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Flammability risk assessment for oil spill response operations

Acta Oceanologica Sinica 2019年第9期38卷 113-119页

作者： Aurelien Hospital Travis Miguez James Stronach Air Coastal and Lake Engineering Department Tetra Tech Canada

Immediately following a spill at sea, released oil ranging from diesel to light crude and diluted bitumen, will initially weather through evaporation, resulting in an elevated concentration of light hydrocarbons in the air. As part of oil spill response operations, first responders use hand-held devices to monitor airborne concent- rations when approaching a spill. The feasibility of using numerical modelling as an additional tool to assess potential flammability and plan response operations in the spill area was explored in this study. The Lower Explosive Limit (LEL) is defined as the minimum concentration of a gas in air, in this case a mixture of evaporated hydrocarbons, which can produce a flash fire in the presence of an ignition source. This ignition source could be triggered by the vessel itself or by spill response operations. A framework was put into place, utilizing a three- dimensional hydrodynamic model (H3D), an oil spill model (SPILLCALC), and an air dispersion model (CALPUFF) to assess the risk of possible ignition of the hydrocarbon vapour in the event of a spill. The study looked at a hypothetical credible worst case tanker spill (16 500 m3) of diluted bitumen (cold lake winter blend) occurring at Arachne Reef in Haro Strait, British Columbia, Canada. SPILLCALC provided one-minute averaged vapour fluxes from the water surface for each of 17 modelled pseudo-components which were used as inputs to CALPUFF. Using the predicted airborne concentrations of each pseudo-component, time-scaled to one-second averages, the flammability potential in the immediate spill area was determined at each grid point using Le Chatelier’s mixing equation. The approach describe here was developed as a proof of concept, and could be established as a real-time system, bringing valuable information in addition to hand-held devices during a spill response, or during a response exercise. This modelling study was conducted as part of Kinder Morgan’s Trans Mountain Pipeline Expan

关键词： oil spill response operations modelling Salish Sea

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BMP decision support system for evaluating stormwater management alternatives

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Frontiers of Environmental Science & Engineering 2009年第4期3卷 453-463页

作者： Mow-Soung CHENG Jenny X.ZHEN Leslie SHOEMAKER Department of Environmental Resources Prince George’s County Government9400 Peppercorn PlaceLargo MD 20774USA tetra tech Inc.10306 Eaton PlaceFairfax VA 22030USA

Princ. George’s County,Maryland,in the Washington *** area has developed a best management practice decision support system(BMPDSS)to support analysis and decision making for stormwater management planning and design at both the site scale and the watershed *** paper presents a detailed description of the BMPDSS.A case study that demonstrates the application of the system is also *** case study involves a Green Highway project located in a highly urbanized area within the Anacostia River watershed of the *** best management practices(BMP)such as bioretention,filter vegetative swale,porous paving,and landscape infiltration are proposed for reducing highway runoff and improving water *** BMPDSS is used to identify and evaluate various alternatives to determine the most costeffective types and combinations of BMPs that minimize the highway runoff pollution.

关键词： best management practices decision support system low impact development geographic information system optimization

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Floating Production Platforms and their Applications in the Development of Oil and Gas Fields in the South China Sea

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Journal of Marine Science and Application 2014年第1期13卷 67-75页

作者： Dagang Zhang Yongjun Chen Tianyu Zhang DMAR Engineering Inc. Beijing DMAR Ocean Tech Inc.

This paper studies the current available options for floating production platforms in developing deepwater oil fields and the potential development models of future oil and gas exploration in the South China Sea. A detailed review of current deepwater platforms worldwide was performed through the examples of industry projects, and the pros and cons of each platform are discussed. Four types of platforms are currently used for the deepwater development: tension leg platform, Spar, semi-submersible platform, and the floating production system offloading. Among these, the TLP and Spar can be used for dry tree applications, and have gained popularity in recent years. The dry tree application enables the extension of the drilling application for fixed platforms into floating systems, and greatly reduces the cost and complexity of the subsea operation. Newly built wet tree semi-submersible production platforms for ultra deepwater are also getting their application, mainly due to the much needed payload for deepwater making the conversion of the old drilling semi-submersible platforms impossible. These platforms have been used in different fields around the world for different environments; each has its own advantages and disadvantages. There are many challenges with the successful use of these floating platforms. A lot of lessons have been learned and extensive experience accumulated through the many project applications. Key technologies are being reviewed for the successful use of floating platforms for field development, and potential future development needs are being discussed. Some of the technologies and experience of platform applications can be well used for the development of the South China Sea oil and gas field.

关键词： floating platform deepwater development oil fielddevelopment deepwater technology platform host

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A Novel Method to Extract Rocks from Mars Images

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Chinese Journal of Electronics 2015年第3期24卷 455-461页

作者： WANG Shuliang CHEN Yasen YUAN Hanning School of Software Beijing Institute of Technology Tencent inc. Hi-tech Park Nanshan District

Automatically extracting rocks from Martian surface images is valuable for hazard avoidance and rover localization in rover missions. To extract rocks, data field on image is proposed to model the interaction between two pixels of an image under the imagery characteristics of Martian surface. Foreground rocks are firstly grouped into clusters by locating the centers and edges in data field after they are differed from background information via binarizing partition. Then target rocks are discovered for the Rover to keep healthy paths. The experiment shows the data field on image is practical and potential.

