• Journal of Chest Surgery
• /
• v.30 no.1
• /
• pp.77-82
• /
• 1997

Sixty children were admitted to he Department of Thoracic and Cardiovascular Surgery, Kyungpook National University Hospital for the treatment of thoracic injuries for about a 10year period ending in August, 1995. We reviewed the hospital records retrospectively, to see the characteristics of the scope and consequences of childhood chest injuries. Mean age was 9 years and forty-six cases(77%) were male. Fifty children(83%) were victims of a blunt trauma. Among the blunt trauma patients, more than 60% were traffic-related. All victims of penetrating trauma were male. Among the blunt trauma patients, rib fracture was the most frequently found (52%) followed by pneumothorax(42%), although significant intrathoracic injuries occurred without rib fractures in )2% of blunt trauma cases. Associated injuries were present in 42% of children reviewed. Most frequently performed surgical procedure was closed thoracostomy(45% ), and ten children required thoracotomy and fifteen needed assisted ventilation. Modified Injury Severi y Scale(MISS) score was measured in the multiple Injured group. MISS score correlated significantly with the length of stay In the intensive care unit. One child(1.7% ), involved in a traffic accident, died of sepsis.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.12
• /
• pp.1577-1583
• /
• 2012

Penetrator with enhanced lateral effect (PELE) is a novel projectile that does not require dynamite and a fuse. It comprises a high-density jacket that is closed at its rear end and filled with a low-density filling material. To study the explosion characteristics of PELE using AUTODYN-3D code, the calculation models of the projectile body and the bullet target were developed and the process of penetrating an aluminum-2024 alloy target using PELE was simulated. The scattering characteristics after PELE penetrated the aluminum-2024 alloy target were studied for different filling materials. The explicit finite element analysis of PELE fragmentation was implemented with the stochastic failure criterion in AUTODYN-3D code. As the filling expanded, the fragments gained velocity and dispersed laterally, increasing the damage area considerably. The number and shape of PELE fragments differed depending on the impact pressure of the filling that fragmented during the penetration and lateral dispersion processes.

• International Journal of Highway Engineering
• /
• v.19 no.2
• /
• pp.7-15
• /
• 2017

PURPOSES : Infiltration of moisture, polluted material, and deicer into concrete, accompanied by freeze and thaw can cause significant deterioration of concrete pavement. In order to protect concrete from deterioration, it is necessary to prevent the infiltration of these concrete external materials. The moisture-repellent agent, which is a surface treatment and maintenance material added to concrete structures to render them water resistant, has advantages such as prevention of water infiltration and security against air permeation. Nano-coat, which is referred to as silicon hydride, is typically used as a moisture-repellent agent. Therefore, in this study, an attempt is made to use penetration-type Nano-coat as an alternative in order to evaluate its applicability through environmental resistance tests. METHODS : This study aimed to evaluate the applicability of penetration-type Nano-coat, which can provide water repellency to concrete, in concrete pavements, through various environmental resistance tests such as freezing and thawing resistance, chloride ion penetration resistance, and surface scaling resistance tests. The applicability of penetration-type Nano-coat was demonstrated based on the specification of KS F 2711, KS F 2456, and ASTM C 672. RESULTS :In the case of penetration-type Nano-coat applied on sound concrete, an increase in concrete durability was demonstrated by the negligible chloride ion penetrability and the absence of scaling, as revealed by visual observation of the surface, after 50 cycles of scaling resistance test. In addition, test result of the application of penetration-type Nano-coat on deteriorated concrete established that concrete surface pretreated by grinding provided improved durability than non-treated concrete. CONCLUSIONS :This study indicates that penetration-type Nano-coat is applicable as an effective alternative, to increase the durability of concrete structures. In addition, it was known that pretreatment of deteriorated concrete surface, such as grinding, is required to improve the long-term performance of concrete pavement.

• International Journal of Highway Engineering
• /
• v.19 no.6
• /
• pp.129-137
• /
• 2017

PURPOSES : The purpose of this study is to develop bridge deck concrete materials based on ordinary Portland cement concrete, and to evaluate the applicability of the developed materials through material properties tests. METHODS : For field implementation, raw material (cement, fine aggregate, and coarse aggregate) properties, fresh concrete properties (slump and air content), strength (compressive, flexural and bond strength) gain, and durability (freeze-thaw resistance, scaling resistance, and rapid chloride penetrating resistance) performance were evaluated in the laboratory. RESULTS : For the selected binder content of $410kg/m^3$, W/B = 0.42, and S/a = 0.48, the following material performance results were obtained. Considering the capacity of the deck finisher, a minimum slump of 150 mm was required. At least 6 % of air content was obtained to resist freeze-thaw damage. In terms of strength, 51.28 MPa of compressive strength, 7.41 MPa of flexural strength, and 2.56 MPa of bond strength at 28 days after construction were obtained. A total of 94.9 % of the relative dynamic modulus of elasticity after 300 cycles of freeze-thaw resistance testing and $0.0056kg/m^2$ of weight loss in a scaling resistance test were measured. However, in a chloride ion penetration resistance test, the result of 3,356 Coulomb, which exceeds the threshold value of the standard specification (1000 Coulomb at 56 days) was observed. CONCLUSIONS : Instead of using high-performance modified bridge deck materials such as latex or silica fume, we developed an optimum mix design based on ordinary Portland cement concrete. A test construction was carried out at ramp bridge B (bridge length = 111 m) in Gim Jai City. Immediately after the concrete was poured, the curing compound was applied, and then wet mat curing was applied for 28 days. Considering the fact that cracks did not occur during the monitoring period, the applicability of the developed material is considered to be high.

