Cr₂O₃/AP 복합체 제조 및 그 열분해 특성

정재윤,김재경,심홍민,김현수,구기갑,Jung, Jae-Yun,Kim, Jae-Kyeong,Shim, Hong-Min,Kim, Hyoun-Soo,Koo, Kee-Kahb 한국공업화학회 2015 공업화학 Vol.26 No.2

Solvent/anti-solvent법으로 제조된 $Cr_2O_3$/과염소산암모늄 에너지 복합체의 X선 회절 분석 결과 $Cr_2O_3$이 내포된 과염소산암모늄 입자는 순수한 과염소산암모늄과 동일한 결정 구조로 확인되었으며 주사전자현미경 사진으로부터 측정된 입방체 형상 결정의 평균입도는 약 $2.5{\mu}m$이었다. 복합체의 열중량 분석으로부터 $Cr_2O_3$에 의해 과염소산암모늄의 고온 분해 영역 분해 온도가 낮아짐을 알 수 있었고, 복합체 분해 반응의 활성화 에너지는 Starlink 방법에 의해 계산되었다. 이와 같은 활성화 에너지의 변화로 인하여, 과염소산암모늄의 분해 반응 메카니즘은 전환율 약 0.25까지는 주로 핵생성에 의한 다공성 구조가 생성되면서 분해되는 것으로 보이며, 전환율 0.3 이상에서는 과염소산암모늄의 격렬한 분해 반응이 승화보다 우선하는 것으로 보인다. $Cr_2O_3/AP$ (ammonium perchlorate) energetic composites were prepared by a method of solvent/anti-solvent. XRD analysis revealed that the crystalline structure of AP in $Cr_2O_3/AP$ composites is the same as that of pure AP. SEM photomicrograph shows that an average size of cuboid $Cr_2O_3/AP$ composites is approximately $2.5{\mu}m$. TGA analysis shows that the addition of submicron $Cr_2O_3$ particles into AP lowers the HTD (high-temperature decomposition) compared to that of neat AP and the activation energy of the $Cr_2O_3/AP$ composites was calculated by the isoconversional Starlink method. Considering changes in the activation energy, the decomposition reaction mechanism of AP was suggested as follows; the decomposition with the formation of nucleation sites renders formation of porous structure in the composites up to conversion of about 0.25 and after further conversion of over 0.3, it seems that decomposition reaction vigorously takes place rather than sublimation of AP.

Classical Swine Fever Virus gp55 항원에 대한 Muscle Fluid 항체 측정

정재윤,정병렬,김봉환,Jung, Jae-yun,Jung, Byeong-yeal,Kim, Bong-hwan 대한수의학회 2003 大韓獸醫學會誌 Vol.43 No.2

The objective of the present study was to investigate the use of fluid released from muscle samples as an alternative to serum for ELISA to detect classical swine fever(CSF) virus antibodies in slaughter pigs. The optimal correspondence between serum 1:20 OD values and muscle fluid OD values was achieved at a muscle fluid dilution of 1:2. Significant correlation was found between serum and neck muscle ELISA ($r_s=0.880$, p<0.0001, ${\kappa}=0.82$; specificity of 97.0% and sensitivity 90.6%). The semimembranous muscle showed similar correlation in CSF ELISA($r_s=0.877$, p<0.0001, ${\kappa}=0.75$; specificity of 94.1% and sensitivity 89.1%). High correlation was obtained between serum and mesenteric lymph node in the CSF ELISA ($r_s=0.937$, p<0.0001, ${\kappa}=0.87$; specificity of 97.1% and sensitivity 93.0%). Measmement agreement between serum ELISA and muscle fluid ELISA was calculated and expressed as limits of agreement. The correspondence of ELISA of serum and muscle fluid indicated limits of agreement. Above 95% of all muscle fluid values were distributed within this limits of agreement. Among the samples used for ELISA for detecting CSFV antibodies, mesenteric lymph node had the most correlation and agreement with serum ELISA. F-test for comparison of variances showed no significant difference between the serum and muscle fluid. In conclusion, muscle fluid is a useful postmortem alternative to serum to detect CSFV antibodies.

