scholarly journals Using X-ray CT Scanned Reconstructed Logs to Predict Knot Characteristics and Tree Value

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 720
Author(s):  
Airu Ji ◽  
Julie Cool ◽  
Isabelle Duchesne
Keyword(s):  
Wood Quality ◽  
Three Dimensional ◽  
Volume Ratio ◽  
Stand Density ◽  
Growth Conditions ◽  
Western Hemlock ◽  
Ct Scanner ◽  
Volume Number ◽  
X Ray ◽  
The Impact

Research Highlights: Stand density was connected with wood quality and lumber production to develop a predictive model to better estimate tree value. Background and Objectives: The available standing wood volume in British Columbia (BC), Canada has consistently decreased since 1990. Better understanding the link between stand growth conditions, knot characteristics, the sawmilling process and product quality is essential in making informed forest management decisions and efficiently utilizing wood. The overall objective was to investigate and predict the impact of tree growth as affected by stand density on knot characteristics, lumber volume and value recoveries for two conifer species, two types of sawmills and three economic scenarios. Materials and Methods: Seventy-two amabilis fir and western hemlock trees were harvested from three stands located on Vancouver Island, BC. Sawlogs were scanned using an X-ray computed tomography (CT) scanner and images were processed to extract knot characteristics and reconstruct three-dimensional (3D) log models. The effects of three diameter at breast height (DBH) classes (30, 40 and 50 cm) and three stand densities on knot characteristics, including knot volume, number of knots, average knot area and knot/tree volume ratio, as well as the simulated lumber volume and value recoveries from two types of sawmills (i.e., Coastal and Interior) under three economic scenarios (i.e., baseline, optimistic, and pessimistic) were investigated. Results: As expected, the knot characteristics of both species increased with the DBH. The difference of knot distribution between amabilis fir and western hemlock suggests that the latter is more sensitive to growth site conditions. The sawmilling simulations revealed that the Coastal mill produced a lower lumber volume due to the type of products manufactured and the primary breakdown patterns being used. Conclusions: The developed linear mixed effects models based on the knot characteristics and tree features could predict the value of a standing tree and can be used for estimating preharvest stand value of similar Coastal Hem-Fir forests.

Analyzing the Impact of X-Ray Tomography on the Reliability of Integrated Circuits

2015 ◽  
Author(s):  
Halit Dogan ◽  
Md Mahbub Alam ◽  
Navid Asadizanjani ◽  
Sina Shahbazmohamadi ◽  
Domenic Forte ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
3D Imaging ◽  
Three Dimensional ◽  
Serial Sectioning ◽  
Promising Technique ◽  
Flash Memories ◽  
X Ray ◽  
3D Information ◽  
The Impact

Abstract X-ray tomography is a promising technique that can provide micron level, internal structure, and three dimensional (3D) information of an integrated circuit (IC) component without the need for serial sectioning or decapsulation. This is especially useful for counterfeit IC detection as demonstrated by recent work. Although the components remain physically intact during tomography, the effect of radiation on the electrical functionality is not yet fully investigated. In this paper we analyze the impact of X-ray tomography on the reliability of ICs with different fabrication technologies. We perform a 3D imaging using an advanced X-ray machine on Intel flash memories, Macronix flash memories, Xilinx Spartan 3 and Spartan 6 FPGAs. Electrical functionalities are then tested in a systematic procedure after each round of tomography to estimate the impact of X-ray on Flash erase time, read margin, and program operation, and the frequencies of ring oscillators in the FPGAs. A major finding is that erase times for flash memories of older technology are significantly degraded when exposed to tomography, eventually resulting in failure. However, the flash and Xilinx FPGAs of newer technologies seem less sensitive to tomography, as only minor degradations are observed. Further, we did not identify permanent failures for any chips in the time needed to perform tomography for counterfeit detection (approximately 2 hours).

Influences of spacing on radial growth and percentage latewood of Douglas-fir, western hemlock, and western redcedar

1980 ◽  
Vol 10 (2) ◽  
pp. 169-175 ◽  
Author(s):  
J. Harry G. Smith
Keyword(s):  
Wood Quality ◽  
Ring Width ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Western Redcedar ◽  
X Ray ◽  
Good Site ◽  
Binocular Microscope ◽  
Reduced Costs ◽  
Ray Methods

Growth in ring width and percentage latewood on a very good site is described for 21-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), 20-year-old western hemlock (Tsugaheterophylla (Raf.) Sarg.), and western redcedar (Thujaplicata Donn) planted at five spacings (0.91 to 4.57 m). Cores extracted at breast height are used to show the effects of spacing through growth rate and crown development, and of age through number of rings from pith for the years 1965 to 1976. Percentages of latewood measured by binocular microscope are compared with results obtainable by X-ray methods for analysis of ring widths and densities. Influences of spacing on wood quality are discussed. It is concluded that wide initial spacings increase ring width and decrease percentage latewood significantly, but the reduced costs and increased sizes at wide spacings provide more than adequate compensation for the moderate reduction in wood quality.

