• Bulletin of the Korean Chemical Society
• /
• v.30 no.10
• /
• pp.2303-2308
• /
• 2009

A thiocyanate poly(vinyl chloride) (PVC) membrane electrode based on [1,2-bis(diphenylphosphino)ethane]dihalopalladium( II), [(dppe)$PdX_2$, X = Cl ($L^1$), X = I ($L^2$)] as active sensor has been developed. The diiodopalladium complex, [(dppe)$PdI_2](L^2$) displays an anti-Hofmeister selectivity sequence: $SCN^-\;>\;I^-\;>\;{ClO_4}^-\;>\;Sal^-\;>\;Br^-\;>\;{NO_2}^-\;>\;{HPO_4}^-\;>\;AcO^-\;>\;{NO_3}^-\;>\;{H_2PO_4}^-\;>\;{CO_3}^{2-}$. The electrode exhibits a Nernstian response (-59.8 mV/decade) over a wide linear concentration range of thiocyanate ($(1.0\;{\times}\;10^{-1}\;to\;5.0\;{\times}\;10^{-6}$ M), low detection limit ($(1.1\;{\times}\;10^{-6}$ M), fast response $(t_{90%}$ = 24 s), and applicability over a wide pH range (3.5∼11). Addition of anionic sites, potassium tetrakis[p-chlorophenyl] borate (KTpClPB) is shown to improve potentiometric anion selectivity, suggesting that the palladium complex may operate as a partially charged carrier-type ionophore within the polymer membrane phase. The reaction mechanism is discussed with respect to UV-Vis and IR spectroscopy. Application of the electrode to the potentiometric titration of thiocyanate ion with silver nitrate is reported.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.10
• /
• pp.1056-1060
• /
• 2004

In this study, 0.96B $i_{0.5}$($Na_{0.84}$ $K_{0.16}$)$_{0.5}$Ti $O_3$ + 0.04SrTi $O_3$ + 0.3 wt% N $b_2$ $O_{5}$+0.2 wt% L $a_2$ $O_3$ + xwt % Mn $O_2$ were investigated as a function of the amount of Mn $O_2$ addition in order to improve dielectric and piezoelectric properties of Lead-free piezoelectric ceramics. With increasing the amount of Mn $O_2$ addition, the density, electromechanical coupling factor( $k_{p}$), piezoelectric constant( $d_{33}$, $g_{33}$) and curie temperature (Tc) showed the maximum value of 5.7 g/㎤, 38 %, 219 pC/N, 26 mVㆍm/N and 32$0^{\circ}C$ at 0.1 wt% Mn $O_2$ addition, respectively, and mechanical quality factor( $Q_{m}$ ) showed the maximum value of 158 at 0.3 wt% Mn $O_2$ addition.ddition.ion.n.

• Journal of Global Scholars of Marketing Science
• /
• v.7
• /
• pp.353-374
• /
• 2001

Price and brand are two major attributes of products that consumer purchases. Price is important because it is often a measure of worth and quality. Some consumers purchase only well-known national brands. However, By reason of the price competition on account of new business condition and depressions, and consumers practical and rational purchasing tendency, consumers tend to purchase private brands(PB hereafter) because as consumers they expect that producers have reasonable and acceptable quality. Accordingly, The study, with intrinsic cue, extrinsic cue, familiarity anything like these cues from the study of Richardson et aI(1994, 1996), intends to present current topics we guide in retailer's promotion strategy for PB. As for investigating how quality evaluation has on effect on the private brands purchasing behavior of discount store grocery items. This study establishes a hypotheses on the basis of the quality evaluation cues of PB and literature review for purchasing behavior and collects materials for consumers about 196, and also analyzes them using a variety of SPSS/PC+package program. Therefore, the findings of this study provide the following managerial implications. 1) Retailer will successful in increasing private brand market share through dramatic improvement in package design, labeling, advertising, and branding strategies. 2) Planned Purchasers have high intention to repurchase PB because they buy them reasonably in accordance with the estimate therefore, they might have word-of-mouth effect for the evaluation of quality and recognition. They need to acknowledge benefits for PB purchases to maintain purchase like that. 3) The main consumers are housewives in their thirties and forties and they something reasonably because they have a lot of family and retailer will work out.

