Viscosities of the Gay-Berne nematic liquid crystal

We present molecular dynamics simulation measurements of the viscosities of the Gay-Berne phenomenological model of liquid crystals in the nematic and isotropic phases. The temperature dependence of the rotational and shear viscosities, including the nonmonotonic behavior of one shear viscosity are in good agreement with experimental data. The bulk viscosities are significantly larger than the shear viscosities, again in agreement with experiment.Comment: 11 pages, 4 Postscript figures, Revte

The Impact of Building Information Modelling (BIM) Strategies in Energy Sustainability Elements to Sustainable Campus Using PLS-SEM Approach

This paper establishes a structural relationship between BIM strategies in eleven (11) energy sustainability elements divided into management and technical aspects that impact a sustainable campus. The work established thirteen (13) benchmarks for independent variables and one (1) dependent variable. The exploratory research design used in this study led to the structural model development being the central focus of the study. A judgmental sampling technique was used to distribute a questionnaire survey among local engineers, assistant engineers, and technicians in Kota Kinabalu, Sabah, Malaysia. The research population survey employed 78 returned questionnaires. The analysis used Partial Least Squares Structural Equation Modelling (PLS-SEM) to test the hypotheses. The result indicate that the management and technical aspects of Energy Sustainability Elements (ESE) have a significant impact on sustainable campus with path coefficients of 2.447 and 5.032, respectively. The findings have revealed that hypothesis 1 and hypothesis 2 were all positive and significant at the 0.05 level, indicating that these two hypotheses are valid and supported. This study provides valuable information and insights for Malaysian universities to achieve a sustainable campus by adopting building information modelling (BIM) strategies in the context of energy efficiency

The Impact of Building Information Modelling (BIM) Strategies in Energy Sustainability Elements to Sustainable Campus Using PLS-SEM Approach

This paper establishes a structural relationship between BIM strategies in eleven (11) energy sustainability elements divided into management and technical aspects that impact a sustainable campus. The work established thirteen (13) benchmarks for independent variables and one (1) dependent variable. The exploratory research design used in this study led to the structural model development being the central focus of the study. A judgmental sampling technique was used to distribute a questionnaire survey among local engineers, assistant engineers, and technicians in Kota Kinabalu, Sabah, Malaysia. The research population survey employed 78 returned questionnaires. The analysis used Partial Least Squares Structural Equation Modelling (PLS-SEM) to test the hypotheses. The result indicate that the management and technical aspects of Energy Sustainability Elements (ESE) have a significant impact on sustainable campus with path coefficients of 2.447 and 5.032, respectively. The findings have revealed that hypothesis 1 and hypothesis 2 were all positive and significant at the 0.05 level, indicating that these two hypotheses are valid and supported. This study provides valuable information and insights for Malaysian universities to achieve a sustainable campus by adopting building information modelling (BIM) strategies in the context of energy efficiency

The impact of Building Information Modelling (BIM) strategies in energy sustainability elements to sustainable campus using PLS-SEM approach

This paper establishes a structural relationship between BIM strategies in eleven (11) energy sustainability elements divided into management and technical aspects that impact a sustainable campus. The work established thirteen (13) benchmarks for independent variables and one (1) dependent variable. The exploratory research design used in this study led to the structural model development being the central focus of the study. A judgmental sampling technique was used to distribute a questionnaire survey among local engineers, assistant engineers, and technicians in Kota Kinabalu, Sabah, Malaysia. The research population survey employed 78 returned questionnaires. The analysis used Partial Least Squares Structural Equation Modelling (PLS-SEM) to test the hypotheses. The result indicates that the management and technical aspects of Energy Sustainability Elements (ESE) significantly impact sustainable campus with path coefficients of 2.447 and 5.032, respectively. Furthermore, the findings have revealed that Hypothesis 1 and Hypothesis 2 were all positive and significant at the 0.05 level, indicating that these two hypotheses are valid and supported. This study provides valuable information and insights for Malaysian universities to achieve a sustainable campus by adopting building information modeling (BIM) strategies in the context of energy efficiency

