• Title/Summary/Keyword: The strength recovery

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A Study of the Physical Properties of Weft Knit Fabrics (위편조직(緯編組織)의 물성(物性)에 관한 연구(硏究))

  • Kim, In-Suk;Lee, Soon-Hong
    • Journal of Fashion Business
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    • v.2 no.4
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    • pp.93-101
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    • 1998
  • Knit products which had been limited only to underwear, recently became popularized, fashionized and highly classified covering even outer garments such as sportswear like golfwear, woman's dress, and man' s suit. As fashion cycle is getting shorter and the more a nation advanced prefers knit to woven fabrics knit industry has a very bright prospect, particularly woman's knit which is sensitive to fashion can be said as a fashion product with high value added. This study is to grasp the physical properties of stitch which are fundamental to the development of knit products. For this purpose, 2/20s of 100% wool were woven by the author of this study to basic plain stitch, rib stitch, varied transfer stitch, and float stitch on a SEMASEIKI cross knitter 7G to test the physical properties, and the result was as follows; 1. As for the relation between knit stitch and rate of extension recovery, rate of extension recovery was higher in the course direction than in the wale direction of three stitches except transfer stitch; rib stitch showed the highest rate of extension recovery in the course direction while float stitch showed the highest rate of extension recovery in the wale direction. 2. As for the relation between knit stitch and bursting strength elastic rib stitch showed higher bursting strength to indicate elasticity is an important factor of bursting strength and float stitch showed higher bursting strength too to indicate that the floating yarn on the surface plays a role of support. 3. As for the relation between knit stitch and air permeability perforated transfer stitch showed the lowest air permeability to prove that the size of perforation affects on the air permeability a great deal. 4. As for the relation between knit stitch and warmth retaining rib stitch through two lined needle bar showed the highest degree. The reason the warmth of perforated transfer stitch didn't decrease much was because the perforation wasn't big enough and content of air increased from the unevenness of the perforated parts through stitch variation. Based upon this result, each stitch can be characteristically summarized as follows; plain stitch showed a stable condition of knit cloth in four kinds of physical property test. And rib stitch is proper to tighten the edge of sleeve or clothe making use of its excellent extension recovery and to make socks for the highest bursting strength and warmth retaining. In the case of transfer stitch, seasonable designs can be taken by controlling the size of loop. Considering the pleasantness, underwear should be made of stitches with good air permeability float stitch was revealed to have color and pattern effects and a great bursting strength. This study has limitations in the aspect that it dealed with a small part of various knit stitches and the items of physical property test were not enough. The author of this study hopes that further studies would make deeper understandings about knit stitch based on more varied stitches and physical property tests ultimately to contribute to the development of fashionable designs proper to maximize the usage, function and originality.

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Changes on Physical Properties of Chrome Leather by Treatment with Artificial Perspiration (크롬유혁의 인공땀액 처리에 의한 물성변화)

  • Yoon, Jeong Ah;Choi, Suk Chul;Lee, Yang Hun;Chun, Tae Il
    • Textile Coloration and Finishing
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    • v.7 no.4
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    • pp.25-32
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    • 1995
  • This study was carried out to examine the influences of fatigue and perspiration on the deterioration of chrome leather for shoes. The samples were treated with acidic and alkaline artificial perspirations and applied cyclic tensile stress, and the elastic recovery from fatigue strain, tensile strength and elongation, stiffness etc. by regions and directions were determined. The physical properties generally indicate considerable difference by regions and directions due to the thickness, entangling state, and arrangement direction of fiber buldles within the leather. By the treatment of artificial perspirations, the length, weight, strength, elastic recovery from fatigue of the lether are decreased and the thicknes, elongation, and stiffness are increased; and their extents by the alkaline perspiration are higher than those by the acidic one. The elastic recovery from fatigue of samples are decreased with increasing fatigue cylcle; and indicate regressive relations against the logarithm of the elapsed time, and the means of regression coefficients are 2.73 > 2.55 > 2.22 for samples treated by the acidic perspiration, untreated, and treated by the alkaline perspiration, respectively. The tensile strength is decreased and elogation is increased by fatigue, but the changes are diminished likely due to a rearrangment of fiber bundles with increasing fatigue cycle. And the samples become a little flexible immediately after fatigue; but stiffen again with elastic recovery from fatigue strain, consequently for some cases their stiffness after recovery are rather greater than those before fatigre.

