• Journal of Ecology and Environment
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• v.33 no.4
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• pp.289-298
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• 2010

A number of characteristics of the Lake H$\ddot{o}$vsg$\ddot{o}$l watershed, such as the lake's location at the edge of the Central Asian continuous permafrost zone, provide a unique opportunity to evaluate possible anthropogenic impacts in this remote area in northern Mongolia. In this study, we compared stream solute concentrations in six sub-watersheds in the Lake H$\ddot{o}$vsg$\ddot{o}$l watershed. Water samples were collected during the summer months between 2003 and 2005. Concentrations of $Cl^-$ ranged from 9.8 to $51.3\;{\mu}mol/L$; average nitrate concentrations were very low and ranged from undetectable to $1.1\;{\mu}mol/L$ and average ${SO_4}^{2-}$ concentration at sampling stations with minimal animal grazing ranged from 66 to $294\;{\mu}mol/L$. Average dissolved organic carbon (DOC) concentrations ranged from 642 to $1,180\;{\mu}mol$ C/L. We did not find statistically significant differences in DOC concentrations among the six streams, although DOC concentrations tended to be higher in the two northernmost streams, possibly related to differences in the active layer above the permafrost. Dissolved organic nitrogen (DON) concentrations were correlated with DOC concentration, and followed the same spatial pattern as those for DOC. In streams in this remote watershed, total dissolved nitrogen was made up of mostly organic N, as has been found for other regions distant from anthropogenic N sources. Overall, these results suggest that future research on the dynamics of DOC and DON in this watershed will be especially insightful in helping to understand how changes in climate and land use patterns will affect transformations, retention, and export of dissolved organic matter within these sub-watersheds in the Lake H$\ddot{o}$vsg$\ddot{o}$l region.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.3
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• pp.245-250
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• 1991

Analysis of the characteristics and the grouping of the species of sown and weeds in artificial pastures was studied applying the principal component analysis method. Presency and coverage of six sown species and fifteen weed species which occurred in pastures of under-grazing and optimumgrazing were subject to analysis. From field survey, species were divided into three groups: the group A included five species such as Festuca arundinacea, Lolium perenne and Dactylis glomerata, etc., the group B included eleven species such as Polygonum longisetum, Agrostis alba and Rumex obtusifolius, etc., and the group C included five species such as Miscanthus sinensis, Rubus palmatus and Artemisia princeps, etc. The group A species corresponded to good pasture conditions and management. On the contrary, the group C species occurred in poor pasture conditions with inadequate management. The group B species corresponded to intermediate pasture conditions and management. Interrelated pair species co-existing and species non-co-existing were discovered. Factor loading as negative for the group A species. positive for the group C species and positive but lower than the group C species for the group B species. From these results it is concluded that the principal component analysis seems to one of the useful tools for the analysis of characteristics of species and the diagnosis of sown pasture vegetation, although further studies are required to get more general information about species characteristics.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.41-47
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• 2001

Ruminal degradation characteristics of dry matter (DM), neutral detergent fiber (NDF) and crude protein (CP) in fresh leaves of two Japanese native grasses (Zoysia japonica and Miscanthus sinensis) and one sown temperate grass (Dactylis glomerata) were investigated by an in sacco method in spring (mid-May), summer (mid-July) and autumn (mid-September). Japanese native grasses had higher NDF and lower CP concentrations than D. glomerata, and the CP concentration in native grasses decreased in autumn. Ruminal degradability of DM, NDF and CP was lower in native grasses than in D. glomerata (p<0.05) in all seasons. DM and NDF degradability decreased in summer for Z. japonica and D. glomerata, while it decreased in autumn for M. sinensis. CP degradability in Z. japonica was constant throughout the seasons, whereas that in M. sinensis greatly decreased in summer and autumn (p<0.05). It was concluded that Z. japonica could stably supply ruminally digestible nutrients for grazing animals in Japanese native pasture. However, the degradation characteristics of freshly chopped native grasses did not fit the exponential model of $D=a+b(1-e^{-ct})$ proposed by Ørskov and McDonald.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.2
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• pp.81-88
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• 2016

