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Статті в журналах з теми "Conventional Transport Modes"
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Hamadneh, Jamil, and Domokos Esztergár-Kiss. "The Influence of Introducing Autonomous Vehicles on Conventional Transport Modes and Travel Time." Energies 14, no. 14 (July 9, 2021): 4163. http://dx.doi.org/10.3390/en14144163.
Повний текст джерелаАнотація:
Introducing autonomous vehicles (AVs) on the market is likely to bring changes in the mobility of travelers. In this work, extensive research is conducted to study the impact of different levels of automation on the mobility of people, and full driving automation needs further study because it is still under development. The impacts of AVs on travel behavior can be studied by integrating AVs into activity-based models. The contribution of this study is the estimation of AVs’ impacts on travelers’ mobility when different travel demands are provided, and also the estimation of AVs’ impact on the modal share considering the different willingness of pay to travel by AVs. This study analyses the potential impacts of AVs on travel behavior by investigating a sample of 8500 travelers who recorded their daily activity plans in Budapest, Hungary. Three scenarios are derived to study travel behavior and to find the impacts of the AVs on the conventional transport modes. The scenarios include (1) a simulation of the existing condition, (2) a simulation of AVs as a full replacement for conventional transport modes, and (3) a simulation of the AVs with conventional transport modes concerning different marginal utilities of travel time in AVs. The simulations are done by using the Multi-Agent Transport Simulation (MATSim) open-source software, which applies a co-evolutionary optimization algorithm. Using the scenarios in the study, we develop a base model, determine the required fleet size of AVs needed to fulfill the demand of the different groups of travelers, and predict the new modal shares of the transport modes when AVs appear on the market. The results demonstrate that the travelers are exposed to a reduction in travel time once conventional transport modes are replaced by AVs. The impact of the value of travel time (VOT) on the usage of AVs and the modal share is demonstrated. The decrease in the VOT of AVs increases the usage of AVs, and it particularly decreases the usage of cars even more than other transport modes. AVs strongly affect the public transport when the VOT of AVs gets close to the VOT of public transport. Finally, the result shows that 1 AV can replace 7.85 conventional vehicles with acceptable waiting time.
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Hamadneh, Jamil, and Domokos Esztergár-Kiss. "Multitasking onboard of conventional transport modes and shared autonomous vehicles." Transportation Research Interdisciplinary Perspectives 12 (December 2021): 100505. http://dx.doi.org/10.1016/j.trip.2021.100505.
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Lebedevas, Sergejus, Saugirdas Pukalskas, and Vygintas Daukšys. "MATHEMATICAL MODELLING OF INDICATIVE PROCESS PARAMETERS OF DUAL-FUEL ENGINES WITH CONVENTIONAL FUEL INJECTION SYSTEM." Transport 35, no. 1 (March 16, 2020): 57–67. http://dx.doi.org/10.3846/transport.2020.12212.
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Modern engine research uses multi-dimensional Mathematical Models (MMs) that are applicable to multi-fuel engines. However, their use involves the availability of detailed technical data on the design and characteristics of the engine, which is not always possible. The use of a one-dimensional MM is more expedient for the prediction of engine parameters, but their application for this purpose has not yet been sufficiently investigated. This publication presents the results of numerical studies evaluating the application of a one-dimensional MM with bi-phase Vibe combustion laws for dual-fuel (DF) Diesel (D) and Natural Gas (NG) engine power parameters. The motor test results of a high-speed 4ČN79.5/95.5 Diesel Engine (DE) with a conventional fuel injection system were used as adequacy criteria. The engines were operated with D100 and DF D20/NG80, in high- (HLM), medium- (MLM), and low- (LLM) load modes, and the angle of Diesel-fuel Injection Timing (DIT) was changed from −1 to −13 °CA in the Before Top Dead Center (BTDC) range. Modelling of the single-phase Vibe combustion law has limited applicability for efficient use only in HLM (with an error of 7%). In the MLM and LLM regimes, owing to non-compliance with real bi-phasic combustion with a strongly extended NG diffusive second phase, the modelling error is 50%. Individual MM matching in MLM and LLM in a DF D20/NG80 experiment detected a burn time increase from between 45 and 50 °CA, to 110 and 200 °CA, respectively. Limited use of the one-dimensional MM in the evaluation of DF engine performance has been identified. When comparing a one-dimensional MM with experimental data, a bi-phase law of heat release characteristic should be considered for better coincidence. In addition, individual MM matching with an experiment on each engine load mode ensured acceptable accuracy in testing and optimising the parameters of the indicator process, including DIT.
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Ghoreyshi, A. A., H. Asadi, and K. Pirzadeh. "A generic transport model for separation of gas mixtures by glassy polymer membranes based on Maxwell–Stefan formulation." RSC Advances 5, no. 60 (2015): 48207–16. http://dx.doi.org/10.1039/c5ra05686a.
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Unitsky, Anatoli E., Dmitry N. Tikhonov, and Michael I. Tsyrlin. "On the prospects of the development of string transport for freight transportation." Innotrans, no. 3 (2021): 7–10. http://dx.doi.org/10.20291/2311-164x-2021-3-7-10.
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This work presents the criteria for choosing a transport for the transportation of cargo. The peculiarities of SkyWay string transport are indicated. The description of various types of string cargo transport is given. The advantages over the conventional modes of transport are presented.
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Ogawa, Matsuto, Ryuichiro Tominaga, and Tanroku Miyoshi. "Tight Binding Simulation of Quantum Transport in Interband Tunneling Devices." VLSI Design 13, no. 1-4 (January 1, 2001): 69–74. http://dx.doi.org/10.1155/2001/31592.
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We have studied quantum transport in both Si and GaAs interband tunneling diodes (ITD's). In the simulation, a non-equilibrium Green's function method based an empirical tight binding theory has been used to take into account evanescent-wave matching at interfaces and realistic band structures. Comparison has been made between the results of our multiband (MB) model and those of conventional two-band (2B) model. As a result, it is found that the current–voltage (I–V) characteristics of the Si ITD have considerably smaller peak current density than the conventional 2B model, since our MB model reflects correctly the indirect gap band structure. On the other hand, in the GaAs ITD, there is small difference between the two models, because tunneling occurs between the conduction band and the valence band at F point. It is also found that the matching of evanescent electron modes is essentially necessary to include the valley-mixing effects at the tunneling interfaces.
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Zhuomin, Dai. "Analysis Model of Conventional Public Transport Hub Based on Grey Correlation Degree." E3S Web of Conferences 283 (2021): 02029. http://dx.doi.org/10.1051/e3sconf/202128302029.
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With the continuous progress of urbanization in China, the urban public transport system has been developing in the direction of three-dimensional and diversified. As a physical carrier of various modes of transportation, the layout and operation efficiency of urban public transport hub directly affect the smoothness of the whole line network. In view of this, this paper carries out systematic analysis of the conventional bus hub and establishes an evaluation index system which can reflect the normal bus hub system effectively; Then, the paper evaluates the operation efficiency of the conventional bus hub system by using the grey correlation analysis theory; Finally, the case analysis is carried out to calculate the comprehensive evaluation value of the object and sort it. The results show that the positive indicators are the per capita transfer area, parking facility rate, transfer sign facility rate and transfer information timeliness. The results of this paper supplement and perfect the current analysis model of public transport hub. The results of the case study show that the model has a high practical value.
