Environmental Protection of Oil and Gas Fields 1997 Subscriptions Welcome

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EFFECT OF ENVIRONMENTAL FIELD ON TROPICAL CYCLONE TRACK AFTER LANDFALL FROM EAST CHINA SEA

The past few years have seen work on the maintenance and decaying mechanisms of tropical cyclones （TCs） over land. Statistic study has been on the landfall frequency and location of TCs and their maintenance, decaying, transition, intensification and dissipation for the past 32 years and that （1） the deeper water accumulates on land, the more favorable it would be for the maintenance of low pressures and vast lakes, and the surface of large rivers and large- sized reservoirs can slow down the decaying of TC lows, （2） the descending and intrusion of cold air from mid- and upper- tropospheric and warm advection from lower troposphere are responsible for TCs transition; and （3） after landfall, TCs tend to accelerate towards areas of intense convection to the northwest, etc. Being mainly numerical simulation and diagnostic analyses for cases covering much detail and depth, most of the studies cannot tell anything in common about how TCs maintain and decay over land. There has been little work on the difference of land track of TCs, which travel with the underlying surface changing from sea to land. The energy supply from the tropical ocean is severely reduced or completely cut off on the one hand, rough land surface is both a blocking and frictional force for TCs to dissipate their energy on the other. In fact, landfall TCs can either maintain for only a few hours and cover a distance of less than 100 km or stay active tbr more than 100 hours and go as farther away as a few thousand km inland. Why do they differ so much？ Why do TCs follow routes that differ dramatically when they land at or near the same sites with identical or similar underlying surface？ It is obvious that the environmental field is one of the essential factors for TCs after landfall. The aim of this paper is to discuss the effect of the environmental field on TCs track over land and to know whicch, synoptic systems or factors play key roles in it so as to provide basis for the forecasting of land track of TCs after landfall.

Application of Low Pressure Plasma Technology in the Field of Environmental Protection

The characteristics of low pressure plasma produced by a gas discharges lie in thatthe energy of the electrons are much higher than that of the heavy particles in the system. Inthis paperl the low-pressure plasma treatment technology for the environmental contaminantswas synthetically studied, and the reaction processing and mechanism between the low-pressureplasma and the environmental contaminants were theoretically analyzed. At last, the prospectsand existing problems on the application of low-pressure plasma in the field of environmentalprotection were discussed.

Welcome Subscription '96 Environment Protection of Oil and Gas Fields

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Review of the field environmental sensing methods based on multi-sensor information fusion technology

Field environmental sensing can acquire real-time environmental information,which will be applied to field operation,through the fusion of multiple sensors.Multi-sensor fusion refers to the fusion of information obtained from multiple sensors using more advanced data processing methods.The main objective of applying this technology in field environment perception is to acquire real-time environmental information,making agricultural mechanical devices operate better in complex farmland environment with stronger sensing ability and operational accuracy.In this paper,the characteristics of sensors are studied to clarify the advantages and existing problems of each type of sensors and point out that multiple sensors can be introduced to compensate for the information loss.Secondly,the mainstream information fusion types at present are outlined.The characteristics,advantages and disadvantages of different fusion methods are analyzed.The important studies and applications related to multi-sensor information fusion technology published at home and abroad are listed.Eventually,the existing problems in the field environment sensing at present are summarized and the prospect for future of sensors precise sensing,multi-dimensional fusion strategies,discrepancies in sensor fusion and agricultural information processing are proposed in hope of providing reference for the deeper development of smart agriculture.

THE OBJE CTIVE ANALOGUE PREDICTION MODEL FOR TROPICAL CYCLONE TRACK WITH COMPREHENSIVE ASSESSMENT OF THE ENVIRONMENT

An objective analogue prediction model for tropical cyclone (TC) track is put forward that comprehensively assesses the environmental field. With the parameters of the tropical cyclone and environmental field at initial and future time, objective analogue criteria are set up in the model. Analogous samples are recognized by comprehensive assessment to historical TC cases for similarity with multivariate criteria,using non-linear analogue indexes especially defined for the purpose. When the historical tracks are coordinateconverted and weighted with reference to analogue indexes,forecast tracks are determined. As shown in model verification and forecast experiments, the model has forecasting skill.

Spatial data modeling for coalfield geological environment

Presented a study on the design and implementation of spatial data modelingand application in the spatial data organization and management of a coalfield geologicalenvironment database.Based on analysis of a number of existing data models and takinginto account the unique data structure and characteristic, methodology and key techniquesin the object-oriented spatial data modeling were proposed for the coalfield geological environment.The model building process was developed using object-oriented technologyand the Unified Modeling Language (UML) on the platform of ESRI geodatabase datamodels.A case study of spatial data modeling in UML was presented with successful implementationin the spatial database of the coalfield geological environment.The modelbuilding and implementation provided an effective way of representing the complexity andspecificity of coalfield geological environment spatial data and an integrated managementof spatial and property data.

