• 생체재료학회지
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• 제22권4호
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• pp.249-258
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• 2018

Background: Mucoadhesive polymers, which may increase the contact time between the polymer and the tissue, have been widely investigated for pharmaceutical formulations. In this study, we developed a new polysaccharide-based mucoadhesive polymer with thermogelling properties. Methods: Hexanoyl glycol chitosan (HGC), a new thermogelling polymer, was synthesized by the chemical modification of glycol chitosan using hexanoic anhydride. The HGC was further modified to include thiol groups to improve the mucoadhesive property of thermogelling HGC. The degree of thiolation of the thiolated HGCs (SH-HGCs) was controlled in the range of 5-10% by adjusting the feed molar ratio. The structure of the chemically modified polymers was characterized by $^1H$ NMR and ATR-FTIR. The sol-gel transition, mucoadhesiveness, and biocompatibility of the polymers were determined by a tube inverting method, rheological measurements, and in vitro cytotoxicity tests, respectively. Results: The aqueous solution (4 wt%) of HGC with approximately 33% substitution showed a sol-gel transition temperature of approximately $41^{\circ}C$. SH-HGCs demonstrated lower sol-gel transition temperatures ($34{\pm}1$ and $31{\pm}1^{\circ}C$) compared to that of HGC due to the introduction of thiol groups. Rheological studies of aqueous mixture solutions of SH-HGCs and mucin showed that SH-HGCs had stronger mucoadhesiveness than HGC due to the interaction between the thiol groups of SH-HGCs and mucin. Additionally, we confirmed that the thermogelling properties might improve the mucoadhesive force of polymers. Several in vitro cytotoxicity tests showed that SH-HGCs showed little toxicity at concentrations of 0.1-1.0 wt%, indicating good biocompatibility of the polymers. Conclusions: The resultant thiolated hexanoyl glycol chitosans may play a crucial role in mucoadhesive applications in biomedical areas.

• Asian-Australasian Journal of Animal Sciences
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• 제25권4호
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• pp.559-568
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• 2012

White (Lohmann LSL) and Brown (ATAK-S) laying hens, were reared under organic and conventional cage rearing systems, and the effects of the rearing system on performance parameters, egg production, egg characteristics, and immune response were investigated. For this purpose, a total of 832 laying hens of two commercial hybrids, i.e., 416 white (Lohmann LSL) and 416 Brown (ATAK-S) layers, were used. The experiment lasted between 23 and 70 wk of age. In this study, the white layers yielded more eggs as compared to the brown layers in both organic and conventional production systems. Egg weight exhibited a similar pattern to that of laying performance. However, the total hen-housed egg number for the white birds in the organic system was fewer than that of white birds in the conventional cage facility; conversely, a contradictory tendency was observed for the brown birds. Livability of the white layers in the organic system was remarkably lower (14%) than that of the brown line, whereas the white line survived better (3.42%) than their brown counterparts in conventional cages. The feed conversion ratio of the white hens was markedly inferior in the organic system as compared to that of the white hens in the conventional system, whereas relatively lower deterioration was reported in brown layers when reared in an organic system. The organic production system increased egg albumen height and the Haugh unit in eggs of the brown layers. The yolk color score of organic eggs was lower than that of conventional eggs for both brown and white hens. The egg yolk ratio of eggs from white layers was found to be higher in organic eggs as compared to those obtained in the conventional system. All organic eggs had heavier shells than those produced in the conventional system. Eggs from brown layers had more protein content than eggs from white layers. Neither housing systems nor genotype influenced egg yolk cholesterol concentration. When compared to conventional eggs, n-3 fatty acid content was lower in organic eggs, and the n-6:n-3 ratio was higher in organic eggs. In conclusion, two hen genotypes showed different responses in terms of performance and egg quality to two different rearing systems. A commercial white strain produced more eggs with higher egg quality as compared to a native brown strain. The brown strain was found to have adapted well to organic production conditions when survival and total egg number was taken into consideration.

• 환경위생공학
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• 제16권2호
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• pp.79-90
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• 2001

Commercial liquid seeds are used for supplying active microbial flora to organic wastewater treatment plants of high feed-to-microorganism ratio and to maintain optimal microbial condition during unsteady state operation of the biological wastewater treatment plant. In addition to bacterial cells, the liquid weeds contain various additives for special purposes as well as organic substrates for energy supply. The additives give physical stability for the maintenance of microbial decomposition activity and ability to control the overgrowth of seed strains. In this work, the effects of addition of two kinds of typical substrate additives, poly aluminum chloride(PAC) and poly aluminum sulfate(PAS) on the consitutional total cell counts(CFU/ml) of four kinds of reorganization liquid seeds(RLS I, RLS II, RLS III and RLS IV) were studied experimentally. The addition of PAC and PAS gave negative effect on TCC constitution for the four seeds studied.

