scholarly journals Experimental Investigation of Crack Initiation and Propagation in the Unreinforced Masonry Specimen Subjected to Vertical Settlement

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Junbo Wang ◽  
Weibing Hu ◽  
Xinyu Wang ◽  
Yaozhe Liang

To study the cracking process of the wall caused by differential settlement under a uniformly distributed load on the top of the wall, a laboratory model experiment was carried out on large-scale masonry specimens, and the acoustic emission (AE) technique and digital close-range industrial photogrammetry were adopted to monitor the AE signals and displacement characteristics of the masonry specimens during loading in real time. The results show that, in the case of differential settlement with small settlement on both sides and large settlement in the middle, two main cracks appear on the left and right sides of the wall, extending obliquely from bottom to top. During the loading process, damage of the wall is aggravated due to the differential settlement, and both cumulative ringing count and energy count have different periods of steep rise. With the increase in the load and activation of the AE event, the AE event becomes active, and the cumulative ringing count and cumulative energy curve have an obvious turning point, where the slope of the curve is substantially higher than that before the turning point. By using digital close-range industrial photogrammetry, it is observed that the main oblique crack on the left is mainly caused by the difference in the vertical deformation, while the main oblique crack on the right is caused by different displacements and deformation directions of the wall on both sides of the crack.

1971 ◽  
Vol 17 (10) ◽  
pp. 1047-1049 ◽  
Author(s):  
S Raymond Gambino ◽  
Ivelice Fonseca

Abstract Comparable results are obtained when serum calcium is measured by a colorimetric cresolpthalein method on the Technicon SMA 12/60 and by atomic absorption spectrophotometry (Instrumentation Laboratory Model 153 instrument), with strontium as an internal standard. Sera from 250 patients with abnormal calcium concentrations, ranging from 4.9 mg/100 ml to 9.0 mg/100 ml, were measured by each method; the difference between the means for each method was only 0.04 mg/100 ml. The standard deviation of the difference between paired results was ±0.16 mg/100 ml. We were unable to discover any effect of drug or disease on the colorimetric assay, which therefore is suitable for use in large-scale surveys. On the other hand, the more precise atomic absorption spectrophotometry is suitable for use as a reference method. In addition, with an internal standard it is fast and simple, making it suitable for emergency assays of calcium 24 h a day.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Tingye Qi ◽  
Guorui Feng

To understand the characteristics of the acoustic emission (AE) and electrical resistivity of cemented coal gangue backfill (CGB) under uniaxial compression, the variations in these characteristics at 1 day, 3 days, and 7 days are analyzed by means of a stress-strain-resistivity-AE test, and the microperformances are investigated. The research results indicate that the AE can reflect the initiation and propagation of cracks and later explain the variation of the resistivity of the specimens under the uniaxial loading. The cumulative energy curve of AE is approximately two straight lines corresponding to the peak stress, and the difference in the linear slope gradually decreased with the increasing curing time due to the lower pore solution content and the compact pore structure. The relationships between the stress and resistivity and the loading condition before and after the peak stress at different curing times were established. Therefore, it is of great significance to predict the stability of the filling body by monitoring the AE and resistivity variations of the filling body. In addition, it is possible to calculate the roof stress using the relation equation between the resistivity and stress.


Author(s):  
Ni Luh Gede Aris Maytadewi Negara ◽  
I Dewa Putu Sutjana ◽  
Luh Made Indah Sri Handari Adiputra

Industrial activities developed from households to large-scale industries, including the development of industries in the field of canning fish. Worker health is one of the important things in a company, can be achieved by choosing the right work method. This study was conducted to determine whether ergonomic oriented working methods in the process of wiping canned sardines can reduce musculoskeletal complaints and fatigue in workers. The study design was two period cross over pre and post-test group desig). The research was conducted at PT. BMP Negara. It was held in December 2016. Total sample were 18 workers who wiping cans of sardines. The difference in conditions between before and after activities using ergonomic un-oriented working methods and ergonomic oriented working methods are compared and tested statistically. Comparison tests were carried out on scores of musculoskeletal complaints and worker fatigue. The results showed that ergonomic oriented working methods decreased of musculoskeletal complaints 17.82% (p<0.05) and fatigue score of 11.86% (p<0.05). The conclusion of this study is that ergonomic oriented working methods in the process of wiping sardine cans reduce musculoskeletal complaints and work fatigue of workers in PT. BMP Negara.


