• Title/Summary/Keyword: Screening condition

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Studies on the Petroleum hydrocarbon-utilizing Microorganisms(Part 1) -On the Production of Protein from the Yeast-cell- (석유(탄화수소) 이용미생물에 관한 연구(제 1보) -효모세포에 의한 석유로부터 단백질 생성에 관하여-)

  • Lee, Ke-Ho;Shin, Hyun-Kyung
    • Applied Biological Chemistry
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    • v.13 no.1
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    • pp.43-50
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    • 1970
  • To study the productivity of single cell protein from the petroleum hydrocarbon utilizing yeasts, 242 soil samples, such as oil soaked soil of gas stations and garage, coal, farm soil, and sewage, from 135 places in Korea were collected. From these samples 468 yeast strains which utilize petroleum hydrocarbon as a sole organic carbon source were isolated and identified by observing the growth rates. For the identified strains optimum culture conditions were determined and analysis of cell components were performed. 1. 90.8% of petroleum hydrocarbon utilizing yeast strains were found from oil soaked soil and about 10% from coal, farm soil and sewage etc. 2. The yeast strain of the highest cell productivity was isolated from oil soaked soil and was identified as Candida curvata HY-69-19. 3. The optimum culture conditions for the selected yeast strain were found to be pH 5.0, $28^{\circ}C$ and affluent aerated state. 4. Candida curvata HY-69-19 was found to utilize favorably the heavy gas oil fractionated at above $268.9^{\circ}C$ as carbon source and urea as inorganic nitrogen source. 5. The growth curve of this strain on heavy gas oil medium showed that the yeast has a lag phase up to 18 hours and logarithmic growth phase between 24 to 42 hours. Generation time was found to be between 3.8 and 4.5 hours during the logarithmic growth phase. 6. About 300 mg dried cells per heavy gas oil was harvested under the culture conditions of adjusted pH to 5.0 at time intervals of 6 hours for 54 hours and heavy gas oil urea for shaking culture medium. 7. Chemical composition of the yeast cell was found to be 40.25%, 14.81%, 24.32% and 10.63% for crude protein, crude lipid, carbohydrate and ashes, respectively.

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Screening of the Optimum Filter Media in the Constructed Wetland Systems through Phosphorus Adsorption Capacities (인의 흡착능 평가를 통한 인공습지 하수처리 시스템의 여재 선발)

  • Lee, Hong-Jae;Seo, Dong-Cheol;Cho, Ju-Sik;Heo, Jong-Soo
    • Korean Journal of Environmental Agriculture
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    • v.22 no.2
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    • pp.148-152
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    • 2003
  • The phosphorus(P) adsorption capacities of various filter media were investigated in relation to the size and types of fitter media to screen the optimum condition. The objective of this study was to evaluate the constructed wetland longevity by improving P adsorption capacity. The maximum P adsorption capacities of filter media A($4{\sim}10\;mm$), B($2{\sim}4\;mm$) and C($0.1{\sim}2\;mm$) were 8, 10 and 22 mg/kg, respectively, showing those increased as the filter media size decreased. Among the experimental media, the optimum filter media size was $0.1{\sim}2\;mm$. When the filter Medium was supplemented with organic materials which were piled up and decayed in the constructed wetland, the P adsorption capacity was significantly enhanced Under the conditions of optimum fitter media size, the respective Maximum P adsorption capacities of filter media C when supplemented with Ca, Mg, Al and Fe were higher than that of filter media C. However the addition of Ca, Mg, Al and Fe to constructed wetland were not recommended because of the possibility of their secondary pollution. The maximum P adsorption capacity of filter media C was 22 mg/kg, but this was increased to 36 mg/kg when filter media C was supplemented with 2% oyster shell.

Production of Conjugated Linoleic Acid by Lactobacillus acidophilus Isolated from Breast-Fed Infants (모유 섭취 신생아 유래 Lactobacillus acidophilus에 의한 Conjugated Linoleic Acid 생성)

