• 제목/요약/키워드: Operating efficiency

Search Result 3,523, Processing Time 0.032 seconds

Experimental Study on Moisture Content According to Addition of Surfactants (계면활성제 첨가에 따른 함수율에 관한 실험적 연구)

  • Kim, Nam-Kyun;Rie, Dong-Ho
    • Fire Science and Engineering
    • /
    • v.29 no.2
    • /
    • pp.79-83
    • /
    • 2015
  • The fire accident is a representative type of disaster that can largely impact on business. Therefore, precautionary measures and rapid initial response is very important when a disaster occurs. The storage of porous combustibles is inevitable in coal yard, plywood processing industry, and others that are currently operating. Initial fire fighting of fire and identifying the ignition point in such a porous combustible storage space are so difficult that if the initial response is failed, being led to deep-seated fire, surface fire is likely to result in secondary damage. In addition, deep-seated fire can cause personal injuries and property damage due to a large amount of toxic gases and reignition. Therefore damage reduction measures is required around the storage space to handle a porous flammable. Improving the penetration performance of the concentration of the surfactant is carried out as underlying study, which is about an deep-seated fire extinguishing efficiency augmentation when using wetting agents. The porous materials used in the experiments is radiata pine wood flour, which occupies more than 75% of the domestic wood market. Fire fighting water is selected as Butyl Di Glycol (BDG), which is being used for infiltration extinguishing agent, and the experiment was carried out by producing a standard solution. The experiment was carried out on the basis of the Deep-Seated Fire Test of NFPA 18. The amount of watering, porous material to the internal amount of penetration, and runoff measurement out of the porous material was conducted. According to experimental results, as the surface tension is reduced, the surfactant concentration macroscopic penetration rate decreases, but infiltration to a porous material is shown to have growth characteristics.

Effect of the Addition of Granular Activated Carbon and Granular Sludge on the Performance of Upflow Anaerobic Sludge Blanket Reactors for Treating Leachate (상향류 혐기성 슬러지 블랭킷 반응조를 이용한 침출수 처리시 입상 활성탄 및 입상슬러지 첨가의 영향)

  • Lee, Chae-Young
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.16 no.4
    • /
    • pp.91-97
    • /
    • 2008
  • The objective of this research is to investigate the effect of the addition of granular activated carbon (GAC) and granular sludge on the performance of upflow anaerobic sludge blanket (UASB) reactors for treating leachate. For the control reactor, sludge obtained from an anaerobic digester was used as a seed material. On the other hand, GAC and granular sludge were incorporated with the seed sludge in the GAC reactor and the Granule reactor, respectively. The shortest acclimation period was observed in the Granule reactor. The GAC reactor also gave comparable performance to the Granule reactor at the beginning of operation. However, as the adsorptive capacity of GAC was exhausted, the effluent COD concentration increased gradually. Once the systems were stabilized, the GAC reactor showed slightly better results than the other two reactors in terms of chemical oxygen demand (COD) removal. COD removal in all reactors was more than 90% at hydraulic retention time of 1.0 day. Furthermore, GAC reactor showed little variation in COD removal rate and remained at 95% with organic loading rate (OLR) of 4.0 to $8.2kg\;COD/m^3.d$. Initial operating period was reduced by the addition of granular sludge, while the treatment efficiency was enhanced by the addition of GAC.

