• Fire Science and Engineering
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• v.25 no.4
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• pp.28-34
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• 2011

For the safe handling of cyclohexanone, the explosion limits at $25^{\circ}C$ were investigated. The lower flash points and AITs (auto-ignition temperatures) by ignition time delay for cyclohexanone were experimented. By using the literatures data, the lower and upper explosion limits of cyclohexanone recommended 1.1 Vol.% ($100^{\circ}C$) and 9.4 Vol.%, respectively. The lower flash points of cyclohexanone were experimented $42{\sim}43^{\circ}C$ by using closed-cup tester and $49{\sim}51^{\circ}C$ by using open cup tester. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for cyclohexanone and the experimental AIT of cyclohexanone was $415^{\circ}C$.

• Fire Science and Engineering
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• v.25 no.2
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• pp.120-125
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• 2011

For the safe handling of n-dodecane, the explosion limits were investigated and the lower flash points and AITs (autoignition temperatures) by ignition delay time were experimented. By using the literatures data, the lower and upper explosion limits of n-dodecanee recommended 0.6 Vol.% and 4.7 Vol.%, respectively. The lower flash points of n-dodecane by using closed-cup tester were experimented $77^{\circ}$ and $80^{\circ}C$. The lower flash points of n-dodecane by using open cup tester were experimented $84^{\circ}C$ and $87^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for n-dodecane. The experimental AIT of n-dodecane was $222^{\circ}C$.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.2
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• pp.211-220
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• 2020

Purpose : The purpose of the present study is to examine the effects of VR training with FES on improving the muscle strength, AROM, and function of the upper limb joints in patients with chronic stroke. Methods : The present study makes use of a pre-post control group design. Thirty patients with chronic stroke were randomly assigned to two groups according to treatment method - the VRFES group and the control group. The VRFES group received 15 minutes of VR training and 15 minutes of FES treatment. The control group received 15 minutes of conservative physical therapy and 15 minutes of VR training. All subjects received 30 minutes of treatment, three times a week, for eight weeks, which amounted to 24 sessions of training. The muscle strength, AROM, and function of the upper extremities were measured before the training and eight weeks after. Upper limb muscle strength was tested using the Digital Manual Muscle Tester while AROM was measured using the Digital Dual Inclinometer. The clinical assessment tools for upper extremity function included the use of the Manual Function Test and the Jebsen-Taylor Hand Function Test. Results : Both groups exhibited great improvements in muscle strength and upper extremity function during the intervention period. The VRFES group exhibited a significant difference in muscle strength, AROM, and function of the upper extremities in comparison with the control group(p<.05). Our results reveal that VRFES is more effective for the muscle strength, AROM, and function of the upper extremities in patients with chronic stroke. Conclusion : VRFES treatment will be used as an important intervention for improving the muscle strength, AROM, and function of the upper extremities in patients with chronic stroke and achieving the functional recovery of the upper extremities.

• Journal of the Korean Society of Safety
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• v.12 no.3
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• pp.114-119
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• 1997

The lower flash points and upper flash points of 2-propanol and toluene mixtures were determined by air-blowing method instead of Tag-closed flash point tester. The relations between the flash points and the composition of the mixtures are as follows, $T_{F.L}=4.3182+6.0909X_1$ $T_{F.U}=39.3636-2.9091X_1$ As results, the experimental data and the estimated values from the relations are considerably agreed, and we could plotted the relative diagram between flash points and the explosive range.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.20-26
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• 2015

For the reliability of the combustible properties of arylic acid, this study was investigated the explosion limits of acrylic acid in the reference data. The flash points and AITs(auto-ignition temperatures) by ignition delay time were experimented. The lower flash points of acrylic acid by using Setaflash and Pensky-Martens closed-cup testers were experimented in $48^{\circ}C$ and $51^{\circ}C$, respectively. The lower flash points of arylic acid by using Tag and Cleveland open cup testers were experimented in $56^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659 tester for acrylic acid. The AIT of acrylic acid was experimented as $417^{\circ}C$. The lower explosion limit(LEL) and the upper explosion limit(UEL) by the measured the lower flash point and the upper flash point of acrylic acid were calculated as 2.2 Vol% and 7.9 Vol%, respectively.

