• Title/Summary/Keyword: Humidity stability

Search Result 261, Processing Time 0.037 seconds

Inorganic-organic Hybrid Proton Conductive Membranes Doped with Phosphoric Acid

  • Huang Sheng-Jian;Lee Yong Su;Lee Hoi Kwn;Kang Won Ho
    • Proceedings of the KAIS Fall Conference
    • /
    • 2004.06a
    • /
    • pp.96-99
    • /
    • 2004
  • A new proton conductive inorganic-organic hybrid membrane doped with $H_3PO_4$ was fabricated via sol-gel process wit 3- glycidoxypropyltrimethoxysilane(GPTMS), 3-aminopropyltriethoxysilane(APTES) and tetraethoxysilane(TEOS) asprecursors. Theproto conductivity of about 3.0$\times10^{-3}S/cm$ was obtained at $120^{\circ}C$ under $50\%$ relative humidity (R.H). DTA curves showed that the thermal stability of the membrane is significantly enhanced by the presence of $SiO_2$ framework up to $250^{\circ}C$. SEM and XRD revealed that the gel is microporou and amorphous. The addition of APTES improved the conductivity of the membranes and the effect of the APTES on the conductivity was also discussed in this paper.

  • PDF

Preparation and application of gel type polymer electrolyte for PEFC (PEFC 연료전지용 겔 타입 고분자 전해질 합성 및 응용)

  • Lee, Sang-Yong;You, Ji-Yeon;Kim, Han-Joo;Oh, Mee-Hye;Park, Soo-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.11a
    • /
    • pp.42-45
    • /
    • 2003
  • Inorganic polymer based hybrid membranes consisting of zirconium oxide and polydimethylsiloxane (PDMS) have been synthesized by sol-gel processes. The hybrid membranes showed thermal stability and flexibility up to $300^{\circ}C$. The membrane becomes proton conducting polymer electrolyte when added with 12-phosphotungstic acid (PWA). The conductivity of the membranes was measured in the temperature range from room temperature to $150^{\circ}C$ under saturated humidity and a maximum conductivity of $5{\times}10^{-5}\;Sm^{-1}$ was obtained at $150^{\circ}C$.

  • PDF

Study about Road-Surrounding Environment Analysis and Monitoring Platform based on Multiple Vehicle Sensors (다중 차량센서 기반 도로주변환경 분석 및 모니터링 플랫폼 연구)

  • Jang, Bong-Joo;Lim, Sanghun;Kim, Hyunjung
    • Journal of Korea Multimedia Society
    • /
    • v.19 no.8
    • /
    • pp.1505-1515
    • /
    • 2016
  • The age of autonomous vehicles has come according to development of high performance sensing and artificial intelligence technologies. And importance of the vehicle's surrounding environment sensing and observation is increasing accordingly because of its stability and control efficiency. In this paper we propose an integrated platform for efficient networking, analysis and monitoring of multiple sensing data on the vehicle that are equiped with various automotive sensors such as GPS, weather radar, automotive radar, temperature and humidity sensors. From simulation results, we could see that the proposed platform could perform realtime analysis and monitoring of various sensing data that were observed from the vehicle sensors. And we expect that our system can support drivers or autonomous vehicles to recognize optimally various sudden or danger driving environments on the road.

A Study on Stability according to the Conservation Environment for Fixative of Korean Mural Painting Layers (한국 흙벽화 채색층 고착제의 보존환경에 따른 안정성 연구)

  • Jin, Byung-hyuk;Wi, Koang-chul
    • Korean Journal of Heritage: History & Science
    • /
    • v.46 no.3
    • /
    • pp.150-171
    • /
    • 2013
  • The most important part of conservation treatment of murals is to preserve them against the risk of a damage by injecting fixative into them when the painting loses its cohesion or powderization of pigments occurred due to occurrence of cracks inside the painting layer. However, studies on the stability of fixative used for painting layers of murals are still insufficient. This study manufactured a mural as a specimen and colored it with four kinds of pigments including oyster shell white, cinnabar, malachite and red clay and applied four kinds of fixative, including, Paraloid $B-72^{(R)}$, Caparol-$binder^{(R)}$, glue and Hydoxypropyl $cellulose^{(R)}$. artificially generated environmental changes in temperature, humidity and ultraviolet rays which may occur after the completion of conservation treatment. Then the changes in physical properties were observed in multifaceted ways such as color stability, contact angle, brilliance, adhesive strength and surface. As a result, this study found that ultraviolet rays and hot?humid environment have a large impact on color stability causing changes in brightness and chroma of all painting layers where the fixative were applied, except for oyster shell white and are considered the main factors of decomposition by accelerating the aging process of fixatives applied. In comparison to the synthetic resins that were also tested in this study, the traditional glue showed satisfactory results in terms of color stability and influence preservation and the hydrophile property. As it showed exceptionally outstanding adhesive strength in all painting layers in the aspect of adhesive strength, it is considered to be highly stabile for the fixation treatment of painting layers of mural.

