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1Risk of transmission of carbapenem-resistant Enterobacteriaceae and related “superbugs” during gastrointestinal endoscopy显示文摘To evaluate the risk of transmission of carbapenem-resistant Enterobacteriaceae(CRE) and their related superbugs during gastrointestinal(GI) endoscopy. Reports of outbreaks linked to GI endoscopes contami-nated with different types of infectious agents, includ-ing CRE and their related superbugs, were reviewed. Published during the past 30 years, both prior to and since CRE's emergence, these reports were obtained by searching the peer-reviewed medical literature(via the United States National Library of Medicine's 'MEDLINE' database); the Food and Drug Administration's Manu-facturer and User Facility Device Experience database, or 'MAUDE'; and the Internet(via Google's search engine). This review focused on an outbreak of CRE in 2013 following the GI endoscopic procedure known as endoscopic retrograde cholangiopancreatography, or ERCP, performed at 'Hospital X' located in the sub-urbs of Chicago(IL; United States). Part of the largest outbreak of CRE in United States history, the infection and colonization of 10 and 28 of this hospital's patients, respectively, received considerable media attention and was also investigated by the Centers for Disease Con-trol and Prevention(CDC), which published a report about this outbreak in Morbidity and Mortality WeeklyReport(MMWR), in 2014. This report, along with the results of an independent inspection of Hospital X's in-fection control practices following this CRE outbreak, were also reviewed. While this article focuses primar-ily on the prevention of transmissions of CRE and their related superbugs in the GI endoscopic setting, some of its discussion and recommendations may also apply to other healthcare settings, to other types of flexible endoscopes, and to other types of transmissible infec-tious agents. This review found that GI endoscopy is an important risk factor for the transmission of CRE and their related superbugs, having been recently as-sociated with patient morbidity and mortality following ERCP. The CDC reported in MMWR that the type of GI endoscope, known as an ERCP endoscope, that Hospi-tal X used to perform ERCP in 2013 on the 38 patients who became infected or colonized with CRE might be particularly challenging to clean and disinfect, because of the complexity of its physical design. If performed in strict accordance with the endoscope manufacturer's labeling, supplemented as needed with professional organizations' published guidelines, however, current practices for reprocessing GI endoscopes, which include high-level disinfection, are reportedly adequate for the prevention of transmission of CRE and their related superbugs. Several recommendations are provided to prevent CRE transmissions in the healthcare setting. CRE transmissions are not limited to contaminated GI endoscopes and also have been linked to other reusable flexible endoscopic instrumentation, including broncho-scopes and cystoscopes. In conclusion, contaminated GI endoscopes, particularly those used during ERCP, have been causally linked to outbreaks of CRE and their related superbugs, with associated patient morbidity and mortality. Thorough reprocessing of these complex reusable instruments is necessary to prevent disease transmission and ensure patient safety during GI endos-copy. Enhanced training and monitoring of reprocessing staffers to verify the proper cleaning and brushing of GI endoscopes, especially the area around, behind andnear the forceps elevator located at the distal end othe ERCP endoscope, are recommended. If the ERCPendoscope features a narrow and exposed channel thathouses a wire connecting the GI endoscope's controhead to this forceps elevator, then this channel's com-plete reprocessing, including its flushing with a deter-gent using a procedure validated for effectiveness, is also emphasized.Lawrence F Muscarella 2014World Journal of Gastrointestinal Endoscopy2014,6,10:26
