• Title/Summary/Keyword: Secondary Source

Search Result 700, Processing Time 0.023 seconds

Regeneration and selection of root resistant Coleus forskohlii A threatened medicinal plant

  • George, Manju M.;Ssubramanian, R.B.;Prajapati, Hiren A.
    • Plant Resources
    • /
    • v.4 no.2
    • /
    • pp.65-74
    • /
    • 2001
  • Coleus forskohlii Briq, of the family Lamiaceae yields a valuable secondary metabolity known as forskolin which is a labdane diterpenoid.. Coleus forskohlii is the only known source of this compound. Forskolin is used in medicine for the treatment of glaucoma, congestive cardiomyopathy and asthma. Morphogenic callus was induced from young leaves on MS medium augmented with NAA and BA. These calli, when subcultured on MS with KN alone gave rise to shoots. The regenerated shoot developed good root system on MS medium fortified with NAA. The fully grown plantlets were transferred to soil for acclimatization. Coleus plant is mainly infected by a fungi Lasiodiplodia theobromae which causes root rot disease. The fungal culture filterate (ECE) of Lasiodiplodia theobromae, has been used in regeneration media to find the MIC and further to select resistant plants to the pathogen. In the present study 40% ECF in the medium showed maximum inhibition and is there fore considered as the MIC level of Coleus forshohlii. This data could prove to be useful for the future for selecting a resistant C.forskohlii plant against the root disease caused by L. theobromae.

  • PDF

Response of the Wave Spectrum to Turning Winds (풍향 변화에 대한 파랑 스펙트럼의 반응)

  • 윤종태
    • Journal of Ocean Engineering and Technology
    • /
    • v.11 no.4
    • /
    • pp.111-121
    • /
    • 1997
  • The spectral energy balance model is composed and the nonlinear interaction is approximated by the discrete interaction parameterization as in WAM model. The numerical results of durational limited growth test agree very well with those of the exact model, EXACT-NL. The response of a wave spectrum to a change in wind direction is investigated numerically for a sequence of direction changes 30$^{\circ}$ , 45$^{\circ}$ , 60$^{\circ}$ , 90$^{\circ}$ . The high frequency components relax more repidly to the new wind direction than the low frequency components and the relaxation process also depends on the wave age. For wind direction changes less than 60$^{\circ}$ , the coupling by nonlinear interaction is so strong that the secondary peak in input source distribution is counteracted by the negative lobe of the nonlinear interaction. For wind direction changes grater than 60$^{\circ}$ , a second independent wind-sea spectrum is generated in the new wind direction, while the old spectrum gradually decays as swell.

  • PDF

Production, Assessment and Marketing of Lichens for Economic Upliftment and Livelihood Generation of Rural Communities in Kumaun Himalaya

  • Pant, Girish Chandra
    • Journal of Forest and Environmental Science
    • /
    • v.30 no.3
    • /
    • pp.267-276
    • /
    • 2014
  • Collection of lichen together with tree twigs of oak and other trees bearing abundant growth of lichens is a common practice among the villagers and the rivals residing near Oak forests in Kumaun Himalaya. Nainital forest division represents about Twenty nine percent vegetation of the Oak forest in Kumaun Himalaya. In Kumaun, the lichen trade share is decreasing at an alarming rate of 21.93% which requires immediate actions by the Government. Lichen contributed significantly to household earnings with off-farm activities and this sector was found second highest income creator after Agriculture. It is a source of cash income during the season of extraction, which increases economic access to food. It has been observed in the present study that the secondary collector and transporters together get maximum share (>50%) of income generated from lichen, thus economic exploitation of the poorly educated people by the traders was still prevalent in the area. To improve the socio-economic standard of the people of Kumaun, it may is necessary to increase and improve the lichens resources of the area. There is a strong need for scientific management, best harvesting practices and strict monitoring of resources. The present study was conducted to assess the present and future resource potential for the conservation and sustainable management of lichens, existing market mechanism, role of Lichens in economic upliftment and livelihood generation of rural communities in Kumaun Himalaya.

A Cost-Effective, Single-Phase Line-Interactive UPS System that Eliminates Inrush Current Phenomenon for Transformer-Coupled Loads

  • Bukhari, Syed Sabir Hussain;Atiq, Shahid;Lipo, Thomas A.;Kwon, Byung-il
    • Journal of Electrical Engineering and Technology
    • /
    • v.11 no.3
    • /
    • pp.675-682
    • /
    • 2016
  • Sudden voltage drops and outages frequently disturb the operation of sensitive loads for domestic, commercial, and industrial use. In some cases, these events may even impair the functioning of relevant equipment. To maintain power under such conditions, a UPS system is usually installed. Once a disturbance happens at the grid side, the line-interactive UPS system takes over the load to prevent an interruption. But, due to magnetic saturation of the transformer, a significant inrush current may occur for the transformer-coupled loads during this transition. The generation of such transient currents may in turn decrease the line voltage and activates over-current protecting devices of the system. In this work, a cost-effective, line-interactive UPS system is proposed that eliminates the inrush current phenomenon associated with transformer-coupled loads. The strategy was implemented by connecting a standard current-regulated voltage source inverter (CRVSI) to the secondary winding of the load transformer. During any transient condition at the grid side, the load current is monitored and regulated to achieve either seamless compensation of the load current or complete transferal of load from grid to the inverter. Experimental results were obtained for a prototype under all possible operating conditions so as to validate the performance of the proposed topology.