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Jena, Suprava, Debu Kumar Pradhan, and Prasanta Kumar Bhuyan. "Modelling automobile users’ response pattern in defining urban street level of service." Transport 34, no. 3 (May 7, 2019): 287–99. http://dx.doi.org/10.3846/transport.2019.9405.
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This paper presents a qualitative study on automobile users’ response pattern to assess the provided transportation service quality under heterogeneous traffic flow conditions. An Automobile Users’ Satisfaction index (AUSi) is established using data sets of questionnaire survey collected from 34 urban street segments of three midsized Indian cities. About 977 respondents with a suitable cross-section of gender, age, driving experience etc. were participated in travellers’ intercept survey. Rasch Model (RM) was applied to identify a set of quantitative measures to analyse the complex process of measuring perceived service quality and degree of drivers’ satisfaction together. The present study comprehends the multidimensional nature of users’ perception to evaluate AUSi with the help of six-dimensional variables such as roadway geometry, traffic facilities, traffic management, pavement condition, safety and aesthetics. RM offers a particular score to each user and each dimensional attribute along with a shared continuum. This way, the attributes those are more demanding to produce satisfaction as well as the variation in response of different modes of transport are evidently identified. The key findings indicate that the participants reported lower satisfaction level mainly due to the absence of separate bike/bus pull-out lanes, improper parking facilities and interruption by non-motorised vehicles/public transit or roadside commercial activities. Fuzzy C-Means (FCM) clustering was applied to classify AUSi scores into six auto Levels Of Service (LOS) categories (A–F) for each street segment. The model was well validated with a significant matching of predicted Automobile users’ LOS (ALOS) service categories with the users’ perceived Overall Satisfaction (OS) scores for fourteen randomly selected segments. This prediction model is new to mixed traffic flow condition, which uses linguistic information and real-life issues of drivers for the current state of services. Hence, the proposed method would be more credible than conventional models to support the decision makers for long term planning and designing road networks on a priority basis
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Smirnov, Sergei A., and Olga Yu Smirnova. "Evaluation of Effectiveness of Different Transport Modes for Regular Mass Freight Transportation." Transportation systems and technology 3, no. 4 (December 15, 2017): 204–20. http://dx.doi.org/10.17816/transsyst201734204-220.
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The article deals with different transport modes for regular mass freight transportation, their efficiency evaluation is conducted on the bases of cost, operational and environmental properties. Introduction. Due to demand in ensuring mass transportations between Southeastern Asia and Europe, there is a topical issue of efficient application of different types of ground transport. There is a request rising, to use cutting edge achievements in technology, to increase speeds of freight transportation for long distance and their safety and environmental friendliness enhancement. Analysis. Consideration of cost properties of application of different transport modes for mass freight transportation allows revealing that the lowest infrastructure cost is typical for conventional railway transport; the lowest prime cost of transportation is ensured by maglev transport with permanent magnets of the “RosMaglev” technology; the lowest commercially profitable mode of transport for today’s level of science and technology is vacuum transport. Operationally, the leading project is “RosMaglev”, with the vacuum transport having the lowest operational efficiency. From environmental and carrying safety points of view, railway transport has gone pretty far in the recent two decades. However, a more sustainable and safe one is the maglev and vacuum modes of transport, which is explained by lack of emissions and other types of pollution, including noise pollution. In terms of safety, maglev transport is the most competitive mode of transport. Whereas, vacuum transport is the most dangerous one. Results. For mass freight transportation, the most promising mode of transport is the “RosMaglev” permanent magnets maglev transport, according to the authors. The technology allows significant increase of infrastructure construction costs. The second most promising mode is conventional railway transport. However, if the demand in transportation is low and the energy efficient traction rolling stock is implemented, the high-speed freight railway transport may be highly competitive, especially in countries with developed high-speed railway network. The vacuum transport holds firmly the third place. Conclusion. The relevance of maglev transport implementation for mass freight transportations is obvious. The maglev technologies now in use in many countries for carrying passengers have proved profitable, safe and convenient. Technical “maturity” of these technologies allows considering all points and factors when constructing maglev freight lines which is very topical due to increasing need in searching transport routes alternative to sea routes.
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Sugiyanto, Gito, Yanto, Aris Wibowo, Toni Tauladan, and Tory Damantoro. "Demand Modeling for Taxi and Ride-hailing Transport Services (RTS)." Civil Engineering Journal 9, no. 5 (May 1, 2023): 1039–58. http://dx.doi.org/10.28991/cej-2023-09-05-03.
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The rapid growth of Ride-hailing Transport Services (RTS) demand is found to have caused a fierce market share battle with conventional taxis in previous decades. In selecting a taxi or RTS, understanding the factors affecting passenger’s decisions is substantial for better development and more reliable transit service. The aims of this study to evaluate the demand for taxis and RTS in the Jakarta Greater Area, Indonesia, using the demand-supply and dynamic models. It has been conducted by using 519 respondents, with the model inputs consisting of waiting and travel time, trip costs, and the destination of the conventional passengers. Moreover, the choice between taxi and RTS was analyzed based on the stated preferences of respondents. The results showed that the waiting and travel time, as well as costs per trip of RTS, were 1.49 and 2.67 minutes lower and IDR10,902 cheaper than a taxi, respectively. The factors influencing the demand for these transport modes were also the number of trips per-day, mode share, the average vehicle occupancy, operating hours/day, passengers and driver waiting time, as well as travel period. In the dynamic model, the addition of variable service area, peak hour, and average vehicles speed was subsequently observed. Based on the results, the requests for these transport modes in the Greater Area of Jakarta were 64,494 and 55,811 vehicle units for the demand-supply and dynamic models, respectively. This proved that the dynamic model was better than the demand-supply, due to the added parameters representing the area’s traffic characteristics. Additionally, subsequent future research are expected to focus on modeling of taxi and RTS demands through the global positioning system data, as well as analysis using machine learning and deep learning. Doi: 10.28991/CEJ-2023-09-05-03 Full Text: PDF
Дисертації з теми "Conventional Transport Modes"
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Gueye, Bonfils. "Processus de développement d'une agglomération et interaction de deux systèmes de transport : mode conventionnel et mode traditionnel à Abidjan." Paris 12, 1989. http://www.theses.fr/1989PA120030.
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Une contradiction majeure a toujours domine les relations entre le systeme conventionnel de transports collectifs et le systeme traditionnel : d'un cote, un environnement institutionnel et juridique caracterise par l'affirmation du monopole du service au mode conventionnel, par consequent la non reconnaissance de la forme artisanale et de l'autre, une situation de deficit permanent de l'offre par rapport a la demande. Dans le cadre de cette contradiction, la coexistence des deux formes de transport amene des inter-relations concurrencielles avec des dimensions conflictuelles ou l'appareil d'etat a souvent pris une part active. Mais face a l'importance des problemes de deplacements a resoudre, cette vision conflictuelle de leurs rapports doit s'effacer devant la consideration de leurs complementarites qui apparaissent a plusieurs niveaux de leurs points d'articulation. Alors, la decision de liberaliser le secteur des transports collectifs amenee par les difficultes croissantes de l'appareil d'etat a soutenir le systeme conventionnel, au niveau des modalites de son application, devrait depasser la vision restrictive de la banque mondiale pour privilegier la construction d'un systeme global base sur les modes existants conjugues avec de nouveaux modes dans le cadre d'une coordination d'ensemble par une " autorite organisatrice" des transports collectifsA major contradiction has always dominated the relationship between the conventional public transportation system and the traditional one in abidjan : in one side an institutional and juridical environnement caracterised by the affirmation of the monopoly of the service to the conventional mode, accordingly the non acknowlegment of the traditional mode and in the auther side a permanent situation of deficit of the offer compared with the needs of transportation. In the outline of that contradiction, the coexistence of the two transportation forms brings concurrential relationships with conflictual aspects where the state apparatus has often taken an active part. But in reference to the importance of travel problems to solve, that conflictual vision of their relations has to be cleaned up in front of their complementarities wich appear at many levels of the points of their articulation. Then, the decision to liberalise the public transport sector brought by the growing difficulties of the state apparatus to sustain the conventional system, at the level of it's application modalities, has to pass the restrictive vision of the world bank to privilege the construction of a global system based on existing modes coupled with new ones in a coordination framework conducted by a "autorite organisatrice" of public transports
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Assongba, Cossi Hervé. "Les contentieux en transport maritime de marchandises par conteneurs." Thesis, Lille 2, 2014. http://www.theses.fr/2014LIL20005/document.
