• Title/Summary/Keyword: desert

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Morphological Landscape of Patagonia and Atacama in the Andes based on Geotourism (지오투어리즘 관점에서 본 안데스 파타고니아와 아타카마의 지형경관)

  • PARK, Jongkwan
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.4
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    • pp.15-28
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    • 2013
  • This paper was made on the basis of geotourism to explain morphological characteristics of Patagonia and Atacama region in the Andes through 10-day fieldwork. The Patagonian landscape was focused on the Torres del Paine National Park, Chile and the Los Glacier National Park, Argentina; on the other hand, the Atacama morphological landscape was investigated around the San Pedro de Atacama. Many geomorphological features such as uplift, semiarid and glacier landscapes can be found in Patagonia, so it is strongly recommended to have an opportunity to enjoy these landforms by geotourism. Massive intrusive rock bodies of granite can be shown in those two National Parks declared a Biosphere Reserve by UNESCO. And, the Atacama Desert located on the forearc depression in the Andes, Chile has also many geomorphological destinations of arid and volcanic landforms; badland, pediplain, pediment, salt lake and geyser. Especially, huge pediplain is one of the greatest view points in the Atacama Desert. Patagonia and Atacama are the best geographical tourism sites to know diverse tectonic landforms made by the conflict between South American and Pacific plates.

Effects of supplementing sweet sorghum with grapeseeds on carcass parameters, and meat quality, amino acid, and fatty acid composition of lambs

  • Jianxin Jiao;Ting Wang;Shanshan Li;Nana Gou;A. Allan Degen;Ruijun Long;Hucheng Wang;Zhanhuan Shang
    • Animal Bioscience
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    • v.36 no.3
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    • pp.461-470
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    • 2023
  • Objective: Sweet sorghum is an important forage crop for ruminants, especially in low rainfall areas. Grapeseeds are an abundant by-product of wine-making and contain bioactive substances that can improve the antioxidant capacity of meat. We examined the effect of sweet sorghum forage with supplementary grapeseeds on carcass and meat quality in lambs. Methods: Twenty-eight Small-tailed Han lambs (body weight = 19.1±1.20 kg), aged 3 to 4 months, were penned, and fed individually. The lambs were divided into four groups (n = 7 each) and were offered one of four diets: i) sweet sorghum silage; ii) sweet sorghum silage + grapeseeds; iii) sweet sorghum hay; and iv) sweet sorghum hay + grapeseeds. The grapeseeds were added to the concentrate at 6% DM and the diets were fed for 100 d. Results: Sweet sorghum silage tended (p = 0.068) to increase hot carcass weight, while grapeseeds tended (p = 0.081) to decrease dressing percentage without affecting other carcass parameters. Lambs consuming supplementary grapeseeds increased (p<0.05) meat redness and tended to decrease (p = 0.075) concentration of methionine in meat. Lambs consuming sweet sorghum silage increased (p<0.001) water content of the meat and had a lower (p<0.05) concentration of n-6 polyunsaturated fatty acids (PUFA) and n-6:n-3 PUFA ratio than lambs consuming sweet sorghum hay. Saturated fatty acids content in meat was lowest (p<0.05) in lambs consuming sweet sorghum silage with grapeseeds. Lambs with supplementary grapeseeds tended (p<0.10) to increase eicosapentaenoic acid and docosahexaenoic acid and have a lower thrombogenic index than lambs not consuming grapeseeds. Conclusion: It was concluded that sweet sorghum with supplementary grapeseeds fed to lambs; i) improved the color of the meat to be more appetizing to the consumer; ii) tended to improve the fatty acids composition of the meat; and iii) lowered thrombogenic index of the meat.

Growth Characteristics of Ultrahigh-density Microalgal Cultures

  • Richmond, Amos
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.6
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    • pp.349-353
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    • 2003
  • The physiological characteristics of cultures of very high cell mass (e.g. 10g cell mass/L), termed“ultrahigh cell density cultures”is reviewed. A close relationship was found between the length of the optical path (OP) in flat-plate reactors and the optimal cell density of the culture as well as its areal (g m$\^$-2/ day$\^$-1/) productivity. Cell-growth inhibition (GI) unfolds as culture density surpasses a certain threshold. If it is constantly relieved, a 1.0cm OP reactor could produce ca. 50% more than reactors with longer OP, e.g. 5 or 10cm. This unique effect, discovered by Hu et al. [3], is explained in terms of the relationships between the frequency of the light-dark cycle (L-D cycle), cells undergo in their travel between the light and dark volumes in the reactor, and the turnover time of the photosynthetic center (PC). In long OP reactors (5cm and above) the L-D cycle time may be orders of magnitude longer than the PC turnover time, resulting in a light regime in which the cells are exposed along the L-D cycle, to long, wasteful dark periods. In contrast, in reactors with an OP of ca. 1.0 cm, the L-D cycle frequency approaches the PC turnover time resulting in a significant reduction of the wasteful dark exposure time, thereby inducing a surge in photosynthetic efficiency. Presently, the major difficulty in mass cultivation of ultrahigh-density culture (UHDC) concerns cell growth inhibition in the culture, the exact nature of which is awaiting detailed investigation.

