• Korean Journal of Materials Research
• /
• v.17 no.10
• /
• pp.560-566
• /
• 2007

AlN plates were fabricated by hot pressing at $1700-1900^{\circ}C$ using yttria and alumina (3 and $10\;{\mu}m$ particle size) powders as additives and characterized: density, thermal conductivity, transverse rupture strength, and grain size measurement by SEM and EDS. Density values of $3.31-3.34\;g/cm^3$ are largely attributed to hot pressing of powder mixtures in carbon mold under $N_2$ atmosphere which caused effective degree of oxygen removal from yttrium-aluminate phase expected to form at $1100^{\circ}C$. The grain size of hot pressed AlN was almost homogeneous, with size approximately from 3.2 to $4.0\;{\mu}m$ after hot pressing. $Al_2O_3$ powder of $3\;{\mu}m$ particle size resulted in better transverse rupture strength and finer grain size compared to $10\;{\mu}m$ $Al_2O_3$ powder. The thermal conductivity of AlN ranged between $83-92.7\;W/m{\cdot}K$ and decreased with $Al_2O_3$ addition. Fine grain size is preferred for better mechanical properties and thermal conductivity.

• Journal of the Korean Arthroscopy Society
• /
• v.13 no.3
• /
• pp.264-267
• /
• 2009

Pigmented villonodular synovitis (PVNS) is a benign proliferative disorder of the synovium of joints. It occurs most commonly in the knee joint. The disease is composed of 2 different forms: diffuse and localized. The localized form is less frequent than the diffuse one. Most cases of localized PVNS involve the anterior compartment of the knee and can be usually easily diagnosed and treated with arthroscopy. We experienced a patient of localized PVNS developed on the posterior cruciate ligament, whose main symptom was persistent pain after trauma. This case occurs rarely and complete removal of the lesion was performed arthroscopically, using posterior trans-septal portal. We report this case with review of literatures.

• Korean Journal of Bronchoesophagology
• /
• v.3 no.1
• /
• pp.84-93
• /
• 1997

The bronchoscopy is usually performed in the patients who present symptoms of wheezing, hemoptysis, signs of airway obstruction, unexplained long-term chronic cough with or without radiologic features of pneumonia, emphysema or atelectasis. The symptoms and signs of cases of suspected airway foreign body are of often cofused with those of asthma pneumonia and other respiratory tract disease. The ventilating bronchoscopy will be helpful for removal of certain foreign bodies as well as alleviating medically-unresponsive bronchopulmonary conditions via removing abnormal secretions or merely improving ventilation. The authors have performed clinical analysis of 59 patients who were suspected of airway foreign bodies and treated by ventilating bronchoscopy from September 1985 to February 1995. The results were as follows: 1) Among the 59 cases of bronchoscopy, 51 cases(97%) were under the age of 3. The ratio of male and female was 2.69:1 2) Most common presenting symptom was coughing(84.7%) followed by dyspnea, fever, wheezing and anterior chest pain. 3) Among 39 cases of identified foreign bodies, abnormal findings in the chest X-ray films were found in 33 cases(84.6%) and most common abnormal radiologic feature was pneumonia in 10 cases(25.6%) followed by combination of pneumonia and emphysema, or emphysema alone. All the 20 cases of absent foreign body presented abnormal radiologic features and common findings were pneumonia and atelectasis. 4) Vegetable foreign bodies were the most common form of removed airway foreign bodies(69.2%) followed by metallic foreign bodies(12.8%) and plastic foreign bodies(7.7%). 5) By distribution of the location of foreign bodies, 29 cases(74.4%) were located in the main bronchus( 16 cases of right side and 13 cases of left side), 8 cases were in the trachea and 2 cases were found at the cordal level. 6) By duration of foreign body lodgement in the airway, 9 cases(23.1%) were removed within 7 to 30 days, 10 cases(5.6%) within 3 days and 5 cases(12.8%) were enlodged over 30 days. 7) In the cases of absent foreign bodies, common bronchoscopic findings were mucopurulent or thick mucoid discharge in the main bronchi, erythema or edema of bronchial mucosa and all the cases were improved after ventilating bronchoscopy with concomitant medical management.

