• Title/Summary/Keyword: 흡습율

Search Result 75, Processing Time 0.03 seconds

Effects of Saligenin Treatment on Acoustical Properties and Adsorption of Soundboard for Traditional Musical Instruments (전통악기 음향판용재의 살리게닌 처리가 음향성 및 흡습성에 미치는 영향)

  • Jung, Hee-Suk;Yoo, Tae-Kyung
    • Journal of the Korean Wood Science and Technology
    • /
    • v.27 no.3
    • /
    • pp.7-16
    • /
    • 1999
  • This research was carried out to compare structure, equilibrium moisture content(EMC), adsorption and acoustical properties between 4 retention levels of saligenin(o-hydroxybenzyl alcohol) treated, heat-treated and untreated chestnut(Castanea crenata S. et Z.) and paulownia(Paulownia spp.) woods. The cell structures of untreated wood and heat-treated wood were not different but the cell wall of saligenin treated wood was thicker than that of untreated wood for both species. EMC of untreated wood was the highest, next was that of heat-treated wood, and that of saligenin treated wood was the lowest, and among saligenin treated woods, EMC was decreased as retention level increased for both species. Adsorption curves were parabolically increased. Acoustical properties of saligenin treated wood were most improved, and the next were those of heat-treated wood. Comprehensive acoustical property was improved at retention level 20% and 30% for chestnut wood, and at retention level 80% for paulownia wood.

  • PDF

Effect of Soaking and Prechilling Treatment on Seed Germination of Phellodendron amurense Rupr. (침수 및 예냉처리가 황벽나무의 종자 발아에 미치는 영향)

  • Choi, Chung-Ho;Seo, Byeong-Soo
    • Korean Journal of Plant Resources
    • /
    • v.22 no.2
    • /
    • pp.111-115
    • /
    • 2009
  • The seeds of Phellodendron amurense have difficulty to obtain because these plants show dioecism with independent distributions. This experiment was conducted to find the effects of soaking and prechilling treatment on the germination of P. amurense seeds. Seeds were soaked for 3, 5 and 10 days (soaking treatment), and placed on petri-dish at $4^{\circ}C$ for 10, 20, 30 and 50 days after soaked at room temperature for 24 hours (prechilling treatment). After the treatments, germination percentage, mean germination time, germination speed and germination performance index were analyzed. As a result of sowing, prechilled seeds for 30 days had the highest percent of germination, whereas all of the soaked seeds showed lower percent of germination than non-treatment (control). In case of mean germination time, only prechilling for 30 days was more effective than control. In germination speed, all of the soaked seeds had lower values than control whereas all prechilled seeds except prechilled seeds for 20 days showed higher values than control. Especially prechilled seeds for 30 days showed the highest rate among the prechilling treatments. Germination performance index was similar to germination speed.

Studies on the Germination Characteristics of Sesame (Sesamum indicum L.) (참깨의 발아특성(發芽特性)에 관(關)한 연구(硏究))