천추 척색종의 수술적 치료 후 장기 추시 결과

정재윤,이재준,서형연,정성택,Chung, Jae-Yoon,Lee, Jae-Joon,Seo, Hyoung-Yeon,Jung, Sung-Taek 대한근골격종양학회 2005 대한골관절종양학회지 Vol.11 No.2

목적: 천추에 발생한 척색종에 대해 수술적 치료를 시행했던 환자들의 장기 추시 결과를 알아보고자 하였다. 대상 및 방법: 천추 척색종으로 수술을 시행받았던 4예를 대상으로 하였으며, 평균 추시 기간은 8.3년(3~11)이었다. 3예에서 후방 도달법을, 1예에서는 전후방 도달법을 통해 종양의 완전 절제를 시행하였으며, 1예에서 제 2천추 신경근 이상을, 3예에서 제 3천추 신경근 이상을 보존하였다. 술 후 배뇨, 배변 장애 유무를 포함한 하지의 운동, 감각 장애 유무를 평가하였고 수술 부위 감염 등의 합병증과 추시상 국소적인 재발 및 원거리 전이 유무를 조사하였다. 결과: 전 예에서 술 후 하지의 운동 장애는 없었으나 1예에서 우하지의 방사통이 심하였고, 1예에서 수술창의 감염이 있었다. 술 후 배뇨 기능은 2예에서 정상이었고 1예에서는 간헐적 요실금을, 1예에서는 지속적인 자가 도뇨를 시행하였다. 배변 기능은 1예에서 정상이었고, 2예에서는 변비를 보였다. 추시상 1예에서 재발 및 전이가 없었고, 1예에서 수술 부위의 재발이, 1예에서 원거리 전이 및 수술 부위의 재발이 있었다. 결론: 천추에 발생한 척색종에 대하여 수술적 절제 후 평균 8년 이상의 생존으로 만족할 만한 결과를 보였으며, 조기 발견을 통한 적극적인 수술적 치료가 상부 천추 신경근의 보존으로 기능 소실의 최소화와 함께 생존을 연장할 수 있는 방법으로 생각된다. Purpose: To evaluate the long term results of surgical treatment for sacral chordoma. Material and Method: We reviewed the records of 4 patients with sacral tumor treated surgical resection. Mean follow-up duration was 8.3 year(3~11). All cases were performed complete resection of tumor mass through posterior approach in 3 cases and anterior-posterior approach in one. The most caudad nerve-roots spared were the second sacral roots in one and the third sacral roots in 3 cases. Functions of voiding and defecation including neurological symptoms of lower extremities, other complications of surgical treatment, and local recurrence or distant metastasis of tumor were evaluated. Result: There was no motor deficit in all cases, but radiating pain was developed in one and wound infection in one. Bladder function was preserved in 2 cases, intermittent incontinence in one, and doing intermittent catheterization in one. Bowel function was preserved in one and 2 cases were suffered from constipation. At the last follow-up, disease-free was in one, local recurrence in one, and local recurrence with distant metastasis in one. Conclusion: The result of surgical resection for sacral chordoma is satisfactory showing average 8 years survival. Early detection and aggressive surgical treatment is the best to prolong survival and to minimize functional deficit with preservation of upper sacral nerves.

이동벽면에 의한 원형 실린더의 지면효과에 관한 전산연구

정재윤,장조원,Jung, Jae-Yoon,Chang, Jo-Won 한국항공운항학회 2006 한국항공운항학회지 Vol.14 No.4

A computational study was carried out in order to investigate the ground effect of a circular cylinder in the presence of a moving wall at a Reynolds number of 2.0${\times}$104. The viscous-incompressible Navier-Stokes equations and Spalart-Allmaras turbulent model of the commercial CFD code were adopted for this numerical analysis. The moving wall was set parallel with the freestream, and the speed of motion was equal to the freestream velocity. The gap ratio is defined as the distance ratio between the circular cylinder diameter and the height from the moving wall. The numerical results show that there are the differences among the each of the stages in evidence of the vorticity contours and the polar diagrams of $C_l$ vs. $C_d$. The 4 stages of the gap ratio are defined according to the flow features, whose stages are divided into small, intermediate, large and convergence gap ratios, respectively.

