• 기술혁신학회지
• /
• 제13권2호
• /
• pp.282-309
• /
• 2010

최근 기술무역에 의한 기술도입은 글로벌 시대에서 핵심적인 기술혁신전략이라고 할 수 있으며, 기술도입의 현황분석을 통해 국가의 기술정책을 수립하는 것은 국가경쟁력 확보에 매우 중요한 요소라고 볼 수 있다. 그러나 기술무역에 대한 연구들의 대부분은 기술무역의 특성파악과 거시적인 현황 및 파급 효과분석에만 초점을 맞추고 있어, 실질적으로 국가의 정책을 수립하는 데에는 이론적/실무적 배경을 제시하지 못하고 있는 실정이다. 따라서 본 연구에서는 한국은행의 '기술도입대가 지급현황' 데이터를 활용하여 지식경제부의 통합기술청사진에서 사전에 정의된 31개 중점기술분야에 대해 기술집중도, 기업집중도, 국가집중도를 분석하고, 기술별 거래되는 기술유형과 기술도입거래대가 유형을 분석하였다. 이를 통해, 기술분야별로 기술거래가 특정 하위기술, 기업, 국가에 집중되는 정도를 분석하고, 기술거래유형의 특성을 분석하여 국내산업의 기술도입 특성을 도출하였다. 본 연구의 결과는 국가에서 기술의 수출 및 수입에 관련된 기술정책을 수립하는 영역에서 뿐만 아니라 국내산업의 기술혁신 특성을 분석하기 위한 중요한 자료로 활용될 수 있을 것이다.

• Journal of Microbiology and Biotechnology
• /
• 제22권11호
• /
• pp.1494-1500
• /
• 2012

Fermentation with filamentous fungi in a bioreactor is a complex dynamic process that is affected by flow conditions and the evolution of the rheological properties of the medium. These properties are mainly affected by the biomass concentration and the morphology of the fungus. In this work, the rheological properties of a fermentation with the fungus Beauveria bassiana under different hydrodynamic conditions were studied and the rheological behavior of this broth was simulated through a mixture of carboxymethyl cellulose sodium and cellulose fibers (CMCNa-SF). The bioreactor was a 10 L CSTR tank operated at different stir velocities. Rheological results were similar at 100 and 300 rpm for both systems. However, there was a significant increase in the viscosity accompanied by a change in the consistence index, calculated according to the power law model, for both systems at 800 rpm. The systems exhibited shear-thinning behavior at all stir velocities, which was determined with the power law model. The mixing time was observed to increase as the cellulose content in the system increased and, consequently, the efficiency of mixing diminished. These results are thought to be due to the rheological and morphological similarities of the two fungal systems. These results will help in the optimization of scale-up production of these fungi.

• 기술혁신학회지
• /
• 제5권3호
• /
• pp.396-411
• /
• 2002

This is an analysis of international mobile displays industry. There has been severe competition in market and technology. In technology, There has been competition between Japan, USA and Korea. On the other hand, there has been competition in the products market between Korea, Japan and Taiwan. Recently Korea has catched-up Japan in mid-size display industry. The response of Japanese firms are as follows: technological collaboration with Taiwanese firms in mid-size and concentration in small and large size displays. New competition, however, has started, since new technologies such as TFT-LCD and OELD have been used in products.

• Nuclear Medicine and Molecular Imaging
• /
• 제41권2호
• /
• pp.158-165
• /
• 2007

Technological advances in molecular imaging made it possible to image synaptic neurotransmitter concentration in living human brain. The dopaminergic system has been most intensively studied because of its importance in neurological as well as psychiatric disorders. This paper provides a brief overview of recent progress in imaging studies of dopamine release induced by pharmacologic and nonpharmacologic stimulations.

• 한국표면공학회지
• /
• 제48권3호
• /
• pp.100-104
• /
• 2015

The nickel alloys gets a great deal of attention due to their good mechanical, chemical and magnetic properties. Especially Ni-P alloy systems are very attractive due to their good corrosion resistance and the wear resistance in important technological applications. In this study, the effects of phosphorus acid concentration in plating solution on composition of Ni-P alloy coatings were studied. The Ni-P electrodeposits of the various P contents were investigated in order to understand effect of the composition on mechanical properties of Ni-P electrodeposits. The mechanical properties of electrodeposits increased as the P content in electrodeposits increase. The results of mechanical properties were explained by grain size and P solid solution effect. The effects of heat treatment on mechanical properties of Ni-P alloy coatings were also studied.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권8호
• /
• pp.1082-1087
• /
• 2014

Thirty-two lambs were distributed in eight treatments under $2{\times}2{\times}2$ factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

