• Title/Summary/Keyword: must cell

Search Result 681, Processing Time 0.024 seconds

Enzymatic Hydrolysis of Cellulose (섬유소(纖維素)의 당화(糖化))

  • Lee, Kye-Joon
    • Korean Journal of Pharmacognosy
    • /
    • v.7 no.2
    • /
    • pp.85-93
    • /
    • 1976
  • Since cellulose is the only organic material that is annually replenishable in very large quantities, we must explore ways to utilize it as a source of energy, food and chemicals. For the utilization of this resource, it is first enzymatic hydrolyzed to glucose, then the glucose can be used as a food, converted single cell protein by microorganism, fermented to clean burning fuel and other chemicals. Cellulolytic enzyme, cellulase, consists of two or three major components, $C_1-cellulase$, $C_x-cellulase$ and ${\beta}-glucosidase$. $C_x-cellulase$ are fairly common but $C_1-cellulase$ are quite rare. Trichoderma viride is the best source of active cellulose, especially $C_1-enzyme$. Saccharification rate of cellulose in greatly influenced by the degree of crystallinity and extent of lignification. But by the pretreatment the substrate with cellulose swelling agent, delignifying reagent and physical treatment, the degree of saccharification is enhanced. Thus, glucose syrups of 2 to 10% concentration are realized from milled newspaper. The enzymatic hydrolysis of such energy rich material, such as cellulose, to glucose is technically feasible and practically achievable on a very large scale.

  • PDF

New Fungicides: Opportunities and Challenges - A Case Study with Dimethomorph

  • Spadafora, V. J.;Sieverding, E.
    • Proceedings of the Korean Society of Plant Pathology Conference
    • /
    • 1998.06a
    • /
    • pp.50-69
    • /
    • 1998
  • Dimethomorph is a novel fungicide with a high level of activity against diseases induced by certain Oomycetes, including fungal populations that are resistant to other products. In several ways, this fungicide illustrates the opportunities and challenges presented by many modern pesticides. The specific mode of action, which affects cell wall formation, is associated with a very high level of performance and low dose rates under field conditions. These low dose rates, combined with a low level of toxicity to non-target organisms present an outstanding safety profile. This same highly-specific mode of action, however, limits the spectrum of activity and suggests the need for a resistance management plan, both of which must be addressed in new product development. In addition, the biological and physiochemical properties of this, and other new products are not adequately described by the traditional classification of fungicides into“protectant”and“systemic”types. These unique profiles provide novel and useful products for disease control.

  • PDF

Determination of Electrode Potential in Micro Electrochemical Machining of Passive Metals (부동화 금속의 미세 전해 가공 시 전극 전위의 선정)

  • Nam Ho-Sung;Kim Bo-Hyun;Chu Chong-Nam;Park Byung-Jin
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.23 no.4 s.181
    • /
    • pp.146-152
    • /
    • 2006
  • In micro electrochemical machining (ECM), electrodes should be prevented from unfavorable oxide and Passive layer formation on the machined surface or overall corrosion of the entire surface. Generally, metal electrodes corrode, passivate or dissolve in the electrochemical cell according to the electrode potential. Therefore, each electrode must maintain its stable potential. Tn this paper, the stable electrode potentials of tool and workpiece were determined using the potentiodynamic polarization test and verified experimentally considering machining stability and surface quality. Stable workpiece electrode potentials of two different passive materials of 304 stainless steel and nickel were determined in the 0.1 M sulfuric acid. Experimental results show good machined surface and fast machining rate using the determined electrode potentials.

A Study on the Dielectric Breakdown Strength and Transparency of Dielectric Layer on the Discharge Electrodes in PDP (PDP에서 방전전극상의 유전층의 절연내력과 투명도에 관한 연구)

  • Lee, Sung-Hyun;Kim, Young-Kee;Chi, Sung-Won;Cho, Jung-Soo;Park, Chung-Hoo
    • Proceedings of the KIEE Conference
    • /
    • 1997.11a
    • /
    • pp.379-381
    • /
    • 1997
  • The dielectric layers in AC plasma display panel(AC PDP) are essential to the discharge cell structure, because they protect metal electrodes from sputtering by positive ion and from a sheath of wall charges which are essential to memory function of AC PDP. Furthermore, this layer should be transparent because the visible light must pass through the layer. In this paper, the dielectric breakdown strength and transparency of the dielectric layer on the discharge electrodes are studied. The variables in this test are the dielectric layer thickness, dielectric firing condition, gas pressure, species of gas and so on.

  • PDF

Low Handover Latency for WiBro Network

  • Tae Ryoo-Kyoo;Park Se-Jun;Roh Jae-Hoon
    • 한국정보통신설비학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.43-46
    • /
    • 2006
  • IEEE 802.16 WirelessMAN aiming to broadband wireless access (BWA) is evolving to 4G mobile communication system through the standardization of IEEE 802.16e supporting mobility on existing fixed WirelessMAN system. It is necessary for hand-over to provide seamless data service while MS (Mobile Station) moves to another BS (Base Station). Because the performance of handover affects packet loss or delay of any communications, it must consider low latency handover mechanism in packet based network. In this paper, we describes handover scheme of IEEE 802.16e with the cell edge interference problem and shows the way to solve the problem in frequency reuse one deployment. Our scheme reduces the handover latency and packet loss probability.

