• Journal of Environmental Science International
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• v.15 no.12
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• pp.1171-1175
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• 2006

Deposited road particles (DRPs) were analysed for heavy metal concentrations at four different roads in a city, Korea. The samples were collected using a roadway surface vacuum cleaning vehicle which was commonly used in collecting roadway surface particles. Six particle size ranges were analyzed separately for twelve heavy metal elements (Cd, Cr, Pb, Ni, Al, As, Co, Cu, Fe, Mn, Zn and Hg). At all sampling sites, the high concentration of the heavy metals occurred in the <74um particle size range, which conventional roadway cleaning vehicles do not remove efficiently. The Pb concentration significantly increased with decreasing particle size of DRPs, and other toxic heavy metals (Cd, Cr and Ni) also showed similar results. The heavy metal concentrations in the smaller size fraction of DRPs is important because they are contaminants that are preferentially transported by road runoff during rainfall.

• Journal of applied mathematics & informatics
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• v.1 no.1
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• pp.1-12
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• 1994

We consider a single channel CSMA/CD system with D homogeneous stations and impeded buffer of infinite size. We find a sufficient condition for the model to be stable under the threshold control policy and derive the limiting distri-bution of the number of messages in the system at the moment of service completion. We also derive the limiting distributing of the number of messages in the system size at arbitrary time by using Markov regenerative processes. Some numerical examples and special cases are also treated.

• Environmental Engineering Research
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• v.21 no.1
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• pp.15-21
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• 2016

Magnesium potassium phosphate cement (MKPC) is an effective agent for solidification/stabilization (S/S) technology. To further explore the mechanism of the S/S by MKPC, two kinds of Cd including $Cd(NO_3)_2$ solution (L-Cd) and municipal solid waste incineration fly ash (MSWI FA) adsorbed Cd (S-Cd), were used to compare the effects of the form of heavy metal on S/S. The results showed that all the MKPC pastes had a high unconfined compressive strength (UCS) above 11 MPa. For L-Cd pastes, Cd leaching concentration increased with the increase of Cd content, and decreased with the increase of curing time. With the percentage of MSWI FA below 20%, S-Cd pastes exhibited similar Cd leaching concentrations as those of L-Cd pastes, while when the content of MSWI FA come up to 30%, the Cd leaching concentration increased significantly. To meet the standard GB5085.3-2007, the highest addition of S-Cd was 30% MSWI FA (6% Cd contained), with the Cd leaching concentration of 0.817 mg/L. The S/S of L-Cd is mainly due to chemical fixation, and the hydration compound of Cd was $NaCdPO_4$, while the S/S of S-Cd is due to physical encapsulation, which is dependent on the pore/crack size and porosity of the MKPC pastes.

• Journal of KSNVE
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• v.9 no.6
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• pp.1247-1258
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• 1999

This paper presents vibration control of a CD-ROM(compact disc-read only memory) drive feeding system consisting of a new type of CD-ROM mount using an electro-rheologocal(ER) fluid. Chemically treated starch particles and silicon oil are used for EF fluid, and its field-dependent yield stresses are experimentally distilled under both the shear and the flow modes. On the basis of the yield stress, an appropriate size of ER CD-ROM mount adapted to conventional feeding system is designed and manufactured. Vibration isolation performance of the proposed mount is evaluated in the frequency domain and compared with that of conventional rubber mount. The ER CD-ROM mount is then installed to the drive feeding system and the system equation of motion is derived. The skyhook controller is then incorporated with the fuzzy technique to improve the performance of ER CD-ROM mount. A set of fuzzy parameters and control rules are obtained from a relation between vertical displacement and pitching motion of the feedng system. Followingthe formulation of the fuzzy-skyhook controller, computer simulation is undertaken in order to evaluate vibration suppression of the CD-ROM drive feeding system subjected to various excitations.

• Journal of Adhesion and Interface
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• v.13 no.4
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• pp.188-192
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• 2012

Herein, CdS-coated PMMA nanoparticles were prepared by in-situ surfactant-free emulsion copolymerization and subsequent CdS coating process. As-prepared CdS/PMMA hybrid particles had 201.7 nm in diameter. The amount of CdS nanocrystals in the hybrid particles was 10.37 wt% determined by TGA and elemental analysis. The size of CdS crystals was 3.55 nm preferentially grown in (111) plane. UV-vis spectrum of PMMA/CdS nanoparticles showed the significant blue-shift in optical illumination. The reason was found because the synthesized CdS nanocrystals on PMMA particles had a different band gap energy of 2.70 eV which was significantly higher than that of known-value of bulk CdS (2.41 eV) due to a quantum confinement effect.

• The Korean Journal of Food And Nutrition
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• v.9 no.3
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• pp.307-313
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• 1996

The study was performed under the various conditions, such as the edible parts and particle sizes of Allium, the concentrations, the temperatures, and the pH of heavy metal solutions to investigate their adsorption capacity of heavy metals by genus Allium. The adsorption amount of Cd by Allium in the aqueous solution was apparently higher than that of Zn by them. The larger the particle size of welsh onion and shallot was, the higher the adsorption of Cd was. But the adsorption ratio was not different. As the temperature increased, the amount of heavy metal adsorption increased in general, but the adsorption of Cd by wild garlic, Zn by garlic decreased. Adsorption of Cd and Zn to Allium was not affected by the various pH. The correlation between the amount of components in edible putts of Allium and that of adsorption of heavy metals was significantly high in amino acids containing sulfhydryl radical (-SH) and vitamin B2.

