• Journal of Adhesion and Interface
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• v.2 no.3
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• pp.9-15
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• 2001

To estimate the effect of the surface state of the EVA foam on an adhesion, the surface was treated with solvents having different values of a solubility parameter and a surface tension. The morphology and the contact angle were measured by SEM and contact angle tester, respectively. The value of the critical surface tension(${\gamma}_{c,0}$) of the EVA foam calculated by Zismann plot was 27.08 dyne/cm. The surface state and the ${\gamma}_c$ of the EVA foam were changed by solvent treatment. The swelling ratio of EVA foam was influenced by solubility parameter of a solvent, on the other hand the degree of change in the surface state was dependent on a surface tension of a solvent. When a surface tension of solvent. When a surface tension of solvent is lower than ${\gamma}_{c,0}$ of the EVA foam, the wettability of a solvent was good and the surface state was greatly changed. The adhesion strength of EVA foam was greatly improved to above 600% as compared to that of the untreated one. As the ${\gamma}_c$ of EVA was closed to the surface tension of the primer, the good adhesion strength was obtained.

• Phonetics and Speech Sciences
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• v.6 no.2
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• pp.55-64
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• 2014

This study measured formant bandwidths of profound hearing impaired children and examined the characteristics of their articulation. For this study, 10 cochlear implanted children(CI), 10 hearing aid children(HA) and 10 normal hearing children(NH) were asked to read 7 Korean vowels(/ɑ, ʌ, o, u, ɯ, i, ɛ/). The subjects' readings were recorded by NasalView and analyzed by Praat. The analysis of the formant bandwidths explains the degree of vocal fold opening and the characteristics of radiation. Through the analysis of formant bandwidth, we can see that the hearing-impaired maintain vocal fold tension when they speak high vowels and characteristics of radiation. Narrower B1 means better maintain vocal fold tension, wider B2 means more front and wider B3 means the rounder lips. CI's B1 was widest and NH's was narrowest. And females' B1 was wider than males'. Among vowels, B1 of /a/ was widest, and B1 of /i/ was narrowest. In the case of B2, HA and NH's B2 was wider than CI's. Females' B2 was wider than males'. And B2 of /i/ was widest, and B2 of /ʌ/ was narrowest. In the case of B3, NH's was widest, and CI's was narrowest. Males' was wider than females'. Among vowels, B3 of /o/ was widest, and B3 of /ɛ/ was narrowest. As a result, first, through the analysis of B1, we can find that NH and males could better maintain vocal fold tension than the hearing-impaired or females, and all children articulate /i/ with vocal fold tension than other vowels. Second, through the analysis of B2, NH and HA articulate vowels with the weaker rounded than CI does. And females articulate vowels with the weaker rounded than males do. Third, through the analysis of B3, NH articulate vowels with the rounder than HA or CI do, and males articulate vowels with the rounder than females do. Through the results, we can expect that the analysis of formant bandwidth will be applied to the therapy of articulation for the hearing-impaired with hearing aids or cochlear implant.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.442-448
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• 2014

Purpose: The objective of this study is to evaluate the effect of neuro-feedback training and transcutaneous electrical nerve stimulation (TENS) on stress, quantitative sensory threshold and pain in patients suffering from tension type headache. Methods: 22 participants who passed the preliminary evaluation were enrolled in the study and 11 participants were randomly assigned to each group. The control group (n=11) was subject to the TENS treatment of which was composed of a 20-minute session for 5 times a week during 4 weeks, and the experimental group (n=11) was subject to both neuro feedback training and TENS treatment for 10 minutes a day and 5 days a week during 4 weeks. The Perceived Stress Scale (PSS) was used to measure a level of stress and the quantitative sensory testing (QST) was used for the measurement of cold pain threshold (CPT) and heat pain threshold (HPT); A degree of pain was evaluated through the headache impact test-6 (HIT-6). Results: In comparision of all dependent variables between the control and subject groups, there were significant differences in stress, quantitative sensory threshold and pain after the treatment (p<0.05), and the experimental group showed significant differences in stress, CPT, HPT and pain (p<0.05) and the control group showed only a significant difference in HPT (p<0.05). Conclusion: Findings of this study demonstrate that the concomitant administration of the TENS treatment and neuro feedback training is effective on alleviation of stress, quantitative sensory threshold and pain in patients with tension type headache.

• Computers and Concrete
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• v.27 no.5
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• pp.395-406
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• 2021

This study experimentally and analytically investigates the shear behavior of corroded reinforced concrete (RC) beams repaired using steel fiber-reinforced concrete (SFRC) in the flexural zone. The experimental parameters are the corrosion degree (0%, 12%, and 17%) and the steel fiber volume in the SFRC (1.0%, 1.5%, and 2.0%). The test results reveal that corrosion degree significantly affects the shear resistance of the beams. The shear capacity of the beam with the corrosion degree of 17% was higher than that of the uncorroded beam, whereas the shear capacity of the beam with the corrosion degree of 12% was lower than that of the uncorroded beam. The shear efficiency of damaged beams can be recovered by repairing them using SFRC that contains a reasonable amount of steel fibers. In addition, two methods to estimate the shear capacity of the repaired beams are developed using the modified truss analogy and strut-and-tie models. The estimated shear capacity of the beam using the modified truss analogy model agrees well with the experimental data.

