Academic literature on the topic 'Nuclear run-off analysis'
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 'Nuclear run-off analysis.'
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 "Nuclear run-off analysis"
1
Shiota, Chiyo, Kazuhiro Ikenaka, and Katsuhiko Mikoshiba. "Developmental Expression of Myelin Protein Genes in Dysmyelinating Mutant Mice: Analysis by Nuclear Run-Off Transcription Assay, In Situ Hybridization, and Immunohistochemistry." Journal of Neurochemistry 56, no. 3 (March 1991): 818–26. http://dx.doi.org/10.1111/j.1471-4159.1991.tb01997.x.
Full text
2
Hampson, IN, MA Cross, CM Heyworth, L. Fairbairn, E. Spooncer, GJ Cowling, and TM Dexter. "Expression and downregulation of cytotoxic cell protease 1 or Granzyme 'B' transcripts during myeloid differentiation of interleukin-3- dependent murine stem cell lines." Blood 80, no. 12 (December 15, 1992): 3097–105. http://dx.doi.org/10.1182/blood.v80.12.3097.3097.
Full textAbstract:
Abstract Using the technique of differential cDNA library screening, we have molecularly cloned a gene that is highly expressed in an undifferentiated myeloid multipotent and growth factor-dependent stem cell line (FDCP-Mix) and that downregulates as these cells are induced to differentiate along monocytic, granulocytic, and erythroid cell lineages. Sequence analysis of this gene has shown homology with a previously cloned gene, cytotoxic cell protease 1 (CCP1 or Granzyme ‘B’), that has been shown to be expressed only in thymocytes, activated T cells, a mast cell line, and peritoneal exudate leukocytes. In situ hybridization, Northern blot analysis, and nuclear run-off assay has confirmed that expression of CCP1 is restricted to the phenotypically primitive multipotent undifferentiated. FDCP-Mix cells that are undergoing self-renewal in the presence of growth factors such as interleukin-3.
3
Hampson, IN, MA Cross, CM Heyworth, L. Fairbairn, E. Spooncer, GJ Cowling, and TM Dexter. "Expression and downregulation of cytotoxic cell protease 1 or Granzyme 'B' transcripts during myeloid differentiation of interleukin-3- dependent murine stem cell lines." Blood 80, no. 12 (December 15, 1992): 3097–105. http://dx.doi.org/10.1182/blood.v80.12.3097.bloodjournal80123097.
Full textAbstract:
Using the technique of differential cDNA library screening, we have molecularly cloned a gene that is highly expressed in an undifferentiated myeloid multipotent and growth factor-dependent stem cell line (FDCP-Mix) and that downregulates as these cells are induced to differentiate along monocytic, granulocytic, and erythroid cell lineages. Sequence analysis of this gene has shown homology with a previously cloned gene, cytotoxic cell protease 1 (CCP1 or Granzyme ‘B’), that has been shown to be expressed only in thymocytes, activated T cells, a mast cell line, and peritoneal exudate leukocytes. In situ hybridization, Northern blot analysis, and nuclear run-off assay has confirmed that expression of CCP1 is restricted to the phenotypically primitive multipotent undifferentiated. FDCP-Mix cells that are undergoing self-renewal in the presence of growth factors such as interleukin-3.
4
Flowers, M. A., Y. Wang, R. J. Stewart, B. Patel, and P. A. Marsden. "Reciprocal regulation of endothelin-1 and endothelial constitutive NOS in proliferating endothelial cells." American Journal of Physiology-Heart and Circulatory Physiology 269, no. 6 (December 1, 1995): H1988—H1997. http://dx.doi.org/10.1152/ajpheart.1995.269.6.h1988.
Full textAbstract:
The expression of endothelin-1 (ET-1) and endothelial constitutive nitric oxide synthase (ecNOS) was assessed in two independent in vitro models: asynchronously differentially proliferating cultures and wounded endothelial cell monolayers. Northern blot analysis of RNA isolated from preconfluent, confluent, and postconfluent cells revealed a fourfold rise in ET-1 mRNA transcripts, whereas levels of ecNOS mRNA transcripts were reduced twofold in proliferating cells. Nuclear run-off analysis demonstrated that increased steady-state ET-1 mRNA content in proliferating cells was mediated, in part, by increased gene transcription. In contrast, ecNOS transcription rates in proliferating cells were not decreased compared with quiescent nonproliferating cells, indicating that mRNA destabilization mediated the decreased ecNOS mRNA levels in proliferating endothelium. Concordant changes in protein expression were documented for both ET-1 and ecNOS. In injured endothelial cell monolayers, in situ cRNA hybridization demonstrated increased mRNA transcript levels for ET-1 in growth fronts of injured endothelial monolayers. These data are taken to indicate that expression of ET-1 and ecNOS is reciprocally regulated in two different models of endothelial cell proliferation.