  • Kim, Choong Soo
    • Korean Journal of Agricultural Science
    • /
    • v.10 no.1
    • /
    • pp.28-60
    • /
    • 1983
  • This study was carried out to define the effects of external factors including temperature, moisture, oxygen and light quality on the germination of sesame seeds and to investigate the change of major chemical constituents of seeds during germination. The results obtained are summarized as follows: 1. The average germination ratio was from 95.8% to 97.2% when it was tested every $5^{\circ}C$ intervals from $20^{\circ}C$ to $35^{\circ}C$ and no significant difference in germination ratio was found within $20^{\circ}C$ to $35^{\circ}C$. But the germination ratio dropped rapidly to 32.2% when seeds were germinated at $15^{\circ}C$ and the coefficient of variation become greater(77%) 2. The days required for germination ranged from 1.16 to 1. 64 at the temperatures of $35^{\circ}C$ to $25^{\circ}C$ and they were 3.07 and 10.4 at the temperatures of $20^{\circ}C$ and $15^{\circ}C$, respectively. 3. Considering the germination ratio and days needed, $15^{\circ}C$ was assumed to be the minimum temperature for germination practically and this temperature is recommended for testing low temperature tolerance of seed germination of sesame cultivars. 4. The varieties shown the highest low temperature tolerance were Shirogoma and Turkey. The next varieties shown some degree of low temperature germination were Suweon #29, Naebok and IS 58. The varieties with 70 to 80% of germination ratio were Maepo, Suweon #14, Kimpo, Moondeok, and Haenam. Among the 90 varieties tested, the varieties with comparatively high degree of low temperature tolerance were about 10%, and 70% of the low temperature tolerant varieties were domestic varieties. 5. At $12^{\circ}C$ the Shirogoma was the only variety which showed over 50% of germination ratio, 71.4% of the varieties showed less than 20% of germination ratio. When the temperature was raised to $27^{\circ}C$ 18 days after placement at $12^{\circ}C$ all the varieties showed over 90% of germination ratio within 2days. 6. The amounts of water imbibition needed for seed germination were 0.48 to 0.62 times of the seed dry weight at $25^{\circ}C$ and were significantly different among sesame cultivars. About 63% of water required for germination was imbibed in 2 hours after placement of seeds under the germination condition. 7. Under saturated moisture condition the average germination ratio was 0.42%. In the soil of which water potential was -0.4bar 64.8% of the seeds germinated and the most adequate soil water potential for sesame seed germination was about -0.4 to -5.5 bar. The germination ratio decreased as the soil water potential declined below -5.5 bar. 8. Six out of 10 varieties were not influenced by 5% of oxygen in air germination chamber, while varieties such as Yecheon, PI 158073, IS 103 and Euisangcheon showed 64 to 91% of germination under the 5% oxygen content. Under anaerobic condition, cotyledones were not emerged but only hypocotyl was emerged and elongated. The germination ratio of IS 103 decreased significantly under anaerobic condition. 9. When the seeds were dried for 24 hours after 12 hours imbibition of water, the seeds of Cheongsong did not lose their germination ability and 27.5% was germinated but Suweon #9 and Early Russian failed to germinate. However, the germination ratio of IS 103 decreased when the seed were dried 24 hours after 4 hours imbibition of water and the germination ability of IS 103 was maintained even though the seeds were dried for 24 hours after 24 hours imbibition of water. 10. During germination, sugar content of sesame seed increased rapidly and activity of ${\alpha}$-amylase increased gradually while starch content decreased significantly. The rates of increase in sugar content and enzyme activity and decrease in starch content were significantly lower at $15^{\circ}C$ compared with those at $25^{\circ}C$. 11. During germination of sesame seeds, lipid content in the seeds dropped rapidly and the activity of alkaline lipase increased significantly at early stage of germination. The rate of decrease in lipid content and increase in emzyme activity was lower at $15^{\circ}C$ than at $25^{\circ}C$. 12. Four out of 6 varieties were not affected in germination by light wave length. But Suweon #8 was inhibited in germination by 600-650nm. and IS 103 by 600 to 650nm and 500 to 550nm of light wave length. Suweon #8 showed high germination ratio under 650 to 760 nm and 500 to 560nm, and IS 103 under 400 to 470nm and complete darkness. 13. The germination ratios increased significantly in the seeds of which 1000 grain weight is heavier. When the seeds were placed at soil 4cm deep, Cheongsong and Early Russian failed to emerge their cotyledones, but Suweon #9 and IS 103 showed 32.5 and 50% cotyledone emergence, respectively. The extracts from sesame plant and soil where the sesame was cultivated previously did not affect in the-germination of sesame seeds. 14. The covering by black or transparent polyethylene films increased germination ratio compared with uncovered seeds. The covering was effective in shortening the days needed for germination and in improving the early seedling growth, number of capsules per plant and grain yield. Difference was not so seizable between the two polyethylene films but the transparent film appeared somewhat more effective than the black one. 15. Simcheon, Cheongsong. Suweon #9. PI 158073 and IS 103 showed lower rate of water absorbtion by seed during germination and Suweon #8, Suweon #26, Orotall and Euisangcheon showed high increase in seed weight after water absorbtion by seed.

  • PDF

Moisture Transmission Characteristics of Fabric for High Emotional Garments -Moisture Transmission Characteristics according to Fiber Properties, Yarn Characteristics and Test Method- (고감성 의류용 직물의 수분이동특성 -섬유소재와 실 특성 및 실험방법에 따른 수분이동특성-)

