• Structural Engineering and Mechanics
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• v.21 no.6
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• pp.635-658
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• 2005

The possibility of detecting a crack in L-shaped pipes filled with fluid based on measurement of transverse natural frequencies is examined. The problem is solved by representing the crack by a massless rotational spring, simulating the out-of-plane transverse vibration only without solving the coupled torsional vibration and using the transfer matrix method for solution of the governing equation. The theoretical solutions are verified by experiments. The cracks considered are external, circumferentially oriented and have straight front. Pipes made of aluminium and mild steel are tested with water as internal fluid. Crack size to pipe thickness ratio ranging from 0.20 to 0.57 and fluid (gauge) pressure in the range of 0 to 10 atmospheres are examined. The rotational spring stiffness is obtained by an inverse vibration analysis and deflection method. The details of the two methods are given. The results by the two methods are presented graphically and show good agreement. Crack locations are also determined by the inverse analysis. The maximum absolute error in the location is 13.80%. Experimentally determined variation of rotational spring stiffness with ratio of crack size to thickness is utilized to predict the crack sizes. The maximum absolute errors in prediction of crack size are 17.24% and 16.90% for aluminium and mild steel pipes respectively.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.12-17
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• 1986

The pericardial adhesions following the first open heart surgery pose a major problem that can increase the morbidity and mortality in cases of reoperation because of the danger of damaging the heart, great vessels or grafts. The purpose of this study was to determine the effect of intrapericardial infusion of 5% dextrose solution and heparin on experimental pericardial adhesions. The 15 white rabbits were divided into three treatment groups of 5 animals each: group 1 [control group], group 2[5% dextrose group] and group 3 [heparin group]. At 4 weeks, all animals were sacrificed and the pericardial adhesions were graded as follows: 1[none], ll[mild], Ill[moderate] and IV[severe]. Histological examination was performed on a subset of each group. The difference of adhesion between control and heparin group was evaluated by Chi-square analysis. The results were as follows: 1. Pericardial adhesions developed in 80% of animals in group 1 and 2. 2. Only 40%> of animals in group 3 had mild to moderate pericardial adhesions. This was significantly different from the control group [P=0.01]. 3. Histological examination showed that the pericardium with adhesion was thickened with fibrosis, while that without adhesion was thin, normal appearance. 4. In group 3, there was no evidence of hemorrhage or hemorrhagic tendency in the pericardium.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.3
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• pp.254-261
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• 2001

It is well known that when long waves propagate from deep ocean onto a continental shelf with a very steep continental slope, the waves reflected from the shore can not propagate offshore and are re-reflected from the continental slope so that large water level fluctuations are induced near the shore. Liu(1986) has analyzed this phenomenon by assuming a topography which has a depth discontinuity along a semicircular offshore boundary, but his solution is erroneous. In the present paper, we correct his analytical solutions for a straight shoreline and a rectangular harbor. The corrected solution is then compared with the numerical results of the Galerkin finite element model of Jeong et al.(1998), which is based on the extended mild-slope equation.

• Biomolecules & Therapeutics
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• v.2 no.3
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• pp.247-255
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• 1994

As a series of safety studies of DA-3030, a new rhO-CSF, its local irritancy was examined in the rabbits after the following treatment; application into the conjunctival sac of the eye(single), subcutaneous injection(single), intramuscular injection(single), and intravenous injection(8-day repeated). In addition, paravenous irritation of DA-3030 was investigated in mice. The results obtained were as follows. 1. In the result of ocular irritation test, 0.03% solution of DA-3030 could be considered as a non-irritating material. 2. The local irritation of DA-3030 by an injection of 0.5mι of its solution subcutaneously or intramuscularly was negligible and not so much different from that of saline. 3. In the vascular irritancy test, macro- and microscopic observations revealed that the irritating activity of DA-3030 in blood vessels was not different from that of saline when they were injected once a day into vein retroauricularis of rabbits for 8 days.4. The paravenous administration of DA-3030 did not induce any abnormal changes at injection sites except mild swelling in 1 mouse at 3 hours after injection which was thought to be due to slow absorption. The above-mentioned results suggest that DA-3030 has no irritating activity when injected through intravenous or subcutaneous route for clinical practice as 0.03% solution.