5
Batistatou, A., C. Volonté, and L. A. Greene. "Nerve growth factor employs multiple pathways to induce primary response genes in PC12 cells." Molecular Biology of the Cell 3, no. 3 (March 1992): 363–71. http://dx.doi.org/10.1091/mbc.3.3.363.
Full textAbstract:
Nerve growth factor (NGF) leads to neuronal differentiation of PC12 cells and promotes their survival in serum-free medium. Past studies have shown that purine analogues block some of the effects of NGF but not others and thus that they can be used to dissect the mechanistic pathways of its action. In the present work we used 2-aminopurine (2-AP) and 6-thioguanine (6-TG) to examine whether NGF causes activation of primary response genes through a single signaling pathway or via multiple pathways. Northern blot analysis and nuclear run-off transcription assays were used to assess the activation of c-fos, c-jun, TIS1, TIS8, and TIS11 after exposure of PC12 cells to NGF in the presence or absence of 2-AP and 6-TG. Our findings indicate that NGF appears to employ at least three distinct pathways to induce early genes in PC12 cells. This suggests that the NGF signaling mechanism diverges at an early point after interaction of NGF with its receptor.
6
Granneman, J. G., and K. N. Lahners. "Regulation of mouse beta 3-adrenergic receptor gene expression and mRNA splice variants in adipocytes." American Journal of Physiology-Cell Physiology 268, no. 4 (April 1, 1995): C1040—C1044. http://dx.doi.org/10.1152/ajpcell.1995.268.4.c1040.
Full textAbstract:
This study examined the regulation of murine beta 3-receptor mRNA and determined whether the recently described mRNA splice variants are differentially regulated by agents that alter total beta 3-receptor mRNA levels. In vivo treatment of mice with the beta 3-receptor agonist BRL-26830 reduced total beta 3-transcripts by 64% in white adipose tissue but did not alter the mRNA splicing pattern. Further analysis in cultured 3T3-F442A adipocytes showed that isoproterenol, dexamethasone, or phorbol 12-myristate 13-acetate also greatly reduced beta 3-receptor mRNA levels without selectively altering poly-U-containing transcripts. Blockade of transcription with actinomycin D produced a rapid loss of beta 3-receptor mRNA, which was prevented by blockade of mRNA translation with cycloheximide. However, neither actinomycin D nor cycloheximide altered the splicing pattern of beta 3-receptor mRNA. Analysis of transcription rate by nuclear run-off assay indicated that 8-bromoadenosine 3',5'-cyclic monophosphate and phorbol 12-myristate 13-acetate reduce beta 3-receptor gene transcription and that suppression of transcription is sufficient to account for the reduction in beta 3-receptor mRNA levels by these agents.
7
Yamasaki, Toshiki, George Klein, Hans-Gustaf Ljunggren, Klas Kärre, Kouzo Moritake, Jonathan T. Paine, and Haruhiko Kikuchi. "Role of histocompatibility antigen gene and proto-oncogene expressions in intracerebral tumorigenicity of mouse neuroblastoma." Journal of Neurosurgery 78, no. 4 (April 1993): 619–29. http://dx.doi.org/10.3171/jns.1993.78.4.0619.
