• 한국초지조사료학회지
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• 제43권4호
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• pp.268-273
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• 2023

본 연구에서는 국내 한우농가에서 주로 이용하고 있는 국내산 조사료 2종과 수입산 조사료 3종의 영양소 함량, 반추위 내 소화율, 발효특성 및 온실가스 발생량을 평가하기 위해 수행되었다. 알팔파는 조단백질 함량이 가장 높은 반면, NDF와 ADF 함량은 가장 낮았으며, 온실가스 측면에서 건물과 NDF 소화율 당 CO₂ 발생량이 낮았다. 한편 티모시는 건물과 NDF 소화율, 반추위 내총 VFA 함량이 가장 높았으며, 온실가스 측면에서 건물과 NDF 소화율 당 CH₄ 발생량이 가장 낮았다. 이상의 연구결과에서, 국내 한우농가에서 주로 이용하고 있는 조사료 중 사료가치(영양소 함량, 반추위 내 발효특성 및 간접 소화율)와 온실가스 저감 측면에서 티모시가 가장 우수한 것으로 사료된다. 따라서 국내에서 가장 많이 생산되고 있는 조사료인 이탈리안라이그라스와 볏짚의 사료가치 증진과 온실가스 저감을 위한 조사료 가공기술 개발이 필요할 것으로 사료된다.

• 한국토양비료학회지
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• 제11권1호
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• pp.17-24
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• 1978

아연결핍(亞鉛欠乏)에 의한 적고발생답(赤枯發生畓)에 대(對)하여 함아연입상용인(含亞鉛粒狀熔燐)과 함아연복합비료(含亞鉛複合肥料)를 시용(施用)하여 효과를 살펴본 바 그 결과(結果)는 다음과 같다. 1. 적고발생답토양(赤枯發生畓土壤)의 석회함량(石灰含量)은 10.5me/100g로서 많았고, pH는 7.03으로서 중성(中性)이었으며, 유효아연은 평균(平均) 3.35ppm, 유효규산은 67.7ppm로서 매우 낮았다. 2. 아연무처리구(亞鉛無處理區)에서의 수도체중(水稻體中)의 아연함량(亞鉛含量)은 이앙후(移秧後) 20일(日)과 출수기(出穗期)에 있어서는 22~23ppm로서 아연흠핍증(亞鉛欠乏症) 발생한계농도(發生限界濃度)인 20ppm를 약간(若干) 상회(上廻)하고 있으나 수확기(收穫期)에는 15ppm로서 훨씬 낮은 값을 보였다. 3. 수도체중(水稻體中)의 N/Zn와 $P_2O_5/Zn$의 비(比)는 아연시용량(亞鉛施用量)이 많을수록 아연무시용구(亞鉛無施用區)($G_0$, $C_0$)에 비(比)해서 낮아지는 경향(傾向)이었다. 4. 초장(草長)과 분벽경수(分蘗莖數)는 아연시용량(亞鉛施用量)의 증가(增加)에 따라 증대(增大)하는 경향(傾向)이었고 출수(出穗)는 아연시용구(亞鉛施用區)가 무시용구(無施用區)에 비해서 약(約 )2주일(週日) 빨랐다. 5. 아연시용구(亞鉛施用區)는 무시용구(無施用區)에 비(比)해서 수량구성요소(收量構成要素)의 제형질(諸形質)을 크게 증대(增大)시켰으며, 특(特)히 정조수량(精粗收量)과 현미수량(玄米收量)에 있어서는 고도(高度)의 유의차(有意差)를 보였으나 아연시용(亞鉛施用) 구간(區間)에는 유의차(有意差)가 인정(認定)되지 않았다.