  • Park, Jeong-Gyu;Song, Won-Ho;Hong, Sung-Moon;Kim, Cherl-Hyun
    • Food Science of Animal Resources
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    • v.28 no.5
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    • pp.580-586
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    • 2008
  • Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of linoleic acid with conjugated double bonds. These conjugated dienes were found to be responsible for many biological properties related to health. The objective of this study was to evaluate the production of cis-9, trans-11 CLA by Lactobacillus acidophilus isolated from breast-fed infants. Nine different cultures were tested for their ability to produce cis-9, trans-11 CLA from free linoleic acid in MRS broth and 8% reconstituted skim milk medium supplemented with linoleic acid at $37^{\circ}C$ for 48 hr. cis-9, trans-11 CLA was not detected or detected in very small amount when cell pellets of strains grown in MRS broth and 8% reconstituted skim milk supplemented with linoleic acid of $200{\mu}g/mL$. However, free cis-9, trans-11 CLA was produced in both media. It appeared that 8% reconstituted skim milk produced more cis-9, trans-11 CLA than MRS broth. L. acidophilus NB 203 and NB 209 produced more cis-9, trans-11 CLA than other tested cultures. The inhibitory effects of supplemented linoleic acid on the growth of L. acidophilus NB 203 and NB 209 were not detected up to $3,000{\mu}g/mL$ linoleic acid addition during the growth at $37^{\circ}C$ for 48 h. The production of cis-9, trans-11 CLA by these two L. acidophilus strains increased in the logarithmic growth phase until 24 hr incubation. Under this experimental condition, the best yield of CLA isomers for L. acidophilus NB 203 and NB 209 could be obtained from medium supplemented with $500{\mu}g/mL$ linoleic acid at $37^{\circ}C$ after 24 hr of incubation. These results indicate that the use of lactic acid bacteria producing free CLA in fermented dairy products may have potential health or nutritional benefits.

Screening of Adsorbent to Reduce Salt Concentration in the Plastic Film House Soil under Continuous Vegetable Cultivation (시설채소재배지의 토양특성과 흡착제 종류별 염류경감 효과)

  • Ok, Yong-Sik;Yoo, Kyung-Yoal;Kim, Yoo-Bum;Chung, Doug-Young;Park, Yong-Ha;Yang, Jae-E.
    • Korean Journal of Environmental Agriculture
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    • v.24 no.3
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    • pp.253-260
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    • 2005
  • Salt accumulation in the plastic film house soils under continuous cultivation condition causes problems such as salt damages to plants, nitrate accumulation in vegetables, groundwater contamination, etc. due to excess application of fertilizers. Objective of this research was to find an optimum adsorbent to reduce salt concentration in the soil solution of plastic film house soils, where crop injuries have been observed due to the salt accumulation. The soils were significantly high in available P $(1,431{\sim}6,516mg\;kg^{-1}),\;NO_3-N\;(117.60{\sim}395.73mg\;kg^{-1})$, exchangeable Ca $(4.06{\sim}11.07\;cmol_c\;kg^{-1})$ and Mg $(2.59{\sim}18.76\;cmol_c\;kg^{-1})$, as compared to those of the average upland soils in Korea. Soils were treated with each of adsorbent such as ion-exchange resin, zeolite, rice bran, etc. at 2% level and prepared into saturated-paste samples. After equilibrium, soil solution was vacuum-extracted from the soil and measured for changes of the pH, EC, and concentrations of $Ca^{2+},\;Mg^{2+},\;K^+,\;Na^+,\;{NH_4}^+,\;{PO_4}^{3-}\;and\;{NO_3}^-$. Rice bran effectively removed ${PO_4}^{3-}\;and\;{NO_3}^-$ in the soil solution up to 100%. Efficiency was decreased in the orders of rice bran > ion-exchange resin > zeolite. Removal efficiencies of zeolite and ion-exchange resin for $Ca^{2+}$ were ranged from 1 to 65% and from 7 to 61%, respectively. Ion-exchange resin was also effective for removing $Mg^{2+},\;K^+,\;Na^+,\;and\;{NH_4}^+$. Overall results demonstrated that rice bran and ion-exchange resin could be applicable for salt accumulated soil to remove the respective anion and cation.

Characterization of Chitin Deacetylase Produced from Mucor rouxii (Mucor rouxii가 생산한 Chitin deacetylase의 특성)

  • SOHN Heung-Sik;PARK Seong-Min;SON Byung-Yil;CHOI Hyeon-Mee;LEE Keun-Tai
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.2
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    • pp.121-126
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    • 1999
  • In order to degrade chitin by enzymatic hydrolysis, it is required from screening highly active deacetylase. To this end, we examined three fungal strains and it turned out that Mucor rouxii produced highly active deacetylase, this enzyme exhibited the highest enzymatic activity against colloidal chitin. The conditions for growing Mucor rouxii are as follows; the effective carbon source, nitrogen source, adequate initial pH, temperature and incubation time were $2\%$ glucose, $1.33\%$ yeast extract, $0.66\%$ pepton, 4.5, $25{\pm}2^{\circ}C$ and 48hr, respectively. The optimum pH and temperature for purified enzyme activity were 5.5 and $40^{\circ}C$, respectively. The purified enzyme was stable at pH ranging from 4.5 to 5.5. However, the enzyme activity was decreased to less than $50\%$ at pH blow 45 and above 7.5. At temperatures above $50^{\circ}C$, the enzyme activity was decreased remarkably. The enzyme was inhibited by LiC1, $HgCl_2$, and $BaCl_2$, but stimulated by $CaCl_2$ and $ZnC1_2$, The activity of purified enzyme was increased by L-cysteine and 2-mercaptoethanol, while decreased by O-phenanthroline, p-CMB, EDTA, and iodoacetate. The $K_m$ and the $V_{max}$ value of purified enzyme were $1.2\%$ and 59.5 U/mg, respectively. The deacetylation activity of purified enzyme was not detected at optimal reaction condition when chitin particle suspension was used.

