Academic literature on the topic 'Scale-up regularity'
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Journal articles on the topic "Scale-up regularity"
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Zhou, Xuhuan, and Weiliang Xiao. "Algebra Properties in Fourier-Besov Spaces and Their Applications." Journal of Function Spaces 2018 (December 4, 2018): 1–10. http://dx.doi.org/10.1155/2018/3629179.
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We estimate the norm of the product of two scale functions in Fourier-Besov spaces. As applications of these algebra properties, we establish the global well-posedness for small initial data and local well-posedness for large initial data of the generalized Navier-Stokes equations. Particularly, we give a blow-up criterion of the solutions in Fourier-Besov spaces as well as a space analyticity of Gevrey regularity.
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Yoneda, Tsuyoshi, Susumu Goto, and Tomonori Tsuruhashi. "Mathematical reformulation of the Kolmogorov–Richardson energy cascade in terms of vortex stretching." Nonlinearity 35, no. 3 (February 7, 2022): 1380–401. http://dx.doi.org/10.1088/1361-6544/ac4b3b.
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Abstract In this paper, with the aid of direct numerical simulations (DNS) of forced turbulence in a periodic domain, we mathematically reformulate the Kolmogorov–Richardson energy cascade in terms of vortex stretching. By using the description, we prove that if the Navier–Stokes flow satisfies a new regularity criterion in terms of the enstrophy production rate, then the flow does not blow up. Our DNS results seem to support this regularity criterion. Next, we mathematically construct the hierarchy of tubular vortices, which is statistically self-similar in the inertial range. Under the assumptions of the scale-locally of the vortex stretching/compressing (i.e. energy cascade) process and the statistical independence between vortices that are not directly stretched or compressed, we can derive the −5/3 power law of the energy spectrum of statistically stationary turbulence without directly using the Kolmogorov hypotheses.
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Hou, Thomas Y. "Blow-up or no blow-up? A unified computational and analytic approach to 3D incompressible Euler and Navier–Stokes equations." Acta Numerica 18 (May 2009): 277–346. http://dx.doi.org/10.1017/s0962492906420018.
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Whether the 3D incompressible Euler and Navier–Stokes equations can develop a finite-time singularity from smooth initial data with finite energy has been one of the most long-standing open questions. We review some recent theoretical and computational studies which show that there is a subtle dynamic depletion of nonlinear vortex stretching due to local geometric regularity of vortex filaments. We also investigate the dynamic stability of the 3D Navier–Stokes equations and the stabilizing effect of convection. A unique feature of our approach is the interplay between computation and analysis. Guided by our local non-blow-up theory, we have performed large-scale computations of the 3D Euler equations using a novel pseudo-spectral method on some of the most promising blow-up candidates. Our results show that there is tremendous dynamic depletion of vortex stretching. Moreover, we observe that the support of maximum vorticity becomes severely flattened as the maximum vorticity increases and the direction of the vortex filaments near the support of maximum vorticity is very regular. Our numerical observations in turn provide valuable insight, which leads to further theoretical breakthrough. Finally, we present a new class of solutions for the 3D Euler and Navier–Stokes equations, which exhibit very interesting dynamic growth properties. By exploiting the special nonlinear structure of the equations, we prove nonlinear stability and the global regularity of this class of solutions.
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Albi, Giacomo, Young-Pil Choi, and Axel-Stefan Häck. "Pressureless Euler alignment system with control." Mathematical Models and Methods in Applied Sciences 28, no. 09 (August 2018): 1635–64. http://dx.doi.org/10.1142/s0218202518400018.
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We study a non-local hydrodynamic system with control. First, we characterize the control dynamics as a sub-optimal approximation to the optimal control problem constrained to the evolution of the pressureless Euler alignment system. We then discuss the critical thresholds that lead to global regularity or finite-time blow-up of strong solutions in one and two dimensions. Finally, we use a finite volume scheme, coupled with an implicit–explicit time integrator to solve numerically the stiff scale of the controlled system. Several numerical simulations are shown to validate the theoretical and computational results of the paper.
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Braley, T. J., A. L. Kratz, D. Whibley, and C. Goldstein. "1142 Comprehensive Phenotyping Of Ambulatory Sleep Patterns In Multiple Sclerosis." Sleep 43, Supplement_1 (April 2020): A435. http://dx.doi.org/10.1093/sleep/zsaa056.1136.
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Abstract Introduction The majority of sleep research in persons with multiple sclerosis (PwMS) has been siloed, restricted to evaluation of one or a few sleep measures in isolation. To fully characterize the impact of sleep disturbances in MS, multifaceted phenotyping of sleep is required. The objective of this study was to more comprehensively quantify sleep in PwMS, using a recently developed multi-domain framework of duration, continuity, regularity, sleepiness/alertness, and quality. Methods Data were derived from a parent study that examined associations between actigraphy and polysomnography-based measures of sleep and cognitive function in MS. Actigraphy was recorded in n=55 PwMS for 7-12 days (Actiwatch2®, Philips Respironics). Sleep metrics included: duration=mean total sleep time (TST, minutes); continuity=mean wake time after sleep onset (minutes), and regularity=stddev wake-up time (hours). ‘Extreme’ values for continuity/regularity were defined as the most extreme third of the distributions. ‘Extreme’ TST values were defined as the lowest or highest sixth of the distributions. Sleepiness (Epworth Sleepiness Scale score) and sleep quality [Pittsburgh Sleep Quality Index (PSQI) sleep quality item] were dichotomized by accepted cutoffs (>10 and >1, respectively). Results Sleep was recorded for a mean of 8.2 days (stddev=0.95). Median (1st, 3rd quartile) values were as follows: duration 459.79 (430.75, 490.60), continuity 37.00 (23.44, 52.57), regularity 1.02 (0.75, 1.32), sleepiness/alertness 8 (4, 12), and sleep quality 1.00 (1.00, 2.00). Extreme values based on data distributions were: short sleep <=426.25 minutes (18%), long sleep >515.5 minutes (16%), poor sleep continuity ≥45 minutes (33%), and poor sleep regularity ≥1.17 hours (33%). Sleepiness and poor sleep quality were present in 36% and 40% respectively. For comparison, in a historical cohort of non-MS patients, the extreme third of sleep regularity was a stddev of 0.75 hours, 13% had ESS of >10, and 16% had poor sleep quality. Conclusion In this study of ambulatory sleep patterns in PwMS, we found greater irregularity of sleep-wake timing, and higher prevalence of sleepiness and poor sleep quality than published normative data. Efforts should be made to include these measures in the assessment of sleep-related contributions to MS outcomes. Support The authors received no external support for this work.
