• Journal of the Korean earth science society
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• v.32 no.1
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• pp.1-11
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• 2011

The impact echo and impulse response methods were applied to the safety inspection of concrete structure, which has the rear cavity. The concrete structure model used in this study was divided into four sections, pure concrete, concrete+cavity, reinforced concrete with iron bar, and reinforced concrete+cavity, respectively. Previous study performed by authors have showed a possibility of success to use these method for detection of the rear cavity of concrete structure. Therefore, we tried to get more enhanced result with IE and IR methods through this study. Especially, IE and IR methods are relatively accurate to map the point of measurement, which makes it possible to interpret the depth of the concrete bed and effect by rear cavity with confidence. Followings were revealed from the results; the IE method shows some small peak zones probably indicating the rear cavity in the frequency lower than the resonance frequency and the changes of mobility and dynamic stiffness in the IR method indicate the weak zones. The proposed methods can be used to delineate the weak zones of the concrete structure.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.2
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• pp.143-149
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• 2004

Background: Some clinical trials have reported that a new analgesic combination of tramadol and acetaminophen provides good efficacy in various pain models. For the more clinical uses of this agent, comparisons about the onset of analgesia and analgesic efficacy in the acute state of pain with the other drugs known as strong analgesics were needed. Purpose: The goal of this study was to compare the times to onset of analgesia and the other analgesic efficacy of 75 mg tramadol/650 mg acetaminophen and 20 mg codeine/500 mg acetaminophen/400 mg ibuprofen in the treatment of acute pain after oral surgery. Patients and Methods: Using a randomized, single-dose, parallel-group, single-center, and active-controlled test design, this clinical study compared the times to onset of analgesia using a two-stopwatch technique and the other analgesic efficacy of the single-dose tramadol/acetaminophen and codeine/acetaminophen/ibuprofen. These were assessed in 128 healthy subjects with pain from oral surgical procedures involving extraction of one or more impacted third molars requiring bone removal. From the time of pain development, the times to onset of perceptible and meaningful pain relief, pain intensity, pain relief, an overall assessment, and adverse events of the study medications were recorded for 6 hours. Results: The demographic distribution and baseline pain data in the two groups were statistically similar. The median times to onset of perceptible pain relief were 21.0 and 24.4 minutes in the tramadol/acetaminophen and codeine/acetaminophen/ibuprofen groups respectively and those to onset of meaningful pain relief were 56.4 and 57.3 minutes, which were statistically similar. The other efficacy variables such as mean total pain relief (TOTPAR) and the sum of pain intensity differences (SPID) were also similar in the early period after pain development and drug dosing. The safety of tramadol/acetaminophen was well tolerated and very comparable to that of codeine/acetaminophen/ibuprofen. Conclusions: In this acute dental pain model, the onset of analgesia and analgesic efficacy of tramadol/acetaminophen was comparable to that of codeine/acetaminophen/ibuprofen. These results showed that tramadol/acetaminophen was recommendable for fast and effective treatment in the management of postoperative acute pain.

• Journal of Periodontal and Implant Science
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• v.49 no.6
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• pp.366-381
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• 2019

Purpose: The purpose of this study was to evaluate the effectiveness of conventional sandblasted, large-grit, acid-etched (SLA) surface coated with a pH buffering solution based on surface wettability, blood protein adhesion, osteoblast affinity, and platelet adhesion and activation. Methods: Titanium discs and implants with conventional SLA surface (SA), SLA surface in an aqueous calcium chloride solution (CA), and SLA surface with a pH buffering agent (SOI) were prepared. The wetting velocity was measured by the number of threads wetted by blood over an interval of time. Serum albumin adsorption was tested using the bicinchoninic acid assay and by measuring fluorescence intensity. Osteoblast activity assays (osteoblast adhesion, proliferation, differentiation, mineralization, and migration) were also performed, and platelet adhesion and activation assays were conducted. Results: In both the wetting velocity test and the serum albumin adsorption assay, the SOI surface displayed a significantly higher wetting velocity than the SA surface (P=0.000 and P=0.000, respectively). In the osteoblast adhesion, proliferation, differentiation, and mineralization tests, the mean values for SOI were all higher than those for SA and CA. On the osteoblast migration, platelet adhesion, and activation tests, SOI also showed significantly higher values than SA (P=0.040, P=0.000, and P=0.000, respectively). Conclusions: SOI exhibited higher hydrophilicity and affinity for proteins, cells, and platelets than SA. Within the limits of this study, it may be concluded that coating an implant with a pH buffering agent can induce the attachment of platelets, proteins, and cells to the implant surface. Further studies should be conducted to directly compare SOI with other conventional surfaces with regard to its safety and effectiveness in clinical settings.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.171-181
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• 2003