2Prevention of stress-related ulcer bleeding at the intensive care unit: Risks and benefits of stress ulcer prophylaxis显示文摘Stress-related mucosal disease is a typical complication of critically ill patients in the intensive care unit(ICU). It poses a risk of clinically relevant upper gastrointestinal(GI) bleeding. Therefore, stress ulcer prophylaxis(SUP)is recommended in high-risk patients, especially those mechanically ventilated > 48 h and those with a manifest coagulopathy. Proton pump inhibitors(PPI) and, less effectively, histamine 2 receptor antagonists(H2RA) prevent GI bleeding in critically ill patients in the ICU. However, the routine use of pharmacological SUP does not reduce overall mortality in ICU patients. Moreover, recent studies revealed that SUP in the ICU might be associated with potential harm such as an increased risk of infectious complications, especially nosocomial pneumonia and Clostridium difficile-associated diarrhea. Additionally, special populations such as patients with liver cirrhosis may even have an increased mortality rate if treated with PPI. Likewise, PPI can be toxic for both the liver and the bone marrow, and some PPI show clinically relevant interactions with important other drugs like clopidogrel. Therefore, the agent of choice, the specific balance of risks and benefits for individual patients as well as the possible dose of PPI has to be chosen carefully. Alternatives to PPI prophylaxis include H2 RA and/or sucralfate. Instead of routine SUP, further trials should investigate risk-adjusted algorithms, balancing benefits and threats of SUP medication in the ICU.Lukas Buendgens Alexander Koch Frank Tacke 2016World Journal of Critical Care Medicine2016,5,1:24
3FAULT TREE ANALYSIS OF SPONTANEOUS COMBUSTION OF SULPHIDE ORES AND ITS RISK ASSESSMENT显示文摘A logic fault tree of mine spontaneous combustion of sulphide ores was built by the fault tree analysis (FTA) based on a lot of mechanism investigation of sulphide ore spontaneous combustion in more than ten mines and review of a great amount of relevantWu Chao(Department of Resources Exploitation Engineering, Central South University of Technology, Changsha, 410083, China ) 1995Journal of Central South University1995,7,2:21
4Endoscopic retrograde cholangiopancreatography associated pancreatitis:A 15-year review显示文摘The aim of this article is to review the literature regarding post-endoscopic retrograde cholangiopancreatography(ERCP) pancreatitis.We searched for and evaluated all articles describing the diagnosis,epidemiology,pathophysiology,morbidity,mortality and prevention of post-ERCP pancreatitis(PEP) in adult patients using the PubMed database.Search terms included endoscopic retrograde cholangiopancreatography,pancreatitis,ampulla of vater,endoscopic sphincterotomy,balloon dilatation,cholangiography,adverse events,standards and utilization.We limited our review of articles to those published between January 1,1994 and August 15,2009 regarding human adults and written in the English language.Publicat ions from the reference sections were reviewed and included if they were salient and fell into the time period of interest.Between the dates queried,seventeen large(> 500 patients) prospective and four large retrospective trials were conducted.PEP occurred in 1-15 in the prospective trials and in 1-4 in the retrospective trials.PEP was also reduced with pancreatic duct stent placement and outcomes were improved with endoscopic sphincterotomy compared to balloon sphincter dilation in the setting of choledocholithiasis.Approximately 34 pharmacologic agents have been evaluated for the prevention of PEP over the last f ifteen years in 63 trials.Although 22 of 63 trials published during our period of review suggested a reduction in PEP,no pharmacologic therapy has been widely accepted in clinical use in decreasing the development of PEP.In conclusion,PEP is a well-recognized complication of ERCP.Medical treatment for prevention has been disappointing.Proper patient selection and pancreatic duct stenting have been shown to reduce the complication rate in randomized clinical trials.Kevin E Woods Field F Willingham 2010World Journal of Gastrointestinal Endoscopy2010,2,5:20
5PM_(2.5)-bound polycyclic aromatic hydrocarbons(PAHs) in Beijing:Seasonal variations,sources,and risk assessment显示文摘Polycyclic aromatic hydrocarbons(PAHs) have been of health concern due to its carcinogenesis and mutagenesis. In this study, we aimed to assess the variations, sources, and lifetime excessive cancer risk(ECR) attributable to PAHs bound to ambient particulate matters with aerodynamic diameter less than 2.5 μm(PM_(2.5)) in metropolitan Beijing, China. We collected24-hour integrated PM_(2.5) samples on daily basis between November 2014 and June 2015 across both central heating(cold months) and non-heating(warm months) seasons, and further analyzed the PAH components in these daily PM_(2.5) samples. Our results showed that total concentrations of PM_(2.5)-bound PAHs varied between(88.6 ± 75.4) ng/m^3 in the cold months and(11.0 ± 5.9) ng/m^3 in the warm months. Benzo[a]pyrene(Ba P), the carcinogenic marker of PAHs,averaged at 5.7 and 0.4 ng/m^3 in the