• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.2
• /
• pp.139-146
• /
• 2014

Sodium borohydride ($NaBH_4$) is considered as a secure metal hydride for hydrogen storage and supply. In this study, the interfacial friction of two-phase flow in the dehydrogenation of aqueous $NaBH_4$ solution in a microchannel with a hydraulic diameter of $461{\mu}m$ is investigated for designing a dehydrogenation chemical reactor flow passage. Because hydrogen gas is generated by the hydrolysis of $NaBH_4$ in the presence of a ruthenium catalyst, two different flow phases (aqueous $NaBH_4$ solution and hydrogen gas) exist in the channel. For experimental studies, a microchannel was fabricated on a silicon wafer substrate, and 100-nm ruthenium catalyst was deposited on three sides of the channel surface. A bubbly flow pattern was observed. The experimental results indicate that the two-phase multiplier increases linearly with the void fraction, which depends on the initial concentration, reaction rate, and flow residence time.

• Journal of the Korean Geotechnical Society
• /
• v.34 no.4
• /
• pp.27-35
• /
• 2018

The objective of this study is to demonstrate the suitability of electromagnetic waves for evaluating necking defects in bored piles using electromagnetic waves. Experiments are conducted with small-scaled defective model pile with diameter of 150 mm and length of 270 mm. Two necking defects are generated at the upper and lower positions on two different sides of the model pile, respectively. The other two necking defects are generated at the upper and lower positions on the same side of the model pile. Electrical wires are installed alongside the stainless steel wire of a steel cage to configure a two-conductor transmission line. A time-domain reflectometer is used to generate and defect electromagnetic waves. The experimental results show that electromagnetic waves are reflected at the necking defects and the end of the model pile. In addition, calculated defect locations are almost the same as actual defect locations. This study demonstrates that electromagnetic waves can be effective tool for evaluating necking defects in bored piles.

• Physical Therapy Korea
• /
• v.19 no.1
• /
• pp.46-55
• /
• 2012

The purpose of this study was to investigate the effect of the two different types of chairs on trapezius muscle activation during dictation tasks. Seventeen university students, each of whom were within ${\pm}1$ standard deviation of the mean Korean standard body size, voluntarily participated in this study. Surface electromyography was used to collect electrical signals from both the upper and lower trapezius muscles. Amplitude Probability Distribution Function (APDF) was performed to analyze the muscle activity. The findings of this study were 1) The backrest-point height of the auditorium chair and the height, length and width of the connected desk were shorter than what was suggested by the KS. Another difference was that the auditorium chair had a bigger angle of the backrest compared to the classroom chair. 2) Regarding within-subject effect the sole statistically significant difference was found between activation of the upper trapezius muscle. The upper trapezius muscle's %RVC in the APDF 10th-50th-90th percentile was statistically higher for participants sitting in the auditorium chair than for participants sitting in the classroom chair (p<.05). 3) There was an interaction effect between the 'two chair-types' and the 'two muscle-sides' in the APDF 10th-50th percentile (p<.05). 4) There was an interaction effect between the 'two chair-types' and the 'three gaze-direction' in the APDF 90th percentile (p<.05). The findings of this study indicated that maintaining a writing posture for a prolonged period of time in an auditorium chair significantly increased the left upper trapezius muscle activation compared to a classroom chair.

• Journal of Oral Medicine and Pain
• /
• v.21 no.2
• /
• pp.293-304
• /
• 1996

The purpose of this study was to investigate the peak electromyographic activity(EMG) and time intervals in firing sequence of Anterior temporalis(TA) and Masseter(MM) on clenching, the number of tender points in the head and neck muscles, the occlusal contact state on clenching, and their relationship. 78 patients with Temporomandibular Disorders(TMDs) participated and were classified into articular or muscular group by clinical signs and symptoms. BioEMG$\textregistered$ of integrated masticatory function analyzer, Biopak$\textregistered$ system(Bioresearch Inc., USA), was used to measure EMG and related items, and T- Scan$\textregistered$(Tekscan, USA), computerized occlusal analyser, was used to record occlusal contact state on maximum voluntary clenching. EMG and occlusal contact were synchronously recorded and analysed with SAS Statistical program. The results of this study were as follows : 1. In total subjects, EMG of TA was lower than that of MM in articular group but in muscular group, vice versa, As a result, the ratio TA to MM was significantly different between the two groups. no significant differece. 3. The number and force of occlusal contact were more in articular group, but there was no significant difference in Total Left-Right statistics(TLR) between the two groups. 4. In unilaterally affected subjects for muscle function, no significant difference was observed between the affected side and the contralateral side in articular group, but in muscular group, the item of the number of tender points showed significant difference. However, for occlusal contact items, contact force in articular group shows significant difference between the two sides. 5. Rate of coincidence of the first firing side of TA with affected side or preferred chewing side was higher and not different between the two groups, but no significant correlation was showed between the first firing side and the first occlusal contact side.

