• Analytical Science and Technology
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• v.30 no.5
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• pp.287-294
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• 2017

As the demand for natural gas increases with industrial development, the supply of natural gas is expected to become unstable with a shortage of imported natural gas. It is hence necessary to meet this demand by introducing and developing various types of natural gas, such as pipeline natural gas (PNG) and substituted natural gas (SNG), in addition to liquefied natural gas (LNG). The components included in PNG as well as their concentrations must be measured accurately, and a standard gas should be developed to accurately measure hydrocarbons ($C_6-C_{10}$), which are trace components included in natural gas. The components in the primary standard gas mixtures (PSMs) developed in the present study were hexane, heptane, octane, nonane, and decane with concentrations of $10-30{\mu}mol/mol$ with methane as the balance gas. Standard hydrocarbon ($C_6-C_{10}$) gas mixtures were prepared in aluminum cylinders by a gravimetric method with traceability following ISO 6142 with raw material gases, for which the purity of each component was analyzed completely. The prepared standard gas mixtures were analyzed by to evaluate the preparation consistency between the standard gas mixtures, the adsorbability of the cylinders, the variation of the stability, and the uncertainty. The results showed that aluminum cylinders have little adsorptive loss on their internal surfaces with excellent long-term stability. The developed standard gas mixture, containing hexane, heptane, octane, nonane, and decane with concentrations of $10-30{\mu}mol/mol$, showed an uncertainty in a range of 0.79 % - 1.63 %.

• Applied Microscopy
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• v.42 no.1
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• pp.43-48
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• 2012

This study shows that ceresin wax, candellila wax and microcrystalline wax mixed together with liquid paraffin oil to produce lipsticks (LS-1, LS-2) and capric/caprylic triglyceride oil added to produce lipsticks (LS-3, LS-4). After each type of lipsticks were molded, LS-1 and LS-3 was put into a cooling chamber ($5^{\circ}C$). LS-2 and LS-4 was put into a cooling chamber ($5^{\circ}C$) for 18 hours and kept in an incubator ($45^{\circ}C$) for 5 hours and put again into a cool chamber ($5^{\circ}C$). After that, the wax's three dimensional network structure was observed under scanning electron microscopy. Regardless of the kind of oil, the LS-1 and LS-3 wax structure had more distinct shape than the lipstick wax structure of LS-2 and LS-4. Also, regardless of the kind of wax, the three dimensional network structure was modified as the storage temperature increased. As a result, the lipstick's molding temperature increased, the wax's structure size also increased and the shape irregularly modified. This modification causes sweating phenomenon which affected lipstick's surface rheological property.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.1-17
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• 2020

Three-dimensional microscopic approaches in histopathology display multiplex properties that present puzzling questions for specimens as related to their comprehensive volumetric information. This information includes spatial distribution of molecules, three-dimensional co-localization, structural formation and whole data set that cannot be determined by two-dimensional section slides due to the inevitable loss of spatial information. Advancement of optical instruments such as two-photon microscopy and high performance objectives with motorized correction collars have narrowed the gap between optical theories and the actual reality of deep tissue imaging. However, the benefits gained by a prolonged working distance, two-photon laser and optimized beam alignment are inevitably diminished because of the light scattering phenomenon that is deeply related to the refractive index mismatch between each cellular component and the surrounding medium. From the first approaches with simple crude refractive index matching techniques to the recent cutting-edge integrated tissue clearing methods, an achievement of transparency without morphological denaturation and eradication of natural and fixation-induced nonspecific autofluorescence out of real signal are key factors to determine the perfection of tissue clearing and the immunofluorescent staining for high contrast images. When performing integrated laboratory workflow of tissue for processing frozen and formalin-fixed tissues, clear lipid-exchanged acrylamide-hybridized rigid imaging/immunostaining/in situ hybridization-compatible tissue hydrogel (CLARITY), an equipment-based tissue clearing method, is compatible with routine procedures in a histopathology laboratory.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.257-262
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• 2006

