scholarly journals Improved method based on dual-energy X-ray absorptiometry for nondestructive evaluation of solid wood moisture content

Holzforschung ◽  
2015 ◽  
Vol 69 (9) ◽  
pp. 1133-1136 ◽  
Author(s):  
Takashi Tanaka
Keyword(s):  
Moisture Content ◽  
Pure Water ◽  
Solid Wood ◽  
Dual Energy ◽  
Wood Moisture ◽  
Strong Negative Correlation ◽  
X Ray ◽  
Wide Range ◽  
Better Than

Abstract An accurate, rapid, and convenient method is presented for moisture content (MC) determination of solid wood based on dual-energy X-ray absorptiometry (DXA). Poly(methyl methacrylate)-equivalent thicknesses (PMMA-EThs) of sugi (Cryptomeria japonica D. Don) wood blocks and pure water were measured by means of a wide range of X-ray tube voltages (20–100 kV). The ratio of the PMMA-ETh of pure water to that of wood decreased as X-ray tube voltage was increased, suggesting that an appropriate pair of tube voltages for DXA is 20 and 100 kV. According to this result, X-ray images of 30 wood samples were taken at 20- and 100-kV tube voltages, and their average PMMA-Eths from both images was determined. There was a strong negative correlation between the wet-basis MC of the wood sample and the ratio of its PMMA-Eth at 100 kV to that at 20 kV. A regression equation was developed for estimating the dry-basis MC of wood samples from their PMMA-ETh ratios. The standard error of estimate was 2.2%, which is better than those determined for electric moisture meters. This approach may lead to the development of a practical, nondestructive moisture meter for wood.

Dual-Energy X-Ray Absorptiometry Analysis for the Determination of Moisture Content in Biomass

2010 ◽  
Vol 4 (4) ◽  
pp. 363-366 ◽  
Author(s):  
R. Kullenberg ◽  
M. Hultnäs ◽  
V. Fernandez ◽  
M. Nylinder ◽  
S. Toft ◽  
...  
Keyword(s):  
Moisture Content ◽  
Dual Energy ◽  
X Ray

scholarly journals Improving the accuracy of wood moisture content estimation in four European softwoods from Spain

2021 ◽  
Vol 30 (1) ◽  
pp. e002
Author(s):  
Juan I. Fernández-Golfín ◽  
Maria Conde Garcia ◽  
Marta Conde Garcia
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Electrical Resistance ◽  
Solid Wood ◽  
Wood Products ◽  
Wood Moisture Content ◽  
Accurate Estimation ◽  
Wood Moisture ◽  
Mathematical Functions ◽  
Measured Moisture Content

Aim of study: To obtain improved models to predict, with an error of less than ± 2.0%, the gravimetric moisture content in four different softwoods commonly present in the Spanish and European markets, based on electrical resistance measurements. This improved moisture content estimation is useful not only for assessing the quality of wood products, especially in the case of laminated products, during the transformation and delivery process, but also for accurately monitoring the evolution of moisture in wood present in bridges and buildings, which is of great importance for its maintenance and service life improvement.Area of study: The study was carried out on samples of Scots, laricio, radiata and  maritime pines of Spanish provenances.Material and methods: On 50x50x20 mm3 solid wood samples (36 per species, 9 per condition), conditioned at 20ºC (±05ºC) and 40±5%, 65±5%, 80±5% or 90±5% Relative Humidity (RH), electrical resistance and oven-dry moisture content was measured. The Samuelsson's model was fitted to data to explain the relationship between the two variables. The accuracy of the model was evaluated by the use of an external sample.Main results: With the proposed mathematical functions the wood moisture content can be estimated with an error of ±0.9% in the four species, confirming the effectiveness of this nondestructive methodology for accurate estimation and monitoring of moisture content.Research highlights: our results allow the improvement of the moisture content estimation technique by resistance-type methodologies.Keywords: Resistance-type moisture meter; species correction.Abbreviations used: MC: Moisture content; RH: relative Humidity; R: electrical resistance; RP: wood electrical resistance measured parallel to the grain; RT: electrical resistance measured perpendicular (transversally) to the grain; GM-MC: gravimetrically measured moisture content.

scholarly journals Graphitic Nitrogen in Carbon Catalysts Important for the Reduction of Nitrite Revealed by 15N NMR Spectroscopy at Natural Abundance

