• Membrane and Water Treatment
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• 제3권3호
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• pp.201-209
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• 2012

Membrane separation technologies have some of advantages are considered a better alternative to traditional methods. Research of novel membranes is very vital for covering the higher required of membrane in several purposes like water desalting technology. In this work polyamide-6/cellulose acetate (PA-6/CA) blend membrane was developed according to the wet phase inversion system. The structures of the prepared membranes were examined by scanning electron microscopy (SEM). SEM images showed uniform particles distribution in the prepared membranes. Moreover, SEM images revealed that the membranes have relatively uniform surface (PA-6/CA). PA-6/CA blend membranes systems are evaluated by using synthetic NaCl solution. The separation performance showed that salt rejection increased with increasing of heat treatment of the casted films and it was improved with increasing of operating pressure.

• 유변학
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• 제10권2호
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• pp.57-64
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• 1998

A pultrusion resin impregnation (PRI) die, which has been developed recently in our laboratory, was used to pre-pare various composite system. The continuous fiber reinforced composites of glass fiber/polypropylene(GFPP) and glass fiber/polyamide 6 (GFPA) were first manufactured by means of the PRI die and then cut into chopped pellets of predet-ermined length. These pellets and either virgin or modified thermoplastic resin were melt-mixed by a twin screw extruder to prepare GF/PA/PP and GF/PA/PPMA system. The mechanical properties of these blends were investigated and discussed in terms of their morphological observations. These preliminary results revealed that this new impregnation die could be suc-cessfully applied to produce prepregs suitavle for the final shaping process.

• Tuberculosis and Respiratory Diseases
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• 제60권2호
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• pp.180-186
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• 2006

배경: 다제내성 결핵환자에서 이차약제로 구성된 처방 복약시 특히 PAS는 심한 위장장애 등의 부작용으로 환자의 치료순응도 저하에 중요한 요인이 되므로 균음전 후 PAS를 처방에서 제외한 경우의 치료경과 특히, 치료종결 후 재발율에 대한 조사를 통해 치료경과 중에 적절한 시점에 처방에서 PAS제외 가능성에 대하여 평가하고자 하였다. 방법: 2000년 1월 1일부터 2001년 12월 31일 동안에 국립마산결핵병원에서 입원 혹은 외래치료를 받았던 452명의 다제내성 결핵환자 중에서 처방에 PAS가 포함된 194명 중 심한 위장장애 등의 부작용 때문에 PAS를 중단한 환자 중 균음전 후 PAS를 제외한 처방을 12개월 이상 유지할 수 있었던 42명을 대상으로 임상적 특성 및 치료종결 후 재발율을 분석하였다. 결과: 대상환자의 남녀성비는 2.5:1, 평균나이는 56.2세였다. 1.2회의 과거치료력이 있었으며, 사용한 약제는 평균 3.9제였다. 내성약제수는 평균 4.3제였으며 처방에 포함된 감수성약제수는 평균 3.9제였다. 치료가 시작된 후 균음전시기는 평균 2.3개월째였으며, PAS 중단 시기는 균음전 후 평균 6개월째였다. 31.6개월의 추구관찰 기간 중 재발환자는 없었다. 결론: 새로운 항결핵제의 개발이 요원하고, 다제내성 결핵에 사용가능한 약제가 제한된 현 상황에서 치료순응도 개선방안을 강구하는 것은 치료효율을 높일 수 있는 최선의 방법 중 하나라고 생각되며, 다제내성 결핵환자에서 PAS가 포함된 처방으로 균음전이 되고 환자가 PAS복약에 따른 부작용을 호소하여 치료순응도가 나빠질 것으로 염려가 되면 균음전 후 6개월 즈음에는 PAS를 처방에서 제외할 수 있을 것으로 판단되었다.

• 한국수소및신에너지학회논문집
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• 제25권6호
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• pp.561-569
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• 2014

Ceria ($CeO_2$) was used to increase the durability of the membrane in the polymer electrolyte membrane water electrolysis (PEMWE) circumstance. The sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK) to improve electrochemical characteristics. After sulfonation reaction, the organic-inorganic blended composite membranes were prepared by means of sol-gel casting method with loading the highly dispersed $CeO_2$ and Cs-substituted molybdophosphoric acid (Cs-MoPA) with cross-linking agent (tetrapropyl orthosilicate). Consequently, the composite membrane CL-SPEEK/Silane 4wt%/Cs-MoPA/Ceria(1%) showed the improved characteristics such as 82% of water content, 0.11136 S/cm of proton conductivity at $80^{\circ}C$, 55.50 MPa of tensile strength and 4.37% of breeding out of MoPA.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제17권4호
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• pp.209-213
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• 2014

