scholarly journals Non-destructive determination and quantification of diffusion processes in wood by means of neutron imaging

Holzforschung ◽  
2009 ◽  
Vol 63 (5) ◽  
Author(s):  
David Mannes ◽  
Walter Sonderegger ◽  
Stefan Hering ◽  
Eberhard Lehmann ◽  
Peter Niemz
Keyword(s):  
Diffusion Processes ◽  
High Sensitivity ◽  
European Beech ◽  
Longitudinal Direction ◽  
Solid Wood ◽  
Neutron Imaging ◽  
Fibre Direction ◽  
Non Invasive ◽  
Paul Scherrer ◽  
Non Destructive

Abstract Diffusion processes in samples of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies [L.] Karst.) were determined and quantified by means of neutron imaging (NI). The experiments were carried out at the neutron imaging facility NEUTRA at the Paul Scherrer Institute in Villigen (Switzerland) using a thermal neutron spectrum. NI is a non-destructive and non-invasive testing method with a very high sensitivity for hydrogen and thus water. Within the scope of this study, diffusion processes in the longitudinal direction were ascertained for solid wood samples exposed to a differentiating climate (dry side/wet side). With NI it was possible to determine the local distribution and consequently the total amount of water absorbed by the samples. The calculated values scarcely differ from those ascertained by weighing (≤3%). The method yields profiles of the water content over the whole sample, thus allowing the local and temporal resolution of diffusion processes within the sample in the main transport direction (longitudinal). On the basis of these profiles, it was possible to calculate the diffusion coefficients along the fibre direction according to Fick's second law.

Defects and Sintering-Induced Diffusion Processes in Yttria-Stabilised Zirconia Nanomaterials Studied by Positron Annihilation Spectroscopy

2014 ◽  
Vol 1 ◽  
pp. 155-172 ◽  
Author(s):  
Ivan Procházka ◽  
Jakub Čížek ◽  
Oksana Melikhova ◽  
Wolfgang Anwand ◽  
Tetyana E. Konstantinova ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Elevated Temperatures ◽  
Diffusion Processes ◽  
High Sensitivity ◽  
Positron Beam ◽  
Positron Annihilation Spectroscopy ◽  
Atomic Scale ◽  
Positron Lifetimes ◽  
Co Precipitation ◽  
Non Destructive

In the present work, zirconia (ZrO2) nanopowders doped with yttria (Y2O3) and chromia (Cr2O3) were prepared by a co-precipitation technique. The nanopowders were then subjected to a calcination and a successive sintering at elevated temperatures up to 1500 °C. The nanostructures in these nanomaterials were characterized by positron annihilation spectroscopy (positron lifetimes and Doppler broadening measurements) which is a non-destructive technique with a high sensitivity to atomic-scale open-volume defects. It was found that the zirconia-based nanomaterials studied contain vacancy-like defects and nanoscale pores. Diffusion processes induced in these nanomaterials by sintering were investigated also by depth sensitive positron annihilation studies using a variable energy slow positron beam. Sintering was found to cause intensive grain growth and a removal of porosity by a migration of pores from the sample interior toward its surface.

Study of Colonial Manuscripts from San Nicolás Coatepec, México, Through UV&IR Imaging and XRF

2012 ◽  
Vol 1374 ◽  
pp. 17-25
Author(s):  
Jocelyn Alcántara García ◽  
José Luis Ruvalcaba Sil ◽  
Marie Van der Meeren
Keyword(s):  
Imaging Techniques ◽  
High Sensitivity ◽  
X Ray ◽  
Historical Material ◽  
Qualitative And Quantitative ◽  
Non Invasive ◽  
History Of ◽  
Material Information ◽  
Non Destructive ◽  
Suitable Technique

