X-ray monitoring in heterogeneous and fractured porous media : experimental measurement and numerical modeling

The complexity of fluid flow in heterogeneous and fractured media has long been a focus in the energy industry. Models have been developed in an attempt to determine the effects of rock heterogeneity, including fractures and laminations, on hydrocarbon flow. These models rely on an integration of data from different scales, including but not limited to seismic, core, and pore-level. This study focuses on the integration of studies at the core and pore-level through X-ray analysis of three unique projects. The first project addresses gas mobility control through X-ray micro-focus visualization of WAG core-flood experiments and interpretation aided by numerical simulation. We use surfactant as our primary mobility control agent to stabilize the nitrogen gas dispersion during WAG injection. We quantify the improvement in sweep efficiency by utilizing an automated fluid injection system monitored by an X-ray micro-focus scanner to quantify how displacement patterns and water saturation change with time. The core-flood device is wirelessly operated through a computer. The resolution of the images permits observation of not only core scale fingering but also pore-scale displacement. Results show that saturation patterns and displacement front during WAG injection are highly influenced by bedding orientation and rock heterogeneity. Without gas mobility control during WAG injection, fingering and early breakthrough occur in those cases in which bedding orientation facilitates gas to flow through high permeability layers. In these cases, sweep efficiency is low during early time injection of nitrogen and only improves after injection is prolonged. With gas mobility control, the displacement efficiency is significantly improved. Simulation work matches experimental data well and replicates saturation patterns measured experimentally in laminated Berea sandstone samples. The second project focuses on understanding how pre-existing fractures and rock heterogeneities can aid the propagation of induced fractures by 3D mapping of fracture networks in Mancos shale core plugs using X-ray micro-CT. Analysis of both intact samples and samples with pre-existing fractures show that induced fractures tend to develop along the same orientation of lamination planes, which more often than not correspond to the same orientation of any pre-existing fractures. The nature of this work requires inspection of fine fracture networks within larger specimens, so scanning at these coarser resolutions to capture the sample in their entirety leads to a compromise on the range of fracture sizes that can be accurately visualized. Moreover, existing limitations of the technique, including blurring effects further complicate interpretation. This project reviews some of these issues and remedies to overcome these limitations. The third project uses X-ray micro-CT to monitor methane hydrate growth and dissociation experiments in sands partially saturated with KI brine under excess-gas and excess-water conditions. The experiments show coexistence of brine, gas, and hydrate at the pore-scale and their evolution towards three-phase equilibrium. Analysis reveals that hydrate first forms as a porous hydrate mixing of brine and gas and then evolves into separate phases as hydrate cages exclude ions. During this time, hydrate growth mobilizes water over long distances. This mobilization of water is critical to explaining heterogeneous hydrate distribution as a result of hydrate ripening. The novel visualization of various pore-scale phenomenon presented here provides new pore-scale experimental insight to the structure and flow behavior of various heterogeneous mediums at a resolution one order of magnitude higher than with medical X-ray CT or other core-scale visualization techniques. The findings are useful for understanding complex flow patterns and structures of heterogeneous mediums.Petroleum and Geosystems Engineerin

Progress of the satellite laser ranging system TROS1000

AbstractThe mobile satellite laser ranging system TROS1000, successfully developed in 2010, achieves a high repetition rate and enables daytime laser ranging. Its measurement range has reached up to 36000 km with an accuracy as precise as 1 cm. Using recent observations in Wuhan, Jiufeng, Xianning, and Rongcheng, Shandong, we introduce the progress made using this mobile observation system

Physical Characterization and Volatile Organic Compound Monitoring of Recycled Polyethylene Terephthalate under Mechanical Recycling

In this study, physical characterization and monitoring of volatile organic compounds (VOCs) were investigated on recycled polyethylene terephthalate (rPET) from a mechanical recycling process and rPET bottles made with different rPET contents, with the aim of tracing the source of rPET and assessing its safety when use as a food contact material. It was found that rPET had a similar thermal stability to that of virgin PET (vPET). rPET bottles did not show any significant changes in groups or structure and exhibit similar crystallization and melting behaviors to vPET. However, there were minor mechanical scratches in the surface micromorphology of rPET bottles, and the color of rPET bottles became darker, greener and yellower as the content of recycled material increased. The solid-state polycondensation process was found to play an important role in the removal of VOCs, as detected by headspace gas chromatography-mass spectrometry (HS-GC-MS), resulting in a very small amount of residual VOCs in rPET. Four VOCs (acetaldehyde, glycol and nonanal at levels less than 1.00 mg/kg; 2-methyl-1,3 dioxolane at levels of 1.72-5.76 mg/kg) were detected in the rPET bottles. This study shows that rPET bottles are qualified for reuse in food contact in terms of thermal properties, structure, morphology and VOC residues, although there is variability in color

miRNA Expression Profile of Saliva in Subjects of Yang Deficiency Constitution and Yin Deficiency Constitution

