Long term environmental effect of tunnel construction in weak soils

2012 ◽  
pp. 1045-1050
Keyword(s):  
Environmental Effect ◽  
Tunnel Construction ◽  
Weak Soils

scholarly journals Modelling flood reservoir integrated with pumped hydropower storage for electricity production using HOMER

2018 ◽  
Vol 225 ◽  
pp. 05021
Author(s):  
Aishah Safi ◽  
Shahrani Anuar ◽  
Daing Mohd Nafiz ◽  
Firdaus Basrawi ◽  
Mohd Nazani ◽  
...  
Keyword(s):  
Environmental Effect ◽  
Model System ◽  
Hybrid Optimization ◽  
Electricity Production ◽  
Lower Reservoir ◽  
Cost Of Energy ◽  
High Emission ◽  
Hybrid Optimization Model ◽  
Water Catchment

This paper presented the potential of flood reservoir integrated with pumped hydropower storage for electricity production in Pekan, Malaysia. Based on the procedure in T echnical Release 55 (T R- 55), the volume of the reservoir to attenuat e flood was 5.2 million3. The volume estimated will be the size of the lower reservoir of proposed PHS and act as flood water catchment during flood seasons. The system proposed an integration of PHS with wind turbines and connect it to the grid. The Hybrid Optimization Model for Electric Renewable (HOMER) software was used to model system for electricity production. The software has simulated 200 different configurations of systems which included the diesel-only system and hybrid wind/diesel system. The standalone diesel system could produce about 25,041,824 kWh of electricity per year and emits 30,030,457 kg/year of pollutants into the atmosphere. Meanwhile, the hybrid wind/diesel could produce 25,668,980 kWh/year of electricity and emits 29,293,174 kg/year of total pollutants into the air. Although, the standalone diesel has the lowest cost of energy among all configurations which is RM 0.852/kWh, but it releases the most amount of carbon dioxide. The high emission of this gasses can have many environmental effect s in a long term.

Performance Stability of Recycle Amine-Free Water-Soluble Coolant in Long Term Operation

2014 ◽  
Vol 625 ◽  
pp. 530-535
Author(s):  
Kenji Yamaguchi ◽  
Yasuo Kondo ◽  
Satoshi Sakamoto ◽  
Mitsugu Yamaguchi ◽  
Ryoichi Nakazawa
Keyword(s):  
Environmental Effect ◽  
Free Water ◽  
Water Soluble ◽  
Water Recovery ◽  
Machining Processes ◽  
Cooling Performance ◽  
Recycling System ◽  
Term Operation ◽  
The Stability

Recently, the concern for the environment has been increasing rapidly. In machining processes, the treatment of water-soluble coolants waste has caused environmental problems. Water-soluble coolants contain surfactants, preservatives, and corrosion inhibitors for maintaining the stability and performance of the coolants. To reduce the management cost and environmental effect of water-soluble coolants, the authors have been studying a recycling system for water-soluble coolants. In the recycling system, oil-free recycle water is isolated from the coolant waste and reused as a diluent of the new coolant. The authors have been developing different types of water recovery methods for the recycling system, and the recovered water from the coolant waste has potential as a diluent for a new coolant. In this report, we focused on the amine (alkanolamine) -free water-soluble coolant. Some amine-free water-soluble coolants have been developed and are commercially available. A reduction in the environmental effect in the waste treatment of coolants is expected with amine-free coolants. We have demonstrated that the amine-free water-soluble coolant has equal or better cooling and lubricating performance compared with the conventional amine-containing coolant. In addition, the amine-free coolant shows good recyclability for the recycling system. The processing time of the recycling treatment of the amine-free coolant has been decreased by half with our recycling process compared with the conventional amine-containing coolant. In this report, we examined the stability, cooling performance and lubricating performance of the recycle amine-free water-soluble coolant in long term operation. The recycle amine-free water-soluble coolant is operated in a 3-axis machining center for several months. We observed concentration, pH, corrosion inhibition performance, cooling performance, and lubricating performance of the coolant. The results from these experiments show the amine-free water-soluble coolant has the advantage to use in the recycling system for water-soluble coolant.

