Modification and laboratory evaluation of a TSI ultrafine condensation particle counter (Model 3776) for airborne measurements

<p>A butanol-type ultrafine condensation particle counter (UCPC, Model 3776, TSI, Inc., Shoreview, MN, USA), which can achieve a 50% detection efficiency diameter (<i>d</i>₅₀) of 2.5 nm using a capillary-sheath structure, was modified and tested in the laboratory for airborne measurements. The aerosol flow rate through the capillary is a key factor affecting the quantification of aerosol particle number concentrations. A pressure-dependent correction factor for the aerosol flow rate was determined using a newly added mass flow meter for the sheath flow and the external calibration system. The effect of particle coincidence in the optical sensing volume was evaluated using an aerosol electrometer (AE, Model 3068B, TSI, Inc.) as a reference. An additional correction factor for the coincidence effect was derived to improve the quantification accuracy at higher concentrations. The particle detection efficiency relative to the AE was measured for mobility diameters of 3.1–50 nm and inlet absolute pressures of 101–40 kPa. The pressure dependence of the <i>d</i>₅₀ value, asymptotic detection efficiency, and shape of the particle detection efficiency curve is discussed, along with simple theoretical calculations for the diffusion loss of particles and the butanol saturation ratio in the condenser.</p> <p>© 2017 American Association for Aerosol Science</p

Lessons learned from Evaluation of an Eco-tour Designed to Support the Conservation Works for Wild Birds : A Case Study of Dollarbird Eurystomus orientalis (Buppousou) and Japanese Murrelet Synthliboramphus wumizusume (Kanmuriumisuzume) Watching Tour in Hiroshima Prefecture <Article>

ブッポウソウとカンムリウミスズメの保護活動を支援する環境事業として野鳥観察を中心としたエコツアーが広島県内で行われている。本稿では,広島市民を対象としたWEB アンケート調査と,ツアー参加者を対象とした,参加動機や評価に関するアンケート調査の結果を報告する。前者からは,鳥の知名度の低さにもかかわらず,1/4程度の回答者がツアーへの関心を示すとともに,野鳥保護や環境教育の効果を認めていることなどが明らかになった。後者からは,参加者が,いわゆる「マニア」層が中心となっていることを確認するとともに,ツアーの評価が,一般向けアンケートで重視される以上に,対象とした鳥を見られたかどうかに左右されることがわかった。今後,ツアー内容の充実や集客方法(宣伝方法)の検討が課題となる。An eco-tour designed to support the conservation works for wild birds is complemented in Hiroshima area. We clarified using two questionnaire surveys how the tour is evaluated. The survey for Hiroshima citizens shows that one forth of them express interest in the tour, instead of their blindness of the targeted birds. They accept a conservational value or an educational value of the tour. On the other hand, the survey for the tour participants shows that they are mainly the bird lovers, and that their evaluation of the tour are dependent on whether they could watch the targeted birds or not. It is necessary to improve tour programs and rethink about effective means of advertising, based on the results of these surveys

Optimal compressive force accelerates osteoclastogenesis in RAW264.7 cells

Mechanical stress produced by orthodontic forces is a factor in the remodeling of periodontal ligaments (PDLs) and alveolar bone. It has been reported that the expression of a number of cytokines associated with osteoclastogenesis is upregulated when compressive forces act on osteoblasts and PDL cells. The present study investigated the effects of compressive forces on the formation of osteoclasts from the macrophage cell line RAW264.7. Compressive forces on osteoclasts were exerted using layers of 3, 5, 7, 9 or 14 glass cover slips on the 4th day of culture for 24 h. The number of osteoclasts was determined by counting the number of cells positive for tartrate-resistant acid phosphatase staining. Osteoclastogenesis advanced rapidly on days four and five. The number of osteoclasts with >8 nuclei peaked when the force of 7 slips was applied, which was therefore regarded as the optimal compressive force. Alterations in the expression of osteoclast-associated genes are associated with changes in the differentiation and fusion of macrophages in response to compressive forces; therefore, osteoclast-associated genes were assessed by reverse transcription quantitative polymerase chain reaction in the present study. The mRNA expression of osteoclast-associated genes increased significantly after 3 h of optimal compression, whereas mRNA expression increased after 24 h in the control group. These findings suggested that osteoclastogenesis of macrophages was accelerated when an optimal compressive force was applied

