• Title/Summary/Keyword: Viscosity characteristics

Search Result 2,114, Processing Time 0.034 seconds

The study on characteristics of viscosity friction coefficient for a motor (전동기 점성마찰계수 특성에 관한 연구)

  • Byun, Yeun-Sub;Mok, Jei-Kyun;Kim, Young-Chol
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.1082-1083
    • /
    • 2007
  • Electric motors are widely used from precision industry to home appliance. For the precision control of the motors, if it is possible, we need the information of the correct motor parameters. In the motor torque equation, the motor inertia moment and the viscosity friction coefficient are regarded as constant. However the viscosity friction coefficient is not constant in the real system. In this paper, we show that the viscosity friction coefficient has the nonlinear property through the real test and we present the nonlinear function for the viscosity friction coefficient.

  • PDF

Systematic study on calcium-dissolved organic matter interaction in a forward osmosis membrane-filtration system (정삼투 멤브레인 공정에서 칼슘이온과 용존 유기물 상호작용에 의한 플럭스 변화 연구)

  • Heo, Jiyong;Han, Jonghun;Kim, Yejin;Her, Namguk
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.30 no.6
    • /
    • pp.737-744
    • /
    • 2016
  • The investigation of effects on fouling propensity with various viscosity of feed solutions would be better understanding for forward osmosis (FO) performance since the fouling propensity was directly influenced with solution viscosity. Therefore, this study was focused on the FO fouling with model foultants (humic acid, alginate) by altering solution viscosity with change of ionic strength (I.S) and $Ca^{2+}$ concentrations. In the comparison between humic acid and alginate, as expected, the alginate generally caused more severe fouling (almost 35.8 % of flux reduction) based on the solution characteristics (high viscosity) and fouling patterns (coil and gel layer). However, interesting point to note is that the fouling propensity of alginate was more severe even though it was applied with low viscosity of feed conditions (I.S = 20 mM, $Ca^{2+}=1mM$). This might be due to that crossed linked gel layer of alginate on the FO membrane surface could be best formed in the condition of $Ca^{2+}$ presence and higher I.S, and that is more dominant to fouling propensity than the low viscosity of feed solutions.

Effects of Dolomite Fine Aggregate and Cement-Based Materials on Viscosity Characteristics, Flow and Flow Time of High-Strength Grout (돌로마이트 잔골재와 시멘트계 재료의 용적 구성비가 고강도 그라우트의 점도 특성, 플로우 및 유하시간에 미치는 영향)

  • Jeong, Min-Gu;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2023.05a
    • /
    • pp.197-198
    • /
    • 2023
  • This study was conducted as part of research and development of high-strength grout. Accordingly, dolomite aggregate was used as a filler incorporated into the high-strength grout. Dolomite aggregate has a disadvantage of increasing the viscosity of the grout due to higher generation of fine powder than other aggregates. Accordingly, in this experiment, it was confirmed that the viscosity, flow time, and flow of high-strength grout change according to the volume composition ratio of dolomite aggregate and cement-based material. All experiments were conducted based on the Korean Industrial Standard KS F 4044, and the mixing factor was applied according to the composition ratio of the binder and the filler. In the experiment, the amount of fine powder contained in the dolomite aggregate rather than the silica sand used in the past is grasped, and after mixing with the grout accordingly, the mixture is proceeded to measure the viscosity in an unhardened state. In addition, the flow and flow time of the grout are evaluated according to the viscosity. As a result of the experiment, it was confirmed that the viscosity and flow time decreased and the flow increased as the volume composition ratio of the dolomite aggregate to the cement-based material increased.

  • PDF

Quality Characteristics of Dumpling Shell Containing Boehmeria nivea Powder (모시잎 분말 첨가에 따른 만두피의 품질 특성)

  • Park, In-Duck
    • Journal of the Korean Society of Food Culture
    • /
    • v.33 no.3
    • /
    • pp.268-275
    • /
    • 2018
  • This study examined the effects of Boehmerianivea powder on the functional and sensory characteristics of dumpling shell. Various dumpling shell samples were prepared with wheat flour containing different amounts of Boehmerianivea powder. The instrumental characteristics were examined and sensory evaluations were performed. According to the amylograph data, the composite Boehmerianivea powder-wheat flour samples had increased gelatinization temperatures with increasing Boehmerianivea powder content; whereas the initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and the maximum viscosity were reduced. The L, a and b Hunter's color values decreased with increasing Boehmerianivea powder content. In addition to the cooked weight, the cooked volume and turbidity of dumpling shell increased with increasing level of Boehmerianivea powder. In terms of the textural characteristics, the addition of Boehmerianivea powder increased the chewiness, smoothness and adhesiveness. The DPPH free radical scavenging activity increased significantly with increasing content of Boehmerianivea powder (p<0.05). Finally, the results of the sensory properties indicated that 5% Boehmerianivea powder had the highest scores. These results suggest that Boehmerianivea powder can be applied to dumpling shells to achieve high quality and functionality.

Quality Characteristics of Mandupi Added with Curcuma aromatica Powder (강황분말을 첨가한 만두피의 품질특성)

  • Park, Bock-Hee;An, Sung-A;Cho, Hee-Sook
    • Journal of the Korean Society of Food Culture
    • /
    • v.29 no.4
    • /
    • pp.348-354
    • /
    • 2014
  • The purpose of this study was to investigate the effects of Curcuma aromatica powder on the functional and sensory characteristics of Mandupi. Various Mandupi samples were prepared with wheat flour along with addition of various amounts of Curcuma aromatica powder, after which instrumental characteristics and sensory evaluations were investigated. According to the amylograph data, the composite Curcuma aromatica powder-wheat flour samples showed increased gelatinization temperatures with increasing Curcuma aromatica powder content, whereas initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity were reduced. In terms of Hunter's color values, L value decreased while a and b values increased with increasing Curcuma aromatica powder content. Besides cooked weight, cooked volume and turbidity of Mandupi increased as the addition level of Curcuma aromatica powder increased. In terms of textural characteristics, addition of Curcuma aromatica powder increased springiness, chewiness, and brittleness, whereas springiness and adhesiveness decreased. Based on sensory evaluations, the overall preference of Mandupi with 3% added Curcuma aromatica powder was higher than that of control.

