• Title/Summary/Keyword: nylon 4/6

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Flow Resistance and Modeling Rule of Fishing Nets -2. Flow Resistance of Bag Nets- (그물어구의 유수저항과 모형수칙 -2. 자루형 그물의 유수저항-)

  • KIM Dae-An
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.28 no.2
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    • pp.194-201
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    • 1995
  • In order to make clear the resistance of bag nets, the resistance R of bag nets with wall area S designed in pyramid shape was measured in a circulating water tank with control of flow velocity v and the coefficient k in $R=kSv^2$ was investigated. The coefficient k showed no change In the nets designed in regular pyramid shape when their mouths were attached alternately to the circular and square frames, because their shape in water became a circular cone in the circular frame and equal to the cone with the exception of the vicinity of frame in the square one. On the other hand, a net designed in right pyramid shape and then attached to a rectangular frame showed an elliptic cone with the exception of the vicinity of frame in water, but produced no significant difference in value of k in comparison with that making a circular cone in water. In the nets making a circular cone in water, k was higher in nets with larger d/l, ratio of diameter d to length I of bars, and decreased as the ratio S/S_m$ of S to the area $S_m$ of net mouth was increased or as the attack angle 9 of net to the water flow was decreased. But the value of ks15m was almost constant in the region of S/S_m=1-4$ or $\theta=15-90^{\circ}$ and in creased linearly in S/S_m>4 or in $\theta<15^{\circ}$ However, these variation of k could be summarized by the equation obtained in the previous paper. That is, the coefficient $k(kg\;\cdot\;sec^2/m^4)$ of bag nets was expressed as $$k=160R_e\;^{-01}(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for the condition of $R_e<100$ and $$k=100(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for $R_e\geq100$, where $S_n$ is their total area projected to the plane perpendicular to the water flow and $R_e$ the Reynolds' number on which the representative size was taken by the value of $\lambda$ defined as $$\lambda={\frac{\pi d^2}{21\;sin\;2\varphi}$$ where If is the angle between two adjacent bars, d the diameter of bars, and 21 the mesh size. Conclusively, it is clarified that the coefficient k obtained in the previous paper agrees with the experimental results for bag nets.

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Nutritional value and in situ degradability of oak wood roughage and its feeding effects on growth performance and behavior of Hanwoo steers during the early fattening period

  • Ju, Ye Ri;Baek, Youl Chang;Jang, Sun Sik;Oh, Young Kyoon;Lee, Sung Suk;Kim, Yong Sik;Park, Keun Kyu
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.6
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    • pp.930-940
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    • 2020
  • Objective: This study was conducted to evaluate changes in nutritional value and in situ dry matter (DM) degradability of oak and pine wood before and after steam-digestion process (60 min/160℃/6 atm) and feeding effect of the oak roughage on performance and behavior of Hanwoo steers. Methods: Chemical composition and tannin concentration were analyzed for oak and pine trees before and after the pretreatment. In situ DM and effective degradability of these samples were assessed using a nylon bag method. In vivo trial was performed to estimate animal performance and behavior, using steers fed total mixed ration (TMR) diets containing 0% (control), 25% (OR-25), and 50% (OR-50) of the oak roughage. Eighteen steers were allocated into nine pens (2 steers/pen, 3 pens/treatment) for 52 days according to body weight (BW) and age. Results: By the steam-digestion treatment, the neutral detergent-insoluble fiber was decreased from 86.5% to 71.5% for oak and from 92.4% to 80.5% for pine, thereby increasing non-fiber carbohydrate. In situ DM degradability of treated oak reached 38% at 72 h, whereas that of untreated oak was only 11.9%. The 0 h degradability of the treated pine increased from 5.9% to 12.1%, but the degradability was unchanged thereafter. Animal performance including BW, average daily gain, DM intake, and feed conversion ratio was not different among control and oak treatments. No differences were detected in animal behavior such as lying, standing, rumination, drinking, and eating, except walking. Walking was higher in control than oak treatments with numerically higher eating and lower lying times, probably due to bulkier characteristics of rice straw in the diet. Conclusion: This study demonstrates that the oak roughage can be substituted for 50% of total forage or 100% of rice straw in TMR diets at early fattening stage of Hanwoo steers.

