scholarly journals A New Method of Removing Fine Particulates Using an Electrostatic Force

2021 ◽  
Vol 18 (12) ◽  
pp. 6199
Author(s):  
Jaeseok Heo ◽  
Yelim Jang ◽  
Michael Versoza ◽  
Gihwan Kim ◽  
Duckshin Park
Keyword(s):  
Particle Size ◽  
Electrostatic Force ◽  
New Method ◽  
Fine Particulates ◽  
Structural Improvement ◽  
Bus Stops ◽  
High Concentrations

Many studies have found that the concentration of fine particulates in the atmosphere has increased. In particular, when using the bus, the situation in which people are exposed to relatively high concentrations of fine particulates is increasing. The purpose of this study is to reduce exposure to these potentially harmful particulates by introducing open shelters at outdoor bus stops. In order to use it as an outdoor fine particulates reduction device, a brush filter using electrostatic force (EF) was used on an experimental scale and the generation of electrostatic force, according to the material, was examined. As electrostatic force was generated, the fine particulates collection performance was about 90% efficiency. In addition, it was confirmed that the efficiency of each particle size was improved by 57% through structural improvement. Finally, through experimentation, it was confirmed that the brush module can be used for about 70 days.

Measurement of the Particle Size of a High-Lightfastness Direct Dye in Cellulose by p-Nitrophenol Adsorption

1977 ◽  
Vol 47 (5) ◽  
pp. 347-350 ◽  
Author(s):  
Charles H. Giles ◽  
Ronald Haslam
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Aggregation Number ◽  
Regenerated Cellulose ◽  
Cellulose Film ◽  
Adsorption Method ◽  
Regenerated Cellulose Film ◽  
Direct Dye ◽  
High Concentrations ◽  
Film Weight

The p-nitrophenol adsorption method has been used to determine the specific surface, and hence the particle size and aggregation number, of a high-lightfastness direct dye (C.I. Direct Green 26) in regenerated cellulose film. The particle size found at high concentrations is of the same order as that found for other dyes of this type, in cellulose film, by Weissbein and Coven, using electron microscopy. The aggregation number rises rapidly with rise in dye concentration in the film to a maximum of the order of 106 at shade depths above about two percent pure dye on film weight.

New method ("SPAC ET") for free thyroxin in serum evaluated.

1986 ◽  
Vol 32 (4) ◽  
pp. 680-683 ◽  
Author(s):  
M Plebani ◽  
L Perobelli ◽  
A Burlina
Keyword(s):  
Functional Status ◽  
Clinical Data ◽  
New Method ◽  
Commercial Method ◽  
High Concentrations

Abstract We analytically and clinically evaluated a new commercial method ("SPAC ET") for simultaneously determining total and free thyroxin in serum. We found the method to be rapid, simple, and precise. Results significantly correlated with those by "symmetric" dialysis and also agreed with the clinical data for patients with extremely low or high concentrations of thyroxin-binding globulin. On contrast, in those patients the most commonly used thyroid indexes (free thyroxin index or thyroxin:thyroxin-binding globulin ratio) failed to correctly reflect the true functional status of the thyroid.

An RP-HPLC-UV Method with SPE for Cefotaxime in All-in-One Total Parenteral Nutritional Admixtures: Application to Stability Studies

2013 ◽  
Vol 96 (2) ◽  
pp. 290-294 ◽  
Author(s):  
Muhammad Shahid Iqbal ◽  
Mohd Baidi Bahari ◽  
Yusrida Darwis ◽  
Muhammad Zahid Iqbal ◽  
Amer Hayat ◽  
...  
Keyword(s):  
Particle Size ◽  
Mobile Phase ◽  
Room Temperature ◽  
Ammonium Acetate ◽  
Stability Studies ◽  
Rp Hplc ◽  
Accuracy And Precision ◽  
Degradation Rates ◽  
High Concentrations ◽  
Spe Method

Abstract A simple and selective RP-HPLC-UV method with SPE was developed and validated for the quantification of cefotaxime in all-in-one total parenteral nutrition (AIO-TPN) admixtures. Chromatographic separation was achieved on a 5 μm particle size C18 DB column (250 × 4.6 mm id) using the mobile phase ammonium acetate (25 mM, pH 4.0)–50% acetonitrile in methanol (80 + 20, v/v). The flow rate was 0.9 mL/min and the detection wavelength was 254 nm. The analyte was extracted from AIO-TPN admixtures by means of an SPE method. The cefotaxime calibration curve was linear over a concentration range of 100–1400 μg/mL with a correlation coefficient of ≥0.9994. The intraday accuracy and precision for cefotaxime were ≤–3.15 and ≤3.08%, respectively, whereas the interday accuracy and precision were ≤–2.48 and ≤2.25%, respectively. The method was successfully applied to stability studies of cefotaxime in the presence of micronutrients together with low and high concentrations of macronutrients in AIO-TPN admixtures. Cefotaxime was degraded by 13.00 and 26.05% at room temperature (25 ± 2°C) after 72 h in low and high macronutrient concentration formulations of AIO-TPN admixtures, respectively. The values of cefotaxime degradation rates for low and high macronutrient concentration formulations of AIO-TPN admixtures were –0.164 and –0.353, respectively. These results indicated that there was higher rate of degradation in the AIO-TPN admixture formulations containing high concentrations of macronutrients.

