• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.3
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• pp.81-87
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• 2014

Conditions of paper manufacturing process should be changed depending on the end use and paper properties. Most of the case, mixed pulps with long softwood fibers and short hardwood fibers are used to achieve proper qualities of product with reasonable production cost. For specialty paper manufacture the wood pulp and cotton linter pulp are usually mixed together. The objectives of this study is to analyze physical, mechanical and fracture mechanical properties of paper depending on SwBKP, HwBKP and cotton linter pulp(CLP) mixing. When the mixing ratio of SwBKP was increased, strength properties, such as tensile, tear, and folding endurance, were also increased. When the mixing ratio of SwBKP and HwBKP was increased, stress concentration index was decreased and fracture toughness was increased.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.4
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• pp.27-33
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• 2013

Manufacturing fabrics from dissolving cellulosic pulp is increasing in these days. For making high quality of cellulose-based fabrics, control of cellulose DP (degree of polymerization), its alpha cellulose content, its brightness, and its crystallinity are important. To process the cellulosic raw material, refining of cellulosic fibers is essential, and it is important to know if refining affects those important cellulose properties. The effects of PFI mill and Valley beater refining on the alpha-cellulose content, cellulose DP, crystallinity, and paper mechanical properties of wood and two different cotton fibers were studied. The results showed that PFI mill refining rarely affected those properties. Fibers refined by a Valley beater displayed a small reduction in fiber length in comparison with those refined by a PFI mill. However, the Valley beater refining method produced almost no changes in cellulose properties, either. The refining process seemed to have very little effect on the cellulose DP, crystallinity index, or alpha-cellulose content until the freeness decreased to around 300 mL CSF for wood and 100 mL CSF for cotton fibers, respectively. There were also no differences in tensile strength development in two refining methods.

• The Journal of Korean Physical Therapy
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• v.20 no.1
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• pp.23-31
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• 2008

Purpose: The purpose of this study was finding out the effects of spinal stabilization exercise using Centaur which is a 3D spinal stabilization sports implement on Chronic low back pain patients over 8 weeks. Methods: 30 patients with DDD were observed during the study. Their average age was 66.88years, height was 152.12cm and average weight was 58.91kg, 4 males and 26 females were involved. 8 various investigations were performed and varied values were compared with reinvestigation done after having exercised 8 weeks using 3-D CENTAUR We used VAS(visual analog scale) in order to see the variation of pain intensity, MOI(modified oswestry index) in order to see limitation of daily life. Results: VAS was lessened from 7.57 to 2.63, limitation of routine life(MOS) from 23.48 to 11.30, there were remarkable differences statistically(p<0.05). As a result of muscular investigation for static spinal stabilization by 8 variations of body deflection, muscular strength were all increased and there were signigicant differences statistically(p<0.05). Conclusion: It has turned out that pain and limitation of routine life was lessened, as a result of 8 weeks exercise using CENTAUR, and deep muscular power was increased. Thus it has turned out that 3-D spinal stabilization exercise has an effect on the strengthening spinal muscles and alleviation of their pain for old patients with DDD.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.41-49
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• 2014

The research was performed to investigate the weathering characteristics of fruit growth paper bags. The bags were used to cover fruits such as grapes and pears. And then they were collected after 30 and 60 days exposure at the orchard. The physical and optical properties of the bags tended to decrease with the exposure times. The larger change on the properties were found on the papers exposed for 30 days. The cover paper for pear showed the largest density changes. The air permeability were decreased with the exposure time in all bags. The cover paper for pear showed the very low values of air permeability. The mechanical properties of the fruit bags showed to be gradually decreased with the length of exposure time. The tear index showed the largest differences. The cover paper for pear showed the rapid decrease on the mechanical properties after 60 days of the exposure. The inner paper, however, showed the strength enough to cover the fruits. The precipitation showed more effect on the degradation of fruit growth paper bags than the light hours.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.1
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• pp.131-142
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• 2004

When the cotton/polyester fiber mixed fabrics were treated with ferrous sulfate and oxalic acid for burn out finishing, it was examined how the effects of process conditions as concentration of burn out agents, temperature, time and pressure act onto the properties of polyester ground fabrics. The results are as follows. The effect of burn out finishing by pressure was greated in 3 kgf/$\textrm{cm}^2$. The properties as white index and tensile strength of polyester ground fabrics were decreased according as processing concentration, temperature time increases. The shrinkage was increased according as processing concentration, temperature time increases. The optimum condition of burn out agents to ferrous sulfate was 30% concentration, 150$^{\circ}C$, 1 min, 3 kgf/$\textrm{cm}^2$ and to oxalic acid was 10% concentration, 110$^{\circ}C$, 1min, 3 kgf/$\textrm{cm}^2$. And the optimum of ferrous sulfate and oxalic acid used in combination was 10% ferrous sulfate and 7% oxalic acid, 110$^{\circ}C$, 1 min., 3 kgf/$\textrm{cm}^2$.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.36-44
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• 2020

With the advent of westernized diet and a lack of exercise, young female college students are paying more attention to their bodyweight and health. Whole-body vibration has been demonstrated to be a suitable training method for improving knee extension maximal strength in young female athletes, as well as the gait performance in elderly women. This study aimed to evaluate the effects of a vertical vibration intervention on the physical fitness and postural balance in young females. Fifty-four young women were recruited; all subjects were randomly assigned to the intervention group and control group. The intervention group underwent vertical vibration with a platform for 12 weeks. The results showed that body mass index and body fat percentage had decreased (P<0.05). In addition, their muscle endurance as indicated by a sit-up test and their flexibility as indicated by a sit-and-reach test were both increased. With regard to postural balance, their 30-second sit-to-stand and timed up and go test results were improved. At the same time, their mean single-leg stance with eyes closed time increased (P<0.05). However, there were no significant differences, meanwhile, for the control group. Overall, the results showed that the whole body vibration (WBV) intervention had some beneficial effects on physical fitness and postural balance in young women.

