• Title/Summary/Keyword: dry season

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Initial Stage of Atmospheric Corrosion of Carbon and Weathering Steels in Thailand Climate

  • Nii, K.;Bhamornsut, C.;Chotimongkol, L.;Vutivat, E.;Nakkhuntod, R.;Jeenkhajohn, P.;Suphonlai, S.
    • Corrosion Science and Technology
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    • v.2 no.4
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    • pp.183-188
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    • 2003
  • Corrosion of carbon and weathering steels were evaluated under 3 environmental exposures in Thailand (urban, rural and marine) for a year. The seasonal study was designed to determine different corrosion mechanisms by 6 months of dry season and 6 months of rainy season in a year. The sheltered exposure racks were used to determine the washing effect of min. At each site, climatic and pollutants analyses were carried out. The present study showed that the difference in corrosion rates of carbon and weathering steels was not so distinguished in both rural (AIT) and urban (TISTR) environments. The corrosion rate of weathering steel was somewhat lower than that of carbon steel and the decreasing tendency of corrosion rate with time was slightly higher for weathering steel than for carbon steel. In marine (Rayong) environment, the corrosion rate was higher and the effect of wet and dry seasons was observed. The corrosion rate in 6 dry months was higher for direct exposure than for sheltered exposure. However, in 6 rainy months. the corrosion rate of sheltered exposure was higher than that of direct exposure. In direct exposure for I year, that is, the first 6 dry months and the next 6 rainy months, the corrosion rate decreased with time. but in sheltered exposure, the corrosion rate did not decrease with time. instead, increased in the next 6 rainy months. This indicated that the protect ive layer formed in the first 6 dry months could be destroyed by high deposition of chloride to r sheltered exposure in the next 6 rainy months; whereas the rust layer for direct exposure could be kept sound due to washing effect in rainy season, even though the deposition rate of chloride was almost the same for direct and sheltered exposures. In marine environment, the weathering steel showed higher corrosion resistance than carbon steel but its corrosion rate was higher than those in other environments.

MINERAL STATUS OF GRAZING CATTLE IN SOUTH SULAWESI, INDONESIA : 1. MACROMINERALS

  • Prabowo, A.;McDowell, L.R.;Wilkinson, N.S.;Wilcox, C.J.;Conrad, J.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.4 no.2
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    • pp.111-120
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    • 1991
  • A study was conducted to determine the macromineral status of grazing cattle in three climatic regions of the province of South Sulawesi, Indonesia. Soil, forage, blood and rib bone samples were collected within the Western, Central and Eastern regions, respectively, in February-March and August-September of 1987. Calcium and magnesium were not deficient in soil samples. For forages, calcium and phosphorus were deficient for all regions and forage sodium was deficient except for the western region in the dry season. Crude protein was deficient during the dry season. The overall percentage of deficient plasma phosphorus samples was 17 or 23% for the wet and dry seasons, respectively. Based on these analyses, macrominerals most likely deficient in both seasons were phosphorus and calcium in all regions, in addition to sodium in the Central and Eastern regions.

The Variation Characteristics of Groundwater Level with Distance from Shoreline in the Jeju Island (제주도 지역의 해안선에서 이격거리에 따른 지하수위 변동특성)

  • Kang, Dong-Hwan;Yang, Sung-Il;Kim, Tae-Yeong;Park, Hyun-Joo;Kwon, Byung-Hyuk
    • The Journal of Engineering Geology
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    • v.18 no.2
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    • pp.167-176
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    • 2008
  • The variation characteristics of groundwater level with distance from shoreline at Jeju Island was investigated using groundwater level data monitored from 257 wells for dry season (December 1998) and wet season (July 1997), respectively. Groundwater levels of the dry season were $7.46{\sim}203.8\;m$ with an average of 60.49 m, while those of the wet season were $4.01{\sim}204.10\;m$ with an average of 57.66 m. Groundwater level of the dry season was higher than that of the wet season, which was caused by heavy rains between June and October, 1998 at the Jeju Island. Correlation coefficients between altitude and groundwater level for dry and wet seasons were above 0.86, and those between dry season and wet season groundwater levels were very high above 0.95. 257 groundwater level data were classified at an interval of 500 m. Average values for altitude, groundwater levels and distance from shoreline were calculated for 17 intervals. Altitude and groundwater level fur dry and wet seasons at $0{\sim}4\;km$ intervals were increased with distance from shoreline, but those at $4{\sim}9\;km$ intervals were irregularity. Linear functions of the groundwater level for dry and wet seasons as distance from shoreline were estimated, and the coefficient of determinant at $0{\sim}4\;km$ interval data was higher than it at $0{\sim}9\;km$ interval data. Increasing rate of groundwater level at $0{\sim}4\;km$ intervals was more 2 times than it at $0{\sim}9\;km$ intervals. This results are caused by linear increase of groundwater level to 4 km from shoreline and by irregularity of groundwater level at the $4{\sim}9\;km$ intervals.

