The internal wall and road surface of tunnel form the background of roadblock or vehicle together, and have a significant influence on the safety and comfort of tunnel lighting. In this paper, the optical simulation p...
The internal wall and road surface of tunnel form the background of roadblock or vehicle together, and have a significant influence on the safety and comfort of tunnel lighting. In this paper, the optical simulation program is adopted to analyze the correlation between the reflectivity of tunnel wall and such illumination indexes as luminance and illuminance of road surface inside a tunnel, as well as the visibility of small target etc. It shows from the study that: (1) The reflectivity of wall on the luminance gain level of road surface is closely related to the luminous intensity distribution of lamps. (2) Under the circumstance that the luminous intensity distribution of lamps is consistent, the linear relations basically exist among the reflectivity of wall, the illuminance and luminance of road surface and the luminance of wall, while the maximum growth slopes are 11.29, 0.45 and 11.50 respectively. (3) The field of vision of driver can be significantly improved by a higher reflectivity of wall. (4) Compared with the three illumination modes, the visibility of small target under the pro-beam lighting is highest (the minimum visibility is 10, and the highest visibility can reach 11.6), while the visibility of small target under the counter-beam lighting is the second-highest and the visibility of small target under the symmetric lighting is most non-obvious.
The use of S355 high strength steel in civilengineering design of structural elements of cranes, bridges or simple engineering parts allows material and economical savings to be achieved meeting the strict constructi...
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The use of S355 high strength steel in civilengineering design of structural elements of cranes, bridges or simple engineering parts allows material and economical savings to be achieved meeting the strict construction requirements. Knowledge of fatigue resistance of the material plays the key role during design and maintenance of the civilengineering structures. With this aim, the fatigue properties (Wöhler field and crack propagation rate curve) of the S355 J0 steel are analyzed according to both traditional and probabilistic models. In the latter case, the ProFatigue and ProPagation software programs are applied in the assessment of experimental fatigue data of S355 J0 for derivation of the probabilistic S–N field and fatigue crack growth rate curve, respectively, where data consist of results for different number of various investigated specimens subject to low cycle and high cycle fatigue with focus on the rolling direction. The results obtained are compared with the customary Basquin formula for the Wöhler-curve and Paris law for the crack growth rate curve, both represented as straight lines in a double-logarithmic scale.
The paper discusses the relevance of ensuring environmentally safe pipeline operation by identifying natural and industrial hazards and the potential impact. An operating trunk pipeline running west to east across a s...
The paper discusses the relevance of ensuring environmentally safe pipeline operation by identifying natural and industrial hazards and the potential impact. An operating trunk pipeline running west to east across a specific territory (constituent entity) was given as an example to show areas likely exposed to the most dangerous destructions. These are natural and man-made pipeline crossovers and intersections designated by the authors as ecologically fragile areas (EFAs). For a natural/industrial impact identification methodology, relevant hazards were identified and classified by the exposure degree for each gas pipeline EFA. Given geodynamic changes, the data collected were to be updated after each change. The article outlines the new methodology also suitable for territorial cartographic zoning subject to hazard factors. An area to be affected by degradation processes of an accident is determined by using the radii of thermal impact and scatter of pipe fragments. Such data help compute flora and fauna damage and, for the best scenario, damage prevented. The key points of this survey may be used to developing computer programs to compute an aggregate hazardous impact on an operating pipeline and simulate emergency scenarios. The practical utility consists in assuring proper EFAs monitoring for timely prevention of accidents.
The article deals with the issues of conducting renovation policy of multi-family buildings made of a large-panel technology. The authors showed a method of estimating the degree of wear of building elements using fuz...
The article deals with the issues of conducting renovation policy of multi-family buildings made of a large-panel technology. The authors showed a method of estimating the degree of wear of building elements using fuzzy logic. Then, the elements requiring repair were selected and the costs of replacing or reinforcing elements were estimated. On the basis of the elements’ wear and costs of repair, elements intended for renovation were selected.
