• 제목/요약/키워드: Physical presence

검색결과 938건 처리시간 0.027초

평면이방성 Mohr-Coulomb 암석 강도의 중간주응력 의존성 (Intermediate Principal Stress Dependency in Strength of Transversely Isotropic Mohr-Coulomb Rock)

  • 이연규
    • 터널과지하공간
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    • 제23권5호
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    • pp.383-391
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    • 2013
  • 1960년대 후반 이래로 수행된 여러 진삼축압축시험 결과에 의하면 암석의 파괴강도는 중간주응력의 크기에 상당한 영향을 받는 것으로 나타나고 있다. 이러한 실험적 결과를 바탕으로 지금까지 중간주응력이 파괴에 미치는 영향을 고려할 수 있는 다양한 3차원 파괴조건식들이 제안되고 있다. 그러나 문헌에 보고된 대부분의 3차원 파괴기준식들은 암석의 진삼축압축 강도를 현상학적으로 재현하기 위한 목적으로 개발되었기 때문에 관련된 강도정수들의 역학적 의미가 명확하지 않다. 이 연구에서는 암석강도의 중간주응력 의존성이 암석 내에 포함된 연약면들의 공간적 분포특성과 관련성이 있다는 가능성을 확인하기 위해 평면이방성 암석모델을 대상으로 수치 진삼축압축시험을 수행하였다. 미소구조텐서 개념을 활용하여 이방성 Mohr-Coulomb 파괴기준식을 개발하였으며 이를 강도기준식으로 활용하고 임계면법을 적용하여 평면이방성 암석의 파괴강도 및 파괴면 방향의 중간주응력 의존성을 분석하였다. 분석결과는 암석에 포함된 미시적 연약면들의 주응력 방향에 대한 방향성이 암석강도의 중간주응력 의존성과 밀접한 관련성이 있음을 암시해준다.

대기오염에 의한 폐장조직 손상 -연구방향의 설정을 위한 논의- (Human Lung Insults due Air Pollutant -A Review for Priority Setting in the Research-)

  • 김건열;백도명
    • 환경위생공학
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    • 제7권2호
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    • pp.95-110
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    • 1992
  • Much progress has been made in understanding the subcellular events of the human lung injuries after acute exposure to environmental air pollutants. Host of those events represent oxidative damages mediated by reactive oxygen species such as superoxide, hydrogen peroxide, and the hydroxy, free radical. Recently, nitric oxide (NO) was found to be endogenously produced by endothelial cells and cells of the reticulo-endothelial system as endothelialderived relaxation factor (EDRF) which is a vasoactive and neurotransmitter substance. Together with superoxide, NO can form another strong oxidant, peroxonitrite. The relative importance of exogenous sources of $N0/N0_2$ and endogenous production of NO by the EDRF producing enzymes in the oxidative stresses to the heman lung has to be elucidated. The exact events leading to chronic irreversible damage are still yet to be known. From chronic exposure to oxidant gases, progressive epithelial and interstitial damages develop. Type I epithelial cells become thicker and cover a smaller average alveolar surface area while thee II cells proliferate instead. Under acute damages, the extent of loss of the alveolar epithelial cell lining, especially type II cells appears to be a good predictor of the ensuing irreversible damage to alveolar compartment. Interstitial matrix undergo remodeling during chronic exposure with increased collagen fibers and interstitial fibroblasts. However, Inany of these changes can be reversed after cessation of exposure. Among chronic lung injuries, genetic damages and repair responses received particular attention in view of the known increased lung cancer risks from exposure to several air pollutants. Heavy metals from foundry emission, automobile traffics, and total suspended particulate, especially polycystic aromatic hydrocarbons have been positively linked with the development of lung cancer. Asbestos in another air pollutant with known risk of lung cancer and mesothelioma, but asbestos fibers are nonauthentic in most bioassays. Studies using the electron spin resonance spin trapping method show that the presence of iron in asbestos accelerates the production of the hydroxy, radical in vitro. Interactions of these reactive oxygen species with particular cellular components and disruption of cell defense mechanisms still await further studies to elucidate the carcinogenic potential of asbestos fibers of different size and chemical composition. The distribution of inhaled pollutants and the magnitude of their eventual effects on the respiratory tract are determined by pollutant-independent physical factors such as anatomy of the respiratory tract and level and pattern of breathing, as well as by pollutant-specific phyco-chemical factors such as the reactivity, solubility, and diffusivity of the foreign gas in mucus, blood and tissue. Many of these individual factors determining dose can be quantified in vitro. However, mathematical models based on these factors should be validated for its integrity by using data from intact human lungs.