This study was conducted to find out the effects of Improvement of Botanical Composition Technology (IBCT) on the forage production and ecological characteristics in a Rumex acetosella-dominated hilly pasture in Pyeongchang, in a period from August 2013 to the end of growing season in October 2015. $2MT\;ha^{-1}$ limestone was applied in August 2013 and April 2014. Liming significantly increased soil pH from 4.69 to 5.47 and then the soil pH consistently hovered at 4.91~4.98. For every grazing time, plant height was found to be higher with the application of IBCT as compared with the control. After grazing, no significant difference in plant height was found between the IBCT group and the control. Changes in the botanical composition of grassland can be affected by a lot of circumstances, but application of IBCT decreased Rumex acetosella from 12% to 2%, while also increasing the proportion of pasture. In relation to the botanical composition of grass, orchardgrass and timothy showed the highest percentages throughout the whole study period. The proportion of Kentucky bluegrass increased over time while tall fescue steadily decreased. The totals for grazing days were 58 in 2014 and 55 in 2015. Average herbage dry matter intake was $7,848kg\;ha^{-1}$ in 2014 and $6,941kg\;ha^{-1}$ in 2015. Due to the application of IBCT, dry matter productivity showed a significant increase of 59% during the first grazing period in 2014 (3,437 kg ha and 5,460 kg ha in control and IBCT). In 2015, the total dry matter yield of the IBCT group was 51% greater than the control ($5,742kg\;ha^{-1}$ and $8,685kg\;ha^{-1}$ in control and IBCT). Under acidic soil conditions, red sorrel can grow more strongly than grasses because it has better tolerance in dry and acidic conditions. Therefore, constant management is required in order to keep red sorrel from dominating the hilly pasture. In this study, the application of IBCT was able to effectively control weeds at all points. As a result, total management, including improvement of soil, overseeding, and application of selective herbicide and fertilizer, is needed to maintain excellent grassland conditions due to the limiting effects of environmental factors on grassland productivity.

• Journal of The Korean Society of Grassland and Forage Science
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• v.16 no.1
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• pp.61-68
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• 1996

Hehage production, botanical composition and soil chemical characteristics were investigated Ween new pastures and old pastures during grazing seasons from May 1993 to October 1994, to find out the condition of pastures grazed by horses on Chdu. Dry matter yields between new pastures and old pastures were 8,757kglha and 7,486kglha respectively. Plant heights of new pastures were 17.4cm. compared with those of old pastures of 12.lcm. The botanical composition of new pastures was composed of grasses about 402, legumes 7~14%, others 18-30% and dead materials 18~ 25%. whiie there were grasses 12%, legumes 3~7%, others 65% and dead materials 15% in old pastures. The contents of crude protein, phosphoms and sodium were lower in old pastures(l3.30, 0.24 and 0.10% respectively) than those in new pastures(l5.47, 0.28 and 0.14% respectively). There was no difference in ADF, NDF, Ca, Mg and K content between the 2 kinds of pastures. The chemical characteristics of the 2 kinds of pastures was shown to be similar, except available phosphorus, comparing 8.18ppm in old pastures with 84.43ppm in new pastures. Although the herbage yield and the soil characteristics of old pastures were lower than those of new pastures, we suppose that the old pastures would be improved, if taken good care of by methods such as oversowing and sometimes applying fertilizer.

• Journal of the Korean Ceramic Society
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• v.38 no.4
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• pp.370-379
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• 2001

PLD(pulsed laser deposition) 기법을 이용하여 LaAl $O_3$(100) 기판 위에 L $a_{0.67}$ $A_{0.33}$Mn $O_{3-{\delta}}$ (A=Ca, Sr, Ba) 에피 박막을 성장하였다. 박막의 격자 상수 및 스트레인 상태는 GID(grazing incidence X-ray diffraction)법과 투과 전자 현미경 법을 이용하여 조사하였다. 박막의 <001> 방향은 기판 표면의 수직방향에 평행하게 놓였으며, 박막의 단위포는 기판과의 격자 불일치에 기인하여 a/c=0.98인 의사-정방정 페롭스카이트(pseudo-tetragonal perovskite) 구조를 가졌다. A 자리의 양이온 반경이 증가함에 따라 단위포의 체적, $\varepsilon$$^{∥}$, 그리고 $\varepsilon$$_{⊥}$이 각각 증가하였다. L $a_{0.67}$ $A_{0.33}$Mn $O_{3-{\delta}}$ (A=Ca, Sr, Ba) 박막의 온도 및 자장에 따른 전기 전도 특성 MR(%), Tc, $T_{MI}$ 들을 조사하였으며, 이 결과들을 박막의 구조적 특성과 상관하여 고찰하였다.여 고찰하였다.