cold and warm months, respectively. Source apportionment analyses illustrated that gasoline, biomass burning, diesel, coal combustion and cooking were the major contributors, accounting for 12.9%, 17.8%, 24.7%, 24.3% and 6.4% of PM_(2.5)-bound PAHs, respectively. The BaP equivalent lifetime ECR from inhalation of PM_(2.5)-bound PAHs was 16.2 cases per million habitants. Our results suggested that ambient particulate reduction from energy reconstruction and adaption of clean fuels would result in reductions PM_(2.5)-bound PAHs and its associated cancer risks. However, as only particulate phased PAHs was analyzed in the present study, the concentration of ambient PAHs could be underestimated.Baihuan Feng Lijuan Li Hongbing Xu Tong Wang Rongshan Wu Jie Chen Yi Zhang Shuo Liu Steven Sai Hang Ho Junji Cao Wei Huang 2019Journal of Environmental Sciences2019,31,3:17
6Inter-basin water transfer-supply model and risk analysis with consideration of rainfall forecast information显示文摘This paper develops a new inter-basin water transfer-supply and risk assessment model with consideration of rainfall forecast information. Firstly, based on the current state of reservoir and rainfall forecast information from the global forecast system (GFS), the actual diversion amount can be determined according to the inter-basin water transfer rules with the decision tree method; secondly, the reservoir supply operation system is used to distribute water resource of the inter-basin water transfer reservoir; finally, the integrated risk assessment model is built by selecting the reliability of water transfer, the reliability (water shortage risk), the resiliency and the vulnerability of water supply as risk analysis indexes. The case study shows that the inter-basin water transfer-supply model with rainfall forecast information considered can reduce the comprehensive risk and improve the utilization efficiency of water resource, as compared with conventional and optimal water distribution models.XI ShuFeng1, WANG BenDe1, LIANG GuoHua1, LI XueSen2 & LOU LiLi3 1 School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian 116024, China 2 Management Bureau of Tanghe Reservoir, Liaoyang 111000, China 3 Institute of Dalian Water Science, Dalian 116013, China 2010Science China(Technological Sciences)2010,53,12:12
7Effect of near-fault earthquake on bridges:lessons learned from Chi-Chi earthquake显示文摘The objective of this paper is to describe the lessons learned and actions that have been taken related to the seismicdesign of bridge structures after the Chi-Chi, Taiwan earthquake. Much variable near-fault ground motion data was collected fromthe rupture of Chelungpu fault during the Chi-Chi earthquake, allowing the seismic response of bridge structures subjected to thesenear-fault ground motions to be carefully examined. To study the near-fault ground motion effect on bridge seismic design codes, atwo-level seismic design of bridge structures was developed and implemented. This design code reflects the near-fault factors in theseismic design forces. Finally, a risk assessment methodology, based on bridge vulnerability, is also developed to assist in decisionsfor reducing seismic risk due to failure of bridges.Chin-Hsiung Loh Wen-I Liao Juin-Fu Chai 2002Earthquake Engineering and Engineering Vibration2002,1,1:11
8Application of quality by design in the current drug development显示文摘Quality by Test was the only way to guarantee quality of drug products before FDA launched current Good Manufacturing Practice. To clearly understand the manufacture processes, FDA generalized Quality by Design(QbD) in the field of pharmacy, which is based on the thorough understanding of how materials and process parameters affect the quality profile of final products. The application of QbD in drug formulation and process design is based on a good understanding of the sources of variability and the manufacture process. In this paper,the basic knowledge of QbD, the elements of QbD, steps and tools for QbD implementation in pharmaceutics field, including risk assessment, design of experiment, and process analytical technology(PAT), are introduced briefly. Moreover, the concrete applications of QbD in various pharmaceutical related unit operations are summarized and presented.Lan Zhang Shirui Mao 2017Asian Journal of Pharmaceutical Sciences2017,12,1:9
