Pipe Wall Damage Detection in Buried Pipes Using Guided Waves

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Rais Ahmad ◽  
Sourav Banerjee ◽  
Tribikram Kundu
Keyword(s):  
Damage Detection ◽  
Wavelet Transforms ◽  
Guided Waves ◽  
Pipe Wall ◽  
The Other ◽  
Buried Pipes ◽  
Before And After ◽  
The Difference

It is well known that cylindrical guided waves are very efficient for detecting pipe wall defects when pipes are open in the air. In this paper it is investigated how efficient the guided waves are for detecting pipe wall damage when the pipes are embedded in the soil. For this purpose guided waves were propagated through pipes that were buried in the soil by placing transmitters on one end of the embedded pipe and receivers on the other end. Received signals for both defect-free and defective pipes were recorded. Then the received signals were subjected to wavelet transforms. To investigate whether embedding the pipe in the soil makes it more difficult to detect the pipe wall defects, the same set of defective and defect-free pipes were studied before and after burying them in the soil. In both cases the defective pipes could be easily identified. Interestingly, contrary to the intuition, it was observed that under certain conditions defective pipes could be identified more easily in buried conditions. For example, the difference between the strengths of the initial parts of the received signal from defect-free and dented pipes was found to be greater for the buried pipes. Some qualitative justification for easier detection of buried dented pipes is provided.

A New Method for Calculating the Volume of Debris Flow Using GIS and RS Technology

2014 ◽  
Vol 511-512 ◽  
pp. 253-258
Author(s):  
Wen Ju Du ◽  
Bing Xie ◽  
Hui Xi Xu
Keyword(s):  
Debris Flow ◽  
The Other ◽  
Mountain Area ◽  
Aerial Photos ◽  
Contour Lines ◽  
Digital Elevation ◽  
Before And After ◽  
Gis And Rs ◽  
The Difference ◽  
New Formula

In this paper, two digital elevation models of debris flow in Yingxiu mountain area are generated; one is from contour lines with manual interpretation before earthquake and the other is from high resolution aerial photos using MapMatrix software. By analyzing three random points which are not in the same edge, a new formula for calculating the volume from these three points to their projection on the datum plane is derived. Then, the volumes of the two DEMs before and after earthquake can be calculated, and the volume of the total debris flow is the difference of those two.

scholarly journals Meditation Practice Improves Short-Term Changes in Heart Rate Variability

2020 ◽  
Vol 17 (6) ◽  
pp. 2128 ◽  
Author(s):  
Kang-Ming Chang ◽  
Miao-Tien Wu Chueh ◽  
Yi-Jung Lai
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Physiological Parameters ◽  
The Other ◽  
Meditation Practice ◽  
Short Term ◽  
Face To Face ◽  
Before And After ◽  
The Difference

Background: It is well known that meditation improves the physical and psychological condition of its practitioners. This study investigated the heart rate variability response of meditation practitioners in two Chan master teaching environments, namely face-to-face and video classes. Methods: Experimental sessions were conducted, one featuring face-to-face classes and the other featuring video classes. The difference in participants’ physiological parameters (blood pressure and heart rate variability) between the two experimental sessions was determined. In the first session, physiological parameters were recorded twice, before and after one teaching course, and the second session took place one month after the first. The first and second sessions had 45 and 27 participants, respectively. Those involved in the first experiment had no experience with meditation, whereas participants in the second experiment had practiced meditation for an average of 9 years (range = 1 to 27 years). Both experiments were conducted once a week, with each session lasting 1.5 h. Results: For both experiments, both heart rate and heart rate variability by age significantly decreased after one teaching course. Conclusions: Chan meditation practitioners benefit from receiving both face-to-face and video class teaching from a Chan master.

scholarly journals On the relation of hydrogen to palladium

1869 ◽  
Vol 17 ◽  
pp. 212-220 ◽  
Keyword(s):  
Hydrogen Gas ◽  
The Other ◽  
Linear Dimensions ◽  
Hydrogen Bubbles ◽  
Before And After ◽  
The Wire ◽  
The Difference ◽  
The One ◽  
A Charge ◽  
The Mind