ABSTRACTThe necessity of studying cultural heritage through non-invasive and non-destructive techniques has led to significant advances in the last decade. One of the most recent advancements in this theme in Mexico is the portable X-ray system SANDRA, which was used to study three manuscripts directly related to the history of “San Nicolás Coatepec”, Mexico. X-ray fluorescence was chosen as the suitable technique because it can provide a fast qualitative and quantitative multielemental high sensitivity analysis. The documents were examined globally, using imaging techniques with UV and IR lighting. This research evinced a change in the composition and evolution of writing materials (inks and pigments) and provided information concerning historical use of the documents and its actual legal value as a property document. It also stressed the need of spanning these results to an extensive research attaining other regions of Mexico, in order to fully understand the Mexican documents particularities, aging and deterioration. This, in turn, will provide not only historical material information but also an invaluable scoop to understand deterioration and conservation issues.

Diffusion Processes in the Sintering of Zirconia-Based Nanomaterials

2013 ◽  
Vol 26 ◽  
pp. 25-31
Author(s):  
Oksana Melikhova ◽  
Jakub Čížek ◽  
Ivan Procházka ◽  
Wolfgang Anwand ◽  
Tetyana E. Konstantinova ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Elevated Temperatures ◽  
Diffusion Processes ◽  
High Sensitivity ◽  
Positron Beam ◽  
Positron Annihilation Spectroscopy ◽  
Atomic Scale ◽  
Slow Positron ◽  
Co Precipitation ◽  
Non Destructive

In the present work, zirconia-based nanomaterials with various stabilizers were prepared by a co-precipitation technique. Defects in these nanomaterials were characterized by positron annihilation spectroscopy which is a non-destructive technique with a high sensitivity to open volume defects and atomic scale resolution. It was found that zirconia-based nanomaterials contain vacancies and also nanoscale and meso-scale pores. Diffusion processes which occur in the nanomaterials sintered at elevated temperatures were investigated by depth sensitive positron annihilation studies on a variable energy slow positron beam. It was found that sintering causes intensive grain growth and residual porosity is removed from samples by diffusion to the surface.

scholarly journals Neutron attenuation coefficients for non-invasive quantification of wood properties

Holzforschung ◽  
2009 ◽  
Vol 63 (4) ◽  
Author(s):  
David Mannes ◽  
Lidija Josic ◽  
Eberhard Lehmann ◽  
Peter Niemz
Keyword(s):  
Attenuation Coefficient ◽  
Wood Properties ◽  
Neutron Imaging ◽  
Minor Role ◽  
Attenuation Coefficients ◽  
Non Invasive ◽  
Scattering Correction ◽  
Strong Linear Correlation ◽  
A Minor ◽  
Paul Scherrer

Abstract Attenuation coefficients and mass attenuation coefficients of wood were determined theoretically and experimentally for thermal and cold neutrons. Experiments were carried out at the neutron imaging facilities at the Paul Scherrer Institute, Villigen (CH). For the calculation of theoretical attenuation coefficients, only the three main elemental components (carbon, oxygen and hydrogen) were taken into consideration. While hydrogen accounts only for 6% (by wt) of wood, over 90% of the attenuation can be attributed to this element. Nitrogen and other trace elements were estimated to have a negligible impact on the theoretical attenuation coefficient. For the experimental determination of the attenuation coefficients, samples from different European and tropical wood species were tested in order to examine the influence of density and extractives content. Experimental results show a very strong linear correlation between attenuation coefficient and wood density irrespective of the tested species and extractives content that play only a minor role. As neutrons are very susceptible to scattering, it is necessary to apply a scattering correction if a quantitative evaluation is intended.

scholarly journals Non-Invasive Testing of Physical Systems Using Topological Sensitivity

2021 ◽  
Vol 11 (3) ◽  
pp. 1341
Author(s):  
María Higuera ◽  
José M. Perales ◽  
María-Luisa Rapún ◽  
José M. Vega
Keyword(s):  
Lamb Waves ◽  
General Purpose ◽  
Mathematical Tool ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Topological Sensitivity ◽  
Physical Systems ◽  
Non Invasive ◽  
Active Infrared Thermography ◽  
Non Destructive

