Determination of slag deposition rate on cooling screen reactor walls by utilisation of slag thickness measurements

Fuel ◽  
2018 ◽  
Vol 228 ◽  
pp. 369-378
Author(s):  
Sofien Mohamed Cavagnol ◽  
Karsten Covella ◽  
Matthias Müller-Hagedorn
Keyword(s):  
Deposition Rate ◽  
Slag Thickness ◽  
Thickness Measurements

The determination of the pressure—viscosity coefficient of a lubricant through an accurate film thickness formula and accurate film thickness measurements

2009 ◽  
Vol 223 (8) ◽  
pp. 1143-1163 ◽  
Author(s):  
H van Leeuwen
Keyword(s):  
Film Thickness ◽  
Viscosity Coefficient ◽  
Test Fluid ◽  
Limited Data ◽  
Ehd Lubrication ◽  
Spacer Layer ◽  
Wide Range ◽  
Approximation Formulas ◽  
Thickness Measurements

The pressure—viscosity coefficient is an indispensable property in the elastohydrodynamic (EHD) lubrication of hard contacts, but often not known. A guess will easily lead to enormous errors in the film thickness. This article describes a method to deduct this coefficient by adapting the value of the pressure—viscosity coefficient until the differences between accurate film thickness approxi-mation values and accurate film thickness measurements over a wide range of values are at a minimum. Eleven film thickness approximation formulas are compared in describing the film thickness of a test fluid with known value of the pressure—viscosity coefficient. The measurement method is based on spacer layer interferometry. It is concluded that for circular contacts the newer more versatile expressions are not better than some older approximations, which are limited to a smaller region of conditions, and that the older fits are as least as appropriate to find the pressure—viscosity coefficient of fluids, in spite of the limited data where they have been based on.

scholarly journals Determination of Physical and Mechanical Properties of Three-layer Boards of Teak (Tectona grandis), Seike (Cedrelinga catenaeformis) and Mascarey (Hieronima alchorneoides), Company PISMADE S.A., Riobamba Canton, Chimborazo Province

2021 ◽  
Author(s):  
J. Criollo Barahona ◽  
D. Román Robalino ◽  
E. Cabezas ◽  
E. Salazar Castañeda
Keyword(s):  
Mechanical Properties ◽  
Compression Test ◽  
Physical And Mechanical Properties ◽  
Tectona Grandis ◽  
Mechanical Tests ◽  
Hyeronima Alchorneoides ◽  
Commercial Use ◽  
Palabras Clave ◽  
Thickness Measurements

The present investigation aims to determine the physical and mechanical properties in three-layer boards of Teak (Tectona grandis), Seike (Cedrelinga catenaeformis) and Mascarey (Hieronima alchorneoides), from the PISMADE S.A. Company, Canton Riobamba, province of Chimborazo. The three specimens used for each of the species in each of the tests performed were worked on using the ASTM D143-94 standard for the tests of parallel compression, perpendicular compression and flexion, and the DIN-52182 standard, with the main variation in thickness measurements caused by the commercial use established by the company. Mechanical tests showed that Seike had the best results, being superior in two tests: perpendicular compression and flexion. Teak tests gave us results that were superior in the perpendicular compression test. Mascarey, unlike the two species mentioned above, had complications during the trials due to problems with the glue between layers. Keywords: physical and mechanical properties of wood, three-layer boards. Resumen La presente investigación pretende: Determinar las propiedades físicas y mecánicas en tableros tricapa de Teca, Seike (Cedrelinga catenaeformis) y Mascarey (Hyeronima alchorneoides), Empresa PISMADE S.A., cantón Riobamba, provincia de Chimborazo; para lo cual se utilizaron 3 probetas por cada una de las especies en cada uno de los ensayos realizados, las mismas fueron trabajadas con base a la Norma ASTM D143-94 para las pruebas de compresión paralela, compresión perpendicular y flexión y la Norma DIN-52182, teniendo como principal variación en las medidas de espesor debido al uso comercial establecido por la empresa. Las pruebas mecánicas mostraron que Seike tuvo los mejores resultados al ser superior en dos ensayos: Compresión perpendicular y flexión. Los ensayos con Teca nos dieron como resultados que es superior en el ensayo de compresión perpendicular. Mascarey a diferencia de las dos especies mencionadas anteriormente tuvo complicaciones con los ensayos debido a problemas con el pegamento entre capas. Palabras clave: propiedades físicas y mecánicas de la madera, tableros tricapa.

