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General Princlpes
Published in Martin B., S.Z., of Industrial Hygiene, 2018
Viscosity measures the flow resistance of a liquid. Different liquids have different viscosities. Syrup and molasses have a high viscosity while water and gasoline have low viscosities. Temperature also affects viscosity. Higher temperatures create less viscous liquids and lower temperatures make liquids more viscous.
Nonaqueous Redox Flow Batteries
Published in Huamin Zhang, Huamin Zhang, Xianfeng Li, Jiujun Zhang, Redox Flow Batteries, 2017
The viscosity is another important parameter, as it determines how easy it is to handle the liquid. Highly viscous liquids are generally not advantageous, since lower viscosities come with easier flow, which is especially favorable for pumping in industrial applications. However, the viscosity is not only important from an engineering point of view, as the diffusion of ions is also dependent on the viscosity. Stoke’s law (Equation 11.2) describes the dependency of the viscosity and the limiting molar conductivity (Λm). The limiting molar conductivity gives the maximum conductivity that can be reached by an ion and is solvent dependent.
Surface wave dispersion in imperfectly bonded flexoelectric-piezoelectric/FGPM bi-composite in contact of Newtonian liquid
Published in Mechanics of Advanced Materials and Structures, 2023
Mahargha Biswas, Sanjeev A. Sahu
The region is filled with nonconductive fluid. It is considered that the nature of the liquid is viscous, i.e. Newtonian liquid. The wave motion in Newtonian liquid is governed by Navier-Stokes equation [28], i.e. where is the 2-D Laplace operator. Here, wl is the velocity field of liquid particle in viscous liquid, η is the viscosity of liquid, and ρl is the density of liquid. The harmonic solution of (1) can be assumed as where k1 is angular wave number and c is common phase velocity. Substituting the value of wl from Eq. (2) into Eq. (1), the governing equation simplifies into
Effect of shape on depth profile Nuclear Magnetic Resonance data of multilayered composite structure
Published in Nondestructive Testing and Evaluation, 2023
Sanjaya K Sahoo, Srinivas Kuchipudi, Ch. Sri Chaitanya, R Narasimha Rao, Manoj K Buragohain
To study the effect of the shape of composite structures on the depth profile NMR data, composite structures with two shapes were manufactured. The matrix used here is a thermosetting type epoxy resin system. The resin system consists of epoxy resin Epofine 1555 and an elevated temperature curing hardener Finehard 5200. Both resin and hardener in liquid form are mixed in a ratio of 100 parts of resin to 27 parts of hardener. The epoxy resin is a highly viscous liquid (10000 cPs) and hardener is a low viscosity liquid (50 cPs). For proper wetting of the fibres, the mix viscosity has to be maintained at 250 to 300 cPs. The mixing is done thoroughly in a heated vessel preferably with a motorised stirrer. The heating is done at 40 °C to 50 °C to achieve the desired mix viscosity. Once the proper mixing is done, the resin is poured into the resin bath of the filament winding machine.
Toluene-induced phase transitions in blue phase liquid crystals
Published in Liquid Crystals, 2019
Marco A. Bedolla Pantoja, Yu Yang, Nicholas L. Abbott
In the next set of experiments, we report the effect on the phase behaviour of addition of structurally distinct non-volatile ternary compounds to BP-forming samples. As noted above, the results presented in this section advance our understanding of the toluene-induced phase transitions. As a reference, we used the LC sample containing 32.5 wt. % of S-811 and added to the sample 1 wt. % of RM257, 5CB, pyrene or polystyrene (PS). The chemical structures of these compounds are found in Figure 6(a–d). We selected these compounds based on their different chemical structures and phase behaviour. RM257 is a mesogen, forming a solid at room temperature that transitions to a nematic at 67°C and to an isotropic liquid at 127°C [29,30]. 5CB is a mesogen that forms a nematic LC at room temperature with a clearing point of 35°C [21]. At room temperature, pyrene is a solid with melting point of 145°C [31]. PS is a viscous liquid at room temperature. Mixtures of the cholesteric LC and 1 wt. % of the different additives were heated until phase transitions into BPs, and subsequently isotropic phases, were observed. Except for PS, we are not aware of prior studies of effect of these different molecules on the phase behaviour of BPs. A previous study by Kasch et al. reports that BPs containing PS exhibit an increased temperature stability [11]. Because the molecular structures of toluene and pyrene have close resemblance (they are both small aromatic compounds), we predicted that the effect of toluene on the phase behaviour of the BP would be most closely replicated by pyrene.