• 상하수도학회지
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• 제19권2호
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• pp.155-160
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• 2005

Gravity thickening process has been widely used in WTP sludge thickening at domestic water treatment plant. The operation method of the process is very simple, however, the process requires long detention time about 24~48 hours for sludge thickening, uses polymer, and low total solids of thickened sludge to increase sludge thickening efficiency. To solve there problems, we studied about flotation process, especially, electro-flotation (EF) process in WTP sludge thickening. Electro-flotation process is simpler than dissolved-air-flotation(DAF) process because EF needs only electrode and current to generate micro-bubbles and the operation is easy. This study was performed at two batch columns to compare interface height, total solids, effluent turbidity between an electro-flotation thickening and a gravity thickening. According to the result, an electro-flotation thickening was that interface height was decreasing, total solids had high concentration, and effluent turbidity was low in comparison with a gravity thickening. Also, it will make the high efficiency of following process, such as a dehydrating process and digestive process. because of high total solids and low moisture content in the sludge.

• 한국환경과학회지
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• 제16권9호
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• pp.1085-1090
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• 2007

The performance of EF (electroflotation) on the thickening of activated sludge were investigated using laboratory scale batch flotation reactor. In this paper, the effects of parameters such as electrode material, NaCl dosage, initial sludge concentration and electrode distance were examined. The results showed that the performance for sludge thickening of the five electrodes lay in: Pt/Ti > Ru/Ti > Ir/Ti > Ti mesh > Ti plate. The more NaCl dosage was high, the more sludge was thickened and the shorter thickening time was obtained. However, considering the final thickening time and sludge concentration, optimum NaCl dosage was 0.5 g/L. Thickening time and sludge concentration was not affected by electrode distance. In DAF (dissolved air flotation) system, optimum recycle ratio was 40% and thickening performance was lower than that of the EF.

• 한국물환경학회지
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• 제20권4호
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• pp.346-351
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• 2004

Because of being produced a great deal of excess sludges from biological wastewater treatment process, the subject regarding treatment and disposal of them has been significantly handled in real plants. It should be considered the alternative treatment with easy operating and cost effective process in rural areas. For the thickening of wasted activated sludge from small scale wastewater treatment facilities, thus, the provisional sludge thickening system was developed by the application of mesh filter module. Three meshes with different pore size(100, 150, $200{\mu}m$) were prepared for filter modules that were used to withdraw effluent from thickening system. A filter module with $100{\mu}m$ mesh was chosen as the most effective thickening material in the viewpoint of volume reduction and effluent quality: the volume reductions of initially injected sludge with 3,600 mg/L and 9,100 mg/L were 95% and 85%, respectively, and the filtered effluents were enough good to be shown below 1.0 mg/L of SS and 1.0 NTU of turbidity. Since the filtration of thickening was influenced by the cake layer formed on mesh filter module and this system was operated in the combination of sludge thickening with gravity settling, the filter modules with smaller pore size and the larger floc size were required for long term operation safely.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.12.1-12.5
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• 2019

Background: Le Fort I osteotomy is one of the surgical procedures now routinely and safely performed. It is possible to move the maxilla in three dimensions, but it is necessary to separate the bones around the maxillary sinus. Therefore, with surgery, maxillary sinus mucosal thickening occurs. By knowing the changes in the sinus mucosa after surgery and the factors affecting it, it is possible to better predict the outcomes of surgery and contribute to safer surgery. In this study, thickening of maxillary sinus mucosa before and after surgery in Le Fort I osteotomy was evaluated using multidetector-row computed tomography (MDCT) images, and the changes in mucosal thickening and the related factors were examined. Methods: Using MDCT images, the maxillary sinus mucosa of 125 patients who had undergone Le Fort I osteotomy was retrospectively evaluated before surgery, 1 month after surgery, and 1 year after surgery. On the MDCT images, the maxillary sinus was judged as mucosal thickening and classified into three grades according to the proportion occupying the maxillary sinus. In the evaluation of factors related to mucosal thickening, the following eight factors were examined: sex, age, diagnosis, operating time, amount of postoperative bleeding, with/without bone graft, with/without multisegmental osteotomy, and with/without macrolide therapy after surgery. Results: The mean age at the time of surgery was 25.6 ± 8 years. Of all 125 patients, 66 had bilateral thickening, 19 had unilateral thickening, and 40 had no thickening. Factors that were significantly related to mucosal thickening were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery. Conclusions: Operative time for the maxilla, bone grafts, and macrolide therapy after surgery were found to be related to mucosal thickening. In addition, MDCT scanning 1 month after surgery was considered to be appropriate for evaluation of maxillary sinus mucosal thickening.