9Levels,trends and risk assessment of arsenic pollution in Yangzonghai Lake,Yunnan Province,China显示文摘The arsenic contamination accident in Yangzonghai Lake,Yunnan has been of wide concern.In order to investigate the arsenic distribution and concentration trends after the accident,samples including lake water,sediments,soil,aquatic organisms and crops were collected in November 2008,as well as in February,May and September 2009.The average arsenic concentrations (arithmetic average) in lake water in the four sampling events were 176.9,147.3,159.3,and 161.1 μg/L,while those in the sediments were 32.87,62.41,62.99,and 46.96 μg/g,respectively.The highest content of total arsenic in soil in the vicinity of Yangzonghai was 23.33 μg/g,which was below the limits of the relevant national standard.The total arsenic levels in most aquatic plants were in the range of 100-200 μg/g,with Vallisneria natans (Lour.) Hara having the highest concentration of ~300 μg/g.The arsenic levels of fish and shrimps were in the range of 1.52-11.4 μg/g (dry weight).WANG ZhenHua1,HE Bin1,PAN XueJun2,ZHANG KeGang1,WANG Chang1,SUN Jing1,YUN ZhaoJun1 & JIANG GuiBin11State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China 2School of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China 2010Science China Chemistry2010,53,8:9
10Risk assessment of gas control and spontaneous combustion of coal under gas drainage of an upper tunnel显示文摘The adjustment of the gas drainage rate has an immediate impact on air leakage in gob,thus resulting in the change of self-heating of coal.While regulating the gas drainage parameters,the risk of spontaneous combustion of coal should be considered.The risk assessment of gas control and spontaneous combustion of coal under gas drainage in a tunnel was investigated at different gas drainage rates.The distributions of the air volume along the working face,the gas management effects and the width of the oxidation zone were subjected to risk analysis.As the simulation results showed,with increasing gas drainage rate,although the safety of gas dilution by ventilation was assured,the intensifying air leakage caused the oxidation zone to move into the deeper gob and led to an increase in the width of the oxidation zone.A risk assessment method was proposed to determine a suitable gas drainage rate for the upper tunnel.The correctness of the risk assessment and the validity of the numerical modelling were confirmed by the field measurements.Tingxiang Chu Pin Li Yuexia Chen 2019International Journal of Mining Science and Technology2019,29,3:9
11Progress and perspectives of quantitative structure-activity relationships used for ecological risk assessment of toxic organic compounds显示文摘Structure-activity relationship (SAR) and quantitative structure-activity relationship (QSAR), collec- tively referred to as (Q)SARs, play an important role in ecological risk assessment (ERA) of organic chemicals. (Q)SARs can fill the data gap for physical-chemical, environmental behavioral and ecotoxicological parameters of organic compounds; they can decrease experimental expenses and reduce the extent of experimental testing (especially animal testing); they can also be used to assess the uncertainty of the experimental data. With the development for several decades, (Q)SARs in envi- ronmental sciences show three features: application orientation, multidisciplinary integration, and in- telligence. Progress of (Q)SAR technology for ERA of toxic organic compounds, including endpoint selection and mathematic methods for establishing simple, transparent, easily interpretable and portable (Q)SAR models, is reviewed. The recent development on defining application domains and diagnosing outliers is summarized. Model characterization with respect to goodness-of-fit, stability and predictive power is specially presented. The purpose of the review is to promote the development of (Q)SARs orientated to ERA of organic chemicals.CHEN JingWen LI XueHua YU HaiYing 2008Science China Chemistry2008,51,7:9
12Risk Governance:Application to Urban Challenges显示文摘Urban areas face multiple risks: they range from natural hazard-induced disasters, fires, and building code violations to social risks such as vandalism, crime, and social disorientation, among others. These risks often interact with each other and cannot be dealt with in isolation. As a means to identify, assess, and manage multiple risks, the concept of ‘‘risk governance'' has been developed, which promises to provide integrative and comprehensive tools to deal with the many manifestations of risks.In this article, risk governance concept has been specifically applied to complex risk situations in urban areas. The concept of risk governance pertains to the many ways in which multiple actors, individuals and institutions, public and private, deal with risks. It includes formal institutions and regimes and informal arrangements. The article first develops an adaptive and integrative model of risk governance and applies this model to the urban environments.After a short summary of the roots of risk governance, key concepts, such as simple, uncertain, complex, and ambiguous risks, are discussed. The main emphasis is on each of the five phases of risk governance: pre-estimation,interdisciplinary assessment, risk evaluation, risk management, and risk communication.Ortwin Renn Andreas Klinke Pia-Johanna Schweizer 2018International Journal of Disaster Risk Science2018,9,4:8