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Tada, Yuki, Yukari Ueda, Kemal Sasaki, Shiro Sugiura, Mieko Suzuki, Hiromi Funayama, Yuka Akiyama, Mayu Haraikawa, and Kumi Eto. "Association of Regular Mealtimes With a Balanced Diet Among Japanese Preschool Children: A Study of Lifestyle Changes After the Spread of COVID-19 Infection." Current Developments in Nutrition 6, Supplement_1 (June 2022): 228. http://dx.doi.org/10.1093/cdn/nzac048.042.
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Abstract Objectives This study examines whether preschool children who maintained regular mealtimes after the spread of COVID-19 infection have better lifestyle habits, like waking up and sleeping early and a more balanced diet, than those who did not. Methods An online cross-sectional survey was conducted among 2,000 individuals who provided meals to preschool children aged 2 to 6 years. The Healthy Diet Score (HDS), on a 40-point scale, was developed to comprehensively assess the dietary balance of preschool children based on their frequency of food intake from 13 food groups. The analysis included data on 1,850 children, excluding those who failed to answer the main questions. The participants were classified into four groups based on their responses regarding the regularity of mealtimes after the spread of COVID-19: ‘regular mealtimes (n = 125),’ ‘originally regular and remains unchanged (n = 1514),’ ‘irregular mealtimes (n = 63),’ and ’originally irregular and remains unchanged (n = 148).’ Multiple regression analysis was conducted with HDS as the dependent variable, and regularity of mealtimes and confounding factors as independent variables. Results Compared to other groups, eighty-two percent of the children whose mealtimes were originally regular and remained unchanged were more likely to wake up and sleep early, to eat a snack 0–1 times per day, and to eat breakfast every day. The mealtime for the group ‘originally regular and remains unchanged’ was significantly and positively associated with a higher HDS even after adjusting for basic characteristics and lifestyle of the children, and the economic status of their guardians (β = 0.131, P < 0.01). Conclusions Preschool children who originally had regular mealtimes and maintained this regularity even after the spread of COVID-19 infection were shown to have better lifestyle habits such as waking up and sleeping early, lower frequency of eating snacks, eating breakfast every day, and a higher HDS. Funding Sources This study is a secondary use analysis of survey data conducted as part of the ‘Research for Effective Development of a Food, Nutrition and Dietary Support Guide for Healthy Development in Early Childhood’ grant from the Ministry of Health, Labor and Welfare's Administrative Promotion Research Project.
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Sementsov, S. V. "Regularities of Creating in the XVIII - Mid XX Centuries a Regular Agglomeration of St. Petersburg - Leningrad and Problems of its Preservation as a World Heritage Object." Advanced Materials Research 1020 (October 2014): 651–54. http://dx.doi.org/10.4028/www.scientific.net/amr.1020.651.
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Before the foundation of St. Petersburg in 1703, there had for centuries existed a developed system of rural settlements located on the flat valleys and areas along the Neva River and around the Ladoga Lake. Since 1703, under the leadership of Peter I and his followers, there was carried out a systematic creation of the capital St. Petersburg agglomeration (St. Petersburg and residential suburbs around it), which was done on the basis of purposefully introduced principles of regularity and harmony of architectural ensembles, by the methods of large-scale reconstruction of the previous irregular system of the population settlement distribution. The scale of this new agglomeration had no analogues in world town-planning practice of the XVIII century and united spaces with the total area over 200 square kilometers, which extended from the town of Sestroretsk in the North to the town of Novgorod in the South, from the town of Narva in the West to the Volkhov River in the East. The regularity and multi-center character of the central city formed according to the pattern of a mesh and cellular structure (with the dimensions of 10 km by 15 km), was supplemented with a regularity of suburban ensembles` layout and multi-kilometer rectilinear axes – roads connecting them. Some of the roads had the length of several hundred km (such as the road from Moscow to St. Petersburg built in 1706-1718, that was as long as nearly 700 km). Huge suburban forest-park and natural-landscape spaces between palace and park ensembles were united as star-patterned compositions. This historically created agglomeration is deservedly included in the List of Objects of the World Heritage, but so far it has not received a unambiguous understanding of its uniqueness and needs a considerable effort in searching new individual ways of the historical heritage preservation. On the basis of the archive records, the contribution presents an analysis of regularities of consecutive and purposeful transformation of the historical rural settlements system existing up to the foundation of St. Petersburg into the capital St. Petersburg agglomeration of regular type.
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Dietz, Albert. "Liquefied Gaseous Fuels (LGF) Spill Test Facility Program." Journal of the IEST 28, no. 5 (September 1, 1985): 34–39. http://dx.doi.org/10.17764/jiet.1.28.5.y637824226530742.
