Using 3D seismic exploration to detect ground fissure

   As a kind of supergene geological phenomenon, ground fissure has brought great inconvenience to human life. In addition, it also has a close relationship with earthquake. However, it is very difficult to ascertain the extension depth of ground fissure since its concealment and uncertainty. In this paper, 3D seismic exploration is used to detect ground fissure in Shanxi Province of China. Specific parameters for seismic data acquisition, processing and interpretation are analysed. Firstly, seismic data acquisition method and its corresponding parameters are discussed. Small dose explosive sources and high frequency geophones are used. Small trace interval and appropriate fold are also adopted. Secondly, seismic data processing is processed from shot record to seismic profile. Multi-domain loop iteration de-noising is used to get high signal-to-noise ratio data. Accurate near surface model, interactive iteration and residual static correction are used to eliminate the impact of low velocity zone and the static correction problem. Large common middle point bin and small velocity analysis interval are used for high accuracy velocity spectrum analysis. The mute parameter of stretching distortion and the migration aperture are researched for shallow ground fissure detection. Thirdly, seismic data interpretation is processed to get ground fissure distribution. Fault enhanced filter is used to improve the signal-to-noise ratio effectively and the chimney cube is used to identify ground fissure automatically. Thus, the specific 3D seismic exploration method used in this paper is suitable for ground fissure detection.Cited as: Shi, S., Liu, Z., Feng, J., Feng, G., Li, M. Using 3D seismic exploration to detect ground fissure. Advances in Geo-Energy Research, 2020, 4(1): 13-19, doi: 10.26804/ager.2020.01.0

Honeybee-inspired electrostatic microparticle manipulation system based on triboelectric nanogenerator

Electrostatic manipulation of particles or droplets has raised huge interests across many fields including biomedical analysis, microchemistry and microfabrication/patterning, because of its merits of simple configu- ration and easy operation. However, traditionally applied bulky high voltage sources for electrostatic manipu- lation not only have potential safety risk to the operator and the devices, but also limit the portability. Here, we proposed an electrostatic microparticle manipulation system (EMMS) based on a triboelectric nanogenerator (TENG). Inspired from the pollen collection principle of honeybees, the EMMS featured a simple pin-to-plate electrodes system, which was electrostatically powered by the high voltage of the TENG. Different manipula- tion modes, including contact manipulation and noncontact manipulation were systematically studied. With a sliding displacement of 5 cm, the TENG delivered an output voltage of ± 3.2 kV, which could manipulate dielectric microparticles with weights of 1.7 mg, 0.9 mg and 13.3 mg at contact manipulation mode, noncontact manipulation (vertical lift) and noncontact manipulation (parallel move) mode, respectively. Manipulation mechanisms for both dielectric and conductive microparticles under different configurations of the pin-to-plate electrodes system were investigated. Finally, potential applications including micropatterning, dust remove and drug release/microchemistry were demonstrated to show the great prospects of the proposed TENG-based EMM

Design guidelines and synthesis of a low dielectric constant inorganic composite for high performance microelectronic packaging

This thesis is on theoretical and experimental studies of a controlled porosity inorganic composite using hollow ceramic microspheres. It evaluated the microsphere geometry issues and physical/electrical properties important to achieving a maximum reduction of the dielectric constant of the resulting composite with a minimum loss in strength. A layered sphere Bruggeman effective-medium model was developed, which describes well, the expected dielectric constant of the composite. The model incorporates the aspect ratio of the microsphere and takes into account the dielectric constant of the hollow sphere wall. While porosity reduces the dielectric constant of the composite, strength is lost with the introduction of porosity. A semi-empirical expression which incorporates an empirical strength-porosity relation and a fairly rigorous treatment of the influence of residual stresses resulting from the thermal expansion mismatch between the sphere wall and the matrix. Calculations of fracture toughness due to the residual stresses are consistent with the variation of experimental strength data. Based on these models, one may identify materials with desirable physical and electrical properties and define sphere geometries so as to maximize the reduction of dielectric constant while minimizing the attendant loss of strength. Finally, this thesis presents an emulsion/water extraction synthesis method for preparing hollow ceramic microspheres suitable for use in the composite. A phenomenological model was developed to correlate the size and aspect ratio of the hollow microspheres to the important process variables. The prediction of the model is in good agreement with the experimental observations. Feasibility and limitations of this synthesis method for preparing various compositions of small size hollow ceramic microspheres are demonstrated.U of I OnlyETDs are only available to UIUC Users without author permissio

Research on the Beibu Gulf Port Container Terminal Operation System Construction Performance Evaluation Based on the AISM-ANP