Purpose: Pathologic aerophagia (PA) may lead to bowel perforation or volvulus in mentally retarded patients. The authors investigated the effects of clonazepam on the management of PA in children with severe to profound mental retardation (MR). Methods: This study was undertaken as a retrospective case analysis of 21 PA patients with MR who were followed for over 12 months and diagnosed as having PA. Patients were assigned to two management groups, that is, to a clonazepam randomized open-labeled, treatment group or a reassurance group. The following were recorded and analyzed; age, response, remission rate to clonazepam treatment, and the side effect of clonazepam. It was defined positive response (response+) as being symptom-free for a whole week within 1 month of commencing treatment and remission(+) as being symptom-free for a whole month within 6 months of treatment. Results: The average age of the 21 PA children with MR was 10 years and 13 patients were female. Symptom duration before diagnosis of PA was 7 months. Clinical features of the clonazepam-trial group (n=11) and the reassurance group (n=10) were non-significantly different. Response(+) was achieved by 2 patients (18.2%) in the clonazepamtrial group and by no patient in the reassurance group. Remission(+) was achieved by 6 patients (54.5%) in the clonazepam-trial group and by one patient (10%) in the reassurance group (p=0.040). Conclusion: When PA children with MR with severe bowel distention are considered for surgical treatment to prevent acute abdomen, a trial of clonazepam could be recommended.

• Natural Product Sciences
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• 제22권4호
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• pp.282-286
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• 2016

Cyanidin-$3{\beta}$-D-glycoside (C3G), which is widely distributed in herbal medicines and functional foods, exhibits anti-inflammatory, anti-oxidant, and anti-scratching behavioral effects. Orally administered C3G is metabolized to protocatechuic acid (PA) by gut microbiota. Therefore, we compared the anti-colitic effect of C3G to that of PA in mice with 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. Orally administered C3G and PA preventively and curatively ameliorated TNBS-induced colitis parameters, including macroscopic colitis score, colon shortening, and increase of myeloperoxidase activity. Treatment with C3G or PA also inhibited the expression of cyclooxygenase-2, inducible NO synthatase, $IL-1{\beta}$, IL-6, and $TNF-{\alpha}$ and the activation of $NF-{\kappa}B$ in the colon of mice with TNBS-induced colitis. Furthermore, these also inhibited lipopolysaccharide-induced $NF-{\kappa}B$ activation and $TNF-{\alpha}$ expression in peritoneal macrophages. The anti-colitic effect of PA was more effective than C3G. Orally administered PA more potently attenuate colitis than C3G by inhibiting $NF-{\kappa}B$ activation and the anti-colitic efficacy of C3G may be dependent on the biotransformation of C3G to PA by gut microbiota.

• Imaging Science in Dentistry
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• 제48권3호
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• pp.161-165
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• 2018

Purpose: To evaluate the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. Materials and Methods: Ten patients with oral and maxillofacial diseases and 28 volunteers drawn from our student doctors were examined by shear wave elastography with a 14-MHz linear transducer using an Aplio 300 apparatus (Canon Medical Systems, Otawara, Japan). A statistical analysis of the shear elastic modulus(kPa) of healthy tissue (the sublingual gland, submandibular gland, anterior belly of the digastric muscle, and geniohyoid muscle) in the 28 volunteers was performed using 1-way repeated measures analysis of variance with the Tukey honest significant difference test. The maximum shear elastic modulus(kPa) of 8 patients with squamous cell carcinoma (SCC) and 2 patients with benign lesions was evaluated with the Mann-Whitney U test. The analysis used a 5% significance level. Results: The mean shear elastic modulus of the sublingual gland ($9.4{\pm}3.7kPa$) was lower than that of the geniohyoid muscle ($19.2{\pm}9.2kPa$, P=.000) and the anterior belly of the digastric muscle ($15.3{\pm}6.1kPa$, P=.004). The maximum shear elastic modulus of the SCCs($109.6{\pm}14.4kPa$) was higher than that of the benign lesions($46.4{\pm}26.8kPa$, P=.044). Conclusion: Our results demonstrated the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. Shear wave elastography has the potential to be an effective technique for the objective and quantitative diagnosis of oral and maxillofacial diseases.

