Blood is one of the vital fluids of the human body. Measurement of its viscosity and other properties is very important in detecting and understanding different cardiovascular diseases. In this study, the blood flow in a concentric cylinder VISCOMETER was simulated numerically. The blood flow patterns were analyzed by applying different rotational speed of inner cylinder. Creation of a Couette flow, end effects and suitable rotational speed limit were analyzed. The amount of the torque applied to the inner cylinder which prevents the generation of the Taylor vortices was also predicted. From the obtained results, one can conclude that these vortices were not as important as the end effects were. In order to keep the blood sample temperature within a constant and acceptable range a thermal bath was used. Heat removal rate with different inflow rates of coolant was also predicted numerically.

Improving the rheological characteristics of tomato paste is an important factor for consumers and is the main index in classification and standardization of this product. Also, it is an important commercial index.By improving the appearance viscosity, we can reduce the amount of tomato for getting an identical level of quality so the total coast is reduced. That it is so important for foreign consumer. There isn’t any proper standard for consistency and tomato paste viscosity in Iran. In this research, we calibrate bostwick consistometer and rotational VISCOMETER in three brix: 12, 16, 20 and three temperatures: 25, 35, 45oc in four interval: 5, 15, 30, 60 seconds of bostwick time. Finally the results showed that the optimum time for their calibration is 30 seconds of bostwick time.

Viscosity measurement could provide valuable information for melting and solidification base processes. In this paper a falling ball VISCOMETER is used for measuring molten zinc viscosity. The molten metals are not transparent, some changes are done in the structure of conventional method for tracing ball movement. To solve this problem and in order to trace the movement of the ball (as a falling object) in the melt, a thin steel rod was connected to the ball. The displacement of the ball could then be evaluated from the rod end, which is outside the melt. Viscosity changes versus temperature is studied and as expected the viscosity of the liquid tends to decrease by increasingthe temperature. In the beginning the rate of viscosity reduction was high (0. 004 cP/° C) but then with increasing temperature the rate of viscosity reduction was decreased (0. 0001 cP/° C). Molten zinc is a shear thinning fluid which means by increasing shear rate and mean speed of falling ball the viscosity of molten zinc would drop.

AHaake VISCOMETER was used for viscosity measurements of aqueous polyvinyl alcohol mixtures at temperatures of 288, 298, and 308 K. It was observed that at low concentration of polyvinyl alcohol, variations of the measured shear stress (τ) versus shear rate (γ) were linear and therefore, the Newtonian behaviour of the studied mixtures is considered. The modified Eyring viscosity model previously proposed by the authors was used to test the measured data for aqueous polyvinyl alcohol mixtures. It was shown that the model is well capable to fit the data and the parameters, of the modle are evaluated.

In this study, predictive capabilities of apparent viscosity of oil-based drilling fluids which is used in National Iranian South Oilfields Company (NISOC) were evaluated using Newtonian and non-Newtonian models to drive a new suitable equation. The non-Newtonian models include Bingham plastic, Power law, Herschel-Bulkley, Casson, and Robertson-Stiff. To validate the results, the calculated viscosity from rheology models was compared to the fann 35 data of VISCOMETER. The results showed that Robertson-Stiff model has the best prediction of shear stress and viscosity with an absolute average percent error of 3. 58. This was followed by Herschel-Bulkley, Casson, Power law, Bingham plastic, and Newtonian with the absolute average percent error of 3. 68, 3. 77, 9. 04, 20. 09, and 44. 02 respectively. Therefore, the new equation was proposed to predict the shear stress for oil-based drilling fluids which is used in Southwestern Iranian Oilfields. In comparison to the results of the experimental data of this study, it was revealed that the proposed equation has a good agreement with the real shear stress and apparent viscosities.

In many manufacturing process which are based on melting and solidification, like casting, measurement of viscosity and prediction of fluidity of molten metal in variant temperatures and alloy composition could improve quality of process and decreasing losses. In this paper different methods for measurement of viscosity like capillary method, oscillating vessel VISCOMETER, falling body or counterbalanced sphere VISCOMETER, oscillating plate method, rotating cylinder and … have been investigated. Arrhenius equation, Andrade treatment, Hildebrand’s free volume theory, Chhabra model and … are the models which were used for estimation of viscosity of metals and alloys and their relation with temperature. Finally comparison of different procedure for viscosity measurement of molten metals is presented.

