ɣ-MnO₂를 이용한 메탄올의 친환경적 처리 특성

위지혜,윤형선,서성규 대한환경공학회 2017 대한환경공학회 학술발표논문집 Vol.2017 No.11

송배전관로 되메움재로 활용하기 위한 국내 순환골재의 다짐 및 열적 특성 평가

위지혜,최항석,홍성연,이대수,박상우 한국지반공학회 2011 한국지반공학회논문집 Vol.27 No.7

Recently, the utilization of recycled aggregates for backfilling a power transmission pipeline trench has been considered due to the issues of eco-friendly construction and a lack of natural aggregate resource. It is important to identify the physical and thermal properties of domestic recycled aggregates that can be used as a backfill material. This paper evaluated thermal properties of concrete-based recycled aggregates with various particle size distributions. The thermal properties of the recycled aggregates and river sand provided by local vendors were measured using the transient hot wire method and the transient needle probe method after performing the standard compaction test. The needle probe method considerably overestimated the thermal resistivity of recycled aggregates especially at the dry of optimum water content because of experiencing disturbance while the needle probe is being inserted into the specimen. Similar to silica sand, the thermal resistivity of recycled aggregates decreased when the water content increased at a given dry density. Also, this paper evaluated some of the existing prediction models for the thermal resistivity of recycled aggregates with the experimental data, and developed a new prediction model for recycled aggregates. This study shows that recycled aggregates can be a promising backfill material substituting for natural aggregates when backfilling the power transmission pipeline trench.

Prospective Study on the Characteristics and Postoperative Improvement of Rhinogenic Headache

위지혜,이지은,홍성룡,신재민,김동영 대한비과학회 2015 Journal of rhinology Vol.22 No.1

Background and Objectives:Headache secondary to sinonasal disease can improve after surgery, but few prospective studies have investigated this outcome. We aimed to evaluate the characteristics of headaches, such as clinical features, underlying disease, and postoperative improvement in patients who underwent nasal surgery, and to identify the characteristics that reliably predict rhinogenic headache. Materials and Method:Of 356 patients who underwent nasal surgery between March and December 2009, 41 patients with headaches were enrolled in this prospective study. Clinical features of headache, such as onset, time of day, duration, frequency, nature, side and location, existence of aura, aggravating and relieving factors and accompanying nasal symptoms, underlying diseases, endoscopic findings, and computed tomography scans of the paranasal sinuses were evaluated. Headache intensity was graded based on a 10-point visual analog scale (VAS) pre- and post-operatively. Results:The most common characteristics of rhinogenic headache included a stabbing or squeezing nature, frontal area location, accompanying nasal obstruction or rhinorrhea, and underlying sinusitis or septal deviation. The subjective intensity of the headache, measured using the VAS score, improved in 80% (33/41) of the patients after surgery. Conclusion:Nasal surgery should be considered when rhinogenic headache is suspected and there are definite nasal pathologies.

망간산화물 촉매 제조 방법에 따른 메탄올 완전 산화 특성

위지혜,안호현,서성규 한국대기환경학회 2018 한국대기환경학회 학술대회논문집 Vol.2018 No.10

Inhibition of Allergic Response by Intranasal Selective NF-κB Decoy Oligodeoxynucleotides in a Murine Model of Allergic Rhinitis

위지혜,ZHANGYULIAN,이채서,김동영 대한천식알레르기학회 2017 Allergy, Asthma & Immunology Research Vol.9 No.1

Purpose: It remains unknown whether local inhibition of Nuclear factor-kappa B (NF-κB) could have therapeutic value in the treatment of allergic rhinitis (AR). This study aimed to evaluate the effect of selective NF-κB inhibition using NF-κB decoy oligodeoxynucleotides (ODNs) for the local treatment of AR in ovalbumin (OVA)-sensitized wild-type mice. Methods: BALB/c mice were sensitized with OVA and alum, and then challenged intranasally with OVA. NF-κB decoy ODNs were given intranasally to the treatment group, and NF-κB scrambled ODNs were given to the sham treatment group. Allergic symptom scores, eosinophil infiltration, cytokine levels in the nasal mucosa, nasal lavage fluid, and spleen cell culture, serum total and OVA-specific immunoglobulins, as well as intercellular adhesion molecure-1 (ICAM-1) in the nasal mucosa, were analyzed. Results: NF- κB decoy ODNs significantly reduced allergic symptoms and eosinophil infiltration in the nasal mucosa. They also suppressed serum levels of total IgE, OVA-specific IgE, and IgG1. IL-5 and TNF-α levels and the expression of ICAM-1 were decreased in the nasal mucosa of the treatment group compared to the positive control and sham treatment groups. In addition, IL-6 levels were significantly decreased in the nasal lavage fluid of the treatment group. Furthermore, NF-κB decoy ODNs significantly reduced expression of the systemic Th2 cytokines, IL-4 and IL-5 in spleen cell culture. Conclusions: This study demonstrates for the first time that local NF-κB inhibition using NF-κB decoy ODNs suppressed the allergic response in a murine AR model. This shows the therapeutic potential of local NF-κB inhibition in the control of AR.

