• Journal of Information Display
• /
• v.8 no.4
• /
• pp.10-14
• /
• 2007

LCD performance is generally evaluated in terms of luminance and color versus viewing angle. In the present paper, we show that this type of display can be favorably characterized in terms of polarization. We show that ELDIM EZContrast instrument which is routinely used for viewing angle measurements can be upgrade for measuring the polarization state of the light at each incidence and azimuth angle. More precisely, the degree of polarization of light, its ellipticity and polarization direction can be measured at each incidence angle between 0 and $88^{\circ}$ and for all the azimuth angles (from 0 to $360^{\circ}$). Important differences between the displays can be detected and related to their internal structures when luminance and color profiles are quite similar. The same setup can also be used to characterize optical components of the LCDs.

• Journal of Electrochemical Science and Technology
• /
• v.7 no.2
• /
• pp.115-131
• /
• 2016

Though battery chemistry and technology had been developed for over a hundred years back, increase in demand for storage energy, in the computer accessories, cell phones, automobile industries for future battery car and uninterrupted power supply, has made, the development of existing and new battery, as an emerging areas of research. With innovation of high energetic inexpensive Nano structure materials, a more energy efficient battery with lower cost can be competitive with the present primary and rechargeable batteries. Materials electrochemistry of electrode materials, their synthesis and testing have been explained in the present paper to find new high efficient battery materials. The paper discusses fundamental of electrochemistry in finding true cell potential, overvoltages, current, specific energy of various combinations of anode-cathode system. It also describes of finding the performance of new electrode materials by various experiments viz. i. Cyclic Voltammetry ii. Chronoamperometry iii. Potentiodynamic Polarization iv. Electrochemical Impedance Spectroscopy (EIS). Research works of different battery materials scientists are discussed for the development of existing battery materials and new nano materials for high energetic electrodes. Problems and prospects of a few promising future batteries are explained.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.537-538
• /
• 2006

Split and recombine type reaction module was made by electrical discharge machining. The reaction module has special features to well mix the two reactants which have high flow ratio or high concentrations difference. It could be achieved by deviding one flow equally by two and inserting second flow in between. The mixing performance was measured by a parallel competing reaction with iodide-iodate system. The result shows that the developed three inlets micromixer has better mixing efficiency than comercialized Y type micromixer.

• Food Science and Biotechnology
• /
• v.14 no.5
• /
• pp.581-585
• /
• 2005

The antimicrobial activity of partially purified enterocin K25, produced by Enterococcus sp. K25, was abolished by proteases such as pepsin and proteinase K. The bacteriocin was resistant to heat treatment at $75^{\circ}C$ for 15 min and lost 75% of its activity at $100^{\circ}C$ for 30 min. Enterocin K25 showed bactericidal mode of action against an indicator strain, Lactobacillus plantarum NCDO 955. Enterocin K25 was purified to 112.6-fold purity via conventional steps of ammonium sulfate precipitation, ion exchange chromatography, and reversed phase high performance liquid chromatography (RP-HPLC). The molecular mass of the purified enterocin K25 was estimated as 4.3 kDa on an electrophoresis gel. Plasmid (${\sim}6.5\;kb$) linkage of production of enterocin K25 was confirmed by plasmid curing.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.6
• /
• pp.76-84
• /
• 2001

Generally fuel injection system using solenoid have some problems between control signal and mechanical movement like as time lag. Main purpose of the present study is to help the design optimization of GDSI for real engine application. We have adopted two different solenoid driving circuit, namely saturation and pick-hold type and have investigated experimentally the current, needle force, needle opening duration and injection quantity. The pick-hold type driving circuit surpassed a saturation type in the response time and pression control of injection quantity. Accordingly, Using characterization data of operating factors such as time constant, driving force and so on, can be evaluated and adjusted to obtain an optimum injector performance.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1996.06c
• /
• pp.812-819
• /
• 1996

This study was performed to quantify microscopically morphological characteristics of cotton fiber to identify parameters for quality evaluation using image analysis . The image of each fiber was captured by a Pc-based color imaging system using a conventional microscope. Ends of individual cotton fibers were glued on a microscope slide without any tension or straightening. A modified watershed technique was implemented to identify individual convolution segments, which were defined as sections of the fiber bordered by two neighboring convolutions. Length, area and perimeter of each convolution segment were measured directly from the image . Average width, shape factor and number of convolution segments in mm were calculated from the measured parameters. The performance of the image analysis algorithm was compared with visual varieties of cotton . The image analysis results agreed with visual inspection in 89.6% of the tested images.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.04a
• /
• pp.7-10
• /
• 2008

Heat release characteristics of live fire load are an important parameter for performance oriented fire safety design of a building. While investigations have been carried out on the fire load and its burning behavior in office, residential and commercial buildings and so on, little effort has been paid for the rational treatment of fire load in post office buildings in Japan. In this report, burning behavior of typical combustible objects in post office buildings are studied by measuring heat release rates of plastic palettes with and without postal envelopes or packages and special containers loading numbers of palettes. The test results suggest that dynamic heat release rate is highly dependent on the condition of palettes especially if they load appropriate amount of postal envelopes or not.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.40 no.3
• /
• pp.30-35
• /
• 2008

Mechanical properties of paper mulberry bast fiber handsheets were investigated to study the characteristics of bast fiber in terms of being suitable for modern paper making process. Tensile, tear and burst strength of handsheets made from bast fiber of paper mulberry were better than those of NBKP handsheets. Smoothness of bast fiber was higher but stiffness was lower than NBKP. Sizing performance of bast fiber were worse. 3D image analysis showed that handsheets of bast fiber had inferior formation and more pores comparing to NBKP.

• Current Photovoltaic Research
• /
• v.3 no.3
• /
• pp.91-96
• /
• 2015

Optical modeling and characterization of transparent dye-sensitized solar cells (DSC) are presented to design and estimate DSC devices numerically. In order to model the inhomogeneous active layer of DSC, the porous structure of titanium oxide ($TiO_2$) and dye mixture, we prepared films consisting of layer by layer of the DSC's basic materials sequentially, and characterized the optical parameters of the films with the effective refractive index, which was extracted from the transmittance and reflectance measurements in ultra violet to near infra-red range. By using the effective refractive index, we made the optical model for DSC, and demonstrated that the optical model based on effective refractive index can be used to design and evaluate the performance of transparent-type DSC modules.

• Journal of the Korean Society for Heat Treatment
• /
• v.24 no.1
• /
• pp.3-9
• /
• 2011

Plasma nitriding of stainless steels has been investigated over a range of temperature from 400 to $500^{\circ}C$ and time from 10 to 20 hours. Characterization of systematic materials was carried out in terms of mechanical properties and corrosion behaviors. The results showed that plasma nitriding conducted at low temperatures not only increased the surface hardness, but also improved the corrosion resistance of STS 316L, STS409L, and STS 420J2. It was found that plasma-nitriding treatment at $500^{\circ}C$ resulted in increasing the corrosion performance of STS 409L and STS 420J2, while STS 316L was observed with server and massive damage on surface due to the formation of CrN.