Academic literature on the topic 'STARS (Computer file)'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'STARS (Computer file).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "STARS (Computer file)"
1
Kurucz, Robert L. "A New Opacity-Sampling Model Atmosphere Program for Arbitrary Abundances." International Astronomical Union Colloquium 138 (1993): 87–97. http://dx.doi.org/10.1017/s0252921100020327.
Full textAbstract:
AbstractI have developed a new version of my model atmosphere program called ATLAS12. It recognizes more than 1000 species, each in up to 10 isotopic forms, including all ions of the elements up through Zn and the first 5 ions of heavier elements up through Es. The elemental abundances are treated as variable with depth. ATLAS12 has 6 input files of line data containing 58,000,000 atomic and molecular lines. For each line the wavelength, identification, lower energy level, gf, radiative, Stark, and van der Waals damping constants are packed into 16 bytes. At each wavelength point in a frequency integration the profiles of all the significant nearby lines are computed and summed. The program and line files will be distributed in the fall of 1992.There are no significant differences at A0 between an opacity-sampled model computed with ATLAS12 and opacity-distribution-function model computed with ATLAS9. ATLAS12 allows arbitrary abundances but is slower. The new program can be used to produce improved models for Am and Ap stars that include the effects of millions of lines.
2
Muzzin, A. V., C. M. Clement, and D. R. Alves. "The distance to the Large Magellanic Cloud from first overtone RR Lyrae variables." International Astronomical Union Colloquium 193 (2004): 180–83. http://dx.doi.org/10.1017/s0252921100010587.
Full textAbstract:
AbstractFourier coefficients have been derived for the V and R light curves of 330 bona fide RR Lyrae first-overtone (RR1) pulsators in 16 MACHO fields near the bar of the LMC. We use the Fourier phase parameter ɸ31 and log P values to select a subsample of these stars which are similar to the RR1s in the Galactic globular cluster M5. Assuming that the M5-like stars in the LMC have absolute magnitudes comparable to the HB stars in M5, we use independent studies to derive their mean absolute V magnitude and compute a visual distance modulus of μLMC = 18.43 ± 0.06 (statistical) ±0.16 (systematic). By selecting stars on the basis of their light curve parameters, we are able to derive a distance modulus that does not depend on the somewhat poorly determined Mv – [Fe/H] relation for RR Lyr stars.
3
Robinson, Edward L., and Martin Bitner. "Measuring the Mass Ratios of X-Ray Transients from the Rotational Broadening of the Secondary Star's Spectrum." International Astronomical Union Colloquium 194 (2004): 207. http://dx.doi.org/10.1017/s0252921100152534.
Full textAbstract:
We describe a new computer program for calculating the spectra of stars that fill their Roche lobes in close binary stars.Soft X-ray Transients (SXTs) are interacting binary stars in which a compact star is stripping mass from a relatively-normal companion star (the secondary star). One step in the usual method for measuring the mass of the compact stars in these systems is to determine the mass ratio from the rotational broadening of the absorption lines in the spectrum of the secondary. With a few outstanding exceptions (e.g., Shahbaz 2003), the observations have typically been analyzed assuming that the observed spectrum can be modeled by convolving the spectrum of a non-rotating star with a line-broadening function appropriate for a rotating, spherical star. The results are often inadequate because 1) the profiles of the absorption lines vary strongly with orbital phase, and 2) the limb darkening differs from line to line so that no single broadening function can represent the behavior of all lines.
4
Kurucz, Robert L. "A new opacity-sampling model atmosphere program for arbitrary abundances." Symposium - International Astronomical Union 176 (1996): 523–26. http://dx.doi.org/10.1017/s0074180900083546.
Full textAbstract:
I have developed a new opacity-sampling version of my model atmosphere program called ATLAS12. It recognizes more than 1000 atomic and molecular species, each in up to 10 isotopic forms. It can treat all ions of the elements up through Zn and the first 5 ions of heavier elements up through Es. The elemental and isotopic abundances are treated as variables with depth. At present ATLAS12 reads atomic line data from Kurucz CD-ROM 1 and diatomic molecular data from Kurucz CD-ROM 15. For each line the wavelength, identification, lower energy level, gf, radiative, Stark, and van der Waals damping constants are packed into 16 bytes. At each wavelength point in a frequency integration the Voigt profiles of all the significant nearby lines are computed and summed. The H, He, and auto-ionizing lines are treated with the appropriate profile functions.The fluxes predicted by ATLAS12 are not accurate in intermediate or narrow bandpass intervals because the sample size is too small. A special stripped version of the spectrum synthesis program SYNTHE is used to generate the surface flux for the converged model using the line data on CD-ROMs 1 and 15. That high resolution spectrum can be used directly or can be instrumentally broadened to compare to low resolution observations.ATLAS12 can be used to produce improved models for Am and Ap stars. It should be very useful for investigating diffusion effects in atmospheres. It can be used to model exciting stars for H II regions with abundances consistent with those of the H II region. These programs and line files will be distributed on CD-ROMs.
5
Leão, I. C., B. L. Canto Martins, S. Alves, G. Pereira de Oliveira, C. Cortés, A. Brucalassi, C. H. F. Melo, D. B. de Freitas, L. Pasquini, and J. R. de Medeiros. "Incidence of planet candidates in open clusters and a planet confirmation." Astronomy & Astrophysics 620 (December 2018): A139. http://dx.doi.org/10.1051/0004-6361/201833123.
Full textAbstract:
Context. Detecting exoplanets in clusters of different ages is a powerful tool for understanding a number of open questions, such as how the occurrence rate of planets depends on stellar metallicity, on mass, or on stellar environment. Aims. We present the first results of our HARPS long-term radial velocity (RV) survey which aims to discover exoplanets around intermediate-mass (between ~2 and 6 M⊙) evolved stars in open clusters. Methods. We selected 826 bona fide HARPS observations of 114 giants from an initial list of 29 open clusters and computed the half-peak to peak variability of the HARPS RV measurements, namely ΔRV∕2, for each target, to search for the best planet-host candidates. We also performed time series analyses for a few targets for which we have enough observations to search for orbital solutions. Results. Although we attempted to rule out the presence of binaries on the basis of previous surveys, we detected 14 new binary candidates in our sample, most of them identified from a comparison between HARPS and CORAVEL data. We also suggest 11 new planet-host candidates based on a relation between the stellar surface gravity and ΔRV∕2. Ten of the candidates are less than 3 M⊙, showing evidence of a low planet occurrence rate for massive stars. One of the planet-host candidates and one of the binary candidates show very clear RV periodic variations, allowing us to confirm the discovery of a new planet and to compute the orbital solution for the binary. The planet is IC 4651 9122b, with a minimum mass of m sini = 6.3 MJ and a semimajor axis a = 2.0 AU. The binary companion is NGC 5822 201B, with a very low minimum mass of m sini = 0.11 M⊙ and a semimajor axis a = 6.5 AU, which is comparable to the Jupiter distance to the Sun.
