Densité et largeur des cernes des populations d'Épinettes blanches de la région forestière des Grands Lacs et du Saint-Laurent

1990 ◽  
Vol 20 (2) ◽  
pp. 121-129 ◽  
Author(s):  
A. Corriveau ◽  
J. Beaulieu ◽  
F. Mothe ◽  
J. Poliquin ◽  
J. Doucet
Keyword(s):  
Relative Density ◽  
Population Level ◽  
White Spruce ◽  
Growth Rings ◽  
X Ray ◽  
Forest Region ◽  
Annual Growth Rings ◽  
Density Analysis ◽  
The Individual

Twenty years after planting, X-ray densitometry and immersion were used to determine the relative density of wood from 28 white spruce populations of the Great Lakes – St. Lawrence forest region. The results showed the same pattern of radial variation in all populations. Wood density decreases for the first few years of growth, then stabilizes for a time, then increases slowly, but steadily. The relative density of wood from white spruce has a slight, negative correlation with the width of the annual growth rings, at either the individual or the population level. However, some populations and individuals do deviate from this trend. Though the populations showed some statistically significant differences in relative density, analysis of variance showed that 85 to 90% was attributable to differences among trees within the same population. This study confirmed the desirability of using relative density as the basis for making mass selections within fast-growing white spruce populations to genetically improve the genetic quality of wood.

Wood density of natural white spruce populations in Quebec

1987 ◽  
Vol 17 (7) ◽  
pp. 675-682 ◽  
Author(s):  
A. Corriveau ◽  
J. Beaulieu ◽  
F. Mothe
Keyword(s):  
Wood Density ◽  
Rapid Growth ◽  
Juvenile Wood ◽  
White Spruce ◽  
Density Variation ◽  
Mature Wood ◽  
Growth Rings ◽  
Breeding Programs ◽  
Genetic Sampling ◽  
The Individual

During genetic sampling of white spruce in 1984, increment cores were taken from 80 populations in order to study wood density variation within species in natural Quebec forests. Results show that wood density differences exist between populations and that wood density is negatively correlated with the width of the growth rings; however, some trees and some populations exhibit both high wood density and rapid growth. A moderate positive link was found between juvenile and mature wood densities at both the individual and population levels. Therefore, breeding programs for the improvement of wood density could be based on selections made on juvenile wood.

Solar Signals in Surface Climate

2015 ◽  
Author(s):  
Joanna D. Haigh ◽  
Peter Cargill
Keyword(s):  
Climate Change ◽  
The Sun ◽  
Climate Data ◽  
Growth Rings ◽  
Surface Climate ◽  
Annual Growth Rings ◽  
Weather And Climate ◽  
Long Time ◽  
Established Technique

This chapter looks at how the Sun varies in terms of its emissions of radiation and particles and how these changes might be associated with variations in weather and climate on Earth. Investigations of climate variability and climate change depend crucially on the existence, length, and quality of meteorological records. Ideally, records would consist of long time series of measurements made by well-calibrated instruments densely situated across the globe. For longer periods, and in remote regions, records have to be reconstructed from indirect indicators of climate known as proxy data. The chapter introduces one well-established technique for providing proxy climate data: dendrochronology, or the study of the successive annual growth rings of trees.

Setting quality improvement priorities for women receiving systemic therapy (ST) for early stage breast cancer (EBC) using population level administrative data.

2016 ◽  
Vol 34 (7_suppl) ◽  
pp. 299-299
Author(s):  
Katherine Enright ◽  
Lingsong Yun ◽  
Alejandro Gonzalez ◽  
Melanie Powis ◽  
Nathan Taback ◽  
...  
Keyword(s):  
Quality Improvement ◽  
Administrative Data ◽  
Early Stage ◽  
Population Level ◽  
Secondary Prophylaxis ◽  
Absolute Difference ◽  
Ontario Cancer Registry ◽  
Institutional Variation ◽  
The Individual

299 Background: Routine evaluation of evidence informed quality measures (QM) can drive improvement in cancer systems by highlighting potential gaps in care. Targeting quality improvement at QMs that demonstrate substantial variation has the potential to make the largest impact on quality at a population level. We aimed to use variation in performance to set priorities for improving the quality of ST for women with EBC. Methods: EBC cases diagnosed 2006 – 2010 in Ontario, Canada were identified in the Ontario Cancer Registry and linked deterministically to multiple health care databases. A panel of QMs, previously developed to be operationalized for administrative data, was applied to reflect the quality of ST. Each QM was evaluated in all patients who met the inclusion criteria for the individual measure. QMs were ranked based on institutional variation in performance using the mean absolute difference (MAD). Results: We identified 28,303 patients, treated at 84 institutions. The performance of each QM is listed in Table 1. Timely receipt of ST, febrile neutropenia (FN) secondary prophylaxis, emergency room visits or hospitalizations, receipt of hormonal therapy (HT) and the use of surveillance imaging represented the 5 QM that demonstrated the greatest variation. Conclusions: Considerable institutional-level variation highlights potentially actionable areas of improvement [Table: see text]

