Journal of Environmental Engineering (Transactions of AIJ)
Online ISSN : 1881-817X
Print ISSN : 1348-0685
ISSN-L : 1348-0685
Volume 80, Issue 716
Displaying 1-19 of 19 articles from this issue
  • Daisuke GOTO, Yoshifumi OHMIYA
    2015Volume 80Issue 716 Pages 839-847
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     In the paper, the effects of three radiation heat transfer environments on prediction of compartment fire behavior are examined by using a model based on zone concept. First, a radiation heat transfer model considering diffuse reflection is formulated by using ray tracing method. And the following calculations are described by the consideration of direct and reflective heat transfers: (a) net heat gain of a layer, Qnet, (b) heat transfer from surroundings to a fuel, qe, (c) heat transfer to adjacent space through to the openings, QR, (d) wall surface temperatures, Tw. Next the theories are incorporated into the predictive model for compartment fire behavior. From the comparison of calculations and experimental results in every environment, the effect of radiation heat transfer environment on the prediction has been cleared.
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  • -Analysis based on the observational data of a real total evacuation drill-
    Hiroyuki KADOKURA, Ai SEKIZAWA, Tomonori SANO, Kosuke FUJII
    2015Volume 80Issue 716 Pages 849-856
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     If a fire or other serious emergency occurs in a high-rise building, all occupants would be forced to evacuate the building under such an extreme event. Also, it is quite probable that many occupants in the building start to evacuate at the same time on this occasion. Further, the staircase would become very congested, if all occupants try to evacuate via a limited number of staircases concurrently. In such a case, it may cause considerable delay of the evacuation time or influence on walking speed of evacuees. To cope with this kind of simultaneous total evacuation, there is a method known as “phased evacuation”, where occupants on a fire origin floor and the floor above will evacuate first and followed by other occupants in different floors to avoid congestion in the staircase. However, it is unclear how the phased evacuation is more efficient than simultaneous total evacuation, because there have been limited studies and data concerning this method of evacuation. To explore the potential availability of phased evacuation, this study analyzes the data obtained by video recording and measuring movement of evacuees during a total evacuation drill conducted in a high-rise office building in Tokyo.
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  • Tomoaki NISHINO, Yugo IMAZU, Akihiko HOKUGO, Hiroaki NOTAKE
    2015Volume 80Issue 716 Pages 857-866
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Two sub-models for spatio-temporal distribution of tsunami-driven debris are proposed: (1) tsunami fragility function for building destruction, and (2) debris drift and accumulation model due to tsunami inundation flow. These modeling are the beginning of model development towards tsunami fire simulation. The tsunami fragility function is the logistic regression model based on the data of the building damage after the 2011 Tohoku Earthquake Tsunami. The debris drift and accumulation model is the extension of the existing model for driftwood by incorporating the debris release model and the blocking effect of surviving buildings on debris movement.
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  • Wataru UMISHIO, Toshiharu IKAGA, Kuniaki OTSUKA, Shintaro ANDO
    2015Volume 80Issue 716 Pages 867-875
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Although it has been recently noted that blood pressure variability is affected by the indoor thermal environment, these effects haven't yet been studied in sufficient detail. Therefore, a field survey on ambulatory blood pressure and indoor temperature was conducted for 7 days in the winter month 2012. On the date that indoor temperature in the bedroom was lowest, morning blood pressure was higher and morning blood pressure surge was larger, compared to the date when temperature was highest. Furthermore, the blood pressure gap between the lowest day and the highest day was larger after getting out of bed than before.
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  • Osamu HASHIMOTO, Daisuke IBARAKI
    2015Volume 80Issue 716 Pages 877-885
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     The purpose of this study was to examine masking systems between desks in open plan offices installed with an appropriate sound masking system. Word intelligibility tests for unwanted speech interference from nearby workstations, and subjective judgements on the degree of discomfort of masking sound were conducted in a simulated office workplace. The results were as follows: (1) The level of masker sound could be decreased to 5-10 dB when focused on desk work relative to the masking level in non-desk work; (2) We showed that the optimum masking level in a desk work environment is a target/masker ratio of -2 dB.
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  • Tsunetoshi NASU, Tsuyoshi NISHIMURA
    2015Volume 80Issue 716 Pages 887-896
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Presented here is a concept for manufacturing windows which are capable of ventilating, regulating sunlight and reducing traffic noise inside the homes of the developing countries in tropical climate zones. A previous study discussed a rectangular soundproofing ventilation unit having an inlet and an outlet located on the opposite face, which results in a reduced outlet area. As a result, the ventilation function is reduced.
