Academic literature on the topic 'Outer Regions (Imaginary place)'
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Journal articles on the topic "Outer Regions (Imaginary place)"
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Craven, Matt. "‘Other Spaces’: Constructing the Legal Architecture of a Cold War Commons and the Scientific-Technical Imaginary of Outer Space." European Journal of International Law 30, no. 2 (May 2019): 547–72. http://dx.doi.org/10.1093/ejil/chz024.
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Abstract In this article, I seek to develop the argument that the law of outer space, as it was to be developed during the 1960s and 1970s, configured outer space as a ‘commons’ in order to displace two prevailing ‘dystopic’ socio-technical imaginaries that were to be associated with the Cold War. One of these was that outer space might become a place of warfare – and, more specifically, a warfare of annihilatory proportions between the two main protagonists of the Cold War; the other, that it might be the object of ‘primitive accumulation’. Drawing upon the work of Herbert Marcuse, I argue that, whilst the nascent code of outer space visibly sought to repress both of these possibilities, it did so by bringing into play a particular ‘technological rationality’, in which each of these aversions were to reappear as sustaining configurations – as what might be called the rational irrationalities of a Cold War commons.
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Machado, Álvaro Manuel. "Culto do lúdico, heteronímia e espírito do lugar em Mário Cláudio / Worship of the playful, heteronomy and spirit of the place in Mario Cláudio." Revista do Centro de Estudos Portugueses 38, no. 59 (November 1, 2018): 11. http://dx.doi.org/10.17851/2359-0076.38.59.11-21.
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Resumo: Análise do romance Tiago Veiga – uma biografia, a partir de uma reflexão sobre o imaginário do espaço portuense e minhoto, concentrada predominantemente na metáfora da casa. Palavras-chave: imaginário; ficção portuguesa contemporânea; Mário Cláudio.Abstract: Analysis of the novel Tiago Veiga – a biography, based on the consideration of the imaginary that the regions of Porto and Minho carry, focused mainly on the metaphor of the house.Keywords: Imaginary; Contemporary Portuguese Fiction; Mario Claudio.
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CLEGG, E. J., T. J. RINGROSE, and J. F. CROSS. "SOME FACTORS AFFECTING MARITAL DISTANCES IN THE OUTER HEBRIDES." Journal of Biosocial Science 30, no. 1 (January 1998): 43–62. http://dx.doi.org/10.1017/s0021932098000431.
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Some factors affecting marital distances have been studied in two Outer Hebridean islands, Harris (843 marriages) and Barra (444 marriages), over the period 1855-1990. In each island marital distances fell before 1900, but then rose to their greatest values after the 1950s. Fishermen generally married at the shortest distances and men in land-based occupations at the longest. The depression in the fishing industry during the 1880s and early 1890s was associated with reductions in marital distances, especially among fishermen. In the different regions of Harris, marital distances were least in the south-east, where settlement was most dense, and greatest in the south-west where it was most sparse.When the association between marital frequencies and inter-settlement distances was studied, it was found that for Harris there was, overall, a trend to endogamous and short-distance marriage. However, this trend was only slight during 1955-90. For Barra a similar trend was found before 1955, but thereafter there appeared to be virtually no connection between marital frequency and inter-settlement distance. Thus the only constraint on marriage was the spatial distribution of settlements. In this situation the chances of random mating with respect to distance are maximised.Application of ‘Central Place’ theory suggested that only since 1946 can any tendency be detected to regard Tarbert in Harris or Castlebay in Barra as Central Places, at least as far as marriage is concerned. In each island the tendency appears to be limited to the settlements closest to the Central Place.
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López Fernández, R., R. M. González Delgado, E. Pérez, R. García-Benito, R. Cid Fernandes, W. Schoenell, S. F. Sánchez, et al. "Cosmic evolution of the spatially resolved star formation rate and stellar mass of the CALIFA survey." Astronomy & Astrophysics 615 (July 2018): A27. http://dx.doi.org/10.1051/0004-6361/201732358.
