Tatsuhara T.,Pacific Consultants Co. |
Arima T.,Nippon Oil Corporation |
Igarashi T.,Hokkaido University |
Tabelin C.B.,Hokkaido University
Engineering Geology | Year: 2012
Hydrothermally altered rock excavated in a tunnel project produces acidic leachate containing hazardous elements that include arsenic (As), lead (Pb), copper (Cu) and zinc (Zn). To mitigate this problem, this paper evaluated a combined neutralization-adsorption system that used readily available and cheap reagents like calcium carbonate (CaCO 3) and partly-weathered volcanic ash. Batch neutralization experiments showed that CaCO 3 was effective in raising the pH of the leachate around neutral while the batch adsorption experiments illustrated that the volcanic ash sample collected near the tunnel project area was highly capable of adsorbing arsenate (As[V]), Pb, Cu and Zn. Under column conditions, the amount of hazardous elements released from the rock increased by several folds and their breakthrough curves had flushing-out trends. The mechanisms of As and heavy metals release probably include the dissolution of soluble phases and pyrite oxidation. Addition of CaCO 3 in the column experiments based on estimates from the batch results underestimated the amount of neutralizer needed to adjust the effluent pH to around 8, resulting only in slight increase of the pH. Nevertheless, the presence of CaCO 3 drastically reduced the amount of hazardous elements released from the altered rock especially during the initial stages of the column experiments. Combining neutralization and adsorption effectively reduced the amount of As and heavy metals in the effluent throughout the duration of the column experiments, which is attributed to the slight neutralizing effect of volcanic ash that raised the pH around circumneutral as well as its rich Al and Fe oxyhydroxide/oxide contents. The combined system immobilized the hazardous elements through a combination of co-precipitation and adsorption reactions and showed potential as an alternative method for the disposal of altered rocks producing acidic leachate. © 2012 Elsevier B.V.
Chigira M.,Kyoto University |
Tsou C.-Y.,Kyoto University |
Matsushi Y.,Kyoto University |
Hiraishi N.,Fukada Geological Institute |
And 2 more authors.
Geomorphology | Year: 2013
Typhoon Talas crossed the Japanese Islands between 2 and 5 September 2011, causing more than 70 deep-seated catastrophic landslides in a Jurassic to Paleogene-lower Miocene accretion complex. Detailed examination of the topographic features of 10 large landslides before the event, recorded on 1-m DEMs based on airborne laser scanner surveys, showed that all landslides had small scarps near their future crowns prior to the slide, and one landslide had linear depressions along its future crown as precursor topographic features. These scarps and linear depressions were caused by gravitational slope deformation that preceded the catastrophic failure. Although the scarps may have been enlarged by degradation, their sizes relative to the whole slopes suggest that minimal slope deformation had occurred in the period immediately before the catastrophic failure. The scarp ratio, defined as the ratio of length of a scarp to that of the whole slope both measured along the slope line, ranged from 5% to 21%. Careful examination of aerial photographs from another four large landslides, for which no high-resolution DEMs were available, suggested that they also developed scarps at their heads beforehand. Twelve of the 14 landslides we surveyed in the field had sliding surfaces with wedge-shaped discontinuities that consisted of faults and bedding, suggesting that the buildup of pore pressure occurs readily on wedge-shaped discontinuities in a gravitationally deformed rock body. Most of the faults were undulatory and were probably thrust faults that formed during accretion. Other types of gravitational deformation were also active; e.g., flexural toppling and buckling were observed to have preceded one landslide. © 2013 Elsevier B.V.
Tabelin C.B.,Hokkaido University |
Igarashi T.,Hokkaido University |
Arima T.,Nippon Oil Corporation |
Sato D.,Shimizu Corporation |
And 2 more authors.
Geoderma | Year: 2014
Construction of tunnels in Hokkaido, Japan often excavates rocks containing substantial amounts of arsenic (As) and boron (B). When these rocks are exposed to the environment, As and B are leached out that could potentially contaminate the surrounding soil and groundwater. Natural geologic materials contain minerals like Al-/Fe-oxyhydroxides/oxides that have As and B adsorption capabilities. Because these materials are widespread and readily available, they could be utilized in the mitigation of As and B leached out from these sources. This paper describes the ability of three natural geologic materials (i.e., pumiceous tuffs, partly-weathered volcanic ashes and coastal marine sediments) to sequester As and B from aqueous solutions and the actual leachate of a hydrothermally altered rock. The adsorption of As fitted well with either the Langmuir or Freundlich isotherm while that of B followed the Henry-type model (linear). Among the samples, those containing substantial amorphous Al and Fe exhibited higher As adsorption. However, the distribution coefficient of B only had a moderate positive correlation with these amorphous phases. The best adsorbent among these natural geologic materials was utilized in the adsorption layer of the column experiments. Adsorption of As was more effective the thicker the adsorption layer, but this retardation was only temporary due to significant changes in the pH. In contrast, the adsorption layer only retarded the migration of B to a limited extent. © 2013 Elsevier B.V.
