• Title/Summary/Keyword: 응집현상

Search Result 388, Processing Time 0.025 seconds

Formulation Studies for Surface Modification and Application to Cosmetics of Jadeite Powder (경옥 가루 표면 개질과 화장품에의 응용을 위한 제형 연구)

  • Kim, Yong Woo;Park, Soo Nam
    • Applied Chemistry for Engineering
    • /
    • v.30 no.2
    • /
    • pp.167-177
    • /
    • 2019
  • The jadeite powder has a disadvantage affecting the stability of the formulation due to the agglomeration of the powder when applied to cosmetic formulations. To overcome this problem, a new composite powder was prepared by modifying the surface of jadeite powder and applied to foundation pact and sun stick. In this study, a triethoxycaprylylsilane among various surface modifiers was selected as an optimum component, and applied to each formulation by making the jadeite powder composite. As a result, the foundation pact maintained the clarity of the product color, and the sun stick gave about 30% higher UV blocking effect in the UVB area compared with that of the blank. In the user sensory evaluation, the formulation containing the jadeite powder composite showed a high score for the overall indicator. The stability evaluation of the formulation was also confirmed that it was stable against discoloration, detachment and hardness. In conclusion, the jadeite powder composite is stable as an inorganic pigment which is applicable to cosmetics as a multifunctional material while maintaining the color clarity of the product and acting as a booster for sunscreen agents.

Ceramic Based Photocatalytic Membrane for Wastewater Treatment: A Review (폐수처리를 위한 세라믹 기반 광촉매 분리막: 총설)

  • Kwak, Yeonsoo;Patel, Rajkumar
    • Membrane Journal
    • /
    • v.32 no.3
    • /
    • pp.181-190
    • /
    • 2022
  • Membrane separation provides various advantages including cost effectiveness and high efficiency over traditional wastewater treatment methods such as flocculation and adsorption. However, the effectiveness of membrane separation greatly declines due to membrane fouling, where pollutants are accumulated on the membrane surface. Among different groups of membranes, ceramic membranes can provide good antifouling properties due to its hydrophilicity and chemical stability. In addition, composite membranes such as graphene oxide modified membranes can help prevent membrane fouling. Recently, hybrid photocatalytic membranes have been proposed as a solution to prevent membrane fouling and provide synergetic effects. Membrane separation can solve the disadvantages of photocatalytic oxidation such as low reutilization rate, while photocatalytic oxidation can help reduce membrane fouling.

Quality Characteristics of Sulgitteok Prepared with Aloe Vera Sap during Storage (알로에 원액 첨가 설기떡의 저장기간에 따른 품질 특성)

  • Choi, Eun-Hi
    • Journal of the Korean Society of Food Culture
    • /
    • v.22 no.3
    • /
    • pp.330-335
    • /
    • 2007
  • This study was conducted to investigate the mechanical and sensory characteristics of aloe Suffitteok prepared with the different ratio of aloe sap for 4 days. Moisture content of Sulgitteok without aloe vera sap was 33.79%, and that of Sulgitteok prepared with 12% aloe vera sap decreased. As the storage time of Sulgitteok increased, moisture content reduced. The cohesiveness, springiness, adhesiveness, gumminess and chewiness of Sulgitteok decreased as aloe vera sap increased. The L values of aloe Sulgitteok significantly decreased with increasing aloe vera sap. The a value of Sulgitteok without aioe vera sap was -0.56, but showed negative value as aloe vela sap increased. The more aloe sap added, the higher b values rose. The overall acceptability of color, flavor, taste, softness and moistness in sensory evaluation showed that Sulgitteok prepared with 9% aloe vera sap had the highest score.

Lived Experience of Suffering for Victims of Torture : among the suspected espionage agents under the military government (고문폭력 생존자가 반추한 고문의 고통 체험 : 군사정권시대 간첩혐의 희생자를 중심으로)

  • Kim, Hyun Kyoung
    • Korean Journal of Social Welfare Studies
    • /
    • v.42 no.2
    • /
    • pp.235-274
    • /
    • 2011
  • The purpose of this study is to understand suffering of torture for victims with suspicion of espionage under the military government in Korea by knowing meaning and structure of empirical phenomena. Methods is to applied to Phenomenological and heuristic Human Becoming Methodology, and the subjects of this study are text for three tortured victims. Results is the structure that the victims accepted their act of espionage under the torture and horror, living with retribution from heaven, surviving pressured times, and fighting for human rights upon release from prison. The conceptual integration of relationship issues were: valuing, imaging, languaging with powering and transforming under the process of revealing-concealing and enabling-limiting. Finally, discussion and practical meaning was reviewed.

