Cracking Mechanism of Long Concrete Bedding Cushion and Prevention Method

2010 ◽  
Vol 163-167 ◽  
pp. 880-887 ◽  
Author(s):  
Zhen Yang Zhu ◽  
Sheng Qiang ◽  
Min Zhi Liu ◽  
Hai Bo Wang
Keyword(s):  
High Temperature ◽  
Temperature Difference ◽  
Temperature Fluctuation ◽  
Control Measure ◽  
Temperature Drop ◽  
Thermal Control ◽  
Cold Season ◽  
Control Measures ◽  
3D Fem ◽  
Cracking Mechanism

The long concrete bedding cushions are more vulnerable to cracking than the dam concrete, even the cushion is much shorter than the dam block, especially those constructed in hot season and the off period lasts long. The cracking mechanism of such cushion is studied and presented in this paper. There are several reasons contribute to the cracks of bedding cushion, but the thermal stress is the main factor. The temperature distribution is always unevenly during the construction period of bedding cushion. During the long off period, temperature drop in local high temperature zone, temperature fluctuation and temperature difference between inside and surface are the main factors causing cracks for bedding cushion without proper thermal control measures. Some thermal control measures are always used in practical engineering, but it can not always effectively prevent bedding cushion from cracking. Reasonable water pipes cooling measure, which can prevent local high temperature at the early age of construction, and effective heat preservation measures in cold season, which can reduce temperature difference between inside and surface and temperature fluctuation, are necessary to prevent cracking. One bedding cushion of concrete dam is numerically stimulated by 3D FEM, and effective temperature control measure is proposed in this paper.

Temperature Control Measures Optimization of RCC Gravity Dam

2012 ◽  
Vol 226-228 ◽  
pp. 1153-1156 ◽  
Author(s):  
Shu Ping Huang ◽  
Jian Yun Fu ◽  
Yan Cai Li
Keyword(s):  
Temperature Control ◽  
Simulation Analysis ◽  
Control Measure ◽  
Control Measures ◽  
Gravity Dam ◽  
Mass Concrete ◽  
Dam Construction ◽  
Construction Technology ◽  
3D Fem ◽  
Single Temperature

With the continuous development of dam construction technology, the RCC dam becomes one of the most popular types of dam in the world with its unique advantages. Temperature control measures research is one of the key issues of design and construction of mass concrete structures. How to choose the proper temperature control measures to prevent concrete cracks becomes the important problem of dam construction technology. In a RCC gravity dam, the climate environment is so severe that a single temperature control measure can’t meet the requirements of temperature control and crack prevention. In this paper, 3D FEM simulation analysis is used to calculate temperature field and thermal creep stress field during the whole construction process. According to the simulation results, the temperature control measures design of the dam has been comprehensively evaluated and the temperature control measures of this project have been put forward.

Characterizing the effectiveness of COVID-19 mitigation measures: A data-centric approach (Preprint)

2020 ◽  
Author(s):  
Lukman Olagoke ◽  
Ahmet E. Topcu
Keyword(s):  
Control Measure ◽  
Control Measures ◽  
World Health ◽  
Mitigation Measures ◽  
Effective Control ◽  
The World ◽  
Decision Making Processes ◽  
And Performance ◽  
Health Organization ◽  
The Impact

BACKGROUND COVID-19 represents a serious threat to both national health and economic systems. To curb this pandemic, the World Health Organization (WHO) issued a series of COVID-19 public safety guidelines. Different countries around the world initiated different measures in line with the WHO guidelines to mitigate and investigate the spread of COVID-19 in their territories. OBJECTIVE The aim of this paper is to quantitatively evaluate the effectiveness of these control measures using a data-centric approach. METHODS We begin with a simple text analysis of coronavirus-related articles and show that reports on similar outbreaks in the past strongly proposed similar control measures. This reaffirms the fact that these control measures are in order. Subsequently, we propose a simple performance statistic that quantifies general performance and performance under the different measures that were initiated. A density based clustering of based on performance statistic was carried out to group countries based on performance. RESULTS The performance statistic helps evaluate quantitatively the impact of COVID-19 control measures. Countries tend show variability in performance under different control measures. The performance statistic has negative correlation with cases of death which is a useful characteristics for COVID-19 control measure performance analysis. A web-based time-line visualization that enables comparison of performances and cases across continents and subregions is presented. CONCLUSIONS The performance metric is relevant for the analysis of the impact of COVID-19 control measures. This can help caregivers and policymakers identify effective control measures and reduce cases of death due to COVID-19. The interactive web visualizer provides easily digested and quick feedback to augment decision-making processes in the COVID-19 response measures evaluation. CLINICALTRIAL Not Applicable

