• Clean Technology
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• v.21 no.1
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• pp.39-44
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• 2015

This study investigated the effects of six metal oxide nanoparticles (NPs: CuO, NiO, TiO₂, Fe₂O₃, Co₃O₄, ZnO) on seed germination and germination index (G.I) for five types of seeds: Brassica napus L., Malva verticillata L., Brassica olercea L., Brassica campestris L., Daucus carota L. NPs of CuO, ZnO, NiO show significant toxicity impacts on seed activities [CuO (6-27 mg/L), ZnO (16-86 mg/L), NiO (48-112 mg/L)], while no significant effects were observed at > 1000 mg/L of TiO₂, Fe₂O₃, Co₃O₄. Tested five types of seed showed different sensitivities on seed germination and root activity, especially on NPs of CuO, ZnO, NiO. Malva verticillata L. seed was highly sensitive to toxic metal oxide NPs and showed following EC₅₀s : CuO 5.5 mg/L, ZnO 16.4 mg/L, NiO 53.4 mg/L. Mostly following order of toxicity was observed, CuO > ZnO > NiO > Fe₂O₃ ≈ Co₃O₄ ≈ TiO₂, where slightly different toxicity order was observed for carrot, showing CuO > NiO ≈ ZnO > Fe₂O₃ ≈ Co₃O₄ ≈ TiO₂.

• Advances in environmental research
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• v.3 no.3
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• pp.207-216
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• 2014

A study was conducted to determine the phytotoxic effect of mercury on seed germination and seedling growth of an important arid legume tree Albizia lebbeck. The seeds germination and seedling growth performance of A. lebbeck responded differently to mercuric chloride treatment (1 mM, 3 mM, 5 mM and 7 mM) as compared to control. Seed germination of A. lebbeck was significantly (p < 0.05) affected by mercury treatment at 1 mM. Root growth of A. lebbeck was not significantly affected by mercury treatment at 1 mM, and 3 mM. Shoot and root length of A. lebbeck were significantly (p < 0.05) affected by 5 mM concentration of mercury treatment. Increase in concentration of mercury treatment at 5 mM and 7 mM significantly (p < 0.05) reduced seedling dry weight of A. lebbeck. The treatment of mercury at 1 mM decreased high percentage of seed germination (22%), seedling length (10%), root length (21.85%) and seedling dry weight (9%). Highest decrease in seed germination (51%), seedling (34%), root length (48%) and seedling dry weight (41%) of A. lebbeck occurred at 7 mM mercury treatment. A. lebbeck showed high percentage of tolerance (78.14%) to mercury at 1 mM. However, 7 mM concentration of mercury produced lowest percentage of tolerance (51.65%) in A. lebbeck. The seed germination potential and seedling vigor index (SVI) clearly decreased with the higher level of mercury. Plantation of A. lebbeck in mercury-polluted area will help in reducing the burden of mercury pollution. A. lebbeck can serve better in coordinating in land management programs in metal contaminated areas. The identification of the toxic concentration of metals and tolerance indices of A. lebbeck would also be helpful for the establishment of air quality standard.

• Textile Coloration and Finishing
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• v.17 no.2 s.81
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• pp.10-18
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• 2005

Silk fabrics mordanted with $Fe^{2+},\;Ni^{2+},\;and\;Cu^{2+}$ were dyed with the aqueous extract of Cassia tora L. seed which was known to include water soluble colorant kaempferol, one of flavonol compounds. Kaempferol can react with free radicals and chelate transition metal ions, which is thought to catalyze processes leading to the appearance of free radicals and have antioxidant activity. In relation to the coordinating and chelating mechanism of the ions with the silk protein and kaempferol, reasonable conclusions should be made on the colorant uptake and the water fastness of the fabric. The amount of the colorant on the fabric was in the order of $Fe^{2+}>Ni^{2+}>Cu^{2+}$. In case of dyeing through coordinaiton bonds between transition metal ions and silk protein and colorants, it was thought that the ions with the smaller secondary hydration shell, the higher preference to the atoms of the ligand coordinated, and the suitable bonding stability for the substitution of primarily hydrated water molecules for colorants led to the higher colorant uptake. The water fastnsess of the fabric was in the order of $Fe^{2+}>Cu^{2+}>Ni^{2+}$. It should be reasonable to choose transition metal ions with weak and strong tendency to the ionic and the coordination bond, respectively, to the carboxylate anion of the silk protein. Although further research needs to be done, the conclusions above may be generally applied to the natural dyeing through the coordination bond mechanism between transition metal ions and colorants and substrates.

• Korean Journal of Metals and Materials
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• v.48 no.1
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• pp.90-100
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• 2010

Micro-conductive patterns were microfabricated on an insulating substrate ($SiO_2$) surface by a selective electroless nickel plating process in order to investigate the formation of seed layers. To fabricate micro-conductive patterns, a thin layer of metal (Cu.Cr) was deposited in the desired micropattern using laser-induced forward transfer (LIFT). and above this layer, a second layer was plated by selective electroless plating. The LIFT process. which was carried out in multi-scan mode, was used to fabricate micro-conductive patterns via electroless nickel plating. This method helps to improve the deposition process for forming seed patterns on the insulating substrate surface and the electrical conductivity of the resulting patterns. This study analyzes the effect of seed pattern formation by LIFT and key parameters in electroless nickel plating during micro-conductive pattern fabrication. The effects of the process variables on the cross-sectional shape and surface quality of the deposited patterns are examined using field emission scanning electron microscopy (FE-SEM) and an optical microscope.