  • Kim, SeungJin;Kim, Hyunah
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.41 no.1
    • /
    • pp.28-42
    • /
    • 2017
  • Moisture transfer characteristics of high emotional garments are important to evaluate wear comfort. Wicking and drying measurement methods are also critical for perspiration absorption and quick dry fabric made of high functional fibers. In this study, the wicking and drying properties of high emotional fabrics made from hybrid composite yarns using CoolMax, Tencel, Bamboo staple fibers and PP. PET CoolMax filaments were also measured and analyzed according to various measuring methods. The wicking property of hybrid composite yarn fabrics by Bireck method was mostly influenced by the structure of hybrid yarns than the absorption rate of constituent fibers; however, both the hygroscopicity of fibers and the composite yarn structure affected the wicking property of the fabrics in the drop method. Concerning drying properties, the KSK 0815B method measuring distilled moisture weight was more relevant to explain the drying characteristics of hybrid yarn fabrics than the KSK 0815A method measuring the time to drying. This study revealed that the drying properties of hybrid yarn fabrics were influenced by the hygroscopicity of constituent fibers, wicking properties of constituent yarns and structure of composite yarns.

Decreasing Rate of Compression Strength for the Corrugated Fiberboard Container by Vibration Fatigue (진동피로에 의한 골판지 상자의 압축강도 저하율)

  • 김만수;정현모;박종민;박정길;김수일;박인식
    • Proceedings of the Korean Society for Agricultural Machinery Conference
    • /
    • 2003.07a
    • /
    • pp.347-352
    • /
    • 2003
  • 농산물 포장화물의 경우 농산물의 손상은 겉포장 상자의 파손에 의한 압상이 주요 원인이다. 따라서 농산물 상자의 경우 압축강도를 특히 중요시 여기고 있으며, 한국산업규격을 비롯해 각종 농산물 관련 규정에서는 압축강도에 의한 상자의 품질관리를 규정화 하고 있다. 골판지 상자의 압축강도는 원단인 골판지의 구성 원지들(라이너, 골심지)의 품질과 이들의 구성 형태 및 상자의 외형 치수 비율에 따라 결정되므로, 원지의 링크라쉬(ring crush), 원단의 수직압축강도(edgewise compression strength)를 통해 상자의 압출강도를 관리하는 것이 보통이다. 또한 골판지 상자는 제작 후 유통 과정을 거치면서, 여러 요인에 의해 압축강도가 현격하게 저하되는데, 이중 수분 흡습에 의한 강도저하와 장기 누적하중, 진동 및 충격 등의 피로로 인한 강도 저하가 가장 크다. 여러 산업 분야에서 골판지 상자의 견고성 문제는 물품의 내수 및 수출시 제품에 대한 신뢰성 확보와 기업의 이미지 제고와 직결되는 중요한 사항이다. 특히, 세계 각 국의 농산물 시장이 개방됨에 따라 우리나라 농산물의 수출도 확대될 전망이고 또한 마땅한 대체재가 개발되지 않는 한 골판지 상자의 이용은 날로 증가될 것으로 전망된다. 따라서 골판지 상자의 압축강도와 내구성 향상에 대한 다각적인 연구가 절실하다. (중략)

  • PDF

Studies on Partial Revegetation of Rock Cut-Slope by Direct Seeding of Woody Species Seeds (수목종자 직파에 의한 암반절개사면 부분녹화)

  • Hong, Sung-Gak;Kim, Jong-Jin;Lee, Duck-Soo;Lee, Ki-Cheol;Yoon, Teok-Seong
    • Korean Journal of Environmental Agriculture
    • /
    • v.18 no.3
    • /
    • pp.265-271
    • /
    • 1999
  • The direct seeding of seeds or the pellets of three native tree species (Pinus densiflora, Parthenocissus tricuspidata and Rhus chinensis) was tried on the rock cut-slope revegetation bed established by construction of mechanical excavation or erosion break with artificially enriched soil medium. The seed $pellet(1{\sim}2\;cubic\;cm)$ made by coating seeds(treated with proper previous pregermination treatments) with the mixture of peatmoss, clay, chemical absorbant(3.5:1.0:0.2, v/v) showed about twice better percent germination than the control seeds. The percent germination and the survival rate of the germinated seedlings were higher in the spring direct seeding than the summer or the fall. The soil medium containing the compost showed extremely low percent $germination(0{\sim}3%)$ which presumably attributed to the compost inducing damping-off disease. The survival rates were affected mainly by shading of natural herbaceous vegetation invading from outside to the revegetation bed. The planting of two year old container seedlings of P. densiflora and P. tricuspidata on August 2, 1998 was successful indicating that it could be an alternative revegetation method in case the summer direct seeding is unfavorable.

