Journal of Environmental Engineering (Transactions of AIJ)
Online ISSN : 1881-817X
Print ISSN : 1348-0685
ISSN-L : 1348-0685
Volume 82, Issue 741
Displaying 1-6 of 6 articles from this issue
  • Kimie YOSHITANI, Takafumi SHIMIZU, Masatomo YOSHIDA
    2017 Volume 82 Issue 741 Pages 915-925
    Published: 2017
    Released on J-STAGE: November 30, 2017
    JOURNAL FREE ACCESS
     In this study, a prediction method of the unexposed surface temperature of a wall is proposed using "inclusive thermal conductivity" that takes into consideration heat and mass transfer in a material containing moisture. Inclusive thermal conductivity is estimated based on the results of temperature measurements from actual fire tests. The proposed method will enable the estimation of thermal conductivities of materials that are difficult to assess using conventional technologies. The inclusive thermal conductivities are estimated by using the finite differential method.
     The estimated thermal conductivities of gypsum board were based on the results of temperature measurements from actual fire test which was conformed in ISO834. On the estimation of the inclusive thermal conductivity, the calculated internal temperatures of the materials and exposed surface temperature on the non-heated side were compared with the experimental results. The inclusive thermal conductivities were estimated considering the moisture behavior and cracks in the materials.
     The inclusive thermal conductivities have some peaks and troughs at various temperatures. The inclusive thermal conductivity of gypsum board becomes larger as the temperature becomes higher. Furthermore, an approximate formalization of the inclusive thermal conductivities was conducted in order to use them in numerical calculations, they are segmented for each temperature region.
     In order to verify the usefulness of inclusive thermal conductivities for temperature prediction, the unexposed surface temperatures were predicted for decreasing material thicknesses of gypsum board. For changing specimen thickness, the inclusive thermal conductivities of predictive calculations were performed by removing layers of the same thickness as the divided layer.
     Calculations using this inclusive thermal conductivity sufficiently captured the temperature history. Unexposed surface temperature prediction is affected by the exposed surface temperature of the fire-resistance test, and that is a high accuracy as the difference of the material thickness is smaller. Exposed surface temperature obtained from the fire-resistance test result influenced the prediction of the unexposed surface temperature. The results confirmed that the inclusive thermal conductivity reflects the influence of moisture movement, evaporation of water, deterioration, or crack formation in the material at high temperatures.
     The prediction accuracy of numerical analysis using the inclusive thermal conductivity was conformed to be practically sufficient.
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  • - A study on Up·PHe·PSe synthetic evaluation system of river landscape Part 1 -
    Rui JIANG, Daisaku NISHINA, Takahiro TANAKA
    2017 Volume 82 Issue 741 Pages 927-937
    Published: 2017
    Released on J-STAGE: November 30, 2017
    JOURNAL FREE ACCESS
     1 Introduction     In order to help us understanding river landscape better and create value as urban river landscape resources, we need more objective and quantitative cognition. Therefore we dedicated to make a Urban planning·Physical evaluation·Psychological evaluation (Up·PHe·PSe) synthetic evaluation system(SES) to describe the river environment more precise and to provide solid foundation for formulating of urban planning.
     2 Outline of the stduy     As a set-up step, in this study, we calculated land usages around the river, and defined five physical quantitative evaluation indexes (PHqi), such as OA, OO, OG, SFD, VMR, to acquire PHe values, conducted psychological experiment about the same photos to acquired PSe values, and then analyzed correlation coefficients among the three parts of SES. After validity of PHqi being confirmed, we also tried to make a predicting model to forecast satisfaction of landscape by PHe values.
     3 Outline of the subjects     In this study, a city river space of Shincheon in Daegu city is investigated as a case. We took 28 photographs of the scenes of river-scape following the stream at viewpoints that set at the center of 14 main bridges on Shincheon, towards upstream and downstream respectively, to acquire PHe values and PSe values. Also, a range of 100 meters from the river boundary of the two sides was selected as study object of a land usage.