2021 ◽  
Vol 18 (4) ◽  
pp. 558-566
Author(s):  
Weiqiang Zhang ◽  
Zhoujian Shi ◽  
Zuoquan Wang ◽  
Shaoteng Zhang

Abstract The changes in the acoustic emission signals of sandstone after treatment at different high temperatures are examined in this study. The results show that there is a critical point on the cumulative energy curve of the acoustic emission signals (almost between 60 and 90% of the ratio of the loading time and the total loading time), which can be used to identify the failure of sandstone that has been damaged by exposure to a temperature of 900°C. As the temperature increases, the position of the critical point gradually changes, which indicates that high temperatures increase the plasticity of rock, and this gradually reduces the brittleness. The changes in b-value of acoustic emission shows that the transition behavior of rock from brittleness to plasticity is more obvious at temperatures higher than 600°C, and the large-scale micro cracking takes place at that temperature range, which is the main reason for the weakening and brittleness and the strengthening of plasticity of the sandstone.


1999 ◽  
Vol 4 (1) ◽  
pp. 6-7
Author(s):  
James J. Mangraviti

Abstract The accurate measurement of hip motion is critical when one rates impairments of this joint, makes an initial diagnosis, assesses progression over time, and evaluates treatment outcome. The hip permits all motions typical of a ball-and-socket joint. The hip sacrifices some motion but gains stability and strength. Figures 52 to 54 in AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, illustrate techniques for measuring hip flexion, loss of extension, abduction, adduction, and external and internal rotation. Figure 53 in the AMA Guides, Fourth Edition, illustrates neutral, abducted, and adducted positions of the hip and proper alignment of the goniometer arms, and Figure 52 illustrates use of a goniometer to measure flexion of the right hip. In terms of impairment rating, hip extension (at least any beyond neutral) is irrelevant, and the AMA Guides contains no figures describing its measurement. Figure 54, Measuring Internal and External Hip Rotation, demonstrates proper positioning and measurement techniques for rotary movements of this joint. The difference between measured and actual hip rotation probably is minimal and is irrelevant for impairment rating. The normal internal rotation varies from 30° to 40°, and the external rotation ranges from 40° to 60°.


VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.


2020 ◽  
Vol 6 (2) ◽  
pp. 187-197
Author(s):  
Nurlaila Suci Rahayu Rais ◽  
Dedeh Apriyani ◽  
Gito Gardjito

Monitoring of warehouse inventory data processing is an important thing for companies. PT Talaga mulya indah is still manual using paper media, causing problems that have an effect on existing information, namely: problems with data processing of incoming and outgoing goods. And the difference between data on the amount of stock of goods available with physical data, often occurs inputting data more than once for the same item, searching for available data, and making reports so that it impedes companies in monitoring inventory of existing stock of goods. Which aims to create a system that can provide updated information to facilitate the warehouse admin in making inventory reports, and reduce errors in input by means of integrated control. In this study, the authors used the data collection method used in this analysis using the method of observation, interviews, and literature review (literature study). For analysis using the PIECES analysis method. Furthermore, the system design used is UML (Unified Modeling Language). The results of this study are expected to produce the right data in the process of monitoring inventory data processing, also can provide the right information and make it easier to control the overall availability of goods.