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정신과 외래환자의 자가간호수행 및 가족기능과 가족 부담감의 관계 (A study on the Family Caregiver Burden for Psychiatric Out-Patients)

  • 김연희
    • 지역사회간호학회지
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    • 제5권1호
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    • pp.64-80
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    • 1994
  • The purpose of this study was to identify factors affecting family caregiver burden, and to identify the relationship between family caregiver burden and family function /self-care of psychiatric out-patient. These data were collected by questionnaire from September 20 to October 8, 1993. The subjects were 285 family caregiver of psychiatric out-patients. The instruments used in this study were Caregiver Burden Inventory(CBI) by Novak(1989), self-care performing by Yu(1992), and Family APGAR by Smilkstein(1979). The data were analyzed by cronbach's $\alpha$, mean, standard deviation, percentage, t-test, ANOVA, Pearson's correlation coefficient, and Stepwise Multiple Regression with SPSS /pc+ program. The result of this study were as follows ; 1. The means of family caregiver Burden revealed total 2.00, Time-Dependence Burden 78, developmental Burden 2.22, physical Burden 1.90, social Burden 1.43, emotional Burden 2.18, financial Burden 1.51. family caregiver burden score showed moderate level. time-dependence burden showed the highest score and social burden showed the lowest score. 2. The means of family function revealed total 5.67. 7 through high-21.4% (61), low through 3-38.6%(110). family function score showed moderate level. 3. The means of patient's self-care performance revealed total 137.71. self-care performance showed moderate level. 4. A ststistically significant correlation between family caregiver burden and patient's demographic variables, age (F=3.83, p<.01), marrital status(F=3.50, p<.01), job(F=3.17, p<.01), diagnosis(F=4.46, p<.01), income (F=4.46, p<.01). No significant differences between family caregiver burden and prevalent period, religion, sex (p>.05). S. A ststistically significant correlation between family caregiver burden and family's demographic variables, age (F=7.34, p<.01), sex(t=-2.63, p<.01), education level(F=7.61, p<.01), income (F=8.13, p<.01), relation with patient (F=6.92, p<.01), job(F=2.03, p<.05), medical service (F=3.89, p<.05), presence of chronically ill without patient(t=-2.01, p<.05) 6. Family function was the highest factor predicting family caregiver burden(R=.4168, $R^2=.1737$), low education level of family, patient's self-care, family income accounted for 36% in family caregiver burden.

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Use of Fast Transfer Analysis Cartridges for Cervical Sampling and Real Time PCR Based High Risk HPV Testing in Cervical Cancer Prevention - a Feasibility Study from South India