• Journal of Korea Foundry Society
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• v.22 no.5
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• pp.265-270
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• 2002

A novel jewelry master pattern manufacturing process which reduce manufacturing steps by employing a Duraform rapid prototyping mold and a low melting alloy has been suggested. The novel process follows the steps of 'jewelry 3D CAD design ${\rightarrow}$ Durafrom RP mold ${\rightarrow}$ low melting alloy master pattern' while the previous process follows more complicated steps of 'jewelry idea sketch ${\rightarrow}$ detailed drawing ${\rightarrow}$ wax carving ${\rightarrow}$ flask ${\rightarrow}$ silver master pattern.' An upper and a lower part of molds have been manufactured of Duraform powder, of which melting point is $190^{\circ}C$. A maser pattern was manufactured by pouring a low melting alloy of Pb-Sn-Bi-Cd, so called Woods Metal, of which melting point is $70^{\circ}C$, into the mold. The master pattern is a shape of a disk of 20mm diameter that contains various design factors. The variations of dimensions, surface roughness, surface pore ratio were measured by an optical microscope, a surface roughness profilometer, and a Rockwell hardness tester. The pattern made of were maeasured by an optical microscope, a surface roughness profilometer, and a Rockwell hardness tester. The pattern made of low melting alloy has sufficient surface hardness, and surface pore ratio to be used as the jewelry master pattern.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.42-48
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• 2016

The usage of the correct combustion properties of the treated substance for the safety of the process is critical. For the safe handling of n-nonane being used in various ways in the chemical industry, the flash point and the autoignition temperature(AIT) of n-nonane was experimented. And, the explosion limit of n-nonane was calculated by using the flash point obtained in the experiment. The flash points of n-nonane by using the Setaflash and Pensky-Martens closed-cup testers measured $31^{\circ}C$ and $34^{\circ}C$, respectively. The flash points of n-nonane by using the Tag and Cleveland open cup testers are measured $37^{\circ}C$ and $42^{\circ}C$. The AIT of n-nonane by ASTM 659E tester was measured as $210^{\circ}C$. The lower explosion limit by the measured flash point $31^{\circ}C$ was calculated as 0.87 vol%. And the upper explosion limit by the measured upper flash point $53^{\circ}C$ was calculated as 2.78 vol%. It was possible to predict lower explosion limit by using the experimental flash point or flash point in the literature.

• Journal of IKEEE
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• v.18 no.1
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• pp.114-118
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• 2014

This paper presents improvement of the production process of a unified fuel heater with the help of the performance evaluation system. In order to enhance a starting capability of diesel-engine car, the unified fuel heater is proposed, which consists of main body, upper plate, stopper, lower plate, PTC, screw, bimetal and terminals. In the proposed heater, the sensor is combined with heater body not only to maximize the performance of car but also to reduce the production cost. The performance test chamber is proposed to evaluate the performance of heater. Especially, an effective manufacturing progress for assembling the heater elements can cut down expenses.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.9 s.180
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• pp.2319-2325
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• 2000

This thesis studied that seven kinds of residual elements(inclusions) had influenced on fracture toughness($K_{IC}$) obtained by Begley-Logsdon and Rolfe-Novak model equation using tensile an d impact test data of I%CrMoV HP(high pressure) rotor steel. $K_{IC}$ design curve of ASME and fracture surface by SEM were also considered, obtained results are summarized as follows $K_{IC}$ was linearly increased with increase of temperature, effect of the inclusions was significantly over FATT. $K_{IC}$ at lower shelf temperature was quantitatively related to yield strength and was agreed well with Begley's equation. It was difficult to determine $K_{IC}$ because of specimen size and tester capacity at upper shelf temperature, but for this view point Rolfe-Novak's equation was useful. The degree of brittle fracture was dependent on FATT fundamentally, adding S, Sb to matrix decreased impact energy and adding Cu, As increased yield(tensile) strength, and the influence of the others minority inclusion was comparatively insignificant.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.462-465
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• 1995

In this research a 2-dimensional motion producer based on two linear motors was developed. When the tester provides some motion through the level attached to the upper moving part of the motion producer, it provides the arbitrary intertia, damping and stiffness characteristics without actual change in physical structure of the motion producer. That is, the active impedance is implemented by controlling input currents supplied to the linear motors. A PID controller with feedforward loop was used to control the currents and pre-processing of input velocity and accleration singals from the encoder and the current singnal from the motor driver circuit are conducted to improve the performance.