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We investigate the cosmic evolution of the absolute and specific star formation rate (SFR, sSFR) of galaxies as derived from a spatially resolved study of the stellar populations in a set of 366 nearby galaxies from the Calar Alto Legacy Integral Field Area (CALIFA) survey. The sample spans stellar masses from M⋆ ~ 109 to 1012M⊙ and a wide range of Hubble types. The analysis combines images obtained with the Galaxy Evolution Explorer (GALEX; far-ultraviolet and near-ultraviolet) and Sloan Digital Sky Survey (SDSS; u, g, r, i, z) with the 4000 Å break, Hβ, and [MgFe]′ indices measured from the CALIFA data cubes to constrain parametric models for the star formation history (SFH), which are then used to study the cosmic evolution of the SFR density (ρSFR), the sSFR, the main sequence of star formation (MSSF), and the stellar mass density (ρ⋆). Several SFH laws are used to fit the observational constrains. A delayed-τ model, SFR ∝ (t0 − t)exp(−(t0 − t)∕τ), provides the best results, in good agreement with those obtained from cosmological surveys. Our main results from this model are that (a) the mass currently in the inner (≤0.5 half-light radius, HLR) regions formed at earlier epochs than the mass in the outer (1–2 HLR) regions of galaxies. The time since the onset of the star formation is longer in the inner regions (t0 ~ 13−10 Gyr) than in the outer ones (t0 ~ 11−9 Gyr) for all the morphologies, while the e-folding timescale τ in the inner region is similar to or shorter than in the outer regions. These results confirm that galaxies of any Hubble type grow inside-out. (b) The sSFR declines rapidly as the Universe evolves, and faster for early- than for late-type galaxies, and for the inner than for the outer regions of galaxies. (c) The evolution of ρSFR and ρ⋆ agrees well with results from cosmological surveys, particularly with the recent results from the Galaxy And Mass Assembly (GAMA), the G10-Cosmological Evolution Survey (COSMOS), and the 3D Hubble Space Telescope (HST) survey. At low redshift, z ≤ 0.5, most star formation takes place in the outer regions of late spiral galaxies, while at z > 2, the inner regions of the progenitors of the current E and S0 are the main contributors to ρSFR. (d) Similarly, the inner regions of galaxies are the main contributor to ρ⋆ at z > 0.5, growing their mass faster than the outer regions, with a lookback time at 50% ρ⋆ of t50 ~ 9 and 6 Gyr for the inner and outer regions. (e) The MSSF follows a power law at high redshift, with the slope evolving with time but always remaining sub-linear, in good agreement with the Illustris simulation. (f) In agreement with galaxy surveys at different redshifts, the average SFH of CALIFA galaxies indicates that galaxies grow their mass mainly in a mode that is well represented by a delayed-τ model, with the peak at z ~ 2 and an e-folding time of ~3.9 Gyr.
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AGRAWAL, MAMTA, NEERU ADLAKHA, and K. R. PARDASANI. "FINITE ELEMENT MODEL TO STUDY THERMAL EFFECT OF UNIFORMLY PERFUSED TUMOR IN DERMAL LAYERS OF ELLIPTICAL SHAPED HUMAN LIMB." International Journal of Biomathematics 04, no. 02 (June 2011): 241–54. http://dx.doi.org/10.1142/s1793524511001362.
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In this paper, a two-dimensional finite element model has been developed to study thermal disturbances in elliptical shaped human limbs involving uniformly perfused tumor. The model incorporates the effect of important physiological parameters like blood mass flow rate, self-controlled metabolic activity and thermal conductivity in dermal regions. For tumor regions the uncontrolled rate of metabolic activity and abnormal rate of blood flow have been incorporated. The outer surface of the limb is exposed to the environment where heat loss takes place via the conduction, convection, radiation and evaporation. Appropriate boundary conditions have been framed. The model has been simulated using MATLAB 7.5 to obtain numerical results.