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.05a
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• pp.81-81
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• 2001

No Abstract (See Full-text)

• Korean Journal of Materials Research
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• v.10 no.10
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• pp.684-690
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• 2000

In order to study effects of interfacial layers between $Pb(Zr,Til)Q_3(PZT)$ films and electrodes for Metal-Ferroelectric-MetaI(MFM) structure capacitors, we have fabricated the capacitors with the Pt/PZT/interfacial-layer/Pt/$TiO_2/SiO_2$/Si structure. $PbTiO_3(PT)$ interfacial layers were formed by sol-gel deposition and PbO, ZrO, and $TiO_2$ thin layers were deposited by reactive sputtering. $TiO_2$ interface layers result in the finest grains of PZT(crystalline Temp. $600^{\circ}C$) films compare to $PbO_2\;and\;ZrO_2$ layers. However, as the thickness of $TiO_2$ layer increases. PZT thin films become rough and electrical characteristics were deteriorated due to remained anatase phase. On the other hand. PT interface layers result in improved morphology of PZT films and do not significantly change ferroelectric properties. It is a also observed that seed layers at the middle and top of PZT films do not give significant effects on grain size but the PT seed layer at the interface between the bottom electrode and the PZT films results in the small grain size.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.1
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• pp.41-47
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• 2012

The LDS(Laser Direct Structuring) is one of the new direct writing methods to fabricate conductive patterns by energy beam. It uses thermoplastic polymers with an additive compound that serves as plating seed after the activation by laser. The advantages of LDS include the miniaturization of electrical components, design flexibility, and a reduced number of production steps. The purpose of this study is to investigate the fundamental mechanism for LDS and the characteristics of conductive patterns by laser parameters. These results were studied by SEM, EDX, and XPS analysis. We have used a 20W pulse-modulated fiber laser and copper electroless plating to fabricate conductive patterns on polymer. The result showed that electroless copper plating seed caused the laser cracking of additive compound. In particular, the additive compound contained in copper metal oxides atoms will be changed to copper metal elements. Also, the characteristics of conductive patterns were dependent on laser parameter, especially laser fluence.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.58.1-58.1
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• 2010

We have developed a novel crystallization process, where the crystallization temperature is lowered compared to the conventional RTA process and the metal contamination is lowered compared to the conventional VIC process. A very-thin a-Si film was deposited and crystallized at $550^{\circ}C$ for 3 h by the VIC process and then a thick a-Si film was deposited and crystallized by the RTA process at $680^{\circ}C$ for 5 min using the VIC poly-Si layer as a crystallization seed layer. The RTA crystallized temperature could be lowered up to $50^{\circ}C$, compared to RTA process alone. The poly-Si film appeared a needle-like growth front and relatively well-arranged (111) orientation. In addition, the Ni concentration in the poly-Si film was lowered to $3{\times}10^{17}\;cm^{-3}$ and that at the poly-Si/$SiO_2$ interface was lowered to $5{\times}10^{19}\;cm^{-3}$. The reduction in metal contamination could be greatly helpful to achieve a low leakage current in poly-Si TFT, which is the critical parameter for commercialization of AMOLED.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.41-41
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• 1998

Rare earth metal films have been used as a buffer layer for growing ferroelectric t thin film or a seed layer for magnetic multilayer. But when it was deposited on s semiconductor substrates for the application of magneto-optic (MO) storage media, it i is difficult to exactly measure magnetic cons떠nts due to shunting current, and so it n needs to grow metal films on insulator substrate to reduce such effect. Recently, it w was reported that ultra-thin Pt layer were epitaxially grown on A12O:J by ion beam s sputtering in 비떠 high vacuum and it can be used as a seed layer for the growth of C Co-contained magnetic multilayer. In this stu$\phi$, Pt thin film were epi떠xially grown on AI2D3 ($\alpha$)OJ) by RF magnetron s sputtering. The crystalline structure was analyzed by transmission electron microscope ( (TEM) and Rutherford Back Scattering (RBS)/Ion Channeling. In TEM study, Pt was b believed to be twinned on AI잉3($\alpha$)01) su$\pi$ace about Pt(ll1) plane.Moreover, RBS c channeling spectra showed that minimum scattering yield of Pt(111)/AI2O:J(1$\alpha$)OJ) was 4 4% and Pt(11J)/AI2D3($\alpha$)OJ) had 3-fold symmetry.

• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.27-36
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• 2010

This study was conducted to evaluate physicochemical parameters; temperature, pH, C/N ratio, water content, organic contents and volume in a pilot-scale(capacity : $100m^3$) ultra thermophilic aerobic composting. There were three types input: municipal wasted sludge, livestock manure and slurry, and food waste produced in Jung-Eb city. Each target material was carried out by the first fermentation(organic waste + seed culture) and the second one(organic waste + seed culture + recycle compost), respectively. During composting, only with supply of air and mixing, the temperature increased $90{\sim}105^{\circ}C$ after every mixing in both periods. The changes of pH, $O_2$, $CO_2$ and $NH_3$ represented typical organic decomposition pattern by microorganisms. Also, all other physicochemical parameters of ultra thermophilic aerobic composting process showed similar or better performance than these of general aerobic composting. Heavy metal concentration of fermented compost adapted to compost fertilizer regulation standard in the heavy metal and hazardous analysis.