• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.4
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• pp.34-40
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• 2000

This study was carried out to evaluate the effects of enzymatic treatment on the characteristics of KOCC. Novozym 342 and Pulpzyme HC were used for this purpose. Enzymatic treatment greatly increased the freeness of KOCC and Novozym 342 was more effective. WRV was improved only when KOCC was treated with 0.1% Pulpzyme HC. Pulpzyme HC was more effective to improve the flexibility of fiber(conformability angle) than Novozym 342. Coarseness of fiber was decreased with the enzymatic treatment. Fines content greatly decreased with 0.01% addition of enzymes. Novozym 342 was more effective than Pulpzyme HC for this purpose. Apparent density, tensile index and tear index decreased with enzymatic treatment, but stiffness increased. Especially the decrease of apparent density, tensile index and tear index by the treatment with Novozym 342 was significant than those of Pulpzyme HC. Therefore Novozym 342 will be suitable for the removal of fines and for bulky sheet, otherwise Pulpzyme HC will be good.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.6
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• pp.73-80
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• 2015

Corn stalk is the lignocellulosic biomass, which remain as leftover after harvesting. To use the corn stalk as raw material for paper industry, soda pulping was applied. In chemical compositional analysis, extractive contents of corn stalk (45.1%) was higher than hardwood. With corn stalk pith, soda pulp yield was 25.3% at 10.6 Kappa number, but 39.5% yield with 14.8 Kappa number for corn stalk rind. Higher extractives content in pith is one of the reason for lower pulp yield than rind. Pith pulp fibers had higher fines content than rind pulp. Pith parenchyma cell was removed as fines during pulping or washing process, which caused the lower yield. To use the corn stalks as a raw material for paper making, de-pith process is essential for higher pulp yield and longer pulp length.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.433-442
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• 2021

In this study, the properties of no-fines polymer concrete with different polymer binder contents were evaluated. The polymer concrete was formulated using a polymeric binder (unsaturated polyester resin), fly ash, and recycled coarse aggregate (60%) and crushed coarse aggregate (40%). The polymeric binder content (4.0-6.0wt.%) was used as an experimental variable because it dramatically affects both the cost-effectiveness and material properties. The results showed that the density, compressive strength, flexural strength both before and after exposure to freezing and thawing increased as the polymer binder content increased, while the absorption, void ratio, permeable voids, coefficient of permeability, and acid resistance (mass loss by acid attack) decreased as the polymeric binder content increased. In particular, even though the void ratio was 18.4% and the water permeability coefficient was 7.3mm/sec, the compressive strength and flexural strength were as high as 38.0MPa and 10.0MPa, respectively, much more significant than those of previous studies. Other properties such as absorption and acid resistance were also found to be excellent. The results appear to be rooted in the increased adhesion of the binder by adding a cross-linking agent and the surface hydrophobicity of the polymer.

• Journal of the Korean Geotechnical Society
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• v.39 no.10
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• pp.5-18
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• 2023

The construction timeline for earthworks can be significantly reduced by substituting the conventional layer-by-layer compaction using a vibratory roller with single-layer compaction through the rapid impact compaction (RIC) method. Dynamic load compaction is well-suited for coarse-grained soils like sand. However, as the supply of sand, the primary reclamation material, becomes scarcer, the utilization of soil with fines is on the rise. To implement the dynamic load compaction, such as RIC, with reclaimed materials containing fines, it's imperative to determine the effective improvement depth. In this study, we assess the impact of the RIC method on the effective improvement depth for clean sand and public fill with fines, comparing field test results before and after RIC application. Our focus is on the cone resistance (q_c) as it pertains to compaction quality control criteria. In conclusion, it becomes evident that standardizing the cone resistance is vital for the quality control of various reclaimed soils with fines. We have evaluated the compaction quality control criteria corresponding to a relative density (Dr) of 70% for clean sand as Q_tn,cs = 110. As a result of this analysis, we propose new quality control criteria for q_c, taking into account the fines content of reclaimed soils, which can be applied to RIC quality control.

• Journal of the Korean Geotechnical Society
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• v.27 no.6
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• pp.63-79
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• 2011

In this study relative density tests of bottom ash and standard sand were carried out. And cyclic triaxial tests for samples with the relative density of 40%, 55%, and 70% were carried out on the basis of the test results. Cyclic triaxial tests were also conducted for fines content with 55% relative density. Residual samples were divided into No.40, No.60, No.60, and No.100, and No.200. In order to avoid crashing that can happen when compaction of the sample is initiated, bottom ash was crushed using the a compact mold. In consideration of the crushing characteristics of each residual samples, the fragmentation rate increased up to 30%, which led to the adjustment of fine-grained amount to 10%, 20%, and 30%. Through the repative triaxial test in accordance with the relative density, resistant characteristics of the liquefaction of bottom ash was analyzed. Test results show that, crushing strength of bottom ash was smaller than that of standard sand, resulting in different liquefaction behavior characteristics. And we could find fines content with maximum resistant characteristics of the liquefaction.