Full textAbstract:
✓ The role of N-myc, c-src, and major histocompatibility complex (MHC, H-2 in the mouse) class I antigen gene expressions in dimethyl sulfoxide (DMSO)-induced differentiation and intracerebral tumorigenicity was examined using a mouse MNB85 neuroblastoma cell line. A fluorescence-activated cell sorter disclosed cell-surface MHC enhancement by DMSO, causing an increase in cytotoxic T-lymphocyte sensitivity. Southern blot analysis verified a single copy of the proto-oncogenes and MHC deoxyribonucleic acids in both untreated and DMSO-treated MNB85 cells. Northern blot analysis indicated that DMSO treatment induced a decrease in N-myc and an increase in c-src and MHC messenger ribonucleic acids. Nuclear run-off transcription assay revealed down-regulation of N-myc at a posttranscriptional level, contrasted with primary up-regulation of c-src at a transcriptional level. Immunoprecipitation after treatment with enzyme endo-beta-N-acetyl-glycoseamidase H proved that the terminal glycosylation of MHC heavy-chain gene products normally occurs in the Golgi apparatus of MNB85 cells. Intracerebral tumorigenicity assay showed that cells highly MHC-expressed by DMSO were less tumorigenic than untreated cells in association with DMSO-augmented cytotoxic T-lymphocyte susceptibility. These results suggest that proto-oncogenes may be linked to cellular differentiation, while cell-surface MHC gene expression influences intracerebral immunosurveillance.
8
Aklilu, F., M. Park, D. Goltzman, and S. A. Rabbani. "Increased PTHRP production by a tyrosine kinase oncogene, Tpr-Met: role of the Ras signaling pathway." American Journal of Physiology-Endocrinology and Metabolism 271, no. 2 (August 1, 1996): E277—E283. http://dx.doi.org/10.1152/ajpendo.1996.271.2.e277.
Full textAbstract:
We have used the Tpr-Met oncogene as a model to examine signaling pathways of growth factors and tyrosine kinase oncogenes that can increase parathyroid hormone-related peptide (PTHRP) production. PTHRP production in Tpr-Met transfected cells, when assessed by Northern blot analysis and radioimmunoassay, was increased four- to eightfold. Treatment of these cells with the transcriptional inhibitor actinomycin D and nuclear run-off assays showed that the major cause of increased PTHRP mRNA was enhanced gene transcription. To analyze the intracellular signaling molecules involved in PTHRP production, stable cell lines expressing a Tyr489 Phe mutant of the Tpr-Met oncoprotein were examined. The mutant fails to activate phosphatidylinositol (PI)-3 kinase or associate with the Grb-2 adaptor protein and caused a significant reduction in PTHRP production. Treatment of wild-type Tpr-Met transfected cells with wortmannin, a PI-3 kinase inhibitor, had no effect on PTHRP production; however, treatment of these cells with lovastatin, an inhibitor of p21ran isoprenylation, significantly reduced PTHRP expression. These results show that PTHRP is a downsteam target of the Tpr-Met oncogene and indicate that the PTHRP stimulating activity is mediated via the Ras signaling pathway.
9
Frigon, NL Jr, L. Shao, AL Young, L. Maderazo, and J. Yu. "Regulation of globin gene expression in human K562 cells by recombinant activin A." Blood 79, no. 3 (February 1, 1992): 765–72. http://dx.doi.org/10.1182/blood.v79.3.765.765.
Full textAbstract:
Abstract Recent studies indicate that a purified protein, activin A, belongs to the transforming growth factor beta (TGF-beta) superfamily. Similar to TGF-beta, activin A can have different biologic activities, depending on the target tissues. We used recombinant activin A to demonstrate a possible regulatory role of this protein in modulating human erythroid differentiation in the human erythroid cell line, K562. Using genomic probes containing the second exon of alpha, beta, gamma, and epsilon globins, relative abundance of various types of globin transcripts in untreated and activin-treated K562 cells was examined with S1 nuclease analysis. Despite considerable homology amongst various globin sequences, these globin probes were highly specific for their unique mRNA species in the analyses. It was shown that the abundance of specific globin probe fragments for gamma and epsilon globins (209 nucleotides) as well as alpha (180 nucleotides), which were protected from S1 digestion, increased many fold in K562 cells treated with activin A. In contrast, there were no specific transcripts of beta globin detected in either the control or activin-treated cells. The increases in the level of fetal and embryonic beta-like and alpha globin transcripts also confirmed earlier studies of Northern and slot- blot analyses using globin cDNA as probes. In addition, nuclear run-off transcription assay using isolated nuclei indicated that most of the increase in the globin transcripts after activin treatment could be attributed to the stimulation of transcription rate for globin genes. Transient transfection assays also provide evidence that activin A significantly stimulated transcriptional activity of an epsilon globin promoter in K562, but not in the nonerythroid Chinese hamster ovary cells. Therefore, it was concluded that activin A exerts its effects on globin gene expression at the level of transcription in erythroid cells.