2018 ◽  
pp. 1-34
Author(s):  
Andrew Jackson

One scenario put forward by researchers, political commentators and journalists for the collapse of North Korea has been a People’s Power (or popular) rebellion. This paper analyses why no popular rebellion has occurred in the DPRK under Kim Jong Un. It challenges the assumption that popular rebellion would happen because of widespread anger caused by a greater awareness of superior economic conditions outside the DPRK. Using Jack Goldstone’s theoretical expla-nations for the outbreak of popular rebellion, and comparisons with the 1989 Romanian and 2010–11 Tunisian transitions, this paper argues that marketi-zation has led to a loosening of state ideological control and to an influx of infor-mation about conditions in the outside world. However, unlike the Tunisian transitions—in which a new information context shaped by social media, the Al-Jazeera network and an experience of protest helped create a sense of pan-Arab solidarity amongst Tunisians resisting their government—there has been no similar ideology unifying North Koreans against their regime. There is evidence of discontent in market unrest in the DPRK, although protests between 2011 and the present have mostly been in defense of the right of people to support themselves through private trade. North Koreans believe this right has been guaranteed, or at least tacitly condoned, by the Kim Jong Un government. There has not been any large-scale explosion of popular anger because the state has not attempted to crush market activities outright under Kim Jong Un. There are other reasons why no popular rebellion has occurred in the North. Unlike Tunisia, the DPRK lacks a dissident political elite capable of leading an opposition movement, and unlike Romania, the DPRK authorities have shown some flexibility in their anti-dissent strategies, taking a more tolerant approach to protests against economic issues. Reduced levels of violence during periods of unrest and an effective system of information control may have helped restrict the expansion of unrest beyond rural areas.


2013 ◽  
Vol 3 (2) ◽  
pp. 438-473
Author(s):  
M. Heri Fadoil

Abstract: Abdul Karim Soroush judges that religious rule is incorrect assessment of the application of Islamic jurisprudence. In a religious society, Islamic jurisprudence obtains the right to govern. It is, of course, necessary to establish a kind of Islamic jurisprudence-based religious rule. Soroush firmly rejects it because such interpretation is too narrow. As for democracy, Soroush argues that the system used is not necessarily equal to that of the Western. On the contrary, Ayatollah Khomeini’s thoughts on religious rule are reflected in the so called wilayat al-faqih. It is a religious scholar-based government. Democracy, according to him, is the values of Islam itself, which is able to represent the level of a system to bring to the country’s progress. Principally, there are some similarities between the ideas of Ayatollah Khomeini and those of Abdul Karim Soroush in term of religiosity. They assume that it is able to sustain the religious system of government. The difference between both lies on the application of religiosity itself. Ayatollah Khomeini applies the concept of a religious scholar-based government, while Abdul Karim Soroush rejects the institutionalization of religion in the government or state.Keywords: Governance, democracy, Abdul Karim Soroush, Ayatollah Khomeini


Author(s):  
Anne Phillips

No one wants to be treated like an object, regarded as an item of property, or put up for sale. Yet many people frame personal autonomy in terms of self-ownership, representing themselves as property owners with the right to do as they wish with their bodies. Others do not use the language of property, but are similarly insistent on the rights of free individuals to decide for themselves whether to engage in commercial transactions for sex, reproduction, or organ sales. Drawing on analyses of rape, surrogacy, and markets in human organs, this book challenges notions of freedom based on ownership of our bodies and argues against the normalization of markets in bodily services and parts. The book explores the risks associated with metaphors of property and the reasons why the commodification of the body remains problematic. The book asks what is wrong with thinking of oneself as the owner of one's body? What is wrong with making our bodies available for rent or sale? What, if anything, is the difference between markets in sex, reproduction, or human body parts, and the other markets we commonly applaud? The book contends that body markets occupy the outer edges of a continuum that is, in some way, a feature of all labor markets. But it also emphasizes that we all have bodies, and considers the implications of this otherwise banal fact for equality. Bodies remind us of shared vulnerability, alerting us to the common experience of living as embodied beings in the same world. Examining the complex issue of body exceptionalism, the book demonstrates that treating the body as property makes human equality harder to comprehend.


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