13Risk assessment in patients undergoing liver resection显示文摘BACKGROUND:Liver resection is still a risky procedure with high morbidity and mortality.It is significant to predict the morbidity and mortality with some models after liver resection.DATA SOURCES:The MEDLINE/PubMed,Web of Science,Google Scholar,and Cochrane Library databases were searched using the terms 'hepatectomy' and 'risk assessment' for relevant studies before August 2012.Papers published in English were included.RESULTS:Thirty-four original papers were included finally.Some models,such as MELD,APACHE II,E-PASS,or POSSUM,widely used in other populations,are useful to predict the morbidity and mortality after liver resection.Some special models for liver resection are used to predict outcomes after liver resection,such as mortality,liver dysfunction,transfusion,or acute renal failure.However,there is no good scoring system to predict or classify surgical complications because of shortage of internal or external validation.CONCLUSION:It is important to validate the models for the major complications after liver resection with further internal or external databases.De-Cai Yu Wei-Bo Chen Chun-Ping Jiang Yi-Tao Ding 2013Hepatobiliary & Pancreatic Diseases International2013,12,5:8
14Geochemical fractionation and ecological risks assessment of benthic sediment-bound heavy metals from coastal ecosystems off the Equatorial Atlantic Ocean显示文摘This study determines the pollution, fractionation, and ecological risks of sediment-bound heavy metals from coastal ecosystems off the Equatorial Atlantic Ocean. Contamination Factor(CF), pollution load index(PLI), and geoaccumulation index(Igeo) were used to assess the extent of the heavy metal pollution, while the potential ecological risk was evaluated using the risks assessment code(RAC) and Hkanson potential ecological risk. The analysis revealed concentrations(mg/g, dw) of the cadmium(Cd),chromium(Cr), copper(Cu), nickel(Ni), and lead(Pb) in sediments for wet and dry seasons vary from 4.40-5.08, 14.80-21.09. 35.03-44.8, 2.14-2.28, and 172.24-196.39, respectively. The results also showed that the metal fractionation percentages in the residual, oxidizable, and reducible fractions are the most significant, while the exchangeable and carbonate bound trace metals are relatively low. The RAC values indicate no risk for Cd and Ni and low risk for other metals at all the studied sites during both seasons.Potential ecological risk analysis of the heavy metal concentrations indicates that Cd had high individual potential ecological risk, while the other metals have low risk at all investigated sites. The multi-elemental potential ecological risk indices(R_1) indicate high ecological risk in all the ecosystems.Nsikak U. Benson Essien D. Udosen Joseph P. Essien Winifred U. Anake Adebusayo E. Adedapo Oyeronke A. Akintokun Omowunmi H. Fred-Ahmadu Abass A. Olajire 2017International Journal of Sediment Research2017,32,3:8
15Dynamic security risk assessment and optimization of power transmission system显示文摘The paper presents a practical dynamic security region (PDSR) based dynamic security risk assessment and optimization model for power transmission system. The cost of comprehensive security control and the influence of uncertainties of power injections are considered in the model of dynamic security risk assessment. The transient stability constraints and uncertainties of power injections can be considered easily by PDSR in form of hyper-box. A method to define and classify contingency set is presented, and a risk control optimization model is given which takes total dynamic insecurity risk as the objective function for a dominant con-tingency set. An optimal solution of dynamic insecurity risk is obtained by opti-mizing preventive and emergency control cost and contingency set decomposition. The effectiveness of this model has been proved by test results on the New Eng-land 10-genarator 39-bus system.YU YiXin1 & WANG DongTao1,2 1 Key Laboratory of Power System Simulation and Control of Ministry of Education, Tianjin University, Tianjin 300072, China 2 School of Computer & Automation, Hebei Polytechnic University, Tangshan 063009, China 2008Science China(Technological Sciences)2008,51,6:7