• Journal of Chest Surgery
• /
• v.19 no.3
• /
• pp.421-428
• /
• 1986

From January 1981 through December 1985, 481 thoracic civilian injuries were reviewed in the Department of Thoracic Surgery, Paik Hospital in Seoul. Sixty two percent of the injuries were caused by traffic accident, 18% fall down, 15% blunt trauma, 2% crushing injury, 2% stab wound, and 0.4% gunshot wound. Peak incidence of the trauma victim was fourth and fifth decades revealing 22% and 27% respectively. Sex ratio was 3.5:1 with male predominance. Elapsed time before admission was less than one hour in 36% and one to six hour in 30%. The types of the injuries were as follows: Non-penetrating injuries were the most part of the wounded, 97.6%. Rib fracture was the most common lesion occupying 292 patient out of 481 [61%]. Of these 292 patients, 72% was multiple rib fracture. The incidence of hemothorax or hemopneumothorax was 19% [102 patients] [Table 4]. Most common associated condition was head injuries, 98 patients [14%]. Thoracoabdominal injuries were seen in 31 patients [0.6%]. Tube thoracostomy was the definitive measures in the 20% of the wounded. Open thoractomy was performed in 5%. Additional procedures for the associated condition were done in the 16% of the cases, for example, reduction of long bone fracture and trephination for the head injury. Among 481 wounded, fatal complication occurred in 13 patients [2.7%]. This paper has also compared two series of patients according to period; one from 1970 to 1980 and the present series [Table 8]. Conclusively, the fatal complications or trauma death may be reduced by the effort 1] rapid transport of the victim, 2] initial correction or resuscitative measures of the circulatory and ventilatory deficit 3] early decision of definitive thoracostomy or thoracotomy and 4] proper prioritizing for the care of the multiple critically injured patient.

• Journal of Soil and Groundwater Environment
• /
• v.15 no.6
• /
• pp.9-16
• /
• 2010

Groundwater sampling was performed at 38 wells where they are located in the areas with high uranium and radon (marked as A and B, respectively) concentrations, which were based on the previous research results. In-situ parameters (temperature, pH, EC, Eh, DO) and natural radionuclides (uranium and radon) were analyzed to figure out the characteristics of groundwater environments. In-situ data did not show any relations to natural radionuclide data, which could be caused by groundwater mixing, depths of wells, and geological settings, etc. But the highest radon well presented relatively low temperature value and the highest uranium well presented relatively low pH values The highest uranium concentration ranging $1.14{\sim}188.19{\mu}g/L$ showed in the area of A region consisted of Jurassic two-mica granite. The areas of Jurassic biotite granite and Cretaceous granite in the A region have the uranium concentrations ranging $0.10{\sim}49.78{\mu}g/L$ and $0.36{\sim}3.01{\mu}g/L$, respectively. The uranium values from between wells of community water systems (CWSs) penetrating fractured bed-rock aquifers and personal boreholes settled in shallow aquifers near the wells of CWSs show big differences. It implies that the groundwaters of the two areas have evolved from different water-rock interaction paths that may caused by various types of wells having different aquifers. High radon activities in the area of B region composed of Precambrian gneiss showed ranging from 6,770 to 64,688 pCi/L. Even though the wells are located in the same geological settings, their rodon concentration presented different according to depth and distance.