Повний текст джерелаАнотація:
Le transport maritime par conteneurs est devenu universel compte tenu de son caractère multimodal. Le succès de ce mode de transport est aussi lié à l’implication de plusieurs professionnels tant du monde privé que du monde public. Cependant, le transport de conteneurs constitue un univers de contentieux parfois inconnus. L’usage de ces boîtes fait l’objet de contentieux de nature privé, mais également des contentieux de nature administrative. Bien que des Conventions internationales règlementent le transport maritime en général, l’inadaptation de certaines de ces normes ne facilite pas la résolution de ces contentieux. Et, comme l’administration des douanes est en amont et en aval dans l’exécution du contrat de transport, son intervention ne reste pas sans soulever des contentieux dont la résolution implique deux ordres de juridictionsThe container shipping has become universal because of its multimodal nature. The success of this mean of transport is also linked to the involvement of many professionals from both private and public sectors. However, the container shipping constitutes a field of litigation sometime ignored. The use of these boxes involves not only litigations of private nature but also of administrative nature. Although some international conventions regulate shipping in general, the unsuitability of some of these norms does not help the settlement of these litigations. And, as the customs administration is upstream and downstream involved in the execution of the contract of carriage, its involvement is a source of disputes whose settlement implies two different kinds of courts
Книги з теми "Conventional Transport Modes"
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Kotzebue, Julia R. Towards Sustainable Transport and Mobility. Perspectives on Travelling and Commuting in Small Island States. Hamburg University Press, 2022. http://dx.doi.org/10.15460/hup.261.1999.
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Small island states are one of the most affected areas by sea-level rise, and sustainable transport development is crucial to their transition towards resiliency. However, their special spatial situations, insularity, geographic remoteness, small populations, and small economies resulted in high transport costs and car dependencies. The book moves away from the conventional focus on urban areas in the Global North and tourism. It gives a different perspective on sustainable transport, travelling, and commuting in the Caribbean and Europe. The authors provide research-based insights and show the state-of-the-art and future approaches for policy-makers, academics, and practitioners. Even beyond small island state research, the book offers an innovative outlook.
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Spaulding, Malcolm L. Estuarine and Coastal Modeling: Proceedings. Amer Society of Civil Engineers, 1990.
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Estuarine and Coastal Modeling: State of the Practice--Proceedings of the Eighth International Conference, November 3-5, 2003, Monterey, California. American Society of Civil Engineers, 2004.
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Adhikari, Puspa L., Wokil Bam, Pamela L. Campbell, Francois Oberhaensli, Marc Metian, Marc Besson, Hugo Jacob, and Peter W. Swarzenski. "Evaluating Microplastic Experimental Design and Exposure Studies in Aquatic Organisms." In Microplastic in the Environment: Pattern and Process, 69–85. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-78627-4_3.
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AbstractEnvironmental microplastic particles (MPs) represent a potential threat to many aquatic animals, and experimental exposure studies, when done well, offer a quantitative approach to assess this stress systematically and reliably. While the scientific literature on MP studies in aquatic environments is rapidly growing, there is still much to learn, and this chapter presents a brief overview of some of the successful methods and pitfalls in experimental MP exposure studies. A short overview of some experimental design types and recommendations are also presented. A proper experimental exposure study will yield useful information on MP-organism impacts and must include the following: a comprehensive MP characterization (e.g., density, buoyancy, type, nature, size, shape, concentration, color, degree of weathering/biofilm formation, an assessment of co-contaminant/surfactant toxicity and behavior, an understanding exposure modes, dose and duration, and the type and life stage of the target species). Finally, more conventional experimental considerations, such as time, costs, and access to clean water, specialized instrumentation, and use of appropriate controls, replicate, and robust statistical analyses are also vital. This short review is intended as a necessary first step towards standardization of experimental MP exposure protocols so one can more reliably assess the transport and fate of MP in the aquatic environment as well as their potential impacts on aquatic organisms.
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Jin, Ying. "Spatial Economics, Urban Informatics, and Transport Accessibility." In Urban Informatics, 115–32. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-15-8983-6_8.
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AbstractOne central pillar in the development of urban science which is key to the development of simulation of models of urban structure is spatial econometrics. In this chapter, we outline the way in which ideas pertaining to accessibility which we define conventionally, as in transport economics, as the relative nearness and size of locations to one another, can be embedded in a wider econometric framework. We are thus able to explore how GDP (gross domestic product) of different locations is influenced by different spatial investments. To illustrate this, we first outline the intellectual context, followed by a review of the most relevant econometric models. We examine the data required for such models and look at various quantifications in terms of elasticities of business productivity with respect to transport accessibility, using ordinary least squares, time-series fixed effects, and a range of dynamic panel-data models which narrow down the valid range of estimates. We then show how the model is applied to Guangdong province (with its connections to Hong Kong and Macau), which is one of the three major mega-city regions and a leading adopter of new technologies in China.
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Janicke, L. "Particle Simulation of Dust Transport and Deposition and Comparison with Conventional Models." In Air Pollution Modeling and Its Application IV, 759–69. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4613-2455-3_41.
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Singer, D. "Mode of Action, Efficacy, and Safety of Radiant Warmers in Neonatology." In Water-filtered Infrared A (wIRA) Irradiation, 167–77. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92880-3_13.
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AbstractGiven the serious adverse effects of hypothermia in term and preterm infants, thermal protection is of paramount importance in neonatal care. To compare potential benefits of wIRA radiators with conventional radiant warmers in neonatology, physical investigations (agar phantoms) and clinical observations (term and preterm neonates) were performed. Physical investigations revealed a fundamental difference in the mode of action between the two types of radiation: Whereas with conventional radiant warmers, the increase in core temperature (phantoms) is preceded by marked elevations in surface temperature, wIRA leads to more direct rises in core temperature and results in smaller amounts of evaporative water loss from the surface. Clinical observations reveal that wIRA causes less skin surface warming than conventional heat irradiation at equal power densities (irradiances). wIRA used as a supplementary source of heat during primary care in the delivery room was found to exert a preventive effect against unintentional heat loss during the subsequent incubator transport of preterm neonates to the intensive care unit. Overall, due to its specific physical properties (“enhanced depth effect with less surface overheating”), wIRA seems to be particularly suited to replace the extra heat losses occurring in preterm or otherwise compromised neonates without undue risk of superficial burns.
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Tipanluisa, Luis, José López-Martínez, Jesús Casanova, and Natalia Fonseca. "Three-Stage Combustion Modeling of a Binary Mixture-Fueled CI CRDI Engine." In Proceedings of the XV Ibero-American Congress of Mechanical Engineering, 257–63. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-38563-6_38.