• Korean Chemical Engineering Research
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• 제43권2호
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• pp.266-271
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• 2005

혼합유기산으로부터 숙신산의 분리를 단극 분리막을 사용한 탈염전기투석장치를 이용하여 행하였다. 전류효율, 회수율, 에너지소요량, 분리비 등의 변화를 pH 값과 초기농도비에 따라 측정하였다. 숙신산의 분리는 숙신산과 아세트산의 이온화율, 분자량, 이온전도도, 전자가 크기 그리고 초기농도비 등으로 해석될 수 있었다.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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• pp.179-182
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• 2004

This study reports the extraction behavior of $\alpha$-lactalbumin using bis(2-ethylhexyl) sulfosuccinate sodium (AOT) reverse micelles. Forward extraction of $\alpha$-lactalbumin in the reverse micellar organic phase from aqueous feed solutions was strongly dependent on the AOT concentration and the complete forward extraction of 0.03 mM $\alpha$-lactalbumin was successfully achieved at an AOT concentration of ca. 100 mM. A similar dependency of the forward extraction on the AOT concentration was obtained in isooctane, n-hexane, and n-octane systems. In the backward extraction from the micellar organic phase, the recovery of the protein as high as ca. 90% was obtained with pH control and/or salt addition.

• Asian-Australasian Journal of Animal Sciences
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• 제27권10호
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• pp.1513-1520
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• 2014

The present aim was to investigate the effects of traditional Chinese medicine prescriptions (TCM) on body temperature, blood physiological parameters, nutrient apparent digestibility and growth performance of beef cattle under heat stress conditions. Twenty-seven beef cattle were randomly divided into three groups as following; i) high temperature control (HTC), ii) traditional Chinese medicine prescriptions I+high temperature (TCM I) and iii) traditional Chinese medicine prescriptions II+high temperature (TCM II) (n = 9 per group). The results showed that the mean body temperature declined in TCM II treatment (p<0.05). Serum $T_3$ and $T_4$ levels with TCM I and TCM II treatments elevated (p<0.05), and serum cortisol levels of TCM I treatments decreased (p<0.05), compared with the HTC group. Total protein, albumin, globulin in TCM II treatments elevated and blood urea nitrogen levels of both TCM treatments increased, but glucose levels of both TCM treatments decreased, compared with the HTC group (p<0.05). The apparent digestibility of organic matter and crude protein with TCM I treatment increased, and the apparent digestibility of acid detergent fiber elevated in both TCM treatments (p<0.05). Average daily feed intake was not different among three groups, however average daily gain increased and the feed:gain ratio decreased with both TCM treatments, compared with the HTC group (p<0.05). The present results suggest that dietary supplementation with TCM I or TCM II improves growth performance of heat stressed beef cattle by relieving heat stress responses and increasing nutrient apparent digestibility.

• 한국유기농업학회지
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• 제13권3호
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• pp.315-332
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• 2005

본 연구는 환경오염원으로 대두되고 있는 생활 폐기물인 남은 음식물에 미생물 lactobacillus와 bacillus를 3:7의 비율로 첨가하여 발효공정을 거친 후, 일부원료와 혼합하여 돼지 사료원으로서 영양적 가치 및 안전성을 검사하였고, 이들 발효 남은 음식물을 양돈사료에 직접적으로 이용하기 위해 완전혼합사료를 제조하여 돼지에게 급여했을 때 돼지의 생산성, 도체특성 및 경제성을 조사하기 위하여 실시하였다. 실험처리군은 발효 남은 음식물을 구성하는 발효펠렛사료와 시판사료를 다양한 비율(T1: 펠렛사료 $100\%$, T2: 펠렛사료 $75\%$+시판사료 $25\%$, T3: 펠렛사료 $50\%$+시판사료 $50\%$, T4: 펠렛사료 $25\%$+시판사료 $75\%$, T5: 시판사료 $100\%$)로 혼합하여 처리군당 육성돈을 4두씩 배치하여 총 20두의 돼지가 본 연구에 사용되었다. 사양시험기간은 10주간 지속되었다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 1 발효 남은 음식물의 수분과 단백질 및 에테르추출물함량은 각각 56.7, 19.5 및 $19.5\%$로 높은 비율을 나타내었고, 염분함량은 $0.39\%$로 나타났다. 2. 발효 남은 음식물 내에서 유해미생물인 살모넬라 및 대장균이 검출되지 않았고, 중금속 및 아플라톡신 B1은 기준치 이하로 나타났다. 3. 발효 남은 음식물 펠렛사료의 영양소 함량은 한국사양표준의 요구량을 $100\%$이상 충족시켰다. 4. 사양시험 성적은 남은 음식물 펠렛사료 혼합비율이 증가함에 따라 사료섭취량이 유의하게 감소하였고(P<0.05), 경제성과 증체율을 고려하면 $75\%$ 혼합비율이 가장 이상적이었다. 5. 도체성적은 발효 남은 음식물 펠렛사료 $50\%$ 혼합구에서 도체율이 가장 높았고, 도체등급은 펠렛사료 $25\%,\;50\%,\;75\%$군에서 모두 A등급을 나타내었다. 6. 제조된 발효 남은 음식물 펠렛사료의 가격은 167.95원으로 일반 시판사료 350원/kg의 약 $52\%$로 사료비 절약효과가 있는 것으로 나타났다. 따라서 본 결과는 발효 남은 음식물사료가 농가의 사료비감소에 효과적인 것으로 나타났다. 이상의 결과로부터 남은 음식물의 사료로서 이용은 환경오염감소와 유기축산의 실천에 기여할 것으로 사료된다. 하지만, 본 연구결과에서 과도한 양의 발효 남은 음식물의 급여는 기호성 감소 및 돼지의 성장지연을 초래할 수 있음을 보여주었다.

