Challenge in high-speed TBM excavation of long-distance water transfer tunnel, Pahang-Selangor Raw Water Transfer Tunnel, Malaysia

2013 ◽  
pp. 1872-1878 ◽  
Author(s):  
T Kawata ◽  
Y Nakano ◽  
T Matsumoto ◽  
A Mito ◽  
F Pittard ◽  
...  
Author(s):  
Ruikang Xue ◽  
Tinglin Huang ◽  
Gang Wen ◽  
Junle Yan ◽  
Qian Liu

Abstract Long-distance water transfer projects are important for water allocation. To enhance our understanding of biofilm growth and changes in water quality during raw water transfer, raw water through long-distance non-full culvert at flow rates of 1.4−2.0 m/s was studied.The results revealed that: (1) the biofilm total cell number (TCC) and heterotrophic plate count (HPC) were the highest at a flow rate of 1.5 m/s, which were 3.7E + 04 cells /cm2 and 1.1E + 03 CFU/cm2, respectively; (2) proteobacteria had the highest relative abundance (RA) among all samples, and the RA in biofilm (78.85%) was higher than that in water (48%−59%); (3) when the pollutants and biofilm were partially shed, the total phosphorus (TP), permanganate index (CODMn), and dissolved organic carbon (DOC) increased by 0.011, 0.36, and 0.5 mg/L at most, respectively; and (4) dissolved oxygen (DO) was sufficient during non-full flow water transport and nitrification occurred. The highest removal rates of ammonium nitrogen (NH+4-N) and nitrous nitrogen (NO2--N) reached 27.16% and 66.76%, respectively. At the flow rates of 2.0 m/s, the efficiency decreased to 10.47% and 41.25%, respectively, due to the shedding of biofilm.


1905 ◽  
Vol 59 (1537supp) ◽  
pp. 24627-24628
Author(s):  
Charles A. Mudge

2019 ◽  
Vol 29 (8) ◽  
pp. 1101-1117
Author(s):  
Lin Yang ◽  
Xiangdong Li ◽  
Jiyuan Tu

Due to the fast development of high-speed rail (HSR) around the world, high-speed trains (HSTs) are becoming a strong competitor against airliners in terms of long-distance travel. Compared with airliner cabins, HST cabins have much larger window sizes. When the big windows provide better lighting and view of the scenery, they also have significant effects on the thermal conditions in the cabins due to the solar radiation through them. This study presents a numerical study on the solar radiation on the thermal comfort in a typical HST cabin. The effect of solar radiation was discussed in terms of airflow pattern, temperature distribution and thermal comfort indices. Parametric studies with seven different daytime hours were carried out. The effect of using the roller curtain was also studied. The overall cabin air temperature, especially near passengers, was found to have significantly increased by solar radiation. Passengers sitting next to windows were recorded to have an obvious thermal comfort variation at different hours of the day. To improve the passengers’ comfort and reduce energy consumption during hot weather, the use of a curtain could effectively reduce the solar radiation effect in the cabin environment.


2016 ◽  
Vol 29 (4) ◽  
pp. e3846
Author(s):  
Xu Zhang ◽  
Naijie Gu ◽  
Junjie Su

1955 ◽  
Vol 100 (599) ◽  
pp. 353-367
Author(s):  
L. M. Hodges
Keyword(s):  

2013 ◽  
Vol 842 ◽  
pp. 445-448
Author(s):  
Wei Chao Yang ◽  
Chuan He ◽  
Li Min Peng

This paper describes the results of numerical work to determine the flow structures of the slipstream and wake of a high speed train on platforms of underground rail station using three-dimensional compressible Euler equation. The simulations were carried out on a model of a simplified three-coach train and typical cross-section of Chinese high-speed railway tunnel. A number of issues were observed: change process of slipstreams, longitudinal and horizontal distribution characteristics of train wind. Localized velocity peaks were obtained near the nose of the train and in the near wake region. Maximum and minimum velocity values were also noticed near to the nose rear tip. These structures extended for a long distance behind the train in the far wake flow. The slipstream in platform shows the typical three-dimensional characteristics and the velocity is about 4 m/s at 6 m away from the edge of platform.


2011 ◽  
Vol 341-342 ◽  
pp. 868-872
Author(s):  
Hui Xin Zhang ◽  
Yan Lu Zheng ◽  
Yan Ran Chen ◽  
Hai Guang Yang

To match, test, and determine the working conditions and correctness of each function of the aircraft measurement system. This article proposes a design of equivalent test platform which can produce digital and analog signals for the self-testing of measurement system. By using the ethernet protocol chip W5300 to achieve the high-speed communication between host computer and equivalent device. Communication uses UDP unicast data transfer mode with advantages of high-speed and long-distance transmission, and the Phenomenon of data packet loss is not easy in transmission.


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