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AbstractThe global trend towards stricter vehicle emission standards requires more knowledge about the use of renewable fuels to design strategies to reduce the use of non-renewable fossil fuels and the environmental impacts of road transport vehicles equipped with Diesel engines. In this study, a simple phenomenological model with three combined Wiebe functions is used to describe the main injection heat release rate of an unmodified heavy-duty diesel engine fueled with binary blends of n-butanol (up to 20% by volume) with diesel fuel. Conventional diesel was used as the reference fuel to compare combustion characteristics with the binary blends (DBu5, DBu10 and DBu20). The results show that the apparent heat release rate ($$AHRR$$) calculated from the model is in good agreement (RMSE ≤ 3.80 J/°CA) with the experimental values. The maximum $$AHRR$$ values (J/°CA) for the fuel blends DBu5, DBu10, DBu20 and the reference diesel were 220.7, 219.1, 211.8 and 217.7 respectively.
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Qin, Shuai, Qingming He, Jiahe Bai, Wenchang Dong, Liangzhi Cao, and Hongchun Wu. "Group Constants Generation Based on NECP-MCX Monte Carlo Code." In Springer Proceedings in Physics, 86–97. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1023-6_9.
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AbstractThe reliability of few-group constants generated by lattice physics calculation is significant for the accuracy of the conventional two-step method in neutronics calculation. The deterministic method is preferred in the lattice calculation due to its efficiency. However, it is difficult for the deterministic method to treat the resonance self-shielding effect accurately and handle complex geometries. Compared to the deterministic method, the Monte Carlo method has the characteristics of using continuous-energy cross section and the powerful capability of geometric modeling. Therefore, the Monte Carlo particle transport code NECP-MCX is extended in this study to generate assembly-homogenized few-group constants. The cumulative migration method is adopted to generate the accurate diffusion coefficient and the leakage correction is performed using the homogeneous fundamental mode approximation. For the verification of the generated few-group constants, a code sequence named MCX-SPARK is built based on NECP-MCX and a core analysis code SPARK to perform the two-step calculation. The physics start-up test of the HPR1000 reactor is simulated using the MCX-SPARK sequence. The results from MCX-SPARK agree well with the results from the design report and a deterministic two-step code Bamboo-C. It is concluded that the NECP-MCX has the ability to generate accurate few-group constants.
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von Vacano, Mechthild. "Going Gojek, or Staying Ojek? Competing Visions of Work and Economy in Jakarta’s Motorbike Taxi Industry." In Beyond the Wage, 211–32. Policy Press, 2021. http://dx.doi.org/10.1332/policypress/9781529208931.003.0010.
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Until recently Indonesia’s motorbike taxi industry resembled a textbook example of the ‘informal sector’—a well-established though legally unrecognised mode of urban transport. However, the arrival of Gojek, a digital ride-hailing platform, in 2016 appeared set to revolutionize the industry with the full force of platform capitalism. The platform’s business model challenged the territorial-distributive principles of the established system of local taxi ranks, while creating a new group of digital drivers which were legally self-employed, though de facto dependent on the algorithmic programming of the platform. Through a comparative case study of conventional (ojek) and platform based (Gojek) taxi drivers in Jakarta, this chapter study points to the structural and economic diversity of work outside the wage. Informed by a deconstructive reading of the in/formality paradigm, it expands the analytical focus from the structural conditions of work to the underlying modes of social and economic organisation, and the often subtle values these modes enact.
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Jellad, Tarek, Khaled Taouil, and Zied Chtourou. "Power Management in Microgrids." In Handbook of Research on Novel Soft Computing Intelligent Algorithms, 141–64. IGI Global, 2014. http://dx.doi.org/10.4018/978-1-4666-4450-2.ch005.
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Conventional power generation stations used to be centralized and located far from customers. The transport and distribution infrastructure incur power losses that are mainly due to cabling resistance. Distributed power generation resources located close to customers are sought as a solution to minimize transport power losses. They are also good alternatives in situations where connection to the grid is not possible due to geographical or economical reasons. Furthermore, the adoption of renewable energies as alternatives for the scarce fossil energy sources paves the way to more distributed energy production. These Distributed energy resources, when located in a limited region, can be interconnected with loads and eventually storages to form a microgrid. A microgrid can operate in off-grid, on-grid, or alternate between these modes while optimizing power quality and cost. Multi-Agent Systems (MAS) and Petri nets could be put into contribution for high level planning of energy exchanges within a microgrid. This strategy has been validated on the basis of a dynamic model for the simulation and optimization of power exchanges between different DERs.
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Beris, Antony N., and Brian J. Edwards. "Non-Conventional Transport Phenomena." In Thermodynamics of Flowing Systems: with Internal Microstructure. Oxford University Press, 1994. http://dx.doi.org/10.1093/oso/9780195076943.003.0015.
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In this chapter, we wish to exploit the availability of the bracket formalism in the description of complex, non-conventional transport phenomena. In the first section, §10.1, we analyze relaxational phenomena in heat and mass transfer. The next section, §10.2, includes the description of phase transitions in inhomogeneous media. The last section, §10.3, contains a first effort to describe inertial effects in viscoelasticity. These problems have rarely been considered in the past, and when they have it has always been from a phenomenological perspective. We explore the availability of the bracket formalism here to provide a more systematic basis for these systems than has heretofore been available, and hence we characterize the models in this chapter as semi-phenomenological. The basic approach that we use is to first establish an appropriate internal variable for the system in consideration, and then to divine an appropriate Hamil-tonian which does, in some limits, produce available phenomenological models. (The latter step indicates why we characterize the models deve-loped in this chapter as “semi-phenomenological.”) As we shall see, describing the models on this more fundamental basis clears up a number of inconsistencies, as well as extending their range of validity without unduly sacrificing their simplicity. In most engineering applications of heat and mass transfer, the simple linear constitutive relations of (6.4-12) are adequate in order to describe the respective transport processes. A couple of very simple examples are the heat flux, when the affinity is the temperature gradient (giving Fourier's law of heat conduction), and the mass diffusion flux, when the affinity is the chemical potential (giving Pick's law of mass diffusion). The importance of such relationships in engineering practice cannot be overestimated. The validity of the linearized equations is generally established by steady-state experiments, so the question that naturally arises is whether or not the same constitutive relationship will hold for transient phenomena. This question cannot be answered as long as only steady-state experiments are performed. From physical considerations alone, it is obvious that the linearized constitutive relationships cannot be complete, in and of themselves.
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"Conventions, Abbreviations, and Variables Used." In Measurements, Mechanisms, and Models of Heat Transport, 407–10. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-809981-0.00029-2.
Повний текст джерелаТези доповідей конференцій з теми "Conventional Transport Modes"
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Purohit, Harsh, Ankit Shah, Nishant Parekh, and Akash Pandey. "Development Concept for Non Conventional Hybrid Engine." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-39960.
