• International Journal of Concrete Structures and Materials
• /
• 제18권3E호
• /
• pp.161-164
• /
• 2006

Cellulose fiber reinforced cement(CFRC) pipe has been gradually introduced in the pipe market as a replacement of previously popular asbestos cement pipes. Since CFRC pipe is still relatively unknown in the pipe market, there are great concerns for the design and application in practice related to the time-dependent behavior of CFRC under long-term sustained loading. This paper presents an experimental investigation of the time-dependent behavior of cellulose fiber reinforced cement(CFRC) pipe. A total of six CFRC pipes were tested under various loading levels, and their vertical deformation was recorded to understand the characteristics of the time-dependent behavior. Based on the test results, a factor of safety(FS) of 1.82 is proposed, and a regression factor(R) of 1.88 is estimated for the application of CFRC pipes in practice.

• 한국식품과학회지
• /
• 제21권1호
• /
• pp.63-67
• /
• 1989

식이섬유가 중금속인 납의 흡수억제 효과를 가지고 있는지를 알아보기 위하여 반투막을 이용한 in vitro법으로 흡수실험을 실시하였다. 식이섬유중 cellulose는 억제효과를 거의 기대할 수 없었고 guar gum과 carboxymethyl cellulose는 약간 나타났으며 citrus pectin과 sodium alginate는 매우 크게 나타났다. 섬유질 식품중 쌀겨, 밀기울, 배추, 무우, 미역은 납의 흡수억제 효과가 컸으며, 귤, 사과, 김은 효과가 다소 적었다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2003년도 학술.기술논문발표회
• /
• pp.103.2-108
• /
• 2003

The purpose of this study is to understand the Physical characteristics of cement mortar about humidity control on indoors and wall crack restraint. Experiments were conducted on the strength, water absorption coefficient, drying-shrinking crack, length change, cracks of mortar plaster bases according to mixture rate by mixing cellulose fiber and diatomite into cement mortar. The excellent tensile & bending reinforcement efficiency of cellulose fiber and void filling ability of diatomite proved to be suppressing cracks of cement. And diatomite seems to improve moisture-protection efficiency of cement mortar because of its high water absorption ratio and slow drying speed.

• 한국화재소방학회:학술대회논문집
• /
• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
• /
• pp.185-192
• /
• 1997

The combustion of cellulose insulation treated with Borax, Boric acid and Aluminum Sulfate as combustion retardants is examined by candle type combustion tester. The cellulose fibers in cellulose insulation are classified by diameter as less than 0.2mm, 0.2mm-0.5mm, 0.5mm-2mm and more than 2mm. The burning behavior of cellulose insulation are studied by LOI (Limit Oxygen Index: Beginning point of smoldering), L- point (Lower point of combustion transition from smoldering- flaming to flaming combustion), LOI, L-point and H-point rise with the increasing particle size of cellulose fibers because thermal decomposition rate of cellulose fiber decreases. The phenomena of combustion transition from smoldering to flaming combustion are determined by the generating rate of combustible gas and the formation rate of combustible gas mixture within the zone of cellulose fiber heated.

• 한국건축시공학회지
• /
• 제7권3호
• /
• pp.83-90
• /
• 2007

This study is to investigate the effects of nylon(NY) and cellulose(CEL) fiber contents on the mechanical properties of the concrete. The results were summarized as following. Test showed that increase of NY and CEL fiber contents decreased fluidity of fresh concrete, so the loss of the fluidity would be considered when they were over added. Air contents were slight increased, but they satisfied the target air content. Bleeding capacity of concrete containing fiber significantly was declined. In addition, concrete containing higher amounts of fiber retarded setting time remarkably. Plastic shrinkage crack was reduced with the use of fiber due to increasing fiber contents and changing fiber classes, and NY fibers to prevent the plastic shrinkage crack effectively. Compressive and tensile strength of almost specimens were increased when air contents of the fresh concrete were fixed according to fiber contents, and flexural strength was increased according to fiber contents. For the impact strength of specimens, the specimen containing $0.6kg/m^3$ of NY fibers, showed the most favorable impact strength, The fiber reinforced concrete using NY fibers exhibited superior mechanical performance, and it was considered that $0.6kg/m^3$ of was desirable as the most favorable adding amount.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2001년도 학술발표회 논문집(Proceedings of the Korean Textile Conference)
• /
• pp.339-342
• /
• 2001