• Journal of the Korean Geosynthetics Society
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• v.23 no.1
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• pp.9-16
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• 2024

In order to evaluate the relationship between the ground confining pressure and the shear characteristics of the pile-soil interface, this study described the comparative results of the existing experimental results and the FEA results using the strength reduction factor. The strength reduction factor was applied to simulate the shear behavior of the pile-soil interface in finite element analysis(FEA). The analysis results showed that the maximum pullout resistance decreased due to the influence of low confining pressure, as the fines content increased. This trend was similar to the previous experimental research, and this FEA model simulated with the interface strength reduction factor was evaluated as reasonable. The analysis results of the variation in the interface strength reduction factor clearly showed that the interface strength reduction factor clearly increased at a high fines content when the confining pressure was 50kPa. However, it was found that the increase rate was low when the confining pressure was 100kPa and 150kPa. Therefore, confining pressure and fines content need to be considered in FEA to evaluate the shear behavior of the pile-soil interface.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.59-65
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• 2002

Recently, densified fuels from biomass are widely used North America and Europe as a regenerable and clean bioenergy. Compaction of sawdust of poplars(Populus tomentiglandulosa and Populus davidiana) with starch glue for densified fuel were studied. Calorific and elemental analysis were carried out to assess these species as fuel. Hot-press process was used and compaction was performed under temperatures from 120 to $160^{\circ}C$ and at pressure of 50kgf/$cm^2$ for prescribed time. Densified fuels were evaluated by its specific gravities, compressive strengths and fines. In the case of with-glue system, when the press temperature is $160^{\circ}C$ and press time is above 7.5 minutes, densified fuels with fines less than 5% can be produced. On the contrary, in the case of without-glue system, densified fuels with fines less than 5% can be produced by controlling the press conditions and the moisture content of sawdust.

• Journal of the korean society of oceanography
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• v.34 no.3
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• pp.144-150
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• 1999

Slope sedimentation on the modern west Florida continental margin is controlled by pelagic carbonate accumulation and off-shelf sedimentation of neritic carbonates and terrigenous fines. Production and deposition of pelagic carbonates by planktonic foraminifera and coccoliths have played a significant role in the total slope sedimentation and are mainly promoted by sea-surface productivity. Organic carbon data reflect the relatively high biological productivity in surface waters, indicating high accumulation of biogenic calcareous sediments. The surface-water productivity in the study area is supported by the relation among microfossil assemblages, carbonate mineralogy and sedimentary organic carbon.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.172-177
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• 1999

Effect of fiber treatment with cellulase (Liftase A40), and with two refining methods (Valley beating and impact refining) on wood fiber and handsheet properties were investigated at three refining levels (300, 400, and 500ml) for two furnishes (NBKP and LBKP). Part of the treated furnishes were classified by 150 mesh screen into fine-free fiber, and fines. Fiber length analysis, WRV, zero-span strength, and other handsheet mechanical properties were compared. The study showed that Liftase A40 lowered the zero-span and the folding endurance of both furnishes (NBKP much more and LBKP much less). Pretreatment with Liftase A 40 followed by refining significantly lowered the fiber length and refining energy to reach to the target freeness. Impact refining, which is done by hitting the fibers vertically with rod at 20% solid content, kept the fiber length increased WRV, and improved handsheet mechanical properties much more than valley beating. Properties of fines from different sources were compared in detail in the study.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.06a
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• pp.34-39
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• 2000

Today's size of production operations in the packaging paper sector I sconstantly increasing , featuring integral processing systems, high-speed paper machines, and the increased marketing of lower basis weight products. The risk factors involved in these large investments lie more than ever in the available furnish potential and ongoing requirements for further closure of water loops and lower operating costs. A comparison is drawn between recovered paper furnish mixtures used in European mills with regard to fibre properties, strength potential and contaminant content, Both the furnish situation and development trends in modern fluting and testliner machines are instigating concept changes in stock preparation, the approach flow as well as in process water and rejects technology. Developments are currently focussed for example on more efficient debris separation using fine slotted screening, optimized refining , more systematic process water management with loop separation and integral water clarification as well as more efficient removal of microstickies, fillers and fines through appropriate combination of rejects handling and water clarification processes. Product quality differentiation depends decisively on strength characteristics as a function of refining , fines removal , paper machine technology, and sizing . Maximum availability of today's high speed paper machines and , as a result, cost effective production can be ensured by optimum balancing of all subsystems with in the overall concept and by reliable control of problems with contaminants and deposits.