Повний текст джерелаАнотація:
Environmental issues and the need for environment-friendly transport have always been a priority for the world due to ever increasing demand of modes of transport. So developing quick and eco friendly vehicle is the trend as of now with most manufacturers globally. There are numerous ways in which manufacturers have tackled these issues. Some of the common approaches undertaken are refinements of existing internal combustion engines. Like developing technologies such as direct injection, VVT (variable valve time), VTEC (variable valve time electronic lift), VGT (variable geometry turbines), reducing engine friction and weight, cam less engines, micro hybrids, etc But the best/optimum compromise between eco friendliness and urge to develop more power with good fuel economy and reduced emission is best met by the development of hybrid engines. Thermal and electric engines both have advantages and disadvantages that are often complementary. Combustion engines offer better range, power and ‘lunge’, but give out exhaust gas, although the current Euro IV norm place strict limits on these. Electric engines are zero-emission and offer very quick pick-up from a stopped position, but the batteries have low range and limited speed. So this complementation of both power trains is exploited in hybrid engines. Now conventional hybrids have many disadvantages such as being bulky with additional weight of battery packs and motors and other auxiliary transmission components, complex and dangerous electric systems, etc. So it is proposed to develop a non conventional hybrid engine which produces power at par with the conventional one and releases emission which is compatible with the stringent emission norms set for the conventional hybrids with considerably lucrative fuel economy comparable with the currently available hybrids in market and yet overcome the drawbacks of the conventional hybrid engines. Also the compact size of the hybrid engine that we propose makes it quite viable to fitted in small vehicles (like bikes, compact cars, etc) which further makes it a more promising technology that can be made available to common people across the globe and there by lead to a better transportation system for people of all class and need. The conceptualization basically includes modification of an inline twin cylinder or a v-twin 4-stroke gasoline engine as a preliminary step towards achieving the above proposed objectives.
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Maroteaux, Fadila, Ezio Mancaruso, Pierre-Lin Pommier, and Bianca Maria Vaglieco. "Theoretical Analysis of Multi-Zone and Transported Probability Density Function Approaches Applied to Low Temperature Combustion Process." In 16th International Conference on Engines & Vehicles. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-24-0060.
Повний текст джерелаАнотація:
<div class="section abstract"><div class="htmlview paragraph">Electrification of transport, together with the decarbonization of energy production are suggested by the European Union for the future quality of air. However, in the medium period, propulsion systems will continue to dominate urban mobility, making mandatory the retrofitting of thermal engines by applying combustion modes able to reduce NOx and PM emissions while maintaining engine performances. Low Temperature Combustion (LTC) is an attractive process to meet this target. This mode relies on premixed mixture and fuel lean in-cylinder charge whatever the fuel type: from conventional through alternative fuels with a minimum carbon footprint. This combustion mode has been subject of numerous modelling approaches in the engine research community. This study provides a theoretical comparative analysis between multi-zone (MZ) and Transported probability density function (TPDF) models applied to LTC combustion process. The generic thermo-kinetic balances for both approaches have been analyzed in term of similarities. Only onion-skin for MZ models have been considered in this study. The governing assumptions linked to sub-models for each approach to describe mixing process for TPDF and interzonal heat and mass transport for MZ are discussed. This step identifies the calibrated model parameters for each approach and their effects on the accuracy in predicting LTC mode simulations. This work shows that the transported probability density function model has fewer parameters to calibrate compared to multi-zone model. Transported probability density function seems easier to use for LTC process.</div></div>
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Solomon, Jose´ E., Jay Kapat, Ranganathan Kumar, and Deepak Srivastava. "Study of Thermal Energy Transport Between Hydrogen Gas Molecules and a Single-Wall Carbon Nanotube Using Molecular Dynamics Simulations." In ASME 2005 Summer Heat Transfer Conference collocated with the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems. ASMEDC, 2005. http://dx.doi.org/10.1115/ht2005-72588.
Повний текст джерелаАнотація:
The focus of the current research is the investigation and characterization of the energy transport between a (10,10) single-wall carbon nanotube (SWCNT) and surrounding molecular hydrogen gas using molecular dynamics (MD) simulations. The MD simulations use Tersoff-Brenner hydrocarbon potential for C-C, C-H, and H-H bonding interactions and the conventional Lennard-Jones potential for soft-sphere gas-CNT collision dynamics of H-H and H-C non-bonding van der Waals interactions. A simulation cell with periodic boundary conditions is created for 1200 carbon atoms in an armchair nanotube configuration and three distinct gas densities corresponding to 252, 500, and 1000 H2 molecules in the same volume. The MD simulation runs are performed with time steps of 0.1 fs and the total simulation times of 40 ps. The simulations are initialized by setting the gas species and CNT at two different temperatures. Initial gas temperatures range from 2000K to 4000K, whereas the carbon nanotube is held at 300K. After the equilibrium temperatures of the CNT and the gas molecules are achieved, the external constraints to maintain the temperature are removed and the thermal energy transport between the two is studied. The kinetic energy exchange between the nanotube and the surrounding gas is monitored to study thermal energy transport over the duration of the simulation. A parameter is proposed, the coefficient of thermal energy transfer (CTET), to characterize the thermal transport properties of the modeled systems based on parameters governing the transport process, thus mimicking the conventional heat transfer coefficient. Values for CTET vary directly with gas density and range from 50 MW/m2K to 250MW/m2K, showing that gas density has a significant impact with higher density corresponding to higher collision rates and higher rates of energy transfer. In contrast, the gas temperature has a lower impact on CTET, with colder gas providing in certain cases a slightly lower value for the coefficient. In order to validate the MD simulations, the time-series data of molecular vibrations of the CNT is converted to a vibrational frequency spectrum through FFT. The characteristic frequencies obtained on the spectra of isolated SWCNT and H2 simulations are compared against the known natural frequencies of the CNT phonon modes and vibrational modes of H2 molecules. The comparison is quite favorable.
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Giuffrè, O., A. Granà, T. Giuffrè, and R. Marino. "How to derive the analytical capacity model for not-conventional urban roundabouts." In URBAN TRANSPORT 2008. Southampton, UK: WIT Press, 2008. http://dx.doi.org/10.2495/ut080551.
Повний текст джерела
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Lanzara, Giulia. "Carbon Nanotube Micropillars for Strain Sensing." In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-47783.
Повний текст джерелаАнотація:
A miniaturized strain sensor based on carbon nanotube (CNTs) micropillars is presented. The micropillars consist of square shaped forests of oriented CNTs sitting on Pt electrodes. The study focused on the analysis of the electron transport mechanisms and their correlation with the device geometry and deformation modes for increasing compression states (up to nearly 80% axial compression). The electrical resistance was found to be nonlinearly related to the device deformation in compression and decompression (full cycle). All tested devices were sensitive to deformations for an extremely wide range of strain values (significantly higher than conventional sensors), with a superior sensitivity for ultra-small deformations which makes them ideal for nanoscale sensing. Finally, it is believed that the CNTs micropillars have the potential to lead to strain sensing devices with a tuneable sensitivity and sensing range capability since the electron transport properties were found to be influenced by the device geometry.
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Fyrileiv, Olav, Kim Mo̸rk, Muthu Chezhian, and Gudfinnur Sigurdsson. "Updated Design Procedure for Free Spanning Pipelines DNV-RP-F105: Multi-Mode Response." In 25th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/omae2006-92098.
Повний текст джерелаАнотація:
In search for new gas and oil fields, the trend in offshore development points towards deeper waters, harsher environment, increased use of subsea installations and use of pipelines to transport the hydrocarbons to processing facilities onshore or in shallower waters. This also implies installation of pipelines at very uneven seabed causing a high number of spans that can be difficult and very costly to intervene. Conventional free span design according to the DNV Recommended Practice DNV-RP-F105 (2002) allows for vortex induced vibrations (VIV) as long as the integrity of the pipeline is within acceptable limits. However, the 2002 issue of the design code mainly covers short and moderate spans. As the knowledge about very long and/or multiple spans, where several vibration modes may be activated, has been limited, such cases have been treated in an assumed conservative way. This paper discusses the technical advancements in free span design in general and with respect to both long free spans and multi-spanning sections where several vibration modes may be activated simultaneously in particular. These advancements form the basis for the updated DNV-RP-F105 (2006). Changes from the former 2002 version are illustrated by an examples and the technical background is discussed.
