Application of Maximum Likelihood Method to Boiler System Identification

A maximum likelihood (ML) method is applied to a boiler system identification. The mathematical model used in this paper is a discrete-time, singleinput and single-output (SISO), constant, linear system excited by an “innovation” process. Since the ML identification is reduced to a nonlinear optimization problem with equality constraints, the Davidon's conjugate gradient method is employed for numerical solutions. By using the given input/output data, the dynamics of the governor/steam pressure and the governor/steam temperature relations are identified as an SISO system, respectively. AIC and a test based on the innovation process are also applied for selecting an appropriate order of the assumed model

In situ approach for characterizing PEMFC using a combination of magnetic sensor probes and 3DFEM simulation

Non-uniform current distributions of proton-exchange membrane fuel cells (PEMFCs) result in unequal utilization of reactants and catalysts in solution. To prevent the degradation of PEMFC, an in situ approach for characterizing PEMFC stacks is needed. In this study, the current distribution of two-cell PEMFC stacks is replicated from measured magnetic flux densities and operating conditions produced by three-dimensional finite element modeling that included electromagnetic field modeling and electrochemical reactions. I–V curves under normal conditions were replicated from electrochemistry and compared to the measured curves, and magnetic flux density distributions were investigated to determine the operating state. From these results, we discuss the potential use of the proposed approach in in situ applications.Theoretical & Computational Chemistr

CAMERA CALIBRATION TECHNIQUE BY PAN-CLOSEUP EXPOSURES FOR INDUSTRIAL VISION METROLOGY

A high precision and easy-to-use CCD camera calibration technique for industrial vision metrology is discussed. A well-known method is self-calibration by convergent camera configuration of a two- or three-dimensional target field. Only with this technique the central part of a sensor area is precisely calibrated, but off the centre the precision rapidly deteriorates. The presented technique is a simultaneous adjustment of both pan and close exposures, which compensates the lack of distortion data in the fringe area of the sensor and offers both uniform and high-precision calibration. Some patterns of camera configuration are compared in an experiment in terms of the precision and its uniformity over the sensor. And the combination of convergent pan exposures and vertical close exposures is proved the best. 1

カガク データ カチョウカ プロジェクト プロジェクト タチアゲ ト ショキ データ コウカイ

We report on the current status of our astronomical data sonification project. This project aims to sonify astronomical data, that is, to convert a visual medium into an audio medium for both scientists and the visually impaired. We hope that sonification can lead to a new way of conceptualizing scientific data. The primary sourcesof the data used for this project come from Japanese satellites dedicated to X-ray astronomy and geophysics. This project is performed in collaboration with Nihon Fukushi University and the Center for Planning and Information Systems (PLAIN center) of the Japan Aerospace Exploration Agency (JAXA) Institute of Space andAstronautical Science (ISAS). Our project began in March 2006. Since this time we have sonified astronomical data sets, including data from X-ray pulsars, and have published these results. In this paper we also discuss future plans for the project, as well as its implications for visually impaired scientists and public

A Production and Delivery Model of Hydrogen from Solar Thermal Energy in the United Arab Emirates

Hydrogen production from surplus solar electricity as energy storage for export purposes can push towards large-scale application of solar energy in the United Arab Emirates and the Middle East region; this region’s properties of high solar irradiance and vast empty lands provide a good fit for solar technologies such as concentrated solar power and photovoltaics. However, a thorough comparison between the two solar technologies, as well as investigating the infrastructure of the United Arab Emirates for a well-to-ship hydrogen pathway, is yet to be fully carried out. Therefore, in this study we aim to provide a full model for solar hydrogen production and delivery by evaluating the potential of concentrated solar power and photovoltaics in the UAE, then comparing two different pathways for hydrogen delivery based on the location of hydrogen production sites. A Solid Oxide Cell Electrolyzer (SOEC) is used for technical comparison, while the shortest routes for hydrogen transport were analyzed using Geographical Information System (GIS). The results show that CSP technology coupled with SOEC is the most favorable pathway for large-scale hydrogen from solar energy production in the UAE for export purposes. Although PV has a slightly higher electricity potential compared to CSP, around 42 GWh/km2 to 41.1 GWh/km2, respectively, CSP show the highest productions rates of over 6 megatons of hydrogen when the electrolyzer is placed at the same site as the CSP plant, while PV generates 5.15 megatons when hydrogen is produced at the same site with PV plants; meanwhile, hydrogen from PV and CSP shows similar levels of 4.8 and 4.6 megatons of hydrogen, respectively, when electrolyzers are placed at port sites. Even considering the constraints in the UAE’s infrastructure and suggesting new shorter electrical transmission lines that could save up to 0.1 megatons of hydrogen in the second pathway, production at the same site with CSP is still the most advantageous scenario

