• Title/Summary/Keyword: Moist

Search Result 514, Processing Time 0.032 seconds

Carbon Stock Variation in Different Forest Types of Western Himalaya, Uttarakhand

  • Shahid, Mohommad;Joshi, Shambhu Prasad
    • Journal of Forest and Environmental Science
    • /
    • v.34 no.2
    • /
    • pp.145-152
    • /
    • 2018
  • Quantification of Carbon stock has become in the contest of changing climate and mitigation potential of forests. Two different forest types, Dry Shiwalik Sal Forest and Moist Shiwalik Sal Forest in Barkot and Lachchiwala of Doon Valley, Western Himalaya are selected for the study. Volume equations, destructive sampling and laboratory analysis are done to estimate the carbon stock in different carbon pools like trees, shrubs, herbs and soils. Considerable variations are observed in terms of carbon stocks in different forest types. In Dry Shiwalik Sal Forest, carbon stock density varied between 129.81 and $136.00MgCha^{-1}$ while in Moist Shiwalik Sal Forest, carbon stock density ranged from 222.29 to $271.67MgCha^{-1}$. Tree species like Shorea robusta, Syzigium cumini, Miliusa velutina, Acacia catechu, and Mallotus philippensis had significant role in carbon sequestration. Shorea robusta had contributed highest in carbon stock due to highest density. Total of 2,338,280.165 Mg carbon stock was estimated in all the forest types.

A Study on the Onset of Condensation in a Supersonic Nozzle of Constant Expansion Rate (팽창율이 일정한 초음속 노즐흐름의 응축개시에 관한 연구)

  • 김병지;권순범;이은수
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.14 no.2
    • /
    • pp.463-469
    • /
    • 1990
  • A rapid expansion of moist air of condensible gas through a supersonic nozzle gives rise to condensation of nonequilibrium and equilibrium processes. Because most of the effects of condensation on the flow are caused by process of nonequilibrium condensation, it is very important to know the onset. condition of nonequilibrium condensation. In the present study, the relation between the initial relative stagnation humidity and the onset Mach number, for the case of the similarity law suggested by Zierep and Lin. Furthermore, the present theoretical result number is compared with the experimental, numerical and other results.

A Study on the Effects of System Pressure on Heat and Mass Transfer Rates of an Air Cooler

  • Jung, Hyung-Ho
    • Journal of Mechanical Science and Technology
    • /
    • v.16 no.5
    • /
    • pp.696-702
    • /
    • 2002
  • In the present paper, the effects of inlet pressure on the heat and mass transfer rates of an air cooler are numerically predicted by a local analysis method. The pressures of the moist air vary from 2 to 4 bars. The psychrometric properties such as dew point temperature, relative humidity and humidity ratio are employed to treat the condensing water vapor in the moist air when the surface temperatures are dropped below the dew point. The effects of the inlet pressures on the heat transfer rate, the dew point temperature, the rate of condensed water, the outlet temperature of air and cooling water are calculated. The condensation process of water vapor is discussed in detail. The results of present calculations are compared with the test data and shows good agreements.

Protective Effect of Ag Coated on Textured YBCO Surface

  • Soh, Daewha;Shan, Yuqiao;Fan, Zhanguo
    • Proceedings of the Materials Research Society of Korea Conference
    • /
    • 1996.11a
    • /
    • pp.171-173
    • /
    • 1996
  • Ag coating on the textured YBCO was prepared by means of a Ag$_2$O brushed coating method. The contact between Ag coating and textured YBCO was examined by sharp knife cut and by the observation of SEM. The critical current densities of different textured YBCO samples, which included YBCO with and without Ag coating, and YBCO with Ag coating after hot moist text, were compared. The Ag coating does not influence the oxygen absorption of textured YBCO, but Ag coating can protect YBCO well from moisture and $CO_2$

  • PDF

Coating using chitosan as a means to prevent dispersion of moist pellet feed in water of aquacultural farm, and bacterial pollution and its lipid oxidation during storage

  • Lee, Ki-Wan;Jeon, You-Jin;Heo, Moon-Soo;Song, Choon-Bok;Ha, Jin-Hwan;Kim, Se-Kwon
    • Proceedings of the Korean Society of Fisheries Technology Conference
    • /
    • 2001.10a
    • /
    • pp.149-150
    • /
    • 2001
  • A fish feed being used most widely in aquacultural farm is a moist pellet (MP) feed which has been being prepared by mixing of commercial dry feed and nutritional oil to raw fish ky. The two major problems in the use of MP feed is to be readily dispersed in water of an aquacultural farm, and to cause lipid oxidation and bacteria infection during storage. The former induce an environmental pollution of the farm and the latter lower nutritional values and develop fish diseasees. (omitted)

  • PDF

Moist Corrosion and Surface Protection of YBCO HTS

  • Lim, Byong-Jae;Soh, Dea-Wha;Fan, Zhanguo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2002.11a
    • /
    • pp.256-259
    • /
    • 2002
  • The critical currents of sintered $YBa_{2}Cu_{3}O_{6.5+\delta}$ were measured as the variables with the corrosive time in the humid air. The corrosive process was studied by means of the current changes. Ag coating on the textured YBCO and polytetrafluoroethylene (PTFE) coating on the sintered YBCO were prepared. The critical current densities of different YBCO samples with and without coatings were compared. Both Ag coating and PTFE coating can well protect YBCO from moisture and $CO_{2}$.

