• Polymer(Korea)
• /
• 제34권1호
• /
• pp.84-87
• /
• 2010

Copper-indium-diselenide (CIS) particles were prepared by the electrochemical reduction from the mixture solution of corresponding ion compounds. The prepared CIS was used as an insertion layer or a blending component in the organic photovoltaic bulk heterojunction cells composed of poly(3-octylthiophene) and fullerene. The increase of CIS content resulted in the rapid decrease of the open-circuit voltage as well as short-circuit current. The photovoltaic parameters were analyzed in relation to the structures, composition, and morphology of the photovoltaic blends.

• Journal of the Korean Society of Clothing and Textiles
• /
• 제27권7호
• /
• pp.843-850
• /
• 2003

Cu/PET film composites were prepared by electroless copper plating method. In order to improve adhesion between electroless plated Cu layer and polyester (PET) film, the effect of pretreatment conditions such as etching method, mixed catalyst composition were investigated. Chemical etching and plasma treatment increased surface roughness in decreasing order of Ar＞HCl＞O$_2$＞NH$_3$. However, adhesion of Cu layer on PET film increased in the following order: $O_2$＜Ar＜HCl＜NH$_3$. It indicated that appropriate surface roughness and introduction of affinitive functional group with Pd were key factors of improving adhesion of Cu layer. PET film was more finely etched by HCI tolution, resulting in an improvement in adhesion between Cu layer and PET film. Plasma treatment with NH$_3$produced nitrogen atoms on PET film, which enhances chemisorption of Pd$^{2+}$ on PET film, resulting in improved adhesion and shielding effectiveness of Cu layer deposited on the Pd catalyzed surface. Surface morphology of Cu plated PET film revealed that Pd/Sn colloidal particles became more evenly distributed in the smaller size by increasing the molar ratio of PdCl$_2$; SnCl$_2$from 1 : 4 to 1 : 16. With increasing the molar ratio of mixed catalyst, adhesion and shielding effectiveness of Cu plated PET film were increased.d.

• Korean Journal of Plant Tissue Culture
• /
• 제22권3호
• /
• pp.165-168
• /
• 1995

The embryos formed from anther culture of peony exhibited divergent morphologies. The frequency of normal embryos with two cotyledons was about two times higher in the embryos formed through direct embryogenesis than those formed from callus. About 69% of the embryos with two cotyledons converted into normal plants, but convention rate of the abnormal embryos with one and three or four cotyledons was only 4 to 9%. The embryos of hem and bowling pin shape did not undergo development into normal plants.

• Bulletin of the Korean Chemical Society
• /
• 제29권3호
• /
• pp.609-614
• /
• 2008

A periodic mesoporous organosilica material was synthesized by microwave heating (PMO-M) using 1,2-bis(trimethoxysilyl)ethane as a precursor in a cationic surfactant solution, and textural properties were compared with those of the product produced by conventional convection heating (PMO-C). These synthesized materials were characterized using XRD, TEM/SEM, N2 adsorption isotherm, 29Si and 13C NMR, and TGA, which confirmed their good structural orders and clear arrangements of uniform 3D-channels. Synthesis time was reduced from 21 h in PMO-C to 2-4 h in PMO-M. PMO-M was made of spherical particles of 1.5-2.2 m m size, whereas PMO-C was made of decaoctahedron-shaped particles of ca. 8.0 m m size. Effect of synthesis temperature, time, and heating mode on the PMO particle morphology was examined. The particle size of PMO-M could be controlled by changing the heating rate by adjusting microwave power level. PMO-M demonstrated improved separation of selected organic compounds compared to PMO-C in a reversed phase HPLC experiment. Ti-grafted PMO-M also resulted in higher conversion in liquid phase cyclohexene epoxidation than by Ti-PMO-C.

