• Korean Journal of Microbiology
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• v.39 no.3
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• pp.197-200
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• 2003

In order to establish effective in situ PCR on the glass slide using the conventional DNA thermal cycler, several parameters should be considered. These include full accessibility of PCR reagents into the cells, prevention of diffusing PCR products out of the cells, loss of PCR reagents by nonspecific adherence onto the glass slide, dryness of PCR reagents by heat, and heat conductivity from the heat block to the glass slide. Especially, to guarantee the full accessibility of PCR reagents to sample, relatively higher concentration of PCR reagents (particularly 4.5 mM of $Mg^{++}$) was required while 5 to 10 units/50 ${\mu}l$ reaction of Taq enzyme was enough as long as the step of pre-PCR incubation was included. Dryness of sample was prevented by addition of distilled water into the empty slots in the heat block, thereby providing the reproducible temperature-time profile of PCR. Observed temperature was lower than the programmed temperature by 3 to $4^{\circ}C$.

• Journal of Surface Science and Engineering
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• v.32 no.3
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• pp.235-238
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• 1999

Silicon dioxide films were prepared by anodizing silicon wafers in an ethylene $glycol+HNO_3(0.04{\;}N)$ at 20 to $70^{\circ}C$. The voltage between silicon anode and platinum cathode was measured during this process. Under the constant current electrolysis, the voltage increased with oxide film growth. The transition time at which the voltage reached the predetermined value depended on the temperature of the electrolyte. After the time of electrolysis reached the transition time, the anodization was changed the constant voltage mode. The depth profile of oxide film/Si substrate was confirmed by XPS analysis to study the influence of the electrolyte temperature on the anodization. Usually, the oxide-silicon peaks disappear in the silicon substrate, however, this peak was not small at $45^{\circ}C$ in this region.

• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.510-517
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• 2019

Increasing proliferation resistance of plutonium by way of increased $^{238}Pu$ content is of interest to the nuclear nonproliferation and international safeguards community. Considering the high alpha decay heat of $^{238}Pu$, increasing the isotopic fraction leads to a noticeably higher amount of heat generation within the plutonium. High heat generation is especially unattractive in the scenario of weaponization. Upon weaponization of the plutonium, the plutonium may generate enough heat to elevate the temperature in the high explosives to above its self-explosion temperature, rendering the weapon useless. In addition, elevated temperatures will cause thermal expansion in the components of a nuclear explosive device that may produce thermal stresses high enough to produce failure in the materials, reducing the effectiveness of the weapon. Understanding the technical limit of $^{238}Pu$ required to reduce the possibility of weaponization is key to reducing the current limit on safeguarded plutonium (greater than 80 at. % $^{238}Pu$). The plutonium vector evaluated in this study was found by simulating public information on Lightbridge's fuel design for pressurized water reactors. This study explores the temperature profile and maximum stress within a simple (first generation design) hypothetical nuclear explosive device of four unique scenarios over time. Analyzing the transient development of both the temperature profile and maximum stress not only establishes a technical limit on the $^{238}Pu$ content, but also establishes a time limit for which each scenario would be useable.

• Korean Journal of Optics and Photonics
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• v.15 no.6
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• pp.563-568
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• 2004

The high temperature proton exchange (HTPE) method was used to fabricate optical waveguides based on LiNbO$_3$, which gives rise to low propagation loss and high polarization extinction ratio. To characterize the refractive index distribution of the fabricated waveguides, the guided modes of each waveguide were observed using the prism coupling method and then the refractive index profile was calculated by the inverse WKB method with the least square fitting. Finally, we showed how the HTPE parameters such as the temperature of PE, the concentration of lithium additive, and the time of PE effect the refractive index profile.

• Atmosphere
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• v.34 no.4
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• pp.417-428
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• 2024

We analyzed 3 radiosonde measurements in May at Yangpyeong (10 May 2019, 19 May 2023, and 10 May 2024), as conducted for the educational purpose. While the number of measurements is limited, we find interesting features using these measured data. First, the Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) reanalysis data at the same time at Yangpyeong show the similar vertical temperature profile to that of radiosonde measurements. Vertical profiles of wind speed and relative humidity from the MERRA-2 data also look similar to those of radiosonde measurements, but the consistency was not much guaranteed in the upper atmosphere (higher than 5 km altitude). Second, the temperature profile from the radiosonde measurement and MERRA-2 dataset at Yangpyeong (located in the east of Seoul) is very analogous to that from the radiosonde measurement at Osan (located in the south of Seoul). Considering that the straight distance between Yangpyeong and Osan is about 60 km, the consistency of temperature profile is remarkable. Vertical wind profile is also generally similar between two regions, but the gap becomes larger as the altitude goes up. While the vertical profile of relative humidity is somewhat different between two regions, the vertical profile of water vapor mixing ratio derived from the relative humidity is rather similar between two regions. This study shows that only small number of additional radiosonde measurements enable us much better evaluation of regional meteorology in a vertical scale.

