898 resultados para Disaster preparedness
Resumo:
This paper is an important part of the national "863" topic :"Reservoir dynamic model, the development environment and the forecast of remaining oil". In this paper, multi-theory, method and technology are synthesized, and sufficiently use the computer method. We use unifies of qualitative and quota, unifies of macroscopic and microscopic, unifies of dynamic and quiescent description of reservoir, unifies of comprehensive research about reservoir and physical mathematical simulation, unifies of three-dimensional and four-dimensional description of reservoir to research the reservoir of channel sand in Gudao oilfield. and we do some research about the last 10 years of the more than 30 year high pressure water injection and polymer water flooding development, dynamic changes and geologic hazard of reservoir fluid field. It discloses the distribution, genesis and controlling factors. The main innovation achievement and the understanding are: we built-up the framework of the strata and structure, and found genetic type, spatial distribution and aeolotropism of the upper Guantao member. We form the macroscopic and microscopic reservoir model of dynamic evolution, disclose the character, distribution of the macroscopic and microscopic parameter,and the relationship with remaining oil. Next we built-up the model about hydrosialite, and find the styles, group of styles, formation mechanism and controlling factors of the reservoir, disclose the affection of the hydrosialite to remaining oil, pollution of the production environment of oilfield and geologic hazard. The geologic hazards are classified to 8 styles first time, and we disclose the character, distribution law, formation mechanism and controlling factors of the geologic hazard. We built-up the model of the distribution of remaining oil in different periods of Gudao oilfield, and disclose the macroscopic and microscopic formation mechanism of remaining oil in different periods, forecast the distribution of the mobile remaining oil, and find that the main cause of the dynamic evolution of all the sub-models of reservoir fluid field is the geologic process of the reservoir development hydrodynamic force. We develop the reservoir fluid field, research of environment disaster and the description about the support theory, method and technology. The use of this theory in Gudao oilfield has obtained very good economic efficiency, and deepened and develops development geology about the continental facies fault-trough basin, and theory of geologic hazard.
Resumo:
The topic of Dynamic reservoir model and the distribution of remaining oil after polymer injection of Shengtuo oilfield is a front problem of "the 11th Five-Year Plan" scientific and technological disciplines of Sinopec Corporation. Reservoirs in study area is distributary channel sandstone. After 34 years of water-injection exploitation and 7 years of polymer injection pilot experiments, a highly complex heterogeneous dynamic evolution has been occurred in macro and micro parameters of reservoir model, together with its flow field. Therefore, it’s essential to construct completed reservoir dynamic model for a successfully prediction of the distribution of remaining oil. With a comprehensive application of multidisciplinary theory and technique, using a variety of data and information to maximize the use of computer technology, combining a static and dynamic, macro and micro and 1~4D integration, the research reveals main features, evolution and mechanism, types of geological disasters and their destructivity of reservoir flow field, the macro field, the micro field, the flow field and reservoir development hydrodynamic geological function in different development periods after a long term of polymer injection in Es2 in Shengtuo oilfield. The principle innovation achievements obtained are: 1. Established A, B, C, D four flow units in target formations, revealed the various features and distribution of flow units. 2. Stated environmental pollution and geological disasters induced during oilfield exploitation in study area, and also explained their formation mechanism, controlling factors, destructivity and approaches to disaster reduction. 3. Established dynamic evolution of the macro parameter model, micro-matrix field, pore network field, clay minerals field, seepage dynamic evolution model of six different exploitation stages in study area, also revealed reservoir flow evolution, the law of evolution mechanism after polymer injection. 4. Established macro and micro distribution model of remaining oil after three mining polymer injection during different water cut periods in study area, revealed the formation mechanism and distribution of remaining oil. 5. Established remaining oilforecasting model in study area, and forecasted the formation and distribution of remaining oil in the following six years. 6. It is proposed that reservoir fluid dynamic geological processes are major driving forces for the evolution of different water cut periods, reservoir macro field after the polymer injection and micro seepage field. 7. Established a dynamic reservoir model, proposed matching theory, methods and technology for the description of the remaining oil characterization and prediction, which can deepen the theory and techniques of continental rift basin development geology. Key words: Polymer reservoir; Geological disasters; Dynamic model; Residual oil forecast
