• Title/Summary/Keyword: Water hardness

Search Result 1,774, Processing Time 0.027 seconds

Physicochemical and Cooking Characteristics of Non-waxy Soft Brown Rice (연질현미의 이화학적 및 취반 특성)

  • Park, Jihye;Shin, Malshick
    • Korean journal of food and cookery science
    • /
    • v.32 no.5
    • /
    • pp.531-540
    • /
    • 2016
  • Purpose: To improve the cooking quality of brown rice, newly inbred soft rice cultivars were investigated. Methods: The physicochemical properties of brown rice flour and water absorption patterns and cooking characteristics of brown rice grain were compared to Ilmi white and brown rice. Results: General composition and total dietary fiber contents of five rices were significantly different with higher ash, protein, and total dietary fiber contents in soft brown rice than white rice. The hardness of raw rice grain was higher in Ilmi brown rice than in soft brown rice. The water absorption increased rapidly in 30 min of white rice and in 4-6 h of brown rices. The apparent amylose content of soft brown rice was lower than that of Ilmi rice. The initial pasting temperature and all viscosities were significantly different, but the trend was not similar. The textural properties of hardness and roughness were higher, but adhesiveness, cohesiveness, and stickiness were lower in Ilmi brown rice than white and soft brown rices. In sensory preference test, not only textural properties, hardness, adhesiveness, cohesiveness, stickiness, and roughness, but also color, glossiness, and roasted flavor were higher in soft brown rices. Especially soft brown rice B showed the best cooking quality among all rices. Conclusion: The results of the study suggested that soft brown rice is developed for cooking with high nutritional and functional quality.

Investigation on surface hardening and corrosion characteristic by water cavitation peening with time for Al 5052-O alloy (5052-O 알루미늄 합금의 워터 캐비테이션 피닝 시간에 따른 표면 경화와 부식 특성에 관한 연구)

  • Kim, Seong-Jong;Hyun, Koang-Yong
    • Corrosion Science and Technology
    • /
    • v.11 no.4
    • /
    • pp.151-156
    • /
    • 2012
  • The cavity formed by the ultrasonic generation in the fluid with the application of water cavitation peening collides into the metal surface. At this time, the surface modification effect such as the work hardening presents by the compressive residual stress formed due to the localized plastic deformation. In this investigation, the water cavitation peening technology in the distilled water with the lapse of time was applied to 5052-O aluminum alloy for aluminum ship of a high value. So, the optimum water cavitation peening time on the effect for surface hardening and anti-corrosion property was investigated. Consequently, the water cavitatin peening time on excellent hardness and corrosion resistance characteristic presented 3.5 min. and 5.0 min, respectively. The surface hardness in the optimum water cavitation peening time was improved approximately 45% compared to the non-WCPed condition. In addition, corrosion current density was decreased.

Factors Affecting Physical Properties of Solid Sunscreen Using Response Surface Methodology (반응표면분석법을 이용한 고형 자외선 차단제의 물성에 영향을 주는 요인)

  • Ryu, Sang Deok;Heo, Min Geun;Yoon, Kyung-Sup
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.45 no.3
    • /
    • pp.237-254
    • /
    • 2019
  • This study is focused on the effect of sodium stearate, which is a hydrophilic gelling agent affecting on the hardness of O/W solid sunscreen cosmetic. The sunscreen of the O/W (oil in water) type is stable, good in use, and relatively easier to stabilize than the sunscreen of the W/O (water in oil) type. Methods for increasing the stability by using emulsifiers, electrolytes, and wax or oil have been studied for solid sunscreen. This study was intended to develop a solid sunscreen stabilized by increasing the hardness using sodium stearate as an O/W type containing more than 40% moisture. Response surface methodology (RSM) was used to analyze the factors affecting the hardness of cosmetics, and sodium stearate, polyol and oil were used for each factor. The hardness and the reaction value was measured using a rheometer. As a result, sodium stearate showed a meaningful value (p < 0.05) among the three factors affecting hardness. In addition, the use of sodium stearate as a hydrophilic gelling agent increased the usability and stability of the solid sunscreen.