     4 Conclusion     Major findings are as follows:
     1) The values of AU are shown that all the 13 sections have large area occupancy of NG, especially section 1 of upstream and section 11~13 of downstream. R2nd-7 is also occurrence of almost every section, while R2nd-15 is mainly occurrence of section 1~7. R3rd is mainly occurrence of section 7~8, which are the central area of Daegu city.
     2) The values of PHe are shown that although the values of OA and OG show similar ranges and mean values, OA of location G~J which are located in city central area are higher than both ends, while OG has contrary tendency. SFD and VMR also show similar tendency, but OO show none distinct tendency.
     3) All the values of PSe show different tendencies of city central area and both ends, while discrepancies still exist between upstream group and downstream group. Factor analysis of psychological evaluation scores are also calculated, five factors are called as Pleasantness, Openness, Complexity, Constructiveness, Green-visibility.
     4) Comparing with the correlation coefficients among values of PHe, PSe and Up, PHe values have more powerful correlation with both PSev and Up. PSe values have certain relationship with land usage or landscape elements, but the corresponding relationship is more significant with PHqi, excepting OO. Therefore, it can be inferred that PHqi certainly have validity of illustrating river landscape and could serve as bridges to connect PSev with AU.
     5) After validity of PHqi being confirmed, we also try to make a predicting model to forecast satisfaction of landscape by PHe values. The results are shown as Table 7. Although OO has lower correlation coefficients with other PSe and Up values, it is selected as an explanatory variable of predicting formulation of openness, which means that OO also has certain power as an PHqi.

     According to the results, we especially emphasized on the function of PHqi that serving as bridges to connect the PSe with Up, and tried to quest for concrete theoretical foundation for urban planning and making urban planning more acceptable in future by developing the adhibition of PHqi as urban planning indexes.
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  • Study on land use scenarios of compact city with mitigating urban warming effect in Kanagawa prefecture Part1
    Makoto YOKOYAMA, Kaoru MATSUO, Takahiro TANAKA, Satoru SADOHARA
    2017 Volume 82 Issue 741 Pages 939-948
    Published: 2017
    Released on J-STAGE: November 30, 2017
    JOURNAL FREE ACCESS
     In recent year, thermal environment in urbanized area is becoming severe and various problems such as health hazard are occurred because of urban warming. So, mitigating the effects of urban warming is needed. On the other hand, depopulation trend has started recently in Japan. It is expected some problems such as declining efficiency of urban management will be occurred by the depopulation in the future, if present land use distribution patterns are not changed greatly. Therefore, compactification of urbanized area is necessary to avoid such problems caused by the depopulation. Compactification of urbanized area needs the discussion "Where urbanized area should be concentrated?". Introducing the viewpoint of mitigating urban warming effect to this discussion is important to create livable and sustainable urban environment.
     Consequently, final objective of this study is designing land use scenarios of compact city with mitigating urban warming effect. To achieve this objective, showing the appropriate area for promoting urbanization from the viewpoint of mitigating urban warming effect is necessary. Also, many major cities locate in coastal areas in Japan. Therefore, mitigation effect for urban warming by sea breeze (sea breeze effect) is expected in such area, and it is considered the zone where sea breeze effect is available is one of the appropriate areas for urbanization in the future. Consequently, the map that gradually shows the relative effectiveness of sea breeze effect in Kanagawa (sea breeze effect map) is made in this paper by using The Weather Research and Forecasting (WRF) model. However, the location of zones where sea breeze effect occur may change by the change of climatic environment such as wind blowing patterns in whole target area that may be caused by the change of land use distribution. Accordingly, the concept of “potential natural climate” is defined and it is used as a baseline in this study. Also, by comparing between the base line and the present climate, urbanization effect on climatic environment is evaluated and it is confirmed whether spatial distribution of sea breeze effect is changed or not by urbanization.
