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Itsubo N.,Tokyo City University | Sakagami M.,Nihon Fukushi University | Kuriyama K.,Kyoto University | Inaba A.,Kougakuin University
International Journal of Life Cycle Assessment | Year: 2012

Purpose Weighting is one of the steps involved in life cycle impact assessment (LCIA). This enables us to integrate various environmental impacts and facilitates the interpretation of environmental information. Many different weighting methodologies have already been proposed, and the results of many case studies with a single index have been published. However, a number of problems still remain. Weighting factors should be based on the preferences of society as a whole so that the life cycle assessment (LCA) practitioner can successfully apply them to every product and service. However, most existing studies do not really measure national averages but only the average of the responses obtained from the people actually sampled. Measuring the degree of uncertainty in LCIA factors is, therefore, one of the most important issues in current LCIA research, and some advanced LCIA methods have tried to deal with the problem of uncertainty. However, few weighting methods take into account the variability between each individual's environmental thoughts. LIME2, the updated version of life cycle impact assessment method based on endpoint modeling (LIME), has been developed as part of the second LCA national project of Japan. One of the aims of LIME2 is to develop new weighting factors which fulfill the following requirements: (1) to accurately represent the environmental attitudes of the Japanese public, (2) to measure the variability between each individual's environmental thoughts and reflect them in the choice of suitable weighting factors. Methods This study adopted the technique of conjoint analysis, which is currently the most advanced methodology available in the field of environmental economics. Using a random sampling process, 1,000 individual responses were collected. Every response was based on an interview survey designed to minimize bias. We used a random parameter logit model to estimate the preferences of society. Statistical values based on this model can be considered to reflect the variability between each individual's environmental thoughts. The calculated results can then be used to develop integration factors in LIME2, enabling us to express LCIA results as a single index, such as external cost. Results and discussion The calculated values were significant statistically at the 1% level (all p values for the safeguard subject coefficients were less than 0.0001), with the exception of "social assets." Based on the calculated results, two types of weighting factor, an economic valuation and a dimensionless index, were obtained. A relative comparison of importance among these four categories indicates that "biodiversity" receives the highest level of recognition, followed by "human health" and "primary production," while the weight of "social assets" rate lower than the other safeguard subjects, in comparison. Using the calculated results produced by the RPL model, the probability density of the variables for individual preferences could then be derived and displayed. The coefficients of variance for the estimated weighting factors were relatively small (in the range from 0.1 to 0.3). Conclusions Accurate weighting factors representing the environmental attitudes of the Japanese public are needed in order to conduct general-purpose LCA for Japanese products. Random, unbiased sampling throughout Japan and an interview survey carried out on 1,000 respondents enabled us to address and solve the problems found with past weighting methodologies. We confirmed that the results of comparisons carried out among safeguard subjects were statistically significant, and showed that the contents of the questionnaires were well understood by the respondents. This study succeeded in visualizing the variability between each individual's environmental thoughts in order to improve the transparency of the weighting factors\-expressing the difference in individual preferences within a certain range. This data can be used to develop integration factors with statistical values which can then be applied to uncertainty analysis in future LCA case studies. © 2012 Springer-Verlag.


Kim S.,University of Tokyo | Zhao P.,Zhejiang University | Aikawa S.,Kougakuin University | Einarsson E.,State University of New York at Buffalo | And 3 more authors.
ACS Applied Materials and Interfaces | Year: 2015

The intrinsic p-type behavior of graphene field-effect transistors (FETs) under ambient conditions poses a fundamental challenge for the assembly of complex electronic devices, such as integrated circuits. In this work, we present a protocol for tunable n-type doping of graphene FETs via poly(vinyl alcohol) (PVA) coating. Using graphene grown by alcohol catalytic chemical vapor deposition, functionalization of the surface by this hydroxyl anion-rich polymer results in an evolution of the FETs from p-type to ambipolar or n-type even under ambient air conditions. The doping level of graphene is strongly related to the PVA film coating parameters, such as solution concentration, hardening temperature, and hardening time. This PVA coating proves to be a simple and stable approach to tuning the Dirac point and doping level of graphene, which is highly desirable and of great significance for the future of graphene-based electronic devices. © 2015 American Chemical Society.