경추에서 발생한 호산구 육아종의 수술적 치료 - 3예 보고 -

정재윤,이재준,김종선,정성택,Chung, Jae-Yoon,Lee, Jae-Joon,Kim, Jong-Seon,Jung, Sung-Taek 대한근골격종양학회 2006 대한골관절종양학회지 Vol.12 No.2

척추에서의 호산구 육아종은 흔하지 않으며, 특히 경추 및 후방 신경궁에서의 발생은 드물다. 또한 호산구 육아종은 자기 공명 영상을 포함한 방사선학적 검사상 추체의 붕괴, 척추경의 소실 및 척추 주변 연부 조직의 종물 형성 등의 소견을 보이므로 다른 악성 골종양이나 전이성 종양 또는 결핵성 척추염 등과 감별을 요한다. 저자들은 각각 제 4 경추, 제 7 경추의 후방 신경궁, 그리고 제 4 경추체에서 발생한 호산구 육아종에 대하여 수술적 치료 후 완치를 보인 3례를 경험하였기에 문헌 고찰과 함께 보고하고자 한다. The involvement in the spine of eosinophilic granuloma is not common. Especially, involvement of cervical spine and posterior neural arch is quite rare. In addition, radiographic findings including magnetic resonance images of eosinophilic granuloma are manifested as vertebral body collapse, loss of pedicle and paravertebral soft mass formation; it must be differentiated with other conditions, such as malignant bone tumor, metastatic cancer or tuberculous spondylitis. We experienced three cases of eosinophilic granuloma involving posterior neural arch of C4, C7, and body of C4 respectively, which were performed surgical treatment and achieved complete healing. We report these cases with review of literatures.

치매유발제인 알루미늄으로 손상된 배양 C6 Glioma 세포에 대한 금은화 추출물의 보호 효과

정재윤,정인주,제갈승주,Jung, Jai-Yun,Jung, In-Ju,Jekal, Seung-Joo 대한임상검사과학회 2017 대한임상검사과학회지(KJCLS) Vol.49 No.3

This study was performed to evaluate the cytotoxicity of aluminum chloride ($AlCl_3$), and the protective effect of Lonicerae flos (LF) extract on $AlCl_3-induced$ cytotoxicity in the cultured C6 glioma cells. Here, the cell viability and antioxidative effects, such as DPPH-radical scavenging activity, superoxide anion scavenging activity, and lipid peroxidation (LP), were assessed. $AlCl_3$ significantly decreased the cell viability in a dose-dependent manner; the $XTT_{50}$ value was measured at $128.8{\mu}M$ of $AlCl_3$. The cytotoxicity of $AlCl_3$ was determined as highly toxic the y Borenfreund and Puerner's toxic criteria. The butylated hydroxytoluene (BHT) and antioxidant both significantly increased the cell viability, which was damaged by $AlCl_3-induced$ cytotoxicity in these cultures. In the protective effect of LF extract on $AlCl_3-induced$ cytotoxicity, the LF extract significantly increased the superoxide anion scavenging activity and inhibitory activity of LP, as well as the DPPH-radical scavenging activity. From these results, it is suggested that the oxidative stress may have been involved in the cytotoxicity of $AlCl_3$, and LP extract effectively protected $AlCl_3-induced$ cytotoxicity through the antioxidative effects. Conclusively, the natural resources, like LP extract, may be a putative therapeutic agent for the treatment of dementia induced by allergen like aluminum correlated with the oxidative stress.

