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1
Kunze, Oliver, and Fabian Frommer. "The Matrix vs. The Fifth Element—Assessing Future Scenarios of Urban Transport from a Sustainability Perspective." Sustainability 13, no. 6 (2021): 3531. http://dx.doi.org/10.3390/su13063531.
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The future of urban transport (including passenger transportation and goods logistics) may develop in significantly different directions. Depending on changes in urban behavior, and depending on decisions made by lawmakers and governmental bodies, as well as by commercial players, this future may show a significantly reduced mobility of people and goods (for example, as depicted in the motion picture The Matrix, where people live immobilized in cocoons) or a significantly increased mobility (for example, as depicted in the motion picture The Fifth Element, where multiple layers of air traffic are added to road and rail traffic). We applied a systems thinking method to create a model for political decision makers and researchers. This model can contribute to a better understanding of the interrelations of societal factors (e.g., behavioral changes in the current COVID-19 situation), technological factors (e.g., the role of data traffic or emerging urban air traffic) and environmental factors (e.g., noise or CO2 emissions) in an urban mobility and logistics system. The research also shows that data traffic has the potential to partially substitute physical passenger and goods traffic under certain circumstances. Thus, data networks should conceptually be regarded as a new mode of transport that plays a role in the urban modal split.
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Lambert, Richard F. "Monetary Cost of a Modal Shift." Transportation Research Record: Journal of the Transportation Research Board 1620, no. 1 (1998): 27–33. http://dx.doi.org/10.3141/1620-05.
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Placing an economic dollar value on the environmental impacts of shifting products from the waterway mode to a land mode is presented. Since the original study, completed in 1991, two of the three modal shift examples discussed have taken place. What caused the modal shifts to take place and their merits are also examined. The fuel cost efficiency of the water mode is compared with that of land modes and the air emission results of burning additional fuel to move the same product tonnage. Freight rate variations between the modes are not discussed because the focus is on environmental impact cost. When comparable, waterborne transportation has an environmental cost impact of one-fifth that of rail and one-tenth that of truck transport. Accident rates on a per ton-mile basis are also discussed, but no dollar figures are available for comparison purposes at this time.
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Dedík, Milan, Karol Hrudkay, and Adrián Šperka. "THE USE OF PROGRESSIVE GRAVITATIONAL METHODS IN THE LOGISTICS OF RAIL PASSENGER TRANSPORT." Acta logistica 8, no. 1 (2021): 19–25. http://dx.doi.org/10.22306/al.v8i1.198.
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The main strategic goal of EU transport policy is to support public passenger transport and railway transport as a key transport mode. It is also very important to develop and improve logistic processes in passenger transport. To meet these goals it is necessary to use professional and scientific methods, for example gravitational methods. These methods can be included among progressive empirical methods and models that are used to generalize specific results and offer a general solution to the problem, from practical knowledge to theoretical formulation. These methods are utilised in the natural sciences but their using in transport processes is very important too. One of the best known empirical methods are Nyvig´s and Lill´s gravitational methods. They are especially used in transport planning and organizing, determining of the traffic potential, optimization and rationalization of timetables and traffic service. In the contribution the authors deals with using of the current and new progressive gravitational methods in the context of rail passenger transport logistics. The first chapter comprises narrow connection of the logistics and rail passenger transport including the explanation of their function in rail passenger transport. The next chapter contains an analysis the current research of raised issues. The most important scientific part conssists of theoretical concept of the gravitational methods in railway passenger transport and its various modifications. Theoretical principles of the new progressive Lill´s gravitational model form including its practical application at the chosen railway passenger transport routes are explained and analyzed in the fourth and the fifth chapter.
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Lunet, Thibaut, Christine Lac, Franck Auguste, Florian Visentin, Valéry Masson, and Juan Escobar. "Combination of WENO and Explicit Runge–Kutta Methods for Wind Transport in the Meso-NH Model." Monthly Weather Review 145, no. 9 (2017): 3817–38. http://dx.doi.org/10.1175/mwr-d-16-0343.1.
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This paper investigates the use of the weighted essentially nonoscillatory (WENO) space discretization methods of third and fifth order for momentum transport in the Meso-NH meteorological model, and their association with explicit Runge–Kutta (ERK) methods, with the specific purpose of finding an optimal combination in terms of wall-clock time to solution. A linear stability analysis using von Neumann theory is first conducted that considers six different ERK time integration methods. A new graphical representation of linear stability is proposed, which allows a first discrimination between the ERK methods. The theoretical analysis is then completed by tests on numerical problems of increasing complexity (linear advection of high wind gradient, orographic waves, density current, large eddy simulation of fog, and windstorm simulation), using a fourth-order-centered scheme as a reference basis. The five-stage third-order and fourth-order ERK combinations appear as the time integration methods of choice for coupling with WENO schemes in terms of stability. An explicit time-splitting method added to the ERK temporal scheme for WENO improves the stability properties slightly more. When the spatial discretizations are compared, WENO schemes present the main advantage of maintaining stable, nonoscillatory transitions with sharp discontinuities, but WENO third order is excessively damping, while WENO fifth order provides better accuracy. Finally, WENO fifth order combined with the ERK method makes the whole physics of the model 3 times faster compared to the classical fourth-order centered scheme associated with the leapfrog temporal scheme.
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Abdel-Gawad, Sameh, and John A. McCorquodale. "Simulation of particle concentration distribution in primary clarifiers." Canadian Journal of Civil Engineering 12, no. 3 (1985): 454–63. http://dx.doi.org/10.1139/l85-053.
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A numerical model to simulate the performance of both rectangular and circular primary clarifiers is presented. The proposed model is restricted to those mean steady flows that are isothermal, of neutral density, low in solids concentration, and nearly two-dimensional.The strip integral technique is used to reduce the partial differential equations of continuity, momentum, and mass transport to a set of ordinary differential equations. The resulting set of equations is numerically integrated using a fifth-order, Runge–Kutta method.The full numerical model contains a hydrodynamic submodel and a transport submodel. The hydrodynamic submodel predicts the velocity field and dispersion characteristics within the clarifier, which are prerequisite for the transport submodel.The model, as presented here, was used to simulate the circular tanks used in the cities of Windsor, Ontario and Waterloo, Ontario. The predicted concentration profiles and removal efficiency were in good agreement with the measured values. Key words: numerical model, primary clarifiers, strip integral technique, transport model, concentration profiles, removal efficiency.
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Posmetev, Valeriy, Vadim Nikonov, Viktor Posmetev, and Igor' Siz'min. "SIMULATION MODEL FOR ESTIMATION OF FOREST TRUCK PERFORMANCE EQUIPPED WITH RECUPERATIVE SPRING-HYDRAULIC FIFTH-WHEEL COUPLING." Forestry Engineering Journal 10, no. 4 (2021): 181–96. http://dx.doi.org/10.34220/issn.2222-7962/2020.4/15.
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The current state and advantages of timber road transport in comparison with other types of transport used for hauling timber are presented. The factors influencing the rational choice of the rolling stock of timber trucks are given. The efficiency of using timber trucks with trailers for transportation of timber has been substantiated. Difficult conditions for the transportation of timber along timber roads, which affect the operability of the towing devices of timber trucks with trailers and the efficiency indicators of timber trucks in general, have been considered. A brief analysis of the work of foreign scientists in the field of increasing vehicle efficiency equipped with various towing devices is presented. A perspective scheme of a recuperative pneumo-hydraulic towing hitch has been proposed to eliminate the identified shortcomings of the considered designs of towing hitch devices. A mathematical model and a computer program based on it have been developed to assess the operability and efficiency of the proposed device, as well as to determine its optimal design parameters. On the basis of the performed computer experiments, it was revealed that the recuperative pneumo-hydraulic towing device allows recuperating the power of 4.7 kW at the maximum acceleration of the trailer relative to the timber truck 0.94 m/s2 when moving a timber truck with a trailer on a model timber road. It was found that the optimal diameter of the plunger cavity of the device, at which the recuperation system provides balanced effective damping, is 49 mm. It has been established that the maximum recuperative power is achieved at a speed of movement of a timber truck with a trailer equal to 32 km/h
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Zhu, Jieshun, Bohua Huang, and Zhaohua Wu. "The Role of Ocean Dynamics in the Interaction between the Atlantic Meridional and Equatorial Modes." Journal of Climate 25, no. 10 (2012): 3583–98. http://dx.doi.org/10.1175/jcli-d-11-00364.1.
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Abstract This study examines a mechanism of the interaction between the tropical Atlantic meridional and equatorial modes. To derive robust heat content (HC) variability, the ensemble-mean HC anomalies (HCA) of six state-of-the-art global ocean reanalyses for 1979–2007 are analyzed. Compared with previous studies, characteristic oceanic processes are distinguished through their dominant time scales. Using the ensemble empirical mode decomposition (EEMD) method, the HC fields are first decomposed into components with different time scales. The authors’ analysis shows that these components are associated with distinctive ocean dynamics. The high-frequency (first three) components can be characterized as the equatorial modes, whereas the low-frequency (the fifth and sixth) components are featured as the meridional modes. In between, the fourth component on the time scale of 3–4 yr demonstrates “mixed” characteristics of the meridional and equatorial modes because of an active transition from the predominant meridional to zonal structures on this time scale. Physically, this transition process is initiated by the discharge of the off-equatorial HCA, which is first accumulated as a part of the meridional mode, into the equatorial waveguide, which is triggered by the breakdown of the equilibrium between the cross-equatorial HC contrast and the overlying wind forcing, and results in a major heat transport through the equatorial waveguide into the southeastern tropical Atlantic. It is also shown that remote forcing from El Niño–Southern Oscillation (ENSO) exerts important influence on the transition from the equatorial to meridional mode and may partly dictate its time scale of 3–4 yr. Therefore, the authors’ results demonstrate another mechanism of the equatorial Atlantic response to the ENSO forcing.