6
Laplace, E., Y. Götberg, S. E. de Mink, S. Justham, and R. Farmer. "The expansion of stripped-envelope stars: Consequences for supernovae and gravitational-wave progenitors." Astronomy & Astrophysics 637 (April 30, 2020): A6. http://dx.doi.org/10.1051/0004-6361/201937300.
Full textAbstract:
Massive binaries that merge as compact objects are the progenitors of gravitational-wave sources. Most of these binaries experience one or more phases of mass transfer, during which one of the stars loses all or part of its outer envelope and becomes a stripped-envelope star. The evolution of the size of these stripped stars is crucial in determining whether they experience further interactions and understanding their ultimate fate. We present new calculations of stripped-envelope stars based on binary evolution models computed with MESA. We use these to investigate their radius evolution as a function of mass and metallicity. We further discuss their pre-supernova observable characteristics and potential consequences of their evolution on the properties of supernovae from stripped stars. At high metallicity, we find that practically all of the hydrogen-rich envelope is removed, which is in agreement with earlier findings. Only progenitors with initial masses below 10 M⊙ expand to large radii (up to 100 R⊙), while more massive progenitors remain compact. At low metallicity, a substantial amount of hydrogen remains and the progenitors can, in principle, expand to giant sizes (> 400 R⊙) for all masses we consider. This implies that they can fill their Roche lobe anew. We show that the prescriptions commonly used in population synthesis models underestimate the stellar radii by up to two orders of magnitude. We expect that this has consequences for the predictions for gravitational-wave sources from double neutron star mergers, particularly with regard to their metallicity dependence.
7
Buonanno, R., A. Buzzoni, C. E. Corsi, F. Fusi Pecci, and A. R. Sandage. "High Precision Photometry of 10,000 Stars in M 3." Symposium - International Astronomical Union 126 (1988): 621–22. http://dx.doi.org/10.1017/s0074180900043345.
Full textAbstract:
A new color-magnitude diagram for M 3 is presented. 10,000 stars have been measured down to V = 22 with an internal accuracy better than 0.03 mag to get complete and very accurate samples over well defined areas.More than 10,000 stars have been measured down to V = 22 in two different areas. In the first, with 3.5 < r < 6.0 arcmin, photometric completeness has been achieved down to V = 21.5 and an algorithm to correct for losses due to unrecoverable crowding and blending has been experimentally computed. In the second, within a square field of 15 × 15 arcmin, completeness has been extended only to V = 18, well below the horizontal branch.Many tests made on the data guarantee an internal photometric accuracy better than 0.03 mag at V = 21. Therefore, both the total population of each branch and the relative star-number ratios are “bona fide” representatives of the corresponding evolutionary time-scales. Here we simply present: 1) the color-magnitude diagram (see Fig. 1) obtained from the reduction of a wide collection of Palomar plates; 2) a table which presents the contribution of the various branches to the integrated cluster light; 3) the preliminary indication that, within the annulus we have considered, the blue stragglers seem to be slightly less centrally concentrated than the subgiants in the same magnitude interval.
8
Penhallow, W. S. "Astrometry with small telescopes." Symposium - International Astronomical Union 118 (1986): 315–16. http://dx.doi.org/10.1017/s0074180900151666.
Full textAbstract:
At the Quonochontaug Observatory of the University of Rhode Island, we specialize in the development of simple seeing limited optical telescopes. Our main instrument is a heavy Serrier trussed f/10.7, .4-m astrometric reflector which provided the last-minute astrometry in the successful prediction of the occultation of SAO 120774 by Herculina in 1978. It is similar in design to the U. S. Naval Observatory 1.5-m reflector. Its scale of 47.1“/mm makes it potentially more powerful than the Lick .5-m, f/7 astrograph. However, its field of view of 1.3° × 1.7° is insufficient to capture enough AGK3R reference stars which are needed to consistently provide tenth-of-a-second-of-arc accuracy. To solve this problem, a .24-.32-m, f/6.3 lensless Schmidt was developed to provide a 3.8° field at 135”/mm and is mounted on the .4-m telescope. It can be used by itself and/or to provide a secondary reference frame for the main instrument. The measures from the plates and film are reduced by a suite of interactive computer programs which allows one to choose the proper reduction model based on the Eichhorn criterion. Over 100 positions of stars, asteroids, comets and supernovae have been provided with these instruments, and a regular observing program including participation in the IHW is underway.
9
Shamir, Lior, and Robert J. Nemiroff. "A Fuzzy Logic Based Algorithm for Finding Astronomical Objects in Wide-Angle Frames." Publications of the Astronomical Society of Australia 22, no. 2 (2005): 111–17. http://dx.doi.org/10.1071/as04072.
Full textAbstract:
AbstractAccurate automatic identification of astronomical objects in an imperfect world of non-linear wide-angle optics, imperfect optics, inaccurately pointed telescopes, and defect-ridden cameras is not always a trivial first step. In the past few years, this problem has been exacerbated by the rise of digital imaging, providing vast digital streams of astronomical images and data. In the modern age of increasing bandwidth, human identifications are many times impracticably slow. In order to perform an automatic computer-based analysis of astronomical frames, a quick and accurate identification of astronomical objects is required. Such identification must follow a rigorous transformation from topocentric celestial coordinates into image coordinates on a CCD frame. This paper presents a fuzzy logic based algorithm that estimates needed coordinate transformations in a practical setting. Using a training set of reference stars, the algorithm statically builds a fuzzy logic model. At runtime, the algorithm uses this model to associate stellar objects visible in the frames to known cataloged objects, and generates files that contain photometry information of objects visible in the frame. Use of this algorithm facilitates real-time monitoring of stars and bright transients, allowing identifications and alerts to be issued more reliably. The algorithm is being implemented by the Night Sky Live all-sky monitoring global network and has shown itself significantly more reliable than the previously used non-fuzzy logic algorithm.