• 상하수도학회지
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• 제19권3호
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• pp.295-300
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• 2005

The performances of electroflotation (EF) on the thickening of activated sludge were investigated using laboratory scale batch flotation reactors. Four activated sludges including bulking sludges were tested. After 30minutes of EF operation, 57-84 % of sludge volume reduction could be achieved by EF, while only about 1.5-14% could be obtained by gravity thickening for the same period. After thickening the effluent water quality in terms of TCOD, SS, and turbidity was improved by EF operation for all sludge samples. It is induced that the air bubbles entrapped in the thickened sludge play a key role in the observed improvement of sludge thickening and effluent quality.

• 한국기계기술학회지
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• 제13권4호
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• pp.23-30
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• 2011

본 연구는 산업용 열교환기 및 상용 파이프의 최적 설계를 위하여 열교환기 내의 사각형 단면 파이프의 shear-thickening 비뉴톤 유체의 압력강하 및 대류 열전달률을 수치해석적으로 수행하였다. shear-thickening 유체의 구성 방정식은 기존의 비뉴톤 유체 멱법칙을 보완한 확장 멱법칙 모델을 채택하였다. 파이프 내의 압력강하를 의미하는 마찰계수와 확장 레이놀즈 수의 곱은 기존 연구의 비교자료와 비교할 때 뉴톤 유체 영역과 멱법칙 영역에서 각각 0.018% 및 0.06% 내에서 일치함을 보였고, 대류 열전달률을 의미하는 뉴셀트 수는 문헌치와 비교할 때 뉴톤 유체 영역과 멱법칙 영역에서 각각 0.025% 및 0.14% 내에서 일치함을 보였다. 비뉴톤 확장 멱법칙 유체 모델의 형태를 띠는 shear-thickening 유체를 열교환기 또는 상용파이프 내의 사각형 단면 파이프 내에서 사용하면 유동지수(n)에 따라서 뉴톤 유체보다 최대 160%의 압력강하를 증가시켰고 최대 14%의 대류 열전달 감소를 발생시킬 수 있었다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제17권2호
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• pp.98-103
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• 2014

Purpose: Gallbladder (GB) wall thickening can be found in various conditions unrelated to intrinsic GB disease. We investigated the predisposing etiologies and the outcome of acalculous GB wall thickening in children. Methods: We retrospectively analyzed 67 children with acalculous GB wall thickening who had visited our institute from June 2010 to June 2013. GB wall thickening was defined as a GB wall diameter > 3.5 mm on abdominal ultrasound examination or computed tomography. Underlying diseases associated with GB wall thickening, treatment, and outcomes were studied. Results: There were 36 boys and 31 girls (mean age, $8.5{\pm}4.8years$ [range, 7 months-16 years]). Systemic infection in 24 patients (35.8%), acute hepatitis in 18 (26.9%), systemic disease in 11 (16.4%), hemophagocytic lymphohistiocytosis in 4 (6.0%), acute pancreatitis in 3 (4.5%), and specific liver disease in 3 (4.5%) predisposed patients to GB wall thickening. Systemic infections were caused by bacteria in 10 patients (41.7%), viruses in 5 patients (20.8%), and fungi in 2 patients (8.3%). Systemic diseases observed were systemic lupus erythematosus in 2, drug-induced hypersensitivity in 2, congestive heart failure in 2, renal disorder in 2. Sixty-one patients (91.0%) received symptomatic treatments or treatment for underlying diseases. Five patients (7.5%) died from underlying diseases. Cholecystectomy was performed in 3 patients during treatment of the underlying disease. Conclusion: A wide range of extracholecystic conditions cause diffuse GB wall thickening that resolves spontaneously or with treatment of underlying diseases. Surgical treatments should be avoided if there are no definite clinical manifestations of cholecystitis.