• Nuclear Engineering and Technology
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• v.45 no.1
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• pp.67-72
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• 2013

Stress corrosion cracking (SCC) behaviors of Alloy 690 were studied in lead-containing aqueous alkaline solutions using the slow strain rate tension (SSRT) tests in 0.1M and 2.5M NaOH with and without PbO at $315^{\circ}C$. The side and fracture surfaces of the alloy were then examined using scanning electron microscopy after the SSRT test. Microstructure and composition of the surface oxide layer were analyzed by using a field emission transmission electron microscopy, equipped with an energy dispersive X-ray spectroscopy. Even though Alloy 690 was almost immune to SCC in 0.1M NaOH solution, irrespective of PbO addition, the SCC resistance of Alloy 690 decreased in a 2.5M NaOH solution and further decreased by the addition of PbO. Based on thermodynamic stability and solubility of oxide, high Cr of 30wt% in the Alloy 690 is favorable to SCC in mild alkaline and acidic solutions whereas the SCC resistance of high Cr Alloy 690 is weakened drastically in the strong alkaline solution where the oxide is not stable any longer and solubility is too high to form a passive oxide locally.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.529-533
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• 2006

To produce fresh-cut fruit products of high quality, the combined effects of postharvest calcium and heat treatment on Tsugaru apple were examined. Whole fruits were treated for 20 min at three different conditions: dipping in 3% $CaCl_2$ solution at $45^{\circ}C$ or ambient temperature, or in heated water at $45^{\circ}C$. The calcium content of the apples dipped in $CaCl_2$ solution at $45^{\circ}C$ was higher than that of the control and the non-heated calcium dipping. The fruits with calcium and heat treatment showed the same pattern of respiration rates as the control did during storage. The browning degree of the apple slices increased to approximately 3% after one-day storage, but no significant difference was observed between the treated and untreated apples. The fruits with $CaCl_2$ solution dipping at $45^{\circ}C$ had higher firmness than those with calcium dipping or heat treatment alone.

• Journal of the Korean institute of surface engineering
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• v.54 no.6
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• pp.371-379
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• 2021

The use of anti-corrosive oil (AC) is inevitable for production of industrial steels to prevent corrosion. The AC is degreased before application of steels, which crucially effects on final products, such as automobile, electricity etc. However, qualitative/quantitative evaluation of degreasing performance are steal insufficient. In this study, degreasing performance of anti-corrosive oil on steel have been studied through X-ray photon spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Commercial automotive steels (AMS) are coated with 4 different anti-corrosive oils (namely AC1-AC4). In XPS, intensity of C1s peak remained after degreasing indirectly indicates incomplete degreasing. Thus, higher C1s peak intensity means less effective degreasing by degreasing agent. peak intensity of C1s peak shows opposite tendency of peak intensity of O1s. We found that EIS analysis is not applicable to mild steel (such as AMS1) due to corrosion during measurement. However, alloy steel can be fully analyzed by EIS and XPS depth profile.

• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.244-250
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• 1993