Tang L.,Japan National Institute for Agro - Environmental Sciences |
Ii R.,Pacific Consultants Co. |
Tokimatsu K.,Japan National Institute of Advanced Industrial Science and Technology |
Itsubo N.,Tokyo City University
International Journal of Life Cycle Assessment | Year: 2015
Purpose: Global warming is exerting a damaging effect on human health. This damage is not only influenced by future climate conditions but also projected economic development and population growth. That being said, there are no health damage factors related to CO2 emissions which take into account future socioeconomic scenarios in life cycle impact assessment (LCIA). Thus, the purpose of the current research is to calculate human health damage factors based on the Special Report on Emission Scenarios (SRESs) developed by the Intergovernmental Panel on Climate Change (IPCC). Methods: The procedure used to calculate the SRES-based damage factors is as follows. First, a framework was developed to calculate damage factors based on multiple parameters: rise in temperature, relative risk increase, mortality rate increase, rise in number of deaths, and disability-adjusted life year (DALY) increase. Secondly, these parameters were calculated for each individual SRES based on the relationship among the parameters and CO2 emissions, GDP, and population values of each scenario. Finally, the damage factor for each SRES was calculated by multiplying all the parameters that had been calculated based on the CO2 emission, GDP, and population data in the corresponding scenarios. Results and discussion: Using this method, the human health damage factors for four SRESs (A1B, A2, B1, and B2) were calculated. The damage factors consisted of six different items: malaria, diarrhea, cardiovascular disease, malnutrition, coastal flooding, and inland flooding. The calculated results by scenario were 2.0 × 10−7, 6.2 × 10−7, 2.1 × 10−7, and 4.2 × 10−7 DALY/kg CO2, respectively. The damage caused by malnutrition is the greatest, followed by diarrhea. Regions of Southeast Asia, Africa, and the Middle East showed the highest damages due to their high damage from malnutrition and diarrhea. With regard to the differences among the four damage factors, the difference between the projected future mortality rate and DALY per death based on the future GDP per capita is greater than the difference between the increases in temperature among scenarios dependent on future CO2 emission. Conclusions: The human health damage factors related to CO2 emissions for four SRESs were estimated. As a result of differences between future socioeconomic scenarios, the largest amount of damage per CO2 emission unit was three times greater than the smallest amount. Therefore, sensitive analysis is highly recommended when seeking to compare damage caused by global warming and other impact categories. © 2015 Springer-Verlag Berlin Heidelberg
Goto K.,Tohoku University |
Takahashi J.,Tohoku University |
Takahashi J.,Tohoku Electric Power Co. |
Oie T.,Tohoku University |
And 2 more authors.
Geomorphology | Year: 2011
We investigated bathymetric data obtained at Kirinda Harbor, Sri Lanka one month before and 2 and 11. months after the 2004 Indian Ocean tsunami. Our bathymetric surveyed data and numerical modeling results suggest that the first run-up tsunami wave transported huge amounts of offshore sea bottom sediment and deposited it in a layer up to 4. m thick along the shoreface slope. In some places, this accreted sediment was not eroded by the backwash because of the particular arrangement of artificial structures and sand dunes. Especially, the sedimentation process and the volume of the sediment transported by the run-up waves can be examined where the influence of the backwash flow was very minor. Remarkable sedimentation attributable to the run-up wave would have occurred mainly by the deposition of the sediment particles along the slope by the run-up waves; the slope was developed toward the stoss side rather than by the settlement of the sediment from the suspension load. We estimated that considerable amounts of sediment were transported by the tsunami from the offshore sea bottom, but most were deposited not on land but in the sea. Eleven months after the tsunami, the harbor bathymetry had almost undergone complete reversion to its pre-tsunami condition, implying that the tsunami impact on permanent geomorphological landforms was limited at this harbor. © 2010 Elsevier B.V.
