• Journal of the Korean Society of Safety
• /
• v.36 no.5
• /
• pp.18-26
• /
• 2021

The effect of heavy construction equipment on the excavated slope is investigated by slope stability analysis. A mobile crane with 500 kN capacity is applied as a working load to the background surface of the excavated slope, in both sandy soil and clay, designed to guarantee the safety of slope stability. Major parameters such as the distance between the edge of the slope and the mobile crane, groundwater level, and ground plate size of the mobile crane are considered. Only 23.8% and 14.3% of the analysis models with sandy soil and clay excavated slope, respectively, satisfied the slope stability. By changing the slope of the sandy soil from 1:1.0 to 1:1.2, the number of analysis models securing slope stability increased from 23.8% to 40.5%. For the clay excavated slope, the analysis models securing slope stability increased from 14.3% to 42.9% by changing slope inclination from 1:0.8 to 1:1.2. In addition, it is found that the increase in the size of the ground plate of the mobile crane increases the analysis models that secure slope stability. Therefore, it is an effective way to relax the excavated slope's inclination angle and simultaneously increase the ground plate size to guarantee stability.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.4
• /
• pp.417-425
• /
• 2015

Semi-dried conger eel Conger myriaster is considered as a health food in Korea due to its richness in vitamins, minerals, proteins and omega-3 fatty acids. This study characterize the sanitary quality of commercial semi-dried conger eel for developing high quality semi-dried products and suggested the guideline for controlling the quality. Moisture content ranged from 41.2% to 73.4% (mean: 61.5%), volatile basic nitrogen ranged from 16.1 to 93.6 mg/100 g (mean: 55.1 mg/100 g), and peroxide value ranged from 15.2 to 69.8 meq/kg. Viable cell counts ranged between 6.51 and 8.53 log CFU/g, while the Escherichia coli count ranged from undetectable to 4.6 log CFU/g. Based on these chemical and microbial findings, we suggest that provisions be established for development of high quality semi-dried conger eel as follows: 50-68% for moisture content, < 50 mg/100 g for volatile basic nitrogen content, < 60 meq/kg for peroxide value, and negative for E. coli. Among the 16 commercial semi-dried conger eel products used in this study, the standard-passed product was only GS-L.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.10
• /
• pp.1359-1366
• /
• 2012

A strain of Streptomyces cavourensis subsp. cavourensis (coded as SY224) antagonistic to Colletotrichum gloeosporioides infecting pepper plants was isolated. SY224 produced lytic enzymes such as chitinase, ${\beta}$-1,3-glucanase, lipase, and protease in respective assays. To examine for antifungal activity, the treatments amended with the nonsterilized supernatant resulted in the highest growth inhibition rate of about 92.9% and 87.4% at concentrations of 30% and 10%, respectively. However, the sterilized treatments (autoclaved or chloroform treated) gave a lowered but significant inhibitory effect of about 63.4% and 62.6% for the 10% supernatant concentration, and 75.2% and 74.8% for the of 30% supernatant concentration in the PDA agar medium, respectively, indicative of the role of a non-protein, heat stable compound on the overall effect. This antifungal compound, which inhibited spore germination and altered hyphal morphology, was extracted by EtOAc and purified by ODS, silica gel, Sephadex LH-20 column, and HPLC, where an active fraction was confirmed to be 2-furancarboxaldehyde by GS-CI MS techniques. These results suggested that SY224 had a high potential in the biocontrol of anthracnose in pepper, mainly due to a combined effect of lytic enzymes and a non-protein, heat-stable antifungal compound, 2-furancarboxaldehyde.

• Journal of Environmental Health Sciences
• /
• v.37 no.4
• /
• pp.306-314
• /
• 2011

Objectives: Respiratory virus infections are the most common disease among all ages in all parts of the world and occur through airborne transmission. The purpose of this study was to detect and quantitate human respiratory viruses in residential environments. Methods: Air samples were collected from the residential space of apartments in the Seoul/Gyeonggi-do area. The samples were collected from indoor and outdoor air. Among respiratory viruses, influenza A virus, influenza B virus, parainfluenza virus, metapneumovirus, respiratory syncytial virus, and adenovirus were investigated by multiplex polymerase chain reaction. Among the virus-positive samples, we performed adenovirus quantification by real-time polymerase chain reaction. Results: Virus detection rates were 44.0%, 3.8%, 3.4%, and 17.3% in spring, summer, autumn, and winter, respectively. The virus detection rate was higher in winter and spring than in summer and autumn. Adenovirus was most commonly detected, followed by influenza A virus and parainfluenza virus. Virus distribution was not significantly different between indoor and outdoor environments. Conclusions: Although virus concentrations were not high in residential environments, residents in houses with detected viruses may have an increased risk of exposure to airborne respiratory viruses, especially in winter and spring.