Analysis of Bubbles in a Three-Dimensional Fluidized Catalyst Bed Using a Fast X-ray CT Scanner.

2003 ◽  
Vol 29 (1) ◽  
pp. 112-117 ◽  
Author(s):  
Tatsuji Kanda ◽  
Takami Kai ◽  
Takeshige Takahashi ◽  
Masaki Misawa ◽  
Naoki Ichikawa ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Ct Scanner ◽  
X Ray ◽  
Fluidized Catalyst Bed

scholarly journals The impact of accumulation rate on anisotropy and air permeability of polar firn at a high-accumulation site

2009 ◽  
Vol 55 (192) ◽  
pp. 625-630 ◽  
Author(s):  
Maria W. Hörhold ◽  
Mary R. Albert ◽  
Johannes Freitag
Keyword(s):  
Accumulation Rate ◽  
Three Dimensional ◽  
Air Permeability ◽  
West Antarctica ◽  
Short Term ◽  
Snow Layer ◽  
High Accumulation ◽  
X Ray ◽  
Degree Of Anisotropy ◽  
The Impact

AbstractThe first three-dimensional properties of polar firn obtained by X-ray microtomography are used to study the microstructure of snow on a 15 m deep firn core from West Antarctica. The snow is found to undergo coarsening down to approximately 2.5 m depth before grain growth and densification become the prevalent mechanisms of microstructure change. In contrast to previous assumptions, distinct anisotropy of the ice and pore geometry is observed throughout the profile, with a maximum at 2.5 m depth. The air permeability and the degree of anisotropy vary with depth and can be linked to short-term changes in accumulation rate via the residence time for which a certain snow layer stays in the uppermost 2.5 m. Patterns of the degree of anisotropy and air permeability of buried polar firn are relative indicators of past accumulation rates.

Dry Effect of Cementitious Materials on Testing Results of X-Ray CT

2012 ◽  
Vol 450-451 ◽  
pp. 187-192 ◽  
Author(s):  
Jian De Han ◽  
Wei Sun ◽  
Gang Hua Pan
Keyword(s):  
Cement Paste ◽  
Three Dimensional ◽  
Cementitious Materials ◽  
Drying Process ◽  
X Ray ◽  
Before And After ◽  
X Ray Computed ◽  
The Mean ◽  
The Impact ◽  
Gray Values

In this study three-dimensional X-ray computed tomography (X-ray CT) is used to investigate the testing results differences of cement paste and mortar before and after drying. It can be found that the mean gray values of paste and mortar before drying are bigger than after drying, and the impact of drying on cement paste is more serious than mortar. In addition, the porosity of non-drying cement paste and mortar is 1.10% and 0.43%, while that of drying cement paste and mortar is 1.55% and 0.70%, respectively. So, the porosity of paste and mortar markedly increases after drying process. The numbers of pores of paste and mortar sharply increase after drying process in particular between 0.01mm3 and 0.1mm3. The impact of drying on smaller pores is more serious than bigger pores.

scholarly journals X-ray Computed Tomography Method for Macroscopic Structural Property Evaluation of Active Twist Composite Blades

Aerospace ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 370
Author(s):  
Joon H. Ahn ◽  
Hyun J. Hwang ◽  
Sehoon Chang ◽  
Sung Nam Jung ◽  
Steffen Kalow ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Structural Properties ◽  
Digital Image ◽  
Torsional Rigidity ◽  
Three Dimensional ◽  
Measured Data ◽  
X Ray ◽  
X Ray Computed ◽  
Active Twist ◽  
The Impact

This paper describes an evaluation of the structural properties of the next-generation active twist blade using X-ray computed tomography (CT) combined with digital image processing. This non-destructive testing technique avoids the costly demolition of the blade structure. The CT scan covers the whole blade region, including the root, transition, and tip regions, as well as the airfoil blade regions, in which there are spanwise variations in the interior structural layout due to the existence of heavy instrumentation. The three-dimensional digital image data are processed at selected radial stations, and finite element beam cross-section analyses are conducted to evaluate the structural properties of the blade at the macroscopic level. The fidelity of the digital blade model is first assessed by correlating the estimated blade mass with the measured data. A separate mechanical measurement is then carried out to determine the representative elastic properties of the blade and to verify the predicted results. The agreement is found to be good to excellent for the mass, elastic axis, flap bending, and torsional rigidity. The discrepancies are less than 2.0% for the mass and elastic axis locations, and about 8.1% for the blade stiffness properties, as compared with the measured data. Finally, a sensitivity analysis is conducted to clarify the impact of modeling the sensor and actuator cables, nose weight, and manufacturing imperfections on the structural properties of the blade.

scholarly journals Impact of real mirror profiles inside a split-and-delay unit on the spatial intensity profile in pump/probe experiments at the European XFEL