Shigeto S.,Japan Science and Technology Agency |
Yamagata Y.,Japan National Institute of Environmental Studies |
Ii R.,Pacific Consultants CO. |
Hidaka M.,Pacific Consultants CO. |
Horio M.,Japan Science and Technology Agency
Applied Energy | Year: 2012
To develop a scenario, easily traceable even for ordinary citizens, toward the national challenge target of 80% CO2 reduction by 2050, we have proposed a new model that calculates the total CO2 emission based on the final consumption. Using the model, we have tested appropriate (locally available) technology based sub-scenarios: (1) energy saving through electrification of all transportation; (2) promotion of wood utilization for housing; (3) introduction of renewable energies; and (4) efficient energy recovery from wastes. Applying the scenarios to the Kyoto-city as a case study, we have found that local 80% CO2 emission reduction could be possible using appropriate technologies including emission reduction from construction of private and public infrastructures, and shifting our final consumption mode into low CO2 emission has a significant impact. We have also argued that it is of interest to examine the future socio-economic change that would influence on people's consumption behavior. © 2011 Elsevier Ltd.
Kumagai K.,Pacific Consultants Co. |
Mori N.,Kyoto University |
Nakajo S.,Kumamoto University
Coastal Engineering Journal | Year: 2016
The extremely intense Typhoon Haiyan (local name Yolanda), struck the Philippines in November 2013, catastrophically impacting the region. It is important to understand the storm surge characteristics and occurrence probability of such super typhoons for reconstruction of the devastated area. This study mainly examines two topics. First, the characteristics of Typhoon Haiyan and its related storm surge were analyzed with a series of numerical experiments using an empirical typhoon model and storm surge model. The maximum surge height and inundation area were estimated and validated against measurements of tides and wind speeds obtained from local agencies NAMRIA and PAGASA, as well as against post-event surveys of maximum inundation heights. Based on the analysis of best hindcast results, the maximum storm surge level was about 5(Formula presented.)m at Tacloban on Leyte Island. Second, the return period of a Haiyan-like typhoon and associated storm surge was estimated with NOAA’s long-term observed IBTrACS typhoon dataset and a stochastic tropical cyclone model. Statistical analysis of typhoons around Tacloban was performed, and the estimated return period of storm surge levels seen during Typhoon Haiyan is 240–360 years. © 2016 World Scientific Publishing Company
Kimori T.,Pacific Consultants Co.
SAVE Value Summit 2014 - SAVE International Annual Conference | Year: 2014
VE is widely applied to road and river projects since many improvement ideas can be generated in a short period of time by the participation of people in various disciplines to engage in concentrated discussions. Because of this, there are many requests to incorporate VE approaches on other projects. This paper examines the points to remember and effects of applying VE in the planning phase of new projects including both disaster prevention and environmental areas, discusses where to be improved, and presents a case study of actual workshop. Through this case study, the future application of VE in planning phase in public works will be presented.
Kimori T.,Pacific Consultants Co.
SAVE Value Summit 2015 | Year: 2015
In recent years, in order for early recognition of project effectiveness, public works projects in Japan have relied on methods that focus on the development of highly effective infrastructure. Furthermore, from the perspective of achieving project effectiveness early on, the importance of giving consideration to the shortening of construction periods during the project planning phase cannot be ignored. However, due to the many uncertainties with respect to construction times during the planning phase, the effective study of how to shorten construction periods is not an easy task. The author has devised a new evaluation method called the Direct Path Method (D.P.M.) which applies VE to the analysis of shortening construction periods during the project planning phase. D.P.M. is a method of extracting functions from the construction schedule to consider creative alternative plans based on those functions, allowing for the effective examination of the reduction of work time in a short period. This paper looks at the approach of this method as well as presenting a practical case example. © Copyright (2015) by SAVE International All rights reserved.
Naka A.,Pacific Consultants CO.
SAVE Value Summit 2013 | Year: 2013
Many operators are involved in providing public services in modern society. Because so many operators are involved, it is sometimes difficult to identify problems even if they exist. Although operators are sometimes aware of problems, they may not clearly specify the problems. It is not difficult for operators to get together to point out problems; however, identifying the clear definition and underlying cause of any given problem are not easy since simple discussion cannot lead to these. The technique to clarify the root cause of problems by organizing the problems using VE technique is discussed in this article. The proposed technique can be used to transform the problems into functions. Consensus building among the operators in a short period of time is achieved. The procedure and the effectiveness of the application are presented in this paper.