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Yao, Mao-Sung, and Ye Cheng. "Cloud Simulations in Response to Turbulence Parameterizations in the GISS Model E GCM." Journal of Climate 25, no. 14 (2012): 4963–74. http://dx.doi.org/10.1175/jcli-d-11-00399.1.
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Abstract The response of cloud simulations to turbulence parameterizations is studied systematically using the GISS general circulation model (GCM) E2 employed in the Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report (AR5). Without the turbulence parameterization, the relative humidity (RH) and the low cloud cover peak unrealistically close to the surface; with the dry convection or with only the local turbulence parameterization, these two quantities improve their vertical structures, but the vertical transport of water vapor is still weak in the planetary boundary layers (PBLs); with both local and nonlocal turbulence parameterizations, the RH and low cloud cover have better vertical structures in all latitudes due to more significant vertical transport of water vapor in the PBL. The study also compares the cloud and radiation climatologies obtained from an experiment using a newer version of turbulence parameterization being developed at GISS with those obtained from the AR5 version. This newer scheme differs from the AR5 version in computing nonlocal transports, turbulent length scale, and PBL height and shows significant improvements in cloud and radiation simulations, especially over the subtropical eastern oceans and the southern oceans. The diagnosed PBL heights appear to correlate well with the low cloud distribution over oceans. This suggests that a cloud-producing scheme needs to be constructed in a framework that also takes the turbulence into consideration.
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Wilson-O’Brien, Amy L., Carrie L. DeHaan, and Suzanne Rogers. "Mitogen-Stimulated and Rapamycin-Sensitive Glucose Transporter 12 Targeting and Functional Glucose Transport in Renal Epithelial Cells." Endocrinology 149, no. 3 (2007): 917–24. http://dx.doi.org/10.1210/en.2007-0985.
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We hypothesized that glucose transporter 12 (GLUT12) is involved in regulation of glucose flux in distal renal tubules in response to elevated glucose. We used the Madin-Darby canine kidney polarized epithelial cell model and neutralizing antibodies to analyze GLUT12 targeting and directional GLUT12-mediated glucose transport. At physiological glucose concentrations, GLUT12 was localized to a perinuclear position. High glucose and serum treatment resulted in GLUT12 localization to the apical membrane. This mitogen-stimulated targeting of GLUT12 was inhibited by rapamycin, the specific inhibitor of mammalian target of rapamycin (mTOR). The functional role of GLUT12 was also examined. We constructed a GLUT12 cDNA containing a c-Myc epitope tag in the fifth exofacial loop. Assays of glucose transport at the apical membrane were performed using Transwell filters. By comparing transport assays in the presence of neutralizing anti-c-Myc monoclonal antibody, we specifically measured GLUT12-mediated glucose transport at the apical surface. GLUT12-mediated glucose transport was mitogen dependent and rapamycin sensitive. Our results implicate mTOR signaling in a novel pathway of glucose transporter protein targeting and glucose transport. Activity of the mTOR pathway has been associated with diabetic kidney disease. Our results provide evidence for a link between GLUT12 protein trafficking, glucose transport and signaling molecules central to the control of metabolic disease processes.
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Weissmann, M., F. J. Braun, L. Gantner, G. J. Mayr, S. Rahm, and O. Reitebuch. "The Alpine Mountain–Plain Circulation: Airborne Doppler Lidar Measurements and Numerical Simulations." Monthly Weather Review 133, no. 11 (2005): 3095–109. http://dx.doi.org/10.1175/mwr3012.1.
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Abstract On summer days radiative heating of the Alps produces rising air above the mountains and a resulting inflow of air from the foreland. This leads to a horizontal transport of air from the foreland to the Alps, and a vertical transport from the boundary layer into the free troposphere above the mountains. The structure and the transports of this mountain–plain circulation in southern Germany (“Alpine pumping”) were investigated using an airborne 2-μm scanning Doppler lidar, a wind-temperature radar, dropsondes, rawinsondes, and numerical models. The measurements were part of the Vertical Transport and Orography (VERTIKATOR) campaign in summer 2002. Comparisons of dropsonde and lidar data proved that the lidar is capable of measuring the wind direction and wind speed of this weak flow toward the Alps (1–4 m s−1). The flow was up to 1500 m deep, and it extended ∼80 km into the Alpine foreland. Lidar data are volume measurements (horizontal resolution ∼5 km, vertical resolution 100 m). Therefore, they are ideal for the investigation of the flow structure and the comparison to numerical models. Even the vertical velocities measured by the lidar agreed with the mass budget calculations in terms of both sign and magnitude. The numerical simulations with the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) (mesh size 2 and 6 km) and the Local Model (LM) of the German Weather Service (mesh size 2.8 and 7 km) reproduced the general flow structure and the mass fluxes toward the Alps within 86%–144% of the observations.
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Righi, M., J. Hendricks, and R. Sausen. "The global impact of the transport sectors on atmospheric aerosol in 2030 – Part 1: Land transport and shipping." Atmospheric Chemistry and Physics 15, no. 2 (2015): 633–51. http://dx.doi.org/10.5194/acp-15-633-2015.
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Abstract. Using the EMAC (ECHAM/MESSy Atmospheric Chemistry) global climate-chemistry model coupled to the aerosol module MADE (Modal Aerosol Dynamics model for Europe, adapted for global applications), we simulate the impact of land transport and shipping emissions on global atmospheric aerosol and climate in 2030. Future emissions of short-lived gas and aerosol species follow the four Representative Concentration Pathways (RCPs) designed in support of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We compare the resulting 2030 land-transport- and shipping-induced aerosol concentrations to the ones obtained for the year 2000 in a previous study with the same model configuration. The simulations suggest that black carbon and aerosol nitrate are the most relevant pollutants from land transport in 2000 and 2030 and their impacts are characterized by very strong regional variations during this time period. Europe and North America experience a decrease in the land-transport-induced particle pollution, although in these regions this sector remains a major source of surface-level pollution in 2030 under all RCPs. In Southeast Asia, however, a significant increase is simulated, but in this region the surface-level pollution is still controlled by other sources than land transport. Shipping-induced air pollution is mostly due to aerosol sulfate and nitrate, which show opposite trends towards 2030. Sulfate is strongly reduced as a consequence of sulfur reduction policies in ship fuels in force since 2010, while nitrate tends to increase due to the excess of ammonia following the reduction in ammonium sulfate. The aerosol-induced climate impact of both sectors is dominated by aerosol-cloud effects and is projected to decrease between 2000 and 2030, nevertheless still contributing a significant radiative forcing to Earth's radiation budget.
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Righi, M., J. Hendricks, and R. Sausen. "The global impact of the transport sectors on atmospheric aerosol in 2030 – Part 1: Land transport and shipping." Atmospheric Chemistry and Physics Discussions 14, no. 16 (2014): 22985–3025. http://dx.doi.org/10.5194/acpd-14-22985-2014.
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Abstract. Using the EMAC global climate-chemistry model coupled to the aerosol module MADE, we simulate the impact of land transport and shipping emissions on global atmospheric aerosol and climate in 2030. Future emissions of short-lived gas and aerosol species follow the four Representative Concentration Pathways (RCPs) designed in support of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We compare the resulting 2030 land-transport- and shipping-induced aerosol concentrations to the ones obtained for the year 2000 in a previous study with the same model configuration. The simulations suggest that black carbon and aerosol nitrate are the most relevant pollutants from land transport in 2000 and 2030, but their impacts are characterized by very strong regional variations during this time period. Europe and North America experience a decrease in the land-transport-induced particle pollution, although in these regions this sector remains the dominant source of surface-level pollution in 2030 under all RCPs. In Southeast Asia, on the other hand, a significant increase is simulated, but in this region the surface-level pollution is still controlled by other sources than land transport. Shipping-induced air pollution is mostly due to aerosol sulfate and nitrate, which show opposite trends towards 2030. Sulfate is strongly reduced as a consequence of sulfur reduction policies in ship-fuels in force since 2010, while nitrate tends to increase due to the excess of ammonia following the reduction in ammonium-sulfate. The aerosol-induced climate impact of both sectors is dominated by aerosol-cloud effects and is projected to decrease between 2000 and 2030, nevertheless still contributing a significant radiative forcing to the Earth's radiation budget.
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Righi, M., J. Hendricks, and R. Sausen. "The global impact of the transport sectors on atmospheric aerosol: simulations for year 2000 emissions." Atmospheric Chemistry and Physics Discussions 13, no. 5 (2013): 13119–89. http://dx.doi.org/10.5194/acpd-13-13119-2013.
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Abstract. We use the EMAC-MADE global aerosol model to quantify the impact of transport emissions (land transport, shipping and aviation) on global aerosol. We consider a present-day (2000) scenario and the CMIP5 emission dataset developed in support of the IPCC Fifth Assessment Report. The model takes also into account particle number emissions, which are derived from mass emissions under different assumptions on the size distribution of particles emitted by the three transport sectors. Additional sensitivity experiments are performed to quantify the effects of the uncertainties behind such assumptions. The model simulations show that the impact of the transport sectors closely matches the emission patterns. Land transport is the most important source of black carbon pollution in USA, Europe and Arabian Peninsula. Shipping strongly contributes to aerosol sulfate concentrations along the most-traveled routes of the northern Atlantic and northern Pacific oceans, with a significant impact along the coastlines. The effect of aviation is mostly confined to the upper-troposphere (7–12 km), in the northern mid-latitudes, although significant effects are also simulated at the ground, due to the emissions from landing and take-off cycles. The transport-induced perturbations to particle number concentrations are very sensitive to the assumptions on the size distribution of emitted particles, with the largest uncertainties obtained for the land transport sector. The simulated climate impacts, due to aerosol direct and indirect effects, are strongest for the shipping sector, as a consequence of the large impact of sulfate aerosol on low marine clouds and their optical properties.
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Smith, D. J., E. A. Gaffney, and J. R. Blake. "Mathematical modelling of cilia-driven transport of biological fluids." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 465, no. 2108 (2009): 2417–39. http://dx.doi.org/10.1098/rspa.2009.0018.