It has often been maintained on chemical grounds that hydrogen gas is the vapour of a highly volatile metal. The idea forces itself upon the mind that palladium with its occluded hydrogen is simply an alloy of this volatile metal, in which the volatility of the one element is restrained by its union with the other, and which owes its metallic aspect equally to both constituents. How far such a view is borne out by the properties of the compound substance in question will appear by the following examination of the properties of what, assuming its metallic character, would have to be named Hydrogenium . 1. Density .—The density of palladium when charged with eight or nine hundred times its volume of hydrogen gas is perceptibly lowered; but the change cannot be measured accurately by the ordinary method of immersion in water, owing to a continuous evolution of minute hydrogen bubbles which appears to be determined by contact with the liquid. However, the linear dimensions of the charged palladium are altered so considerably that the difference admits of easy measurement, and furnishes the required density by calculation. Palladium in the form of wire is readily charged with hydrogen by evolving that gas upon the surface of the metal in a galvanometer containing dilute sulphuric acid as usual. The length of the wire before and after a charge is found by stretching it on both occasions by the same moderate weight, such as will not produce permanent distention, over the surface of a flat graduated measure. The measure was graduated to hundredths of an inch, and by means of a vernier, the divisions could be read to thousandths. The distance between two fine cross lines marked upon the surface of the wire near each of its extremities was observed.

scholarly journals Comparing Meal Satisfaction Based on Different Types of Tableware: An Experimental Study of Japanese Cuisine Culture

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1546
Author(s):  
Tomoko Hasegawa ◽  
Nobuyuki Sakai
Keyword(s):  
Food Industry ◽  
The Other ◽  
Food Preparation ◽  
Japanese Culture ◽  
Japanese People ◽  
Perceptual Evaluation ◽  
Different Types ◽  
Before And After ◽  
The Difference ◽  
Plastic Containers

In Japan, as in other countries, the externalization of food preparation is increasing. Japanese people are interested in the combination of food and tableware and they are concerned about transferring ready-made meals from plastic containers to natural tableware. This study aimed to examine the varying evaluations of meals due to differences in tableware. In this study, we investigated the effect of tableware on meal satisfaction, which is emphasized in Japanese culture. We studied the difference in the evaluation of ready-made meals (a rice ball, salad, croquette, and corn soup) before, during, and after a meal under two conditions: plastic tableware and natural wooden tableware. The results showed that there was no difference in the perceptual evaluation of taste and texture during the meal, except for the color of the salad and the temperature of the soup. On the other hand, meals served on natural wooden tableware were rated more positively than those served on plastic tableware before and after meals. These results suggest that, in Japan, the use of tableware, even for ready-made meals, increases the level of meal satisfaction. These findings have implications for both the providers and consumers of ready-made meals as well as the food industry.

THE MEANING OF “O ΠOTE” ON IN ARISTOTLE’S ON GENERATION AND CORRUPTION AND PARTS OF ANIMALS: TOWARDS A BETTER UNDERSTANDING OF PHYSICS, IV, 11 AND 14

Méthexis ◽  
2012 ◽  
Vol 25 (1) ◽  
pp. 71-91
Author(s):  
GIAMPAOLO ABBATE
Keyword(s):  
The Other ◽  
Physical Research ◽  
Before And After ◽  
Points Of View ◽  
The Difference ◽  
Definition Of

In the end of the section 219a 10-21 of the 11th chapter of Physics IV Aristotle defines the ‘before and after’ in movement as follows: «The ‘before and after’ in motion is identical ὅ ποτε ὂυ with motion, yet differs from it τò εἶυατ αύτῷ, and is not identical with motion t (11. 19-21)». These lines convey the answer to the question whether the ‘before’ and after’ are the same thing as movement or not: in one sense, ὅ ποτε ὂυ, they are, in another sense, τò εἶυαι, they are not. But, first and foremost, the opposition of ὅ ποτε ὂυ to то τò εἶυαι is very useful to Aristotle to solve the main aporia of the chapter about the contradictory – at a first sight – and concurrent diversity and identity of the instant, τò υῠυ. Therefore, this aporia will be solved, if only ὅ ποτε ὂυ and то τò εἶυαι mean two really opposing points of view. But what are these points of view? What do they really mean? As it is well known, the phrase ὅ ποτε ὂυ is one of the most enigmatic in the Aristotelian corpus, and yet one of the most important in his physical research because concerns the nature and definition of time. The lower was the agreement among the scholars, with greater force the debate has flared up. An alternative way for attempting to successfully tackle the problem is take in consideration the occurrence of the same phrase in other works than Physica, since the other occurrences of it in the 11th and 14th chapter of the same book are of no help. It is present in only two other works: On Generation and Corruption, I, 3, 319b 3 and Parts of Animals, II, 2, 649a 15; II, 3, 649b 24. In both works we are led to take ὅ ποτε ὂυ as being associated to such terms as ύποκεἰμενον and ύπóκειται. So, Aristotle seems to point out a contrast between a formal respect and a material respect by the opposition of τò εἶυαι to ὅ ποτε ὂυ. The reading of all passages from Physics – particularly, 219a 20-21 – wherein ὅ ποτε ὂυ occurs provides further confirmation of this contrast. As matter of fact, in all three works τò εἶυαι was employed by Aristotle for the same purpose: to set out the difference between a substratum of its own and its ability to actually exist just as substratum underlying worldly things. This difference implies that a substratum cannot but be limited by or relating to time. A condition which is emphasized by the presence of the term ποτε. In conclusion, each instant comes out from the division by the ‘before and after’ of movement’s substratum. If this substratum is found to exist in time, the ‘before and after’ turns out to be ‘what that is now and then’ (ὅ ποτε ὂυ), which, reversely, is the same as the ‘before and after’ in the movement. The occurrences of the incomplete phrase (as ὅ ποτε plus other verbal voices than ὂυ) in other works substantiate this view.

