1,512 research outputs found
Cogeneration Technology Alternatives Study (CTAS). Volume 4: Energy conversion systems
Industrial processes from the largest energy consuming sectors were used as a basis for matching a similar number of energy conversion systems that are considered as candidate which can be made available by the 1985 to 2000 time period. The sectors considered included food, textiles, lumber, paper, chemicals, petroleum, glass, and primary metals. The energy conversion systems included steam and gas turbines, diesels, thermionics, stirling, closed-cycle and steam injected gas turbines, and fuel cells. Fuels considered were coal, both coal and petroleum-based residual and distillate liquid fuels, and low Btu gas obtained through the on-site gasification of coal. An attempt was made to use consistent assumptions and a consistent set of ground rules specified by NASA for determining performance and cost. The advanced and commercially available cogeneration energy conversion systems studied in CTAS are fined together with their performance, capital costs, and the research and developments required to bring them to this level of performance
Cogeneration Technology Alternatives Study (CTAS). Volume 3: Industrial processes
Cogenerating electric power and process heat in single energy conversion systems rather than separately in utility plants and in process boilers is examined in terms of cost savings. The use of various advanced energy conversion systems are examined and compared with each other and with current technology systems for their savings in fuel energy, costs, and emissions in individual plants and on a national level. About fifty industrial processes from the target energy consuming sectors were used as a basis for matching a similar number of energy conversion systems that are considered as candidate which can be made available by the 1985 to 2000 time period. The sectors considered included food, textiles, lumber, paper, chemicals, petroleum, glass, and primary metals. The energy conversion systems included steam and gas turbines, diesels, thermionics, stirling, closed cycle and steam injected gas turbines, and fuel cells. Fuels considered were coal, both coal and petroleum based residual and distillate liquid fuels, and low Btu gas obtained through the on site gasification of coal. An attempt was made to use consistent assumptions and a consistent set of ground rules specified by NASA for determining performance and cost. Data and narrative descriptions of the industrial processes are given
Cogeneration Technology Alternatives Study (CTAS). Volume 5: Cogeneration systems results
The use of various advanced energy conversion systems is examined and compared with each other and with current technology systems for savings in fuel energy, costs, and emissions in individual plants and on a national level. About fifty industrial processes from the largest energy consuming sectors were used as a basis for matching a similar number of energy conversion systems that are considered as candidate which can be made available by the 1985 to 2000 time period. The sectors considered included food, textiles, lumber, paper, chemicals, petroleum, glass, and primary metals. The energy conversion systems included steam and gas turbines, diesels, thermionics, stirling, closed cycle and steam injected gas turbines, and fuel cells. Fuels considered were coal, both coal and petroleum based residual and distillate liquid fuels, and low Btu gas obtained through the on site gasification of coal. The methodology and results of matching the cogeneration energy conversion systems to approximately 50 industrial processes are described. Results include fuel energy saved, levelized annual energy cost saved, return on investment, and operational factors relative to the noncogeneration base cases
Cogeneration Technology Alternatives Study (CTAS). Volume 2: Analytical approach
The use of various advanced energy conversion systems were compared with each other and with current technology systems for their savings in fuel energy, costs, and emissions in individual plants and on a national level. The ground rules established by NASA and assumptions made by the General Electric Company in performing this cogeneration technology alternatives study are presented. The analytical methodology employed is described in detail and is illustrated with numerical examples together with a description of the computer program used in calculating over 7000 energy conversion system-industrial process applications. For Vol. 1, see 80N24797
Evaluation of Vascular Control Mechanisms Utilizing Video Microscopy of Isolated Resistance Arteries of Rats
This protocol describes the use of in vitro television microscopy to evaluate vascular function in isolated cerebral resistance arteries (and other vessels), and describes techniques for evaluating tissue perfusion using Laser Doppler Flowmetry (LDF) and microvessel density utilizing fluorescently labeled Griffonia simplicifolia (GS1) lectin. Current methods for studying isolated resistance arteries at transmural pressures encountered in vivo and in the absence of parenchymal cell influences provide a critical link between in vivo studies and information gained from molecular reductionist approaches that provide limited insight into integrative responses at the whole animal level. LDF and techniques to selectively identify arterioles and capillaries with fluorescently-labeled GS1 lectin provide practical solutions to enable investigators to extend the knowledge gained from studies of isolated resistance arteries. This paper describes the application of these techniques to gain fundamental knowledge of vascular physiology and pathology in the rat as a general experimental model, and in a variety of specialized genetically engineered designer rat strains that can provide important insight into the influence of specific genes on important vascular phenotypes. Utilizing these valuable experimental approaches in rat strains developed by selective breeding strategies and new technologies for producing gene knockout models in the rat, will expand the rigor of scientific premises developed in knockout mouse models and extend that knowledge to a more relevant animal model, with a well understood physiological background and suitability for physiological studies because of its larger size