     The major findings are as follows: 1) Correlation between air temperature distribution patterns of present climate and potential natural climate is high during daytime. Therefore, it is considered promoting urbanized area based on potential natural climatic environment is effective to mitigate urban warming effect. 2) As a result of relevant analysis, the negative correlation between wind velocity and air temperature is seen in the present climate during morning when sea breeze starts to blow. However, the small negative correlation in potential natural climate is seen because of wind without cooling effect. Accordingly, removing wind without cooling effect seems to be needed to make sea breeze effect map in this area. 3) Sea breeze effect map is made by using three criteria (wind direction, wind velocity and air temperature rising) in potential natural climate. As a result, the strong negative correlation is seen between sea breeze effect hours and air temperature during the daytime. So, it is considered designing land use scenarios of compact city with mitigating urban warming effect is possible by using the sea breeze effect map in this area.
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  • Kazuhiro YUASA, Takahiro TSURUSAKI, Sei YAMASAKI
    2017 Volume 82 Issue 741 Pages 949-955
    Published: 2017
    Released on J-STAGE: November 30, 2017
    JOURNAL FREE ACCESS
     The demands of photovoltaic generation (PV) are increasing as the public eco-awareness grows, but there is concern of enormous volume disposal of PV panels in the near future. It is calculated by Ministry of the Environment that if the PV panels life expectancy were 25 years, its final disposal amount reaches 800,000 ton in 2040. And its disposal amount is equivalent to 6% of the present final disposal amount of whole Japan. Considering the load to future's final disposal site, its influence can't be ignored any more.
     For this reason, some companies are already working to develop the recycling method of PV panels in Japan. However, details of its reductive effect of environmental load is not so certain. So the purpose of this study is to uncover the reduction in CO2 emissions by the recycling of PV panel's glasses (main constituent materials of PV panels are glasses which accounts for more than 50 % by the weight ratio.) through the inventory analysis.
     At first, we carried out hearing survey on PV panels disposal service vendors, recycled products manufacturers and so on, in order to grasp component materials of PV panels (5 kinds of PV panels were targeted in this research), manufacturing process of recycled products, specification of prosessing apparatus, etc.
     Then we set two flow charts based on hearing survey. First are proposal procedures that are processes of PV panel's glasses recycling to ceramic tiles, paving blocks, and sound proof panels. Second is currently procedure as a comparison that is process of PV panels recycling to roadbed materials (we also considered that currently procedure is landfill disposing without PV panel's glass recycling). We calculated respective procedure's CO2 emissions per PV panel ton treatment by the inventory analysis.
     The followings are the main findings of this study:
     ·Each of PV panels are composed of different materials ratio, so there are difference of reduction in CO2 emissions between respective PV panels.
     ·At the time of recycling to ceramic tiles, it was confirmed that the fuel consumption in the baking process can be reduced 33 % by using glass, not a natural raw material like a feldspar. Therefore, the substantial CO2 reduction effect was suggested.
     ·Recycling to ceramic tiles, paving blocks and sound proof panels using glass of PV panels gave more than 10 % CO2 reduction ratio, even when any PV panels were subjected. It was the case when CIGS PV panels are recycled to sound proof panel that the CO2 reduction ratio becomes biggest, and its CO2 reduction ratio was 61%.
     ·We showed that which productization or occasion of PV panel kinds are able to get the amount of CO2 reduction beyond 140kg-CO2. It was the case when CIGS PV panels are recycled to ceramic tiles that the amount of CO2 reduction becomes biggest, and its amount of CO2 reduction was 441.6kg-CO2.
     ·Amount of CO2 reduction didn't become substantial minus effects in the comparison even when the currently procedure is landfill disposing. Combined with the volume reduction of final waste, it is suggested that PV panel recycling reads to significant reduction of environmental load.
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  • Go MIYAZAKI, Yusuke NAKAJIMA
    2017 Volume 82 Issue 741 Pages 957-966
    Published: 2017
    Released on J-STAGE: November 30, 2017
    JOURNAL FREE ACCESS
     Combined elementary and junior high school is increasing in recent years. In this research, the energy consumption of a combined elementary and junior high school with other public facilities was examined in detail, and the energy consumption tendency and the influences of other public facilities were analyzed. The results are shown as follows.