이상 트래픽 탐지를 위한 로버스트 추정 방법 비교 연구

정재윤,김삼용,Jung, Jae-Yoon,Kim, Sahm 한국통계학회 2011 Communications for statistical applications and me Vol.18 No.4

본 연구는 이상치가 존재하는 자료에 적용될 수 있는 방법을 비교한 연구로서, 이분산 시계열 모형 하에서 로버스트 추정 방법의 효용성을 보이고자 한다. GARCH 모형하에서 이상치 탐지 기법과 GARCH 모형을기반한 로버스트 추정방법의 성능을 비교하였다. 실제 인터넷 트래픽 자료에 두 방법을 적용했을때, 로버스트 추정방법이 이상치 탐지 기법에 비해 덜 복잡하고 성능이 우수함을 입증하였다. This paper shows the performance evaluation of a robust estimator based on the GARCH model. We first introduce the method of a robust estimate in the GARCH model and the method of an outlier detection in the GARCH model. The results of the real internet traffic data show the out-performance of the robust estimator over the outlier detection method in the GARCH model. In addition, the method of the robust estimate is less complex than the method of the outlier detection method in the GARCH model.

이개에 발생한 모낭암종 1예

정재윤(Jae-Yun Jung),박으뜸(Euteum Park),이기일(Ki-Il Lee) 대한두경부종양학회 2006 대한두경부 종양학회지 Vol.22 No.2

Trichilemmal carcinoma is a rare malignant neoplasm of the hair follicle from the outer root of the hair follicle sheath. This tumor can be misleading, and a false diagnosis of a squamous cell carcinoma. We report a case of trichilemmal carcinoma with a review of literature. The patient presented with an exophytic well circumscribed nodular mass on the left auricle, which was detected 6 months ago. Histopathologically, the tumor consisted of atypical clear cells which contained abundant glycogen. The tumor cells shows lobular growth pattern with necrosis, foci of trichilemmal keratinization and peripheral pallisading. Total excision and repair with full-thickness skin graft was done with minimal surgical morbidity. The patient has been free of recurrence or metastasis for 8 months.

보문 : 모발염색제 성분인 초산납에 대한 어성초 추출물의 항산화 및 미백효과

정재윤 ( Jai Yun Jung ),오영희 ( Young Hee Oh ),박신희 ( Shin Hee Park ),윤미영 ( Mi Young Yoon ),표애자 ( Ae Ja Pyo ),김선주 ( Sun Ju Kim ),유영월 ( Yeong Wol Yu ),정인주 ( In Ju Jung ) 대한미용학회(구 대한미용과학회) 2014 대한미용학회지 Vol.10 No.2

To evaluate the antioxidative and whitening effects of Houttuynia cordata Thunb (HCT) extract on lead acetate (LA), hair dye component, cell viability was measured by colorimetric assay after NIH3T3 fibroblasts were cultured in media containing various concentrations of LA. And also, the effect of antioxidant, vitamin E on LA-induced cytotoxicity was analysed. For the protective effect of HCT extract on LA-induced cytotoxicity, NIH3T3 fibroblasts were pretreated with 110 or 130 μg/mL of HCT extract for 2 h before the treatment of LA. And also, the antioxidative and melanogenic effects of HCT extract were assessed by superoxide dismutase (SOD)-like activity, total amount of melanin and tyrosinase activity. In this study, LA significantly decreased cell viability in dose-dependent manner. And the XTT50 value was calculated at 48.3 μM of LA. In the effect of antioxidant, vitamin E, it effectively prevented LA-induced cytotoxicity by the significant increase of cell viability. In the protective effect of HCT extract on LA-induced cytotoxicity, HCT extract significantly increased cell viability which was decreased by the cytotoxicity induced by LA, and also it showed the antioxidative effect by SOD-like activity. In the melanogenesis, HCT extract showed the decreased of amount of melanin and tyrosinase activity. From these results, it is suggested that the cytotoxicity of LA is involved in oxidative stress, and HCT extract effectively prevented the cytotoxicity and the melanogenesis induced by LA.

기술논문(技術論文) : 공기정화 살균기 개발 및 성능검증 연구

정재윤 ( Jae Yoon Jung ),장조원 ( Jo Won Chang ) 한국항공운항학회 2006 한국항공운항학회지 Vol.14 No.3