10
Frigon, NL Jr, L. Shao, AL Young, L. Maderazo, and J. Yu. "Regulation of globin gene expression in human K562 cells by recombinant activin A." Blood 79, no. 3 (February 1, 1992): 765–72. http://dx.doi.org/10.1182/blood.v79.3.765.bloodjournal793765.
Full textAbstract:
Recent studies indicate that a purified protein, activin A, belongs to the transforming growth factor beta (TGF-beta) superfamily. Similar to TGF-beta, activin A can have different biologic activities, depending on the target tissues. We used recombinant activin A to demonstrate a possible regulatory role of this protein in modulating human erythroid differentiation in the human erythroid cell line, K562. Using genomic probes containing the second exon of alpha, beta, gamma, and epsilon globins, relative abundance of various types of globin transcripts in untreated and activin-treated K562 cells was examined with S1 nuclease analysis. Despite considerable homology amongst various globin sequences, these globin probes were highly specific for their unique mRNA species in the analyses. It was shown that the abundance of specific globin probe fragments for gamma and epsilon globins (209 nucleotides) as well as alpha (180 nucleotides), which were protected from S1 digestion, increased many fold in K562 cells treated with activin A. In contrast, there were no specific transcripts of beta globin detected in either the control or activin-treated cells. The increases in the level of fetal and embryonic beta-like and alpha globin transcripts also confirmed earlier studies of Northern and slot- blot analyses using globin cDNA as probes. In addition, nuclear run-off transcription assay using isolated nuclei indicated that most of the increase in the globin transcripts after activin treatment could be attributed to the stimulation of transcription rate for globin genes. Transient transfection assays also provide evidence that activin A significantly stimulated transcriptional activity of an epsilon globin promoter in K562, but not in the nonerythroid Chinese hamster ovary cells. Therefore, it was concluded that activin A exerts its effects on globin gene expression at the level of transcription in erythroid cells.
Dissertations / Theses on the topic "Nuclear run-off analysis"
1
White, Hilary Louise. "Transcription in the human #beta# globin locus." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337833.
Full textConference papers on the topic "Nuclear run-off analysis"
1
Leung, W. H. "On the MEGAPIE Target Thermal Hydraulics: A RELAP5 Analysis." In 12th International Conference on Nuclear Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/icone12-49378.
Full textAbstract:
A new type of liquid-metal target is designed for the Spallation Neutron Source in PSI. LBE is selected to be the target material and the primary coolant as well. RELAP5/MOD 3.2 is used to analyze the system thermal hydraulics. The nominal conditions are chosen based on temperature constraints from the design assessments. The steady state results are in the proximity of the design specifications and the heat removal capacity is adequately deployed. The normal thermal hydraulic transients, namely the proton beam and beam interrupt, are studied. A basic PID (Proportional, Integral, Derivative) control is implemented in the RELAP5 for regulating the target temperature. It is found that the control chain works very well for the beam trip in limiting the temperature fluctuations. In a beam interrupt, the proton beam is completely turned off without recovering. The transition from full power to hot-standby is quite smooth, but it becomes oscillatory in the long run due to the timelags in the cooling loops’ responses. An off normal case of target main coolant trip has also been studied. Without the main pump, the target can still be operated in the natural circulation mode, and the control can cope with the normal beam transients and restarting the target from hot standby.
2
Duan, Tianying, Peide Zhou, Bin Long, Yun Hu, Yizhe Liu, Chen Huang, Huajin Yu, et al. "Preliminary Research and Design in the Nuclear Island Systems of 1500MWt Standing-Wave Reactor." In 2013 21st International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icone21-16134.
