Advanced Materials Research Vols. 433-440

Abstract: This article has used the equations of coupled heat-moisture anisothermal flow of the unsaturated soil, and conducted the numerical simulation coupling of heat and humidity by FLAC. By comparing the calculation result with the test result, it shows that the calculation result is close to the experiment result. The error is tending to be larger as the depth of the soil adds. The maximum error between the calculation and the experiment result is 1°C, and the smallest one is 0.1°C. Moreover due to the hysteresis of the heat transfer in the soil, the middle of the soil occurs temperature concentration phenomenon; Their trends of water migration variation are similar as the depth of the soil adds. The model of the coupling of heat and moisture is able to better simulate the change of heat and moisture of the soil under circulating action of temperature.

Abstract: Gas hydrates with ice-like structures presenting in submarine sediments, are stable only at low temperature and high pressure, and are an energy source and an environmental hazard. This article analyses the distributing regulation of gas hydrates in the ocean from mass data which are gained from DSDP\ODP\IODP and other fields. The controlling factors of accumulation were discussed which include characters of marine geology, such as sedimentary velocity, content of the TOC, granularity of sediment, hydro-dynamic condition and ocean productivity.

Abstract: Fluid saturation and pressure are two of most important reservoir parameters during oil and gas production scheme adjustment. A method to compute the change of fluid saturation and pressure with multi-parameters regression was presented based on time-lapse seismic inversion data. Rock physical models of unconsolidated sand rock reservoirs were determined according to the real field’s conditions to analyze how seismic attributes change with variation of reservoir parameters. The radial basis function artificial neural network which was trained by this model was used to predict saturation and effective pressure. The predicted results are of high consistency with reservoir numerical simulation, which provide valuable reference for reservoir dynamic monitoring.

Abstract: In order to determine the effect of different light source’s spectrum to a subjects’ visual performance, this experiment examined three fluorescent lamps with a colour temperature of 2700K, 4000K and 6500K and an incandescent lamp. The results were compared to the average recognition rate a “reference person” from different light sources. Experimental results show significant differences in the recognition rate from different optical spectrum light source and recognition rate value. We determined the best combination of ambient and chalkboard light source and propose avoiding combination for classroom lighting that is clearly inferior. This article provides selection reference for optimal classroom ambient and blackboard lighting. In recent years, the study of psychological and physiological effect of light has become one of the most important field in lighting research[1]. Studies has shown that different light spectrum could affect human circadian rhythm, body temperature and alertness, which directly affecting work efficiency and health[2]. The effects by classroom light spectrum on efficiency and health cannot be ignored, as the students are exposed to one particular lighting environment for extended periods of time. Through a systematic survey of classroom lighting in several universities in Chongqing and Chengdu, T5 fluorescent of high colour temperature about 6500K was the predominant choice for classroom general lighting as well as blackboard lighting. Many students complained that they tired easily at this colour temperature. In another study on classroom light source[3] students’ preference for colour temperature is not fixed but varies according to classroom’s function and illuminance level. It was insufficient to choose colour temperature of classroom lighting based on the results of the above questionnaire. We therefore chose and compared T5 fluorescent lamps of 2700K, 4000K and 6500K colour temperature on the visual performance and their effects on study efficiency, asthenopia and physiological rhythm. Due to space limitations this article only discusses the contrast experiment of visual performance.

Abstract: With the development of tunneling technology and the increase of transportation, the mobiles are discharging more and more heat into the tunnel nowadays, which will cause the temperature enhancement. In this paper, general method of calculating the heat discharge is studied, and temperature distribution in the tunnels, which use different ventilation systems, is studied according to the one-dimensional steady state theory. One tunnel is taken for example to calculate the temperature distribution. The result can b e used in the relevant design and research.

Abstract: The reduction of sauter mean diameter (SMD) of droplets means the percent of the evaporated fuel, which is important to the formation of the combustible mixture in a port-injection gasoline engine during cold-start. Three-dimensional numerical simulation of SMD of the droplets in the inlet port of a gasoline engine was employed using the CFD software. This paper presented the effect of multi-parameters on SMD of the droplets including initial droplet velocity, intake temperature, fuel temperature, injection timing and engine speed. The simulation results show that the most influential parameters on SMD of the droplets are intake temperature and fuel temperature. The fuel evaporation rates increase approximately linearly with the intake air temperature and fuel temperature increasing. The initial droplet velocity and injection timing have a little effect on the fuel evaporation. As engine speed increases, SMD of the droplets firstly decreases and then increases. After intake-valve-open (IVO), back flow of gas in cylinders results in steep reduction of droplet diameter.

Abstract: Through the column simulation experiments, this paper researched on the naphthalene migration in the typical aquifer media-gravel sand and coarse sand in a petroleum contaminated field. The research also quantified the retardation of the two medium to the important petroleum component-naphthalene, by giving the retardation parameter after the chlorine breakthrough experiment. The results showed that the migration of naphthalene in the medium is not only influenced by the convection and the dispersion, but also the adsorption and the biodegradation, which is much stronger in the coarse sand than it is in the gravel sand.

Abstract: It is difficult to achieve high resolution for guided wave signals used in pipe inspection. The main reasons include overlap of the reflected waves, diversity of the guided wave’s mode and so on. This paper presents a minimum entropy deconvolution algorithm to solve the problem caused by low resolution of the measured signals. Some experiments were carried out to validate the algorithm. The experimental set-up consists of two pipes, one excitor and two accelerometers. The excitor was used to generate the guided wave signals. Two accelerometers were attached to the pipe end and pipe wall respectively，and were used to measure the guided wave signals. Results show that good estimate of the reflection coefficient is obtained and the resolution of measured signals has been improved. As a result, the length of two pipe samples has been calculated with a reasonable accuracy and the position of the defect in experimental pipe has also been acertained. All of these show a new efficient way for guided wave signal processing in pipe inspection.

Abstract: To verify the design of a standalone photovoltaic (PV) system, a test facility has been installed. This paper describes a platform to test the stand-alone solar system according to the IEC62124 standard. Essentially, this entire system involves the integration of a Personal Computer (PC), Data Acquisition (DAQ), an AC load and a solar array simulator (SAS) to test and simulate a stand-alone PV system. The main functions of this test facility are data acquisition, display, save and analysis data and print reports. The information obtained by monitoring parameters, such as average battery’s temperature, voltage and current is fed to the PC via the DAQ for analysis. This customized control interface has been developed by utilizing Labview software. This new system boasts of high accuracy measurements coupled with the commercial viability of low cost.

Abstract: The number of the high slope along the highway is much more, except this, the geological conditions is complex. To ensure the driving safety and the normal operation of the highway, it’s meaningful to monitor the deformation trend of high slope and discover abnormal phenomenon timely and treat it. The paper taking freeway high slope monitoring project as an example, study the purpose of high slope stability monitoring, the monitoring method and the setting of the monitoring net. It also analysis the monitoring results. The results show that the monitoring spot displacements of the slope are small and there is no symptom to occur geological disaster such as landslide, slump, avalanches and so on. The slope is basically stable. The monitoring result has verified the feasibility and the effectiveness of the monitoring scheme. Expecting this can offer reference and gather experience for similar projects