• Corrosion Science and Technology
• /
• 제21권1호
• /
• pp.32-40
• /
• 2022

The o-Vanillin - Glutamine Schiff base [2-Hydroxy-3-Methoxy BenzylidineCarbomyl) -2-Butanoic Acid] was examined for low carbon steel corrosion inhibition in acid media. Weight loss studies were carried out at three different temperatures to determine the inhibition efficiency (IE). Electrochemical impedance spectroscopy revealed that the charge transfer resistance controlled the corrosion reaction and Tafel polarization indicated that the Schiff base acts as mixed mode of inhibitor. SEM images were recorded for the surface morphology of the low carbon steel surface. DFT studies revealed corrosion control mechanisms using quantum chemical parameters such as E_HOMO, E_LUMO, energy gap (∆E), chemical Hardness (η), chemical Softness (σ), Electronegativity (χ), and the fraction of electron transferred (∆N), which is calculated using Gaussian software 09. The gas-phase geometry was fully optimized in the Density Functional Theory (DFT/B3LYP-6-31G (d)).The DFT results are in good agreement with the experimental results. All the results proved that the Schiff Base (2-Hydroxy-3-Metoxy BenzylidineCarbomyl) -2-Butanoic is a suitable alternative for corrosion inhibition of low carbon steel in acid media.

• Progress in Superconductivity and Cryogenics
• /
• 제8권4호
• /
• pp.15-18
• /
• 2006

REBCO coated conductors (RE: rare earth elements) have recently drawn great attention since they are known to possess stronger flux pinning centers in high magnetic fields compared with YBCO coated conductors. In this study, $GdBa_2Cu_3O_{7-d}(GdBCO)$ was selected to investigate the influence of the distance between target and substrate and substrate temperature on the superconducting properties of GdBCO films on the $SrTiO_3(100)$ substrate. Samples were fabricated by pulsed laser deposition (PLD) with a Nd:YAG laser (355nm). Under a given oxygen pressure of 800mTorr, we changed the distance between target and substrate from 5.5cm to 7.0cm and the substrate temperature from $750^{\circ}C\;to\;850^{\circ}C$. The crystallinity and texture of GdBCO films were analyzed by X-ray diffraction (XRD), and the surface morphology was observed by the scanning electron microscopy (SEM). Tc and Jc values were measured by the four point probe method. High quality GdBCO films with Tc of 89.7K and Jc over $1MA/cm^2$ at 77 K in self field were successfully fabricated by optimizing processing parameters. The detailed processing conditions, microstructure and superconducting properties will be presented for a discussion.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• 제25권8호
• /
• pp.664-669
• /
• 2012

Nano-structured one-dimensional $Na_2Ti_6O_{13}$ particles were synthesized by a molten salt process. Effects of processing parameters on the microstructure and band gap energy of the $Na_2Ti_6O_{13}$ powder were studied in this paper. For the synthesis of the $Na_2Ti_6O_{13}$ particles, two different raw materials of tubular shaped Na-titanate (Na-TiNT) and spherical shaped $TiO_2$ were utilized. Synthesizing with the raw material of Na-TiNT, around 70nm thick 1D-$Na_2Ti_6O_{13}$ with the bandgap energy of 3.5 eV was obtained at $810^{\circ}C$. Below $810^{\circ}C$ or without the presence of NaCl, 1D-$Na_2Ti_6O_{13}$ was in a relatively short in length and agglomerated state. With the processing temperature increased, the thickness of the 1D-$Na_2Ti_6O_{13}$ was also observed to be increased. On the other hand, when $TiO_2$ was employed as a raw material, the mixed amount of $Na_2CO_3$ played an important role in transforming the morphology and phase of the raw material, affecting the bandgap energy of the synthesized product. Specific surface area of the synthesized 1D-$Na_2Ti_6O_{13}$ was significantly affected by the raw and mixed materials as well as processing temperature. When Na-TiNT was processed at $810^{\circ}C$ with NaCl, the specific surface area of the 1D-$Na_2Ti_6O_{13}$ showed the best value of 30.63 $m^2/g$.

