MAKOTO AKAI - Academia.edu (original) (raw)

Papers by MAKOTO AKAI

Research paper thumbnail of Interface visualization of multiphase flow by using a fast x-ray CT scanner. Development of sensitive semi-conductor detector and its application to two-phase flow measurement

Research paper thumbnail of Qualification of High Performance Heat Pump - Evaluation of COP for “Super Heat Pump”

Heat Pumps, 1990

ABSTRACT Qualification methodology for high performance compression heat pump systems developed u... more ABSTRACT Qualification methodology for high performance compression heat pump systems developed under the Japanese national R&D project “Super Heat Pump Energy Accumulation System” has been studied. Particular attention has been paid for data fluctuations caused by variation in operational environment, characteristic time of the system, thermal disturbances, and electromagnetic noise from a power supply or control/auxiliary systems. The operation data were collected every 10 seconds for a few hours, and the averaging procedures have been examined to eliminate the influences of possible external disturbance with a wide spectrum of frequency. Through detailed analysis of the results, the optimum procedure to evaluate the stationary performance of heat pump system has been developed.

Research paper thumbnail of 高出力密度，高効率な水電解・燃料電池可逆セルスタックの開発

Research paper thumbnail of 8-20 ロバストなエネルギー需給構造に向けた指標体系((7)エネルギー需給,Session 8 エネルギー評価・経済)

Research paper thumbnail of Policy Parity for CCS? – Public Preference on Low Carbon Electricity

Energy Procedia, 2017

To examine the rationale for policy parity of three basic low carbon power sources, the consumer ... more To examine the rationale for policy parity of three basic low carbon power sources, the consumer preference for those power sources was evaluated by choice experiment through a public survey in December 2015-January 2016. A sample with decent representativeness was obtained by two stage stratified sampling and door-to-door canvassing. The choice questions were designed with realistic attributes simulating power retail market starting from April 2016. Through the data analysis, using random parameter logit model, we found that respondents' WTP shows that they considered not only CO2 emission reductions but also the characteristics of the three methods of low carbon power generation. It is also found that WTP is 11 yen per 1% increase in renewables, 14 yen per 1% decrease in nuclear (this WTP varies from one individual to another), and 4 yen per 1% increase in thermal power generation with CCS. The results of WTPs for the share of renewables and CCS in the power mix of new electricity retail companies in the future market rationalizes the necessity of policy parity to some extent for those technologies implying inclusion of CCS in the FIT but not nuclear.

Research paper thumbnail of An international experiment on CO2 ocean sequestration

Greenhouse Gas Control Technologies 4, 1999

ABSTRACT The ocean represents the largest potential sink for anthropogenic CO2. In order to bette... more ABSTRACT The ocean represents the largest potential sink for anthropogenic CO2. In order to better understand this potential, Japan, Norway, and the United States signed a Project Agreement for International Collaboration on CO2 Ocean Sequestration in December ...

Research paper thumbnail of K-2101 二酸化炭素処理を伴う化石燃料改質型高効率発電システムに関する研究(S27-1 次世代エネルギー源に対応した発電技術(1))(S27 次世代エネルギー源に対応した発電技術)

Research paper thumbnail of Viscosity measurement of aqueous solutions saturated by CO_2 under aquifer conditions

The proceedings of the JSME annual meeting, 2003

Research paper thumbnail of Public acceptance of CO2 capture and storage technologyA survey of public opinion to explore influential factors