  • Vijayalakshmi, Ramshankar;Viveka, Thangaraj Soundara;Malliga, JS;Murugan, Kothandaraman;Kanchana, Albert;Arvind, Krishnamurthy
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권14호
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    • pp.5993-5999
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    • 2015
  • Background: Molecular testing for human papillomavirus (HPV) is the most objective and reproducible of all cervical cancer screening tests and also less demanding in terms of training and quality assurance. However, there is an impending need for cost effective molecular HPV testing methods with sampling ease, easy storage measures and minimum turn around times suitable for a low resource setting. Objective : Our aim was to evaluate the feasibility of using a fast transfer analysis (FTA) mini elute cartridge for cervical sampling to identify high risk HPV by real time PCR and to compare molecular HPV testing and Pap cytology testing to predict histologically confirmed cervical precancer (CIN 2+ lesions) in a cervical cancer prevention program. Materials and Methods: This was conducted as a pilot study (n=200) on women sampled using FTA mini elute cartridges, genotyped by two different real time PCR assays, detecting 13 high risk HPV (HR HPV) species, including HPV16 along with its physical DNA status. Results obtained from each of the tests were compared and analysed using suitable statistical tests. Results: With FTA mini elute cartridge samples HR HPV positivity was seen in 48/200 (24%). Of these, presence of HPV 16 DNA was observed in 28/48 (58.3%) women. High risk HPV was positive in 20% (37/185) of women with benign cytology and 73.3% (11/15) of women with abnormal cytology findings. A very significant correlation (${\chi}^2=22.090$ ; p=0.000) was observed between cytology and HR HPV findings showing an increasing trend of HR HPV prevalence in 50% (1/2) of LSIL, 75% (3/4) of HSIL and 100% (3/3) of SCC. Of the CIN 2+ lesions identified by histopathology, 88.9% (8/9) had HR HPV. A significant association (${\chi}^2=11.223$ ; p=0.001) of HR HPV and histopathologically confirmed CIN 2+ lesions was found. Sensitivity of the two tests were comparable but specificity of Pap testing was better (90.7% vs 70.4%) to predict histopathologically diagnosed cervical precancers. Conclusions: The current study explored the feasibility of using a FTA mini elute cartridge for cervical sampling for the first time in India as a part of a community based cervical cancer prevention program. We suggest that FTA based sampling is suitable and feasible for real time based HPV testing. Molecular HR HPV testing can be more sensitive and useful to identify high risk women requiring Pap testing which is more specific to detect histologically confirmed cervical precancer.

Outcomes Based on Risk Assessment of Anastomotic Leakage after Rectal Cancer Surgery

  • Gong, Jian-Ping;Yang, Liu;Huang, Xin-En;Sun, Bei-Cheng;Zhou, Jian-Nong;Yu, Dong-Sheng;Zhou, Xin;Li, Dong-Zheng;Guan, Xin;Wang, Dong-Feng
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권2호
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    • pp.707-712
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    • 2014
  • Purpose: Anastomotic leakage (AL) is associated with high morbidity and mortality, high reoperation rates, and increased hospital length of stay. Here we investigated the risk factors for AL after anterior resection for rectal cancer with a double stapling technique. Patients and Methods: Data for 460 patients who underwent primary anterior resection with a double stapling technique for rectal carcinoma at a single institution from 2003 to 2007 were prospectively collected. All patients experienced a total mesorectal excision (TME) operation. Clinical AL was defined as the presence of leakage signs and confirmed by diagnostic work-up according to ICD-9 codes 997.4, 567.22 (abdominopelvic abscess), and 569.81 (fistula of the intestine). Univariate and logistic regression analyses of 20 variables were undertaken to determine risk factors for AL. Survival was analysed using the Cox regression method. Results: AL was noted in 35 (7.6%) of 460 patients with rectal cancer. :Median age of the patients was 65 (50-74) and 161 (35%) were male. The diagnosis of AL was made between the 6th and 12th postoperative day (POD; mean 8th POD). After univariate and multivariate analysis, age (p=0.004), gender (p=0.007), tumor site (p<0.001), preoperative body mass index (EMI) (p<0.001), the reduction of TSGF on 5th POD less than 10U/ml (p=0.044) and the pH value of pelvic dranage less than or equal to 6.978 on 3rd POD (p<0.001) were selected as 6 independent risk factors for AL. It was shown that significant differences in survival of the patients were AL-related (p<0.001), high ASA score related (p=0.036), high-level EMI related (p=0.007) and advanced TNM stage related

Chemical-nutritional characteristics and aromatic profile of milk and related dairy products obtained from goats fed with extruded linseed