Nitrogen Balance in Goats Fed Flemingia (Flemingia Macrophylla) and Jackfruit (Artocarpus Heterophyllus) Foliage Based Diets and Effect of a Daily Supplementation of Polyethylene Glycol (PEG) on Intake and Digestion

  • Mui, Nguyen Thi;Ledin, Inger;Uden, Peter;Binh, Dinh Van
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.5
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    • pp.699-707
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    • 2002
  • Diets with foliage of Flemingia (Flemingia macrophylla) or Jackfruit (Artocapus heterophyllus were fed to goats with the objective to study nitrogen (N) balance and effect of a daily supplementation of polyethylene glycol (PEG) on intake and digestion. In experiment 1, three male Alpine${\times}$Jamnapary goats with initial weights varying from 26.9 to 27.7 kg were used in a $3{\times}3$ Latin square design in the dry season. Three Alpine${\times}$Bachthao crosses, 15.3-16.7 kg, were used in the same design in the wet season. The three diets were based on chopped whole sugar cane complemented with the two green foliages, Jackfruit and Flemingia, or soybean meal (SBM). The level of dry matter (DM) offered was 4% of body weight (BW), 2.7% as foliage and 1.3% as chopped whole sugar cane. The amount of SBM offered was calculated to give the same amount of crude protein (CP) as the foliages. Each experimental period lasted 32 days (14 days for adaptation, 7 days for collection and 10 days for rest). Feed intake, apparent digestibility of DM, organic matter (OM), CP, neutral detergent fiber (NDF) and acid detergent fiber (ADF) and retained nitrogen (N) were measured by total faecal and urine collection. In experiment 2, four male goats (Alpine${\times}$Jamnapary) with initial weights from 17.1 to 23.1 kg were used in a $4{\times}4$ Latin square design. The four treatments were Jackfruit or Flemingia with or without addition of PEG, which was fed at a level of 5 g/goat and day by mixing with a small amount of rice bran. Each experimental period lasted 15 days (8 days for adaptation, 7 days for collection). Measurements were done as in experiment 1. The DM digestibility was highest (65.9-74.3%) for goats fed the SBM diet in both the dry and wet season. The DM digestibility of goats fed the Jackfruit and the Flemingia diets was similar in both the dry (58.6-59.2% respectively) and the wet season (53.9-56.1% respectively). The CP digestibility was highest (73.0-73.6%) for the SBM diet followed by the Jackfruit diet (47.0-38.5%) and was lowest (36.8-30.0%) for the Flemingia diet in both dry and wet seasons, respectively. The NDF digestibility was low for both the Jackfruit (36.4%) and Flemingia (38.0%) diets in the wet season. All diets resulted in a positive N balance. The N retention was highest (0.465-0.604 g/kg $W^{0.75}$) in the SBM diets and lowest (0.012-0.250 g/kg $W^{0.75}$) in the Flemingia diet. Addition of PEG had no effect on feed intake for any of the diets. PEG added in the Flemingia diet had a positive effect only on NDF digestibility, but the digestibility of the Jackfruit diet was significantly increased. Supplementation with PEG reduced digestibility and N retention of Flemingia, possibly because of the low tannin level, but increased digestibility and N retention for Jackfruit foliage.