Experimental results of the Li-Pb-Pt system obtained by the high temperature drop calorimetry

2021 ◽  
pp. 115824
Author(s):  
S. Terlicka ◽  
A. Dębski ◽  
W. Gąsior ◽  
A. Fornalczyk ◽  
M. Saternus
Keyword(s):  
High Temperature ◽  
Temperature Drop ◽  
Experimental Results ◽  
Drop Calorimetry

scholarly journals Using Commercial Compost as Control Measures against Cucumber Root-Rot Disease

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Kamel Kamal Sabet ◽  
Magdy Mohamed Saber ◽  
Mohamed Adel-Aziz El-Naggar ◽  
Nehal Samy El-Mougy ◽  
Hatem Mohamed El-Deeb ◽  
...  
Keyword(s):  
Root Rot ◽  
Control Measure ◽  
Disease Incidence ◽  
Pathogenic Fungi ◽  
Pythium Ultimum ◽  
Control Measures ◽  
Infested Soil ◽  
Fungal Isolates ◽  
Cucumber Root

Five commercial composts were evaluated to suppress the root-rot pathogens (Fusarium solani (Mart.) App. and Wr, Pythium ultimum Trow, Rhizoctonia solani Kuhn, and Sclerotium rolfsii Sacc.) of cucumber plants under in vitro and greenhouse conditions. In vitro tests showed that all tested unautoclaved and unfiltrated composts water extracts (CWEs) had inhibitor effect against pathogenic fungi, compared to autoclaved and filtrated ones. Also, the inhibitor effects of 40 bacteria and 15 fungi isolated from composts were tested against the mycelial growth of cucumber root-rot pathogens. Twenty two bacteria and twelve fungal isolates had antagonistic effect against root-rot pathogens. The antagonistic fungal isolates were identified as 6 isolates belong to the genus Aspergillus spp., 5 isolates belong to the genus Penicillium spp. and one isolate belong to the genus Chaetomium spp. Under greenhouse conditions, the obtained results in pot experiment using artificial infested soil with cucumber root-rot pathogens showed that the compost amended soil reduced the percentage of disease incidence, pathogenic fungi population, and improved the cucumber vegetative parameters as shoot length, root length, fresh weight, and dry weight. These results suggested that composts are consequently considered as control measure against cucumber root-rot pathogens.

Control (supervisory) measures: innovations of Federal Law “On State Control (Supervision) and Municipal Control in the Russian Federation”

2021 ◽  
pp. 25-32
Author(s):  
O.V. Shinkareva ◽  
V.A. Dikikh
Keyword(s):  
Russian Federation ◽  
Control Measure ◽  
Control Measures ◽  
State Control ◽  
Federal Law ◽  
Field Inspection ◽  
Control Actions ◽  
The Russian Federation

The article is devoted to the analysis of the types of control measures that will be carried out in accordance with Federal Law No. 248-FZ of the “On State Control (Supervision) and Municipal Control in the Russian Federation”, the main provisions of which will enter into force on July 1, 2021. This law also applies to the activities of organizations that are subject to licensing. Types of control (supervisory) measures are considered, in particular, control and monitoring procurement, inspection visit, raid inspection, documentary and field inspection, as well as monitoring compliance with mandatory requirements and field examination. The essence of each type of control measure, the basis for carrying out the measures, control actions that can be used in their implementation are analyzed.

scholarly journals Enthalpy of formation of U3Si2: A high-temperature drop calorimetry study

