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Search Results: 1 - 10 of 230 matches for " Daichi Iwase "
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Evaluation of Carbon Dioxide Absorption Characteristics Lithium Ortho-Silicate in Chemical Heat Storage  [PDF]
Takehiro Esaki, Daichi Iwase, Noriyuki Kobayashi
Journal of Materials Science and Chemical Engineering (MSCE) , 2017, DOI: 10.4236/msce.2017.54006
Abstract: We report the development of technology that may contribute to a reduction in greenhouse gas emissions and improve the energy efficiency of the CO2 capture process. Lithium ortho-silicate is a suitable solid sorbent for capturing CO2. This reversible chemical reaction is also applicable to chemical heat storage. The absorption reaction characteristics of lithium ortho-silicate were studied by a thermogravimetric method and a volumetric method that demonstrated the influence of heat and mass transfer limitations in a packed bed designed to be as small as possible. We developed a method for measuring the absorption reaction characteristics in the experiments. In the experiments, a constant conversion fraction of 60% was observed. The reaction system was stable to repetition. The CO2 absorption rate depends on the CO2 pressure and reactor temperature. The absorption rate was determined at several reactor temperatures when the conversion fraction was 0.3. In this study, the maximum absorption rate was obtained at 670oC. It was demonstrated that lithium ortho-silicate is suitable for use in a chemical heat storage system.
The Management of Capital Allocation for Sustainable Municipal Solid Waste Management System: A Case Study of Bang Saen, Thailand
Daichi Iwase,Sittipong Dilokwanich
EnvironmentAsia , 2013,
Abstract: This paper attempted to analyze and understand the management of capital allocation for sustainable municipal solid waste management system at Bang Saen, Thailand. Financial, manufactured, human, social and natural capital was the focus of this study. Capital allocation to five capitals, activities of the stakeholders related to municipal solid waste management, and the output of these activities were analyzed. The investigation was carried out by reviewing documents, conducting in-depth interviews with various stakeholders including the Saensuk municipality officials, locals and tourists, and carrying out field observations. Results showed that total output from five capitals is influenced by activity performance of stakeholders, which is dependent on input to five capitals. However, input was made without assessments of output produced by the activities of the stakeholders, which stemmed from the absence of a policy goal on municipal solid waste management and action plans to achieve its goal. Capital was mostly allocated to financial and manufactured capitals in terms of support of municipal solid waste collection, transportation and disposal. Findings suggest that capital should be allocated to activities related to human, social and natural capitals that can help improve activity performance of the stakeholders, and therefore improve total output and sustainability of the system. Well-designed activities could generate improved output, which is made by readjusting input based on assessments of output and by reflecting feedback in decision making on capital allocation. For this reason, the municipality has to set a clear policy goal of municipal solid waste management, short-term, and long-term action plans. Finally, recommendation is given to municipality.
Long-Term Durability and Reactivation of Thermochemical Heat Storage Driven by the CaO/Ca(OH)2 Reversible Reaction  [PDF]
Kazuki Kuwata, Takehiro Esaki, Daichi Iwase, Hiroyuki Ito, Shijie Li, Xixian Yang, Hongyu Huang, Noriyuki Kobayashi
Journal of Materials Science and Chemical Engineering (MSCE) , 2017, DOI: 10.4236/msce.2017.511003
Abstract: Thermochemical heat storage is a promising technology for improving thermal energy efficiency. To investigate the durability of the CaO/Ca(OH)2 reaction and develop a reactivation method, repetitive charging/discharging operation of a packed bed reactor with a thick packed bed was conducted, and variations in the discharging behavior, final conversion, and reactant activity were investigated. Owing to the formation of a deactivated sintered reactant block, the discharging time halved and the final conversion ratio decreased by the 53rd discharging operation. To enhance durability, a reactivation method using high-pressure vapor was implemented during the 54th discharging operation. Following reactivation, the final conversion increased 15%, and the discharging time tripled when compared with the discharging operation before reactivation, confirming the success of this simple reactivation method.
The Validity of the Reduction of Disposable Plastic Checkout Bags in Japan  [PDF]
Masakazu Yamashita, Daichi Toyofuku
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.39118
Abstract: This study examined the effect of reducing disposable plastic checkout bags used in supermarkets, convenience stores, and so on in Japan. Considering that even when these checkout bags are abolished, alternative waste bags should be newly produced, because these checkout bags have been reused as household waste bags so far, and the corresponding amount of oil is still necessary to produce them, the amount of oil saved by this bag reduction was found to be 0.2 L/person/year at most. Further, it was demonstrated that the necessity to purchase substitute bags may increase the household and financial burden on consumers.
Associahedra, Multiplihedra and units in $A_{\infty}$ form
Norio Iwase
Mathematics , 2012,
Abstract: Jim Stasheff gave two apparently distinct definitions of an $A_{m}$ form, $m \leq \infty$ in [15,16]. It is also claimed that the two definitions are equivalent in [15,16], while it is not apparently clear for us. That is why we are trying to clarify related things and to show that the claim is actually true under a `loop-like' hypothesis in this paper. Along with these two definitions, we must construct Associahedra and Multiplihedra as convex polytopes with piecewise-linearly decomposed faces to manipulate units in $A_{\infty}$ form. This is done in Iwase [8,9], Iwase-Mimura [10] or by Haiman [7] especially on Associahedra, followed recently by Forcey [6] and Mau-Woodward [12], while the origin of Associahedra goes back to Tamari [17]. In this paper, we follow [10] on the geometric constructions of Associahedra and Multiplihedra. In Appendix, we also explain how we can construct Associahedra or Multiplihedra as polytopes on the (half) lattice by taking a shadow or collecting words from trivalent or bearded trees.