Physicochemical and Sensory Properties of Baekseolgi Prepared with Different Combinations of Xylitol and Sucralose (자일리톨·수크랄로스 혼합 첨가 백설기의 이화학적·관능적 품질 특성)

  • Jo, Hyeri;Surh, Jeonghee
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.44 no.9
    • /
    • pp.1339-1346
    • /
    • 2015
  • In a previous study, baekseolgi with xylitol or sucralose was comparable to baekseolgi with sugar in terms of all sensory characteristics. However, the hardness of sucralose baekseolgi increased considerably during storage while that of xylitol baekseolgi remained unchanged. To improve the physical limitations observed in sucralose baekseolgi, a combination of sucralose and xylitol were substituted for sugar when preparing baekseolgi (SL0~SL100, SLn; baekseolgi where sugar was replaced with n% sucralose and 100-n% xylitol based on relative sweetness to sugar). All SLn baekseolgi samples were not significantly different from sugar baekseolgi in terms of sensory properties. The moisture content was not different between sugar and xylitol baekseolgi (SL0), but decreased significantly as the amount of sucralose increased (P<0.01), which correlated with cohesiveness of baekseolgi. Texture profile analysis revealed that hardness of SLn baekseolgi increased without any noticeable change in moisture content after storage at $4^{\circ}C$ for 7 days. In addition, the hardness after storage was the highest in sucralose baekseolgi (SL100), which was comparatively lower in SL0~SL80 containing xylitol presumably due to the hygroscopic characteristics of xylitol. In particular, SL20 was found to be comparable to sugar baekseolgi in terms of moisture and cohesiveness during storage. The results showed that the combination of xylitol and sucralose could be a potential sugar substitute in terms of not only sensory characteristics but also physicochemical properties.

A Mineralogical and Gemological Studies for the Enhancement of Tanzania Ruby by Heat Treatment (탄자니아산 루비의 열처리에 의한 보석·광물학적 품질개선 연구)

  • Kim, Seon-Ok;Wang, Sookyun;Oh, Sul-Mi;Park, Hee Yul;Park, Maeng-Eon
    • Economic and Environmental Geology
    • /
    • v.47 no.6
    • /
    • pp.563-569
    • /
    • 2014
  • Ruby is one of the most favor colored gem, for beautiful red tone, be high in scarcity value. However, rubies with high quality are produced in restricted regions, such as in Thailand, Sri Lanka, Myanmar, and Tanzania etc., and they have been gradually exhausted by mining for a long period. Therefore, improving qualities of low level rubies with various treatments is arising an alternative way to obtain better rubies. Gemological and mineralogical properties of the natural ruby from Tanzanian were studied with heat treatments. Those characteristics were compared between only heat and adding flux materials under heating. Tanzanian raw rubies were applied a heat treatment ($1,600^{\circ}C$ for 6 hours). However, chromameter and UV-Vis analyses found that a simple heat treatment is inappropriated for the Tanzanian ruby. Although $Cr^{3+}$ containing for red color in the ruby increased with heat treatment, the ruby displays dark medium red because of Fe in the ruby as a form of $Fe_2O_3$. The low transparency after heat treatment is attributed to the recrystallization of $SiO_2$ which has a low melting point. Chromameter confirmed adding Pb-containing flux under heating greatly improves the clarity and color of Tanzanian rubies with micro-fractures and cavities on the surface. EMPA results show that Pb as an additive fills the cavities and cracks on raw Tanzanian rubies during the heat treatment. As a rewult of it, the quality of the Tanzanian ruby raw dramatically improved. These results indicate that the heat treatment with an additive (Pb in this study) is an effective way to obtain better quality of the Tanzanian ruby. Consequently, this study suggests a suitable method to improve the properties of the Tanzanina ruby. The result of this study would provide useful information to upgrade the qualities of similar gem stones such as corundum and sapphire.

A Study on the Shape and Movement in Dissolved Air Flotation for the Algae Removal (수중조류제거(水中藻類除去)를 위한 가압부상(加壓浮上)에 있어서 기포(氣泡)의 양태(模態)에 관한 연구(研究))

