• Title/Summary/Keyword: Valence control

Search Result 26, Processing Time 0.026 seconds

The Effect of Cichorium intybus Extract on Hepatotoxicity in Rats

  • Park Ji-Young;Kim Eun-Kyung
    • Journal of Environmental Health Sciences
    • /
    • v.32 no.3
    • /
    • pp.235-239
    • /
    • 2006
  • Cichorium intybus (Compositae) has been used for fevers, dyspepsia, headache and jaundice, as a demulcent. Also, it has relaxation effects and relief effects against coffee and teas, and is widely used as food. We investigated anti-lipid peroxidative effects and liver protective activity on $CCl_4$ induced lipid peroxidation and hepatotoxicity in rats. MeOH Ex. enhanced the inhibition of anti-lipid peroxidative effects in liver lipid. In chemical parameters obtained from serum analysis, MeOH Ex. revealed significant decrease on hepatotoxicity. The results were as follows; 1. The inhibitory effects of lipid peroxidation were shown in accordance with the increase of samples' concentration level. 2. In chemical parameters obtained from serum analysis, the activities of GOT, GPT, AlP were restored to near the normal level. The contents of cholesterol and BUN showed inhibitory effects with valence. 3. The weights of liver and spleen were not able to restore to the normal level. But on a general level, they were reduced more than the control group.

Fabrication and Characterization of a-Si:H Films by a Remote Plasma Enhanced CVD (Remote Plasma Enhanced CVD에 의한 수소화된 비정질 실리콘 박막의 제작 및 특성연구)

  • Yang, Young-Sik;Yoon, Yeer-Jean;Jang, Jin
    • Proceedings of the KIEE Conference
    • /
    • 1987.07a
    • /
    • pp.513-516
    • /
    • 1987
  • Hydrogenated amorphous silicon (a-Si:H) films have been deposited, for thye first time, by a remote plasma chemical vapor deposition. The hydrogen radical play a important role to control the deposition rate, The bonded hydrogen content to silicon is independent of hydrogen partial pressure in the plasma. Optical gap of deposited a-Si:H lies between 1.7eV and 1.8eV and all samples have sharp absorption edge. B-doped a-Si:H films by a RPECVD has a high doping efficiency compared with plasma CVD. The Fermi level of 100ppm B-doped film lies at 0.5eV above valence band edge.

  • PDF

N-type doping and band gap change of Calix adsorbed on Graphene

  • Park, Seon-Min;Yang, Se-Na;Kim, Gi-Jeong;Kim, Bong-Su;No, Gwang-Hyeon;Lee, Han-Gil
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2010.02a
    • /
    • pp.341-341
    • /
    • 2010
  • Electronic structure of Calix adsorbed on epitaxial graphene (EG) was investigated using high resolution photoemission spectroscopy (HRPES). Increasing the deposition of calix molecule, we found that EG becomes n-type doping using secondary edge measurement (work function change). As we observe bonding nature of O 1s peak, we found that single O 1s peak can be clearly distinguished in the spectra indicating equivalent adsorption state. Finally, we were able to control the band gap of EG using valence band spectra as we change the amount of calix molecule. In this study, we will propose the possibility of band gap modulation of EG using calix molecule.

  • PDF

A Study on the Reaction Characteristics of Steam Reforming Reaction over Catalyzed Porous Membrane (다공성 촉매 분리막을 이용한 수증기 개질 반응 특성 연구)

  • Hong, Sung Chang;Lee, Sang Moon
    • Applied Chemistry for Engineering
    • /
    • v.25 no.2
    • /
    • pp.198-203
    • /
    • 2014
  • In this study, steam reforming reaction and surface characteristics of Ni metal foam plate were investigated. Valence state of Ni could be changed by pretreatment, and metallic Ni species exposed on surface as a active site play important role in steam reforming reaction. Porous catalytic membrane also was prepared by mixing of Ni metal foam plate and Ni-YSZ catalyst to control the pore size and assign the catalytic function in Ni metal foam plate. In SEM analysis results, Pore size of Ni metal foam plate could be controlled and Ni-YSZ catalyst well dispersed on surface. Ni based porous catalytic membrane had a similar steam reforming activity regardless of space velocity.

