Investigating out-of-specification test results of mass concentration of total suspended particulates in air based on metrological concepts—a case study

In this paper a case study about concrete strength assessment of bridge structure experiencing fire is discussed. Assessment methods include activities of visual inspection, concrete testing by Hammer Test, Ultrasonic Pulse Velocity Test, and Core Test. Then, test results are compared with the requirement of RSNI T-12-2004. Test results show that surface concrete at the location of fire deteriorates so that its quality is decreased into the category of Very Poor with ultrasonic pulse velocity ranges between 1,14 – 1,74 km/s. From test results also it can be known that concrete compressive strength of inner part of bridge pier ranges about 267 – 274 kg/cm2 and concrete compressive strength of beam and plate experiencing fire directly is about 173 kg/cm2 and 159 kg/cm2. It can be concluded that surface concrete strength at the location of fire does not meet the requirement of RSNI T-12-2004. So, repair on surface concrete of pier, beam, and plate at the location of fire is required.

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Seasonal Variations and Evidence for the Effectiveness of Pollution Controls on Water-Soluble Inorganic Species in Total Suspended Particulates and Fine Particulate Matter from Xi’an, China

Journal of the Air & Waste Management Association ◽

10.3155/1047-3289.58.12.1560 ◽

2008 ◽

Vol 58 (12) ◽

pp. 1560-1570 ◽

Cited By ~ 96

Author(s):

Zhenxing Shen ◽

Richard Arimoto ◽

Junji Cao ◽

Renjian Zhang ◽

Xuxiang Li ◽

...

Keyword(s):

Particulate Matter ◽

Seasonal Variations ◽

Fine Particulate Matter ◽

Water Soluble ◽

Suspended Particulates ◽

Total Suspended Particulates ◽

Fine Particulate ◽

Inorganic Species

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Investigation of the Sedimentation Property of Backfill Material on the Basis of Rheological Test: A Case Study of Iron Tailings

Journal of Chemistry ◽

10.1155/2018/9530767 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Yong Wang ◽

Aixiang Wu ◽

Lianfu Zhang ◽

Hongjiang Wang ◽

Fei Jin

Keyword(s):

Shear Stress ◽

Shear Rate ◽

Mass Concentration ◽

Filling Material ◽

Quantitative Characterization ◽

Filling Materials ◽

Characterization Studies ◽

Rheological Test ◽

Sedimentation Property

Sedimentation of filling materials could cause pipe blocking accident in mines. However, few quantitative characterization studies have investigated the sedimentation characteristics of filling materials. In this study, the sedimentation property of iron tailings with a cement-sand ratio of 1 : 4 and mass concentration of 73%∼82% was investigated based on rheology measurements. Results showed that shear stress increased as shear rate rose from 0 s−1to 120 s−1. The shear stress increased as the filling material concentration increased as well. However, when the shear rate was reversed from 120 s−1to 0 s−1, the shear stress presented an increase-constant-decrease change pattern as the mass concentration increases in the rheological curve. Accordingly, the sedimentation performance of iron tailings filling material was divided into three types: intense sedimentation (the ascending rheological curve) in the mass concentration range of 73%∼76%, slight sedimentation (the constant rheological curve) in the mass concentration range of 77%∼79%, and almost no sedimentation (the descending rheological curve) in the mass concentration range of 80%∼82%. The associated mechanism involving slurry mass concentration-rheological curves-sedimentation performance was illustrated. A correlation between the pipeline rheology and filling material sedimentation performance was established, which provides a practical guide to avoid pipeline blocking while transporting the filling material.

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Distributions of phthalic esters carried by total suspended particulates in Nanjing, China

Environmental Monitoring and Assessment ◽

10.1007/s10661-011-2458-z ◽

2011 ◽

Vol 184 (11) ◽

pp. 6789-6798 ◽

Cited By ~ 43

Author(s):

Wenxin Wang ◽

Yinlong Zhang ◽

Shuiliang Wang ◽

Chinbay Q. Fan ◽

Hui Xu

Keyword(s):

Suspended Particulates ◽

Total Suspended Particulates

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Formation and evolution mechanism of regional haze: a case study in the megacity Beijing, China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-16259-2012 ◽

2012 ◽

Vol 12 (7) ◽

pp. 16259-16292 ◽

Cited By ~ 5

Author(s):

X. Liu ◽

J. Li ◽

Y. Qu ◽

T. Han ◽

L. Hou ◽

...

