• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.461-466
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• 2014

The advantages and disadvantages of the various models of crushed ESWL (Extracorporeal Shock Wave Lithotripsy) and their various side effects due to pre-treatment have been reported. We look for the appropriate intensity of the shock wave in the electromagnetic ESWL treatment of patients with lower Inferior Ureter Stones and measure the total running time of C-arm saw. This study is based on the January-June 2014 launch of 65 patients of C university hospital located in Gyeongbuk, who conducted ESWL without pre-treatment. Patients are composed of 48 male and 17 female which were more common in men, while the most common age is 50s. The occurrence of lower urinary tract stones were left and they were more absent than 5mm in size in 39 of the most common. Optimal intensity is one of the suitable intensity of pain, and it is possible to switch the strength of impact to C if one appeals pain. In addition, the C-arm of the total operating time showed $241.73{\pm}30.37$ seconds, which is the size of the lower urinary tract that showed a significant difference (p <0.05). Therefore, ESWL treatment without pre-enforce treatment, the standard for the impact frequency and impact strength depending on the site of ureteral stones is required. The standard for total operating time of C-arm generated for ureteral stones is needed in order to reduce radiation exposure, and the standard for the total operating time for the criteria is needed depending on the site in order to minimize the exposure.

• Polymer(Korea)
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• v.34 no.1
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• pp.14-19
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• 2010

Applying acrylic silane monomer for determent of weathering damage of stone cultural assets from various sources was investigated to improve inorganic affinity of polymer impregnated to the stone for conservation treatment using impregnation of acrylic polymers under pressure. Radical polymerization was carried out with various mixture ratios of methacrylate (MMA), as the base monomer, and vinyl trimethoxy silane (VTMS). Subsequently, according to the changes of glass transition temperatures, average molecular weights, and storage moduli of the obtained copolymers, the case of adding 1 wt% of benzoyl peroxide, polymerization for 8 hrs, and mixing 5 mol% of VTMS to MMA was the optimum condition of monomer ratio and polymerization. Practically, fresh granites collected in domestic site and weathered stones were treated by following the obtained result above, and then, the moisture absorption, impact, acid resistance, and adhesion properties of the treated stones were compared to those of the corresponding stones treated with MMA only. It was found that those properties of the stones treated with PMV5 were considerably improved.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8293-8298
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• 2016

Background: Urinary stones are known predisposing factors for upper urinary tract carcinoma (UUTC) which are commonly detected at advanced stage with poor outcome because of rarity and lack of specific criteria for early detection. Aims and objectives: The main aim was to evaluate the impact of age, gender andstone characteristics on risk of developing UUTC in patients with chronic nephrolithiasis. We also discuss the role of aberrant angiogenesis (AA) and immunohistochemical expression of p53, p16INK4a, CK20 and Ki-67 in diagnosis of pelvicalyceal neoplastic (NL) and pre-neoplastic lesions (PNL) in these patients. Materials and Methods: Retrospective analysis of pelvicalyceal urothelial lesions from 88 nephrectomy specimens were carried out in a tertiary care centre from June 2012 to December 2014. Immunohistochemistry (IHC) was performed on 37 selected cases. Computed image analysis was performed to analyse aberrant angiogenesis. Results: All UUTC (5.7%) and metaplastic lesions were found to be associated with stones. Some 60% were pure squamous cell carcinoma and 40% were transitional cell carcinoma. Odd ratios for developing NL and PNL lesions in presence of renal stone, impacted stones, multiple and large stag horn stones were 9.39 (95% CI 1.15-76.39, p value 0.05), 6.28 (95% CI 1.59-24.85, p value 0.000) and 7.4 (95% CI, 2.29-23.94, p value 0.001) respectively. When patient age was ${\geq}55$, the odds ratio for developing NL was 3.43 (95% CI 1.19-9.88, p value 0.019). IHC analysis showed that mean Ki-67 indices were $3.15{\pm}3.63%$ for non-neoplastic lesions, $10.0{\pm}9.45%$ for PNL and $28.0{\pm}18.4%$ for NL. Sensitivity and specificity of CK20, p53, p16INK4a, AA were 76% and 95.9%; 100% and 27.5%; 100% and 26.5%; 92.3 % and 78.8% respectively. Conclusions: Age ${\geq}55years$, large stag horn stones, multiple stones and impacted stones are found to be associated with increased risk of NL and PNL in UUT. For flat lesions, a panel of markers, Ki 67 index >10 and presence of aberrant angiogenesis were more useful than individual markers.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.10-11
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• 2019

Interior stone walls are using commonly in non-bearing lightweight walls of apartments. The stones of interior wall were two types, one is a granite stone, another is a marble stone. Granite stone is attached by the epoxy adhesive and marble stone is attached by dedicated anchor and fastener. The impact resistance test was carried out interior stone walls in accordance with KS F 2613. The test methods included the impact resistance tests by each of soft impact body and hard impact body. The results of the test have proved that interior stone walls can withstand the soft impact bodies and hard impact bodies that are likely to happen in everyday life.