  • PDF

Private Procurement for Constructions and Operation of Buman Road in Daegu (도시 인프라 시설을 위한 민자 유치 -대구시 범안로 민자도로의 운영 실태와 대책-)

  • Choi, Byung-Doo
    • Journal of the Korean association of regional geographers
    • /
    • v.13 no.6
    • /
    • pp.674-694
    • /
    • 2007
  • Recently private procurement projects for urban infrastructure have been emphasized and introduced by government(both central and local) as an important method to supplement public budget shortage and to improve creativity and efficiency in its construction and operation, and hence to promote regional development. But these private procurement projects seem to be implemented under the neoliberal condition of urban policy for private capital to extend its sphere of investment and to ensure its opportunity of profit. Such private procurement projects for urban infrastructure have been legislated and widely applied since 1994 in S. Korea, but in recent years they have triggered out a variety of serious problems. In results of this study on the private procurement for construction and operation of Burnan Road in Daegu, it can be pointed out, it has led serious problems such as overestimation of traffic volume in plan, over-appropriation of construction cost and appurtenant business, irYational operation and account of the operating firm, problem in refinancing and change in contents of practical agreement, and over-compensation of minimum operation revenue. Some measures that can be considered as alternatives to resolve those problems and to operate more rationally the Buman Road include those of increasing traffic revenues, of reducing supports of public financing, and withdrawal of (part or whole of) operational right from the private firm.

  • PDF

Characterization of Denitrifier Community in Independent Anoxic Reactor Using Modified BAF Process (Modified BAF 공정을 이용한 독립적인 무산소조에서 탈질미생물 군집의 특성)

  • Park, Jeung-Jin;Jeung, Young-Rok;Yu, Jae-Cheul;Hur, Sung-Ho;Choi, Won-Seok;Byun, Im-Gyu;Lee, Tae-Ho;Park, Tae-Joo
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.28 no.7
    • /
    • pp.752-756
    • /
    • 2006
  • The independent anoxic reactor was introduced in biological aerated filters as the regulation of water quality requirement, especially total nitrogen, had been strengthened. The process studied in this work was upflow $Biobead^{(R)}$ process which was used commercial invented for removal of organic materials and nitrification. For the purpose of evaluating the independent anoxic reactor, PCR-DGGE, of the molecular biological methods, was performed. Two types of nitrite reductase genes were selected. One is nirS represented cytocrome $cd_1$ nitrite reductase gene and the other is nirK represented Cu-containing nitrite reductase gene. Denitrifier community in the independent anoxic reactor was analyzed with PCR-DGGE using these two denitrifying functional genes. As the result of the PCR, only nirS gene was detected between nirS and nirK. With the result of the DGGE, specific bands became strong, as the operating days were longer, nitrate loading rate was increased. otherwise those of the initial activated sludge showed various bands. In the consequence of the sequence of DGGE bands, various denitrifiers were sequenced in the initial activated sludge, while specific denitrifiers like alcaligenes faecalis were predominant in the anoxic reactor. Consequently, introduction of the independent anoxic reactor made it possible to achieve 96% denitrification efficiency, and was proper for the modification of BAF process.

Organizational Culture Difference of Social Enterprises and Commercial Enterprises, and Impact Relations on Social and Economic Outcomes (사회적기업과 영리기업간 조직문화차이와 조직성과에 미치는 영향)

  • Kim, Mi-Hwa;Lee, Yong-Jae
    • The Journal of the Korea Contents Association
    • /
    • v.16 no.12
    • /
    • pp.667-676
    • /
    • 2016
  • The purpose of study was to determine the differences in organizational culture between social enterprises and commercial enterprises and assess the impact on organizational performance in Korea. Main results are as follows. First, Social enterprises employ a lot of low-imcome women and the elderly worker. Second, rational culture is high in profit businesses, but cultural group is high in social enterprises. In commercial enterprise, productivity and efficiency, planning and goal setting, assessing goals and looking for the evaluation of the performance are important. and in social enterprise, affinity and participation, employees individual development and group morale and cohesion, emphasis on mutual cooperation and trust are important. In addition, both social performance and economic performance, social enterprises are higher than in commercial enterprises. Social enterprises are operating transparently based on workers participation and understanding is expected that economic performance is also highly recognized. Third, social performance is higher development and group culture are higher in commercial enterprises, and development, group and hierarchy culture are higher in social enterprises. Economic performance is higher reasonal culture is lower in commercial enterprises, and group culture is higher in social enterprises. Therefore, the social enterprise workers are recognizing social and economic performance are higher than commercial enterprise workers. In short, social enterprises is making discriminatory organizational culture, and this is contributing to achieving organizational performance.