• The Plant Pathology Journal
• /
• v.34 no.2
• /
• pp.150-156
• /
• 2018

The genome sequences of two novel monopartite RNA viruses were identified in a common eelgrass (Zostera marina) transcriptome dataset. Sequence comparison and phylogenetic analyses revealed that these two novel viruses belong to the genus Amalgavirus in the family Amalgaviridae. They were named Zostera marina amalgavirus 1 (ZmAV1) and Zostera marina amalgavirus 2 (ZmAV2). Genomes of both ZmAV1 and ZmAV2 contain two overlapping open reading frames (ORFs). ORF1 encodes a putative replication factory matrix-like protein, while ORF2 encodes a RNA-dependent RNA polymerase (RdRp) domain. The fusion protein (ORF1+2) of ORF1 and ORF2, which mediates RNA replication, was produced using the +1 programmed ribosomal frameshifting (PRF) mechanism. The +1 PRF motif sequence, UUU_CGN, which is highly conserved among known amalgaviruses, was also found in ZmAV1 and ZmAV2. Multiple sequence alignment of the ORF1+2 fusion proteins from 24 amalgaviruses revealed that +1 PRF occurred only at three different positions within the 13-amino acid-long segment, which was surrounded by highly conserved regions on both sides. This suggested that the +1 PRF may be constrained by the structure of fusion proteins. Genome sequences of ZmAV1 and ZmAV2, which are the first viruses to be identified in common eelgrass, will serve as useful resources for studying evolution and diversity of amalgaviruses.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.25 no.2
• /
• pp.99-103
• /
• 2014

A laryngeal web is connective tissue covered with epithelium stretching between both sides of the true vocal cords. Laryngeal webs were first reported by Fleischmann in 1882, and they cause upper airway obstruction and abnormalities of phonation. Congenital webs result from an arrest of reabsorption of the epithelium of the larynx at the tenth week of the fetus. The most common site of webbing is the anterior commissural glottic area, followed by other glottic areas and rarely subglottic or supraglottic areas. We have experienced two cases of congenital laryngeal webs. The webs were operated in two different methods. The first was excised under magnified vision through a laryngoscope, with a silastic keel secured between the raw surfaces of the separated mucosa. In the second case, the deepithelialized surfaces were exposed for a certain time length to mitomycin C to prevent postoperative webbing. We, hereby, report our experience of the diagnosis and management of two cases of a rare entity known as the congenital laryngeal web, and discuss the results with relevant studies.

• Steel and Composite Structures
• /
• v.30 no.2
• /
• pp.109-121
• /
• 2019

This paper presents the second part of the modeling for the strap combined footings, this part shows a mathematical model for design of strap combined footings subject to axial load and moments in two directions to each column considering the soil real pressure acting on the contact surface of the footing for one and/or two property lines of sides opposite restricted, the pressure is presented in terms of an axial load, moment around the axis "X" and moment around the axis "Y" to each column, and the methodology is developed using the principle that the derived of the moment is the shear force. The first part shows the optimal contact surface for the strap combined footings to obtain the most economical dimensioning on the soil (optimal area). The classic model considers an axial load and a moment around the axis "X" (transverse axis) applied to each column, i.e., the resultant force from the applied loads is located on the axis "Y" (longitudinal axis), and its position must match with the geometric center of the footing, and when the axial load and moments in two directions are presented, the maximum pressure and uniform applied throughout the contact surface of the footing is considered the same. A numerical example is presented to obtain the design of strap combined footings subject to an axial load and moments in two directions applied to each column. The mathematical approach suggested in this paper produces results that have a tangible accuracy for all problems and it can also be used for rectangular and T-shaped combined footings.