Lattice Boltzmann Simulations of Liquid Crystal Hydrodynamics

We describe a lattice Boltzmann algorithm to simulate liquid crystal hydrodynamics. The equations of motion are written in terms of a tensor order parameter. This allows both the isotropic and the nematic phases to be considered. Backflow effects and the hydrodynamics of topological defects are naturally included in the simulations, as are viscoelastic properties such as shear-thinning and shear-banding.Comment: 14 pages, 5 figures, Revte

Breaking conjugate pairing in thermostatted billiards by magnetic field

We demonstrate that in the thermostatted three-dimensional Lorentz gas the symmetry of the Lyapunov spectrum can be broken by adding to the system an external magnetic field not perpendicular to the electric field. For perpendicular field vectors, there is a Hamiltonian reformulation of the dynamics and the conjugate pairing rule still holds. This indicates that symmetric Lyapunov spectra has nothing to do with time reversal symmetry or reversibility; instead, it seems to be related to the existence of a Hamiltonian connection.Comment: 4 pages, 3 figure

Lyapunov instability of fluids composed of rigid diatomic molecules

We study the Lyapunov instability of a two-dimensional fluid composed of rigid diatomic molecules, with two interaction sites each, and interacting with a WCA site-site potential. We compute full spectra of Lyapunov exponents for such a molecular system. These exponents characterize the rate at which neighboring trajectories diverge or converge exponentially in phase space. Quam. These exponents characterize the rate at which neighboring trajectories diverge or converge exponentially in phase space. Qualitative different degrees of freedom -- such as rotation and translation -- affect the Lyapunov spectrum differently. We study this phenomenon by systematically varying the molecular shape and the density. We define and evaluate ``rotation numbers'' measuring the time averaged modulus of the angular velocities for vectors connecting perturbed satellite trajectories with an unperturbed reference trajectory in phase space. For reasons of comparison, various time correlation functions for translation and rotation are computed. The relative dynamics of perturbed trajectories is also studied in certain subspaces of the phase space associated with center-of-mass and orientational molecular motion.Comment: RevTeX 14 pages, 7 PostScript figures. Accepted for publication in Phys. Rev.

Bulk and Interfacial Shear Thinning of Immiscible Polymers

Nonequilibrium molecular dynamics simulations are used to study the shear thinning behavior of immiscible symmetric polymer blends. The phase separated polymers are subjected to a simple shear flow imposed by moving a wall parallel to the fluid-fluid interface. The viscosity begins to shear thin at much lower rates in the bulk than at the interface. The entire shear rate dependence of the interfacial viscosity is consistent with a shorter effective chain length $s^*$ that also describes the width of the interface. This $s^*$ is independent of chain length $N$ and is a function only of the degree of immiscibility of the two polymers. Changes in polymer conformation are studied as a function of position and shear rate.Shear thinning correlates more closely with a decrease in the component of the radius of gyration along the velocity gradient than with elongation along the flow. At the interface, this contraction of chains is independent of $N$ and consistent with the bulk behavior for chains of length $s^*$. The distribution of conformational changes along chains is also studied. Central regions begin to stretch at a shear rate that decreases with increasing $N$, while shear induced changes at the ends of chains are independent of $N$.Comment: 8 pages, 8 figure

An insight into amorphous shear band in magnetorheological solid by atomic force microscope

Micro mechanism consideration is critical for gaining a thorough understanding of amorphous shear band behavior in magnetorheological (MR) solids, particularly those with viscoelastic matrices. Heretofore, the characteristics of shear bands in terms of formation, physical evolution, and response to stress distribution at the localized region have gone largely unnoticed and unexplored. Notwithstanding these limitations, atomic force microscopy (AFM) has been used to explore the nature of shear band deformation in MR materials during stress relaxation. Stress relaxation at a constant low strain of 0.01% and an oscillatory shear of defined test duration played a major role in the creation of the shear band. In this analysis, the localized area of the study defined shear bands as varying in size and dominantly deformed in the matrix with no evidence of inhibition by embedded carbonyl iron particles (CIPs). The association between the shear band and the adjacent zone was further studied using in-phase imaging of AFM tapping mode and demonstrated the presence of localized affected zone around the shear band. Taken together, the results provide important insights into the proposed shear band deformation zone (SBDZ). This study sheds a contemporary light on the contentious issue of amorphous shear band deformation behavior and makes several contributions to the current literature