A_{\infty}-method in Lusternik-Schnirelmann category
Norio Iwase
Mathematics , 2002,
Abstract: To clarify the method behind the paper "Ganea's conjecture on Lusternik-Schnirelman category" by the author, a generalisation of Berstein-Hilton Hopf invariants is defined as `higher Hopf invariants'. They detect the higher homotopy associativity of Hopf spaces and are studied as obstructions not to increase the LS category by one by attaching a cone. Under a condition between dimension and LS category, a criterion for Ganea's conjecture on LS category is obtained using the generalised higher Hopf invariants, which yields the main result of "Ganea's ..." for all the cases except the case when $p=2$. As an application, conditions in terms of homotopy invariants of the characteristic maps are given to determine the LS category of sphere-bundles-over-spheres. Consequently, a closed manifold $M$ is found not to satisfy Ganea's conjecture on LS category and another closed manifold $N$ is found to have the same LS category as its `punctured submanifold' $N-\{P\}$, $P \in N$. But all examples obtained here support the conjecture in "Ganea's ...".
Lusternik-Schnirelmann category of a sphere-bundle over a sphere
Norio Iwase
Mathematics , 2002,
Abstract: A criterion to determine the L-S category of a total space of a sphere-bundle over a sphere is given in terms of homotopy invariants of its characteristic map, and thus providing a complete answer to Ganea's Problem 4. As a result, we obtain a necessary and sufficient condition for such a total space $N$ to have the same L-S category as its `once punctured submanifold' $N\smallsetminus\{P\}$, $P \in N$. Also a necessary condition for such a total space $M$ to satisfy Ganea's conjecture is obtained.
A generalization of the Artin-Tate formula for fourfolds
Daichi Kohmoto
Mathematics , 2010,
Abstract: We give a new formula for the special value at s=2 of the Hasse-Weil zeta function for smooth projective fourfolds under some assumptions (the Tate and Beilinson conjecture, finiteness of some cohomology groups, etc.). Our formula may be considered as a generalization of the Artin-Tate(-Milne) formula for smooth surfaces, and expresses the special zeta value almost exclusively in terms of inner geometric invariants such as higher Chow groups (motivic cohomology groups). Moreover we compare our formula with Geisser's formula for the same zeta value in terms of Weil-\'etale motivic cohomology groups, and as a consequence (under additional assumptions) we obtain some presentations of weight two Weil-\'etale motivic cohomology groups in terms of higher Chow groups and unramified cohomology groups.
An Application of Gamma Distribution to the Income Distribution and the Estimation of Potential Food Demand Functions  [PDF]
Shunsuke Mori, Daichi Nakata, Tomohiro Kaneda
Modern Economy (ME) , 2015, DOI: 10.4236/me.2015.69095
Abstract: Poverty and hunger are the central issues against the sustainable development. Today, more than 800 million people are suffering from insufficient nutrition according to FAO (FAO, 2010). However, on the other hand, it is often pointed out that the per capita food production already meets the demand for the per capita food requirement. The above contradictory observation suggests that many people cannot access the food market because of the low income. The availability of electricity and other energy is also the case. Since these issues are mainly caused by the inequity of income distribution, its quantitative analysis is indispensable to evaluate the societal policy towards the sustainable future. However, since the existing indicators such as Gini coefficients do not represent the income distribution explicitly, they fail to assess the effects of social policy for the improvement of purchasing power of poor people. Population of absolute poverty who gets less than 1.25 US dollar per day is also provided by World Bank. This indicator does not show the distribution pattern of middle to high income classes. The authors would thus point out the need for an alternative method. This paper describes an application of Gamma distribution to the income distribution patterns. The parameters are statistically estimated based on the income quintile data provided by World Bank. The results show how the income distribution has changed historically by country. Based on the future income distribution and the simulation results of the author’s crop market model, we evaluate the share of people who cannot afford the major crop. The authors also propose a procedure to estimate the potential food demand function considering the income distribution changes, suggesting that the future demand could be affected by not only the per-capita income growth but the income distribution changes.
Effect of Low-Dose Sodium Bicarbonate Supplementation on Intermittent Endurance Performance  [PDF]
Sakura Tanaka, Daichi Yamaguchi, Shoji Igawa
Food and Nutrition Sciences (FNS) , 2018, DOI: 10.4236/fns.2018.911094
Abstract: In this study, we investigated the effect of sodium bicarbonate (NaHCO3) supplementation at a dose of 0.2 g·kg1 40 min before an exercise on intermittent endurance performance and gastrointestinal distress. The participants were six healthy male students of a university. The Yo-Yo intermittent recovery test level 2 (Yo-Yo IR2) was used for the evaluation of intermittent endurance. The participants ingested water (Cont) or NaHCO3 independently at three timings. After drinking water, the Yo-Yo IR1 was performed for 2 min as warm-up. After resting for 5 min, the Yo-Yo IR2 was initiated. The measurement items were exercise distance, nutrition intake, biochemical test results, and blood gas analysis findings. The participants who ingested NaHCO3 had a 14% extended distance than those who ingested Cont, and 2/3 of those who took NaHCO3 showed a better motor performance. No significant difference was observed between the participants who took Cont and NaHCO3 in terms of pH level at baseline, and the NaHCO3 level was significantly higher during pre- and post-exercise (p < 0.05). No significant difference was observed between the participants who took Cont and NaHCO3 in terms of bicarbonate ion level at baseline, and the NaHCO3 level was significantly higher during pre- and post-exercise (p < 0.05). In conclusion, even when the participants ingested NaHCO3 at a low dose (0.2 g·kg1), their exercise ability during an intermittent endurance test has improved. Furthermore, when digestive absorption is considered, eating a meal in advance may be able to suppress the onset of gastrointestinal distress.
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