• KSBB Journal
• /
• 제11권1호
• /
• pp.58-64
• /
• 1996

K-carrageenan에 고정화시킨 Zymomonas mobilis를 이용한 연속적인 sorbitol 생산에 대하여 연구하였다. Toluene과 glutaraldehyde로 처리하여 투과성을 증대시킨 세포를 alginate나 chitin 고정화 공정에서 어느 정도의 효소활성을 보였으나 210시간 이상의 공정반응에서는 sorbitol 생성량이 감소되었다. 독성이 적고 투과성을 증가시키는 물질로서 toluene 대신 CTAB(Cetyltrimethylammoniumbromide)를 사용하였다. CTAB로 투과성을 증가시킨 세포를 k-carrageenan에 고정화하여 CSTR과 packed bed reactor를 이용하여 sorbitol 생산을 시도하였으며 CSTR보다도 (25일) packed bed reactor에서 (30일) 더 긴 시간 효소활성도가 유지되었다. Two-stage 연속공정에서는 희석비율이 (dilution rate, $h^{-1}$) 증가함에 따라서 sorbitol 생성률이 증가되었으며 희석비율 0.32 $h^{-1}$에서 첫번째와 두번째 반응조에서 각각 $15g/\ell-h,$ $22g/\ell-h의$ sorbitol 생성률을 얻었다. 0.32$h^{-1}$보다 높은 희석비율에서는 생성를이 감소되었다.

• 한국주조공학회지
• /
• 제10권1호
• /
• pp.57-63
• /
• 1990

Continuous casting of the $Al-CuAl_2$ eutectic composite was carried out by the upward continuous casting process. The morphology of the eutectic growth and the stability of solid-liquid interface were investigated under various growth conditions. It was possible to get the planar solid-liquid interface at the condition of $G_L/R$＝$3.6{\times}10^3^{\circ}Csec/mm^2$. And the colony structures were formed at the conditions of $G_L/R$ < $R=0.33{\times}10^3^{\circ}Csec/mm^2$. The inter-lamellar spacing of $Al-CuAl_2$ eutectic composite was decreased with the increase of pulling speed. The reduction of inter-lamellar spacing & value of $G_L/R$ caused the increase of ultimate tensile strength and Rockwell hardness in $Al-CuAl_2$ eutectic composite.

• KSBB Journal
• /
• 제4권1호
• /
• pp.11-14
• /
• 1989

Tower fermentor를 이용한 연속 알콜발효에서 cell re-cycle과 aeration에 대한 영향을 검토하였다. 균주는 floc-culationg 효모인 Saccharomyces cerecisiae TS4를 를 사용하였다. 15% glucose를 사용한 cell recycle system의 연속 알콜발효에서 cell 농도는 50%/1였고, ethanol productiv는 26.4g EtOH/l-hr로서 cell농도가 가장 높은 값을 나타내었으며, aeration rate는 3.8$\times$ $10^-^3$ VVM이상부터는 ethanol pro-ductivity가 감소하였다.

• 충청수학회지
• /
• 제33권3호
• /
• pp.365-374
• /
• 2020

Given a noncompact semisimple Lie group G and its maximal compact Lie subgroup K such that the right multiplication of each element in K gives an isometry on G, consider a principal bundle G → G/K, which is a Riemannian submersion. We study the infinitesimal holonomy isometries. Given a closed curve at eK in the base space G/K, consider the holonomy displacement of e by the horizontal lifting of the curve. We prove that the correspondence is continuous.

• KSBB Journal
• /
• 제10권5호
• /
• pp.598-603
• /
• 1995

현재 국내 주정공장에서 사용되고 있는 타파오카를 액화 및 당화시켜 얻은 당화액과 당화액에서 분 리된 고형분으로 회분실험과 total cell retention c culture 실험을 하였다. 당화액에 의한 회분 실험결과 에탄올 수율은 0.48 g-ethanol/g- (reducing s sugar)으로서 약 $180g/\ell$의 환원당이 36시간만에 거의 다 소모되어 약 $84g/\ell$의 에탄올이 생성되었다. 이 때 최종 효모농도는 $8.5{\times}107$ cellsjml(약$2.30g/\ell$) 이었다. 원료 중 환원당농도가 $224g/\ell$이고 희석속도가 $0.18h^{-1}$ 인 total cell retention culture 실험에서는 효모농도가 약 $40g/\ell$, 잔류 환원당농도 가 약 $15g/\ell$로서 포도당은 거의 소모된 것으로 나 타났다. 에탄올농도는 약 $81.4g/\ell$로서 이의 부피 생산성이 약 $14.7g/\ell$-h이었다. 원료 중 환원당농도가 $205g/\ell$ 이고 희석속도가 $0.2h^{-1}$이며 bleed가 있 는 cell retention culture 실험에서는 효모의 농도가 약 $22g/\ell$까지 증가하였고 에탄올농도는 $685g/\ell$부근에서 진통하였으며 생산성은 약 $13.6g/\ell$-h이 다. 약 $12g/\ell$의 잔류 환원당 중에 약 $4.5g/\ell$의 포도당이 포함되어 있었다. 타피오카 당화액으로부터 분리된 고형분을 사용한 실험을 통하여 고형분도 기 질로서 효용가치가 어느 정도 있는 것으로 판명되었으며 당화액 발효조와 별도로 고형분 발효조의 개발도 필요한 것으로 생각되었다.