• Food Science of Animal Resources
• /
• v.31 no.5
• /
• pp.782-790
• /
• 2011

The effects of soy protein isolate (SPI) and red bean protein isolate (RBPI) on gelling properties of pork myofibrillar protein (MP) in the presence of microbial transglutaminase (MTG) were studied at 0.45 M NaCl. MP paste was incubated with MTG (0.1%) at various levels (0.1, 0.3, 0.5, and 1%) of SPI and RBPI before incubating at $4^{\circ}C$ for 4 h. The rheological property results showed that MP gel shear stress increased with increasing RBPI concentration. Cooking yield (CY) of the MP gel increased with increasing RBPI and SPI, whereas gel strength (GS) was not affected by adding RBPI or SPI. Thus, effects of incubation time (0, 4, 8, 10, and 12 h) were measured at 0.1% SPI and RBPI. GS values of the MP gel at 10 and 12 h were similar and were higher than those of the others. CY values were highest when RBPI (0.1%) was added, regardless of incubation time. The protein patterns indicated that incubating the MP with MTG for 10 h resulted in protein crosslinking between MP and RBPI or SPI. Based on these results, RBPI and SPI could be used as an ingredient to increase textural properties and cooking yield of meat protein gel.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.58 no.5
• /
• pp.81-90
• /
• 2016

Due to droughts and water shortages causing severe damage to crops and other vegetations, much attention has been given to efficient irrigation for upland farming. However, little information has been known to measure soil moisture levels in a field scale and apply their spatial variability for proper irrigation scheduling. This study aimed to characterize the spatial variability and temporal stability of soil water contents at depths of 10 cm, 20 cm and 30 cm on flat (loamy soil) and hill-slope fields (silt-loamy soil). Field monitoring of soil moisture contents was used for variogram analysis using GS+ software. Kriging produced from the structural parameters of variogram was applied for the means of spatial prediction. The overall results showed that the surface soil moisture presented a strong spatial dependence at the sampling time and space in the field scale. The coefficient variation (CV) of soil moisture was within 7.0~31.3 % in a flat field and 8.3~39.4 % in a hill-slope field, which was noticeable in the dry season rather than the rainy season. The drought assessment analysis showed that only one day (Dec. 21st) was determined as dry (20.4 % and 24.5 % for flat and hill-slope fields, respectively). In contrary to a hill-slope field where the full irrigation was necessary, the centralized irrigation scheme was appeared to be more effective for a flat field based on the spatial variability of soil moisture contents. The findings of this study clearly showed that the geostatistical analysis of soil moisture contents greatly contributes to proper irrigation scheduling for water-efficient irrigation with maximal crop productivity and environmental benefits.

• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.11
• /
• pp.943-950
• /
• 2016

The purpose of this study was to evaluate and compare by finite element analysis the biomechanical performance, in terms of cervical stand-alone cage screw insert angle (Type 3 - 5: 2 Screws) and screw arrangement (Type 6 and 7: 3 Screws / Type 8 and 9: 4 Screws), and the range of motion (ROM) of traditional anterior cervical discectomy of a fusion device (Type 1: Cage / Type 2: Cage + ACP). Our study suggests that the biomechanical behavior of a postoperative cervical spine could indeed be influenced by design features, such as screw angle and number of screws. In particular, ROM and the risk of subsidence were more sensitive during extension about type 5 (Insert Angle $20^{\circ}$). Our study also suggested that the number of screw asymmetries between up and down for type 6 and 7 could result in differences in the risk of screw fracture manifesting in different clinical aspects.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.14 no.2
• /
• pp.145-149
• /
• 2010