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Cilia-driven flow occurs in the airway surface liquid, in the female and male reproductive tracts and enables symmetry-breaking in the embryonic node. Viscoelastic rheology is found in healthy states in some systems, whereas in others may characterise disease, motivating the development of mathematical models that take this effect into account. We derive the fundamental solution for linear viscoelastic flow, which is subsequently used as a basis for slender-body theory. Our numerical algorithm allows efficient computation of three-dimensional time-dependent flow, bending moments, power and particle transport. We apply the model to the large-amplitude motion of a single cilium in a linear Maxwell liquid. A relatively short relaxation time of just 0.032 times the beat period significantly reduces forces, bending moments, power and particle transport, the last variable exhibiting exponential decay with relaxation time. A test particle is propelled approximately one-fifth as quickly along the direction of cilia beating for scaled relaxation time 0.032 as in the Newtonian case, and mean volume flow is abolished, emphasizing the sensitivity of cilia function to fluid rheology. These results may have implications for flow in the airways, where the transition from Newtonian to viscoelastic rheology in the peri-ciliary fluid may reduce clearance.
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Dvulit, Zoryana, Liana Maznyk, and Ivanna Danyliuk. "Modeling in the field of freight transportation: ambivalence of management decisions in the conditions of quarantine restrictions and economic competition." Management and Entrepreneurship in Ukraine: the stages of formation and problems of development 2021, no. 1 (2021): 104–18. http://dx.doi.org/10.23939/smeu2021.01.104.
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The study focuses on the ambiguity of management decisions in conditions of economic competition and quarantine restrictions. It is concluded that in the field of freight transportation there are antagonistic interests of the environment in the process of making management decisions by managers of JSC “Ukrzaliznytsia”. The classification of information situations related to the uncertainty of the environment is used, according to which the fifth information situation most closely corresponds to the current situation in the market of transport services. The choice of the fifth information situation is due to the factors caused by the government’s decisions to impose quarantine restrictions. Most of these factors have had a negative impact on the expectations of businesses in general and cargo owners in particular. The state of economic competition in the field of freight transportation was studied by analyzing the structure of goods by different modes of transport for January-November 2019-2020, indicating the absence of significant changes or restrictions on freight traffic. Thus, quarantine restrictions did not cause irreparable damage to the railway industry directly, but they indirectly affected a number of indicators. Analysis of economic competition, level of uncertainty, degree of ambivalence of government decisions and structural and dynamic analysis of the market of transport services in January-November 2019-2020, allowed creating a methodology that ensures the validity of management decisions in economic competition and ambivalence of government actions. It consists of 6 stages: formulation of the purpose; formation of the corresponding information base; formation of an expert group; direct survey; selection of the most promising solutions for stabilizing the situation in the field of rail freight; assessment of the homogeneity of the expert group. The application of this technique gives railway companies additional competitive advantages, even in conditions of growing uncertainty and risk.
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Saldías, F. J., A. Comellas, C. Guerrero, K. M. Ridge, D. H. Rutschman, and J. I. Sznajder. "Time course of active and passive liquid and solute movement in the isolated perfused rat lung model." Journal of Applied Physiology 85, no. 4 (1998): 1572–77. http://dx.doi.org/10.1152/jappl.1998.85.4.1572.
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The isolated perfused rat lung model (IL) is used to study alveolar epithelial transport properties. Most of the previous studies have been done over a short period of time and have not used the same preparation as a control and intervention group. We evaluated whether the IL preparation could be used for a prolonged period of time (5 h) and studied the rates of active Na+ transport, lung liquid clearance, and passive movement of solutes. Active Na+ transport and lung liquid clearance were stable from 1 to 5 h. The passive movement of small solutes (Na+, mannitol) did not change significantly, and albumin movement increased slightly at the fifth hour. Total RNA isolated from IL after 5 h was intact, and the Na+-K+-ATPase activity in alveolar type II cells isolated at the end of 5-h experiments was equal to Na+-K+-ATPase function from freshly isolated alveolar type II cells. Finally, we measured the stimulatory effect of the β-adrenergic-agonist terbutaline and the inhibitory effect of the Na+-K+-ATPase-antagonist ouabain by using the same animal as a control. Accordingly, the isolated perfused lung model is functionally stable for at least 5 h, and it could be utilized to evaluate the effect of different interventions by using the same preparation.
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Deng, Aijun, Nelson L. Seaman, Glenn K. Hunter, and David R. Stauffer. "Evaluation of Interregional Transport Using the MM5–SCIPUFF System." Journal of Applied Meteorology 43, no. 12 (2004): 1864–86. http://dx.doi.org/10.1175/jam2178.1.
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Abstract Improved understanding of transport issues and source–receptor relationships on the interregional scale is dependent on reducing the uncertainties in the ability to define complex three-dimensional wind fields evolving in time. The numerical models used for this purpose have been upgraded substantially in recent years by introducing finer grid resolution, better representation of subgrid-scale physics, and practical four-dimensional data assimilation (FDDA) techniques that reduce the accumulation of errors over time. The impact of these improvements for interregional transport is investigated in this paper using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) and the Second-Order Closure Integrated Puff (SCIPUFF) dispersion model to simulate the 1983 Cross-Appalachian Tracer Experiment (CAPTEX-83) episode 1 of 18–19 September 1983. Combining MM5 and SCIPUFF makes it possible to verify predicted tracer concentrations against observed surface concentrations collected during the CAPTEX-83 study. Conclusions from this study are as follows. 1) Not surprisingly, a baseline model configuration reflecting typical capabilities of the late 1980s (70-km horizontal grid, 15 vertical layers, older subgrid physics, and no FDDA) produced large meteorological errors that severely degraded the accuracy of the surface tracer concentrations predicted by SCIPUFF. 2) Improving the horizontal and vertical resolution of the MM5 to 12 km (typical for current operational model) and 32 layers led to some improvements in the statistical skill, but the further addition of more advanced physics produced much greater reductions of simulation errors. 3) The use of FDDA, along with 12-km resolution and improved physics, produced the overall best performance. 4) Further reduction of the horizontal grid size to 4 km had a detrimental effect on meteorological and plume-dispersion solutions in this case because of misrepresentation of convection associated with a cold front by the MM5's explicit moist physics.
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Sivilevičius, Henrikas. "MODELLING THE INTERACTION OF TRANSPORT SYSTEM ELEMENTS / TRANSPORTO SISTEMOS ELEMENTŲ SĄVEIKOS MODELIAVIMAS / МОДЕЛИРОВАНИЕ ВЗАИМОДЕЙСТВИЯ ЭЛЕМЕНТОВ ТРАНСПОРТНОЙ СИСТЕМЫ". TRANSPORT 26, № 1 (2011): 20–34. http://dx.doi.org/10.3846/16484142.2011.560366.
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Economy and nonproductive sectors of each country could not function without a transport system (TS). Having analysed research works on the interaction of separate TS elements, it was identified that there is no common model for all types of interaction. TS consists of material (physical) objects: traffic participants and freight to be carried, a transportation process and operations’ control. TS classification scheme devised according to systematically selected criteria, showing that several criteria are often applied at the same time in official documents, is presented. Original TS physical elements’ interaction model with 6 interaction levels is presented as well. The model is suitable for all modes of transport. Six levels of interaction are distinguished: autointeraction of transport elements, the first level; TS elements’ interaction, the second level; TS elements’ interaction with external environment, the third level; interaction of transport modes, the fourth level; TS interaction with the country's economy and nonproductive sectors, the fifth level; and TS impact on the country's GAV (Gross Added Value), the sixth level. Properties and factors influencing on the results and parameters of interaction have been systematized. Levels and properties of interaction have been analyzed as well. To evaluate the importance of interaction levels to the parameters of the transportation process, the method of Analytic Hierarchy Process (AHP) has been recommended. Santrauka Kiekvienos šalies ūkio ir negamybinės veiklos sektoriai negalėtų funkcionuoti be transporto sistemos. Išanalizavus mokslo darbus, skirtus atskirų transporto sistemos elementų sąveikai tirti, nustatyta, kad visas sąveikos rūšis vienijančio modelio nėra. Transporto sistemą sudaro materialūs (fiziniai) transporto objektai: eismo dalyviai ir kroviniai, kuriuos reikia vežti, transportavimo procesas ir veiklos reguliavimas. Pateikta transporto sistemos klasifikavimo pagal sistemiškai pasirinktus kriterijus schema, rodanti, kad oficialiuose dokumentuose dažnai vienu metu taikomi keli kriterijai. Pateiktas originalus transporto sistemos fizinių elementų sąveikos modelis, kuriame išskirti šeši sąveikos lygmenys. Modelis tinka visoms transporto rūšims. Pirmajam lygmeniui priskirta transporto elementų autosąveika, antrajam—transporto sistemos elementų tarpusavio sąveika, trečiajam—transporto sistemos elementų sąveika su išorine aplinka, ketvirtajam—transporto rūšių sąveika, penktajam—transporto sistemos sąveika su šalies ūkio ir negamybinės veiklos sektoriais, šeštajam—transporto sistemos įtaka šalies bendrajai pridėtinei vertei. Susisteminti sąveikos požymiai ir veiksniai, turintys įtakos fizinės sąveikos rezultatui ir jos parametrams. Išanalizuoti sąveikos lygmenys ir jos savybės. Sąveikos lygmenų prioritetui (svarbai) transportavimo proceso parametrams vertinti pasiūlyta taikyti Analytic Hierarchy Process (AHP) metodą, kurio pagrindą sudaro elementų porinio lyginimo matrica. Skaičiuojamajame pavyzdyje nustačius transporto sistemos elementų skirtingų lygmenų sąveikos svorį kelių transporto saugumui įrodytas AHP metodo tinkamumas transporto sistemos elementų sąveikai modeliuoti. Резюме Различные секторы хозяйственной и непроизводственной деятельности любого государства не могли бы функционировать без транспортной системы. На основе анализа научных трудов, посвященных исследованиям взаимодействия отдельных элементов транспортной системы, установлено, что не существует модели, объединяющей все виды и уровни взаимодействий. Транспортная система включает в себя разные материальные (физические) объекты. Это участники движения и грузы, которые необходимо перевозить, транспортный процесс и регулирование деятельности. Приведена схема классификации транспортной системы по системным подходам, установленным критериям, свидетельствующая о том, что зачастую в официальных документах одновременно применяется несколько критериев. Предложена оригинальная модель взаимодействия физических элементов транспортной системы, в которой выделены 6 уровней взаимодействий. Модель пригодна для всех видов транспорта. Первый уровень присвоен взаимодействию транспортных элементов, т. е «внутреннему» взаимодействию однородных материальных элементов транспортной системы, второй – взаимодействию материальных составляющих элементов транспортной системы, третий – взаимодействию материальных составляющих элементов транспорта с внешней, окружающей средой, четвертый – взаимодействию различных видов транспорта, пятый – взаимодействию транспортной системы с секторами хозяйственной и непроизводственной деятельности страны, шестой – влиянию взаимодействия транспортной системы c сектором экономики, а также влиянию непроизводственной деятельности страны на экономику (внутренний валовый продукт), предопределяющую прожиточный уровень населения. В модель включено влияние науки и исследований. Систематизированы признаки и факторы, оказывающие влияние на результат физического взаимодействия элементов транспортной системы и ее параметры. Выполнен анализ уровней взаимодействия и его свойств. Для определения приоритета (весомости) различных отдельных уровней взаимодействия на параметры процесса транспортирования предлагается применять метод анализа иерархий (Analytic Hierarchy Process), основу которого составляет матрица попарного сравнения элементов. На примере расчета весомости различных уровней взаимодействия элементов транспортной системы, влияющих на безопасность дорожного транспорта, доказана пригодность -метода AHP для моделирования взаимодействия элементов транспортной системы.