  • PDF

Development of Organic Compound Fertilizer Based on Treated Human Waste (분뇨잔사(糞尿殘渣)를 이용(利用)한 유기종합비료(有機綜合肥料) 개발(開發))

  • Shin, Jae-Sung;Seong, Ki-Seog;Lim, Dong-Kyu
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.17 no.1
    • /
    • pp.55-59
    • /
    • 1984
  • An organic compound fertilizer was manufactured using wet oxidation human waste as principal source of phosphorus and organic matter. The waste was treated with sulfuric and glutamic acids to increase the available and water-soluble $P_2O_5$ contents. The treatment of 0.1 N sulfuric acid with 24 hours curing was best way in recovering the maximum percentage of $P_2O_5$ originally in the waste. The particle size distribution of trial product varied considerably in the amount of glutamic acid used for granulation. The number of relatively large fertilizer particles was increased as the amount of glutamic acid was increased. The granule crushing strength was generally high in large granules in which 12.5 weight percent of glutamic acid were used for granulation. The trial product showed high moisture absorption due to its porous structure and chemical makeup.

  • PDF

Studies on Short Term Hardening Method of Tree Seedlings for Afforestation of Cut-Rock Slope (암반절개사면 녹화용 강건묘목의 속성육묘법에 관한 연구)

  • Hong, Sung-Gak;Kim, Jong-Jin
    • Korean Journal of Environmental Agriculture
    • /
    • v.17 no.4
    • /
    • pp.358-361
    • /
    • 1998
  • This study was carried out to develop a short term hardening method of tree seedlings of Rhus chinensis Mill., Evodia daniellii Hemsley and Parthenocissus tricuspidata(Sieb. et Zucc.) Planck for afforestation on a concave and a crack of cut-rock slope. The seedlings were grown in a cylinder shaped pot made of polyvinyl net with the soil media of peatmoss, vermiculite, clay, compost, fertilizer, and absorbant(40:25:19:15:1:0.1, v:v). They were cultivated in a greenhouse for four months and in field condition for two months. During the last three months of the growing period the seedlings were hardened by periodic desiccation and irrigation in 4 to 10 days interval. The hardened seedlings showed lower leaf water potential, higher leaf osmotic pressure, and lower T/R ratio than those before the hardening. The hardened seedlings survived well on the soil medium in the concave of cut-rock slope.

  • PDF

Dimensional Change of PEG-Freeze Dried Waterlogged Woods Exposed at Various Humidity Conditions (PEG처리 후 동결건조한 수침고목재의 습도조건에 따른 상태변화)

  • Kim, Soo-Chul;Park, Won-Kyu;Yi, Yong-Hee
    • Journal of Conservation Science
    • /
    • v.16 s.16
    • /
    • pp.110-118
    • /
    • 2004
  • In order to evaluate two-step treatment of PEG-freeze drying for highly-degraded waterlogged ash woods (Fraxinus PP.; ca. 5,700 BP), which were excavated from peat lands in western Korea, dimension stability was examined during 45 months after complete treatment. The samples pre-treated with PEG in water solution showed better dimensional stabilities than the ones with PEG in t-butanol(TBA) solution. It suggests that TBA reduced the flexibility of wood cells and overflying by TBA induced micro-checks during freeze drying. Micro-checks results in fragile wood structures and consequently, large shrinkage by moisture absorbances of high PEG contents during exposure in humid condition. The results suggest that PEG in water-solution treatment is better than PEG in t-butanol as pretreament for freeze drying of highly-degraded waterlogged ash woods.

  • PDF

Prediction of Shelf-Life of Chewing Gum Based on Moisture Gain and Loss (흡탈습량에 의한 츄잉껌의 Shelf-Life 예측)

  • Chung, Duk-Ho;Lee, Yoon-Hyung;Yoo, Myung-Shik;Pyun, Yu-Ryang
    • Korean Journal of Food Science and Technology
    • /
    • v.24 no.2
    • /
    • pp.122-126
    • /
    • 1992
  • The shelf-life of wrapped chewing gum(7 sticks) under the climate condition of Seoul was predicted by using moisture gain equation to reach safe moisture limits of 3.16% (dry basis). The overall water vapor permeability of multilayer packaging material was about 0.00045g water/pack day mmHg. The water activity of chewing gum at any temperature was predictable using Clausius-Clapeyron equation. The most significant loss of shelf-life was occurred between June and July, and most products reached the end of shelf-life at July and August. The product which were made in October and November had the longest shelf-life as seven months.

  • PDF