• Applied Chemistry for Engineering
• /
• 제16권3호
• /
• pp.379-384
• /
• 2005

Polyurethane foams (PUFs) were prepared from polymeric 4,4'-diphenylmethane diisocyanate (PMDI), seven polyols with different functionalities and OH values, silicone surfactant, two catalysts, and three blowing agents. Chlorofluorocarbon (CFC-11), hydrochlorofluorocarbon (HCFC-141b) and hydrofluorocarbon (HFC-365mfc) were used as blowing agents. The effect of gelling and blowing catalysts on basic properties and cell structure of PUF with HCFC-141b was investigated. The cell size of the PUF decreased with an increase in the amount of catalyst from 0 to 2 pph (parts per hundred polyol). In the case of gelling type catalyst, the compressive strength increased from 11.9 to $12.66kg_f/cm^2$ with an increase in the amount catalyst from 0 to 2 pph but the density did not change significantly. The gelling time, density, and compressive strength of the PUF with three different blowing agents were measured. There was no detectable change in their properties. However, the cell structure of PUF with HCFC-141b was not uniform as in the other systems.

• Journal of the Korean Electrochemical Society
• /
• 제6권3호
• /
• pp.196-202
• /
• 2003

We investigated the effect of both 4 types additives and $0.5wt\%\;Pb_3O_4$ which have been reported to show an improvement on the performance of Zinc anode. And Experimental methods such as corrosion potential measurement, potentiodynamic polorization test and charging-discharging cycle life test were carried out in $40 wt\%$ KOH with $Pb_3O_4(0.5, \;10\;&\;2.0wt\%)$ and 4 types additives $(0.4wt\%\;of\;Ca(OH)_2$, 0.025M of Citrate, Tartrate and Gluconate). Corrosion potential was shifted to high direction and also changed to high and low direction repeatedly with increasing of $Pb_3O_4$ quantity. However by adding $0.5wt\%\;Pb_3O_4$, corrosion potential shifted to low direction and showed stable condition. Furthermore it was well known that corrosion resistance was predominantly increased compared to no addition and improved charging-discharging property with adding additives. By SEM analysis, it was concluded that the morphology of surface in case of only $0.5wt\%\;Pb_3O_4$ addition was nearly the same as that of Tartrate additive and in the other additives such as $Ca(OH)_2$, Citrate, Tartrate and Gluconate, their morphologies showed dendrite growth. Eventually it was thought that the additive of Tartrate indicated comparatively good corrosion resistance effect as well as charging-discharging property improvement among those four types additives.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권12호
• /
• pp.1963-1973
• /
• 2018

Objective: This study was conducted to evaluate the effect of dietary energy and lipase supplementation on growth performance, nutrient digestibility, serum profiles, intestinal morphology, small intestinal digestive enzyme activities, biochemical index of intestinal development and noxious gas emission in weaning pigs. Methods: A total of 240 weaning pigs ([Yorkshire${\times}$Landrace]${\times}$Duroc) with an average body weight (BW) of $7.3{\pm}0.12kg$ were used in this 28-d experiment. Weaning pigs were randomly allocated to 4 dietary treatments in a $2{\times}2$ factorial arrangement with 2 levels of energy (net energy = 2,470 kcal/kg for low energy diet and 2,545 kcal/kg for basal diet) and 2 levels of lipase (0 and 1.5 U/g of lipase) according to BW and sex. There were 6 replications (pens) per treatment and 10 pigs per pen (5 barrows and 5 gilts). Results: Weaning pigs fed the low energy diet had lower (p<0.05) gain-to-feed ratio (G:F) throughout the experiment, apparent digestibility of dry matter, nitrogen, ether extract, and gross energy during d 0 to 14, average daily gain during d 15 to 28, lipase activity in duodenum and ileum and protein/DNA in jejunum (p<0.05), respectively. Lipase supplementation had no effect on growth performance but affected apparent nutrient digestibility (p<0.05) on d 14 and enhanced lipase activity in the duodenum and ileum and protease activity in duodenum and jejunum of pigs (p<0.05) fed the low energy diet. Lipase reduced serum low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG), $NH_3$ production (p<0.05) from the feces. Conclusion: The low energy diet decreased G:F throughout the experiment and nutrient digestibility during d 0 to 14 as well as lipase activity in duodenum and ileum. Lipase supplementation increased nutrient digestibility during d 0 to 14 and exerted beneficial effects on lipase activity in duodenum and ileum as well as protease activity in duodenum and jejunum, while reduced serum LDL-C, TG and fecal $NH_3$.