10
Tognelli, Emanuele, Pier Giorgio Prada Moroni, Scilla Degl’Innocenti, Maurizio Salaris, and Santi Cassisi. "Protostellar accretion in low mass metal poor stars and the cosmological lithium problem." Astronomy & Astrophysics 638 (June 2020): A81. http://dx.doi.org/10.1051/0004-6361/201936723.
Full textAbstract:
Context. The cosmological lithium problem, that is, the discrepancy between the lithium abundance predicted by the Big Bang nucleosynthesis and the one observed for the stars of the “Spite plateau”, is one of the long standing problems of modern astrophysics. Recent hints for a possible solution involve lithium burning induced by protostellar mass accretion on Spite plateau stars. However, to date, most of the protostellar and pre-main sequence stellar models that take mass accretion into account have been computed at solar metallicity, and a detailed analysis on the impact of protostellar accretion on the lithium evolution in the metal-poor regime, which is relevant for stars in the Spite plateau, is completely missing. Aims. The purpose of this paper is to fill this gap, analysing, in detail, for the first time the effect of protostellar accretion on low metallicity low-mass stars with a focus on pre-main sequence lithium evolution. Methods. We computed the evolution from the protostar to the main-sequence phase of accreting models with final masses equal to 0.7 and 0.8 M⊙, and three metallicities Z = 0.0001, Z = 0.0010, and Z = 0.0050, corresponding to [Fe/H] ∼ −2.1, −1.1 (typical of Spite plateau stars), and [Fe/H] ∼ −0.42, respectively. We followed the temporal evolution of the chemical composition by considering nuclear burning, convective mixing, and diffusion. The effects of changing some of the main parameters affecting accreting models, that is the accretion energy (i.e. cold versus hot accretion), the initial seed mass Mseed and radius Rseed, and the mass accretion rate ṁ (also considering episodic accretion), have been investigated in detail. Results. As for the main stellar properties and in particular the surface 7Li abundance, hot accretion models converge to standard non-accreting ones within 1 Myr, regardless of the actual value of Mseed, Rseed, and ṁ. Also, cold accretion models with a relatively large Mseed (≳10 MJ) or Rseed (≳1 R⊙) converge to standard non-accreting ones in less than about 10−20 Myr. However, a drastically different evolution occurs whenever a cold protostellar accretion process starts from small values of Mseed and Rseed (Mseed ∼ 1 MJ, Rseed ≲ 1 R⊙). These models almost entirely skip the standard Hayashi track evolution and deplete lithium before the end of the accretion phase. The exact amount of depletion depends on the actual combination of the accretion parameters (ṁ, Mseed, and Rseed), achieving in some cases the complete exhaustion of lithium in the whole star. Finally, the lithium evolution in models accounting for burst accretion episodes or for an initial hot accretion followed by a cold accretion phase closely resemble that of standard non-accreting ones. Conclusions. To significantly deplete lithium in low-mass metal poor stars by means of protostellar accretion, a cold accretion scenario starting from small initial Mseed and Rseed is required. Even in this extreme configuration leading to a non-standard evolution that misses almost entirely the standard Hayashi track, an unsatisfactory fine tuning of the parameters governing the accretion phase is required to deplete lithium in stars of different mass and metallicity – starting from the Big Bang nucleosynthesis abundance – in such a way as to produce the observed Spite plateau.
Dissertations / Theses on the topic "STARS (Computer file)"
1
Underhill, Nic. "Developing a validation process for an adaptive computer-based spoken English language test." Thesis, Sheffield Hallam University, 2000. http://shura.shu.ac.uk/20468/.
Full textAbstract:
This thesis explores the implications for language test validation of developments in language teaching and testing methodology, test validity and computer-based delivery. It identifies a range of features that tests may now exhibit in novel combinations, and concludes that these combinations of factors favour a continuing process of validation for such tests. It proposes such a model designed around a series of cycles drawing on diverse sources of data. The research uses the Five Star test, a private commercial test designed for use in a specific cultural context, as an exemplar of a larger class of tests exhibiting some or all of these features. A range of validation activities on the Five Star test is reported and analysed from two quite different sources, an independent expert panel that scrutinised the test task by task and an analysis of 460 test results using item-response theory (IRT). The validation activities are critically evaluated for the purpose of the model, which is then applied to the Five Star test. A historical overview of language teaching and testing methodology reveals the communicative approach to be the dominant paradigm, but suggests that there is no clear consensus about the key features of this approach or how they combine. It has been applied incompletely to language testing, and important aspects of the approach are identified which remain problematic, especially for the assessment of spoken language. They include the constructs of authenticity, interaction and topicality whose status in the literature is reviewed and determinability in test events discussed. The evolution of validity in the broader field of educational and psychological testing informs the development of validation in language testing and a transition is identified away from validity as a one-time activity attaching to the test instrument towards validation as a continuing process that informs the interpretation of test results. In test delivery, this research reports on the validation issues raised by computer-based adaptive testing, particularly with respect to test instruments such as the Five Star test that combine direct face-to-face interaction with computer-based delivery. In the light of the theoretical issues raised and the application of the model to the Five Star test, some implications of the model for use in other test environments are presented critically and recommendations made for its development.
2
Faber, Liz W. "From Star Trek to Siri: (Dis)Embodied Gender and the Acousmatic Computer in Science Fiction Film and Television." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/dissertations/731.
