• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.60-67
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• 2018

Recently, environment-friendly cultivation technology is popular. A cultivator is useful for turning over the stall bedding in a poultry farm. In this study, a rotary-based cultivator with a rechargeable battery was developed for eco-friendly management of broiler chickens. From the results of the test run, the clustered stall bedding was approximately divided into up and down layers. Through experimental evaluation, the working width was more than 60 cm, and the noise was less than 80 dB. The output of the motor was 400 W, and the speed of rotation was 3000 rpm. Electric battery type cultivators are expected to be widely used in the livestock industry.

• Journal of Powder Materials
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• v.18 no.4
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• pp.322-326
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• 2011

Inkjet printing was successfully done using Cu nano powder ink after these Cu nano powders were dry-coated with 1-octanethiol for oxidation prevention. 1-octanethiol, which is Self-Assembled Multi-layers (SAMs), was coated approximately 10-nm thick on the surface of Cu nano powders. 1-Octanol, which has the same chain length as that for 1-octanethiol, was used as a solvent to make the ink for inkjet printing. As a result, the fabricated ink was dispersed for about 4 weeks, and after printing and heat treatment at $350^{\circ}C$ for 4 hours, the resistivity for the printed pattern was measured to be $1.15{\times}10^{-5}{\Omega}{\cdot}cm$.

• Journal of Pharmaceutical Investigation
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• v.25 no.2
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• pp.101-108
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• 1995

The surface of albumin microspheres could be modified with methotrexate (MTX) by using 1,3-dicyclohexylcarbodiimide (DCC). Surface-modified albumin microspheres entrapping no MTX (SAMS), free MTX (SAMSF) and MTX-bovine serum albumin (BSA) conjugates (SAMSC) were prepared. respectively, and their release characteristics were investigated in the presence of trypsin using a dissolution tester. The mean diameters of all the microspheres were $5{\sim}8\;{\mu}m$, and their shapes was small and uniform. MTX bound tn their surfaces was released slower than the entrapped free MTX, and laster than the entrapped MTX-BSA conjugates. Also, surface-modified MTX was scarcely released in the absence of a proteolytic enzyme. Therefore, the surface-modified MTX may be released rapidly from SAMSC at the target site, and thereafter MTX may be released slowly from the encapsulated MTX-BSA conjugates in SAMSC for a long period.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.811-813
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• 2003

We investigated the electrical properties of self-assembled (4,4'-Di(ethynylphenyl)-2'-nitro-1-thioacetylbenzene), which has been well known as a conducting molecule having possible application to molecular level negative differential resistance(NDR)[1]. Generally, the phenomenon of NDR can be characterized by the decreasing current with the increasing voltage[2]. To deposit the SAM layer onto gold electrode, we transfer the prefabricated nanopores into a 1mM self-assembly molecules in THF solution. Au(111) substrates were prepared by ion beam sputtering method of gold onto the silicon wafer. As a result, we measured the voltage-current properties and confirmed the negative differential resistance properties of self-assembled organic thin film and measured, using Scanning Tunneling Microscopy(STM).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.141-144
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• 2004

Molecular self-assembled of surfactant viologens are recently interesting because they can be from functional electrodes as well as micelle assemblies which can be profitably utilized for display devices, electrochemical studies and electrocatalysis as electron acceptor or electron mediator. The electrochemical behavior of self-assembled viologen monolayer on Au electrode surface has been investigated with QCM which has been known as nano-gram order mass detector. A monolayer of viologen is immobilized on the gold electrode surface and the normal potentials corresponding to the to the successive one-electron transfer processes of the viologen actives are two peaks in 0.1mol/l phosphate buffer solution respectively. These result suggest that the viologen SAMs are stable and well-behaved monolayers.

• Journal of The Korean Association For Science Education
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• v.16 no.3
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• pp.249-259
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• 1996

The purpose of this study was to analyze relationships among science achievement, science process skills and affective perception of high school students. The affective perception was included attitude toward science and science anxiety in the study. The instruments were developed HARS and SAMS for this study. The subject was sampled 1,115 students by stratified cluster sampling method. The major findings of this study were as follows: The tendency to affective perception was investigated according to students variables. Atittude toward science was showed a negative perception on female than male, in rural area than city. Science anxiety was percepted highly on female than male, in rural area than city. Attitude toward science showed positive relations to science process skills, science achievement, but which showed negative relation to science anxiety. Science anxiety showed negative relations among science process skills, science achievement and attitude toward science. Structural relationships among affective perception, science process skills and science achievement were analyzed by effect size through the path analysis on the independent and dependent variables. By the results, it was indicated that there have significant direct effect not only affective perception influence on science achievement but also on science process skills in hypothesized model. Prediction of science achievement and science process skills were clarified to characteristics of the affective perception.Therefore, understanding about affective perception will be helpful to make the strategy of science teaching