Extraction of Pigment from Sea Mustard ( Undaiia pinnatinda) using Supercritical Carbon Dioxide and Entrainer (초임계 이산화탄소와 보조용매를 이용한 미역으로부터 색소 추출)

  • HONG Seok-Ki;CHUN Byung-Soo;PARK Sun-Young
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.34 no.3
    • /
    • pp.213-217
    • /
    • 2001
  • In order to develop a new separation technology, supercritical fluid extraction process was used to produce high purity pigments and fatty acids from seaweed (Undaria pinnatifida). Supercritical carbon dioxide was used as a solvent and ethanol as an entrainer. The sample was treated by a frozen drier and experiments were conducted with a semi-batch flow system at various operating conditions (pressure range, $10.3\~17.2$ MPa; temperature range, $30\~45^{\circ}C$: particle size, $500\~1,000{\mu}m$ extraction time, 60 min). Characteristics of the recovered pigment (chlorophyll a) and fatty acids were determined by UV-spectrophotometry and gas chromatography, respectively. The highest extraction efficiency for fatty acids and pigments was achieved at 12.4 MPa, $35^{\circ}C$, $500{\mu}m$of seaweed size.

  • PDF

Development of a Model of a Day Care Center for Rural Elderly People (농촌형 노인 주간보호시설 모형개발)

  • Kang, Kyung-Sook
    • Research in Community and Public Health Nursing
    • /
    • v.15 no.4
    • /
    • pp.551-565
    • /
    • 2004
  • Purpose: The purpose of this study is to develop a day care center model focused on public health institutions for the elderly residing in their homes. Method: Research design for this study was a mult-level research, which consisted of a related literature review, an Internet search for knowledge of the current situation at home and abroad, on-site interviews, questionnaires collected from a sample of residents in a rural area, and a key-informants approach. Results: 1) The subjects of service - Generalized service should be provided to the elderly, 65 years and older, regardless of their assets. 2) The contents of service - Providing pre-health oriented and post-social welfare service that can integrate and satisfy a wide variety of public health and welfare needs of the elderly would strengthen the health care service of a day care center for the elderly. 3) Delivery system - Basic-level local self-governments should become a central operating body, and establishing a properly adjusted delivery system to a rural area after considering the efficiency and the access of vulnerable rural areas is needed based on modification of 'a Special Law for Agricultural and Fishery Areas' (rural public health center>rural health sub-center ${\rightarrow}$ unified health sub-center ${\rightarrow}$ public health hospital (public health center) ${\rightarrow}$ public welfare office). 4) Facility - Public health facilities such as public health centers and sub-centers should be located in areas that can easily access the facilities. 5) Funding - For day care center for the elderly in local self-government, the central government should modify a relevant implementation of subsidy in and provide some facilities and service regardless of the degree of self reliance of local self-government. 6) Human resources - It is needed to guarantee the period of workers of a day care center for the elderly, at least 3 to 5 years, with considering their specialty on aged care and avoiding circulation based positions. Furthermore, appropriate specially trained personnel such as medical workers and social workers should be placed to take care of both health service and welfare through strengthening of 'rules of law of elderly welfare,' Conclusion: future research is needed to test the model through a demonstration study using a model which may be developed in the future and to standardize the appraisal criteria of people hoping to enter a day care center for the elderly.