16Optimizing Emergency Logistics for the Offsite Hazardous Waste Management显示文摘Hazardous wastes pose increasing threats to people and environment during the processes of offsite collection,storage,treatment,and disposal.A novel game theoretic model,including two levels,is developed for the corresponding optimization of emergency logistics,where the upper level indicates the location and capacity problem for the regulator,and the lower level reflects the allocation problem for the emergency commander.Different from other works in the literature,we focus on the issue of multi-quality coverages (full and partial coverages) in the optimization of facility location and allocation.To be specific,the regulator decides the location plan and the corresponding capacity of storing emergency groups for multiple types of hazmats,so to minimizes the total potential environmental risk posed by incident sites;while the commander minimizes the total costs to provide an efficient allocation policy.To solve the bi-level programming model,two solution techniques,namely a KKT condition approach and a heuristic model,are designed and compared.The proposed model and solution techniques are then applied to a hypothetical case and a real-world case to demonstrate the practicality and provide managerial insights.Jiahong Zhao Ginger Y.Ke 2019Journal of Systems Science and Systems Engineering2019,28,6:6
17Prognostic significance of computed tomography-detected extramural vascular invasion in colon cancer显示文摘AIM: To compare disease-free survival(DFS) between extramural vascular invasion(EMVI)-positive and-negative colon cancer patients evaluated by computed tomography(CT).METHODS: Colon cancer patients(n = 194) undergoing curative surgery between January 2009 and December 2013 were included. Each patient's demographics, cancer characteristics, EMVI status, pathological status and survival outcomes were recorded. All included patients had been routinely monitored until December 2015. EMVI was defined as tumor tissue within adjacent vessels beyond the colon wall as seen on enhanced CT. Disease recurrence was defined as metachronous metastases, local recurrence, or death due to colon cancer. Kaplan-Meier analyses were used to compare DFS between the EMVI-positive and-negative groups. Cox's proportional hazards models were used to measure the impact of confounding variables on survival rates.RESULTS: EMVI was observed on CT(ct EMVI) in 60 patients(30.9%, 60/194). One year after surgery, there was no statistically significant difference regarding the rates of progressive events between EMVI-positive and-negative patients [11.7%(7/60) and 6.7%(9/134), respectively; P = 0.266]. At the study endpoint, the EMVI-positive patients had significantly more progressive events than the EMVI-negative patients [43.3%(26/60) and 14.9%(20/134), respectively; oddsratio = 4.4, P < 0.001]. Based on the Kaplan-Meier method, the cumulative 1-year DFS rates were 86.7%(95%CI: 82.3-91.1) and 92.4%(95%CI: 90.1-94.7) for EMVI-positive and EMVI-negative patients, respectively. The cumulative 3-year DFS rates were 49.5%(95%CI: 42.1-56.9) and 85.8%(95%CI: 82.6-89.0), respectively. Cox proportional hazards regression analysis revealed that ctE MVI was an independent predictor of DFS with a hazard ratio of 2.15(95%CI: 1.12-4.14, P = 0.023). CONCLUSION: ctE MVI may be helpful when evaluating disease progression in colon cancer patients.Xun Yao Su-Xing Yang Xing-He Song Yan-Cheng Cui Ying-Jiang Ye Yi Wang 2016World Journal of Gastroenterology2016,22,31:6
18Preliminary survivability analysis of manned spacecraft following orbital debris penetration显示文摘Meteoroid and orbital debris(M/OD) may cause severe damages or even catastrophic failures for long-term manned spacecrafts in orbit due to the hypervelocity impact(HVI) destruction.It is essential to quantitatively assess the M/OD risk of manned spacecraft.In this paper,the catastrophic failure as-sessment function is successfully integrated into the Meteoroid & Orbital Debris Assessment and Op-timization System Tools(MODAOST),which is the M/OD risk assessment system developed by China Academy of Space Technology.The survivability assessment for the US Lab by MODAOST was con-sistent with that of the Manned Spacecraft Crew Survivability computer code(MSCSurv).Meanwhile,the simulation process showed that this function was more effective than MSCSurv for the application of the standard methodology of M/OD risk assessment instead of the Monte Carlo model.This function expands the ability of MODAOST in predicting the survivability of the typical catastrophic failure modes such as crew hypoxia and the critical cracking.ZHANG Yong HAN ZengYao LI Ming ZHENG ShiGui 2009Science China(Technological Sciences)2009,52,5:6