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Curir, Anna, Giuseppe Murante, Eva Poglio, and Álvaro Villalobos. "The dual nature of the Milky Way stellar halo." Proceedings of the International Astronomical Union 6, S271 (June 2010): 145–52. http://dx.doi.org/10.1017/s1743921311017558.
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AbstractThe theory of the Milky Way formation, in the framework of the ΛCDM model, predicts galactic stellar halos to be built from multiple accretion events starting from the first structure to collapse in the Universe.Evidences in the past few decades have indicated that the Galactic halo consists of two overlapping structural components, an inner and an outer halo. We provide a set of numerical N-body simulations aimed to study the formation of the outer Milky Way (MW) stellar halo through accretion events between a (bulgeless) MW-like system and a satellite galaxy. After these minor mergers take place, in several orbital configurations, we analyze the signal left by satellite stars in the rotation velocity distribution. The aim is to explore the orbital conditions of the mergers where a signal of retrograde rotation in the outer part of the halo can be obtained, in order to give a possible explanation of the observed rotational properties of the MW stellar halo.Our results show that the dynamical friction has a fundamental role in assembling the final velocity distributions originated by different orbits and that retrograde satellites moving on low inclination orbits deposit more stars in the outer halo regions and therefore can produce the counter-rotating behavior observed in the outer MW halo.
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Feast, M. W. "Post-AGB Variables and Stellar Mass-Loss." Symposium - International Astronomical Union 177 (2000): 207–16. http://dx.doi.org/10.1017/s0074180900002424.
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A brief review is given of the various types of star which are thought to be in the immediate post-AGB stage of evolution. The paper then concentrates on the properties of the RCB stars and particularly on the mass-loss process in these stars. It is suggested that grain formation takes place over the cool regions of giant convection cells in a super-Eddington outflow and in the form of small clouds or puffs. Attention is drawn to observations which suggest that grain formation in the outer atmospheres of Miras and other cool giants may also take place in puffs rather than in spherical shells. Evidence on the long-term variation of the circumstellar dust emission from RCB stars is summarized.
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Gerhard, Ortwin. "Star Formation in Virgo Intracluster Space." Symposium - International Astronomical Union 217 (2004): 480–85. http://dx.doi.org/10.1017/s0074180900198237.
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A number of candidate isolated compact HII regions have been discovered on combined Hα, [OIII], and broadband images in the Virgo cluster. One point-like source was spectroscopically confirmed as an HII region; this object is powered by a small starburst with an estimated mass of ~ 400 M⊙ and age of ~ 3 Myr. The object is located in the diffuse outer halo of NGC 4388, or could possibly be in intracluster space. Several resolved HII candidates are seen in the extended (~ 35 kpc) emission line region north-east of NGC 4388, perhaps triggered by the jet from the galaxy's nucleus. Star formation can thus take place far outside the main star forming regions of galaxies. The origin of the gas, the star formation, and some implications are discussed.
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Makrariya, Akshara, and Neeru Adlakha. "Two-dimensional finite element model to study temperature distribution in peripheral regions of extended spherical human organs involving uniformly perfused tumors." International Journal of Biomathematics 08, no. 06 (October 15, 2015): 1550074. http://dx.doi.org/10.1142/s1793524515500746.
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Temperature as an indicator of tissue response is widely used in clinical applications. In view of above a problem of temperature distribution in peripheral regions of extended spherical organs of a human body like, human breast involving uniformly perfused tumor is investigated in this paper. The human breast is assumed to be spherical in shape with upper hemisphere projecting out from the trunk of the body and lower hemisphere is considered to be a part of the body core. The outer surface of the breast is assumed to be exposed to the environment from where the heat loss takes place by conduction, convection, radiation and evaporation. The heat transfer from core to the surface takes place by thermal conduction and blood perfusion. Also metabolic activity takes place at different rates in different layers of the breast. An elliptical-shaped tumor is assumed to be present in the dermis region of human breast. A finite element model is developed for a two-dimensional steady state case incorporating the important parameters like blood flow, metabolic activity and thermal conductivity. The triangular ring elements are employed to discretize the region. Appropriate boundary conditions are framed using biophysical conditions. The numerical results are used to study the effect of tumor on temperature distribution in the region.
