scholarly journals The Impact of Anatomical Characteristics on the Structural Integrity of Wood

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 199 ◽  
Author(s):  
Lukas Emmerich ◽  
Georg Wülfing ◽  
Christian Brischke
Keyword(s):  
Structural Integrity ◽  
Growth Ring ◽  
High Energy ◽  
Anatomical Characteristics ◽  
Hardwood Species ◽  
Wide Range ◽  
Ray Density ◽  
Impact Milling ◽  
Multiple Impact ◽  
The Impact

The structural integrity of wood is closely related to its brittleness and thus to its suitability for numerous applications where dynamic loads, wear and abrasion occur. The structural integrity of wood is only vaguely correlated with its density, but affected by different chemical, physico-structural and anatomical characteristics, which are difficult to encompass as a whole. This study aimed to analyze the results from High-Energy Multiple Impact (HEMI) tests of a wide range of softwood and hardwood species with an average oven-dry wood density in a range between 0.25 and 0.99 g/cm³ and multifaceted anatomical features. Therefore, small clear specimens from a total of 40 different soft- and hardwood species were crushed in a heavy vibratory ball mill. The obtained particles were fractionated and used to calculate the ‘Resistance to Impact Milling (RIM)’ as a measure of the wood structural integrity. The differences in structural integrity and thus in brittleness were predominantly affected by anatomical characteristics. The size, density and distribution of vessels as well as the ray density of wood were found to have a significant impact on the structural integrity of hardwoods. The structural integrity of softwood was rather affected by the number of growth ring borders and the occurrence of resin canals. The density affected the Resistance to Impact Milling (RIM) of neither the softwoods nor the hardwoods.

Detection of fungal decay by high-energy multiple impact (HEMI) testing

Holzforschung ◽  
2006 ◽  
Vol 60 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Christian Brischke ◽  
Christian Robert Welzbacher ◽  
Andreas Otto Rapp
Keyword(s):  
Structural Changes ◽  
Brown Rot ◽  
High Energy ◽  
White Rot ◽  
Fungal Decay ◽  
Highly Correlated ◽  
Thermally Modified Wood ◽  
Impact Milling ◽  
Multiple Impact ◽  
Steel Balls

Abstract The suitability of a previously described high-energy multiple impact (HEMI) test for the detection of early fungal decay was examined. The HEMI test characterises the treatment severity of thermally modified wood by stressing the treated material by thousands of impacts of pounding steel balls. This method differentiates between heat treatment intensities, which are manifest as structural changes in the wood. Similar changes in wood structure are known for wood decayed by fungi. Pine (Pinus sylvestris L.) decayed by brown rot and beech (Fagus sylvatica L.) decayed by white rot were tested. Mass loss caused by fungal decay and resistance to impact milling (RIM) determined in HEMI tests were found to be highly correlated. Testing of non-degraded pine, beech, and ash (Fraxinus exelsior L.) showed only marginal effects of wood density on RIM. Furthermore, annual ring angles and RIM of spruce (Picea abies Karst.) were not correlated. Accordingly, the detection of RIM reduction in decayed wood is not masked by variations in density and orientation of the annual rings. Previous results showed no adverse effects of weathering on RIM. Thus, the detection of fungal decay with HEMI tests is feasible not only for laboratory purposes, but also for wood in outdoor applications that has already undergone weathering.

Impact of X-ray induced radiation damage on FD-MAPS of the ARCADIA project

2022 ◽  
Vol 17 (01) ◽  
pp. C01035
Author(s):  
C. Neubüser ◽  
T. Corradino ◽  
S. Mattiazzo ◽  
L. Pancheri
Keyword(s):  
Power Consumption ◽  
Radiation Damage ◽  
High Energy ◽  
Full Potential ◽  
Sensor Design ◽  
Charge Collection Efficiency ◽  
X Ray ◽  
Active Pixel ◽  
Wide Range ◽  
The Impact

