A Method for the Rapid Characterization of Combustion Properties of Liquid Fuels Using a Tubular Burner

2007 ◽  
Author(s):  
N. D. Love ◽  
R. N. Parthasarathy ◽  
S. R. Gollahalli
Keyword(s):  
Liquid Fuel ◽  
High Sensitivity ◽  
Radiant Heat ◽  
Liquid Fuels ◽  
Pollutant Emission ◽  
Emission Characteristics ◽  
Air Stream ◽  
Combustion Properties ◽  
Rapid Characterization

Knowledge of the combustion and pollutant emission characteristics is important in the application of both existing and newly developed fuels. A technique for the rapid characterization of flame radiation properties and emission characteristics of liquid fuels was developed for this purpose. Liquid fuel was injected into a heated air stream at known rates with a syringe pump; the feed line was heated (temperature of 425°C) to pre-vaporize the fuel before burning, to avoid the effects of evaporation parameters on measurements. Temperatures of the fuel and air were monitored using K-type thermocouples embedded within the feed lines. A laminar methane-air flame was issued from a stainless steel tubular burner (9.5mm inner diameter) and used as the ignition source. The methane supply was shut off after the onset of the burning of the vaporized liquid fuel, in order to eliminate the effects of burning methane in the measurements. Several liquid fuels were tested, including commercially available petroleum-based No. 2 diesel fuel, canola methyl ester (CME B 100) biodiesel, kerosene, methanol, toluene, and selected alkanes. A steady burning flame was achieved for all fuels. Radiative heat flux measurements were made with a high-sensitivity pyrheliometer and the radiant fraction of heat release calculated. The radiant heat fraction served as an indication of sooting tendency of the fuels. NO, CO, and CO2 emission measurements were also made. The measurements demonstrate the feasibility of the current technique for the rapid characterization of combustion properties of liquid fuels, utilizing small fuel quantities.

Rapid Characterization of Radiation and Pollutant Emissions of Biodiesel and Hydrocarbon Liquid Fuels

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
N. D. Love ◽  
R. N. Parthasarathy ◽  
S. R. Gollahalli
Keyword(s):  
Radiant Heat ◽  
Development Stage ◽  
Pollutant Emissions ◽  
Liquid Fuels ◽  
Emission Properties ◽  
Diesel Fuels ◽  
Combustion Properties ◽  
Inner Diameter ◽  
Rapid Characterization

As a result of decreasing petroleum supplies, new fuel sources, such as transesterified biofeedstock based oils and their blends with petroleum diesel fuels, have emerged with potential to partially replace conventional diesel and gasoline fuels. Although these fuels have shown some promising results in engine studies, their basic combustion properties have not been well documented. Also, research is underway to develop new fuels from other sources or by altering their molecular structure to be fungible with conventional fuels. Thus, there is a need for tests to characterize the combustion and emission properties of these new liquids, which are available only in small quantities at the research and development stage. This paper deals with a technique that meets those goals. The fuel was prevaporized and mixed with air and burnt in a tubular burner (9.5 mm inner diameter) at atmospheric pressure under laminar conditions. A pilot methane/air flame was used as the ignition source. The test conditions were so chosen that the measured properties could be attributed primarily to the fuel chemical structure. Several liquid fuels were tested, including commercially available petroleum-based No. 2 diesel fuel, canola methyl ester (CME B100) biodiesel, kerosene, methanol, toluene, and selected alkanes. The radiative heat flux from the flames was measured using a wide-angle pyrheliometer; the emissions from the flames were sampled to measure the concentration of CO, CO2, and NO. The measured radiant heat fraction values and the emission indices of NO and CO of both petroleum-derived and biofuels agreed well with those found in literature; thus, the feasibility of this method to rapidly characterize the combustion and emission properties of new liquids, such as biofuels, is demonstrated.

High Sensitivity External Leak Detection for Liquid Fuel Pipelines

2004 ◽  
Author(s):  
David G. Parman ◽  
Ken McCoy
Keyword(s):  
Liquid Fuel ◽  
Risk Mitigation ◽  
Detection System ◽  
High Sensitivity ◽  
Leak Detection ◽  
Liquid Fuels ◽  
Detection Methods ◽  
Environmental Damage ◽  
Distributed Sensor ◽  
Environmentally Sensitive Areas

Pipeline risk mitigation in high consequence areas can be facilitated through the use of a high sensitivity external leak detection (HSELD) system. Such systems have been implemented for both off-site and on-site pipeline applications, including the Longhorn Pipeline (Texas) and the Madrid Barajas International Airport (Spain). We define high-sensitivity external leak detection as a leak detection system that will continuously and automatically detect very small amounts of liquid fuels and is physically independent of pipeline pumping operations. In addition, such systems monitor their own integrity on a continuous basis, without requiring periodic recalibration or operator interaction. The HSELD system we describe incorporates a distributed sensor cable, installed in a slotted PVC conduit which is run in close proximity to the pipeline. Many pipeline leaks start out as very small cracks or holes resulting from corrosion and wear. In their initial stages, such leaks go undetected by standard leak detection methods, but over time large volumes of liquid fuel may leak into the environment. In high consequence areas, such as above aquifers and other environmentally sensitive areas, the leak may go undetected until traces show up in water samples. The critical characteristic of an effective HSELD is its ability to detect and accurately locate very small volumes of liquid fuels, so that these small leaks can be identified, cleaned up and repaired before environmental damage is done.

scholarly journals Rapid characterization of feline leukemia virus infective stages by a novel nested recombinase polymerase amplification (RPA) and reverse transcriptase-RPA