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The Department of Energy (DOE) is constructing a facility at the Nevada Test Site (NTS) which will be capable of the rapid release of large quantities of cryogenic or pressurized flammable or toxic materials. The facility is being built in concert with and in response to the needs of many industrial and governmental organizations. The facility is designed to satisfy the need for information for risk assessment, emergency response, regulation, plant design, plant siting, and hazard mitigation. It will be capable of spilling up to 200 m3 (53,000 gal) of cryogenic fluids such as Liquefied Natural Gas (LNG) or refrigerated ammonia at rates between 5 and 100 m3/min (1,000-26,000 gpm). In addition, up to 90 m3 (24,000 gal) of ambient temperature materials such as Liquefied Petroleum Gas (LPG) or chlorine, with pressures up to 2,000 kpa (300 psi), can be released at rates between 2 and 20 m3/min (500-5,000 gpm). An extensive sensor and data acquisition system is available to acquire data on spill characteristics such as rate, volume, temperature, and pressure; downwind gas concentration and aerosol characteristics; meteorological parameters; and blast or fire effects. The Frenchman Flat area of the NTS provides a uniquely favorable environment in which to perform large-scale atmospheric dispersion tests. Steady winds from the southwest occur with great regularity during the summer months for a variety of atmospheric stability conditions. Large-scale tests with toxic materials are possible because only limited access, federally controlled land is present for some 60 km (37 mi) downwind.
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Schille, Joerg, Jose R. Chirinos, Xianglei Mao, Lutz Schneider, Matthias Horn, Udo Loeschner, and Vassilia Zorba. "Formation of Nano- and Micro-Scale Surface Features Induced by Long-Range Femtosecond Filament Laser Ablation." Nanomaterials 12, no. 14 (July 20, 2022): 2493. http://dx.doi.org/10.3390/nano12142493.
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In this work, we study the characteristics of femtosecond-filament-laser–matter interactions and laser-induced periodic surface structures (LIPSS) at a beam-propagation distance up to 55 m. The quantification of the periodicity of filament-induced self-organized surface structures was accomplished by SEM and AFM measurements combined with the use of discrete two-dimensional fast Fourier transform (2D-FFT) analysis, at different filament propagation distances. The results show that the size of the nano-scale surface features increased with ongoing laser filament processing and, further, periodic ripples started to form in the ablation-spot center after irradiation with five spatially overlapping pulses. The effective number of irradiating filament pulses per spot area affected the developing surface texture, with the period of the low spatial frequency LIPSS reducing notably at a high pulse number. The high regularity of the filament-induced ripples was verified by the demonstration of the angle-of-incidence-dependent diffraction of sunlight. This work underlines the potential of long-range femtosecond filamentation for energy delivery at remote distances, with suppressed diffraction and long depth focus, which can be used in biomimetic laser surface engineering and remote-sensing applications.
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Erb, Denise J., Kai Schlage, and Ralf Röhlsberger. "Uniform metal nanostructures with long-range order via three-step hierarchical self-assembly." Science Advances 1, no. 10 (November 2015): e1500751. http://dx.doi.org/10.1126/sciadv.1500751.
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Large-scale nanopatterning is a major issue in nanoscience and nanotechnology, but conventional top-down approaches are challenging because of instrumentation and process complexity while often lacking the desired spatial resolution. We present a hierarchical bottom-up nanopatterning routine using exclusively self-assembly processes: By combining crystal surface reconstruction, microphase separation of copolymers, and selective metal diffusion, we produce monodisperse metal nanostructures in highly regular arrays covering areas of square centimeters. In situ grazing incidence small-angle x-ray scattering during Fe nanostructure formation evidences an outstanding structural order in the self-assembling system and hints at the possibility of sculpting nanostructures using external process parameters. Thus, we demonstrate that bottom-up nanopatterning is a competitive alternative to top-down routines, achieving comparable pattern regularity, feature size, and patterned areas with considerably reduced effort. Intriguing assets of the proposed fabrication approach include the option for in situ investigations during pattern formation, the possibility of customizing the nanostructure morphology, the capacity to pattern arbitrarily large areas with ultrahigh structure densities unachievable by top-down approaches, and the potential to address the nanostructures individually. Numerous applications of self-assembled nanostructure patterns can be envisioned, for example, in high-density magnetic data storage, in functional nanostructured materials for photonics or catalysis, or in surface plasmon resonance–based sensing.
Books on the topic "Scale-up regularity"
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Isett, Philip. Accounting for the Parameters and the Problem with the High-High Term. Princeton University Press, 2017. http://dx.doi.org/10.23943/princeton/9780691174822.003.0019.
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This chapter provides a list of all the parameters and summarizes their current status while also discussing the problem with the High–High term. These include the parameters used to mollify the Reynolds stress in space and along the coarse scale flow, the parameter used to mollify the velocity field in space, the lifespan parameter, and the parameter used to make sure the phase functions are high frequency. In addition to the High–High term, the chapter considers the Transport term, which becomes large when a short lifespan is chosen. It also shows how the Transport term could be made to have the size required for regularity up to 1/3.
Book chapters on the topic "Scale-up regularity"
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Jucker, Rolf. "How to Raise the Standards of Outdoor Learning and Its Research." In High-Quality Outdoor Learning, 123–32. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-04108-2_6.
