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04292 Carbon-based standards for electron paramagnetic resonance spectroscopy
16 Fuel science and technology (fundamental science, analysis, instrumentation) 95104288 Approximate closed form analytical solution of the desublimation problem In a porous medium
9SlO42Q3 Certifled reference materlals for the quality control of fluorine In coal, fly ash and clay
Rai, K. N. and Rai, S. Inr. .I. .&rergy Res., Jun. 1995, 19, (4), 279-288. An approximate analytical method for solving a desublimation problem is presented. The method is based on the criterion that the total error over the domain of interest which results from introducing an approximate solution into the governing equation of a boundary-value problem must be kept to a minimum. The results thus obtained are compared with the corresponding exact solution and are in good agreement. The method has now been applied to a problem where the Luikov number is a linear function of moisture concentration. The effect of variability of Luikov number with nondimensional moisture concentration, nondimensional frozen-moisture concentration as well as the location of the moving desublimation front are shown graphically.
t$t;\;agrviller,
P.
et al.,
Fresenius’ J. Anal. Chem., 1994, 350, (3),
A group of laboratories
has worked on various intercomparisons in the frame of the BRC-programme (European Commission) to improve their methods for fluorine determination, especially for coal analysis. These exercises allowed to detect and remove sources of error. Methods were improved to such an extent that the certification of fluorine and chlorine in different materials could be envisaged and the BCR consequently decided to produce coal, fly ash and clay materials certified by their F content.
95104294
Cooling of stacks of plates shielded by porous
screens
Asphaltene association In crude oil as studied by Galtsev, V. E. er al., Fuel, May 1995, 74, (S), 670-673. Asphaltene association in crude oil in the native condition was studied using electron-nuclear double resonance (ENDOR) spectroscopy. Most of the asphaltene molecules are associated with each other in the range from room temperature up to 90°C. The core of the associate is a stack of condensed aromatic sheets of characteristic radius approximately 10A. The effect of dilution by various low-molecular-weight solvents on destruction of the associates was observed. The extent of associate destruction was not found to correlate with the solvent polarity. The outer coordination sphere of a micelle with the asphaltene associate as a core is assumed to be sufficiently labile to allow the low-molecular-weight solvents used to reach the core.
Automated maceral analysis using fluorescence microscopy and image analysis
95104288
Cloke, M. er al., Fuel, May 1995, 74, (5), 659-669. The paper describes the feasibility of using fluorescence microscopy in conjunction with normal white light microscopy and image analysis in order to carry out fully automated maceral analysis. A short review of current image systems shows a lack of success in distinguishing the liptinite speces from the resin media used to form the coal block. Fluorescent lightmg is commonly used during manual analysis and in this paper fluorescence is shown to provide a means of performing automated maceral analysis which includes an accurate determination of the liptinite content. The work presented indicates that the system can be used with a wide range of coals from around the world. A realistic assessment of repeatability and reproducibility is also made.
95104289
Automatic coal petrographic analysls by optlcal
lmaglng Celeski, J. C. et al., Rev. Metall.lCah. Inf: Tech., 1994, 91, (3), 395403. (In French) Coal petrographic analysis in support of quality control in steelmaking, is carried out by automatic image analysis using a high-resolution video camera of images from optical microscopy.
Automatic Industrial-use analyzer for water, vola95104290 tile and ash components Izumitani, S. et al., (Assigned to) Kansai Electric Power Co.; Ngk Insulators Ltd., JAP. Pat. JP. 06,288,887, Oct. 1994. The automatic industrial-use analyzer is suited for use in determination of water, volatile and ash components in coal.
95104291 Bulk fluld temperature and pipe wall temperature may be dlfferent dependlng upon the bulk fluld Lichtenstein, T. Heaf Transfer Engng., Oct.-Dec. 1994, 15, (4) 75-77. Knowing the bulk fluid temperature is often critical in the determination of the amount of emissions. When trying to determine the bulk temperature of a process stream, engineers must take care to determine whether measuring the uioe wall temoerature will eive a reasonable aooroximation of the bulk temperature. If the pipe walr temperature will’not give a reasonable approximation of the bulk fluid temperature, further calculations must be performed.