Chromium concentration and half-life in rats biological samples after intravenous administration of soluble trivalent and hexavalent chromium compounds (흰쥐에 정맥 주사한 수용성 크롬의 분포 및 배설)

  • Kim, Yong-Lae;Kim, Chy-Nyon;Roh, Jaehoon
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.11 no.1
    • /
    • pp.9-16
    • /
    • 2001
  • Chromium exposure can be in the forms of environmental pollution and occupational exposure. The harmful effects of chromium on the body greatly differ depending on its valence or solubility. Accordingly, the recommended permissible exposure limit for each chromium compound is different. This study investigated the increase or decrease of distribution and excretion of total chromium exposed simultaneously the soluble Cr+6 and Cr+3 compounds. There were no difference of total chromium concentration in plasma, red bloods cells, urine, organs between simultaneously injected and individually injected soluble Cr+6 and Cr+3 compound. The chromium clearances in urine also showed that there were two phases in the two groups. In the first phase, biological half lives of the total chromium of the two groups have been similar within 24 hr., but in the second phase, biological half life of the group injected simultaneously was 62.7 hr. and was less than that of the other group's 188.3 hr. The average concentration of total chromium in plasma was same with the control, and that of RBCs was $0.218nmol/m{\ell}$ and was slightly increased in comparison with $0.121nmol/m{\ell}$ of the control, which was not statistically significant. As a result, there were no differences of distribution and excretion of chromium between the group exposed simultaneously and the other group exposed separately the soluble Cr+6 and Cr+3 compounds. The biological half life of chromium of the former group in urine was less than that of the other group.

  • PDF

The Intelligent Determination Model of Audience Emotion for Implementing Personalized Exhibition (개인화 전시 서비스 구현을 위한 지능형 관객 감정 판단 모형)

  • Jung, Min-Kyu;Kim, Jae-Kyeong
    • Journal of Intelligence and Information Systems
    • /
    • v.18 no.1
    • /
    • pp.39-57
    • /
    • 2012
  • Recently, due to the introduction of high-tech equipment in interactive exhibits, many people's attention has been concentrated on Interactive exhibits that can double the exhibition effect through the interaction with the audience. In addition, it is also possible to measure a variety of audience reaction in the interactive exhibition. Among various audience reactions, this research uses the change of the facial features that can be collected in an interactive exhibition space. This research develops an artificial neural network-based prediction model to predict the response of the audience by measuring the change of the facial features when the audience is given stimulation from the non-excited state. To present the emotion state of the audience, this research uses a Valence-Arousal model. So, this research suggests an overall framework composed of the following six steps. The first step is a step of collecting data for modeling. The data was collected from people participated in the 2012 Seoul DMC Culture Open, and the collected data was used for the experiments. The second step extracts 64 facial features from the collected data and compensates the facial feature values. The third step generates independent and dependent variables of an artificial neural network model. The fourth step extracts the independent variable that affects the dependent variable using the statistical technique. The fifth step builds an artificial neural network model and performs a learning process using train set and test set. Finally the last sixth step is to validate the prediction performance of artificial neural network model using the validation data set. The proposed model is compared with statistical predictive model to see whether it had better performance or not. As a result, although the data set in this experiment had much noise, the proposed model showed better results when the model was compared with multiple regression analysis model. If the prediction model of audience reaction was used in the real exhibition, it will be able to provide countermeasures and services appropriate to the audience's reaction viewing the exhibits. Specifically, if the arousal of audience about Exhibits is low, Action to increase arousal of the audience will be taken. For instance, we recommend the audience another preferred contents or using a light or sound to focus on these exhibits. In other words, when planning future exhibitions, planning the exhibition to satisfy various audience preferences would be possible. And it is expected to foster a personalized environment to concentrate on the exhibits. But, the proposed model in this research still shows the low prediction accuracy. The cause is in some parts as follows : First, the data covers diverse visitors of real exhibitions, so it was difficult to control the optimized experimental environment. So, the collected data has much noise, and it would results a lower accuracy. In further research, the data collection will be conducted in a more optimized experimental environment. The further research to increase the accuracy of the predictions of the model will be conducted. Second, using changes of facial expression only is thought to be not enough to extract audience emotions. If facial expression is combined with other responses, such as the sound, audience behavior, it would result a better result.