     To improve this problem, a rectangular soundproofing ventilation unit featuring an inlet and an outlet which is located on the crossed right angle face is proposed in this work. First, the outlet sound pressure is calculated based on the wave equation. Next, to maximize the sound proofing ability, the shape and location of the inlet and the outlet are determined by an investigation of the distribution of higher order mode waves formed inside the soundproofing ventilation unit. Finally, experimental results based on the reverberation chamber method are shown to be in reasonable agreement with our theoretical predictions.
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  • Naoya KUBO, Kazunori NISHIMURA, Nobuyoshi KIYOTA
    2015Volume 80Issue 716 Pages 897-903
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Magnetic shielding in a building requires a method for thermal radiation. Therefore, magnetic shielding effectiveness when magnetic material of perforated metal surrounds four aspects of electric power line circumference was examined by both of a physical experiment with practical size of three-phase electric power line and a simulation experiment with finite element method. In the results, high magnetic shielding effectiveness was observed under a condition of large opening ratio, however the condition can easily lead magnetic saturation at relatively low AC current. In addition, a difference of opening alignments made a small difference which can be ignored.
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  • Investigation on the outdoor and indoor radiant-exergy distributions for micro-climatic design of buildings
    Keita YAMAZAKI, Kunihiko FUJIWARA, Masanori SHUKUYA
    2015Volume 80Issue 716 Pages 905-915
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     This paper describes the cooling effect of trees on outdoor and indoor environment in summer, making use of the concept of radiant exergy, which should be applied to the design of buildings and their surrounding open space. The measurement of air temperature, humidity, wind velocity, globe temperature and surface temperature for two days was carried out in order to estimate the radiant exergy of indoor space and outdoor space in the vicinity of buildings and where a lot of trees are planted. We compared the radiant exergy emitted from window surfaces towards the indoor space in north-facing rooms and that in south-facing rooms on the third and sixth floor. Hot indoor radiant environment especially in the perimeter zones, was found due to the warm exergy available from outside and the incident solar radiation reflected by brick pavement outdoors and the roof surface of residential buildings in the vicinity. We have confirmed, through this series of measurement and calculation, that the currents of “warm” and “cool” radiant exergy is useful in quantifying the radiant environmental conditions of indoors and outdoors.
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  • Ken UNNO, Emika MIYAKE, Shin-ichi TANABE
    2015Volume 80Issue 716 Pages 917-923
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Different kinds of adaptive opportunities are selected in bedrooms, such as air conditioning and natural ventilation; however, the thermal environment created by these measures is not necessarily good for sleep. In this research, a field survey was carried out to investigate the effect of the total thermal environment and its variation on sleep. First, we investigated the effect of airflow and found that an increase in air turbulence causes an increase in the duration of wakefulness. Next, we adjusted the comfort equation for sleep and calculated the thermal load on the body and its variation. We found that both negative and positive increase in the heat load on the body causes an increase in the probability of awakening. An increase in its variation also resulted in an increase in the probability of awakening. We concluded that when planning a pleasant thermal environment for sleep, it is important to consider the total thermal environment and to take into account the effect of its variation as potential cause of sleep disruption.
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  • Study on naturally cross-ventilated house using large-eddy simulation(LES) part 1
    Yasuo TAKANO, Shin-ichi AKABAYASHI, Yoshihide TOMINAGA, Jun SAKAGUCHI, ...
    2015Volume 80Issue 716 Pages 925-934
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Natural cross ventilation in house is commonly used as ventilation method in Japan. It is influenced by wind direction, distribution of wind velocity and total pressure on walls. Cross ventilation is not observed with using Reynolds Averaged Navier-Stokes Simulation (RANS), nevertheless occurs in actual phenomena. Flow field in the house varies depending on fluctuating wind. For example, cross ventilation is affected by the wind turbulence around the house, in case of two openings positioned symmetrically on opposite walls parallel to wind direction. Therefore, replicating actual phenomena with using CFD is very important to provide evaluation method for ventilation design. Recently, unsteady fluid flow phenomena are analyzed using Large-Eddy Simulation (LES). In this study, opening conditions and wind direction are calculation variables, five cross ventilated simple house models are calculated using LES. Distributions of instantaneous wind speed ratio and pressure, mean wind speed ratio about cross-ventilated houses are reported. In opening conditions that time-averaged inflow is not observed, instantaneous inflow caused by pressure difference on the walls is generated by turns at each opening. Unsteady cross ventilation is replicated with using LES under opening conditions that obtain no-ventilation in steady-state flow field.