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AbstractThe review summarised here found that there is no comprehensive or regular (repeated) survey of the scale of outdoor learning in the UK. There are some studies of specific outdoor learning activities (e.g., of particular types, or in particular parts of the UK). In these, some authors express concern about barriers to delivering outdoor learning and a reduction in outdoor learning. With respect to the current research base, the review revealed that the quality of research methodology and design is overall rather limited. The studies analysed for the review provide extensive evidence of the effects of outdoor learning. However, the effect sizes of outdoor learning are mostly small to moderate. Most robust effects found are non-educational outcomes such as attitudes, skills and relationship to nature. Educational attainment is seriously under-researched, so there is a mismatch between research topics and the pressure for schools to reach educational outcomes. Longer programmes seem more effective and strong benefits are associated with well-designed preparatory and follow-up work. Practitioners mostly lack a mental model or theory of change for their educational intervention, which severely limits what can be reasonably said about its impact. Recommendations therefore include for practitioners to develop theories of change, for researchers to create a system to regularly capture high quality baseline data and for all actors concerned to prioritise important research topics and develop an open access culture.
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Peralta, Dan-el Padilla. "Temple Construction." In Divine Institutions, 31–78. Princeton University Press, 2020. http://dx.doi.org/10.23943/princeton/9780691168678.003.0002.
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This chapter presents a quantitative reconstruction of temple building during the fourth and third centuries, evaluating the scale of the monumental intervention into Rome's topography and the labor demands that it triggered. The temple constructions of the middle Republic exemplify a social commitment to smallness — repetitive smallness. When it comes to size, no temple that was erected during the middle Republic compares to the Capitoline Temple of Jupiter Optimus Maximus. Yet what the middle Republic lacks in the size of its temple foundations it makes up for in their sheer number, and in the rhythms that the regularity of their construction imposed on Roman civic life. The chapter then explores the political and economic inputs that had to be coordinated for temples to rise from the ground. It also considers the possibility that the relatively minimal upfront costs of temple construction were a means of veiling the far greater costs of secular monumental projects: the aqueducts and roads that from the period of the Samnite Wars engineered a profound and lasting revolution in how Romans and non-Romans interacted with and conceived the res publica.
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Antonio Mayoral Chavando, José, Valter Silva, Danielle Regina Da Silva Guerra, Daniela Eusébio, João Sousa Cardoso, and Luís A.C. Tarelho. "Review Chapter: Waste to Energy through Pyrolysis and Gasification in Brazil and Mexico." In Gasification [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98383.
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Millions of tons of forest residues, agricultural residues, and municipal solid waste are generated in Latin America (LATAM) each year. Regularly, municipal solid waste is diverted to landfills or dumpsites. Meanwhile, forest and agricultural residues end up decomposing in the open air or burnt, releasing greenhouse gases. Those residues can be transformed into a set of energy vectors and organic/chemical products through thermochemical conversion processes, such as pyrolysis and gasification. This book chapter provides information on current examples of gasification on large scale in the world, which typically operate at 700°C, atmospheric pressure, and in a fluidized bed reactor. The produced gas is used for heat and energy generation. Whereas pyrolysis at a large scale operates around 500°C, atmospheric pressure, and in an inert atmosphere, using a fluidized bed reactor. The produced combustible liquid is used for heat and energy generation. The decision of using any of these technologies will depend on the nature and availability of residues, energy carries, techno-socio-economic aspects, and the local interest. In this regard, the particular situation of Brazil and Mexico is analyzed to implement these technologies. Its implementation could reduce the utilization of fossil fuels, generate extra income for small farmers or regions, and reduce the problem derived from the accumulation of residues. However, it is concluded that it is more convenient to use decentralized gasification and pyrolysis stations than full-scale processes, which could be an intermediate step to a large-scale process. The capabilities of numerical models to describe these processes are also provided to assess the potential composition of a gas produced from some biomass species available in these countries.
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Darwall-Smith, Robin. "Theology and Religion in Georgian Oxford." In History of Universities: Volume XXXV / 1, 83–108. Oxford University PressOxford, 2022. http://dx.doi.org/10.1093/oso/9780192867445.003.0005.
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Abstract Theology was pervasive throughout Georgian Oxford: its members had to attend services in College chapels, and most Fellows of Colleges had to take holy orders and study theology. Yet Georgian theology suffers from Victorian disdain for its perceived dry dogmatism. This chapter therefore aims to provide some reappraisal. What to a Victorian seem dry and unemotional would to many Georgians appear seemly and restrained; to them moderation was a virtue, and enthusiasm something to fear. The importance of preaching has been underrated in Georgian Oxford: clerics were expected to preach regularly, and a good preacher could hope to win a reputation and even preferment. Sermons were regularly printed, exchanged and used—and occasionally sent up. The University Press, often written off during this period as a time of torpor, in fact published many sermons during this time, mainly on commission. On a larger scale, much of Georgian Oxford’s greatest scholarly work, such as that by Lowth, Kennicott and Routh, was done in theology rather than classics. As regards varieties of belief, Oxford’s most famous religious ‘export’, Methodism, in fact set down few roots there, and arguably the less well known Hutchinsonians proved more influential. Earlier in the century there had been some dangerously unorthodox thinkers in Oxford, most notably the Deist Matthew Tindal, but they proved less influential in the long run. It is therefore important not to forget the orthodoxy of most Oxford clerics, and the training which they received, especially in the later part of the century. Edward Bentham’s inaugural lecture as Regius Professor of Divinity is discussed as an example of this training.
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Tinker, Peter B., and Peter Nye. "Solute Transport and Crop Growth Models in the Field." In Solute Movement in the Rhizosphere. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195124927.003.0015.