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.5
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• pp.182-188
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• 2003

We have demonstrated a fluidic technique for self-assembly of microfabricated parts onto substrate using patterned shapes of magnetic force self-assembled monolayers (SAMs). The metal particles and the array were fabricated using the micromachining technique. The metal particles were in a multilayer structure (Au, Ti, and Ni). Sidewalls of patterned Ni dots on the array were covered by thick negative photoresist (SU-8), and the array was magnetized. The array and the particles were mixed in buffer solution, and were arranged by magnetic force interaction. Binding direction of the metal particle onto Ni dots was controlled by multilayer structure and direction of magnetization. A quarter of total Ni dots were covered by the particles. The binding direction of the particles was controllable, and condition of particles was almost even with the Au surface on top. The particles were successfully arranged on the array.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.104-111
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• 2010

The heterogeneous electron transfer at $SiMo_{12}O_{40}^{4-}$ monolayers on GC, HOPG, and Au electrode surfaces are investigated using cyclic voltammetric and electrochemical impedance spectroscopic (EIS) methods. The electron transfer of negatively charged $Fe(CN)_6^{3-}$ species is retarded at $SiMo_{12}O_{40}^{4-}$-modified electrode surfaces, while that of positively charged $Ru(NH_3)_6^{3+}$species is accelerated at the modified surfaces. This is due to the electrostatic interactions between $SiMo_{12}O_{40}^{4-}$ layers on surfaces and charged redox species. The electron transfer kinetics of a neutral redox species, 1,1‘-ferrocenedimethanol (FDM), is not affected by the modification of electrode surfaces with $SiMo_{12}O_{40}^{4-}$, indicating the $SiMo_{12}O_{40}^{4-}$ monolayers do not impart barriers to electron transfer of neutral redox species. This is different from the case of thiolate SAMs which always add barriers to electron transfer. The effect of $SiMo_{12}O_{40}^{4-}$ layers on the electron transfer of charged redox species is dependent on the kind of electrodes, where HOPG surfaces exhibit marked effects. Possible mechanisms responsible for different electron transfer behaviors at $SiMo_{12}O_{40}^{4-}$ layers are proposed.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3103-3108
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• 2010

Conducting polymers (CPs) are widely used as matrixes for the entrapment of enzymes in analytical chemistry and biosensing devices. However, enzyme-catalyzed polymerization of CPs is rarely used for immunosensing due to the difficulties involved in the quantitative analysis of colloidal CPs in solution phase. In this study, an enzyme-amplified electrocatalytic immunosensor employing a CP as a redox marker has been developed. A polyanionic polymer matrix, $\alpha$-amino-$\omega$-thiol terminated poly(acrylic acid), was employed for precipitation of CP. The acrylic acid group acts as a polyanionic template. The thiol terminus of the polymer was used to produce self-assembled monolayers (SAMs) on Au electrodes and the amine terminus was employed for immobilization of biomolecules. In an enzymeamplified sandwich type immunosensor, the polyaniline (PANI) produced enzymatically is attracted by the electrostatic force of the matrix polymer. The precipitated PANI was characterized by electrochemical methods.

• Journal of Integrative Natural Science
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• v.4 no.4
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• pp.311-314
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• 2011

Application of self-assembled monolayers (SAMs) to the fabrication of organic thin film transistor has been recently reported very often since it can help to provide ohmic contact between films as well as to form simple and effective electrode pattern. Accordingly, quality of these ultra-thin films is becoming more imperative. In this study, in order to manufacture a high quality SAM pattern, a hydrophobic alkylsilane monolayer and a hydrophilic aminosilane monolayer were selectively coated on $SiO_2$ surface through the consecutive procedures of a micro-contact printing (${\mu}CP$) and dip-coating methods under extremely dry condition. On a SAM pattern cleaned with SC1 solution immediately after ${\mu}CP$, poly(3,4-ethylenedioxythiophene) (PEDOT) source and drain electrode array were very selectively and nicely vapour phase polymerized. On the other side, on a SC1-untreated SAM pattern, PEDOT array was very poorly polymerized. It strongly suggests that the SC1 cleaning process effectively removes unwanted contaminants on SAM pattern, thereby resulting in very selective growth of PEDOT electrode pattern.