• The Journal of Korean Physical Therapy
• /
• v.27 no.5
• /
• pp.311-314
• /
• 2015

Purpose: This study attempted to determine intra-rater reliability and inter-rater reliability for measurement of foot form using the FPI-6 (Foot Posture Index) in patients with hemiplegia caused by stroke. Methods: Twenty two stroke patients were recruited into the research and their foot posture was evaluated using the FPI. Two raters assessed 6 items sequentially in accordance with the FPI-6 manual. This procedure involved asking the subject to take several steps in-place, prior to settling into a comfortable stance position with double limb support. Subjects were instructed to stand still with their arms by their sides and look straight ahead. FPI-6 values ranged from -2 to +2 for each of the six criteria and from -12 to +12 for the total score, indicating a position for each foot either along the supinated (negative score) to pronated (more than +6) continuum of foot posture. Results: The results showed that intra-rater reliability and inter-rater reliability for a total FPI-6 score was high: 0.807-0.888. An almost perfect agreement between the two raters was identified in the foot's morphological classification (Somer's D=0.712; p<0.05). Intra-percentage agreement was high (88.6%). Conclusion: The FPI-6 is a quick, simple, and reliable clinical tool with demonstrated good to excellent intra-rater reliability and good inter-rater reliability when used in assessment of the stroke patient's foot.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.43 no.3 s.309
• /
• pp.41-50
• /
• 2006

This paper presents a novel ultrasonic sensor system to overcome limited distance detection range that can be measured only more than 30cm by single ultrasonic transducer. This is accomplished by separation of receiving capacitive ultrasonic transducer from transmitting capacitive ultrasonic transducer. And hardwares and software of the system are described in detail. The system makes very close range as well as long range detect by wireless precisely. Frequency of trigger pulse is 10Hz, but it is very low frequency for transmitting data in wireless module. Therefore, for triggering between receiver and transmitter, an algorithm for mixing and distinguishing trigger pulse from carrier pulse by software is proposed. The system is designed by common microprocessor 8051. The performance of the proposed method has been assessed through two types. The first, transmitting and receiving transducer are put on both sides. And then, distance of two point is measured as far as 0mm. Secondly, transmitting transducer send out ultrasonic pulse and measure the time of flight(TOF) until a first echo from an object detected by the detached receiving transducer. The distance between the detached transducers and a reflecting object is measured as far as 7cm. Images of measured ultrasonic waves and TOF for two methods presented to prove effectiveness of results.

• The Korean Journal of Community Living Science
• /
• v.13 no.2
• /
• pp.1-11
• /
• 2002

This study was conducted to estimate the amounts of the electromagnetic wave penetrating from a cellular phone in a pocket of dress shirt, as well as to test how different the penetration amounts were under the conditions of wearing. It was also investigated the possibilities that the amounts of the electromagnetic wave penetrating could be decreased by using twofold pocket or electromagnetic wave free fabric. The amounts of the electromagnetic wave penetrating were measured in the following five cases; one-layered pocket with 10 different fabrics as dress shirt, a pocket adding a layer of knitted cotton, two-layered pocket with same fabric as dress shirt, two-layered pocket adding a layer of knitted cotton, and one-layered pocket adding a layer of electromagnetic wave free fabric. Each of these five cases were measured using the front and back sides of a cellular phone facing to the body. The results were as follows; 1) The amounts of the electromagnetic wave penetrating were not significantly different in 10 different fabrics and were all above the caution range (0.02mW/$cm^2$). 2) The amounts of the electromagnetic wave penetrating in cases of the back side of the cellular phone to the body, were more than in cases of the front side. 3) There is a significantly differences in part on adding a knitted under wear to one and two layers of the pocket in the case of penetration amount under the wearing conditions. 4) The amounts of the electromagnetic wave penetrating in cases of adding a layer of electromagnetic wave free fabric, were close to the safe standard value of it. The above results suggested that facing the front side of cellular phone to the body and using extra layering with some electromagnetic wave free fabrics might have some protective effects again to the penetration amounts.