Full textAbstract:
Recent advancements in voice-interactive technology such as Apple's Siri application, IBM's Watson, and Google's Now are not just the products of innovative computer scientists; they have been directly influenced by fictional technology. Computer scientists and programmers have openly drawn inspiration from Science Fiction texts such as Gene Roddenberry's television show Star Trek and Stanley Kubrick's 1968 2001: A Space Odyssey in order to create more effective voice-interactive programs. Such comparisons between present-day technology and past Science Fiction (hereafter, Sci-Fi) texts are even more apt than computer scientists seem to have intended; not only are Watson, Siri, and Now real-world versions of fictional computers, but each of them also hides the ways in which the computer is implicitly embodied and gendered by its voice. Real and fictional computers alike are generally voiced by a human: the Star Trek computer by Majel Barrett; Hal-9000 by Douglas Rain; and Watson by Jeff Woodman. Mysteriously, both Apple and Google have worked hard to hide the vocal origins of Siri and Now respectively. But the question remains: why do these programs even have gendered voices? In particular, why is Siri--the digital equivalent of a secretary--female? And why hide their voices' corporeal origins? Aside from technological inspiration, how have the underlying ideological gender assumptions in Sci-Fi texts like 2001 and Star Trek influenced the creation of such programs? What does the fact of the shift from Sci-Fi representations to scientific innovation reveal about the perpetuation of ideological assumptions about gender roles? How do other representations of computer voices confirm or problematize the gendering of computer voices? In this dissertation, I seek to answer these questions by examining the historical, theoretical, and aesthetic trace of the computer voice from Star Trek in 1966 to Siri in 2013. The voice-interactive computer, I argue, may be understood as a paradoxically acousmatic character: a disembodied voice that is simultaneously embodied through non-humanoid computer-objects. Through psychoanalytic interpretations, historical contextualizations, and transtextual considerations, I show how representations of acousmatic computers are positioned within narrative texts as gendered subjects, playing out particular gender roles that are situated within each text's historical context. I attend to the textual problem of location in Sci-Fi by dividing the analyses into two categories: extra-terrestrial and terrestrial. This division is important in understanding the roles of voice-interactive computers, as spaceships provide a uniquely different environment than terrestrial structures such as houses, office buildings, or prisons. Further, spaceships always already imply a womb-like habitat, a mothership that controls and maintains all aspects of the life forms within it; terrestrial computers, on the other hand, tend to connote varying gendered subjectivities and anxieties within historical contexts of technological innovation and cultural change. In this first part, I focus on extra-terrestrial voice-interactive computers in Star Trek (Paramount, 1966-1969), 2001: A Space Odyssey (Stanley Kubrick, 1968), Dark Star (John Carpenter, 1974), Quark (NBC, 1977-1978), Star Trek: The Next Generation (Paramount, 1987-1994), and Moon (Duncan Jones, 2010). In the second part, I examine terrestrial computers; these computers may be further divided into two, gendered subsections of masculine and feminine functions. The texts featuring masculine-voiced computers tend to act as the son to their programmer/creator fathers or, conversely, as all-knowing fathers, thereby reinforcing patriarchal rule. These films, Colossus: The Forbin Project (Joseph Sargent, 1970), THX 1138 (George Lucas, 1971), Rollerball (Norman Jewison, 1975), and Demon Seed (Donald Cammell, 1977), narrativize cultural and business struggles in the 1970s surrounding militarization and corporatization. I then examine the films of the early 1980s, TRON (Steven Lisberger, 1982) and Electric Dreams (Steven Barron, 1984), that express a rapidly-changing cultural conception of computers, set in narratives of homosocial struggle. And finally, I discuss computers in the 1990s and 2000s that serve in domestic roles, particularly those texts that feature domestic spaces run by female-voiced computers or, literally, house-wives. These texts, Fortress (Stuart Gordon, 1992), Smart House (LeVar Burton, 1999), and Eureka (SyFy, 2006-2012), position computers as replacements for human women who are absent from the home. Additionally, I examine two texts that feature male servants--Demon Seed (an anomaly among representations of domestic servitude) and Iron Man (Jon Favreau, 2008). I then return to Siri by examining representations of her programming, voice, and body in popular culture. By thus exploring the representations of gendered acousmatic computers within the context of computer history and changing gender norms, I self-reflexively examine how artificial intelligence may be presented in a gendered context, and how this may reflect changing notions of gender in digital culture.
3
Banoobhai-Anwar, Ilhaam. "The role of e-commerce in five-star hotels in the Cape Town Metropole." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2489.
Full textAbstract:
Thesis (MTech (Tourism and Hospitality Management))--Cape Peninsula University of Technology, 2016.Electronic commerce, popularly referred to as e-commerce, is the latest catchphrase surrounding the Internet and its many functions. In the past, the Internet was solely used for information seeking, but the 21st century has brought a new global economy to the fore – one that is conducted online. Tourism is seen as a driver of economic growth, contributing both to the Gross Domestic Product (GDP) of South Africa (SA) and creating jobs in the hospitality sector. E-commerce does not only provide a platform for business to be conducted online but also an opportunity for consumers to interact directly with industry. Many studies have been done previously about the perceived benefits of e-commerce in the retail sector, yet none in Cape Town and at five-star hotels in particular. It is well known that holidaymakers conduct an online search prior to booking accommodation; some of those potential guests in turn choose to finalise their bookings online. The purpose of the study was to investigate the role of e-commerce in five-star hotels in the Cape Town Metropole. The main objective of this study was to define what e-commerce is for five-star hotels in the Cape Town Metropole and determine if the hotels are using e-commerce as a booking method. Online questionnaires were used to gather primary data and a literature review was presented as secondary data. The findings of this study showed that all the hotels surveyed use online bookings and half of the respondents believe Online Travel Agents (OTAs) generate more revenue than traditional methods of room reservation. When asked to rank methods of room’s reservations, there was a slight difference between telephone bookings and e-commerce as number one. This could mean that while electronic methods are popular, they have not completely replaced traditional methods. The researcher recommends that five-star hotel managers train the rooms’ division staff to respond to negative reviews on social media, as this was one of the findings. The hotels should also learn how to effectively use their social media presence to increase room sales.
4
Kullberg, James C. "An experimental and numerical study of secondary flows and film cooling effectiveness in a transonic cascade." Honors in the Major Thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/454.
