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      • KCI등재

        보조호르몬요법을 받는 여성 유방암 환자의 모발 변화와 치료 실태에 대한 기초 연구

        이재경 ( Jae Kyung Lee ),김창현 ( Chang-hyun Kim ),홍동균 ( Dongkyun Hong ),정경은 ( Kyung Eun Jung ),서영준 ( Young-joon Seo ),김창덕 ( Chang-deok Kim ),이진선 ( Jin Sun Lee ),권인선 ( In Sun Kwon ),박상현 ( Sanghyun Park ),이영 대한피부과학회 2021 대한피부과학회지 Vol.59 No.7

        Background: Hormone therapy, which includes tamoxifen and aromatase inhibitors, is the most common adjuvant therapy used for breast cancer. However, only a few studies have reported endocrine therapy induced alopecia. Objective: We investigated the effects of long-term adjuvant hormone therapy on hair in patients with breast cancer, in addition to patients’ concerns and current treatment for hair loss. Methods: Patients completed a questionnaire that included information on self-perceived hair changes after each adjuvant therapy session, distress, and current treatment for hair loss. Using a folliscope, we measured hair density and thickness in each patient and in healthy controls. Results: The study included 93 patients with breast cancer (mean age 51.9±9.8 years). The density and hair thickness were 106.36±21.85 hairs/cm2 and 0.07±0.01 mm in the patient group and 147.86±30.67 hairs/cm2 and 0.07±0.01 mm in the control group (n=98, mean age 52.10±8.40 years), respectively. The mean hair density was significantly lower in the patient group than in the control group; however, no statistically significant intergroup difference was observed in hair thickness. Among 76 patients who perceived hair changes after adjuvant therapy, 71.1% (n=54) were distressed with regard to hair changes. However, only 7.8% of the patients, including two who were treated by dermatologists, currently received treatment for hair changes. Conclusion: Dermatologists should be familiar with hair changes in patients with breast cancer and provide appropriate education to encourage patients to consult dermatologists for hair loss and thinning after breast cancer treatment. (Korean J Dermatol 2021;59(7):521∼526)

      • KCI등재

        조기 천장골염의 자기공명영상 소견

        김태환 ( Tae Hwan Kim ),전재범 ( Jae Bum Jun ),심승철 ( Seung Cheol Shim ),장대국 ( Dae Kook Chang ),고회관 ( Hee Kwan Koh ),정성수 ( Sung Soo Jung ),이인홍 ( In Hong Lee ),배상철 ( Sang Cheol Bae ),유대현 ( Dae Hyun Yoo ),전의용 대한류마티스학회 1998 대한류마티스학회지 Vol.5 No.2

