937 resultados para material flow management
Resumo:
The most outstanding conceptual challenge of modern crisis management is the principle of consent. It is not a problem only at the operational level - it challenges the entire decision-making structures of crisis management operations. In post-cold war times and especially in the 21st century, there has been a transition from peacekeeping with limited size and scope towards large and complex peace operations. This shift has presented peace operations with a dilemma. How to balance between maintaining consent for peace operations, whilst being able to use military force to coerce those attempting to wreck peace processes? To address such a dilemma, this research aims to promote understanding, on what can be achieved by military crisis management operations (peace support operations) in the next decade. The research concentrates on the focal research question: Should military components induce consent or rely on the compliance of conflicting parties in crisis management operations of the next decade (2020 – 2030)? The focus is on military – political strategic level considerations, and especially on the time before political decisions to commit to a crisis management operation. This study does not focus on which actor or organisation should intervene. The framework of this thesis derives from the so called ‘peacebuilding space’, the scope of peace operations and spoiler theory. Feasibility of both peace enforcement and peacekeeping in countering future risk conditions are analysed in this framework. This future-orientated qualitative research uses the Delphi-method with a panel of national and international experts. Citation analysis supports identification of relevant reference material, which consists of contemporary literature, the Delphi-questionnaires and interviews. The research process followed three main stages. In the first stage, plausible future scenarios and risk conditions were identified with the Delphi-panel. In the second stage, operating environments for peace support operations were described and consequent hypotheses formulated. In the third stage, these hypotheses were tested on the Delphi-panel. The Delphi-panel is sufficiently wide and diverse to produce plausible yet different insights. The research design utilised specifically military crisis management and peace operations theories. This produced various and relevant normative considerations. Therefore, one may argue that this research; which is based on accepted contemporary theory, hypotheses derived thereof and utilising an expert panel, contributes to the realm of peace support operations. This research finds that some degree of peace enforcement will be feasible and necessary in at least the following risk conditions: failed governance; potential spillover of ethnic, religious, ideological conflict; vulnerability of strategic chokepoints and infrastructures in ungoverned spaces; as well as in territorial and extra-territorial border disputes. In addition, some form of peace enforcement is probably necessary in risk conditions pertaining to: extremism of marginalised groups; potential disputes over previously uninhabited and resource-rich territories; and interstate rivalry. Furthermore, this research finds that peacekeeping measures will be feasible and necessary in at least risk conditions pertaining to: potential spillover of ethnic, religious, ideological conflict; uncontrolled migration; consequences from environmental catastrophes or changes; territorial and extra-territorial border disputes; and potential disputes over previously uninhabited and resource-rich territories. These findings are all subject to both generic and case specific preconditions that must exist for a peace support operation. Some deductions could be derived from the research findings. Although some risk conditions may appear illogical, understanding the underlying logic of a conflict is fundamental to understanding transition in crisis management. Practitioners of crisis management should possess cognizance of such transition. They must understand how transition should occur from threat to safety, from conflict to stability – and so forth. Understanding transition is imperative for managing the dynamic evolution of preconditions, which begins at the outset of a peace support operation. Furthermore, it is pertinent that spoilers are defined from a peace process point of view. If spoilers are defined otherwise, it changes the nature of an operation towards war, where the logic is breaking the will of an enemy - and surrender. In peace support operations, the logic is different: actions towards spoilers are intended to cause transition towards consent - not defeat. Notwithstanding future developments, history continues to provide strategic education. However, the distinction is that the risk conditions occur in novel futures. Hence, lessons learned from the past should be fitted to the case at hand. This research shows compelling evidence that swaying between intervention optimism and pessimism is not substantiated. Both peace enforcement and peacekeeping are sine qua non for successful military crisis management in the next decade.