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Worthington, Mark T., Lauren Browne, Emily H. Battle, and Roger Qi Luo. "Functional properties of transfected human DMT1 iron transporter." American Journal of Physiology-Gastrointestinal and Liver Physiology 279, no. 6 (2000): G1265—G1273. http://dx.doi.org/10.1152/ajpgi.2000.279.6.g1265.
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Recently, mutation of the DMT1 gene has been discovered to cause ineffective intestinal iron uptake and abnormal body iron metabolism in the anemic Belgrade rat and mkmouse. DMT1 transports first-series transition metals, but only iron turns on an inward proton current. The process of iron transport was studied by transfection of human DMT1 into the COS-7 cell line. Native and epitope-tagged human DMT1 led to increased iron uptake. The human gene with the Belgrade rat mutation was found to have one-fifth of the activity of the wild-type protein. The pH optimum of human DMT1 iron uptake was 6.75, which is equivalent to the pH of the duodenal brush border. The transporter demonstrates uptake without saturation from 0 to 50 μM iron, recapitulating earlier studies of isolated intestinal enterocytes. Diethylpyrocarbonate inhibition of iron uptake in DMT1-transfected cells suggests a functional role for histidine residues. Finally, a model is presented that incorporates the selectivity of the DMT1 transporter for transition metals and a potential role for the inward proton current.
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Evans, J. P. "Changes in Water Vapor Transport and the Production of Precipitation in the Eastern Fertile Crescent as a Result of Global Warming." Journal of Hydrometeorology 9, no. 6 (2008): 1390–401. http://dx.doi.org/10.1175/2008jhm998.1.
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Abstract This study investigates changes in the types of storm events occurring in the Fertile Crescent as a result of global warming. Regional climate model [fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5)–Noah] simulations are run for the first and last five years of the twenty-first century following the Special Report on Emissions Scenarios (SRES) A2 experiment. Then the precipitation events are classified according to the water vapor fluxes that created them. At present most of the region’s precipitation is from westerly water vapor fluxes. Results indicate that the region will increasingly get its precipitation from large events that are dominated by southerly water vapor fluxes. The increase in these events will occur in the transition seasons, especially autumn.
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Righi, M., J. Hendricks, and R. Sausen. "The global impact of the transport sectors on atmospheric aerosol: simulations for year 2000 emissions." Atmospheric Chemistry and Physics 13, no. 19 (2013): 9939–70. http://dx.doi.org/10.5194/acp-13-9939-2013.
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Abstract. We use the EMAC (ECHAM/MESSy Atmospheric Chemistry) global model with the aerosol module MADE (Modal Aerosol Dynamics model for Europe, adapted for global applications) to quantify the impact of transport emissions (land transport, shipping and aviation) on the global aerosol. We consider a present-day (2000) scenario according to the CMIP5 (Climate Model Intercomparison Project Phase 5) emission data set developed in support of the IPCC (Intergovernmental Panel on Climate Change) Fifth Assessment Report. The model takes into account particle mass and number emissions: The latter are derived from mass emissions under different assumptions on the size distribution of particles emitted by the three transport sectors. Additional sensitivity experiments are performed to quantify the effects of the uncertainties behind such assumptions. The model simulations show that the impact of the transport sectors closely matches the emission patterns. Land transport is the most important source of black carbon (BC) pollution in the USA, Europe and the Arabian Peninsula, contributing up to 60–70% of the total surface-level BC concentration in these regions. Shipping contributes about 40–60% of the total aerosol sulfate surface-level concentration along the most-traveled routes of the northern Atlantic and northern Pacific oceans, with a significant impact (~ 10–20%) along the coastlines. Aviation mostly affects aerosol number, contributing about 30–40% of the particle number concentration in the northern midlatitudes' upper troposphere (7–12 km), although significant effects are also simulated at the ground, due to the emissions from landing and take-off cycles. The transport-induced perturbations to the particle number concentrations are very sensitive to the assumptions on the size distribution of emitted particles, with the largest uncertainties (about one order of magnitude) obtained for the land transport sector. The simulated climate impacts, due to aerosol direct and indirect effects, are strongest for the shipping sector, in the range of −222.0 to −153.3 mW m−2, as a consequence of the large impact of sulfate aerosol on low marine clouds and their optical properties.
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Wang, Pijun, Soichiro Hata, Yansen Xiao, John W. Murray, and Allan W. Wolkoff. "Topological assessment of oatp1a1: a 12-transmembrane domain integral membrane protein with three N-linked carbohydrate chains." American Journal of Physiology-Gastrointestinal and Liver Physiology 294, no. 4 (2008): G1052—G1059. http://dx.doi.org/10.1152/ajpgi.00584.2007.
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Organic anion transport protein 1a1 (oatp1a1), a prototypical member of the oatp family of highly homologous transport proteins, is expressed on the basolateral (sinusoidal) surface of rat hepatocytes. The organization of oatp1a1 within the plasma membrane has not been well defined, and computer-based models have predicted possible 12- as well as 10-transmembrane domain structures. Which of oatp1a1's four potential N-linked glycosylation sites are actually glycosylated and their influence on transport function have not been investigated in a mammalian system. In the present study, topology of oatp1a1 in the rat hepatocyte plasma membrane was examined by immunofluorescence analysis using an epitope-specific antibody designed to differentiate a 10- from a 12-transmembrane domain model. To map glycosylation sites, the asparagines at the each of the four N-linked glycosylation consensus sites were mutagenized to glutamines. Mutagenized oatp1a1 constructs were expressed in HeLa cells, and effects on protein expression and transport activity were assessed. These studies revealed that oatp1a1 is a 12-transmembrane-domain protein in which the second and fifth extracellular loops are glycosylated at asparagines 124, 135, and 492, whereas the potential glycosylation site at asparagine 62 is not utilized, consistent with its position in a transmembrane domain. Constructs in which more than one glycosylation site were eliminated had reduced transport activity but not necessarily reduced transporter expression. This was in accord with the finding that fully unglycosylated oatp1a1 was well expressed but located intracellularly with limited transport ability as a consequence of its reduced cell surface expression.
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Evans, J. P., and R. B. Smith. "Water Vapor Transport and the Production of Precipitation in the Eastern Fertile Crescent." Journal of Hydrometeorology 7, no. 6 (2006): 1295–307. http://dx.doi.org/10.1175/jhm550.1.
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Abstract The study presented here attempts to quantify the significance of southerly water vapor fluxes on precipitation occurring in the eastern Fertile Crescent region. The water vapor fluxes were investigated at high temporal and spatial resolution by using a Regional Climate Model [fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5)–Noah land surface model] to downscale the NCEP–NCAR reanalysis. Using the Iterative Self-Organizing Data Analysis Techniques (ISODATA) clustering algorithm, the 200 largest precipitation events, occurring from 1990 through 1994, were grouped into classes based on the similarity of their water vapor fluxes. Results indicate that, while southerly fluxes were dominant in 24% of tested events, these events produced 43% of the total precipitation produced by the 200 largest events. Thus, while the majority of precipitation events occurring in the Fertile Crescent involve significant water vapor advected from the west, those events that included southerly fluxes produced much larger precipitation totals. This suggests that changes that affect these southerly fluxes more than the westerly fluxes (e.g., changes in the Indian monsoon, movement of the head of the Persian Gulf, etc.) may have a relatively strong affect on the total precipitation falling in the Fertile Crescent even though they affect relatively few precipitation events. To obtain a clearer view of the precipitation mechanisms, the authors used a linear model, along with the estimated water vapor fluxes, to downscale from 25 to 1 km. The result shows a spectrum of mountain scales not seen in the regional model, exerting tight control on the precipitation pattern.
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Vijayaraghavan, K., J. Herr, S. Y. Chen, and E. Knipping. "Linkage between an advanced air quality model and a mechanistic watershed model." Geoscientific Model Development Discussions 3, no. 3 (2010): 1503–48. http://dx.doi.org/10.5194/gmdd-3-1503-2010.
