• Bulletin of the Korean Chemical Society
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• 제35권4호
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• pp.1023-1028
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• 2014

Protonated caffeine ($CH^+$) and glucosamine ($GH^+$) overlapped in an analysis with ion mobility spectrometryquadrupole mass spectrometry. Ethyl lactate vapor (L) at different concentrations from 0 to 22 mmol $m^{-3}$ was added as a buffer gas modifier to separate these signals. The drift times of $CH^+$ and $GH^+$ increased with L concentration. The drift time increase was associated to clustering equilibria of $CH^+$ and $GH^+$ with one molecule of L and the equilibrium of $GH^+$ was more displaced to the formation of $GLH^+$ than that of $GLH^+$. $GH^+$ clustered more to L than $CH^+$ because $GLH^+$ formed more stable hydrogen bonds (26.30 kcal/mol) than $GLH^+$ (24.66 kcal/mol) and the positive charge in $GH^+$ was more sterically accessible than in $CH^+$. The aim of this work was to use theoretical calculations to guide the selection of a buffer gas modifier for IMS separations of two compounds that overlap in the mobility spectra and predict this separation, simplifying that empirical process.

• 멤브레인
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• 제24권5호
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• pp.358-366
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• 2014

Chitosan에 HNT (halloysite nanotube)의 함량을 0, 3, 5, 10 wt%로 가하여 chitosan-HNT 복합막을 제조하였다. 복합막의 구조는 FT-IR, XRD, TGA, SEM으로 알아보았다. 기체투과 실험은 $30^{\circ}C$, $4kg/cm^2$ 조건에서 수행하였고, chitosan-HNT 복합막의 HNT 함량 변화에 따른 $CO_2$와 $CH_4$의 기체투과도와 선택도를 조사하였다. Chitosan-HNT 복합막의 기체 투과도는 HNT 함량이 3 wt%에서 가장 큰 값을 보였고, 그 이상의 함량에서는 감소하였다. 선택도($CO_2/N_2$)는 0~10 wt% 범위에서 HNT 내의 OH기와 $CO_2$ 간의 친화력으로 인하여 증가하였고, 약 1.3~3.8의 값을 보였다.

• 한국조경학회지
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• 제23권1호
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• pp.111-122
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• 1995

12 populatiDns of Ch indicum L. and it's variation antogenous in Tforea were selected throughout the country and their morphological characteristics were studied in this paper. The results are as follows. 1) The mean of the plant height is 97.3cm. Ch. indicunl is 76.5cm and Ch. boreale is 116. 6cm in height. The number of nodes is 58 on the average. The color of the stem is generally black-red in the case of Ch. indicum and is green for Ch. boreale. 2) The leaves of Ch. inficum are smaller In size and thicker than chose of Ch. boreale, and it has a stipule. This fact enables us to distinguish one species from the other, however, the Gyukpo-population of Ch. indicum has a large leaf, and Byunsan-population of Ch. boreale has a stipule so that the above fact is not an exact criterion on which to base one classification. 3) The size of the capitulum is 24.9mm for Ch. indicum and 15.6mm in the case of Ch. boreaje so that the difference between species is admitted. It was confirmed hat the size of the capitulum has positive correlation to that of the pedicel and has egative correlation to the number of flowers, so that of inflorescence, Ch. indicumhas corymb, and Ch. boreale has crowed corymb or umbel-type.The number of ligulates is 19 on the average, which no the difference being founnd between species and populations.4) The cluster analysis of morphological characteristics showed that Ch. indicum wasdivided into two groups, which was shown thought to be due to the difference of speciesbetween Ch. indicum and Ch. boreale. However, it could not be shown that their morphological characteristics explain a geographical relationship between populations

• 센서학회지
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• 제24권4호
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• pp.258-263
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• 2015

In order to prevent drink-driving by detecting concentration of alcohol from driver's exhale breath, twenty chemical sensors fabricated. The one of purposes for sensor array which consists of those sensors is to discriminate between target gas(alcohol) and interference gases($CH_3CH_2OH$, CO, NOx, Toluene, and Xylene). Wilks's lambda was presented to achieve above purpose and optimal sensors were selected using the method. In this paper, step-wise sensor elimination based on Euclidean distance was investigated for selecting optimal sensors and compared with a result of Wilks's lambda method. The selectivity and sensitivity of sensor array were used for comparing performance of sensor array as a result of two methods. The data acquired from selected sensor were analyzed by pattern analysis methods, principal component analysis and Sammon's mapping to analyze cluster tendency in the low space (2D). The sensor array by stepwise sensor elimination method had a better sensitivity and selectivity compared to a result of Wilks's lambda method.