• Fibers and Polymers
• /
• 제3권1호
• /
• pp.1-7
• /
• 2002

Cellulose carbonate was prepared by the reaction of cellulose pulp and $CO_2$ with treatment reagents, such as aqueous $Zncl_2$ (20-40 wt%) solution, acetone or ethyl acetate, at -5-$0^{\circ}C$ and 30-40 bar ($CO_2$) for 2 hr. Among the treatment reagents, ethyl acetate was the most effective. Cellulose carbonate was dissolved in 10% sodium hydroxide solution containing zinc oxide up to 3 wt% at -5-$0^{\circ}C$. Intrinsic viscosities of raw cellulose and cellulose carbonate were measured with an Ubbelohde viscometer using 0.5 M cupriethylenediamine hydroxide (cuen) as a solvent at $20^{\circ}C$ according to ASTM D1795 method. The molecular weight of cellulose was rarely changed by carbonation. Solubility of cellulose carbonate was tested by optical microscopic observation, UV absorbance and viscosity measurement. Phase diagram of cellulose carbonate was obtained by combining the results of solubility evaluation. Maximum concentration of cellulose carbonate for soluble zone was increased with increasing zinc oxide content. Cellulose carbonate solution in good soluble zone was transparent and showed the lowest absorbance and the highest viscosity. The cellulose carbonate and its solution were stable in refrigerator (-$5^{\circ}C$ and atmospheric pressure).

• 한국식품영양과학회지
• /
• 제32권3호
• /
• pp.474-478
• /
• 2003

우렁쉥이 추출 불용성 식이섬유를 5%, 10%, 20% 첨가한 식이 후 실험쥐 집단의 영양생리학적 특성변화를 조사하였다. Cellulose 급여에 따른 총 식이량에는 차이가 없었으나 식이 중 cellulose의 함량이 높아짐에 따라 체중은 감소하였으며 식이효율의 조절, 배변량 증가, 변의 수분 증가, 식이의 장 통과시간 단축, 장 길이의 증가 등의 유의적인 효과를 나타내었다. 우렁쉥이 식이섬유를 급여한 실험쥐의 혈청분석 결과 total cholesterol, LDL-cholesterol, 중성 지질 및 인지질, 혈당은 식이섬유의 함량이 높아짐에 따라 감소하였으며 HDL-cholesterol은 식이섬유의 함량이 높아짐에 따라 증가하였다. 따라서 우렁쉥이 식이섬유를 첨가한 가공식품을 섭취할 경우 배변량의 조절, 변비 및 비만조절, 혈청 지질의 감소와 같은 유용한 생리적 효과가 있을 것으로 기대된다.

• 한국식품영양과학회지
• /
• 제23권6호
• /
• pp.887-893
• /
• 1994

This study was undertaken to dtermine whether dietary fibers had an effect on postprandial plasma lipoprotein and liver lipid composition in rats. Each experimental diet ocntained 10 % dietary fiber by weight. All animals were sacrificed in postprandial state. Sodium alginate-fed animals has significantly lower plasma cholesterol, VLDL-, LDL-cholesterol, TG, and protein levels than did the fiber-free control group. In addition, liver cholesterol and TG concentrations were the lowest in sodium alginate -fed animals. There was no significant change in HDL-cholesterol levels among experimental groups. Cellulose-fed animals also have lower plasma cholesterol and TG levels than fiber-free controls, but liver TG concentrations were not different from those in fiber-free controls. This study demonstrates that dietary fiber included in the diet of rats is able to alter postprandial lipoportein cholesterol and TG, and that sodium alginate, a soluble fiber, was the most effective in lowering plasma and liver cholesterol and TG.

• 한국식품조리과학회지
• /
• 제14권4호
• /
• pp.333-338
• /
• 1998

산마의 총 식이섬유가 2-AF와 MNNG에 대해서는 각각12.4%와 18.7%의 억제효과를 나타냈으며, 재배마는 33.2%와 49.1%의 억제효과를 보여 재배마의 $\alpha$-cellulose는 각각 0.5%, 1.0%농도에서 70.0%와 76.9%로 가장 높은 억제효과를 나타냈으며 MNNG에 대해서는 모든 농도에서 90% 이상의 억제효과를 나타냈다. Pectin의 2-AF에 대한 억제효과는 산마의 경우 0.1% 농도일 때 42.5%로 가장 높았고, 재배마는 억제효과를 나타내지 않았다. MNNG에 대해서는 산마 1.0%와 재배마 0.7% 농도일 때 각각 51.8% 와 31.0%로 가장 높은 억제효과를 나타냈다. 반응 시간에 따른 억제 효과는 2-AF에 대해 산마, 재배마 및 표품의 $\alpha$-cellulose (0.5%)는 3시간일 때, MNNG에 대해서는 6시간일 때 최고의 억제 효과를 나타냈다. 산마, 재배마 및 표품의 pectin(1.0%)의 2-AF에 대해 반응 시간이 경과함에 따라 억제 효과가 점진적으로 감소하였으며 MNNG에 대해 1시간 30분일 때 높은 억제 효과를 나타냈다. 산마와 재배마에서 추출한 $\alpha$-cellulose와 pectin은 2-AF에 의해 유발되는 돌연변이원성에 비해 MNNG에 의해 유발되는 돌연변이원성을 더 효과적으로 억제하였다.