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In this chapter we deal with vegetation growing in the field. This introduces new and challenging questions of scale and heterogeneity, in time and space, of the environment in which plants grow. It builds on the concepts and methods explained in earlier chapters, especially the movement of water and solutes (chapters 2, 3 and 4) and the distribution of roots (chapter 9) in field soils. In some cases, it requires changes and simplifications in the methods that we have used earlier. The problems of dealing with water and nutrient movement and uptake at the field scale are discussed first. The modelling approach that we developed in the earlier chapters of this book, up to the end of chapter 10, logically resumes at section 11.3. This covers both uptake models and the more complex combined crop growth and uptake models that simulate the main interactions with the environment. This chapter considers increasingly complex systems: first, uniform monocultures, including models of a ‘green leaf crop’, a root crop, a cereal, and a tree crop. At this level, the presence of weeds or groundcover is deliberately ignored. Interspecies competition is included later, with vegetation composed of more or less regularly spaced plants of more than one species. This occurs in many agricultural systems, such as mixtures of forage species and agroforestry systems. The competition processes become even more complicated where there is no spatial symmetry, and models of crop/weed mixtures, grass/legume mixtures, and planted woodlands are used as examples. Progress with crops has been more rapid because of their more regular structure, so we deal mainly with these, but we believe that similar ideas will be applied to natural vegetation also, and this is discussed in section 11.5. Most of these models have a water submodel, or, if not, one could be added. As the physical basis is normally rather similar for all water models, one model for water uptake is explained in some detail (section 11.1.2), but elsewhere water uptake is dealt with very briefly. For each model, the preferred order of discussion is water; growth, including economic yield; nitrogen; potassium; phosphorus; and other nutrients, unless the logic of the subject demands a different order.
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Pörtner, Hans-O., and Magda Gutowska. "Effects of Ocean Acidification on Nektonic Organisms." In Ocean Acidification. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199591091.003.0013.
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The average surface-ocean pH is reported to have declined by more than 0.1 units from the pre-industrial level ( Orr et al. 2005 ), and is projected to decrease by another 0.14 to 0.35 units by the end of this century, due to anthropogenic CO2 emissions (Caldeira and Wickett 2005 ; see also Chapters 3 and 14). These global-scale predictions deal with average surface-ocean values, but coastal regions are not well represented because of a lack of data, complexities of nearshore circulation processes, and spatially coarse model resolution (Fabry et al. 2008 ; Chapter 3 ). The carbonate chemistry of coastal waters and of deeper water layers can be substantially different from that in surface water of offshore regions. For instance, Frankignoulle et al. ( 1998 ) reported pCO2 (note 1) levels ranging from 500 to 9400 μatm in estuarine embayments (inner estuaries) and up to 1330 μatm in river plumes at sea (outer estuaries) in Europe. Zhai et al. (2005) reported pCO2 values of > 4000 μatm in the Pearl River Estuary, which drains into the South China Sea. Similarly, oxygen minimum layers show elevated pCO2 levels, associated with the degree of hypoxia (Millero 1996). These findings suggest that some coastal and mid-water animals, both pelagic and benthic, are regularly experiencing hypercapnic hypercapnic conditions (i.e. elevated pCO2 levels), that reach beyond those projected in the offshore surface ocean. These organisms might, therefore, be preadapted to relatively high ambient pCO2 levels. The anthropogenic signal will nonetheless be superimposed on the pre-existing natural variability. These phenomena lead to the question of whether future changes in the ocean’s carbonate chemistry pose a serious problem for marine organisms. Those with calcareous skeletons or shells, such as corals and some plankton, have been at the centre of scientific interest. However, elevated CO2 levels may also have detrimental effects on the survival, growth, and physiology of marine animals more generally (Pörtner and Reipschläger 1996; Seibel and Fabry 2003; Fabry et al. 2008; Pörtner 2008; Melzner et al. 2009a).
Conference papers on the topic "Scale-up regularity"
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Zoccola, Paul J. "Excitation by Flow Over an Obstructed Opening." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33374.
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The effect on flow-induced cavity resonance of the presence of an obstruction, or a grid made up of regularly spaced obstructions, in the cavity opening is considered. The presence of a single obstruction or of a grid generally alters the flow so that the excitation occurs on the smaller length scale created by the obstruction. However, discussion of resonant excitation on the length scale encompassing the obstructions has not been found in the literature. For this study, measurements of cavity pressure due to flow over a cavity with obstructions or grids of varying dimensions in the opening were made. Measurements of the flow field around a single obstruction were also made. The cavity pressure measurements show that flow over an opening with a grid does result in the occurrence of classical resonant excitation at the large length scale. The frequency of the excitation and the amplitude of the response at the large length scale are reduced, depending on the dimensions of the obstruction. Flow field results show the effects that an obstruction has on the flow, including effects on the vortex convection velocity and the energy production distribution.
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Khan, Abdul Muqtadir, Denis Emelyanov, Rostislav Romanovskii, and Olga Nevvonen. "Advanced Modeling Capability to Enhance Near-Wellbore and Far-Field Bridging in Acid Fracturing Field Treatments." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206255-ms.
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Abstract Different applications of fracture bridging and diversion are used regularly in carbonate acid fracturing without an in-depth understanding of the physical phenomena that dominate the processes involved in the bridging and diversion process. The extension of modeling capabilities in conjunction with yard-scale and field-scale experiences will increase our understanding of these processes. A robust multimodal diversion pill and polylactic acid fiber-laden viscous acid were utilized for near-wellbore and far-field bridging, respectively. Numerous field treatments demonstrated the uncertainty of achieving effective diversion. An existing multiphysics model was extended to develop functionalities to model diversions at different scale. Extensive laboratory testing was conducted to understand the scale of bridging and diversion mechanisms. Finally, a bridging yard test was designed, and field case studies were used to integrate all the branches. Field cases showed a diversion pressure up to 4,000 psi depending on perforation strategy, pill volume, and pill seating rate. Correlations showed the interdependence of multiple parameters in diversion processes. The field studies motivated modeling capabilities to simulate the critical diversion processes at high resolution and quality. The model simulates diverting agents that reduce leakoff in the fracture area and their effects on fracture geometry. The approach considers the acid reaction kinetics coupled with geomechanics and fluid transport. Different diverting agent concentrations required for bridging can be modeled effectively. A yard test was designed to confirm the integrity of the pill material through completion valves (minimum inside diameter 9.5 mm) and analyzed with high-resolution imaging. All the theoretical, mathematical, and numerical findings from modeling were integrated with laboratory- and yard-scale experimentation results to develop and validate near-wellbore and far-field diversion modeling. Analytical correlations were formulated from injection rate, particulate material concentration, pill volumes, fracture width, etc., to incorporate and validate the model. This study enhances understanding of the different diversion mechanisms from high-fidelity theoretical modeling approach integrated with a practical experimental view at laboratory and field scale. Current comprehensive research has significant potential to make the modeling approach a reliable method to develop tight carbonate formations around the globe.