The nose fairings of KSR-III are designed to be separated from the rocket by explosive force at the mission altitude to expose the payload. Adequate amount of separation force should be imposed to allow safe separation without collision between the fairings and the rocket, and the separation device was designed for the separation at very high altitude where almost no air load was expected. As the development of KSR-III goes on, several design changes have made and lower separation altitude of 45km is expected as a result. Under these circumstances, it is required to determine if the nose fairings can be separated without collision with much severer air load than for the design condition. In this study, the 6-DOF motion analysis program, PASEM, which was developed to predict the strap-on booster separation, is modified to simulate the pivotal motion of the fairings at early stages of separation. The accuracy of pivot motion simulation is validated by comparison with the results of ground test and the accurate separation conditions are deduced from it. Trajectory simulations are performed to see if separation without collision is possible with varying angle of attack, direction of gravity, and the effect of gust. It is also found that reducing the separation angle of the clamshell hinge from 60 degrees to 40 degrees can enhance separation safety and separation at lower altitude of 40km can be done without collision.

• Journal of Technologic Dentistry
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• v.36 no.2
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• pp.99-110
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• 2014

Purpose: This study was carried out in order to examine the relationship of job satisfaction and social support on the dental technicians and to analyze its influence. Methods: A self-reported questionnaire survey was carried out by having convenience sampling as 220 dental technicians who work in Seoul Metropolis, Gyeonggi-do Province, Daejeon and Chungnam Province. A research tool was used questionnaire that was proved reliability and validity. It was prepared with totally 37 questions such as 12 items for subjects' general characteristics, 18 items for job satisfaction measurement, and 7 items for social support measurement. An analysis of the collected data was computationally processed by using SPSS Win 17.0 program. An analytical technique was made by using statistical techniques such as frequency & percentage, T-test or One-way ANOVA analysis. The following are the analytical results of the collected materials. Results: As a result of analyzing research subjects' job satisfaction level, there was significant difference(P<0.05) in items of religion, hobby life, working environment, and rest time out of daily work. The whole mean in job satisfaction was indicated to be relatively high with 3.13. However, job satisfaction with social recognition, salary, and safety was indicated lowly. As a result of analyzing research subjects' social support level, there was significant difference(P<0.05) in items of age, working environment, and rest time out of daily work. The whole mean in social support was indicated to be relatively high with 3.49. As a result of analyzing correlation between job satisfaction and social support, all variables were indicated to be positive correlation in high significance level, thereby having been indicated that the higher job satisfaction leads to the higher social support. Conclusion: As a result of this study, there is high correlation between social support and job satisfaction. An effort and a support are considered to be necessary for forming positive personal relations among members such as relationship with family member and with fellow employee, for improving the working conditions, and for enhancing dental technicians' pride and social recognition in order to promote dental technician's job satisfaction.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.836-842
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• 2010

Hovenia dulcis var. koreana Nakai has been reported to liver function improvement effect as functional materials for food and medicine. On these facts, biological activity and safety test were conducted to evaluate biological activities of the fruit petiole and root extracts of H. dulcis as a potential cosmeceutical ingredient. Cosmeceutica activities of different extracts were examined by l.l-diphenyl-2-picrylhydrazyl (DPPH) radical generation, the ABTS+ cation decolorization, tyrosinase activity, collagenase activity and elastase activity compared with the properties of the commercial antioxidant butylated hydroxytoluene (BHT) and L-ascorbic acid (AA). The antioxidant activities HDFW, HDFE, HDRW and HDRE were 83.6%, 39.6%, 85.9% and 74.5% in DPPH assay, 99.5%, 13.7%, 96.4% and 88.6% in ABTS assay. Tyrosinase inhibitiory activities HDFW were 56.0% at 1,000 ppm. Measured the inhibition effect of the H. dulcis about collagenase and elastase where break the peptide bonds in collagen and enzyme from the class of proteases where exists in the dermis. The H. dulcis was inhibition the two kind enzymesm, collagenase activities being on a high scale inhibition, was same concentration. Uses the anti oxidation effect and a anti-wrinkle effect of this resultant H. dulcis and with the functional cosmetics use is thought with the fact that will be possible.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1588-1593
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• 2014