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Broad, Amanda J., and Jennifer G. DeLuca. "The right place at the right time: Aurora B kinase localization to centromeres and kinetochores." Essays in Biochemistry 64, no. 2 (May 14, 2020): 299–311. http://dx.doi.org/10.1042/ebc20190081.
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Abstract The fidelity of chromosome segregation during mitosis is intimately linked to the function of kinetochores, which are large protein complexes assembled at sites of centromeric heterochromatin on mitotic chromosomes. These key “orchestrators” of mitosis physically connect chromosomes to spindle microtubules and transduce forces through these connections to congress chromosomes and silence the spindle assembly checkpoint. Kinetochore-microtubule attachments are highly regulated to ensure that incorrect attachments are not prematurely stabilized, but instead released and corrected. The kinase activity of the centromeric protein Aurora B is required for kinetochore-microtubule destabilization during mitosis, but how the kinase acts on outer kinetochore substrates to selectively destabilize immature and erroneous attachments remains debated. Here, we review recent literature that sheds light on how Aurora B kinase is recruited to both centromeres and kinetochores and discuss possible mechanisms for how kinase interactions with substrates at distinct regions of mitotic chromosomes are regulated.
Books on the topic "Outer Regions (Imaginary place)"
Book chapters on the topic "Outer Regions (Imaginary place)"
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Blanco, María del Pilar, and Joanna Page. "Introduction." In Geopolitics, Culture, and the Scientific Imaginary in Latin America, 1–22. University Press of Florida, 2020. http://dx.doi.org/10.5744/florida/9781683401483.003.0001.
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The transnational transfers of ideas, technologies, materials, and people that have shaped the history of science in Latin America are marked, as in any region, by asymmetries of power. These are often replicated or even magnified in the narratives we have forged about that history. The journeys to Latin America of some of Europe’s most famous naturalists (Humboldt and Darwin, for example) are often depicted as the heroic overcoming by European science of savage local terrains and ways of life. Those epic explorers are recast, in other narratives, as the forerunners of (neo)colonial exploitation in the history of the ransacking of Latin America’s mineral riches to pay for European imperial ventures, repeated in the often-illegal plundering of the region’s dinosaur fossils to swell museum collections in Europe and North America. In such accounts, Latin America becomes the arena for European adventures, the testing ground for new scientific theories, or the passive victim of colonial profiteering, but rarely a place of innovation. It is certainly the case that over the centuries the flow of natural resources, data, and expertise from Latin America to more developed regions has generally been to the benefit of those regions and has not reduced an imbalance of power that dates back to the colonial period.
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Breindl, Yana. "From the Internet to the Corridors." In E-Politics and Organizational Implications of the Internet, 277–94. IGI Global, 2012. http://dx.doi.org/10.4018/978-1-4666-0966-2.ch016.
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European Institutions constitute venues of access for digital rights advocacy networks wishing to influence policy-making on issues of intellectual property rights, internet regulation, and the respect of civil rights in digital environments. Inspired by the hacker imaginary and free and open source principles, digital rights advocacy networks make intensive use of internet tools in order to organize and consolidate a collective identity and build a transnational public sphere. This study focuses on the “No Software Patents” campaign that aimed at influencing the directive on the patentability of computer-implemented inventions (2002-2005) and on the “Telecoms package” campaign, with the objective to remove “graduated response” amendments within a wider set of European telecommunication directives (2007-2009). By discussing the advocacy techniques – both online and offline – that were developed by this activist network, we provide an insight into power struggles that are currently taking place in Europe, but also in other regions of the world.
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Ferguson, Rex. "Secretions." In Identification Practices in Twentieth-Century Fiction, 119–58. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198865568.003.0004.
