• Journal of radiological science and technology
• /
• v.34 no.4
• /
• pp.263-269
• /
• 2011

Since the spine radiography were explained differently at every several hospitals and textbooks. the technique has not been accurately defined and interfered each other. We would like to define the most appropriate positioning for clinical cases, and reference books, by comparing scoliotic angle and lordotic angle. From Mar 2009 to Sep 2011, 85 patient cases were studied, who had not been undergone surgical treatment among spondylopathy patients. Scoliotic angle and lordotic angle were measured, using Cobb's method. We analyzed statistically using t-test(SPSS 18), and evaluated spine general radiography position. Moreover, we researched on the actual condition at 10 university hospitals in Seoul. The results of scoliotic angle measurement, the value at erect position showed 20.98% higher than supine position, and it has statistical significance (p<.01). In lordotic angle measurement, the value at neutral holding position represented 29.3% higher than supine position, and it also has statistical significance(p<.01). The results of clinical survey, supine posine(70.0%) took much higher possession than erect position(30.0%). In conclusion, compare to supine position, erect position shows increased scoliotic and lordotic angle. It was agreed with the importance of clinical erect position radiography, which gravity affects. So clinical radiologist must recognize the difference, and conduct an accurate study.

• International Journal of Air-Conditioning and Refrigeration
• /
• v.13 no.2
• /
• pp.99-106
• /
• 2005

Falling film heat transfer has been widely used in many applications in which heat and mass transfer occur simultaneously, such as evaporative coolers, cooling towers, absorption chillers, etc. In such cases, it is desirable that the falling film spreads widely on the surface to form a thin liquid film to enlarge contact surface and to reduce the thermal resistance across the film and/or the flow resistance to the vapor stream over the film. In this respect, hydrophilic treatment of the surface has been tried to improve the surface wettability by decreasing the contact angle between the liquid and the surface. However, the hydrophilic treatment was found not very effective to increase the surface wettedness of inclined surfaces, since the liquid flow forms rivulet patterns instead of a thin film as it flows down the inclined surface and accelerates gradually by the gravity. In this work, a novel method is suggested to improve the surface wettedness enormously. In this work, the surface is treated to have a thin hydrophilic porous layer on the surface. With this treatment, the liquid can spread widely on the surface by the capillary force resulting from the porous structure. In addition to this, the liquid can be held within the porous structure to improve surface wettedness regardless of the surface inclination. The experiment on the evaporative cooling of inclined surfaces has been conducted to verify the effectiveness of the surface treatment. It is measured that the latent heat transfer increases almost by $80\%$ at the hydrophilic porous layer coated surface as compared with the untreated surface.

• Journal of The Korean Society of Integrative Medicine
• /
• v.11 no.2
• /
• pp.159-168
• /
• 2023

Purpose : This study aimed to investigate how neuromuscular electrical stimulation (NMES) affects the balance ability of patients who have undergone total knee arthroplasty owing to osteoarthritis. Methods : Thirty patients who had undergone total knee arthroplasty were randomized to an experimental group (n=15) and a control group (n=15). The experimental group received conventional physical therapy for 50 minutes and NMES treatment for 30 minutes, whereas the control group received conventional physical therapy for 50 minutes and active range of motion (AROM) exercises for 30 minutes. Within-group and between-group changes in static and dynamic balance ability before and after the 4-week intervention were analyzed. Results : In the within-group comparison, sway velocity in the center of gravity and total distance were significantly improved in both the experimental and control groups (p<.05), with no significant differences between the groups (p>.05). In the within-group comparison, both the experimental and control groups showed significant improvement in the functional reach test and movement velosity (p<.05). In the between-group comparison, the experimental group showed a significantly better improvement than the control group in the functional reach test (p<.05), but there was no significant difference in the movement velosity test (p>.05). Conclusion : In this study, NMES improved the static and dynamic balance in patients who had undergone total knee arthroplasty. Compared with AROM exercises, there was a greater effect on dynamic balance partially; however, the overall effect was similar. Therefore, NMES may be one option among various interventions to improve the balance ability in patients who have undergone total knee arthroplasty. In particular, this method may be effective when it is difficult to apply balance training for patients with total knee arthroplasty in a clinical setting.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.1
• /
• pp.425-430
• /
• 2017

RFID is a technology that uses radio frequency to read information in tags attached to objects or people. Because it reads the information without contact when tracking the location using tags in a RFID system, there can be errors between the actual position and measured position. In this paper, three methods (the method of radiation pattern, the method of the median value, and the method using both the radiation pattern and median value) are proposed to identify the location of objects or people using the RFID technique. The location identification system based on RFID was constructed and tags were arranged in a square pattern. The real location and experimentally predicted location of an object containing a reader were compared to confirm the error. Instead of the existing papers that obtained the approximately location of a reader by calculating the center of gravity of all tags read by that reader, in this study, the predicted location was obtained by the median value and the radiation pattern. This study validated which method was the most efficient among the three methods proposed in this paper through the data of the read tags. As a result, the method of the median value had the smallest error among those assessed.