• Environmental Analysis Health and Toxicology
• /
• v.30
• /
• pp.4.1-4.11
• /
• 2015

Objectives: This survey was designed to conduct the first nationwide dietary exposure assessment on hazardous substances including the intakes of functional food and herbal medicine. In this paper, we introduced the survey design and the results of the dietary exposure status and internal exposure levels of lead (Pb), cadmium (Cd), and mercury (Hg). Methods: We selected 4867 subjects of all ages throughout Korea. We conducted a food survey, dietary survey, biomonitoring, and health survey. Results: Pb and Cd were the highest (median value) in the seaweed ($94.2{\mu}g/kg$ for Pb; $594{\mu}g/kg$ for Cd), and Hg was the highest in the fish ($46.4{\mu}g/kg$). The dietary exposure level (median value) of Pb was $0.14{\mu}g/kg$ body weight (bw)/d, $0.18{\mu}g/kg$ bw/d for Cd, and $0.07{\mu}g/kg$ bw/d for Hg. Those with a blood Pb level of less than $5.00{\mu}g/dL$ (US Centers for Disease Control and Prevention, reference value for those 1 to 5 years of age) were 99.0% of all the subjects. Those with a blood Cd level with less than $0.30{\mu}g/L$ (German Federal Environmental Agency, reference value for non-smoking children) were 24.5%. For those with a blood Hg level with less than $5.00{\mu}g/L$ (human biomonitoring I, references value for children and adults, German Federal Environmental Agency) was 81.0 % of all the subjects. Conclusions: The main dietary exposure of heavy metals occurs through food consumed in a large quantity and high frequency. The blood Hg level and dietary exposure level of Hg were both higher than those in the European Union.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.1
• /
• pp.78-91
• /
• 2018

In order to understand the distributions of organic matter and heavy metal concentrations in the surface sediment of Jaran Bay, we measured the grain size, total organic carbon (TOC), total nitrogen (TN), and heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) in surface sediments collected at 15 stations in this bay in November 2014. The sediment consisted of finer sediment such as mud and clay, with 8.6-9.8Ø($9.3{\pm}0.3$Ø) of mean grain size. The concentrations of TOC and TN in the sediment ranged from 1.51-2.39 % ($1.74{\pm}0.22%$) and 0.20-0.33 % ($0.23{\pm}0.03%$), respectively, and did not show spatial difference. The carbon to nitrogen ratio (C/N ratio) ranged from 5-10, indicating that organic matter in the sediment originated from oceanic sources such as animal by-products from fish and shellfish farms. The concentrations of Cr, Fe, and Mn were much higher in the mouth of the bay than in the inner bay, and the concentrations of As, Cd, Cu, Hg, Pb, and Zn showed an opposite distribution pattern. Based on the results of the sediment quality guidelines (SQGs), enrichment factor (EF), geoaccumulation index ($I_{geo}$), pollutant load index (PLI), and ecological risk index (ERI), the surface sediment in Jaran Bay is not polluted or only slightly polluted with Cd, Cr, Cu, Hg, Pb, and Zn, whereas it is moderately to strongly polluted with As. In particular, some regions in the bay were identified as having a considerable risk status, indicating that metal concentration in the sediment could impact benthic organisms. Thus, the systematic management for marine and land sources of organic matter and heavy metals around Jaran Bay is necessary in order to ensure seafood safety and maintain sustainable production on shellfish farms.

• Fisheries and Aquatic Sciences
• /
• v.2 no.2
• /
• pp.149-154
• /
• 1999

Response Surface Methodology was applied for optimizing the processing parameters of ultrasound treatment in order to produce low-molecular alginate. The use of ultrasound significantly reduced viscosity of alginate solutions. Suggested parameters of ultrasound treatment for maximum reduction of alginate molecular weight were: specific intensity, 115.81 $W/cm^2$ at 20kHz frequency; treatment time, 35.55 min; temperature, $20.08^{\circ}C$; alginate concentration, $2.5\%$. Low-molecular alginate obtained by ultrasound had two peaks on Sepharose CL-6B gel filtration. The viscosities of control, fraction I, and fraction II at $0.1\%$ concentration and $25^{\circ}C$ were 3.07, 1.23, and 0.82cps, respectively. Molecular weights of control, fraction I, and fraction II alginates were 336,500, 70,400, and 52,800 daltons, and their solubilities were 3, 6, and $14\%$, respectively. The lower molecular weight of alginate, the lower the alcohol precipitation and the higher $Ca^{2+}$ ion binding capacities. Heavy metal ion binding capacities of alginates were high in the following order of Pb, Cd, Zn, and Co.

• Proceedings of the IEEK Conference
• /
• 2004.06b
• /
• pp.363-366
• /
• 2004

PZT thin films were formed by rf-magnetron sputtering on $Pt/Ti/SiO_2/Si$ substrate. Bulk PZT target containing $5\%$ excess PbO was used. They were formed with in-situ process at $650^{\circ}C$ as total thickness of 175 and 250 nm after the depositing of thin PZT films at room temperature, i. e. 2-step Sputtering. It was found that the ferroelectric perovskite phase is formed at $650^{\circ}C$ by XRD and the interface between room temp.-layer and $650^{\circ}C$ -layer is not existent. In the samples undergoing 2-step sputtering the dielectric constant was 600 or more and the leakage current density was $2{\times}10^{-7}A/cm^2$. So, we found that the room temp.-layer on the bottom electrode stabilize the underlaid layers.