Measurement of Dry deposition at Seoul, Chunchon and Anmyon-do by Using Filter pack Method (필터팩을 이용한 서울과 춘천, 안면도의 건성 강하량 측정)

  • Kim, Man-Goo;Kang, Mi-Hee;Hong, Young-Min;Park, Ki-Jun;Lee, Bo-Kyung;Lee, Dong-Soo;Kim, San
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.1
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    • pp.19-29
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    • 2001
  • Atmospheric concentrations of acidic pollutant were measured by the 4 stage filter pak method at Chunchon and by the 3 stage filter pack method at Seoul and Anmyon-do from January to December 1998. The sample was collected for 24 hours on every Wednesday. Concentrations of particulate matters were highest at Anmyon-do. The particulate concentration was much higher during the warm season than other seasons. While the particulate concentration was higher during the warm season, the concentration of gaseous matter was higher in winter. Dry deposition flux was calculated by using reported deposition velocities and concentration of pollutants measured in this study. The dry deposition velocities used in this study for SO$_2$, SO$_{4}^{2}$, HNO$_3$,NO$_{3}^{-}$ and NH$_3$ were 0.29, 0.15, 2.08( 2.13 only for Anmyon-do), 0.20 and 1.00cm/sec, respectively. At Chunchon, annual sulfur flux originated from dry deposition was 384 kg/$textrm{km}^2$, and the flux from wet deposition was 782kg/$textrm{km}^2$. Dry deposition of sulfur was 33% of total sulfur deposition. The annual nitrogen flux originated from dry deposition was 1,892kg/$textrm{km}^2$. And the flux from wet deposition was 1,066kg/$textrm{km}^2$. Dry deposition of nitrogen was 64% of total nitrogen deposition. Dry deposition as well as wet deposition have to be considerd in the study on acidification of environment such as soil or watershed.

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The Analysis of Potential Discharge by Dam in Han River Basin at Dry Season (한강 팔당하류의 갈수 시 댐 용수공급 가능유하량 분석)

  • Kim, Young-Kyu;Choi, Gye-Woon;Ham, Myeong-Soo;Kim, Nam-Won
    • Journal of Korea Water Resources Association
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    • v.41 no.11
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    • pp.1143-1152
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    • 2008
  • Korea is located in a monson area, so that 2/3 of precipitation is fallen down in rainy season and dry season has few rainfall. Also, water quality gets worse during dry season by shortage of water. In this paper, the method, which is a physical way to improve water quality by dilution through over supplied water from big reservoir or dam, is analyzed at Han-river basin. For the sake of the analysis, the basin is divided in 33 catchments and each catchments' natural flow is simulated by SWAT-K and the future water demand is estimated by using statistics data. It is considered that Han-river basin has two big reservoirs(Chung-ju dam, So-yang gang dam) and potential discharge by dam is calculated through case of supply water from each dam and supply water from both dams.

YIELD AND DIGESTIBILITY OF FORAGES IN EAST INDONESIA I. LEGUMES

  • Bulo, D.;Blair, G.J.;Stur, W.;Till, A.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.7 no.3
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    • pp.325-333
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    • 1994
  • This study was undertaken at Gowa, South Sulawesi, Indonesia as part of a larger forage genetic resource evaluation project. The experimental program consisted of a field experiment where grasses and legume species were grown in monocultures and the yield, N content and rumen bag digestibility using goats were measured. The field experiment was conducted from December 1985 to October 1986. Eight species of legumes (Desmodium heterophyllum cv. John-stone, Desmodium triflorum from Gowa, South Sulawesi, Arachis sp. from Maiwa, South Sulawesi, Clitoria ternalea CPI 50973, Macroptilium atropurpureum ev. Siratro, Neonotonia wightii cv. Tinaroo, Centrosema pubescens CPI 58575, Centrosema plumeri CPI 58568) were grown as monocultures. After establishment all plants were cut to a uniform height of 5 cm, and subsequent cuts were made on regrowth after 14, 28, 42, and 56 days (cycle 1). Cycle 2 commenced towards the end of the wet season and continued for 157 days into the dry season. The highest yielding legumes were C. ternatea in the wet season and Arachis sp. in the dry season. The mean rumen bag dry matter digestibility (RBDMD) of legumes of 67.6% for leaf material (averaged over all cycles and ages) was 7.6% higher than for stem material. The RBDMD of Arachis was significantly higher than all other species. The RBDMD of all legumes declined with age. Calculation of yield of digestible DM (yield $\times$ RBDMD) showed that Arachis sp. was the best legume. The combination of plant "quality" with yield measures is a valuable adjunct to routine agronomic survey procedures in plant evaluation programs. Arachis sp. appears to offer considerable promise and should be more widely evaluated.