• The Journal of the Acoustical Society of Korea
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• v.22 no.1
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• pp.78-87
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• 2003

High-frequency (126-㎑) bottom backscattering measurements with various bottom types were conducted at the water tank in Ocean Acoustic Laboratory, Hanyang University. For the purpose of investigating the energy distribution of bottom scattering with various bottom types, the sediment was varied with gravel, sand, sandy mud and mixed bottoms. To examine the anisotropic nature of the scattering due to the orientations of bottom ripple, the footprints were made transverse and longitudinal to the direction of incident wave. The total scattering characteristics are that the larger grazing angles the larger backscattering strengths become and backscattering strengths for a transverse ripple case are higher than those of longitudinal ripple case. finally, the variations of scattering strength depend mainly on the ripple's orientation.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.148-155
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• 2010

Water quality and plankton community dynamics after the introduction of two domestic freshwater shellfishes (Unio douglasiae Griffith & Pidgeon and Cipangoplaudina chinese malleata Reeve), were monitored daily in enclosures, which constructed in the tidal zone of eutrophic agricultural reservoir (Shingu reservoir, Korea) for one week between July 31 and August 6, 2007. This biomanipulation study to improve the water quality of eutrophic lake, comprised eight enclosures (duplicate x four kinds), enclosure had no mussels (Control), stocked only with U. douglasiae at density of 60 individuals (UD), stocked only with C. chinese malleata at density of 60 individuals (CCM), and combined-stocked with 30 individuals of UD and 30 individuals of CCM (MIX), respectively. Our results clearly indicate that UD strongly decreased the concentration of chlorophyll-a and increased the water transparency, whereas CCM and MIX (included CCM) did increase algal density or decrease transparency, due perhaps to the disturbance of C. chinese malleata. Therefore, the field application of shellfish to enhance the water quality of eutrophic agricultural reservoir, should consider the grazing characteristics of biological control agents, especially active moving animals like snail.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8_spc
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• pp.1296-1305
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• 2019

There have been recent advances concerning research of the feeding and nutrition of dairy goats in a wide array of areas. Ruminally emitted methane and supplementary feedstuffs to a lesser extent make appreciable contributions to the carbon footprint of dairy goats, with the former affected by type of production system and associated dietary characteristics. Unique behavior of goats necessitates careful consideration of the nature of confinement facilities to achieve optimal production by animals differing in social hierarchy. Physiological conditions such as nutritional needs and perhaps health status may influence diet selection by goats in both grazing and confinement settings. Some research suggests that low concentrations of protein and fat in milk of high-yielding dairy goat breeds could involve the type and nature of dietary ingredients as influencing end products of ruminal fermentation. With the relationship between milk urea nitrogen concentration and efficiency of dietary protein utilization, through future research the measure may be a useful tool for diet formulation as in dairy cattle. Effects of dietary inclusion of sources of fats and oils vary considerably depending on their nature, as is also true for byproduct feedstuffs and conventional ones being substituted for. Supplementation of dairy goats with sources of polyunsaturated fatty acids can affect oxidative stress and various feedstuffs influence antioxidant status; however, research addressing the significance of such changes under practical production settings would be beneficial.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3121-3125
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• 2023

Neutron conversion detectors that use ¹⁰B-enriched boron carbide are feasible alternatives to ³He-based detectors. We prepared boron carbide films at micron-scale thickness using direct-current magnetron sputtering. The structural characteristics of natural B₄C films, including density, roughness, crystallization, and purity, were analyzed using grazing incidence X-ray reflectivity, X-ray diffraction, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and scanning electron microscopy. A beam profile test was conducted to verify the practicality of the ¹⁰B-enriched B₄C neutron conversion layer. A clear profile indicated the high quality of the neutron conversion of the boron carbide layer.