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Debris Landslide is one of the types of landslides with the widest distribution, largest quantity, and the closest relationship with engineering construction. It is also one of the most important types of landslides that can cause disaster. This kind of landslide often occurs in the loose slopes which are made up of loose congeries formed by earth filling, residual soil, slope wash, dilapidation, landslide or full weathered material of hard rock. Rainfall is always the chief inducing factor of debris Landslide. Therefore, to research stability of debris Landslide during rainfall not only has important theoretical significance for understanding developing law and deformation and failure mechanism of debris landslide, but also has important practical significance for investigating, appraising, forecasting, preventing and controlling debris landslides. This thesis systematically summarized the relationships between rainfall and landslide, the method to survey water table in the landslides, the deformation and failure mechanism of debris landslide, and the progress in the stability analysis of landslides based on the analyses of data collected widely at home and abroad. The problems in the study of the stability of debris landslide during rainfall was reviewed and discussed. Due to the complicated geological conditions and the random rainfall conditions, the research on the landslides' stability must be based on engineering geological qualitative analysis. Through the collection of the data about the Panxi region and the Three Gorges Reservoir region, the author systematically summarized the engineering geological conditions, hydro-geological condition, distribution characteristics of stress field in the slope, physical and mechanical properties and hydro-mechanical properties of debris. In the viewpoint of dynamics of soil water and hydromechanics, physical process of rainfall to supply groundwater of debris landslides can be divided into two phases, i.e. non-saturated steady infiltrating phase and saturated unsteady supplying phase. The former can be described by mathematical model of surface water infiltration while the latter can be described by equivalent continuous medium model of groundwater seepage. With regard to specific hydrological geology system, we can obtain the dynamic variation law of water content, water table, landslide stability of rock and soil mass, along with quantity and duration of rainfall after the boundary condition on hydrological geology has been ascertained. This is a new way to study the response law of groundwater in the landslides during rainfall. After wet face of rock and soil mass connects with ground water table, the raising of water table will occur due to the supply of rainfall. Then interaction between ground water and rock and soil mass will occur, such as the action of physics, water, chemistry and mechanics, which caused the decrease of shearing strength of sliding zone. According to the action of groundwater on rock and soil mass, a concise mechanical model of debris landslide’s deformation was established during rainfall. The static equilibrium condition of landslide mass system was achieved according to the concise mechanical model, and then the typical deformation and failure process and failure mode of debris landslide during rainfall were discussed. In this thesis, the former limiting equilibrium slice method was modified and improved based on shearing strength theory of , a stability analysis program of debris landslide was established and developed taking account of the saturated-unsaturated seepage, by introducing the shearing strength theory of unsaturated soil mass made by (1978). The program has reasonable data storage and simple interface and is easy to operate, and can be perfectly used to carry out sensitivity analysis of influencing factors of landslides' stability, integrated with the program of Office Excel. The design of drainage engineering are always bases on empirical methods and is short of effective quantitative analysis and appraise, therefore, the conception of critical water table of debris landslide was put forward. For debris landslides with different kinds of slide face in the engineering practice, a program to search the critical water table of debris landslide was developed based on native groundwater table. And groundwater table in the slope should be declined below the critical water table in the drainage works, so the program can be directly used to guide drainage works in the debris landslide. Taking the slope deformation body in the back of former factory building of Muli Shawan hydroelectric power station as an example, a systematic and detailed research on debris landslides' stability during rainfall was researched systematically, the relationship among quantity of rainfall, water table and stability of slope was established, the debris landslides' stability in process of rainfall from dynamic viewpoint was analyzed and researched.
Resumo:
The velocity field is important to investigate the motion and strain parameters of the block. It is also important to investigate the deformation of the fault, for example, the accumulation of strain and stress, at the boundary of the block. The dislocation model is a classic method to simulate the velocity field. In dislocation model, the aseismic crustal deformation is regarded as the sum of the rigid block motion and the effect of the locked fault. We modify the dislocation model in two aspects. Firstly, the block motion is assumed to be the sum of rotation and linear strain rather than the rigid motion. Secondly, the elastic layered-earth model rather than the homogenous half-space model is applied to calculate the effect of the locked part. The 1990~1995 annually Global Position System (GPS) velocity data of the Taiwan area are used in our dislocation model. The misfit of our modified model is smaller than that of the origin model clearly. Our simulation shows, in eastern Coastal Range, the velocity decreases northward rapidly from Chimei Fault, which may result from the high crustal compressive rate of about 30 mm•a-1 at Chimei Fault. The lock of fault in southern part is stronger than that in northern part generally. In western Taiwan, the most strongly locked faults appear in the southern Coastal Plain where many disaster earthquakes occur frequently. The calculated strain and rotation rates consist with previous results in most areas. The strain rate field reveals the nearly NW-SE compression in most parts of Taiwan with a fan-shaped distribution. The rotation rate field reveals anticlockwise rotation in eastern and southern Taiwan while clockwise rotation in western and northern Taiwan, generally.
