• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.54-59
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• 2003

Recently, densified pellet fuel from wood biomass is widely used at North America and Europe as a regenerable and clean carbon neutral bioenergy. High-pressure compaction of sawdust of Hyunsasi-poplar (Populus alba ${\times}$ P. glandulosa) to form a densified fuel was studied. Calorific and elemental analysis were carried out to assess Hyunsasi-poplar clones as fuels. Hot-press process was adopted for compaction of sawdust and compaction was performed under temperature from 100 to 180$^{\circ}C$, at pressure of 250 to 1000 kgf/$\textrm{cm}^2$, and for 2.5 to 10 minutes. Densified fuels were evaluated by its oven-dry density and fines after 5-minute shaking test. The target density and fines of densified fuels were over 1.2 g/$\textrm{cm}^2$ and below 0.5%, respectively. When the press-temperature is over 160$^{\circ}C$, densified fuels with density eve. 1.2 g/$\textrm{cm}^2$ and with fines below 0.5% can be produced. And the pressure over 750 kgf/$\textrm{cm}^2$ was effective for this production. It was found that the optimum press condition for preparation of densified fuel was 180$^{\circ}C$ -1000 kgf/$\textrm{cm}^2$ minutes.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.6
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• pp.992-1001
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• 1996

The binding of polyethylene glycol (PEG, average molecular weight 600) to cotton fabrics was achieved by using pad-dry-cure process in the presence of citric acid, MgCl3·6H3O, DMDHEU, and TEAHCL. Treated fabrics were dyed with direct, acid, and basic dye. Wrinkle recovery angles, durable press rate, wettability, dyeability and color fastness to washing of all treated cottons were evaluated. The results of this study were as follows: 1. The wrinkle resistance of the PEG treated cottons was increased by increasing PEG and DMDHEU concentration. 2. The wettability of the PEG treated cottons was decreased by increasing PEG and DMDHEU concentration, increased by increasing TEAHCL concentration. 3. PEG/DMDHEU/TEAHCL treated cottons had greater affinity on direct, acid, and basic dye than untreated cottons, and dyeability of the modified cottons was improved compare to untreated fabrics. 4. Color fastness to washing of the PEG/DMDHEU/TEAHCL treated cottons was good except for the wash fastness of the direct dye.

• Computers and Concrete
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• v.14 no.6
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• pp.635-656
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• 2014

A rational estimation of moisture distribution in structural concrete is vital for predicting the possible extent and rate of progression of impending degradation processes. The paper proposes a numerical scheme for analysing the evolution of moisture distribution in concrete subjected to wetting-drying exposure caused by intermittent periods of rainfall. The proposed paradigm is based on the stage wise implementation of non-linear finite element (FE) analysis, with each stage representing a distinct phase of a typical wet-dry cycle. The associated boundary conditions have been constituted to realize the influence of various meteorological elements such as rain, wind, relative humidity and temperature on the exposed concrete surface. The reliability of the developed scheme has been demonstrated through its application for the simulation of experimentally recorded moisture profiles reported in published literature. A sensitivity analysis has also been carried out to study the influence of critical material properties on simulated results. The proposed scheme is vital to the service life modelling of concrete structures in tropical climates which largely remain exposed to the action of alternating rains.

• Advances in concrete construction
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• v.2 no.3
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• pp.209-227
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• 2014

The use of limestone fines (LF) in mortar and concrete can in certain ways improve performance and thus has become more and more commonplace. However, although LF is generally regarded as a filler, it is up to now not clear how much filling effect it could have and how best the filling effect could be utilized. Herein, the packing density and filling effect of LF were studied by measuring the packing densities of LF, (LF + cement) blends and (LF + cement + fine aggregate) blends under dry and wet conditions, and measuring the performance of mortars made with various amounts of LF added. It was found that the addition of LF would not significantly increase the packing density of (LF + cement) blends but would fill into the paste to increase the paste volume and paste film thickness, and improve the flow spread and strength of mortar.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.99-105
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• 2016

The increase of wet web solid content after wet press and dry compressive strength were observed in lab study by judicious application of wood flour and starch for the old corrugated container (OCC). Pearl starch was better than cationic starch in strength development, but cationic starch was better for drainage. Application of vacuum on the mixed solution of wood flour and starch helped strength development further without loss of other properties. The effect of wood flour addition on wet web solid content improved as the wet pressing pressure increased. The use of wood flour and starch mixture improved wet web solid contents further.