Manufacture of Water-Resistant Corrugated Board Boxes for Agricultural Products in the Cold Chain System(II) - Application Methods of Chemicals for Improving Water and Moisture Resistance of Corrugated Boards - (농산물 저온유통용 내수 골판지 상자의 제조(제2보) - 골판지의 내수 및 내습성 향상을 위한 약품 적용 방법 -)

  • Jo, Jung-Yeon;Min, Choon-Ki;Shin, Jun-Seop
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
    • /
    • 2004.04a
    • /
    • pp.192-210
    • /
    • 2004
  • Application methods of chemicals were investigated tn minimize strength reduction of corrugated boards under the high humidity environment encountered in the cold chain system. Starch insolubilizers were introduced in the starch solution preparation of the Stain hall method and their insolubilization effect of starch binder were estimated. The performance of water repellent agents(WRA) and moisture proof agents(MPA) were evaluated in terms of water and moisture resistance. And effects of the combination of the chemicals and the coating method were also examined. Addition of the polyamine polyamide insolubilizer to the main part in the Stain hall process improved the binding force and water resistance of starch, which contributed to minimize the strength reduction of paper under the high humidity environment. AZC and Glyoxal type insolubilizers could not be used in the experiment due to an excessively increased viscosity of starch solution and the poor stability. Conventional WRA treatment to the base paper enhanced water and moisture resistance very slightly even though water repellency of the paper reached R10 by the treatment. MPA showed excellent performance than WRA not only in water and moisture resistance but in water repellency. Double coating on paper with MPA was more effective than the single coating at the same coating weight. A newly developed MPA showed excellent performance and runnability only by a single coating instead of a double coating.

  • PDF

Carbohydrate Characteristics and Storage Stability of Korean Confections Kangjeong and Dashik (강정과 다식의 탄수화물(炭水化物) 특성(特性) 및 저장성(貯藏性))

  • Lee, Hei-Sook;Lee, Su-Rae
    • Korean Journal of Food Science and Technology
    • /
    • v.18 no.6
    • /
    • pp.421-426
    • /
    • 1986
  • The carbohydrate characteristics and storability of two Korean traditional confections Seban-kangjeong (a Korean fried waxy-rice cookie) and starch-dashik (a Korean pressed starch cookie) were studied as compared with two Western confections fried cookie and biscuit. Seban-kangjeong showed lower contents of starch and sucrose and higher content of reducing sugar whereas starch-dashik showed higher contents of starch and sucrose and lower content of reducing sugar. Moisture content was higher in Korean confections than in Western confections. The degree of gelatinization was higher in Seban-kangjeong and fried cookie which were made through a frying process. Moisture adsorption isotherms were constructed for the four products. In storage test for 6 months under different temperature and humidity conditions, the relative humidity maintaining the initial moisture content of products was 68% for Seban-kangjeong and starch-dashik and 20% for fried cookie and biscuit. The ratio of retrogradation in storage was 15% in Seban-kangjeong, 20% in starchdashik and 28% in fried cookie and biscuit, showing the lowest progress in freezer storage.

  • PDF

Dry aging of beef; Review

  • Dashdorj, Dashmaa;Tripathi, Vinay Kumar;Cho, Soohyun;Kim, Younghoon;Hwang, Inho
    • Journal of Animal Science and Technology
    • /
    • v.58 no.5
    • /
    • pp.20.1-20.11
    • /
    • 2016
  • The present review has mainly focused on the specific parameters including aging (aging days, temperature, relative humidity, and air flow), eating quality (flavor, tenderness and juiciness), microbiological quality and economic (shrinkage, retail yields and cost) involved beef dry aging process. Dry aging is the process where beef carcasses or primal cuts are hanged and aged for 28 to 55 d under controlling environment conditions in a refrigerated room with $0^{\circ}$ to $4^{\circ}C$ and with relative humidity of 75 to 80 %. However there are various opinions on dry aging procedures and purveyors of such products are passionate about their programs. Recently, there has been an increased interest in dry aging process by a wider array of purveyors and retailers in the many countries. Dry aging process is very costly because of high aging shrinkage (6 to 15 %), trims loss (3 to 24 %), risk of contamination and the requirement of highest grades meat with. The packaging in highly moisture-permeable bag may positively impact on safety, quality and shelf stability of dry aged beef. The key effect of dry aging is the concentration of the flavor that can only be described as "dry-aged beef". But the contribution of flavor compounds of proteolysis and lipolysis to the cooked dry aged beef flavor is not fully known. Also there are limited scientific studies of aging parameters on the quality and palatability of dry aged beef.