This experiment was carried out to investigate the effect of hypoglycemic yogurt as a clinical test with person both who have diabetes and who don't have diabetes. Diabetes is a disease caused by unused and accumulated glucoses produced via the foods digestion due to the lack of insulin or lower tissue reaction to insulin. Patients with diabetes or complications of diabetes are on the rise annually. For the therapy and prevention of diabetes, a yogurt made from functional materials such as insulin-resistant FK-23 lactic acid bacteria, Pinitol, edible fiber which delays glucose-absorption, extract powder of glucose-absorption-inhibitory white bean and low-caloric Erythritol and banaba extract is effective for reduce or restrain the blood glucose levels. The blood glucose levels after a meal of non-diabetic persons were lower after drinking a hypoglycemic yogurt than they after drinking general yogurt. The blood glucose levels after a meal of 10 diabetic patients were checked after drinking the yoghurt. As a result, 19 mg/dL, 30 mg/dL, 31 mg/dL of blood glucose levels decreased in 30 min, 60 min and 120 min respectively after drinking the yogurt. Blood glucose inhibition rates of 80 % of the tested patients also decreased. The blood glucose level of the diabetic patients having drunk the yogurt for 30 days consistently decreased into 59 mg/dL in 120 min after a meal.

• Journal of Life Science
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• v.16 no.6
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• pp.1029-1035
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• 2006

The study was designed to investigate the influence of feeding Eosungcho(houttutnia cordata Thunb) on the meat quality of porks. Experimental groups were divided into control group(C), 5%(T1) and 10%(T2) Eosungcho powder feeding group, and than administered for 12 weeks. And then pork's loins were storaged at $4^{\circ}C$, for 23 days after vaccum packed. TBARS was increased(P<0.05) during storage days in all samples, while it's contents were lower Eosungcho feding groups than control group. Total cholesterol contents of pork's loin, were $48.9{\pm}0.2\;mg/100\;g$ in control group, $39.1{\pm}0.2\;mg/100\;g$ in T1 group and $37.8{\pm}0.3\;mg/100\;g$ in T2 group. 4 kinds of cholesterol oxides($7{\beta}-hydroxycholesterol$, 19-hydroxycholesterol, ${\alpha}-$ and ${\beta}-epoxide$) detected in pork's loin. Cholesterol oxides concentration of pork's loin was increased during storage and lowest in T2 group.

• Korean Journal of Food Science and Technology
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• v.12 no.4
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• pp.272-277
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• 1980

The tolerance of useful bacterial spores to the conditions of tablet making, specifically, the destruction of bacterial spores upon compressional pressure was investigated. The damage of bacterial spores occurred mainly during the tabletting. The bacterial spores obeyed a logarithmic destruction rate upon compressional pressure. The spore destruction rate was dependent upon the strains of microorganism. The Decimal Reduction Pressure, designated as P-value, were $2.9\;ton/cm^2$, $2.6\;ton/cm^2$ and $2.1\;ton/cm^2$ for the spores of Bacillus subtilis, Bacilus coagulans and Clostridium butyricum, respectively, and $1.7\;ton/cm^2$ for the vegetative cell of Streptococcus faecalis. The spore destruction upon compressional pressure was influenced by the type of filler. The P-value of the spore of B. coagulans was $2.8\;ton/cm^2$ in the lactose filler, but $2.0\;ton/cm^2$ in the starch filler. The number of viable spores was inversely proportional to the hardness and density of tablet, in case that the same type of filler was used. The starch filler, which resulted in the lower hardness and lower density of tablet, caused higher spore destruction rate compared with the lactose filler.

• Journal of Aquaculture
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• v.13 no.1
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• pp.87-99
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• 2000

Field survey on the variational characteristics of water quality and chlorophyll a concentraion were carried out at the 25 stations for four seasons in Kogum-sudo(Straits) southern coast of Korean Peninsula from Feburuary to October in 1993. We made an analysis on biological factor as chlorophyll a concentraion as well as physicio-chemical factors such as water temperature salinity sigma-t transparency dissolved oxygen(DO) chemical oxygen demand(COD) nutrients (ammonia, nitrite, nitrate, phosphate, and silicate) N/P ratio and suspended solid(SS). The waters in the Kogum-sudo were not stratified due to the tidal mixing. And the high productivity in photic layer were supported by high nutrients concentration from bottom waters. The high concen-trations of suspended solid in straits had a bad influence upon marine biology of nature and cultivations. In Kogum-sudo had a sufficient nutrients for primary productivity during a year. Especially phosphate and inorganic nitrogen were high the other side silicate was very low. The source of nutrients supply depend on rather mineralization of organic matters and input of seawater from outside than input of freshwaters from lands. Phytoplankton biomass as measured by chlorphyll a concentratiion was very high all the year round and it was controlled by the combination o f several environmental factors especially of phosphate in summer and dissolved nitrogen in other seasons.