Research on Signal Transfer of GPR Used in Frontal Detecting of Tunnel Construction

2013 ◽  
Vol 307 ◽  
pp. 75-78
Author(s):  
Fu Min Zhu ◽  
Ya Fei Li ◽  
Quan Gan
Keyword(s):  
Power Supply ◽  
Tunnel Construction ◽  
Signal Transfer ◽  
Dc Power ◽  
Geological Conditions ◽  
Control Computer ◽  
Online Detecting ◽  
Shield Machine

At first, this paper discusses the unfavorable environment where a tunnel is constructed by shield machine. As a novel solution, GPR is employed to detect some undesirable obstacles or geological conditions to ensure a smooth tunnel construction. After a brief introduction about the implementation of the detecting system, this paper raises the problem about the signal transferring between the antenna and the GPR body, and between the GPR and the control computer, which are far away arranged each other in two different cabins with relative rotating motion and under a very difficult connection condition. Two signal transferring methods, by cable or by wireless, and their advantage and limitations are discussed. This paper then proposes some key mechanical and electrical modifications on the central swivel joint or some other assemblies of the shield machine to meet the requirement for the signal transferring of the GPR. As this GPR system is supposed to be long-term online detecting equipment, this paper provides a dedicatedly designed power supply to replace the original DC power of the GPR.

scholarly journals Pb in halide perovskites for photovoltaics: reasons for optimism

2021 ◽  
Author(s):  
Arindam Mallick ◽  
Iris Visoly-Fisher
Keyword(s):  
Solar Cells ◽  
Environmental Effect ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Industrial Processing ◽  
Term Stability ◽  
Long Term Stability ◽  
Halide Perovskites ◽  
Conversion Efficiencies

Following the achievement of impressive power conversion efficiencies of perovskite solar cells (PSCs), the current challenges of this technology include long-term stability, upscaling for industrial processing, and its environmental effect....

Testing Predictions of Marine Fish and Shellfish Landings from Environmental Variables

1987 ◽  
Vol 44 (9) ◽  
pp. 1568-1573 ◽  
Author(s):  
K. F. Drinkwater ◽  
R. A. Myers
Keyword(s):  
Environmental Variables ◽  
Environmental Effect ◽  
Degrees Of Freedom ◽  
Gulf Of Maine ◽  
Fishing Effort ◽  
Fish Stocks ◽  
Environmental Models ◽  
The Mean ◽  
Fish And Shellfish

Previous studies by Sutcliffe and co-workers using exploratory analysis found correlations between environmental variables and lagged annual catch for several Gulf of St. Lawrence and Gulf of Maine fish and shellfish stocks. The present study tests these relationships using recent data. For 6 of the 13 stocks investigated, correlations between the 9–14 yr of new catch data and that predicted from the environmental models remained high (r > 0.5) and of the same sign; however, individually none was statistically significant (p > 0.05) after accounting for the loss of degrees of freedom due to the high autocorrelation in the data. The hypothesis of an overall environmental effect on the landings was considered. It could not be substantiated as the correlation coefficient for 5 of the 13 stocks reversed sign using the new data, but changes in fishing effort are believed to mask detection of environmentally induced variability in the landings of many stocks. The utility of environmentally based predictions was also tested. Overall, the mean deviations of the predicted catch based on environmental regressions were similar to predictions based on the long-term means but were higher than predictions using lagged catch. Environmentally based predictions of landings for invertebrate stocks were generally more accurate than those for fish stocks.

scholarly journals Numerical study of long-term settlement following twin tunnel construction

2015 ◽  
pp. 23-29
Author(s):  
Rafael Martínez ◽  
Felix Schroeder ◽  
David Potts
Keyword(s):  
Numerical Study ◽  
Tunnel Construction ◽  
Twin Tunnel

Automatic Detection of the Grout Layer of Metro Tunnel by GPR

2014 ◽  
Vol 556-562 ◽  
pp. 2719-2722
Author(s):  
Cun Chang Qin ◽  
Hui Lin Zhou ◽  
Qi Ming Yu ◽  
Xi Yuan
Keyword(s):  
Ground Penetrating Radar ◽  
Automatic Detection ◽  
The Other ◽  
Shield Tunnel ◽  
Jiangxi Province ◽  
Tunnel Construction ◽  
Term Basis ◽  
Metro Tunnel ◽  
Ground Penetrating

The grout behind the lining segments have a powerful influence on the long-term basis in shield tunnel construction in gravel sand and round gravel layers. Grouting layer detection in the shield construction is important. Two aspects are usually be used to evaluate the effectiveness of the grout treatment, one is the thickness of the Grouting layer and the other is to determine the presence and distribution of any damage in grouting layer. This study reports on the applications of the ground penetrating radar (GPR) and associated work carried out on Nanchang Metro line 1, Jiangxi province of China. After raw data preprocessing the results of the radar image are used to evaluate the thickness and hidden trouble of the grout layer automatically.

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