Spectral Analysis of Guanine and Cytosine Fluctuations of Mouse Genomic DNA
We study global fluctuations of the guanine and cytosine base content (GC%)
in mouse genomic DNA using spectral analyses. Power spectra S(f) of GC%
fluctuations in all nineteen autosomal and two sex chromosomes are observed to
have the universal functional form S(f) \sim 1/f^alpha (alpha \approx 1) over
several orders of magnitude in the frequency range 10^-7< f < 10^-5 cycle/base,
corresponding to long-ranging GC% correlations at distances between 100 kb and
10 Mb. S(f) for higher frequencies (f > 10^-5 cycle/base) shows a flattened
power-law function with alpha < 1 across all twenty-one chromosomes. The
substitution of about 38% interspersed repeats does not affect the functional
form of S(f), indicating that these are not predominantly responsible for the
long-ranged multi-scale GC% fluctuations in mammalian genomes. Several
biological implications of the large-scale GC% fluctuation are discussed,
including neutral evolutionary history by DNA duplication, chromosomal bands,
spatial distribution of transcription units (genes), replication timing, and
recombination hot spots.Comment: 15 pages (figures included), 2 figure
Extending displacement-based earthquake loss assessment (DBELA) for the computation of fragility curves
This paper presents a new procedure to derive fragility functions for populations of buildings that relies on the
displacement-based earthquake loss assessment (DBELA) methodology. In the method proposed herein,
thousands of synthetic buildings have been produced considering the probabilistic distribution describing the
variability in geometrical and material properties. Then, their nonlinear capacity has been estimated using the
DBELA method and their response against a large set of ground motion records has been estimated. Global limit
states are used to estimate the distribution of buildings in each damage state for different levels of ground
motion, and a regression algorithm is applied to derive fragility functions for each limit state. The proposed
methodology is demonstrated for the case of ductile and non-ductile Turkish reinforced concrete frames with
masonry infills
Using a prisoner advisory group to develop diversity research in a maximum-security prison
This paper addresses groupwork processes with a group of prisoners advising a research project in a maximum-security prison in England. The research project (Appreciative Inquiry into the Diversity Strategy of HMP Wakefield. RES-000-22-3441) was funded by the Economic and Social Research Council (ESRC) and lasted 9 months. The research explored the experiences of prisoners in diverse minority groupings and the strategies of the prison to accommodate the complex needs of these groups. The Prisoner Advisory Group (PAG) was made up of representatives from Black and Minority Ethnic (BME) prisoners; older prisoners (over 60s); Disabled prisoners (with physical disabilities, learning difficulties; and mental health problems); Gay, Bi-sexual and Transgender prisoners; and prisoners affiliated to Faith groups. It met regularly during the research. The paper considers the forming norming and performing aspects of establishing an effective participant voice in a prison-based project. It considers the contribution of the PAG to developing a research strategy that engaged prisoners in the research. It reflects on the nature of âparticipative researchâ in general and whether such research is possible within a high-security prison environment
The dust content of the Crab Nebula
We have modelled the near-infrared to radio images of the Crab Nebula with a Bayesian SED
model to simultaneously fit its synchrotron, interstellar (IS), and supernova dust emission. We
infer an IS dust extinction map with an average AV = 1.08 ± 0.38 mag, consistent with a small
contribution (22 per cent) to the Crabâs overall infrared emission. The Crabâs supernova dust
mass is estimated to be between 0.032 and 0.049 M (for amorphous carbon grains) with an
average dust temperature Tdust = 41 ± 3 K, corresponding to a dust condensation efficiency
of 8â12 per cent. This revised dust mass is up to an order of magnitude lower than some
previous estimates, which can be attributed to our different IS dust corrections, lower SPIRE
flux densities, and higher dust temperatures than were used in previous studies. The dust
within the Crab is predominantly found in dense filaments south of the pulsar, with an average
V-band dust extinction of AV = 0.20â0.39 mag, consistent with recent optical dust extinction
studies. The modelled synchrotron power-law spectrum is consistent with a radio spectral
index αradio = 0.297 ± 0.009 and an infrared spectral index αIR = 0.429 ± 0.021. We have
identified a millimetre excess emission in the Crabâs central regions, and argue that it most
likely results from two distinct populations of synchrotron emitting particles. We conclude
that the Crabâs efficient dust condensation (8â12 per cent) provides further evidence for a
scenario where supernovae can provide substantial contributions to the IS dust budgets in
galaxies
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