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Metelka, Stanislav, and Vít Janoš. "Prerequisites of the successful tram-train system as a part of the regional railway network." In 6th International Conference on Road and Rail Infrastructure. University of Zagreb Faculty of Civil Engineering, 2021. http://dx.doi.org/10.5592/co/cetra.2020.1132.
Повний текст джерелаАнотація:
The idea of connecting the two of the closest urban and suburban rail-based public transport systems was proposed more than 40 years ago and it boasts a proclaimed support from the regional authorities. However, many of the systems either did not achieve their goals or became financially inefficient as they replaced the conventional railway systems in a wider range than it had initially been planned. That resulted in an inappropriate competition between the public transportation modes. This paper aims to define the prerequisites needed for the establishment of a successful, both financially and operationally sane tram-train system as a substantial part of the regional railway network An analysis of the various current tram-train systems in the selected European cities is made and special attention is paid to their distinctive features including the offered capacity, density, technical compatibility, and operational aspects. Using the conclusions of the analysis and the current technical and operational requirements to be met, a recommendation for the design and organization of the planned tram-train lines and networks is stated, which may help the transport planners design such costly systems in a way it can use its overall advantages in favor of the passengers and an increase of the public transportation modal share.
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Holmegaard Kristensen, Hans Otto. "Model for Environmental Assessment of Container Ship Transport." In SNAME Maritime Convention. SNAME, 2010. http://dx.doi.org/10.5957/smc-2010-t41.
Повний текст джерелаАнотація:
A generic computer model for systematic investigations of container ship designs is described in this paper. The primary statistical data on container ships used for the model development are also presented. The model can be used to calculate exhaust gas emissions from container ships, including emissions of carbon dioxide (CO2). A calculation procedure to estimate the newly designated Energy Efficiency Design Index (EEDI), which is under development at the International Maritime Organization (IMO), is included in the model. Different ship design parameters have been varied to see the influence of these parameters on the EEDI. It is found possible to reduce EEDI by roughly 20 % without reducing ship speed, but only by changing some of the design parameters, such as reducing the sea margin by using a derated main engine, increasing the length of the ship by 5 %, and reducing steel weight by 3 % via steel weight optimization.
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Kossioris, Theodoros, Joschka Schaub, Markus Ehrly, Johannes Maiterth, Ruben Keizer, and Dieter an der Put. "Evaluation of a Serial-parallel Hybrid Powertrain Concept for a Heavy Duty Truck." In FISITA World Congress 2021. FISITA, 2021. http://dx.doi.org/10.46720/f2021-epv-078.
Повний текст джерелаАнотація:
According to latest European Union (EU) findings, CO2 emissions from heavy duty vehicles, including lorries, buses and coaches, account for about 6 % of the total CO2 emissions in the Union and to about 25 % of the total CO2 emissions from road transport. It is expected that without further measures, the share of CO2 emissions from heavy duty vehicles will increase by around 9 % between 2010 and 2030. The constant growth in demand for on-road transport underlines the urgency of cleaner and more fuel-efficient global on-road transport vehicles fleets. In February 2019, the EU finally decided to set CO2 limits for on-road commercial vehicles for the first time. Legislation requires a 15 % CO2 reduction scenario in 2025 and a 30 % CO2 reduction scenario in 2030 based on the 2019 baseline fleet. Most heavy-duty vehicles (HDVs) are nowadays powered by diesel engines. Diesel powertrain hybridization has demonstrated its ability to significantly reduce the fuel consumption and thus the CO2 emissions in various medium duty and heavy duty applications. This paper presents a comprehensive simulation study to evaluate the fuel savings potential of a serial-parallel hybrid heavy duty truck. The innovative configuration consists of a transmission with a reduced number of gears and parts designed to achieve a good compromise between system losses and weight. The two electric machines integrated into the dedicated hybrid transmission system enable three different driving modes, namely electric driving with one or two electric machines, serial driving and a parallel mode. The fuel economy results as well as the tailpipe pollutant emissions are compared with a conventional powertrain and a parallel hybrid (P2) configuration in different operating profiles. A future emissions legislation scenario is therefore introduced. Optimal sizing of the electrical components of the hybrid configurations (battery and electric machines) will be considered. Also, the total purely electric driving range of the electrified powertrains will be compared to current industrial benchmarks.
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Barrilero, Marta, Anke Sauerlander-Biebl, Alexander Sohr, and Tobias Hesse. "Development of a demand responsive transport system with improvement analysis on conventional public transport: A case study for Schorndorf, Germany." In 2017 5th IEEE International Conference on Models and Technologies for Intelligent Transportation Systems (MT-ITS). IEEE, 2017. http://dx.doi.org/10.1109/mtits.2017.8005626.
Повний текст джерелаЗвіти організацій з теми "Conventional Transport Modes"
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Oakil, Abu Toasin, Ahm Mehbub Anwar, Alma Alhussaini, Nourah Al Hosain, Abdelrahman Muhsen, and Anvita Arora. Urban Transport Energy Demand Model for Riyadh: Methodology and Preliminary Analysis. King Abdullah Petroleum Studies and Research Center, June 2023. http://dx.doi.org/10.30573/ks--2023-mp03.
Повний текст джерелаАнотація:
Saudi Arabia intends to reduce its greenhouse gas (GHG) emissions by 278 million tonnes of CO2 equivalent annually by 2030, according to its Nationally Determined Contribution to the United Nations Framework Convention on Climate Change (UNFCCC). Among many policies it is introducing, a mass transit system and transit-oriented development are being advanced with the expectation of reducing energy consumption and GHG emissions in Riyadh. To what extent such an initiative can reduce energy consumption and GHG emissions is an important question. In this paper, a methodology is developed to systematically measure the impact of mass transit and transit-oriented development in Riyadh on energy demand.
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Jury, William A., and David Russo. Characterization of Field-Scale Solute Transport in Spatially Variable Unsaturated Field Soils. United States Department of Agriculture, January 1994. http://dx.doi.org/10.32747/1994.7568772.bard.