Particle Size Effects in Geological Analyses by X-Ray Fluorescence

1985 ◽  
Vol 29 ◽  
pp. 587-592
Author(s):  
K.K. Nielson ◽  
V.C. Rogers
Keyword(s):  
Particle Size ◽  
Quantitative Analysis ◽  
Size Effects ◽  
Light Element ◽  
New Method ◽  
X Ray ◽  
Particle Size Effects ◽  
Sample Matrix ◽  
Xrf Analysis ◽  
The Matrix

Particle-size effects can cause significant errors in x-ray fluorescence (XRF) analysis of particulate materials. The effects are usually removed when samples are fused or dissolved to standardize the matrix for quantitative analysis. Recent improvements in numerical matrix corrections reduce the need to standardize the sample matrix via fusion or dissolution, particularly when the CEMAS method is used to estimate unmeasured light-element components of undefined materials for matrix calculations. A new method to correct for particle-size effects has therefore been examined to potentially avoid the need for destructive preparation of homogeneous samples.

scholarly journals THE EFFECT OF THE ELECTRON-OPAQUE PORE MATERIAL ON EXCHANGES THROUGH THE NUCLEAR ANNULI

1965 ◽  
Vol 25 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Carl M. Feldherr
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Nuclear Envelope ◽  
Colloidal Gold ◽  
Maximum Size ◽  
Amoeba Proteus ◽  
Gold Particles ◽  
High Concentrations

To investigate the extent to which the electron-opaque pore material can regulate nucleocytoplasmic exchanges which occur through the nuclear annuli, experiments were performed in which polyvinylpyrrolidone (PVP)-coated colloidal gold particles (25 to 170 A in diameter) were microinjected into the cytoplasm of amebas (Amoeba proteus). The cells were fixed at various times after injection and examined with the electron microscope in order to determine the location of the gold particles. High concentrations of gold were found associated with the pore material at specific points adjacent to and within the pores. It is tentatively suggested that such specific accumulations could be a means of selecting substances from the cytoplasm for transport through the pores. Particles were also scattered throughout the ground cytoplasm and nucleoplasm. A comparison of the diameters of particles located in these two regions showed that the ability of materials to penetrate the nuclear envelope is a function of their size. It was estimated that the maximum size of the particles able to enter the nucleus is approximately 125 to 145 A indiameter. The regulation of exchanges with regard to particle size is thought to be dependent on the specific organization of the electron-opaque pore material.

scholarly journals The Role of Volume Diffusion in the Metamorphism of Snow

1967 ◽  
Vol 6 (48) ◽  
pp. 879-891 ◽  
Author(s):  
P. V. Hobbs ◽  
L. F. Radke
Keyword(s):  
Particle Size ◽  
Excellent Agreement ◽  
Volume Diffusion ◽  
Theoretical Expression ◽  
Uniform Temperature ◽  
Rate Of Increase ◽  
High Concentrations

A theoretical expression is derived for the rate of increase in the density of a compact of uniform ice spheres due to volume diffusion in the ice. The diffusion occurs due to the existence of high concentrations of vacancies in the ice just beneath the concave surfaces of the necks which grow between the ice spheres. Accurate measurements on the densification of a compact of ice spheres as a function of time, temperature, and particle size are found to be in excellent agreement with the theory The importance of this process in the metamorphism of dry snow at a uniform temperature is discussed.

In Situ Observation of Growing Process of Particles in Silane Plasmas and Their Effects on Amorphous Silicon Deposition

1991 ◽  
Vol 235 ◽  
Author(s):  
Masaharu Shiratani ◽  
Yukio Watanabe
Keyword(s):  
Particle Size ◽  
Electrostatic Force ◽  
Negative Ions ◽  
Particle Growth ◽  
Mie Scattering ◽  
Negative Ion ◽  
Dust Particles ◽  
Modulation Method ◽  
Rf Discharge ◽  
In Situ Observation

ABSTRACTIn rf silane plasmas, growing process and behavior of dust particles and presence of negative ions are studied by square-wave-amplitude-modulating an rf discharge voltage. By combining the rf modulation method with Mie scattering methods, particle behavior together with temporal evolutions of particle size and density is revealed. While the rf modulation is effective for the suppression of particle growth, small particles are found to exist still in the discharge space for a larger duty cycle. Further, particles seem to be suspended around an rf electrode by counter balance between an electrostatic force due to time-averaged sheath electric field and a force increasing with particle size. The development of particle growth also affects the rf discharge itself, resulting in inhomogeneity of film properties. Negative ion detection is carried out as a first step for studying whether they cause the particle formation. It is found that negative ions are formed in rf silane discharges even for a low concentration of 0.5%SiH4 and their formation is due to attachment to dissociated radicals rather than dissociative attachment of SiH4.

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