• Geomechanics and Engineering
• /
• 제17권5호
• /
• pp.465-473
• /
• 2019

Biocementation due to the microbially induced calcium carbonate precipitation (MICP) process is a potential technique that can be used for soil improvement. However, the effect of biocementation may be affected by many factors, including nutrient concentration, bacterial strains, injection strategy, temperature, pH, and soil type. This study investigates mainly the effect of chemical concentration on the formation of calcium carbonate (e.g., quantity, size, and crystalline structure) and unconfined compressive strength (UCS) using different treatment time and chemical concentration in the biotreatment. Two chemical concentrations (0.5 and 1.0 M) and three different treatment times (2, 4, and 8 cycles) were studied. The effect of chemical concentrations on the treatment was also examined by making the total amount of chemicals injected to be the same, but using different times of treatment and chemical concentrations (8 cycles for 0.50 M and 4 cycles for 1.00 M). The UCS and CCC were measured and scanning electron microscopy (SEM) analysis was carried out. The SEM images revealed that the sizes of calcium carbonate crystals increased with an increase in chemical concentrations. The UCS values resulting from the treatments using low concentration were slightly greater than those from the treatments using high concentration, given the CCC to be more or less the same. This trend can be attributed to the size of the precipitated crystals, in which the cementation efficiency increases as the crystal size decreases, for a given CCC. Furthermore, in the high concentration treatment, two mineral types of calcium carbonate were precipitated, namely, calcite and amorphous calcium carbonate (ACC). As the crystal shape and morphology of ACC differ from those of calcite, the bonding provided by ACC can be weaker than that provided by calcite. As a result, the conditions of calcium carbonate were affected by test key factors and eventually, contributed to the UCS values.

• Journal of Microbiology and Biotechnology
• /
• 제17권3호
• /
• pp.414-419
• /
• 2007

Botryococcus braunii is a green colonial fresh water microalga and it is recognized as one of the renewable resources for production of liquid hydrocarbons. CFTRI-Bb-l and CFTRI-Bb-2 have been reported for the first time and their performance with regard to growth and biochemical profile is presented here. The present study focused on effect of carbon dioxide $(CO_2)$ on biomass, hydrocarbon, carbohydrate production, fatty acid profile, and carotenoid content in various species of B. braunii (LB-572, SAG 30.81, MCRC-Bb, N-836, CFTRI-Bb-l, and CFTRI-Bb-2) at 0.5, 1.0, and 2.0% (v/v) levels using a two-tier flask. $CO_2$ at 2.0% (v/v) level enhanced growth of the organism, and a two-fold increase in biomass and carotenoid contents was observed in all the B. braunii strains studied compared with control culture (without $CO_2$ supplementation). At 1 % and 2% (v/v) $CO_2$ concentrations, palmitic acid and oleic acid levels increased by 2.5 to 3 folds in one of the strains of B. braunii (LB-572). Hydrocarbon content was found to be above 20% at 2% $CO_2$ level in the B. braunii LB-572, CFTRI-Bb-2, CFTRI-Bb-l, and N-836 strains, whereas it was less than 20% in the SAG 30.81 and MCRC-Bb strains compared with control culture. This culture methodology will provide information on $CO_2$ requirement for growth of algae and metabolite production. B. braunii spp. can be grown at the tested levels of $CO_2$ concentration without much influence on culture pH.

• Asian-Australasian Journal of Animal Sciences
• /
• 제26권6호
• /
• pp.896-904
• /
• 2013

Cattle breeds have a striking effect on milk, including milk composition and technological characteristics. This study aims to compare milk composition, acidification activity, viscosity, milk dispersion system stability and casein molecular weight among three buffalo breeds in China. The technological characteristics of milk produced by three cattle breeds of river buffalo (Murrah), crossbreed 1st generation ($F_1$), crossbreed multiple generation ($F_H$, $H{\geq}3$) buffaloes were investigated. Cattle breeds showed evident effect on milk protein, fat and total solids content, but little effect on most of buffalo casein molecular weight. Milk fat, protein content and the viscosity of buffalo milk from river buffalo were lower than those of $F_1$ and $F_H$, so was the buffer capacity. The viscosity was negatively correlated to temperature and concentration. Results of stability coefficient showed that milk dispersion system had the best dynamic stability characteristics under pH 6.6 and 6 times dilution, while zeta potential of Murrah milk was slightly higher than that of hybrid offspring ($F_1$, $F_H$). SDS-PAGE results showed that buffalo ${\alpha}_s$-casein had a slightly faster mobility than standard ${\alpha}_s$-casein; while buffalo ${\beta}$-casein showed a slightly slower mobility than standard ${\beta}$-casein. There is no clear differences in molecular weight of ${\alpha}_s$-, ${\beta}$-, and ${\kappa}$-casein among Murrah, $F_1$ and $F_H$.

• 한국미생물·생명공학회지
• /
• 제49권2호
• /
• pp.181-191
• /
• 2021

The present study addresses isolation, optimization, partial purification, and characterization of a haloalkaline serine protease from a newly isolated haloarchaeal strain isolated from Wadi El Natrun in Egypt. We expected that a two-step sequential statistical approach (one variable at a time, followed by response surface methodology) might maximize the production of the haloalkaline serine protease. The enzyme was partially purified using Hiprep 16/60 sephacryl S-100 HR gel filtration column. Molecular identification revealed the newly isolated haloarchaeon to be Natrialba hulunbeirensis strain WNHS14. Among several tested physicochemical determinants, casamino acids, KCl, and NaCl showed the most significant effects on enzyme production as determined from results of the One-Variable-At-A-time (OVAT) study. The BoxBehnken design localized the optimal levels of the three key determinants; casamino acids, KCl, and NaCl to be 0.5% (w/v), 0.02% (w/v), and 15% (w/v), respectively, obtaining 62.9 U/ml as the maximal amount of protease produced after treatment at 40℃, and pH 9 for 9 days with 6-fold enhancement in yield. The enzyme was partially purified after size exclusion chromatography with specific activity, purification fold, and yield of 1282.63 U/mg, 8.9, and 23%, respectively. The enzyme showed its maximal activity at pH, temperature, and NaCl concentration optima of 10, 75℃, and 2 M, respectively. Phenylmethylsulfonyl fluoride (PMSF, 5 mM) completely inhibited enzyme activity.