With the continuous development of smart ports, the construction of port information systems has become the construction focus of the future development of such ports. However, the existing performance evaluation system for port information systems represents a research gap. It cannot effectively achieve specific improvement in the construction of information systems for port services and capabilities. In this paper, an evaluation index system was forged from the three perspectives of the operating level, management capability, and economic efficiency. As a first step, starting from the current situation of Beibu Gulf Port (Port B) construction, the three dimensions of the evaluation index system were determined using the scheme of literature review, questionnaire research, and fieldwork. Additionally, through adversarial interpretive structural modeling (AISM), it is concluded that the port loading and unloading operation capability and service level are the fundamental factors for measuring the construction performance of the container terminal operation system (CTOS). The results are used as input to construct an analytic network process (ANP) model to obtain the index weights. Finally, the gray clustering method (GCM) is introduced to construct a quantitative evaluation model to quantitatively evaluate the construction performance of the Port B CTOS. The quantitative benefits brought by the construction of the CTOS are finally verified. The scores of the corresponding dimensions of the port before and after the construction of the CTOS system in Beibu Gulf Port are obtained experimentally. The conclusion shows that the construction of CTOS makes the port operating level module improve the most, from 40.023 to 70.733 points; at the same time, it is found that two aspects, i.e., green security and economic benefits, in current construction are directions requiring further work in future port construction. Finally, a visualized quantitative analysis and evaluation method for the performance of smart port construction is proposed

A Mature-Tomato Detection Algorithm Using Machine Learning and Color Analysis

An algorithm was proposed for automatic tomato detection in regular color images to reduce the influence of illumination and occlusion. In this method, the Histograms of Oriented Gradients (HOG) descriptor was used to train a Support Vector Machine (SVM) classifier. A coarse-to-fine scanning method was developed to detect tomatoes, followed by a proposed False Color Removal (FCR) method to remove the false-positive detections. Non-Maximum Suppression (NMS) was used to merge the overlapped results. Compared with other methods, the proposed algorithm showed substantial improvement in tomato detection. The results of tomato detection in the test images showed that the recall, precision, and F1 score of the proposed method were 90.00%, 94.41 and 92.15%, respectively

The effect of anodized Ti on output performance of biomedical compatible triboelectric nanogenerators used for controlling the degradation of Mg-3wt%Zn-0.8wt%Zr

Triboelectric nanogenerators (TENGs) can convert amorphous mechanical energy into electrical energy and solve the issue of source power for biological electronics implanted in the human body. Biomedical metal Ti was selected as the bottom plate, to fabricate a TENG with a poly-L-lactic-acid (PLLA) Ti structure. The Ti sheets were treated with a two-step anodization method, and the growth of titanium dioxide nanotube arrays (TNTAs) was controlled by variation in anodic oxidation time. The results showed that the output voltage and current of the PLLA-TNTAs biocompatible triboelectric nanogenerator (BCTENG), prepared by the two-step anodization method under 60 V for 6 h, can reach 220.6 V and 15.1 μA, respectively. The output voltage and current increased by 96.3% and 91.1%, respectively, compared with TENGs prepared without using the anode oxidation method. The choice of materials and modification of the surface morphology of the TENG components was found to be critical for increasing the triboelectrically generated surface charge. The output of the BCTENG can regulate degradation of magnesium alloys freely by using cathodic protection

Identification of Key Amino Acid Residues Determining Product Specificity of 2,3-Oxidosqualene Cyclase in <i>Siraitia grosvenorii</i>

Sterols and triterpenes are structurally diverse bioactive molecules generated through cyclization of linear 2,3-oxidosqualene. Based on carbocationic intermediates generated during the initial substrate preorganization step, oxidosqualene cyclases (OSCs) are roughly segregated into a dammarenyl cation group that predominantly catalyzes triterpenoid precursor products and a protosteryl cation group which mostly generates sterol precursor products. The mechanism of conversion between two scaffolds is not well understood. Previously, we have characterized a promiscuous OSC from Siraitia grosvenorii (SgCS) that synthesizes a novel cucurbitane-type triterpene cucurbitadienol as its main product. By integration of homology modeling, molecular docking and site-directed mutagenesis, we discover that five key amino acid residues (Asp486, Cys487, Cys565, Tyr535, and His260) may be responsible for interconversions between chair&#8315;boat&#8315;chair and chair&#8315;chair&#8315;chair conformations. The discovery of euphol, dihydrolanosterol, dihydroxyeuphol and tirucallenol unlocks a new path to triterpene diversity in nature. Our findings also reveal mechanistic insights into the cyclization of oxidosqualene into cucurbitane-type and lanostane-type skeletons, and provide a new strategy to identify key residues determining OSC specificity