• Clinical and Experimental Reproductive Medicine
• /
• v.23 no.1
• /
• pp.87-94
• /
• 1996

For evaluating the suitability of human follicular fluid(HFF) as protein supplement in ART, this preliminary study was performed to examine the maturation promoting activity of HFF on mouse follicular oocytes in vitro. Mouse follicular oocytes were collected from ovaries of 21-28 day old ICR mice by puncturing the antral follicles with fine needle at 48 hours after PMSG injection. The oocytes were rinsed and cultured in modified Whittingham's $T_6$ medium containing purines or dbcAMP to maintain meiotic arrest, and different concentrations of HFF were added into the culture medium to examine the effect of HFF on releasing the oocytes from the suppressive influence of the meiotic inhibitors. As a control for HFF, the maturation promoting activity of human fetal cord serum(HFCS) was investigated and compared with the activity of HFF. While HFF was separated, by molecular weight(M.W), into high M.W. fraction(M.W>30,000) and low M.W. fraction(M.W<30,000) and the effects of the fractions on meiotic resumption were investigated in the presence of the meiotic inhibitors. Also hormone analysis was performed to compare the content of hormones in HFF with that in HFCS. Same concentrations of HFF and HFCS induced similar germinal vesicle break down(GVBD) rates of the oocytes meiotic arrested by purines(4mM hypoxanthine+0.75mM adenosine), but the extrusion rate of 1st polar body(PB) of the oocytes cultured in HFF(65.0%, P<0.05) was significantly higher than that(51.6%) in HFCS. While, in the presence of 200 M dbcAMP, the maturation promoting activity of HFF (GVBD: 70.5%, $p<10^{-6}$; 1st PB extrusion: 67.1%, $p<10^{-3}$) was significantly greater than that of HFCS(GVBD: 35.2%; 1st PB extrusion: 41.1%). The oocytes cultured in the fraction of HFF containing high M.W. components showed higher meiotic maturation rates than the oocytes cultured in the low M.W. fraction of HFF. Gonadotropins and $E_2$ were known to improve the completion of maturation changes, and the levels of these hormones were higher in HFF than in HFCS. Therefore, HFF was more effective than HFCS to use for promoting meiotic resumption of mouse oocytes in vitro.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.427-427
• /
• 2016

Organic-inorganic hybrid perovskite have attracted significant attention as a new revolutionary light absorber for photovoltaic device due to its remarkable characteristics such as long charge diffusion lengths (100-1000nm), low recombination rate, and high extinction coefficient. Recently, power conversion efficiency of perovskite solar cell is above 20% that is approached to crystalline silicon solar cells. Planar heterojunction perovskite solar cells have simple device structure and can be fabricated low temperature process due to absence of mesoporous scaffold that should be annealed over 500 oC. However, in the planar structure, controlling perovskite film qualities such as crystallinity and coverage is important for high performances. Those controlling methods in one-step deposition have been reported such as adding additive, solvent-engineering, using anti-solvent, for pin-hole free perovskite layer to reduce shunting paths connecting between electron transport layer and hole transport layer. Here, we studied the effect of alkali metal halide to control the fabrication process of perovskite film. During the morphology determination step, alkali metal halides can affect film morphologies by intercalating with PbI2 layer and reducing $CH3NH3PbI3{\cdot}DMF$ intermediate phase resulting in needle shape morphology. As types of alkali metal ions, the diverse grain sizes of film were observed due to different crystallization rate depending on the size of alkali metal ions. The pin-hole free perovskite film was obtained with this method, and the resulting perovskite solar cells showed higher performance as > 10% of power conversion efficiency in large size perovskite solar cell as $5{\times}5cm$. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma optical emission spectrometry (ICP-OES) are analyzed to prove the mechanism of perovskite film formation with alkali metal halides.

• The Korea Journal of Herbology
• /
• v.22 no.2
• /
• pp.17-24
• /
• 2007

Objectives : Licorice has been commonly used as a detoxification agent. We previously reported that licorice and its component, liquiritigenin, exhibits cytoprotective activity against Pb-induced toxicity. The present study was conducted to evaluate the effect of liquiritigenin on the lead-induced cytotoxicity in PC-12 cells. Methods : PC-12 cells were pre-treated with liquiritigenin, and further incubated with lead 100 ${\mu}M$ for $12^{\sim}48$ hours. The viability of PC-12 cells was measured by MTT assay, and the levels of proteins were analysed by western blot. Results : Severe cytotoxicity was induced and nitric oxide (NO) production was augmented by the exposure of lead. Liquiritigenin protected cells from lead-induced cytoxicity and reduced NO production in a dose-dependent manner. The inhibition of NO production was due to the suppression of iNOS protein via the inhibition of $NF-{\kappa}B$ nuclear translocation, determined by western blot analysis. Conclusions : These results suggest that liquiritigenin may exert cytoprotective effect against lead toxicity by inhibiting NO production.