• 한국재료학회지
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• 제22권4호
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• pp.180-184
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• 2012

Nanostructures of ZnO, such as nanowires, nanorods, nanorings, and nanobelts have been actively studied and applied in electronic or optical devices owing to the increased surface to volume ratio and quantum confinement that they provide. ZnO seed layer (about 40 nm thick) was deposited on Si(100) substrate by RF magnetron sputtering with power of 60 W for 5 min. ZnO nanorods were grown on ZnO seed layer/Si(100) substrate at $95^{\circ}C$ for 5 hr by hydrothermal method with concentrations of $Zn(NO_3)_2{\cdot}6H_2O$ [ZNH] and $(CH_2)_6N_4$ [HMT] precursors ranging from 0.02M to 0.1M. We observed the microstructure, crystal structure, and photoluminescence of the nanorods. The ZnO nanorods grew with hexahedron shape to the c-axis at (002), and increased their diameter and length with the increase of precursor concentration. In 0.06 M and 0.08 M precursors, the mean aspect ratio values of ZnO nanorods were 6.8 and 6.5; also, ZnO nanorods had good crystal quality. Near band edge emission (NBE) and a deep level emission (DLE) were observed in all ZnO nanorod samples. The highest peak of NBE and the lower DLE appeared in 0.06 M precursor; however, the highest peak of DLE and the lower peak of NBE appeared in the 0.02 M precursor. It is possible to explain these phenomena as results of the better crystal quality and homogeneous shape of the nanorods in the precursor solution of 0.06 M, and as resulting from the bed crystal quality and the formation of Zn vacancies in the nanorods due to the lack of $Zn^{++}$ in the 0.02 M precursor.

• 한국도시환경학회지
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• 제18권4호
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• pp.523-530
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• 2018

오존층의 파괴물질인 CFCs의 대체물로써 $SF_6$의 사용량이 늘어나면서 대기 중의 $SF_6$의 농도가 높아지고 있다. $SF_6$은 지구온난화가스중의 하나로써 대기 중에서 3,200년 이상 머무를 뿐만 아니라 온난화지수도 매우 높아 무려 22,800이나 된다. 그러나, 대기 중에서의 $SF_6$ 농도는 낮은 수준이어서 검출한계이하인 경우가 많다. 본 연구에서는 이러한 극미량 $SF_6$ 농도를 정확하게 분석하기 위해서 $GC-{\mu}ECD$를 이용한 12가지 분석방법을 실험적으로 고찰하였다. 극미량 $SF_6$ 농도를 가장 정확하게 분석할 수 있는 방법은 Carboxen-1000 물질을 사용한 흡착관과 저온농축 고온탈착 방식의 농축장치에 역추출방식의 분석법을 사용할 경우가 최상의 효율을 나타냈다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권8호
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• pp.1258-1265
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• 2007

Metabolizable energy (ME) required for basal metabolism, activity and growth was considered as the criterion for targeting specific increases in body weight (100 g/week) of broiler chicks during the grower phase (5-20 weeks) and its impact was evaluated on breeder performance. Broiler female chicks (460) from a synthetic dam line were randomly distributed to 4 test groups with 23 replicates of 5 birds each and housed in cages. The first group (ME-100) was offered a calculated amount of ME by providing a measured quantity of grower diet (160 g protein and 2,600 kcal ME/kg) which increased with age and weight gain (133-294 kcal/bird/day). The other three groups were offered 10 or 20% less ME (ME-90 and ME-80, respectively) and 10% excess ME (ME-110) over the control group (ME-100). From 21 weeks of age, a single breeder diet (170 g protein and 2,600 kcal ME/kg) was uniformly fed to all groups and the impact of grower ME restriction on breeder performance evaluated up to 58 weeks. The targeted body weight gain of 1,600 g in a 16-week period was achieved by pullets of the ME-100 group almost one week earlier by gaining 8.7 g more weight per week. However, pullets in the ME-90 group gained 1,571 g during the same period, which was closer to the targeted weight. At 20 weeks of age, the conversion efficiency of feed (5.21-5.37), ME (13.9-14.1 kcal/g weight gain) and protein (0.847-0.871 g/g weight gain), eviscerated meat yield, giblet and tibia weights were not influenced by ME restriction, but the weights of abdominal fat and liver were higher with increased ME intake. Reduction of ME by 10% in the grower period significantly delayed sexual maturity (169.3 d), but increased egg production (152.5 /bird) with better persistency. Improved conversion efficiency of feed, ME and protein per g egg content were also observed in this group up to 56 weeks. The fertility and hatchability at 58 weeks of age were higher in the ME-90 group compared to the control and 10% excess ME feeding. In conclusion, the present study revealed the possibility of achieving targeted weight gain in broiler growers by feeding measured quantities of ME during the rearing period with consequential benefits in breeder performance.

• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.1038-1047
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• 2008

This study aimed at targeting fixed increases in body weight (100 g/wk) by quantitatively regulating energy allowances (ME) in broiler breeders from 5 to 20 wks of age. Four energy regimes were tested: 1. The energy required for maintenance, activity and growth was calculated for 100 g increases in body weight/wk and a measured quantity of grower diet (160 g protein and 2,600 kcal ME/kg) was offered to the control group (ME-100) to achieve the anticipated weight gain. The energy allowances increased with age from 132 to 294 kcal/d. 2. Additionally, three energy regimes were considered, quantitatively reducing ME by 10% (ME-90) or 20% (ME-80) and increasing by10% (ME-110) over the control group. Each test group had 23 replicates5 female chicks housed in cages. The influence of energy regimes and age on growth, nutrient digestibility, carcass attributes, bone parameters and stress was evaluated at 4 wk intervals. Quantitative ME restriction by 10% (119-265 kcal/d) produced an average weight gain of 98.1 g/wk, which was closer to the targeted increase of 100 g/wk, whereas the control group attained it nine days earlier. Restriction of energy by 10 or 20% produced better conversion efficiency of feed, energy and protein and apparent digestibility of protein, Ca and P than 10% excess ME. Energy regimes did not influence eviscerated meat yield, but higher energy allowances (ME-110) significantly increased abdominal fat pad and liver weights and decreased giblet weight, percent muscle protein and tibia ash. Relatively higher stress was recorded in ME-restricted groups, as reflected by wider heterophil and lymphocyte ratios and increased bursa weight. Early age (5-12 wk) significantly influenced bone mineralization, conversion efficiency of feed, energy and protein and apparent digestibility of protein, Ca and P, while later ages (13-20 wk) increased eviscerated meat yield, abdominal fat, tibia weight and muscle protein and reduced stress. Energy regime x age interactions were significant and are discussed. In conclusion, the synthetic broiler line used in our study responded positively to controlled energy feeding during the rearing period. Breeders offered 119-265 kcal/d, a reduction of 10% energy over the control group, were more effective in regulating grower performance than the latter. In addition to energy regimes, age intervals also exhibited significant influence on specific parameters during the grower phase.

• 센서학회지
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• 제33권1호
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• pp.40-47
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• 2024

The creation of vertically aligned one-dimensional (1D) nanostructures through the decoration of n-type tin oxide (SnO₂) on p-type chromium oxide (Cr₂O₃) constitutes an effective strategy for enhancing gas sensing performance. These heterostructures are deposited in multiple stages using a glancing angle deposition technique with an electron beam evaporator, resulting in a reduction in the surface porosity of the nanorods as SnO₂ is incorporated. In comparison to Cr₂O₃ films, the bare Cr₂O₃ nanorods exhibits a response 3.3 times greater to 50 ppm H₂S at 300℃, while the SnO₂-decorated Cr₂O₃ nanorods demonstrate an eleven-fold increase in response. Furthermore, when subjected to various gases (CH₄, H₂S, CO₂, H₂), a notable selectivity toward H₂S is observed. This study paves the way for the development of p-type semiconductor sensors with heightened selectivity and sensitivity towards H₂S, thus advancing the prospects of gas sensor technology.

• 한국자원식물학회지
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• 제32권5호
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• pp.615-632
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• 2019

본 연구는 경상북도 중북부지역 낙동강 중류의 하천 식물상을 밝히고, 생활형을 파악하여 향후 유사지역 하천에서의 관속식물상 조사연구에 기초자료를 제공하고자 실시하였다. 현지조사는 2016년 5월부터 10월, 2017년 4월부터 10월에 걸쳐 영강, 내성천, 병성천, 위천 및 감천 등 5개 하천에서 실시하였고, 조사결과 조사지역에서 생육하는 관속식물은 99과 288속 421종 4아종 39변종 10품종 등 총 474분류군이었다. 이 중 양치식물은 8과 8속 10종 1변종 등 11분류군, 나자식물은 3과 3속 4종 등 4분류군, 쌍자엽식물 73과 217속 312종 3아종 25변종 8품종 등 348분류군, 단자엽식물 14과 60속 95종 1아종 13변종 2품종 등 111분류군으로 나타났다. 특산식물은 5분류군이 조사되었고, 식물구계학적특정종으로 중요도가 높은 III등급 이상을 살펴보면 V등급은 조사되지 않았으며, IV등급 3분류군, III등급 5분류군이 조사되었다. 희귀식물은 7분류군이 조사되었고, 귀화식물은 73분류군으로 조사되었다. 조사지역 소산식물의 생활형 분석결과 Th 159분류군, H 91분류군, HH 68분류군, G 52분류군, N 35분류군, MM 32분류군, M 25분류군, Ch 12분류군, E 1분류군 등으로 나타났다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권1호
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• pp.49-60
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• 2016