Experimental investigation of effects of sand contamination on strain modulus of railway ballast

  • Kian, Ali R. Tolou;Zakeri, Jabbar A.;Sadeghi, Javad
    • Geomechanics and Engineering
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    • v.14 no.6
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    • pp.563-570
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    • 2018
  • Ballast layer has an important role in vertical stiffness and stability of railway track. In most of the Middle East countries and some of the Asian ones, significant parts of railway lines pass through desert areas where the track (particularly ballast layer) is contaminated with sands. Despite considerable number of derailments reported in the sand contaminated tracks, there is a lack of sufficient studies on the influences of sand contamination on the ballast vertical stiffness as the main indicator of track stability. Addressing this limitation, the effects of sand contamination on the mechanical behavior of ballast were experimentally investigated. For this purpose, laboratory tests (plate load test) on ballast samples with different levels of sand contamination were carried out. The results obtained were analyzed leading to derive mathematical expressions for the strain modulus ($E_V$) as a function of the ballast level of contamination. The $E_V$ was used as an index for evaluation of the load-deformation characteristics and bearing capacity of track substructure. The critical limit of sand contamination, after which the $E_V$ of the ballast reduces drastically, was obtained. It was shown that the obtained research results improve the current track maintenance approach by providing key guides for the optimization of ballast maintenance planning (the timing of ballast cleaning or renewal).

Variations of Airborne Fungal Spore Composition due to the Asian Dust Trajectories (황사 이동 경로에 따른 대기 부유 곰팡이 포자의 변화)

  • 김종호;여환구
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.1
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    • pp.69-76
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    • 2004
  • Asian Dust samples were collected in the ambient air of Seosan, Western Korea, in spring of 2000∼2002. PM (Particulate Matter) concentrations were 199,8$\mu\textrm{g}$/㎥ in the first Asian Dust period (March, 23∼24) and 249.4$\mu\textrm{g}$/㎥ in the second period (April, 7∼9) of 2000. Compared with the concentrations in 2000, relatively low PM concentrations, 157.3$\mu\textrm{g}$/㎥ were measured in the periods of 2001 (April, 24∼26). Especially high PM concentration 953.1$\mu\textrm{g}$/㎥ were measured in the periods of 2002 (March, 21∼22). The variation in the PM concentration was observed according to the time for the formation of Asian dust. Considering the particle size distributions of Asian dust, a high concentration was also observed in coarse particle region. The results of backward trajectory model showed the route of the dust storms from northern area of Mongol and Gobi desert. Various mycelia grown from fungal spores were observed on the PM samples and identified at the genus level. All the genera from the three years (2000∼2002), Fusarium, Aspergillus, Penicillium, Basipetospora, Epicoccum and Monotospora are hyphomycetes in the division Fungi imperfecti (Deuteromycota). Fungal composition on the dust sample in March, 2000 was similar to the result of March, 2002. However, the result of April, 2001 was obviously different from the other dust periods. The variations of fungal compositions between the dust periods could be caused by the trajectories of the dust storms.

Autonomous Flight Experiment of a Foldable Quadcopter with Airdrop Launching Function (고공 비행개시가 가능한 접이식 쿼더콥터 자율비행 실험)

  • Lee, Cheonghwa;Chu, Baeksuk
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.2
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    • pp.109-117
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    • 2018
  • The experimental results are presented of an autonomous flight algorithm of a foldable quadcopter with airdrop launching functions. A foldable wing structure enabled the quadcopter to be inserted into a rocket container with limited space. The foldable quadcopter was then separated from the rocket in the air. The flight pattern was tracked using a global positioning system (GPS) with various sensors, including an inertial measurement unit (IMU) module until a designated target position was reached. Extensive field tests were conducted through an international rocket competition, ARLISS 2017, which was held in Black Rock Desert, Nevada, USA. The flight trajectory record of the experiments is stored in electrically erasable programmable read-only memory (EEPROM) embedded in the main control unit. The flight record confirmed that the quadcopter successfully separated from the rocket, executed flight toward the target for a certain length of time, and stably landed on the ground.

