of isotopologues of propane we have taken the spectra of the 2-D and 2,2-D_2 substituted species. There have been no studies of these species since the early IR studies. We recorded high resolution (Δν = 0.0009 \\wn) FTS data on the Canadian Light Source Far-IR beamline. The spectra of all bands of both species in the region examined (500 - 1250 \\wn) show torsionally perturbed lines, all but one band appearing globally perturbed. Virtually all bands were not amenable to analysis at present except for the νb{15} (B_{1}) A-type band centered at 954.709 \\wn. One can still see a few perturbed lines with torsional components but overall most lines were single and could be readily assigned using traditional methods. The spectrum is modelled well using PGOPHER. No MW determined GS constants were available so we have analyzed about 3500 levels to determine both ground state and upper state rotational constants. Friedman & Turkevich, J. Chem. Phys. 17, 1012 ff. (1949) McMurry, Thornton & Condon, J. Chem. Phys. 17, 918 ff. (1949) McMurry & Thornton, J. Chem. Phys. 19, 1014 ff.(1951) Gayles & King, Spectrochim. Acta 21, 543 ff.(1965) Kondo & Saeki, Spectrochim. Acta 29A, 735 ff. (1973) Western, J. Quant. Spectrosc. Rad. Transf. 186, 221 ff. (2017).

Tools to improve planning, implementation, monitoring, and evaluation of complementary feeding programmes.

PubMed

Untoro, Juliawati; Childs, Rachel; Bose, Indira; Winichagoon, Pattanee; Rudert, Christiane; Hall, Andrew; de Pee, Saskia

2017-10-01

Adequate nutrient intake is a prerequisite for achieving good nutrition status. Suboptimal complementary feeding practices are a main risk factor for stunting. The need for systematic and user-friendly tools to guide the planning, implementation, monitoring, and evaluation of dietary interventions for children aged 6-23 months has been recognized. This paper describes five tools, namely, ProPAN, Optifood, Cost of the Diet, Fill the Nutrient Gap, and Monitoring Results for Equity System that can be used in different combinations to improve situation analysis, planning, implementation, monitoring, or evaluation approaches for complementary feeding in a particular context. ProPAN helps with development of strategies and activities designed to change the behaviours of the target population. Optifood provides guidance for developing food-based recommendations. The Cost of the Diet can provide insight on economic barriers to accessing a nutritious and balanced diet. The Fill the Nutrient Gap facilitates formulation of context-specific policies and programmatic approaches to improve nutrient intake, through a multistakeholder process that uses insights from linear programming and secondary data. The Monitoring Results for Equity System helps with analysis of gaps, constraints, and determinants of complementary feeding interventions and adoption of recommended practices especially in the most vulnerable and deprived populations. These tools, and support for their use, are readily available and can be used either alone and/or complementarily throughout the programme cycle to improve infant and young child-feeding programmes at subnational and national levels. © 2017 John Wiley & Sons Ltd.

First High Resolution Analysis of the ν21 Band of Propane at 921.4 wn: Evidence of Large-Amplitude Tunnelling Effects

NASA Astrophysics Data System (ADS)

Perrin, Agnes; Kwabia Tchana, F.; Flaud, Jean-Marie; Manceron, Laurent; Demaison, Jean; Vogt, Natalja; Groner, Peter; Lafferty, Walter

2015-06-01

A high resolution (0.0015 wn) IR spectrum of propane, C_3H_8, has been recorded with synchrotron radiation at the French light source facility at SOLEIL coupled to a Bruker IFS-125 Fourier transform spectrometer. A preliminary analysis of the ν21 fundamental band (B1, CH3 rock) near 921.4 wn reveals that the rotational energy levels of 211 are split by interactions with the internal rotations of the methyl groups. Conventional analysis of this A-type band yielded band centers at 921.3724(38), 921.3821(33) and 921.3913(44) wn for the AA, EE and AE+EA tunneling splitting components, respectively. These torsional splittings most probably are due to anharmonic and/or Coriolis resonance coupling with nearby highly excited states of both internal rotations of the methyl groups. In addition, several vibrational-rotational resonances were observed that affect the torsional components in different ways. The analysis of the B-type band near 870 wn (ν8, sym. C-C stretch) which also contains split rovibrational transitions due to internal rotation is in progress. It is performed by using the effective rotational Hamiltonian method ERHAM with a code that allows prediction and least-squares fitting of such vibration-rotation spectra. A. Perrin et al., submitted to J. Mol. Spectrosc. P. Groner, J. Chem. Phys. 107 (1997) 4483; J. Mol. Spectrosc. 278 (2012) 52.

Spatial Analysis and Quantification of the Thermodynamic Driving Forces in Protein-Ligand Binding: Binding Site Variability

PubMed Central

Raman, E. Prabhu; MacKerell, Alexander D.

2015-01-01

The thermodynamic driving forces behind small molecule-protein binding are still not well understood, including the variability of those forces associated with different types of ligands in different binding pockets. To better understand these phenomena we calculate spatially resolved thermodynamic contributions of the different molecular degrees of freedom for the binding of propane and methanol to multiple pockets on the proteins Factor Xa and p38 MAP kinase. Binding thermodynamics are computed using a statistical thermodynamics based end-point method applied on a canonical ensemble comprising the protein-ligand complexes and the corresponding free states in an explicit solvent environment. Energetic and entropic contributions of water and ligand degrees of freedom computed from the configurational ensemble provides an unprecedented level of detail into the mechanisms of binding. Direct protein-ligand interaction energies play a significant role in both non-polar and polar binding, which is comparable to water reorganization energy. Loss of interactions with water upon binding strongly compensates these contributions leading to relatively small binding enthalpies. For both solutes, the entropy of water reorganization is found to favor binding in agreement with the classical view of the “hydrophobic effect”. Depending on the specifics of the binding pocket, both energy-entropy compensation and reinforcement mechanisms are observed. Notable is the ability to visualize the spatial distribution of the thermodynamic contributions to binding at atomic resolution showing significant differences in the thermodynamic contributions of water to the binding of propane versus methanol. PMID:25625202

Task sequence planning in a robot workcell using AND/OR nets

NASA Technical Reports Server (NTRS)

Cao, Tiehua; Sanderson, Arthur C.

1991-01-01

An approach to task sequence planning for a generalized robotic manufacturing or material handling workcell is described. Given the descriptions of the objects in this system and all feasible geometric relationships among these objects, an AND/OR net which describes the relationships of all feasible geometric states and associated feasibility criteria for net transitions is generated. This AND/OR net is mapped into a Petri net which incorporates all feasible sequences of operations. The resulting Petri net is shown to be bounded and have guaranteed properties of liveness, safeness, and reversibility. Sequences are found from the reachability tree of the Petri net. Feasibility criteria for net transitions may be used to generate an extended Petri net representation of lower level command sequences. The resulting Petri net representation may be used for on-line scheduling and control of the system of feasible sequences. A simulation example of the sequences is described.

Alternative Fuels Data Center

Science.gov Websites

electricity, propane, or natural gas are exempt from state motor vehicle emissions inspections after receiving Alternative Fuel Vehicle (AFV) Emissions Inspection Exemption Vehicles powered exclusively by

Alternative Fuels Data Center

Science.gov Websites

vehicles altered to operate on propane, natural gas, methane gas, ethanol, or electricity are classified as information about vehicle conversion certification requirements, see the Alternative Fuels Data Center's

Statoil-Himont outlines Antwerp operations

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

Not Available

1992-05-04

Norway's Den morske Stats Oljeselskap AS, the North Sea's largest oil producer, and Himont Inc., the world's largest producer of polypropylene, believe their joint venture complex near Antwerp has changed the traditional structure of the petrochemical industry. At a briefing and press conference, executives from the two companies and their new joint venture, North Sea Petrochemicals, covered their venture and its first 2 months of operation and presented their outlook for the polypropylene market. Statoil stressed its intent to expand petrochemical operations in Europe. The company supplies the complex with all the propane feed and refinery grade propylene its uses.more » The propane comes from Statoil's offshore production, the imported refinery grade propylene from Statoil's Mongstad, Norway, refinery. This paper describes the propylene production process used in Antwerp.« less

An analytical study of nitrogen oxides and carbon monoxide emissions in hydrocarbon combustion with added nitrogen, preliminary results

NASA Technical Reports Server (NTRS)

Bittker, D. A.

1979-01-01

The effect of combustor operating conditions on the conversion of fuel-bound nitrogen (FBN) to nitrogen oxides NO sub x was analytically determined. The effect of FBN and of operating conditions on carbon monoxide (CO) formation was also studied. For these computations, the combustor was assumed to be a two stage, adiabatic, perfectly-stirred reactor. Propane-air was used as the combustible mixture and fuel-bound nitrogen was simulated by adding nitrogen atoms to the mixture. The oxidation of propane and formation of NO sub x and CO were modeled by a fifty-seven reaction chemical mechanism. The results for NO sub x and CO formation are given as functions of primary and secondary stage equivalence ratios and residence times.

Autothermal reforming of propane over Mg-Al hydrotalcite-like catalysts.

PubMed

Lim, You-Soon; Park, Nam-Cook; Shin, Jae-Soon; Kim, Jong-Ho; Moon, Dong-Ju; Kim, Young-Chul

2008-10-01

The performance of hydrotalcite-like catalysts in propane autothermal reforming for hydrogen production was studied in fixed-bed flow reactor. Hydrotalcite-like catalysts were synthesized by coprecipitation and modified co-precipitation by the impregnation method and those were promoted by the addition of noble metals. Reaction test results indicated that hydrotalcite-like catalysts of modified method were showed higher H2-yield than co-precipitation method because surface Ni particles of catalysts by modified method were more abundant. When added noble metals, the activity was enhanced because the size of nickel particles was decreased and degree of dispersion was increased. Also the carbon deposit is low after the reaction. When solvent of solution was changed, activity was increased. It is because degree of dispersion was increased.

Multipoint Ignition of a Gas Mixture by a Microwave Subcritical Discharge with an Extended Streamer Structure

NASA Astrophysics Data System (ADS)

Aleksandrov, K. V.; Busleev, N. I.; Grachev, L. P.; Esakov, I. I.; Ravaev, A. A.

2018-02-01

The results of experimental studies on using an electrical discharge with an extended streamer structure in a quasioptical microwave beam in the multipoint ignition of a propane-air mixture have been reported. The pulsed microwave discharge was initiated at the interior surface of a quartz tube that was filled with the mentioned flammable mixture and introduced into a microwave beam with a subbreakdown initial field. Gas breakdown was initiated by an electromagnetic vibrator. The dependence of the type of discharge on the microwave field strength was examined, the lower concentration threshold of ignition of the propane-air mixture by the studied discharge was determined, and the dynamics of combustion of the flammable mixture with local and multipoint ignition were compared.

Effects of percentage of blockage and flameholder downstream counterbores on lean combustion limits of premixed, prevaporized propane-air mixture

NASA Technical Reports Server (NTRS)

Fernandez, M. A. B.

1983-01-01

Lean combustion limits were determined for a premixed prevaporized propane air mixture with flat plate flame stabilizers. Experiments were conducted in a constant area flame tube combustor utilizing flameholders of varying percentages of blockage and downstream counterbores. Combustor inlet air velocity at ambient conditions was varied from 4 to 9 meters per second. Flameholders with a center hole and four half holes surrounding it were tested with 63, 73, and 85 percent blockage and counterbore diameters of 112 and 125 percent of the thru hole diameter, in addition to the no counterbore configuration. Improved stability was obtained by using counterbore flameholders and higher percentages of blockage. Increases in mixture velocity caused the equivalence ratio at blowout to increase in all cases.