Full textAbstract:
As one kind of fast reactor, the Traveling-Wave Reactor (TWR) utilizes depleted uranium with a small amount of enriched uranium/ plutonium which is used to kick off the chain reaction. The TWR can run for decades without refueling or removing any used fuel from the reactor. The most challenging issues on TWR are fuel design, structural material for fuel cladding, core physics process analysis and core physics design. Based on the present technology of fuel and structural material, a new concept named Standing-Wave Reactor (SWR) which is the preliminary stage of the TWR is proposed. The wave of fission would move through the depleted uranium core by fuel transfer in SWR. According to the concept of SWR and the published data of fuel and material, the R&D works on 1500MWt SWR have been performed, which cover the reactor core, reactor structure, process system et.al. The preliminary results confirm the feasibility of SWR. Meanwhile, the design of reactor core and the main systems which is based on the technologies of available pool sodium-cooled fast reactor has been accomplished.
3
Yamamoto, Shinji, and Toshiro Kitamura. "Best Practices in Japan of Human Resource Development for NPP O&M: Roles and Lessons From Training Centers." In 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48137.
Full textAbstract:
The use of best practices and their lateral expansion as a benchmark is one of effective methods of “knowledge management (NK)”. Best practices of human resources development were collected (selected examples are listed below) from all 11 training centers annexed to the nuclear power plants in Japan and lessons were learned for possible lateral development for improving other stakeholders’ NK. Such best practices will provide productive information for designing their own human resources development strategies. Examples of collected good practices: • Exhibition of troubles and negative legacies: The actual machineries, equipment or components, explanatory documents or news articles of the past troubles experienced by themselves are effective to maintain and refresh the awareness and preparedness of trainees and other employees for recurrence prevention. The exhibitions are open to the visitors, too. • Experience-type training facilities: Off-normal conditions of components and systems are simulated for the staff practical training by the use of the facilities which provide an off-normal environment. Examples are: water hammers, abnormal vibrations and noises of rotating machineries, pump cavitations, pinholes, plumbing airs, etc. • Advanced simulators for operators training: Each electric company has its own simulators for training their own operating staff. These simulators are annexed to the nuclear power plants and used to train the operation staff by the experienced shift managers. The operation staff use the simulator for continually confirming the operation procedures and the plant behavior, etc. specific to their plants. Training for generic plant behavior and operators’ responses are mainly outsourced to the dedicated training centers run by the Owners’ Groups (BWR, PWR). • The SAT methods: The IAEA proposed SAT (Systematic Approach to Training) approach is applied to the training of the operating staff and the maintenance staff. It is structured in a flow of Job analysis ← Training program design ← Training material development ← Training ← Evaluation. • Training in real situations: An example is a trainee actually hung with a lifeline on a harness to learn a method of putting on the lifeline. On the other hand, the efficiency (availability) of the training facilities for maintenance work is very limited, because each electric company installs the training facilities individually. Experiences of ICONE-16 participants from other countries in improving the availability are of our interest.
4
Colón Rodríguez, José, Nor Farida Harun, Nana Zhou, Edward Sabolsky, and David Tucker. "System Analysis of a 100kW Internal Combustion Engine (ICE) Solid Oxide Fuel Cell (SOFC) Hybrid Configuration." In ASME 2020 Power Conference collocated with the 2020 International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/power2020-16620.
Full textAbstract:
Abstract Due to the intermittent nature of the renewable power plants and the rigid operation of existing plans, the need for flexible power production is eminent. Hybrid energy systems have shown potential for flexible power production capable to fulfill the power demands and maintain the efficiency. This work studies different design cases of a 100kW Internal Combustion Engine (ICE) and Solid Oxide Fuel Cell (SOFC) hybrid system. Anode off-gas from the fuel cell stack provided the chemical energy to run the ICE. Heat management of the anode exhaust was considered to attain the operational limits of the ICE in the present configuration. A turbocharger was used to deliver the necessary air flow for both the fuel cell stack and the engine. A series of 25 design cases were chosen to analyze the performance and the potential flexibility of this cycle. The 25-design points resulted from a matrix composed of the variation of fuel utilization and reformer operating temperature, ranging from 70% to 90% and 600K to 1000K, respectively. At each design point, hardware was re-sized to match the desired conditions. The cycle performance and fuel cell distributed profiles are discussed in this paper. It is discovered that the system efficiency increases as the fuel utilization increases following a nearly linear behavior. The highest efficiency attained is 62% at a reformer operating temperature of 800K and a 90% fuel utilization. The minimum external fuel required to maintain turbocharger in operation decreases with the increase on the reformer temperature. Power contribution between ICE and SOFC follows a linear behavior closely overlapping each trend at different reforming operational temperatures. The impact of external reforming and internal on-anode reforming is also discussed. It is found that there is an optimal balance between the external and internal reforming. The optimal methane content in this work is shown to be around ∼18 vol%.