Porosity Determination of Thermal Barrier Coatings

1988 ◽  
Author(s):  
Mark Van Roode ◽  
Brad Beardsley
Keyword(s):  
Thermal Conductivity ◽  
Optical Microscopy ◽  
Thermal Barrier Coatings ◽  
Eddy Current ◽  
Water Immersion ◽  
Critical Factor ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Thickness Measurements

Coating porosity is believed to be a critical factor for the thermal conductivity of thermal barrier coatings (TBC’s). A number of different techniques have been used to determine the porosities of thermal barrier coatings for diesel applications as part of a NASA/DOE sponsored study. A comparison is made between methods based on water immersion, optical microscopy, eddy current thickness measurements, and Archimedes principle for TBC porosity determination.

Biosynthetic growth hormone increases the collagen deposition rate in rat aorta and heart

1995 ◽  
Vol 132 (2) ◽  
pp. 195-199 ◽  
Author(s):  
A Brüel ◽  
H Oxlund
Keyword(s):  
Growth Hormone ◽  
Deposition Rate ◽  
Rat Aorta ◽  
Left Ventricular ◽  
Collagen Deposition ◽  
Tissue Samples ◽  
Threefold Increase ◽  
Aortic Intima

Brüel A, Oxlund H. Biosynthetic growth hormone increases the collagen deposition rate in rat aorta and heart. Eur J Endocrinol 1995;132:195–9. ISSN 0804–4643 Disorders of the cardiovascular system often are associated with alterations in the metabolism of the collagens of these tissues. A method for in vivo determination of collagen deposition rate in small tissue samples is delineated and used for assessment of the effect of biosynthetic growth hormone (GH) injections on the collagen deposition rate in rat aorta and cardiac musculature. Rats were injected with GH, and the controls with saline, twice daily for 7 days. The in vivo collagen deposition rate was measured by injecting iv a large dose of [3H]-proline with a flooding dose of "cold" proline, followed by determination of the production of [3H]-hydroxyproline during a 4-h labelling period. Extractable collagens that were not bound in the tissue and therefore do not contribute mechanical strength to it were removed from the samples. 3H-Labelled- and "cold" amino acids were assessed by reversed-phase HPLC combined with simultaneous flow scintillation detection on the same sample. In the control group the deposition per hour was 0.13 ± 0.02% (mean ± sem) in aortic intima media and 0.72 ± 0.09% in cardiac left ventricular musculature. Growth hormone induced a threefold increase (p < 0.001 and p < 0.01, respectively) in the collagen deposition rate: 0.45 ± 0.06% in aortic intima media and 2.43 ± 0.45% in cardiac left ventricular musculature. The method described enables a rapid and sensitive determination of collagen deposition per hour in small tissue samples from experimental animals. The collagen deposition rate of cardiac musculature is fivefold higher compared with that of aortic intima media. Biosynthetic GH induces a threefold increase in the collagen deposition rate of these tissues. Hans Oxlund, Department of Connective Tissue Biology, Institute of Anatomy, University of Aarhus, DK-8000 Aarhus C, Denmark

scholarly journals Determination of the Rate of Snow Accumulation at the Pole of Relative Inaccessibility, Eastern Antarctica: A Comparison of Glaciological and Isotopic Methods

1968 ◽  
Vol 7 (50) ◽  
pp. 273-287 ◽  
Author(s):  
E. Picciotto ◽  
R. Cameron ◽  
G. Crozaz ◽  
S. Deutsch ◽  
S. Wiloain
Keyword(s):  
Accumulation Rate ◽  
Snow Accumulation ◽  
List Type ◽  
Maximum Value ◽  
Isotopic Methods ◽  
Isotope Profile ◽  
Order Of Magnitude ◽  
Thickness Measurements ◽  
Snow Thickness