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DNA profiling, in which individual being is identified by its cellular structures, was first developed by the geneticist Alec Jeffreys in the 1980s. That this source of identity also forms the instructions through which living organisms are generated has complicated profiling’s place in the cultural imaginary of the late twentieth century. So, while profiling actually deals only in non-coding regions of the genome—matter often referred to as ‘junk DNA’—the significance of DNA as a substance of forensic analysis, in the late twentieth century imaginary, is its resonance as the apparent blueprint of existence. The notable features that this blurring of concepts brings about include a conceptualization of identity as a mass of information; notions to do with codes and coding; the presence of the body in the fluids which spill beyond its bounds; and a sense of the body as an archive of heredity and primitivism. In writing specifically about genetic research, Richard Powers’s The Gold Bug Variations (1991) serves a dual function in this chapter, as both an explicatory document and thematic example. But the more substantive analysis is reserved for the work of J. G. Ballard which, from its science fiction origins in novels such as The Drowned World (1962), through the controversial era of Crash (1973), to its trilogy of autobiographical texts (Empire of the Sun (1984), The Kindness of Women (1991), and Miracles of Life (2008)) articulates a form of identity that has close, though often oblique, affinities with all the most prominent features of DNA profiling.
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Supak, Stacy, Yu-Fai Leung, and Kevin Stewart. "Geotourism potential in North Carolina perspectives from interpretation at state parks." In Geotourism: the tourism of geology and landscape. Goodfellow Publishers, 2010. http://dx.doi.org/10.23912/978-1-906884-09-3-1063.
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Established in 1789 as the 12th state, North Carolina lies in the eastern seaboard of the United States of America between the Appalachian mountain range and the Atlantic Ocean. It is ranked 28th with respect to its size (139,389 square kilometers) and is the 10th most populated state with 9.1 million residents as of 2007 (US Census Bureau, 2008). The state was known for its farming/tobacco, textile and furniture industries, but substantial transformation has taken place over the past few decades and now the service industry, led by tourism, is the major part of the state’s economy (Gade, 2008). North Carolina has a unique and rich natural heritage which includes geological, landscape and biological resources that span three physiographic regions: the Appalachian Mountains, the Piedmont Plateau and the Coastal Plain (Horton et al., 1991; Stewart and Roberson, 2007). This natural heritage forms an integral part of the network of attractions enticing local, out-of-state and international tourists, who spent over $17 billion in the state and generated almost 200,000 jobs in 2007 (TIA, 2008). Indeed, North Carolina’s tourism promotional material (e.g., travel guides, brochures, websites) routinely highlight physical landscapes such as the Great Smoky Mountains, peaks like Pilot Mountain and geomorphic features such as waterfalls. Many of these geological features and attractions can be found in North Carolina’s state park (NCSP) system, which received over 12.8 million visitors in 2007– 2008 (Leung et al., 2009), with an estimated annual economic impact of $289 million to local economies (NCDPR, 2009). Landform-dependent recreation opportunities draw tourists to the state as well, with skiers enjoying the mountains and kitesurfers flocking to sandy beaches at the Outer Banks. In addition, mineral hunting has become a popular tourist activity with several independent contractors offering mine tours, cave tours and gemstone mining.
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Kovacs, William J. "Male Reproductive Function." In Textbook of Endocrine Physiology. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199744121.003.0012.