An Examination of the Crystalline Quality of 200mm Diameter Silicon Substrates using X-ray Topography

1997 ◽  
Vol 469 ◽  
Author(s):  
J. Curley ◽  
P. J. McNally ◽  
A. Reader ◽  
T. Tuomi ◽  
M. Taskinen ◽  
...  
Keyword(s):  
Quality Control ◽  
Manufacturing Industry ◽  
Cmos Technology ◽  
Critical Dimensions ◽  
X Ray ◽  
Substrate Quality ◽  
Ic Manufacturing ◽  
The Individual ◽  
Oxygen Precipitates

ABSTRACTThe continued decrease in critical dimensions and increasing integration levels in Si CMOS technology is imposing ever tighter constraints on quality control parameters for the IC manufacturing industry. One very important issue is the need to ensure a uniform, high quality Si substrate, i.e. minimise defect/dislocation densities and eliminate strain distributions in the starting wafer material. A comprehensive Synchrotron X-Ray Topography (SXRT) study was applied to commercially supplied 200mm diameter Si wafers. These wafers, which all included a surface Si epilayer growth were supplied from manufacturers from around the globe. The study revealed not only differences in the overall quality of the wafers, but also differences in the quality of the individual Silicon epilayers and substrates. In all wafers the substrate quality varied dramatically with position across the wafer, as measured by the distribution of oxygen precipitates and stacking faults in the wafer. This distribution also varied significantly from manufacturer to manufacturer. The strain fields induced by the growth of lightly doped Si epilayers were also observed to qualitatively vary with location on a wafer, together with (as expected) thickness of the epilayers. The results clearly indicate that optimal quality control for such commercial wafers has not yet been achieved.

A PROCEDURE BASED ON CONDITIONAL PROBABILITIES TO ESTIMATE PROPORTIONS AND DENSITIES OF TISSUES FROM X-RAY IMAGES OF QUERCUS PETRAEA SAMPLES

IAWA Journal ◽  
2002 ◽  
Vol 23 (3) ◽  
pp. 235-252 ◽  
Author(s):  
Edith Guilley ◽  
Frédéric Mothe ◽  
Gérard Nepveu
Keyword(s):  
Quercus Petraea ◽  
Tissue Type ◽  
Accurate Estimation ◽  
Conditional Probabilities ◽  
Growth Rings ◽  
Axial Parenchyma ◽  
X Ray ◽  
Density Maps ◽  
Annual Growth Rings ◽  
Earlywood Vessels

This paper describes a procedure to estimate within-ring proportions and densities of earlywood vessels, fibres and parenchyma, and then validates the procedure for each tissue type. The procedure uses conditional probabilities for these estimates. It was developed using 16 annual growth rings of contrasting anatomy sampled from five mature sessile oaks (Quercus petraea Liebl.). The X-ray images of the sampled rings were converted into density maps and the two components of the rings (i.e. earlywood and latewood) were delimited manually. First, mean tissue densities of individual rings were estimated from anatomical characteristics combined with a simple analysis of the frequency histograms of density in earlywood and latewood. Second, the procedure used the radial position and density of each point of a digitised ring to calculate a probability for a point belonging to either vessels, multiseriate wood rays, fibres or axial parenchyma. The procedure was evaluated using i) measurements of tissue proportions from anatomical sections and ii) measurements of tissue densities performed on X-ray images. The validation demonstrates that the procedure provides an accurate estimation of the proportion and density of earlywood vessels, fibres and axial parenchyma in earlywood and latewood. However, it also demonstrates that the procedure is not sufficiently effective to estimate the proportion of multiseriate wood rays.

X-Ray Microtomograph Detection of Internal Defects for a UD Prepreg Composite

2015 ◽  
Vol 818 ◽  
pp. 295-298
Author(s):  
Michal Petrů ◽  
Martina Syrovátková ◽  
Marcela Kolínová ◽  
Ondra Novák
Keyword(s):  
Composite Structures ◽  
Current Trend ◽  
Matrix Analysis ◽  
Carbon Fibres ◽  
Internal Defects ◽  
X Ray ◽  
The Individual ◽  
Material Composite ◽  
Fibre Matrix

The current trend particularly in industrial and commercial sectors is to search for alternatives to the current structural materials made from new lightweight materials. One option is to use unconventional material composite structures which have a combined fibre/matrix. Analysis of UD prepregs with unidirectional carbon fibres was performed. These special unconventional materials can be used for both flat and shaped structural products. The extent and quality of the saturation of the fibre layers in the resulting composite are important features for the whole complex of its parameters and influence its quality and mechanical properties. The experimental study also included an exploration of the inner structure and interactions of the individual components and detection of internal defects in the carbon UD prepreg composite using an X-ray microtomograph. The results illustrated the detection of microcracks, which significantly influence the resulting synergy of the composite and which were previously undetected.