• Asian-Australasian Journal of Animal Sciences
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• 제24권4호
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• pp.471-478
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• 2011

The objectives were to compare the ability of various rumen microbial fractions to reduce nitrate and to assess the effect of nitrate on in vitro fermentation characteristics. Physical and chemical methods were used to differentiate the rumen microbial population into the following fractions: whole rumen fluid (WRF), protozoa (Pr), bacteria (Ba), and fungi (Fu). The three nitrogen substrate treatments were as follows: no supplemental nitrogen source, nitrate or urea, with the latter two being isonitrogenous additions. The results showed that during 24 h incubation, WRF, Pr and Ba fractions had an ability to reduce nitrate, and the rate of nitrate disappearance for the Pr fraction was similar to the WRF fraction, while the Ba fraction needed an adaptation period of 12 h before rapid nitrate disappearance. The WRF fraction had the greatest methane ($CH_4$) production and the Pr fraction had the greatest prevailing $H_2$ concentration (p<0.05). Compared to the urea treatment, nitrate diminished net gas and $CH_4$ production during incubation (p<0.05), and ammonia-N ($NH_3$-N) concentration (p<0.01). Nitrate also increased acetate, decreased propionate and decreased butyrate molar proportions (p<0.05). The Pr fraction had the highest acetate to propionate ratio (p<0.05). The Pr fraction as well as the Ba fraction appears to have an important role in nitrate reduction. Nitrate did not consistently alter total VFA concentration, but it did shift the VFA profile to higher acetate, lower propionate and lower butyrate molar proportions, consistent with less $CH_4$ production by all microbial fractions.

• 대한치과보철학회지
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• 제58권4호
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• pp.275-281
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• 2020

목적: 의치 연성이장재 적용기간 경과에 따른 물성저하 및 표면거침성이 의치구내염 발생을 야기할 수 있으며 이 논문의 목적은 항균물질인 키토산-은나노 복합체를 환원법으로 합성하고 이것을 연성이장재에 투여 후 그 특성을 평가하는 것이다. 재료 및 방법: 질산은과 키토산 분말로 혼합 정제된 키토산-은나노 복합체를 자외선 가시광선 및 적외선 분광법으로 분석하고 연성이장재 분말에 각각 0(대조군), 1.0, 3.0 및 5.0의 질량 분율로 첨가 후 단량체 용액과 각각 중합하였다. 항균복합체가 첨가된 연성이장재 시편의 특성은 중합완료 24 시간과 7 일 후 미세인장강도, 은 이온 용출 그리고 색조변화 등을 통하여 각각 평가하였다. 결과: 분광분석을 통하여 안정적인 키토산-은나노 복합체의 합성을 확인하였다. 대조군과 비교 시 복합체첨가에 따른 연성이장재의 유의한 인장강도 변화는 나타내지 않았고 (P > .05) 은 이온 용출은 복합체 투여량에 대하여 농도비례적으로 측정되었으며 색조변화량 또한 농도비례적으로 증가되었다 (P < .05). 결론: 키토산-은나노 복합체가 투여된 연성이장재는 적절한 물성과 은 이온 용출 특성을 가진 보철생체재료의 가능성을 도출하였고 임상 적용을 위한 항균실험 및 색조 안정성 등의 연구들이 추후 필요할 것으로 사료된다.

• 대한화학회지
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• 제24권4호
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• pp.288-294
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• 1980

$CH_3O(CO)Cl,\;CH_3S(CO)Cl\;및\;CH_3S(CS)Cl$/TEX>의 가메탄올 분해반응속도를 메탄올-아세토니트릴 혼합용매하에서 결정하였다. 반응속도는 주로 벌크한 용매성질에 의해서만 아니라 일부 친전자적 특수용매화에 의해서도 영향을 받는다는 것이 실험결과로 알려졌다. 용매의 극성은 반응속도에 영향을 미치는 중요인자는 아니지만, $S_N1$형의 천이상태 안정화에 기여함을 알았다. $CH_3S(CS)Cl$/TEX>의 가메탄올 분해반응은 메탄올에 의한 이탈기의 특수 용매효과 및 큰 유전상수를 가진 용매에 의한 천이상태 안정화가 중요한 $S_N1$형으로 진행됨을 알았다. $CH_3O(CO)Cl$의 가메탄올 분해반응은 위의 경우와는 반대로 $S_N2$형으로 진행됨을 알았다.