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Bablitch, Douglas, Rupeet Malhotra, Rick Frappa, and Scott Warner. "Design and Installation of a Permeable Treatment Wall to Passively Remove Strontium-90 From Groundwater at a Former Commercial Nuclear Fuel Reprocessing Facility in New York." In ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2011. http://dx.doi.org/10.1115/icem2011-59292.
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A permeable treatment wall (PTW) was designed and installed at the West Valley Development Project (WVDP), a former commercial nuclear fuel reprocessing facility in New York, to passively remove and contain the expansion of strontium-90 (Sr-90) in the site groundwater. AMEC engineers and geologists have collaborated with researchers at the State University of New York at Buffalo (UB) and West Valley Environmental Services LLC to design and install an approximately 260 meter (860-foot) long by 0.9 meter (3-foot) thick zone of granular zeolite (a natural aggregate composed of approximately 85 percent of the mineral clinoptilolite) that will remove Sr-90 in situ from groundwater through ion-exchange reactions. The PTW was designed to meet the functional objectives for up to 20 years; performance monitoring will be conducted regularly and will be used to assess the lifetime efficacy of the PTW. The zeolite-filled PTW was the selected remedial alternative due to its hydraulically passive operations and lower life-cycle cost over other more traditional active treatment alternatives such as pump and treat. The design relied heavily on detailed site characterization of site soils and groundwater conditions and bench and pilot scale evaluations of various zeolite materials. The design specified the use of a one-pass trencher to simultaneously remove unconsolidated aquifer material composed of glaciofluvial-derived silt, sand, and gravel from ground surface to depths up to approximately 9 meters (30 feet) and replace the excavated zone with zeolite along the entire alignment while keying the PTW at least 0.9 meter (3 feet) into the underlying low-permeability glacial till. Several technology demonstrations were conducted to assess implementability using the one-pass trencher prior to completing the final design. During full-scale implementation, excavated sediment was conveyed directly into a prefabricated containment structure pending final disposition. The passive design provides a cost effective and sustainable alternative for treatment of Sr-90 and potentially other exchangeable radioactive ions in groundwater where these constituents migrate in unconsolidated materials.
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Andersen, Pål Østebø. "Extended Fractional Flow Theory for Steady State Relative Permeability Experiments With Capillary End Effects – Transient Solutions and Time Scales." In 2022 SPWLA 63rd Annual Symposium. Society of Petrophysicists and Well Log Analysts, 2022. http://dx.doi.org/10.30632/spwla-2022-0031.
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Steady state core flooding experiments are regularly performed for estimation of relative permeability functions which are key inputs for simulation of multiphase flow in porous media. Such tests can be time demanding, thus it is valuable to find the relation between fluid flow properties, injection conditions and the time for the desired measurements of stabilized average saturation and pressure drop to be obtained. The phases we consider are oil and water but could be any immiscible phases. An injection condition is specified by the total injected volumetric rate Qt and the fraction F of the total rate due to water. At steady state at these injection conditions there is no change with time in pressures or saturations. We consider the transition from the steady state of one injection condition, when one or both of Qt and F are changed, until the steady state of the new injection conditions have developed. The spatial saturation distributions at steady state are known analytically from solutions derived by Andersen (2021a). From the method of characteristics, a solution is constructed to describe the velocity of each saturation traveling between the two steady state profiles. The velocity for each saturation is estimated based on an effective fractional flow function that combines contributions of advective and capillary forces to one saturation dependent function. The solution allows us to interpret experimental data, forecast the time scale of the tests at each condition and suggest a more optimal scheme to conduct the experiments as they proceed. Assuming an imbibition setup, the solution implies frontal displacement and short time scales when increasing the fraction F where the flow function is convex. This is the case at sufficiently low saturations. At higher saturations the flow function becomes concave and the saturations travel with individual speeds proportional to the flow function derivative. The time scale is limited by the slowest saturation. At high saturations the saturation speed approaches zero giving an infinite time scale. In a water-wet case, capillary end effects shift the saturation profiles up to include slower high saturations and increase the time scale. In an oil-wet case the saturation profiles are shifted down such that the slowest saturations are faster or travel a shorter distance, thus reducing the time scale. The model is validated by comparing the proposed analytical solution with numerical solutions.
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Mudde, Robert F. "Gravity Driven Bubbly Flows: The Role of Vortical Structures." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45672.