• Atmosphere
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• v.24 no.4
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• pp.523-532
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• 2014

In this study, thermal tropopause height defined from WMO (World Meteorological Organization) using temperature profile derived from Advance Microwave Sounding Unit-A (AMSU-A; hereafter named AMSU) onboard EOS (Earth Observing System) Aqua satellite is retrieved. The temperature profile of AMSU was validated by comparison with the radiosonde data observed at Osan weather station. The validation in the upper atmosphere from 500 to 100 hPa pressure level showed that correlation coefficients were in the range of 0.85~0.97 and the bias was less than 1 K with Root Mean Square Error (RMSE) of ~3 K. Thermal tropopause height was retrieved by using AMSU temperature profile. The bias and RMSE were found to be -5~ -37 hPa and 45~67 hPa, respectively. Correlation coefficients were in the range of 0.5 to 0.7. We also analyzed the change of tropopause height and temperature in middle troposphere in the extreme heavy rain event (23 October, 2003) associated with tropopause folding. As a result, the distinct descent of tropopause height and temperature decrease of ~8 K at 500 hPa altitude were observed at the hour that maximum precipitation and maximum wind speed occurred. These results were consistent with ERA (ECMWF Reanalysis)-Interim data (potential vorticity, temperature) in time and space.

• Korea-Australia Rheology Journal
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• v.21 no.3
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• pp.149-153
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• 2009

Profile development of the melt spinning process of poly(ethylene terephthalate) (PET) was simulated by a numerical method under the consideration of two constitutive equations of Newtonian and upper convected Maxwell (UCM) models. The viscoelastic characteristics of the polymer were considered via UCM constitutive equation that considered relaxation time as a function of temperature and molecular weight. The UCM model predicted the diameter profile better than the Newtonian, while velocity development was slower than the Newtonian model. Viscoelasticity played an important role in accurately predicting diameter profile. However, even though neck-like deformation was observed in the UCM model, the exact position of the deformation under high speed spinning was not obtained.

• Journal of the Semiconductor & Display Technology
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• v.11 no.2
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• pp.63-69
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• 2012

As decreasing size of chips, the need of wafer level packaging is increased in semi-conductor and display industries. Temperature uniformity is a crucial factor in vacuum soldering process to guarantee quality of bonding between chips and wafer. In this paper, a stepwise iterative algorithm has been suggested to obtain output profile of each heat source. Since this algorithm is based on open-loop stepwise iterative experimental technique, it is easier to implement and cost effective than real time feedback controls. Along with some experiments, it was shown that the suggested algorithm can remarkably improve temperature uniformity of wafer during whole heating process compared with the ordinary manual trial-and error method.

• Journal of Korea Foundry Society
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• v.26 no.5
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• pp.211-216
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• 2006

The study for thixoextrusion process of 7075, 7003 Al wrought alloys and AZ31 Mg wrought alloy was carried out with respect to reheating rate, isothermal holding temperature and time with an emphasis to the effect of homogenization on thixotropic micro-structures during the partial remelting, especially in the low liquid fraction ($f_L<0.2$). The liquid fraction and average grain size with respect to reheating profile such as reheating rate, isothermal holding temperature and time were almost uniform. It is considered very useful for thixoextrusion in terms of process control such as billet temperature control and actual extrusion time. Micro-structural controls of 7075, 7003 Al wrought alloys and AZ31 Mg wrought alloy before and after homogenization were available and thixotropic microstructures were obtained in both specimens.

• The Korean Journal of Food And Nutrition
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• v.17 no.3
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• pp.313-321
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• 2004

Separation-concentration of sulfur containing heterocyclic compounds(SCHC) from many reaction meat flavors manufactured with Maillard reaction was carried out. Profile of SCHC was identified and analyzed by GC and GC-MSD. The results were as follows. 1. Profile of SCHC could be identified 7 kinds thiazole and 11 kinds thiophene, the major produced compounds were thiophene, thiazolidine, 4-methyl-5-thiazole ethanol. 2. In the case of SCHC, relationship between changes of reaction conditions and the kind of produced components were as same, but produced amounts appeared the difference. Producing amount of complexed SCHC and caramellike note as well as oxygen containing heterocyclic compounds were high level more than high reaction temperature and long time reaction period. 3. Producing ratio of comparative simple structural SCHC were the highest level at reaction conditions of moisture content 50%, reaction temperature 100$^{\circ}C$ and reaction time 2 hours. Reaction conditions for the revelation of reaction meat flavor were below 110$^{\circ}C$ and less than 2 hours. 4. Relationship between moisture content and reaction temperature as well as reaction time had very relative relation. From the change of moisture content and reaction conditions could be obtained the simultaneously profile. Signal presentation for production of reaction meat flavor could be from extraction-separation-concentration of SCHC through simplification of raw-materials in the flavor and seasoning food industry.