• Title/Summary/Keyword: Psi ($\Psi$)

Search Result 1,235, Processing Time 0.025 seconds

Ostwald Ripening Stability of Curcumin-Loaded MCT Nanoemulsion: Influence of Various Emulsifiers

  • Kim, Sun-Hyung;Ji, Yeun-Sun;Lee, Eui-Seok;Hong, Soon-Taek
    • Preventive Nutrition and Food Science
    • /
    • v.21 no.3
    • /
    • pp.289-295
    • /
    • 2016
  • Curcumin is a flavonoid found in the rhizome of the turmeric plant (Curcuma longa L.) and has recently attracted interest because it has numerous biological functions and therapeutic properties. In the present study, we attempted to incorporate curcumin into medium-chain triglyceride (MCT) nanoemulsions (0.15 wt% curcumin, 10 wt% MCT oil, and 10 wt% emulsifiers) with various emulsifiers [polyoxyethylene (20) sorbitan monolaurate (Tween-20), sorbitan monooleate (SM), and soy lecithin (SL)]. The physicochemical properties of the nanoemulsions including the Ostwald ripening stability were investigated. The initial droplet size was found to be 89.08 nm for the nanoemulsion with 10 wt% Tween-20 (control), and when Tween-20 was partially replaced with SM and SL, the size decreased: 73.43 nm with 4 wt% SM+6 wt% Tween-20 and 67.68 nm with 4 wt% SL+6 wt% Tween-20 (prepared at 15,000 psi). When the nanoemulsions were stored for 28 days at room temperature, the droplet size increased as the storage time increased. The largest increase was observed for the control nanoemulsion, followed by the 4 wt% SL+6 wt% Tween-20 and 4 wt% SM+6 wt% Tween-20 systems. The Turbiscan dispersion stability results strongly supported the relationship between droplet size and storage time. The time-dependent increase in droplet size was attributed to the Ostwald ripening phenomenon. Thus, the Ostwald ripening stability of curcumin-loaded MCT nanoemulsions with Tween-20 was considerably improved by partially replacing the Tween-20 with SM or SL. In addition, curcumin may have acted as an Ostwald ripening inhibitor.

Crystal Structure and Dielectric Responses of Pulsed Laser Deposited (Ba, Sr)$TiO_3$ Thin Films with Perovskite $LaNiO_3$ Metallic Oxide Electrode

  • Lee, Su-Jae;Kang, Kwang-Yong;Jung, Sang-Don;Kim, Jin-Woo;Han, Seok-Kil
    • The Korean Journal of Ceramics
    • /
    • v.6 no.3
    • /
    • pp.258-261
    • /
    • 2000
  • Highly (h00)-oriented (Ba, Sr)TiO$_3$(BST) thin films were grown by pulsed laser deposition on the perovskite LaNiO$_3$(LNO) metallic oxide layer as a bottom electrode. The LNO films were deposited on SiO$_2$/Si substrates by rf-magnetron sputtering method. The crystalline phases of the BST film were characterized by x-ray $\theta$-2$\theta$, $\omega$-rocking curve and $\psi$-scan diffraction measurements. The surface microsturcture observed by scanning electron microscopy was very dense and smooth. The low-frequency dielectric responses of the BST films grown at various substrate temperatures were measured as a function of frequency in the frequency range from 0.1 Hz to 10 MHz. The BST films have the dielectric constant of 265 at 1 kHz and showed multiple dielectric relaxation at the low frequency region. The origin of these low-frequency dielectric relaxation are attributed to the ionized space charge carriers such as the oxygen vacancies and defects in BST film, the interfacial polarization in the grain boundary region and the electrode polarization. We studied also on the capacitance-voltage characteristics of BST films.