Full textAbstract:
Experimental tests on a transonic annular rig are time-consuming and expensive, so it is desirable to use experimental results to validate a computational model which can then be used to extract much more information. The purpose of this work is to create a numerical model that can be used to simulate many different scenarios and then to apply these results to experimental data.; In the modern world, gas turbines are widely used in aircraft propulsion and electricity generation. These applications represent a massive use of energy worldwide, so even a very small increase in efficiency would have a significant beneficial economic and environmental impact. There are many ways to optimize the operation of a gas turbine, but a fundamental approach is to increase the turbine inlet temperature to increase the basic thermodynamic efficiency of the turbine. However, these temperatures are already well above the melting temperature of the components. A primary cooling methodology, called film cooling, creates a blanket of cool air over the surface and is an effective way to help protect these components from the hot mainstream gasses. This paper focuses on the effect of the film holes upstream of the first row of blades in the turbine because this is the section that experiences the highest thermal stresses. Many factors can determine the effectiveness of the film cooling, so a complete understanding can lead to effective results with the minimum flow rate of coolant air. Many studies have been published on the subject of film cooling, but because of the difficulty and expense of simulating turbine realistic conditions, many authors introduce vast simplifications such as low speed conditions or linear cascades. These simplifications do not adequately represent the behavior of a turbine and therefore their results are of limited use. This study attempts to eliminate many of those simplifications. The test rig used in this research is based on the NASA-GE E³ design, which stands for Energy Efficient Engine. It was introduced into the public domain to provide an advanced platform from which open-literature research could be performed.B.S.M.E.
Bachelors
Engineering and Computer Science
Mechanical Engineering
5
Scarlato, Michele. "Sicurezza di rete, analisi del traffico e monitoraggio." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3223/.
Full textAbstract:
Il lavoro è stato suddiviso in tre macro-aree.
Una prima riguardante un'analisi teorica di come funzionano le intrusioni, di quali software vengono utilizzati per compierle, e di come proteggersi (usando i dispositivi che in termine generico si possono riconoscere come i firewall).
Una seconda macro-area che analizza un'intrusione avvenuta dall'esterno verso dei server sensibili di una rete LAN.
Questa analisi viene condotta sui file catturati dalle due interfacce di rete configurate in modalità promiscua su una sonda presente nella LAN.
Le interfacce sono due per potersi interfacciare a due segmenti di LAN aventi due maschere
di sotto-rete differenti. L'attacco viene analizzato mediante vari software.
Si può infatti definire una terza parte del lavoro, la parte dove vengono analizzati i file
catturati dalle due interfacce con i software che prima si occupano di analizzare i dati di
contenuto completo, come Wireshark, poi dei software che si occupano di analizzare i dati di
sessione che sono stati trattati con Argus, e infine i dati di tipo statistico che sono stati trattati
con Ntop.
Il penultimo capitolo, quello prima delle conclusioni, invece tratta l'installazione di Nagios, e
la sua configurazione per il monitoraggio attraverso plugin dello spazio di disco rimanente su
una macchina agent remota, e sui servizi MySql e DNS. Ovviamente Nagios può essere
configurato per monitorare ogni tipo di servizio offerto sulla rete.
6
Jiang, Hui-Ru, and 江蕙如. "Analysis of International Five-star Hotel Homepages -Computer-mediated Communication Perspectives." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/48341859572887653924.
Full textAbstract:
碩士銘傳大學
應用英語學系碩士在職專班
101
With the ever rising influence of the Internet, the worldwide hotel industry has increased its use of e-marketing strategies, which has brought with it some changes in what influences hotel business performance. Several researchers (e.g., Baldry & Thibault, 2006; Kress & van Leeuwen, 2006; Lemke, 1998; Martin, 2002; O''Halloran, 2004a, 2005; Royce & Bzowcher, 2006; van Leeuwen, 2005; Ventola et al., 2004) have paid attention to multimodality, but very few researchers have probed into the hotel website homepage. Website homepages mainly consist of promotional texts that are different from traditional printed texts. The target research genre in this study is five-star hotel website homepages. The present study investigated and compared 60 five-star hotel homepages across Europe and the Asia Pacific area. The data embraces countries where English is the native language and where it is spoken as a second or foreign language. The authors of this study eliminated the variance of semiotic investigation and concentrated on hyperlinks, move structures, and linguistic features. The instrument this study applied to examine the communication features on the hotel homepages was adapted from Ahmed Abbasi and Hsinchun Chen’s CMC framework (2008) and was grounded in systemic functional linguistic theory (SFLT). The adapted framework, meanwhile, incorporated Inger Askehave and Anne Ellerup Nielsen’s (2003) homepage move structure and hyperlinks analyses. Further discussions of linguistic feature frequencies used WordSmith Tools 5.0 (Scott, 2010) as the statistical tool to examine verb, noun, and adjective categories. The result shows that there are more similarities than differences in the hyperlinks and move structures analyses when Asia Pacific and European hotel homepages were compared. The linguistic feature results imply that the usage between the research regions involved in the same achievements for how to promote the hotel brandwidth and the concerns of business performance. The valuable results of the study provide the prospective hoteliers, website designers, and hotel industry a guiding principle while constructing hotel websites. The usability of website structure, functions of hyperlinks and cross-culture language differences are three major elements for those who are involved in the hotel industry.
Books on the topic "STARS (Computer file)"
1
Green, James A. CHANDRA: Chandrasekhar sets of white dwarfs or supernova cores. Wichita, Kan: Greenwood Research, 1994.
Find full text
2
Junichiro, Makino, and Hut Piet 1952-, eds. Astrophysical supercomputing using particle simulations: Proceedings of the 208th Symposium of the International Astronomical Union held in Tokyo, Japan, 10-13 July 2001. San Francisco, Calif: Published on behalf of IAU by the Astronomical Society of the Pacific, 2003.
Find full text
3
Gupta, K. K. STARS--an integrated, multidisciplinary, finite-element, structural, fluids, aeroelastic, and aeroservoelastic analysis computer program. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1997.
Find full text
5
Wang, Wally. Start!: The no nonsense guide to Windows XP. New York: McGraw-Hill/Osborne, 2003.
Find full text
8
Tsiyoni, Joseph. Start using WordPerfect immediately. Scottsdale, AZ: Shairon Int'l. Trade Co., 1992.
Find full text
9
Sagman, Stephen W. Getting your start in Hollywood. Berkeley, CA: Peachpit Press, 1991.
Find full text
10
Stacy, Sue Varnon. WordPerfect 6.0 DOS, quick start. Cincinnati: South-Western Pub., 1995.
Find full textBook chapters on the topic "STARS (Computer file)"
1
Klešč, Marián. "On the Crossing Numbers of Cartesian Products of Stars and Graphs on Five Vertices." In Lecture Notes in Computer Science, 324–33. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-10217-2_32.