5
Hawila, Mohammad A., and Karen Vierow Kirkland. "RCIC Turbo-Pump Scaling Through CFD and Model Testing for the Texas A&M University NHTS Facility." In 2018 26th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/icone26-81119.
Full textAbstract:
One of the requirements for licensing a nuclear power plant in the U.S is the capability to survive and recover from a station blackout according to the U.S Nuclear Regulatory Commission (USNRC). Station blackout is the loss of all off-site and onsite power simultaneously. Therefore, experimental test facilities are being constructed and operated to test the performance of the related safety systems in a nuclear power plant. Design and construction of a test facility creates the need to perform scaling analysis to ensure proper representation of key components and phenomena of interest. One of the main outcomes of the scaling analysis is the quantitative estimation of the Similarity Level (SL), which requires derivation of dimensionless scaling parameters and prediction of appropriate input values for the scaling parameters. To study the performance of the Reactor Core Isolation Cooling (RCIC) system, the Nuclear Heat Transfer Systems (NHTS) Laboratory at Texas A&M University has constructed and is operating a RCIC test facility. This paper presents the scaling analysis with reference to a full-size RCIC system and the RCIC system turbine was used as the main component for scaling. The input parameters for dimensionless scaling parameters were obtained through experimental measurements and CFD analysis. The CFD analysis is for the ZS-1 RCIC system turbine model. The STAR-CCM+ CFD code was used in this study to create and run simulations for steady state normal and abnormal operating conditions for the NHTS-developed CAD models. The input for the dimensionless scaling parameters was estimated. Input parameters were collected both experimentally and from CFD simulations and inserted into these equations. As a result, a high degree of similarity was confirmed, with a minimum of 82% between the NHTS and full-size RCIC systems. The 82% represents the amount of transfer properties conserved between the two systems. Consequently, this high similarity level allows the NHTS RCIC system to be used to study the behavior of the full-size RCIC system under Beyond Design Bases Accident (BDBA) conditions. Future work is to study and model other components of the RCIC system such as the suppression chamber to estimate similarity levels and study their effects on behavior of the system under BDBA.
6
Virgen, Matthew Miguel, and Fletcher Miller. "Analysis of a Combined Cycle Plant Using a Small Particle Receiver to Drive a Primary Brayton Cycle." 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/es2015-49317.
Full textAbstract:
All current commercial CSP plants operate at relatively low thermodynamic efficiency due to lower temperatures than similar conventional plants and due to the fact that they all employ Rankine conversion cycles. We present here an investigation on the effects of adding a bottoming steam power cycle to a hybrid CSP plant based on a Small Particle Heat Exchange Receiver (SPHER) driving a gas turbine as the primary cycle. Due to the high operating temperature of the SPHER being considered (over 1000 Celsius), the exhaust air from the primary Brayton cycle still contains a tremendous amount of exergy. While in the previous analysis this fluid was only used in a recuperator to preheat the Brayton working fluid, the current analysis explores the potential power and efficiency gains from instead directing the exhaust fluid through a heat exchanger to power a Rankine steam cycle. Not only do we expect the efficiency of this model to be competitive with conventional power plants, but the water consumption per kilowatt-hour will also be reduced by nearly two thirds as compared to most existing concentrating solar thermal power plants as a benefit of having air as the primary working fluid, which eliminates the condensation step present in Rankine-cycle systems. Coupling a new steam cycle model with the gas-turbine CSP model previously developed at SDSU, a wide range of cases were run to explore options for maximizing both power and efficiency from the proposed CSP combined cycle gas turbine (CCGT) plant. Due to the generalized nature of the bottoming cycle modeling, and the varying nature of solar power, special consideration had to be given to the behavior of the heat exchanger and Rankine cycle in off-design scenarios. The trade-offs of removing the recuperator for preheating the primary fluid are compared to potential overall power and efficiency gains in the combined cycle case.
7
Cumpston, J., and John D. Pye. "Optimisation of Paraboloidal Dish Fields for Direct-Steam Generation." 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/es2015-49712.