        목적: 천장골염의 유무가 척추 관절염의 진단에 중요한데 단순 골반 검사에서 변화가 없는 환자를 대상으로 MRI를 이용하여 천장골염의 조기변화 소견 및 MRI방법에 따른 장점을 비교하고자 하였다. 대상 및 방법: 단순 골반 검사에서 천장골염 유무가 확실하게 구분되지 않은 혈청 음성 척추 관절염 환자 26명을 대상으로 MRI를 시행하고 염증의 주침범위치를 천측과 장측, 관절의 상하로 구분하고, MRI방법에 따른 변화를 비교하였다. 결과: 모든 예에서 조영 증강되는 판누스를 관찰할 수 있었고, Grade I 이하에서는 장골측과 관절하부, 인대성 관절보다 활막성 관절을 더 많이 침범하였다. Grade II 이상에서도 장골측과 관절 하부에 더 많았으나 인대성 관절을 Grade I이하에서보다 더 많이 침범하였다. 관절 주변 지방 침착역시 장골측과 관절 하부에 더 주로 침범하였고 Grade II 이상에서 약간 더 많았다. 관절 주변 골염은 Grade 0에서는 없었고, Grade I에서는 주로 장골측과 관절 하부에서 92%가 양성이었고, Grade II에서는 93%에서, Grade III에서는 64%에서 양성으로, 장골측을 주로 침범하였으나 관절 상하부의 구분은 없었다. 인대성 천장골 관절은 Grade I 이하에서 38%, II 이상에서는 94%에서 침범하였다. 관절 주변 골염과 지방 침착, 그리고 판누스의 관찰에는 MPGR보다 스핀에코 영상이 좋았고, 관절면의 불규칙성 또는 관절강의 확대와 관절 강직여부의 관찰에는 스핀에코에 비해 MPGR 영상이 좋았고, 연골하 경화는 비슷하였다. 천장골염의 정도와 ESR, CRP와의 연관성은 없었다. 걸론: 천장골 관절에서 염증의 시작은 주로 장골 측과 관절의 하부에서 먼저 시작되고, 관절이 진행될수록 장골측에서 천골측까지로 범위가 확대 되었다. MRI방법에 의한 차이로 초기단계에는 스핀에코 영상이 관절염을 확인하는데 도움이 되고 관절면이 불규칙하게 되고 경화가 되어 병이 진행된 상태에서는 MPGR영상이 진단에 더 도움이 되었다. 염증성 배부 동통이 있는 경우 단순 골반 검사에서 이상이 없는 환자인 경우에도 MRI 검사를 시행하여 천장골염의 유무를 확인하는 것이 중요하다. Objective: The early detection of sacroiliitis on X-ray is important to diagnose spondyloarthropathy(SpA). The conventional radiography, bone scan, and computer tomogram have the problems of sensitivity, specificity, and side effects. We examined sacroiliitis using MR imaging in patients who had inflammatory back pain, but no definite changes in conventional radiogrphy. Other radiologic techniques were compared in detection of early sacroillitis. Methods: Twenty six patients with SpA were examined. The MRI findings of both sacroiliac joints were evaluated in every patients, such as pannus, periarticular osteitis and fat accumulation, subchondral sclerosis, and joint space changes(irregularity, ankylosis). Also we analyzed the changes of sacroiliac joints in sacroiliitis. Results: The predominant sites of involvement were upper aspect and iliac surface of sacroiliac joint in subchondral sclerosis, lower and iliac in pannus, periarticular fat accumulation, and iliac in periarticular osteitis. The MPGR images were superior to spin echo images in evaluation of joint space changes(irregularity, and ankylosis). Conclusions: Sacroiliitis is initiated in iliac side and lower portion of sacroiliac joints. MRI can detect early changes of sacroiliitis in patients with no conventional radiographic changes. MRI seems to be needed in patients with inflammatory back pain.

      • 백서에서 동종 신경이식시 항 T임파구 단일클론항체 분포에 관한 조직화학적 연구

        홍창섭,김경욱,임창준,정대현 단국대학교 치의학연구소 1991 논문집 Vol.3 No.-

        Nerve allografts as a bridge through which lost nerve can regenerate is useful in the repair of peripheral nerve defect resulting from trauma, neoplasm and leprosy. But immunological rejection and complicated scar formation is an unaboidable problem in the application of allogenic nerves. This article is intended to study histopathological and immunohistochemical response after fresh allogenic sciatic nerve grafts in rats. 12 male Sprague- Dawley rats were used as the experimental animals. A 2cm skin incision was made on the lateral aspects of limb, parallel to the femur. 1cm-long sciatic nerve trunk taken from the one rat was resected at the middle of the to high, and it was transplanted to the same area of the other rat with perineural suture method. Observation was made at the postoperative 1, 3, 8, 16 day. The results were as follows. 1. Histopathologically, destruction of the perineural sheath was observed only in 1-day group. 2. Mild degenerative changes of the nucleus and cytoplasm of Schwann cells were ovserved in the 1-day and 3-day groups. These changes gradually resolved. 3. Hollow space phenomena of the nucleus and cytoplasm of schwann cells were observed. The response was mild in the 1 day and 3 day groups, and moderate in the 8 day group. The phenomena were not identified in the 16 day group. 4. Immunohistochemical studies revealed pan T cells and cytotoxic T cells in the 1 day group. Increased numbers of cytotoxic T Cells and helper T cells were observed in the 3 and 8 day groups. 5. According to these results, after transplantation of fresh allogenic sciatic nerve an inflammatory response was observed up to 8 days and then gradually resolved. Degenerative changes were more severe up to 8 days, but an the 16th day they had resolved histopathologically and immunopathologically.