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Effects of Heat Input and Preheat/interpass Temperature on Strength and Impact Toughness of Multipass Welded Low Alloy Steel Weld Metal (다층용접한 저합금 용접금속의 강도와 인성에 미치는 입열량 및 예열/패스간 온도의 영향)

  • Bang, Kook-soo;Jung, Ho-shin;Park, Chan
    • Journal of Ocean Engineering and Technology
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    • v.29 no.6
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    • pp.481-487
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    • 2015
  • The effects of the heat input and preheat/interpass temperatures on the tensile strength and impact toughness of multipass welded weld metal were investigated and interpreted in terms of the recovery of the alloying elements and microstructure. Increases in both the heat input and preheat/interpass temperatures decreased the tensile strength of the weld metal. A lower recovery of alloying elements, especially Mn and Si, and smaller area fraction of acicular ferrite in the weld metal were observed in higher heat input welding, resulting in a lower tensile strength. In contrast, only a microstructure difference was observed at a higher preheat/interpass temperature. The impact toughness of the weld metal gradually increased with an increase in the heat input because of the lower tensile strength. However, it decreased again when the heat input was larger than 45 kJ/cm because of the much smaller area fraction of acicular ferrite. No effect of the preheat/interpass temperature on the impact toughness was observed. The formation of a weld metal heat-affect zone showed little effect on the impact toughness of the weld metal in this experiment.

The Effects of Music Therapy on recovery of consciousness and vital signs in post operative patient in the recovery room (음악요법이 수술직후 환자의 의식회복과 활력징후에 미치는 영향)

  • Kim Sook-Jung;Jun Eun-Hee
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.7 no.2
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    • pp.222-238
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    • 2000
  • The purpose of this study was to demonstrate the effect of music therapy as a nursing intervention on changes in recovery of consciousness and vital signs for postoperative patients in the recovery room. The subject for this study were fifty three of postoperative patients who were transferred from the OR to the RR at Kwangju Christian Hospital in Kwangju City. Thirty of them were assigned to the experimental group, and twenty three, to the control group. The age of the subject was between twenty and sixty years of age. The subject had a general anesthesia without any special complications, and they were not completely awake. The data were collected for six months from July 1999 to February 2000. The method used was to compare the condition of the subjects in each group at the beginning and at certain times repeatedly. The features observed were the level of consciousness, the frequency of complaints of pain, and vital signs of the subject before and 15 minutes, 30 minutes, and 60 minutes after hearing their favorite music for 30 minutes. The results are as follows 1. The recovery of consciousness was revealed through significant changes in facial expression, facial color, and grip strength in the experimental group more strongly than in the control group. No significant changes were shown in verbal order. The differences in recovery of consciousness in the pre-post music therapy between the two groups was not significant in verbal order, facial expression, or grip strength. However, significant changes were seen in facial color. 2. There were no significant differences between the two groups in changes in the frequency of pain complaints after music therapy. However, a significant difference was shown in the pre-post music therapy scres. 3. Vital signs did not show a significant difference between the two groups. However, the $SPO_2$ of the experimental group was significantly elevated after 60 minutes. The difference pre-post to the music therapy in the vital signs between two groups was significant only in body temperature. This study showed that the effect of music therapy given to postoperative patients is that it promotes changes in facial expression, facial color, and grip strength helping recovery of consciousness, stabilizing vital signs, elevating levels of $SPO_2$. and reducing complaints of pain. It is recommended that if the patient wants it music therapy be given right after surgery in the recovery room as a nursing intervention.

