Automatic Approach for Fast Processing and Data Analysis of Seismic Ahead-Prospecting Method: A Case Study in Yunnan, China

The seismic ahead-prospecting method is useful to detect anomalous zones in front of the tunnel face. However, most existing seismic detection method is designed for drilling and blasting tunnel. The detection method should be improved to satisfy the rapid tunneling of Tunnel Boring Machines (TBMs). This study focuses on reducing the time spent on seismic data processing and result analysis. Therefore, to reduce the data processing time, an automatic initial model establishment method based on surrounding rock grade is proposed. To reduce the time spent on result analysis and avoid subjective judgment, a modified k-means++ method is adopted to interpret the detecting results and extracting anomalous zones. The efficacy of the developed method is demonstrated by field tests. The fractured zones such as cavity collapse and fissure are successfully predicted and identified

Temperature segregation of warm mix asphalt pavement: Laboratory and field evaluations

© 2017 Elsevier Ltd Temperature segregation refers to as different mixture cooling areas during construction in asphalt pavements. The objective of this study is to evaluate the effect of temperature segregation on warm mix asphalt (WMA) with laboratory and field tests. The performance of WMA compacted at four various temperatures was evaluated in the laboratory. The temperatures were measured during construction in the field sections with infrared thermography and plug-in thermometers. The pavement quality indicator (PQI) was applied to measure the density and the air void content at 216 testing locations the day after construction. In addition, field cores were collected to verify some of the PQI results. The test results showed that temperature segregation of WMA had a remarkable effect on the aggregate structure, density, water stability, high temperature stability, low temperature cracking and tensile strength. The reason for temperature segregation and related preventive measures are recommended at the same time. Based on the study, the preliminary temperature segregation criteria are recommended with the consideration of the field measurement. In application, the temperature segregation of a typical gradation with a nominal maximum aggregate size of 19 mm, referred to as AC-20 WMA, was suggested to be divided into four levels in view of the air void content: no segregation, low-level segregation, medium-level segregation and high-level segregation. The corresponding temperature differences were \u3c 3 °C, 3–8 °C, 8–18 °C and \u3e 18 °C, respectively

Selective Recognition of Gallic Acid Using Hollow Magnetic Molecularly Imprinted Polymers with Double Imprinting Surfaces

Gallic acid is widely used in the field of food and medicine due to its diversified bioactivities. The extraction method with higher specificity and efficiency is the key to separate and purify gallic acid from complex biological matrix. Herein, using self-made core-shell magnetic molecularly imprinted polymers (MMIP) with gallic acid as template, a hollow magnetic molecularly imprinted polymer (HMMIP) with double imprinting/adsorption surfaces was prepared by etching the mesoporous silica intermediate layer of MMIP. The characterization and adsorption research showed that the HMMIP had larger specific surface area, higher magnetic response strength and a more stable structure, and the selectivity and saturated adsorption capacity (2.815 mmol/g at 318 K) of gallic acid on HMMIP were better than those of MMIP. Thus, in addition to MMIP, the improved HMMIP had excellent separation and purification ability to selectively extract gallic acid from complex matrix with higher specificity and efficiency