      • SCIEKCI등재

        Bone Marrow T Cells are Superior to Splenic T Cells to Induce Chimeric Conversion After Non-Myeloablative Bone Marrow Transplantation

        ( Hyun Sil Park ),( Seok Goo Cho ),( Min Jung Park ),( So Youn Min ),( Hong Seok Chang ),( Hee Je Kim ),( Seok Lee ),( Chang Ki Min ),( Jong Wook Lee ),( Woo Sung Min ),( Chun Choo Kim ),( Ho Youn Kim 대한내과학회 2009 The Korean Journal of Internal Medicine Vol.24 No.3

        Background/Aims: The bone marrow functions not only as the primary B-lymphocyte-producing organ but also as a secondary lymphoid organ for CD4 and CD8 cell responses and a site of preferential homing and persistence for memory T cells. Bone marrow T (BM-T) cells are distinguished from peripheral blood T cells by surface phenotype, cytokine secretion profile, and immune functions. In this study, we evaluated the alloreactive potential of donor lymphocyte infusion (DLI) using BM-T cells in mixed chimerism compared to that using spleen T (SP-T) cells. Methods: Cells were prepared using established procedures. BM-T cells were obtained as a by-product of T-cell depletion in BM grafting and then cryopreserved for subsequent DLI. We performed DLI using BM-T cells in allogeneic mixed chimera mice on post-BMT day 21. Results: When the same dose of T cells, 5-10×105 (Thy1.2+), fractionated from BM and spleen were administered into mixed chimeras, the BM-T group showed complete chimeric conversion, with self-limited graftversus-host disease (GVHD) and no pathological changes. However, the SP-T group showed persistent mixed chimerism, with pathological signs of GVHD in the liver and intestine. Conclusions: Our results suggest that DLI using BM-T cells, even in small numbers, is more potent at inducing chimeric conversion in mixed chimerism than DLI using SP-T cells. Further study is needed to determine whether cryopreserved BM-T cells are an effective cell source for DLI to consolidate donor-dominant chimerism in clinical practice without concerns about GVHD. (Korean J Intern Med 2009;24:252-262)

      • KCI등재

        Dangyuja (Citrus grandis Osbeck) Peel Improves Lipid Profiles and Alleviates Hypertension in Rats Fed a High-Fat Diet

        Hyun Ju Hong,Ju Youn Jin,Heekyoung Yang,Won Young Kang,Dong Geon Kim,Sunyi Lee,Younghun Choi,Jae Hoon Kim,Chang Hoon Han,Young Jae Lee 한국실험동물학회 2010 Laboratory Animal Research Vol.26 No.4

        Obesity is a major public health problem and significant risk factor for many serious diseases including coronary artery disease, cancer, and diabetes. This study was performed to investigate the hypolipidemic effects and anti-hypertensive effect of Dangyuja (Citrus grandis Osbeck) peel, which is bred on Jeju island, in rats fed a high-fat diet. This study was conducted on 4 equal rat groups which were fed as follows; normal diet group (ND), high fat diet group (HFD), high fat diet supplemented with powdered peel of Dangyuja (1%, wt/wt) group (HFD+Dangyuja), and high fat diet treated with sibutramine simultaneously at a dose of 10 ㎎/㎏ group (HFD+Sibutramine). After feeding the high fat diet, body weight gain and relative weight of adipose tissues and liver significantly increased in HFD group, but Dangyuja peel supplementation protected these HFD-induced changes. The levels of serum triglyceride, total cholesterol, low-density lipoprotein (LDL)-cholesterol, and the atherogenic index significantly decreased in the HFD+Dangyuja peel group compared with the HFD group. The systolic blood pressure was significantly increased by feeding the high fat diet, whereas the supplementation of Dangyuja peel effectively prevented the elevation of blood pressure. Therefore, these results suggest that Dangyuja exerts a beneficial effect on obesity by improving lipid metabolism and alleviating obesity-related hypertension.

      • Effect of Extreme Heatwaves on the Mortality and Cellular Immune Responses of Purplish Bifurcate Mussel Mytilisepta virgata (Wiegmann, 1837) (=Septifer virgatus) in Indoor Mesocosm Experiments

        Hyun-Ki Hong,Chang Wan Kim,Jeong-Hwa Kim,Nobuhisa Kajino,Kwang-Sik Choi 제주대학교 해양과학연구소 2021 해양과환경연구소 연구논문집 Vol.45 No.-

