scholarly journals Research on the Decompression Effects of Shaft Explosion-Proof Door at Different Lifting Heights

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xue-Bo Zhang ◽  
Shuai-Shuai Shen ◽  
Zhi-Yang Gao ◽  
Ming Yang ◽  
Jing-Zhang Ren
Keyword(s):  
Shock Wave ◽  
Pressure Sensor ◽  
Testing System ◽  
Test Results ◽  
Gas Explosion ◽  
Exponential Relationship ◽  
Emergency Rescue ◽  
Set Up ◽  
Explosion Accidents

To study the decompression effects of shaft explosion-proof door at different lifting heights, this paper designed the gas explosion testing system. Based on the test results, this paper made a numeric analysis of the change regularities of the shock wave overpressure when the shaft explosion-proof door was lifted at different heights. Finally, this paper determined the proper lifting height of the shaft explosion-proof door and put forward the active decompression concept. The research showed that (1) the shock wave overpressure at the explosion-proof door decreased in a power exponential relationship as the lifting height increased. When the lifting height increased from 0 cm to 5 cm, the peak overpressure at the explosion-proof door decreased from 36.06 kPa to 22.47 kPa, dropping by 37.7%. When it was lifted at a height of 40 cm, the overpressure dropped to 11.20 kPa and the decompression reached 68.9%. (2) The overpressure at the ventilator decreased in a power exponential relationship as the lifting height increased. When the lifting height of the explosion-proof door increased from 0 cm to 5 cm, the decompression ratio reached the maximum 18.4%. After that, the decompression effect became worse and worse. (3) The explosion-proof door could depressurize and protect the ventilator at gas explosion but with limited effects. To protect the ventilator and the explosion-proof door to the maximum, it was suggested that the pressure sensor was set up somewhere in the mine where the gas explosion is likely to occur. In this way, the explosion was sensed in time and the explosion-proof door could be actively lifted for decompression. This paper was of great guiding significance in optimizing the design of the explosion-proof door equipment, reducing the loss of gas explosion accidents as well as carrying out the emergency rescue.

Research and Development of Nanometer Al2O3 Material Made for Rapid Detection of Gas Concentration Sensor

2013 ◽  
Vol 303-306 ◽  
pp. 42-44
Author(s):  
Hai Chen Li
Keyword(s):  
Research And Development ◽  
Gas Sensor ◽  
Rapid Detection ◽  
Test Results ◽  
Gas Explosion ◽  
Powder Preparation ◽  
Preparation Technology ◽  
Gas Concentration ◽  
Explosion Accidents ◽  
Sensor Detection

Coal Face Gas Concentration Overrun Is the Leading Cause of China Coal Mine Fatal Gas Explosion Accidents Reasons. Therefore, Research and Development of Rapid Detection of Gas Sensor Can Avoid Gas Explosion Accident Key. this Paper Studies the Al2o3 Nanometer Powder Preparation Technology, by Doping Rare Earth Material so that the Gas Sensor Detection Element Surface Area Was Greatly Improved; its Sensitivity and Stability Are Greatly Improved. According to the Test Results Show that, the Rapid Gas Sensor for Methane Reaction Time Is 6 Seconds, Recovery Time of 8 Seconds.

A process mining approach to improve emergency rescue processes of fatal gas explosion accidents in Chinese coal mines

2019 ◽  
Vol 111 ◽  
pp. 154-166 ◽  
Author(s):  
Zhen He ◽  
Qiong Wu ◽  
Lijie Wen ◽  
Gui Fu
Keyword(s):  
Process Mining ◽  
Coal Mines ◽  
Gas Explosion ◽  
Emergency Rescue ◽  
Explosion Accidents ◽  
Chinese Coal

Investigation of Damage Effect by Shock Wave on Structures in Excavation Roadway

2010 ◽  
Vol 439-440 ◽  
pp. 1438-1443
Author(s):  
Zhi Ming Qu
Keyword(s):  
Shock Wave ◽  
Ventilation System ◽  
Influential Factors ◽  
Damage Effect ◽  
Gas Explosion ◽  
Gas Detonation ◽  
Damage Degree ◽  
Explosion Mechanics ◽  
Set Up ◽  
Physical And Mathematical Models

Using the theory of explosion mechanics and gas detonation dynamics and the conservation law of mass, momentum and energy, the physical and mathematical models of damage effect are set up in excavation roadway during gas explosion. In view of gas concentration, accumulation position, volumes and states of spaces, the shock wave damage on structures in the roadway during gas explosion. The damage effects are characterized of heat and mechanic damage. Meanwhile, the high temperature and pressure are formed in different degree. With the action of overpressure and impulse, the damage degree is different with different geometric structures in ventilation system. By means of basic condition, influential factors, procedure features and simulation, some unnecessary structures or barriers should be cleared in order to keep smooth the ventilation system.

