• 수산해양기술연구
• /
• 제51권2호
• /
• pp.163-170
• /
• 2015

Recently LED fish-attracting lamps have been more widely used in fisheries as low-cost and high-efficiency fishing gear, and development of long-life high-efficiency lamps is required through the design of LED packages to optimize heat resistance. This study developed an improved LED fish-attracting lamp with excellent heat performance, which was verified using a numerical model. Heat-resistance design factors such as the heat-radiation fin shape, PCB type, and LED chip count were investigated and optimized. Comparison with a commercial 180-W LED fishing lamp showed that the increase in initial temperature was 40% higher than that of the surrounding LED chip because of design errors in contact thermal resistance. The 250-W LED lamp developed in this study has a characteristic with thermal rising in linearly stable according to the heat source. In addition, luminance efficiency was improved by 20-65% by using flow-visualization simulation. A decrease of 45% in total power consumption with a fuel-cost reduction of over 55% can be expected when using these optimized heat release design factors.

• 대한화학회지
• /
• 제23권6호
• /
• pp.368-373
• /
• 1979

염화 N,N-이메틸 및 N,N-이에틸카르바모일의 가용매분해반응과 할라이드 교환$(Cl^-,\;Br^-,\;I^-)$반응, 및 염화 N,N-이페닐카르바모일의 가용매분해반응을 속도론적으로 연구하였다. 속도자료와 MO결과로부터 (1) 이 알킬화합물들은$S_N2$ 메카니즘으로, 이페닐화합물은 $S_N1$ 메카니즘으로 반응함을 알았고, (2) 염화이온교환에서는 결합절단이 중요한 반면, $Br^-$ 및 $I^-$ 교환반응에서는 결합 형성이 중요함을 알 수 있었다.

• 한국태양에너지학회:학술대회논문집
• /
• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
• /
• pp.195-198
• /
• 2011

Liquid desiccant material, such as lithium chloride (LiCl) or halide slits are usually used on air conditioning application for controlling the humidity of high Outdoor Air (OA). Solar energy is usually used to heat the liquid in regeneration process of those desiccant. The mass transfer it self is driven by the temperature different between the liquid desiccant and the input air. This experiment study is analyzing the characteristic of the aqueous LiCl-air temperature different in variance specific gravity, especially in range of temperature different using the solar energy as the heat generator. The experiment has done by variating the concentration of the LiCl with specific gravity 1.210 and 1.150. For the comparison the pure water is also used. The result show that the mass transfer rate is increased in every variation as the increases of the temperature different, and the weeker aqueous solution of the LiCl the highest mass transfer coefficient.

• 대한화학회지
• /
• 제19권1호
• /
• pp.11-15
• /
• 1975

Carbonyl 탄소원자의 반응성에 대한 연구의 일환으로 N,N-dimehtylcarbamoyl chloride와 N,N-diethylcarbamoyl chloride의 할로겐 교환반응을 아세톤 용매속에서 방사성 할라이드 이온을 사용하여 두 온도에서 속도론적으로 연구하였다. 그 결과를 alkylchloroformate의 경우와 비교하면, 친핵성의 순서는 비슷한 경향을 나타내나, 반응속도는 가용매분해나 alkylchloroformate의 경우보다 느리다. 활성화 피라미터 ${\Delta}H^*$나${\Delta}S^*$는$Cl^{\rightarrow}Br^{\rightarrow}I^-$는순서로 감소한다. 이 결과를 용매화 효과, bond-breaking, bond-formation 및 electronic requirment로 설명하였다.

• 대한화학회지
• /
• 제9권3호
• /
• pp.142-147
• /
• 1965

p-Phenylenediamine dihydrochloride의 結晶構造를 X-線 廻折法을 利用하여 解明하였다. 이結晶은 三斜晶係에 屬하며, 空間群은 $C_i1-P{\bar\1}$ 이고, 格子常數는 $a= 4.38{\pm}0.02, b=5.90{\pm}0.02, c=8.76{\pm}0.03{\AA}, {\alpha}=1101{\pm}1, {\beta}=96{\pm}1^{\circ}$이다. 그리고 單位格子속에는 들어있는 化學單位數,Z는 1이다. 各原子의 座標는 a, b 및 c軸에 따른 二次原的인 電子密度의 投影 및 ($F_o-F_c$) 合成에 依하여 얻었다. 이 結晶構造와 이미 硏究된 aliphatic diamine의 hydrogen halide 들의 構造와를 比較하였다.