        In the rocky intertidal environment, the frequency and duration of heatwaves have increased over the last decade, possibly due to global climate change. Heatwaves often result in lethal or sub-lethal disturbances in benthic animals by changing their metabolic activities. In this study, we investigated the impacts of extreme heatwave stress on the hemocyte functions of Mytilisepta virgata and subsequent mortality to gain a better understanding of the potential causes and consequences of mass mortality events in this mussel during summer. We discriminated three types of hemocytes in the hemolymph, granulocytes, hyalinocytes, and blast-like cells, using flow cytometry and revealed that granulocytes were the major hemocyte involved in cellular defensive activities, such as phagocytosis and reactive oxygen species (ROS) production. For the experiment, mussels were exposed to a 40◦C air temperature for 12 h per day over 5 days under laboratory conditions as a simulated semi-diurnal tidal cycle. Mortality began to occur within 3 days after beginning the experiment, and all mussels had died by the end of the experiment. Flow cytometry indicated that the mussels exposed to high air temperatures produced significantly more ROS than did the control mussels within 2 days after the onset of the experiment, which may have caused oxidative stress. Such high levels of ROS in the hemolymph increased DNA damage in hemocytes after 3 days of exposure and decreased the phagocytosis of hemocytes 4 days after the experiment began. The observed mortality and decline in immune capacity suggested that an extreme heat event occurring in the rocky intertidal ecosystem during summer could exert sublethal to lethal impacts on macrobenthic animals.

      • KCI등재

        자궁경부암 조직에서 동시항암화학방사선치료의 반응 예측인자로서 p53, Bc1-2, Bax, Survivin의 분석: 예비보고

        김현진 ( Hyun Jin Kim ),이정필 ( Jung Pil Lee ),박재선 ( Jae Sun Park ),임현이 ( Hyun Ee Lym ),유희석 ( Hee Sug Ryu ),장기홍 ( Ki Hong Chang ) 대한산부인과학회 2008 Obstetrics & Gynecology Science Vol.51 No.2

        목적: 자궁경부암 환자에서 동시항암화학방사선요법 시, 치료 반응에 따른 세포고사 조절 유전자들인 p53, Bc1-2, Bax, Survivin의 발현 양상의 변화를 분석하여 치료 반응을 예측할 수 있는 지표를 확인하고자 한다. 연구방법: 아주대병원 산부인과에서 침윤성 자궁경부암으로 진단 후, weekly cisplatin (40 mg/m2)을 이용한 동시항암화학방사선요법을 받은 환자 14명을 대상으로 하여 치료 시작 전과 2번째, 4번째 항암화학요법 후, 총 3회의 자궁경부 조직생검을 시행하였다. 각 자궁경부 생검 조직에서 면역화학염색과 Western blotting을 시행하고 이들 자궁경부암 조직에서 세포고사 조절 유전자들의 발현 양상을 분석하였으며, 이를 각 환자의 임상병리학적 예후인자들과 비교 분석하였다. 결과: 동시항암화학방사선요법에 반응이 없는 치료 무반응군은 2예 (14.3%)였으며, 이 군에서 p53과 Bax 발현은 치료 전과 치료 중 모두에서 관찰되지 않았으나 Bc1-2와 Survivin은 모두 강한 발현을 보였다. 한편, 완전관해 또는 부분관해를 보인 치료 반응군은 각각 11예 (78.6%), 1예 (7.1%)였으며, 이 군에서 세포고사 조절 유전자 중 Bc1-2 발현은 치료가 진행됨에 따라 감소하는 양상을 보였으며, 다른 단백의 발현은 유의한 변화를 보이지 않았다. 임상병리학적 예후인자들과 면역조직화학적 염색 결과 사이의 상관관계를 분석한 결과, p53, Bc1-2, Bax, Survivin 발현의 변화와 예후인자들 사이에 유의한 상관관계가 없었다. 결론: 본 예비 연구 결과에 따르면, Bcl-2 발현이 동시항암화학방사선요법의 치료 반응을 치료 종결 전에 미리 예측할 수 있는 하나의 지표로 사용될 가능성이 있는 것으로 판단된다. 그러나 이와 같은 가능성을 확립하기 위해서는 앞으로 더 많은 환자군을 대상으로 한 연구가 필요하리라 생각된다. Objective: The objective of this study is to explore changes of the expression of apoptosis-regulating genes, p53, Bc1-2, Bax, and Survivin in cervical cancer tissues during concurrent chemoradiotherapy (CCRT). Methods: The expressions of apoptosis-regulating genes were evaluated in 14 patients with invasive squamous cell carcinoma of the cervix, who underwent 6 cycles of CCRT using weekly cisplatin, with immunohistochemical staining and Western blot of p53, Bc1-2, Bax, Survivin. Specimens of the cervical carcinomas were obtained by punch biopsy before starting CCRT and just after 2nd and 4th cycle of weekly cisplatin. We analysed the results with clinicopathological factors of the patients. Results: Among 14 patients, 2 (14.3%) patients did not respond to CCRT. In these 2 cases, p53 and Bax were not expressed before and during therapy, while the expressions of Bc1-2 and Survivin were increased. Complete response and partial response were obtained in 11 cases (78.6%) and 1 case (7.1%), respectively. In this reponse group, Bc1-2 expressiondecreased seriallyduring the treatment, but the expression ofother apoptosis-regulating genes showed no significant change. There was no correlation between the clinicopathological prognostic factors and expressions of p53, Bc1-2, Bax, and Survivin. Conclusion: In this preliminary study, we deduced that Bc1-2 expression might predict response of CCRT even before completing treatment. In order to establish this possibility, a large scaled study should be needed in the future.

