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Online Appendix to ‘Two Lost Items of Humeana’, The Library
The following is an online Appendix to my article: ‘Two Lost Items of Humeana’, published in The Library. The Appendix transcribes the image of National Library of Scotland, F. R. 118--the ‘Register of the Proceedings of the Curators and Keeper’ of the Library of the Faculty of Advocates-- reproduced by Dickson in 1932 and Hillyard in 1989
BIM-Based End-of-Lifecycle Decision Making and Digital Deconstruction: Literature Review
This article is the second part of a two-part study, which explored the extent to which Building Information Modelling (BIM) is used for End-of-Lifecycle (EoL) scenario selection to minimise the Construction and Demolition Waste (CDW). The conventional literature review presented here is based on the conceptual landscape that was obtained from the bibliometric and scientometric analysis in the first part of the study. Seven main academic research directions concerning the BIM-based EoL domain were found, including social and cultural factors, BIM-based Design for Deconstruction (DfD), BIM-based deconstruction, BIM-based EoL within LCA, BIM-aided waste management, Material and Component Banks (M/C Banks), off-site construction, interoperability and Industry Foundation Classes (IFC). The analysis highlights research gaps in the path of raw materials to reusable materials, i.e., from the deconstruction to M/C banks to DfD-based designs and then again to deconstruction. BIM-based EoL is suffering from a lack of a global framework. The existing solutions are based on local waste management policies and case-specific sustainability criteria selection. Another drawback of these ad hoc but well-developed BIM-based EoL prototypes is their use of specific proprietary BIM tools to support their framework. This disconnection between BIM tools and EoL tools is reportedly hindering the BIM-based EoL, while no IFC classes support the EoL phase information exchange
Numerical investigation of bridges with the aim of condition assessment in applying the Deformation Area Difference method (DAD-method) and selecting appropriate measurement techniques
Condition assessment of existing road bridges gains ever increasing importance today as bridges are getting older and the inflow of heavy traffic is constantly increasing. The further development of recognized techniques and the development of new methods for early and accurate detection of damage to the structure are made possible by means of innovative technological progress. In this contribution, the principles of Defor-mation Area Difference Method (DAD-Method) for condition assessment of bridges are presented. This method is based on the further processing of measured and computed deformation values. The application of the DAD-Method requires a precise recording of the deflection of a load-deflection test. On the basis of theoretical cal-culations, this method has allowed to identify as well as to localise damage to a structure. The DAD-Method is independent of a reference measurement and insensitive to global influences such as temperature fluctuations. For precise detection of deformations, the most modern measuring instruments and methods like photogram-metry, total stations, displacement sensors, strain gauges and levelling are compared to each other. In collabo-ration with the appropriate measurement technology, the localisation of damage in bridges becomes possible
Static load deflection experiment on a beam for damage detection using the Deformation Area Difference Method
A reliable and safety infrastructure for both transport and traffic is becoming increasingly important today. The condition assessment of bridges remains difficult and new methods must be found to provide reliable information. A meaningful in-situ assessment of bridges requires very detailed investigations which cannot be guaranteed by commonly used methods.
It is known that the structural response to external loading is influenced by local damages. However, the detection of local damage depends on many factors such as environmental effects (e.g. temperature), construction layer (e.g. asphalt) and accuracy of the structural response measurement. Within the paper, a new so-called Deformation Area Difference (DAD) Method is presented. The DAD method is based on a load deflection experiment and does not require a reference measurement of initial condition. Therefore, the DAD method can be applied on existing bridges. Moreover, the DAD method uses the most modern technologies such as high precision measurement techniques and attempts to combine digital photogrammetry with drone applications.