Carbon-based standards for electron paramagnetlc 95104292 resonance spectroscopy Auteri, F. P. er al., Appl. Magn. Reson., 1994, 6, (l), 287-308. To meet the need for a eood new EPR intensitv and e-value standard whose paramagnetic speciis are C-based radicals,’ several materials were studied, including coal, fusinite (a coal maceral), and several carbohydrate chars.
Bejan, A. et al., Heat & Fluid Flow, Feb. 1995, 16, (l), 16-24. The paper addresses the question of how to cool a stack of parallel, heatgenerating boards when the flow is impeded by electromagnetic screens placed upstream and downstream of the stack.
95104295
Crude oils: Characterization of waxes precipitated on cooling by d.s.c. and thermomicroscopy Letoffe. J. M. et al.. Fuel. Jun. 1995. 74. 161. 810-817. Mixtures~of 2 and 4’wt% of pure paraffins‘in’a crude oil matrix and 14 crude oils were characterized by differential scanning calorimetry (d.s.c.) and thermomicroscopy at a cooling rate of 2 K minq in the temperature range from t80 to -20°C. Pour points were also determined. In the temperature range used, a constant value of 200J kg” for the enthalpy of precipitation was determined. For crude oils which contain >lOwt% of n-paraffins, the pour point is reached when approximately 2wt% of waxes have precipitated. By thermomicroscopy, it was observed for mixtures of pure paraffins and crude oil matrix that the size of the crystals is small and depends on the length of paraffinic chains at the pour point.
95104298
Detection of high-molecular-mass materials In coal-derived liquids by Independent techniques (Letter) Herod, A. A. and Kandiyoti,
R.
Fuel, May 1995, 74, (5), 784-786.
Determination of high-i! materials In low-i! medium by X-ray scattering techniques
95104297
Arikan, P. er al., Nucl. Instrum. Methods Phys. Rex. Sect. B, 1995, 95, (l), 82:86. Discusses the quantitative determination of high-Z elements (mineral matter and ash) in low-Z medium (coal) by X-ray scattering techniques.
Determlnatlon of metallic elements In crude oll95104298 water emulslons by flame AAS
Platteau, 0. and Carrillo, M. Fuel, May 1995, 74, (S), 761-767. A method is presented for the determination of V, Ni, Fe, Mg and Na in highly stable crude oil-water emulsions of which Orimulsion, a new fuel product from the Venezuelan oil industry, is a typical example. The method is based on a dry ashing procedure for sample preparation which includes a dehydration process in the presence of ethyl alcohol, and determination of elements by flame atomic absorption spectrometry. Interference studies for major components in the matrix have been made using a factorial experimental design. Recoveries for the elements range from 95.8 to 104.3% with relative standard deviations lower than t/- 4%.
95104299
Determination of trace elements In coal ash by arc spectrographic analysls wlth halide buffer
Wang, G. et al., Guangpu Shiyanshi, 1994, 11, (3) 38-43. (In Chinese) Describes a method for determining trace elements in coal ash with improved detection limit.
Effect of fluld propertles of heat transfer In channels wlth offset strlp flns y;r$Q. et al., Experimental Heat Transfer, Jul.-Sep. 1994, 7, (3), 95104300
__. ___.
A set of experiments was devised to investigate the effect of Prandtl number on the thermal performance of offset strip fins and to verify the extension of Kays and London air test data to liquids.
Equlpment for the measurement of natural-gamma 95104301 radlatlon for the analysis of ash content and the content of partlcular chemical elements In coal Alvarez Alvarez, M. C. and Dopico Vivero, M. T. Nucl. Geophys., 1994, 8, (5), 505-506. Describes a system which has been developed for natural gamma-radiation measurements of coal, for use in the determination of ash in coal washery streams.