  • PDF

Mechanism of Energy Transfer and Improvement Moist Stability of BaMg$Al_{10}O_{17}$:$Eu^{2+}$, $Mn^{2+}$ Phosphor

  • Liu, Ru-Shi;Ke, Wei-Chih
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.235-238
    • /
    • 2009
  • BaMg$Al_{10}O_{17}$ (BAM) co-doped with $Eu^{2+}$ and $Mn^{2+}$ was synthesized in a solid-state reaction and their luminescence properties were investigated as functions of the concentrations of the sensitizer and activator. BAM:$Eu^{2+}$ had a broad blue emission band at 450 nm and BAM:$Mn^{2+}$ exhibited green emission at 514 nm. The energy transfer from $Eu^{2+}$ to $Mn^{2+}$ was mainly of the resonance-type via an electric dipole-quadrupole interaction. Additionally, the addition of various fluxes such as $AlF_3$ and $BaF_2$ in the synthesis improves the moist and thermal stability. This is particularly important for the phosphor in white light emitting diodes (LEDs).

  • PDF

Extreme Rainfall and Flood related to Tropical Moisture Exports Related Extreme in Korea

  • Uranchimeg, Sumiya;Kwon, Hyun-Han;Kim, Kyung-Wook
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2018.05a
    • /
    • pp.170-170
    • /
    • 2018
  • In some case studies, the heavy precipitation events and rapid cyclogenesis in the extratropics can be caused by moist and warm tropical air masses. Tropical Moisture Exports (TME) correspond to the meridional transport of moist air masses, primarily born in tropical oceanic areas, to higher latitudes; and are closely related to flood events, especially in the mid-latitudes. The TME for the region of interest is mostly estimated by the back tracking approach using Lagrangian Analysis Tools (LAGRANTO) from ECMWF Re-Analysis (ERA) data. In this study, we aim to estimate the TME that are related to rainfall in Korea. The major moisture sources of the TME that contribute to heavy rainfall and extreme floods in Korea are identified. The TME is found to have significant connection with extreme events in Korea such as heavy rainfall and extreme flood events. The results show the most of the moisture sources comes from the west Pacific during the warm half of the year and it contributes significantly to the annual TME and is linked to the East Asian monsoon.

  • PDF

The Unsteady Cavity Flow Oscillation in Supersonic Moisture Air Stream (초음속 습공기 유동에서 비정상 공동유동의 진동)

  • Shin, Choon-Sik;Lee, Jong-Sung;Kim, Heuy-Dong;Setoguchi, Toshiaki
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2008.11a
    • /
    • pp.341-344
    • /
    • 2008
  • Numerical simulations have been carried out for a supersonic two-dimensional flow over open, rectangular cavities (length-to-depth ratios are L/D = 1.0) in order to investigate the effect of non-equilibrium condensation of moist air on supersonic flows around the cavity for the flow Mach number 1.83 at the cavity entrance. In the present computational investigation, a condensing flow was produced by an expansion of moist air in a Laval nozzle. The results obtained showed that in the case with non-equilibrium condensation for L/D = 1.0, amplitudes of oscillation in the cavity became smaller than those without the non-equilibrium condensation. Furthermore, the occurrence of the non-equilibrium condensation reduced the peaks of power spectrum density and the frequency of the flow field oscillation increased in comparison with the case of $S_0$ = 0.

  • PDF

Study on the Flow of Briquette Gas in the Ondol Heating System (Chimney Draft of Low Temperature Moist Air) (온돌의 연탄개스유량에 관한 연구(1) (함습저온열기류의 굴뚝통풍력))

  • Min Man-Ki
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
    • /
    • v.4 no.2
    • /
    • pp.119-128
    • /
    • 1975
  • Natural draft and flow which low temperature moist gas produces in the chimney of an Ondol heating system were numerically analysed. Among several factors involved inlet gas temperature has the strongest influence on the chimney performance and then next specific humidity of the gas. Thermal conductivity of the chimney wall, however, has little influence on the performance of such a low temperature chimney. Under given flow conditions there exists an optimum chimney height which gives a maximum flow rate for a given chimney diameter. This optimum value of chimney height inereases with increase in chimney diameter, inlet gas temperature and specific humidity.

  • PDF