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Abstract. An offline linkage between two advanced multi-pollutant air quality and watershed models is presented. The models linked are (1) the Advanced Modeling System for Transport, Emissions, Reactions and Deposition of Atmospheric Matter (AMSTERDAM) (a three-dimensional Eulerian plume-in-grid model derived from the Community Multiscale Air Quality (CMAQ) model) and (2) the Watershed Analysis Risk Management Framework (WARMF). The pollutants linked include gaseous and particulate nitrogen, sulfur and mercury compounds. The linkage may also be used to obtain meteorological fields such as precipitation and air temperature required by WARMF from the outputs of the meteorology chemistry interface processor (MCIP) that processes meteorology simulated by the fifth generation Mesoscale Model (MM5) or the Weather Research and Forecast (WRF) model for input to AMSTERDAM. The linkage is tested in the Catawba River basin of North and South Carolina for ammonium, nitrate and sulfate. Modeled air quality and meteorological fields transferred by the linkage can supplement the conventional measurements used to drive WARMF and may be used to help predict the impact of changes in atmospheric emissions on water quality.
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J. Hudson, Mark. "Towards a prehistory of the Great Divergence:." Documenta Praehistorica 46 (December 6, 2019): 30–43. http://dx.doi.org/10.4312/dp.46-2.
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This essay argues that the primary socio-economic formations of premodern Japan were formed in the Bronze Age via processes of ancient globalisation across Eurasia. Multi-crop cereal agriculture combining rice, millet, wheat and barley with a minor contribution from domesticated animals spread from Bronze Age Korea to Japan at the beginning of the first millennium BC. This agricultural system gradually expanded through the archipelago while engendering new economic niches centred on trade, raiding and specialised fishing. From the fifth century AD the horse became widely used for warfare, transport and overseas trade. While alluvial rice farming provided staple finance for the early state, it is argued here that the concept of the ‘maritime mode of production’ better explains economic processes in the nonstate spaces of Japan until the early seventeenth century. Despite this diversity in socio-economic formations, the post-Bronze Age globalisation of food in Japan appears to have been delayed compared to many other regions of Eurasia and to have been less impacted by elite consumption. Further research is required to confirm this suggestion and the essay outlines several areas where archaeological research could contribute to debates over the ‘Great Divergence’ and the economic development of the modern world.
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J. Hudson, Mark. "Towards a prehistory of the Great Divergence:." Documenta Praehistorica 46 (December 6, 2019): 30–43. http://dx.doi.org/10.4312/dp.46.2.
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This essay argues that the primary socio-economic formations of premodern Japan were formed in the Bronze Age via processes of ancient globalisation across Eurasia. Multi-crop cereal agriculture combining rice, millet, wheat and barley with a minor contribution from domesticated animals spread from Bronze Age Korea to Japan at the beginning of the first millennium BC. This agricultural system gradually expanded through the archipelago while engendering new economic niches centred on trade, raiding and specialised fishing. From the fifth century AD the horse became widely used for warfare, transport and overseas trade. While alluvial rice farming provided staple finance for the early state, it is argued here that the concept of the ‘maritime mode of production’ better explains economic processes in the nonstate spaces of Japan until the early seventeenth century. Despite this diversity in socio-economic formations, the post-Bronze Age globalisation of food in Japan appears to have been delayed compared to many other regions of Eurasia and to have been less impacted by elite consumption. Further research is required to confirm this suggestion and the essay outlines several areas where archaeological research could contribute to debates over the ‘Great Divergence’ and the economic development of the modern world.
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Pleim, Jonathan E. "A Combined Local and Nonlocal Closure Model for the Atmospheric Boundary Layer. Part I: Model Description and Testing." Journal of Applied Meteorology and Climatology 46, no. 9 (2007): 1383–95. http://dx.doi.org/10.1175/jam2539.1.
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Abstract The modeling of the atmospheric boundary layer during convective conditions has long been a major source of uncertainty in the numerical modeling of meteorological conditions and air quality. Much of the difficulty stems from the large range of turbulent scales that are effective in the convective boundary layer (CBL). Both small-scale turbulence that is subgrid in most mesoscale grid models and large-scale turbulence extending to the depth of the CBL are important for the vertical transport of atmospheric properties and chemical species. Eddy diffusion schemes assume that all of the turbulence is subgrid and therefore cannot realistically simulate convective conditions. Simple nonlocal closure PBL models, such as the Blackadar convective model that has been a mainstay PBL option in the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) for many years and the original asymmetric convective model (ACM), also an option in MM5, represent large-scale transport driven by convective plumes but neglect small-scale, subgrid turbulent mixing. A new version of the ACM (ACM2) has been developed that includes the nonlocal scheme of the original ACM combined with an eddy diffusion scheme. Thus, the ACM2 is able to represent both the supergrid- and subgrid-scale components of turbulent transport in the convective boundary layer. Testing the ACM2 in one-dimensional form and comparing it with large-eddy simulations and field data from the 1999 Cooperative Atmosphere–Surface Exchange Study demonstrates that the new scheme accurately simulates PBL heights, profiles of fluxes and mean quantities, and surface-level values. The ACM2 performs equally well for both meteorological parameters (e.g., potential temperature, moisture variables, and winds) and trace chemical concentrations, which is an advantage over eddy diffusion models that include a nonlocal term in the form of a gradient adjustment.
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Drumond, Anita, Milica Stojanovic, Raquel Nieto, Sergio Martin Vicente-Serrano, and Luis Gimeno. "Linking Anomalous Moisture Transport And Drought Episodes in the IPCC Reference Regions." Bulletin of the American Meteorological Society 100, no. 8 (2019): 1481–98. http://dx.doi.org/10.1175/bams-d-18-0111.1.
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AbstractDroughts are complex and may be triggered by different mechanisms, such as atmospheric circulation, moisture transport, and thermodynamic processes. Significant research has been completed to characterize precipitation in the Intergovernmental Panel on Climate Change (IPCC) reference regions (RRs), but a systematic analysis of atmospheric transport linked to drought episodes is still missing. This article describes a catalog in which the drought episodes over the RRs are identified during 1980–2015, and the role of the moisture transport anomalies from the respective major climatological moisture sources during the most severe meteorological drought episode registered for each RR is analyzed. For each of the 27 RRs defined in the IPCC Fifth Assessment Report, drought episodes were identified at 1-, 6-, and 12-month time scales through the standardized precipitation evapotranspiration index (SPEI). SPEI values were computed using time series of the monthly precipitation and atmospheric evaporative demand (AED) averaged over each RR. The approach, which was applied to both identify the major climatological moisture sources and sinks for each RR and to investigate anomalies in moisture transport during the episode, is based on the Lagrangian flexible particle dispersion model (FLEXPART), integrated with the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim) data. For each RR, the following components were analyzed: a) moisture uptake over sources, b) moisture supply from the sources into the RR, and c) moisture supply from the RR into its sink. Although performed for just one case, this analysis illustrates how the moisture transport may impact the RR during extreme conditions. The results are organized in a web page available to the scientific community and stakeholders.
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Pérez-Santos, Iván, Romanet Seguel, Wolfgang Schneider, et al. "Synoptic-scale variability of surface winds and ocean response to atmospheric forcing in the eastern austral Pacific Ocean." Ocean Science 15, no. 5 (2019): 1247–66. http://dx.doi.org/10.5194/os-15-1247-2019.
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Abstract. In the Southern Hemisphere, macroscale atmospheric systems such as westerly winds and the southeast Pacific subtropical anti-cyclone (SPSA) influence the wind regime of the eastern austral Pacific Ocean. The average and seasonal behaviors of these systems are well known, although wind variability at different time and distance scales remains largely unexamined. Therefore, the main goal of this study was to determine the variabilities of surface winds on a spatiotemporal scale from 40 to 56∘ S, using QuikSCAT, Advanced Scatterometer (ASCAT), and the fifth major global European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis (ERA5) surface-wind information complemented with in situ meteorological data. In addition, interactions between the atmospheric systems, together with the ocean–atmosphere response, were evaluated for the period 1999–2018. The empirical orthogonal function detected dominance at the synoptic scale in mode 1, representing approximately 30 % of the total variance. In this mode, low and high atmospheric pressure systems characterized wind variability for a 16.5 d cycle. Initially, mode 2 – which represents approximately 22 % of the variance – was represented by winds from the west/east (43–56∘ S), occurring mostly during spring and summer/fall and winter at an annual timescale (1999–2008) until they were replaced by systems cycling at 27.5 d (2008–2015). This reflects the influence of the baroclinic annular mode in the Southern Hemisphere. Mode 3, representing approximately 15 % of the variance, involved the passage of small-scale low and high atmospheric pressure (LAP and HAP) systems throughout Patagonia. Persistent Ekman suction occurred throughout the year south of the Gulf of Penas and beyond the Pacific mouth of the Strait of Magellan. Easterly Ekman transport (ET) piled these upwelled waters onto the western shore of South America when winds blew southward. These physical mechanisms were essential in bringing nutrients to the surface and then transporting planktonic organisms from the oceanic zone to Patagonian fjords and channels. In the zonal band between 41 and 43∘ S, the latitude of Chiloé Island, upward Ekman pumping and Ekman transport during spring and summer favored a reduced sea surface temperature and increased chlorophyll a (Chl a) levels; this is the first time that such Ekman upwelling conditions have been reported so far south in the eastern Pacific Ocean. The influence of the northward-migrating LAP systems on the ocean–atmosphere interphase allowed us to understand, for the first time, their direct relationship with recorded nighttime air temperature maxima (locally referred to as “nighttime heatwave events”). In the context of global climate change, greater attention should be paid to these processes based on their possible impact on the rate of glacier melting and on the austral climate.
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Kranenburg, R., C. Hendriks, M. Schaap, and A. Segers. "Source apportionment using LOTOS-EUROS: module description and evaluation." Geoscientific Model Development Discussions 5, no. 4 (2012): 3957–91. http://dx.doi.org/10.5194/gmdd-5-3957-2012.