• Journal of Aquaculture
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• v.21 no.3
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• pp.190-195
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• 2008

We investigated the changes in growth, digestive enzymes activities, nucleic acids contents and RNA/DNA ratio of flounder Paralichthys olivaceus larvae (C for Paracyclopina nana, A for Artemia, and M for Mix of C and A) for 14 to 28 DAH. Body length of flounder larvae showed the best in the C trial at 28 DAH. The change of nucleic acids contents showed faster in C and M trials than A trial. And RNA/DNA ratio showed the significantly faster changes in C trial than A trial. High metamorphosis rates were also observed in C and M trial. $\alpha$-amylase activities increased gradually up to 28 DAH in all trials. Total alkaline protease (TAP) activities of A trial showed the highest value to 9 mU/larvae at 26 DAH. But others trials showed lower to $5{\sim}6$ mU/larva than A trial. TAP:$\alpha$-amylase activity ratio did not significantly changed to $0.025{\sim}0.053$ in A trial during the experiments. But, C and M trials tended to gradually decrease from $0.078{\sim}0.083$ (initial) to $0.013{\sim}0.018$ (final). Therefore, it shown the ratio gradually decreased of TAP:$\alpha$-amylase activity, stability of TAP activity, and rapid change of nucleic acids in trials grown positively. Thus, because P. nana could continuously supply the optimal nutrients for flounder larvae, we suggested the supplement of the copepod to an efficient feed of the flounder larvae.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4C
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• pp.333-341
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• 2002

This article is written to make a foundation for effective radio network engineering by enabling the accurate traffic assumption between Base Station (BTS : Base Station Transceiver Subsystem) md Repeater through the scientific and systematic analysis of mobile traffic dealt within CDMA Base Station. Among these, Repeater, having direct physical connection with BTS, simply does the remote relay function but the volume of the traffic flowed into the repeater is not accountable. The total BTS traffic is the sum of traffic dealt by the BTS and multiple Repeaters. In this article, we tried traffic analysis of this kind by adopting RTD (Round Trip Delay) which is specially designed to measure distribution of the distance between the Base Station and the Mobile station by differentiating the traffic dealt by BTS from traffic dealt by Repeaters. The fact that the connection between mobile station and BTS via Repeater (which is located remotely) yields far more delay than the direct connection between mobile station and BTS is the clue of this article. Based on this fact, Time Delay equipment was put at the receiving side of the Repeater to add certain amount of delay to the traffic to BTS and the result showed that the 99.78% of the traffic can be identified.

• Korean Journal of Materials Research
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• v.8 no.2
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• pp.135-140
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• 1998

Drag reduction produced by dilute solution of water soluble ionic polymer-surfactant complex under turbulent flow in a rotating disk apparatus(RDA) was investigated in this study. Three different molecular weights of polyacrylic acid(PAA) were adopted as drag reducing additives, and distilled water was used as a solvent. Experiments were undertaken to observe the dependence of drag reduction on various factors such as polymer molecular weight, molecular expansions and flexibility, rotating speed of the disk and polymer concentration. Specific considerations were put on conformational difference between surfactant and polymer, and effect of pH on ionic polymer possessing various molecular conformation through pH. The complex of ionic polymer and surfactant(Sodium Dodecyl Sulfate) behaves like a large polyelectrolyte. Surfactant changes the polymer conformation and then increases the dimension of the polymer. The radius of gyration, hydrodynamic volume and relative viscosity of the polymer-surfactant system are observed to be greater than those of polymer itself. Such surfactant-polymer complex has enhanced drag reduction properties.