Full textAbstract:
We investigate losses and costs associated with direct steam generation via parabolidal dish concentrators and steam transport to a central steam Rankine power cycle for electricity generation. This study presents a power plant model that accounts for the effects of shading, steam transport, energy conversion at the power block, and capital costs of land and pipework. The pipe network topology used was optimised using a genetic algorithm based on evolution of minimal spanning trees connecting all dishes to a central power block. Optimal pipe sizing of the network is determined by considering the trade-off of frictional losses against thermal losses and material costs. Weather data provides input for the solar resource, and shading is calculated using an established numerical model. The plant model is used to determine the collector layout for which the effective annual revenue is maximised. Results show that the optimal rectangular layout is closely spaced in the North-south direction, along which most of the pipe links run, while East-west spacing is less important. The annual thermal performance of the optimised dish field on a per-unit-area basis is then compared to simulation of a parabolic trough employed for the same purpose. A detailed breakdown of the thermal analysis used forms the basis of comparison between the collector types, giving the overall advantage and a comparison of various sources of loss. We demonstrate that dish fields can collect approximately 49% more thermal energy annually per unit collector area than a trough system employed for the same purpose.
8
Iino, Kenji, Ritsuo Yoshioka, Masao Fuchigami, and Masayuki Nakao. "What Could Have Saved Fukushima From Its Severe Accident." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-65069.
Full textAbstract:
The Great East Japan Earthquake on March 11, 2011 triggered huge tsunami waves that devastated the northeast region of Japan along the Pacific coastline. The Tokyo Electric Power Company (TEPCO) owned Fukushima Daiichi Nuclear Power Plant (Fukushima-1) survived the earthquake, however, not the tsunami that followed. Four of the 6 reactor units underwent Station Blackout. Unit 5 lost all its own AC power, however, it shared AC power with Unit 6. Units 1, 3, and 4 had hydrogen explosions that destroyed their reactor buildings, and even worse, 1, 2, and 3 had core meltdowns to release a large amount of radioactive material to their surroundings. The accident was rated Level 7 on the International Nuclear Event Scale, the worst level defined by International Atomic Energy Agency (IAEA). Reports and papers have been published by a number of entities including the Japanese Diet, Government, TEPCO, IAEA, and more. They give detail explanation of how the accident developed into a nuclear disaster explaining the direct and background causes and faults made after the accident broke out. Finding the accident process, i.e., how it happened, and its causes of why it happened, are the most important first steps in accident analysis. Figuring out how to prevent similar events in the future, or even if it is possible to do so, however, is equally important for our future. We started our study in 2014 to find what actions TEPCO could have taken before the accident for preventing it from growing into a catastrophe. Then in February 2015, we set the goal of our study group to find answers to the following two questions: A. Was the huge tsunami, induced by a huge earthquake, predictable at Fukushima-1? B. If it was predictable, what preparations at Fukushima-1 could have reduced the severity of the accident? In response to our invitation to experts in the nuclear field, active and retired people gathered from academia, manufacturers, utility companies, and even regulators. After a series of tense discussions, we reached the conclusions that: Aa. Tsunami of the level that hit Fukushima-1 in 2011 was well predictable, and, Ba. The accident would have been much less severe if the plant had prepared a set of equipment, and most of all, had exercised actions against such tsunami. Preparation at the plant to prevent the severe accident consisted of the following items 1 through 7, and drills in 8: 1. A number of 125Vdc and 250Vdc batteries, 2. Portable underwater pumps, 3. Portable AC generators with sufficient gasoline supply to run the pumps, and 4. High voltage AC power truck This set applied only to this specific accident. For preparing against many other situations that could have taken place at Fukushima-1, we recommend having, in addition, the following equipment and modifications. 5. Portable compressor to drive air-operated valves for venting, 6. Watertight modification to RCIC and HPCI control and instrumentation, 7. Fire engines for alternate low pressure water injection after vent (Fukushima-1 had three). Just making these preparations would not have been sufficient. Activating valves with DC batteries, for example, takes disengaging the regular power supply lines and hooking up the batteries. 8. Drills against extended loss of all electric power and seawater pump This item 8, on and off-site drills was the most important preparation that should had been made. All other necessary preparations to save the plant in such cases would have followed logically.