      • 묵논의 식생천이에 관한 연구

        이창석,박현숙,유영한,홍선기 서울여자대학교 자연과학연구소 1998 자연과학연구논문집 Vol.10 No.-

        폐경년도가 다른 묵논에서 식생요인과 환경요인의 변화를 분석하여 천이계열 및 천이의 추진 기작을 밝혔다. 조사지소는 경작 중인 논, 폐경 후 3년(초기 묵논), 7년(중기 묵논) 및 10년째의 묵논(후기 묵논) 및 묵논에 인접한 계곡림(극상림)의 5단계로 구분하였다. 경작 중인 논, 초기 묵논, 중기 묵논, 후기 묵논 및 계곡림에서 각 조사지소의 우점종으로 판단한 천이계열은 뚝새풀군락→사마귀풀군락→갯버들군락→오리나무군락의 순서로 나타났다. 천이단계별 우점종의 분포와 그것의 생활령을 분석하여 파악된 천이의 추진기작은 내성모델을 따르는 것으로 밝혀졌다. 천이단계에 따른 다양성지수의 변화에서 종품부도와 종다양성지수는 초기에 증가하고 중기에 감소하였다가 그 이후 다시 증가하는 경향을 보였으나 균등성지수는 큰 변화가 없었다. 직경급분포도에서 중기 묵논의 갯버들개체군은 정규분포형을, 후기 묵논의 것은 역 J자형을 보여 전자는 그들이 과거적 어느 한 시기에 동시적으로 출현하였음을 반영하고, 후자의 것은 그들이 현재 경쟁상태에 있음을 반영하였다. 후기 묵논에 성립된 오리나 무개체군의 직경급분포도는 역 J자형을 보여 그들이 침입단계에 있음을 반영하였고, 계곡립의 것은 정규분포형을 보여 그들이 안정상태에 있음을 반영하였다. 이러한 식생요인에 대한 분석 결과, 현재 논으로 이용되고 있는 지역의 잠재자연식생은 오리나무군락이 될 것으로 판단되었다. 천이의 진행에 따른 토양환경요인의 변화에서 수분한량은 초기 묵논에서 현저히 증가되었고, 중기 이후의 묵논에서 감소하였다. pH는 큰 변화를 나타때지 않았고, 유기물, N, P, K, Ca 및 Mg함량은 천이의 진행에 따라 증가하는 경향을 보였다. To clarify the vegetational sere and driving mechanism of succession, vegetation and soil environmental factors were investigated in the old paddy field with different in the lapsed years after abandonment, Study sites were divided into 5 stages of the paddy field under cultivation, the old paddy fields of the initial, middle and late stages, and the climax forest of the mountainous valley near to the abandoned paddy fields. Sere estimated from dominant species of above mentioned study sites was shown in the order of Alpecurus aequalis var. amurensis community, Aneilema keisak community, Juncus effusus var. decipiens community, Salix gracilityla community, and Alnus japonica communt. y. Driving mechanism of succession inferred from the distribution of dominant species in each successional stage and their life form was based on the tolerance model. Species richness and diversity indices steadily increased since the middle stage but evenness index did not show any distinct change. In frequency distribution diagrams of diameter classes, Salix gracilistyla population of the middle and the late stages showed normal and reverse J-shaped distribution patterns, respectively. Result of the former reflects that individuals composing of that poulation were invaded simultaneously in a given time of the past and that the latter suggests that they are in state of intraspecific competition. Distribution diagram of Alnus japonica population in the late stage showed reverse J-shaped distribution pattern reflects that those individulas are in the stages of invasion and that of the valley forest showed normal distribution pattern suggests that they are in stable stage. From the results of analyses on those vegetation data, it was interpreted that potential natural vegetation of the present paddy field might be Alnus japonica community. In changes of soil environmental factors with the progression of succession, soil moisture content rapidly increased in the initial stage and then decreased since the middle stage. Organic matter, N. P. K, Ca and Mg contents tended to increase with the succession stage but pH did not show any distinct change.

