• Korean Journal of Poultry Science
• /
• v.14 no.2
• /
• pp.89-96
• /
• 1987

The purpose of this paper to present morphological normal chick chromosomes and develope avian cytogenetic techniques including chromosome preparation and banding technique. The early chick embryos provide a consistent source of material with hish mitotic cells. Although chick embryo tissue gives excellent preparations, the 4-5 days embryo is somewhat incovenient materials, Most imp of ant for avian Chromosome analysis are the technical protocols to achieve adequate preservation, spreading, and staining of the full chromosome complement. To precise chromosome analysis, pro-metaphase states are required. Best results of banding will be obtained from air dried slides prepared from early chick embryos that have been aged at least 1 week. Good G-banding differentiation is achieved by adequate trypsin digestion fellowed by staining in Goe,sa dye. The results of C-banding is influenced by many factors including the conditions of Ba(OH)$_2$, HCl treatment, and state of rinsing. In addition to precisely interprets banding patterns, the densitometric analysis is recommended.

• Current Photovoltaic Research
• /
• v.1 no.2
• /
• pp.115-121
• /
• 2013

ZnO film has been used for CIGS solar cells as a buffer layer as itself or by doping Mg and Sn; ZnO film also has been used as a transparent conducting layer by doping Al or B for solar cells. Since ZnO itself is a host material for many applications it is necessary to understand the electrical and optical properties of ZnO film itself with various preparation conditions. We prepared ZnO films by converting ZnS precursor into ZnO film by thermal annealing. ZnO film was formed at low temperature as low as $500^{\circ}C$ by annealing a ZnS precursor layer in air. In the air annealing, the electrical resistivity decreased monotonically with increasing annealing temperature; the intensity of the green photoluminescence at 505 nm increased up to $750^{\circ}C$ annealing. The electrical resistivity further decreased and the intensity of green emission also increased in reducing atmospheres. The results suggest that deep-level defects originated by oxygen vacancy enhanced green emission, which reduce light transmittance and enhance the recombination of electrons in conduction band and holes in valence. More oxidizing environment is necessary to obtain defect-free ZnO film for higher transparency.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.1
• /
• pp.54-60
• /
• 2006

In this paper, we describe a bio-fluidic device for adaptive sample pretreatment, in order to optimize the conditions under which absorbance assays can be conducted. This device can be successfully applied to the measurement of Escherichia coli (E. coli) concentrations using adaptive dilution, with which the dilution ratio can be adjusted during the dilution. Although many attempts have been previously made to miniaturize complex biochemical analyses at the chip scale, very few sample pretreatment processes have actually been miniaturized or automated at this point. Due to the lack of currently available on-chip pretreatments, analytical instruments tend to suffer from a limited range of analysis. This occasionally hinders the direct and quantitative analysis of specific analyses obtained from real samples. In order to overcome these issues, we exploit two novel strategies: dilution with a programmable ratio, and to-and-fro mixing. The bio-fluidic device consists of a rectangular chamber constructed of poly(dimethylsiloxane) (PDMS). This chamber has four openings, an inlet, an outlet, an air control, and an air vent. Each of the dilution cycles is comprised of four steps: detection, liquid drain, buffer injection, and to-and-fro mixing. When using adaptive sample pretreatment, the range in which E. coli concentrations can be measured is broadened, to an optical density (O.D.) range of $0.3{\sim}30$. This device may prove useful in the on-line monitoring of cell concentrations, in both fermenter and aqueous environments.

• Proceedings of the SAREK Conference
• /
• 2007.11a
• /
• pp.606-611
• /
• 2007

Pulsation is an inherent phenomenon in reciprocating compressors. It interacts with piping to cause vibrations and performance problems. Indiscriminately connecting to a compressor can be dangerous and cost money in the form of broken equipment and piping, poor performance, inaccurate metering, unwanted vibration, and sometimes noise. Piping connected to a compressor can materially affect the performance and response. To minimize these detrimental effects, reciprocating compressor system should be equipped by pulsation suppression system. This study discusses pressure pulsation phenomena occurred in a reciprocating compressor system. An experiment applied air compressor unit, as pulsating pressure generator, has been done. The compressor was connected sequentially to a snubber model and pressure tank. Sensor probes were placed on the inlet and outlet pipes of snubber. Compressor was driven by a motor controlled by a frequency regulator. The experiment was conducted by adjusting the regulator at 40Hz. General information about an internal gas flow can be achieved by numerical analysis approach. Information of the velocity, pressure and turbulence kinetic energy distribution are presented in this paper. Based on this result, the design improvement might be done.

• Journal of Sensor Science and Technology
• /
• v.15 no.4
• /
• pp.237-244
• /
• 2006

Atomic force microscope (AFM) has become a common tool for the structural and physical studies of biological macromolecules, mainly because it provides the ability to perform experiments with samples in a buffer solution. In this study, structure of proteins and nucleic acids has been studied in their physiological environment that allows native intermolecular complexes to be formed. Cr and Au were deposited on p-Si (100) substrate by thermal evaporation method in sequence with the thickness of $200{\AA}$ and $500{\AA}$, respectively, since Au is adequate for immobilizing biomolecules by forming a self-assembled monolayer (SAM) with semiconductor-based biosensors. The SAM, streptavidin and biotin interacted each other with their specific binding energy and their adsorption was analyzed using the Bio-AFM both in a solution and under air environment. A silicon nitride tip was used as a contact tip of Bio-AFM measurement in a solution and an antimony doped silicon tip as a tapping tip under air environment. Actual morphology could also be obtained by 3-dimensional AFM images. The length and agglomerate size of biomolecules was measured in stages. Furthermore, $R_{a}$ (average of surface roughness) and $R_{ms}$ (mean square of surface roughness) and surface density for the adsorbed surface were also calculated from the AFM image.