  • Bennato, Francesca;Ianni, Andrea;Innosa, Denise;Grotta, Lisa;D'Onofrio, Andrea;Martino, Giuseppe
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권1호
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    • pp.148-156
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    • 2020
  • Objective: This study aimed to evaluate the effect of dietary integration with extruded linseed (EL) on fatty acid (FA) and aromatic profile of goat cheese after 60 (T60) days of ripening. Methods: Thirty goats were divided in two groups. The control group (CG) was fed with conventional diet, whereas the experimental group (EL+) was fed with conventional diet supplemented with 10% of EL. Milk samples were collected on 30 and 60 days of trial to determinate chemical-nutritional composition and FA profile. At the end of experiment, six cheese-making sessions (3 for each group) were carried out using a pooled milk sample obtained from the 15 goats of each group. At 60 days of ripening, cheeses were analyzed for chemical-nutritional composition, FA and aromatic profile. Results: An increase in the milk production, protein, fat and lactose were evidenced in the EL+ goats. Conversely, a reduction of somatic cells was observed in the EL+ compared with the CG. However, no variation was observed for urea and casein levels content in milk samples, and no changes in protein and lipid content were found for cheeses in the two experimental groups. Dietary supplementation with EL modified the FA profile of milk. There was a decrease in saturated FAs and an increase in polyunsaturated FAs. Chemical composition of T60 cheese did not differ between the two groups but a different FA profile was observed. In T60 cheese obtained from EL+ milk, an increase in short-chain FA and a decrease in medium and long-chain FA were observed. The EL diet led to cheeses with butanoic acid 2 times higher compared to CG cheeses. Moreover, a greater presence of aldehyde compounds and alcohols were observed in the cheeses of experimental group. Conclusion: The present study pointed out that EL supplementation may improve the chemical and physical qualities of goat milk and cheeses.

부레를 가진 어류의 음향산란 강도에 관한 연구: 참돔의 길이 및 행동에 따른 산란강도 (Study on the Backscattered Signal of Swimbladdred Fish: Target Strength due to Length and Behavior of Red Seabream (Pagrus Major))

  • 강돈혁;황두진;나정열;김수암
    • 한국음향학회지
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    • 제20권5호
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    • pp.100-109
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    • 2001
  • 부레를 가진 어류의 산란 강도를 조사하기 위하여 길이가 다른 참돔 (red seabream, pagrus major)을 이용한 음향 실험을 실시하였다. 대상 어류를 살아 있는 상태로 - (1) 망 내에 각각 넣은 후, (2) 자유 유영 상태로 놓은후 - 3개의 음향센서 (38, 120, 200kHz)를 이용하여 길이에 따른 산란강도를 측정하였다. 실험 결과 길이에 따른 참돔의 산란 강도는 각 주파수별로 TS/sub 38㎑/=20 log/sub 10(l)/ -66.41, TS/sub 120㎑/=20 log/sub lo(1)/ -71.80, TS/sub 200㎑/=20 log/sub 10(1)/ -73.94로 나타났다. 실험 결과와 이론 모델을 비교하기 위하여 어류의 형태를 근거로 한 Helmholtz-Kirchhoff 음선 근사법을 사용한 결과, 산란강도는 어류 몸체보다는 부레에 의한 효과가 95%이상으로 나타났다. 한편, 수신된 산란강도 자료를 이용한 확률밀도 함수로부터 어류의 행태에 따른 산란강도 변위는 망 내의 산란체에서는 가우스 확률밀도함수 (Gaussian PDF)로, 자유 유영 상태에서는 레일리 확률밀도함수 (Rayleigh PDF) 특성을 나타냈다.

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자극과 배경의 대비, 배경 텍스쳐 밀도, 자극의 화면 시차가 크로스톡 지각에 미치는 영향 (The Effects of Stimulus-background Contrast, Background Texture Density and Screen Disparity of Stimulus on Crosstalk Perception)

  • 박종진;이형철;김신우
    • 방송공학회논문지
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    • 제18권2호
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    • pp.225-236
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    • 2013
  • 3D 영상을 시청하면서 느끼는 고유한 피로를 입체 시각 피로라고 부른다. 이 현상을 유발시키는 주된 요인으로 꼽히는 것은 화면시차, 상 흐림, 크로스톡 (crosstalk)의 세 가지 요인으로 알려져 있다. 이 중 화면 시차와 상 흐림은 영상 콘텐츠에 의하여 결정되며, 사용하는 디스플레이 종류에 관계없이 직접 조작할 수 있다. 그러나 크로스톡 요인은 다른 요인과는 다르게 3D 디스플레이의 물리적인 특성에 의하여 결정되는 요인이며 따라서 손쉽게 감소시키거나 제거하는 것이 불가능하다. 그러나 크로스톡이 입체 시각 피로에 미치는 영향은 자극 특성에 의하여 달라지며, 이러한 자극 특성은 조작 가능하다. 따라서 크로스톡이 입체 시각 피로에 미치는 영향을 확인하려면 크로스톡 지각에 영향을 미치는 자극 특성의 효과를 확인하여야 한다. 이런 목적을 달성하기 위하여 상대적 깊이 판단 과제를 사용하여 자극 특성 (자극과 배경의 대비, 배경 텍스쳐 밀도, 자극의 화면 시차)이 크로스톡 지각에 미치는 영향을 확인하였다. 그 결과 영상에 배경이 존재하고 자극의 화면시차가 적을 때 지각되는 크로스톡이 감소함을 시사하는 결과를 얻었다.

