http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
방사광을 이용한 FeV<SUB>2</SUB>O<SUB>4</SUB> 스피넬 산화물의 덩치상태와 분말상태의 전자구조 차이 연구
황지훈(Jihoon Hwang),김대현(D. H. Kim),이은숙(Eunsook Lee),강정수(J.-S. Kang),김우철(W. C. Kim),김철성(C. S. Kim),한상욱(S. W. Han),홍순철(S. C. Hong),박병규(B.-G. Park),김재영(J.-Y. Kim) 한국자기학회 2011 韓國磁氣學會誌 Vol.21 No.6
The electronic structure of ferrimagnetic spinel oxide of FeV<SUB>2</SUB>O<SUB>4</SUB> has been investigated by employing soft x-ray absorption spectroscopy (XAS) and soft x-ray magnetic circular dichroism (XMCD). The Fe 2p and V 2p XAS spectra show that the valence states of Fe and V ions are ~Fe<sup>2.3+</sup> mixed-valent states and ~V3+ states, respectively. In Fe 2p XMCD spectra, finite XMCD signals are observed for divalent Fe<sup>2+</sup> states only, but not for Fe<sup>3+</sup> states. This finding indicates that the magnetic moments of Fe<sup>2+</sup> ions are ordered ferromagnetically but that those of Fe<SUP>3+</SUP> ions are cancelled, implying that Fe<sup>2+</sup> ions play an important role in determining magnetic properties of FeV<SUB>2</SUB>O<SUB>4</SUB>.
슬롯밀링시험을 이용한 높은 변형률 속도 조건하에서 Zircaloy-4 의 유동응력 결정
황지훈(Jihoon Hwang),김낙수(Naksoo Kim),이형일(Hyungyil Lee),김동철(Dongchoul Kim) 대한기계학회 2013 大韓機械學會論文集A Vol.37 No.1
핵연료 지지격자 소재로 사용되는 zircaloy-4의 유동응력을 Johnson-Cook 모델로 결정하고, 모델의 재료상수를 역 공학으로 도출했다. 변형률 항의 상수 A, B, n과 변형률 속도 항의 ε? 은 인장시험을 통해 결정했다. 상수 C, m을 역 공학으로 도출하기 위해 슬롯밀링시험을 수행하고, 유한요소해석으로 모사했다. 실험과 해석으로 얻은 결과의 차이를 오차함수, 즉 최소화 대상 목적함수로 설정했고, 이 함수를 최소로 하는 C, m을 도출했다. 도출한 상수의 타당성을 검증하기 위해 상관계수를 살펴봤고, 전단시험과 해석을 수행해 교차 검증했다. 상관계수는 모든 조건에 대해 0.97이상으로 실험과 해석결과 사이에 강한 상관관계가 있음을 확인했다. 전단시험과 해석의 전단면 형상 및 최대하중을 비교하여 도출한 유동응력 모델이 타당함을 보였다. The flow stress of zircaloy-4 used in the spacer grid supporting a nuclear fuel rod was determined by the Johnson-Cook model, and model parameters were determined using reverse engineering. Parameters such as A, B, n and ε? were determined by the tensile test result. To obtain the parameters C and m, a slot milling test and numerical simulation were performed. The objective functions were defined as the difference between the experimental and the simulation results, and then, the parameters were determined by minimizing the objective function. To verify the validity of the determined parameters, cross-verification for each case was conducted through a shearing test and simulation. The results tend to show agreement with the experimental results, such as the features of sheared edges and maximum punch force, with the correlation coefficients exceeding at least 0.97.