• Geomechanics and Engineering
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• v.3 no.4
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• pp.255-266
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• 2011

Knowledge of seismic earth pressure against rigid retaining wall is very important. Mononobe-Okabe method is commonly used, which considers pseudo-static approach. In this paper, the pseudo-dynamic method is used to compute the distribution of seismic earth pressure on a rigid cantilever retaining wall supporting dry cohesionless backfill. Planar rupture surface is considered in the analysis. Effect of various parameters like wall friction angle, soil friction angle, shear wave velocity, primary wave velocity, horizontal and vertical seismic accelerations on seismic earth pressure have been studied. Results are presented in terms of tabular and graphical non-dimensional form.

• Structural Engineering and Mechanics
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• v.23 no.3
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• pp.309-323
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• 2006

In this paper, seismic response of a free-standing ship located in a dry dock and supported by an arrangement of n keel blocks due to base excitation is addressed. Formulation of the problem including derivation of governing equations in various modes of motion as well as transition conditions from one mode to another is given in Moghaddasi and Bargi (2006) by same authors. On the base of numerical solution for presented formulation, several numbers of analyses are conducted to study sensitivity of system's responses to some major contributing parameters. These parameters include friction coefficients between contacting surfaces, block dimensions, peak ground acceleration, and the magnitude of vertical ground acceleration. Finally, performance of a system with usual parameters normally encountered in design is investigated.

• Smart Structures and Systems
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• v.4 no.5
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• pp.549-563
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• 2008

The ability of an electroactive polymer, IPMC (Ionic Polymer Metal Composites,) to produce electric charge under mechanical deformations may be exploited for the development of next generation of energy harvesters. Two different electrode types (gold and platinum) were employed for the experiments. The sample was tested under dynamic conditions, produced through programmed shaking. In order to evaluate the potential of IPMC for dry condition, these samples were treated with ionic liquid. Three modes of mechanical deformations (bending, tension and shear) were analyzed. Experimental results clearly indicate that IPMCs are attractive applicants for energy harvesting, with inherent advantages like flexibility, low cost, negligible maintenance and virtually infinite longevity. Besides, preliminary energy harvesting model of IPMC has been formulated based upon the work of previous investigators (Newbury 2002, Newbury and Leo 2002, Lee, et al. 2005, Konyo, et al. 2004) and the simulation results reciprocate experimental results within acceptable error.

• Geomechanics and Engineering
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• v.12 no.4
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• pp.675-688
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• 2017

The anchor block is a specially designed concrete member intended to withstand pullout or thrust forces from backfill material of an internally stabilized anchored earth retaining wall by passive resistance of soil in front of the block. This study presents small-scale laboratory experimental works to investigate the pullout capacity of a concrete anchor block embedded in air dry sand and located at different distances from yielding boundary wall. The experimental setup consists of a large tank made of fiberglass sheets and steel framing system. A series of tests was carried out in the tank to investigate the load-displacement behavior of anchor block. Experimental results are then compared with the theoretical approaches suggested by different researchers and codes. The appropriate placement of an anchor block and the passive resistance coefficient, which is multiplied by the passive resistance in front of the anchor block to obtain the pullout capacity of the anchor, were also studied.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.7
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• pp.987-994
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• 2000

Cotton fabrics were finished with mixture of BTCA and silicone by pad-dry-cure process to achieve better mechanical properties than those of finished with BTCA alone. The changes of mechanical properties o( finished cotton fabrics were measured with by the KES-FB System and the hand values were calculated from the data of mechanical properties. With the durable press finish with BTCA tensile, bending, shear and compression properties increased. In hand values, Stiffness Crispness and Anti-Drape Stiffness increased, and Fullness & Softness decreased. Whereas silicone treatment reduced bending and shear properties and improved tensile and compressional resilience. Thus, Stiffness Crispness and Anti-Drape Stiffness decreased, and Fullness & Softness increased. These results indicated that BTCA treatment restricts fiber/yarn mobility in the fabric structure due to crosslinking, but silicone treatment reduces inter-fiber and inter-yarn frictional forces. Therefore, finish with mixture of BTCA and silicone provided cotton fabrics with a lower Stiffness, Crispness and Anti-Drape Stiffness and a higher Fullness & Softnesss than finish with BTCA alone.