Thermodynamics of micelle formation in a water-alcohol solution of sodium tetradecyl sulfate

NASA Astrophysics Data System (ADS)

Shilova, S. V.; Tret'yakova, A. Ya.; Barabanov, V. P.

2016-01-01

The effects of addition of ethanol and propan-1-ol on sodium tetradecyl sulfate micelle formation in an aqueous solution are studied via microprobe fluorescence microscopy and conductometry. The critical micelle concentration, quantitative characteristics of micelles, and thermodynamic parameters of micelle formation are determined. Addition of 5-15 vol % of ethanol or 5-10 vol % of propan-1-ol is shown to result in a lower critical micelle concentration than in the aqueous solution, and in the formation of mixed spherical micelles whose sizes and aggregation numbers are less than those for the systems without alcohol. The contribution from the enthalpy factor to the free energy of sodium tetradecyl sulfate micelle formation is found to dominate in mixed solvents, in contrast to aqueous solutions.

Gas-phase binding energies for non-covalent Aβ-40 peptide/small molecule complexes from CID mass spectrometry and RRKM theory.

PubMed

Mayer, Paul M; Martineau, Eric

2011-03-21

The gas-phase binding of small molecules to the Amyloid β-40 peptide generated by electrospray ionization has been explored with collision-induced dissociation mass spectrometry and kinetic rate theory. This study discusses a simple procedure used to theoretically model the experimental breakdown diagrams for the Aβ-40 peptide complexed with a series of aminosulfonate small molecules, namely homotaurine, 3-cyclohexylamino-2-hydroxy-1-propanesulfonic acid (CAPSO), 3-(1,3,4,9-tetrahydro-2H-β-carbolin-2-yl)propane-1-sulfonic acid, 3-(1,3,4,9-tetrahydro-2H-β-carbolin-2-yl)butane-1-sulfonic acid, and 3-(cyclohexylamino)propane-1-sulfonic acid. An alternative procedure employing an extrapolation procedure for k(E) is also discussed.

Evaluation of Polyethylene-Based Long Lasting Treated Bed Net Netprotect on Anopheles Mosquitoes, Malaria Incidence, and Net Longivity in Western Kenya

PubMed Central

Odhiambo, M. T. O.; Skovmand, O.; Vulule, J. M.; Kokwaro, E. D.

2013-01-01

We studied the effect on malaria incidence, mosquito abundance, net efficacy, net use rate, chemical analysis, and holes of a long lasting insecticide treated bed net (Netprotect) in western Kenya, 2007–2010. Nets were hung in 150 households 6 months before they were hung in a second, 2 km away. Indoor resting densities were monitored by pyrethrum spray catch and malaria cases by passive detection using clinical manifestations and rapid diagnostic test. The probability of finding An. arabiensis in the control area was 2.6 times higher than that in intervention area during the first 6 months. Human blood feeding index of Anopheles funestus declined 17%. After bed nets were hung in the second area, malaria incidence declined 25% down to the level in the first area. Incidence remained at this low level for 2 years. 90% of collected nets were efficacious after 3-year use. Deltamethrin dosage declined from 1.9 to 0.5 g/kg over 3 years. Attrition rate after 3 years was 21%. WHO hole index changed from 333 to 114 to 381 over the three years. This index summarizes the numbers of holes in size categories and multiplies with the mean hole area per category. It is very sensitive to the impact of big holes in a few nets. PMID:24194770

The NetLogger Toolkit V2.0

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

Gunter, Dan; Lee, Jason; Stoufer, Martin

2003-03-28

The NetLogger Toolkit is designed to monitor, under actual operating conditions, the behavior of all the elements of the application-to-application communication path in order to determine exactly where time is spent within a complex system Using NetLogger, distnbuted application components are modified to produce timestamped logs of "interesting" events at all the critical points of the distributed system Events from each component are correlated, which allov^ one to characterize the performance of all aspects of the system and network in detail. The NetLogger Toolkit itself consists of four components an API and library of functions to simplify the generation ofmore » application-level event logs, a set of tools for collecting and sorting log files, an event archive system, and a tool for visualization and analysis of the log files In order to instrument an application to produce event logs, the application developer inserts calls to the NetLogger API at all the critical points in the code, then links the application with the NetLogger library All the tools in the NetLogger Toolkit share a common log format, and assume the existence of accurate and synchronized system clocks NetLogger messages can be logged using an easy-to-read text based format based on the lETF-proposed ULM format, or a binary format that can still be used through the same API but that is several times faster and smaller, with performance comparable or better than binary message formats such as MPI, XDR, SDDF-Binary, and PBIO. The NetLogger binary format is both highly efficient and self-describing, thus optimized for the dynamic message construction and parsing of application instrumentation. NetLogger includes an "activation" API that allows NetLogger logging to be turned on, off, or modified by changing an external file This IS useful for activating logging in daemons/services (e g GndFTP server). The NetLogger reliability API provides the ability to specify backup logging locations and penodically try to reconnect broken TCP pipe. A typical use for this is to store data on local disk while net is down. An event archiver can log one or more incoming NetLogger streams to a local disk file (netlogd) or to a mySQL database (netarchd). We have found exploratory, visual analysis of the log event data to be the most useful means of determining the causes of performance anomalies The NetLogger Visualization tool, niv, has been developed to provide a flexible and interactive graphical representation of system-level and application-level events.« less

Mathematical evaluation of community level impact of combining bed nets and indoor residual spraying upon malaria transmission in areas where the main vectors are Anopheles arabiensis mosquitoes

PubMed Central

2013-01-01

Background Indoor residual insecticide spraying (IRS) and long-lasting insecticide treated nets (LLINs) are commonly used together even though evidence that such combinations confer greater protection against malaria than either method alone is inconsistent. Methods A deterministic model of mosquito life cycle processes was adapted to allow parameterization with results from experimental hut trials of various combinations of untreated nets or LLINs (Olyset®, PermaNet 2.0®, Icon Life® nets) with IRS (pirimiphos methyl, lambda cyhalothrin, DDT), in a setting where vector populations are dominated by Anopheles arabiensis, so that community level impact upon malaria transmission at high coverage could be predicted. Results Intact untreated nets alone provide equivalent personal protection to all three LLINs. Relative to IRS plus untreated nets, community level protection is slightly higher when Olyset® or PermaNet 2.0® nets are added onto IRS with pirimiphos methyl or lambda cyhalothrin but not DDT, and when Icon Life® nets supplement any of the IRS insecticides. Adding IRS onto any net modestly enhances communal protection when pirimiphos methyl is sprayed, while spraying lambda cyhalothrin enhances protection for untreated nets but not LLINs. Addition of DDT reduces communal protection when added to LLINs. Conclusions Where transmission is mediated primarily by An. arabiensis, adding IRS to high LLIN coverage provides only modest incremental benefit (e.g. when an organophosphate like pirimiphos methyl is used), but can be redundant (e.g. when a pyrethroid like lambda cyhalothin is used) or even regressive (e.g. when DDT is used for the IRS). Relative to IRS plus untreated nets, supplementing IRS with LLINs will only modestly improve community protection. Beyond the physical protection that intact nets provide, additional protection against transmission by An. arabiensis conferred by insecticides will be remarkably small, regardless of whether they are delivered as LLINs or IRS. The insecticidal action of LLINs and IRS probably already approaches their absolute limit of potential impact upon this persistent vector so personal protection of nets should be enhanced by improving the physical integrity and durability. Combining LLINs and non-pyrethroid IRS in residual transmission systems may nevertheless be justified as a means to manage insecticide resistance and prevent potential rebound of not only An. arabiensis, but also more potent, vulnerable and historically important species such as Anopheles gambiae and Anopheles funestus. PMID:23324456

T cell infiltrate and outcome following resection of intermediate-grade primary neuroendocrine tumours and liver metastases.

PubMed

Katz, Steven C; Donkor, Charan; Glasgow, Kristen; Pillarisetty, Venu G; Gönen, Mithat; Espat, N Joseph; Klimstra, David S; D'Angelica, Michael I; Allen, Peter J; Jarnagin, William; Dematteo, Ronald P; Brennan, Murray F; Tang, Laura H

2010-12-01

Tumour-infiltrating lymphocytes (TILs) have been shown to predict survival in numerous malignancies. The importance of TILs in primary pancreatic neuroendocrine tumours (NETs) and NET liver metastases (NETLMs) has not been defined. We identified 87 patients with NETs and 39 with NETLMs who had undergone resection. Immunohistochemistry was performed to determine TIL counts. Recurrence-free survival (RFS) and overall survival (OS) were determined using the log-rank test. The median follow-up time was 62 months in NET patients and 48 months in NETLM patients. Vascular invasion and histologic grade were the only independent predictors of outcome for NETs and NETLMs, respectively. Analysis of intermediate-grade NETs indicated that a dense T cell (CD3+) infiltrate was associated with a median RFS of 128 months compared with 61 months for those with low levels of intratumoral T cells (P= 0.05, univariate analysis). Examination of NETLMs revealed that a low level of infiltrating regulatory T cells (Treg, FoxP3+) was a predictor of prolonged survival (P < 0.01, univariate analysis). A robust T cell infiltrate is associated with improved RFS following resection of intermediate-grade NETs, whereas the presence of more Treg correlated with shorter OS after treatment of NETLMs. Further study of the immune response to intermediate-grade NETs and NETLMs is warranted.

Alternative Fuels Data Center

Science.gov Websites

benefits resulting from the Department of Agriculture and Consumer Services' propane and natural gas vehicle rebates. The Office submitted a final report to the Department of Agriculture and Consumer

Do HMO and its for-profit expansion jeopardize the survival of hospital safety net services?

PubMed

Shen, Yu-Chu

2009-03-01

This study examines the effect of health maintenance organizations (HMOs) and for-profit HMO share on the survival of safety net services in hospitals between 1990 and 2004. The primary data sources are the American Hospital Association Annual Surveys, the Medicare hospital cost reports, and the HMO enrollment and ownership data from Interstudy. I analyze the risks of shutting down each safety net service separately using the proportional hazard models. I find that the risks of shutting down hospital safety net services do not vary by different levels of overall HMO penetration. However, conditional on the overall HMO penetration level, increasing for-profit presence of HMO does increase the risks of shutting down several safety net services. Policies evaluating the for-profit expansion or ownership conversion of health plans should take this potential adverse effect into consideration.

Integrating evidence-based practices for increasing cancer screenings in safety net health systems: a multiple case study using the Consolidated Framework for Implementation Research.