Full text
2
Gomes, Maria Isabel, Lourdes B. Afonso, Nelson Chibeles-Martins, and Joana M. Fradinho. "Multi-start Local Search Procedure for the Maximum Fire Risk Insured Capital Problem." In Lecture Notes in Computer Science, 219–27. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-96151-4_19.
Full text
3
Tseng, Chiao-I. "Truthfulness and Affect via Digital Mediation in Audiovisual Storytelling." In Beyond Media Borders, Volume 1, 175–95. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-49679-1_5.
Full textAbstract:
Abstract This chapter investigates different ways in which the film techniques of digitally mediated images—such as found footage, diegetic camera, and computer screen—achieve story truthfulness and affective engagement in the viewer’s narrative interpretation process. The pursuit of truthful storytelling is to demonstrate objective facts, while mediated images in film are predominantly subjective. The chapter starts by reviewing the perennial paradox of two seemingly mutually exclusive narrative functions and then tackles the paradox by proposing a multi-leveled framework, synthesizing semiotic conceptualization and cognitive research findings. It also analyzes the various forms of digital mediated images in films over the last two decades and sheds light on how the functions of truthfulness and affective engagement can be closely intertwined rather than in conflict.
4
Glatzmaier, Gary A. "Postprocessing." In Introduction to Modeling Convection in Planets and Stars. Princeton University Press, 2013. http://dx.doi.org/10.23943/princeton/9780691141725.003.0005.
Full textAbstract:
This chapter explains how to write a postprocessing code, and more specifically how to study the nonlinear simulations using computer graphics and analysis. It first considers how to compute and store results in a file during the computer simulation, assuming the Fourier transforms to x-space are done within the main computational code during the simulation. It then describes the postprocessing code for reading these files and displaying the various fields, along with the use of graphics software packages that provide additional, more sophisticated visualizations of the scalar and vector data. It also discusses the computer analysis of several additional properties of the solution, focusing on measurements of nonlinear convection such as Rayleigh number, Nusselt number, Reynolds number, and kinetic energy spectrum.
5
Holliday, Christopher. "Monsters, Synch: A Taxonomy of the Star Voice." In The Computer-Animated Film, 144–64. Edinburgh University Press, 2018. http://dx.doi.org/10.3366/edinburgh/9781474427883.003.0008.
Full textAbstract:
This chapter proposes that the ascription of star speech (as a dynamic sound form) to the computer-animated film’s puppet performers contributes to the effect and impact of their many screen performances. This chapter takes the star voice to be a unique instrument of performance that lies at the cornerstone of computer-animated film acting, and begins by implicating the potency of the star voice within wider industrial discourses. These include local dubbing practices, sound technology, and the multiplication of star sound across a range of consumer and multi-media products. The formal and structural importance of the star voice to computer-animated film performance is illustrated through the work of prominent film sound theorist Michel Chion and his work on synchresis, a neologism produced out of the combination of “synchronism” and “synthesis”. By extending Chion’s account, this chapter uses descriptors derived from synchresis to outline three prominent synchretic unions operating at the level of character design. A significant innovation here is the development of a taxonomy of the star voice as it is inscribed formally into computer-animated films—anthropomorphic, autobiographic and acousmatic synchresis—which give new precision to the analysis of star voices in animation.
6
Hicks, Mar. "When Did the Fire Start?" In Your Computer Is on Fire, 11–26. The MIT Press, 2021. http://dx.doi.org/10.7551/mitpress/10993.003.0003.
Full text
7
Philip, Kavita. "How to Stop Worrying about Clean Signals and Start Loving the Noise." In Your Computer Is on Fire, 363–76. The MIT Press, 2021. http://dx.doi.org/10.7551/mitpress/10993.003.0024.
Full text
8
Pournelle, Jerry. "Basic Troubleshooting." In 1001 Computer Words You Need to Know. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195167757.003.0009.
Full textAbstract:
Is your computer a little problematic? Slowing down? And you’re not ready to call in expert help? Try these tricks. As always, back up important data first. 1. A surprising number of computer problems—inexplicable system crashes, random program shutdowns, “not enough memory” errors—are caused by faulty RAM chips. These errors are normally hard to diagnose by yourself, but on Windows, the free program Memtest86 (http://www.mem test86.com) makes it easy. On Macintosh OS 9, use RAM Check 2.1, which can be downloaded at http://ftp.traffictrak.com/RAMCheck21.sit or http://download.digidesign.com/support/digi/mac/utilities/ RMCheck210.sea.hqx(.) You can also try Techtool Pro for OS 9 or OS X. 2. Four big demons of computers are dust, heat, moisture, and static. You can take some preventive measures, like covering your CPU and monitor when they’re not in use and protecting your computer by drinking your coffee away from the computer, but demons will strike no matter what you do, and they manifest their presence in odd ways. The most common is disk corruption, which shows up as disappearing or corrupt files and folders. Regular disk maintenance is important to keep these demons at bay. The most well-known tool for repairing disk drives is Norton Utilities (http://www.symantec.com), which is included in Norton System Works. You can use it to diagnose and fix already corrupt files, but it is most useful for preventive maintenance. Using these utilities to optimize or defragment your hard drive on a regular basis makes individual files as contiguous as possible, which can increase the speed at which files and programs are opened. However, Norton Utilities can sometimes cause problems of its own, particularly on older computers, if it is installed to run in the background. If you open System Works and click on Options, Norton Utilities, and then the Startup tab, you can uncheck the boxes that would instruct the program to start whenever you boot up. Then it’s up to you to decide how often you need to activate it, perhaps somewhere between once a week and once a month.
9
Finn, Ed. "Building the Star Trek Computer." In What Algorithms Want. The MIT Press, 2017. http://dx.doi.org/10.7551/mitpress/9780262035927.003.0003.