A Study on the Distribution and Composition of Floating Debris in the Coast of Korea II. Transport of Debris in Middle Part of Southern Sea (연안어장의 부유성 폐기물 분포와 조성에 관한 연구 II. 남해 중부해역의 폐기물 수송)

  • KIM Jong-Hwa
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.3
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    • pp.338-344
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    • 1999
  • Floating debris was recorded from a training ship, $\sharp$1 Kwanaksan, of Pukyong National University with about 10 knots speed at July 15th and 20th of 1997. The sampled area is the middle of southern sea of Korea, divided into 44 unit segments on survey routes. Debris fabrication materials were categorized with 6 items using the following; man-made or natural wood items, paper and cardboard, nylon netting and rope, styrofoam, plastics, floating metal and glass containers. All identified items within a 100 $\pm$ 2 m wide band were recorded but ignored if beyond this boundary. The results of distribution and transport of floating debris in the area are as follows: 1. The quantities of debris during the survey were distributed from $1.6\~369.7\;items/km^2$. The most obvious trend is the widespread distribution of all debris. The highest densities of all debris were discovered in the coastal waters of Namhae and Yokji island, and of about 50 km off from the southward of Yokji and about 74 km off from the eastward of Komun island. Especially many of small styrofoams within $\phi$20 cm were observed in these segments. 2. Styrofoams and plastics were composed of $83.5\%$ among all debris, next woods items, $9.8\%$. 3. The quantities, distribution shapes and composition of debris were varied as the observed duration and the natures of each items. 4. These phenomena are concluded that firstly they depend on the river discharges included debris due to precipitation falls, secondly inflow or dumping debris are drifting to the off-shore by Kuroshio currents present at their adjacent sea, But on the basis of the observed data it is difficult that source position, quantities and inflow items of debris are identified, and also the transport processes is pursue. further more surveys are continuously being investigated, and from this it is hoped that a much wider coverage can be achieved, perhaps on all sites of the Coast of Korea and contributed to the stationary area, finding of sources, removal method of debris and resistants of marine productivity.

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The Effect of the Water Extract of Uncariae Ramulus et Uncus on Gliosis in the Middle Cerebral Artery Occlusion(MCAO) Rats (조구등이 MCAO 모델 흰쥐에서 gliosis 억제에 미치는 영향)

  • Kim, Sang-Woo;Kim, Sun-Ae;Song, Bong-Keun
    • The Journal of Internal Korean Medicine
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    • v.31 no.4
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    • pp.763-774
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    • 2010
  • Objectives : In condition of brain infarction, irreversible axon damage occurs in central nerve system(CNS), because gliosis becomes physical and mechanical barrier to axonal regeneration. Reactive gliosis induced by ischemic injury such as middle cerebral artery occlusion is involved with up-regulation of GFAP and CD81. The current study is to examine the effect of the Uncariae Ramulus et Uncus on CD81 and GFAP expression in the rat brain following middle cerebral artery occlusion. Methods : In order to study ischemic injuries on brain, infarction was induced by middle cerebral artery occlusion(MCAO) using insertion of a single nylon thread, through the internal carotid artery, into a middle cerebral artery. Cresyl violet staining, cerebral infarction size measurement, immunohistochemistry and microscopic examination were used to detect the expression of CD81 and GFAP and the effect on the infarct size and pyramidal cell death in the brain of the rat with cerebral infarction induced by MCAO. Results : The following results were obtained 1. Measuring the size of cerebral infartion induced by MCAO in the rat after injection of Uncariae Ramulus et Uncus showed the size was decreased. 2. Intravenous injection of Uncariae Ramulus et Uncus showed pyramidal cell death protection in the hippocampus in the MCAO rat. 3. Water extract injection of Uncariae Ramulus et Uncus decreased GFAP expression significantly in the MCAO rat. 4. Uncariae Ramulus et Uncus water extract decreased CD81 expression in the MCAO rat. 5. The administration of water extract of Uncariae Ramulus et Uncus induced up-regulation of c-Fos expression significantly compared with MCAO. 6. The admistration of water extract of Uncariae Ramulus et Uncus increased ERK expression significantly compared with MCAO. Conclusion : We observed that Uncariae Ramulus et Uncus could suppress the reactive gliosis, which disturbs the axonal regeneration in the brain of the rat with cerebral infaction after MCAO by controlling the expression of CD81 and GFAP. The effect may be modulated by the up-regulation of c-Fos and ERK. These results suggest that Uncariae Ramulus et Uncus can be a candidate to regenerate CNS injury.