Radiometric Characteristics of Geostationary Ocean Color Imager (GOCI) for Land Applications

  • Lee, Kyu-Sung;Park, Sung-Min;Kim, Sun-Hwa;Lee, Hwa-Seon;Shin, Jung-Il
    • Korean Journal of Remote Sensing
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    • v.28 no.3
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    • pp.277-285
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    • 2012
  • The GOCI imagery can be an effective alternative to monitor short-term changes over terrestrial environments. This study aimed to assess the radiometric characteristics of the GOCI multispectral imagery for land applications. As an initial approach, we compared GOCI at-sensor radiance with MODIS data obtained simultaneously. Dynamic range of GOCI radiance was larger than MODIS over land area. Further, the at-sensor radiance over various land surface targets were tested by vicarious calibration. Surface reflectance were directly measured in field using a portable spectrometer and indirectly derived from the atmospherically corrected MODIS product over relatively homogeneous sites of desert, tidal flat, bare soil, and fallow crop fields. The GOCI radiance values were then simulated by radiative transfer model (6S). In overall, simulated radiance were very similar to the actual radiance extracted from GOCI data. Normalized difference vegetation index (NDVI) calculated from the GOCI bands 5 and 8 shows very close relationship with MODIS NDVI. In this study, the GOCI imagery has shown appropriate radiometric quality to be used for various land applications. Further works are needed to derive surface reflectance over land area after atmospheric correction.

Long-Term Reliable Test of Photovoltaic Modules (태양광모듈의 장기적 신뢰성 실험)

  • Kim, Kyung-Soo;Kwon, Oh-Eun;Kang, Gi-Hwan;Yu, Gwon-Jong;Yoon, Soon-Gil
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1405-1405
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    • 2011
  • Sudden earthquake is changing national energy stratagem for future energy resource. In case Germany, current nuke power station will be shut down with several decades. Newly constructed build in Japan must have photovoltaic system as a obligations.. As a long-term sustainable energy one, PV should give confidence to customers up to more than 20 years. Today, IEC 61215 and IEC 61646 standards are representative one for ensuring performance and safety of PV module. But it is still needed to develop more realistic test method. For example, if we think about extreme condition like desert and North Pole, the temperature condition describe in test standards can have little effect on life time expectation of PV module. Installation speed of PV system is very high, but establishing test standards are very complex and not easy. So in this paper, I tried to open the long-term test method for PV module to ensure 25 year's old life time. It is just starting point of PV related long-term test methods. The specific and technical explanation will be shown in the following paper in detail.

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HAZARD ASSESSMENT OF CURRENT STATE OF VEGETATION DEGRADATION USING GIS, A CASE STUDY: SADRA REGION, IRAN

  • Masoudi, Masoud;Amiri, E.
    • Journal of Ecology and Environment
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    • v.36 no.1
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    • pp.49-56
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    • 2013
  • The entire land of Southern Iran faces problems arising out of various types of land degradation of which vegetation degradation forms one of the major types. The present work introduces a model developed for assessing the current status of hazard of vegetation degradation using Geographic Information System (GIS). This kind of assessment differs from those assessments based on vulnerability or potential hazard assessments. The Sadra watershed which covers the upper reaches of Marharlu basin, Fars Province, has been chosen for a hazard assessment of this type of degradation. The different kinds of data for indicators of current status of vegetation degradation were gathered from collecting of field data and also records of the governmental offices of Iran. Taking into consideration three indicators of current status of vegetation degradation the model identifies areas with different hazard classes. By fixing the thresholds of severity classes of the three indicators including per cent of vegetation cover, biomass production and ratio of actual biomass to potential biomass production, a hazard map for each indicator was first prepared in GIS. The final hazard map of current status of vegetation degradation was prepared by intersecting three hazards in the GIS. Results show areas under severe hazard class have been found to be widespread (89 %) while areas under moderate and very severe hazard classes have been found less extensive in the Sadra watershed. The preparation of hazard maps based on the GIS analysis of these indicators will be helpful for prioritizing the areas to initiate remedial measures.

Climatic Features of Extratropical Cyclones During the Spring-time Yellow Dust Events in Korea (한반도 봄철 황사 발생시 동아시아 온대저기압의 기후학적 특징)

  • Lee, Jaeyeon;Kim, Junsu;Son, Seok-Woo
    • Atmosphere
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    • v.26 no.4
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    • pp.565-576
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    • 2016
  • The yellow dust events in Korea are often associated with extratropical cyclones (ETCs) that travel across the source regions of yellow dusts. Although such synoptic patterns are well documented, climatic features of ETCs themselves during the yellow dust events are not well understood. The present study reports climatic features of spring-time ETCs, which accompany the yellow dust events in Korea, by tracking individual ETCs with an automated tracking algorithm. By analyzing Lagrangian tracks of ETCs from 1979 to 2014, it is found that, during yellow dust events, ETCs are located around Vladivostok, Russia. They are typically originated from the leeside of Altai-Sayan mountains about three days before the onset of the yellow dust events, and travel either eastward or southeastward in time. While their tracks are not unusual, they grow faster over the source regions of the yellow dusts, possibly lifting desert dusts above the planetary boundary layer, and further develop slowly as they travel eastward.