19Integrated rockfall hazard and risk assessment along highways: An example for Jiuzhaigou area after the 2017 Ms 7.0 Jiuzhaigou earthquake, China显示文摘This work addresses the integrated assessment of rockfall(including landslides) hazards and risk for S301, Z120, and Z128 highways, which are important transportation corridors to the world heritage site Jiuzhai Valley National Park in Sichuan, China. The highways are severely threatened by rockfalls or landslide events after the 2017 Ms 7.0 Jiuzhaigou earthquake. Field survey(September 14-18 th, 2017, May 15-20 th, 2018, and September 9-17 th, 2018), unmanned aerial vehicle(UAV), and satellite image identified high-relief rockfalls and road construction rockfalls or landslides along the highway. Rockfall hazard is qualitatively evaluated using block count, velocity, and flying height through a 3D rockfall simulation at local and regional scales. Rockfall risk is quantitatively assessed with rockfall event probability, propagation probability, spatial probability, and vulnerability for different block volume classes. Approximately 21.5%, 20.5%, and 5.3% of the road mileage was found to be subject to an unacceptable(UA) risk class for vehicles along S301, Z120, and Z128 highways, respectively. Approximately 20.1% and 3.3% of the road mileage belong to the UA risk class for tourists along Z120 and Z128 highways, respectively. Results highlighted that high-relief rockfall events were intensively located at K50 to K55(Guanmenzi to Ganheba) and K70 to K72(Jiudaoguai to Shangsizhai Village) road mileages along S301 highway and KZ18 to KZ22(Five Flower Lake to Arrow Bamboo Lake) road mileages, KZ30(Swan Lake to Virgin Forests), and KY10.5 kilometers in Jiuzhai Valley. Rockfalls in these locations were classified under the UA risk class and medium to very high hazard index. Road construction rockfalls were located at K67(Jiuzhai Paradise) and K75–K76 kilometers along S301 highway and KZ12 to KZ14(Rhino Lake to Nuorilang Waterfall), KZ16.5 to KZ17.5(Golden Bell Lake), KY5(Lower Seasonal Lake), and KY14(Upper Seasonal Lake) kilometers along Z120 and Z128 highway in Jiuzhai Valley. Rockfalls in these areas were within a reasonable practicable risk to UA risk class and very low to medium hazard index. Finally, defensive measures, including flexible nets, concrete walls, and artificial tunnels, could be selected appropriately on the basis of the rockfall hazard index and risk class. This study revealed the integration between qualitative rockfall hazard assessment and quantitative rockfall risk assessment, which is crucial in studying rockfall prevention and mitigation.LI Xiao-ning LING Si-xiang SUN Chun-wei XU Jian-xiang HUANG Tao 2019Journal of Mountain Science2019,16,6:5
20Differentiation degree combination weighting method for investment decision-making risk assessment in power grid construction projects显示文摘Power grid construction projects are distinguished by their wide variety,high investment,long payback period,and close relation to national development and human welfare.To improve the investment accuracy in such projects and effectively prevent investment risks,this paper proposes an investment optimization decision-making method for multiple power grid construction projects under a certain investment scale.Firstly,an in-depth analysis of the characteristics and development requirements of China’s power grid projects was performed.Thereafter,the time sequence and holographic method was adopted to conduct multi-dimensional,multi-perspective risk assessment of different parts of power grid projects,and a holographic risk assessment index system was developed.Moreover,an investment decision model considering the comprehensive risk based on combination weighting was developed according to the output and input of power grid construction projects.A new combination weighting optimization method that takes into account the investment willingness of enterprises was designed to improve the current weighting evaluation methods.Finally,the validity and applicability of the proposed evaluation method were verified by case examples.Yuan Chang Chenmiao Liu Minghua Liu Wenxia Liu Zongqi Liu Heng Zhang Yan Zheng 2019Global Energy Interconnection2019,2,5:5
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