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Effects of Different Cool-down Exercise Methods on Muscle Strength and Endurance of the Lower Extremities

  • Bae, Chang-Hwan;Cho, Sung-Hyoun;HwangBo, Gak
    • International Journal of Contents
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    • v.8 no.2
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    • pp.97-102
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    • 2012
  • The purpose of this study was to investigate the effects of various cool-down exercises on muscular strength and endurance. After receiving a treadmill training for main exercise, the subjects conducted isotonic and isometric cool-down exercises four times for three weeks. Isotonic exercise with leg press of 10kg was repeated by 20 times and isometric exercise was conducted at flexion of hip joint and knee joint with leg press of 10kg by maintaining it for 6 sec and resting for 2 sec by 20 times. Muscular strength after exercise was measured with 1 RM by times and muscular endurance with maximum repetition frequency using time to keep for loading the weight of 10 RM and 65% of maximum muscular strength. As a result of comparing and analyzing measured values, exercise recovery shape of isotonic and isometric cool-down group were more effective than rest recovery shape of the control group. The isometric cool-down group was more effective than isotonic cool-down group. In conclusion, isometric exercise was more effective than isotonic exercise or simple rest on muscular strength and endurance.

A computational analysis of the scarf angle on a composites repair

  • Kim, Yun-Hae;Jo, Young-Dae;Murakami, Ri-Ichi
    • International Journal of Ocean System Engineering
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    • v.1 no.1
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    • pp.9-15
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    • 2011
  • This study examined the relationship between the scarf angle and stress distribution, and estimated the strength recovery via a finite element analysis. The following conclusions were drawn from this study. Resin will fracture due to a tensile load with a high scarf angle, which is similar to the patch repair method. An applied stress can be loaded to a repaired laminate if the scarf angle is $5^{\circ}$. The Von-Mises stress increases with decreasing scarf angle, with the exception of a scarf angle of $30^{\circ}$, where the scarf angle can indicate the rates of shear and normal stresses. Strength recovery can be better if the scarf angle is decreased to a lower angle. However, scarf machining requires more time, a high skill level and considerable expense. Therefore, a scarf angle of $5^{\circ}$ is the most effective for a repair. These results may provide a guide for engineers wishing to formulate a standard for repair. The scarf angle needs to be carefully managed for a more efficient composite repair.

Dielectric Recovery Characteristics between Poles of 800kV Model Interrupter -I. Effects or separation between Moving Main Contact and Moving Arcing Contact- (800kV 모델차단부의 극간 절연회복특성 -I. 가동주접점과 가동아크접점간 이격거리의 변화에 대한 영향분석-)

  • Shin, Y.J.;Park, K.Y.;Chang, K.C.;Song, K.D.;Jeong, J.K.;Song, W.P.;Kang, J.H.
    • Proceedings of the KIEE Conference
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    • 1994.11a
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    • pp.270-273
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    • 1994
  • The capacitive current breaking capability as well as the short circuit current breaking capability is a very important factor in the performance of a circuit breaker. The dielectric recovery capability between poles should be considered in the desist of a circuit breaker because approximately two times of the maximum power system voltage might be applied between poles after the capacitive current be interrupted. The electric field and flow field analyses were utilized in the calculation of dielectric recovery characteristics between poles of 800kV model interrupter. The results show that the separation between moving main contact and moving arcing contact will affect to decrease significantly the electric field strength of a moving arcing contact and an insulation cover, to increase slightly the electric field strength of a fixed arcing contact and to decrease consequently the dielectric recovery capability between poles of the interrupter.

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A Study on the Durable Press Finish by Wet-Fixation Processes for Rayon Fabrics (I) - One Bath and Two Bath Processes - (레이온 직물의 Wet-Fixation에 의한 DP가공에 관한 연구(I) - 일욕법과 이욕법의 비교 -)

  • Hu Yoon Sook;Kim Eun Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.13 no.3 s.31
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    • pp.242-251
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    • 1989
  • The purpose of this study was to investigate the changes in easy-care and strength properties of the wet fixation processed viscose rayon fabrics. Rayon fabrics were treated with mixed resins of melamine formaldehyde (MF) and DMDHEU by one bath and two bath wet fixation processes. The MF/DMDHEU mixed resin concentrations were 50/100, 50/150, 100/100, 100/150 and 150/100(g/1). Magnasium chloride was used as a catalyst. Treated fabrics were evaluated by nitrogen content, DP rating, wrinkle recovery angle, breaking strength, tearing strength and abrasion resistance. The properties were compared to the fabrics treated by conventional Pad-Dry-Cure (PDC) method. Wet fixation processed fabrics showed DP ratings of higher than 3 and higher than 275 degrees of wrinkle recovery angles in all the mixed resin concentrations. Wet fixation processed fabrics showed increase in breaking strength and tearing strength but decrease in abrasion resistance. However, the decrease in abrasion resistance was much less than the conventional PDC treated fabrics. The one bath wet fixation processed fabrics showed better physical properties than the two bath processed fabrics in general. The optimum treatment condition was the mixed resin concentration of MF/DMDHEU, 100/100 g/l in one bath wet fixation process.