Resumo:
The condensation rate has to be high in the safety pressure suppression pool systems of Boiling Water Reactors (BWR) in order to fulfill their safety function. The phenomena due to such a high direct contact condensation (DCC) rate turn out to be very challenging to be analysed either with experiments or numerical simulations. In this thesis, the suppression pool experiments carried out in the POOLEX facility of Lappeenranta University of Technology were simulated. Two different condensation modes were modelled by using the 2-phase CFD codes NEPTUNE CFD and TransAT. The DCC models applied were the typical ones to be used for separated flows in channels, and their applicability to the rapidly condensing flow in the condensation pool context had not been tested earlier. A low Reynolds number case was the first to be simulated. The POOLEX experiment STB-31 was operated near the conditions between the ’quasi-steady oscillatory interface condensation’ mode and the ’condensation within the blowdown pipe’ mode. The condensation models of Lakehal et al. and Coste & Lavi´eville predicted the condensation rate quite accurately, while the other tested ones overestimated it. It was possible to get the direct phase change solution to settle near to the measured values, but a very high resolution of calculation grid was needed. Secondly, a high Reynolds number case corresponding to the ’chugging’ mode was simulated. The POOLEX experiment STB-28 was chosen, because various standard and highspeed video samples of bubbles were recorded during it. In order to extract numerical information from the video material, a pattern recognition procedure was programmed. The bubble size distributions and the frequencies of chugging were calculated with this procedure. With the statistical data of the bubble sizes and temporal data of the bubble/jet appearance, it was possible to compare the condensation rates between the experiment and the CFD simulations. In the chugging simulations, a spherically curvilinear calculation grid at the blowdown pipe exit improved the convergence and decreased the required cell count. The compressible flow solver with complete steam-tables was beneficial for the numerical success of the simulations. The Hughes-Duffey model and, to some extent, the Coste & Lavi´eville model produced realistic chugging behavior. The initial level of the steam/water interface was an important factor to determine the initiation of the chugging. If the interface was initialized with a water level high enough inside the blowdown pipe, the vigorous penetration of a water plug into the pool created a turbulent wake which invoked the chugging that was self-sustaining. A 3D simulation with a suitable DCC model produced qualitatively very realistic shapes of the chugging bubbles and jets. The comparative FFT analysis of the bubble size data and the pool bottom pressure data gave useful information to distinguish the eigenmodes of chugging, bubbling, and pool structure oscillations.
Resumo:
As the requirement for agriculture to be environmentally suitable there is a necessity to adopt indicators and methodologies approaching sustainability. In Brazil, biodiesel addition into diesel is mandatory and soybean oil is its main source. The material embodiment determines the convergence of inputs into the crop. Moreover, the material flows are necessary for any environmental analysis. This study evaluated distinct production scenarios, and also conventional versus GMO crops, through the material embodiment and energy analysis. GMO crops demanded less indirectly applied inputs. The energy balance showed linearity with yield, whereas for EROI, the increases in input and yield were not affected.
Resumo:
ABSTRACT Knowledge of natural water availability, which is characterized by low flows, is essential for planning and management of water resources. One of the most widely used hydrological techniques to determine streamflow is regionalization, but the extrapolation of regionalization equations beyond the limits of sample data is not recommended. This paper proposes a new method for reducing overestimation errors associated with the extrapolation of regionalization equations for low flows. The method is based on the use of a threshold value for the maximum specific low flow discharge estimated at the gauging sites that are used in the regionalization. When a specific low flow, which has been estimated using the regionalization equation, exceeds the threshold value, the low flow can be obtained by multiplying the drainage area by the threshold value. This restriction imposes a physical limit to the low flow, which reduces the error of overestimating flows in regions of extrapolation. A case study was done in the Urucuia river basin, in Brazil, and the results showed the regionalization equation to perform positively in reducing the risk of extrapolation.