Compatibility Study of Excipients for Pravastatin Tablet (Pravastatin 정제 연구를 위한 첨가제와의 적합성 연구)

  • Kim, Kang Min
    • Journal of Life Science
    • /
    • v.28 no.4
    • /
    • pp.472-477
    • /
    • 2018
  • Pravastatin sodium is a 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor used in the treatment of hypercholesterolemia by reducing cholesterol biosynthesis. Pharmaceutical excipients of commonly used including water, diluents, stabilizers, disintegrants, lubricants and colorants, and were identified for compatibility. All tests were performed by means of physical mixture of pravastatin and the excipients, which were placed in a press-through-pack (PTP) and incubated under accelerated conditions ($40^{\circ}C$ and 75% relative humidity) for 3 months. The blends of pravastatin with all excipients developed white, off white, and light brown powders, which showed no changes upon visual analysis. Accelerated conditions changed the degradation profile of pravastatin calcium in the HPLC system when mixed with different excipients. Although most excipients can have minor effects on pravastatin stability, the major degradation product from pravastatin was lactone. Low-level interaction (assay and impurity) was induced by all excipients except for microcrystalline cellulose and croscarmellose sodium. These excipients increased lactone impurity in 3 months by as much as 0.22% and 0.18% respectively. The total mixture slightly increased the lactone impurity (by 0.43% in 3 months) of pravastatin. There was no change in the assays of all excipients. These results will be helpful in studying tablet size reductions for convenience of use.

Manufacture of Water-Resistant Corrugated Board Boxes for Agricultural Products in the Cold Chain System(II). -Application Methods of Chemicals for Improving Water and Moisture Resistance of Corrugated Boards- (농산물 저온유통용 내수 골판지 상자의 제조(제2보) - 골판지의 내수 및 내습성 향상을 위한 약품 적용 방법 -)

  • 조중연;민춘기;신준섭
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.36 no.2
    • /
    • pp.60-69
    • /
    • 2004
  • Application methods of chemicals were investigated to minimize strength reduction of corrugated boards under the high humidity environment encountered in the cold chain system. Starch insolubilizers were introduced in the starch solution preparation of the Stein hall method and their insolubilization effect of starch binder were estimated. The performance of water repellent agents(WRA) and moisture proof agents(MPA) were evaluated in terms of water and moisture resistance. And effects of the combination of the chemicals and the coating method were also examined. Addition of the polyamine polyamide insolubilizer to the main part in the Stein hall process improved the binding force and water resistance of starch, which contributed to minimize the strength reduction of paper under the high humidity environment. AZC and Glyoxal type insolubilizers could not be used in the experiment due to an excessively increased viscosity of starch solution and the poor stability. Conventional WRA treatment to the base paper enhanced water and moisture resistance very slightly even though water repellency of the paper reached R10 by the treatment. MPA showed excellent performance than WRA not only in water and moisture resistance but in water repellency. Double coating on paper with MPA was more effective than the single coating at the same coating weight. A newly developed MPA showed excellent performance and runnability only by a single coating instead of a double coating.

A Study on Socio-economic Investment Effects of Ginger Storage in Artificial Caves (In the Case of Seochun Districts in Chungnam Province) (토굴을 이용한 생강저장의 사회 경제적 투자효과 분석 - 서산지역을 중심으로 -)

  • Lee, Mu Won;Lim, Jae Hwan
    • Korean Journal of Agricultural Science
    • /
    • v.25 no.2
    • /
    • pp.310-320
    • /
    • 1998
  • This study is aimed at identifying the socio-economic effects of storage of ginger in artificial caves. The gingers stored in artificial caves in Seochun, 12 sampled areas, were surveyed to get information on the socio-economic effects. The surveyed data were processed by TSP, Qbasic and B/C Ratio computer programs and analyzed the decision making criteria such as B/C ratio, NPV and IRR. The socio-economic effects of the storages of the gingers are as follows. 1. The storage benefits per ton was showed as 184,050won. 2. Considering 10% of the opportunity cost of capital, the uper limits of investments for the cave storages was analyzed as 6,784 thousand won for ginger. 3. The investment of the natural cave storages was revealed economically feasible considering the decision making criteria as B/C ratio = 1.33, NPV = 35.059 thousand won and IRR = more than 100%. The other socio-economic effects of the ginger storages was expected as ; 1. The cave storages will contribute to increase consumer's and producer's welfare through the control of supply and demand and price stability. 2. Long-term storage of ginger without damaging quality and grades will be made on account of the storage conditions as relatively low temperature, high humidity and indifferent affects from the outside climate. 3. Utilization of the underground space, the caves, for storage will maximize the land use and the sustainable environment considering the mountainous area, two third of the total national land area. 4. Construction costs of the underground storage facilities as caves are cheaper than the ground storage facilities by 15 to 20% in general. In conclusion, the underground space like natural and artificial caves are considered the most suitable for storage of ginger on account of the storage conditions as temperature, humidity and blocking the sun light. Accordingly a study on convenient utilization of new development of artificial caves should be made considering transportation and input-output of the farms. Financial support of the government should be institutionally rearranged for the successful implementation of storing farm products like ginger in natural and man-made caves.

  • PDF