关键词： Data fields Mars image Rock extraction

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China＇s Sponge City construction： A discussion on technical approaches

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Frontiers of Environmental Science & Engineering 2017年第4期11卷 39-49页

作者： Haifeng Jia Zheng Wang Xiaoyue Zhen Mike Clar Shaw L. Yu School of Environment Tsinghua University Beijing 100084 China Beijing Orient tetra tech Ecological technology Ltd. Beijing 100051 China tetra tech Fairfax VA 22030 USA Department of Civil & Environmental Engineering University of Virginia Charlottesville VA 22904 USA

Sinc. 2014, China has been implementing the Sponge City Construction initiative, which represents an enormous and unprecedented effort by any government in the world for achieving urban sustainability. According to preliminary estimates, the total investment on the Sponge City Plan is roughly 100 to 150 million Yuan （RMB）（$15 to $22.5 million） average per square kilometer or 10 Trillion Yuan （RMB）（$1.5 Trillion） for the 657 cities nationwide. The Sponge City Plan （SCP） calls for the use of natural processes such as soil and vegetation as part of the urban runoff control strategy, which is similar to that of low impact development （LID） and green infrastructure （G1） practices being promoted in many parts of the world. The SCP inc.udes as its goals not only effective urban flood control, but also rainwater harvest, water quality improvement and ecological restoration. So far, the SCP implementation has encountered-some barriers and challenges due to many factors. The present paper presents a review of those barriers and challenges, oftizrs discussions and recommendations on several technical aspects such as control goals and objectives; planning/design and construction of LID/GI practices; performance evaluation. Several key recommendations are proposed on Sponge City implementation strategy, Site-specific regulatory fi＇amework and technical gmdance, Product innovation and certification, LID/GI Project financing, LID/G1 profcssional training and certification, public outreach and education. It is expected that the successful implemen!atiun of the. SCP not only will bring about a sustainable, eco-friendly urbanization process in China, but also contribute enormously to the LID/Gl research and development with the vast amount of relevant data and experiences generated from the Sponge City construction projects.

关键词： Low impact development Green infrastructure (GI) Sponge City Barriers Construction strategies

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Use of centrifugal-gravity concentration for rejection of talc and recovery improvement in base-metal flotation

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International Journal of Minerals,Metallurgy and Materials 2016年第8期23卷 859-867页

作者： Bern Klein Naci Emre Altun Hassan Ghaffari NBK Institute of Mining Engineering The University of British Columbia Department of Mining Engineering Middle East Technical University tetra tech Metallurgy

The possibility of using a centrifugal-gravity concentrator to reject Mg-bearing minerals and minimize metal losses in the flotation of base metals was evaluated. Sample characterization, batch scoping tests, pilot-scale tests, and regrind-flotation tests were conducted on a Ni flotation tailings stream. Batch tests revealed that the Mg grade decreased dramatically in the concentrate products. Pilot-scale testing of a continuous centrifugal concentrator（Knelson CVD6） on the flotation tailings revealed that a concentrate with a low mass yield, low Mg content, and high Ni upgrade ratio could be achieved. Under optimum conditions, a concentrate at 6.7% mass yield was obtained with 0.85% Ni grade at 12.9% Ni recovery and with a low Mg distribution（1.7%）. Size partition curves demonstrated that the CVD also operated as a size classifier, enhancing the rejection of talc fines. Overall, the CVD was capable of rejecting Mg-bearing minerals. Moreover, an opportunity exists for the novel use of centrifugal-gravity concentration for scavenging flotation tailings and/or after comminution to minimize amount of Mg-bearing minerals reporting to flotation.

关键词： flotation base metals talc centrifugation gravity concentrators

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A refined risk explicit interval linear programming approach for optimal watershed load reduction with objective-constraint uncertainty tradeoff analysis

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Frontiers of Environmental Science & Engineering 2016年第1期10卷 129-140页

作者： Pingjian YANG Feifei DONG Yong LIU Rui ZOU Xing CHEN Huaicheng GUO College of Environmental Science and Engineering Peking University the Key Laboratory of Water and Sediment Sciences Ministry of Education Beijing 100871 China School of Natural Resources and Environment University of Michigan Ann Arbor MI 48109 USA Yurman International Center for Pleantu Lakes Kunming 650034 China tetra tech Inc. Fairfax VA 22030 USA

To enhance the effectiveness of watershed load reduction decision making, the Risk Explicit Interval Linear Programming （REILP） approach was developed in previous studies to address decision risks and system returns. However, REILP lacks the capability to analyze the tradeoff between risks in the objective function and constraints. Therefore, a refined REILP model is proposed in this study to further enhance the decision support capability of the REILP approach for optimal watershed load reduction. By introducing a tradeofffactor （α） into the total risk function, the refined REILP can lead to different compromises between risks associated with the objective functions and the constraints. The proposed model was illustrated using a case study that deals with uncertainty- based optimal load reduction decision making for Lake Qionghai Watershed, China. A risk tradeoff curve with different values of a was presented to decision makers as a more flexible platform to support decision formulation. The results of the standard and refined REILP model were compared under 11 aspiration levels. The results demon- strate that, by applying the refined REILP, it is possible to obtain solutions that preserve the same constraint risk as that in the standard REILP but with lower objective risk, which can provide more effective guidance for decision makers.