2021 ◽  
Vol 28 (1) ◽  
pp. 350-361
Author(s):  
V. Kärcher ◽  
S. Roling ◽  
L. Samoylova ◽  
A. Buzmakov ◽  
U. Zastrau ◽  
...  
Keyword(s):  
Three Dimensional ◽  
High Energy ◽  
Coherence Time ◽  
High Energy Density ◽  
Fast Fourier Transformation ◽  
Pump Probe ◽  
X Ray ◽  
Delay Unit ◽  
Optical Layout ◽  
The Impact

For the High-Energy-Density (HED) beamline at the SASE2 undulator of the European XFEL, a hard X-ray split-and-delay unit (SDU) has been built enabling time-resolved pump/probe experiments with photon energies between 5 keV and 24 keV. The optical layout of the SDU is based on geometrical wavefront splitting and multilayer Bragg mirrors. Maximum delays between Δτ = ±1 ps at 24 keV and Δτ = ±23 ps at 5 keV will be possible. Time-dependent wavefront propagation simulations were performed by means of the Synchrotron Radiation Workshop (SRW) software in order to investigate the impact of the optical layout, including diffraction on the beam splitter and recombiner edges and the three-dimensional topography of all eight mirrors, on the spatio-temporal properties of the XFEL pulses. The radiation is generated from noise by the code FAST which simulates the self-amplified spontaneous emission (SASE) process. A fast Fourier transformation evaluation of the disturbed interference pattern yields for ideal mirror surfaces a coherence time of τc = 0.23 fs and deduces one of τc = 0.21 fs for the real mirrors, thus with an error of Δτ = 0.02 fs which is smaller than the deviation resulting from shot-to-shot fluctuations of SASE2 pulses. The wavefronts are focused by means of compound refractive lenses in order to achieve fluences of a few hundred mJ mm−2 within a spot width of 20 µm (FWHM) diameter. Coherence effects and optics imperfections increase the peak intensity between 200 and 400% for pulse delays within the coherence time. Additionally, the influence of two off-set mirrors in the HED beamline are discussed. Further, we show the fluence distribution for Δz = ±3 mm around the focal spot along the optical axis. The simulations show that the topographies of the mirrors of the SDU are good enough to support X-ray pump/X-ray probe experiments.

Three-dimensional study of poly(lactic co-glycolic acid) micro-porous microspheres using hard X-ray nano-tomography

2014 ◽  
Vol 21 (5) ◽  
pp. 1175-1179 ◽  
Author(s):  
Dajiang Wang ◽  
Na Li ◽  
Zhili Wang ◽  
Kun Gao ◽  
Yongming Zhang ◽  
...  
Keyword(s):  
Glycolic Acid ◽  
Three Dimensional ◽  
Volume Ratio ◽  
Biologically Active ◽  
Plga Microspheres ◽  
Full Field ◽  
X Ray ◽  
Shape Distribution ◽  
Porous Microspheres ◽  
Microstructural Parameters

Poly(lactic co-glycolic acid) (PLGA) is widely used in diverse fields, especially in delivering biologically active proteins and drugs. For these applications, the knowledge of morphology and microstructure of PLGA micro-porous microspheres is of great importance since they strongly influence the drug delivering efficiency. In this study, micro-porous PLGA microspheres loaded by bovine serum albumin are investigated by using a full-field Zernike phase contrast transmission hard X-ray microscope. From three-dimensional reconstructions and segmentations, fundamental microstructural parameters such as size, shape, distribution and volume ratio among pores and proteins inside PLGA microspheres were obtained. These parameters are useful to understand the relationship between the internal microstructure and drug encapsulation, as well as the drug release efficiency of PLGA microspheres. The presented results demonstrate the capability of hard X-ray nano-tomography to characterize porous microspheres loaded with proteins and drugs, and also open a way to analyse, optimize and design new PLGA microspheres for specific applications.

A Three-Dimensional Consideration of Variant Human Fibrinogens

1998 ◽  
Vol 80 (07) ◽  
pp. 1-9 ◽  
Author(s):  
Stephen Everse ◽  
Glen Spraggon ◽  
Russell Doolittle
Keyword(s):  
Amino Acid ◽  
Genetic Variants ◽  
Three Dimensional ◽  
Large Core ◽  
Human Fibrinogen ◽  
X Ray ◽  
Small Deletion ◽  
Dimensional Consideration ◽  
The Impact ◽  
Large Insertion

SummaryRecently reported X-ray structures for large core fragments derived from human fibrinogen and fibrin make it possible to correlate structural and functional anomalies of known genetic variants. Here we examine a variety of amino acid replacements previously reported for hereditary dysfibrinogenemias, most of which are associated with impaired fibrin polymerization. For many of these we have modeled in the mutant amino acid and considered the structural consequences. We have also examined the cases of a small deletion and a large insertion, as well as the impact of substitutions in the GPRPam ligand that was co-crystallized with fragment double-D.

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