PubMed

Liang, Shuting; Kegler, Michelle C; Cotter, Megan; Emily, Phillips; Beasley, Derrick; Hermstad, April; Morton, Rentonia; Martinez, Jeremy; Riehman, Kara

2016-08-02

Implementing evidence-based practices (EBPs) to increase cancer screenings in safety net primary care systems has great potential for reducing cancer disparities. Yet there is a gap in understanding the factors and mechanisms that influence EBP implementation within these high-priority systems. Guided by the Consolidated Framework for Implementation Research (CFIR), our study aims to fill this gap with a multiple case study of health care safety net systems that were funded by an American Cancer Society (ACS) grants program to increase breast and colorectal cancer screening rates. The initiative funded 68 safety net systems to increase cancer screening through implementation of evidence-based provider and client-oriented strategies. Data are from a mixed-methods evaluation with nine purposively selected safety net systems. Fifty-two interviews were conducted with project leaders, implementers, and ACS staff. Funded safety net systems were categorized into high-, medium-, and low-performing cases based on the level of EBP implementation. Within- and cross-case analyses were performed to identify CFIR constructs that influenced level of EBP implementation. Of 39 CFIR constructs examined, six distinguished levels of implementation. Two constructs were from the intervention characteristics domain: adaptability and trialability. Three were from the inner setting domain: leadership engagement, tension for change, and access to information and knowledge. Engaging formally appointed internal implementation leaders, from the process domain, also distinguished level of implementation. No constructs from the outer setting or individual characteristics domain differentiated systems by level of implementation. Our study identified a number of influential CFIR constructs and illustrated how they impacted EBP implementation across a variety of safety net systems. Findings may inform future dissemination efforts of EBPs for increasing cancer screening in similar settings. Moreover, our analytic approach is similar to previous case studies using CFIR and hence could facilitate comparisons across studies.

Squeeze-SegNet: a new fast deep convolutional neural network for semantic segmentation

NASA Astrophysics Data System (ADS)

Nanfack, Geraldin; Elhassouny, Azeddine; Oulad Haj Thami, Rachid

2018-04-01

The recent researches in Deep Convolutional Neural Network have focused their attention on improving accuracy that provide significant advances. However, if they were limited to classification tasks, nowadays with contributions from Scientific Communities who are embarking in this field, they have become very useful in higher level tasks such as object detection and pixel-wise semantic segmentation. Thus, brilliant ideas in the field of semantic segmentation with deep learning have completed the state of the art of accuracy, however this architectures become very difficult to apply in embedded systems as is the case for autonomous driving. We present a new Deep fully Convolutional Neural Network for pixel-wise semantic segmentation which we call Squeeze-SegNet. The architecture is based on Encoder-Decoder style. We use a SqueezeNet-like encoder and a decoder formed by our proposed squeeze-decoder module and upsample layer using downsample indices like in SegNet and we add a deconvolution layer to provide final multi-channel feature map. On datasets like Camvid or City-states, our net gets SegNet-level accuracy with less than 10 times fewer parameters than SegNet.

Alternative Fuels Data Center

Science.gov Websites

mixture containing at least 85% methanol, denatured ethanol, or other alcohols; natural gas, propane , hydrogen, or coal derived liquid fuels; or fuels derived from biological materials. PEVs are defined as

25 CFR 700.105 - Utility charges.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Policies and Instructions Definitions § 700.105 Utility charges. Utility charges means the cost for heat, lighting, hot water, electricity, natural gas, butane, propane, wood, coal or other fuels water, sewer and...

Modeling of Biometric Identification System Using the Colored Petri Nets

NASA Astrophysics Data System (ADS)

Petrosyan, G. R.; Ter-Vardanyan, L. A.; Gaboutchian, A. V.

2015-05-01

In this paper we present a model of biometric identification system transformed into Petri Nets. Petri Nets, as a graphical and mathematical tool, provide a uniform environment for modelling, formal analysis, and design of discrete event systems. The main objective of this paper is to introduce the fundamental concepts of Petri Nets to the researchers and practitioners, both from identification systems, who are involved in the work in the areas of modelling and analysis of biometric identification types of systems, as well as those who may potentially be involved in these areas. In addition, the paper introduces high-level Petri Nets, as Colored Petri Nets (CPN). In this paper the model of Colored Petri Net describes the identification process much simpler.

Evaluation of Toxic Air Emissions

DTIC Science & Technology

1995-06-01

108394 106445 98828 94757 3547044 334883 Calcium Cyanamide Caprolactam Captan Carbaryl Carbon disulfide Carbon Tetrachloride Carbonyl sulfide Catechol...Phosphorus Phthalic anhydride Polychlorinated biphenyls (Aroclors) 1,3-Propane sultone beta-Propiolactone Propionaldehyde Propoxur (Baygon) Propylene

Final Rule (signed September 26, 2016)

EPA Pesticide Factsheets

New Listings of Substitutes; Changes of Listing Status; and Reinterpretation of Unacceptability for Closed Cell Foam Products under the SNAP Program; and Revision of Clean Air Act Section 608 Venting Prohibition for Propane.

Propane Supply and Security Act of 2014

THOMAS, 113th Congress

Rep. Latta, Robert E. [R-OH-5

2014-09-15

House - 09/30/2014 Referred to the Subcommittee on General Farm Commodities and Risk Management. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Modeling safety requirements of an FMS using Petri-nets

NASA Astrophysics Data System (ADS)

Hanna, Moheb M.; Buck, A. A.; Smith, R.

1993-08-01

This paper is concerned with the modelling of safety requirements using Petri nets as a tool to model and simulate a Flexible Manufacturing System (FMS). The FMS cell described comprises a pick and place robot, a multi-head drilling machine together with a vision system and illustrates how the hierarchical structure of Petri nets can be used to ensure that all fail- safe requirements are satisfied; block diagrams together with fully detailed example Petri nets are given. The work demonstrates the use of cell and robot control Petro nets together with robot subnets for the x, y and z axes and associated output nets; the control and output nets are linked together with a safety net. Individual machines are linked with the control and safety nets of an FMS at cell level. The paper also illustrates how a Petri net can act as a decision maker during image inspection and identifies the unsafe conditions that can arise within an FMS.

Norepinephrine Transporter Heterozygous Knockout Mice Exhibit Altered Transport and Behavior

PubMed Central

Fentress, HM; Klar, R; Krueger, JK; Sabb, T; Redmon, SN; Wallace, NM; Shirey-Rice, JK; Hahn, MK

2013-01-01

The norepinephrine (NE) transporter (NET) regulates synaptic NE availability for noradrenergic signaling in the brain and sympathetic nervous system. Although genetic variation leading to a loss of NET expression has been implicated in psychiatric and cardiovascular disorders, complete NET deficiency has not been found in people, limiting the utility of NET knockout mice as a model for genetically-driven NET dysfunction. Here, we investigate NET expression in NET heterozygous knockout male mice (NET+/−), demonstrating that they display an ~50% reduction in NET protein levels. Surprisingly, these mice display no significant deficit in NET activity, assessed in hippocampal and cortical synaptosomes. We found that this compensation in NET activity was due to enhanced activity of surface-resident transporters, as opposed to surface recruitment of NET protein or compensation through other transport mechanisms, including serotonin, dopamine or organic cation transporters. We hypothesize that loss of NET protein in the NET+/− mouse establishes an activated state of existing, surface NET proteins. NET+/− mice exhibit increased anxiety in the open field and light-dark box and display deficits in reversal learning in the Morris Water Maze. These data suggest recovery of near basal activity in NET+/− mice appears to be insufficient to limit anxiety responses or support cognitive performance that might involve noradrenergic neurotransmission. The NET+/− mice represent a unique model to study the loss and resultant compensatory changes in NET that may be relevant to behavior and physiology in human NET deficiency disorders. PMID:24102798

40 CFR 90.329 - Catalyst thermal stress test.

Code of Federal Regulations, 2010 CFR

2010-07-01

....3 Carbon Dioxide 3.8 Water Vapor 10 Sulfer dioxide 20 Oxides of nitrogen 280 Hydrogen 3500 Hydrocarbon* 4000 Nitrogen = Balance * Propylene/propane ratio = 2/1. (c) Phase 2 engines. The catalyst...

40 CFR 90.329 - Catalyst thermal stress test.

Code of Federal Regulations, 2014 CFR

2014-07-01

....3 Carbon Dioxide 3.8 Water Vapor 10 Sulfer dioxide 20 Oxides of nitrogen 280 Hydrogen 3500 Hydrocarbon* 4000 Nitrogen = Balance * Propylene/propane ratio = 2/1. (c) Phase 2 engines. The catalyst...

40 CFR 90.329 - Catalyst thermal stress test.

Code of Federal Regulations, 2011 CFR

2011-07-01

....3 Carbon Dioxide 3.8 Water Vapor 10 Sulfer dioxide 20 Oxides of nitrogen 280 Hydrogen 3500 Hydrocarbon* 4000 Nitrogen = Balance * Propylene/propane ratio = 2/1. (c) Phase 2 engines. The catalyst...

40 CFR 90.329 - Catalyst thermal stress test.

Code of Federal Regulations, 2012 CFR

2012-07-01

....3 Carbon Dioxide 3.8 Water Vapor 10 Sulfer dioxide 20 Oxides of nitrogen 280 Hydrogen 3500 Hydrocarbon* 4000 Nitrogen = Balance * Propylene/propane ratio = 2/1. (c) Phase 2 engines. The catalyst...

40 CFR 90.329 - Catalyst thermal stress test.

Code of Federal Regulations, 2013 CFR

2013-07-01

....3 Carbon Dioxide 3.8 Water Vapor 10 Sulfer dioxide 20 Oxides of nitrogen 280 Hydrogen 3500 Hydrocarbon* 4000 Nitrogen = Balance * Propylene/propane ratio = 2/1. (c) Phase 2 engines. The catalyst...

Alternative Fuels Data Center

Science.gov Websites

natural gas (LNG) and propane used as motor fuel in diesel gallon equivalents (DGEs). For taxation compressed natural gas (CNG) used as motor fuel in gasoline gallon equivalents (GGEs). CNG must be reported

Alternative Fuels Data Center

Science.gov Websites

with gasoline; natural gas and liquid fuels domestically produced from natural gas; propane; coal -derived liquid fuels; hydrogen; electricity; pure biodiesel (B100); fuels, other than alcohol, derived

46 CFR 25.26-1 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... is intended to be used for sleeping and is provided with installed bunks and mattresses. EPIRB means... preparation and extended storage of food. This does not include small alcohol or propane stoves with limited...

46 CFR 25.26-1 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... is intended to be used for sleeping and is provided with installed bunks and mattresses. EPIRB means... preparation and extended storage of food. This does not include small alcohol or propane stoves with limited...

46 CFR 25.26-1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... is intended to be used for sleeping and is provided with installed bunks and mattresses. EPIRB means... preparation and extended storage of food. This does not include small alcohol or propane stoves with limited...

46 CFR 25.26-1 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... is intended to be used for sleeping and is provided with installed bunks and mattresses. EPIRB means... preparation and extended storage of food. This does not include small alcohol or propane stoves with limited...

78 FR 34105 - Proposed Information Collection Activity; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-06

... include Natural Gas, Electricity, Fuel Oil, Propane, Wood and Coal. The average annual primary home energy... using a secondary source of heat. Annual Heating Fuel Consumption: The grantee would need to collect...

Synthesis of enantiopure antiobesity drug lorcaserin.

PubMed

Smilovic, Ivana Gazic; Cluzeau, Jerome; Richter, Frank; Nerdinger, Sven; Schreiner, Erwin; Laus, Gerhard; Schottenberger, Herwig

2018-05-15

Acylation of enantiomerically pure (R)-2-(3-chlorophenyl)propan-1-amine using chloroacetyl chloride, followed by borane reduction and aluminum chloride catalyzed cyclization yielded enantiopure lorcaserin. Copyright © 2018 Elsevier Ltd. All rights reserved.

Parent's Guide to Preventing Inhalant Abuse

MedlinePlus

... irritability, or restlessness. What could be other telltale behaviors of inhalant abuse? Inhalant abusers also may exhibit ... to three companions, the four teenagers had taken gas from a family's grill propane tank. They put ...