2020 ◽  
Author(s):  
Zheng Chen ◽  
Aleksander Jaworski ◽  
Jianhong Chen ◽  
Tetyana Budnyak ◽  
Ireneusz Szewczyk ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Reduction Reaction ◽  
Nitrite Reduction ◽  
15N Nmr ◽  
Carbon Catalyst ◽  
X Ray ◽  
Wide Range ◽  
Alkaline Conditions

Metal-free nitrogen-doped carbon is considered as a green functional material, but the structural determination of the atomic positions of nitrogen remains challenging. We recently demonstrated that directly-excited solid state <sup>15</sup>N NMR (ssNMR) spectroscopy is a powerful tool for the determination of such positions in an N-doped carbon at natural <sup>15</sup>N isotope abundance. Here we present a green chemistry approach to the synthesis of N-doped carbon using cellulose as precursor, and a study of the catalytic properties and atomic structures of the related catalyst. The N-doped carbon (NH<sub>3</sub>) was obtained by oxidation of cellulose with HNO<sub>3</sub> followed by ammonolysis at 800°C. It had a N content of 6.5 wt.% and a surface area of 557 m<sup>2 </sup>g<sup>–1</sup>, and <sup>15</sup>N ssNMR spectroscopy provided evidence for graphitic nitrogen besides of regular pyrrolic and pyridinic nitrogen. This structure determination enabled probing the role of graphitic nitrogen for electrocatalytic reactions, such as the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and nitrite reduction reaction. The N-doped carbon catalyst (NH<sub>3</sub>) had higher electrocatalytic activities in OER and HER under alkaline conditions and a higher activity for nitrite reduction, as compared with a catalyst prepared by carbonization of the HNO<sub>3</sub>-treated cellulose in N<sub>2</sub>. The electrocatalytic selectivity for nitrite reduction of the N-doped carbon catalyst (NH<sub>3</sub>) was directly related to the graphitic nitrogen functions. Complementary structural analysis by means of <sup>13</sup>C and <sup>1</sup>H ssNMR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and low-temperature N<sub>2 </sub>adsorption were preformed and provided support to the findings. The results show that directly-excited <sup>15</sup>N ssNMR at natural <sup>15</sup>N abundance is generally capable to provide information on N-doped carbon materials, and it is expected that the approach can be applied to a wide range of solids with an intermediate amount of N atoms.

The petrology of the Mount Padbury mesosiderite and its achondrite enclaves

1966 ◽  
Vol 36 (276) ◽  
pp. 1029-1060 ◽  
Author(s):  
G. J. H. McCall
Keyword(s):  
Microscopic Analysis ◽  
Host Material ◽  
Refractive Indices ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
X Ray ◽  
Wide Range ◽  
Varied Range ◽  
Optical Determination

SummaryThe petrography of the Mount Padbury meteorite, previously briefly recorded, is described in some detail. Both the metalliferous host material of the mesosiderite and the varied range of silicate-rich, virtually metal-free enclaves (including both familiar achondrite material and unfamiliar achondrite material) are described. Eucrite, brecciated eucrite, and a peculiar ‘shocked’ form of eucrite (resembling some terrestrial flaser-gabbros) are the calcium-rich achondrite types represented; hypersthene achondrite (including typical diogenite material and unfamiliar material) and olivine achondrite (granular aggregates of olivine not entirely similar to the unique chassignite and single crystals up to 4 in. in length) are the calcium-poor achondrite types represented. The eucrite displays more or less uniform mineralogy, but the mineral constituents are present in varying proportions, and there is a wide range of textural variations recognized. The silicate grain fragments enclosed in the metallic reticulation to form the mesosiderite host material are, significantly, entirely of minerals seen within the achondrite enclaves—plagioclase, hypersthene, pigeonite, olivine, and tridymite.These results include microscopic analysis of thin sections and polished sections, X-ray diffraction studies, optical determination of refractive indices using mineral grain mounts, and chemical analyses.The wider implications of this new and unique meteorite find are briefly considered.

Dual-energy X-ray absorptiometry with digital radiograph for evaluating moisture content of green wood

2015 ◽  
Vol 49 (4) ◽  
pp. 713-723 ◽  
Author(s):  
Chul-Ki Kim ◽  
Jung-Kwon Oh ◽  
Jung-Pyo Hong ◽  
Jun-Jae Lee
Keyword(s):  
Moisture Content ◽  
Dual Energy ◽  
Green Wood ◽  
X Ray ◽  
Digital Radiograph
Sign in / Sign up

Export Citation Format

Share Document