• Journal of Biosystems Engineering
• /
• v.38 no.2
• /
• pp.87-94
• /
• 2013

Purpose: Pineapple is now the third most important tropical fruit in world production after banana and citrus. Phytosanitary irradiation is recognized as a promising alternative treatment to chemical fumigation. However, most of the phytosanitary irradiation studies have dealt with physiochemical properties and its efficacy. Accurate dose calculation is crucial for ensuring proper process control in phytosanitary irradiation. The objective of this study was to optimize phytosanitary irradiation treatment of pineapple in various radiation sources using Monte Carlo simulation. Methods: 3-D geometry and component densities of the pineapple, extracted from CT scan data, were entered into a radiation transport Monte Carlo code (MCNP5) to obtain simulated dose distribution. Radiation energy used for simulation were 2 MeV (low-energy) and 10 MeV (high-energy) for electron beams, 1.25 MeV for gamma-rays, and 5 MeV for X-rays. Results: For low-energy electron beam simulation, electrons penetrated up to 0.75 cm from the pineapple skin, which is good for controlling insect eggs laid just below the fruit surface. For high-energy electron beam simulation, electrons penetrated up to 4.5 cm and the irradiation area occupied 60.2% of the whole area at single-side irradiation and 90.6% at double-side irradiation. For a single-side only gamma- and X-ray source simulation, the entire pineapple was irradiated and dose uniformity ratios (Dmax/Dmin) were 2.23 and 2.19, respectively. Even though both sources had all greater penetrating capability, the X-ray treatment is safer and the gamma-ray treatment is more widely used due to their availability. Conclusions: These results are invaluable for optimizing phytosanitary irradiation treatment planning of pineapple.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.4
• /
• pp.308-317
• /
• 2016

The tail flip of the decapod shrimp is a main feature in escaping behavior from the mesh of the codend in the trawl. The characteristics of tail flip in target prawn was observed and analyzed in a water tunnel in respect of flow condition and mesh penetration by a high speed video camera (500 fps). The tail bending angle or bending time in static water was significantly different than in flow water (0.7 m/s) and resultantly the angular velocity in static water was significantly higher than in flow water when carapace was fixed condition. When escaping through vertical traverse net panel in water flow the relative moving angle and relative passing angle to flow direction during tail flip, it significantly decreases the number of shrimps escaping than the case of blocking shrimp. The bending angles of tail flip between net blocking and passing through mesh were not significantly different while the bending time of shrimp passing through mesh was significantly longer than when shrimp blocking on the net. Accordingly the angular velocity of passing through mesh was significantly slower than blocking on the net although the angular velocity of the tail flip was not significantly related with carapace length. The main feature of tail flip for mesh penetration was considered as smaller diagonal direction as moving and passing angle in relation to net panel as right angle to flow direction rather than the angular velocity of tail flip.

• Korean Journal of Head & Neck Oncology
• /
• v.14 no.2
• /
• pp.191-198
• /
• 1998

Objectives: We performed an immunohistochemical study to examine the place of neovascularization in the tumorigenic process of follicular thyroid carcinoma and to determine whether tumor angiogenic activity in follicular carcinoma plays a role in tumor aggression. Materials & Methods: We studied 63 follicular thyroid carcinomas and compared with 22 follicular adenomas. The areas of capsular invasion, vascular invasion and cellular atypism of the tumor were confimed on H & E stains. The paraffin embedded tissues were stained by the use of monoclonal antibodies against Ag CD34. Microvesseles were counted in the area of highest vascular density at 200 times magnification. The microvessel densities(MVD) were analized in relation to histologic type and location of the tumors. Results: There were 59 minimal invasive types and 4 widely invasive types of carcinoma. In the histologic specimens of carcinomas, capsular invasion was identified in all the cases, vascular invasion in 46 and cellular atypism in 24. Mean values of the MVDs of the minimal invasive carcinomas, the widely invasive carcinomas and the adenomas were $263.8{\pm}69.2,\;256.l{\pm}49.3\;and\;241.5{\pm}159.4$, respectively and there was no significant difference between each group. In follicular carcinomas, there was a regional difference of the MVDs. The areas of tumor showing cellular atypism and adjacent to or penetrating the capsule, in which represents the tumorigenic process of carcinoma, had a higher rate of vascularization, than other areas of the tumor(p<0.05). However, these features were not noted in the follicular adenomas. Conclusion: Although there was no significant difference of the MVD between follicular carcinomas and adenomas, there was a regional difference of the MVD within the carcinomas and the values were significantly higher in the more malignant areas, as indicated by cellular atypism and capsular invasion. Therefore, tumor angiogenic activity measured by MVD may play a role in tumor aggression in follicular thyroid carcinoma.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.9 no.2
• /
• pp.69-76
• /
• 2009

Infiltration is the process of water penetrating from the ground surface into soil. Infiltration plays an important role on affecting ground water surface and surface flow during rainy season. The amount of infiltration water would be decreased as the urbanization would increase. Such phenomenons would make streamflow decrease or stream run dry. In this study the cumulative infiltration and the infiltration capacity of ground surface have been determined by the field experiment at three sites in the Hankyong National University, Korea. Three type pervious pedestrian blocks of the cumulative infiltration and the infiltration capacity have also been determined at the same site of the ground surface. It has been shown that one of three type blocks in terms of infiltration capacity is almost same as that of ground surface. The Kostiakov type has been adopted to determine the cumulative infiltration and the infiltration capacity for each site. The Horton type has been also adopted to determine the cumulative infiltration and the infiltration capacity. The value of parameter k for each site is determined and soil type would be identified corresponding to the value of parameter.