• Electrical & Electronic Materials
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• v.8 no.6
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• pp.737-743
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• 1995

Two step RTD(Rapid Thermal Diffussion) of P into silicon wafer using tungsten halogen lamp was used to fabricated very shallow n$^{+}$p junction. 1st RTD was performed in the temperature range of 800.deg. C for 60 see and the heating rate was in the 50.deg. C/sec. Phosphrous solid source was transfered on the silicon surface. 2nd RTD process was performed in the temperature range 1050.deg. C, 10sec. Using 2 step RTD we can obtain a shallow junction 0.13.mu.m in depth. After RTD, the Ti-silicide process was performed by the two step RTA(Rapid Thermal Annealing) to reduced the electric resistance and to improve the n$^{+}$p junction diode. The titanium thickness was 300.angs.. The condition of lst RTA process was 600.deg. C of 30sec and that of 2nd RTA process was varied in the range 700.deg. C, 750.deg. C, 800.deg. C for 10sec-60sec. After 2 step RTA, sheet resistance was 46.ohm../[]. Ti-silicide n+p junction diode was fabricated and I-V characteristics were measured.red.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.4
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• pp.417-422
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• 2010

Atmosphere Plasma of Gas Discharge (APGD) has been used in plasma sources for material processing such as etching, deposition, surface modification and so on due to having no thermal damages. The APGD researches on AC source with high frequency have been mainly processed. However, DC APGD studies have been not. In order to understand APGD further, it is necessary to study on fundamental properties of DC APGD. In this paper, we developed a one-dimensional fluid simulation model with capacitively coupled plasma chamber at the atmosphere pressure (760 [Torr]). Nine kinds of Ar discharge particles such as electron (e), positive ions ($Ar^+$, $Ar_2^+$) and neutral particles ($Ar_m^*$, $Ar_r^*$, $Ar_h^*$, $Ar_2^*$(1), $Ar_2^*$(3) and Ar gas) are considered in the computation. The simulation was worked at the current range of 1~15 [mA]. The characteristics of voltage-current were calculated and the structure of Joule heating were discussed. The spatial distributions of Ar DC APGD and the mechanism of power consumption were also investigated.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.597-601
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• 2006

The advantages of solar energy are that it is renewable, infinite supplied and environmentally safe energy source. However, solar energy related products have the problems such as the limitation for installation, problems in maintenance and insufficient reliability which have been the barrier to consumers to satisfy the purchase need for solar heat related products. In this regard, in order to support the solar energy related companies the necessity for various technical information required for the commercialization of new products such as various performance test necessary for the certification of solar energy system, standardization for facilities and products, performance evaluation method and the measurement of performance is suggested. The purpose of this paper is to design the monitoring system for positive tests of system linked household hot water system using solar heat out of various solar energy systems, to establish an analysis and monitoring system for performance maintenance and operation technique, and to configure the centralized detection network by utilizing remote monitoring system. This research also aims at conducting monitoring for operation and performance evaluation in relation to database establishment and analytical evaluation and at describing the method of enhancing the reliability of solar energy system through the development of performance evaluation program.

• Laser Solutions
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• v.18 no.1
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• pp.12-17
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• 2015

This work performed numerical analysis of electromagnetic field and thermal phenomena occurring in femtosecond laser irradiation of silver nanowires. The local electric field enhancement was computed to calculate the optical energy dissipation as a Joule heating source and the thermal transport was analysed based on the two-temperature model (TTM). Electron temperature increased up to 1000K after 50fs and its spatial distribution became homogeneous after 80fs at the fluence of 100mJ/cm2. The result of this work is expected to contribute to revealing the photothermal effects on silver nanowires induced by femtosecond laser irradiation. Although the highest increase of lattice temperature was substantially below the melting point of silver, the experimental results showed resolidification and fragmentation of the silver nanowire into nanoparticles, which cannot be explained by the photothermal mechanism. Further studies are thus needed to clarify the physical mechanisms.