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Gravity driven bubbles are found in many industrial applications. Two typical reactors are the bubble column, in which the liquid is stagnant and the air lift reactor in which the liquid circulates, under the action of gravity, through the reactor. These reactors are attractive for a number of reasons: they have no moving parts and are thus low in maintenance; the size can be enormous (diameters of several meters, heights of tens of meters) allowing large volume flows to be processed; good mixing and heat transfer characteristics, etc. Our knowledge about the structure of the flow induced is rather limited. This makes design, fine tuning of operation and scale up still difficult. The two-phase flow in a bubble reactor is complicated. In the bubble columns, the liquid exhibits a large-scale circulation in a time averaged sense, with upward flow in the center and downward flow in the wall region. The first reliable data on this large-scale circulation date back to the work of Hills (174). In 1984, Franz et al. reported on the motion of what was later called vortical structures, eddy like structures (with sizes on the order of the column diameter) that move through the bubbly mixture. These vortical structures have been research more extensive during the last ten year by e.g. Fan and coworkers, Dudukovic and coworkers and Mudde & Van den Akker. The structures are found for a wide range of gas fractions, ranging from a few percent to well above 20%. The vortical structures seem to be a universal feature of the gravity driven bubble flows as they were also found in air lift reactors. For this reactor it has been reported that the liquid flow behaves more or less like the superposition of a net liquid flow and the complicated flow features found in the bubble column. The similarities will be high lighted. The vortical structures have important consequences for e.g. the (pseudo-)turbulence and the mixing in the bubbly flow. In 2-dimensional equipment they appear very regular and a separation between the low frequency fluctuations and the high frequency ‘turbulence’ is easily made. However, in 3-dimensional columns the situation is more complicated. LDA data show that the vortical structures are still responsible for a the occurrence of low frequency oscillations (on the order of 0.1Hz), but they are no longer appearing regularly and a separation of frequencies is no longer possible. Finally, the newest experiment seem to show that the vortical structures can be suppressed up to gas fraction of (at least) 10%. These new experiments suggest that the gravity driven bubbly flow is not inherently unstable, but rather sensitive to the conditions at the gas inlet.
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Chen, Zhaohua, Bill Jefferies, Paul Adlakha, Bahram Salehi, and Des Power. "Automatic Linear Disturbance Footprint Extraction Based on Dense Time-Series Landsat Imagery." In 2014 10th International Pipeline Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/ipc2014-33172.
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Linear disturbances from the construction of pipelines, roads and seismic lines for oil and gas extraction and mining have caused landscape changes in Western Canada; however these linear features are not well recorded. Inventory maps of pipelines, seismic lines and temporary access routes created by resource exploration are essential to understanding the processes causing ecological changes in order to coordinate resource development, emergency response and wildlife management. Mapping these linear disturbances traditionally relies on manual digitizing from very high resolution remote sensing data, which usually limits results to small operational area. Extending mapping to large areas is challenging due to complexity of image processing and high logistical costs. With increased availability of low cost satellite data, more frequent and regular observations are available and offer potential solutions for extracting information on linear disturbances. This paper proposes a novel approach to incorporate spectral, geometric and temporal information for detecting linear features based on time series data analysis of regularly acquired, and low cost satellite data. This approach involves two steps: multi-scale directional line detection and line updating based on time series analysis. This automatic method can effectively extract very narrow linear features, including seismic lines, roads and pipelines. The proposed method has been tested over three sites in Alberta, Canada by detecting linear disturbances occurring over the period of 1984–2013 using Landsat imagery. It is expected that extracted linear features would be used to facilitate preparation of baseline maps and up-to-date information needed for environmental assessment, especially in extended remote areas.
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Chhabra, Narender K., and James R. Scholten. "All Angle-of-Attack Hydrodynamic Model for Underwater Vehicles Validated by Tank Test Data." In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-1256.
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Abstract An underwater vehicle’s design and operation requires prediction of its performance at various velocities and angles-of-attack or of sideslip. Traditional models based upon headway motion at substantial speeds use coefficient-based equations of motion. Simulations based upon these coefficients are not valid for hover, low speeds, or high angles-of-attack or of sideslip. To remedy this severe limitation, nonlinear hydrodynamic models valid for all attitudes of underwater vehicles have been developed and are presented here. These models are derived from the physics of hydrodynamic phenomena. Forces and moments for the total vehicle are obtained by relying on body-buildup techniques. For the vehicle’s hull, the models are profile drag, lift, crossflow force, and added mass. For appendages such as fins, the models are lift and drag when unstalled, normal force when stalled, transition between unstalled and stalled conditions, and hull interference effects. Whenever the equations contain parametric coefficients such as added-mass, drag, and lift, values are specified for all angles-of-attack and sideslip with a minimal use of empirical look-up tables. These models represent the state-of-the-art in low speed hydrodynamics at all angles-of-attack. The hydrodynamic models presented here have been improved and validated by analysis and comparison with test data. Sub-scale versions of two different vehicles have been tested in tow-tanks at all angles-of-attack. The models have been implemented in a C language computer code which runs at high speed with no iteration required. This code is utilized regularly in faster-than-real-time vehicle performance simulations.
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Al-Busaidi, Salim, Qasim Hinaai, Rajeev Ranjan Kumar, Ying Ru Chen, Redha Hasan Al Lawatia, Dai Guo Yu, Amit Kumar Singh, and Surej Kumar Subbiah. "Successful Drilling Campaign of High Angled Wells in Tight Gas Fields using 3D Geomechanical Modeling and Real-Time Monitoring." In SPE/IADC Middle East Drilling Technology Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/202123-ms.