Full textAbstract:
This chapter explores the ways in which Google, Apple, and other corporations have turned the development of cultural algorithms into epistemological quests for both self-knowledge and universal knowledge. This effort to construct a new framework for reality has its roots in Diderot and d’Alembert’s Encyclopédie, a keystone of the European Enlightenment. Apple’s intelligent assistant Siri, Spike Jonze’s film Her, and Google’s ambition to realize the Star Trek computer serve as exemplars for the algorithmic pursuit of knowledge. These quests are both romantic and rational, seeking a transcendent state of knowing, a state that can be reached only with mechanisms that ultimately eclipse the human. Through their ambitions to develop algorithms that can “answer, converse, and anticipate” with ever-greater intimacy, the technology titans shaping our algorithmic future are constructing a new epistemological framework of what is knowable and desirable: an intellectual hierarchy of needs that will ultimately map out not only the public sphere of information but the interior space of human identity.
10
Liston, Noelle Molé. "Conclusion." In The Truth Society, 142–64. Cornell University Press, 2020. http://dx.doi.org/10.7591/cornell/9781501750786.003.0007.
Full textAbstract:
This chapter recounts the emergence of the Five Star Movement and its dependence on algorithmic technologies. It discusses the venue of knowing the world and knowledge of the self as it is once more firmly and singularly rooted in the human corporeal self and shifted toward mathematical algorithms and computers. It describes living in a world in which knowledge is not just run through algorithms but also customized to the individual shape of what the world is about and who should rule it. The chapter speculates what the new material infrastructures of knowledge mean for democratic governance in an age dominated by highly sophisticated but indecipherable and invisible forms of intelligence. It elaborates how the mirror in the 2018 film I Exist serves as a kind of double illusion as it is considered a fake religion icon that is created for someone else's financial gain, not individual enlightenment.
Conference papers on the topic "STARS (Computer file)"
1
Leino, Juha. "Recommending additional study materials: Binary ratings vis–à–vis five–star ratings." In 27th International BCS Human Computer Interaction Conference (HCI 2013). BCS Learning & Development, 2013. http://dx.doi.org/10.14236/ewic/hci2013.12.
Full text
2
Tulimilli, Bhaskar Rao, Steven A. Lottes, Pradip Majumdar, and Milivoje Kostic. "Three-Dimensional Scouring Analysis for Open Channel Pressure Flow Scour Under Flooded Bridge Decks." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-65529.
Full textAbstract:
A three-dimensional stream bed scour modeling methodology was developed using well-benchmarked commercial Computational Fluid Dynamics (CFD) software to compute the bed shear stress distribution used to calculate bed displacements and to re-mesh the computational domain as the bed is displaced. This study extends a previously developed two-dimensional iterative scouring procedure to predict the final shape and size of the scour-hole under pressure-scour flow conditions for flooded bridge decks using commercial CFD software. The current approach uses single phase flow models with an assumed flat water surface using a symmetric slip top boundary to simulate a free-surface flow condition, quasi-steady simulation to obtain the bed shear, and a moving boundary formulation based on an empirical correlation for critical shear stress to iteratively deform the bed under supercritical shear conditions until an equilibrium scour condition is obtained. The model solves the flow field using Reynolds Averaged Navier-Stokes (RANS) equations and the high Reynolds number k–epsilon turbulence model using the commercial CFD software STAR-CD. A Bash script was developed to use a Python script to compute bed displacements from the computed shear stress distribution and generate a STAR-CD processor command file to displace the bed followed by a step using the STAR-CCM+ software to remesh the domain as the bed is displaced and bed shear distribution is recomputed in an iterative procedure until the equilibrium bed contour is reached. Simulations were performed for different inundation ratios and for mean sand diameters of 1 mm and 2 mm. The model agrees reasonably well with limited experimental data for equilibrium scour shape and size with fully submerged cases compared to the cases where the bridge deck is partially submerged. This developed three-dimensional CFD scour computation procedure provides a basis for testing of additional scour related physical models while also providing an evaluation tool that can be used immediately by engineers engaged in scour risk analysis and assessment.
3
Malik, M. Afzaal, Badar Rashid, Syed Adnan Qasim, and Shahab Khushnood. "Modeling and Simulation of Elastohydrodynamic Lubrication of Piston Skirts Considering Elastic Deformation in the Initial Engine Start-Up." In ASME/STLE 2004 International Joint Tribology Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/trib2004-64101.
Full textAbstract:
The presence of Elasto-hydrodynamic Lubrication (EHL) film between opposing piston and liner surfaces prevents possible solid-to-solid contact and wear. This enhances engine life manifold as compared to when the EHL film is non-existent in the initial engine startup or breaks down during normal engine operation. Forced dry sliding of piston during engine cranking followed by partial lubrication in the initial engine startup leads to adhesive wear. This research investigates the possibility of an EHL film on such an occasion by considering elastic deformation of opposing piston skirt and liner surfaces due to Elasto-hydrodynamic (EHD) pressures. The geometry of piston skirts is defined and governing equations are applied to determine hydrodynamic pressures. The EHL film thickness profile generated by inverse solution technique and its expression is defined by incorporating contact geometry and EHD pressures in the piezoviscous regime. A computer code is developed and used to simulate the performance parameters and their behavior during initial engine startup. Due to critical factors such as engine speed, redial clearance between piston skirts and liner and lubricant viscosity, a time dependent 2-D EHL film profile is generated. The simulated results indicate that, despite piston eccentricities due to secondary oscillatory motion, EHL film established between the opposing piston skirts and liner surfaces prevented possible solid-to-solid contact in the entire duration of 720-degree crankshaft rotation, which corresponds to four piston strokes.
4
Huang, Chintien, and Yu-Jui Chang. "Polynomial Solution to the Five-Position Synthesis of Spatial CC Dyads via Dialytic Elimination." In ASME 2000 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/detc2000/mech-14102.
Full textAbstract:
Abstract This paper presents a polynomial solution to the five-position synthesis of spatial cylindrical-cylindrical dyads. The solution procedures start with the simplification of the synthesis equations derived by Tsai and Roth. The simplified equations are solved by Sylvester’s dialytic elimination method to obtain a univariate polynomial equation of degree six, which gives at most 6 CC dyads for the five-position synthesis. A numerical example with six real solutions is provided.
5
Vemulapalli, Prabath, Prashant Mohan, Jami J. Shah, and Joseph K. Davidson. "User Defined Assembly Features and Pattern Recognition From STEP AP203." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-35295.