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The testes are the source of both germ cells and hormones essential for male reproductive function. The production of both sperm and steroid hormones is under complex feedback control by the hypothalamic-pituitary system. The testis consists of a network of tubules for the production and transport of sperm to the excretory ducts and a system of interstitial cells (called Leydig cells) that express the enzymes required for the synthesis of androgens. The spermatogenic or seminiferous tubules are lined by a columnar epithelium composed of the germ cells themselves as well as supporting Sertoli cells surrounded by peritubular tissue made up of collagen, elastic fibers, and myofibrillar cells. Tight junctions between Sertoli cells at a site between the spermatogonia and the primary spermatocyte form a diffusion barrier that divides the testis into two functional compartments, basal and adluminal. The basal compartment consists of the Leydig cells surrounding the tubule, the peritubular tissue, and the outer layer of the tubule containing the spermatogonia. The adluminal compartment consists of the inner two-thirds of the tubules containing primary spermatocytes and germ cells in more advanced stages of development. The base of the Sertoli cell is adjacent to the basement membrane of the spermatogenic tubule, with the inner portion of the cell engulfing the developing germ cells so that spermatogenesis actually takes place within a network of Sertoli cell cytoplasm. The mechanism by which spermatogonia pass through the tight junctions between Sertoli cells to begin spermatogenesis is unknown. The close proximity of the Leydig cell to the Sertoli cell with its embedded germ cells is thought to be critical for normal male reproductive function. The seminiferous tubules empty into a network of ducts termed the rete testis. Sperm are then transported into a single duct, the epididymis. Anatomically, the epididymis can be divided into the caput, the corpus, and the cauda regions. The caput epididymidis consists of 8 to 12 ductuli efferentes, which have a larger lumen tapering to a narrower diameter at the junction of the ductus epididymidis.
Conference papers on the topic "Outer Regions (Imaginary place)"
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Di´az, M. Cortina, H. Boye, I. Hapke, J. Schmidt, Y. Staate, and Z. Zhekov. "Flow Boiling in Mini and Microchannels." In ASME 2004 2nd International Conference on Microchannels and Minichannels. ASMEDC, 2004. http://dx.doi.org/10.1115/icmm2004-2367.
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Flow boiling heat transfer characteristics of water and hydrocarbons in mini and microchannels are experimentally studied. Two different test section geometries are employed; a circular channel with a hydraulic diameter of 1500 μm, and rectangular channels with height values of 300–700 μm and a width of 10mm. In both facilities the fluid flows upwards and the test sections, made of the nickel alloy Inconel 600, are directly electrically heated. Thus the evaporation takes place under the defined boundary condition of constant heat flux. Mass fluxes between 25 and 350 kg/(m2s) and heat fluxes from 20 to 350 kW/m2 at an inlet pressure of 0.3 MPa are examined. Infrared thermography is applied to scan the outer wall temperatures. These allow the identification of different boiling regions, boiling mechanisms and the determination of the local heat transfer coefficients. Measurements are carried out in initial, saturated and post-dryout boiling regions. The experimental results in the region of saturated boiling are compared with available correlations and with a physically founded model developed for convective boiling.
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Sedlmaier, Julia, Peter Habisreuther, Nikolaos Zarzalis, and Peter Jansohn. "Influence of Liquid and Gaseous Fuel on Lifted Flames at Elevated Pressure Stabilized by Outer Recirculation." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-25823.
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Lifting a flame from the flow generating nozzle to some distance apart has a wide variety of effects on the properties of the resulting combustion phenomenon. The reason of this influence is the generation of a non-reacting flow domain where mixing takes place prior to the combustion reaction. It is obvious that the quality of premixing that can be achieved strongly depends on the time that is given to flow and the intensity of the turbulence that is mixing fuel and air. The most important parameter that is characterizing this time is the size of the premixing zone quantified by the so called lift-off height (LOH). Additionally, when employing liquid fuel the lift-off of a flame provides time to achieve better pre-evaporation of the fuel. As a consequence, better mixing of fuel and air helps to avoid high temperature regions that may be a result from an inhomogeneous equivalence ratio distribution. From safety considerations a major advantage of this method compared to the application of a premixing duct is that the risk of hardware destruction by flame flash back can be eliminated. The current work extents the knowledge on lifted flames by the investigation of flames that are generated with an airblast atomizing nozzle that was designed to resemble systems close to application. Lifting of the flame is achieved applying a combination of swirling and non-swirling inflow ducts. A wide range of operating conditions as well as gaseous and liquid fuels are used to investigate their influence on the lift-off height. The lift-off height and location of the reaction zone was determined by means of chemiluminescence of OH* and it is shown, that the impact of pressure drop and preheating temperature on the LOH is different for gaseous and liquid fuels.