Fabrication, temperature-dependent local structural and electrical properties of VO2 thin films

  • Jin, Zhenlan;Hwang, In-Hui;Park, Chang-In;Han, Sang-Wook
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2015.08a
    • /
    • pp.169.2-169.2
    • /
    • 2015
  • $VO_2$ is a well-known a metal-to-insulator-transition (MIT) material, accompanied with a first order structural phase transition near room temperature. Because of the structural phase transition and the MIT occur near a same temperature, there is an ongoing argument whether the MIT is induced by the structural phase transition. $VO_2$ exhibits a relatively weak anti-oxidization ability and can be oxidized to higher-valence oxides (e.g., $V_4$ $O_7$ or $V_2$ $O_5$) when annealed at a high temperature in an oxygen-rich atmosphere. We fabricated $VO_2$ films on $Al_2$ $O_3$ (0001) substrates using a DC magnetron sputtering deposition process with carefully control the $O_2$ percentage in an atmosphere. X-ray diffraction measurements from the films showed only (0l0) peaks with no extra peaks, indicating b-oriented films. The temperature-dependent local structural properties of $VO_2$ films were investigated by using in-situ X-ray absorption fine structure (XAFS) measurements at the V K edge. XAFS revealed that the structural phase transition was occurred nearly $70^{\circ}C$ for heating process and reproducible. Resistance measurements as a function of temperature (R-T) demonstrated that the resistance of $VO_2$ films was changed by a factor of 4 near $75^{\circ}C$ which was higher than $68^{\circ}C$ reported from a $VO_2$ bulk. We will discuss the MIT of $VO_2$ films, comparing with the local structural properties determined by XAFS measurements.

  • PDF

Illness Representations of Cancer among Healthy Residents of Kolkata, India

  • Das, Lala Tanmoy;Wagner, Christina D.;Bigatti, Silvia M.
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.2
    • /
    • pp.845-852
    • /
    • 2015
  • Cancer illness representations and screening history among residents of Kolkata, India, were investigated along with socio-demographic characteristics in an effort to understand possible motivations for health behavior. A total of 106 participants were recruited from community locations in Kolkata, India and completed surveys including demographics, the illness perception questionnaire-revised (IPQ-R), and previous experience with cancer and screening practices. Participants were 51.5% college educated, 57% female, 51.5% full-time employed with average age of 32.7 years (R: 18-60 years). Descriptive statistics were generated for the subscales of the IPQ-R, cancer-screening practices and cancer experience. Correlation analyses were conducted to investigate associations between cancer representations and socio-demographic variables. Univariate ANOVAs were calculated to determine gender differences in IPQ-R subscales and differences between participants who knew someone diagnosed with cancer versus those who did not. While 76% of participants knew someone with cancer, only 5% of the sample engaged in cancer screening. Participants perceived cancer as a serious illness with negative emotional valence. Younger age (r(100)=-.36, p<0.001) and male gender (F(1, 98)=5.22, p=0.01, ${\eta}_2$=0.05) were associated with better illness coherence. Males also reported greater personal control (F(1, 98)=5.34, p=0.02, ${\eta}_2$=0.05) were associated with better illness coherence. Low screening rates precluded analyses of the relationship between illness representations and cancer screening. Cancer was viewed as a threatening and uncontrollable disease among this sample of educated, middle class Kolkata residents. This view may act as a barrier to seeking cancer screening. Public awareness campaigns aimed at improving understanding of the causes, symptoms and consequences of cancer might reduce misunderstandings and fear, especially among women and older populations, who report less comprehension of cancer.