Fuel and Energy Abstracts July 1995
301
9SlO42Q3 Certifled reference materlals for the quality control of fluorine In coal, fly ash and clay
Rai, K. N. and Rai, S. Inr. .I. .&rergy Res., Jun. 1995, 19, (4), 279-288. An approximate analytical method for solving a desublimation problem is presented. The method is based on the criterion that the total error over the domain of interest which results from introducing an approximate solution into the governing equation of a boundary-value problem must be kept to a minimum. The results thus obtained are compared with the corresponding exact solution and are in good agreement. The method has now been applied to a problem where the Luikov number is a linear function of moisture concentration. The effect of variability of Luikov number with nondimensional moisture concentration, nondimensional frozen-moisture concentration as well as the location of the moving desublimation front are shown graphically.
t$t;\;agrviller,
P.
et al.,
Fresenius’ J. Anal. Chem., 1994, 350, (3),
A group of laboratories
has worked on various intercomparisons in the frame of the BRC-programme (European Commission) to improve their methods for fluorine determination, especially for coal analysis. These exercises allowed to detect and remove sources of error. Methods were improved to such an extent that the certification of fluorine and chlorine in different materials could be envisaged and the BCR consequently decided to produce coal, fly ash and clay materials certified by their F content.
95104294
Cooling of stacks of plates shielded by porous
screens
Asphaltene association In crude oil as studied by Galtsev, V. E. er al., Fuel, May 1995, 74, (S), 670-673. Asphaltene association in crude oil in the native condition was studied using electron-nuclear double resonance (ENDOR) spectroscopy. Most of the asphaltene molecules are associated with each other in the range from room temperature up to 90°C. The core of the associate is a stack of condensed aromatic sheets of characteristic radius approximately 10A. The effect of dilution by various low-molecular-weight solvents on destruction of the associates was observed. The extent of associate destruction was not found to correlate with the solvent polarity. The outer coordination sphere of a micelle with the asphaltene associate as a core is assumed to be sufficiently labile to allow the low-molecular-weight solvents used to reach the core.
Automated maceral analysis using fluorescence microscopy and image analysis
95104288
Cloke, M. er al., Fuel, May 1995, 74, (5), 659-669. The paper describes the feasibility of using fluorescence microscopy in conjunction with normal white light microscopy and image analysis in order to carry out fully automated maceral analysis. A short review of current image systems shows a lack of success in distinguishing the liptinite speces from the resin media used to form the coal block. Fluorescent lightmg is commonly used during manual analysis and in this paper fluorescence is shown to provide a means of performing automated maceral analysis which includes an accurate determination of the liptinite content. The work presented indicates that the system can be used with a wide range of coals from around the world. A realistic assessment of repeatability and reproducibility is also made.
95104289
Automatic coal petrographic analysls by optlcal
lmaglng Celeski, J. C. et al., Rev. Metall.lCah. Inf: Tech., 1994, 91, (3), 395403. (In French) Coal petrographic analysis in support of quality control in steelmaking, is carried out by automatic image analysis using a high-resolution video camera of images from optical microscopy.
Automatic Industrial-use analyzer for water, vola95104290 tile and ash components Izumitani, S. et al., (Assigned to) Kansai Electric Power Co.; Ngk Insulators Ltd., JAP. Pat. JP. 06,288,887, Oct. 1994. The automatic industrial-use analyzer is suited for use in determination of water, volatile and ash components in coal.
95104291 Bulk fluld temperature and pipe wall temperature may be dlfferent dependlng upon the bulk fluld Lichtenstein, T. Heaf Transfer Engng., Oct.-Dec. 1994, 15, (4) 75-77. Knowing the bulk fluid temperature is often critical in the determination of the amount of emissions. When trying to determine the bulk temperature of a process stream, engineers must take care to determine whether measuring the uioe wall temoerature will eive a reasonable aooroximation of the bulk temperature. If the pipe walr temperature will’not give a reasonable approximation of the bulk fluid temperature, further calculations must be performed.