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Abstract. To design effective mitigation strategies the origin of air pollutants needs to be known. Chemistry transport models can be used to assess the origin of air pollution across a large domain. However, in traditional simulations the information on origin is lost and brute force scenario studies are performed to assess the origin. Alternatively, one can trace the origin of air pollutants throughout a simulation using a labeling approach. In this paper we document and demonstrate a newly developed labeling module for the chemistry transport model LOTOS-EUROS which tracks the source allocation for all particulate matter components and precursor gases. Dedicated simulations confirmed that the new module functions correctly. The new module provides more accurate information about the source contributions than using a brute force approach with scenario runs as the chemical regime remains unchanged. An important advantage of the new module is the reduction of computation costs and analysis work associated with the calculations. The new module was applied to assess the origin of particulate nitrate across the Netherlands. Averaged across the Dutch territory the main contributions to nitrate derive from road and non-road transport as well as power plants. Overall, only one-fifth of the concentration derived from sources located inside the country. The new technology enables new research directions as improved information on pollution origin is desired for policy support as well as scientific applications.
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Makinde, Oluwole Daniel, V. Nagendramma, Chakravarthula S. K. Raju, and A. Leelarathnam. "Effects of Cattaneo-Christov Heat Flux on Casson Nanofluid Flow Past a Stretching Cylinder." Defect and Diffusion Forum 378 (September 2017): 28–38. http://dx.doi.org/10.4028/www.scientific.net/ddf.378.28.
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In this paper, we investigate the combined effects of Brownian motion, thermophoresis and Cattaneo-Christov heat flux on Casson nanofluid boundary layer flow over a stretching cylinder. The governing partial differential equations (PDEs) are obtained and transformed into a system of ordinary differential equations (ODEs) by employing appropriate similarity solution. The model nonlinear boundary value problem is tackled numerically using fourth-fifth order Runge-Kutta integration scheme with shooting technique. Effects of various thermophysical parameters on the velocity, temperature and concentration profiles as well as skin friction and Sherwood number are presented graphically and discussed quantitatively. It is found that thermal relaxation parameter minimizes the temperature field and boosting the rate of heat transfer per unit volume. This heat flux conditions are very useful for thermal transport control in manufacturing and chemical industries.
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Ramesh, GK, K. Ganesh Kumar, Ali J. Chamkha, and Rama Subba Reddy Gorla. "Effects of chemical reaction and activation energy on a Carreau nanoliquid past a permeable surface under zero mass flux conditions." Proceedings of the Institution of Mechanical Engineers, Part N: Journal of Nanomaterials, Nanoengineering and Nanosystems 234, no. 1-2 (2019): 47–57. http://dx.doi.org/10.1177/2397791419881090.
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Arrhenius condition has been broadly utilized as a model of the temperature impact on the rate compound responses and organic procedure. Hence, our aim of this article is to examine the effects of chemical reaction and activation energy on a Carreau nanoliquid in a permeable surface. For thermal and mass transport curiosities, the cumulative upgrade of convective type condition and zero mass transition have been considered. The overseeing sets of partial differential equations are rendered into coupled nonlinear ordinary differential equations. The arrangement of the subsequent ordinary differential equations is acquired with the assistance of the Runge-Kutta-Fehlberg-fourth-fifth order (RKF-45) procedure. The influence of relevant parameters and physical quantities is investigated. The results show that the presence of reaction rate and energy activation term decelerates the temperature and concentration gradients.
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Stenke, A., M. Schraner, E. Rozanov, T. Egorova, B. Luo, and T. Peter. "The SOCOL version 3.0 chemistry–climate model: description, evaluation, and implications from an advanced transport algorithm." Geoscientific Model Development 6, no. 5 (2013): 1407–27. http://dx.doi.org/10.5194/gmd-6-1407-2013.
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Abstract. We present the third generation of the coupled chemistry–climate model (CCM) SOCOL (modeling tools for studies of SOlar Climate Ozone Links). The most notable modifications compared to the previous model version are (1) the dynamical core has been updated with the fifth generation of the middle-atmosphere general circulation model MA-ECHAM (European Centre/HAMburg climate model), and (2) the advection of the chemical species is now calculated by a mass-conserving and shape-preserving flux-form transport scheme instead of the previously used hybrid advection scheme. The whole chemistry code has been rewritten according to the ECHAM5 infrastructure and transferred to Fortran95. In contrast to its predecessors, SOCOLvs3 is now fully parallelized. The performance of the new SOCOL version is evaluated on the basis of transient model simulations (1975–2004) with different horizontal (T31 and T42) resolutions, following the approach of the CCMVal-1 model validation activity. The advanced advection scheme significantly reduces the artificial loss and accumulation of tracer mass in regions with strong gradients that was observed in previous model versions. Compared to its predecessors, SOCOLvs3 generally shows more realistic distributions of chemical trace species, especially of total inorganic chlorine, in terms of the mean state, but also of the annual and interannual variability. Advancements with respect to model dynamics are for example a better representation of the stratospheric mean state in spring, especially in the Southern Hemisphere, and a slowdown of the upward propagation in the tropical lower stratosphere. Despite a large number of improvements model deficiencies still remain. Examples include a too-fast vertical ascent and/or horizontal mixing in the tropical stratosphere, the cold temperature bias in the lowermost polar stratosphere, and the overestimation of polar total ozone loss during Antarctic springtime.
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Iselin, John P., William J. Gutowski, and Joseph M. Prusa. "Tracer Advection Using Dynamic Grid Adaptation and MM5." Monthly Weather Review 133, no. 1 (2005): 175–87. http://dx.doi.org/10.1175/mwr-2850.1.
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Abstract A dynamic grid adaptation (DGA) technique is used to numerically simulate tracer transport at meso- and regional scales. A gridpoint redistribution scheme is designed to maximize heuristic characteristics of a “good” grid. The advective solver used in conjunction with the DGA is the multidimensional positive definite advection transport algorithm (MPDATA). The DGA results for regional tracer transport are compared against results generated using the leapfrog as well as MPDATA advection schemes with uniformly spaced, static grids. Wind fields for all tracer transport algorithms are provided by the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5). A mesoscale-sized test case with idealized initial condition and wind field clearly shows qualitatively and quantitatively the advantage of using the dynamic adaptive grid, which is a marked reduction in numerical error. These results are further corroborated by more realistic test cases that used NCEP–NCAR reanalysis data from 6–11 March 1992 to set initial and boundary conditions for (i) a mesoscale-sized, 24-h simulation with an idealized initial tracer field, and (ii) a regional, 5-day simulation with water vapor field initialized from the reanalysis data but then treated as a passive tracer. A result of interest is that MPDATA substantially outperforms the leapfrog method with fourth-order artificial dissipation (central to MM5) in all of our test cases. We conclude that with dynamic grid adaptation, results with approximately the same accuracy as a uniform grid may be obtained using only a quarter of the grid points of the uniform grid MPDATA simulations. Compared to results generated using the leapfrog method on a uniform grid, the DGA does even better.
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Melnyk, Leonid Hr. "Phase Transition: Comprehending the Deep Meaning of the Phenomenon." Mechanism of an Economic Regulation, no. 1 (2019): 109–16. http://dx.doi.org/10.21272/mer.2019.83.09.
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A reader will meet two essays, which can be conventionally called the fairy stories: “Phase transition” and “Fifth dimension”. In the first essay, the reader will get acquainted with the essence of phase transitions, which mean a jump-like change in the state of a system. The paper considers the role of phase transitions in the development of nature and social systems. The reader will also be able to view the contours of the modern phase transition to the new socio-economic formation that takes place during the Third and Fourth Industrial Revolutions. In particular: new things should appear, new types of alternative energy; new technologies (based on the use of 3D printers); fully automated production (“Internet of things”, “smart networks”); new communications (modes of transport and communication); unmanned transport; new economic relations (solidary economy); new needs of people (use of information for personality for development of people); a new reality of global management of human civilization (based on the “cloud” as a planetary system of memory); a new style of life, aimed at the personality development of man. The second essay – “Fifth Dimension” – depicts a figurative picture of forming the prerequisites for phase transitions in society. They are formed by the accumulation of unresolved problems that cannot be solved by society at the existing level of socio-economic development. This is precisely what the inevitable process of the phase transition to a new formation makes. The essay also reveals the role of social prediction as the basis of justified strategic management of social development. This ensures sustainable state of the socio-natural system, leaving sufficient opportunities for future generations to meet their social and economic needs. The paper shows the significance of such reality as the “cloud”, which at the moment serves as a global system of memory, is evolving in the direction of transformation into a planetary center of decision-making – a kind of meta-intelligence. Key words: phase transition, socio-economic formation, social development, transformation, “cloud”.
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Stenke, A., M. Schraner, E. Rozanov, T. Egorova, B. Luo, and T. Peter. "The SOCOL version 3.0 chemistry-climate model: description, evaluation, and implications from an advanced transport algorithm." Geoscientific Model Development Discussions 5, no. 4 (2012): 3419–67. http://dx.doi.org/10.5194/gmdd-5-3419-2012.
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Abstract. We present the third generation of the coupled chemistry-climate model (CCM) SOCOL (modeling tools for studies of SOlar Climate Ozone Links). The most notable modifications compared to the previous model version are: (1) the dynamical core has been updated with the fifth generation of the middle-atmosphere general circulation model MA-ECHAM, and (2) the advection of the chemical species is now calculated by a mass-conserving and shape-preserving flux-form transport scheme instead of the previously used hybrid advection scheme. The whole chemistry code has been rewritten according to the ECHAM5 infrastructure and transferred to Fortran95. In contrast to its predecessors, SOCOLvs3 is now fully parallelized. The performance of the new SOCOL version is evaluated on the basis of transient model simulations (1975–2004) with different horizontal (T31 and T42) resolutions, following the approach of the CCMVal-1 model validation activity. The advanced advection scheme significantly reduces the artificial loss and accumulation of tracer mass in regions with strong gradients that was observed in previous model versions. Compared to its predecessors, SOCOLvs3 generally shows more realistic distributions of chemical trace species, especially of total inorganic chlorine, in terms of the mean state, but also of the annual and interannual variability. Advancements with respect to model dynamics are for example a better representation of the stratospheric mean state in spring, especially in the Southern Hemisphere, and a slowdown of the upward propagation in the tropical lower stratosphere. Despite a large number of improvements model deficiencies still remain. Examples include a too fast vertical ascent and/or horizontal mixing in the tropical stratosphere, the cold temperature bias in the lowermost polar stratosphere, and the overestimation of polar total ozone loss during Antarctic springtime.