关键词： refined risk explicit interval linear program-ming decision making objective-constraint uncertaintytradeoff aspiration level Lake Qionghai Watershed

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Naval derusting wastewater containing high concentration of iron, treated in UV photo-Fenton-like oxidation

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Journal of Environmental Sciences 2010年第7期22卷 991-997页

作者： Daeik Kim Jason Kou-Chaw Chen Teh Fu Yen Sonny Astani Department of Civil and Environmental Engineering Viterbi School of Engineering University of Southern California BooKang tech. inc. Korea Building

The UV photooxidation with Fe（Ⅲ） and H2O2 was employed to treat a naval derusting wastewater, which contains the high COD （chemical oxygen demand） and various metal concentrations exceptionally with high concentrations of citric acid and iron. Because of its iron containment, the Fenton-like reaction automatically took place with the added amount of H2O2. The decomposition rate was found in a sequence of： UV/HEOE/Fe（Ⅲ）〉 UV/H2O2 〉 Fe（Ⅱ）/H2O2. Two H2O2 injection methods, single and multiple points, were evaluated. The multiple-point H2O2 injection was more efficient to decompose the citric acid. The decomposition of the synthetic citric acid and the real derusting citric acid wastewater was also compared. The 93% COD reduction of the derusting wastewater was achieved using the UV/HEOE/Fe（Ⅲ） treatment.

关键词： naval derusting wastewater citric acid UV photooxidation Fenton-like

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ARCosmetics:a real-time augmented reality cosmetics try-on system

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Frontiers of Computer Science 2023年第4期17卷 15-28页

作者： Shan AN Jianye CHEN Zhaoqi ZHU Fangru ZHOU Yuxing YANG Yuqing MA Xianglong LIU Haogang ZHU tech.&Data Center *** Inc.Beijing 100176China State Key Lab of Software Development Environment Beihang UniversityBeijing 100191China

A virtual cosmetics try-on system provides a realistic try-on experience for consumers and helps them efficiently choose suitable *** this article,we propose a real-time augmented reality virtual cosmetics try-on system for smartphones(ARCosmetics),taking speed,accuracy,and stability into consideration at each step to ensure a better user experience.A novel and very fast face tracking method utilizes the face detection box and the average position of facial landmarks to estimate the faces in continuous frames.A dynamic weight Wing loss is introduced to assign a dynamic weight to every landmark by the estimated error during *** balances the attention between small,medium,and large range error and thus inc.eases the accuracy and *** also designed a weighted average method to utilize the information of the adjacent frame for landmark refinement,guaranteeing the stability of the generated *** experiments conducted on a large 106-point facial landmark dataset and the 300-VW dataset demonstrate the superior performance of the proposed method compared to other state-of-the-art *** also conducted user satisfaction studies further to verify the efficiency and effectiveness of our ARCosmetics system.

关键词： facial landmark localization face tracking stabilization augmented reality virtual try-on

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欧洲与北美制造的烧结青铜含油轴承性能的比较

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粉末冶金技术 2006年第4期24卷 304-309页

作者： Haward I.Sanderrow Leander F.Pease 韩凤麟 President Management & Engineering TechnologiesMET Group Inc. President Powder-Tech AssociatateInc.

多孔性青铜含油轴承是全世界都在生产的,最早与最无处不用的现代粉末冶金产品。然而,各地区产品之间仍存在着明显差异。近期发布的粉末冶金材料的全球标准ISO5755,其中有2个描述轴承材料性能的数据表。其中列举的几项关键性轴承特性和M... 详细信息

多孔性青铜含油轴承是全世界都在生产的,最早与最无处不用的现代粉末冶金产品。然而,各地区产品之间仍存在着明显差异。近期发布的粉末冶金材料的全球标准ISO5755,其中有2个描述轴承材料性能的数据表。其中列举的几项关键性轴承特性和MPIF标准35或相应的ASTM标准中列出的轴承性能有所不同。因此,MPIF标准委员会进行一项小型试验,对标准90%(质量分数)Cu-10%(质量分数)Sn轴承的关键特性进行了对比。这项研究的样品零件来自欧洲与北美的大批量生产厂家。数据证实孔隙度与径向压溃强度不同,这种差异是原料粉与制造工艺的微妙差异所致。最终用户应该了解这些差异,和确认ISO5755中列举的特性能满足他们对轴承的要求。

关键词：粉末冶金轴承性能青铜含油轴承

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