• Journal of Animal Science and Technology
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• 제63권1호
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• pp.16-24
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• 2021

The suppressive effect of monensin as an ionophore-feed additive on enteric methane (CH4) emission and renewable methanogenesis were evaluated. To clarify the suppressive effect of monensin a respiratory trial with head cage was performed using Holstein-Friesian steers. Steers were offered high concentrate diets (80% concentrate and 20% hay) ad libitum with or without monensin, galacto-oligosaccharides (GOS) or L-cysteine. Steers that received monensin containing diet had significantly (p < 0.01) lower enteric CH4 emissions as well as those that received GOS containing diet (p < 0.05) compared to steers fed control diets. Thermophilic digesters at 55℃ that received manure from steers fed on monensin diets had a delay in the initial CH4 production. Monensin is a strong inhibitor of enteric methanogenesis, but has a negative impact on biogas energy production at short retention times. Effects of the activity of coprophagous insects on CH4 and nitrous oxide (N2O) emissions from cattle dung pats were assessed in anaerobic in vitro continuous gas quantification system modified to aerobic quantification device. The CH4 emission from dungs with adults of Caccobius jessoensis Harold (dung beetle) and the larvae of the fly Neomyia cornicina (Fabricius) were compared with that from control dung without insect. The cumulative CH4 emission rate from dung with dung insects decreased at 42.2% in dung beetles and 77.8% in fly larvae compared to that from control dung without insects. However, the cumulative N2O emission rate increased 23.4% in dung beetles even though it reduced 88.6% in fly larvae compared to dung without coprophagous insects. It was suggested that the antibacterial efficacy of ionophores supplemented as a growth promoter still continued even in the digested slurry, consequently, possible environmental contamination with the antibiotics might be active to put the negative impact to land ecosystem involved in greenhouse gas mitigation when the digested slurry was applied to the fields as liquid manure.

• 한국수산과학회지
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• 제24권2호
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• pp.117-122
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• 1991

Nauplius에서 Adult까지 각 생장단계의 Tigriopus japonicus에 수종의 이료의 효과를 비교한 결과 다음과 같은 결과를 얻었다. 단일 이료로서 Acinetobacter sp. AG-3균주 건조효모, Chlorella sp. 및 Tide pool에서 분리한 단세포조류(Chlorococcum sp.)균주를 투여하여, 4일후에 T. japonicus의 체중 및 체장증가를 측정한 결과, Nauplius에 대해서는 Yeast, (Bacteria+ Chlococcum sp.), Chlorococcum sp., (Bacterla+chlorella sp.), Bacteria, Chlorella sp.의 순으로 효과가 저하되었고 Copepodite는 (Bacteria+Chlorococcum sp.)가 가장 좋았고, Yeast, Chlorococcum sp., (Bacteria+ Chlorella sp.) , Bacteria, Chlorella sp.의 순으로 이료 효과가 저하되었으며, Adult에서는 Copepodite와 같이 (Bacteria+ Chlorococcum sp.), Chlorococcum sp., Yeast, (Bacteria+ Chlorella sp.), Bacteria, Chlorella sp.의 순으로 먹이 효과의 저하가 관찰되었다. T. japonicus 개체에 24시간 동안 섭취된 미생물량(C)과 체중증가량(P)를 각각 탄소양으로 환산하여 섭취 이료의 전환효율$(P/C, \%)$을 구한 결과 각 이료 미생물의 전환효율은 T. japonicus의 각 생장단계에 있어서 $21.6-68.7\%$범위의 차이를 보였다. 이료 세균 및 단세포조류와 혼합 이료는 T. japonicus증식에 충분한 이료 가치가 있음을 알 수가 있었다.

• 한국미생물·생명공학회지
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• 제12권4호
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• pp.285-291
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• 1984

액상발효유 제조시에 유산균 starter의 단백질 분해능이 산생성과 제품의 단백질 안정성에 미치는 영향을 조사하였다. L. bulgarious CH 2, L. helviticus IAM 1042, L. jugurti 3048은 우유에 배양할 때에 비교적 높은 단백질 분해능을 나타내었으나 L. casei YIT 9018은 단백질 분해능이 아주 약했다. 또 단백질 분해능이 높은 균들은 낮은 균들보다 우유에서의 증식과 산생성 속도가 빨랐다. 유단백질의 분해가 가장 심하게 이루어지는 시기는 균의 대수증식기이었고, 배양개시로부터 24∼48시간 이후에서는 유단백질의 분해가 거의 더 진행되지 않았다. L. bulgaricus CH 2, L. helviticus IAM 1042, L. jugurti 3048, L. acidophilus L 54, L. casei 3012로 제조된 발효유들은 모두 유단백질 분해가 비교적 심하게 일어났고, pH 3.5에서의 유단백질 용해도가 낮았고, 제품의 저장시에 유단백질 침전이 심하게 생성되었다. 그러나 artificial acidification이나 L. casei YIT 9018에 의하여 제조된 제품들은 유단백질의 분해가 거의 없었고, pH 3.5 에서의 단백질 용해도도 높았고, 저장시에 침전도 전혀 발생되지 않았다.