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Abstract The field under study is witnessing an increasing trend in NPT events while drilling vertical wells through high stressed shale formations and the underlying depleted sandstone reservoir in the same section. The field has multiple sets of faults with lateral variations in stress azimuth and completion quality with the regional strike-slip regime. High angled wells are being planned to increase reservoir coverage and perform hydro fracturing. This paper provides details of capturing stress regime variation along with the effects of depletion in offset wells and identify suitable azimuth of planned well with drilling risks through a 3D geomechanical study. Comprehensive 1D mechanical earth models are constructed using open hole logs, core data and available hydro-fracturing results for wells in the field. Rock mechanical properties have been calibrated at well scale as per core data. Poro-elastic horizontal strain method at well scale indicates a strike-slip to reverse fault variation with significant horizontal stress anisotropy as evident from the closure pressure range of 9,500 psi to 12,500 psi. 3D numerical geomechanical model has been constructed considering structural discontinuities, rock mechanical properties and formation pressure to estimate the principal stresses. Stress direction data from dipole sonic measurements and breakout azimuth from borehole image logs are used for calibration in 3D model incorporating faults. Stress path for depletion has been estimated. Results from the study suggested change in casing policy specifically to have a liner isolating the overburden formations where more than 800 m should be drilled prior to entering the depleted reservoir formation. 3D geomechanical analysis reckons that the mud weight should be in the range of 12.7 kPa/m to 13.1 kPa/m during building up the well profile at 80 deg inclination in overlying shale while 1D study suggesting a range of 13.2 kPa/m to 13.7 kPa/m. Along well path at 80deg to 90deg deviation within reservoir layer toward minimum horizontal stress azimuth, mud weight requirement was found to be much lower at 11.5 kPa/m to 12.1 kPa/m. Apart from mud weight, BHA and chemicals were optimized to avoid differential sticking and better hole cleaning for respective sections. Actual mud weight used was in the range of 12.8 kPa/m to 13.1 kPa/m for building up with no torque and drag issue while running liner and BHA trips. Mud weight was maintained in the range of 11.5 kPa/m to 11.8 kPa/m in the horizontal section with minimum breakouts and smoother hole condition. Cuttings shape and size analysis were performed regularly to check well behavior and manage downhole pressure higher than shear failure limit. Using 3D Geomechanical study and continuous monitoring of drilling parameters in near real-time, the buildup and reservoir sections have been drilled within schedule with no major NPT event and saved at least one week of rig days.
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Wildash, Clint, and Steve Webster. "Dual Process Welding of Steel Plate." In ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/omae2002-28587.
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Large scale fabrication and welding industries, such as those involved in offshore construction, are continuously striving to improve productivity, while maintaining quality levels required by the applicable design codes and standards. To achieve this, new improved welding technologies are regularly being evaluated. One area of development is to combine different welding processes to produce a welded joint exhibiting properties and productivity benefits that neither process could achieve individually. One promising combination is the use of both arc and laser beam welding for products such as pipeline. The welding procedure development work described, was carried out in two stages. Stage 1 (discrete dual processing) investigated the production of a welded joint using both arc and laser welding at separate times. The welds produced for this work, demonstrate that significant increases in welding speed are achievable in comparison to using either process individually. Stage 2 (simultaneous dual processing) investigated arc and laser welding of the joint at the same time from opposing plate faces, with the laser weld pool trailing the arc weld pool so that the former was positioned in the area of highest preheat temperature. The use of arc preheat significantly reduced the hardness of the laser welds to more acceptable levels. The main disadvantage identified for both stages of work was that fit up of the laser welded part of the joint needed to be good to accommodate the autogenous laser weld. Both Stages were shown to be capable of producing full penetration welds at higher productivity than using either process individually. It has been demonstrated that for 19 mm thick plate, an overall doubling of welding speed could be achieved using dual process as opposed to submerged arc welding, which is currently widely used to weld fabricated products such as pipeline. Future work to be carried will include extensive destructive testing on the welds to assess the benefits of Stage 1 and 2, which will be reported in another paper.
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Kaouche, Salim, Pawan Agrawal, Osama Keshtta, Yann Bigno, Mohamed Elhassan, Shaikh Rakkad Al Ameri, Abdullah Al Ghailani, and Mohamed Saidoun. "Enhanced Approach for Asphaltene Risks Study to Unlock Hundred Millions Barrels Stranded Oil." In ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/211318-ms.
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Abstract Severe Asphaltene deposition is encountered in some wells drilled in newly developed reservoirs of one of Abu Dhabi's giant offshore assets (Field AD), and for the first time, full well plugging with Asphaltene is experienced in the field. While successful curative clean up treatments are regularly made, the relatively high intervention frequency (once every month per well) has impeded the full-scale development of these reservoirs. This study shows how understanding the mechanism of Asphaltene stability/instability in field conditions can unlock the production of under-developed reservoirs (with hundred millions barrels of OIP) by anticipating and considering preventive measures during the design of new wells to limit Asphaltene deposition. In order to prevent the occurrence of Asphaltene deposition from reservoir formation to surface level, a Flow Assurance study was launched by the operating company with close support from the international partner. The objective was to determine the Asphaltene Deposition Phase Envelope (ADE) of the reservoir fluid by measuring onset pressures with Visual (High Pressure ‘HP’ Microscope) and Near Infrared Solid Detection System (SDS) as a function of 2 main variables: Different temperatures to investigate Asphaltene risks over the oil production pathway (at reservoir formation, and from wellbore to surface facilities) & Different Gas compositions to investigate the effect of rich Gas-Cap gas and injected lean gas on the Asphaltene stability. Also, the segregation of the nature of Asphaltenes within the reservoir has been investigated by using the experimental approach named ‘ASCI (Asphaltene Solubility Class Index) experiment’ introduced by the international partner (SPE-164184) to rank Asphaltenes’ solubility with atmospheric dead oil samples taken in different locations. In addition to that, 2 more experiments were performed: Organic – Inorganic test on solid sample to determine the composition and the nature of the solid deposit (whether it is Asphaltene or other type of depositions) & SARA analysis on atmospheric samples. This paper presents the improved work-flow based on the collaboration of the local operator and the international partner, introduces the use of ASCI (Asphaltene Solubility Class Index) experiment and discusses the results of the study and its way-forward.