• Geomechanics and Engineering
• /
• 제36권1호
• /
• pp.19-26
• /
• 2024

Erigen's nonlocal thermoelasticity model is used to study the effect of viscosity on a micropolar thermoelastic solid in the context of the multi-phase-lag model. The harmonic wave analysis technique is employed to convert partial differential equations to ordinary differential equations to get the solution to the problem. The physical fields have been presented graphically for the nonlocal micropolar thermoelastic solid. Comparisons are made with the results of three theories different in the presence and absence of viscosity as well as the gravity field. Comparisons are made with the results of three theories different for different values of the nonlocal parameter. Numerical computations are carried out with the help of Matlab software.

• Carbon letters
• /
• 제14권1호
• /
• pp.45-50
• /
• 2013

Polyacrylonitrile (PAN) copolymers of different molecular weights were synthesized by a suspension polymerization and precipitation polymerization method. The rheology behaviors of the synthesized PAN copolymers were investigated in relation to their molecular weight, solid content and melting temperature. The influence of "historical effects" on the spinning solution of PAN was studied by analyzing the laws of viscosity considering the diversification time and temperature. The viscosity disciplines of each spinning solution conformed well to the rheological universal laws in a comparison of the suspension polymerization product with that of precipitation polymerization. Viscosity changes in the swelling process of dissolution were gentler in the suspension polymerization product; a small amount of water will quickly debase the solution viscosity, and high-speed mixing can greatly shorten the time required by the spinning solution to reach the final viscosity.

• 펄프종이기술
• /
• 제44권2호
• /
• pp.67-73
• /
• 2012

Structural stability and shock absorption are important properties for corrugated board. In order to maintain structural stability, adhesive properties between top/bottom liners and corrugated medium are not only essential but also important for productivity and product quality. Borax has been an essential ingredient in corrugating adhesive solution. Borax increases viscosity, bonding between starchs and green adhesive bond. The objective of this research is to improving adhesive strength and viscosity stability by adding cross-linking agent instead of borax. Rheology and penetration of main starch gelatinization slurry were affected by borax addition level. Borax increased viscosity and decreased viscosity stability, while cross-linking additives increased viscosity stability and adhesive strength by anchoring effect.

• 대한화장품학회지
• /
• 제19권1호
• /
• pp.108-126
• /
• 1993

유화, 가용화, 겔화 등의 화장품 제형에서 폴리옥시에칠렌 토코페릴에테르의 기능에 대해 연구하였다. Liquid paraffin의 유화에 있어서 POE(10)TE는 O/W 유화에서 우수한 유화능을 나타내었다. W/o 및 O/W 유화에서 oil 과 polyol 류의 함량 증가가 점도에 미치는 영향에 대해서도 연구하였다. O/W 유화에서 점도는 liquid paraffin 약 70% 함량에서 급격히 증가하기 시작하였으며, propylene glycol 첨가시는 약간의 증가만 나타내었다. 그러나 W/O 유화에서 점도는 liquid paraffin의 함량 증가에 따라 감소하였고, propylene glycol함량 증가에 대해서도 감소하는 경향을 나타내었다. Perfume oil의 가용화에 있어서 POE(18)TE는 우수한 가용화능을 나타내었다. Poe(n)TE의 gelling effect는 폴리옥시에칠렌의 사슬의 증가에 따라 50 mol 까지는 상승하는 현상을 나타내었다.

• Journal of Nutrition and Health
• /
• 제26권6호
• /
• pp.793-803
• /
• 1993

This study was designed to measure viscosity, osmolality and in vitro flow rates via nasogastric tubes for 6 types of commercially available and 9 hospital-blenderized enteral solutions and to examine the effect of viscosity and osmolaility of enteral formula on the flow rates in gravity drip administration. Each solution was infused through 18, 16, 14, 12 French sizes of silicone rubber tube. Flow rates were measured six times at $25^{\circ}C$ using formula bags and drip sets hung at a uniform height on a intravenous drip stand with tube uniformly positioned in collecting container. Viscosity ranged widely from 16.0 to 195.5 cps with mean, 64.61$\pm$64.42 for hospital-blenderized formula while mean viscosity of commercial formula was 7.60$\pm$4.84 cps. Mean osmolality of commercial formula and hospital-blenderized formula were 370$\pm$100.80, 540.33$\pm$89.37 mOsm/kg respectively. There was negative relationship between viscosity of formula and flow rates through tubes but no significant relationship between flow rates and osmolalty. Some of hospital-blenderized formula was too viscous to be infused througth tube with gravity drip administration and the recipe of formula requires to be modiifed. On the other hand, commercial formula with the low viscosity flows too rapidly with large bore size tubes. Smaller size of tube must be selected for hyperosmolar solution to decrease possible side effects associated with tube feeding. Two kinds of regression equations for flow rates obtained according to viscosity and tube sizes were also presented for the purpose of practical uses. In conclusion, this study emphasizes that viscosity of fomula, osmolality, patient's tolerance and comfort, caloric density should be considered in the selection of tubes for gravify drip administration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제30권2호
• /
• pp.81-84
• /
• 2004