Повний текст джерелаАнотація:
This report describes activity conducted in several lines of research associated with field-scale water and solute processes. A major effort was put forth developing a stochastic continuum analysis for an important class of problems involving flow of reactive and non reactive chemicals under steady unsaturated flow. The field-scale velocity covariance tensor has been derived from local soil properties and their variability, producing a large-scale description of the medium that embodies all of the local variability in a statistical sense. Special cases of anisotropic medium properties not aligned along the flow direction of spatially variable solute sorption were analysed in detail, revealing a dependence of solute spreading on subtle features of the variability of the medium, such as cross-correlations between sorption and conductivity. A novel method was developed and tested for measuring hydraulic conductivity at the scale of observation through the interpretation of a solute transport outflow curve as a stochastic-convective process. This undertaking provided a host of new K(q) relationships for existing solute experiments and also laid the foundation for future work developing a self-consistent description of flow and transport under these conditions. Numerical codes were developed for calculating K(q) functions for a variety of solute pulse outflow shapes, including lognormal, Fickian, Mobile-Immobile water, and bimodal. Testing of this new approach against conventional methodology was mixed, and agreed most closely when the assumptions of the new method were met. We conclude that this procedure offers a valuable alternative to conventional methods of measuring K(q), particularly when the application of the method is at a scale (e.g. and agricultural field) that is large compared to the common scale at which conventional K(q) devices operate. The same problem was approached from a numerical perspective, by studying the feasibility of inverting a solute outflow signal to yield the hydraulic parameters of the medium that housed the experiment. We found that the inverse problem was solvable under certain conditions, depending on the amount of noise in the signal and the degree of heterogeneity in the medium. A realistic three dimensional model of transient water and solute movement in a heterogeneous medium that contains plant roots was developed and tested. The approach taken was to generate a single realization of this complex flow event, and examine the results to see whether features were present that might be overlooked in less sophisticated model efforts. One such feature revealed is transverse dispersion, which is a critically important component in the development of macrodispersion in the longitudinal direction. The lateral mixing that was observed greatly exceeded that predicted from simpler approaches, suggesting that at least part of the important physics of the mixing process is embedded in the complexity of three dimensional flow. Another important finding was the observation that variability can produce a pseudo-kinetic behavior for solute adsorption, even when the local models used are equilibrium.
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Hammouti, A., S. Larmagnat, C. Rivard, and D. Pham Van Bang. Use of CT-scan images to build geomaterial 3D pore network representation in preparation for numerical simulations of fluid flow and heat transfer, Quebec. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/331502.
Повний текст джерелаАнотація:
Non-intrusive techniques such as medical CT-Scan or micro-CT allow the definition of 3D connected pore networks in porous materials, such as sedimentary rocks or concrete. The definition of these networks is a key step towards the evaluation of fluid flow and heat transfer in energy resource (e.g., hydrocarbon and geothermal reservoirs) and CO2 sequestration research projects. As material heterogeneities play a role at all scales (from micro- to project-scale), numerical models represent a powerful tool for bridging the gap between small-scale measurements provided by X-ray imaging techniques and larger-scale transport properties. This study uses pre-existing medical CT-scan datasets of reference material, namely glass beads and conventional reservoir rocks (Berea sandstone, Boise sandstone, Indiana limestone) to extract the 3D geometry of connected pores using an open-source software (Spam). Pore networks from rock samples were generated from dry and then saturated samples. Binarized datasets were produced for these materials (generated by a thresholding technique) to obtain pore size distribution and tortuosity, as well as preferential paths for fluid flow. Average porosities were also calculated for comparison with those obtained by conventional commercial laboratory techniques. The results obtained show that this approach works well for medium and coarse-grained materials that do not contain a large percentage of fine particles. However, this approach does not allow representative networks to be obtained for fine-grained rocks, due to the fact that small pores (or pore throats) cannot be taken into account in the datasets obtained from the medical CT-Scan. A next step, using datasets produced from a micro- CT scan, is planned in order to be able to generate representative networks in this type of material as well.
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Rempel, K. U., A. E. Williams-Jones, and K. Fuller. An experimental investigation of the solubility and speciation of uranium in hydrothermal ore fluids. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328995.
Повний текст джерелаАнотація:
Experimental data on the solubility and speciation of uranium in hydrothermal solution is required to improve genetic models for the formation of ore deposits, yet very few data of this type have been published. Of particular interest is the oxidation state of the uranium in solution, as conventional wisdom suggests that U is dissolved in the oxidized U(VI) state and precipitated as reduced U(IV) minerals, yet recent experiments have shown ppm-level solubility for U(IV). This study investigated the mobility of reduced U(IV) and oxidized U(VI) in acidic (pH = 2), fluoride- bearing and alkaline (pH = 10), chloride-bearing solutions at 100-200°C and 1 to 15.8 bars (0.1-1.58 MPa). Preliminary data for the mobility of U(IV) in pH 2 fluids with 0.01 m F- show concentrations of 1.76 to 3.92 ppm U at 200°C, indicating that, contrary to common belief, the reduced U(IV) can be transported in solution. We have also conducted experiments on U(VI) solubility in pH 2 fluoride-bearing, and pH 10 chloride-bearing solutions. Uranium concentrations in the F- -bearing experiments ranged from 624 to 1570 ppm (avg. 825 ppm, n = 6) at 100°C, 670 to 1560 ppm (avg. 931 ppm, n = 4) at 150°C, and 3180 to 7550 ppm (avg. 5240, n = 9) at 200°C. In comparison, U concentrations in the Cl- -bearing runs range from 86.1 to 357 ppm (avg. 185 ppm, n = 15) at 200°C. Clearly, oxidized U(VI) is very readily mobilized in hydrothermal fluids. However, the measured concentrations of U(VI) are independent of those of F- or Cl-, suggesting the formation of U oxide or hydroxide species rather than U chlorides or fluorides. These experimental data will be verified and supplemented in future experiments, which will be used to derive the stoichiometry and thermodynamic constants for the dominant uranium species in hydrothermal solutions. The data from this study will then be integrated into a comprehensive genetic model for uranium ore-forming systems.
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Warrick, Arthur W., Gideon Oron, Mary M. Poulton, Rony Wallach, and Alex Furman. Multi-Dimensional Infiltration and Distribution of Water of Different Qualities and Solutes Related Through Artificial Neural Networks. United States Department of Agriculture, January 2009. http://dx.doi.org/10.32747/2009.7695865.bard.
Повний текст джерелаАнотація:
The project exploits the use of Artificial Neural Networks (ANN) to describe infiltration, water, and solute distribution in the soil during irrigation. It provides a method of simulating water and solute movement in the subsurface which, in principle, is different and has some advantages over the more common approach of numerical modeling of flow and transport equations. The five objectives were (i) Numerically develop a database for the prediction of water and solute distribution for irrigation; (ii) Develop predictive models using ANN; (iii) Develop an experimental (laboratory) database of water distribution with time; within a transparent flow cell by high resolution CCD video camera; (iv) Conduct field studies to provide basic data for developing and testing the ANN; and (v) Investigate the inclusion of water quality [salinity and organic matter (OM)] in an ANN model used for predicting infiltration and subsurface water distribution. A major accomplishment was the successful use of Moment Analysis (MA) to characterize “plumes of water” applied by various types of irrigation (including drip and gravity sources). The general idea is to describe the subsurface water patterns statistically in terms of only a few (often 3) parameters which can then be predicted by the ANN. It was shown that ellipses (in two dimensions) or ellipsoids (in three dimensions) can be depicted about the center of the plume. Any fraction of water added can be related to a ‘‘probability’’ curve relating the size of the ellipse (or ellipsoid) that contains that amount of water. The initial test of an ANN to predict the moments (and hence the water plume) was with numerically generated data for infiltration from surface and subsurface drip line and point sources in three contrasting soils. The underlying dataset consisted of 1,684,500 vectors (5 soils×5 discharge rates×3 initial conditions×1,123 nodes×20 print times) where each vector had eleven elements consisting of initial water content, hydraulic properties of the soil, flow rate, time and space coordinates. The output is an estimate of subsurface water distribution for essentially any soil property, initial condition or flow rate from a drip source. Following the formal development of the ANN, we have prepared a “user-friendly” version in a spreadsheet environment (in “Excel”). The input data are selected from appropriate values and the output is instantaneous resulting in a picture of the resulting water plume. The MA has also proven valuable, on its own merit, in the description of the flow in soil under laboratory conditions for both wettable and repellant soils. This includes non-Darcian flow examples and redistribution and well as infiltration. Field experiments were conducted in different agricultural fields and various water qualities in Israel. The obtained results will be the basis for the further ANN models development. Regions of high repellence were identified primarily under the canopy of various orchard crops, including citrus and persimmons. Also, increasing OM in the applied water lead to greater repellency. Major scientific implications are that the ANN offers an alternative to conventional flow and transport modeling and that MA is a powerful technique for describing the subsurface water distributions for normal (wettable) and repellant soil. Implications of the field measurements point to the special role of OM in affecting wettability, both from the irrigation water and from soil accumulation below canopies. Implications for agriculture are that a modified approach for drip system design should be adopted for open area crops and orchards, and taking into account the OM components both in the soil and in the applied waters.