  • PDF

A Study on the Legal Issues of Proposed Korean Airport Facility Act (공항시설법 제정(안)의 내용과 쟁점)

  • Kim, Tae-Han
    • The Korean Journal of Air & Space Law and Policy
    • /
    • v.26 no.2
    • /
    • pp.101-124
    • /
    • 2011
  • Since 1961, Aviation Act has regulated all aspects related to air transport business, aviation safety and airport. However, we are to face the new challenges that have to support air transport business more efficiently and air transportation services to the people effectively in condition of the globally competitive air transport industry. In this sense, the government proposed to devide "Aviation Act" into 'Air Transport Business Act', 'Aviation Safety Act', 'Airport Facility Act' in a timely manner. At first I am to take a look about the laws of traffic-related legislation and national laws of Japanese aviation system, and to evaluate implications. In addition, the background, the organization and the main information of the Act (Draft) will be introduced. And I would like to discuss the issues raised and suggest an alternative. In particular, the name of the Act (Draft), the specifying of airport manager operater, accounting method of airport development projects belong to the nation, the delegation of the authority and other issues are discussed to provide a starting point. In conclusion, the division of current "Aviation Act" is considered absolutely necessary. To stimulate fair competition, safety regulations and efficiency, the legislation process would be desirable in the direction of the total development of the aviation industry as well as ensuring aviation safety.

  • PDF

Simulation and Control of the Molten Carbonate System using Aspen $Dynamics^{TM}$ and ACM (Aspen $Dynamics^{TM}$와 ACM을 이용한 용융탄산염 연료전지 시스템의 모사 및 제어)

  • Jeon, Kyoung Yein;Kwak, Ha Yeon;Kyung, Ji Hyun;Yoo, Ahrim;Lee, Tae Won;Lee, Gi Pung;Moon, Kil Ho;Yang, Dae Ryook
    • Korean Chemical Engineering Research
    • /
    • v.49 no.4
    • /
    • pp.423-431
    • /
    • 2011
  • Recentincreasing awareness of the environmental damage caused by the $CO_2$ emission of fossil fuelsstimulated the interest in alternative and renewable sources of energy. Fuel cell is a representative example of hydrogen energy utilization. In this study, Molten Carbonate Fuel Cell system is simulated by using $Aspen^{TM}$. Stack model is consisted of equilibrium reaction equations using $ACM^{TM}$(Aspen Custom Modeler). Balance of process of fuel cell system is developed in Aspen $Plus^{TM}$ and simulated at steady-state. Analysis of performance of the system is carried out by using sensitivity analysis tool with main operating parameters such as current density, S/C ratio, and fuel utilization and recycle ratio.In Aspen $Dynamics^{TM}$, dynamics of MCFC system is simulated with PID control loops. From the simulation, we proposed operation range which generated maximum power and efficiency in MCFC power plant.

Recovery of Intracellular Enzyme Using Phage Lysogen and Expanded Bed Adsorption (Phage Lysogen과 Expanded Bed Adsorption을 이용한 세포내 효소의 회수)

  • 장우진;윤현식구윤모
    • KSBB Journal
    • /
    • v.11 no.6
    • /
    • pp.663-668
    • /
    • 1996
  • In the production of recombinant protein using E. coli, phage lysogen system can be usefully applied for simultaneously achieving protein production at high cell concentration and recovery by cell disruption in the same bioreactor. A major drawback of this system is that the intracellular product and complex broth components are mixed together in culture broth and hence purification efficiency is reduced. With the E. coli double-lysogen system, the expanded bed adsorption is very useful because the pretreatment processes in a routine bioseparation process can be done in a single column operation, and therefore may contribute towards lowering the operating cost of overall recovery/purification process. In the operation of EBA, it has been observed that the change in broth feed volume does not influence much the protein recovery in a tested range. The amount of protein adsorption per mL of resin was increased from $3.44{\times}106unit to 5.28{\times}106unit$ by doubling the column length. By two-fold increase of the column diameter, the ratio of protein concentration in eluent to that in feed was increased from 0.8 to 2.1. It is concluded from the present investigation that the increase of column length and diameter is necessary to enhance the protein adsorption amount per volume of resin and protein concentration in the eluent. The development of resins with various physical properties will be necessary for more extensive application of EBA.

  • PDF