Bis­[4,4′-(propane-1,3-di­yl)­dipiperidin­ium] β-octa­molybdate(VI)

PubMed Central

Driss, Mohamed; Ksiksi, Rekaya; Ben Amor, Fatma; Zid, Mohamed Faouzi

2010-01-01

The title compound, bis­[4,4′-(propane-1,3-di­yl)­dipiperidin­ium] β-octa­molybdate(VI), (C13H28N2)2[Mo8O26], was produced by hydro­thermal reaction of an acidified aqueous solution of Na2MoO4·2H2O and 4,4′-trimethyl­ene­dipiperidine (L). The structure of the title compound consists of β-octa­molybdate(VI) anion clusters and protonated [H2 L]2+ cations. The octa­molybdate anion is located around an inversion center. N—H⋯O hydrogen bonds between the cations and anions ensure the cohesion of the structure and result in a three-dimensional network. PMID:21579027

Conglomerate formative precursor of chiral drug timolol: 3-(4-Morpholino-1,2,5-thiadiazol-3-yloxy)-propane-1,2-diol

NASA Astrophysics Data System (ADS)

Bredikhin, Alexander A.; Zakharychev, Dmitry V.; Fayzullin, Robert R.; Bredikhina, Zemfira A.; Gubaidullin, Aidar T.

2015-05-01

Solid state properties of 3-(4-N-morpholino-1,2,5-thiadiazol-3-yloxy)-propane-1,2-diol 3, the synthetic precursor of popular drug timolol, have been investigated. The original solubility test, the data of X-ray diffraction and DSC methods indicate that the compound is prone to spontaneous resolution. Diol 3 crystallizing from both enantiopure or racemic feed material forms "guaifenesin-like" crystal packing in which the classic H-bonded bilayers, framed in both sides by hydrophobic molecular fragments, act as the basic supramolecular motif. The main chain conformation of the molecules in the crystals of diol 3 differs from that in the guaifenesin crystals, and this fact changes the absolute configuration of spiral columns formed by intermolecular hydrogen bonds in crystals of 3 as compared with guaifenesin crystals.

[Chemical hazards in the workplace environment of painting restorer].

PubMed

Jezewska, Anna; Szewczyńska, Małgorzata

2012-01-01

This paper presents the results of the identification of chemical substances present in the air in the workplace of painting restorer. Identification tests were carried out in university and museum easel paintings conservation studios. Air samples were taken for testing at various stages of restoration works. In the qualitative analysis chemical substances in the air samples were measured by GC-MSD and HPLC-DAD methods. In the air samples collected during the cleaning of paintings, such substances as aliphatic and aromatic hydrocarbons, acetone, ethanol and terpenes were mainly identified. While the painting was doubled toluene and while varnished, propan-2-ol, propane, butane and substances derived from turpentine and white spirit were mainly emitted. During the course of painting conservation numerous chemical substances that may pose a threat to the worker's health were identified in their breathing zone.

New Whole-House Solutions Case Study: Hydronic Heating Coil Versus Propane Furnace, Rehoboth Beach, Delaware

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

None

2014-01-01

In this project involving two homes, the IBACOS team evaluated the performance of the two space conditioning systems and the modeled efficiency of the two tankless domestic hot water systems relative to actual occupant use. Each house was built by Insight Homes and is 1,715-ft2 with a single story, three bedrooms, two bathrooms, and the heating, ventilation, and air conditioning systems and ductwork located in conditioned crawlspaces. The standard house, which the builder offers as its standard production house, uses an air source heat pump (ASHP) with supplemental propane furnace heating. The Building America test house uses the same ASHPmore » unit with supplemental heat provided by the DHW heater (a combined DHW and hydronic heating system, where the hydronic heating element is in the air handler).« less

Testing of aircraft passenger seat cushion materials. Full scale, test description and results, volume 1

NASA Technical Reports Server (NTRS)

Schutter, K. J.; Gaume, J. G.; Duskin, F. E.

1981-01-01

Eight different seat cushion configurations were subjected to full-scale burn tests. Each cushion configuration was tested twice for a total of sixteen tests. Two different fire sources were used. They consisted of one liter of Jet A fuel for eight tests and a radiant energy source with propane flame for eight tests. Both fire sources were ignited by a propane flame. During each test, data were recorded for smoke density, cushion temperatures, radiant heat flux, animal response to combustion products, rate of weight loss of test specimens, cabin temperature, and for the type and content of gas within the cabin atmosphere. When compared to existing passenger aircraft seat cushions, the test specimens incorporating a fire barrier and those fabricated from advanced materials, using improved construction methods, exhibited significantly greater fire resistance.

Combining CO 2 reduction with propane oxidative dehydrogenation over bimetallic catalysts

DOE PAGES

Gomez, Elaine; Kattel, Shyam; Yan, Binhang; ...

2018-04-11

In this paper, the inherent variability and insufficiencies in the co-production of propylene from steam crackers has raised concerns regarding the global propylene production gap and has directed industry to develop more on-purpose propylene technologies. The oxidative dehydrogenation of propane by CO 2 (CO 2-ODHP) can potentially fill this gap while consuming a greenhouse gas. Non-precious FeNi and precious NiPt catalysts supported on CeO 2 have been identified as promising catalysts for CO 2-ODHP and dry reforming, respectively, in flow reactor studies conducted at 823 K. In-situ X-ray absorption spectroscopy measurements revealed the oxidation states of metals under reaction conditionsmore » and density functional theory calculations were utilized to identify the most favorable reaction pathways over the two types of catalysts.« less

Cellulose tris-(3,5-dimethylphenylcarbamate)-based chiral stationary phase for the enantioseparation of drugs in supercritical fluid chromatography: comparison with HPLC.

PubMed

Kalíková, Květa; Martínková, Monika; Schmid, Martin G; Tesařová, Eva

2018-03-01

A cellulose tris-(3,5-dimethylphenylcarbamate)-based chiral stationary phase was studied as a tool for the enantioselective separation of 21 selected analytes with different pharmaceutical and physicochemical properties. The enantioseparations were performed using supercritical fluid chromatography. The effect of the mobile phase composition was studied. Four different additives (diethylamine, triethylamine, isopropylamine, and trifluoroacetic acid) and isopropylamine combined with trifluoroacetic acid were tested and their influence on enantioseparation was compared. The influence of two different mobile phase co-solvents (methanol and propan-2-ol) combined with all the additives was also evaluated. The best mobile phase compositions for the separation of the majority of enantiomers were CO 2 /methanol/isopropylamine 80:20:0.1 v/v/v or CO 2 /propan-2-ol/isopropylamine/trifluoroacetic acid 80:20:0.05:0.05 v/v/v/v. The best results were obtained from the group of basic β-blockers. A high-performance liquid chromatography separation system composed of the same stationary phase and mobile phase of similar properties prepared as a mixture of hexane/propan-2-ol/additive 80:20:0.1 v/v/v was considered for comparison. Supercritical fluid chromatography was found to yield better results, i.e. better enantioresolution for shorter analysis times than high-performance liquid chromatography. However, examples of enantiomers better resolved under the optimized conditions in high-performance liquid chromatography were also found. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Trace-gas metabolic versatility of the facultative methanotroph Methylocella silvestris.

PubMed

Crombie, Andrew T; Murrell, J Colin

2014-06-05

The climate-active gas methane is generated both by biological processes and by thermogenic decomposition of fossil organic material, which forms methane and short-chain alkanes, principally ethane, propane and butane. In addition to natural sources, environments are exposed to anthropogenic inputs of all these gases from oil and gas extraction and distribution. The gases provide carbon and/or energy for a diverse range of microorganisms that can metabolize them in both anoxic and oxic zones. Aerobic methanotrophs, which can assimilate methane, have been considered to be entirely distinct from utilizers of short-chain alkanes, and studies of environments exposed to mixtures of methane and multi-carbon alkanes have assumed that disparate groups of microorganisms are responsible for the metabolism of these gases. Here we describe the mechanism by which a single bacterial strain, Methylocella silvestris, can use methane or propane as a carbon and energy source, documenting a methanotroph that can utilize a short-chain alkane as an alternative to methane. Furthermore, during growth on a mixture of these gases, efficient consumption of both gases occurred at the same time. Two soluble di-iron centre monooxygenase (SDIMO) gene clusters were identified and were found to be differentially expressed during bacterial growth on these gases, although both were required for efficient propane utilization. This report of a methanotroph expressing an additional SDIMO that seems to be uniquely involved in short-chain alkane metabolism suggests that such metabolic flexibility may be important in many environments where methane and short-chain alkanes co-occur.

Near-infrared incoherent broadband cavity enhanced absorption spectroscopy (NIR-IBBCEAS) for detection and quantification of natural gas components.

PubMed

Prakash, Neeraj; Ramachandran, Arun; Varma, Ravi; Chen, Jun; Mazzoleni, Claudio; Du, Ke

2018-06-28

The principle of near-infrared incoherent broadband cavity enhanced absorption spectroscopy was employed to develop a novel instrument for detecting natural gas leaks as well as for testing the quality of natural gas mixtures. The instrument utilizes the absorption features of methane, butane, ethane, and propane in the wavelength region of 1100 nm to 1250 nm. The absorption cross-section spectrum in this region for methane was adopted from the HITRAN database, and those for the other three gases were measured in the laboratory. A singular-value decomposition (SVD) based analysis scheme was employed for quantifying methane, butane, ethane, and propane by performing a linear least-square fit. The developed instrument achieved a detection limit of 460 ppm, 141 ppm, 175 ppm and 173 ppm for methane, butane, ethane, and propane, respectively, with a measurement time of 1 second and a cavity length of 0.59 m. These detection limits are less than 1% of the Lower Explosive Limit (LEL) for each gas. The sensitivity can be further enhanced by changing the experimental parameters (such as cavity length, lamp power etc.) and using longer averaging intervals. The detection system is a low-cost and portable instrument suitable for performing field monitorings. The results obtained on the gas mixture emphasize the instrument's potential for deployment at industrial facilities dealing with natural gas, where potential leaks pose a threat to public safety.

Estimation of lower flammability limits of C-H compounds in air at atmospheric pressure, evaluation of temperature dependence and diluent effect.

PubMed

Mendiburu, Andrés Z; de Carvalho, João A; Coronado, Christian R

2015-03-21

Estimation of the lower flammability limits of C-H compounds at 25 °C and 1 atm; at moderate temperatures and in presence of diluent was the objective of this study. A set of 120 C-H compounds was divided into a correlation set and a prediction set of 60 compounds each. The absolute average relative error for the total set was 7.89%; for the correlation set, it was 6.09%; and for the prediction set it was 9.68%. However, it was shown that by considering different sources of experimental data the values were reduced to 6.5% for the prediction set and to 6.29% for the total set. The method showed consistency with Le Chatelier's law for binary mixtures of C-H compounds. When tested for a temperature range from 5 °C to 100 °C, the absolute average relative errors were 2.41% for methane; 4.78% for propane; 0.29% for iso-butane and 3.86% for propylene. When nitrogen was added, the absolute average relative errors were 2.48% for methane; 5.13% for propane; 0.11% for iso-butane and 0.15% for propylene. When carbon dioxide was added, the absolute relative errors were 1.80% for methane; 5.38% for propane; 0.86% for iso-butane and 1.06% for propylene. Copyright © 2014 Elsevier B.V. All rights reserved.