• Journal of the Korean GEO-environmental Society
• /
• v.2 no.2
• /
• pp.13-22
• /
• 2001

In this study, centrifuge model tests were fulfilled to investigate the characteristics of bearing capacity of paper ash as a filling material. The model tests were done varying the footing width and gravity level. The settlement and vertical soil pressure by loading were measured. The results from the tests were compared with the one from FLAC program using finite difference method and bearing capacity theory. After all, it was shown that the characteristics of load-settlement represented the local shear failure, which the settlement ratio s/B showed inflection point around 25~30%. As g-level and footing width were increasing, the load strength was increasing. The ultimate bearing capacity from the tests was very closed the results from Terzaghi's theory. As the distance from footing center was increasing, the vertical soil pressure was decreasing. If E/B is higher than 7, the stress by loading was almost increasing. The vertical displacement from loading was the largest one around under the footing and was almost occurred when the depth>4cm and E/B is higher than 5.0.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.3
• /
• pp.370-380
• /
• 2016

The black pine logs damaged by pine wilt disease in Jeju-do were heat-treated to extend the utilization of domestic trees damaged by pine wilt disease. The heat-treatment of wood requires wood to be heated to $56^{\circ}C$ for 30 min at the core. The average moisture content and top-diameter of the black pine logs were ranged from 46% to 141% and from 180 mm to 500 mm, respectively. And the basic specific gravity and oven-dry specific gravity of the black pine logs were 0.47 and 0.52, respectively. The time required for heat-treatment at $105^{\circ}C$ temperature was ranged from 7.7 h to 44.2 h, depending on moisture content and top-diameter. The temperature distribution was used to predict the time required for heat-treatment of black pine log with various moisture contents and top-diameters using finite difference method. The thermal properties of wood including the thermal conductivity and specific heat in accordance with moisture content were calculated. Heat transfer coefficient for mixed convection in form of adding natural convection and forced convection was used for heat transfer analysis. The error between the measured and predicted values ranged from 3% to 45%. The predicted times required for heat-treatment of black pine log with 50% moisture content and 200 mm, 300 mm, and 400 mm top-diameter were 10.9 h, 18.3 h, and 27.0 h, respectively. If the initial moisture content of black pine log is 75%, heat treatment times of 13.6 h, 22.5 h, and 32.8 h were predicted in accordance with top-diameter. And if the initial moisture content of black pine log is 100%, heat treatment times of 16.2 h, 26.5 h, and 38.2 h were predicted in accordance with top-diameter. When the physical properties of logs damaged by pine wilt disease are presented, these results can be applicable to the heat-treatment of red pine and Korean pine logs as well.

• Journal of the Korean Wood Science and Technology
• /
• v.34 no.5
• /
• pp.42-51
• /
• 2006

The this study, the effect of rice husk flour (RHF) as scavenger on formaldehyde emission rate and formaldehyde content from urea-formaldehyde (UF) resin bonded RHF content wood particleboards (PB). Two type of particle size ($30{\mu}m$ and $300{\mu}m$) of RHF was premixed with the UF resin at 5% and 15% by weight. The performance of UF resins is greatly influenced by the curing characteristics in their curing processing. The curing behavior was monitored activation energy ($E_a$) by DSC and pH variation according to RHF contents. PB with dimensions of $27cm{\times}27cm{\times}0.7cm$ was prepared at a specific gravity of 0.75 using $E_1$ and $E_2$ class UF resins. Formaldehyde emission and formaldehyde content from RHF filled PB bonded with UF resin was measured by 24 h desiccator and perforator method, respectively. RHF causes an increased pH of UF resin. $E_a$ of the modified UF resin decreased independently of RHF particle size. As the pH and the $E_a$ variation of the UF resin containing RHF increased, the amount of formaldehyde content decreased. The formaldehyde emission and formaldehyde content levels of the PB bonded with 15 wt% of $30{\mu}m$ RHF and $E_2$ type UF resin were low and satisfied grade $E_1$, as measured by 24 h desiccator and perforator method. The result of a comparison between 24 h desiccator and perforator test using PB showed that the linear regression analyses show a good correlation between the results for the 24 h desiccator and the perforator tests. The linear regression of a correlation between the desiccator and the perforator was Y=4.842X-0.064 ($R^2=0.989$). RHF was effective at reducing formaldehyde emission and formaldehyde content in urea-formaldehyde adhesives when used as scavenger.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.4
• /
• pp.412-418
• /
• 2014