  • PDF

Experimental and Numerical Analysis of A Novel Ceria Based Abrasive Slurry for Interlayer Dielectric Chemical Mechanical Planarization

  • Zhuanga, Yun;Borucki, Leonard;Philipossian, Ara;Dien, Eric;Ennahali, Mohamed;Michel, George;Laborie, Bernard;Zhuang, Yun;Keswani, Manish;Rosales-Yeomans, Daniel;Lee, Hyo-Sang;Philipossian, Ara
    • Transactions on Electrical and Electronic Materials
    • /
    • v.8 no.2
    • /
    • pp.53-57
    • /
    • 2007
  • In this study, a novel slurry containing ceria as the abrasive particles was analyzed in terms of its frictional, thermal and kinetic attributes for interlayer dielectric (ILD) CMP application. The novel slurry was used to polish 200-mm blanket ILD wafers on an $IC1000_{TM}$ K-groove pad with in-situ conditioning. Polishing pressures ranged from 1 to 5 PSI and the sliding velocity ranged from 0.5 to 1.5 m/s. Shear force and pad temperature were measured in real time during the polishing process. The frictional analysis indicated that boundary lubrication was the dominant tribological mechanism. The measured average pad leading edge temperature increased from 26.4 to $38.4\;^{\circ}C$ with the increase in polishing power. The ILD removal rate also increased with the polishing power, ranging from 400 to 4000 A/min. The ILD removal rate deviated from Prestonian behavior at the highest $p{\times}V$ polishing condition and exhibited a strong correlation with the measured average pad leading edge temperature. A modified two-step Langmuir-Hinshelwood kinetic model was used to simulate the ILD removal rate. In this model, transient flash heating temperature is assumed to dominate the chemical reaction temperature. The model successfully captured the variable removal rate behavior at the highest $p{\times}V$ polishing condition and indicates that the polishing process was mechanical limited in the low $p{\times}V$ polishing region and became chemically and mechanically balanced with increasing polishing power.

CERAMOGRAPHY ANALYSIS OF MOX FUEL RODS AFTER AN IRRADIATION TEST

  • Kim, Han-Soo;Jong, Chang-Yong;Lee, Byung-Ho;Oh, Jae-Yong;Koo, Yang-Hyun
    • Nuclear Engineering and Technology
    • /
    • v.42 no.5
    • /
    • pp.576-581
    • /
    • 2010
  • KAERI (Korea Atomic Energy Research Institute) fabricated MOX (Mixed Oxide) fuel pellets as a cooperation project with PSI (Paul Scherrer Institut) for an irradiation test in the Halden reactor. The MOX pellets were fitted into fuel rods that included instrumentation for measurement in IFE (Institutt for Energiteknikk). The fuel rods were assembled into the test rig and irradiated in the Halden reactor up to 50 MWd/kgHM. The irradiated fuel rods were transported to the IFE, where ceramography was carried out. The fuel rods were cut transversely at the relatively higher burn-up locations and then the radial cross sections were observed. Micrographs were analyzed using an image analysis program and grain sizes along the radial direction were measured by the linear intercept method. Radial cracks in the irradiated MOX were observed that were generally circumferentially closed at the pellet periphery and open in the hot central region. A circumferential crack was formed along the boundary between the dark central and the outer regions. The inner surface of the cladding was covered with an oxide layer. Pu-rich spots were observed in the outer region of the fuel pellets. The spots were surrounded by many small pores and contained some big pores inside. Metallic fission product precipitates were observed mainly in the central region and in the inside of the Pu spots. The average areal fractions of the metallic precipitates at the radial cross section were 0.41% for rod 6 and 0.32% for rod 3. In the periphery, pore density smaller than 2 ${\mu}m$ was higher than that of the other regions. The grain growth occurred from 10 ${\mu}m$ to 12 ${\mu}m$ in the central region of rod 6 during irradiation.