단순 포진 감염으로 오인된 자매에서 발생한 소아 얼굴 백선 2 례
황지훈 ( Jihoon Hwang ),강지만 ( Ji-man Kang ),안종균 ( Jong Gyun Ahn ) 대한소아감염학회 2021 Pediatric Infection and Vaccine Vol.28 No.1
얼굴 백선은 얼굴에 발생하는 드문 피부 사상균 감염으로, 붉은 발진과 함께 작은 융기가 있는 피부 병변이 특징적이다. 소아에서 얼굴 백선은 흔하지 않으며 다양한 피부질환과 발진 양상이 유사하여, 단순포진감염, 접촉 피부염, 원판형 홍반성 루푸스, 여드름, 아토피 피부염 등으로 오진 될 수 있다. 본 증례에서는 4살, 3살의 자매가 베트남 여행을 다녀온 후 발생한 피부염으로 본원에 내원하였고, 아토피 피부염에 합병된 단순포진감염을 의심하여 항바이러스제제 및 전신 스테로이드 제제를 투약하였으나, 경과는 호전되지 않았다. 혈액 검사상 혈청 beta-D-glucan 수치가 두 환자 모두에서 상승되어 있었고, 약 2주 후 언니의 피부 진균 배양 검사에서 T. interdigitale이 동정 되었다. 두 환자 모두 국소 및 전신 항진균 요법 후 재발이나 부작용 없이 회복되었다. 소아에서 기존 치료에 반응하지 않는 얼굴의 피부 병변은 반드시 진균 검사를 통해서 얼굴 백선의 가능성을 확인해야 하며, beta-D-glucan 검사는 보조적 수단으로서 얼굴 백선 진단에 도움을 줄 수 있다. Tinea faciei is a rare dermatophyte infection of the face that most often appears as a facial rash, followed by patches of small and raised bumps. Since it is uncommon in children and has similar rash patterns with various skin diseases, it is likely to be misdiagnosed as herpes simplex infection, contact dermatitis, disc-shaped lupus erythematosus, acne, and atopic dermatitis. In this case, siblings aged 3 and 4 were hospitalized due to skin rashes that occurred after traveling to Vietnam, and were administered antiviral drugs and systemic steroids under suspicion of herpes simplex infection with atopic dermatitis. Despite administration of these drugs, skin lesions did not show improvement. Serum beta-D-glucan assays were elevated in both patients, and after approximately 2 weeks, Trichophyton interdigitale was cultured in the older sister's skin fungal culture test. Both patients recovered after local and systemic antifungal therapy, without relapse or side effects. Skin lesions on the face, which do not respond to the existing treatment in children, should be checked for the possibility of tinea faciei through repeated fungal tests, and the beta-D-glucan assay can be a useful tool in diagnosing tinea faciei.
연 X선 방사광 분광법을 이용한 TCr₂O₄(T = Fe, Co, Ni) 스피넬 산화물의 전자구조 연구
김현우(Hyun Woo Kim),황지훈(Jihoon Hwang),김대현(D. H. Kim),이은숙(Eunsook Lee),강정수(J.-S. Kang) 한국자기학회 2013 韓國磁氣學會誌 Vol.23 No.5
The electronic structures of TCr₂O₄ (T = Fe, Co, Ni) spinel oxides have been investigated by employing synchrotron radiation-based soft X ray absorption spectroscopy (XAS). The measured 2p XAS spectra of transition-metal ions reveal that Cr ions are trivalent (Cr<SUP>3+</SUP>), and all the T (T = Fe, Co, Ni) ions are divalent (Fe<SUP>2+</SUP>, Co<SUP>2+</SUP>, Ni<SUP>2+</SUP>). It is also found that most of T (T = Fe, Co, Ni) ions occupy the A sites under the tetrahedral symmetry, while Cr ions occupy mainly the B sites under the octahedral symmetry. These findings show that the structures of TCr₂O₄ (T = Fe, Co, Ni) are very close to the normal spinel structures. Based on these findings, it is expected that Jahn-Teller (JT) effects are important in FeCr₂O₄ and NiCr₂O₄. In contrast, CoCr₂O₄ maintains the cubic structure without having the JT distortion since both Cr<SUP>3+</SUP> and Co<SUP>2+</SUP> ions are non-JT ions. This work suggests that the antiferromagnetic interaction between Cr<SUP>3+</SUP> and T<SUP>2+</SUP> ions plays an important role in determining the magnetic properties of TCr₂O₄ (T = Fe, Co, Ni).