Risk Prevention Measures for Three-Tower and Four-Span Suspension Bridge under Vehicle Fire

2014 ◽  
Vol 919-921 ◽  
pp. 590-597
Author(s):  
Mu Yu Liu ◽  
Wei Tian ◽  
Ying Wang ◽  
Wu Jing ◽  
Xi Chen
Keyword(s):  
Reporting System ◽  
Suspension Bridge ◽  
Risk Prevention ◽  
Public Security ◽  
Alarm System ◽  
Prevention Measures ◽  
Fire Control ◽  
Emergency Rescue ◽  
Report System ◽  
Set Up

Risk prevention measures were put forward about vehicle burning in operating periods for three-tower and four-span suspension bridge, combining with the characteristics of bridge vehicle burning accident. The article set up a traffic reporting system of the tankers for a bridge, and determined the report system of tankers across the bridge. Tankers should passed in the middle of the lane near the median under the guidance of bridge manager. Significant indicators were set on both ends of the bridge, so that vehicles could shunt rapidly in extreme fire conditions. Department of public security, fire control, transportation, bridges management center should get together to establish accident emergency rescue leading group, and formulated the security system of fire resistance and rescue organization for YingWuzhou Yangtze river bridge. Video monitoring alarm system and fire control facilities were set up in side pier, side tower, middle of the main span and the middle tower, which provided reliable and prevention measures for bridge operation.

Framework and performance analysis of college English testing system based on data mining technology

2021 ◽  
pp. 1-11
Author(s):  
Liu Narengerile ◽  
Li Di ◽  
Keyword(s):  
Data Mining ◽  
Test System ◽  
Test Time ◽  
Testing System ◽  
Test Results ◽  
System Software ◽  
Examination System ◽  
Mining Technology ◽  
College English ◽  
And Performance

At present, the college English testing system has become an indispensable system in many universities. However, the English test system is not highly humanized due to problems such as unreasonable framework structure. This paper combines data mining technology to build a college English test framework. The college English test system software based on data mining mainly realizes the computer program to automatically generate test papers, set the test time to automatically judge the test takers’ test results, and give out results on the spot. The test takers log in to complete the test through the test system software. The examination system software solves the functions of printing test papers, arranging invigilation classrooms, invigilating teachers, invigilating process, collecting test papers, scoring and analyzing test papers in traditional examinations. Finally, this paper analyzes the performance of this paper through experimental research. The research results show that the system constructed in this paper has certain practical effects.

Promoting positive washforward through personalised test feedback and other benefits: Piloting a computer-based testing system

2020 ◽  
Vol 10 (1) ◽  
pp. 235-244
Author(s):  
Elena A. M. Gandini ◽  
Tania Horák
Keyword(s):  
Foreign Language ◽  
Testing System ◽  
Test Results ◽  
Test Feedback ◽  
Teachers And Students ◽  
Computer Based ◽  
Computer Based Testing ◽  
The University ◽  
Future Learning ◽  
Personalised Feedback

AbstractThis contribution reports on the developing and piloting of a computer-based version of the test of English as a foreign language produced by the University of Central Lancashire (UCLan), where it is currently used for the admission of international students and the subsequent evaluation of their language progress. Among other benefits, computer-based testing allows for better and individualised feedback to both teachers and students, and it can provide a more authentic test experience in light of the current digital shift that UK universities are undergoing. In particular, the qualitative improvement in the feedback available for test-takers and teachers was for us a crucial factor. Providing students with personalised feedback, that is, directly linked to their performance, has positive washforward, because it means we can guide their future learning, highlighting the areas they need to work on to improve their language skills and giving them suggestions on how to succeed in academia. Furthermore, explaining the meaning of test results in detail improves transparency and ultimately washback, as teachers can use the more accessible marking criteria, together with information on how their students performed, to review plans and schemes of work for subsequent courses.

Development and Verification of Modeling Practice for CFD Decay Calculations to Obtain Roll Damping of FPSO

2021 ◽  
Author(s):  
Arjen Koop ◽  
Pierre Crepier ◽  
Sebastien Loubeyre ◽  
Corentin Dobral ◽  
Kai Yu ◽  
...  
Keyword(s):  
Model Test ◽  
Test Results ◽  
Cfd Modelling ◽  
Roll Damping ◽  
Natural Period ◽  
Computational Mesh ◽  
Safety Studies ◽  
Offshore Industry ◽  
Decay Tests ◽  
Set Up

Abstract Estimates for roll damping are important input parameters for simulation studies on vessels operating at sea, e.g. FPSO mooring in waves, wind and current, workability and operability investigations, Dynamic Position studies, ship-to-ship operations and safety studies of vessels. To accurately predict the motions of vessels this quantity should be determined with confidence in the values. Traditionally, model experiments in water basins using so-called decay tests are carried out to determine the roll damping. With recent advancements in CFD modelling, the offshore industry has started using CFD as an alternative tool to compute the roll damping of FPSO’s. In order to help adopt CFD as a widely accepted tool, there is a need to develop confidence in CFD predictions. Therefore, a practical CFD modelling practice is developed within the Reproducible CFD JIP for roll decay CFD simulations. The Modelling Practice describes the geometry modelling, computational mesh, model set-up and post-processing for these type of CFD calculations. This modelling practice is verified and validated by three independent verifiers against available model test data. This paper provides an overview of the developed modelling practice and the calculated CFD results from the verifiers. The CFD modelling practice is benchmarked against available model test results for a tanker-shaped FPSO. By following this modelling practice, the CFD predictions for the equivalent linear damping coefficient and natural period of the roll motions are within 10% for all verifiers and within 10% from the model test results. Therefore, we conclude that when following the developed modelling practice for roll decay simulations, reliable, accurate and reproducible results can be obtained for the roll damping of tanker-shaped FPSOs.