It is well known that malignant tumor have hypoxic cell fraction, which is radio resistant and is one of the most important cause of local recurrence after radiotherapy. One of the causes of hypoxia in tumor is blood flow decrease due to increase in blood flow resistance and one of the causes of increased blood flow resistance could be attributed to the increase in blood viscosity. For the evaluation of the change of blood viscosity in oral cancer, experiments were carried out to test the change of blood viscosity among the normal control and xenografted oral cancer nude mice. Relative viscosity measured against distilled water was $3.30{\pm}0.14$ for normal control, and $3.67{\pm}0.62$ for tumor bearing mice at the first time of blood sampling in experimental period ($100mm^3$ $200mm^3$). There was no statistically significant difference between the control group and experimental group (p>0.05). However, as the tumor grew, significant difference of blood viscosity was detected at the third time of blood sampling (control group:$3.37{\pm}0.59$, and experimental group: $4.31{\pm}0.41\;300mm^3$

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제30권3호
• /
• pp.181-185
• /
• 2004

Malignant tumor have hypoxic cell fraction, which makes radio-resistant and hypoxia in tumor is a result from the blood flow decrease caused by increase in blood flow resistance. Blood viscosity increase is major factor of increased blood flow resistance and it could be attributed to the decrease in blood deformability index. For the evaluation of the change of blood viscosity and blood deformability in oral squamous cell carcinoma, we perform the test of the change of those factors between the normal control group and oral squamous cell carcinoma cell patient group. Relative viscosity measured against distilled water was $5.25{\pm}0.14$ for normal control group, and $5.78{\pm}0.26$ for the SCC patient group and there was statistical significance between the groups. However, there was no significant difference between the groups in blood viscosity between the groups by tumor size (T1+T2 vs T3+T4). Also, there was no significant difference between the normal control group and SCC patient group in blood deformability index and between the groups by tumor size (T1+T2 vs T3+T4). Increase in blood viscosity was confirmed with this study and it can be postulated that modification blood viscosity might contribute to decrease of hypoxia fraction in oral squamous cell carcinoma, thus improve the effect of radiotherapy and it can be assumed that the main factor of blood viscosity increase is not decrease of blood deformability in oral squamous cell carcinoma.

• Preventive Nutrition and Food Science
• /
• 제13권1호
• /
• pp.40-44
• /
• 2008

Response surface methodology (RSM) was used for analyzing the manufacturing process of Prunus mume extract-added vinegared red pepper paste (maesil chokochujang) with respect to sensory quality properties. Experiments were carried out according to a central composite design, selecting the amount of kochujang, amount of maesil extract, and type of sugar in the mixture as independent variables; sensory attributes such as flavor, taste, color, and mouthfeel viscosity as response variables. The polynomial models developed by RSM for sensory color and mouthfeel viscosity were highly effective to describe the relationships between the factors studied and the responses. The estimated response surfaces confirmed that the amount of kochujang had a positive effect on color (p<0.001) whereas the amount of maesil extract had a positive effect on mouthfeel viscosity (p<0.001). Increase in the amount of kochujang led to a sharp increase of the sensory score on color at all the maesil extract and sugar type levels. On the other hand, increase in the amount of maesil extract caused a sharp increase in the mouthfeel viscosity value regardless of kochujang concentration and type of sugar. The differences among samples made with different types of sugar were not significant (p>0.05).

• Journal of applied mathematics & informatics
• /
• 제26권1_2호
• /
• pp.161-176
• /
• 2008

The effect of variable viscosity on MHD mixed convection Hiemenz flow over a thermally stratified porous wedge plate has been studied in the presence of suction or injection. The wall of the wedge is embedded in a uniform Darcian porous medium in order to allow for possible fluid wall suction or injection and has a power-law variation of the wall temperature. An approximate numerical solution for the steady laminar boundary-layer flow over a wall of the wedge in the presence of thermal diffusion has been obtained by solving the governing equations using numerical technique. The fluid is assumed to be viscous and incompressible. Numerical calculations are carried out for different values of dimensionless parameters and an analysis of the results obtained shows that the flow field is influenced appreciably by the magnetic effect, variable viscosity, thermal stratification and suction / injection at wall surface. Effects of these major parameters on the transport behaviors are investigated methodically and typical results are illustrated to reveal the tendency of the solutions. Comparisons with previously published works are performed and excellent agreement between the results is obtained.

• 한국응용과학기술학회지
• /
• 제26권4호
• /
• pp.422-427
• /
• 2009

We have investigated the effects of polyols and NaCl on the rheological behaviours of surfactant mixtures. Sodium lauryl ether sulfate (SLES), cocamidopropyl betaine (CAPB), disodium cocoamphodiacetate (DSCA), cocamide DEA (CDEA) and lauroyl/myristoyl DEA (LMDE) were used as surfactants. The polyols added into the surfactant mixture were 1,3-butylene glycol, propylene glycol, glycerin, sorbitol, dipropylene glycol, PEG 1500 and PEG 400. The addition of amphoteric surfactant to SLES aqueous solution lead to increase the height of foam and the viscosity of the system. The addition of nonionic surfactant, LMDE or CDEA to the SLES aqueous solution increased the viscosity and the effect of LMDE was better than that of CDEA. The effect of adding polyols and NaCl into the surfactant mixture aqueous solution lead to increase or decrease the viscosity of the systems depending on the concentration of NaCl and the kinds of polyols. These results can be explained through the salting in or salting out of surfactant of the systems.