난백 알레르기 환자에서 발생한 식품유발 급성 췌장염 1예
이예슬 ( Yeseul Lee ),황지훈 ( Jihoon Hwang ),김수경 ( Su Kyung Kim ),김미진 ( Mi Jin Kim ),전태연 ( Tae Yeon Jeon ),김지현 ( Jihyun Kim ),안강모 ( Kangmo Ahn ),김지원 ( Jiwon Kim ) 대한천식알레르기학회 2022 Allergy Asthma & Respiratory Disease Vol.10 No.2
Acute pancreatitis (AP) rarely occurs in association with food allergy (FA), and the mechanism is not clearly explored. We herein report a rare case of egg protein-induced AP. A 5-year-old girl was brought to the hospital because of tongue pruritus and an increased level of egg white-specific immunoglobulin E. During an oral food challenge, she developed hives, abdominal pain and vomiting after ingestion of a cumulative of 610 mg of boiled egg white (70 mg of protein). After management with intramuscular injection of epinephrine and orally administered prednisolone and levocetirizine, her skin symptoms improved. The next day, blood tests showed elevated levels of amylase and lipase, and computed tomography revealed a swollen pancreas with a low-attenuated necrotic portion. She was diagnosed with AP and treated with food restriction, intravenous methylprednisolone and gabexate mesilate. The serum levels of amylase and lipase were reduced to normal levels on day 5 and her symptoms completely resolved on day 10. A suspicion of food-induced AP is required for correct diagnosis and proper management in children with FA when they manifest severe abdominal pain. (Allergy Asthma Respir Dis 2022;10:123-126)
김철곤(Cheulgon Kim),황지훈(Jihoon Hwang),서형준(Hyeongjoon Seo),모진용(Jinyong Mo),정두한(Duhan Jung),홍석무(Seokmoo Hong) 대한기계학회 2015 大韓機械學會論文集A Vol.39 No.4
에어컨 실내기 조립 시 부품간 간섭이 발생하는 위치와 원인 분석을 위해, 3차원 공차해석을 수행하고 부품공차 및 조립 갭을 최적화했다. 민감도 분석을 통해 초기 설계에서 drain과 body 조립부의 불량발생 확률이 72.6%로 가장 높은 것을 확인했고, 또한 유한요소해석(FEA)을 활용 에어컨 실내기의 난방작동 시 열 변형으로 인해 최대 약 1mm의 변위가 발생하여 부품간 간섭이 발생할 수 있음을 확인했다. 이런 부품간 간섭을 최소화기 위해서 3D 공차 해석의 민감도 분석결과를 토대로 drain의 부품공차를 수정하였다. 개선 공차 반영 해석결과 불량률이 0.03%로 크게 감소함을 확인하였다. 또한, 개선공차 반영 시 에어컨 작동 중 열 변형이 발생하여도 부품간 간섭이 발생하지 않음을 FEA를 통해 검증하였다. To identify locations and causes of interference among parts of an indoor air-conditioning unit, a 3D tolerance analysis was performed and optimized with respect to assembly gaps and the tolerance of each part . The maximum value of the defect rate resulting from the tolerance analysis was found to be 72.6 at the assembly portion of the body and drain. The maximum displacement caused by the thermal deformation during a heating operation was calculated to be approximately 1 mm by using finite element analysis (FEA). Therefore, it is possible that an interference among the assembled parts occurs. The tolerance of the drain was modified by the results of the sensitivity analysis. As a result, the defect rate was greatly reduced to 0.03. Through the FEA results of the indoor air?conditioning unit , it was shown that the improved tolerance of the drain decreased the interference among the assembled parts even though thermal deformation occurs during operation.