Greenhouse Gas Control Technologies 7, 2005

Carbon capture and storage technology (CCS) represents a potential effective tool in managing car... more Carbon capture and storage technology (CCS) represents a potential effective tool in managing carbon emissions. Its effectiveness ultimately hinges upon its acceptability by the public. Little is known about how willing the general public will accept various options of CCS. This study's purpose is twofold. It first seeks to assess general perceptions of various forms of CCS. It then seeks to identify various factors that influence public acceptance of CCS. The study was done with a survey conducted in the Japanese cities of Tokyo and Sapporo in December 2003. Two versions of a survey questionnaire were administered to adults residing in this city through multi-stage sampling. One version provided limited education about CCS; the other version, a full education version, provided more extensive information about CCS. A total of 1,006 respondents participated in the study, equating to a total response rate of 63.9%. Data were analyzed using factor analysis, comparisons of means and rank order distributions, and through a multiple regression model. The findings of the study suggest that the general public generally supports CCS as a part of larger national climate policy. However, they are negatively disposed about implementation of specific CCS options involving deep-sea dilution option of ocean storage, lake type option of ocean storage, onshore option of geological storage, and offshore option of geological storage. Education about CCS affects public acceptance. In specific, the more information respondents obtained about CCS, the more likely they are to support those storage options except for onshore option of geological storage. Four important factors influencing public opinion involve environmental impacts and risks caused by injection of CO 2 (including possibility of leakage), effectiveness of CCS based on realizing the CCS as one of useful mitigation options of the climate change, societal responsibility for the environment, and relation of CCS with maintenance on fossil fuel use. Each affects public acceptability for CCS in general as well as support for implementation of four specific technology types of CCS.

Research paper thumbnail of Mortality Risk Valuation for Environmental Policy

Most benefit-cost analyses of reductions in air pollutants and other pollutants carrying mortalit... more Most benefit-cost analyses of reductions in air pollutants and other pollutants carrying mortality risks rely on estimates of the value of reductions in such risks produced by compensating wage studies, or contingent valuation studies that value risk reductions in the context of transport or job-related accidents. As the authors argue below, these estimates are inappropriate when valuing risk changes produced by environmental programs. The objectives of this paper are to explain why these estimates are inappropriate and to describe an improved approach to valuing reductions in risk of death from environmental programs, especially programs to reduce air pollution. The authors have implemented this approach in a pilot study in Tokyo, Japan. The paper provides estimates of the value of a statistical life based on the pilot study and describes extensions of the approach based on test results. The preliminary results from the Tokyo pilot indicate that individuals are able to distinguish ...

Research paper thumbnail of Economic valuation in LCA-potential in supporting decision making

Proceedings First International Symposium on Environmentally Conscious Design and Inverse Manufacturing, 1999

ABSTRACT The benefit of integrating life cycle assessment (LCA) and the monetary valuation techni... more ABSTRACT The benefit of integrating life cycle assessment (LCA) and the monetary valuation technique has been proposed by reviewing standardization work in ISO and existing impact assessment methodologies as well as discussing its potential use in the decision-making process in industry. In order to obtain necessary data in applying the approach to Japanese society, a contingent valuation method (CVM) survey to estimate benefits of small reductions of mortality risk associated with ambient air pollution exposures has been conducted in the Tokyo area

Research paper thumbnail of Those Who Care CCS -Results from Japanese Survey on Public Understanding of CCS

SSRN Electronic Journal, 2019

Research paper thumbnail of Those who care about CCS—Results from a Japanese survey on public understanding of CCS

International Journal of Greenhouse Gas Control, 2019

In order to assess the present status of the general public's awareness and opinion on Carbon Cap... more In order to assess the present status of the general public's awareness and opinion on Carbon Capture and Storage (CCS) and to analyze attributes of groups who have different opinions on CCS, a Japanese social survey was conducted in 2015. The results of the survey showed that the majority of the Japanese general public did not know much about CCS but were interested in CCS without any opinion on CCS as a part of climate policy portfolio. In terms of implementation of CCS, the Not in My Backyard (NIMBY) perception on CCS influenced opinions, while about half of the respondents did not have clear opinions on a hypothetical plan of implementing offshore CCS near their home. Respondents were categorized to four groups, who were consistently positive, consistently negative, changeable or fundamentally indifferent to CCS, and the points of communication for each group were discussed to get a consensus on CCS policy and implementation. The survey found that some of the characteristics of indifferent people toward CCS had a low level of consciousness regarding concerns on climate change issues and politically passive on national political issues. Required information to communicate CCS issues for each group were identified by the analysis. The results of our analysis highlighted the importance of informing the Japanese general public about the technological maturity, positive and negative impacts or risks of CCS, and the necessity of climate change mitigation action in communicating the issues surrounding CCS implementation.