The DAD method uses information given in the curvature course from a theoretical model of the structure and compares it to real measurements. The paper shows results from a laboratory load-deflection experiment with a steel beam which has been gradually damaged at distinct positions. The load size is chosen so that the maximum deflection does not exceed the serviceability limit state. With the data obtained by the laboratory experiment, the damage degree, which can still be detected by the DAD method, is described. Furthermore, the influence of measurement accuracy on damage detection is discussed
Laboratory experiment for damage assessment using the DAD-method
In the following, a new analytical method, the Deformation Area Difference (DAD) method for damage assessment of bridge structures is applied using experimental test results of a statically loaded beam. An essential prerequisite for the application of this method is a high precise measurement of the deflection line. In this paper, the results from a laboratory experiment using modern measurement techniques such as photogrammetry and displacement sensors are discussed. A reinforced concrete beam is stepwise loaded until reaching the ultimate limit state. The DAD-method is applied to the resulting data from the measurements and the outcome is discussed for further optimisation of the method. In principle, the measured deflection line of the beam contains already essential information on discontinuities which occur due to cracking. These entries are processed and visualised using the DAD-method. This study shows that a high accuracy of the measurement techniques in combination with the DAD-method can become an effective tool for damage detection
Curvature based DAD-method for damage localisation under consideration of measurement noise minimisation
Several research projects on condition assessment of bridges have proven that structural responses from dynamic excitation or static loading are influenced by local damages and thus, could be used for the detection and localisation of damages. Particularly, the curvature of structures is directly depending on their stiffness. In order to localise the discontinuities in curvature lines resulting from damage, this paper uses the so-called Deformation Area Difference Method (DAD), which is based on static load deflection tests on bridge structures. The DAD-method for damage localisation is presented within the paper using a theoretical example, which is then verified by two laboratory experiments. The first experiment consists of a reinforced concrete beam, which is loaded stepwise until failure of the concrete in the compression zone. Due to the load increase, the tensile zone of the beam starts cracking, leading to a stiffness reduction. The application of the DAD-method allows identifying the cracked area from the measurement of the deflection line. However, a challenge and a prerequisite for the applicability of the DAD-method is the highly accurate measurement of the deflection line. Therefore, one of the most modern measurement techniques such as digital photogrammetry is applied. Nonetheless, the accuracy of each measurement technique is limited. The second laboratory experiment consists of a steel beam, which is locally damaged at three positions. The degree of the damage is stepwise increased in order to identify at which degree of damage the applied DAD-method is still able to identify and localise damage.
In this work, the focus lies on the minimisation of the effect of noise resulting from the limited measurement precision. Possible solutions were examined and proposed based on methods such as data smoothing using polynomial regression, consideration of standard deviation and measurement point variation. The reduction of the noise effect leads to an increase in the sensitivity of the damage localisation. The DAD-method has proven its potential for practical application through the successful localisation of cracking in the concrete beam
The Deformation Area Difference (DAD) method for condition assessment of reinforced structures
The investigation and condition assessment of bridges have a very high priority in the construction industry today.
Particularly, due to the fact that many bridge structures are getting old and partly reach the end of their
useful life, the control and condition assessment of bridge structures have become very important and essential.
The present research work introduces an efficient new method for condition assessment called the Deformation
Area Difference (DAD) Method. This new method represents an attractive alternative to visual inspection and
long-term monitoring. In this paper, the new method with its theoretical background is presented and explained
by means of a laboratory experiment and some additional theoretical calculation examples. The experimental
investigations have been realised on a reinforced concrete beam, which has been gradually loaded until failure.
For each load step, the stiffness reduction and the apparent cracking have been monitored. High-precision measurements
such as close-range photogrammetry, digital levelling and displacement sensors have been used for
the determination of the deflection curve. The DAD method has been applied to identify the area of the crack
pattern of the laboratory experiment. Furthermore, the method is discussed with regard to the load level and
the precision of the deformation measurements. On the basis of the laboratory experiment, the applicability of
the DAD method for damage detection could be proven. Furthermore, the sensitivity of the method with regard
to the damage degree, the static system, the damage position and the impact of temperature variation were
analysed
Обзор и назначение экономических информационных систем
ObjectivesThis study was designed to develop a technique to selectively increase the sympathetic tone to the heart by cardiac sympathetic nerve stimulation (SNS).BackgroundAccess to the cardiac sympathetic neurons may allow modulating the adrenergic tone of the heart while avoiding systemic side effects.MethodsCardiac sympathetic nerves course within neural sleeves along the subclavian artery. Because of this proximity, transvascular SNS was attempted with electrode catheters inside the subclavian artery in 16 pigs.ResultsRight/left (R-/L-) SNS (20 Hz) during ventricular pacing at 200/min evoked a >100% increase of left ventricular systolic pressure (baseline: 51 ± 1 mm Hg; L-SNS: 118 ± 26 mm Hg; R-SNS: 116 ± 33 mm Hg; p < 0.001) while systemic vascular resistance remained unchanged. There was a sigmoid dose-response curve with rapid on- and offset of the effect during SNS initiation/cessation. Positive inotropic effects persisted for 12 h of continued SNS (n = 4). Besides positive dromotropic effects, L-SNS/R-SNS yielded a 41% and 77% sinus rate increase, respectively.ConclusionsThe neural adrenergic tone to the heart can be selectively increased by catheter stimulation of cardiac efferent sympathetic nerves
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