Resumo:
ABSTRACT For drip irrigation design and management, it is necessary to know the relation between flow and pressure acting on emitters. In the case of subsurface drip irrigation, the backpressure phenomenon may change the hydraulic characteristics of emitters. Thus, this study aimed at determining such relationship between flow and pressure of different driplines in surface and subsurface conditions; aiming to find possible differences in hydraulic behavior. We tested four emitter types; two pressure compensating (D5000 and Hydro PCND) and two non-pressure compensating (TalDrip and Jardiline). Emitter flow rates were attained in atmospheric conditions and submerged in water, in which submergence levels represented backpressure. Assays were performed using inlet pressures of 80, 100, 120, and 150 kPa for the Hydro PCND dripline and 25, 50, 100, and 150 kPa for the other ones; the backpressures were of 0.49, 1.47, 2.45, 4.41 and 6.37 kPa with four replications. The emitters had their proportionality constants and discharge exponents changed in submerged applications, representing backpressure effect. Non-pressure compensating emitters had their discharge exponent decreased, while in pressure compensating ones, it was increased. Backpressure reduced emitter flow rates at all evaluated pressures.
Resumo:
Tutkielman tarkoituksena oli tutkia palkkakirjanpitoon liittyviä näkökulmia ja niiden vaikutuksia talousohjaukseen sekä tuoda esille kehitysideoita palkkakirjanpitäjien ja controllerien välisen yhteistyön kehittämiseksi. Lähtökohtana tarkasteltiin talousohjauksen ja palkkakirjanpidon yhteistyön nykytilaa ja aiempia tutkimuksia. Tämä tutkimus on empiirinen tapaustutkimus jossa tutkimusmetodina on käytetty kvalitatiivista analyysiä. Tutkimus on toteutettu puolistrukturoituja haastatteluja ja havainnointia apuna käyttäen. Tutkimuksessa nousi esille globalisaation ja yhteiskunnan muutoksen tuo-mat haasteet. Muutosten myötä molempien osapuolten tehtävien muuttu-minen ja erilaisissa palvelukeskuksissa toimiminen on muuttanut toimintaa ja osapuolten rooleja. Tulokset osoittavat että palkkakirjanpitäjien tiedon tuottamista controllereille, voidaan kehittää parhaiten panostamalla tiedon välitykseen, yhteistyönrakentamiseen ja tuottamalla erilaisia raportteja ennusteiden tueksi. Lisäksi on ymmärrettävä taustatekijät ja kasvatettava molempien osapuolten talousohjauksen ja palkkakirjanpidon tuntemusta. Nämä muutokset havainnollistamalla päästään rakentamaan hyvää ja laadukasta tiedon tuottamista, jolloin palkkakirjanpitäjät voivat olla paremmin osana liike-elämän tukemista.
Resumo:
After decades of mergers and acquisitions and successive technology trends such as CRM, ERP and DW, the data in enterprise systems is scattered and inconsistent. Global organizations face the challenge of addressing local uses of shared business entities, such as customer and material, and at the same time have a consistent, unique, and consolidate view of financial indicators. In addition, current enterprise systems do not accommodate the pace of organizational changes and immense efforts are required to maintain data. When it comes to systems integration, ERPs are considered “closed” and expensive. Data structures are complex and the “out-of-the-box” integration options offered are not based on industry standards. Therefore expensive and time-consuming projects are undertaken in order to have required data flowing according to business processes needs. Master Data Management (MDM) emerges as one discipline focused on ensuring long-term data consistency. Presented as a technology-enabled business discipline, it emphasizes business process and governance to model and maintain the data related to key business entities. There are immense technical and organizational challenges to accomplish the “single version of the truth” MDM mantra. Adding one central repository of master data might prove unfeasible in a few scenarios, thus an incremental approach is recommended, starting from areas most critically affected by data issues. This research aims at understanding the current literature on MDM and contrasting it with views from professionals. The data collected from interviews revealed details on the complexities of data structures and data management practices in global organizations, reinforcing the call for more in-depth research on organizational aspects of MDM. The most difficult piece of master data to manage is the “local” part, the attributes related to the sourcing and storing of materials in one particular warehouse in The Netherlands or a complex set of pricing rules for a subsidiary of a customer in Brazil. From a practical perspective, this research evaluates one MDM solution under development at a Finnish IT solution-provider. By means of applying an existing assessment method, the research attempts at providing the company with one possible tool to evaluate its product from a vendor-agnostics perspective.