  • PDF

Tutorial on Drug Development for Central Nervous System

  • Yoon, Hye-Jin;Kim, Jung-Su
    • Interdisciplinary Bio Central
    • /
    • v.2 no.4
    • /
    • pp.9.1-9.5
    • /
    • 2010
  • Many neurodegenerative diseases, such as Alzheimer's and Parkinson's disease, are devastating disorders that affect millions of people worldwide. However, the number of therapeutic options remains severely limited with only symptomatic management therapies available. With the better understanding of the pathogenesis of neurodegenerative diseases, discovery efforts for disease-modifying drugs have increased dramatically in recent years. However, the process of translating basic science discovery into novel therapies is still lagging behind for various reasons. The task of finding new effective drugs targeting central nervous system (CNS) has unique challenges due to blood-brain barrier (BBB). Furthermore, the relatively slow progress of neurodegenerative disorders create another level of difficulty, as clinical trials must be carried out for an extended period of time. This review is intended to provide molecular and cell biologists with working knowledge and resources on CNS drug discovery and development.

Wafer Burn-in Method for SRAM in Multi Chip Package (Multi Chip Package의 SRAM을 위한 웨이퍼 Burn-in 방법)

  • Yoon, Jee-Young;Ryu, Jang-Woo;Kim, Hoo-Sung;Sung, Man-Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.18 no.6
    • /
    • pp.506-509
    • /
    • 2005
  • This paper presents the improved burn-in method for the reliability of SRAM in Multi Chip Package (MCP). Semiconductor reliability is commonly improved by the burn-in process. Reliability Problem is very significant in the MCP which includes over two chips in a package because the failure of one SRAM chip has a large influence on the yield and quality of the other chips such as Flash Memory, DRAM, etc. Therefore the quality of SRAM must be guaranteed. To improve the qualify of SRAM, we applied the improved wafer level burn-in process using multi cell selection method in addition to the previously used methods and it is found to be effective in detecting particular failures. Finally, with the composition of some kinds of methods, we achieved the high quality of SRAM in MCP.

The corrosion-resistant of Al-coated xstainless in molten carbonate (알루미늄 코팅처리 스테인레스강의 융탄산염 내부식성)

  • 조남웅;장세기;전재호;신정철
    • Journal of the Korean institute of surface engineering
    • /
    • v.31 no.1
    • /
    • pp.3-11
    • /
    • 1998
  • Molten Carbonate Fuel cell is a promising new type electric power generation system which can achieve high efficiency, lower matrrial cost and high operating temperature Making internal reforming possible. Although the development of the MCEC is progressing rapidly toward commercialization, two important tchological problems such as dissolution of NiO cathode and not corrosion of metallic separator plate must be resolved. Because MCFC is operated at $650^{\circ}C$ and the electrolyte is very corrosive, corrosion-resistance of separator plated against oxidation abd molten carbonate is required. Al-coating on separator material for corrosion-resistance was carried out by painting, thermal spraying. hot dipping and vacuum vapour deposition. The corrosion of Al-coated STS 316S and 316L in molten carbonate at $700^{\circ}C$was studied. Vacuum vapour deposition and thermal spraing for Al-coating on STS 310S and 316L were the most effective methods for protecting thestainless steel corrosion in molten carbonate.

  • PDF

Revolution of Dead-Cell: Production of New Generation by Intracytoplasmic Dried-Sperm Injection in Mammal

  • Kim, Duk-Im;Kim, Chang Jin;Lee, Kyung-Bon
    • Reproductive and Developmental Biology
    • /
    • v.39 no.3
    • /
    • pp.69-76
    • /
    • 2015
  • In a conventional sense, dried-spermatozoa are all dead and motionless due to the lost of their natural ability to penetrate oocytes both in vivo and in vitro. However, their nuclei are completely able to contribute to normal embryonic development even after long-term preservation in a dried state when the dried-spermatozoa are microinjected into the oocytes. In this sense, dried spermatozoa must still be alive. Thus, defining spermatozoa as alive or dead seems rather arbitrary. Several drying method of sperm including freeze-drying, evaporative/convective-drying and heat-drying were represented in this review. Although the drying protocol reported here will need further improvement, the results suggest that it may be possible to store the male genetic resources.

Complement regulation: physiology and disease relevance

  • Cho, Heeyeon
    • Clinical and Experimental Pediatrics
    • /
    • v.58 no.7
    • /
    • pp.239-244
    • /
    • 2015
  • The complement system is part of the innate immune response and as such defends against invading pathogens, removes immune complexes and damaged self-cells, aids organ regeneration, confers neuroprotection, and engages with the adaptive immune response via T and B cells. Complement activation can either benefit or harm the host organism; thus, the complement system must maintain a balance between activation on foreign or modified self surfaces and inhibition on intact host cells. Complement regulators are essential for maintaining this balance and are classified as soluble regulators, such as factor H, and membrane-bound regulators. Defective complement regulators can damage the host cell and result in the accumulation of immunological debris. Moreover, defective regulators are associated with several autoimmune diseases such as atypical hemolytic uremic syndrome, dense deposit disease, age-related macular degeneration, and systemic lupus erythematosus. Therefore, understanding the molecular mechanisms by which the complement system is regulated is important for the development of novel therapies for complement-associated diseases.