Study on Rheological Characteristics of Self-Compacting Concrete using Glass Bubble (글라스 버블을 사용한 자기 충전 콘크리트의 레올로지 특성에 관한 연구)

  • Lee, Han-Yong;Yoon, Seob;Seo, Tae-Seok
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2017.11a
    • /
    • pp.73-74
    • /
    • 2017
  • In this study, unlike high flowing concrete, using glass bubble to develop self-compacting concrete(hereinafter referred to as "SCC") with excellent filler performance by evaluating both flowability and yield stress, viscosity An experiment was conducted. Experimental results show that when 1 kg of glass bubbles are used, it is effective in stabilizing the physical properties of concrete, reducing the yield stress and viscosity.

  • PDF

Quality Characteristics of Sulgidduk Containing Added Red Ginseng Powder (홍삼분말을 첨가한 설기떡의 품질특성)

  • Shin, Seung-Mee;Jung, Jung-Suk;Han, Myung-Ryun;Kim, Ae-Jung;Kim, Young-Ho
    • Korean journal of food and cookery science
    • /
    • v.25 no.5
    • /
    • pp.586-592
    • /
    • 2009
  • Sulgidduk samples containing 2, 4, and 8% red ginseng powder and a control[ED highlight - consider specifying what the control was, if 0%, then change to Sulgidduk samples containing 0(control), 2, 4 and 8%] were examined for moisture content, color, gelatinization properties, textural characteristics, and sensory qualities to determine the optimal ratio of red ginseng powder in the formulation. The moisture contents among the samples did not differ significantly. Specifically, they ranged from 39.64 to 40.69%, and increased as the red ginseng powder content increased. Additionally, the lightness decreased and the yellowness and redness increased as the red ginseng powder content increased. Evaluation of the gelatinization properties revealed that the, peak viscosity(P), hold viscosity(H), final viscosity(F), setback, and time to peak viscosity decreased with increasing red ginseng powder content, but the breakdown and temperature to peak viscosity did not differ significantly among samples[ED highlight - please ensure my changes are correct]. The hardness and adhesiveness decreased with increasing red ginseng powder content, as did the cohesiveness, gumminess, and chewiness; however, the springiness did not differ significantly among samples. Sulgidduk containing 4% red ginseng received the highest scores for flavor, taste, texture and overallquality. Based on the above results of the sensory and texture analyses, Sulgidduk containing 4% red ginseng had the highest quality[ED highlight - please ensure my changes are correct].

Characteristics of Chitosan-treated Cotton Fabric (키토산으로 처리한 면직물 물성에 관한 연구)

  • 최인례
    • The Research Journal of the Costume Culture
    • /
    • v.5 no.3
    • /
    • pp.151-158
    • /
    • 1997
  • This study was to find out the differences of the characteristics on chitosan from source, the crab and the shrimp. Chitosan was depolymerized in NaBO₃·4H₂O under various reaction time and temperature. 4 Chosen chitosan dissolved in acetic acid and treated to cotton fabrics. The cotton fabrics treated with chitosan showed an exellent antibacterial activity irrespective of the viscosity. Stiffness of the treated cotton fabrics increased 3∼8 times than untreated cotton fabric, it gives harshness to treated cotton fabrics, it gives harshness to treated cotton fabrics like linen. Air permeability of the treated cotton fabrics increased. Stiffness and air permeability are respective to viscosity of the chitosan.

  • PDF

A Rheological Study of Topical Vehicles

  • Min, Shin-Hong;Rhee, Shanghi;Kim, Yong-Bae
    • Archives of Pharmacal Research
    • /
    • v.2 no.2
    • /
    • pp.89-97
    • /
    • 1979
  • To find out the rheological characteristics of several pharamaceutical semisolid products, experiments were carriedout over the temperature range of 20 to 30 .deg.C . From continuous shear rheograms obtained with a Ferranti-Shirley cone and plate viscometer, loop area, shear rates, ryild values, limiting viscosities and activation energies were calculated. The systems were metastable and their viscosity decreased with time. As the temperature was raised, products studied showed a decrease in viscosity and yield value.

  • PDF

Experimental Study on Spray Etching Process In Micro Fabrication of Lead Frame

  • Jung, Ji-Won;Choi, Gyung-Min;Kim, Duck-Jool
    • Journal of Mechanical Science and Technology
    • /
    • v.18 no.12
    • /
    • pp.2294-2302
    • /
    • 2004
  • The objective of this study is to obtain detailed information for the micro fabrication of lead frames by applying spray technology to wet etching process. Wet etching experiments were performed with different etching parameters such as injection pressure, distance from nozzle tip to etched substrate, nozzle pitch and etchant temperature. The characteristics of single and twin spray were measured to investigate the correlation between the spray characteristics and the etching characteristics. Drop size and velocity were measured by Phase-Doppler Anemometer (PDA). Four liquids of different viscosity were used to reveal the effects of viscosity on the spray characteristics. The results indicated that the shorter the distance from nozzle tip and the nozzle pitch, the larger etching factor became. The average etching factor had good positive correlation with average axial velocity and impact force. It was found that the etching characteristics depended strongly on the spray characteristics.