     1) The energy consumption of combined elementary and junior high schools increased after unification in all schools in Shinagawa Ward.
     2) The power consumption of the school building of Saturday and Sunday were more than half of that of the weekday. As for this factor, the influence of an integrated learning facilities in the school building and operation of 24 hours ventilation in night-time was guessed. The gas consumption for GHP occupied about two-thirds of the annual total gas consumption in the school building.
     3) The power consumption of the nursery school and pool building were occupied by underground heat pump for heated pool warming and pool filter device approximately 50% in the year. The gas consumption of nursery school and pool building were mostly occupied by boilers, which were used for hot water supply and heating of the nursery school, and shower, heating and warming assistance of the pool.
     4) As for the annual comparison of the primary energy consumption per floor space, the nursery school and pool building was about 4.5 times of the school building. It is shown that the energy consumption of the nursery school and pool building accounted for about 40% of whole school A building.
     5) As a result of having estimated the energy consumption of other public facilities which is not included in the general elementary and junior high school, other public facilities accounted for about 45%. The energy consumption per floor space of school A building except these other public facilities is about only 9% larger than average conventional elementary and junior high school.
     As above, when the energy consumption trend of such school facilities is evaluated, consideration of the influence with other public facilities is necessary. In addition, it is believed that appropriate setting of the operation schedule of the ventilation equipment and appropriate setting an air conditioning area and temperature are important.
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  • Kenichi HASEGAWA, Hiroshi YOSHINO, U YANAGI, Kenichi AZUMA, Haruki OSA ...
    2017 Volume 82 Issue 741 Pages 967-975
    Published: 2017
    Released on J-STAGE: November 30, 2017
    JOURNAL FREE ACCESS
     The Great East Japan Earthquake occurred on March 11, 2011, causing severe damage to cities in the Tohoku district along the coast of the Pacific Ocean. Many people in the Tohoku area lost their homes, and as a result, more than 50,000 temporary housing units were built in three affected prefectures. Most temporary housing units were terrace houses built closely together with subpar thermal insulation and energy conservation, so potential problems concerning indoor thermal and acoustic environments, as well as the air quality, are a serious concern. Therefore, the objective of the present study was to clarify the relationship between the indoor and outdoor environment of temporary housing and the overall living situation of temporary housing residents. We also sought to propose an optimal method for the environmental design of temporary housing and to suggest ways to improve environmental policies.
     We conducted a questionnaire survey regarding the environmental factors and self-reported health conditions of residents living in temporary housing in and around Sendai city in the summer of 2011 and the winter of 2012. Questionnaires were distributed by mail to 99 temporary housing units in the summer and 152 in the winter, with response rates of 77.8% and 57.9%, respectively. In addition, we performed multivariable logistic regression analysis to investigate the association between adverse health effects and influencing factors related to living in temporary housing.
     Based on the results, 78.7% of the respondents answered that there was visible condensation on the surfaces of doors and windows, and 46.6% answered that they had observed mold growth in the winter. About 40% of the respondents reported that they used exhaust fans in the lavatory or bathroom continuously for ventilation. On the other hand, about half of the respondents only used exhaust fans when using the toilet or taking a bath. These results suggest that air circulation and ventilation are inadequate in temporary housing.
     The questionnaires also included items regarding the following health-related symptoms: ocular symptoms, nasal symptoms, respiratory symptoms, dermal symptoms and mental symptoms. The results showed that the prevalence of each symptom was about 40%, and that symptom onset was within 3 months after moving into the temporary housing. Adjusted odds ratios for each health symptom in the summer and winter were calculated using a multivariable logistic regression model adjusted for age, gender, and smoking status. In the summer, the risk of ocular, nasal, respiratory and dermal symptoms increased significantly with closer proximity to industrial plants (p<0.05). In the winter, the risk of nasal, respiratory, and dermal symptoms increased significantly with increased frequency of hanging the laundry indoors (p<0.05). These results suggest that among residents of temporary housing, the outdoor air environment is associated with health symptoms during the summer and the indoor air environment is associated with adverse health effects during the winter.
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