• 펄프종이기술
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• 제37권3호
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• pp.33-40
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• 2005

In this study, a nano-colloidal silica sol was applied to control the anti-slip property by spraying on kraft paper. Two kinds of nano-colloidal silica sol which have cationic and anionic charge were applied in kraft paper, and the friction and physical strength properties of kraft paper were investigated. The application of colloidal silica sol on wet web in wet-end process by spraying method was tried to improve the friction property and to avoid the general problems of machine contaminations caused by the scattering of sprayed silica particles in dryer part. The physical properties of sheet were also improved by the application of wet web spraying method, and the optimum conditions of wet web spraying operation were closely related with the conditions of pH and electrical charge of wet web and silica sol.

• 한국가구학회지
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• 제18권2호
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• pp.106-110
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• 2007

This study was performed to find potentialities of the leaves of gingko tree (Gingko biloba L.) as a raw material for particleboard (PB) manufacturing. Various amounts of the leaves were mixed with wasted wood particles to manufacture PB. Physical and mechanical properties, such as density, internal bond (IB) strength, and modulus of rupture (MOR) of manufactured PB were not much different from those of the control board. Formaldehyde emission values decreased with increasing the amount of leaves. Especially, the formaldehyde emission of PB made with 5 percent of leaves was decreased to 1.31 mg/l, which is about 36% lower emission than that of the control. From these results, the leaves of gingko tree may be considered as an additive of lowering formaldehyde emission in a functional PB manufacturing process.

• 한국염색가공학회지
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• 제14권6호
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• pp.313-318
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• 2002

Chitosan is known to be an excellent biocompatible natural polymer. Recently, with a growing interest of health and environment, chitosan which is good in no harmful effect on human body and environment, has been watched as the finish treatment of hygiene and pleasantness. The purpose of this study is to develop multi functional fabrics by chitosan added on acrylic acid grafted cotton fabrics. Therefore physical properties such as moisture regain, air permeability, whiteness, static voltage and tensile strength of chitosan added on acrylic acid grafted cotton fabrics were investigated. The results are as follows ; According to increased chitosan's concentration, grafting yield was decreased. Therefore thickness of film by treated chitosan added on acrylic acid grafted cotton fabric became thin. FT R spectra of chitosan add on acrylic acid grafted cotton fabric clearly showed peaks of COOH and $NH_2$, Moisture regain, static voltage of chitosan add on acrylic acid grafted cotton fabrics were increased than control. Air permeability, whiteness and tensile strength were decreased than control.

• 제어로봇시스템학회논문지
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• 제10권11호
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• pp.1006-1011
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• 2004

Carbon nanotubes have outstanding properties which make them useful for a number of high-technology applications. Especially, single-walled carbon nanotube (SWNT), working under physical conditions (in aqueous solution) and converting electrical energy into mechanical energy directly, can be a good substitute for artificial muscle. The carbon nanotube structure simulated in this paper is an isotropic cantilever type with an adhesive tape which is sandwiched between two SWNTs. For predicting the geometrical and physical parameters such as deflection, slope, bending moment and induced force with various applied voltages, the analytical model for a 3 layer bimorph nanotube actuator is developed by applying Euler-Bernoulli beam theory. The governing equation and boundary conditions are derived from energy Principles. Also, the brief history of carbon nonotube is overviewed and its properties are compared with other functional materials. Moreover, an electro-mechanical coupling coefficient of the carbon nanotube actuator is discussed to identify the electro-mechanical energy efficiency.

• Journal of the Korean Wood Science and Technology
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• 제29권3호
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• pp.47-58
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• 2001

For finding both ways of recycling the wood and plastic wastes and solving the problem of free formaldehyde gas emission through manufacturing wood particle-polypropylene fiber composite board without addition of formaldehyde-based thermosetting resin adhesive, control particleboards and nonwoven web composite boards from wood particle and polypropylene fiber formulation of 50 : 50, 60 : 40, and 70 : 30 were manufactured at density levels of 0.5, 0.6, 0.7, and 0.8 g/$cm^3$, and were tested both in the physical and mechanical properties according to ASTM D 1037-93. In the physical properties, control particleboard had significantly higher moisture content than composite board. In composite board, moisture content decreased with the increase of target density only in the board with higher content of polypropylene fiber and also appeared to increase with the increase of wood particle content at a given target density. Control particleboard showed significantly greater water absorption than composite board and its water absorption decreased with the increase of target density. In composite board, water absorption decreased with the increase of target density at a given formulation but increased with the increase of wood particle content at a given target density. After 2 and 24 hours immersion, control particleboard was significantly higher in thickness swelling than composite board and its thickness swelling increased with the increase of target density. In composite board, thickness swelling did not vary significantly with the target density at a given formulation but its thickness swelling increased as wood particle content increased at a given target density. Static bending MOR and MOE under dry and wet conditions increased with the increase of target density at a given formulation of wood particle and polypropylene fiber. Especially, the MOR and MOE under wet condition were considerably larger in composite board than in control particleboard. In general, composite board showed superior bending strength properties to control particleboard, And the composite board made from wood particle and polypropylene fiber formulation of 50 : 50 at target density of 0.8 g/$cm^3$ exhibited the greatest bending strength properties. Though problems in uniform mixing and strong binding of wood particle with polypropylene fiber are unavoidable due to their extremely different shape and polarity, wood particle-polypropylene fiber composite boards with higher performance, as a potential substitute for the commercial particleboards, could be made just by controlling processing variables.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.50.3-50
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• 2001