Assessment of Primordial Radionuclides in Pakistani Red Bricks and Associated Radiation Doses

Specific activity of primordial radionuclides and associated radiation hazards due to 40K, 226Ra, and 232Th have been measured in backed red brick samples, collected from five highly populated areas of the North West Frontier Province of Pakistan. For the detection, analysis and data acquisition, a high purity germanium detector was used. Associated external doses were calculated using a Monte Carlo neutron photon transport code. A theoretical model to determine the gamma dose rate at 1 m height from the floor, made of bricks, was employed for the calculation of mass attenuation coefficient and self-absorption in the floor for the gamma energies of these radionuclides and their progeny. Monte Carlo simulation shows that in this study the floor, having more than an effective thickness of 15 cm, contributes very little to the external gamma dose rate. The values of the external dose rate and annual effective dose are found to be much lower than the world average as well as from other countries of the world.

AlphaMobileSensing:A virtual testbed for mobile environmental monitoring

Environmental monitoring plays a critical role in creating and maintaining a comfortable,productive,and healthy environment.Built upon the advancements of robotics and data processing,mobile sensing demonstrates its potential to address problems regarding cost,deployment,and resolution that stationary monitoring encounters,which therefore has attracted increasing research attentions recently.To facilitate mobile sensing,two key algorithms are needed:the field reconstruction algorithm and the route planning algorithm.The field reconstruction algorithm is to reconstruct the entire environment field from spatially-and temporally-discrete measurements collected by the mobile sensors.The route planning algorithm is to instruct the mobile sensors where the mobile sensor needs to move to for the next measurements.The performance of mobile sensors highly depends on these two algorithms.However,developing and testing those algorithms in the real world is expensive,challenging,and time-consuming.To address these issues,we proposed and implemented an open-source virtual testbed,AlphaMobileSensing,that can be used to develop,test,and benchmark mobile sensing algorithms.AlphaMobileSensing aims to help users more easily develop and test the field reconstruction and route planning algorithms for mobile sensing solutions,without worrying about hardware fault,test accidents(such as collision during the test),etc.The separation of concerns can significantly reduce the cost of developing software solutions for mobile sensing.For versatility and flexibility,AlphaMobileSensing was wrapped up using the standardized interface of OpenAI Gym,and it also provides an interface for loading physical fields that were generated by numerical simulations as virtual test sites to perform mobile sensing and retrieving monitoring data.We demonstrated applications of the virtual testbed by implementing and testing algorithms for physical field reconstruction in both static and dynamic indoor thermal environments.AlphaMobileSensing provides a novel and flexible platform to develop,test,and benchmark mobile sensing algorithms more easily,conveniently,and efficiently.AlphaMobileSensing is open sourced at https://github.com/kishuqizhou/AlphaMobileSensing.

Demonstration of Magnetic Energy Harvesting from Electrical Appliances

The purpose of this study is to use magnetic field of 50/60 Hz up to 0.2 mT for energy source. This paper focuses on magnetic energy harvesting from electrical appliances which can be also used for power consumption monitoring. The magnetic energy harvesting device consists of an energy harvesting module, Cockcroft-Walton circuit and storage capacitor. First of all, typical magnetic fields around several electrical appliances are investigated. In order to harvest 10 mJ energy, the shape of magnetic flux concentration flange in energy harvesting module and number of steps in Cockcroft-Walton circuit are considered. From experimental results, magnetic energy harvesting of 17 mJ from a refrigerator is successfully demonstrated.

Uncertain process-based data integration and residual lifetime evaluation of PCB in airborne equipment with ADT and field data

Accurately evaluating the lifespan of the Printed Circuit Board(PCB)in airborne equipment is an essential issue for aircraft design and operation in the marine atmospheric environment.This paper presents a novel evaluation method by fusing Accelerated Degradation Testing(ADT)data,degradation data,and life data of small samples based on the uncertainty degradation process.An uncertain life model of PCB in airborne equipment is constructed by employing the uncertain distribution that considers the accelerated factor of multiple environmental conditions such as temperature,humidity,and salinity.In addition,a degradation process model of PCB in airborne equipment is constructed by employing the uncertain process of fusing ADT data and field data,in which the performance characteristics of dynamic cumulative change are included.Based on minimizing the pth sample moments,an integrated method for parameter estimation of the PCB in airborne equipment is proposed by fusing the multi-source data of life,degradation,and ADT.An engineering case illustrates the effectiveness and advantage of the proposed method.