Abstract Recent advancements in Monolithic Active Pixel Sensors (MAPS) demonstrated the ability to operate in high radiation environments of up to multiple kGy’s, which increased their appeal as sensors for high-energy physics detectors. The most recent example in such application is the new ALICE inner tracking system, entirely instrumented with CMOS MAPS, that covers an area of about 10 m2. However, the full potential of such devices has not yet been fully exploited, especially in respect of the size of the active area, power consumption, and timing capabilities. The ARCADIA project is developing Fully Depleted (FD) MAPS with an innovative sensor design, that uses a proprietary processing of the backside to improve the charge collection efficiency and timing over a wide range of operational and environmental conditions. The innovative sensor design targets very low power consumption, of the order of 20 mW cm−2 at 100 MHz cm−2 hit flux, to enable air-cooled operations of the sensors. Another key design parameter is the ability to further reduce the power regime of the sensor, down to 5 mW cm−2 or better, for low hit rates like e.g. expected in space experiments. In this contribution, we present a comparison between the detector characteristics predicted with Technology Computer Aided Design (TCAD) simulations and the ones measured experimentally. The comparison focuses on the current-voltage (IV) and capacitance-voltage (CV) characteristics, as well as noise estimated from in-pixel capacitances of passive/active pixel matrices. In view of the targeted applications of this technology, an emphasis is set on the modeling of X-ray induced radiation damage at the Si-SiO2 interface and the impact on the in-pixel sensor capacitance. The so-called new Perugia model has been used in the simulations to predict the sensor performance after total ionizing doses of up to 10 Mrad.

Satellite-derived shorelines reveal fascinating dynamics for the last three decades on Danube Delta coast

2021 ◽  
Author(s):  
Florin Tatui ◽  
Georgiana Anghelin ◽  
Sorin Constantin
Keyword(s):  
Satellite Images ◽  
High Energy ◽  
Data Availability ◽  
Danube Delta ◽  
Dune System ◽  
Temporal Scales ◽  
Wide Range ◽  
The Impact ◽  
Sentinel 2

<p>Shoreline, as the interface between the upper shoreface and the beach-dune system, is sensitive to all changes from both the underwater and sub-aerial parts of the beach at a wide range of temporal scales (seconds to decades), making it a good indicator for coastal health. While more traditional techniques of shoreline monitoring present some shortcomings (low temporal resolution for photointerpretation, reduced spatial extension for video-based techniques, high costs for DGPS in-situ data acquisition), freely available satellite images can provide information for large areas (tens/hundreds of km) at very good temporal scales (days).</p><p>We employed a shoreline detection workflow for the dynamic environment of the Danube Delta coast (Black Sea). We focused on an index-based approach using the Automated Water Extraction Index (AWEI). A fully automated procedure was deployed for data processing and the waterline was estimated at sub-pixel level with an adapted image thresholding technique. For validation purposes, 5 Sentinel-2 and 5 Landsat based results were compared with both in-situ (D)GPS measurements and manually digitized shoreline positions from very high-resolution satellite images (Pleiades – 0.5 m and Spot 7 – 1.5 m). The overall accuracy of the methodology, expressed as mean absolute error, was found to be of approximately 7.5 m for Sentinel-2 and 4.7 m for Landsat data, respectively.</p><p>More than 200 Landsat (5 and 8) and Sentinel-2 images were processed and the corresponding satellite-derived shorelines between 1990 and 2020 were analysed for the whole Romanian Danube Delta coast (130 km). This high number of shorelines allowed us the discrimination of different patterns of coastline dynamic and behaviour which could not have been possible using usual surveying techniques: the extent of accumulation areas induced by the 2005-2006 historical river floods, the impact of different high-energy storms and the subsequent beach recovery after these events, the alongshore movement of erosional processes in accordance with the dominant direction of longshore sediment transport, multi-annual differences in both erosional and accumulation trends. Moreover, a very important result of our analysis is the zonation of Danube Delta coast based on multi-annual trends of shoreline dynamics at finer alongshore spatial resolution than before. This has significant implications for future studies dealing with different scenarios of Danube Delta response to projected sea level rise and increased storminess.</p><p>The presented approach and resulting products offer optimal combination of data availability, accuracy and frequency necessary to meet the monitoring and management needs of the increasing number of stakeholders involved in the coastal zone protection activities.</p>

scholarly journals Non-standard neutrino and Z′ interactions at the FASERν and the LHC

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Kingman Cheung ◽  
C. J. Ouseph ◽  
TseChun Wang
Keyword(s):  
Large Hadron Collider ◽  
Neutral Current ◽  
Hadron Collider ◽  
Gauge Coupling ◽  
High Energy ◽  
Forward Search ◽  
Neutrino Interactions ◽  
Wide Range ◽  
Search Experiment ◽  
The Impact

Abstract We study the impact of non-standard neutrino interactions in the context of a new gauge boson Z′ in neutral-current deep-inelastic scattering performed in ForwArd Search ExpeRiment-ν (FASERν) and in monojet production at the Large Hadron Collider (LHC). We simulate the neutral-current deep-inelastic neutrino-nucleon scattering νN → νN at FASERν in the presence of an additional Z′ boson, and estimate the anticipated sensitivities to the gauge coupling in a wide range of Z′ mass. At the LHC, we study the effect of Z′ on monojet production, which can be enhanced in regions with large missing transverse momenta. We then use the recent results from ATLAS with an integrated luminosity of 139 fb−1 to improve the limits on the gauge coupling of Z′. We interpret such limits on Z′ gauge couplings as bounds on effective non-standard neutrino interactions. We show that the FASERν and the LHC results cover the medium and high energy scales, respectively, and complement one another.