• Journal of Korean Society on Water Environment
• /
• v.37 no.2
• /
• pp.92-102
• /
• 2021

In this study, the distribution characteristics according to the type of BOD and the effect of nitrogenous oxygen demand (NOD) and algal oxygen demand on BOD in three streams (Bokhacheon, Byeongseongcheon, and Gulpocheon) were evaluated. Although the BOD and NOD concentrations demonstrated a difference in the three streams, the carbonaceous BOD(CBOD)/BOD ratio was 0.75 (p=0.053, one-way ANOVA), and there was no significant difference in the three streams (r2≥0.92, p<0.0001). The NOD concentration of the Bokhacheon with high NH3-N was 1.7±1.3 mg/L, which was the highest among the three streams and showed a significant correlation with BOD. Seasonal variations in NOD in the three streams did not show a significant correlation with changes in NH3-N concentration (r2<0.28, p≥0.1789), and there was no significant difference in NOD even though NH3-N concentration in Gulpocheon was about twice that of Byeongseongcheon (p=0.870, one way ANOVA). The particulate CBOD(PCBOD)/CBOD ratio of the three streams was 0.55~0.64, and about 60% of the biodegradable organic matter was present in the particulate form. When the Chl.a concentration in the stream was more than 7 ㎍/L, the PCBOD tended to increase with the Chl.a concentration (r2=0.61, p=0.003). In the three streams, particulate NOD accounted for 81% of NOD; however, despite the large variation in NH3-N concentration (0.075~3.182 mg/L), there was no significant difference in soluble NOD(SNOD) concentration that ranged from 0.1 to 0.3 mg/L. In this study, the low contribution rate of SNOD to NOD is considered as a result of the removal of nitrifying bacteria along with the particles during the filtration process.

• International Neurourology Journal
• /
• v.22 no.4
• /
• pp.246-251
• /
• 2018

Purpose: To determine whether responses to serotonin are altered in bladder strips from cats diagnosed with a naturally occurring form of bladder pain syndrome/interstitial cystitis termed feline interstitial cystitis (FIC). Methods: Full thickness bladder strips were isolated from aged matched healthy control cats and cats with clinically verified FIC. Bladder strips were mounted in an organ bath and connected to a tension transducer to record contractile activity. A serotonin dose response ($0.01-10{\mu}M$) was determined for each strip with the mucosa intact or denuded. Results: Bladder strips from control and FIC cats contracted in response to serotonin in a dose-dependent manner. The normalized force of serotonin-evoked contractions was significantly greater in bladder strips from cats with FIC (n=7) than from control cats (n=4). Removal of the mucosa significantly decreased serotonin-mediated responses in both control and FIC bladder preparations. Furthermore, the contractions in response to serotonin were abolished by $1{\mu}M$ atropine in both control and FIC bladder strips. Conclusions: The effect of serotonin on contractile force, but not sensitivity, was potentiated in bladder strips from cats with FIC, and was dependent upon the presence of the mucosa in control and FIC groups. As atropine inhibited these effects of serotonin, we hypothesize that, serotonin enhances acetylcholine release from the mucosa of FIC cat bladder strips, which could account for the increased force generated. In summary, FIC augments the responsiveness of bladder to serotonin, which may contribute to the symptoms associated with this chronic condition.

• Journal of Gastric Cancer
• /
• v.19 no.1
• /
• pp.72-82
• /
• 2019

Purpose: Despite its clinical benefits, enhanced recovery after surgery (ERAS) is less widely implemented for gastric cancer surgery. This nationwide survey investigated the current status of the implementation of ERAS in perioperative care for gastric cancer surgery in South Korea. Materials and Methods: This survey enrolled 89 gastric surgeons from 52 institutions in South Korea. The questionnaire consisted of 24 questions about the implementation of the ERAS protocols in the management of gastric cancer surgery. The survey was carried out using an electronic form sent via email. Results: Of the 89 gastric surgeons, 58 (65.2%) answered that they have knowledge of the concept and details of ERAS, 45 (50.6%) of whom were currently applying ERAS for their patients. Of the ERAS protocols, preoperative education (91.0%), avoidance of preoperative fasting (68.5%), maintenance of intraoperative normothermia (79.8%), thromboprophylaxis (96.5%), early active ambulation (64.4%), and early removal of urinary catheter (68.5%) were relatively well adopted in perioperative care. However, other practices, such as avoidance of preoperative bowel preparation (41.6%), provision of preoperative carbohydrate-rich drink (10.1%), avoidance of routine abdominal drainage (31.4%), epidural anesthesia (15.9%), single-dose prophylactic antibiotics (19.3%), postoperative high oxygen therapy (36.8%), early postoperative diet (14.6%), restricted intravenous fluid administration (53.9%), and application of discharge criteria (57.3%) were not very well adopted for patients. Conclusions: Perioperative management of gastric cancer surgery is largely heterogeneous among gastric surgeons in South Korea. Standard perioperative care based on scientific evidence needs to be established to improve the quality of surgical care and patient outcomes.