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The unsaturated expansive soil is a hotspot and difficulty in soil mechanics inland and outland. The expansive soil in our China is one of the widest in distributing and greatest in area, and the disaster of expansive soil happens continually as a result. The soil mechanics test, monitor, numerical simulation and engineering practice are used to research swell and shrinkage characteristic, edge strength characteristic and unsaturated strength characteristic of Mengzi expansive soil. The seep and stability of the slope for expansive soil associated with fissure are analyzed and two kinds of new technique are put forward to be used in expansive soil area, based on disaster mechnics proposed of the slope.The technique of reinforcement in road embankment is optimized also. Associated with engineering geology research of Mengzi expansive soil, mineral composition, chemical composition, specific area and cation content, dissolubility salt and agglutinate, microcosmic fabric characteristic, cause of formation and atmosphere effect depth are analyzed to explain the intrinsic cause and essence of swell and shrinkage for expansive soil. The rule between swell-shrinkage and initial state, namely initial water content, initial dry density and initial pressure, can be used to construction control. Does Response model is fit to simulate the rule, based on ternary regression analysis. It has great meaning to expansive soil engineering in area with salt or alkali. The mechanics under CD, CU and GCU of expansive soil is researched by edge surface theory to explain the remarkable effect of consolidation pressure, initial dry density, initial water content, cut velocity, drainage and reinforcement to the edge strength characteristic. The infirm hardening stress strain curves can be fitted with hyperbola model and the infirm softening curves can be fitted with exponential model. The normalization theory can be used to reveal the intrinsic unity of the otherness which is brought by different methods to the shear strength of the same kinds of samples. The unsaturated strain softening characteristic and strength envelope of remolding samples are researched by triaxial shear test based on suction controlled, the result of which is simulated by exponential function. The strength parameters of the unsaturated samples are obtained to be used in the unsaturated seep associated with rainfall. The elasticity and plasticity characters of expansive soil are researched to attain the model parameters by using modified G-A model. The humidification destroy characteristic of expansive soil is discussed to research the disaster mechanism of the slope with the back pressure increasing and suction decreasing under bias pressure consolidation. The indoor and outdoor SWCCs are measured to research the effect factors and the rule between different stress and filling environment. The moisture absorption curves can express the relationship between suction and water content in locale. The SWCCs of Mengzi expansive soil are measured by GDS stress path trixial system. The unsaturated infiltration function is gained to research seep and stability of the slope of expansive soil. The rainfall infiltration and ability of slope considering multifarious factors are studied by analyzing fissure cause of Mengzi expansive soil. The mechanism of the slope disaster is brought forward by the double controlling effect between suction and fissure. Two new kinds of technique are put forward to resolve disaster of expansive soil and the technique of reinforcement on embankment is optimized, which gives a useful help to solving engineering trouble.