Distribution and behavior of baseline soil CO₂ were investigated in a candidate geologic CO₂ storage site in Pohang, with measuring CO₂ concentrations and carbon isotopes in the vadose zone as well as CO₂ fluxes and concentrations through ground surface. This investigation aimed to assess the baseline CO₂ levels and to build the CO₂ monitoring system before injecting CO₂. The gas in the vadose zone was collected using a peristaltic pump from the depth of 60 cm below ground surface, and stored at gas bags. Then the gas components (CO₂, O₂, N₂, CH₄) and δ¹³C_CO2 were analyzed using GC and CRDS (cavity ringdown spectroscopy) respectively in laboratory. CO₂ fluxes and CO₂ concentrations through ground surface were measured using Li-COR in field. In result, the median of the CO₂ concentrations in the vadose zone was about 3,000 ppm, and the δ¹³C_CO2 were in the wide range between −36.9‰ and −10.6‰. The results imply that the fate of CO₂ in the vadose zone was affected by soil property and vegetations. CO₂ in sandy or loamy soils originated from the respiration of microorganisms and the decomposition of C₃ plants. In gravel areas, the CO₂ concentrations decreased while the δ¹³C_CO2 increased because of the mixing with the atmospheric gas. In addition, the relation between O₂ and CO₂, N₂, and the relation between N₂/O₂ and CO₂ implied that the gases in the vadose zone dissolved in the infiltrating precipitation or the soil moisture. The median CO₂ flux through ground surface was 2.9 g/m²/d which is lower than the reported soil CO₂ fluxes in areas with temperate climates. CO₂ fluxes measured in sandy and loamy soil areas were higher (median 5.2 g/m²/d) than those in gravel areas (2.6 g/m²/d). The relationships between CO₂ fluxes and concentrations suggested that the transport of CO₂ from the vadose zone to ground surface was dominated by diffusion in the study area. In gravel areas, the mixing with atmospheric gases was significant. Based on this study result, a soil monitoring procedure has been established for a candidate geologic CO₂ storage site. Also, this study result provides ideas for innovating soil monitoring technologies.

• 멤브레인
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• 제29권1호
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• pp.51-60
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• 2019

분리막 소재의 투과도와 선택도 사이의 trade-off 관계로 인해 여전히 많은 연구가 필요하다. 특히 고분자 분리막에 무기물 나노입자가 들어가 있을 때, 기체투과 거동의 학문적 이해는 여전히 부족하다. 따라서 본 연구에서는 분리막 소재로 가장 많이 사용되는 PDMS에 2~5 nm의 기공을 가지고 있으며 직경이 약 5 nm 크기의 aluminosilicate hollow nanoparticles인 allophane을 이용하여 복합매질 분리막을 제조하여 기체투과특성을 연구하였다. 대표적인 분리막 소재인 PDMS에 친수성 allophane, 그리고 나노입자에 undecylenic acid로 표면을 개질한 allophane을 막 내부에 고르게 분산시켜 함량 별로 복합매질 분리막을 제조하였다. 나노입자가 분산된 혼합매질 분리막 내에서 기체의 투과 특성을 파악하고, 이에 따른 기체투과 거동과 나노입자가 가지고 있는 기공의 역할을 평가하고자 하였다. 표면개질된 allophane을 첨가함에 따라 기체 투과도와 산소/질소 그리고 이산화탄소/메탄의 선택도가 동시에 점진적으로 향상되는 결과를 얻었다.