In this paper, for better boarding performance and pleasant boarding sensitivity of the ship, comparison and analysis was performed of motion sickness questionnaire with MSI(Motion Sickness Incidence) calculation based on ship motion theory(Strip Method) due to sea condition, incident angle in main sail way, economic speed, and calculation position of the training ship Kaya of Pukyong National University. On theses works, the rougher sea conditions became, the higher total motion sickness rate was occurred. The weights of vertical acceleration and the rates of MSI were higher at the bridge and the accommodation, which were located farther from the center of gravity of the ship. And effects of the vertical acceleration of the ship were increased in rolling then in head sea. In comparison between motion sickness questionnaire with MSI calculation, when the vertical acceleration increased, the motion sickness rate increased. The location to increase vertical acceleration and the location to cause motion sickness were agreed.

• Archives of Plastic Surgery
• /
• v.36 no.4
• /
• pp.380-384
• /
• 2009

Purpose: Autologous vessels remain the gold standard for vascular grafts in microanastomoses. However, they are sometimes unavailable and have a limited long - term patency. Synthetic vessels have high success rates in large - diameter reconstructions but failed when used as small - diameter grafts due to graft occlusion. It has been proved that endothelial cell seeding improves prosthesis performance and long - term patency. Among polyurethane, PET and ePTFE, polyurethane has the best affinity to endothelial cells and mechanical properties closest to human vessels. We examined the ability of endothelial cells to attach to a polyurethane graft manufactured by the electrospinning method. Methods: Endothelial cells, which were cultured from porcine internal jugular veins, were attached to polyurethane grafts with an internal diameter of 3 mm. The same cells were attached to allogeneic decellularized porcine internal carotid artery grafts as controls. Both of the 10 mm - long grafts were exposed to endothelial cells in a well for 1 hour. Each well contained $2{\times}10^5$ endothelial cells. The graft materials were rotated through 90 degrees every 15 minutes in order to minimize the effect of gravity. The extent of cell attachment was examined with the MTT assay. Results: The MTT assay showed good incorporation of endothelial cells into both grafts. For the evaluation of affinity, the number of attached cells was counted at 10 fields of microscopic examination with ${\times}40$ magnification. Endothelial cells adhered more to polyurethane grafts (mean, $127.4{\pm}6.2cells$) compared to porcine artery grafts (mean $45.8{\pm}5.1cells$)(p<0.05,Mann - Whitney test). Conclusion: In this study, we attached porcine endothelial cells to polyurethane grafts, manufactured by electrospinning. The grafts exhibited a better affinity to endothelial cells than allogeneic decellularized porcine internal carotid artery grafts. It is suggested that the time required for endothelial cells to attach to decellulized artery grafts may be longer than that which is required for attachment to polyurethane grafts.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.4
• /
• pp.1208-1218
• /
• 2019

The study is on the cosmetic solubilizing power of organic plant surfactants. The blended high purity polyglyceryl-10 oleate and polyglyceryl-10 stearate mixtures were synthesized using organically certified raw materials to develop surfactants having excellent solubilizing power. The mixture is called "Solubil ORG-1300". The appearance of this material is a pale yellowish paste, with a specific odor. The specific gravity was 1.12 and it was high purity that acid value was 0.072±0.1. The HLB value of this natural surfactant was averaged = 15.1 and calculated through the Griffin equation. Mechanically it is explained how organic surfactant are available with fragrance and oils. The solubilizing test was determined by eye evaluation method through the dissolving performance test for the two oils and measured the transmittance at 890 nm using a UV spectrophotometer to measure the transparency. The results showed that the concentration of surfactant needed to make Bergamot oil available requires approximately more 2 times. It was also found that the concentration of surfactant needed to make the tocoperyl acetate available was about 8 times higher. Experiments on the solubility resulting from pH changes showed stabilized usable solubilizing power even in acidic areas of pH=3.5, neutral areas of pH=7.2, and alkaline areas of pH=1.5. Experiments on the solubility according to pH variation showed good solubility stabilized in acidic areas of pH=3.5, neutral areas of pH=7.2, and alkaline areas of pH=11.5. As an application of cosmetics, the company successfully developed a prescription for moisturizing activity based on these results, it is expected that a wide range of applications will be available for skin care, baby lotion, sensitivity or atopic skin cosmetics.