Effect of Washing Solution Characteristics on the Removal and Color of Cocoa Stains (세탁용수의 특성에 따른 코코아 오구의 세척성과 색상)

  • Chung, Hae-Won;Kim, Hyo-Jeong
    • Fashion & Textile Research Journal
    • /
    • v.14 no.3
    • /
    • pp.492-500
    • /
    • 2012
  • Cocoa is a popular drink for children and contains healthy polyphenols however; a deep brown stain is left when cocoa is spilled over clothes. The main pigments in cocoa are anthocyanins that change in washing solutions with different alkalinity and metals. The removal and color changes in a cocoa stain after washing with various pH solutions and water hardness were studied. Alkalinity and the water hardness of washing solutions were important factors for the removal of cocoa stains. The removal of cocoa things in washing solutions without detergent was low (and even became negative after removal and darker) in solutions with a pH 9 and above. The cocoa stain was not removed and only the fabric color faded, although the cocoa stained cloth was washed with Korea tap water that has a pH of 7. The cocoa stain removal in detergent solutions was conspicuously higher than for only water. Even in detergent solutions, the cocoa stain removal decreased as water hardness increased. Cocoa stain removal was more effective and the color dimmest when the stained cloth was washed in a solution without the metal cations, and the bleach added with the detergent at a temperature of $40^{\circ}C$ and for longer than 20 minutes. Effective and economical equipment for tap water softening for a washing machine should be developed and used to improve cocoa stain removal.

Differences of Water Absorption Property and Seed Viability according to Morphological Characters in Soybean Genotypes

  • Kim, Seok-Hyeon;Kim, Ji-Na;Chung, Jong-Il;Shim, Sang-In
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.51 no.1
    • /
    • pp.59-65
    • /
    • 2006
  • The impermeable seed coat is valuable trait in soybean because impermeable seed retain viability for longer period than permeable seed under adverse conditions such as delayed harvest or prolonged storage. Soybean seeds of various size showing different seed hardness were examined for their water absorption and seed viability under adverse storage conditions. Of one hundred thirty nine genotypes, eight types of seeds having different seed hardness and seed size were used as material. Soybean genotypes showing high hard seed rate, GSI13125 (89%), GSI10715 (54%), and GSI10284 (42%), were slow in water absorption and low in the electroconductivity of seed leachate in distilled water. Germination of GSI10284 and GSI13125 that have higher hard seed rate was less affected by CSVT and artificial aging treatment indicating higher seed storability. The higher storing ability of both collections was confirmed by electroconductivity test for leachate. GSI10122 showed low seedling emergence when the seeds were artificially aged. This genotype was considered as to having a poor storing ability based on difference of electroconductivity before and after artificial aging. Among tests conducted in the experiment, CSVT could be used for determining storage life in legumes. In conclusion, water absorption property of seed was strongly related to the hardness that is directly related to the seed viability and storing ability in soybean seed.

A Study on the Content of Manganese and Chrome in the Ground Water in Seoul Area (Based on non-water supply area) (서울 일부지역 정호수의 망간, 크롬함량 조사연구 상수시설 미설치지역을 중심으로)

  • 구성회;우세홍;이성호;이부웅
    • Journal of Environmental Health Sciences
    • /
    • v.1 no.1
    • /
    • pp.41-45
    • /
    • 1974
  • A study was carried out to determine the content of Mn and Cr in the ground water in Seoul area, where municipal water supply system was not installed, from Nov. 1 to Nov. 30, 1973. In this study, authors examined the hardness, pH, water temperature and Cl ion to investigate the general conditions of the ground water. For this study, samples were collected from 46 wells which were located in outpart of Seoul city, and Mn and Cr were determined with the Spectronic-20. The following results were obtained: 1) Average value of the ground water conditions of the wells were 13.3$\circ$C in temperature, pH 6.3, hardness 159 ppm and Cl ion 41 ppm. 2) In the manganese concentration, the highest area was Yeongdeungpo-Ku(0.318 ppm), while the lowest area was Sungbuk-Ku(0.065 ppm) and the mean concentration of the whole district was 0.196 ppm. 3) In the chrome concentration, the highest area was Yeongdeungpo-Ku(0.031 ppm), while the lowest area was Dobong-Ku (trace) and the mean concentration of the whole district was 0.012 ppm.