Inkjet Aerosol Generator as Monodisperse Particle Number Standard

<div><p>The AIST-inkjet aerosol generator (IAG) can generate highly monodisperse solid or liquid aerosol particles in the particle diameter range from 0.3 to 20 μm at precisely known particle generation rates. The device has been developed for evaluating the counting efficiencies of optical and condensation particle counters. Particle generation efficiency of the IAG is defined as the number of aerosol particles generated by one voltage pulse sent to an inkjet head. The 95% confidence interval of the efficiency were 0.998 ± 0.006 within the 0.4 to 10 μm particle diameter range. The efficiencies remained close to unity when the droplet generation rates were within 20–500 s⁻¹ and 100–900 s⁻¹ using ultrapure-water and isopropyl alcohol (IPA) as the solvent of the inkjet solution, respectively. The operating aerosol flowrate range of the IAG is currently 0.5 and 1.0 L/min. The coefficients of variations (C.V.) of the size distributions were 2 to 3% indicating the generated particles were highly monodisperse. The generated particle sizes were defined as the volume equivalent diameter, <i>D</i>_ve. The uncertainty analysis on the factors affecting <i>D</i>_ve indicated that 95% confidence interval of the D_ve is expected to be ±5%. The uncertainty of <i>D</i>_ve was entirely caused by the uncertainty of the average mass of a droplet. The reproducibility of particle sizes within 0.5 to 10 μm was evaluated using an aerodynamic particle sizer. The C.V. of the measured particle sizes were less than 6% and 4% when NaCl particles and ionic liquid droplets were generated, respectively.</p><p>Copyright 2014 American Association for Aerosol Research</p></div

Accessory Scrotum With Perineal Lipoma: Pathologic Evaluation Including Androgen Receptor Expression

Accessory scrotum is an unusual developmental anomaly defined as additional scrotal tissue in addition to a normally developed scrotum. The accessory scrotum arises posterior to the normally located scrotum and does not contain a testis. We report a case of an 18-month-old boy with an accessory scrotum attached to a perineal lipoma. We resected both and determined histologically that they were of the same tissue as the scrotum, including the presence of androgen receptor expression. To the best of our knowledge, this is the first case to assess androgen receptor expression in an accessory scrotum using immunostaining

Extending traceability in airborne particle size distribution measurements beyond 10 µm : Counting efficiency and unit-to-unit variability of four aerodynamic particle size spectrometers

The aim of this study was to establish traceable number concentration measurements of airborne particles beyond 10 μm in particle size. To this end, the primary standards for particle number concentration at the National Metrology Institutes of Switzerland and Japan were further developed to extend their measurement capabilities. Details on the upgraded setup are provided. An inter-comparison of the two primary standards using an optical particle counter as transfer standard showed that these agree well within the stated uncertainties at polystyrene (PS) equivalent optical diameter of 15 µm. Subsequently, four Model 3321 (TSI Inc., USA) aerodynamic particle size spectrometers (APS) were calibrated against the primary standard of Switzerland using size-certified PS spheres with optical/aerodynamic diameter up to 20 µm as test aerosols. The counting efficiency profile and unit-to-unit variability of the APS units were determined. The results presented here can be useful for the analysis and interpretation of data collected by the different atmospheric aerosol networks worldwide. The outlined methodology can also be applied in the calibration of automated bio-aerosol monitors

Aerosol-to-liquid collection: A method for making aqueous suspension of hydrophobic nanomaterial without adding dispersant

<p>This article introduces an aerosol-based technique to make aqueous suspension of hydrophobic nanomaterial without adding dispersant. The method is intended for making a test-sample for evaluating the toxicities of nanomaterial by intra-tracheal administration. The method can wet the surface of hydrophobic nanomaterial within a few seconds. After the wetting process five to ten minutes of sonication assisted with manual stirring can fully disperse the hydrophobic nanomaterials in water. Two types of TiO₂ nanomaterial were used in this study; Tayca JMT-150IB whose surfaces are coated with negatively charged hydrophobic functional group, and P25 whose surfaces are naturally hydrophilic. Nanomaterials are aerosolized by a dry-method and become micrometer-sized agglomerates. Then supersaturated water vapor is condensed onto these airborne agglomerates by using a growth tube collector. The collected suspension (CS) of hydrophobic nanomaterial (JMT-150IB) is prepared in two steps; airborne agglomerates are collected onto a flat surface then transferred to liquid-water and subsequently sonicated for complete dispersion. This method works equally well for making the CS of hydrophilic nanomaterial. Size distribution measurements of the CS show that airborne agglomerates of TiO₂ dissociate into smaller units of agglomerates once they are captured into water, and the sizes of the agglomerates are in the nanometer to sub-micrometer range. Light scattering technique is used to show that a short sonication process can reproduce the particle number concentration of the CS after long storage.</p> <p>Copyright © 2017 American Association for Aerosol Research</p