Laser doppler velocimetry for flow measurements in pulp and paper research

"June 1996.""Submitted to TAPPI Engineering Conference, Chicago, Illinois, September 16-19, 1996.

Towards a "Swiss Army Knife" for Scalable User-Defined Temporal (k,X)(k,\mathcal{X})-Core Analysis

Querying cohesive subgraphs on temporal graphs (e.g., social network, finance network, etc.) with various conditions has attracted intensive research interests recently. In this paper, we study a novel Temporal $(k,\mathcal{X})$-Core Query (TXCQ) that extends a fundamental Temporal $k$-Core Query (TCQ) proposed in our conference paper by optimizing or constraining an arbitrary metric $\mathcal{X}$ of $k$-core, such as size, engagement, interaction frequency, time span, burstiness, periodicity, etc. Our objective is to address specific TXCQ instances with conditions on different $\mathcal{X}$ in a unified algorithm framework that guarantees scalability. For that, this journal paper proposes a taxonomy of measurement $\mathcal{X}(\cdot)$ and achieve our objective using a two-phase framework while $\mathcal{X}(\cdot)$ is time-insensitive or time-monotonic. Specifically, Phase 1 still leverages the query processing algorithm of TCQ to induce all distinct $k$-cores during a given time range, and meanwhile locates the "time zones" in which the cores emerge. Then, Phase 2 conducts fast local search and $\mathcal{X}$ evaluation in each time zone with respect to the time insensitivity or monotonicity of $\mathcal{X}(\cdot)$. By revealing two insightful concepts named tightest time interval and loosest time interval that bound time zones, the redundant core induction and unnecessary $\mathcal{X}$ evaluation in a zone can be reduced dramatically. Our experimental results demonstrate that TXCQ can be addressed as efficiently as TCQ, which achieves the latest state-of-the-art performance, by using a general algorithm framework that leaves $\mathcal{X}(\cdot)$ as a user-defined function

Development characteristics and main controlling factors of Carboniferous volcanic reservoirs in the Shixi area, Junggar Basin

The Carboniferous volcanic reservoirs in the Shixi area of the Junggar Basin are complex and diverse. Identifying the characteristics and main factors controlling high-quality volcanic reservoirs is the key to increasing oil and gas reserves and production in this area. Through core observations, thin section identification, physical property and pore structure analyses, combined with production data, the main controlling factors and development modes of high-quality reservoirs were analysed. The results show that the Carboniferous strata in the Shixi area mainly contain andesite and dacite of overflow facies, followed by volcanic breccia and tuff of explosive facies. Volcanic reservoirs in the study area are high-porosity–low-permeability and medium-porosity–low-permeability reservoirs. Volcanic breccia of explosive facies has the best physical properties, showing the characteristics of high porosity and medium permeability. The reservoir space is mainly composed of gas cavities, corrosion pores and fractures, among which the corrosion pores are the most important reservoir spaces of the Carboniferous volcanic rocks. Lithology and lithofacies, weathering and corrosion, and fractures are the main factors controlling the development of high-quality volcanic reservoirs. Volcanic rocks that had experienced weathering and denudation for a long time developed a large number of secondary corrosion pores due to the corrosion of soluble minerals or volcanic ash. Fractures further improved the physical properties, causing volcanic rocks to eventually develop into weathering crust reservoirs. The physical properties of the volcanic rocks far away from the weathering crust were improved through primary gas cavities and structural fractures, and these volcanic rocks eventually developed into the inner reservoir

Pretreatment of Woody Biomass for Biofuel Production

Biofuel production from woody biomass through the sugar platform requires efficient production of fermentable sugars either chemically and enzymatically by hydrolyzing polysaccharides in wood cell walls. Enzymatic sugar production is a mature technology that can produce high quality sugars but requires a pretreatment step to open wood cell wall structure to improve its accessibility to enzymes, because nature produces wood as a structural material that is not easily accessible to most microbes to deconstruct into basic building blocks such as simple sugars. Unfortunately, pretreatment is the most expensive step in biofuel production through enzymatic saccharification and fermentation. This is especially true for woody biomass due to its high lignin content and strong physical integrity. Pretreatment softwood and harvest softwood forest residue, the feedstock NARA project proposed to use, is even more difficult. Most existing pretreatment processes cannot produce good enzymatic digestibility from softwood. In this webinar, I will outline the basic principles of pretreatment, its limitations, and its effect on downstream co-product development. Especially, I will discuss the SPORL pretreatment NARA adopted for bio-jet fuel production, its versatility, performance, kinetics based process scale-up, and lignin co-product. Webinar available at https://www.youtube.com/watch?v=hu-SHlVisWc

Surfactant Spray: A Novel Technology to Improve Flotation Deinking Performance: Final Report

Based on the fundamental understanding of ink removal and fiber loss mechanism in flotation deinking process, we developed this innovative technology using surfactant spray to improve the ink removal efficiency, reduce the water and fiber loss, reduce the chemical consumption and carry over in the flotation deinking. The innovative flotation deinking process uses a spray to deliver the frothing agent during flotation deinking to control several key process variables. The spray can control the foam stability and structure and modify the fluid dynamics to reduce the fibers entrapped in the froth layer. The froth formed at the top part of the flotation column will act as a physical filter to prevent the penetration of frothing agent into the pulp suspension to eliminate fiber contamination and unfavorable deinking surface chemistry modification due to surfactant adsorption on the fiber surface. Because of the filter effect, frothing agents will be better utilized. Under the sponsorships of the US Dept. of Energy (DOE) and the member companies of the Institute of Paper Science and Technology, we studied the chem-mechanical mechanism of surfactant spray for flotation deinking using different furnishes, chemicals, and flotation devices in the past four years. In the final year of the project, we successfully conducted mill trials at Abitibi-Consolidated, Inc., Snowflake paper recycling operation of 100% mixture of ONP/OMG. Results from laboratory, pilot-plant and mill trials indicated that surfactant spray technology can significantly reduce fiber loss in flotation deinking. It can be concluded that paper industry can profit greatly when this technology is commercialized in flotation deinking mills