Research paper thumbnail of Solubility measurement of supercritical carbon dioxide in sodium chloride solution

Proceedings of thermal engineering conference, 2002

Geelogical 9 ． terage of carbon dioxide〔 CO2) has been investigated as an option f ()r reducing t... more Geelogical 9 ． terage of carbon dioxide〔 CO2) has been investigated as an option f ()r reducing the concentration of CO2 into the atmosphere ． When the possibility of geological storage 重 echnique is discussed ， it is important to estimate the total amount of stored COz ． And it requires information about the thermophysical properties ， such as solubility ． Measurement of the solubility of CO2 in pure water has been studied ， whereas that in so 【 面 ons that include an electrolyte such as sodium chloride (NaC1) has not ． ln 山 is s田 dy， to determine Ihe CO2 storage capacity a重 saline aquifers ， we measured the solubility of CO2 in NaCl solution 、 Based on the resu ］ ts ， we determined a prediction equatien for lhe solubility as a 員mction oftemperature ， pressure， and salinity ． Key 距彿 鷹 ： solubility ， carbon dioxide(CO2) ， water ， sodium chloride ， supercriticat ， geological storage of COz

Research paper thumbnail of Simple estimation methodology of leakage from geologic storage of CO2

Greenhouse Gas Control Technologies 7, 2005

The objective of this paper is to develop a simple methodology to estimate amount of such leakage... more The objective of this paper is to develop a simple methodology to estimate amount of such leakages, which can be utilized by those who do not have sufficient simulation resources, in order to create a basis for CCS accounting. We develop leak estimation methodology based on quality of cap rocks (seal quality). To quantify quality of cap rocks, we newly developed Cap-rock Quality Factors (CQF). CQF is calculated reflecting features of site, height of cap rock, depth of the site and possibility of three types of leakage, leakage via matrix of cap-rock, leakage via fracture of cap-rock, and leakage via wells. We use two different interpretations of CQF, Conduit Model and Membrane Model, to estimate amount of leakage by category of cap-rock (seal) quality. Conduit Model can be generally applicable to "certain structural seal" category and Membrane Model applicable to "uncertain seal" category.

Research paper thumbnail of エネルギー収支分析に基づく再生可能エネルギー利用技術の評価

Transactions of the Japan Society of Mechanical Engineers Series B, 1993

Research paper thumbnail of Simple estimation methodology of leakage from ocean storage of CO2 for policy makers

Greenhouse Gas Control Technologies 7, 2005

The objective of this paper is to develop a simple methodology to estimate amount of such leakage... more The objective of this paper is to develop a simple methodology to estimate amount of such leakages, which can be utilized by those who do not have sufficient simulation resources, in order to create a basis for CCS accounting. We develop leak estimation methodology based on quality of cap rocks (seal quality). To quantify quality of cap rocks, we newly developed Cap-rock Quality Factors (CQF). CQF is calculated reflecting features of site, height of cap rock, depth of the site and possibility of three types of leakage, leakage via matrix of cap-rock, leakage via fracture of cap-rock, and leakage via wells. We use two different interpretations of CQF, Conduit Model and Membrane Model, to estimate amount of leakage by category of cap-rock (seal) quality. Conduit Model can be generally applicable to "certain structural seal" category and Membrane Model applicable to "uncertain seal" category.