scholarly journals Investigating the Influence of Process Parameters on the Structural Integrity of an Additively Manufactured Nickel-Based Superalloy

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1191
Author(s):  
Hani Hilal ◽  
Robert Lancaster ◽  
Dave Stapleton ◽  
Gavin Baxter
Keyword(s):  
Structural Integrity ◽  
Influence Of Process Parameters ◽  
Nickel Based Superalloy ◽  
Industrial Sectors ◽  
Heat Treated ◽  
Wide Range ◽  
Heat Treated Condition ◽  
Near Net Shape ◽  
Semi Empirical ◽  
The Impact

Additive manufacturing (AM) is a novel near net shape manufacturing technology that joins metallic powders layer upon layer in conjunction with 3D model data and as such offers tremendous potential to a wide range of industrial sectors given its ability to produce highly intricate components with very little material wastage. Subsequently, the aerospace industry has become particularly interested in utilising AM as a means of manufacturing nickel-based superalloys for high-temperature applications, such as non-rotating components within gas turbine engines, which are traditionally fabricated through traditional cast and wrought methodologies. As a result of this, a detailed understanding of the influence of key process variables on the structural integrity of the different experimental builds is required. A semi-empirical quantitative approach for melt track analysis has been conducted and the impact on melt track sizing and defect forming mechanisms in the as-built and heat-treated condition is investigated.

scholarly journals Recent Developments of the Linear Matching Method Framework for Structural Integrity Assessment

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Daniele Barbera ◽  
Haofeng Chen ◽  
Yinghua Liu ◽  
Fuzhen Xuan
Keyword(s):  
Finite Element ◽  
Cyclic Loading ◽  
Structural Integrity ◽  
Direct Methods ◽  
Matching Method ◽  
Integrity Assessment ◽  
Wide Range ◽  
The Impact ◽  
Linear Matching Method

The linear matching method (LMM) subroutines and plug-in tools for structural integrity assessment are now in extensive use in industries for the design and routine assessment of power plant components. This paper presents a detailed review and case study of the current state-of-the art LMM direct methods applied to the structural integrity assessment. The focus is on the development and use of the linear matching method framework (LMMF) on a wide range of crucial aspects for the power industry. The LMMF is reviewed to show a wide range of capabilities of the direct methods under this framework, and the basic theory background is also presented. Different structural integrity aspects are covered including the calculation of shakedown, ratchet, and creep rupture limits. Furthermore, the crack initiation assessments of an un-cracked body by the LMM are shown for cases both with and without the presence of a creep dwell during the cyclic loading history. Finally, an overview of the in house developed LMM plug-in is given, presenting the intuitive graphical user interface (GUI) developed. The efficiency and robustness of these direct methods in calculating the aforementioned quantities are confirmed through a numerical case study, which is a semicircular notched (Bridgman notch) bar. A two-dimensional axisymmetric finite element model is adopted, and the notched bar is subjected to both cyclic and constant axial mechanical loads. For the crack initiation assessment, different cyclic loading conditions are evaluated to demonstrate the impact of the different load types on the structural response. The impact of creep dwell is also investigated to show how this parameter is capable of causing in some cases a dangerous phenomenon known as creep ratcheting. All the results in the case study demonstrate the level of simplicity of the LMMs but at the same time accuracy, efficiency, and robustness over the more complicated and inefficient incremental finite element analyses.

scholarly journals A Non-Tuned Machine Learning Technique for Abutment Scour Depth in Clear Water Condition

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 301 ◽  
Author(s):  
Hossein Bonakdari ◽  
Fatemeh Moradi ◽  
Isa Ebtehaj ◽  
Bahram Gharabaghi ◽  
Ahmed A. Sattar ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Fundamental Equation ◽  
Percentage Error ◽  
Scour Depth ◽  
Clear Water ◽  
Dimensionless Variable ◽  
Sediment Size ◽  
Wide Range ◽  
Abutment Scour ◽  
The Impact