It is a common view that the high temperature of the drilling fluid can lead to the dissociation of gas hydrate during drilling through hydrate-bearing sediments. This study indicates that the hydrate dissociation in ...
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The state's emphasis on energy conservation and emission reduction has been continuously strengthened, and the use of clean energy has received great attention. As the fourth generation of power technology, fuel c...
The state's emphasis on energy conservation and emission reduction has been continuously strengthened, and the use of clean energy has received great attention. As the fourth generation of power technology, fuel cell technology has developed rapidly abroad. Household fuel cells have achieved market-oriented development in Japan. In order to understand the technical applicability of household fuel cells in China, a survey on household living habits and energy consumption in cities and towns was carried out. The application of fuel cells in China was preliminarily analyzed from three aspects: the situation of family members at home, the use of domestic appliances and bathing habits.
Taking a 500,000 t/a straw briquette fuel plant in Baoding area of Hebei Province as an example, this paper establishes a life cycle energy consumption and environmental emission analysis model of straw solid fuel. Ba...
Taking a 500,000 t/a straw briquette fuel plant in Baoding area of Hebei Province as an example, this paper establishes a life cycle energy consumption and environmental emission analysis model of straw solid fuel. Based on this model, the energy saving and greenhouse gas emission reduction potential of straw solid particles as typical briquette fuels are quantitatively analyzed. Secondly, the life cycle energy consumption and environmental emissions are analyzed. Finally, from the point of view of energy consumption and environmental emissions, the potential value of environmental impact is calculated by standardization and sensitivity analysis is carried out. The results show that the energy consumption of straw granulation stage (compression molding stage) accounts for the largest proportion in the solid particle manufacturing life cycle, reaching 32.30%. Compared with fossil fuels, solid particles have a large emission reduction advantage, which provides basic data for the utilization of straw solid granular forming fuel.
Firstly, Interaction between soil and pile which is caused by pit opening is analysed through FLAC3D, the flexural moment and earth pressure of pile can be extracted through the program. Secondly, through the analysis...
Firstly, Interaction between soil and pile which is caused by pit opening is analysed through FLAC3D, the flexural moment and earth pressure of pile can be extracted through the program. Secondly, through the analysis of the soil pressure on the pile side, a simplified algorithm that engineers can simply estimate the flexural moment is obtained. Finally, the earth pressure is obtained by geotechnical centrifuge experiment and then the flexural moment is recalculated through this algorithm, the two results are basically consistent, the feasibility of the method is verified.
Geothermal energy is a kind of sustainable renewable and clean resources. However, when using this energy source, there are serious problems such as excessive tail water discharge and insufficient utilization of geoth...
Geothermal energy is a kind of sustainable renewable and clean resources. However, when using this energy source, there are serious problems such as excessive tail water discharge and insufficient utilization of geothermal energy. Especially in rural areas, how to use geothermal energy at low cost and efficiently is an urgent problem to be solved. The use of geothermal cascade can reduce the temperature of tail water to a certain extent, make full use of geothermal energy in each temperature section, and increase the utilization rate of geothermal energy. Based on the research status of geothermal cascade utilization at home and abroad, this paper proposes a new type of rural geothermal cascade utilization system, and attempts to analyse this system, and finds that this system can increase the utilization rate of geothermal energy at low cost.
Extreme weather changes have been increasing in the recent times also in the eastern Slovakia. Extremely dry periods alternate with above-average precipitation. In the paper the drought indices were evaluated: Standar...
Extreme weather changes have been increasing in the recent times also in the eastern Slovakia. Extremely dry periods alternate with above-average precipitation. In the paper the drought indices were evaluated: Standardized Evapotranspiration Index (SPEI) and Standardized Precipitation Index (SPI). Using the non-parametric statistical Mann-Kendall test. The evaluated period was 1960 – 2015 at selected river and climatological stations in the eastern Slovakia. The results showed that no clean significant trends occurred in all evaluated indices and stations.
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