Research paper thumbnail of Influential information and factors for social acceptance of CCS: The 2nd round survey of public opinion in Japan

Energy Procedia, 2009

A public survey was conducted concerning carbon capture and storage technology (CCS) in the month... more A public survey was conducted concerning carbon capture and storage technology (CCS) in the months of February and April 2007 in Japan, Previously another CCS survey took place in December 2003, and a set of the questions asked in the 2007 survey were purposely the same as that used in the 2003 survey, Japanese adults were randomly selected to answer a questionnaire either in printed format or in online format. Several versions of the questionnaire were used, and each contained a different educational part, imparting relevant CCS information. 334 people successfully responded to our paper survey in Tokyo and Sapporo while 2156 people completed our online survey across the nation. The questionnaire for the survey contained 5 sets of different information package on CCS and questions asking pros and cons on CCS implementation to analyze influence of information provided on CCS. Based on the results of survey we found: that not many people still know about CCS. Those who have knowledge on CCS show a preference for CCS implementation, however; preference was decreased after obtaining information which we considered was neutral on CCS. These results suggest a possibility that information on negative aspects of CCS (risks, etc.) would not be well known in the general public. We also found that preference for CSS decreased slightly after providing different information on CCS to respondents in the group with the newspaper articles which we considered neutral in comparison with other groups. The newspaper articles contained the information on negative opinions against CCS besides risk-related information as well as information based on an IPCC Special Report: it is assumed that such negative opinions may have influenced opinion formation of respondents. Since CCS is new technology, information about how other people or entities evaluate CCS would influence public opinion. In the sub-sample provided with industrial and natural analogues of preference on geological storage, the views were slightly more positive about CSS in comparison with reported opinions of other groups. This implies information on natural or industrial analogue would help manage perception of risk in a positive way. The result of path analysis to data of a public survey identified four factors, (1) risks and leakage, (2) effectiveness of CCS, (3) responsibility, and (4) fossil fuel use. We found that the factor of understanding the effectiveness of CCS is most positively influential for general acceptance of CCS. I Implementation of geological storage and the factor of risks and leakage become much more influential negatively in the implementation of geological storage compared to general acceptance of CCS, implying that implementation of CC2 geological storage also needs careful communication of risk.

Research paper thumbnail of Morbidity Valuation with a Cessation Lag: Choice Experiments for Public- and Private-Goods Contexts in Japan

We conducted a choice experiment presenting respondents with risk reductions for three types of i... more We conducted a choice experiment presenting respondents with risk reductions for three types of illnesses related to air pollution—pollen allergy, chronic bronchitis, and lung cancer—splitting the sample to test the effects of private-good and public-good contexts on the value of a statistical case (VSC) of each illness type. The results indicate that pollen allergy would be valued less than chronic bronchitis, which would be valued less than lung cancer. In terms of the private/public goods context, when exogenous rates of time preference/discount rates were applied to the estimation procedure, the VSC for a specific illness almost always was larger for the public-goods context. However, because estimated rates of time preference are far larger in the private-goods context (17% versus 1.3%), the benefits are lower, and, as they are the denominator in the VSC calculation, the VSCs are larger. We also find some effects that could be attributed to paternalistic altruism on the rate of...

Research paper thumbnail of Introduction of the global ocean ecosystem model “DONGRI” and its implementation to investigate the biochemical effects on global warming

Greenhouse Gas Control Technologies 7, 2005

A global ocean ecosystem model, "DONGRI" was developed. The purposes of this model are, (1) to un... more A global ocean ecosystem model, "DONGRI" was developed. The purposes of this model are, (1) to understand the physical and biochemical processes/interactions within ocean system or among air and ocean system and (2) to predict the effects of anthropogenic CO 2 or purposeful CO 2 enrichment to/from ocean considering not only physical but also biochemical processes in a several millennium time scale. The model was applied to the global ocean divided into 9 regions in horizontal and 26-29 layers in vertical, and air system described as one box. In this stage, fine description of biochemical processes through multi model components (i.e. total CO 2 (TCO 2), phytoplankton, zooplankton, detritus, dissolved organic matter, oxygen, NO 3-N, PO 4-P, CaCO 3 , pH and total alkalinity (TALK)) was applied to only the North Pacific but other areas also include the simplified biochemical effects. The calculated period was from year 1750 to 8000A.D. The model outputs reproduced the observed data well on each model components and flux values. By using this model, first, we present TCO 2 /TALK production/consumption mechanism caused by biochemical processes. Next, we indicate the effect of ecosystem response against the global warming on CO 2 storage in air and ocean quantitatively.