Techno-Economic Analysis of Solar Thermal Hydrogen Production in the United Arab Emirates

Solar thermal technology can provide the United Arab Emirates and the Middle East region with abundant clean electricity to mitigate the rising levels of carbon dioxide and satisfy future demand. Hydrogen can play a key role in the large-scale application of solar thermal technologies, such as concentrated solar plants, in the region by storing the surplus electricity and exporting it to needed countries for profit, placing the Middle East and the United Arab Emirates as major future green hydrogen suppliers. However, a hydrogen supply chain comparison between hydrogen from CSP and other renewable under the UAE’s technical and economic conditions for hydrogen export is yet to be fully considered. Therefore, in this study we provide a techno-economic analysis for well-to-ship solar hydrogen supply chain that compares CSP and PV technologies with a solid oxide water electrolyzer for hydrogen production, assuming four different hydrogen delivery pathways based on the location of electrolyzer and source of electricity, assuming the SOEC can be coupled to the CSP plant when placed at the same site or provided with electric heaters when placed at PV plant site or port sites. The results show that the PV plant achieves a lower levelized cost of electricity than that of the CSP plant with 5.08 ¢/kWh and 8.6 ¢/kWh, respectively. Hydrogen production results show that the scenario where SOEC is coupled to the CSP plant is the most competitive scenario as it achieves the payback period in the shortest period compared to the other scenarios, and also provides higher revenues and a cheaper LCOH of 7.85 $/kgH2

A Production and Delivery Model of Hydrogen from Solar Thermal Energy in the United Arab Emirates

Hydrogen production from surplus solar electricity as energy storage for export purposes can push towards large-scale application of solar energy in the United Arab Emirates and the Middle East region; this region’s properties of high solar irradiance and vast empty lands provide a good fit for solar technologies such as concentrated solar power and photovoltaics. However, a thorough comparison between the two solar technologies, as well as investigating the infrastructure of the United Arab Emirates for a well-to-ship hydrogen pathway, is yet to be fully carried out. Therefore, in this study we aim to provide a full model for solar hydrogen production and delivery by evaluating the potential of concentrated solar power and photovoltaics in the UAE, then comparing two different pathways for hydrogen delivery based on the location of hydrogen production sites. A Solid Oxide Cell Electrolyzer (SOEC) is used for technical comparison, while the shortest routes for hydrogen transport were analyzed using Geographical Information System (GIS). The results show that CSP technology coupled with SOEC is the most favorable pathway for large-scale hydrogen from solar energy production in the UAE for export purposes. Although PV has a slightly higher electricity potential compared to CSP, around 42 GWh/km2 to 41.1 GWh/km2, respectively, CSP show the highest productions rates of over 6 megatons of hydrogen when the electrolyzer is placed at the same site as the CSP plant, while PV generates 5.15 megatons when hydrogen is produced at the same site with PV plants; meanwhile, hydrogen from PV and CSP shows similar levels of 4.8 and 4.6 megatons of hydrogen, respectively, when electrolyzers are placed at port sites. Even considering the constraints in the UAE’s infrastructure and suggesting new shorter electrical transmission lines that could save up to 0.1 megatons of hydrogen in the second pathway, production at the same site with CSP is still the most advantageous scenario