1,354 research outputs found

    Технология транспортировки высокопарафинистых нефтей с применением депрессорных присадок

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    Объектом исследования являются технологии транспортировки высокопарафинстой нефти. Цель работы – анализ различных технологических решений, позволяющих улучшить перекачку высокопарафинистых нефтей. В процессе исследования рассматривались различные способы перекачки высокопарафинистых нефтей путем улучшения реологических характеристик; приведена технология, способы, параметры обработки высокопарафинистых нефтей депрессорными присадками. В результате исследования были определены положительные и отрицательные стороны различных технологий транспортировки высокопарафинистых нефтей, проанализирована технология обработки нефти депрессорной присадки, параметры обработки.The object of the research is the technology of transportation of high-paraffin oil. The purpose of the work is to analyze various technological solutions that allow improving the transmission of highly paraffinic oils. In the process of investigation, various ways of transmission highly paraffinic oils by improving rheological characteristics were considered; the technology, methods, parameters of treatment of highly paraffinic oils with depressant additives are given. As a result of the work, the positive and negative aspects of various technologies for transporting highly paraffinic oils were determined, the technology of oil treatment of the depressant additive, processing parameters were analyzed

    Интеллектуальные энергосистемы. Т. 1

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    Настоящий сборник содержит материалы V Международного молодежного форума "Интеллектуальные энергосистемы", проведенного 9 - 13 октября 2017г. на базе Энергетического института Томского политехнического университета

    Разработка технологии ручной дуговой и механизированной под слоем флюса сварки нахлесточных соединений пластин

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    В выпускной квалификационной работе разработана технология ручной дуговой и механизированной сварки под слоем флюса нахлёсточных соединений пластин из стали 10Г2С1Д, предложено устройство для сварки. Произведены расчеты режимов сварки. В экономической части ВКР выполнен расчет экономического эффекта от внедрения новой технологии. Рассмотрены вопросы безопасности труда производственных рабочих и охраны окружающей среды. Выпускная квалификационная работа бакалавра выполнена в текстовом редакторе Microsoft Word 2016In final qualifying wok the technology of manual arc and mechanized welding under a layer of flux of lap joints of plates from steel 10G2C1D, is developed, the device for welding is suggested. Calculations of welding modes are dene. In economic pat of final qualifying work, the calculation of the economic effect from the introduction of new technology is fulfilled. Issues of labor safety of industrial warblers and environmental protection are considered. The final qualifying work is done in a text editor Microsoft word 2016

    Large-Amplitude Ultraviolet Variations in the RR Lyrae Star ROTSE-I J143753.84+345924.8

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    The NASA Galaxy Evolution Explorer (GALEX) satellite has obtained simultaneous near and far ultraviolet light curves of the ROTSE-I Catalog RR Lyrae ab-type variable star J143753.84+345924.8. A series of 38 GALEX Deep Imaging Survey observations well distributed in phase within the star's 0.56432d period shows an AB=4.9mag variation in the far UV (1350-1750A) band and an AB=1.8mag variation in the near UV (1750-2750A) band, compared with only a 0.8mag variation in the broad, unfiltered ROTSE-I (4500-10000A) band. These GALEX UV observations are the first to reveal a large RR Lyrae amplitude variation at wavelengths below 1800A. We compare the GALEX and ROTSE-I observations to predictions made by recent Kurucz stellar atmosphere models. We use published physical parameters for the comparable period (0.57433d), well-observed RR Lyrae star WY Antliae to compute predicted FUV, NUV, and ROTSE-I light curves for J143753.84+345924.8. The observed light curves agree with the Kurucz predictions for [Fe/H]=-1.25 to within AB=0.2mag in the GALEX NUV and ROTSE-I bands, and within 0.5mag in the FUV. At all metallicities between solar and one hundredth solar, the Kurucz models predict 6-8mag of variation at wavelengths between 1000-1700A. Other variable stars with similar temperature variations, such as Cepheids, should also have large-amplitude FUV light curves, observable during the ongoing GALEX imaging surveys.Comment: This paper will be published as part of the Galaxy Evolution Explorer (GALEX) Astrophysical Journal Letters Special Issue. Links to the full set of papers will be available at http:/www.galex.caltech.edu/PUBLICATIONS after November 22, 200

    The GALEX UV luminosity function of the cluster of galaxies Abell 1367

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    We present the GALEX NUV (2310 A) and FUV (1530 A) galaxy luminosity functions of the nearby cluster of galaxies A1367 in the magnitude range -20.3< M_AB < -13.3. The luminosity functions are consistent with previous (~ 2 mag shallower) estimates based on the FOCA and FAUST experiments, but display a steeper faint-end slope than the GALEX luminosity function for local field galaxies. Using spectro-photometric optical data we select out star-forming systems from quiescent galaxies and study their separate contributions to the cluster luminosity function. We find that the UV luminosity function of cluster star-forming galaxies is consistent with the field. The difference between the cluster and field LF is entirely due to the contribution at low luminosities (M_AB >-16 mag) of non star-forming, early-type galaxies that are significantly over dense in clusters.Comment: 4 pages, 4 figures, 1 table. Accepted for publication in Astrophysical Journal Letter