Research paper thumbnail of Interface visualization of multiphase flow by using a fast x-ray CT scanner. Development of sensitive semi-conductor detector and its application to two-phase flow measurement

Research paper thumbnail of Qualification of High Performance Heat Pump - Evaluation of COP for “Super Heat Pump”

Heat Pumps, 1990

ABSTRACT Qualification methodology for high performance compression heat pump systems developed u... more ABSTRACT Qualification methodology for high performance compression heat pump systems developed under the Japanese national R&D project “Super Heat Pump Energy Accumulation System” has been studied. Particular attention has been paid for data fluctuations caused by variation in operational environment, characteristic time of the system, thermal disturbances, and electromagnetic noise from a power supply or control/auxiliary systems. The operation data were collected every 10 seconds for a few hours, and the averaging procedures have been examined to eliminate the influences of possible external disturbance with a wide spectrum of frequency. Through detailed analysis of the results, the optimum procedure to evaluate the stationary performance of heat pump system has been developed.

Research paper thumbnail of 高出力密度，高効率な水電解・燃料電池可逆セルスタックの開発

Research paper thumbnail of 8-20 ロバストなエネルギー需給構造に向けた指標体系((7)エネルギー需給,Session 8 エネルギー評価・経済)

Research paper thumbnail of Policy Parity for CCS? – Public Preference on Low Carbon Electricity

Energy Procedia, 2017

To examine the rationale for policy parity of three basic low carbon power sources, the consumer ... more To examine the rationale for policy parity of three basic low carbon power sources, the consumer preference for those power sources was evaluated by choice experiment through a public survey in December 2015-January 2016. A sample with decent representativeness was obtained by two stage stratified sampling and door-to-door canvassing. The choice questions were designed with realistic attributes simulating power retail market starting from April 2016. Through the data analysis, using random parameter logit model, we found that respondents' WTP shows that they considered not only CO2 emission reductions but also the characteristics of the three methods of low carbon power generation. It is also found that WTP is 11 yen per 1% increase in renewables, 14 yen per 1% decrease in nuclear (this WTP varies from one individual to another), and 4 yen per 1% increase in thermal power generation with CCS. The results of WTPs for the share of renewables and CCS in the power mix of new electricity retail companies in the future market rationalizes the necessity of policy parity to some extent for those technologies implying inclusion of CCS in the FIT but not nuclear.

Research paper thumbnail of An international experiment on CO2 ocean sequestration

Greenhouse Gas Control Technologies 4, 1999

ABSTRACT The ocean represents the largest potential sink for anthropogenic CO2. In order to bette... more ABSTRACT The ocean represents the largest potential sink for anthropogenic CO2. In order to better understand this potential, Japan, Norway, and the United States signed a Project Agreement for International Collaboration on CO2 Ocean Sequestration in December ...

Research paper thumbnail of K-2101 二酸化炭素処理を伴う化石燃料改質型高効率発電システムに関する研究(S27-1 次世代エネルギー源に対応した発電技術(1))(S27 次世代エネルギー源に対応した発電技術)

Research paper thumbnail of Viscosity measurement of aqueous solutions saturated by CO_2 under aquifer conditions

The proceedings of the JSME annual meeting, 2003

Research paper thumbnail of Public acceptance of CO2 capture and storage technologyA survey of public opinion to explore influential factors