Intermediate Decoding Skills. NetNews. Volume 4, Number 4

ERIC Educational Resources Information Center

LDA of Minnesota, 2004

2004-01-01

Intermediate decoding refers to word analysis skills that are beyond a beginning, one-syllable level as described in an earlier NetNews issue, yet are just as important for building adult level reading proficiency. Research from secondary settings indicates that struggling readers in middle school or high school programs often read between the…

Nutritional status and nutritional risk in patients with neuroendocrine tumors.

PubMed

Borre, Mette; Dam, Gitte Aarøe; Knudsen, Anne Wilkens; Grønbaek, Henning

2018-03-01

Malnutrition is frequent among patients with malignancies and associated with impaired function, reduced quality of life and increased mortality. Few data are available in patients with neuroendocrine tumors (NET) on nutritional status, nutritional risk, and nutrition impact symptoms (NIS). We aimed to assess nutritional status (NS) and risk, level of function and associations with NIS in NET patients. In a cross-sectional study of NET patients, we measured body mass index (BMI) and handgrip strength (HGS) as markers of NS and muscle function assessed by HGS. The nutritional risk score (NRS) was determined by NRS-2002. NIS was assessed by the eating symptoms questionnaire (ESQ), and disease-related appetite questionnaire (DRAQ). We included 186 patients (51% women), median age 66 years. We observed low BMI (<20.5 kg/m 2 ) in 12%, low HGS in 25%, and impaired level of function in 43% of the patients. About 38% were at nutritional risk, more frequent in patients with residual disease (45% versus 29%, p < .05). Both low HGS, impaired level of function and being at nutritional risk were associated with the NIS: Nausea, vomiting, stomach ache and dry mouth (p < .05) whereas poor appetite and early satiety were only associated with being at nutritional risk and having impaired level of function (p < .05, all). Almost 40% of NET patients were at nutritional risk; and 25% had impaired HGS associated with specific NIS that preclude food intake. We recommend that NET outpatients are screened with NRS-2002 and that HGS and NIS are determined if NET patients need nutritional therapy.

Temporal control of bidirectional lipid-droplet motion in Drosophila depends on the ratio of kinesin-1 and its co-factor Halo

PubMed Central

Arora, Gurpreet K.; Tran, Susan L.; Rizzo, Nicholas; Jain, Ankit; Welte, Michael A.

2016-01-01

ABSTRACT During bidirectional transport, individual cargoes move continuously back and forth along microtubule tracks, yet the cargo population overall displays directed net transport. How such transport is controlled temporally is not well understood. We analyzed this issue for bidirectionally moving lipid droplets in Drosophila embryos, a system in which net transport direction is developmentally controlled. By quantifying how the droplet distribution changes as embryos develop, we characterize temporal transitions in net droplet transport and identify the crucial contribution of the previously identified, but poorly characterized, transacting regulator Halo. In particular, we find that Halo is transiently expressed; rising and falling Halo levels control the switches in global distribution. Rising Halo levels have to pass a threshold before net plus-end transport is initiated. This threshold level depends on the amount of the motor kinesin-1: the more kinesin-1 is present, the more Halo is needed before net plus-end transport commences. Because Halo and kinesin-1 are present in common protein complexes, we propose that Halo acts as a rate-limiting co-factor of kinesin-1. PMID:26906417

7 CFR 1956.143 - Debt restructuring-hospitals and health care facilities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... demonstrate the ability to pay the debt, as restructured, at the end of this delay period. Net recovery value. A calculation of the net value of the collateral and other assets held by the debtor. This value... net recovery value and level of debt the facility will support will be made. It is anticipated that...

7 CFR 1956.143 - Debt restructuring-hospitals and health care facilities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... demonstrate the ability to pay the debt, as restructured, at the end of this delay period. Net recovery value. A calculation of the net value of the collateral and other assets held by the debtor. This value... net recovery value and level of debt the facility will support will be made. It is anticipated that...

7 CFR 1956.143 - Debt restructuring-hospitals and health care facilities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... demonstrate the ability to pay the debt, as restructured, at the end of this delay period. Net recovery value. A calculation of the net value of the collateral and other assets held by the debtor. This value... net recovery value and level of debt the facility will support will be made. It is anticipated that...

Tissue-specific uptake and bioconcentration of the oral contraceptive norethindrone in two freshwater fishes.

PubMed

Nallani, Gopinath C; Paulos, Peter M; Venables, Barney J; Edziyie, Regina E; Constantine, Lisa A; Huggett, Duane B

2012-02-01

The environmental presence of the oral contraceptive norethindrone (NET) has been reported and shown to have reproductive effects in fish at environmentally realistic exposure levels. The current study examined bioconcentration potential of NET in fathead minnow (Pimephales promelas) and channel catfish (Ictalurus punctatus). Fathead minnows were exposed to 50 μg/l NET for 28 days and allowed to depurate in clean water for 14 days. In a minimized 14-day test design, catfish were exposed to 100 μg/l NET for 7 days followed by 7-day depuration. In the fathead test, tissues (muscle, liver, and kidneys) were sampled during the uptake (days 1, 3, 7, 14, and 28) and depuration (days 35 and 42) phases. In the catfish test, muscle, liver, gill, brain, and plasma were collected during the uptake (days 1, 3, and 7) and depuration (day 14) stages. NET tissue levels were determined by gas chromatography-mass spectrometry (GC-MS). Accumulation of NET in tissues was greatest in liver followed by plasma, gill, brain, and muscle. Tissue-specific bioconcentration factors (BCFs) ranged from 2.6 to 40.8. Although NET has been reported to elicit reproductive effects in fish, the present study indicated a low potential to bioconcentrate in aquatic biota.

Effects of biomass burning on summertime nonmethane hydrocarbon concentrations in the Canadian wetlands

NASA Technical Reports Server (NTRS)

Blake, D. R.; Smith, T. W., Jr.; Chen, T.-Y.; Whipple, W. J.; Rowland, F. S.

1994-01-01

Approximately 900 whole air samples were collected and assayed for selected C2-C10 hydrocarbons and seven halocarbons during the 5-week Arctic Boundary Layer Expedition (ABLE) 3B conducted in eastern Canadian wetland areas. In more than half of the 46 vertical profiles flown, enhanced nonmethane hydrocarbon (NMHC) concentrations attributable to plumes from Canadian forest fires were observed. Urban plumes, also enhanced in many NMHCs, were separately identified by their high correlation with elevated levels of perchloroethene. Emission factors relative to ethane were determined for 21 hydrocarbons released from Canadian biomass burning. Using these data for ethane, ethyne, propane, n-butane, and carbon monoxide enhancements from the literature, global emissions of these four NMHCs were estimated. Because of its very short atmospheric lifetime and its below detection limit background mixing ratio, 1,3-butadiene is an excellent indicator of recent combustion. No statistically significant emissions of nitrous oxide, isoprene, or CFC 12 were observed in the biomass-burning plumes encountered during ABLE 3B. The presence of the short-lived biogenically emitted isoprene at altitudes as high as 3000 m implies that mixing within the planetary boundary layer (PBL) was rapid. Although background levels of the longer-lived NMHCs in this Canadian region increase during the fire season, isoprene still dominated local hydroxyl radical photochemistry within the PBL except in the immediate vicinity of active fires. The average biomass-burning emission ratios for hydrocarbons from an active fire sampled within minutes of combustion were, relative to ethane, ethene, 2.45; ethyne 0.57; propane, 0.25; propene, 0.73; propyne, 0.06; n-butane, 0.09; i-butane, 0.01; 1-butene, 0.14; cis-2-butene, 0.02; trans-2-butene, 0.03; i-butylene, 0.07; 1,3-butadiene, 0.12; n-pentane, 0.05; i-pentane, 0.03; 1-pentene, 0.06; n-hexane, 0.05; 1-hexene, 0.07; benzene, 0.37; toluene, 0.16.

Process-scale modeling of elevated wintertime ozone in Wyoming.

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

Kotamarthi, V. R.; Holdridge, D. J.; Environmental Science Division

2007-12-31

Measurements of meteorological variables and trace gas concentrations, provided by the Wyoming Department of Environmental Quality for Daniel, Jonah, and Boulder Counties in the state of Wyoming, were analyzed for this project. The data indicate that highest ozone concentrations were observed at temperatures of -10 C to 0 C, at low wind speeds of about 5 mph. The median values for nitrogen oxides (NOx) during these episodes ranged between 10 ppbv and 20 ppbv (parts per billion by volume). Measurements of volatile organic compounds (VOCs) during these periods were insufficient for quantitative analysis. The few available VOCs measurements indicated unusuallymore » high levels of alkanes and aromatics and low levels of alkenes. In addition, the column ozone concentration during one of the high-ozone episodes was low, on the order of 250 DU (Dobson unit) as compared to a normal column ozone concentration of approximately 300-325 DU during spring for this region. Analysis of this observation was outside the scope of this project. The data analysis reported here was used to establish criteria for making a large number of sensitivity calculations through use of a box photochemical model. Two different VOCs lumping schemes, RACM and SAPRC-98, were used for the calculations. Calculations based on this data analysis indicated that the ozone mixing ratios are sensitive to (a) surface albedo, (b) column ozone, (c) NOx mixing ratios, and (d) available terminal olefins. The RACM model showed a large response to an increase in lumped species containing propane that was not reproduced by the SAPRC scheme, which models propane as a nearly independent species. The rest of the VOCs produced similar changes in ozone in both schemes. In general, if one assumes that measured VOCs are fairly representative of the conditions at these locations, sufficient precursors might be available to produce ozone in the range of 60-80 ppbv under the conditions modeled.« less

Research, Development and Demonstration of Micro-CHP Systems for Residential Applications - Phase I

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

Robert A. Zogg

The objective of the Micro-CHP Phase I effort was to develop a conceptual design for a Micro-CHP system including: Defining market potential; Assessing proposed technology; Developing a proof-of-principle design; and Developing a commercialization strategy. TIAX LLC assembled a team to develop a Micro-CHP system that will provide electricity and heating. TIAX, the contractor and major cost-share provider, provided proven expertise in project management, prime-mover design and development, appliance development and commercialization, analysis of residential energy loads, technology assessment, and market analysis. Kohler Company, the manufacturing partner, is a highly regarded manufacturer of standby power systems and other residential products. Kohlermore » provides a compellingly strong brand, along with the capabilities in product development, design, manufacture, distribution, sales, support, service, and marketing that only a manufacturer of Kohler's status can provide. GAMA, an association of appliance and equipment manufacturers, provided a critical understanding of appliance commercialization issues, including regulatory requirements, large-scale market acceptance issues, and commercialization strategies. The Propane Education & Research Council, a cost-share partner, provided cost share and aided in ensuring the fuel flexibility of the conceptual design. Micro-CHP systems being commercialized in Europe and Japan are generally designed to follow the household thermal load, and generate electricity opportunistically. In many cases, any excess electricity can be sold back to the grid (net metering). These products, however, are unlikely to meet the demands of the U.S. market. First, these products generally cannot provide emergency power when grid power is lost--a critical feature to market success in the U.S. Even those that can may have insufficient electric generation capacities to meet emergency needs for many U.S. homes. Second, the extent to which net metering will be available in the U.S. is unclear. Third, these products are typically not designed for use in households having forced hot-air heating, which is the dominant heating system in the U.S. The U.S. market will also require a major manufacturer that has the reputation and brand recognition, low-cost manufacturing capability, distribution, sales, and service infrastructure, and marketing power to achieve significant market size with a previously unknown and unproven product. History has proven time and time again that small-to-medium-size manufacturers do not have the resources and capabilities to achieve significant markets with such products. During the Phase I effort, the Team developed a conceptual design for a Micro-CHP system that addresses key DOE and U.S. market needs: (1) Provides emergency power adequate for critical household loads, with none of the key drawbacks associated with typical, low-cost emergency generators, such as liquid fuel storage, inability to power ''hard-wired'' loads, need to run temporary extension cords for plug loads, manual set up required, susceptibility to overload, and risk of failure due to lack of maintenance and infrequent operation; (2) Requires no special skills to install--plumbers, electricians and HVAC technicians will typically have all necessary skills; (3) Can be used with the major residential fuels in the U.S., including natural gas and propane, and can be easily adapted to fuel oil as well as emerging fuels as they become available; and (4) Significantly reduces household energy consumption and energy costs.« less

Prognosis Related to Metastatic Burden Measured by 18F-Fluorocholine PET/CT in Castrate Resistant Prostate Cancer

PubMed Central

Kwee, Sandi A.; Lim, John; Watanabe, Alex; Kromer-Baker, Kathleen; Coel, Marc N.