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Reddy, M. G., and S. A. Shehzad. "Molybdenum disulfide and magnesium oxide nanoparticle performance on micropolar Cattaneo-Christov heat flux model." Applied Mathematics and Mechanics 42, no. 4 (2021): 541–52. http://dx.doi.org/10.1007/s10483-021-2713-9.
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AbstractThis article intends to illustrate the Darcy flow and melting heat transmission in micropolar liquid. The major advantage of micropolar fluid is the liquid particle rotation through an independent kinematic vector named the microrotation vector. The novel aspects of the Cattaneo-Christov (C-C) heat flux and Joule heating are incorporated in the energy transport expression. Two different nanoparticles, namely, MoS2 and MgO, are suspended into the base-fluid. The governing partial differential equations (PDEs) of the prevailing problem are slackening into ordinary differential expressions (ODEs) via similarity transformations. The resulting mathematical phenomenon is illustrated by the implication of fourth-fifth order Runge-Kutta-Fehlberg (RKF) scheme. The fluid velocity and temperature distributions are deliberated by using graphical phenomena for multiple values of physical constraints. The results are displayed for both molybdenum disulphide and magnesium oxide nanoparticles. A comparative benchmark in the limiting approach is reported for the validation of the present technique. It is revealed that the incrementing material constraint results in a higher fluid velocity for both molybdenum disulphide and magnesium oxide nanoparticle situations.
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Righi, M., J. Hendricks, and R. Sausen. "The global impact of the transport sectors on atmospheric aerosol in 2030 – Part 2: Aviation." Atmospheric Chemistry and Physics Discussions 15, no. 23 (2015): 34035–62. http://dx.doi.org/10.5194/acpd-15-34035-2015.
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Abstract. We use the EMAC (ECHAM/MESSy Atmospheric Chemistry) global climate-chemistry model coupled to the aerosol module MADE (Modal Aerosol Dynamics model for Europe, adapted for global applications) to simulate the impact of aviation emissions on global atmospheric aerosol and climate in 2030. Emissions of short-lived gas and aerosol species follow the four Representative Concentration Pathways (RCPs) designed in support of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We compare our findings with the results of a previous study with the same model configuration focusing on year 2000 emissions. We also characterize the aviation results in the context of the other transport sectors presented in a companion paper. In spite of a relevant increase in aviation traffic volume and resulting emissions of aerosol (black carbon) and aerosol precursor species (nitrogen oxides and sulfur dioxide), the aviation effect on particle mass concentration in 2030 remains quite negligible (on the order of a few ng m-3), about one order of magnitude less than the increase in concentration due to other emission sources. Due to the relatively small size of the aviation-induced aerosol, however, the increase in particle number concentration is significant in all scenarios (about 1000 cm-3), mostly affecting the northern mid-latitudes at typical flight altitudes (7–12 km). This largely contributes to the overall change in particle number concentration between 2000 and 2030, which results also in significant climate effects due to aerosol-cloud interactions. Aviation is the only transport sector for which a larger impact on the Earth's radiation budget is simulated in the future: The aviation-induced RF in 2030 is more than doubled with respect to the year 2000 value of −15 mW m-2, with a maximum value of −63 mW m-2 simulated for RCP2.6.
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Righi, Mattia, Johannes Hendricks, and Robert Sausen. "The global impact of the transport sectors on atmospheric aerosol in 2030 – Part 2: Aviation." Atmospheric Chemistry and Physics 16, no. 7 (2016): 4481–95. http://dx.doi.org/10.5194/acp-16-4481-2016.
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Abstract. We use the EMAC (ECHAM/MESSy Atmospheric Chemistry) global climate–chemistry model coupled to the aerosol module MADE (Modal Aerosol Dynamics model for Europe, adapted for global applications) to simulate the impact of aviation emissions on global atmospheric aerosol and climate in 2030. Emissions of short-lived gas and aerosol species follow the four Representative Concentration Pathways (RCPs) designed in support of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We compare our findings with the results of a previous study with the same model configuration focusing on year 2000 emissions. We also characterize the aviation results in the context of the other transport sectors presented in a companion paper. In spite of a relevant increase in aviation traffic volume and resulting emissions of aerosol (black carbon) and aerosol precursor species (nitrogen oxides and sulfur dioxide), the aviation effect on particle mass concentration in 2030 remains quite negligible (on the order of a few ng m−3), about 1 order of magnitude less than the increase in concentration due to other emission sources. Due to the relatively small size of the aviation-induced aerosol, however, the increase in particle number concentration is significant in all scenarios (about 1000 cm−3), mostly affecting the northern mid-latitudes at typical flight altitudes (7–12 km). This largely contributes to the overall change in particle number concentration between 2000 and 2030, which also results in significant climate effects due to aerosol–cloud interactions. Aviation is the only transport sector for which a larger impact on the Earth's radiation budget is simulated in the future: the aviation-induced radiative forcing in 2030 is more than doubled with respect to the year 2000 value of −15 mW m−2 in all scenarios, with a maximum value of −63 mW m−2 simulated for RCP2.6.
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Lilford, Richard, Dmitri Nepogodiev, Peter J. Chilton, et al. "Methodological issues in economic evaluations of emergency transport systems in low-income and middle-income countries." BMJ Global Health 6, no. 3 (2021): e004723. http://dx.doi.org/10.1136/bmjgh-2020-004723.
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A recent systematic review identified few papers on the economic evaluation of systems for emergency transport of acutely ill or injured patients. In addition, we found no articles dealing with the methodological challenges posed by such studies in low-income or middle-income countries. We therefore carried out an analysis of issues that are of particular salience to this important topic. This is an intellectual study in which we develop models, identify their limitations, suggest potential extensions to the models and discuss priorities for empirical studies to populate models. First, we develop a general model to calculate changes in survival contingent on the reduced time to treatment that an emergency transport system is designed to achieve. Second, we develop a model to estimate transfer times over an area that will be served by a proposed transfer system. Third, we discuss difficulties in obtaining parameters with which to populate the models. Fourth, we discuss costs, both direct and indirect, of an emergency transfer service. Fifth, we discuss the issue that outcomes other than survival should be considered and that the effects of a service are a weighted sum over all the conditions and severities for which the service caters. Lastly, based on the above work, we identify priorities for research. To our knowledge, this is the first study to identify and frame issues in the health economics of acute transfer systems and to develop models to calculate survival rates from basic parameters, such as time delay/survival relationships, that vary by intervention type and context.
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Otun, Olayinka, Adeolu Dina, and Adeola Bamigboye. "An Examination of the Determinants of The Mode of Transport to Primary Health Facilities in A Developing Region." Indonesian Journal of Geography 46, no. 2 (2014): 167. http://dx.doi.org/10.22146/ijg.5786.
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Access to primary health facilities is a key determinant of the overall well being of the population in an area. In rural regions were distances to public facilities are usually longer compared to urban areas, it is not clear if people are still willing to walk to use these facilities. It is pertinent therefore to clarify such uncertainty since walking distance is a standard measure used to plan such public facilities particularly in rural regions. The objective of this study therefore is to provide a framework to determine the factors that will influence a health care service seeker in a developing region to walk or use other means of transport to a primary health facility. The case study for this research is Ijebu North Local Government Area of Ogun state made up of eleven urban and rural wards. One hundred and fifty households were selected at random for interview. Logit regression was used to describe how some predictor variables were used to explain the likelihood of a particular household walking to a primary health facility. The predicting model in this study was able to classify 80.0% of the cases correctly. This simply shows that the predictors (independent variables) contribute to the predicting power of the logistic regression model. The pseudo R-squares of Cox and Snell’s R-square and Nagelkerke’s R also show that our logistic model is relevant to predicting whether a household will walk or use a vehicle while attending a health facility. In our study, we noted that settlement status (p=0.00) and transport cost to health facility (p=0.00) contributed significantly to the prediction. This study also reveals that the odds for household members in an urban area to walk to the health facility often used is 88.1% lower than the odds for a household in a rural area. It was revealed that households that are poor are 49% times more likely to walk to the health facility they frequently used. The knowledge of the factors that will determine whether health care service seekers in a developing region will want to walk or not will assist government in the planning and provision of health facilities.
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Kranenburg, R., A. J. Segers, C. Hendriks, and M. Schaap. "Source apportionment using LOTOS-EUROS: module description and evaluation." Geoscientific Model Development 6, no. 3 (2013): 721–33. http://dx.doi.org/10.5194/gmd-6-721-2013.
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Abstract. To design effective mitigation strategies, the origin of emissions which produce air pollutants needs to be known. Contributors to air pollutants can be emission sources, like road traffic or industry, but also be more specified to emission from one location or from a specified time. Chemistry transport models can be used to assess the origin of air pollution across a large domain. However, in traditional simulations the information on origin is lost and brute force scenario studies are performed to assess the origin. Alternatively, one can trace the origin of air pollutants throughout a simulation using a labeling approach. In this paper we document and demonstrate a newly developed labeling module for the chemistry transport model LOTOS-EUROS which tracks the source allocation for all particulate matter components and precursor gases. Dedicated simulations confirmed that the new module functions correctly. The new module provides more accurate information about the source contributions than using a brute force approach with scenario runs as the chemical regime remains unchanged. An important advantage of the new module is the reduction of computation costs and analysis work associated with the calculations. The new module was applied to assess the origin of particulate nitrate across the Netherlands. Averaged across the Dutch territory, the main contributions to nitrate are derived from road and non-road transport as well as power plants. Overall, only one-fifth of the concentration derived from sources located inside the country. The new technology enables new research directions as improved information on pollution origin is desired for policy support as well as scientific applications.