Greenhouse Gas Control Technologies 7, 2005

Carbon capture and storage technology (CCS) represents a potential effective tool in managing car... more Carbon capture and storage technology (CCS) represents a potential effective tool in managing carbon emissions. Its effectiveness ultimately hinges upon its acceptability by the public. Little is known about how willing the general public will accept various options of CCS. This study's purpose is twofold. It first seeks to assess general perceptions of various forms of CCS. It then seeks to identify various factors that influence public acceptance of CCS. The study was done with a survey conducted in the Japanese cities of Tokyo and Sapporo in December 2003. Two versions of a survey questionnaire were administered to adults residing in this city through multi-stage sampling. One version provided limited education about CCS; the other version, a full education version, provided more extensive information about CCS. A total of 1,006 respondents participated in the study, equating to a total response rate of 63.9%. Data were analyzed using factor analysis, comparisons of means and rank order distributions, and through a multiple regression model. The findings of the study suggest that the general public generally supports CCS as a part of larger national climate policy. However, they are negatively disposed about implementation of specific CCS options involving deep-sea dilution option of ocean storage, lake type option of ocean storage, onshore option of geological storage, and offshore option of geological storage. Education about CCS affects public acceptance. In specific, the more information respondents obtained about CCS, the more likely they are to support those storage options except for onshore option of geological storage. Four important factors influencing public opinion involve environmental impacts and risks caused by injection of CO 2 (including possibility of leakage), effectiveness of CCS based on realizing the CCS as one of useful mitigation options of the climate change, societal responsibility for the environment, and relation of CCS with maintenance on fossil fuel use. Each affects public acceptability for CCS in general as well as support for implementation of four specific technology types of CCS.

Research paper thumbnail of Mortality Risk Valuation for Environmental Policy

Most benefit-cost analyses of reductions in air pollutants and other pollutants carrying mortalit... more Most benefit-cost analyses of reductions in air pollutants and other pollutants carrying mortality risks rely on estimates of the value of reductions in such risks produced by compensating wage studies, or contingent valuation studies that value risk reductions in the context of transport or job-related accidents. As the authors argue below, these estimates are inappropriate when valuing risk changes produced by environmental programs. The objectives of this paper are to explain why these estimates are inappropriate and to describe an improved approach to valuing reductions in risk of death from environmental programs, especially programs to reduce air pollution. The authors have implemented this approach in a pilot study in Tokyo, Japan. The paper provides estimates of the value of a statistical life based on the pilot study and describes extensions of the approach based on test results. The preliminary results from the Tokyo pilot indicate that individuals are able to distinguish ...

Research paper thumbnail of Economic valuation in LCA-potential in supporting decision making

Proceedings First International Symposium on Environmentally Conscious Design and Inverse Manufacturing, 1999

ABSTRACT The benefit of integrating life cycle assessment (LCA) and the monetary valuation techni... more ABSTRACT The benefit of integrating life cycle assessment (LCA) and the monetary valuation technique has been proposed by reviewing standardization work in ISO and existing impact assessment methodologies as well as discussing its potential use in the decision-making process in industry. In order to obtain necessary data in applying the approach to Japanese society, a contingent valuation method (CVM) survey to estimate benefits of small reductions of mortality risk associated with ambient air pollution exposures has been conducted in the Tokyo area

Research paper thumbnail of Those Who Care CCS -Results from Japanese Survey on Public Understanding of CCS

SSRN Electronic Journal, 2019

Research paper thumbnail of Those who care about CCS—Results from a Japanese survey on public understanding of CCS

International Journal of Greenhouse Gas Control, 2019

In order to assess the present status of the general public's awareness and opinion on Carbon Cap... more In order to assess the present status of the general public's awareness and opinion on Carbon Capture and Storage (CCS) and to analyze attributes of groups who have different opinions on CCS, a Japanese social survey was conducted in 2015. The results of the survey showed that the majority of the Japanese general public did not know much about CCS but were interested in CCS without any opinion on CCS as a part of climate policy portfolio. In terms of implementation of CCS, the Not in My Backyard (NIMBY) perception on CCS influenced opinions, while about half of the respondents did not have clear opinions on a hypothetical plan of implementing offshore CCS near their home. Respondents were categorized to four groups, who were consistently positive, consistently negative, changeable or fundamentally indifferent to CCS, and the points of communication for each group were discussed to get a consensus on CCS policy and implementation. The survey found that some of the characteristics of indifferent people toward CCS had a low level of consciousness regarding concerns on climate change issues and politically passive on national political issues. Required information to communicate CCS issues for each group were identified by the analysis. The results of our analysis highlighted the importance of informing the Japanese general public about the technological maturity, positive and negative impacts or risks of CCS, and the necessity of climate change mitigation action in communicating the issues surrounding CCS implementation.