PubMed | Kougakuin University, State University of New York at Buffalo, University of Tokyo and Zhejiang University
Type: Journal Article | Journal: ACS applied materials & interfaces | Year: 2015

The intrinsic p-type behavior of graphene field-effect transistors (FETs) under ambient conditions poses a fundamental challenge for the assembly of complex electronic devices, such as integrated circuits. In this work, we present a protocol for tunable n-type doping of graphene FETs via poly(vinyl alcohol) (PVA) coating. Using graphene grown by alcohol catalytic chemical vapor deposition, functionalization of the surface by this hydroxyl anion-rich polymer results in an evolution of the FETs from p-type to ambipolar or n-type even under ambient air conditions. The doping level of graphene is strongly related to the PVA film coating parameters, such as solution concentration, hardening temperature, and hardening time. This PVA coating proves to be a simple and stable approach to tuning the Dirac point and doping level of graphene, which is highly desirable and of great significance for the future of graphene-based electronic devices.


Isakozawa S.,Hitachi High-Technologies | Kaji K.,Hitachi High-Technologies | Tamura K.,Hitachi High-Technologies | Zhang X.F.,Hitachi High-Technologies | And 2 more authors.
Journal of Electron Microscopy | Year: 2010

A new windowless X-ray energy-dispersive spectroscopy (XEDS) detector has been developed for an analytical electron microscope (AEM). Different from the conventional XEDS detectors, the new detector does not contain an ultra-thin window (UTW) and a vacuum gate valve which are the major causes of low X-ray detection sensitivity and vibration problems for AEM imaging, respectively. The performance of the newly designed detector was examined at an AEM column vacuum level of 10-5 Pa. The X-ray detectability was improved considerably; in particular, the sensitivity for detecting nitrogen characteristic X-ray signal was three times higher than that of the conventional UTW detectors. © The Author 2010. Published by Oxford University Press on behalf of Japanese Society of Microscopy. All rights reserved.


Isoda H.,Kyoto University | Nakagawa M.,Shinshu University | Kawai N.,Kougakuin University | Koshihara M.,University of Tokyo | Araki Y.,Japan Building Research Institute
WCTE 2014 - World Conference on Timber Engineering, Proceedings | Year: 2014

The horizontal composite structure consisting of reinforced concrete and timber frame is tested at full scale shaking table tests in parameters of specification of the floor and number of stories. Although the eccentricity of this model is large, there was no damage against a artificial wave in return period of 495 years. Moreover, it turned out that modification of a timber frame can be reduced by raising the rigidity of horizontal diaphragm to concentrate the shearing force at the reinforced concrete wall. In a two-story specimen, the connection between a timber frame and the reinforced concrete wall was damaged. This is considered the second story is easy to be shaken because the rigidity of timber frame falls. Furthermore, the relation between a real action and the design method was considered.


PubMed | Hitachi High-Technologies and Kougakuin University
Type: Journal Article | Journal: Microscopy (Oxford, England) | Year: 2016

A new in situ environmental transmission electron microscope (ETEM) was developed based on a 300 kV TEM with a cold field emission gun (CFEG). Particular caution was taken in the ETEM design to assure uncompromised imaging and analytical performance of the TEM. Because of the improved pumping system between the gun and column, the vacuum of CFEG was largely improved and the probe current was sufficiently stabilized to operate without tip flashing for 2-3 h or longer. A high brightness of 2.5 10(9) A/cm(2) sr was measured at 300 kV, verifying the high quality of the CFEG electron beam. A specially designed gas injection-heating holder was used in the in situ TEM study at elevated temperatures with or without gas around the TEM specimen. Using this holder in a 10 Pa gas atmosphere and specimen temperatures up to 1000C, high-resolution ETEM performance and analysis were achieved.