• Journal of the Korean Solar Energy Society
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• v.34 no.3
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• pp.1-11
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• 2014

The Korean government plans to introduce the building energy performance standard which regulates the annual energy consumption of buildings. This paper aimed to set up the reference building from database based on the building design trends for non-residential buildings. We surveyed the design data of 435 non-residential buildings which were granted building permission from 2007 to 2011. And we conducted estimation on the heating & cooling load and the energy consumption of the reference building using ECO2 program. From results, the reference building of non-residential buildings was office building which had a total 7 floors and $20,838m^2$ gross floor area. And it suggests the design reference data of building envelope, HAVC, heat source equipment and lighting system for the reference building. The total annual energy use of the reference building was $151.9kWh/m^2yr$.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.12
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• pp.1123-1131
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• 2005

The floor material is known as the most influential emission source of the residential building, because most floor material is made of wood compound and adhesive like a plywood flooring. Moreover, floor heating system keeps the inside temperature of the material high. As the emission of hazardous chemical compound from the construction material is influenced by many factors, it is necessary to analyze the emission characteristics of the floor material to improve IAQ. In this study, numerical analysis is performed to investigate the emission characteristics of the floor material affected by several factors such as temperature, air exchange rate, initial concentration, and internal diffusion coefficient. A simulation program is also written based on the mass transfer theory. The simulation results show that there is some level of difference on the TVOC concentration when each of the factors is variable.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.8
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• pp.641-651
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• 2003

In order to assess the reliability of a building energy simulation program (TRNSYS) from the standpoint of user, a set of verification experiment and calculation of cooling load for a test space is carried out. This work is a complement of the previous study that dealt with heating load for the same space. The test space is kept airtight to eliminate the source of uncertainties in modeling. A window-mounted, on/off controlled air-conditioner is used for cooling, whose performance has been established a priori. The calculation encompasses two models for evaluating cooling load in TRNSYS: energy rate control and temperature level control. Comparison of the total cooling loads obtained from different sets of experimental data enables to validate the measurements. The experimental result shows that the latent load is fairly large even in the absence of apparent air change in the space, which needs to be clarified. Each of hourly and daily accumulated sensible loads is compared between the experiment and two calculation models. Despite an inconsistency associated with solar irradiation, both of the models agree favorably with the experiment within a tolerance, illustrating their capability of properly predicting space thermal loads.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2753-2760
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• 2021

This paper proposes using sodium-cooled fast reactor technologies for use in hydrogen vapor methane (SMR) modification. Using three independent energy rings in the Russian BN-600 fast reactor, steam is generated in one of the steam-generating cycles with a pressure of 13.1 MPa and a temperature of 505 ℃. The reactor's second energy cycles can increase the gas-steam mixture's temperature to the required amount for efficient correction. The 620 ton/hr 540 ℃ steam generated in this cycle is sufficient to supply a high-temperature synthesis current source (700 ℃), which raises the steam-gas mixture's temperature in the reactor. The proposed technology provides a high rate of hydrogen production (approximately 144.5 ton/hr of standard H₂), also up to 25% of the original natural gas, in line with existing SMR technology for preparing and heating steam and gas mixtures will be saved. Also, exergy analysis results show that the plant's efficiency reaches 78.5% using HTR heat for combined hydrogen and power generation.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2670-2689
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• 2022

STREAM - a lattice transport calculation code with method of characteristics for the purpose of light water reactor analysis - has been developed by the Computational Reactor Physics and Experiment laboratory (CORE) of the Ulsan National Institute of Science and Technology (UNIST). Recently, efforts have been taken to develop a photon module in STREAM to assess photon heating and the influence of gamma photon transport on power distributions, as only neutron transport was considered in previous STREAM versions. A multi-group photon library is produced for STREAM based on the ENDF/B-VII.1 library with the use of the library-processing code NJOY. The developed photon solver for the computation of 2D and 3D distributions of photon flux and energy deposition is based on the method of characteristics like the neutron solver. The photon library and photon module produced and implemented for STREAM are verified on VERA pin and assembly problems by comparison with the Monte Carlo code MCS - also developed at UNIST. A short analysis of the impact of photon transport during depletion and thermal hydraulics feedback is presented for a 2D core also from the VERA benchmark.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.33 no.3
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• pp.50-57
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• 2004

This article reviews absorption cooling R＆D in Europe from the viewpoint of fundamentals, cycle development and applications. The review contains information on R＆D, predominantly of public projects in the field of sorption cooling. We report on research which is performed in Europe with some stress on Germany. There is progress in fundamentals, thermodynamic cycle design, and also applications. In the fundamentals part the discussion about thermodynamics, working pairs, and heat and mass transfer is reflected. Today's discussion on thermodynamic cycles is not very strong. Main focus is on special solid sorption cycles, compression­sorption hybrids, and open cycles, In the applications part the chilling business is the main issue. Some interest is given to the improvement of efficiency on and the adaptation to low temperature waste heat use, but the stress is on the use of solar energy as heat source. The area of heat pumping for heating purposes is less prominent but not at all negligible. Finally, industrial heat pumping involves the reverse cycle (heat transformer, heat pump type Ⅱ) also, but there is no significant activity.