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The Study on rheology of the lithosphere and the environments of the seismogenic layer is currently the basic project of the international earthquake research. Yunnan is the ideal place for studying this project. Through the multi-disciplinary comprehensive study of petrology, geophysics, seismo-geology, rock mechanics, etc., the depth-strength profiles of the lithosphere have been firstly constructed, and the seismogenic layer and its geophysical and tectonic environments in Yunnan have been systematically expounded in this paper. The related results achieved are of the important significances for further understanding the mechanism of strong earthquake generation, dividing the potential foci and exposing recent geodynamical processes in Yunnan. Through the comprehensive contrast of the metamorphic rocks in early and middle Proterozoic outcropping on the surface, DSS data and experimental data of rock seismic velocity under high temperature and high pressure, the petrological structure of the crust and upper mantle has been studied on Yunnan: the upper, middle and lower crust is composed of the metamorphic rocks of greenschist, amphibolite and granulite facies, respectively or granitoids, diorites and gabbros, respectively, and the upper mantle composed of the peridotites. Through the contrast studies of the heat flow and epicenters of the strong earthquakes, the distribution of the geotemperature and the data of focal depth, the relationship of between seismicity and geothermal structure of the lithosphere in Yunnan has been studied: the strong earthquakes with magnitude M ≥ 6.0 mainly take place at the geothermal gradient zone, and the seismic foci densely distribute between 200~500 ℃ isogeotherms. On the basis of studies of the rock properties and constituents of the crust and upper mantle and geothermal structure of the lithosphere, the structure of the rheological stratification of the lithosphere has been studied, and the corresponding depth-strength profiles have been constructed in Yunnan. The lithosphere in majority region of Yunnan has the structure of the rheological stratification, i.e. the brittle regime in the upper crust or upper part of the upper crust, ductile regime in the middle crust or lower part of the upper crust to middle crust, ductile regime in the lower crust and ductile regime in the subcrustal lithosphere. The rheological stratification has the quite marked lateral variations in the various tectonic units. The distributions of the seismogenic layer have been determined by using the high accurate data of focal depth. Through the contrast of the petrological structure, the structure of seismic velocity, electric structure, geotemperature structure, and rheological structure and the study of the focal mechanism in the seismogenic layer, the geophysical environments of the seismogenic layer in Yunnan have been studied. The seismogenic layer in Yunnan is located at the depths of 3 ~ 20 km; the rocks in the seismogenic layer are composed of the metamorphic rocks of greenschist to amphibolite facies (or granites to diorites); the seismogenic layer and its internal focal regions of strong earthquakes have the structure of medium properties with the relatively high seismic velocity, high density and high resistivity; there exists the intracrustal low seismic velocity and high conductivity layer bellow the seismogenic layer, the geotemperature is generally 100~500 ℃ in the depth range in which the seismogenic layer is located. The horizontal stress field predominates in the seismogenic layer, the seismogenic layer corresponds to the brittle regime of the upper crust or brittle regime of the upper crust to semibrittle regime of the middle crust. The formation of the seismogenic layer, preparedness and occurrence of the strong earthquakes is the result of the comprehensive actions of the source fault, rock constituent, structure of the medium properties, distribution of the geotemperature, rheological structure of the seismogenic layer and its external environments. Through the study of the structure, active nature, slip rate, segmentation of the active faults, and seismogenic faults, the tectonic environments of the seismogenic layer in Yunnan have been studied. The source faults of the seismogenic layer in Yunnan are mainly A-type ones and embody mainly the strike slip faults with high dip angle. the source faults are the right-lateral strike slip ones with NW-NNW trend and left-lateral strike slip ones with NE-NEE trend in Southwestern Yunnan, the right-lateral strike slip ones with NNW trend and left-lateral strike slip ones with NNE trend (partially normal ones) in Northwestern Yunnan, the right-lateral strike slip ones with NWW trend in Central Yunnan and left-lateral strike slip ones with NW-NNW trend in Eastern Yunnan. Taking Lijiang earthquake with Ms = 7.0 for example. The generating environments of the strong earthquake and seismogenic mechanical mechanism have been studied: the source region of the strong earthquake has the media structure with the relatively high seismic velocity and high resistivity, there exists the intracrustal low velocity and high conductivity layer bellow it and the strong earthquakes occur near the transitional zone of the crustal brittle to ductile deformation. These characteristics are the generality of the generating environments of strong earthquakes. However, the specific seismogenic tectonic environments and action of the stress field of the seismic source in the various regions, correspondingly constrains the dislocation and rupture mechanical mechanism of source fault of strong earthquake.