Determination of Optimal Conditions of Pressure Toasting on Legume Seeds for Dairy Deed Industry : I. Effects of Pressure Toasting on Nutritive Values of Lupinus albus in Lactating Dairy Cows

  • Yu, P.;Goelema, J.O.;Tamminga, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.8
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    • pp.1205-1214
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    • 1999
  • Whole lupinus albus seeds were pressure toasted at temperatures of 100, 118 and $136^{\circ}C$ for 3, 7, 15 and 30 min to study rumen degradation and post-rumen digestion and to determine optimal heating conditions for the Dutch dairy feed industry. In sacco nylon bag and mobile bag techniques were employed for rumen and intestine incubations to determine ruminal degradation characteristics and intestinal digestion of crude protein (CP) in 4 lactation rumen cannulated and 4 lactating intestinal cannulated Dutch dairy cows fed 47% hay and 53% concentrate according to Dutch dairy requirements. Measured rumen degradation characteristics were soluble fraction (S), undegradable fraction (U), potentially degradable fraction (D), lag time (T0) and rate of degradation (Kd) of insoluble but degradable fraction. Percentage bypass feed protein (BCP), ruminal microbial protein synthesized based on available nitrogen (N_MP) and that based on available energy (E_MP), true protein supplied to the small intestine (TPSI), truly absorbed BCP (ABCP), absorbed microbial protein (AVP) in the small intestine, endogenous protein losses in the digestion (ENDP), true digested protein in the small intestine (TAP or DVE in Dutch) and degraded protein balance (PDB or OEB in Dutch) were totally evaluated using the new Dutch DVE/OEB System. Pressure toasting decreased (p<0.001) rumen degradability of CP. It reduced S (p<0.05) and Kd (p=0.06), increased D (p<0.05) and U (p<0.01) but did not alter T0 (p>0.05), thus resulting in dramatically increased BCP (p<0.001) with increasing time and temperature from 73.7 (raw) up to 182.5 g/kg DM ($136^{\circ}C/15min$). Although rumen microbial protein synthesized based on available energy (E_MP) was reduced, true protein (microbial and bypass feed protein) supplied to the small intestine (TPSI) was increased (p<0.001) from 153.1 (raw) to 247.6 g/kg DM ($136^{\circ}C/15min$). Due to digestibility of BCP in the intestine not changing (p>0.05) average 87.8%, the absorbed BCP increased (p<0.001) from 62.3 (raw) to 153.7 g/kg DM ($136^{\circ}C/15min$). Therefore DVE value of true digested protein in the small intestine was significantly increased (p<0.001) from 118.9 (raw) to 197.0 g/kg DM ($136^{\circ}C/15min$) and OEB value of degraded protein balance was significantly reduced (p<0.001) from 147.2 (raw) to 63.1 g/kg DM ($136^{\circ}C/15min$). It was concluded that pressure toasting was effective in shifting degradation of CP of lupinus albus from the rumen to small intestine without changing intestinal digestion. Further studies are required on the degradation and digestion of individual amino acids and on the damaging effects of processing on amino acids, especially the first limiting amino acids.

Effects of strong shading on growth and yield in sweet potato (Ipomoea batatas L. LAMK.)

  • Shin, Jong Moo;Song, Seon Hwa;Park, Chan Young;Lee, Hyeon Young;Shim, Sang In
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.241-241
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    • 2017
  • Sweet potatoes (Ipomoea batatas (L.) LAMK.,) have been cultivated in Central and South America for about 2000 years and are now grown mainly in Asia and South America. Sweet potatoes are annual in the temperate region, but are classified as perennial in the tropical region. In 2000, the cultivation area of sweet potatoes decreased to about 16,000 ha in 2000, but the cultivation area increased slightly in recent 20,000 ha in Korea. Sweet potatoes do not show higher maximum dry matter production of 120 ~ 150g per plant, and the leaf area index (LAI), which maximizes dry matter production, is known as 3.0 ~ 4.0. As the leaf area increase, the penetration of light into the canopy becomes poor, and sufficient photosynthesis cannot be achieved in the lower leaves, on the other hand the respiration increase, which results in poor dry matter production. This study was conducted to know the responses of sweet potatoes to intensive shading treatment of 80% shading. This experiment was conducted for about 42 days from September 6, 2016 to October 18, 2016 at Gyeongsang National University Experimental Farm, Jinju, Korea. The plant canopy was shaded with black nylon 80% shade cloth suspended 1.2 m above the ground. The photosynthetic rate, stomatal conductance, chlorophyll fluorescence, SPAD and NDVI were measured in 3 replicates every 7 days after shading initiation. After the fresh weight was measured, the samples were dried at $80^{\circ}C$ in a dry oven and measured. By the 80% shading treatment, chlorophyll fluorescence of the treated plants was slightly higher than that of the control, the SPAD value was higher by 3.4 and NDVI value was higher by 0.01. However, photosynthetic rate and stomatal conductance were lower than those of the control. The stomatal conductance of the control were two times higher than those of the control and the photosynthetic rate of the control was four times higher than that of the control. In control, plant showed a tendency to steadily increase in fresh weight and dry weight. However, in the case of shading treatment, the tendency to increase in the fresh and dry weight of tuberous roots was not clear. The fresh weight of shoot showed a tendency to increase steadily while the difference between treatment and control was not large, but tended to decrease after frost.