scholarly journals Human capital and the decision to exploit innovative opportunity

2016 ◽  
Vol 54 (7) ◽  
pp. 1615-1632 ◽  
Author(s):  
Manoj Chandra Bayon ◽  
Esteban Lafuente ◽  
Yancy Vaillant
Keyword(s):  
Human Capital ◽  
Adult Population ◽  
Population Level ◽  
New Venture ◽  
Competitive Advantages ◽  
Strategic Action ◽  
Content Type ◽  
Self Confidence ◽  
The Individual

Purpose – The purpose of this paper is to examine the direct and interaction effect of individuals’ human capital input and human capital output in the form of entrepreneurial self-confidence on the decision to exploit innovative opportunities. Design/methodology/approach – Using a strategic entrepreneurship perspective, the authors suggest that when individuals with high human capital decide to exploit opportunities they do so by thinking and acting strategically. Strategic action(s) involves pursuing competitive advantages that enable a new venture to get a foothold in the market. The authors argue that such competitive advantages arise from the exploitation of innovative opportunities and individuals with high human capital are more likely to exploit innovative opportunities when they develop entrepreneurial self-confidence. The empirical analysis is based on a random sample of individuals from the adult population who are in the process of creating a new venture. Findings – The results suggest that although human capital inputs and human capital output in the form of entrepreneurial self-confidence are significant factors in influencing the decision to exploit innovative opportunities, human capital inputs interact in different ways with human capital output in influencing this decision. Research limitations/implications – The main limitation of the authors’ study is the use of single item measures as indicators of innovative opportunity and human capital output (entrepreneurial self-confidence). Practical implications – From a macro-perspective, the main implication of the study is that it is possible to assess the quality of entrepreneurship in an economy through individuals’ human capital and the proportion of innovative opportunities in the economy. Moreover, because not all types of human capital inputs influences the exploitation of innovative opportunities, policy makers can be selective in their policy interventions in spawning quality entrepreneurship in their economy. Originality/value – Based on population-level data the authors’ study provides empirical evidence of the nature of entrepreneurial decisions being at the earliest phases of the entrepreneurial process. The study shows the importance of founders’ human capital inputs and outputs in influencing the quality of entrepreneurship in an economy. Moreover, the study extends the understanding the individual-opportunity nexus in promoting innovative entrepreneurship in an economy.

scholarly journals Selected Properties of Hardfacing Layers Created by PTA Technology

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 134
Author(s):  
Janette Brezinová ◽  
Ján Viňáš ◽  
Anna Guzanová ◽  
Jozef Živčák ◽  
Jakub Brezina ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Base Material ◽  
Mold Material ◽  
X Ray ◽  
Plasma Transferred Arc ◽  
Transferred Arc ◽  
The Individual ◽  
The Impact

The paper presents research results on the quality of hardfacing layers made during the renovation of unheated mold surfaces designed for injection of aluminum alloys using the plasma transferred arc (PTA) technology. As mold material, the medium alloy steel X38CrMoV5-1 (H11) was used. For the formation of functional layers, three types of additives in the form of powder were applied: two types on an iron basis with the designation HSS 23 and HSS 30 and one type on a nickel basis with the designation DEW Nibasit 625-P. The hardfacing layers were made on a 120 × 350 × 50 mm plate in two layers on the plasma hardfacing machine PPC 250 R6. The quality of the layers was evaluated by means of nondestructive and destructive tests. The surface integrity of the layers was assessed using visual and capillary tests. The samples passed these tests. The impact of the parameters used and the mixing of the hardfacing metal with base material, as well as the structure analysis, were assessed by means of light and electron microscopy (SEM). The chemical composition of the elements was determined by energy-dispersive X-ray spectroscopy (EDX) analysis using a SEM microscope. The hardness of the individual layers was evaluated. Since, during operation, molds are subjected to significant wear due to friction, the friction coefficients for selected temperatures were determined by the equipment for the evaluation of tribology properties. Based on the experiments conducted, all three types of additives can be used for renovation. However, from a tribology perspective, the additive DEW Nibasit 625-P on a nickel alloy basis is recommended for renovation.

Semi-automated methods for 3-D reconstruction of macromolecular complexes

1995 ◽  
Vol 53 ◽  
pp. 42-43
Author(s):  
B. Carragher ◽  
M. Whittaker
Keyword(s):  
Three Dimensional ◽  
Time Saving ◽  
Macromolecular Complexes ◽  
Symmetry Properties ◽  
Dimensional Reconstruction ◽  
Experienced Operator ◽  
Projection Images ◽  
The Individual ◽  
Natural Symmetry

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.

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