• Journal of Adhesion and Interface
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• v.19 no.1
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• pp.13-18
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• 2018

At ruthenium (Ru) catalyst was exposed from the atmosphere, the degree of catalyst activation decreased. The change of catalyst activity with the number of days of exposure to air for the Ru catalyst was confirmed using the surface tension method quantitatively. Mechanical properties and surfactant change after polymerization by DCPD using Ru catalyst for each air exposure day was evaluated. The Ru catalyst mixed with a dilution agent was exposed in the air and color was monitored for each day. Surface tension was measured using Wilhelmy and PTFE and associated with different catalyst activities. Heat was measured in real time during polymerizing DCPD with Ru catalyst. After polymerization, tensile strength was measured for p-DCPD and the change of material property was measured. Interfacial properties were also evaluated via microdroplet pull-out tests between glass fiber and p-DCPD. The surface tension was stable until the 4 days (33 dyne/cm) whereas the surface energy increased at the 10 days (34 dyne/cm), which could be correlated with oxidation of the catalyst. Tensile property and interfacial shear strength (IFSS) was also stable until the 4 days (tensile strength: 38 MPa and IFSS: 26 MPa) whereas the mechanical property decrease at 10 days (tensile strength: 15 MPa and IFSS: 3 MPa) dramatically.

• Wind and Structures
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• v.7 no.3
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• pp.203-214
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• 2004

This paper describes a method for developing a multi-degree-of freedom aero-elasto-plastic model of a base-isolated mid-rise building. The horizontal stiffness of isolators is modeled by several tension springs and the vertical support is performed by air pressure from a compressor. A lead damper and a steel damper are modeled by a U-shaped lead line and an aluminum line. With this model, the frequency ratio of torsional vibration to sway vibration, and plastic displacements of isolation materials can be changed easily when needed. The results of isolation material tests and free vibration tests show that this model provides the object performance. The peak displacement factors are about 4.5 regardless of wind speed in wind tunnel tests, but their gust response factor decreases with increment of wind speed.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.257-260
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• 2006

This paper reports results of a study conducted to assess the effect of degree of corrosion of reinforcing steel bar on their mechanical properties. Reinforcing steel bars, 13mm in diameter, that were corroded by electrically accelerated corrosion method in concrete specimens were removed and tested in tension. Results indicated that the level of reinforcement corrosion influenced yield point, the tensile strength and elongation of steel bars.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.25.4-25
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• 2001

In this paper, a five degree-of-freedom haptic device is proposed. The proposed haptic device has a pen which is suspended by tensioned six strings. Human operator handles the pen. Six DC motors are used as actuators to generate tensions in six strings to make resultant force feedback at the pen to the human operator Six encoders are used for calculating the movement of the pen. A digital controller is used for generate control signals for the suitable tension in the six strings. A current amplifiers is used for amplifying the control signals. Cable-suspended system has advantages of structure simplicity (only with several strings driven by motors without using other tensioning mechanisms), low inertia, and high force-to-weight ratio. Pen-based system has advantages of compactness and ...

• Membrane Journal
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• v.5 no.2
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• pp.74-80
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• 1995

Asymmetric poly(vinyl alcohol) (PVA) membranes were prepared by varying the precipitation conditions of the phase inversion technique, and the influences of precipitation conditions on the water uptake of the membrane were investigate. The degree of water uptake of the membrane increased and reached a certain maximum value, as the precipitation time increased. However, it decreded after that. As the precipition temperauure became lower, the degree of water uptake increased more or less. The addition of a nonionic surfactant to the precipitaon solution was effective reducing the precipitation time by lowering the surface tension of the precipitation solution, but ig didn't change the maximum value of its own degree of water uptake. In addition, the relationship between the degree of water uptake and the separation characteristics and mechanical properies of the membrane were investigated. The selectivity factor of the membrane for pervaperation separation decreased, but the permeate flux increased, respectively, with increasing the degree of water uptake. The tensile strength and elongation of the membrane, respectively, increased to a maximum value with increasing the degree of water uptake, and then decreased abtuptly.

• Journal of Veterinary Clinics
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• v.39 no.6
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• pp.353-359
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• 2022

Several suture patterns can be used for cystotomy closure, and a continuous suture pattern is the most commonly used. In this study, the fluid-tight ability and other suitabilities of continuous appositional sutures, such as the simple continuous suture pattern (SC), running suture pattern (RN), and Ford interlocking suture pattern (FI), were compared for cystotomy closure. Cystotomy closure was performed using each suture method in 10 cases of ex vivo swine bladders in each group. Suture time, leakage site, suture length, bursting pressure (BP), bursting volume (BV), and circular bursting wall tension (CBWT) were measured. Suture time and suture length were the shortest in RN and the longest in FI. Leakage occurred in two places: the incision line directly and the hole made by the suture. Leakage occurred through the incision line in 4 bladders of the RN group and 2 bladders of the FI group, but not in the SC group, and in the rest of the bladders, leakage occurred through the suture hole. The values of BP, BV, and CBWT increased in the order of FI, SC, and RN. Suture time and suture length can be considered as factors related to healing and side effects. In this study, leakage through the incision was found in a less appositional area; therefore, leakage through the hole could be considered an indicator of better apposition. Good apposition is one of the conditions required for ideal cystotomy closure. The bursting strength representing the fluid-tight ability can be expressed as the CBWT. RN is expected to be efficient and cause a small degree of foreign body reaction; however, it is expected to be less stable. FI has the greatest fluid-tightness ability, but it has been proposed that side effects due to foreign body reactions most frequently occur in FI. In conclusion, SC, which is expected to have a sufficient degree of fluid-tightness and appropriate recovery, is preferable to other continuous appositional suturing methods for cystotomy closure.