• 한국가금학회지
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• 제36권2호
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• pp.139-147
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• 2009

본 연구는 교잡육용계에서 최적 수준의 유기 사료 영양소 함량을 구명하고자 에너지 및 단백질 수준이 다른 사료 급여가 육색육용계의 생산성, 혈액 성상 및 계육 품질에 미치는 영향을 구명하기 위해 수행하였다. 공시동물은 0, 6, 11 주령 유색육용계를 사용하였다. 시험 사료의 에너지 및 단백질 수준은 0~5주에 ME 3,000, 3,050, 3,100 kcal/kg, CP 21, 22%, 6~10주는 ME 3,050, 3,100, 3,150 kcal/kg, CP 19, 20%, 11~15주는 3,100, 3,150 kcal/kg, CP 17, 18%로 하였다. 처리구는 0~5, 6~10주에 $2{\times}3$ factorial design으로 총 6개 처리구 이고 처리구당 4반복, 반복당 20수씩, 11~15주는 $2{\times}2$ factorial design이며, 총 4개 처리구, 3반복, 반복당 28수씩 배치하였다. 0~5주의 증체량은 에너지 수준이 증가할수록 증가하는 경향을 보였다. 사료 섭취량은 에너지 수준이 높을수록 현저하게 감소하였다(P<0.05). 사료 요구율은 ME 3,100 처리구가 ME 3,000, 3,050 처리구보다 통계적으로 감소하였고 단백질은 생산성에 영향을 미치지 않았다(P<0.05). 6~10주간 증체량, 사료 섭취량은 에너지 수준이 높을수록 각각 증가 및 감소하는 경향을 나타내었고, 사료 요구율은 ME 3,100, 3,150 처리구가 ME 3,050 처리구보다 유의하게 감소되었고, 단백질 처리구들은 생산성에 영향을 미치지 않았다(P<0.05). 11~15주간 증체량, 사료 섭취량은 에너지가 높고 단백질이 낮은 처리구에서 증가하는 경향을 나타내었다. 사료 요구율은 ME 3,150 처리구가 ME 3,000 처리구보다 두드러지게 감소하였고, CP 처리구는 차이가 없었다(P<0.05). 각 기간별 생산성에 대한 에너지 및 단백질 간 교호 작용은 나타내지 않았다. 혈액 성상 및 계육 품질은 에너지와 단백질 수준에 따른 처리구간 유의적인 차이가 없으며 교호 작용도 없었다. 따라서 0~5주 사료의 에너지 수준은 3,100 kcal/kg, 단백질은 21%, 6~10주는 ME 3,100 혹은 3,150 kcal/kg, CP 19%이고 후기 사료의 에너지 및 단백질 수준은 혹서기에 영향을 받아 적정 수준을 정할 수 없다. 본 연구 결과는 사양 기간별 수행한 결과이므로 0~15주간 수행하는 추가 시험이 필요하다.

• 한국막학회:학술대회논문집
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• 한국막학회 1994년도 춘계 총회 및 학술발표회
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• pp.29-32
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• 1994

The increasing environmental risks exert strong demands for the knowledge of environmentally significant compounds and the reduction of such compounds on the earth. The risk reduction can, in principle, be most effectively achieved by minimizing the formation of environmental pollutants, by-products in many cases, during processes in factories, power plants and other sources. This can be done by on-line, real time monitoring the formation of pollutants at the moment when they are formed, and thereby through the feed-back control of the process.

• 한국막학회:학술대회논문집
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• 한국막학회 1991년도 추계 총회 및 학술발표회
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• pp.1-3
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• 1991

A novel membrane separation process for the separation of liquid mixture is Pervaporation. The term, 'pervaporation', is a combination of permeation and evaporation, and was first introduced by kober[1] in 1917. In this technique, the liquid mixture in feed is in contact with one side of a dense non-porous membrane and after diffusing through the membrane is removed from the downstream side in the vapor phase, but is usually condensed afterwards to obtain a permeate in liquid from.