The construction of a simple portable electromagnetic vibrator from commercially available components     

Timothy Dean  Hoang Nguyen  Anton Kepic  David Halliday 《Geophysical Prospecting》2019,67(6):1686-1697

Since its introduction in the late 1950s, hydraulic vibrators have become the dominant source for land seismic surveys. The hydraulic vibrators typically used for commercial land seismic acquisition, however, are large, costly to operate and expensive to purchase. This inhibits their use for small-scale and short-duration surveys as well as Vibroseis research. In this paper we describe, in detail, the construction of a portable vibrator from commercially available components for a cost of less than $US2,000. Data shows that the vibrator is able to successfully transmit sweeps from 15 to 180 Hz with different spectral contents. The vibrator produces a stronger signal than a sledgehammer and we estimate its output to be around 1 kN. The frequency content of the data was concentrated at lower frequencies (<100 Hz) and the ground-roll was far more energetic than that produced using a sledgehammer.  相似文献   

Zeta potential of porous rocks in contact with mixtures of monovalent and divalent electrolytes     

Luong Duy Thanh  Rudolf Sprik  Xuan Ca Nguyen 《Geophysical Prospecting》2019,67(5):1354-1368

The zeta potential is one of the most important parameters influencing the electrokinetic coupling. Most reservoir rocks are saturated or partially saturated by natural water containing various types of ions (mostly monovalent and divalent ions). Therefore, understanding how the zeta potential behaves for mixtures of electrolytes is very important. In this work, measurements of the zeta potential for four different silica-based samples saturated by seven different mixtures of monovalent and divalent electrolytes are then carried out at a fixed ionic strength. It is seen that the magnitude of the measured zeta potential decreases with increasing divalent cation fraction. The experimental results are then explained by a model developed for mixtures of monovalent and divalent electrolytes. The result shows that the theoretical model is able to reproduce the main trend of the variation of the zeta potential with divalent cation fractions. Additionally, the model can fit the experimental data reported in literature well for reasonable values of the input parameters.  相似文献   

情理整合视角下旅游者环境责任行为与 意愿悖离研究——基于Logistic-ISM模型     

段正梁  彭振  杨左  鲍青  阮氏莲 《热带地理》2021,41(1):104-113

基于对岳麓山景区447位旅游者的实地调研,运用拓展的计划行为理论并结合Logistic回归模型,分析影响两者发生悖离的因素,并进一步利用ISM解释结构模型分析各因素之间的逻辑关系.从Logistic回归结果看,旅游者的行为态度、感知行为控制等相关理性认知越好,发生悖离的可能性越低;旅游者积极环境情感和消极环境情感对悖离...  相似文献   

The roles of the reversibility and irreversibility of capillary bonds on the impact dynamics of agglomerates     

Vo  Thanh-Trung  Nguyen  Trung-Kien 《Acta Geotechnica》2023,18(1):217-233

Acta Geotechnica - Wet agglomerates such as iron-ores, tablets, and aggregates are omnipresent in multi–field industries. However, our understanding of the impact dynamics of these materials...  相似文献