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Various numbers of ancient landslides of various scales are frequently distributed on both banks of reservoirs, especially large reservoirs, both in China and abroad. During inundation and operation of theses reservoirs, some of the landslides are reactivated, which caused losses of people's lives and properties to various extents, some even disasters. Systematic studies are, however, very few on the reservoir-induced reactivation mechanism and development tendency prediction. Based on investigation of reservoir-induced reactivation phenomena of ancient landslides and relevant existing research problems, a systematic study is carried out on the field identification, induced reactivation mechanism, development tendency prediction, risk decision-making and treatment of reservoir-related ancient landslides, through analysis of large numbers of engineering geological investigation results, scientific experimental and research results, in combination with prevention and treatment practices of reservoir-related landslides both in China and abroad, and a series of research results have been obtained. 1. On the basis of study of the distribution features, genesis mechanism of ancient landslides on river banks, a set of scientific methods are summarized on field identification of ancient landslides, and a significant method named "lithologic sequence method" or "indicator layer method", is proposed, which is proved to be very useful. 2. A detail study is made on the reservoir-induced hydraulic effects and material mechanic effects (or softening effects) on the ancient landslide through model and case studies, which concludes that the magnitude and properties of reservoir-induced hydraulic effects are related to the shapes of sliding planes, water content and permeability of landslide materials and variation rate and magnitude of reservoir levels; the magnitude of material mechanic effects are related to the material composition (including mineral composition and grain size), natural water content and saturation state of sliding zones. Also a sensitive analysis is made on the factors that are related to the stabilities of the landslides, which indicate that the stability of a landslide is more sensitive to the groundwater head h_w in the slides and the inner friction angleψof sliding zones than others. 3. The joint inducing mechanism of rainfall and reservoir is also discussed in the paper through model analysis and case study, which proves that reservoir inundation increases firstly the sensitivity of a landslides to rainfall through reduction of its stability or cracking deformation which will increase the rainfall infiltration to the slide body, and then rainfall triggers reactivation or intensifies the reservoir-induced deformation of a landslide. 4. Based on rheologic test results of sliding zones of several reservoir-related ancient landslides, the rheologic characteristics of sliding zones have been discussed in detail and several typical rheologic models have been set up, which well explains the dynamic process of slide deformation. The response types to reservoir inundation and development tendency of reservoir -related ancient landslide are discussed in the paper based on field investigation results. And prediction methods for reservoir-related landslides have been studied based on the Mate-Synthetic principle of quantitative and qualitative analysis, as well as combination of computation and internal mechanism analysis, and a rheologic analytical method is proposed which is proved very useful for prediction of the landslide development tendency. 6. In disaster-prevention and treatment of reservoir-related landslides, risk decision-making has been proved very significant both in engineering and economics. Based on the practices in disaster-prevention and treatment of reservoir-related landslides both in China and abroad, the disaster-prevention risk decision-making for reservoir-related landslides has been proposed in terms of philosophy, methods and procedures, and well put into practice. A summary is also made through case study of the experiences of treatment of reservoir-related landslides both in China and abroad in terms of principle, methods and technical lines. 7 A detail study is made as a case study of the reactivated Maoping ancient landslide on the left bank of the Geheyan Reservoir on Qingjiang river in Hubei province, China, including its field identification features, reservoir-induced reactivation characteristics and mechanism, development tendency prediction and proposed counter measures based on risk analysis.
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In this paper, We analyzed the geological and geographical settings of dinosaurs extinction at the end of Cretaceous, especially the effect of the change of the elements contents on dinosaurs extinction. We studied basis on the two typical sections-Cretaceous-Paleocene boundary (Baishantou section (in Jiayin, Heilongjiang province of China) and Arkhara-Boguchan Coal Mine section (in Far East of Russian)) and Longgushan section (in Jiayin, Heilongjiang province of China) mainly. This work provided some evidences for forecasting the effects of global environmental change on bio-circle. The followings are the primary gains: According to the paleo-climate indexes (CaO/MgO,Sr/Ba) and the results of Factor Analysis, we found that there were similar climate in Baishantou section and Arkhara-Boguchan Coal Mine section near the K/E boundary, and both of them took on the trend of temperature declining and precipitation heightening after transitory high-temperature and drought. There are similar change and evlution rule of the elements contents near the boundary in the both sections (Baishantou section and Arkhara-Boguchan Coal Mine section). Both iron group elements and chalcophile elements appeared obvious abnormity. There are not visible correlation between the change of elements contents and climate indexes. This shows that the elements abnormity maybe came from the factors excluding climate or the factors were too many to conceal the influence of climate. --The result of cluster analysis showed that the boundary between BST3-8 and BST3-9 may be the K/E boundary of Baishantou section, and the top of twofold coal were the K/E boundary of Arkhara-Boguchan Coal Mine section which was consistent with accepted conclusion formerly. By contrast of elements contents in dinosaur bones and general organism, in surrounding rock and general sand stone, the regulation of the change of elements contents in dinosaur bones and surrounding rock, we confirmed that dinosaur extinction in Jiayin were relative with the high abnormities of Sr, Ba, Pb, Cr and the low abnormity of Zn, at least, it was them which speeded up dinosaurs extinction. After a series of analysis, we concluded that dinosaurs extinction of this areas tied up with the relative high background values of geo-chemical elements , paleo-climate and disaster incidents. First of all, high background values provided the necessary condition for the accumulation of the elements. Secondly, the drought climate adverse to the survival of dinosaurs, and led them to extinct gradually. finally, disaster incidents, the eruption of volcano or the collision of aerolites, made them exit this planet.