Applications of XPS and SIMS for the development of Si quantum dot solar cell

  • 김경중;홍승휘;김용성;이우;김영헌;서세영;장종식;신동희;최석호
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.297-297
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    • 2010
  • Precise control of the position and density of doping elements at the nanoscale is becoming a central issue for realizing state-of-the-art silicon-based optoelectronic devices. As dimensions are scaled down to take benefits from the quantum confinement effect, however, the presence of interfaces and the nature of materials adjacent to silicon turn out to be important and govern the physical properties. Utilization of visible light is a promising method to overcome the efficiency limit of the crystalline Si solar cells. Si quantum dots (QDs) have been proposed as an emission source of visible light, which is based on the quantum confinement effect. Light emission in the visible wavelength has been reported by controlling the size and density of Si QDs embedded within various types of insulating matrix. For the realization of all-Si QD solar cells with homojunctions, it is prerequisite not only to optimize the impurity doping for both p- and n-type Si QDs, but also to construct p-n homojunctions between them. In this study, XPS and SIMS were used for the development of p-type and n-type Si quantum dot solar cells. The stoichiometry of SiOx layers were controlled by in-situ XPS analysis and the concentration of B and P by SIMS for the activated doping in Si nano structures. Especially, it has been experimentally evidenced that boron atoms in silicon nanostructures confined in SiO2 matrix can segregate into the Si/$SiO_2$ interfaces and the Si bulk forming a distinct bimodal spatial distribution. By performing quantitative analysis and theoretical modelling, it has been found that boron incorporated into the four-fold Si crystal lattice can have electrical activity. Based on these findings, p-type Si quantum dot solar cell with the energy-conversion efficiency of 10.2% was realized from a [B-doped $SiO_{1.2}$(2 nm)/$SiO_2(2\;nm)]^{25}$ superlattice film with a B doping level of $4.0{\times}10^{20}\;atoms/cm^2$.

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슬관절 퇴행성 관절염의 관절경적 치료 - 기졔적 증상이 있는 군과 없는 군과의 비교 - (Arthroscopic Treatment of Osteoarthritis of the Knee(Comparison of the groups with and without mechanical symptom))

  • 김철호;임창균;조성우;김기형;문진웅
    • 대한정형외과스포츠의학회지
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    • 제2권2호
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    • pp.149-152
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    • 2003
  • 목적: 관절경 술식으로 치료한 퇴행성 슬관절염 환자에서 기계적 증상의 유무에 따른 임상 결과를 알아 보고자 하였다. 대상 및 방법: 2000년 10월부터 2002년 1월까지 슬관절의 퇴행성 관절염 으로 관절경 수술을 받은 60명 60례를 대상으로 하였다 추시 기간은 평균 15개월(12$\~$30개월)이었다. 수술전 단순 방사선 소견과 문진 그리고 이학적 검사로 기계적 증상의 유무를 판단 하였다. 치료 결과는 Baumgaertner의 평가 방법을 이용하였다. 결과: 술전 Baumgaertner score는 기계적 증상이 있는 군에서 평균 3.1점에서 술후 8.1점이었으며 기계적 증상이 없었던 군에서는 술전 3.5점에서 술후 5.4점으로 기계적 증상이 있었던 환자군에서 더 높은 만족도를 나타냈다. 결론: 퇴행성 관절염에서 기계적 증상이 있는 경우 관절경적 치료는 의미 있는 치료방법이라고 사료되나 보다 많은 증례에 대한 연구가 필요할 것으로 사료된다

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