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Performance Evaluation of Reconstruction Algorithms for DMIDR (DMIDR 장치의 재구성 알고리즘 별 성능 평가)

  • Kwak, In-Suk;Lee, Hyuk;Moon, Seung-Cheol
    • The Korean Journal of Nuclear Medicine Technology
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    • v.23 no.2
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    • pp.29-37
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    • 2019
  • Purpose DMIDR(Discovery Molecular Imaging Digital Ready, General Electric Healthcare, USA) is a PET/CT scanner designed to allow application of PSF(Point Spread Function), TOF(Time of Flight) and Q.Clear algorithm. Especially, Q.Clear is a reconstruction algorithm which can overcome the limitation of OSEM(Ordered Subset Expectation Maximization) and reduce the image noise based on voxel unit. The aim of this paper is to evaluate the performance of reconstruction algorithms and optimize the algorithm combination to improve the accurate SUV(Standardized Uptake Value) measurement and lesion detectability. Materials and Methods PET phantom was filled with $^{18}F-FDG$ radioactivity concentration ratio of hot to background was in a ratio of 2:1, 4:1 and 8:1. Scan was performed using the NEMA protocols. Scan data was reconstructed using combination of (1)VPFX(VUE point FX(TOF)), (2)VPHD-S(VUE Point HD+PSF), (3)VPFX-S (TOF+PSF), (4)QCHD-S-400((VUE Point HD+Q.Clear(${\beta}-strength$ 400)+PSF), (5)QCFX-S-400(TOF +Q.Clear(${\beta}-strength$ 400)+PSF), (6)QCHD-S-50(VUE Point HD+Q.Clear(${\beta}-strength$ 50)+PSF) and (7)QCFX-S-50(TOF+Q.Clear(${\beta}-strength$ 50)+PSF). CR(Contrast Recovery) and BV(Background Variability) were compared. Also, SNR(Signal to Noise Ratio) and RC(Recovery Coefficient) of counts and SUV were compared respectively. Results VPFX-S showed the highest CR value in sphere size of 10 and 13 mm, and QCFX-S-50 showed the highest value in spheres greater than 17 mm. In comparison of BV and SNR, QCFX-S-400 and QCHD-S-400 showed good results. The results of SUV measurement were proportional to the H/B ratio. RC for SUV is in inverse proportion to the H/B ratio and QCFX-S-50 showed highest value. In addition, reconstruction algorithm of Q.Clear using 400 of ${\beta}-strength$ showed lower value. Conclusion When higher ${\beta}-strength$ was applied Q.Clear showed better image quality by reducing the noise. On the contrary, lower ${\beta}-strength$ was applied Q.Clear showed that sharpness increase and PVE(Partial Volume Effect) decrease, so it is possible to measure SUV based on high RC comparing to conventional reconstruction conditions. An appropriate choice of these reconstruction algorithm can improve the accuracy and lesion detectability. In this reason, it is necessary to optimize the algorithm parameter according to the purpose.

Experimental Study on the Evaluation of frost-Resistance of High-Strength Concrete Damaged by frost at Early Age in Cold Climates (동절기 초기재령에서 동해를 받은 고강도콘크리트의 내동해성 평가에 관한 실험적 연구)

  • 권영진
    • Journal of the Korea Concrete Institute
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    • v.13 no.2
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    • pp.139-145
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    • 2001
  • One of ways to make high-strength concrete is for the mix contain particles graded down to the finest size : this is achieved by the use of fly ash, silica fume which fills the spaces between the cement particle and between the aggregate and the cement particles. And, the mix needs a sufficient workability. This is achieved by the use of a superplasticizer. This study is to investigate frost resistance of high-strength concrete at early age, with ratio of tensile strength and recovery of compressive strength, when high-strength concrete is placed in cold climates. According to this study, it is necessary to ensure 4 % of air content, 5 kgf/$\textrm{cm}^2$ of tensile strength, at least, for frost resistance of high-strength concrete at early age.