scholarly journals RATIO OF COMMERCIAL ELECTRICITY LOSSES IN POWER NETWORKS BEFORE AND AFTER INSTALLATION OF INTELLIGENT METERING DEVICES

2021 ◽  
pp. 86-98
Author(s):  
Georgi M. Mikheev ◽  
Ayrat G. Ziganshin ◽  
Dmitriy A. Mironov
Keyword(s):  
Electric Power ◽  
The Other ◽  
Power Losses ◽  
Power Networks ◽  
Electric Networks ◽  
Before And After ◽  
The Difference ◽  
The Republic ◽  
Power Metering ◽  
Transmission And Distribution

Relative losses of electric power during transmission and distribution in electric networks are considered in the paper. The components of commercial losses of electric power and their structure are given. From the presented data of technical and commercial losses of some areas of power networks of «ПАО «MRSK of Volga» – «Chuvashenergo» following the results of one month 2020, calculated with the use of «RAP-Standard» program according to the statements of power sales, it follows that total losses are from 11,6 to 17%. By the example of two sections of power grid companies of PAO MRSK of Volga – Chuvashenergo and the Republic of Tatarstan a comparison of commercial losses before and after the installation of intelligent power metering devices was made. It is estimated that the difference in electric power losses after installation of «smart» electric meters at both sites of the above mentioned enterprises was significantly reduced: at one site from 14 to 5.1%, and at the other – from 17.3 to 9.4%. It is shown that specific losses after installation of intellectual metering devices in Verkhneuslonsky district settlement of JSC «Grid Company» Buinskie Power Networks per one metering device decreased by 19.7%.

Comparison of Several Methods for Optimal Sensor Placement in Structural Health Monitoring

2011 ◽  
Vol 250-253 ◽  
pp. 3254-3257
Author(s):  
Xiao Meng Sun ◽  
Zi Cai Yan ◽  
Da Yong Zhu
Keyword(s):  
Damage Detection ◽  
Fisher Information ◽  
Health Monitoring ◽  
Optical Sensor ◽  
Structural Damage ◽  
The Other ◽  
Structural Damage Detection ◽  
The Difference ◽  
Methods Numerical ◽  
Sensor Locations

This paper begins with an introduction of two existing methods of prioritizing sensor locations, effective independence (EI) method and damage sensitivity (DS) method, followed by a new method (DRS) based on the harmony between damage identifiability and modal observability. For the comparison of these methods, the difference and relationship between these Fisher information matrixes (FIMs) is examined by a quasi-analytical mode. In addtion, this approach discusses the adaptability of the three methods. Numerical example indicates the limitation of EI method and DS method, and DRS method effectively avoids the contradiction between the two different optimization criterions. Finally, utilizing the result of the optical sensor locations, the results of structural damage detection by DRS method are much more accurate comparing with the other two methods on the whole.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

SHM of Composite Mono-Stringer Elements Based on Guided Waves

2019 ◽  
Vol 827 ◽  
pp. 464-469 ◽  
Author(s):  
D.G. Bekas ◽  
M. Mora Mendias ◽  
Zahra Sharif Khodaei ◽  
Evangelos Karachalios ◽  
F.J. Chamorro Alonso ◽  
...  
Keyword(s):  
Damage Detection ◽  
Health Monitoring ◽  
Guided Waves ◽  
Impact Damage ◽  
Guided Wave ◽  
Piezoelectric Transducers ◽  
Weighted Energy ◽  
Wave Measurements ◽  
Before And After ◽  
Manufacturing Technologies

In this work, the applicability of structural health monitoring (SHM) technique for damage detection in two composite mono-stringers representative of composite fuselage are investigated. The two different manufacturing technologies are co-curing and co-bonding of composite mono-stringers to the skin. The panels were then impacted at the foot of the stringer to cause Barely Visible Impact Damage (BVID). Piezoelectric transducers were surface mounted on the mono-stringers, guided wave measurements before and after impact were taken and used for detecting damage based on Weighted Energy Arrival Method (WEAM).

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