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  • Development of computer simulated person with numerical respiratory tract model - part2
    Sung-Jun YOO, Kazuhide ITO
    2015Volume 80Issue 716 Pages 935-943
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     The effects of air pollution found in indoors and prevention of exposure to hazardous compounds are an important issue in the interest of public health. In this research, Computer Simulated Person (CSP) that integrated thermo-regulation and numerical respiratory tract model is developed for applying comprehensive assessment of health risk caused by indoor environmental quality problem. Especially, this paper (part 2) reports the internal integration procedure of virtual manikin and numerical respiratory tract by way of convective heat and moisture transfer analyses for improvement of thermo-regulation model. Furthermore respiratory exposure to contaminated air under different contaminant generation was studied using CSP and unsteady CFD technique.
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  • Evaluation of sterlizing efficacy of ultrasonic fogging with hypochlorite or slightly acid electrolzed solutions in an actual large space
    Makoto YAMAGUCHI, Koichi ISAWA, Yoko YAMADA, Risa KAWAKAMI, Kazuyuki T ...
    2015Volume 80Issue 716 Pages 945-952
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Recently attention has been focused on countermeasures against microorganisms such as viruses and microbe, in connection with pandemics of new forms of influenza or SARS, and the occurrence of bioterrorism. Also, in pharmaceutical or food production facilities, a high standard of internal environment of the facility is required, including countermeasures against microorganisms. These countermeasures from the facility point of view include partitioning of work zones (zoning), and cleaning the air using HEPA filters. However, when workers/researchers are working within a facility, dispersion of dust or adhering microbe brought in from clothes, etc., cause pollution of the air. In this report, the sterilization performance of weak acid hypochlorous solution used as the chemical substance was verified. In addition, the sterilization performance in an actual space varied not only with the chemical substance used, but also with the condition of the room, the air conditioning system, the method of spraying, etc. Therefore, from the above sterilization performance tests using chemical substances, the raw data required for a computational fluid mechanics (CFD) model were derived. A method that enables the effect of the chemical substance to be predicted under various conditions was investigated, and the results are reported.
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  • Akira TAKAKUSAGI, Mine SUDO
    2015Volume 80Issue 716 Pages 953-962
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Lavatories are one of the most important functions in buildings. However their failures and troubles have not been grasped. On the basis of maintenance records in lavatories at certain large-scale hospital, this paper presents basics data for maintenance plan and design of lavatories by analyzing contents of failures and troubles, the occurrence frequency, restoration time and unavailability. In addition, lavatories at a large-scale office building were also analyzed to reveal the specificity of hospital. The analyzed data are 3,292 cases; 59.9% of failures and troubles in sanitary equipment. The failures and troubles of the closet bowls occupied 46% of the entire the lavatories. Most causes were clogging, and clogging by toilet paper was 61.9%. In case of an office building, there are many failures and troubles of the drainage stopper of the washstand and deliberate clogging. In the failures and troubles of lavatories, the events that restored on the day when failures and troubles occurred accounted for 93.7%. A method to calculate event probability of failures and troubles such as clogging or water leaking in toilet booth, and the round numbers were shown using the survey data.
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  • Analysis of life stage and bathing habits
    Souki TOMIYAMA, Makoto SATOH, Hiroki NAKAJIMA, Masayuki MAE
    2015Volume 80Issue 716 Pages 963-971
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     The purpose of this study is to clarify the effects of housing appliances such as energy-efficient water heaters and co-generation system and diversifying family composition and bathing habits on Energy Consumption especially hot water usage which is dominant in Japanese households. We conducted a web questionnaire survey to the dwellers of detached houses in temperate and cold climate. First, we analyzed the household characteristics and kinds of heating appliances they use based on the type of water heaters they use then compared the amount of energy they consume. Secondly, by focusing on the age of householders as an indicator of households'life stage, we found that the older the householders get, the more annual income they get, the older house they live and the more energy they consume. Finally, we quantified the effects of the life stage and bathing habits on the hot water energy consumption by conducting a multiple regression analysis and found that men in their 40s and women in their 20s, 60s and older consume much hot water energy.