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Yan, Kai, Xiaojiang Wu, and Jianbin Liu. "Thermal Performance of Steam Receiver in Tower-Type Solar Power Plants." In ASME 2017 Power Conference Joint With ICOPE-17 collocated with the ASME 2017 11th International Conference on Energy Sustainability, the ASME 2017 15th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2017 Nuclear Forum. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/power-icope2017-3482.
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In this paper, the thermal performance of steam receiver in tower-type solar power plants has been performed using the tower-type solar receiver design program developed by Shanghai boiler works Co Ltd. In the program, the integrated effect of three types of heat transfer, i.e. heat conduction, convection and radiation, in the process of heat transfer of receivers has been considered. With integrating the characteristics and the working conditions of receivers of both steam and molten salt, the developed program can be used to perform the thermal performance calculations for the receivers of both working fluids. The proposed program was validated through Solar Two project and the satisfactory results achieve. A steam receiver in a tower-type solar power plant with double superheats is selected as an example for thermal performance calculation. In view of the receiver operating in subcritical status, the thermal performance calculation is carried out for two sections, the one for evaporation and that for superheat. In evaporation section, the working fluid is circulated with a circulating pump at a very high circulating ratio. At the outlet of panels, the qualities of working fluid can reach to maximum about 0.35. Besides, the great difference of qualities of working fluid at the outlet of panels is observed. Even for some pipes of some panels, the working fluid at the outlet is in liquid phase. The distribution of metal temperature at fin end of panels in the evaporation region varies dramatically from place to place and reaches to over 520 °C. In superheat region, the temperature of the outer front crown of tubes is concerned. The highest front point temperature of pipe, which reaches to maximum over 660 °C, is in the middle region of the last parts of the primary superheat pass. The thermal efficiency distribution of the receiver, including the evaporation and the superheat regions, are also performed. The results show that the averaged efficiency is about 86%. Besides, the phenomenon of negative thermal efficiency happens in both two regions. That is because the solar incidence cannot compensate the natural heat loss due to incident radiation reflection, the pipe wall infrared radiation and convective heat loss.
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Murakami, Toshihiro, Rei Takei, and Tomio Okawa. "Variation of Critical Heat Flux by Flow Oscillation in a Small Vertical Channel." In 17th International Conference on Nuclear Engineering. ASMEDC, 2009. http://dx.doi.org/10.1115/icone17-75147.
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The effect of sinusoidal oscillation of inlet mass flux on the critical heat flux (CHF) in forced convective boiling was investigated in experiment and numerical calculation. In the experiment, the test section was a small stainless steel round tube of 5 mm in inside diameter, filtrated and deionized tap water was used as a test fluid, and the flow direction was set to vertical upward. The heated length was 1,600 mm. Electric power supplied to a circulation pump was varied periodically to oscillate the inlet mass flux sinusoidally. Direct current was passed through the test section tube to heat it ohmically. The occurrence of critical heat flux condition was detected using the signal from the thermocouples that were spot-welded on the outer wall of the test section tube. In the present experimental conditions, it was expected that the critical heat flux condition was triggered by the dryout of liquid film in annular two-phase flow regime. The main experimental parameters were the time-averaged inlet mass flux and the amplitude and period of flow oscillation. The system pressure was also used as an important experimental parameter since a boiling water reactor is operated under high pressure condition. If the oscillation period is long enough, it is expected that the critical heat flux under the flow oscillation condition is close to that for the steady state when the flow rate is equal to the minimum flow rate in the oscillatory condition. On the other hand, the decrease of the critical heat flux would be mitigated if the oscillation period is shortened, since interaction would take place between the thin and thick film regions within a boiling channel. In accordance with this expectation, the critical heat flux measured under the flow oscillation condition was reduced with an increase in the oscillation period. It was demonstrated that the reduction of critical heat flux under flow oscillation condition can be correlated fairly well using the concept of dimensionless heated length. Numerical calculations using a one-dimensional three-fluid model were also carried. The calculated critical heat fluxes for flow oscillation conditions increased with increased value of dimensionless heated length, as in the present experiment.