• International Journal of Fluid Machinery and Systems
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• v.8 no.2
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• pp.73-84
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• 2015

Aerating hydroturbines have recently been proposed as an effective way to mitigate the problem of low dissolved oxygen in the discharge of hydroelectric power plants. The design of such a hydroturbine requires a precise understanding of the dependence of the generated bubble size distribution upon the operating conditions (viz. liquid velocity, air ventilation rate, hydrofoil configuration, etc.) and the consequent rise in dissolved oxygen in the downstream water. The purpose of the current research is to investigate the effect of location of air injection on the resulting bubble size distribution, thus leading to a quantitative analysis of aeration statistics and capabilities for two turbine blade hydrofoil designs. The two blade designs differed in their location of air injection. Extensive sets of experiments were conducted by varying the liquid velocity, aeration rate and the hydrofoil angle of attack, to characterize the resulting bubble size distribution. Using a shadow imaging technique to capture the bubble images in the wake and an in-house developed image analysis algorithm, it was found that the hydrofoil with leading edge ventilation produced smaller size bubbles as compared to the hydrofoil being ventilated at the trailing edge.

• Journal of Yeungnam Medical Science
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• v.31 no.1
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• pp.56-60
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• 2014

Hepatic portal venous gas (HPVG) is a rare radiographic finding associated with severe intra-abdominal disease and fatal outcome. Most cases of HPVG are historically related to mesenteric ischemia accompanied by bowel necrosis. The current spread of computed tomography scan promotes not only the early detection of related severe diseases but also the identification of other causes of HPVG. It has been reported in many non-fatal conditions, such as inflammatory bowel disease, intra-abdominal abscess, bowel obstruction, paralytic ileus, endoscopic retrograde cholangiopancreatography and endoscopic sphincterotomy, and gastric dilatation. Among these, paralytic ileus is a very rare condition, with no case yet reported in South Korea. Reported herein is a case of HPVG in paralytic ileus, which was treated well internally and was promptly resolved.

• Journal of Yeungnam Medical Science
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• v.30 no.1
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• pp.39-42
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• 2013

Cholelithiasis, duodenal ulcer, duodenal perforation and tumor invasion may lead to choledochoduodenal fistula (CDF). CDF often has no specific symptoms and may be incidentally detected in an upper gastrointestinal radiographic study or endoscopy; but in some cases, it may be accompanied by recurrent cholangitis and liver abscess. In this paper, a case of recurrent liver abscess caused by CDF is reported. A 62-year-old female was admitted to the authors' hospital because of right upper quadrant pain and fever. The abdominal computed tomography showed a liver abscess in the right lobe. A duodenal fistulous orifice was detected with endoscopy, and a contrast was injected through the duodenal orifice using a catheter under fluoroscopy. The injection of the contrast revealed a fistulous track between the duodenal bulb and the common hepatic duct. In fistulas complicated by recurrent liver abscess, surgery or medical management may be needed. The CDF in this case study was treated via endoscopic clipping.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.130-134
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• 1996

Background: This study was designed to determine the distance from skin to lumbar epidural space in obstetric parturients and whether weight, height, or PI (ponderal index, $kg/m^2$) might influence the epidural depth. Methods: 71 obstetric patients undergoing elective cesarean section during epidural anesthesia in L2-3 level were partitioned into groups according to their prepregnant BMI(body mass index), and in each group weight, height, PI, epidural depth were measured. Results: All patients were classified as underweight(n=18), normal(n=49), overweight(n=4) and no one was partitioned into obese group. the distance from skin to lumbar epidural space was found to be 3.7 cm(underweight), 4.1 cm(normal), 4.7 cm(over weight) and total mean distance was found to be 4.0 cm. The epidural depth had correlation with weight and height in underweight, and weight and PI in normal, but had no correlation with any measurements in overweight group. Conclusion: These results suggest body weight may be a useful parameter for predicting the distance from skin to lumbar epidural space in underweight and normal weight obstetric parturients.

• Macromolecular Research
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• v.17 no.3
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• pp.187-191
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• 2009

Platinum (Pt) nanoparticles were prepared by the liquid-phase reduction of tetraammineplatinum (II) chloride $([Pt(NH_3)_4]Cl_2)$ using Nafion as a stabilizer under various conditions of the Nation phase. This method is novel in its use of electrostatic interactions between the Pt complex ions and sulfonic groups in the hydrated Nation molecules. The synthesized Pt nanoparticles of the recast film system had a cubic shape. In the case of the Nation solution system, the Pt nanoparticles mainly had a spherical shape. The shapes and sizes of the Pt nanoparticles were strongly influenced by the Nation phase.

• Tunnel and Underground Space
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• v.20 no.3
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• pp.153-168
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• 2010

A fifth equation is required to determine the five independent elastic constants of a transversely isotropic rock from compression test of a single specimen. As an approximation proposed by Saint-Venant has been used for long time, it may cause an erroneous result in some cases, especially for specimen with low angle of anisotropy. Three equations were suggested replacing this traditional equation and proved to be applicable by the model analysis in the previous studies. As Saint-Venant's approximation is turned out the same as the first one of them, it has the characteristics that the apparent Young's modulus is monotonously increasing according to the anisotropic angle. The methodology to analyze the elastic constants from four independent strain measurements by uniaxial compressive test of a single standard specimen is concisely described, and the necessity and compatibility of new suggested equations are discussed. Saint-Venant's approximation can determine the elastic constants close to true values and other equations may be unnecessary in specimens with medium to large angle. Nevertheless, they may become applicable because they can produce the almost same amount. For the specimens of small angle of anisotropy, Saint-Venant's approximation may result in out of general ranges or thermodynamic constraints, but other suggested equations can produce the almost true value. Thus they can be applied before other alternative equation is known. The guide map constructed by model study may decide the most compatible one of the three equations.