Carbon-based standards for electron paramagnetlc 95104292 resonance spectroscopy Auteri, F. P. er al., Appl. Magn. Reson., 1994, 6, (l), 287-308. To meet the need for a eood new EPR intensitv and e-value standard whose paramagnetic speciis are C-based radicals,’ several materials were studied, including coal, fusinite (a coal maceral), and several carbohydrate chars.
Bejan, A. et al., Heat & Fluid Flow, Feb. 1995, 16, (l), 16-24. The paper addresses the question of how to cool a stack of parallel, heatgenerating boards when the flow is impeded by electromagnetic screens placed upstream and downstream of the stack.
95104295
Crude oils: Characterization of waxes precipitated on cooling by d.s.c. and thermomicroscopy Letoffe. J. M. et al.. Fuel. Jun. 1995. 74. 161. 810-817. Mixtures~of 2 and 4’wt% of pure paraffins‘in’a crude oil matrix and 14 crude oils were characterized by differential scanning calorimetry (d.s.c.) and thermomicroscopy at a cooling rate of 2 K minq in the temperature range from t80 to -20°C. Pour points were also determined. In the temperature range used, a constant value of 200J kg” for the enthalpy of precipitation was determined. For crude oils which contain >lOwt% of n-paraffins, the pour point is reached when approximately 2wt% of waxes have precipitated. By thermomicroscopy, it was observed for mixtures of pure paraffins and crude oil matrix that the size of the crystals is small and depends on the length of paraffinic chains at the pour point.
95104298
Detection of high-molecular-mass materials In coal-derived liquids by Independent techniques (Letter) Herod, A. A. and Kandiyoti,
R.
Fuel, May 1995, 74, (5), 784-786.
Determination of high-i! materials In low-i! medium by X-ray scattering techniques
95104297
Arikan, P. er al., Nucl. Instrum. Methods Phys. Rex. Sect. B, 1995, 95, (l), 82:86. Discusses the quantitative determination of high-Z elements (mineral matter and ash) in low-Z medium (coal) by X-ray scattering techniques.
Determlnatlon of metallic elements In crude oll95104298 water emulslons by flame AAS
Platteau, 0. and Carrillo, M. Fuel, May 1995, 74, (S), 761-767. A method is presented for the determination of V, Ni, Fe, Mg and Na in highly stable crude oil-water emulsions of which Orimulsion, a new fuel product from the Venezuelan oil industry, is a typical example. The method is based on a dry ashing procedure for sample preparation which includes a dehydration process in the presence of ethyl alcohol, and determination of elements by flame atomic absorption spectrometry. Interference studies for major components in the matrix have been made using a factorial experimental design. Recoveries for the elements range from 95.8 to 104.3% with relative standard deviations lower than t/- 4%.
95104299
Determination of trace elements In coal ash by arc spectrographic analysls wlth halide buffer
Wang, G. et al., Guangpu Shiyanshi, 1994, 11, (3) 38-43. (In Chinese) Describes a method for determining trace elements in coal ash with improved detection limit.
Effect of fluld propertles of heat transfer In channels wlth offset strlp flns y;r$Q. et al., Experimental Heat Transfer, Jul.-Sep. 1994, 7, (3), 95104300
__. ___.
A set of experiments was devised to investigate the effect of Prandtl number on the thermal performance of offset strip fins and to verify the extension of Kays and London air test data to liquids.
Equlpment for the measurement of natural-gamma 95104301 radlatlon for the analysis of ash content and the content of partlcular chemical elements In coal Alvarez Alvarez, M. C. and Dopico Vivero, M. T. Nucl. Geophys., 1994, 8, (5), 505-506. Describes a system which has been developed for natural gamma-radiation measurements of coal, for use in the determination of ash in coal washery streams.
Fuel and Energy Abstracts July 1995
301