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Khan, Mair, T. Salahuddin, Muhammad Malik Yousaf, Farzana Khan, and Arif Hussain. "Variable diffusion and conductivity change in 3D rotating Williamson fluid flow along with magnetic field and activation energy." International Journal of Numerical Methods for Heat & Fluid Flow 30, no. 5 (2019): 2467–84. http://dx.doi.org/10.1108/hff-02-2019-0145.
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Purpose The purpose of the current flow configurations is to bring to attention the thermophysical aspects of magnetohydrodynamics (MHD) Williamson nanofluid flow under the effects of Joule heating, nonlinear thermal radiation, variable thermal coefficient and activation energy past a rotating stretchable surface. Design/methodology/approach A mathematical model is examined to study the heat and mass transport analysis of steady MHD Williamson fluid flow past a rotating stretchable surface. Impact of activation energy with newly introduced variable diffusion coefficient at the mass equation is considered. The transport phenomenon is modeled by using highly nonlinear PDEs which are then reduced into dimensionless form by using similarity transformation. The resulting equations are then solved with the aid of fifth-order Fehlberg method. Findings The rotating fluid, heat and mass transport effects are analyzed for different values of parameters on velocity, energy and diffusion distributions. Parameters like the rotation parameter, Hartmann number and Weissenberg number control the flow field. In addition, the solar radiation, Joule heating, Prandtl number, thermal conductivity, concentration diffusion coefficient and activation energy control the temperature and concentration profiles inside the stretching surface. It can be analyzed that for higher values of thermal conductivity, Eckret number and solar radiation parameter the temperature profile increases, whereas opposite behavior is noticed for Prandtl number. Moreover, for increasing values of temperature difference parameter and thermal diffusion coefficient, the concentration profile shows reducing behavior. Originality/value This paper is useful for researchers working in mathematical and theoretical physics. Moreover, numerical results are very useful in industry and daily-use processes.
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Draxler, Roland R. "The Use of Global and Mesoscale Meteorological Model Data to Predict the Transport and Dispersion of Tracer Plumes over Washington, D.C." Weather and Forecasting 21, no. 3 (2006): 383–94. http://dx.doi.org/10.1175/waf926.1.
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Abstract The data from a yearlong tracer dispersion experiment over Washington, D.C., in 1984 were used to evaluate Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) dispersion model calculations using coarse global meteorological reanalysis data [NCEP–NCAR and 40-Yr ECMWF Re-Analysis (ERA-40)] and calculations using meteorological data fields created by running a high-resolution meteorological model [fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5)]. None of the meteorological models were optimized for urban environments. The dispersion calculation using the ERA-40 data showed better performance than those using the NCEP–NCAR data and comparable performance to those using MM5 data fields. Calculations with MM5 data that used shorter-period forecasts were superior to calculations that used forecast data that extended beyond 24 h. Daytime dispersion model calculations using the MM5 data showed an underprediction bias not evident in calculations using the ERA-40 data or for nighttime calculations using either meteorological dataset. It was found that small changes in the wind direction for all meteorological model data resulted in dramatic improvements in dispersion model performance. All meteorological data modeled plume directions were biased 10°–20° clockwise to the measured plume direction. This bias was greatest when using the global meteorological data. A detailed analysis of the wind observations during the November intensive, which had the greatest difference between the model and measured plume directions, showed that only the very lowest level of observed winds could account for the transport direction of the measured plume. In the Northern Hemisphere, winds tend to turn clockwise with height resulting in positive directional transport bias if the lowest-level winds are not represented in sufficient detail by the meteorological model.
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Smith, David. "The fifth mode." Construction Research and Innovation 7, no. 1 (2016): 12–15. http://dx.doi.org/10.1080/20450249.2016.11874018.
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Tekleselassie, Hailyie. "DDoS Detection on Internet of Things using Unsupervised Algorithms." E3S Web of Conferences 297 (2021): 01005. http://dx.doi.org/10.1051/e3sconf/202129701005.
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Through the growth of the fifth-generation networks and artificial intelligence technologies, new threats and challenges have appeared to wireless communication system, especially in cybersecurity. And IoT networks are gradually attractive stages for introduction of DDoS attacks due to integral frailer security and resource-constrained nature of IoT devices. This paper emphases on detecting DDoS attack in wireless networks by categorizing inward network packets on the transport layer as either “abnormal” or “normal” using the integration of machine learning algorithms knowledge-based system. In this paper, deep learning algorithms and CNN were autonomously trained for mitigating DDoS attacks. This paper lays importance on misuse based DDOS attacks which comprise TCP SYN-Flood and ICMP flood. The researcher uses CICIDS2017 and NSL-KDD dataset in training and testing the algorithms (model) while the experimentation phase. accuracy score is used to measure the classification performance of the four algorithms. the results display that the 99.93 performance is recorded.
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Vacchi, Marco, Cristina Siligardi, Erika Iveth Cedillo-González, Anna Maria Ferrari, and Davide Settembre-Blundo. "Industry 4.0 and Smart Data as Enablers of the Circular Economy in Manufacturing: Product Re-Engineering with Circular Eco-Design." Sustainability 13, no. 18 (2021): 10366. http://dx.doi.org/10.3390/su131810366.
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The digital transformation of manufacturing firms, in addition to making operations more efficient, offers important opportunities both to promote the transition to a circular economy and to experiment with new techniques for designing smarter and greener products. This study integrates Industry 4.0 technologies, smart data, Life Cycle Assessment methodology, and material microstructural analysis techniques to develop and apply a circular eco-design model that has been implemented in the Italian ceramic tile manufacturing industry. The model has been initially adopted in a simulation environment to define five different scenarios of raw material supply, alternative to the current production one. The scenarios were then validated operationally at laboratory scale and in a pilot environment, demonstrating that a proper selection of raw material transport systems significantly improves the environmental performance of the ceramic product. Both the results of the laboratory tests and of the pre-industrial experiments have demonstrated the technological feasibility of the solutions identified with circular eco-design, enabling the re-engineering of the ceramic product as the fifth of the 6Rs of the circular economy.
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Abbasbandy, S., and M. Mustafa. "Analytical and numerical approaches for Falkner–Skan flow of MHD Maxwell fluid using a non-Fourier heat flux model." International Journal of Numerical Methods for Heat & Fluid Flow 28, no. 7 (2018): 1539–55. http://dx.doi.org/10.1108/hff-08-2017-0316.
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Purpose This paper aims to describe the laminar flow of Maxwell fluid past a non-isothermal rigid plate with a stream wise pressure gradient. Heat transfer mechanism is analyzed in the context of non-Fourier heat conduction featuring thermal relaxation effects. Design/methodology/approach Flow field is permeated to uniform transverse magnetic field. The governing transport equations are changed to globally similar ordinary differential equations, which are tackled analytically by homotopy analysis technique. Homotopy analysis method-Padè approach is used to accelerate the convergence of homotopy solutions. Also, numerical approximations are made by means of shooting method coupled with fifth-order Runge-Kutta method. Findings The solutions predict that fluid relaxation time has a tendency to suppress the hydrodynamic boundary layer. Also, heat penetration depth reduces for increasing values of thermal relaxation time. The general trend of wall temperature gradient appears to be similar in Fourier and Cattaneo–Christov models. Research limitations/implications An important implication of current research is that the thermal relaxation time considerably alters the temperature and surface heat flux. Originality/value Current problem even in case of Newtonian fluid has not been attempted previously.
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Nevison, C. D., M. Manizza, R. F. Keeling, et al. "Evaluating the ocean biogeochemical components of earth system models using atmospheric potential oxygen (APO) and ocean color data." Biogeosciences Discussions 11, no. 6 (2014): 8485–529. http://dx.doi.org/10.5194/bgd-11-8485-2014.
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Abstract. The observed seasonal cycles in atmospheric potential oxygen (APO) at a range of mid to high latitude surface monitoring sites are compared to those inferred from the output of 6 Earth System Models participating in the fifth phase of the Coupled Model Intercomparison Project (CMIP5). The simulated air–sea O2 fluxes are translated into APO seasonal cycles using a matrix method that takes into account atmospheric transport model (ATM) uncertainty among 13 different ATMs. Half of the ocean biogeochemistry models tested are able to reproduce the observed APO cycles at most sites, to within the current large ATM uncertainty, while the other half generally are not. Net Primary Production (NPP) and net community production (NCP), as estimated from satellite ocean color data, provide additional constraints, albeit more with respect to the seasonal phasing of ocean model productivity than the overall magnitude. The present analysis suggests that, of the tested ocean biogeochemistry models, CESM and GFDL ESM2M are best able to capture the observed APO seasonal cycle at both Northern and Southern Hemisphere sites. In the northern oceans, the comparison to observed APO suggests that most models tend to underestimate NPP or deep ventilation or both.
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Hepp, Gerold, and Matthias Zessner. "Assessing the Impact of Storm Drains at Road Embankments on Diffuse Particulate Phosphorus Emissions in Agricultural Catchments." Water 11, no. 10 (2019): 2161. http://dx.doi.org/10.3390/w11102161.
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This study presents a simple mapping key suitable for quick and systematic assessments of the types of agricultural and civil engineering structures present in a certain agricultural catchment as well as the impact they may have on the spatial distribution of critical source areas. An application of this mapping key to three small sub-catchments of a case study catchment with an area of several hundred square kilometres (one-stage cluster sampling) in Austria clearly reveals that road embankments with subsurface drainage can exert a major influence on emissions and transport pathways of sediment-bound pollutants like particulate phosphorus (PP). Due to this, the semi-empirical, spatially distributed PhosFate model is extended to separately model PP emissions into surface waters via storm drains along road embankments. Furthermore, the overall share of road embankments with subsurface drainage on all road embankments in the case study catchment is inferred with the help of a Bayesian hierarchical model. The combination of the results of these two models shows that the share of storm drains at road embankments on total PP emissions ranges from about one fifth to one third in the investigated area.