Pinning-depinning of the contact line during drop evaporation on textured surfaces: A lattice Boltzmann study.

The evaporation of the liquid droplet on a structured surface is numerically investigated using the lattice Boltzmann method. Simulations are carried out for different contact angles and pillar widths. From the simulation for the Cassie state, it is found that the evaporation starts in a pinned contact line mode.

Interdependence and the cost of uncoordinated responses to COVID-19.

Social distancing is the core policy response to coronavirus disease 2019 (COVID-19). But, as federal, state and local governments begin opening businesses and relaxing shelter-in-place orders worldwide, we lack quantitative evidence on how policies in one region affect mobility and social distancing in other regions and the consequences of uncoordinated regional policies adopted in the presence of such spillovers. To investigate this concern, we combined daily, county-level data on shelter-in-place policies with movement data from over 27 million mobile devices, social network connections among over 220 million Facebook users, daily temperature and precipitation data from 62,000 weather stations, and county-level census data on population demographics to estimate the geographic and social network spillovers created by regional policies across the United States.

Numerical investigation of vibration-induced droplet shedding on smooth surfaces with large contact angles.

In this work, numerical simulations are performed to study the droplet response to the vertical vibration of the substrate, under various frequencies and amplitudes using the multiphase lattice Boltzmann method. First, the numerical results are validated against published experimental data. The effects of droplet size, surface wettability, amplitude, and frequency of the vibrating substrate on droplet detachment are studied.

Numerical investigation of vibration-induced droplet shedding on microstructured superhydrophobic surfaces.

The vibration-induced droplet shedding mechanism on microstructured superhydrophobic surfaces was simulated using the lattice Boltzmann method. The numerical simulations of natural droplet oscillations for various surface structures show that the natural frequency of the droplet is strongly dependent on surface morphology. The results show good agreement with basic theoretical values.

Coalescence-induced droplet detachment on low-adhesion surfaces: A three-phase system study.

Coalescing water droplets on superhydrophobic surfaces can detach from the surface without the aid of any external forces. This self-propelled droplet detachment mechanism is useful in many applications, such as phase change heat transfer enhancement, self-cleaning surfaces, and anti-icing and antidew coatings. In this article, the coalescence-induced droplet jumping in a three-phase system is numerically investigated.

Numerical simulation of three-component multiphase flows at high density and viscosity ratios using lattice Boltzmann methods.

In this paper, we propose a multiphase lattice Boltzmann model for numerical simulation of ternary flows at high density and viscosity ratios free from spurious velocities. The proposed scheme, which is based on the phase-field modeling, employs the Cahn-Hilliard theory to track the interfaces among three different fluid components. Several benchmarks, such as the spreading of a liquid lens, binary droplets, and head-on collision of two droplets in binary- and ternary-fluid systems, are conducted to assess the reliability and accuracy of the model.

Consistent simulation of droplet evaporation based on the phase-field multiphase lattice Boltzmann method.

In the present article, we extend and generalize our previous article [H. Safari, M. H.

Extended lattice Boltzmann method for numerical simulation of thermal phase change in two-phase fluid flow.

In this article, a method based on the multiphase lattice Boltzmann framework is presented which is applicable to liquid-vapor phase-change phenomena. Both liquid and vapor phases are assumed to be incompressible. For phase changes occurring at the phase interface, the divergence-free condition of the velocity field is no longer satisfied due to the gas volume generated by vaporization or fluid volume generated by condensation.

Phase-field modeling by the method of lattice Boltzmann equations.

In this paper, at first, a lattice Boltzmann method for binary fluids, which is applicable at low viscosity values, is developed. The presented scheme is extension of the free-energy-based approach to a multi-relaxation-time collision model. Various benchmark problems such as the well-known Laplace law for stationary bubbles and capillary-wave test are conducted for validation.

Bone mineral density in kidney transplant recipients and patients on hemodialysis: a comparison with healthy individuals.

Introduction: We measured bone mineral density (BMD) before and after transplantation to determine the frequency and severity of preoperative and postoperative osteoporosis and compare them with the BMD in healthy individuals.

Materials And Methods: We determined the BMD at the lumbar spine and femoral levels in 22 men and 18 women who were on long-term dialysis in Yazd, Iran, and a group of kidney transplant recipients including 43 men and 18 women. They were compared with each other and healthy individuals studied in a recent study in Iran.

Evaluation of secondary hyperparathyroidism in patients undergoing hemodialysis.

Renal osteodystrophy is a complication of chronic kidney disease (CKD) that present in low and high turnover patterns. This disorder has a key role in the disability of CKD patients in whom early diagnosis and treatment can result in better outcome. We studied hyperparathyroidism prevalence and its relationship with renal osteodystrophy in our advanced CKD population.