Purpose: Recently, $^{18}F$-FDG Fusion PET which has a high sensitivity for diagnosing cancer is being used for purpose of health examination. This study is to demonstrate that $^{18}F$-FDG fusion PET study is useful for diagnosing an early stage cancer. Materials and Methods: This research has been conducted with 2790 patients visited Seoul National University Hospital Healthcare System (SNUHHS) for $^{18}F$-FDG fusion PET study for a health examination from February, 2004 to December 2008. PET/CT images were acquired from skull base to femur after 1 hour from injecting $^{18}F$-FDG 0.14 mCi/kg to the patients. GEMINI GS (Philips, Netherlands) was used for scanning. Results: From February 2004 to December 2008, $^{18}F$-FDG Fusion PET study was performed for 99,009 patients among all patients who visited SNUHHS and 2,790 patients was performed. Diagnostic rate for malignant cancer was 0.95% for the patients who were not examined by $^{18}F$-FDG Fusion PET study. 1.94% was for the patients who were. The rate of malignant tumor was showed 10% and benign tumor was 90% among 542 patients who showed abnormality in the PET/CT images. Types and rates of malignant tumor showed thyroid cancer: 31.5%, lung cancer: 14.8%, stomach cancer: 9.3%, rectum cancer: 3.7%, breast cancer: 3.7%, metastasis cancer: 16.7%. Nonspecific lymph node in the mediastinum, physiologic uptake in the colon, diffuse mild hypermetabolism in bilateral thyroid gland were shown as a benign tumor. Conclusion: The diagnostic rate of malignant tumor with $^{18}F$-FDG Fusion PET for a purpose of health examination was relatively higher than general medical examination. Consequently, it is superior and useful for applying $^{18}F$-FDG Fusion PET study for health examination.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.2
• /
• pp.196-203
• /
• 2003

The application of sealants is a highly technique-sensitive procedure, requiring an extremely dry field prior to placement. Moisture contamination of the etched enamel surface before sealant placement is cited as the main reason for sealant failure. The purpose of this study was to evaluate the effects of different methods of sealant application on the shear bond strength of sealants to enamel. In groups 1, 2, 3, 4 Teethmate(unfilled sealant) was used, while Ultraseal XTplus(filled sealant) was used in groups 5, 6, 7, 8. Groups 1 and 5(control) were acid etched for 15 seconds using 35% phosphoric acid, washed and then dried. In groups 2, 6 drying agents were applied, and in groups 3, 7 bonding agents were applied and light cured. In groups 4 and 8 both drying agent and bonding agent were applied. Then sealant was cured to the specimen using molds 3mm in diameter and 2mm in height. Thermocycling was performed and shear bond strength was finally measured. The following results were obtained : 1. Groups using filled sealant(groups 5, 6, 7, 8) showed higher shear bond strengths compared to groups using unfilled sealant(groups 1, 2, 3, 4). 2. Among groups using unfilled sealant(groups 1, 2, 3, 4), groups 2, 3, 4 showed significantly higher shear bond strength compared to group 1(p<0.05). There were no significant differences among groups 2, 3 and 4. 3. There were no significant differences(p>0.05) among groups using filled sealant(groups 5, 6, 7, 8). 4. When modes of fracture were examined, cohesive failure was observed in groups 2, 3 and 4.

• Korean Journal of Food Science and Technology
• /
• v.42 no.5
• /
• pp.598-604
• /
• 2010

Electron donating ability (EDA), reducing power, total phenolic contents, total flavonoid contents, antimicrobial activity, and ${\alpha}$-glucosidase inhibitory effects of twenty-two sorghum varieties were examined using ethanol extracts (70%, v/v). The electron donationg abilities (EDA) of Mesusu and Bulgeunjangmoksusu (94% at 10 ${\mu}g$/mL) indicated higher antioxidant activity compared to those of other varieties and standard antioxidants such as BHT (13%) and BHA (74%). The reducing power of Mesusu ($OD_{700}$=0.71) suggested higher antioxidant activity, which was dependent on sample concentration. Bitjarususu showed the highest content of total phenolics (22.9 mg GAE/g); however, extracts from Heuinsusu exhibited the lowest content of total phenolics (16.4 mg GAE/g). Jangmoksusu showed the highest total flavonolic contents (3.5 mg QE/g), and Sigyeongsusu and Chal (GS) susu displayed the most antibacterial activity (MIC=8 ${\mu}g$/mL) against Escherichia coli. Extracts of Bulgeunjangmoksusu, Moktaksusu, and Ginjangmoksusu showed the highest ${\alpha}$-glucosidase inhibitory effect (98%) at the concentration of 5 ${\mu}g$/mL.