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Quality Changes of Fresh-Cut Potatoes during Storage Depending on the Packaging Treatments (신선한 감자절편의 포장방법에 따른 저장 중 품질변화)

  • Lim, Jeong-Ho;Choi, Jeong-Hee;Hong, Seok-In;Jeong, Moon-Cheol;Kim, Dong-Man
    • Korean Journal of Food Science and Technology
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    • v.37 no.6
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    • pp.933-938
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    • 2005
  • To investigate pertinent packaging treatment of fresh-cut potatoes (Solanum tuberosum L.), potato cubes were subjected to passive, gas exchange, and vacuum packaging conditions. Low density polyethylene film (LDPE), polypropylene film (PP), anti-fogging film (AP), and perforated film (PF) were used as passive packaging treatments. Mixed gases of 5% $CO_2/5%\;O_2$ (MA1) and 10% $CO_2/5%\;O_2$ (MA2) were applied as gas exchange packaging. Packs filled with cubes were kept at $5^{\circ}C$, and changes in weight loss, surface color, vitamin C content and sensory quality of cubes were analyzed during storage. Respiration rate of cubes was 2.11 times higher than that of intact raw potatoes at $5^{\circ}C$. Gas concentrations in passive packaging was maintained at 1-2% $O_2$ and 4-14% $CO_2$ after 7 days. Gas levels changed depending on films used. Cubes packed in PP and MA2 showed lowest weight loss and browning during storage. Firmness of cubes was not affected by packaging treatment. Vitamin C content was highest in cubes packed with AF. Cubes packed in MA2 showed highest quality upto 10days storage, followed by those packed in PP and AF.

Quality characteristics of steamed rice cake with Schisandra chinensis powder or extract added prior to storage (오미자 분말 및 추출물 첨가 설기떡의 저장 중 품질특성)

  • Kim, Dae-Hyun;Cho, Jeong-Seok;Park, Jung-Hoon;Kim, Jae-Hwan;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.23 no.7
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    • pp.923-930
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    • 2016
  • The purpose of this study was to improve the quality of the steamed rice cakes added with powder and extract of Schisandra chinensis (SC). Steamed rice cakes were prepared by adding SC using 1% hot-air dried SC powder (DP), hot-air dried SC extract (DE), freeze dried SC powder (FP) and, frozen SC extract (FE). After packaging with nylon/polyethylene films, the cakes were stored at $25^{\circ}C$ for 5 days. The FE-treated steamed rice cake had the lowest pH value. The $L^*$ value of the control cakes was highest immediately after processing and decreased during storage. The $a^*$ values of FP- and FE-treated steamed rice cakes were higher than those of DP- and DE-treated cakes. The $b^*$ values of DP- and DE-treated steamed rice cakes were higher than those of FP- and FE-treated cakes. Total phenolic contents of DP and DE were lower than those of FP and FE. Anthocyanin contents of DP- and DE-treated steamed rice cakes were lower than those of FP- and FE-treated cakes. Schisandrin contents of DP- and FP-treated steamed rice cakes were lower than those of DE- and FE-treated cakes. Ferric reducing antioxidant power assays revealed that DP and DE had lower antioxidant powers than those of FP and FE. The results of this study indicate that, among the treatments methods used, the steamed rice cake treated with FE had the highest functional component and antioxidant activity levels.

In-vivo Studies on Effect of Lipo-PGE1 on Neoangiogenesis of Composite Graft in a Rabbit Model (가토모델에서 Lipo-PGE1이 복합조직이식편의 미세혈관신생에 미치는 영향)