Factors Influencing Mental Health among Late School age Children (학령기 후기 아동의 정신건강과 영향요인)

  • Lee, Hyun-Ju;Kim, Hee-Kyung
    • The Journal of Korean Academic Society of Nursing Education
    • /
    • v.18 no.1
    • /
    • pp.149-158
    • /
    • 2012
  • Purpose: The purpose of this study was to identify the factors influencing mental health among late elementary age children. Methods: The research design was a secondary data analysis. Data were collected from 746 students in grades 5 or 6, and analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients and stepwise multiple regression with the SPSS/PC 18.0 program. Results: The average score of mental health was $3.42{\pm}0.55$. There were significant differences in mental health according to health status, economic status, scholastic performance, relationships with friends, relationships with the teachers, atmosphere of the home, number of siblings and the source of trouble. Stepwise multiple regression analysis showed influencing factors of stress, negative reaction under stress, self-esteem, teacher support, and friend support support and explained 41.4% of total variance in late elementary age children's mental health. Conclusion: These results may contribute to a better understanding of mental health in late elementary age children. The results of the present study indicate a need to develop nursing interventions to prevent and manage elementary school-age children's negative reaction under stress.

Partial Multipath Routing Scheme to avoid interpath interference in Wireless Multimedia Sensor Networks (무선 멀티미디어 센서 네트워크에서 경로간 간섭회피를 위한 부분 다중경로 라우팅 기법)

  • Lee, Kang-Gun;Park, Hyung-Kun
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.19 no.8
    • /
    • pp.1917-1924
    • /
    • 2015
  • Efficient routing algorithm is required to transmit data from source to destination by multi-hop transmission in wireless sensor networks. In the multi-hop transmission, multipath routing can be one of the solutions to cope with the traffic congestion and unstable link condition. In this paper, we propose partial multipath routing which does not establish a secondary full routing path but a partial multipath to complement some poor links, and it can enable stable data transmission and reduce the number of nodes in routing path and the required total power compared with conventional multipath routing.

A Novel High Step-Up Converter with a Switched-Coupled-Inductor-Capacitor Structure for Sustainable Energy Systems

  • Liu, Hongchen;Ai, Jian;Li, Fei
    • Journal of Power Electronics
    • /
    • v.16 no.2
    • /
    • pp.436-446
    • /
    • 2016
  • A novel step-up DC-DC converter with a switched-coupled-inductor-capacitor (SCIC) which successfully integrates three-winding coupled inductors and switched-capacitor techniques is proposed in this paper. The primary side of the coupled inductors for the SCIC is charged by the input source, and the capacitors are charged in parallel and discharged in series by the secondary windings of the coupled inductor to achieve a high step-up voltage gain with an appropriate duty ratio. In addition, the passive lossless clamped circuits recycle the leakage energy and reduce the voltage stress on the main switch effectively, and the reverse-recovery problem of the diodes is alleviated by the leakage inductor. Thus, the efficiency can be improved. The operating principle and steady-state analyses of the converter are discussed in detail. Finally, a prototype circuit at a 50 kHz switching frequency with a 20-V input voltage, a 200-V output voltage, and a 200-W output power is built in the laboratory to verify the performance of the proposed converter.

Novel Single Switch DC-DC Converter for High Step-Up Conversion Ratio

  • Hu, Xuefeng;Gao, Benbao;Huang, Yuanyuan;Chen, Hao
    • Journal of Power Electronics
    • /
    • v.18 no.3
    • /
    • pp.662-671
    • /
    • 2018
  • This paper presents a new structure for a step up dc-dc converter, which has several advantageous features. Firstly, the input dc source and the clamped capacitor are connected in series to transfer energy to the load through dual voltage multiplier cells. Therefore, the proposed converter can produce a very high voltage and a high conversion efficiency. Secondly, a double voltage clamped circuit is introduced to the primary side of the coupled inductor. The energy of the leakage inductance of the coupled inductor is recycled and the inrush current problem of the clamped circuits can be shared equally by two synchronous clamped capacitors. Therefore, the voltage spike of the switch tube is solved and the current stress of the diode is reduced. Thirdly, dual voltage multiplier cells can absorb the leakage inductance energy of the secondary side of the coupled inductor to obtain a higher efficiency. Fourthly, the active switch turns on at almost zero current and the reverse-recovery problem of the diodes is alleviated due to the leakage inductance, which further improves the conversion efficiency. The operating principles and a steady-state analysis of the continuous, discontinuous and boundary conduction modes are discussed in detail. Finally, the validity of this topology is confirmed by experimental results.

Review on the East Pyrolysis of Biomass and Characteristics of Bio-Oil (바이오매스의 Fast Pyrolysis 공정과 Bio-Oil의 특성)

  • Myung So-Yuung;Park Young-Kwon;Jeon Jong-Ki;Kim Joo-Sik
    • Resources Recycling
    • /
    • v.13 no.1
    • /
    • pp.3-13
    • /
    • 2004
  • The use of biomass has attracted extensive attention from the beginning of civilization. However, intensive researches on the biomass from the view point of the development of alternative energy have been carried out just recently. Fast pyrolysis, as a tool for the utilization of the biomass as the secondary energy source has drawn great attentions due to high applicability for the production of several valuable materials from biomass. This review paper focuses on the recent developments of pyrolysis process and reports the characteristics of bio-oil, which is the main product of fast pyrolysis of biomass.

A Study on the Abbreviation of Titles of Periodicals (잡지명(雜誌名)의 약기(略記)에 관한 연구(硏究))

  • Suh, Han-Soo;Park, Young-Seo
    • Journal of Information Management
    • /
    • v.19 no.2
    • /
    • pp.55-90
    • /
    • 1988
  • The abbreviation of titles of periodicals was studied as a part of standardizations in bibliographic information inscription which were needed for dissemination of scientific and technological informations. The fundamental principles and the base draft were framed for the range of application, the titles of periodicals which should be abbreviated and the conditions and methods of abbreviation. The rules given in this base draft for abbreviation of titles are applicable to write out the secondary source and to describe the references.

  • PDF