• Tunnel and Underground Space
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• v.26 no.5
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• pp.363-374
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• 2016

All five independent elastic constants of a transversely isotropic rock sometimes need to be determined from a single specimen. Saint-Venant approximation has been widely used for a long time in the analysis of single specimen test. This paper has proven how this empirical equation can be mathematically transformed into a form of the apparent Young's modulus based on theory of elasticity. The transformed equation is a monotonous function on anisotropic angle and can be useful in the analysis of the in-situ stress measurement in an anisotropic rock mass. The estimations of data in literatures have shown that the measured values of $G^2$ are uniform on anisotropic angles and smaller than that of Saint-Venant's case. This decrement may be caused by sliding of the interface of strata and the decrement rate is inferred to relate well with the combination of bonding condition of strata and strength of rock material. Accumulation of these kinds of studies in the future enables to define the decrement and to determine elastic constants of a transversely isotropic rock from a single specimen from modifying Saint-Venant approximation.

• Journal of Yeungnam Medical Science
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• v.27 no.2
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• pp.159-164
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• 2010

Hematoma of gastric wall is very rare, and occasionally associated with coagulopathy, trauma, peptic ulcer disease, and therapeutic endoscopy. Ischemic gastric necrosis is also rare because of the abundant anastomotic supply to the stomach, and it is usually associated with surgery and disruption of the major vessels. Endoscopic submucosal injection of hypertonic saline-epinephrine (HS-E) is a safe, cost-effective, and widely used therapy for hemostasis but it may cause tissue necrosis and perforation. We describe a case of gastric wall hematoma with oozing bleeding after endoscopic gastric mucosa biopsy in 71-year old woman with chronic renal failure and angina pectoris undergoing anti-platelet medication. We injected a small dose of HS-E (7ml) for controlling oozing bleeding. Two days later, endoscopy showed huge ulcer with necrotic tissue at the site of previously hematoma. Therefore we should pay particular attention for hematoma and mucosal necrosis when performing endoscopic procedure in a patients with high bleeding and atherosclerotic risk.

• Journal of Chest Surgery
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• v.47 no.6
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• pp.510-516
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• 2014

Background: Acute cerebral infarction is a major risk factor for postoperative neurologic complications in cardiac surgery. However, the outcomes associated with acute silent cerebral infarction (ASCI) have not been not well established. Few studies have reported the postoperative outcomes of these patients in light of preoperative Diffusion-weighted magnetic resonance imaging (DWI). We studied the postoperative neurologic outcomes of patients with preoperative ASCI detected by DWI. Methods: We retrospectively studied 32 patients with preoperative ASCI detected by DWI. None of the patients had preoperative neurologic symptoms. The mean age at operation was $68.8{\pm}9.5$ years. Five patients had previous histories of stroke. Four patients had been diagnosed with infective endocarditis. Single cerebral infarct lesions were detected in 16 patients, double lesions in 13, and multiple lesions (>5) in three. The median size of the infarct lesions was 4 mm (range, 2 to 25 mm). The operations of three of the 32 patients were delayed pending follow-up DWI studies. Results: There were two in-hospital mortalities. Neurologic complications also occurred in two patients. One patient developed extensive cerebral infarction unrelated to preoperative infarct lesions. One patient showed sustained delirium over one week but recovered completely without any neurologic deficits. In two patients, postoperative DWI confirmed that no significant changes had occurred in the lesions. Conclusion: Patients with preoperative ASCI showed excellent postoperative neurologic outcomes. Preoperative ASCI was not a risk factor for postoperative neurologic deterioration.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1797-1800
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• 2016

Background: Research in the field of informational needs of breast cancer patients is scarce. In the few published articles, these needs were usually not satisfied. The main objective of this study was to evaluate satisfaction regarding informational needs in women with breast cancer. The long-term goal was to guide physician-patient communication to meet these needs. Materials and Methods: A survey with 21 questions was completed by 84 female patients receiving chemotherapy in a one-day hospital in Beirut, Lebanon. All patients were aware of their disease and agreed to participate in the survey. Results: The doctor was the major source of information for patients followed by media (radio and television). The level of knowledge of patients concerning their disease was proportional to the number of information sources. Women aged younger than 45 years, diagnosed during the last three months before the survey and certified from high school were less satisfied with information given by the oncologist. The missing information was in relation with the steps of the treatment after the chemotherapy regimen, the risk of a family member (sisters and daughters) of developing the disease and management of lymphedema. Conclusions: This study generated a scale for the degree of satisfaction of information received by women with breast cancer from their oncologist. The physician can use this scale to improve his or her skills of communication to patients and diminish their level of fear and anxiety.