A review of available results on non-destructive testing of physical systems, using the concept of topological sensitivity, is presented. This mathematical tool estimates the sensitivity of a set of measurements in some given sensors, distributed along the system, to defects/flaws that produce a degradation of the system. Such degradation manifests itself on the properties of the system. The good performance of this general purpose post-processing method is reviewed and illustrated in some applications involving non-destructive testing. These applications include structural health monitoring, considering both elastodynamic ultrasonic guided Lamb waves and active infrared thermography. Related methods can also be used in other fields, such as diagnosis/prognosis of engineering devices, which is also considered.

scholarly journals Prevalence and Photobiology of Photosynthetic Dinoflagellate Endosymbionts in the Nudibranch Berghia stephanieae

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2200
Author(s):  
Ruben X. G. Silva ◽  
Paulo Cartaxana ◽  
Ricardo Calado
Keyword(s):  
Food Deprivation ◽  
Photosynthetic Efficiency ◽  
Rapid Decrease ◽  
Complete Loss ◽  
Symbiotic Association ◽  
Non Invasive ◽  
Sea Slugs ◽  
Non Destructive ◽  
Over Time

Berghia stephanieae is a stenophagous sea slug that preys upon glass anemones, such as Exaiptasia diaphana. Glass anemones host photosynthetic dinoflagellate endosymbionts that sea slugs ingest when consuming E. diaphana. However, the prevalence of these photosynthetic dinoflagellate endosymbionts in sea slugs appears to be short-lived, particularly if B.stephanieae is deprived of prey that host these microalgae (e.g., during bleaching events impacting glass anemones). In the present study, we investigated this scenario, along with food deprivation, and validated the use of a non-invasive and non-destructive approach employing chlorophyll fluorescence as a proxy to monitor the persistence of the association between sea slugs and endosymbiotic photosynthetic dinoflagellates acquired through the consumption of glass anemones. Berghia stephanieae deprived of a trophic source hosting photosynthetic dinoflagellate endosymbionts (e.g., through food deprivation or by feeding on bleached E. diaphana) showed a rapid decrease in minimum fluorescence (Fo) and photosynthetic efficiency (Fv/Fm) when compared to sea slugs fed with symbiotic anemones. A complete loss of endosymbionts was observed within 8 days, confirming that no true symbiotic association was established. The present work opens a new window of opportunity to rapidly monitor in vivo and over time the prevalence of associations between sea slugs and photosynthetic dinoflagellate endosymbionts, particularly during bleaching events that prevent sea slugs from incorporating new microalgae through trophic interactions.

scholarly journals Role of MRI evaluation in acute secondary inability to walk in children

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
K. H. Sedeek ◽  
K. Aboualfotouh ◽  
S. M. Hassanein ◽  
N. M. Osman ◽  
M. H. Shalaby
Keyword(s):  
Transverse Myelitis ◽  
High Sensitivity ◽  
Acute Disseminated Encephalomyelitis ◽  
Limb Weakness ◽  
Non Invasive ◽  
Highly Sensitive ◽  
Common Causes ◽  
Bilateral Lower Limb ◽  
Severity Of The Disease

Abstract Background Acute bilateral lower limb weakness is a common problem in children which necessitates a rapid method for diagnosis. MRI is a non-invasive imaging technique that produces high-quality images of the internal structure of the brain and spinal cord. Results MRI was very helpful in reaching rapid and prompt diagnosis in children with acute inability to walk. Acute disseminated encephalomyelitis (ADEM), Guillain–Barré syndrome (GBS), and acute transverse myelitis (ATM) were the most common causes in our study. MRI proved to be of high sensitivity in detecting the lesions and reaching the diagnosis in ADEM and GBS; however, there was no significant relation between the lesions’ size, enhancement pattern, and severity of the disease or prognosis, yet in ATM the site of the lesion and number of cord segment affection were significantly related to the severity of the disease and prognosis. Conclusion MRI is a quick tool to reach the diagnosis of children with acute secondary inability to walk, and to eliminate other differential diagnosis which is essential for proper treatment and rapid full recovery. It is highly sensitive in detecting the lesions, their site and size.