This study evaluated the genotoxic effects of 30 kGy of X-ray irradiation to four foods (chicken, egg powder, dried green onion, and black pepper). In bacterial reversion assay with Salmonella Typhimurium TA98, TA100, TA1535, and TA1537, the X-ray irradiated foods did not show a significantly increased number of revertant colonies in the presence or absence of the S9 metabolic activation system. In chromosomal aberration tests with Chinese hamster ovary (CHO) cells, the X-ray irradiated foods showed no increase in the frequency of chromosomal aberrations. In in vivo mouse micronucleus assay, the X-ray irradiated foods did not show any increase in the frequency of polychromatic erythrocytes with micronuclei. These results indicate that 30 kGy of X-ray irradiation to four foods (chicken, egg powder, dried green onion, and black pepper) showed no genotoxic effects under these experimental conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.5
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• pp.429-435
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• 2016

Cold stretching(CS) pressure vessels from ASS304 (austenitic stainless steel 304) are used for the transportation and storage of liquefied natural gas(LNG). CS pressure vessels are manufactured by pressurizing the finished vessels to a specific pressure to produce the required stress ${\sigma}_k$. After CS, there is some degree of plastic deformation. Therefore, CS vessels have a higher strength and lighter weight compared to conventional vessels. In this study, we investigate the tensile and fatigue behavior of ASS304 sampled by CS pressure vessels in accordance with the ASME code at cryogenic temperature. From the fatigue test results, we show S-N curves using a statistical method recommended by JSEM-S002. We carried out the fractography of fractured specimens using scanning electron microscopy (SEM).

• The Journal of Pediatrics of Korean Medicine
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• v.27 no.1
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• pp.36-49
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• 2013

Objectives The goal of this review is to investigate clinical and experimental studies on external application treatment for atopic dermatitis in Korean literature and to propose for the better method of clinical studies in order to seek more effective treatment. Methods Electronic researches were performed with KTKP, OASIS, National Assembly Library, Korean Medicine Database, KISS, DBpia, and KISTI. Results and Conclusions In Twenty six studies, the numbers of clinical and experimental studies are respectively 10 (38.46%) and 16 (61.54%). The numbers of studies that used herbal complex were 20 (76.92%), and out of that, 6 studies had used a single herbal medicine (23.08%). The external application with oriental medicine for the atopic dermatitis used with Phellodendri Cortex (7), Sophorae Radix (6), Scutellariae Radix (6), Lonicerae Flos (5), Coptidis Rhizoma (5) and so on. Among the clinical studies, the 5 studies were double-blind and randomized-controlled study (50%). The numbers of studies that used Hanifin and Rajka Diagnostic Criteria (1980) were 6 (60%), and that used the Diagnostic Criteria in Korean Atopic Dermatitis (2005) were 4 (40%). Among the clinical studies, categories to evaluate of atopic dermatitis are respectively SCORAD Index (80%), Total IgE (80%), Eosinophil count (70%) and so on. All of the clinical studies (100%) showed a statistically significant decline in atopic dermatitis according to the SCORAD Index, Modified SCORAD Index, the Clinic index score. Among the experimental studies, the numbers of studies that used NC/Nga mice were 9 (56.25%), and out of that 5 studies used BALB/c mice (31.25%). Most of the studies (68.75%) used DNCB as allergy inducing materials. The scales for evaluation of atopic dermatitis were Clinical skin severity score, Histopathologic examination, Immunohematologic examination, safety test and so on. In 12 cases (75%) of experimental studies, the IgE level of experimental group showed a statistically significant decline after using external application. In 8 study cases (50%), Clinical skin severity score of experimental group showed a statistically significant decline after using external application.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.242-248
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• 2017

This study was conducted to develop a cylindrical paperpot manufacturing equipment which is capable of continuously producing paperpots with a constant size. The equipment consists of the soil supply part, the paper supply part, the pot manufacturing part, the paperpot cutting part and its process for manufacturing paperpot from the soil supply to the paperpot cutting is continuously performed. As a result of the performance test using this equipment, we suggest that the optimal moisture content and injection pressure to supply soil are 50%~60%, and 0.5 Mpa respectively. Moreover the appropriate temperature for adhesive strength is $150{\sim}160^{\circ}C$ taking into account the performance of device and adhesion time. Also, considering the cutting speed and safety, it is appropriate to adopt a straight blade having a clean plan at a minimum angle of $30^{\circ}$. In addition, the manufacturing capacity of the developed equipment was 3300 pots per hour.