Abutment scour is a complex three-dimensional phenomenon, which is one of the leading causes of marine structure damage. Structural integrity is potentially attainable through the precise estimation of local scour depth. Due to the high complexity of scouring hydrodynamics, existing regression-based relations cannot make accurate predictions. Therefore, this study presented a novel expansion of extreme learning machines (ELM) to predict abutment scour depth (ds) in clear water conditions. The model was built using the relative flow depth (h/L), excess abutment Froude number (Fe), abutment shape factor (Ks), and relative sediment size (d50/L). A wide range of experimental samples was collected from the literature, and data was utilized to develop the ELM model. The ELM model reliability was evaluated based on the estimation results and several statistical indices. According to the results, the sigmoid activation function (correlation coefficient, R = 0.97; root mean square error, RMSE = 0.162; mean absolute percentage error, MAPE = 7.69; and scatter index, SI = 0.088) performed the best compared with the hard limit, triangular bias, radial basis, and sine activation functions. Eleven input combinations were considered to investigate the impact of each dimensionless variable on the abutment scour depth. It was found that ds/L = f (Fe, h/L, d50/L, Ks) was the best ELM model, indicating that the dimensional analysis of the original data properly reflected the underlying physics of the problem. Also, the absence of one variable from this input combination resulted in a significant accuracy reduction. The results also demonstrated that the proposed ELM model significantly outperformed the regression-based equations derived from the literature. The ELM model presented a fundamental equation for abutment scours depth prediction. Based on the simulation results, it appeared the ELM model could be used effectively in practical engineering applications of predicting abutment scour depth. The estimated uncertainty of the developed ELM model was calculated and compared with the conventional and artificial intelligence-based models. The lowest uncertainty with a value of ±0.026 was found in the proposed model in comparison with ±0.50 as the best uncertainty of the other models.

scholarly journals DESIGN, DEVELOPMENT AND VALIDATION OF AN IMPACT WEAR TESTING DEVICE FOR THE MINERALS INDUSTRY

1969 ◽  
Author(s):  
Lokesh K. Thakur ◽  
Peter Radziszewski
Keyword(s):  
Wear Mechanism ◽  
High Energy ◽  
Wear Testing ◽  
Impact Wear ◽  
Design Development ◽  
Charge Motion ◽  
Wear Model ◽  
Motion Simulator ◽  
Wide Range ◽  
The Impact

Total steel media wear in a given mill (ball or SAG) grinding process is a product of three recognized wear mechanisms-impact, abrasion, and corrosion of which the contribution of each wear mechanism to total media wear has not been well established. A total media wear model can be defined on the assumption that the effect of each wear mechanism can be independently determined and this effect can be tied to mill charge motion as determined or estimated using a charge motion simulator, which allows for a total media wear model to be defined as the summation of the wear results of each mechanism. This necessitates the need for developing impact, abrasion and corrosion wear testers that will allow the study of media wear over a wide range of energy levels. Refinement of the impact test will allow studying how impact media wear at high energies behaves as a function of those energies. This work is focused on design and development of a high-energy impact wear tester. A comprehensive illustration on designing the newest version of the impact wear tester is explained in detail in order to exhibit how theoretical, virtual and experimental analyses could be integrated while designing a mechanical system.

Structural Integrity of a Spar in Collision With a Large Supply Vessel

2013 ◽  
Author(s):  
Xinguo Ning ◽  
Bob L. Zhang ◽  
Sudhakar Tallavajhula
Keyword(s):  
Kinetic Energy ◽  
Structural Integrity ◽  
Impact Force ◽  
High Energy ◽  
Progressive Damage ◽  
Element Analysis ◽  
Impact Speed ◽  
Integrity Assessment ◽  
Damage Models ◽  
The Impact

The objectives of this study are to establish numerical approaches to evaluate the structural integrity of a generic Spar hull in collision with a large supply vessel and to reveal its progressive collision damage characteristics. Dynamic and nonlinear finite element analysis is implemented using ABAQUS/Explicit module [1] respectively for two collision scenarios. One is a realistic simulation where the impact kinetic energy governed by an initial impact speed and total mass of a ship is gradually depleted during the collision. The other is a simplified analytical method where the impact speed of a ship bow throughout the collision is constant or the total impact energy is unlimited. With a combination of calibrated material progressive damage models and Mises plasticity, progressive collision damages of the hull structures are accurately captured for structural integrity assessment. The collision energy absorption characteristics, the impact force-deformation curves, the progressive damage modes and the correlation between the impact force, kinetic energy and damages are revealed. Based on numerical investigation, the two analytical scenarios are compared and the implication for the design analysis is elucidated. As a complementary to the ABS code [2], the alternative collision damage criterion in ABS MODU [3] applicable to column-stabilized units is justified to be applicable to a Spar subjected to high-energy impact.

Sign in / Sign up

Export Citation Format

Share Document