• Journal of Ocean Engineering and Technology
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• v.35 no.6
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• pp.403-413
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• 2021

As the size of ships increases, the size and output power of their thrusters also increase. When a large ship berths or unberths, the jet flow produced from its thruster has an adverse effect on the stability of quay walls. In this study, we conducted a numerical analysis to examine the impact of the thruster jet flow of a 30,000 TEU container ship, which is expected to be built in the near future, on the stability of a quay wall. In the numerical simulation, we used the fluid-structure interaction analysis technique of LS-DYNA, which is calculated by the overlapping capability using an arbitrary Lagrangian Eulerian formulation and Euler-Lagrange coupling algorithm with an explicit finite element method. As the ship approached the quay wall and the vertical position of the thruster approached the mound of the quay wall, the jet flow directly affected the foot-protection blocks and armor stones. The movement and separation of the foot-protection blocks and armor stones were confirmed in the area affected directly by the thruster jet flow of the container ship. Therefore, the thruster jet flows of ultra-large ships must be considered when planning and designing ports. In addition, the stability of existing port structures must be evaluated.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.2
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• pp.166-171
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• 2023

Backgrounds/Aims: Routine execution of intraoperative cholangiography (IOC) in laparoscopic cholecystectomy (LC) is considered a good practice to help early identification of biliary duct injuries (BDIs) or common bile duct (CBD) stones. This study aimed to determine the impact of IOC during LC. Methods: This is a retrospective, monocentric study, including patients with a LC performed from January 2020 to December 2021. Results: Of 303 patients, 215 (71.0%) were in the IOC group and 88 (29.0%) in the no-IOC group. IOC was incomplete or unclear in 10.7% of patients, with a failure rate of 14.7%. Operating time was 15 minutes longer in the IOC group (p = 0.01), and postoperative complications were higher (5.1% vs. 0.0%, p = 0.03). There were three BDIs (0.99%), all included in the IOC group; only one was diagnosed intraoperatively, and the other two were identified during the postoperative course. Regarding identifying CBD stones, IOC showed a sensitivity of 77%, a specificity of 98%, an accuracy of 97.2%, a positive predictive value of 63% and a negative predictive value of 99%. Conclusions: Systematic IOC has shown no specific benefits and prolonged operative duration. IOC should be performed on selected patients or in situations of uncertainty on the anatomy.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.4
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• pp.113-122
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• 2018

A hydraulic breaker is an attachment of an excavator, and it crushes stones. Recently, research to reduce the impact and noise of breakers are ongoing. In this paper, a method to improve the upper, lower, and side dampers, which act as insulation for the attenuation of vibration during breaker operation, is studied through testing and simulation. To obtain the nonlinear material constants required for the simulation, the biaxial tensile test was performed with urethane, which is a material used for dampers. The existing parts and the improved parts were compared and evaluated using the LS-DYNA program. As a result, 50% of the equivalent stress was reduced in the bracket body of the hydraulic breaker, and the equivalent stress of the side damper was also decreased. We verified that the fatigue conditions were satisfied by performing a fatigue analysis.

• Carbon letters
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• v.10 no.2
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• pp.114-122
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• 2009

Crushed, depitted peach stones were impregnated activated with 50% $H_3PO_4$ followed by pyrolysis at $500^{\circ}C$. Two activated carbons were produced, one under its own evolved gases during pyrolysis, and the second conducted with air flow throughout the carbonization stage. Physicochemical properties were investigated by several procedures; carbon yield, ash content, elemental chemical analysis, TG/DTG and FTIR spectra. Porosity characteristics were determined by the conventional $N_2$ adsorption at 77 K, and data analyzed to get the major texture parameters of surface area and pore volume. Highly developed activated carbons were obtained, essentially microporous, with slight effect of air on the porous structure. Oxygen was observed to be markedly incorporated in the carbon matrix during the air treatment process. Cation exchange capacity towards Cu (II) and Cd (II) was tested in batch single ion experimental mode, which proved to be slow and a function of carbon dose, time and initial ion concentration. Copper was up taken more favorably than cadmium, under same conditions, and adsorption of both cations was remarkably enhanced as a consequence of the air treatment procedure. Sequestration of the metal ions was explained on basis of the combined effect of the oxygen functional groups and the phosphorous-containing compounds; both contributing to the total surface acidity character.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.525-532
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• 2001

In this study, performance of reinforced railroad roadbeds with the crushed stones was investigated through the real scale railroad roadbed tests. Several real scale reinforced railroad roadbeds were constructed in the laboratory with different subgrade conditions and were tested with the estimated actual train loads including the impact loading of train. The affecting factors such as settlement, earth pressure and stress change at the surface of reinforced roadbed, subgrade layers as well as surface of rails were measured. It was found through the actual testing that for the roadbed with the same thickness, the settlement and vibration level (velocity) of reinforced roadbed decreases with the increase of reaction modulus of subgrade. The settlement of reinforced roadbed with the same reaction modulus of subgrade also decreases with the increase of thickness of the reinforced roadbed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.449-455
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• 2001

도로교통소음의 저감을 위해 설치되는 방음벽의 성능평가를 위해서는 흡음률 및 투과손실과 같은 음향성능에 대한 평가뿐만 아니라, 풍압 및 충격하중과 같은 구조성능과 방음판 제작에 사용되는 재질에 관한 성능평가도 수반되어야 한다. 따라서, 본 논문에서는 이러한 방음벽의 성능평가를 위한 음향 구조 및 재질에 관한 시험 및 평가방법을 제시하였다.