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Improvement Strategy & Current Bidding Situation on Apartment Management of Landscape Architecture (공동주택 조경관리 입찰 실태와 개선방안)

  • Hong, Jong-Hyun;Park, Hyun-Bin;Yoon, Jong-Myeone;Kim, Dong-Pil
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.4
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    • pp.41-54
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    • 2020
  • This study was conducted to provide basic data for a transparent and fair bidding system by identifying problems and suggesting improvement measures through an analysis of the bidding status for construction projects and service-related landscaping of multi-family housing. To this end, we used the data from the "Multi-Family Housing Management Information System (K-apt)" that provides the history of apartment maintenance, bidding information, and the electronic bidding system to examine the winning bid status and amount, along with the size and trends of the winning bids by year, and the results of the selection of operators by construction type. As a result, it was found that out of the total number of successful bids (36,831), 4.4% (16,631) were in the landscaping business, and the average winning bid value was found to be about 24 million won. According to the data, 73% of the landscaping cases were valued between 3 million won and 30 million won, and 58.6% of the cases were in the field of "pest prevention and maintenance". 36% of the total number of bids were awarded from February to April, with "general competitive bidding" accounting for 59.8% of the bidding methods. As for the method of selecting the winning bidder, 55% adopted the "lowest bid" and "electronic bidding method," and 45% adopted the "qualification screening system" and "direct bidding method." As an improvement to the problems derived from the bidding status data, the following are recommended: First, the exception clause to the current 'electronic bidding method' application regulations must be minimized to activate the electronic bidding method so that a fair bidding system can be operated. Second, landscaping management standards for green area environmental quality of multi-family housing must be prepared. Third, the provisions for preparing design books, such as detailed statements and drawings before the bidding announcement, and calculating the basic amount shall be prepared so that fair bidding can be made by specifying the details of the project concretely and objectively must be made. Fourth, for various bidding conditions in the 'business operator selection guidelines', detailed guidelines for each condition, not the selection, need to be prepared to maintain fairness and consistency. These measures are believed to beuseful in the fair selection of landscaping operators for multi-family housing projects and to prepare objective and reasonable standards for the maintenance of landscaping facilities and a green environment.

Research Framework for International Franchising (국제프랜차이징 연구요소 및 연구방향)