Offsite Consequence Analysis and safety management system process integration plan of safety management system (장외영향평가 및 공정안전관리제도의 통합 안전환경관리방안에 관한 연구)

  • Kim, Dong-Jun;Lee, In-Bok;Moon, Jin-Young;Chun, Young-Woo
    • Journal of the Korea Safety Management & Science
    • /
    • v.18 no.3
    • /
    • pp.63-70
    • /
    • 2016
  • The main point of this study is to find out duplicates and differences among various regulations from different organizations. Also, it focuses on creating a reasonably unified regulation system to standardize safety & environment management. In this study, I analyzed the commonalities and the differences of two systems which are typical korean Process Safety Management System and off-site Consequence Analysis. It is confirmed that there are 25 species of overlapped material of those two systems and assessment like handling material information, facilities lists, hazardous substances and list of machine power. Process safety report focuses on onsite workers and facility protect. On the other hand, off-site Consequence Analysis focuses on design, arrangement and management of handling facility from off-site influence. I found difference two system of Enforcement purposes and way. Contradiction of Harmful information of Chemicals Control Act and occupation safety and health acts from same material. To be specific, There are no unit rule of occupation safety and health acts. so it permit inch, psi etc. But Chemicals Control Act provides that m, Mpa units. Therefore, Each regulatory duplication of items for chemicals management, standardization is writing so that you can coordinate overlapping items in the measures the need to be presented.

Effects of Ozone on Photosynithetic Activity in Chloroplast of Barley (Hordeum vulgare L.) (오존이 보리(Hordeum vulgare L.) 엽록체의 광합성 활성에 미치는 영향)

  • 정화숙
    • Journal of Plant Biology
    • /
    • v.38 no.4
    • /
    • pp.399-407
    • /
    • 1995
  • The effects of 0.5 and 1.0 ppm of ozone on the developing chloroplast of barley (Hordeum vulgare L) seedling during greening were investigated by PSI and II activities, chlorophyll fluorescence, and the contents of chlorophyll. Etiolated barley seedling was treated 0.5 and 1.0 ppm ozone for the first 4 h during greening. In 24 h greening experiment, the contents of chlorophyll were decreased by increasing ozone concentration from 0.5 ppm to 1.0 ppm. In 24 h greening experiment, Fo, Fv, Fm and qE were greatly decreased as the concentration of ozone was increased, but those were not considerably decreased in 48 h greening experiment. In another experiment, the developing barley seedling was treated with 0.5 and 1.0 ppm ozone for the last 4 h during greening period, which was 24 h or 48 h. In both experiments the PS II activity was decreased as the concentration of ozone was increased, but not in PS I activity. Fv, Fm and Fv/Fo were also decreased as the concentration of ozone was increased. qP and qR were strikingly decreased as the concentration of ozone was increased in both experiments.iments.

  • PDF

Streptochlorin Isolated from Streptomyces sp. Induces Apoptosis in Human Hepatocarcinoma Cells Through a Reactive Oxygen Species-Mediated Mitochondrial Pathway

  • Shin, Dong-Yeok;Shin, Hee-Jae;Kim, Gi-Young;Cheong, Jae-Hun;Choi, Il-Whan;Kim, Se-Kwon;Moon, Sung-Kwon;Kang, Ho-Sung;Choi, Yung-Hyun
    • Journal of Microbiology and Biotechnology
    • /
    • v.18 no.11
    • /
    • pp.1862-1867
    • /
    • 2008
  • Streptochlorin is a small molecule isolated from marine Streptomyces sp. that is known to have antiangiogenic and anticancer properties. In this study, we examined the effects of this compound on reactive oxygen species (ROS) production and the association of these effects with apoptotic tumor cell death, using a human hepatocarcinoma Hep3B cell line. The results of this study demonstrated that streptochlorin mediates ROS production, and that this mediation is followed by a decrease in the mitochondrial membrane potential (MMP, ${\Delta}{\Psi}_m$), activation of caspase-3, and downregulation of antiapoptotic Bcl-2 protein. The quenching of ROS generation by N-acetyl-L-cysteine administration, a scavenger of ROS, reversed the streptochlorin-induced apoptosis effects via inhibition of ROS production, MMP collapse, and the subsequent activation of caspase-3. These observations clearly indicate that ROS are involved in the early molecular events in the streptochlorin-induced apoptotic pathway. Taken together, our data imply that streptochlorin-induced ROS is a key mediator of MMP collapse, which leads to the caspase-3 activation, culminating in apoptosis.