    GALEX UV Spectroscopy and Deep Imaging of LIRGs in the ELAIS S1 field

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    The ELAIS S1 field was observed by GALEX in both its Wide Spectroscopic and Deep Imaging Survey modes. This field was previously observed by the Infrared Space Observatory and we made use of the catalogue of multi-wavelength data published by the ELAIS consortium to select galaxies common to the two samples. Among the 959 objects with GALEX spectroscopy, 88 are present in the ELAIS catalog and 19 are galaxies with an optical spectroscopic redshift. The distribution of redshifts covers the range 0<z<1.60<z<1.6. The selected galaxies have bolometric IR luminosities 10<Log(LIR)<1310<Log(L_{IR})<13 (deduced from the 15μm15 \mu m flux using ISOCAM) which means that we cover a wide range of galaxies from normal to Ultra Luminous IR Galaxies. The mean (σ\sigma) UV luminosity (not corrected for extinction) amounts to Log(λ.L1530)=9.8(0.6)Log(\lambda.L_{1530}) = 9.8 (0.6) L_\sun for the low-z (z0.35z \le 0.35) sample. The UV slope β\beta (assuming fλλβf_\lambda \propto \lambda^\beta) correlates with the GALEX FUV-NUV color if the sample is restricted to galaxies below z<0.1z < 0.1. Taking advantage of the UV and IR data, we estimate the dust attenuation from the IR/UV ratio and compare it to the UV slope β\beta. We find that it is not possible to uniquely estimate the dust attenuation from β\beta for our sample of galaxies. These galaxies are highly extinguished with a median value AFUV=2.7±0.8A_{FUV} = 2.7 \pm 0.8. Once the dust correction applied, the UV- and IR-based SFRs correlate. For the closest galaxy with the best quality spectrum, we see a feature consistent with being produced by a bump near 220nm in the attenuation curve.Comment: This paper has been published as part of the GALEX ApJL Special Issue (ApJ 619, L63

    The GALEX-VVDS Measurement of the Evolution of the 1500A Luminosity Function

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    We present the first measurement of the galaxy luminosity function at 1500A between 0.2<z<1.2 based on GALEX-VVDS observations (1000 spectroscopic redshifts for galaxies with NUV<24.5) and at higher z using existing datasets. Our main results are summarized as follows : (i) luminosity evolution is observed with Delta(Mstar)=-2.0 mag between z=0 and z=1 and Delta(Mstar)=-1.0mag between z=1 and z=3. This confirms that the star formation activity was significantly higher in the past. (ii) the LF slopes vary between -1.2< alpha <-1.65, with a marginally significant hint of increase at higher z. (iii) we split the sample in three restframe (B-I) intervals providing an approximate spectral type classification: Sb-Sd, Sd-Irr and unobscured starbursts. We find that the bluest class evolves less strongly in luminosity than the two other classes. On the other hand their number density increases sharply with z (15% in the local universe to 55% at z=1) while that of the reddest classes decreases.Comment: 4 pages, 4 figures. This paper will be published as part of the Galaxy Evolution Explorer (GALEX) Astrophysical Journal Letters Special Issue.Links to the full set of papers will be available at : http://www.galex.caltech.edu/PUBLICATIONS/ after November 22, 200

    GALEX UV Color-Magnitude Relations and Evidence for Recent Star Formation in Early-type Galaxies

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    We have used the GALEX UV photometric data to construct a first near-ultraviolet (NUV) color-magnitude relation (CMR) for the galaxies pre-classified as early-type by SDSS studies. The NUV CMR is a powerful tool for tracking the recent star formation history in early-type galaxies, owing to its high sensitivity to the presence of young stellar populations. Our NUV CMR for UV-weak galaxies shows a well-defined slope and thus will be useful for interpreting the restframe NUV data of distant galaxies and studying their star formation history. Compared to optical CMRs, the NUV CMR shows a substantially larger scatter, which we interpret as evidence of recent star formation activities. Roughly 15% of the recent epoch (z < 0.13) bright (M[r] < -22) early-type galaxies show a sign of recent (< 1Gyr) star formation at the 1-2% level (lower limit) in mass compared to the total stellar mass. This implies that low level residual star formation was common during the last few billion years even in bright early-type galaxies.Comment: This paper will be published as part of the Galaxy Evolution Explorer (GALEX) Astrophysical Journal Letters Special Issue. Links to the full set of papers will be available at http://www.galex.caltech.edu/PUBLICATIONS/ after November 22, 200

    A systematic review of methods used to study fish in saltmarsh flats

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    There is a growing body of research highlighting the importance of saltmarshes as habitats for fish for feeding, refuge from predation and reproduction. However, more work is needed on fish on vegetated marsh flats (or surfaces). We reviewed 60 studies that used 21 methods to sample fish assemblages on saltmarsh flats. Drop samplers, fyke nets and pop nets were most frequently employed, with considerably more studies being conducted in graminoid than succulent marsh. Reporting of sampling temporal and tidal details, environmental variables and fish attributes was inconsistent. Most of the papers focussed on one or more of conservation management, comparisons among habitat types, and the use of saltmarsh (including fish activity type or residency status). Important potential areas of research include the relationships between the fish assemblages of saltmarsh flats and coastal fisheries, the effects of invasive plant species and marsh restoration efforts in areas outside the United States, and the potential effects of sea-level rise on vegetated flats as fish habitat. Sampling methods that provide density measures are likely to be most useful for most of this research. Thus, drop samplers and pop nets are an appropriate choice, the former in graminoid saltmarshes and the latter in succulent saltmarshes
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