Research paper thumbnail of Solubility measurement of supercritical carbon dioxide in sodium chloride solution

Proceedings of thermal engineering conference, 2002

Geelogical 9 ． terage of carbon dioxide〔 CO2) has been investigated as an option f ()r reducing t... more Geelogical 9 ． terage of carbon dioxide〔 CO2) has been investigated as an option f ()r reducing the concentration of CO2 into the atmosphere ． When the possibility of geological storage 重 echnique is discussed ， it is important to estimate the total amount of stored COz ． And it requires information about the thermophysical properties ， such as solubility ． Measurement of the solubility of CO2 in pure water has been studied ， whereas that in so 【 面 ons that include an electrolyte such as sodium chloride (NaC1) has not ． ln 山 is s田 dy， to determine Ihe CO2 storage capacity a重 saline aquifers ， we measured the solubility of CO2 in NaCl solution 、 Based on the resu ］ ts ， we determined a prediction equatien for lhe solubility as a 員mction oftemperature ， pressure， and salinity ． Key 距彿 鷹 ： solubility ， carbon dioxide(CO2) ， water ， sodium chloride ， supercriticat ， geological storage of COz

Research paper thumbnail of Simple estimation methodology of leakage from geologic storage of CO2

Greenhouse Gas Control Technologies 7, 2005

The objective of this paper is to develop a simple methodology to estimate amount of such leakage... more The objective of this paper is to develop a simple methodology to estimate amount of such leakages, which can be utilized by those who do not have sufficient simulation resources, in order to create a basis for CCS accounting. We develop leak estimation methodology based on quality of cap rocks (seal quality). To quantify quality of cap rocks, we newly developed Cap-rock Quality Factors (CQF). CQF is calculated reflecting features of site, height of cap rock, depth of the site and possibility of three types of leakage, leakage via matrix of cap-rock, leakage via fracture of cap-rock, and leakage via wells. We use two different interpretations of CQF, Conduit Model and Membrane Model, to estimate amount of leakage by category of cap-rock (seal) quality. Conduit Model can be generally applicable to "certain structural seal" category and Membrane Model applicable to "uncertain seal" category.

Research paper thumbnail of エネルギー収支分析に基づく再生可能エネルギー利用技術の評価

Transactions of the Japan Society of Mechanical Engineers Series B, 1993

Research paper thumbnail of Simple estimation methodology of leakage from ocean storage of CO2 for policy makers

Greenhouse Gas Control Technologies 7, 2005

The objective of this paper is to develop a simple methodology to estimate amount of such leakage... more The objective of this paper is to develop a simple methodology to estimate amount of such leakages, which can be utilized by those who do not have sufficient simulation resources, in order to create a basis for CCS accounting. We develop leak estimation methodology based on quality of cap rocks (seal quality). To quantify quality of cap rocks, we newly developed Cap-rock Quality Factors (CQF). CQF is calculated reflecting features of site, height of cap rock, depth of the site and possibility of three types of leakage, leakage via matrix of cap-rock, leakage via fracture of cap-rock, and leakage via wells. We use two different interpretations of CQF, Conduit Model and Membrane Model, to estimate amount of leakage by category of cap-rock (seal) quality. Conduit Model can be generally applicable to "certain structural seal" category and Membrane Model applicable to "uncertain seal" category.