Background/Aims: Based on the theory of constitution in Traditional Chinese Medicine (TCM), the Chinese Han population has been classified into nine constitutions. Of these, Yang deficiency constitution mainly exhibit cold intolerance while Yin deficiency constitution mainly exhibit heat intolerance. Some studies have been carried out to explore the modern genetic and biological basis of such constitution classification, but more remains to be done. MicroRNA (miRNA) serves as post-transcriptional regulators of gene expression and may play a role in the classification process. Here, we examined miRNA expression profile of saliva to further improve the comprehensiveness of constitution classification. Methods: Saliva was collected from Chinese Han individuals with Yang deficiency, Yin deficiency and Balanced constitutions (n=5 each), and miRNA expression profile was determined using the Human miRNA OneArray®v7. Based on 1.5 Fold change, means log2|Ratio|≥0.585 and P-value< 0.05, differentially expressed miRNA was screened. Target genes were predicted using DIANA-TarBasev7.0 and analysis of KEGG pathway was carried out using DIANA-mirPathv.3. Results: We found that 81 and 98 differentially expressed miRNAs were screened in Yang deficiency and Yin deficiency constitution, respectively. Among them, 16 miRNAs were identical and the others were unique. In addition, the target genes that are regulated by the unique miRNAs were significantly enriched in 27 and 20 signaling pathways in Yang deficiency and Yin deficiency constitution, respectively. Thyroid hormone signaling pathway is present in both constitutions. These unique miRNAs that regulated target genes of thyroid hormone signaling pathway may be associated with cold intolerance or heat intolerance. Conclusion: The results of our study show that Yang deficiency and Yin deficiency constitutions exhibit systematic differences in miRNA expression profile. Moreover, the distinct characteristics of TCM constitution may be explained, in part, by differentially expressed miRNAs

The Linked Data Benchmark Council (LDBC): Driving competition and collaboration in the graph data management space

Graph data management is instrumental for several use cases such as recommendation, root cause analysis, financial fraud detection, and enterprise knowledge representation. Efficiently supporting these use cases yields a number of unique requirements, including the need for a concise query language and graph-aware query optimization techniques. The goal of the Linked Data Benchmark Council (LDBC) is to design a set of standard benchmarks that capture representative categories of graph data management problems, making the performance of systems comparable and facilitating competition among vendors. LDBC also conducts research on graph schemas and graph query languages. This paper introduces the LDBC organization and its work over the last decade

The Linked Data Benchmark Council (LDBC): Driving competition and collaboration in the graph data management space

Graph data management is instrumental for several use cases such as recommendation, root cause analysis, financial fraud detection, and enterprise knowledge representation. Efficiently supporting these use cases yields a number of unique requirements, including the need for a concise query language and graph-aware query optimization techniques. The goal of the Linked Data Benchmark Council (LDBC) is to design a set of standard benchmarks that capture representative categories of graph data management problems, making the performance of systems comparable and facilitating competition among vendors. LDBC also conducts research on graph schemas and graph query languages. This paper introduces the LDBC organization and its work over the last decade

Intelligent Perception System of Robot Visual Servo for Complex Industrial Environment

Robot control based on visual information perception is a hot topic in the industrial robot domain and makes robots capable of doing more things in a complex environment. However, complex visual background in an industrial environment brings great difficulties in recognizing the target image, especially when a target is small or far from the sensor. Therefore, target recognition is the first problem that should be addressed in a visual servo system. This paper considers common complex constraints in industrial environments and proposes a You Only Look Once Version 2 Region of Interest (YOLO-v2-ROI) neural network image processing algorithm based on machine learning. The proposed algorithm combines the advantages of YOLO (You Only Look Once) rapid detection with effective identification of ROI (Region of Interest) pooling structure, which can quickly locate and identify different objects in different fields of view. This method can also lead the robot vision system to recognize and classify a target object automatically, improve robot vision system efficiency, avoid blind movement, and reduce the calculation load. The proposed algorithm is verified by experiments. The experimental result shows that the learning algorithm constructed in this paper has real-time image-detection speed and demonstrates strong adaptability and recognition ability when processing images with complex backgrounds, such as different backgrounds, lighting, or perspectives. In addition, this algorithm can also effectively identify and locate visual targets, which improves the environmental adaptability of a visual servo syste

Header for SPIE use Advanced Lifting-Based Motion-Threading (MTh) Technique for the 3D Wavelet Video Coding

This paper proposes an advanced motion-threading technique to improve the coding efficiency of the 3D wavelet coding. We extend the original motion-threading technique to the lifting wavelet structure. This extension solves the artificial motion thread truncation problem in long support temporal wavelet filtering, and enables the accuracy of motion alignment to be fractional-pixel with guaranteed perfect reconstruction. Furthermore, the mismatch problem in the motion-threading caused by occlusion or scene-change is considered. In general, the temporal wavelet decomposition consists of multiple layers. Unlike the original motion-threading scheme, in the proposed scheme each layer owns one set of motion vectors so as to achieve both high coding efficiency and temporal scalability. To reduce the motion cost, direct mode is used to exploit the motion vector correlation. An R-D optimized technique is introduced to estimate motion vectors and select proper prediction modes for each macroblock. The proposed advanced motion-threading scheme can outperform the original motionthreading scheme up to 1.5~5.0 dB. The experimental results also demonstrate that the 3D wavelet coding scheme can be competitive with the start-of-the-art JVT video standard on coding efficiency