2015-01-01

This study investigates the prognostic significance of metabolically active tumor volume (MATV) measurements applied to fluorine-18 fluorocholine (FC) PET/CT in castrate-resistant prostate cancer (CRPC). Methods FC PET/CT imaging was performed in 30 patients with CRPC. Metastatic disease was quantified on the basis of maximum standardized uptake value (SUVmax), MATV, and total lesion activity (TLA = MATV × mean SUV). Tumor burden indices derived from whole-body summation of PET tumor volume measurements (ie. net MATV and net TLA) were evaluated as variables in Cox regression and Kaplan-Meier survival analyses. Results Net MATV ranged from 0.12 cm3 to 1543.9 cm3 (median 52.6 cm3). Net TLA ranged from 0.40g to 6688.7g (median 225.1g). PSA level at the time of PET correlated significantly with net MATV (Pearson r = 0.65, p = 0.0001) and net TLA (r = 0.60, p = 0.0005) but not highest lesional SUVmax of each scan. Survivors were followed for a median 23 months (range 6 – 38 months). On Cox regression analyses, overall survival was significantly associated with net MATV (p = 0.0068), net TLA (p = 0.0072), and highest lesion SUVmax (p = 0.0173), and borderline associated with PSA level (p = 0.0458). Only net MATV and net TLA remained significant in univariate-adjusted survival analyses. Kaplan-Meier analysis demonstrated significant differences in survival between groups stratified by median net MATV (log-rank P = 0.0371), net TLA (log-rank P = 0.0371), and highest lesion SUVmax (log-rank P = 0.0223). Conclusions Metastatic prostate cancer detected by FC PET/CT can be quantified based on volumetric measurements of tumor metabolic activity. The prognostic value of FC PET/CT may stem from this capacity to assess whole-body tumor burden. With further clinical validation, FC PET-based indices of global disease activity and mortality risk could prove useful in patient-individualized treatment of CRPC. PMID:24676753

Using fuzzy logic to integrate neural networks and knowledge-based systems

NASA Technical Reports Server (NTRS)

Yen, John

1991-01-01

Outlined here is a novel hybrid architecture that uses fuzzy logic to integrate neural networks and knowledge-based systems. The author's approach offers important synergistic benefits to neural nets, approximate reasoning, and symbolic processing. Fuzzy inference rules extend symbolic systems with approximate reasoning capabilities, which are used for integrating and interpreting the outputs of neural networks. The symbolic system captures meta-level information about neural networks and defines its interaction with neural networks through a set of control tasks. Fuzzy action rules provide a robust mechanism for recognizing the situations in which neural networks require certain control actions. The neural nets, on the other hand, offer flexible classification and adaptive learning capabilities, which are crucial for dynamic and noisy environments. By combining neural nets and symbolic systems at their system levels through the use of fuzzy logic, the author's approach alleviates current difficulties in reconciling differences between low-level data processing mechanisms of neural nets and artificial intelligence systems.

Alternative Fuels Data Center

Science.gov Websites

motor fuel tax on a gallon equivalent basis. Alternative fuels include natural gas, propane, hydrogen , and hythane. A gallon equivalent is defined as 5.660 pounds (lbs.) of compressed natural gas, 6.06 lbs

Alternative Fuels Data Center

Science.gov Websites

per gasoline gallon equivalent (GGE). The liquefied natural gas (LNG) tax rate is $0.243 per diesel gallon equivalent (DGE). For taxation purposes, one GGE is equal to 5.75 pounds (lbs.) of propane and

Alternative Fuels Data Center: Propane Related Links

Science.gov Websites

Amerex Corporation's Vehicle Fire Suppression Systems are designed to warn the vehicle operator and suppress the fire, protecting both equipment and employees. Automatic systems suppress the fire in its

10 CFR 205.13 - Where to file.

Code of Federal Regulations, 2010 CFR

2010-01-01

...; (3) The pricing of propane, butane and natural gasoline pursuant to part 212 of this chapter and the allocation of butane and natural gasoline pursuant to part 211 of this chapter; (4) The allocation and...

10 CFR 205.13 - Where to file.

Code of Federal Regulations, 2011 CFR

2011-01-01

...; (3) The pricing of propane, butane and natural gasoline pursuant to part 212 of this chapter and the allocation of butane and natural gasoline pursuant to part 211 of this chapter; (4) The allocation and...

Alternative Fuels Data Center

Science.gov Websites

Alternative Fuel Vehicle (AFV) Registration A fee of $75 is required for the registration of an AFV state motor fuel tax laws. Compressed natural gas, liquefied natural gas, and propane are not subject to

Zion National Park Propane-to-Electric Shuttle Bus Testing | Transportation

Science.gov Websites

storage requirements based on the fleet's unique operation. NREL will process and analyze the data using specialized tools-including the Drive-Cycle Rapid Investigation, Visualization, and Evaluation (DRIVE) tool

Light hydrocarbons vertical profiles and fluxes in a french rural area

NASA Astrophysics Data System (ADS)

Kanakidou, M.; Bonsang, B.; Lambert, G.

By means of manned hot air balloon flights, in July 1986, an experiment was conducted in a rural area of southwest France in order to determine the production at ground level of non-methane hydrocarbons in the C 2-C 6 range. Flux determinations were based on vertical profiles before and after the development of a temperature inversion layer which allowed the measurement of the NMHC accumulation close to ground level. The main species produced in the late afternoon were acetylene, propane, ethene, propene and ethane with production rates of the order of 0.5 to 2 × 10 -4g of C m -2 h -1. Isoprene was found to be the main other unsaturated species also produced. The fluxes and the atmospheric content of the air column before the inversion are consistent with an average OH radical concentration of 2 × 10 6 cm -3.

Overcoming rule-based rigidity and connectionist limitations through massively-parallel case-based reasoning

NASA Technical Reports Server (NTRS)

Barnden, John; Srinivas, Kankanahalli

1990-01-01

Symbol manipulation as used in traditional Artificial Intelligence has been criticized by neural net researchers for being excessively inflexible and sequential. On the other hand, the application of neural net techniques to the types of high-level cognitive processing studied in traditional artificial intelligence presents major problems as well. A promising way out of this impasse is to build neural net models that accomplish massively parallel case-based reasoning. Case-based reasoning, which has received much attention recently, is essentially the same as analogy-based reasoning, and avoids many of the problems leveled at traditional artificial intelligence. Further problems are avoided by doing many strands of case-based reasoning in parallel, and by implementing the whole system as a neural net. In addition, such a system provides an approach to some aspects of the problems of noise, uncertainty and novelty in reasoning systems. The current neural net system (Conposit), which performs standard rule-based reasoning, is being modified into a massively parallel case-based reasoning version.

Norepinephrine transporter heterozygous knockout mice exhibit altered transport and behavior.

PubMed

Fentress, H M; Klar, R; Krueger, J J; Sabb, T; Redmon, S N; Wallace, N M; Shirey-Rice, J K; Hahn, M K

2013-11-01

The norepinephrine (NE) transporter (NET) regulates synaptic NE availability for noradrenergic signaling in the brain and sympathetic nervous system. Although genetic variation leading to a loss of NET expression has been implicated in psychiatric and cardiovascular disorders, complete NET deficiency has not been found in people, limiting the utility of NET knockout mice as a model for genetically driven NET dysfunction. Here, we investigate NET expression in NET heterozygous knockout male mice (NET(+/-) ), demonstrating that they display an approximately 50% reduction in NET protein levels. Surprisingly, these mice display no significant deficit in NET activity assessed in hippocampal and cortical synaptosomes. We found that this compensation in NET activity was due to enhanced activity of surface-resident transporters, as opposed to surface recruitment of NET protein or compensation through other transport mechanisms, including serotonin, dopamine or organic cation transporters. We hypothesize that loss of NET protein in the NET(+/-) mouse establishes an activated state of existing surface NET proteins. The NET(+/-) mice exhibit increased anxiety in the open field and light-dark box and display deficits in reversal learning in the Morris water maze. These data suggest that recovery of near basal activity in NET(+/-) mice appears to be insufficient to limit anxiety responses or support cognitive performance that might involve noradrenergic neurotransmission. The NET(+/-) mice represent a unique model to study the loss and resultant compensatory changes in NET that may be relevant to behavior and physiology in human NET deficiency disorders. © 2013 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Microcystin distribution in physical size class separations of natural plankton communities

USGS Publications Warehouse

Graham, J.L.; Jones, J.R.

2007-01-01

Phytoplankton communities in 30 northern Missouri and Iowa lakes were physically separated into 5 size classes (>100 ??m, 53-100 ??m, 35-53 ??m, 10-35 ??m, 1-10 ??m) during 15-21 August 2004 to determine the distribution of microcystin (MC) in size fractionated lake samples and assess how net collections influence estimates of MC concentration. MC was detected in whole water (total) from 83% of takes sampled, and total MC values ranged from 0.1-7.0 ??g/L (mean = 0.8 ??g/L). On average, MC in the > 100 ??m size class comprised ???40% of total MC, while other individual size classes contributed 9-20% to total MC. MC values decreased with size class and were significantly greater in the >100 ??m size class (mean = 0.5 ??g /L) than the 35-53 ??m (mean = 0.1 ??g/L), 10-35 ??m (mean = 0.0 ??g/L), and 1-10 ??m (mean = 0.0 ??g/L) size classes (p < 0.01). MC values in nets with 100-??m, 53-??m, 35-??m, and 10-??m mesh were cumulatively summed to simulate the potential bias of measuring MC with various size plankton nets. On average, a 100-??m net underestimated total MC by 51%, compared to 37% for a 53-??m net, 28% for a 35-??m net, and 17% for a 10-??m net. While plankton nets consistently underestimated total MC, concentration of algae with net sieves allowed detection of MC at low levels (???0.01 ??/L); 93% of lakes had detectable levels of MC in concentrated samples. Thus, small mesh plankton nets are an option for documenting MC occurrence, but whole water samples should be collected to characterize total MC concentrations. ?? Copyright by the North American Lake Management Society 2007.

Determinants of Bed Net Use in Southeast Nigeria following Mass Distribution of LLINs: Implications for Social Behavior Change Interventions

PubMed Central

Russell, Cheryl L.; Sallau, Adamu; Emukah, Emmanuel; Graves, Patricia M.; Noland, Gregory S.; Ngondi, Jeremiah M.; Ozaki, Masayo; Nwankwo, Lawrence; Miri, Emmanuel; McFarland, Deborah A.; Richards, Frank O.; Patterson, Amy E.