Research paper thumbnail of Influential information and factors for social acceptance of CCS: The 2nd round survey of public opinion in Japan

Energy Procedia, 2009

A public survey was conducted concerning carbon capture and storage technology (CCS) in the month... more A public survey was conducted concerning carbon capture and storage technology (CCS) in the months of February and April 2007 in Japan, Previously another CCS survey took place in December 2003, and a set of the questions asked in the 2007 survey were purposely the same as that used in the 2003 survey, Japanese adults were randomly selected to answer a questionnaire either in printed format or in online format. Several versions of the questionnaire were used, and each contained a different educational part, imparting relevant CCS information. 334 people successfully responded to our paper survey in Tokyo and Sapporo while 2156 people completed our online survey across the nation. The questionnaire for the survey contained 5 sets of different information package on CCS and questions asking pros and cons on CCS implementation to analyze influence of information provided on CCS. Based on the results of survey we found: that not many people still know about CCS. Those who have knowledge on CCS show a preference for CCS implementation, however; preference was decreased after obtaining information which we considered was neutral on CCS. These results suggest a possibility that information on negative aspects of CCS (risks, etc.) would not be well known in the general public. We also found that preference for CSS decreased slightly after providing different information on CCS to respondents in the group with the newspaper articles which we considered neutral in comparison with other groups. The newspaper articles contained the information on negative opinions against CCS besides risk-related information as well as information based on an IPCC Special Report: it is assumed that such negative opinions may have influenced opinion formation of respondents. Since CCS is new technology, information about how other people or entities evaluate CCS would influence public opinion. In the sub-sample provided with industrial and natural analogues of preference on geological storage, the views were slightly more positive about CSS in comparison with reported opinions of other groups. This implies information on natural or industrial analogue would help manage perception of risk in a positive way. The result of path analysis to data of a public survey identified four factors, (1) risks and leakage, (2) effectiveness of CCS, (3) responsibility, and (4) fossil fuel use. We found that the factor of understanding the effectiveness of CCS is most positively influential for general acceptance of CCS. I Implementation of geological storage and the factor of risks and leakage become much more influential negatively in the implementation of geological storage compared to general acceptance of CCS, implying that implementation of CC2 geological storage also needs careful communication of risk.

Research paper thumbnail of Morbidity Valuation with a Cessation Lag: Choice Experiments for Public- and Private-Goods Contexts in Japan

We conducted a choice experiment presenting respondents with risk reductions for three types of i... more We conducted a choice experiment presenting respondents with risk reductions for three types of illnesses related to air pollution—pollen allergy, chronic bronchitis, and lung cancer—splitting the sample to test the effects of private-good and public-good contexts on the value of a statistical case (VSC) of each illness type. The results indicate that pollen allergy would be valued less than chronic bronchitis, which would be valued less than lung cancer. In terms of the private/public goods context, when exogenous rates of time preference/discount rates were applied to the estimation procedure, the VSC for a specific illness almost always was larger for the public-goods context. However, because estimated rates of time preference are far larger in the private-goods context (17% versus 1.3%), the benefits are lower, and, as they are the denominator in the VSC calculation, the VSCs are larger. We also find some effects that could be attributed to paternalistic altruism on the rate of...

Research paper thumbnail of Introduction of the global ocean ecosystem model “DONGRI” and its implementation to investigate the biochemical effects on global warming

Greenhouse Gas Control Technologies 7, 2005

A global ocean ecosystem model, "DONGRI" was developed. The purposes of this model are, (1) to un... more A global ocean ecosystem model, "DONGRI" was developed. The purposes of this model are, (1) to understand the physical and biochemical processes/interactions within ocean system or among air and ocean system and (2) to predict the effects of anthropogenic CO 2 or purposeful CO 2 enrichment to/from ocean considering not only physical but also biochemical processes in a several millennium time scale. The model was applied to the global ocean divided into 9 regions in horizontal and 26-29 layers in vertical, and air system described as one box. In this stage, fine description of biochemical processes through multi model components (i.e. total CO 2 (TCO 2), phytoplankton, zooplankton, detritus, dissolved organic matter, oxygen, NO 3-N, PO 4-P, CaCO 3 , pH and total alkalinity (TALK)) was applied to only the North Pacific but other areas also include the simplified biochemical effects. The calculated period was from year 1750 to 8000A.D. The model outputs reproduced the observed data well on each model components and flux values. By using this model, first, we present TCO 2 /TALK production/consumption mechanism caused by biochemical processes. Next, we indicate the effect of ecosystem response against the global warming on CO 2 storage in air and ocean quantitatively.