Electronic Structure of the SrTiO3(001) Surfaces: Effects of the Oxygen Vacancy and Hydrogen Adsorption

  • Takeyasua, K.;Fukadaa, K.;Oguraa, S.;Matsumotob, M.;Fukutania, K.
    • Applied Science and Convergence Technology
    • /
    • v.23 no.5
    • /
    • pp.201-210
    • /
    • 2014
  • The influence of electron irradiation and hydrogen adsorption on the electronic structure of the $SrTiO_3$ (001) surface was investigated by ultraviolet photoemission spectroscopy (UPS). Upon electron irradiation of the surface, UPS revealed an electronic state within the band gap (in-gap state: IGS) with the surface kept at $1{\times}1$. This is considered to originate from oxygen vacancies at the topmost surface formed by electron-stimulated desorption of oxygen. Electron irradiation also caused a downward shift of the valence band maximum indicating downward band-bending and formation of a conductive layer on the surface. With oxygen dosage on the electron-irradiated surface, on the other hand, the IGS intensity was decreased along with upward band-bending, which points to disappearance of the conductive layer. The results indicate that electron irradiation and oxygen dosage allow us to control the surface electronic structure between semiconducting (nearly-vacancy free: NVF) and metallic (oxygen de cient: OD) regimes by changing the density of the oxygen vacancy. When the NVF surface was exposed to atomic hydrogen, in-gap states were induced along with downward band bending. The hydrogen saturation coverage was evaluated to be $3.1{\pm}0.8{\times}10^{14}cm^{-2}$ with nuclear reaction analysis. From the IGS intensity and H coverage, we argue that H is positively charged as $H^{{\sim}0:3+}$ on the NVF surface. On the OD surface, on the other hand, the IGS intensity due to oxygen vacancies was found to decrease to half the initial value with molecular hydrogen dosage. H is expected to be negatively charged as $H^-$ on the OD surface by occupying the oxygen vacancy site.

Oxygen Permeation and Hydrogen Production of BaCo1-x-yFexZryO3-δ by a Modified Glycine-nitrate Process (MGNP) (Modified glycine-nitrate process(MGNP)로 합성한 BaCo1-x-yFexZryO3-δ 산소투과도 및 수소생산성)

  • Yi, Eunjeong;Hwang, Haejin
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.24 no.1
    • /
    • pp.29-35
    • /
    • 2013
  • A dense mixed ionic and electronic conducting ceramic membrane is one of the most promising materials because it can be used for separation of oxygen from the mixture gas. The $ABO_3$ perovskite structure shows high chemical stability at high temperatures under reduction and oxidation atmospheres. $BaCo_{1-x-y}Fe_xZr_yO_{3-{\delta}}$ (BCFZ) was well-known material as high mechanical strength, low thermal conductivity and stability in the high valence state. Glycine Nitrate Process (GNP) is rapid and effective method for powder synthesis using glycine as a fuel and show higher product crystallinity compared to solid state reaction and citrate-EDTA method. BCFZ was fabricated by modified glycine nitrate process. In order to control the burn-up reaction, $NH_4NO_3$ was used as extra nitrate. According to X-Ray Diffraction (XRD) results, BCFZ was single phase regardless of Zr dopants from y=0.1 to 0.3 on B sites. The green compacts were sintered at $1200^{\circ}C$ for 2 hours. Oxygen permeability, methane partial oxidation rate and hydrogen production ability of the membranes were characterized by using Micro Gas Chromatography (Micro GC) under various condition. The high oxygen permeation flux of BCFZ 1-451 was about $1ml{\cdot}cm^{-2}s^{-1}$. Using the humidified Argon gas, BCFZ 1-433 produced hydrogen about $1ml{\cdot}cm^{-2}s^{-1}$.