Thermal Resistivity Measurement of Recycled Aggregates and Comparison with Conventional Prediction Model

위지혜(Wi, Jihae),홍성연(Hong, Sungyun),최항석(Choi, Hangseok) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.11

Use of recycled aggregates that are constituents of concrete or asphalt-based structures has become popular because the recycling is an eco-friendly way to overcome the depletion of natural aggregates. In order to adopt the recycled aggregates for backfilling a power transmission pipeline trench, their thermal resistivity should be low enough to prevent thermal runaway in the transmission system. In this study, a series of laboratory tests with QTM-500 and KD2 Pro was performed to measure the thermal resistivity of recycled aggregates prepared from various sources. Relationships between the thermal resistivity of recycled aggregates and the water content have been obtained with consideration of compaction effort. Similar to natural soils, the thermal resistivity of the recycled aggregates decreases with increasing the water content. In addition, this study compared the experimental data with conventional prediction models for the thermal resistivity in the literature, which suggests the availability of the recycled aggregates as backfill material substituting for natural aggregates when backfilling the power transmission pipeline trench.

AMO 촉매를 이용한 메탄올의 저온 산화 특성

위지혜, 이상득, 서성규 전남대학교 연안환경문제연구소 2017 環境硏究論文集 Vol.17 No.-

Effect of Lifestyle Modification Using a Smartphone Application on Obesity With Obstructive Sleep Apnea: A Short-term, Randomized Controlled Study

조성우,위지혜,유수영,허은영,류보림,김유정,이중식,김정훈 대한이비인후과학회 2018 Clinical and Experimental Otorhinolaryngology Vol.11 No.3

Objectives. To investigate the short-term effects of a lifestyle modification intervention based on a mobile application (app) linked to a hospital electronic medical record (EMR) system on weight reduction and obstructive sleep apnea (OSA). Methods. We prospectively enrolled adults (aged >20 years) with witnessed snoring or sleep apnea from a sleep clinic. The patients were randomized into the app user (n=24) and control (n=23) groups. The mobile app was designed to collect daily lifestyle data by wearing a wrist activity tracker and reporting dietary intake. A summary of the lifestyle data was displayed on the hospital EMR and was reviewed. In the control group, the lifestyle modification was performed as per usual practice. All participants underwent peripheral arterial tonometry (WatchPAT) and body mass index (BMI) measurements at baseline and after 4 weeks of follow-up. Results. Age and BMI did not differ significantly between the two groups. While we observed a significant decrease in the BMI of both groups, the decrease was greater in the app user group (P<0.001). Apnea-hypopnea index, respiratory distress index, and oxygenation distress index did not change significantly in both groups. However, the proportion of sleep spent snoring at >45 dB was significantly improved in the app user group alone (P=0.014). In either group, among the participants with successful weight reduction, the apnea-hypopnea index was significantly reduced after 4 weeks (P=0.015). Multiple regression analyses showed that a reduction in the apnea-hypopnea index was significantly associated with BMI. Conclusion. Although a short-term lifestyle modification approach using a mobile app was more effective in achieving weight reduction, improvement in OSA was not so significant. Long-term efficacy of this mobile app should be evaluated in the future studies.

수평형 지중열교환기 설계를 위한 토양 열전도도 예측 모델 평가

손병후,위지혜,박상우,임지희,최항석 한국지반공학회 2013 한국지반공학회논문집 Vol.29 No.2

Among the various thermal properties, thermal conductivity of soils is one of the most important parameters to design a horizontal ground heat exchanger for ground-coupled heat pump systems. It is well known that the thermal conductivity of soil is strongly influenced by its density and water content because of its particulate structure. This paper evaluates some of the well-known prediction models for the thermal conductivity of particulate media such as soils along with the experimental results. The semi-theoretical models for two-component materials were found inappropriate to estimate the thermal conductivity of dry soils. It comes out that the model developed by Cote and Konrad provides the best overall prediction for unsaturated sands available in the literature. Also, a parametric analysis is conducted to investigate the effect of thermal conductivity, water content and soil type on the horizontal ground heat exchanger design. The results show that a design pipe length for the horizontal ground heat exchanger can be reduced with an increase in soil thermal conductivity. The current research concludes that the dimension of the horizontal ground heat exchanger can be reduced to a certain extent by backfilling materials with a higher thermal conductivity of solid particles.

수직 밀폐형 지중열교환기 뒤채움재로서 시멘트 그라우트의 적용성 검토 수직 밀폐형 지중열교환기 뒤채움재로서 시멘트 그라우트의 적용성 검토

박문서,위지혜,이철호,최항석,강신형 한국지반공학회 2010 한국지반공학회논문집 Vol.26 No.7

In this paper, the applicability of cement grout has been studied as an alternative to bentontite grout to backfill ground heat exchangers. To provide an optimal mixture design, the groutabilty and thermal conductivity of cement grouts with various mixture ratios were experimentally evaluated and compared. The unconfined compression strength of cement grout specimen was measured, which was exposed to cyclic temperature variation ranging from 50℃ to -5℃. In addition, the integrity of the interface between circulating HDPE pipes and cement grout was evaluated by performing equivalent hydraulic conductivity tests, on the specimen, in which a pipe locates at the center of the specimen.