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Harris, L. B., P. Adiban, and E. Gloaguen. The role of enigmatic deep crustal and upper mantle structures on Au and magmatic Ni-Cu-PGE-Cr mineralization in the Superior Province. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328984.
Повний текст джерелаАнотація:
Aeromagnetic and ground gravity data for the Canadian Superior Province, filtered to extract long wavelength components and converted to pseudo-gravity, highlight deep, N-S trending regional-scale, rectilinear faults and margins to discrete, competent mafic or felsic granulite blocks (i.e. at high angles to most regional mapped structures and sub-province boundaries) with little to no surface expression that are spatially associated with lode ('orogenic') Au and Ni-Cu-PGE-Cr occurrences. Statistical and machine learning analysis of the Red Lake-Stormy Lake region in the W Superior Province confirms visual inspection for a greater correlation between Au deposits and these deep N-S structures than with mapped surface to upper crustal, generally E-W trending, faults and shear zones. Porphyry Au, Ni, Mo and U-Th showings are also located above these deep transverse faults. Several well defined concentric circular to elliptical structures identified in the Oxford Stull and Island Lake domains along the S boundary of the N Superior proto-craton, intersected by N- to NNW striking extensional fractures and/or faults that transect the W Superior Province, again with little to no direct surface or upper crustal expression, are spatially associated with magmatic Ni-Cu-PGE-Cr and related mineralization and Au occurrences. The McFaulds Lake greenstone belt, aka. 'Ring of Fire', constitutes only a small, crescent-shaped belt within one of these concentric features above which 2736-2733 Ma mafic-ultramafic intrusions bodies were intruded. The Big Trout Lake igneous complex that hosts Cr-Pt-Pd-Rh mineralization west of the Ring of Fire lies within a smaller concentrically ringed feature at depth and, near the Ontario-Manitoba border, the Lingman Lake Au deposit, numerous Au occurrences and minor Ni showings, are similarly located on concentric structures. Preliminary magnetotelluric (MT) interpretations suggest that these concentric structures appear to also have an expression in the subcontinental lithospheric mantle (SCLM) and that lithospheric mantle resistivity features trend N-S as well as E-W. With diameters between ca. 90 km to 185 km, elliptical structures are similar in size and internal geometry to coronae on Venus which geomorphological, radar, and gravity interpretations suggest formed above mantle upwellings. Emplacement of mafic-ultramafic bodies hosting Ni-Cr-PGE mineralization along these ringlike structures at their intersection with coeval deep transverse, ca. N-S faults (viz. phi structures), along with their location along the margin to the N Superior proto-craton, are consistent with secondary mantle upwellings portrayed in numerical models of a mantle plume beneath a craton with a deep lithospheric keel within a regional N-S compressional regime. Early, regional ca. N-S faults in the W Superior were reactivated as dilatational antithetic (secondary Riedel/R') sinistral shears during dextral transpression and as extensional fractures and/or normal faults during N-S shortening. The Kapuskasing structural zone or uplift likely represents Proterozoic reactivation of a similar deep transverse structure. Preservation of discrete faults in the deep crust beneath zones of distributed Neoarchean dextral transcurrent to transpressional shear zones in the present-day upper crust suggests a 'millefeuille' lithospheric strength profile, with competent SCLM, mid- to deep, and upper crustal layers. Mechanically strong deep crustal felsic and mafic granulite layers are attributed to dehydration and melt extraction. Intra-crustal decoupling along a ductile décollement in the W Superior led to the preservation of early-formed deep structures that acted as conduits for magma transport into the overlying crust and focussed hydrothermal fluid flow during regional deformation. Increase in the thickness of semi-brittle layers in the lower crust during regional metamorphism would result in an increase in fracturing and faulting in the lower crust, facilitating hydrothermal and carbonic fluid flow in pathways linking SCLM to the upper crust, a factor explaining the late timing for most orogenic Au. Results provide an important new dataset for regional prospectively mapping, especially with machine learning, and exploration targeting for Au and Ni-Cr-Cu-PGE mineralization. Results also furnish evidence for parautochthonous development of the S Superior Province during plume-related rifting and cannot be explained by conventional subduction and arc-accretion models.
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RESEARCH ON DYNAMIC LOAD CARRYING CAPACITY OF ASSEMBLED INTERNAL STIFFENING WIND TURBINE TOWER BASED ON MULTI-SCALE MODELING. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.513.
Повний текст джерелаАнотація:
"The development of wind power technology requires higher and larger wind turbines, which requires the bearing tower to increase its height and diameter. The assembled internal stiffened wind turbine tower divides the tower into multiple arc plates along the longitudinal direction, which can be easy transported to the site for assembly. That can solve the problem of height limit in highway transportation. At the same time, the internal stiffener provides better stability and can replace the bottom tower section of conventional wind turbine tower. In this study, the tower section of assembled internal stiffened wind turbine is modeled, and the longitudinal segmented tower section is assembled to the actual full-scale tower section model for nonlinear dynamic analysis. The influence of weld is considered by multi-scale modeling, combined with the plastic damage theory of steel materials. The whole collapse process of tower wall instability and deformation failure of wind turbine tower under the extreme wind condition is simulated, and the influence of various parameters of tower section on its bearing capacity is analysed. The damage position and damage development during tower collapse are predicted by using plastic damage theory, so as to provide reference for the design of assembled internally stiffened wind turbine tower."
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RESEARCH ON DYNAMIC LOAD CARRYING CAPACITY OF ASSEMBLED INTERNAL STIFFENING WIND TURBINE TOWER BASED ON MULTI-SCALE MODELING. The Hong Kong Institute of Steel Construction, March 2023. http://dx.doi.org/10.18057/ijasc.2023.19.1.11.
Повний текст джерелаАнотація:
The development of wind power technology requires higher and larger wind turbines, which requires the bearing tower to increase its height and diameter. The assembled internal stiffened wind turbine tower divides the tower into multiple arc plates along the longitudinal direction, which can be easy transported to the site for assembly. That can solve the problem of height limit in highway transportation. At the same time, the internal stiffener provides better stability and can replace the bottom tower section of conventional wind turbine tower. In this study, the tower section of assembled internal stiffened wind turbine is modeled, and the longitudinal segmented tower section is assembled to the actual full-scale tower section model for nonlinear dynamic analysis. The influence of weld is considered by multi-scale modeling, combined with the plastic damage theory of steel materials. The whole collapse process of tower wall instability and deformation failure of wind turbine tower under the extreme wind condition is simulated, and the influence of various parameters of tower section on its bearing capacity is analysed. The damage position and damage development during tower collapse are predicted by using plastic damage theory, so as to provide reference for the design of assembled internally stiffened wind turbine tower.