Hematotoxicity and vascular irritation of DA-125, a new anthracycline antitumor antibiotic, were investigated in mice and rabbits. In hematotoxicity study, healthy male ICR mice were treated with DA-125 by a single intravenous injection at doses of 18 and 24 mg/kg. After 4, 8, 12 and 16 days WBC count, RBC count, hemoglobin concentration, hematocrit value, and platelet counts were measured respectively. As a positive control, 12 mg/kg of doxorubicin (DXR) was used in the same manner. Remakable reductions of WBC counts in groups treated with DA-125 or DXR were observed 4 days after administration and returned to normal range 8 days after injection in groups of DA-125 18 mg/kg and DXR 12 mg/kg. The recovery of leukopenia induced in a group of DA-125 24 mg/kg took about 16 days after administration. The RBC counts, hemoglobin concentrations and hematocrit values also decreased in all drug treated groups on day 8 and recovered thereafter. The platelet counts of groups treated with DA-125 or DXR decreased on day 4 and recovered from day 8 of experiment. Local vascular irritation of DA-125 was also assessed in rabbits. The obtained results can be summarized as follows. 1. Thrombophlebitis was not induced even after daily intravenous administration of 0.4% solution of DA-125 or 0.2% solution of DXR for 7 days. 2. Macro- and microscopic observations revealed that the irritative activity of 0.4% solution of DA-125 in blood vessels was not so much different from that of saline when they were injected once a day into vein retroauricularis of rabbits for 7 days. 3. Mild inflammatory reaction was noted around vessels in rabbits treated with 0.2% solution of DXR after consecutive intravenous infusion for more than 5 days. 4. The potencies of vascular irritation of the test solutions were summarized in the following order; saline = 0.4% DA-125<0.2% DXR. These results indicated that DA-125 showed similar pattern of hematotoxicity with DXR but was less hematotoxic than DXR, and that 0.4% solution of DA-125 did not elicit unusual toxic properties when injected through intravenous route for clinical practice.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.205-208
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• 2001

The bitterness of brewers yeast slurry decreased by washing with mild caustic soda solution followed by washing with 0.85% (w/v) NaCl solution The higher concentration of caustic soda was, the lower the bitterness unit(BU) of washed yeast slurry was. The lethal rate of yeast cells increased. When the concentration of caustic soda solution increased from 0.05%(w/v) to 0.25%(w/v), the BU of brewers yeast slurry was decreased from 45 to 3, but yeast cells viability decreased from 93% to 0%. The optimum washing conditions of brewers yeast slurry were as follows: the concentration of caustic soda solution was $0.07{\sim}0.1%$(w/v) and the contact time of brewers yeast slurry with caustic soda was $10{\sim}20$ minutes. The similar washing effect was obtained when the brewers yeast slurry was washed with 20%(v/v) ethanol solution.

• The Journal of Internal Korean Medicine
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• v.43 no.5
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• pp.864-873
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• 2022

Objective: The purpose of this case study was to report the symptom improvement effect of integrative Korean medicine treatment based on Pyongsim Solution: Cheonwangbosim-dan in a patient with variant angina and asthma symptoms. Methods: This 68-year-old male patient was treated with Pyongsim Solution, Gamihyangsayukgunja-tang, Gwakhyangjunggi-san, acupuncture, pharmacopuncture, and cupping therapy for 24 days. The European Quality of Life-5 Dimensions-5 Levels profile, Numerical Rating Scale score, and pulse rate per minute were measured on admission, at two weeks of hospitalization, and upon discharge to assess the clinical outcomes. Results: After treatment, the "mobility" dimension profile of the European Quality of Life-5 Dimensions-5 Levels changed from 1 to 1, "self-care" changed from 1 to 1, "usual activity" changed from 3 to 2, "pain/discomfort" changed from 4 to 3, and "anxiety/depression" changed from 3 to 2. The Numerical Rating Scale score for chest pain decreased from 7 to 5, chest tightness decreased from 6 to 4, sleep disturbance decreased from 6 to 3, polydipsia decreased from 5 to 3, and stomach discomfort decreased from 5 to 3. All the profiles of these five dimensions were unchanged for 11 days in the period between the two weeks of hospitalization and discharge. There were also no changes in the profiles of either "mobility" or "self-care" throughout the entire 24-day hospitalization period. Conclusion: This case report shows that integrative Korean medicine treatment based on Pyongsim Solution can improve the symptoms of patients with variant angina and mild intermittent asthma, suggesting that Pyongsim Solution could be an important herbal medication for treatment.