• Journal of Powder Materials
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• v.29 no.6
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• pp.453-458
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• 2022

We successfully synthesize water-dispersible CTAB-capped CdSe@ZnS quantum dots with the crystal size of the CdSe quantum dots controlled from green to orange colors. The quenching effect of Fe(DTC)₃ is very efficient to turn off the emission light of quantum dots at four molar ratios of the CdSe quantum dots, that is, the effective covering the surface of quantum dots with Fe(DTC)₃. However, the reaction with Fe(DTC)₃ for more than 24 h is required to completely realize the quenching effect. The highly quenched quantum dots efficiently detect nitric oxide at nano-molar concentration of 110nM of NO with 34% of recovery of emission light intensity. We suggest that Fe(DTC)₃-hybridized CdSe@ZnS quantum dots are an excellent fluorescence resonance energy transfer probe for the detection of nitric oxide in biological systems.

• IMMUNE NETWORK
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• v.23 no.3
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• pp.25.1-25.15
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• 2023

Mucosal environments harbour lymphocytes, which express several adhesion molecules, including intestinal homing receptors and integrin αE/β7 (CD103). CD103 binds E-cadherin, an integrin receptor expressed in intestinal endothelial cells. Its expression not only enables homing or retention of T lymphocytes at these sites but is also associated with increased T lymphocyte activation. However, it is not yet clear how CD103 expression is related to the clinical staging of breast cancer, which is determined by factors such as the size of the tumor (T), the involvement of nearby lymph nodes (N), and presence of metastasis (M). We examined the prognostic significance of CD103 by FACS in 53 breast cancer patients and 46 healthy controls enrolled, and investigated its expression, which contributes to lymphocyte recruitment in tumor tissue. Patients with breast cancer showed increased frequencies of CD103⁺, CD4⁺CD103⁺, and CD8⁺CD103⁺ cells compared to controls. CD103 was expressed at a high level on the surfaces of tumor-infiltrating lymphocytes in patients with breast cancer. Its expression in peripheral blood was not correlated with clinical TNM stage. To determine the localisation of CD103⁺ cells in breast tissue, tissue sections of breast tumors were stained for CD103. In tissue sections of breast tumors stained for CD103, its expression in T lymphocytes was higher compared to normal breast tissue. In addition, CD103⁺ cells expressed higher levels of receptors for inflammatory chemokines, compared to CD103^- cells. CD103⁺ cells in peripheral blood and tumor tissue might be an important source of tumor-infiltrating lymphocyte trafficking, homing, and retention in cancer patients.

• Parasites, Hosts and Diseases
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• v.48 no.2
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• pp.171-174
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• 2010

The anti-tumorigenic effects of Toxoplasma gondii (RH) antigens were studied in a murine sarcoma-180 tumor model. To determine the anti-tumor effects, the reduction in tumor size and expression of CD31 (an angiogenesis marker in the tumor tissue) were examined after injection of BALB/c mice with T. gondii lysate antigen (TLA) or formalin-fixed, proliferation-inhibited, T. gondii tachyzoites. Tumors were successfully produced by an intradermal injection of sarcoma-180 cells with plain Matrigel in the mid-backs of mice. After injection with TLA or formalin-fixed T. gondii tachyzoites, the increase in tumor size and weight nearly stopped while tumor growth continued in control mice that were injected with PBS. CD31 expression in TLA-treated or formalin-fixed T. gondii-injected mice was lower than the control mice. Accordingly, the present study shows that the treatment of mice with formalin-fixed T. gondii or TLA in the murine sarcoma-180 tumor model results in a decrease of both tumor size and CD31 expression.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.47-56
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• 2005

A series of radiotracer experiments were employed to quantitatively compare the biokinetics of uptake from the dissolved phase (influx rates), uptake from the various types of food source (assimilation efficiency), and loss (efflux) of Ag between Potamocorbula amurensis and Macoma balthica. Simultaneously, influx rates of dissolved Cd in both clams were determined to compare with those of Ag. Effects of salinity on influx rates were evaluated in these 2 euryhaline species, as were effects of clam size. Influx rate of Ag and Cd (${\mu}g g^{-1}$ [dry wt.] $d^{-1}$) increased linearly with metal concentrations. Influx rates of Ag in both clams were 3 to 4 times those of Cd. Absolute influx rates of the 2 metals were 4 to 5 times greater in P. amurensis than M. balthica, probably because of differences in biological attributes (i.e. clearance rate or gill surface area). As salinity was reduced from 20 to 2.5 psu, the influx rate of Cd in P. amurensis increased 4-fold and that of Ag increased 6-fold, consistent with expected changes in speciation. Weight-specific metal influx rates (${\mu}g g^{-1}$ [dry wt.] $d^{-1}$) were negatively correlated with the tissue dry weight of the clams, but most rate constants determining physiological turnover of assimilated metals were not affected by clam size.