• Conservation Science in Museum
• /
• v.2
• /
• pp.77-82
• /
• 2000

The purpose of this study is to evaluate the effect of ART-SORB which is commonly used in museums and galleries at home and abroad including National Museum of Korea, so as to collect useful information to control micro-environment. Experiment was conducted in air-tight condition in order to evaluate only the effect of ART-SORB excluding any influence from outside factors. A certain amount of ART-SORB considering the case size and ART-SORB in cassette type were used to evaluate the humidity controlling capability. The result showed that target humidity was reached in 10~17 hours in case of using corresponding amount of ART-SORB to the cubic volume and in 5~6 hours in case of excessive use of cassette type ART-SORB. And it also showed that humidity can be controlled in the range of RH 50~70%. In addition, ART-SORB was excellent at raising humidity at low humidity and poor at high humidity. Therefore, ART-SORB turned out to be an effective humidity buffer for controlling micro-environment of such artifacts as wooden ware, lacquer ware and paintings, which require high humidity. However, unfortunately, there are some difficulties in applying this result to real condition, given the fact that this study was conducted under firm air-tight case. Therefore, ART-SORB can be fully effective only in firm air-tight case.

• Korean Journal of Medicinal Crop Science
• /
• v.8 no.2
• /
• pp.123-128
• /
• 2000

This study was carried out to determine factors affecting on the mass propagation of Rehmannia glutinosa seedlings in bioreactor culture. Air-lift type bioreactor was more compatible to shoot formation than stirrer type. Fifty grams(90 stem explants) of inoculum in 1.5L medium was placed into 2.5L bioreactor with aeration rate of 0.5 v.v.m., which was proper for effective shoot formation. Adding MES as pH buffer to culture medium increased the numbers of shoot formation. Adding 5g/l of anti-vitrifying agent into culture medium was highly effective for diminishing the rate of vitrification in shoots formed.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1714-1715
• /
• 2011

In this work, highly conductive organic solvent-based polyaniline(PANI) was used as an anode in organic photovoltaic cells (OPV) based on poly - (3-hexylthiophene) and [6,6] - phenyl - C60 - butyricacid methyl ester (P3HT : PCBM). The transmittance of the used PANI film were 87.67% and 86.57% at 550nm, and its sheet resistance were 454 ${\Omega}/{\Box}$ and 298 ${\Omega}/{\Box}$. We fabricated ITO-free OPV cells using PANI as an anode, which exhibited an external power conversion efficiency of 2.28% with a result of Jsc of 6.922mA/cm2, Voc of 0.6093V, and FF of 54.10% under an illumination of air mass(AM) 1.5G (100mW/$cm^2$). We used ink-jet printing to deposit buffer layer and active layer on a glass substrate.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.9
• /
• pp.3443-3447
• /
• 2011

The spectroscopic behavior of catechin (5,7,3',4'-tetrahydroxyflavan-3-ol), has been studied in the presence and the absence of air using UV-vis absorption spectrophotometry and fluorescence spectroscopy. The UV-vis absorption spectrum of catechin shows a very sharp and strong absorption maximum peak at 275 nm in deaerated water. New absorption maximum peaks appeared in aerated water, as well as in basic aqueous solution, caused by the oxidation of catechin. The absorbances in the UV-vis absorption spectrum of catechin decreased when the solution was left in the dark for a long time. The fluorescence emission spectrum of catechin after a long time period differs markedly from that in freshly prepared solution; the fluorescence maxia shifted as time passes after adding catechin to the solutions. When the deaerated basic catechin solutions were left in the dark for a long time, their fluorescence quantum yields were found to be nearly zero. This suggests that the oxidized catechin molecules were seen to have slowly undergone successive chemical reactions in basic buffer solution.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1276-1279
• /
• 2005

The long-term stability of pentacene thin-film transistors (TFTs) encapsulated with a transparent $SnO_2$ thin-film prepared by ion beam assisted deposition (IBAD) was investigated. With a buffer layer of thermally evaporated 100 nm $SnO_2$ film deposited prior to IBAD process, our encapsulated OTFTs sustained its initial field-effect mobility up to one month and then gradually degraded showing only 37% reduction compared to 90% reduction of non-encapsulated OTFTs after 100 days in air ambient. The encapsulated OTFTs also exhibited superior on/off current ratio of over $10^5$ to that of the unprotected devices $({\sim}10^4)$ which was reduced from ${\sim}10^6$ before aging. Therefore, the enhanced long-term stability of our encapsulated OTFTs should be attributed to well protection of permeation of $H_2O$ and $O_2$ into the devices by the IBAD $SnO_2$ thin-film which could be used as an effective inorganic gas barrier for transparent organic electronic devices.