  • Kim, Ju-Young;Lim, Young-Kyun;Shim, Jae-Duck
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.4
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    • pp.61-118
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    • 2008
  • The purpose of this research is to construct research framework for international franchising based on existing literature and to identify research components in the framework. Franchise can be defined as management styles that allow franchisee use various management assets of franchisor in order to make or sell product or service. It can be divided into product distribution franchise that is designed to sell products and business format franchise that is designed for running it as business whatever its form is. International franchising can be defined as a way of internationalization of franchisor to foreign country by providing its business format or package to franchisee of host country. International franchising is growing fast for last four decades but academic research on this is quite limited. Especially in Korea, research about international franchising is carried out on by case study format with single case or empirical study format with survey based on domestic franchise theory. Therefore, this paper tries to review existing literature on international franchising research, providing research framework, and then stimulating new research on this field. International franchising research components include motives and environmental factors for decision of expanding to international franchising, entrance modes and development plan for international franchising, contracts and management strategy of international franchising, and various performance measures from different perspectives. First, motives of international franchising are fee collection from franchisee. Also it provides easier way to expanding to foreign country. The other motives including increase total sales volume, occupying better strategic position, getting quality resources, and improving efficiency. Environmental factors that facilitating international franchising encompasses economic condition, trend, and legal or political factors in host and/or home countries. In addition, control power and risk management capability of franchisor plays critical role in successful franchising contract. Final decision to enter foreign country via franchising is determined by numerous factors like history, size, growth, competitiveness, management system, bonding capability, industry characteristics of franchisor. After deciding to enter into foreign country, franchisor needs to set entrance modes of international franchising. Within contractual mode, there are master franchising and area developing franchising, licensing, direct franchising, and joint venture. Theories about entrance mode selection contain concepts of efficiency, knowledge-based approach, competence-based approach, agent theory, and governance cost. The next step after entrance decision is operation strategy. Operation strategy starts with selecting a target city and a target country for franchising. In order to finding, screening targets, franchisor needs to collect information about candidates. Critical information includes brand patent, commercial laws, regulations, market conditions, country risk, and industry analysis. After selecting a target city in target country, franchisor needs to select franchisee, in other word, partner. The first important criteria for selecting partners are financial credibility and capability, possession of real estate. And cultural similarity and knowledge about franchisor and/or home country are also recognized as critical criteria. The most important element in operating strategy is legal document between franchisor and franchisee with home and host countries. Terms and conditions in legal documents give objective information about characteristics of franchising agreement for academic research. Legal documents have definitions of terminology, territory and exclusivity, agreement of term, initial fee, continuing fees, clearing currency, and rights about sub-franchising. Also, legal documents could have terms about softer elements like training program and operation manual. And harder elements like law competent court and terms of expiration. Next element in operating strategy is about product and service. Especially for business format franchising, product/service deliverable, benefit communicators, system identifiers (architectural features), and format facilitators are listed for product/service strategic elements. Another important decision on product/service is standardization vs. customization. The rationale behind standardization is cost reduction, efficiency, consistency, image congruence, brand awareness, and competitiveness on price. Also standardization enables large scale R&D and innovative change in management style. Another element in operating strategy is control management. The simple way to control franchise contract is relying on legal terms, contractual control system. There are other control systems, administrative control system and ethical control system. Contractual control system is a coercive source of power, but franchisor usually doesn't want to use legal power since it doesn't help to build up positive relationship. Instead, self-regulation is widely used. Administrative control system uses control mechanism from ordinary work relationship. Its main component is supporting activities to franchisee and communication method. For example, franchisor provides advertising, training, manual, and delivery, then franchisee follows franchisor's direction. Another component is building franchisor's brand power. The last research element is performance factor of international franchising. Performance elements can be divided into franchisor's performance and franchisee's performance. The conceptual performance measures of franchisor are simple but not easy to obtain objectively. They are profit, sale, cost, experience, and brand power. The performance measures of franchisee are mostly about benefits of host country. They contain small business development, promotion of employment, introduction of new business model, and level up technology status. There are indirect benefits, like increase of tax, refinement of corporate citizenship, regional economic clustering, and improvement of international balance. In addition to those, host country gets socio-cultural change other than economic effects. It includes demographic change, social trend, customer value change, social communication, and social globalization. Sometimes it is called as westernization or McDonaldization of society. In addition, the paper reviews on theories that have been frequently applied to international franchising research, such as agent theory, resource-based view, transaction cost theory, organizational learning theory, and international expansion theories. Resource based theory is used in strategic decision based on resources, like decision about entrance and cooperation depending on resources of franchisee and franchisor. Transaction cost theory can be applied in determination of mutual trust or satisfaction of franchising players. Agent theory tries to explain strategic decision for reducing problem caused by utilizing agent, for example research on control system in franchising agreements. Organizational Learning theory is relatively new in franchising research. It assumes organization tries to maximize performance and learning of organization. In addition, Internalization theory advocates strategic decision of direct investment for removing inefficiency of market transaction and is applied in research on terms of contract. And oligopolistic competition theory is used to explain various entry modes for international expansion. Competency theory support strategic decision of utilizing key competitive advantage. Furthermore, research methodologies including qualitative and quantitative methodologies are suggested for more rigorous international franchising research. Quantitative research needs more real data other than survey data which is usually respondent's judgment. In order to verify theory more rigorously, research based on real data is essential. However, real quantitative data is quite hard to get. The qualitative research other than single case study is also highly recommended. Since international franchising has limited number of applications, scientific research based on grounded theory and ethnography study can be used. Scientific case study is differentiated with single case study on its data collection method and analysis method. The key concept is triangulation in measurement, logical coding and comparison. Finally, it provides overall research direction for international franchising after summarizing research trend in Korea. International franchising research in Korea has two different types, one is for studying Korean franchisor going overseas and the other is for Korean franchisee of foreign franchisor. Among research on Korean franchisor, two common patterns are observed. First of all, they usually deal with success story of one franchisor. The other common pattern is that they focus on same industry and country. Therefore, international franchise research needs to extend their focus to broader subjects with scientific research methodology as well as development of new theory.

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