Responses of Grassland Net Primary Productivity to Environmental Variables in Northern China

Various environmental factors affect net primary productivity （NPP） of grassland ecosystem. Extensive reports on the effects of environmental variables on NPP can be found in literature. However, the agreement on the relative importance of various factors in shaping the spatial pattern of grassland NPP has not yet been reached. Here a grassland in situ NPP database comprising 602 samples in northern China for 1980-1999 was developed based on a literature review of published biomass and forage yield field measurements. Correlation analyses and dominance analysis were used to quantify the separate and combined effects of environmental variables （climate topography and soil） on spatial variation in NPP separately. Grassland NPP ranged from 4.76 g C m-2a-1 to 975.94gCm-2a-1, showing significant variations in space. NPP increased with annual precipitation and declined with annual mean temperature significantly. Specifically, precipitation had the greatest impact on deserts, followed by steppes and meadows. Grassland NPP decreased with increasing altitude because of water limitation, and positively correlated with slope, but weakly correlated with aspect. Soil quality showed positive effects on NPP. Annual precipitation was the dominant factor affecting the spatial variability of net primary productivity, followed by elevation.

Application of high-level environmental field factor in TC's sudden recurvature process

Using the 6-hourly reanalysis data of European Center ERA-Interim with horizontal resolution of 0.25°×0.25°and hourly typhoon operational data provided by the CMA(China Meteorological Administration),a new high-level environmental field factor is derived,and its application during the recurvature period of No.14 Typhoon Yagi and No.18 Typhoon Rumbia in 2018 is compared and analyzed.According to the comparison study,there is always a clear positive abnormal value area of high-level environmental field factor on the northeast of Rumbia during its northward movement,implying an obvious alteration of ∇·u and a big negative gradient of ∇u on the northeast of Rumbia.With the eastward movement of the westerly trough and the strengthening of the subtropical westerly jet,Rumbia is expected to veer northeast.However,the change of high-level environmental field factor on the northeast of Yagi is not noticeable,and Yagi is far away from the upper-level jet stream,which is not conducive to Yagi's northeast recurvature.

Recognition on the forming-vanishing process and underlying mechanisms of the hypoxia off the Yangtze River estuary

On the basis of compiled multidisciplinary historical data in 2006-2007 and incorporation of relevant simulation results and re- mote sensing data, we performed an in-depth study of the generation and dissipation process of the hypoxic zone and its distribu- tion morphology and structure off the Yangtze River estuary, Based on the hydrological circulation dynamics, reproduction of phytoplankton （leading to the decomposition of organic matter）, and other factors, we comprehensively and systematically inves- tigated the generation and dissipation of the hypoxic zone and underlying mechanisms for the seasonal variation in its position, explored the multi-factorial synergistic reactions during the generation and dissipation process of the hypoxic zone, and revealed the controlled mechanism for the morphology and structure of the hypoxic zone＇s distribution. Our studies indicate that in the winter and spring seasons, the hydrological environment off the Yangtze River estuary provides a water body with relatively low contents of dissolved oxygen （DO）, which is the background for the formation of a hypoxic zone. After entering into the summer season, the hypoxic zone gradually develops towards the north and becomes mature. Because of the impact of the terrain, local decomposition of organic matter, and upwelling of the Kuroshio subsurface water in July-August, the bypoxic zone off the Yang- tze River estuary exhibits the characteristics of discontinuous distribution in space and has a south and north ＂dual-core＂ structure in the inner continental shelf. In addition, there is a hypoxic core in the eastern outer continental shelf. The degrees of hypoxia vary for different areas; they are strongest overall in the north, next strongest in the south; they are weakest on the outer continen- tal shelf. In summer, the hypoxic zone in the north is related to the northward differentiation of the southern hypoxic zone and re- sults from local development and intensification. In August, the hypoxic zone in the north reaches its peak, and after September, it rapidly retreats southward and disappears because of weakening stratification. In the fall, there is hypoxic zone along the coast of Zhejiang in the south, and there is also a low-DO area to the southwest of Jeju Island, with both zones disappearing rapidly. In addition, the change of dynamic environment also causes the low-DO area of the outer continental shelf to move outward in the fall. The variation in the intensity of the stratification and its cumulative effects as a barrier of vertical DO transportation over long pe- riods of time have a significant impact on the degree of hypoxia in the hypoxic zone. In addition, the seasonal variations in the size of the stratified region, intensity of each current system/water mass, upwelling, front, and high-value area of phytoplankton biomass jointly restrict the extension of the hypoxic zone in the inner continental shelf and latitudinal （south-north direction） movement of its location off the Yangtze River estuary. The combined effect of dynamic factors, such as that of the Kuroshio subsurface water, causes a low-DO core in the outer continental shelI： The bottom cold water to the north of the East China Sea is the dynamic basis for the formation of the low-DO area to the southwest of Jeju Island during the fall season. The special seabed to- pography and mud area distribution off the Yangtze River estuary have a certain degree of influence on the development of the hypoxic zone. The generation and dissipation of the hypoxic zone and its distribution morphology off the Yangtze River estuary, and seasonal variation of its structure and position are a result of the synergistic effects of various factors.