scholarly journals Through thick and thin: Diagnosis of transthyretin cardiac amyloidosis through non-invasive multimodality imaging

2021 ◽  
pp. 201010582110061
Author(s):  
Raja Ezman Raja Shariff ◽  
Hafisyatul Aiza Zainal Abidin ◽  
Sazzli Kasim
Keyword(s):  
Cardiac Amyloidosis ◽  
Troponin T ◽  
Multimodality Imaging ◽  
High Sensitivity ◽  
Dark Blood ◽  
Non Invasive ◽  
Doppler Study ◽  
Alternative Means ◽  
High Sensitivity Troponin T

Cardiac amyloidosis is a severely underdiagnosed cause of heart failure with preserved ejection fraction. We report a case of highly probable transthyretin (ATTR) cardiac amyloidosis (ATTR-CA) diagnosed through the assistance of non-invasive multimodality imaging. An 81-year-old man presented with worsening dyspnoea, reduced effort tolerance and limb swelling. Examination and bedside investigations demonstrated congestive cardiac failure. On arrival, N-terminal-pro B-type natriuretic peptide was 2400 ng/L, and high-sensitivity troponin T was 78 mmol/L. Echocardiography showed severe left and right ventricular hypertrophy, and a Doppler study revealed diastolic dysfunction. Cardiac magnetic resonance imaging revealed on non-conventional dark blood sequence an abnormal inversion time for nulling myocardium suggestive of infiltrative disease, including amyloidosis. The patient was referred for nuclear-based studies involving technetium-99m pyrophosphate which demonstrated changes highly diagnostic of ATTR-CA. Early diagnosis of ATTR-CA remains paramount due to the increasing availability of disease-modifying therapies. Current guidelines recognise the role of multimodality imaging in confidently recognising the disease without the need for histological evidence in the appropriate context, providing an alternative means of diagnosis.

scholarly journals The grades and freshness assessment of eggs based on density detection using machine vision and weighing sensor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Supakorn Harnsoongnoen ◽  
Nuananong Jaroensuk
Keyword(s):  
Machine Vision ◽  
Vision System ◽  
Low Cost ◽  
Measuring System ◽  
Coefficient Of Determination ◽  
Water Displacement ◽  
Non Invasive ◽  
Future Potential ◽  
Non Destructive ◽  
Egg Freshness

AbstractThe water displacement and flotation are two of the most accurate and rapid methods for grading and assessing freshness of agricultural products based on density determination. However, these techniques are still not suitable for use in agricultural inspections of products such as eggs that absorb water which can be considered intrusive or destructive and can affect the result of measurements. Here we present a novel proposal for a method of non-destructive, non-invasive, low cost, simple and real—time monitoring of the grading and freshness assessment of eggs based on density detection using machine vision and a weighing sensor. This is the first proposal that divides egg freshness into intervals through density measurements. The machine vision system was developed for the measurement of external physical characteristics (length and breadth) of eggs for evaluating their volume. The weighing system was developed for the measurement of the weight of the egg. Egg weight and volume were used to calculate density for grading and egg freshness assessment. The proposed system could measure the weight, volume and density with an accuracy of 99.88%, 98.26% and 99.02%, respectively. The results showed that the weight and freshness of eggs stored at room temperature decreased with storage time. The relationship between density and percentage of freshness was linear for the all sizes of eggs, the coefficient of determination (R2) of 0.9982, 0.9999, 0.9996, 0.9996 and 0.9994 for classified egg size classified 0, 1, 2, 3 and 4, respectively. This study shows that egg freshness can be determined through density without using water to test for water displacement or egg flotation which has future potential as a measuring system important for the poultry industry.

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