Earozoru Kenkyu
Online ISSN : 1881-543X
Print ISSN : 0912-2834
ISSN-L : 0912-2834
Search
Advanced search
OR
Browse
Search
Volume 16, Issue 3
Autumn
Displaying 1-7 of 7 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Feature Articles —Diesel Exhaust Particles—
Research Papers
  • Numerical Evaluation of g-Jitter Effect on the Diffusion Coefficient of Small Particles under Micro-Gravity
    Masazumi HIGUCHI, Hiroshi TAKANO, Masayuki ITOH
    2001 Volume 16 Issue 3 Pages 202-208
    Published: September 20, 2001
    Released on J-STAGE: January 15, 2009
    DOIhttps://doi.org/10.11203/jar.16.202
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    From the viewpoint of g-jitter effect on the diffusion coefficient of fine particles, the particle migration by non-stochastic Brownian force was numerically discussed with the report of shuttle mission STS-85 regarding the increase of diffusion coefficient in micro-gravity field. In the numerical analysis, a physical model based on the generalized Langevin equation was constructed for the evaluation of dynamic light scattering. Most results showed no increase in the diffusion coefficient within the framework of our model, but some types of particle migration with oscillatory acceleration by the g-jitter effect at very low frequency still indicated a possibility on such a boost for the diffusion coefficient.
    View full abstract
    Download PDF (791K)
  • Determination of Organic Phosphate Triesters in Indoor and Outdoor Air
    Ikue SAITO, Aya ONUKI, Hiroshi SETO
    2001 Volume 16 Issue 3 Pages 209-216
    Published: September 20, 2001
    Released on J-STAGE: January 15, 2009
    DOIhttps://doi.org/10.11203/jar.16.209
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The concentrations of airborne organic phosphate triesters (11 compounds) were measured. The samples were collected from 44 rooms of 22 houses, 22 offices of 11 buildings and 17 points outdoors in Tokyo. Air sampling was carried out using a quartz fiber filter for the first stage and a solid phase extraction disc (EmporeTM C18) for the second stage at a flow rate of 10 l/min for 24 hours. The samples were extracted with acetone and organic phosphate triesters were analyzed by GC-FPD. The six compounds detected in almost all indoor air were triethylphosphate (TEP), tributylphosphate (TBP), tris(2-chloroisopropyl)phosphate (TCIPP), tris(2-chloroethyl)phosphate (TCEP), tris(butoxyethyl)phosphate (TBEP) and triphenylphosphate (TPHP). The compound detected with the highest median concentration in houses was TBP (12.0 ng/m3), while that in offices was TCIPP (19.3 ng/m3). The median concentration ratio of indoor to outdoor of these 6 compounds varied from 2.1 to 18.3. A comparison of houses and offices in terms of concentration showed that the median of the 6 compounds were higher in offices, but the maximum were higher in houses. In particular the maximum concentration of TCIPP in houses was as high as 14 μg/m3, which was 115 times higher than that in offices.
    View full abstract
    Download PDF (680K)
  • Diameters and Distribution of Airborne Particles Dispersed by Bed-making in Laminar Airflow of Biological Clean Room
    Yoshihiro ASANO, Yasuko TAKAHASHI
    2001 Volume 16 Issue 3 Pages 217-222
    Published: September 20, 2001
    Released on J-STAGE: January 15, 2009
    DOIhttps://doi.org/10.11203/jar.16.217
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The purpose of this study was to examine how many particles and airborne microorganisms are dispersed through nurses' care and to describe the distribution of particles in laminar airflow. Although the amenity in biological clean room (BCR) is of great importance for reverse-isolated patients, taking care of a patient in BCR with direct contact or face-to-face is strictly limited in many facilities in Japan. Nurses have conceived from their experiences that they could benefit more from active intervention rather than strict isolation of an immunocompromised patient, and some literatures have supported this. However, little was known about the actual risk of air contamination caused by nurses. We built a mockup patient room with HEPA filter unit and conducted an experimental study using bed making, which appears to generate the most number of particles compared to other nursing care behaviors. While changing unwoven or cotton sheets, we got samples of M Air TTM to find colonies of bacteria and the number of particles by laser particle counter. There were some difference in particle diameter spectrum between unwoven sheets and cotton bed sheets.
    View full abstract
    Download PDF (705K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top