Nonlinear feedback control scheme for reactive distillation column has been proposed. The proposed control scheme is derived in the framework of Nonlinear Internal Model Control. The product compositions and liquid and vapor flow rates in sections of the reactive distillation column are estimated from selected tray temperature measurements by an observer. The control scheme is applied to example reactive distillation column in which two products are produced in a single column and the reversible reaction A + B = C + D occurs. The relative volatilities are favorable for reactive distillation so that the reactants are intermediated boilers between the light product C and the heavy product D. Ideal physical properties, kinetics and ...

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 1995년도 추계학술강연 및 발표대회 강연 및 발표논문 초록집
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• pp.11-11
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• 1995

• 한국염색가공학회지
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• 제10권5호
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• pp.24-31
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• 1998

The effects of DMDHEU alone and DMDHEU/Fluorochemical(FC) combined treatment on the physical properties of 75％/25％ cotton/polyester(CP) blended fabrics were investigated. FC water repellent and DMDHEU durable press finishes were applied in combination to CP fabrics to provide good water repellency as well as great durable press(DP) performance. The physical properties of the fabrics were evaluated by wrinkle recovery angle(WRA), DP performance, contact angle, demand wettability, and water repellency. The durable press/water repellent finished(DP/WR) CP fabrics show considerably improved WRA and DP performance. The DP/WR finishes do not change the water contact angie of polyester fibers significantly, while the DP finishes increase it. Both DP and DP/WR finishes increase the contact angle of cotton fibers. The water uptake amount increases in the following order : DP/WR cotton, DP/WR CP＜DP cotton, DP CP ＜ Control CP, Control cotton. The water uptake amount increases in the following order DP/WR CP, DP/WR cotton ＜DP cotton ＜DP CP＜Control CP, Control cotton. Considerable improvements for water repellency are imparted to the CP fabrics treated with DP/WR, and the level of improvement is not significantly different from that of the DP/WR cotton fabrics. These results lead to the conclusion that DP/YVR treatments a single pad bath on CP are effective finishes for improving both DP performance and water repellency.

• 한국토양비료학회지
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• 제48권5호
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• pp.564-569
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• 2015

In highland crop fields, saprolite is piled up approximately every three years as deep much as 20 to 30 cm because farmers expect that adding new materials may improve productivity and mitigate hazards by continuous cultivation of a single crop. Piling saprolite, however, has been reported to induce poor soil drainage. Effects of deep ploughing with a spading machine and an excavator were studied in sites located in Daekwanryeong-myeon, Pyeongchang in which soil physical properties were deteriorated by piled saprolite. The soil made of parent material of Samgag series was piled up over surface soil of Haggog series naturally developed in the area. Carrot was cultivated in the field. Productivity and growth factors of carrot were compared among control and deep ploughing by a spading machine and an excavator. Effective soil depth extended to 60 cm or greater by 60 cm deep ploughing by an excavator or 50 cm deep ploughing by a spading machine. On the other hand, effective soil depth was within 50 cm at control plot. Productivity of carrot responded to amelioration of soil physical properties. The productivity was greater in deep ploughing treatments than that of control or 30 cm ploughing. It suggested that increased productivity by deep ploughing was mainly related to breaking plough pan which inhibited extension of rooting zone.

• 한국축산식품학회지
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• 제29권3호
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• pp.302-309
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• 2009

This study investigated the effects of infrared (IR) radiation combined with air blast thawing on the physical properties of pork. Regardless of air velocity, increasing IR dosage produced an exponential increase in the thawing rate of pork. This rate increased further when air blast velocity was increased. IR treatments showed significantly lower thawing loss than that of 0 Watt treatment, while increasing air velocity significantly increased thawing loss of pork (p<0.05). Increasing both IR power and air velocity tended to decrease the cooking loss of pork. Moreover, increased IR power tended to decrease the water holding capacity and shear force of pork. The shear force changes were not significant (p>0.05). Shear force also increased with increasing air velocity. In addition, the higher the air velocity the higher the shear force of pork. In Commission Internationale de l'Eclairage (CIE) colour determination, control of temperature prevented discolouration from overheating of sample surface. The results suggest that IR dosage combined with air blast has potential in thawed meat quality aspects, and that humidity control could prevent surface drying.