The rate of snow accumulation has been measured at the U.S.S.R. station situated at the Pole of Relative Inaccessibility (eastern Antarctic plateau). Five independent methods were used. The results, expressed in g cm−2 year−1, are as follows: (1)Accumulation-stake measurements show an accumulation of 3·1±0·5 in 1965. A maximum value of 3·6 for the 6–year interval 1959–65 is derived from snow-thickness measurements.(2)Firn stratigraphy was found difficult to interpret in terms of annual layers. An upper limit of 12 g cm−2 year−1 is suggested.(3)18O/16O ratios were measured along the upper 235 cm. Assuming that each maximum in the isotope profile corresponds to a summer season, the accumulation would be 8·6±0·9.(4)Gross β radioactivity as a function of depth was measured on three firn sections. The 1955 radioactive fall-out horizon is clearly marked, enabling the derivation of an average accumulation of 3·0±0·3.(5)The average accumulation over the last 80 years, derived from the 210Pb distribution with depth, is 3·1±0·3.A multi-annual average accumulation rate of (3·0±0·3) is thus firmly established, as well as the validity of both the 210Pb method and the 1955 radioactive fall-out horizon method. Stratigraphie studies lead to uncertain results. Oxygen isotope variations give accumulation values which are too high by a factor of two at least.Accumulation values of the same order of magnitude (2·8±0·2) were derived from radioactive fall-out measurements at the U.S. “Plateau” station.

scholarly journals Bioinspired Low-Frequency Material Characterisation

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
C. Hopper ◽  
S. Assous ◽  
P. B. Wilkinson ◽  
D. A. Gunn ◽  
P. D. Jackson ◽  
...  
Keyword(s):  
Sound Velocity ◽  
Medical Physics ◽  
Low Frequency ◽  
High Sensitivity ◽  
Prediction Errors ◽  
Low Frequencies ◽  
Longitudinal Sound Velocity ◽  
Velocity Prediction ◽  
Thickness Measurements

New-coded signals, transmitted by high-sensitivity broadband transducers in the 40–200 kHz range, allow subwavelength material discrimination and thickness determination of polypropylene, polyvinylchloride, and brass samples. Frequency domain spectra enable simultaneous measurement of material properties including longitudinal sound velocity and the attenuation constant as well as thickness measurements. Laboratory test measurements agree well with model results, with sound velocity prediction errors of less than 1%, and thickness discrimination of at least wavelength/15. The resolution of these measurements has only been matched in the past through methods that utilise higher frequencies. The ability to obtain the same resolution using low frequencies has many advantages, particularly when dealing with highly attenuating materials. This approach differs significantly from past biomimetic approaches where actual or simulated animal signals have been used and consequently has the potential for application in a range of fields where both improved penetration and high resolution are required, such as nondestructive testing and evaluation, geophysics, and medical physics.

Determination of the Compressive Material Properties of the Supraspinatus Tendon

2000 ◽  
Vol 123 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Mark E. Zobitz ◽  
Zong-Ping Luo ◽  
Kai-Nan An
Keyword(s):  
Material Properties ◽  
Three Dimensional ◽  
Supraspinatus Tendon ◽  
Hyperelastic Material ◽  
Compressive Properties ◽  
Energy Potential ◽  
The Matrix ◽  
Three Dimensional Models ◽  
Thickness Measurements

A methodology was developed for determining the compressive properties of the supraspinatus tendon, based on finite element principles. Simplified three-dimensional models were created based on anatomical thickness measurements of unloaded supraspinatus tendons over 15 points. The tendon material was characterized as a composite structure of longitudinally arranged collagen fibers within an extrafibrillar matrix. The matrix was formulated as a hyperelastic material described by the Ogden form of the strain energy potential. The hyperelastic material parameters were parametrically manipulated until the analytical load-displacement results were similar to the results obtained from indentation testing. In the geometrically averaged tendon, the average ratio of experimental to theoretical maximum indentation displacement was 1.00 (SD: 0.01). The average normalization of residuals was 2.1g (SD: 0.9g). Therefore, the compressive material properties of the supraspinatus tendon extrafibrillar matrix were adequately derived with a first-order hyperelastic formulation. The initial compressive elastic modulus ranged from 0.024 to 0.090 MPa over the tendon surface and increased nonlinearly with additional compression. Using these material properties, the stresses induced during acromional impingement can be analyzed.

Sign in / Sign up

Export Citation Format

Share Document