• 대기
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• 제19권1호
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• pp.37-51
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• 2009

Kinematic characteristics of a heavy rainfall event occurred in Changma front are analyzed using synoptic weather charts, satellite imagery and NCEP(National Centers for Environmental Prediction) / NCAR(National Centers for Atmospheric Research) reanalysis data. The heavy rainfall is accompanied with mesoscale rain clouds developing over the Southwest region of Korea during the period from 0300 LST to 2100 LST 25 June 2006. The surface cyclone in the Changma front is generated and developed rapidly when it meets following vertical conditions: The maximum value of relative vorticity is appeared at 700 hPa and is extended gradually near the surface. It is thought that the vertical structure of relative vorticity is closely related with the descent of strong wind zone exceeding $10ms^{-1}$. The jet core at 200 hPa is shifted southward and extended downward and the low-level jet stream associated with upper-level jet stream appeared at 850 hPa. Kinematic features of heavy rainfall system at cyclone-generating point are as follows: In the generating stage of cyclone, the relative vorticity below 850 hPa increased and the convergence below 850 hPa and the divergence at 400 hPa are intensified by southward movement of jet core at 200 hPa. The heavy rainfall system seems to locate to the south of the exit region of upper-level jet streak; In the developing stage of cyclone, the relative vorticity below 850 hPa and the convergence near surface are further strengthened and upward vertical velocity between 850 hPa and 200 hPa is increased.

• Geomechanics and Engineering
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• 제15권1호
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• pp.659-668
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• 2018

A series of direct shear tests were implemented on three different types of specimens (i.e., clean Perth sand, sand containing 10, 20 and 30% bentonite, sand containing 1, 3 and 5% slag, and sand containing 10, 20 and 30% bentonite with increasing percentages of added slag (1%, 3% and 5%). This paper focuses on the shear stress characteristics of clean sand and sand mixtures. The samples were tested under different three normal stresses (100, 150 and 200 kPa) and three curing periods of no curing time, 7 and 14 days. It was observed that the shear stresses of clean sand and mixtures were increased with increasing normal stresses. In addition, the use of slag has improved the shear strength of the sand-slag mixtures; the shear stresses rose from 128.642 kPa in the clean sand at normal stress of 200 kPa to 146.89 kPa, 154 kPa and 161.14 kPa when sand was mixed with 1%, 3% and 5% slag respectively and tested at the same normal stress. Internal friction angle increased from $32.74^{\circ}$ in the clean sand to $34.87^{\circ}$, $37.12^{\circ}$ and $39.4^{\circ}$ when sand was mixed with 1%, 3% and 5% slag respectively and tested at 100, 150, and 200 kPa normal stresses. The cohesion of sand-bentonite mixtures increased from 3.34 kPa in 10% bentonite to 22.9 kPa, 70.6 kPa when sand was mixed with 20% and 30% bentonite respectively. All the mixtures of clean sand, different bentonite and slag contents showed different behaviour; some mixtures exhibited shear stress more than clean sand whereas others showed less than clean sand. The internal friction angle increased, and cohesion decreased with increasing curing time.

• 한국식품과학회지
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• 제29권6호
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• pp.1322-1326
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• 1997

미세캡슐화를 위한 기초 연구로 다양한 다당류의 점도를 측정하고, 분무건조법을 이용하여 미세캡슐을 제조하여 특성을 비교하였다. 10% maltodexrin의 점도는 2.2 mPa.s, 10% gum arabic은 9.2 mPa.s, 10% dextran은 13.0 mPa.s, 1% gum locust bean은 4660.0 mPa.s, 1% gum karaya는 77.0 mPa.s로 측정되었다. 분무건조기를 이용하여 제조한 각종 다당류의 미세캡슐을 전자현미경으로 관찰한 결과, gum arabic은 20%의 농도에 비하며 30%에서 입자가 크게 형성되었으나 40%에서는 섬유상의 늘어진 형태가 관찰되었다. Maltodextrin 30%메서 고른 분포의 원형 입자가 관찰되었으며, 40%의 농도에서는 다양한 크기의 입자가 뭉쳐서 관찰되었다. Dextran은 20%에서 구형의 캡슐이 골고루 관찰되었으나, 30%이상의 농초에 서는 섬유상의 형태가 관찰되었다. Gum arabic : maltodextrin (1:3, w/w) 경우에서는 20%, 30%, 40%농도에서 구형의 캡슐이 고르게 관찰되었고 농도가 높을수록 입자의 크기가 증가하였다.