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The present paper studies focus on the symptoms of the post-traumatic stress disorder in adolescents post-disaster. 482 students from 6 secondary schools and 17 primary schools in the extremely severe disaster areas in Mianzhu, Sichuan province and 785 students from 3 primary schools and 9 secondary schools in the severe disaster areas in Baoji, Shaanxi respectively were surveyed on the symptoms of the post-traumatic stress disorder and the extent of disaster exposure after the Wenchuan earthquake. Self-compiled background information questionnaire and CRIES were used for the investigation. In this study, we contrast the extent of disaster exposure in the two areas in order to explore the related factors about the post-traumatic stress disorder in adolescent post-disaster. The main results of this paper can be summarized as follows: 1. There are significant positive corrections between the post-traumatic stress disorder and the extent of disaster exposure(get trapped in the earthquake、relatives and friends have been injured in the earthquake、look at relatives and friends dying in the earthquake).The more exposed in the disaster, the more serious symptom of the post-traumatic stress disorder. The trauma exposure indicators (get trapped in the earthquake, relatives and friends have been injured in the earthquake、look at relatives and friends dying in the earthquake)were all significant predictors for PTSD severity. 2. There are significant sex difference in the extent(F=8.750, p <0.05) and the incidence rate of PTSD(χ =20.735, df=5,p =0.001), the extent and the incidence rate of girls in Mianzhu is significantly higher than that of boys. 3. The age is also an influence factor of PTSD. The extent (F=7.246, p <0.001)and the incidence rate (χ =20.735, df=5,p =0.001)of PTSD get higher as adolescent in Mianzhu get older. 4. As the extremely severe disaster areas, the extent of disaster exposure of Mianzhu areas significantly higher than that of the severe disaster areas Baoji. However, there are not difference in the extent of PTSD between two areas(t=0.181,df=1265,p=0.857), there are only significant difference in the incidence rate of PTSD between two areas(χ =8.766,df=1,p=0.003), the incidence rate of PTSD in Mianzhu areas significantly higher than that of Baoji areas.
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The problem of terrorism can be analyzed by means of a wide array of research theories and models. There is however a question which of these may be regarded as especially useful to analyze different aspects of terrorism such as its reasons, characteristics and effects. Among concepts or theories which more or less fulfill the above-mentioned requirements, one can mention: chaos theory, decision theory, spatial competition theory, exchange theory, black box theory, theory of disaster, system model, model of billiard balls, core model, asymmetrical model, network model or concept of hybridity.
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Natural and human-made disasters cause on average 120,000 deaths and over US$140 billion in damage to property and infrastructure every year, with national, regional and international actors consistently responding to the humanitarian imperative to alleviate suffering wherever it may be found. Despite various attempts to codify international disaster laws since the 1920s, a right to humanitarian assistance remains contested, reflecting concerns regarding the relative importance of state sovereignty vis-à-vis individual rights under international law. However, the evolving acquis humanitaire of binding and non-binding normative standards for responses to humanitarian crises highlights the increasing focus on rights and responsibilities applicable in disasters; although the International Law Commission has also noted the difficulty of identifying lex lata and lex ferenda regarding the protection of persons in the event of disasters due to the “amorphous state of the law relating to international disaster response.” Therefore, using the conceptual framework of transnational legal process, this thesis analyses the evolving normative frameworks and standards for rights-holders and duty-bearers in disasters. Determining the process whereby rights are created and evolve, and their potential internalisation into domestic law and policy, provides a powerful analytical framework for examining the progress and challenges of developing accountable responses to major disasters.
