• 지질공학
• /
• 제27권3호
• /
• pp.255-265
• /
• 2017

상주시 임곡리에 굴착된 심도 100 m 지하수공(PW-2)의 적정양수량을 산정하였다. 시추코아와, 물리검층 자료에 의하면 지하수 산출 심도는 26.1~26.5, 28.0~30.0, 33, 58, 71 m로 해석된다. 단계양수시험에 의하면 40, 55, 70, 90, $132m^3/d$의 양수량으로 70일간 양수시 수위강하량은 각각 6.48, 11.56, 18.07, 28.99, 60.26 m로 예상되었다. $117m^3/d$으로 250분간 실시한 일정량양수시험에서는 양수 경과시간 120~150분에 영향추가 불투수층 경계조건에 도달하여 급격한 수위강하가 일어나 PW-2의 한계채수량은 $90m^3/d$로 산정하였으며 이때의 수위강하량은 28.82~31.27 m이다. 적정양수량은 한계채수량의 범위내의 정류상태여야 하기 때문에 PW-2의 적정양수량은 $70{\sim}90m^3/d$로 제시하였다. 불투수층 경계조건에서 직선의 기울기가 급해지며 지하수의 DO와 ORP가 증가하는 것으로 보아 PW-2를 중심으로 한 기반암지하수의 발달은 제한적인 것으로 추정된다.

• 한국주조공학회지
• /
• 제5권4호
• /
• pp.258-270
• /
• 1985

The structures and mechanical properties of undirectionally solidified Sn-Zn eutectic alloys have been examined over the growth range 7mm/h to 6,000mm/h. The structures of unidirectionally solidified Sn-Zn eutectic alloys were primarily broken-lamellar at growth rates below 760mm/h and became fibrous at higher growth rates above that. At a growth rate 3,084mm/h the structures were fibrouse only. There is no dendrites at any growth rates, but occasionally ribbon-like morphologies were seen. The under cooling increased parabolically with growth rate increase. The hardness of specimes increased with growth rates increase but heat-treated specimen decreased after growth rates 760mm/h and became constant value. The effect of heat-treatment was good at lower growth rate. At room temperature tensile strength increased with growth rates up to R=990mm/h and then tensile strength became near-constant value. The effect of heat-treatment was well at lower growth rate.

• Elastomers and Composites
• /
• 제12권1호
• /
• pp.27-32
• /
• 1977

The kinetics of azo-coupling reaction of N-acetyl-H-acid (1-acetamino-8-hydroxynaphthalene-3, 6-disulfonic acid) with several heterocyclic diasonium compounds such as diazotiged 3-aminopyridine, 3-aminoquinoline, 8-aminoauinoline and aniline was studied. It was found that reactions proceeded at remarkably different rate. Reaction rate was in increasing order; 3-aminopyridine, 3-aminoquinoline, 8-aminoauinoline and aniline. And the activation energies were 9.62, 10.10, 10.39, 10.70 Kcal/mole, respectively. Especially, the rate constant of 3-aminopyridine was 100 times larger than that of benzene diasonium compound even in strong acidity. Hammett plot was also made of the rate constants obtained against the heterocyclic substituent constants reported in the literature. A good linear relationship was obtained and the reaction constant of N-acetyl H-acid was calculated to be 3.14.

• 대한기계학회논문집A
• /
• 제25권3호
• /
• pp.399-407
• /
• 2001

The Surface, generated by end milling operation, is deteriorated by tool runout, vibration, friction, tool deflection, etc. Especially in cornering cut, surface accuracy is usually determined by varying cutting forces, which causes tool deflections. Cutting conditions like feed rate is usually kept constant during machining a part, which causes dimensional error in severe cutting. Cornering cut is a typical example of deterioration of surface accuracy when constant feed rate is applied. Therefore it becomes important to develop NC post processor module to determine optimal cutting conditions in various cutting situations. In this paper, cutting force is predicted in cornering cut with flat end mill and feed rate is determined by constraining constantly resultant force. Also some control characteristics of CNC machining center are evaluated.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2017년도 춘계학술대회
• /
• pp.641-644
• /
• 2017

LTE(Long Term Evolution) 기술은 스마트폰 중심의 모바일 인터넷으로 상징되는 상용 통신을 넘어 산업 및 긴급 통신 분야로 사용이 확대되고 있다. 본 논문에서는 다양한 분야로 보급되고 있는 LTE 기술의 전송 성능을 응용 트래픽 수준에서 분석해 본다. 성능 분석은 NS-2를 기반으로 한 컴퓨터 시뮬레이션을 사용하여 수행하며, CBR(Constant Bit rate), VBR(Variable Bit Rate) 등의 트래픽을 분석 대상으로 한다. 본 논문의 결과와 방법은 LTE 기반 네트워크의 연구 및 개발에 활용될 수 있을 것으로 생각된다.