• 대한수학회보
• /
• 제38권4호
• /
• pp.709-718
• /
• 2001

In this paper we show that if D and G are continuous linear Jordan derivations on a Banach algebra A satisfying [D(x), x]x - x[G(x),x] $\epsilon$ rad(A)for all $\epsilon$ A, then both D and G map A into rad(A).

• 대한수학회지
• /
• 제34권3호
• /
• pp.581-598
• /
• 1997

This paper is concerned with the impulsive control problem $$ \dot{x}(t) = f(t, x) + g(t, x)\dot{u}(t), t \in [0, T], x(0) = \overline{x}, $$ where u is a possibly discontinuous control function of bounded variation, $f : R \times R^n \mapsto R^n$ is a bounded and Lipschitz continuous function, and $g : R \times R^n \mapsto R^n$ is continuously differentiable w.r.t. the variable x and satisfies $\mid$g(t,\cdot) - g(s,\cdot)$\mid$ \leq \phi(t) - \phi(s)$, for some increasing function $\phi$ and every s < t. We show that the map $u \mapsto x_u$ is Lipschitz continuous when u ranges in the set of step functions whose total variations are uniformly bounded, where $x_u$ is the solution of the impulsive control system corresponding to u. We also define the generalized solution of the impulsive control system corresponding to a measurable control functin of bounded variation.

• Journal of Korean Neurosurgical Society
• /
• 제48권5호
• /
• pp.429-433
• /
• 2010

Objective : This prospective study evaluated the use of continuous sedation using propofol and remifentanil when carpal tunnel release (CTR) was performed under local anesthesia. Methods : We sedated 60 patients undergoing CTR using local anesthesia with remifentanil at loading and continuous doses of $0.5\;{\mu}g\;kg^{-1}$ and $0.05\;{\mu}g\;kg^{-1}min^{-1}$, respectively, and propofol, using a target controlled infusion (TCI) pump set to a target of $2\;{\mu}g\;mL^{-1}$ (group A), or with the same drug doses except that the continuous remifentanil dose was $0.07\;{\mu}g\;kg^{-1}min^{-1}$ (group B) or $0.1\;{\mu}g\;kg^{-1}min^{-1}$ (group C). Results : In group B, the levels of pain when local anesthetics were administered (p = 0.001), intraoperative pain (p < 0.001) and anxiety (p = 0.001) were significantly lower than those of group A. Furthermore, the incidence of adverse events, including desaturation (p < 0.001) and vomiting (p = 0.043), was significantly lower in group B than in group C. Conclusion : Continuous sedation using an appropriate dose of remifentanil and propofol can be used as safe, efficacious ambulatory anesthesia in cases of CTR under local anesthesia, performed using only 2 mL of local anesthetic, with a high degree of patient satisfaction.

• 대한물리치료과학회지
• /
• 제11권3호
• /
• pp.5-13
• /
• 2004

The use of therapeutic ultrasound(US) in humans with malignant neoplasms has been contra-indicated in physical therapy practice. Some studies have shown the results after application of US inhibited of tumor growth but some studies have shown the results facilitated of tumor growth in mouse. The purpose of this study were to determine the effects of US on rectal sarcoma(CT-26) in mouse and to determine the histological change of tumor. Thirty-five female BALB/C mouse, age 6 to 8 weeks received subcutaneous injection of 0.1 105 tumor cells. When tumors grew to 5 mm in diameters, the mouse were randomly assigned to control group(n=7) and high powered continuous US group(n=7) and low powered continuous US group(n=7) and high powered pulsed US group(n=7) and low powered pulsed US group(n=7). The experimental group (four groups) received 10 treatments over a 10-day period of 3 MHz ultrasound. Tumor dimension were measured on days 1(start of treatment), 5(midtreatment), and 10(end of treatment, preexcision and postexcision). Tumors were weighed after excision and the mouse were observated histological change of tumor. All tumors grew larger over time. Mean tumor weights(in grams) and volumes(in cubic millimeters) were 2.063 g and $2729.313\;mm^3$ for the high powered continuous US group 1.881 g and $2428.002\;mm^3$ for the low powered continuous US group 1.730 g and $2381.002\;mm^3$ for the high powered pulsed US 1.673 g and $2289.562\;mm^3$ for the low powered pulsed US group 1.670 g and $2297.333\;mm^3$ for the control group. Ultrasound increased the weight and volume of subcutaneous tumor in mouse. We urge caution in the use of ultrasound in the areas of tumors.

• KSBB Journal
• /
• 제16권5호
• /
• pp.511-515
• /
• 2001

TCE및 TCE 분해산물의 높은 독성으로 인하여 TCE 분해 효소 및 세포 불활성화가 일어나서 장기간 안정되게 반응기 운전이 어렵다는 단점을 극복하고, TCE와 성장기질사이의 경쟁적 저해관계로 인한 처리효율 감소도 막기 위하여 TCE분해단계와 세포 및 효소 재활성화 단계를 구분시킨 2단계 CSTR/TBF 시스템을 개발하였다. B. ceapcia G4를 분해 미생물로 사용하였으며, 탄소원인 phenol과 공기 및 배지가연속적으로 공급되는 CSTR에서 효소 및 세포 재활성를 도모하고, TBF에서는 폐가스에 포함된 기사의 TCE를 공기와 함께 공급하여 B. cepcia G4 미생물막에의한 TCE가 분해되도록 구성하였다. 2단계 CSTR/TBF 시스템은 유입 TCE 농도가 15pp $m_{v}$까지도 100% 수준의 처리 효율을 보여주었으며, 고농도의 TCE를 안정적으로 장기간 처리할 수 있었다.다.