The Effects of Sand Play Therapy on Parenting Stress and Saliva Cortisol Levels of Parents Undergoing Child Counseling Programs (자녀가 상담을 받고 있는 부모의 양육스트레스와 타액 코티졸에 미치는 모래놀이치료 효과)

  • Kim, Young-Mi;Jang, Mi-Kyung;Kim, Min-Kyeong;Kim, Jin-Kyung
    • Korean Journal of Child Studies
    • /
    • v.33 no.3
    • /
    • pp.83-97
    • /
    • 2012
  • The purpose of this study is to investigate the effects of sand play therapy on the parenting stress and saliva cortisol levels of parents undergoing child counseling programs. The study was conducted with 13 parents who were undergoing child counseling programs. The sessions were held every week for 45 minutes from July, 2011 to September, 2011. To evaluate the effects of sand play therapy, pre test and post test were conducted and the results were then analyzed. The therapy sessions consist of parents making sand boxes, and this was done without consideration of any particular theme. The instrument used was Abidin (1990)'s Parenting Stress Instrument (PSI). Saliva cortisol levels were obtained at the pre-post stage of the sand play therapy. The data were analyzed by means of frequency and the Wilcoxon Rank Sum Test was conducted by the SPSS. The major findings were as follows; There were significant differences in terms of the decreases in the areas of perception of all the parenting stresses examined, including daily life stress, child temperament stress, child relationship stress, and learning-expectation stress, as well as in saliva cortisol levels. Finally, this study suggests that parenting stress and saliva cortisol levels have a positive relationship, and the effects of sand play therapy were significant with decreases in parenting stress and saliva cortisol levels. There is a clear need for parents undergoing child counseling programs to engage in sand play therapy to decrease parenting stress and saliva cortisol levels.

Characteristics of Soil Parameter for Lade's Single Work-Hardening Constitutive Model with Relative Density of Baekma River Sands (백마강 모래의 상대밀도에 따른 Lade의 단일항복면 구성모델의 토질매개변수 특성)

  • Cho, Won-Beom;Kim, Chan-Kee;Kim, Joong-Chul
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.31 no.1C
    • /
    • pp.11-17
    • /
    • 2011
  • This study was performed a series of the isotropic compression-expansion tests and the drained triaxial tests with various the relative densities 25%, 50%, 80% and 100% for Baekma river sand. Using the tests results the characteristic of the parameters of Lade's single hardening constitutive model were investigated. The soil parameters Kur and n representing elastic behavior are not much affected by the change of the relative density. The other parameters such as failure criterion (m, ${\eta}_1$), hardening function (C, p) and plastic potential (${\Psi}_2$, ${\mu}$) are in a positive linear relationship with the relative density. Since the soil parameters h and $\alpha$ representing yield function do not change much to the change of relative density and also closely related to failure criterion, they can be replaced by failure criterion ${\eta}_1$. We also observed that predicted values from the Lade's single hardening constitutive model were well consistent with the observed data.

15,000psi Grade Control Systems Development for the Mud System in Offshore (해양 시추용 15,000psi급 머드 시스템에 대한 제어 시스템 개발)

  • Lee, Sang-Mok;Cho, Bae-Seok;Kim, Tae-Hyoung;Hwang, Jong-Deok;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2017.05a
    • /
    • pp.673-676
    • /
    • 2017
  • The Offshore drilling system of domestic drilling systems (drill rigs, drill ship) in Korea is dependent on full imports and the monopolistic situation of a few foreign large corporations is intensifying. In addition, most of domestic technology development tries to develop single product oriented products until now, but it is necessary to develop monitoring control system for package unit commercialization by approaching package development method. Therefore, we will develop a control monitoring system that can integrate the single equipment of the mud system developed previously.

  • PDF