Mochizuki S.,Tokyo Metroplitan University | Yanagida S.,Kougakuin University | Fujie H.,Tokyo Metroplitan University | Fujie H.,Kougakuin University
ASME 2013 Summer Bioengineering Conference, SBC 2013 | Year: 2013

We developed a frictional tester that can determine the coefficient of friction even though cartilage surface is inclined to 15 degree. The coefficient of friction of articular cartilage deteriorates in proteoglycan-degenerated and collagen fiber-degenerated articular cartilage. Copyright © 2013 by ASME.


Maeda H.,Soka University | Soneda Y.,Japan National Institute of Advanced Industrial Science and Technology | Higuchi A.,Soka University | Iizuka M.,Soka University | Nagamoto H.,Kougakuin University
Bulletin of the Chemical Society of Japan | Year: 2012

Current generation from Na 2SO 3 aqueous solution was found to occur by using PAN-based carbon fibers with heat treatment at 700 °C. Sixty mL of 0.1M Na 2SO 3 and 80mL of 0.5M H 2SO 4 were added into the anode cell and cathode cell, respectively, and current generation was performed for 10 h. As a result, the current value increased from background current of 0.04 to 22.3mA after 5min. Afterward, the current was almost constant, and decreased a little in the final stage, accompanied by decrease of the amount of Na 2SO 3. The current efficiency was calculated to be 91%. The mechanism of the current generation is assumed to be described by the equation: SO 3 2- + 2OH - →SO 4 2- + H 2O + 2e -. In the current generation using a 30ω resistor, the current was 11.3 mA, so that the voltage is calculated to be 0.339V. The maximum electric power of this cell is calculated to be 3.83mW. Next, 60mL of 0.02M H 2SO 3 was added to the anode cell, and current generation was performed for 4 h as well as in the case of Na 2SO 3. As a result, the current was 8.25mA after 6min. Afterward, the value linearly decreased, and the value was 3.80mA after 3 h. The current generation almost finished after 4 h. In this case, the current efficiency was 28%. Furthermore, chemical groups on the surface of carbon fibers with heat treatment were measured by X-ray photoelectron spectroscopy. The element analysis on the surface resulted in: C, 82 atom%; N, 7.2 atom%; and O, 10.9 atom%; the existence of COO, C=O, CO, CC, C=C, CN, and C=N groups was thus suggested. © 2012 The Chemical Society of Japan.


Maeda H.,Soka University | Nagamoto H.,Kougakuin University
Carbon - Science and Technology | Year: 2012

Carbon fibers treated at 700° C for 10 min were found to have O2 reduction activity when being used as a cathode. The special type of partition combined with both cationic and anionic exchange membranes was applied between anode cell and cathode cell in order touse a highly acidic solution such as 0.5 M H2SO4 as an electrolyte of the cathode cell for increasing the efficiency of O2 reduction activity. The current generation from NAD+ and NADH recycling system combined with D-gluconolactone production from 500 mg of D-glucose was performed by applying only carbon fibers for both anode and cathode. The total current volume obtained was 81.4 mAh during the reaction for 10 h , and the current efficiency was 93%. One gram of carbon fibers was pressed with Nafion paste on a piece of carbon paper (area : 50 mm×50 mm) with heating to prepare the cathode, and this construct was combined with conventional fuel cell. The power density was 3.6 mW/cm2, and the total power volume was calculated to be 90 mW per 1 g of carbon fibers. © Applied Science Innovations Pvt. Ltd., India.


Otsuka T.,Kougakuin University | Goto O.,Kougakuin University | Nimura S.,Kougakuin University
AIJ Journal of Technology and Design | Year: 2010

In Japan if the heritage building designated by government is restored largely, the documentation record is published. Some documentations of wooden heritage building included the record of that's all members. But we can't know the wooden quality of each member in these documentations. In this paper we propose new method for the recording the wooden quality. So we will be able to know how to use woods and understand future demands of high quality woods in the restoration.

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