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sitthichok Lacharoje ◽  
Somporn Techangamsuwan ◽  
Nuntaree Chaichanawongsaroj
Keyword(s):  
Reverse Transcriptase ◽  
Leukemia Virus ◽  
High Sensitivity ◽  
Viral Disease ◽  
Recombinase Polymerase Amplification ◽  
Feline Leukemia Virus ◽  
Immunochromatographic Assay ◽  
Rapid Characterization ◽  
And Control

AbstractFeline leukemia virus (FeLV) is a major viral disease in cats, causing leukemia and lymphoma. The molecular detection of FeLV RNA and the DNA provirus are important for staging of the disease. However, the rapid immunochromatographic assay commonly used for antigen detection can only detect viremia at the progressive stage. In this study, nested recombinase polymerase amplification (nRPA) was developed for exogenous FeLV DNA provirus detection, and reverse transcriptase polymerase amplification (RT-RPA) was developed for the detection of FeLV RNA. The approaches were validated using 108 cats with clinicopathologic abnormalities due to FeLV infection, and from 14 healthy cats in a vaccination plan. The nRPA and RT-RPA assays could rapidly amplify the FeLV template, and produced high sensitivity and specificity. The FeLV detection rate in regression cats by nRPA was increased up to 45.8% compared to the rapid immunochromatographic assay. Hence, FeLV diagnosis using nRPA and RT-RPA are rapid and easily established in low resource settings, benefiting FeLV prognosis, prevention, and control of both horizontal and vertical transmission.

Ultrastructural identification of three types of sensory setae on copepod antennae

1995 ◽  
Vol 53 ◽  
pp. 956-957
Author(s):  
T. M. Weatherby ◽  
P.H. Lenz
Keyword(s):  
Phase Locking ◽  
Membrane Surface ◽  
Reaction Times ◽  
High Sensitivity ◽  
Structural Features ◽  
Calanoid Copepods ◽  
Marine Food Webs ◽  
Dendritic Membrane ◽  
Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

Pollutant emission from a heat station supplied with agriculture biomass and wood pellet mixture

2012 ◽  
Vol 33 (2) ◽  
pp. 231-242 ◽  
Author(s):  
Marek Juszczak ◽  
Katarzyna Lossy
Keyword(s):  
Carbon Monoxide ◽  
Pollutant Emission ◽  
Heat Output ◽  
Wood Pellets ◽  
Wood Pellet ◽  
Carbon Monoxide Concentration ◽  
Heat Efficiency ◽  
Air Stream ◽  
Fuel Mixtures ◽  
Lower Carbon

Pollutant emission from a heat station supplied with agriculture biomass and wood pellet mixtureTests for combustion of hay and sunflower husk pellets mixed with wood pellets were performed in a horizontal-feed as well as under-feed (retort) wood pellet furnace installed in boilers with a nominal heat output of 15 and 20 kW, located in a heat station. During the combustion a slagging phenomenon was observed in the furnaces. In order to lower the temperature in the furnace, fuel feeding rate was reduced with unaltered air stream rate. The higher the proportion of wood pellets in the mixture the lower carbon monoxide concentration. The following results of carbon monoxide concentration (in mg/m3presented for 10% O2content in flue gas) for different furnaces and fuel mixtures (proportion in wt%) were obtained: horizontal-feed furnace supplied with hay/wood: 0/100 - 326; 30/70 - 157; 50/50 - 301; 100/0 - 3300; horizontal-feed furnace supplied with sunflower husk/wood: 50/50 - 1062; 67/33 - 1721; 100/0 - 3775; under-feed (retort) furnace supplied with hay/wood: 0/100 - 90; 15/85 - 157; 30/70 - 135; 50/50 - 5179; under-feed furnace supplied with sunflower husk/wood: 67/33 - 2498; 100/0 - 3128. Boiler heat output and heat efficiency was low: 7 to 13 kW and about 55%, respectively, for the boiler with horizontal-feed furnace and 9 to 14 kW and 64%, respectively, for the boiler with under-feed furnace.

scholarly journals Average fractional polarization of extragalactic sources at Planck frequencies

2018 ◽  
Vol 618 ◽  
pp. A29 ◽  
Author(s):  
T. Trombetti ◽  
C. Burigana ◽  
G. De Zotti ◽  
V. Galluzzi ◽  
M. Massardi
Keyword(s):  
High Sensitivity ◽  
Point Sources ◽  
Distribution Analysis ◽  
Microwave Background ◽  
Residual Noise ◽  
Upper Limits ◽  
Dusty Galaxies ◽  
Using Data ◽  
Polarization Fraction

Recent detailed simulations have shown that an insufficiently accurate characterization of the contamination of unresolved polarized extragalactic sources can seriously bias measurements of the primordial cosmic microwave background (CMB) power spectrum if the tensor-to-scalar ratio r ∼ 0.001, as predicted by models currently of special interest (e.g., Starobinsky’s R2 and Higgs inflation). This has motivated a reanalysis of the median polarization fraction of extragalactic sources (radio-loud AGNs and dusty galaxies) using data from the Planck polarization maps. Our approach, exploiting the intensity distribution analysis, mitigates or overcomes the most delicate aspects of earlier analyses based on stacking techniques. By means of simulations, we have shown that the residual noise bias on the median polarization fraction, Πmedian, of extragalactic sources is generally ≲0.1%. For radio sources, we have found Πmedian ≃ 2.83%, with no significant dependence on either frequency or flux density, in good agreement with the earlier estimate and with high-sensitivity measurements in the frequency range 5–40 GHz. No polarization signal is detected in the case of dusty galaxies, implying 90% confidence upper limits of Πdusty ≲ 2.2% at 353 GHz and of ≲3.9% at 217 GHz. The contamination of CMB polarization maps by unresolved point sources is discussed.

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