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  • Yuya TAKANE, Shouhei AOKI, Yukihiro KIKEGAWA, Youhei YAMAKAWA, Masayuk ...
    2015Volume 80Issue 716 Pages 973-983
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Extreme high temperature events occur frequently in Nagoya city of Japan, and have been of great concern recently because they bring risks to the energy supply, public health, and more. In this study, changes in electricity demand and thermal comfort in Nagoya city with future climate change were projected by WRF-CM-BEM which coupled a multi-layer urban canopy model CM, and a building energy model BEM in a regional climate model WRF. The results showed that summer time daily mean electric demand and human thermal comfort (SET*) in Nagoya city were projected to increase by about +4.9 W/floor m2 and 2.8 °C in the 2070s, respectively. However, sensitivity experiments indicated that urban greening adaptation strategy have the potential to reduce by 33% and 10% of above projected values, respectively. In comparison with urban greening, anthropogenic heat reduction strategy was estimated to have smaller influence to improve future electric demand and human thermal comfort in Nagoya city.
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  • Megumi YANAGISAWA, Toshiharu IKAGA, Shintaro ANDO, Kimihiro HINO, Tanj ...
    2015Volume 80Issue 716 Pages 985-992
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     In this study, we conducted a questionnaire survey and actual measurement to examine the relationship between indoor thermal environment, insulation efficiency, and physical activity. Results indicated that, first, people who perform less physical activity in winter compared with fall tend to live in colder houses. Second, after adjusting for biological factors, socioeconomic status, lifestyle, and outdoor temperature, greater physical activity was associated with higher minimum temperature of the lavatory and corridor. Lastly, high insulation efficiency can be considered effective for promotion of physical activity, as shown by the correlation between indoor thermal environment and insulation efficiency.
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  • -Efforts of municipality-
    Takaho ITOIGAWA
    2015Volume 80Issue 716 Pages 993-1000
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     In summer, TV and radio often announces the alarm of heatstroke. City office put posters for preventing heatstroke on the wall. But, every year about 40,000 to 50,000 people are cared by first aid for heatstroke. This study aims to find the effective approach for preventing heatstroke. Especially this study puts eyes on efforts of municipality.
     Based on heatstroke incidence and heatstroke prevention, this study was analyzed on following 3 aspect.
     1. 70% of municipality used paper and human resource to prevent heatstroke.
     2. This study defined the coverage as a measurement of the degree of the effect of the heatstroke measure.
     3. There is a possibility that more resource can reduce more heatstroke.
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  • Etsuko MIZUTANI, Daisuke OGURA, Takeshi ISHIZAKI, Masaru ABUKU, Juni S ...
    2015Volume 80Issue 716 Pages 1001-1011
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     Hagia Sophia in Istanbul has been suffering from severe degradation of the outside and inside walls and the paintings on the inside wall surfaces mainly due to liquid water transport and salt crystallization. In order to elucidate the degradation mechanism and then propose a suitable method for preservation, we have conducted a long-term field survey of Hagia Sophia from 2010 until 2014 and numerical analyses of simultaneous heat and moisture transfer in the walls. It was found that high moisture content — primarily due to penetration and evaporation of rain water and partly due to consequent salt crystallization — generally leads to degradation of both inside and outside walls. It was observed that the moisture content of the north inside wall is higher than that of the south inside wall due to less solar radiation. Also, there are high possibilities that evaporation mainly at the middle-layer mortar caused salt crystallization and exfoliation of the inside stucco wall surfaces and that the exfoliation of the inside finishing material of the wall caused further subsequent exfoliation of the inner layers.
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  • Single point method using a range fan and carbon dioxide of a combustion gas
    Motoya HAYASHI, Yoshinori HONMA, Kenichi HASEGAWA, Hoon KIM
    2015Volume 80Issue 716 Pages 1013-1020
    Published: 2015
    Released on J-STAGE: November 11, 2015
    JOURNAL FREE ACCESS
     The aim of this study is to use the building environmental performance as a base of healthy life of victims after great east japan earthquake in 2011. The equivalent leakage areas of the houses for victims were investigated and an easy measurement method was developed to the airtight levels to be high in the houses. The results showed the followings.
     1. The equivalent leakage area varied in the houses and are not enough for the latest building code for energy saving in some cases under the high housing demand for the victims.
     2. An easy examination method using a fan in kitchen is useful to check the airtight levels in houses which equivalent leakage area is less than about 2.0 cm2/m2.
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