  • Kim, Hwan Gi;Jeong, Tae Seop
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.4 no.4
    • /
    • pp.79-93
    • /
    • 1984
  • The dissolved air flotation(DAF) has been shown to be efficient process for the removal of algae ftom water. The efficiency of DAF can be affected by the volume ratio of pressurized liquid to sample, the pressure pressurized liquid, the contact time, the appropriate coagulant and its amount, the water temperature, the turbulence of reactor, the bubble size and rising velocity etc. The purpose of this paper is to compare the practical bubble rising velocity with the theoretical one, to investigate the adhesion phenomenon of bubbles and floc, and the influence of bubble size and velocity upon the process. The results through theoretical review and experimental investigation are as follows: Ives' equation is more suitable than Stokes' equation in computation of the bubble rising velocity. The collection of bubble and algae floc is convective collection type and resulted from absorption than adhesion or collision. The treatment efficiency is excellent when the bubble sizes are smaller than $l00{\mu}m$, and the turbulence of reactor is small. In the optimum condition of continuous type DAF the volume ratio of pressurized liquid to sample is 15%, the contact time in reactor is 15 minutes, the pressure of pressurized liquid is $4kg/cm^2$ and the distance from jet needle to inlet is 30cm.

  • PDF

Changes in Physical Properties of Ham and Loin from Low-Fat Pork Cuts during Chilling after Thawing (해동 후 돼지고기 저지방 부위 뒷다리살과 등심의 냉장 중 물리적 특성 변화)

  • Moon, Yoon-Hee
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.23 no.4
    • /
    • pp.487-495
    • /
    • 2013
  • The vacuum packaged ham and loin from low-fat pork cuts were frozen at $-20^{\circ}C$ for 3 months and thawed. Then, the thawed meat was chilled at $3^{\circ}C$, and impacts of chilling period on changes in physical properties of raw meat and cooked meat were investigated. In the case of raw meat, the pH value, $L^*$ value, drip losses, water holding capacity and gumminess of ham increased significantly on the 4th day compared with the 0th day of chilling after thawing. However the cooking losses, hardness and chewiness decreased significantly. The loin showed a similar tendency on the 2nd day of chilling after thawing. In the case of cooked meat, changes in physical properties during chilling period after thawing showed a similar tendency as raw meat, but pH value, $L^*$ value and $a^*$ value did not show significant difference. The springiness and cohesiveness of both raw meat and cooked meat did not show significant difference during chilling period after thawing. The sensory tenderness of ham and loin improved significantly on the 4th day and 2nd day during chilling after thawing, respectively.

A Study on the Antilipidperoxidative Effects of Brazilin and Hematoxylin(I) (천연색소 Brazilin 및 Hematoxylin의 항지질 과산화활성에 관한 연구 (I))

  • 문창규;하배진;이수환;목명수
    • Journal of Food Hygiene and Safety
    • /
    • v.2 no.1
    • /
    • pp.35-40
    • /
    • 1987
  • The antilipidperoxidative effects of Brazilin and Hematoxylin were investigated at the levels of liver~total homogenates, -microsomal fraction, -mitochondrial fraction and the sera of SD-rats intoxicated with $CCl_4$ and ethanol. Both natural dyes markedly inhibited the lipidperoxidation induced by $CCl_4$ and ethanol. Brazilin and Hematoxylin showed the inhibitory effects on the both enzymatic (NADPH-dependent) and nonenzymatic (Ascorbate-induced) lipidperoxidation pathways. but it is supposed that the antilipidperoxidative powers of them mainly result from the inhibition of the nonenzymatic lipidperoxidation.

  • PDF

Phase Transition and Formatio of $TiSi_2$ Codeposited on Atomicaily Clean Si(111) (초청정 Si기판에 동시 증착된 $TiSi_2$ 의 상전이 및 형성)

  • Gang, Eung-Yeol;Jo, Yun-Seong;Park, Jong-Wan;Jeon, Hyeong-Tak;Nemaniah, R.J.
    • Korean Journal of Materials Research
    • /
    • v.4 no.1
    • /
    • pp.107-112
    • /
    • 1994
  • The phase transition and the surface and interface morphologies of $TiSi_2$ formed on atomically clean Si substrates are investigated. 200$\AA$ Ti and 400$\AA$ Si films on Si(ll1) have been codeposited at elevated temperatures (400~$800^{\circ}C$) in ultrahigh vacuum. The phase transition of TiSiL is characterized with using XRD. The results distinguish the formation of the C49 and C54 crystalline titanium silicides. The surface and interface morphologies of titanium silicides have been examined with SEM and TEM. A relatively smootb surface is observed for the C49 phase while a rough surface and interface are observed for C54 phase. The islanding of the C54 phase becomes severe at high temperature ($800^{\circ}C$). Islands of TiSiL have been observed at temperatures above $700^{\circ}C$ but no islands are observed at temperatures below $600^{\circ}C$. For films deposited at $400^{\circ}C$ and 500%. weak XRD peaks corresponding to TiSi were observed and TEM micrographs exhibited small crystalline regions of titanium silicide at the interface.

  • PDF