Addition of Tubifex accelerates dewatering of oil sands tailings

2016 ◽  
Vol 43 (12) ◽  
pp. 1025-1033 ◽  
Author(s):  
Xiaojuan Yang ◽  
Miguel de Lucas Pardo ◽  
Maria Ibanez ◽  
Lijun Deng ◽  
Luca Sittoni ◽  
...  
Keyword(s):  
Oil Sands ◽  
Land Reclamation ◽  
Test Results ◽  
Anionic Polymer ◽  
Fine Tailings ◽  
Fluid Fine Tailings ◽  
Oil Sands Tailings ◽  
Set Up ◽  
Solids Content

Accelerating dewatering of fluid fine tailings (FFT) to facilitate land reclamation is a major challenge to the oil sands industry in Canada. A new method was tested, addition of Tubifex to FFT. Tubifex is an indigenous earthworm in Canada. The survival rate tests showed that Tubifex can survive in oil sands tailings and penetrate to 42 cm depth (maximum depth tested). Columns (5 L of FFT) were set-up with tailings alone, Tubifex treated tailings and polymer-Tubifex treated tailings. Test results showed that (a) the final mud–water interface of tailings alone was 26% higher than that of Tubifex treated tailings; (b) solids content of Tubifex treated tailings was 21% more than that of tailings alone; (c) Tubifex was capable to accelerate the dewatering process of both cationic and anionic polymer treated tailings; (d) anionic polymer was superior in facilitating long-term dewatering and its coupled effects with Tubifex were better than the cationic polymer.

scholarly journals Are Australian Teachers Making the Grade? A Study of News Coverage of Naplan Testing

2015 ◽  
Vol 154 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Kathryn Shine
Keyword(s):  
News Media ◽  
News Coverage ◽  
Developed Countries ◽  
Testing System ◽  
Journalism Education ◽  
Test Results ◽  
National Assessment ◽  
The Subject ◽  
Standardised Testing ◽  
And Training

The standardised testing of school children has been the subject of significant news media attention in recent years in many developed countries around the world. This article examines the reporting of annual National Assessment Program Literacy and Numeracy (NAPLAN) tests in three major Australian newspapers, with a particular focus on the portrayal of school teachers in the coverage. Overall, teachers were presented as strongly opposed to NAPLAN and the publication of test results, yet the newspapers themselves supported the tests as an important accountability measure. Teachers were depicted as trying to influence the testing system through teaching to the test and cheating. They were presented as generally inadequate as teachers, and were blamed for perceived failings in the educational system. These findings point to implications for teacher recruitment and retention, and for journalism education and training.

scholarly journals How to Implement Safe, Efficient and Cost-Effective SARS-CoV-2 Testing in Urban and Rural Schools within One Month

COVID ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 717-727
Author(s):  
Parastoo Kheiroddin ◽  
Magdalena Gründl ◽  
Michael Althammer ◽  
Patricia Schöberl ◽  
Linda Plail ◽  
...  
Keyword(s):  
Data Transfer ◽  
Cost Effective ◽  
Testing System ◽  
Successful Implementation ◽  
Rural And Urban ◽  
Local Involvement ◽  
Working Day ◽  
Set Up ◽  
The Individual ◽  
Time Required

(1) Background: With vaccination and new variants of SARS-CoV-2 on the horizon, efficient testing in schools may enable prevention of mass infection outbreaks, keeping schools safe places and buying time until decisions on feasibility and the necessity of vaccination in children and youth are made. We established, in the course of the WICOVIR (Where Is the COrona VIRus) study, that gargle-based pool-PCR testing offers a feasible, efficient, and safe testing system for schools in Germany when applied by central university laboratories. (2) Objectives: We evaluated whether this approach can be implemented in different rural and urban settings. (3) Methods: We assessed the arrangements required for successful implementation of the WICOVIR approach in a variety of settings in terms of transport logistics, data transfer and pre-existing laboratory set-up, as well as the time required to establish the set-up. (4) Results: We found that once regulatory issues have been overcome, all challenges pertaining to logistics, data transfer, and laboratory testing on different platforms can be solved within one month. Pooling and depooling of samples down to the individual test result were achievable within one working day in all settings. Local involvement of the community and decentralized set-ups were keys for success. (5) Conclusion: The WICOVIR gargle-based pool-PCR system is so robust and simple that it can be implemented within one month in all settings now or in future pandemics.

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