2015-01-01

Millions of long-lasting insecticide treated nets (LLINs) have been distributed as part of the global malaria control strategy. LLIN ownership, however, does not necessarily guarantee use. Thus, even in the ideal setting in which universal coverage with LLINs has been achieved, maximal malaria protection will only be achieved if LLINs are used both correctly and consistently. This study investigated the factors associated with net use, independent of net ownership. Data were collected during a household survey conducted in Ebonyi State in southeastern Nigeria in November 2011 following a statewide mass LLIN distribution campaign and, in select locations, a community-based social behavior change (SBC) intervention. Logistic regression analyses, controlling for household bed net ownership, were conducted to examine the association between individual net use and various demographic, environmental, behavioral and social factors. The odds of net use increased among individuals who were exposed to tailored SBC in the context of a home visit (OR = 17.11; 95% CI 4.45–65.79) or who received greater degrees of social support from friends and family (ptrend < 0.001). Factors associated with decreased odds of net use included: increasing education level (ptrend = 0.020), increasing malaria knowledge level (ptrend = 0.022), and reporting any disadvantage of bed nets (OR = 0.39; 95% CI 0.23–0.78). The findings suggest that LLIN use is significantly influenced by social support and exposure to a malaria-related SBC home visit. The malaria community should thus further consider the importance of community outreach, interpersonal communication and social support on adoption of net use behaviors when designing future research and interventions. PMID:26430747

Genetic deletion of the norepinephrine transporter decreases vulnerability to seizures

PubMed Central

Kaminski, Rafal M.; Shippenberg, Toni S.; Witkin, Jeffrey M.; Rocha, Beatriz A.

2005-01-01

Norepinephrine (NE) has been reported to modulate neuronal excitability and act as endogenous anticonvulsant. In the present study we used NE transporter knock-out mice (NET-KO), which are characterized by high levels of extracellular NE, to investigate the role of endogenous NE in seizure susceptibility. Seizure thresholds for cocaine (i.p.), pentylenetetrazol (i.v.) and kainic acid (i.v.) were compared in NET-KO, heterozygous (NET-HT) and wild type (NET-WT) female mice. The dose-response curve for cocaine-induced convulsions was significantly shifted to the right in NET-KO mice, indicating higher seizure thresholds. The threshold doses of pentylenetetrazol that induced clonic and tonic seizures were also significantly higher in NET-KO when compared to NET-WT mice. Similarly, NET-KO mice displayed higher resistance to convulsions engendered by kainic acid. For all drugs tested, the response of NET-HT mice was always intermediate. These data provide further support for a role of endogenous NE in the control of seizure susceptibility. PMID:15911120

Poster 4: Investigating the first steps of hydrocarbon condensation in the laboratory and in Titan's atmosphere

NASA Astrophysics Data System (ADS)

Biennier, Ludovic; Bourgalais, Jeremy; Benidar, Abdessamad; Le Picard, Sebastien

2016-06-01

Hydrocarbons formed in Titan's cold atmosphere, starting with ethane C2H6, ethylene C2H4, acetylene C2H2, propane C3H8,... up to benzene C6H6, play some role in aerosol production, cloud processes, rain generation and Titan's lakes formation. We have started to study in the laboratory the kinetics of the first steps of condensation of these hydrocarbons. Rate coefficients are very sensitive to the description of the potential interaction surfaces of the molecules involved. Combined theoretical and experimental studies at the molecular level of the homogenous nucleation of various small molecules should improve greatly our fundamental understanding. This knowledge will serve as a model for studying more complex nucleation processes actually taking places in planetary atmospheres. Here we present the first experimental kinetic study of the dimerization of two small hydrocarbons: ethane C2H6 and propane C3H8. We have performed experiments to identify the temperature and partial densities ranges over which small hydrocarbon clusters form in saturated uniform supersonic flows. Using our unique reactor based on a Laval nozzle expansions, the kinetics of the formation has also been investigated down to 23 K. The chemical species present in the reactor are probed by a time of flight mass spectrometer equipped with an electron gun for soft ionization of the neutral reagents and products. This work aims at putting some constraints on the role of small hydrocarbon condensation in the formation of haze particles in the dense atmosphere of Titan.

Arctic springtime observations of volatile organic compounds during the OASIS-2009 campaign

NASA Astrophysics Data System (ADS)

Hornbrook, Rebecca S.; Hills, Alan J.; Riemer, Daniel D.; Abdelhamid, Aroob; Flocke, Frank M.; Hall, Samuel R.; Huey, L. Gregory; Knapp, David J.; Liao, Jin; Mauldin, Roy L.; Montzka, Denise D.; Orlando, John J.; Shepson, Paul B.; Sive, Barkley; Staebler, Ralf M.; Tanner, David. J.; Thompson, Chelsea R.; Turnipseed, Andrew; Ullmann, Kirk; Weinheimer, Andrew J.; Apel, Eric C.

2016-08-01

Gas-phase volatile organic compounds (VOCs) were measured at three vertical levels between 0.6 m and 5.4 m in the Arctic boundary layer in Barrow, Alaska, for the Ocean-Atmosphere-Sea Ice-Snowpack (OASIS)-2009 field campaign during March-April 2009. C4-C8 nonmethane hydrocarbons (NMHCs) and oxygenated VOCs (OVOCs), including alcohols, aldehydes, and ketones, were quantified multiple times per hour, day and night, during the campaign using in situ fast gas chromatography-mass spectrometry. Three canister samples were also collected daily and subsequently analyzed for C2-C5 NMHCs. The NMHCs and aldehydes demonstrated an overall decrease in mixing ratios during the experiment, whereas acetone and 2-butanone showed increases. Calculations of time-integrated concentrations of Br atoms, ∫[Br]dt, yielded values as high as (1.34 ± 0.27) × 1014 cm-3 s during the longest observed ozone depletion event (ODE) of the campaign and were correlated with the steady state Br calculated at the site during this time. Both chlorine and bromine chemistry contributed to the large perturbations on the production and losses of VOCs. Notably, acetaldehyde, propanal, and butanal mixing ratios dropped below the detection limit of the instrument (3 parts per trillion by volume (pptv) for acetaldehyde and propanal, 2 pptv for butanal) during several ODEs due to Br chemistry. Chemical flux calculations of OVOC production and loss are consistent with localized high Cl-atom concentrations either regionally or within a very shallow surface layer, while the deeper Arctic boundary layer provides a continuous source of precursor alkanes to maintain the OVOC mixing ratios.

High-Throughput and Low-Latency Network Communication with NetIO

NASA Astrophysics Data System (ADS)

Schumacher, Jörn; Plessl, Christian; Vandelli, Wainer

2017-10-01

HPC network technologies like Infiniband, TrueScale or OmniPath provide low- latency and high-throughput communication between hosts, which makes them attractive options for data-acquisition systems in large-scale high-energy physics experiments. Like HPC networks, DAQ networks are local and include a well specified number of systems. Unfortunately traditional network communication APIs for HPC clusters like MPI or PGAS exclusively target the HPC community and are not suited well for DAQ applications. It is possible to build distributed DAQ applications using low-level system APIs like Infiniband Verbs, but it requires a non-negligible effort and expert knowledge. At the same time, message services like ZeroMQ have gained popularity in the HEP community. They make it possible to build distributed applications with a high-level approach and provide good performance. Unfortunately, their usage usually limits developers to TCP/IP- based networks. While it is possible to operate a TCP/IP stack on top of Infiniband and OmniPath, this approach may not be very efficient compared to a direct use of native APIs. NetIO is a simple, novel asynchronous message service that can operate on Ethernet, Infiniband and similar network fabrics. In this paper the design and implementation of NetIO is presented and described, and its use is evaluated in comparison to other approaches. NetIO supports different high-level programming models and typical workloads of HEP applications. The ATLAS FELIX project [1] successfully uses NetIO as its central communication platform. The architecture of NetIO is described in this paper, including the user-level API and the internal data-flow design. The paper includes a performance evaluation of NetIO including throughput and latency measurements. The performance is compared against the state-of-the- art ZeroMQ message service. Performance measurements are performed in a lab environment with Ethernet and FDR Infiniband networks.

33 CFR 127.005 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Chlorine T Dimethylamine F+T Ethane F Ethyl chloride F+T Ethylene F Ethylene oxide F+T Methyl-acetylene and propadiene (mixtures) F Methyl bromide F+T Methyl chloride F+T Propane F Propylene F Sulphur dioxide T Vinyl...

33 CFR 127.005 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Chlorine T Dimethylamine F+T Ethane F Ethyl chloride F+T Ethylene F Ethylene oxide F+T Methyl-acetylene and propadiene (mixtures) F Methyl bromide F+T Methyl chloride F+T Propane F Propylene F Sulphur dioxide T Vinyl...

Alternative Fuels Data Center: Seattle Bakery Delivers With Biodiesel

Science.gov Websites

Delivers With Biodiesel Trucks Discover how Essential Baking Company in Seattle, Washington, relies on Alpha Baking Company Augments Its Fleet With Propane Delivery Trucks Nov. 2, 2013 Photo of a man fueling

Alternative Fuels Data Center: Propane Fueling Infrastructure Development

Science.gov Websites

availability is the foundation for the acceptance of any fuel. Fleets depend on being able to locate fuel fuel systems and containers in vehicles, and the National Fire Prevention Association's NFPA 58

CARBINOLAMINES AND GEMINAL DIOLS IN AQUEOUS ENVIRONMENTAL ORGANIC CHEMISTRY

EPA Science Inventory

Organic chemistry textbooks generally treat geminal diols as curiosities-exceptions to the stability of the C=O double bond. However, most aldehydes of environmental significance, to wit, trichloroethanal (chloral), methanala (formaldehyde), ethanal (acetaldehyde), and propanal ...

40 CFR 1065.340 - Diluted exhaust flow (CVS) calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... action does not resolve a failure to meet the diluted exhaust flow verification (i.e., propane check) in... subsonic venturi flow meter, a long-radius ASME/NIST flow nozzle, a smooth approach orifice, a laminar flow...

[Regeneration of the ciliary beat of human ciliated cells].

PubMed

Wolf, G; Koidl, B; Pelzmann, B

1991-10-01

The influence of an isotonic, alkaline saline solution (diluted "Emser Sole" or brine from the spa of Bad Ems) on the ciliary beat of isolated cultured human ciliated cells of the upper respiratory tract was investigated. The ciliary beat was observed via an inverted phase contrast microscope (Zeiss Axiomat IDPC) and measured microphotometrically under physiological conditions and after the damaging influence of 1% propanal solution. Under physiological conditions the saline solution had a positive, although statistically not significant influence on the frequency of the ciliary beat. After damage of the cultivated cells by 1% propanal solution, the saline solution had a significant better influence on the regeneration of the cultured cells than a physiological sodium chloride solution. It is concluded that diluted brine from Bad Ems has a positive effect on the ciliary beat of the respiratory epithelium and accelerates its regeneration after damage by viral and bacterial infections, surgery or inhaled noxae.

Effect of concentration of polyfunctional monomers on physical properties of acrylonitrile butadiene rubber under electron-beam irradiation

NASA Astrophysics Data System (ADS)

Yasin, Tariq; Ahmed, Shamshad; Ahmed, Munir; Yoshii, Fumio

2005-06-01

An investigation has been undertaken to find out the effect of concentration of different polyfunctional monomers (PFMs) on the physical properties of the acrylonitrile-butadiene rubber (NBR) crosslinked by electron beam (EB). The PFMs used were diethylene glycol dimethacrylate, trimethylol propane trimethacrylate and trimethylol propane triacrylate. The physical properties of EB-irradiated NBR sheets were evaluated by measuring the tensile strength, elongation percent at break, hardness and gel fraction. The results showed a remarkable increase in tensile strength, hardness and gel fraction as the concentration of PFMs was increased from 1 part per hundred (phr) to 5 phr in the NBR samples whereas elongation percent decreased in a steady manner. The improvement in physical properties of radiation crosslinked NBR in the presence of PFMs may be attributed to its increased crosslinking density as observed by the corresponding increase in gel content.