  • PDF

A Development of the Guideline for the Heating Water Quality in Apartment Houses with District Heating System (공동주택 지역난방 수질기준 설정에 관한 연구)

  • Kim, Yong-Ki;Lee, Tae-Won;Woo, Dal-Sik;Oh, June;Ahn, Chang-Koo
    • Proceedings of the SAREK Conference
    • /
    • 2008.11a
    • /
    • pp.493-498
    • /
    • 2008
  • Particles or deposit formed by corrosion of the pipe material bring about bad influences on the heating systems with inconvenience, energy loss and so on. In order to obtain the non-corrosive environments, the circulation hot water should properly be treated in several ways to satisfy one or more conditions of the followings: suitable pH-level, low hardness, low oxygen content, low conductivity, low level of chlorides and sulphur compounds and low level of solid particles. This experimental study was carried out to develope the new guidelines on the optimal water quality and directions for water quality management in heating systems. As results, it was recommended that the heating water be maintained pH-level not less than 8, hardness contents as $CaCO_3$ no more than 50 mg/L, turbidity no more than 10 NTU and T-Fe contents 1 mg/L below.

  • PDF

A STUDY ON SURFACE HARDNESS OF COMPOSITE RESINS ACCORDING TO STORAGE CONDITON AND HEAT TREATMENT (보관조건과 열처리에 따른 복합레진의 표면경도에 관한 연구)

  • Kang, Seung-Hoon;Min, Byung-Soon
    • Restorative Dentistry and Endodontics
    • /
    • v.19 no.1
    • /
    • pp.194-204
    • /
    • 1994
  • The purpose of this study was to evaluate the surface hardness of composite resins according to heat treatment. storage condition and storage time. In this study. two kinds of composite resin inlays and one kind of conventional posterior composite resin were used as experimental materials. One hundred eighty composite resin specimens were constructed from composite resin inlays and conventional posterior composite resin. The conditions of this study were heat treatment. storage condition and storage time. Hardness readings were taken from the top surface of each samples using the Vickers microhardness tester(MHT-l. Matsuzawa. Japan}. The following results from this study were obtained: 1. Regardless of storage condition. both composite resin inlay and conventional posterior composite resin have a higher surface hardness under heat treatment than not. 2. Composite resins with heat treatment have a higher surface hardness under dry storage than under water immersion. 3. In case of Clearfil Photo Posterior and Brilliant Enamel with heat treatment. there was no significant difference with time. but Clearfil CR Inlay with heat treatment. there was statistical difference after 24 hours. 4. Surface hardness of composite resins with coarse hybrid type was higher than that of composite resin with fine hybrid type.

  • PDF

Reforming of Expanded Graphite for Improving Fire Resistance of Fireproof Sealant (방화용 실란트의 내화성 향상을 위한 첨가제로서 팽창흑연의 개질)

  • Hong, In Kwon;Lee, Won Jae;Lim, Hyun Seok;Lee, Seung Bum
    • Applied Chemistry for Engineering
    • /
    • v.28 no.4
    • /
    • pp.437-441
    • /
    • 2017
  • This study was carried out to investigate the volumetric expansion ratio and hardness of expanded graphite after coating with various resins which were used as an additive of fireproof sealant. The coating thickness of the resin, which represents the coating rate, was dependent of the drying speed of the resin and the viscosity of the resin. Therefore the coating thickness was shown as follows: polyvinyl acetate > acrylic resin > urethane resin > water soluble latex. Furthermore, the volumetric expansion ratio was as follows: urethane resin > water soluble latex > acrylic resin > polyinyl acetate and the hardness was as follows: polyvinyl acetate resin > acrylic resin > water soluble latex > urethane resin. This showed that the volume of expansion was reduced by expansion, which was not covered by coating, but significantly increased by increasing hardness and allowed it to be used as a refractory addition. According to the response surface methodology, the optimized addition amount and stirring speed of acrylic resin were 37.6 wt% and 441.4 rpm, respectively.