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A wireless sensor network can become partitioned due to node failure, requiring the deployment of additional relay nodes in order to restore network connectivity. This introduces an optimisation problem involving a tradeoff between the number of additional nodes that are required and the costs of moving through the sensor field for the purpose of node placement. This tradeoff is application-dependent, influenced for example by the relative urgency of network restoration. In addition, minimising the number of relay nodes might lead to long routing paths to the sink, which may cause problems of data latency. This data latency is extremely important in wireless sensor network applications such as battlefield surveillance, intrusion detection, disaster rescue, highway traffic coordination, etc. where they must not violate the real-time constraints. Therefore, we also consider the problem of deploying multiple sinks in order to improve the network performance. Previous research has only parts of this problem in isolation, and has not properly considered the problems of moving through a constrained environment or discovering changes to that environment during the repair or network quality after the restoration. In this thesis, we firstly consider a base problem in which we assume the exploration tasks have already been completed, and so our aim is to optimise our use of resources in the static fully observed problem. In the real world, we would not know the radio and physical environments after damage, and this creates a dynamic problem where damage must be discovered. Therefore, we extend to the dynamic problem in which the network repair problem considers both exploration and restoration. We then add a hop-count constraint for network quality in which the desired locations can talk to a sink within a hop count limit after the network is restored. For each new problem of the network repair, we have proposed different solutions (heuristics and/or complete algorithms) which prioritise different objectives. We evaluate our solutions based on simulation, assessing the quality of solutions (node cost, movement cost, computation time, and total restoration time) by varying the problem types and the capability of the agent that makes the repair. We show that the relative importance of the objectives influences the choice of algorithm, and different speeds of movement for the repairing agent have a significant impact on performance, and must be taken into account when selecting the algorithm. In particular, the node-based approaches are the best in the node cost, and the path-based approaches are the best in the mobility cost. For the total restoration time, the node-based approaches are the best with a fast moving agent while the path-based approaches are the best with a slow moving agent. For a medium speed moving agent, the total restoration time of the node-based approaches and that of the path-based approaches are almost balanced.
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This paper introduces new results obtained from a statistical investigation into a 3071-observation data set collected from a Vietnamese nationwide entrepreneurship survey. From established relationships, such factors as preparedness, financial resources and participation in social networks are confirmed to have significant effects on entrepreneurial decisions. Entrepreneurs, both financially constrained and unconstrained, who have a business plan tend to start their entrepreneurial ventures earlier. Also, financial constraints have a profound impact on the entrepreneurial decisions. When perceiving the likelihood of success to be high, an entrepreneur shows the tendency for prompt action on business ideas. But when seeing the risk of prolonging the waiting time to first revenue, a prospective entrepreneur would be more likely to wait for more favorable conditions despite the vagueness of "favorable". Additionally, empirical computations indicate that there is a 41.3% probability that an extant entrepreneur who is generating revenue sees high chance of success. Past work and entrepreneurial experiences also have positive impacts on both the entrepreneurial decisions and perceived chance of success.
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At 8.18pm on 2 September 1998, Swissair Flight 111 (SR 111), took off from New York’s JFK airport bound for Geneva, Switzerland. Tragically, the MD-11 aircraft never arrived. According to the crash investigation report, published on 27 March 2003, electrical arcing in the ceiling void cabling was the most likely cause of the fire that brought down the aircraft. No one on board was aware of the disaster unfolding in the ceiling of the aircraft and, when a strange odour entered the cockpit, the pilots thought it was a problem with the air-conditioning system. Twenty minutes later, Swissair Flight 111 plunged into the Atlantic Ocean five nautical miles southwest of Peggy’s Cove, Nova Scotia, with the loss of all 229 lives on board. In this paper, the Computational Fluid Dynamics (CFD) analysis of the in-flight fire that brought down SR 111 is described. Reconstruction of the wreckage disclosed that the fire pattern was extensive and complex in nature. The fire damage created significant challenges to identify the origin of the fire and to appropriately explain the heat damage observed. The SMARTFIRE CFD software was used to predict the “possible” behaviour of airflow as well as the spread of fire and smoke within SR 111. The main aims of the CFD analysis were to develop a better understanding of the possible effects, or lack thereof, of numerous variables relating to the in-flight fire. Possible fire and smoke spread scenarios were studied to see what the associated outcomes would be. This assisted investigators at Transportation Safety Board (TSB) of Canada, Fire & Explosion Group in assessing fire dynamics for cause and origin determination.
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There is now a broad scientific consensus that the global climate is changing in ways that are likely to have a profound impact on human society and the natural environment over the coming decades. The challenge for Facilities Mangers is to ensure that business continuity plans acknowledge the potential for such events and have contingencies in place to ensure that their organisation can recover from an extreme weather event in a timely fashion. This paper will review current literature/theories pertinent to extreme weather events and business continuity planning; will consider issues of risk; identify the key drivers that need to be considered by Facilities Managers in preparing contingency/disaster recover plans; and identify gaps in knowledge (understanding and toolkits) that need to be addressed. The paper will also briefly outline a 3 year research project underway in the UK to address the issues