• 대한전자공학회논문지TC
• /
• 제45권2호
• /
• pp.83-91
• /
• 2008

전력선 통신을 이용한 MH(메탈핼라이드) 램프용 조광제어시스템을 구성하기 위하여, 전력선 모뎀 및 MH 램프용 전자식 안정기를 설계하고, 안정기가 전력선 채널에 미치는 영향을 분석하였다. 전력선이 통신채널로써 사용될시 채널의 특성은 부하에 의하여 변화하게 되므로, 부하는 전력선 통신에 적합하도록 설계되어야 한다. 따라서 본 논문에서는 전력선 통신에 적합한 전자식 안정기를 제안하고, ASK와 FSK 두 종류의 전력선 모뎀을 설계하여 맨체스터 코드와 DS/SS 방식을 각각 적용하였다. 실험결과, DS/SS 방식이 적용된 FSK 전력선 모뎀이 가장 우수한 특성을 갖는 것으로 확인 되었다.

• Bulletin of the Korean Chemical Society
• /
• 제32권3호
• /
• pp.768-778
• /
• 2011

Calixpyrroles and related macrocycles are non-planer synthetic anion receptors that have attracted considerable attentions in recent years. Although the synthesis of calix[4]pyrrole (known as meso-octamethylporphyrinogen) was reported more than 100 years ago, the anion binding properties were first discovered in 1996. The simple calix[4]pyrroles can be synthesized in single step in high yield by condensation of pyrrole with acetone. The compounds showed preferential binding for halide anions including fluoride, phosphate, carboxylate, and chloride in organic media. Efforts to improve the anion affinity of calix[4]pyrrole and to enhance its selectivity have led to the synthesis of a variety of new calixpyrrole derivatives. Among the various modifications, introduction of straps on one side of the calix[4]pyrroles are the most effective. Incorporation of aromatic rings other than pyrroles also exhibited interesting binding behaviour. Introduction of signalling units as part of the strapping element enable to detect the anions on chromogenic or fluorogenic fashion. Finding of the anion transport properties across the membrane and cytotoxic effects of the calix[4]pyrroles open new window for calixpyrrole-related research. The polymer-incorporated systems have also been employed as anion complexants in solvent-solvent extraction. These old, yet easy-to-make macrocycles have well advanced more recently with the discovery of the ion-pair complexation properties. In this review, the synthetic developments and anion binding properties of calixpyrroles for the last decades will be discussed and will cover the advances in calixpyrrole chemistry.

• 조명전기설비학회논문지
• /
• 제21권6호
• /
• pp.1-7
• /
• 2007

본 논문에서는 도로 조명용 광원으로 쓰이는 메탈핼라이드램프, 고압나트륨램프, PLS의 세 가지 광원에 대해 안개 발생시 시인성을 평가하기 위해 특정한 인공 안개 조건하에서 각 광원들에 대한 피시험자들의 평가를 분석하여 명소시에는 고압나트륨램프가 시인성이 좋고 암소시에는 PLS가 시인성이 좋다는 결과를 얻었으며 이 결과는 앞으로의 도로 조명용 광원의 선택에 있어서 도움을 줄 수 있을 것으로 기대된다.

• 한국재료학회지
• /
• 제12권5호
• /
• pp.391-397
• /
• 2002

Synthesis and process development of nano-size Ti powder by SFE(Sodium/halide Flame Encapsulation) method were investigated. Four concentric coflow burner was used and its flame configuration was $TiCl_4/Ar/Na/Ar$ in order from the center. Flame has been controlled by the various processing parameters such as temperature of burner and flow rates of both $TiCl_4$(g) precursor and Na(g). It was found that yellow-colored flame was shown in the flow rates of 70cc/min of $TiCl_4$(g) precursor and 2 $\ell$ /min of Na(g) which were regarded as optimum flame condition. The powders encapsuled by NaCl were produced having the average powder size of 250nm. The results of X-ray diffraction showed that powders from the optimized condition consisted of pure Ti and NaCl. TEM analysis confirmed that the several Ti powders of 20-100nm were encapsulated with NaCl. After removing sodium chloride by heat treatment, the spherical Ti powders with the size range of 80 to 150nm were obtained.

• KIEAE Journal
• /
• 제9권1호
• /
• pp.23-30
• /
• 2009

A lightcourt design is typically used to address issues concerning aesthetics, feeling, and mood. From the view point of environmental aspect, as an ecological shaft space, it plays a key role in controlling inner quality. In particularly, the lightcourt concept allows the exploitation of daylighting by bring natural light into the center of the building, thus eliminating dark deep spaces. Additionally, the lightcourt shades the inner space in summer. The amount of light available at the base of the lightcourt depends on a number of factors; translucency of the top, reflectance and the geometry of the space. In this paper is to exemplify a lightcourt configuration with a sloped wall. It promises the maximized a sense of freedom and daylighting availability. It is a matter of course that the lightcourt with open-top plays a role as a light source for the adjacent space to the lightcourt. A series of lighting simulation provides performance data of daylighting with changing photometric factors. For the case that a skylight is not available, an electric lighting design with metal halide lamps has been established to create luminous ceiling. As expected, a sloped lightcourt with open-top exposes its superiority of daylighting source. Ancillary considerations to enhance of daylighting potential for the adjacent space have been issued with performance data.