  • Park, Ji-Ung;Eo, Su-Rak;Cho, Sang-Hun;Choi, Jong-Sun;Kim, Eo-Jin
    • Archives of Plastic Surgery
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    • v.37 no.6
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    • pp.721-725
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    • 2010
  • Purpose: The survival of composite graft is dependent on three steps, (1) plasmatic imbibitions, (2) inosculation, and (3) neovascularization. Among the many trials to increase the survival rate of composite graft, prostaglandin E1 (PGE1) has beneficial effects on the microcirculatory level with vasodilating, antithrombotic, anti-inflammatory and neoangiogenic properties. Lipo-PGE1 which is lipid microspheres containing PGE1 had developed to compensate the systemic and local side effects of PGE1. This study was proposed to determine whether Lipo-PGE1 administration enhanced the survival of composite graft through neovascularization quantitatively in a rabbit ear model. Methods: Fourteen New Zealand White Rabbits each weighing 3~4 kg were divided in two groups: (1) intravenous Lipo-PGE1 injection group and (2) control group. A $2{\times}1\;cm$ sized, full-thickness rectangular composite graft was harvested in each auricle. Then, the graft was reaaproximated in situ using a 5-0 nylon suture. For the experimental group, $3{\mu}g$/kg/day of Lipo-PGE1 ($5{\mu}g$/mL) was administered intravenously through the marginal vein of the ear for 14 days. The control group was received no pharmacologic treatment. On the 14th postoperative day, composite graft of the ear was harvested and immunochemistry staining used Monoclonal mouse anti-CD 31 antibody was performed. Neoangiogenesis was quantified by counting the vessels that showed luminal structures surrounded by the brown color-stained epithelium and counted from 10 random high-power fields (400x) by independent blinded observer. Statistical analysis (Wilcoxon Signed Ranks test for nonparametric data) was performed using SPSS v12.0, with values of p<0.05 considered significant. Results: The mean number of the microvessels was $15.48{\pm}8.65$ in the experimental group and $9.82{\pm}7.25$ in the control group (p=0.028). Conclusion: The use of Lipo-PGE1 facilitated the neoangiogenesis, resulted in the improvement of the survival rate of graft. On the basis of this results, we could support wider application of Lipo-PGE1 for more effective therapeutic angiogenesis and successful survival in various cases of composite graft in the human.

Effects of Film Treatment on Sprouting Ability and Growth Properties of Ginseng Seedlings (묘삼의 필름포장 처리가 저온저장 중 생장과 품질에 미치는 영향)

  • Eun Ha Chang;Ji-Weon Choi;Ji Hyun Lee;Sooyeon Lim;Haejo Yang;Il Sheob Shin
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2020.08a
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    • pp.81-81
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    • 2020
  • 본 연구는 새싹인삼(Panax ginseng sprout) 재배용으로 이용하기 위한 묘삼(종삼)의 장기 저온저장 시 사용되는 필름의 종류가 묘삼의 출아율이나 생육에 영향을 미치는 지 조사하기 위해 수행되었다. 포장에 사용된 필름은 다공성물질인 제올라이트와 페그마타이트가 5% 함유된 50㎛ low density polyethylene(기능성 LDPE) 필름과 nylon/polyethylene 80 ㎛(Ny/PE) 필름에 묘삼을 100g씩 포장한 후 골판지 상자에 담아 -2℃의 저장고에서 10개월 동안 저장하면서 8개월째부터 2개월마다 시료를 꺼내어 5℃에서 5일 동안 온도 순화를 시킨 후 1차 조사에서는 육안조사로 실험실에서 건전한 묘삼과 부패 묘삼을 조사하였고, 건전한 묘삼만 새싹인삼 수경재배 농가에 재식한 후 2차 조사로 묘삼의 출아율과 출아된 묘삼이 새싹인삼으로 건전하게 생육한 비율을 조사하였다. 조사결과 Ny/PE 필름에 8개월 저장된 묘삼의 경우 1차 육안검사 시 뇌두부위가 검게 변하여 묘삼이 대부분 고사된 것으로 조사되었다. 필름 개봉 전 필름 내부의 O2 및 CO2 가스농도를 측정한 결과 O2 농도는 1.91%, CO2 농도는 38.9%로 측정되었고, 필름 개봉 시 알코올 냄새의 이취가 나는 것으로 보아 Ny/PE 필름으로 포장 된 묘삼이 -2℃의 저온저장기간 동안에도 호흡을 하면서 필름 내 산소를 완전히 소모하고 혐기적인 환경으로 변화시켜 대사활동이 불가능하였기 때문에 뇌두의 싹이 고사된 것으로 조사되었다. 반면 기능성 필름으로 포장한 묘삼은 저장 8개월에 정식 후 74.3%의 출아율을 보였고, 건전한 새싹인삼의 비율은 67.2%로 조사되었다. 정식 전·후 묘삼의 개체수 대비 건전 출아율의 비율은 56.7%를 나타내어 Ny/PE 필름으로 포장한 묘삼의 결과와 큰 차이를 보였다. 기능성필름의 개봉 전 필름 내부의 O2 및 CO2 가스농도를 측정한 결과 O2 농도는 12.9%, CO2 농도는 4.6%로 측정되어 묘삼의 저온저장 시 필름을 적용할 경우 공기의 유동이 원활이 이루어져 내부 O2 농도를 일정 수준 이상 유지해주는 필름을 사용하는 것이 묘삼의 출아와 생육에 좋은 것으로 조사되었다.

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