Keyword(s):

Wind Speed ◽

Mass Concentration ◽

Empirical Relationship ◽

Surface Wind ◽

Atmospheric Environment ◽

Evolution Mechanism ◽

Regional Haze ◽

Formation And Evolution ◽

The Government

Abstract. The main objective of this study is to investigate the formation and evolution mechanism of the regional haze in megacity Beijing by analyzing the process of a severe haze that occurred 20–27 September 2011. Mass concentration and size distribution of aerosol particles as well as aerosol optical properties were concurrently measured at the Beijing urban atmospheric environment monitoring station. Gaseous pollutants (SO2, NO-NO2-NOx, O3, CO) and meteorological parameters (wind speed, wind direction, and relative humidity (RH)) were simultaneously monitored. Meanwhile, aerosol spatial distribution and the height of planetary boundary layer (PBL) were retrieved from the signal of satellite and LIDAR (light detection and ranging). Results showed that high intensity of local pollutants from Beijing urban source is the fundamental cause that led to the regional haze. Meteorological factors such as higher RH, weak surface wind speed, and decreasing height of PBL played an important role on the deterioration of air quality. New particle formation was considered to be the most important factor contributing the formation of haze. In order to improve the atmospheric visibility and reduce the occurrence of the haze, the mass concentration of PM2.5 at dry condition should be less than 60 µg m−3 in Beijing according to the empirical relationship of visibility, PM2.5 mass concentration and RH. This case study may provide valuable information for the public to recognize the formation mechanism of the regional haze event over the megacity, which is also useful for the government to adopt scientific approach to forecast and eliminate the occurrence of regional haze in China.

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Challenges to Overcome and Scaffolding to Build on

International Journal of Computer-Assisted Language Learning and Teaching ◽

10.4018/ijcallt.2019070104 ◽

2019 ◽

Vol 9 (3) ◽

pp. 50-67

Author(s):

Hao Yang ◽

Zhiqiang Ma

Keyword(s):

Teacher Perceptions ◽

Flipped Classroom ◽

Public University ◽

Test Results ◽

Learning Behavior ◽

Long Term Effects ◽

Exploratory Case Study ◽

Flipped Classrooms

While current research on the flipped classroom generally focuses on test results and (or) student/teacher perceptions as a measurement of its pedagogical efficacy, students' adaptation to it and the essential conditions for its application are rarely explored. This exploratory case study aims to rectify this by examining how university students adapted to flipped classrooms implemented in a public university in East China. The findings suggest that while the flipped model is impeded by entrenched polarity between students in terms of their learning dispositions and academic competence, students do develop a prototype of theories of learning, a sense of better self through learning from their peers and an awareness of the importance of intrinsic motivation. A gradualist approach is thus proposed for implementing flipped classrooms, which requires longitudinal studies accordingly to understand its long-term effects on learning behavior hitherto left unexplored.

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Experimental Study on the Transverse Effective Bending Rigidity of Segmental Lining Structures

Advances in Civil Engineering ◽

10.1155/2020/8836505 ◽

2020 ◽

Vol 2020 ◽

pp. 1-20

Author(s):

Yong-feng Tang ◽

Han-cheng Chen ◽

Zhen-wei Ye ◽

Ting-jin Liu ◽

Yu-bing Yang

Keyword(s):

Regression Equation ◽

Shield Tunnel ◽

Outer Diameter ◽

Test Results ◽

Bending Rigidity ◽

Segmental Lining ◽

Ring Model ◽

Scale Models ◽

Elastic Stage

The transverse effective rigidity ratio is a key parameter when the uniform rigidity ring model is adopted to design or numerically analyse segmental lining structures commonly used on a shield-driven tunnel. Traditionally, the transverse effective rigidity ratio η is treated as a constant, which can be evaluated through theoretical analysis and model tests. In this study, scale models were designed and tested to investigate the variation of the transverse effective rigidity ratio in the segmental linings’ flattening deformation process. The test results suggested that in the elastic stage, the transverse effective rigidity ratio fluctuated between 0.667 and 0.734 for the stagger-jointed rings and fluctuated between 0.503 and 0.642 for the straight-jointed rings. When segmental linings were squashed and started to crack at the circumferential joints, the transverse effective rigidity ratio decreases sharply. Then, a regression equation was obtained to fit the variation trend of η with the increase of horizontal convergence to the outer-diameter ratio (ΔD/Dout). Finally, in a case study, the regression equation was adapted to determine the value of η of an operated shield tunnel which was once surcharged accidentally and deformed severely so as to numerically predict the prospective deformation induced by the upcoming adjacent excavation. Numerical results indicated that as the value of η decreases, the horizontal convergences of shield tunnel induced by adjacent excavation increase significantly and even more than doubled in the case study. Comparatively, through taking account of the operating tunnels’ exiting transverse deformation, the predicted deformation tends to be unfavourable.

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