The effect of plant spacing on several agronomic traits of a soybean variety under the tropical environment (열대환경하에 있어서 대두재식밀도가 각종형질에 미치는 영향)

  • Kwon, Shin-Han;Quyen, Nguyen H.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.7 no.1
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    • pp.133-137
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    • 1969
  • This experiment was conducted to determine the optimum row width and plant spacing within row under the tropical environment for a leading soybean variety Palmetto and it was carried out at Eakmat Experiment Station in Vietnam. The experiments were arranged in a split plot design with four replications and the test was repeated twice in two years. Variations for seed yield due to the distance between rows were significant at 1 per cent level in 1967 test(dry season growing) and at 5 per cent level in 1968 test. Significant differences for plant height, lodging, maturity, number of branches per plant, and number of pods per plant due to the row width were not found in both tests, while significant differences in difference spacing within row was found in all traits studied. Interaction between width of row and spacing within row for seed yield and plant height were found at five percent level in 1967 test. These results indicate that close planting may increase in seed yield and plant height in both seasons, and decrease in loadging. From these studies, one could be understood that the plant population, particularly in dry season, plays decisive roles on seed yield in soybean culture, and the maximum plant height and minimum value of lodging index were also observed in closest spacing plots. The highest soybean yield in late planting would be expected by a combinations of 30 cm(between rows)${\times}$5cm(between hills) plot, while 40cm ${\times}$ 5cm planting method would be suggested for rainy season growing. Highest seed yield was obtained at closet spacing in both dry and rainy season, and these results led to drilling method in seeding where about 20 seeds per meter of row could be recommended. Besides the seed yield, the close planting may produce some advantages, such as increase plant height and decrease lodging, weeds and erosion of surface soil.

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Is 'Dry Changma' a Case of Contradictio In Adjecto?: Changma and Natural Kinds ('마른 장마'는 진정 형용모순인가?: 장마와 자연종)

Seasonal Production Performance of Angora Rabbits under Sub-temperate Himalayan Conditions

  • Bhatt, R.S.;Sharma, S.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.3
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    • pp.416-420
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    • 2009
  • An experiment of one-year duration was conducted on sixteen adult male German Angora rabbits under sub-temperate Himalayan conditions, to assess the effect of seasons on their body weight, wool production and quality, plane of nutrition and the digestibilities of nutrients. The daily meteorological attribute viz. minimum and maximum temperature; relative humidity and rainfall were recorded during winter (October to March), summer (April to June) and rainy (July to September) seasons. Biological parameters viz. body weight at the time of shearing, wool yield of individual rabbit, quality attributes of wool, fortnightly dry matter intake, chemical composition of feed and fodder and digestibilities of nutrients were recorded. Average minimum and maximum ambient temperature during winter, summer and rainy seasons were 4.6${\pm}$1.9 and 21.4${\pm}$2.8; 13.6${\pm}$2 and 30.3${\pm}$2; and 20.0${\pm}$1.4 and $31.0{\pm}1.8^{\circ}C$, respectively. The average relative humidity and total rainfall during winter, summer and rainy season were 69.5${\pm}$2.9% and 74.7${\pm}$21.8 mm; 58.6${\pm}$2.2% and 38.1${\pm}$18.1 mm; and 69${\pm}$4.2% and 104.0${\pm}$43.7 mm, respectively. The body weight of rabbits increased during all seasons, however, the maximum average daily weight gain of 3.47${\pm}$0.1 g was observed during the rainy season. The wool yield differed significantly (p$\leq$0.05) among different seasons with highest (140.4${\pm}$10 g) and lowest (108.5${\pm}$6.9 g) during winter and summer, respectively. The wool yield during the rainy season was 123.3${\pm}$5.2 g. The wool quality attributes revealed non-significant differences for staple length, fiber diameter, medulation percent, percent pure fibers and percent guard hairs. Plane of nutrition revealed significant (p$\leq$0.05) differences for concentrate intake. The concentrate intake was highest during winter (124.4${\pm}$2.6 g) followed by summer (86.8${\pm}$8.9 g) and rainy (80.7${\pm}$11.8 g) seasons. The reverse trend was observed in roughage intake with significantly (p${\leq}$0.05) lower intake during winter and highest during summer months. As a result total dry matter intake during different seasons was similar. Significant differences (p${\leq}$0.05) were observed for digestibilities of crude protein, crude fiber, ether extract, acid detergent fiber and cellulose. Digestibility of crude protein was highest during winter whereas the digestibilities of crude fiber, ether extract, acid detergent fiber and cellulose remained higher during the rainy season. During the winter season, the dry matter used for producing 100 g of wool was substantially lower than during other seasons and was concluded to be the best season for production of Angora wool under subtemperate Himalayan conditions.