• 대한핵의학회지
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• 제31권1호
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• pp.43-49
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• 1997

이 연구에서 우리는 관동맥우회로술을 시행한 환자에서 수술 전에 게이트 심근 SPECT에서 심근벽의 수축기 두꺼워짐을 보아 수술 후 심근벽 운동이상의 호전을 예측할 수 있는지 조사하였다. 연구 결과 심근벽의 수축기 두꺼워짐이 좋은 분절은 생존심근이라 할 수 있었으나 심근벽의 수축기 두꺼워짐이 좋지 못하여도 생존심근이 아니라고 단정할 수 없었다. 심근벽 두꺼워짐 여부의 예측능은 심근 관류 감소의 중증도, 심근벽 운동 장애의 정도와 관련이 없었다. 게이트 심근 SPECT로 심근벽 두꺼워짐을 자극할 방법을 도입하고 자극 후 변화를 보는 방법으로 게이트 심근 SPECT를 시행하여 생존심근을 찾는 예민도와 음성예측율을 높일 필요가 있다.

• 대한환경공학회지
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• 제31권8호
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• pp.641-648
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• 2009

본 연구는 미세기포 발생펌프가 장착된 하수슬러지 부상농축 장치를 이용하여 화학적인 개량 및 교반조건에 따른 하수슬러지 부상농축효율을 나타내었다. 하수슬러지의 부상농축은 Gt 값보다는 응집제 종류에 더 큰 영향을 받았다. 응 집제 종류에 따른 하수슬러지 부상농축효율은 $Al_2(SO_4)_3$ < PSO-M < $Fe_2(SO_4)_3$ 응집제 순으로 높게 나타났다. 회분식 실험에서 도출된 운전조건을 이용하여 1.6 $m^3$/d 용량의 하수슬러지 부상농축장치를 2시간동안 연속적으로 운전할 수 있었으며, A/S 비가 0.029~0.019 mL/mg에서 슬러지 농축율은 300.0~335.7%로서 매우 효율적이었다.

• 대한영양사협회학술지
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• 제30권1호
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• pp.11-28
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• 2024

This study aimed to establish the optimal amount of thickening agent for the appropriate viscosity in soups and beverages, which are part of the dysphagia diet. The soups were bean sprout soup and soybean paste soup; the beverages were orange juice, regular milk, and low-fat milk; the thickening agent was one type of xanthan gum product. After adding the thickening agents (from 1 g to 5 g per 200 mL of the test food), syringe tests were conducted over time (5, 10 and 15 minutes) to verify the effects of the amount of thickening agent added per sample and the time between addition and achieving the resulting viscosity, and to establish the optimal addition conditions to reach IDDSI levels 1, 2, and 3 of the dysphagia diet. Water (based on 200 mL) was used as the standard control. These results provide a useful basis for customized diets based on the patient's dysphagia severity. On the other hand, this study is limited by including only liquid foods in the dysphagia diet and one type of xanthan gum-based thickening agent. Therefore, it is necessary to conduct continuous research, based on the study results, to modify the viscosity of the dysphagia diet using various thickening agents and foods and prevent nutritional deficiencies by managing the diet according to the patient's swallowing ability.