Biotransformation of natural gas and oil compounds associated with marine oil discharges.

PubMed

Brakstad, Odd Gunnar; Almås, Inger K; Krause, Daniel Franklin

2017-09-01

Field data from the Deepwater Horizon (DWH) oil spill in the Gulf of Mexico (GoM) suggested that oxidation of gas compounds stimulated biodegradation of oil compounds in the deep sea plume. We performed experiments with local seawater from a Norwegian fjord to examine if the presence of dissolved gas compounds (methane, ethane and propane) affected biodegradation of volatile oil compounds, and if oil compounds likewise affected gas compound oxidation. The results from the experiment showed comparable oil compound biotransformation rates in seawater at 5 °C between seawater with and without soluble gases. Gas oxidation was not affected by the presence of volatile oil compounds. Contrary to DWH deep sea plume data, propane oxidation was not faster than methane oxidation. These data may reflect variations between biodegradation of oil and gas in seawater environments with different history of oil and gas exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

The water soluble axially disubstituted silicon phthalocyanines: photophysicochemical properties and in vitro studies.

PubMed

Göksel, Meltem; Biyiklioglu, Zekeriya; Durmuş, Mahmut

2017-08-01

Two novel silicon(IV) phthalocyanines bearing 1,3-bis[3(dimethylamino)phenoxy]propan-2-ol or 1,3-bis[3(diethylamino)phenoxy]propan-2-ol groups at their axial positions were synthesized. These phthalocyanines were converted into their water soluble derivatives by the quaternization reaction with methyl iodide. The quaternized phthalocyanines show excellent solubility aqueous solutions without any aggregation which makes them potential photosensitizers for use in photodynamic therapy (PDT). For this reason, the photophysical and photochemical properties such as fluorescence quantum yields, lifetimes, singlet oxygen generation and photodegradation of both non-ionic (3 and 5) and quaternized cationic silicon(IV) phthalocyanines were investigated. Furthermore, the cytotoxicity of PDT was determined by colorimetric proliferation assay against to hepatocellular carcinoma (HuH-7) cancer cells. In this study, the cells were incubated with a novel water soluble silicon(IV) phthalocyanine derivatives and thereafter the cells were illuminated using broad-band incoherent light source.

The best news for LPG in Denmark is diesel conversion breakthrough

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

Not Available

Throughout Scandanavia, taxes seem to drive the marketplace. Governments do not want to encourage consumption of alcoholic beverages, so they tax them heavily, thereby actually discouraging their use. Using the same means, they dictate the fate of the various fuels. Taxes have depressed propane's use to a large extent; today it is priced at three times natural gas, with the result that it accounts for only 0.5%-0.7% of total energy consumption. But, this paper reports on a potential new star that has appeared on the horizon, as participants in the People-to-People sojourn to Scandanavia last August learned. It's a programmore » of converting diesel buses to propane, and officials of the company that is marketing it, Skibby Motor A/S, are so confident of its success that they have already begun a campaign of introducing it to the U.S.« less

Main-group compounds selectively oxidize mixtures of methane, ethane, and propane to alcohol esters.

PubMed

Hashiguchi, Brian G; Konnick, Michael M; Bischof, Steven M; Gustafson, Samantha J; Devarajan, Deepa; Gunsalus, Niles; Ess, Daniel H; Periana, Roy A

2014-03-14

Much of the recent research on homogeneous alkane oxidation has focused on the use of transition metal catalysts. Here, we report that the electrophilic main-group cations thallium(III) and lead(IV) stoichiometrically oxidize methane, ethane, and propane, separately or as a one-pot mixture, to corresponding alcohol esters in trifluoroacetic acid solvent. Esters of methanol, ethanol, ethylene glycol, isopropanol, and propylene glycol are obtained with greater than 95% selectivity in concentrations up to 1.48 molar within 3 hours at 180°C. Experiment and theory support a mechanism involving electrophilic carbon-hydrogen bond activation to generate metal alkyl intermediates. We posit that the comparatively high reactivity of these d(10) main-group cations relative to transition metals stems from facile alkane coordination at vacant sites, enabled by the overall lability of the ligand sphere and the absence of ligand field stabilization energies in systems with filled d-orbitals.

Cinnamic acid hydrogen bonds to isoniazid and N'-(propan-2-ylidene)isonicotinohydrazide, an in situ reaction product of isoniazid and acetone.

PubMed

Sarcevica, Inese; Orola, Liana; Veidis, Mikelis V; Belyakov, Sergey

2014-04-01

A new polymorph of the cinnamic acid-isoniazid cocrystal has been prepared by slow evaporation, namely cinnamic acid-pyridine-4-carbohydrazide (1/1), C9H8O2·C6H7N3O. The crystal structure is characterized by a hydrogen-bonded tetrameric arrangement of two molecules of isoniazid and two of cinnamic acid. Possible modification of the hydrogen bonding was investigated by changing the hydrazide group of isoniazid via an in situ reaction with acetone and cocrystallization with cinnamic acid. In the structure of cinnamic acid-N'-(propan-2-ylidene)isonicotinohydrazide (1/1), C9H8O2·C9H11N3O, carboxylic acid-pyridine O-H···N and hydrazide-hydrazide N-H···O hydrogen bonds are formed.

The influence of fuel type to combustion characteristic in diffusion flame drying by computational fluid dynamics simulation

NASA Astrophysics Data System (ADS)

Septiani, Eka Lutfi; Widiyastuti, W.; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

2017-05-01

Diffusion flame spray drying has become promising method in nanoparticles synthesis giving several advantages and low operation cost. In order to scale up the process which needs high experimentation time and cost, Computational Fluid Dynamics (CFD) by Ansys Fluent 15.0 software has been used. Combustion characteristic in diffusion flame reactor may affects particle size distribution. This study aims to observe influence of fuel type to combustion characteristic in the reactor. Large Eddy Simulation (LES) and non-premixed combustion model are selected for the turbulence and combustion model respectively. Methane, propane, and LPG in 0.5 L/min were used as type of fuel. While the oxidizer is air with 200% excess of O2. Simulation result shown that the maximum temperature was obtained from propane-air combustion in 2268 K. However, the stable temperature contour was achieved by methane-air combustion.

Enhanced oil recovery system

DOEpatents

Goldsberry, Fred L.

1989-01-01

All energy resources available from a geopressured geothermal reservoir are used for the production of pipeline quality gas using a high pressure separator/heat exchanger and a membrane separator, and recovering waste gas from both the membrane separator and a low pressure separator in tandem with the high pressure separator for use in enhanced oil recovery, or in powering a gas engine and turbine set. Liquid hydrocarbons are skimmed off the top of geothermal brine in the low pressure separator. High pressure brine from the geothermal well is used to drive a turbine/generator set before recovering waste gas in the first separator. Another turbine/generator set is provided in a supercritical binary power plant that uses propane as a working fluid in a closed cycle, and uses exhaust heat from the combustion engine and geothermal energy of the brine in the separator/heat exchanger to heat the propane.

Reduced chemical kinetic model of detonation combustion of one- and multi-fuel gaseous mixtures with air

NASA Astrophysics Data System (ADS)

Fomin, P. A.

2018-03-01

Two-step approximate models of chemical kinetics of detonation combustion of (i) one hydrocarbon fuel CnHm (for example, methane, propane, cyclohexane etc.) and (ii) multi-fuel gaseous mixtures (∑aiCniHmi) (for example, mixture of methane and propane, synthesis gas, benzene and kerosene) are presented for the first time. The models can be used for any stoichiometry, including fuel/fuels-rich mixtures, when reaction products contain molecules of carbon. Owing to the simplicity and high accuracy, the models can be used in multi-dimensional numerical calculations of detonation waves in corresponding gaseous mixtures. The models are in consistent with the second law of thermodynamics and Le Chatelier's principle. Constants of the models have a clear physical meaning. The models can be used for calculation thermodynamic parameters of the mixture in a state of chemical equilibrium.

Identification of five substituted phenethylamine derivatives 5-MAPDB, 5-AEDB, MDMA methylene homolog, 6-Br-MDMA, and 5-APB-NBOMe.

PubMed

Liu, Cuimei; Jia, Wei; Qian, Zhenhua; Li, Tao; Hua, Zhendong

2017-02-01

This paper reports analytical properties of five substituted phenethylamine derivatives seized from a clandestine laboratory. These five derivatives include 5-(2-methylaminopropyl)-2,3-dihydrobenzofuran (5-MAPDB, 1), 5-(2-aminoethyl)-2,3-dihydrobenzofuran (5-AEDB, 2), N,2-dimethyl-3-(3,4-methylenedioxyphenyl)propan-1-amine (MDMA methylene homolog, 3), 6-bromo-3,4-methylenedioxymethamphetamine (6-Br-MDMA, 4), and 1-(benzofuran-5-yl)-N-(2-methoxybenzyl)propan-2-amine (5-APB-NBOMe, 5). These compounds were identified by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance spectroscopy (NMR). No analytical properties about compounds 1-4 have appeared until now, making this the first report on these compounds. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Chemical kinetic reaction mechanism for the combustion of propane

NASA Technical Reports Server (NTRS)

Jachimowski, C. J.

1984-01-01

A detailed chemical kinetic reaction mechanism for the combustion of propane is presented and discussed. The mechanism consists of 27 chemical species and 83 elementary chemical reactions. Ignition and combustion data as determined in shock tube studies were used to evaluate the mechanism. Numerical simulation of the shock tube experiments showed that the kinetic behavior predicted by the mechanism for stoichiometric mixtures is in good agrement with the experimental results over the entire temperature range examined (1150-2600K). Sensitivity and theoretical studies carried out using the mechanism revealed that hydrocarbon reactions which are involved in the formation of the HO2 radical and the H2O2 molecule are very important in the mechanism and that the observed nonlinear behavior of ignition delay time with decreasing temperature can be interpreted in terms of the increased importance of the HO2 and H2O2 reactions at the lower temperatures.

Formation and decomposition of ethane, propane, and carbon dioxide hydrates in silica gel mesopores under high pressure.

PubMed

Aladko, E Ya; Dyadin, Yu A; Fenelonov, V B; Larionov, E G; Manakov, A Yu; Mel'gunov, M S; Zhurko, F V

2006-10-05

The experimental data on decomposition temperatures for the gas hydrates of ethane, propane, and carbon dioxide dispersed in silica gel mesopores are reported. The studies were performed at pressures up to 1 GPa. It is shown that the experimental dependence of hydrate decomposition temperature on the size of pores that limit the size of hydrate particles can be described on the basis of the Gibbs-Thomson equation only if one takes into account changes in the shape coefficient that is present in the equation; in turn, the value of this coefficient depends on a method of mesopore size determination. A mechanism of hydrate formation in mesoporous medium is proposed. Experimental data providing evidence of the possibility of the formation of hydrate compounds in hydrophobic matrixes under high pressure are reported. Decomposition temperature of those hydrate compounds is higher than that for the bulk hydrates of the corresponding gases.