This work is an experimental study of the temperature and volume fraction effects, which provides a new model for the nanofluid viscosity of MWCNTs-EG. The MWCNT viscosity with a diameter between 1 and 2 nm in EG is calculated at 30 to 60 °C and the volume fractions of 0.025 to 0.3 using a VISCOMETER. The type of VISCOMETER is Brookfield, and its model is DV-I Prime. It was observed that the viscosity decreased, while the temperature increased, and at high volume fractions of the nanofluids, it showed non-Newtonian properties. Since no study has yet been carried out on this nanofluid, it is for the first time that a new equation about viscosity is obtained. The Einstein and Bachelor models are compared with the empirical relationships, and also to observe the similarities, a new Newtonian formula is offered.

based drilling fluid, rheology modifier and enhanced oil recovery. Moreover, structure and microstructure of these polymers are of important in above-mentioned applications. Acrylamide homopolymer and acrylamide/styrene copolymer were synthetized using micellar polymerization for application in the water-based drilling fluid. FTIR, NMR and some theoretical calculations were used to characterize (micro)structure of the polymers. In addition, conversion was obtained using gravimetric method. Ubbelohde VISCOMETER was used to evaluate viscosity-average molecular weight. Apparent viscosity was measured by Brookfield VISCOMETER. Synthesized polymers were used in the water-based drilling fluids with three different concentrations and rheological and fluid loss properties were evaluated before and after hot rolling at 120 ° C for 16 h. Moreover, FTIR and NMR results showed successful synthesis of the homo-and copolymers with high conversions. Average hydrophobic styrene block length was calculated by theoretical method to be 3. Results showed that both conversion and molecular weight values were higher in the case of synthetized homopolymer. It was attributed to increase in the possibility of chain transfer to surfactant in the micellar copolymerization reactions. Results showed that despite higher molecular weight in the acrylamide homopolymer case, viscosities of the acrylamide/styrene copolymer aqueous solutions were better in similar concentrations. It was attributed to the hydrophobic association between styrene units. Finally, results showed that both homo-and copolymer caused an improvement in the rheology and fluid loss properties of the water-based drilling fluid. Although rheological properties were reduced after hot rolling or in the presence of salt in the drilling fluids, drilling fluids prepared with acrylamide/styrene copolymer showed more ability to preserve their rheological properties due to the formation of physical network resulting from the hydrophobic associations.

Background: As a national policy all Iranian children under two-years-old should consume oral supplements such as iron, A+D vitamin, and multivitamin drops. Sugars and acids are widely used in pediatric medications including supplements, and long-term consumption of these drugs is associated with higher risk of dental decay and erosion. Consideraing the importance of nutritional supplementation for children, and the lack of research regarding sugar type, amount of acidity and viscosity of Iranian medications, the aim of the present study is to determine the sugar type, pH, and viscosity in common nutritional supplements in children. Materials and methods: In this experimental study, we extract the first fifty liquid pediatric medications (more than a million pack sales in one year), according to the Pharmaceutical Statistics of Food and Drug Administration of the Islamic Republic of Iran. By asking pediatricians from Childern’ s Medical Center and Phamacists from the selected pharmacies in Tehran, the most prescribed and sold pediatric liquid oral supplements were determined. Filnally we selected 24 supplements and two samples of each medicine were provided. In the next step we determined the sugar type based on labeling information, the pH using the pH meter pp-15 device, and the viscosity by Dial Reading VISCOMETER device. The data were analyzed by descriptive statistical methods. Results: From 24 supplements, only six medications offered information about the sugar component (sodium saccharin) and the others provide none information. In terms of the acidity of the drugs, all drugs placed in the critical pH (lower than 5. 5). The mean of pH in AD drops, iron drops, multivitamin drops, and other supplements were 4. 12, 1. 9, 3. 2, and 4, respectively. In addition, the mean of viscosity in all medications was low and desirable, which in millipascal-second (mPa-s). level. The mean of viscosity in AD drops, iron drops, multivitamin drops, and other supplements were 38. 1, 22. 4, 38. 6, and 27. 3 mPa-s, respectively. Conclusion: Due to the lack of appropriate information on the labeling of the supplements, the pharmaceutical companies should offer sufficient information about their products to increase the awareness of parents to choose supplements with less risk of dental caries. Considering the pH was lower than the critical level in all medications, providing necessary standards by the pharmaceutical companies enjoys a special importance. In addition, applying the preventive dental care after supplements consumption by parents should be adviced. Due to the favorable viscosity levels of the supplements, it seems that the pH of the drug is the most important factor regarding dental caries and erosion

Viscosities and densities are measured experimentally for three binary liquid mixtures of Aniline + Toluene, Aniline + o-Xylene and Aniline + Mesitylene using Ostwald’ s VISCOMETER and specific gravity bottle at T = 303. 15 K. Viscosities have also been calculated using empirical relations including Bingham relation, Kendall-Munroe relation, Arrhenius-Eyring relation, Croenaurer-Rothfus-Kermore relation and Gambrill relation. The validity of these correlations has been verified by respective deviations between calculated values and experimental values. These results show that positive deviations are present in all the three binary mixtures at T = 303. 15 K. The results of all the relations are comparatively in good agreement with experimental results. These are used to draw the characteristics of the molecular association among the components of respective binary liquid mixtures.