2018 ◽  
Vol 507 ◽  
pp. 44-49 ◽  
Author(s):  
Xiaofeng Guo ◽  
Joshua T. White ◽  
Andrew T. Nelson ◽  
Artaches Migdisov ◽  
Robert Roback ◽  
...  
Keyword(s):  
High Temperature ◽  
Enthalpy Of Formation ◽  
Temperature Drop ◽  
Drop Calorimetry

scholarly journals SELF-REPORTED MALARIA AND MOSQUITO AVOIDANCE IN RELATION TO HOUSEHOLD RISK FACTORS IN A KENYAN COASTAL CITY

2005 ◽  
Vol 37 (6) ◽  
pp. 761-771 ◽  
Author(s):  
JOSEPH KEATING ◽  
KATE MACINTYRE ◽  
CHARLES M. MBOGO ◽  
JOHN I. GITHURE ◽  
JOHN C. BEIER
Keyword(s):  
Rural Areas ◽  
Mosquito Control ◽  
Control Measure ◽  
Control Measures ◽  
Level Control ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Household Level ◽  
Household Factors ◽  
History Of

A geographically stratified cross-sectional survey was conducted in 2002 to investigate household-level factors associated with use of mosquito control measures and self-reported malaria in Malindi, Kenya. A total of 629 households were surveyed. Logistic regressions were used to analyse the data. Half of all households (51%) reported all occupants using an insecticide-treated bed net and at least one additional mosquito control measure such as insecticides or removal of standing water. Forty-nine per cent reported a history of malaria in the household. Of the thirteen household factors analysed, low (OR=0·23, CI 0·11, 0·48) and medium (OR=0·50, CI 0·29, 0·86) education, mud–wood–coral (OR=0·0·39, CI 0·24, 0·66) and mud block–plaster (OR=0·47, CI 0·25, 0·87) wall types, farming (OR=1·38, CI 1·01, 1·90) and travel to rural areas (OR=0·48, CI 0·26, 0·91) were significantly associated with the use of mosquito control, while controlling for other covariates in the model. History of reported malaria was not associated with the use of mosquito control (OR=1·22, CI 0·79, 1·88). Of the thirteen covariates analysed in the second model, only two household factors were associated with history of malaria: being located in the well-drained stratum (OR=0·49, CI 0·26, 0·96) and being bitten while in the house (OR=1·22, CI 0·19, 0·49). These results suggest that high socioeconomic status is associated with increased household-level mosquito control use, although household-level control may not be enough, as many people are exposed to biting mosquitoes while away from the house and in areas that are more likely to harbour mosquitoes.

scholarly journals Estimating Economic Losses Caused by COVID-19 under Multiple Control Measure Scenarios with a Coupled Infectious Disease—Economic Model: A Case Study in Wuhan, China

2021 ◽  
Vol 18 (22) ◽  
pp. 11753
Author(s):  
Xingtian Chen ◽  
Wei Gong ◽  
Xiaoxu Wu ◽  
Wenwu Zhao
Keyword(s):  
Infectious Disease ◽  
Economic Model ◽  
Control Measure ◽  
Central Valley ◽  
Economic Cost ◽  
Assessment Method ◽  
Control Measures ◽  
Economic Losses ◽  
Multiple Control ◽  
Health Crisis

Background: The outbreak of the COVID-19 epidemic has caused an unprecedented public health crisis and drastically impacted the economy. The relationship between different control measures and economic losses becomes a research hotspot. Methods: In this study, the SEIR infectious disease model was revised and coupled with an economic model to quantify this nonlinear relationship in Wuhan. The control measures were parameterized into two factors: the effective number of daily contacts (people) (r); the average waiting time for quarantined patients (day) (g). Results: The parameter r has a threshold value that if r is less than 5 (people), the number of COVID-19 infected patients is very close to 0. A “central valley” around r = 5~6 can be observed, indicating an optimal control measure to reduce economic losses. A lower value of parameter g is beneficial to stop COVID-19 spread with a lower economic cost. Conclusion: The simulation results demonstrate that implementing strict control measures as early as possible can stop the spread of COVID-19 with a minimal economic impact. The quantitative assessment method in this study can be applied in other COVID-19 pandemic areas or countries.

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