Full textAbstract:
Tolerance allocation is important aspect in designing as well as manufacturing. Mating features in an assembly are important from the tolerance point of view and govern the tolerance schema. Presence of patterns within these features also plays an important role in the allocation of different tolerance classes. Identification of these assembly features and patterns are previously done manually. This research is aimed at automating these processes. The automation starts with the recognition of the assembly features in the assembly. The algorithms for feature recognition are designed such that they can handle any user defined assembly feature. The input for feature recognition is a STEP file containing information of the assembly. And the output file contains information of the recognized assembly features. Then patterns are identified from these assembly features. This paper discusses these two processes in detail. Also to facilitate the user, define new assembly features an alternate system called assembly feature tutor is developed. This paper also explains the working of this tutor.
6
Abutayeh, Mohammad. "Adapting Steady State Solar Power Models to Include Transients." In ASME 2015 9th International Conference on Energy Sustainability collocated with the ASME 2015 Power Conference, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/es2015-49021.
Full textAbstract:
Quite a few computer programs have been developed to model power plant performance. These software codes are geared towards modeling steady state operations which is usually sufficient for conventional power plants. Solar thermal power plants undergo lengthy transient start–up and shut–down operations due to the sporadic nature of solar radiation; therefore, valid modeling of their performance must address those unsteady state operations. A novel scheme has been developed to fine–tune steady state solar power generation models to accurately take account of the impact of those transient operations. The suggested new scheme is implemented by adjusting solar radiation input data and has been shown to significantly improve modeling accuracy by moving modeled results closer to matching real operating data.
7
Brown, Samuel J., Eldon Husband, and Jerry L. Lyons. "Testing and Risk Analysis are Key Elements of Post Construction Problem Solving: A Case History of System Failure and Fire Hazards." In ASME 2005 Pressure Vessels and Piping Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/pvp2005-71303.
Full textAbstract:
Hazardous thermal hydraulic loading conditions and unintended plant shut downs from turbine trips that are identified shortly after a plant start up may be the tip of the iceberg of even greater interrelated hazards and costly damages. This paper presents a case study to further illustrate (from ASME PVP2002-1124 paper) additional considerations for the testing and risk analysis to identify a systematic approach to reduce the hazards and risks of equipment failure from thermal hydraulic forces and secondary hazards (such as fires) to the plant and personnel. This paper examines problems of turbine trip caused by fuel computer controlled regulator valves that results in thermal hydraulic forces from compressor pressure wave surges in the process system that result in piping “Y” fitting (45° laterals) failures in the process piping from crack growth and brittle fracture which lead to process chemical release and fires.
8
Xiaohui Du, Lin Liu, Jing Zhang, Juanxiu Liu, Yutang Ye, and Yong Liu. "A computed 3-D temperature filed reconstruction algorithm applied to start duration detection under the deep liquid layer in the solid-liquid chemical reaction." In 2015 12th International Computer Conference on Wavelet Active Media Technology and Information Processing (ICCWAMTIP). IEEE, 2015. http://dx.doi.org/10.1109/iccwamtip.2015.7493983.
Full text
9
Simpson, Timothy W., Elizabeth Kisenwether, and Gregory R. Pierce. "Driving Entrepreneurial Innovation Through the Learning Factory: The Power of Interdisciplinary Capstone Design Projects." In ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/detc2013-12492.
Full textAbstract:
Founded in 1995, the mission of the Learning Factory at the Pennsylvania State University has been to integrate real-world, hands-on design/build experience into the engineering classroom through industry-sponsored capstone design projects. While the Learning Factory began like many other capstone design programs, a new college-wide capstone model emerged over the past five years to enable interdisciplinary design teams across multiple departments. First 3, then 4, 5, 8, and now 12 engineering majors regularly collaborate in what has become the largest industry-supported and college-wide capstone design program in the nation. Now more than 70% of the capstone design teams involve students from two or more disciplines, with some teams consisting of 4–5 different engineering majors. At the same time that we improved our ability to work across disciplinary boundaries, many entrepreneurs and start-up firms became aware of our capstone design program, and we found ourselves working with more and more of them on projects involving concept development and prototyping. In fact, the more interdisciplinary the program became, the better we could meet their needs, which often required input from 3 or more engineering disciplines as well as non-engineering disciplines. As a result, the number of capstone design projects sponsored by “real” entrepreneurs and start-ups has increased eight-fold over the past five years: from 5 projects in 2007/08 to over 40 projects in 2011/12. We discuss the factors that contributed to this growth, including industry-friendly intellectual property and non-disclosure agreements, a low-cost sponsorship model, a multidisciplinary capstone design section that satisfied the ABET requirements among all participating departments, and student interest in making a significant and immediate impact on their industry-sponsored project. The risks and challenges of working with start-ups and entrepreneurs is also discussed, namely, managing sponsor’s expectations, working with non-technical sponsors, clarifying project scope, avoiding project creep, and emphasizing the educational experience over project outcomes. Recent start-up successes are discussed along with a student entrepreneurial team’s capstone project prototype that lead to a successful fund-raising campaign on Kickstarter.
10
Husaini, S. Mahmood, Riyad K. Qashu, David Y. Arai, and Jeffrey S. Summy. "Waterhammer Analysis of Fire Protection System Due to Draining of High Elevation Headers." In ASME 2002 Pressure Vessels and Piping Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/pvp2002-1130.
Full textAbstract:
This paper presents a methodology for analyzing the potential for water hammer in fire protection systems of nuclear power plants due to draining of high elevation headers. A transient thermal hydraulic analysis was performed that modeled the combined San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 Fire Protection System in general and the high elevation piping in minute detail. The purpose of this analysis was to simulate a postulated scenario that actuates a sprinkler system resulting in the draining of high elevation headers, followed by the start up of the main pumps. The analysis was based on a generalized computer program that utilizes the Method of Characteristics (MOC) numerical scheme. The forcing functions generated by the hydraulic analyses indicated that some hangers would be over loaded. In order to mitigate the water hammer and reduce the loads, the system was analyzed by modeling vacuum breakers at selected locations. The cushioning effect of the air introduced into the system by using vacuum breakers was found to significantly reduce the intensity of the water hammer. Subsequent stress and pipe support analysis predicted there will be no damage to the hangers. The details of the hydraulic analysis, such as the model, pressure and velocity time histories at selected locations, and forcing functions for the cases with and without vacuum breakers are included. Only the conclusions of the stress and pipe support analysis are presented.