• Journal of odor and indoor environment
• /
• v.17 no.4
• /
• pp.372-380
• /
• 2018

To abate the problem of odor from restaurants, a hybrid adsorbent consisting of organic and inorganic materials was developed and evaluated using acetaldehyde as a model compound was deveioped and evaluated. Powders of activated carbon, bentonite, and calcium hydroxide were mixed and calcinated to form adsorbent structure. The surface area of the hybrid adsorbent was smaller than that of high-quality activated carbon, but its microscopic image showed that contours and pores were developed on its surface. To determine its adsorption capacity, both batch isotherm and continuous flow column experiments were performed, and these results were compared with those using commercially available activated carbon. The isotherm tests showed that the hybrid adsorbent had a capacity 40 times higher than that of the activated carbon. In addition, the column experiments revealed that breakthrough time of the hybrid adsorbent was 2.5 times longer than that of the activated carbon. These experimental results were fitted to numerical simulations by using a homogeneous surface diffusion model (HSDM); the model estimated that the hybrid adsorbent might be able to remove acetaldehyde at a concentration of 40 ppm for a 5-month period. Since various odor compounds are commonly emitted as a mixture when meat is barbecued, it is necessary to conduct a series of experiments and HSDM simulations under various conditions to obtain design parameters for a full-scale device using the hybrid adsorbent.

• Particle and aerosol research
• /
• v.14 no.4
• /
• pp.145-151
• /
• 2018

Rod shaped Potassium hexatitanate ($K_2Ti_6O_{13}$) was synthesized from colloidal mixture of $TiO_2$, KOH and graphene oxide (GO) by aerosol spray drying and post heat treatment. Firstly, $TiO_2-KOH-GO$ composites were fabricated by aerosol spray drying in argon atmosphere. The composites were then calcined to form a rod shaped morphology of potassium titanate (KTO) in the presence of graphene at $900^{\circ}C$ for 3 h in argon atmosphere. Finally, the rod shaped KTO was obtained after removal of graphene (GR) at $800^{\circ}C$ and 3 h in air atmosphere. Characterization of the synthesized $K_2Ti_6O_{13}$ was carried out using the XRD, BET and FE-SEM. The length and diameter of the synthesized $K_2Ti_6O_{13}$ could be controlled by weight fraction of GO in the aerosol precursor. The length of $K_2Ti_6O_{13}$ rod increased with decreasing its diameter as GO concentration increased. The aspect ratio of the synthesized $K_2Ti_6O_{13}$ rod was controlled from 5 to 13.

• Environmental Engineering Research
• /
• v.24 no.3
• /
• pp.521-528
• /
• 2019

Electrochemical method was used for the fracturing flow-back fluid treatment in Guangyuan oilfield. After performing electrolysis, we found that the amount of $H_2$ gas produced by electrode was closely related to the combination mode of electrodes and electrode materials. Using an aluminium electrode resulted in a large $H_2$ production of each electrode combination, whereas inert anode and cathode materials resulted in low $H_2$ production. Then, the relationship between the gas production of $H_2$ and the treatment efficiency of fracturing flow-back fluid in Guangyuan oilfield was studied. Results showed that the turbidity removal and decolourisation rates of fracturing flow-back fluid were high when $H_2$ production was high. If the $H_2$ production of inert electrode was large, the energy consumption of this inert electrode was also high. However, energy consumption when an aluminium anode material was used was lower than that when the inert electrode was used, whereas the corresponding electrode combination production of $H_2$ was larger than that of the inert electrode combination. When the inert electrode was used as anode, the gas production type was mainly $O_2$, and $Cl_2$ was also produced and dissolved in water to form $ClO^-$. $H_2$ production at the cathode was reduced because $ClO^-$ obtained electrons.

• The Research Journal of the Costume Culture
• /
• v.29 no.4
• /
• pp.572-584
• /
• 2021

The emergence of environmental and social issues has led to global discussions for the realization of sustainable development. The purpose of this study is to propose a method of sustainable fashion design using waste Hanbok, focusing on men's Hanbok with cultural values. The study utilizes literature research and fashion design development. From the literature study, reform was judged to be a higher concept encompassing reduction, recycling, and upcycling. Reduction is a design method through removal, and recycling design transforms from its original form into a completely different product. Upcycling design focuses on improvement and change in functionality. Accordingly, nine redesigns using men's Hanbok were developed from which three were produced. Consequently, the reduction design demonstrated a small range of variation without changing the item, and cultural sustainability was confirmed through the design that removed the components and recombined the Hanbok. Second, recycling redesign can be reconstituted into a different item. Third, upcycling enables various designs through module assembly, which prolongs the lifespan of the product and confirms its value as a raw material for waste Hanbok. This study is meaningful in realizing sustainable fashion and suggesting practical measures for the sustainability of Korean traditional culture and creative fashion design planning.