      • KCI등재

        2 ㎓ 선형 위상 천이 특성을 갖는 소형 아날로그 위상천이기

        오현석(Hyun-Seok Oh),최재홍(Jae-Hong Choi),정해창(Hae-Chang Jeong),허윤성(Yun-Seong Heo),염경환(Kyung-Whan Yeom) 한국전자파학회 2011 한국전자파학회논문지 Vol.22 No.1

        본 논문에서는 2 ㎓ 선형 위상 천이 특성을 갖는 위상천이기를 설계 및 제작하여 보였다. 소형의 위상 천이기 구현을 위해 집중소자로 구성된 전통과 회로망(all pass network)을 기반으로 위상천이기를 구성하고, 박막 세라믹 공정을 이용하여 제작하였다. 또한, 선형의 위상 천이 특성을 얻기 위해 버랙터(varactor) 다이오드에 직렬 커패시터를 연결하여, 전압에 대한 커패시턴스를 선형화함으로써 비선형성을 개선하였다. 전통과 회로망에 나타나는 인덕터는 스파이럴 인덕터로 구현하고, 이를 다이오드 바이어스 회로에 활용하여 4 ㎜×4 ㎜ 면적을 가지는 소형 위상천이기를 구성할 수 있었다. 또한, 온-웨이퍼(on wafer)로 측정을 위해 입출력은 CPW(Coplanar Waveguide) 형상으로 구현하였으며, 제작된 위상천이기는 버랙터 조정 전압 0~5 V에 대하여, 2 ㎓에서 삽입 손실은 약 4.2~4.7 ㏈, 위상 변화량은 약 79°였으며, 예상한대로 선형 위상 천이 특성을 보였다. In this paper, we present a 2 ㎓ compact analog phase shifter with linear phase-tune characteristic. The compact phase shifter was designed base on a lumped all pass network and implemented using a ceramic substrate fabricated with thin-film technique. For a linear phase-tune characteristic, a capacitance of the varactor diode for a tuning voltage was linearized by connecting series capacitor and subsequently produced an almost linear capacitance change. The inductor and bias circuit in the all pass network was implemented using a spiral inductors for small size, which results in the size reduction to 4 ㎜×4 ㎜. In order to measure the phase shifter using the probe station, two CPW pads are included at the input and output. The fabricated phase shifter showed an insertion loss of about 4.2~4.7 ㏈ at 2 ㎓ band and a total 79° phase change for DC control voltage from 0 to 5 V, and showed linear phase-tune characteristic as expected in the design.

      • KCI등재

        가교시스템이 다른 고무재료의 경도에 대한 온도의 영향

        진현호 ( Hyun Ho Jin ),홍창국 ( Chang Kook Hong ),조동련 ( Dong Lyun Cho ),강신영 ( Shin Young Kaang ) 한국고무학회 2008 엘라스토머 및 콤포지트 Vol.43 No.4

        본 연구에서는 다양한 온도에서 고무재료의 경도에 대한 가교시스템의 영향에 대해 고찰하였다. 다양한 가교밀도의 시편을 얻기 위하여, NR과 SBR에 여러 가지 함량의 황 또는 peroxide를 첨가하여 가교하였다. 가교된 고무시편의 온도변화에 따른 경도변화와 가교밀도 변화를 측정하고 상호관계를 고찰하였으며, 시편에 발생하는 온도응력을 측정하여 온도변화에 따른 엔트로피의 변화를 조사하였다. 실온 이상에서 NR과 SBR 시편은 온도가 증가함에 따라 경도가 증가하였으며, 측정된 온도응력도 온도가 증가함에 따라 증가하였다. 그러나 측정조건 내에서 시편의 가교밀도 변화는 온도의 변화에 의해 거의 영향이 없었고 가교시스템에도 무관하였다. In this study, the effects of curing system on the hardness of rubber materials at various temperature were investigated. NR and SBR were compounded with various sulfur or peroxide content, in order to obtain various crosslink densities. The changes of hardness and crosslink density were measured as a function of temperature and the relationship was examined. The thermal stresses were also measured in order to investigate the effect of entropy as a function of temperature. The hardness of NR and SBR compounds increased with increasing temperature above room temperature, and the measured thermal stress increased as temperature increased. However, the crosslink densities were not changed by temperature change.

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