• Bulletin of the Korean Chemical Society
• /
• 제11권4호
• /
• pp.343-347
• /
• 1990

A thermal decomposition of the tert-butoxy radical has been studied in the gas phase over the pressure range of 1-200 torr at $413_{\circ}K$ using di-tert-butyl peroxide + trimethylsilane mixtures. The relative rate constants were obtained by studying the competitive reactions between tert-butoxy radical decomposition 4(t-BuO·→ CH_3COCH_3 + CH_3·)$ and hydrogen abstraction reaction from trimethylsilane $(t-BuO·+ HSi(CH_3)_3 → t-BuOH + Si(CH_3)_3)·).$ The conventional RRKM calculations were carried out to compare the observed fall-off behavior of the decomposition rate constant $({\kappa}_d)$ with the theoretical predictions using reasonable values of input parameters. In all cases the calculated half-rate pressure $(P_{1/2})$ were significantly higher than those observed. The failure of RRKM to reproduce the fall-off behavior led us to suggest that not all of vibrational modes contribute to excitation (leading to decomposition) on the same time scale.

• 한국응용과학기술학회지
• /
• 제12권2호
• /
• pp.145-150
• /
• 1995

The Kinetics velocity for hydrolysis reaction of vanillylidene imine derivatives has been measured by ultra-violet ray spectrophotometer in 20wt% $dioxane-H_2O$ at $25^{\circ}C$. It was measured the reaction rate Constant of vanillylidene imine derivatives that can be applied widely following to pH-change at $25^{\circ}C$. Final products that hydrolyzed the vanillylidene imine certified in vanillin and aniline derivative, and the effect of substitution radical that has affected on hydrolysis reaction was largely promoted to reaction rate by electron attrating group in acidity and electron donoring group in basic. From the results of rate constant to hydrolysis reaction, substituent radical effect and final products. It has certified the hydrolysis reaction mechanism of vanillylidene imine derivatives.

• 약학회지
• /
• 제28권3호
• /
• pp.169-177
• /
• 1984

Release characteristics of salicylic acid from ethylcellulose(EC) films containing varying ratio of dieththylphthalate (DEP) were studied. Mathematical analysis of the release data showed that the release behavior actually conforms with the Higuchi's diffusion-controlled model. The release rate constants(k) were independent from the film thickness and the pH of release medium, but were proportional to the concentration of salicylic acid itself. The logarithm of the release rate constant (log k) increased as the concentration of DEP was increased. In conclusion, hydrophobic plastisizer DEP seemed to be very useful in controlling release rate constant of slightly soluble drugs as like salicylic acid without changing it's release characteristics.

• Journal of Pharmaceutical Investigation
• /
• 제20권3호
• /
• pp.145-152
• /
• 1990

Zirconium pyrithione complex was prepared by reaction of sodium-pyrithione solution and zirconyl chloride solution. The physico-chemical properties of the complex was examined by means of IR, XRD, DSC and NMR. And the stability of Zr-complex was investigated on the basis of accelerated stability analysis under conditions of temp. elevation, UV radiation and pH dependence. The result indicates that the ratio of the ligand to metal in Zr-pyrithione complex was determined 4:1, and its stability constant was $4.643{\times}10^4$. The rate order of decomposition of the complex was apparent first-order reaction of which rate constant and the decomposition rate was not only accelerated by effect of heat and UV radiation but was catalyzed by specific acid-base catalysis considered the pH dependence for the hydrolysis of the complex and the suspension was most stable over the range pH 4-8 indicating that solvent catalysis is the primary made of reaction in this region.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.291-292
• /
• 2006

This paper presents rate-distortion optimization that is considered sequence statistics(complexity) to choose the best macroblock mode decision in H.264. In previous work, Lagrange multiplier is derived by the function of constant value 0.85 and QP so that is not the proper Lagrange multilplier for any image sequence. The proposed algorithm solves the problem by changing constant value 0.85 into adaptive value which is influenced by image complexity, and by reducing the encoder complexity to estimate the image statistics with the multiplication of transformed, quantized rate and distortion. Proposed algorithm is achieved the bit-rate saving up to 5% better than previous method.