• Journal of the Korean Geotechnical Society
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• v.33 no.12
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• pp.127-139
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• 2017

Site investigation including boring and various in-situ borehole test (Pressuremeter test, Borehole shear test, Downhole test, Suspension PS logging, Density logging) and X-ray fluorescence analysis for rock core sample were performed to estimate geotechnical properties and weathering degree of weathered granite rock in Goyang. Deformation modulus, shear strength parameter and shear wave velocity estimated through in-situ borehole test had a tendency to increase with depth. And several chemical weathering indices evaluated by X-ray fluorescence analysis had a general tendency of reducing weathering degree in accordance with depth. Also, relationship between VR determined as a representative weathering index and the geotechnical properties was analyzed.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.80.2-80.2
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• 2011

The sudden decrease of galactic cosmic ray (GCR) intensity observed by ground neutron monitor (NM) is called a Forbush decrease (FD) event. The intensity time profile of FD event looks like the geomagnetic storm visualized by geomagnetic storm index Dst. Oh et al. [2008] and Oh and Yi [2009] classified the FD events into two kinds by criteria of the overlapping simultaneity of main phase in universal time (UT). The FD event is defined simultaneous if the main phase parts observed by the stations distributed evenly around the Earth are overlapped in UT and non-simultaneous if ones are overlapped in each station's local time (LT). They suggested the occurrence mechanisms of two kind FD events related to the interplanetary magnetic structures such as the interplanetary shock (IP shock) and magnetic cloud. According to their model, the simultaneity of FD depends on the strength and propagation direction of interactive magnetic structures overtaking the Earth. Now the STEREO mission can visualize the emergence and propagation direction of the coronal mass ejection (CME) in 3-dimension in the heliosphere. Thus, it is possible to test the suggested mechanisms causing two different types of FD events. One simultaneous FD observed on February 17, 2011 may be caused by a CME heading directly toward the Earth observed on February 15, 2011 by the STEREO mission. The simultaneity of FD event is proved to be a useful analysis tool in figuring out the geo-effectiveness of solar events such as interplanetary CMEs and IP shocks.

• PNF and Movement
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• v.16 no.1
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• pp.105-113
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• 2018

Purpose: The aim of this study was to explore the effects of dynamic balance training on pain, physical function, and dynamic balance in individuals with knee osteoarthritis. Methods: Fourteen patients with knee osteoarthritis participated in this study. The patients were randomly assigned to two groups: an experimental group (n=7) or a control group (n=7). All the patients took part in a lower extremity strength program for 30 min. In addition, the experimental group participated in a 30-min dynamic balance program. Both groups performed the program five times a week for 3 weeks. Outcomes, including the numeric rating scale (NRS), Western Ontario and MacMaster Universities Arthritis Index (WOMAC), and Community Balance and Mobility Scale (CB&M), were measured at baseline and after 3 weeks. Results: Both groups showed pre-to-post intervention improvements on all outcome measures (p<0.05). The experimental group showed a significant improvement in WOMAC (p = 0.00; Z = -2.82) and CB&M (p = 0.03; Z = -2.20) scores after the intervention as compared with those of the control group. Conclusion: The results revealed that dynamic balance training improved physical function, as well as balance ability, in patients with knee osteoarthritis as compared with that of a control group with no balance training.

• Polymer(Korea)
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• v.39 no.2
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• pp.200-209
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• 2015

In this study, the influence of dilauroyl peroxide on mechanical and thermal properties of different polypropylene (PP) matrices was investigated. Polypropylene matrices, different molecular weight isotactic PP containing 0.01, 0.02, 0.04, 0.06, 0.08, and 0.1 wt% of dilauroyl peroxide (DLP) were prepared by using a single-screw extruder. The effect of the visbreaking agent (DLP) on mechanical, physical, thermal and morphological properties of different molecular weight PP had been studied. Mechanical properties (tensile strength at break point, at yield and elongation at break point), melt flow index (MFI), scanning electron microscope (SEM) and differential scanning calorimetric (DSC) analyses of these matrices were examined. Melting ($T_m$) and crystallization ($T_c$) temperatures, crystallinity ratio (%) and enthalpies were determined. The microstructure of isotactic polypropylene matrix was investigated by scanning electron microscopy (SEM). From SEM analysis, it was observed that the surface disorder increased by the increasing amount of DLP. As a result of DSC analyses, the crystallinity ratio of the PP matrices has varied between 1.64-7.27%. Mechanical properties of the matrices have been improved. Particularly, the mechanical tests of PP have given interesting results when compounded with 0.06-0.08 wt% dilauroyl peroxide (DLP). Mechanical properties and thermal decomposition processes were all changed by increasing the amount of DLP in the matrix structure.