An Introduction to the BFS Method and Its Use to Model Binary NiAl Alloys

We introduce the Bozzolo-Ferrante-Smith (BFS) method for alloys as a computationally efficient tool for aiding in the process of alloy design. An intuitive description of the BFS method is provided, followed by a formal discussion of its implementation. The method is applied to the study of the defect structure of NiAl binary alloys. The groundwork is laid for a detailed progression to higher order NiAl-based alloys linking theoretical calculations and computer simulations based on the BFS method and experimental work validating each step of the alloy design process

Use of satellite images to assess forage production in the rangelands of Zacatecas

La producción de forraje en los agostaderos del estado de Zacatecas es muy variable, debido a que las condiciones del clima, suelo y manejo también lo son. Debido a las grandes extensiones de pastizales con que se cuenta en el Estado y ante la necesidad de valorar la producción de materia seca en los pastizales, es necesario contar con herramientas de medición técnica y económicamente factibles. El í­ndice de vegetación de diferencia normalizada (NDVI) se ha utilizado con éxito para estimar la producción primaria de pastizales. El objetivo de este estudio fue ajustar un modelo de regresión míºltiple con base en datos de producción del estrato herbáceo y sus valores correspondientes de NDVI, para estimar espacialmente la producción de forraje en los pastizales de Zacatecas. Se obtuvo un modelo de regresión míºltiple para los tres años en conjunto, con un valor de R2 de 0.66 (PForage yields in the rangelands of Zacatecas are variable, due to soil, weather and management. The Zacatecas state has large rangeland areas which need to be continuously monitored to define a management plan of vegetation use. To estimate forage yield some easy, reliable and inexpensive measuring tools are needed. The Normalized Difference Vegetation Index (NDVI) has been used successfully to this end. The aim of this study was to set a multiple regression model based on forage production data and corresponding NDVI values, which can help to assess spatial herbage production in the rangelands of Zacatecas. Field samplings of herbage yield were carried out across the rangelands of the State for three years. NDVI data were associated to forage yields and a multiple regression model was set for estimating forage yield in Zacatecas. The R2 value was 0.66 (

Supporting video SV1 from Soiled adhesive pads shear clean by slipping: a robust self-cleaning mechanism in climbing beetles

Beetle climbing glass with 45-micron bead

Studying Stickiness: Methods, Trade-Offs, and Perspectives in Measuring Reversible Biological Adhesion and Friction

Controlled, reversible attachment is widely spread throughout the animal kingdom: from ticks to tree frogs, whose weights span from 2 mg to 200 g, and from geckos to mosquitoes, who stick under vastly different situations, such as quickly climbing trees and stealthily landing on human hosts. A fascinating and complex interplay of adhesive and frictional forces forms the foundation of attachment of these highly diverse systems to various substrates. In this review, we present an overview of the techniques used to quantify the adhesion and friction of terrestrial animals, with the aim of informing future studies on the fundamentals of bioadhesion, and motivating the development and adoption of new or alternative measurement techniques. We classify existing methods with respect to the forces they measure, including magnitude and source, i.e., generated by the whole body, single limbs, or by sub-structures. Additionally, we compare their versatility, specifically what parameters can be measured, controlled, and varied. This approach reveals critical trade-offs of bioadhesion measurement techniques. Beyond stimulating future studies on evolutionary and physicochemical aspects of bioadhesion, understanding the fundamentals of biological attachment is key to the development of biomimetic technologies, from soft robotic grippers to gentle surgical tools

Data underlying the publication: Hydrodynamic shear dissipation and transmission in lipid bilayers

This dataset includes three m-files associated with the plots for the experimental data (Figure 2 in the manuscript) and numerical simulations (Figure 4 in the manuscript). The associated mat and txt files containing the data are included. The m-files will call these files

Wrinkling Instability and Adhesion of a Highly Bendable Gallium Oxide Nanofilm Encapsulating a Liquid-Gallium Droplet

The wrinkling and interfacial adhesion mechanics of a gallium-oxide nanofilm encapsulating a liquid-gallium droplet are presented. The native oxide nanofilm provides mechanical stability by preventing the flow of the liquid metal. We show how a crumpled oxide skin a few nanometers thick behaves akin to a highly bendable elastic nanofilm under ambient conditions. Upon compression, a wrinkling instability emerges at the contact interface to relieve the applied stress. As the load is further increased, radial wrinkles evolve, and, eventually, the oxide nanofilm ruptures. The observed wrinkling closely resembles the instability experienced by nanofilms under axisymmetric loading, thus providing further insights into the behaviors of elastic nanofilms. Moreover, the mechanical attributes of the oxide skin enable high surface conformation by exhibiting liquid-like behavior. We measured an adhesion energy of 0.238 ± 0.008 J m^–2 between a liquid-gallium droplet and smooth flat glass, which is close to the measurements of thin-sheet nanomaterials such as graphene on silicon dioxide

Wrinkling Instability and Adhesion of a Highly Bendable Gallium Oxide Nanofilm Encapsulating a Liquid-Gallium Droplet

The wrinkling and interfacial adhesion mechanics of a gallium-oxide nanofilm encapsulating a liquid-gallium droplet are presented. The native oxide nanofilm provides mechanical stability by preventing the flow of the liquid metal. We show how a crumpled oxide skin a few nanometers thick behaves akin to a highly bendable elastic nanofilm under ambient conditions. Upon compression, a wrinkling instability emerges at the contact interface to relieve the applied stress. As the load is further increased, radial wrinkles evolve, and, eventually, the oxide nanofilm ruptures. The observed wrinkling closely resembles the instability experienced by nanofilms under axisymmetric loading, thus providing further insights into the behaviors of elastic nanofilms. Moreover, the mechanical attributes of the oxide skin enable high surface conformation by exhibiting liquid-like behavior. We measured an adhesion energy of 0.238 ± 0.008 J m^–2 between a liquid-gallium droplet and smooth flat glass, which is close to the measurements of thin-sheet nanomaterials such as graphene on silicon dioxide

Wrinkling Instability and Adhesion of a Highly Bendable Gallium Oxide Nanofilm Encapsulating a Liquid-Gallium Droplet

The wrinkling and interfacial adhesion mechanics of a gallium-oxide nanofilm encapsulating a liquid-gallium droplet are presented. The native oxide nanofilm provides mechanical stability by preventing the flow of the liquid metal. We show how a crumpled oxide skin a few nanometers thick behaves akin to a highly bendable elastic nanofilm under ambient conditions. Upon compression, a wrinkling instability emerges at the contact interface to relieve the applied stress. As the load is further increased, radial wrinkles evolve, and, eventually, the oxide nanofilm ruptures. The observed wrinkling closely resembles the instability experienced by nanofilms under axisymmetric loading, thus providing further insights into the behaviors of elastic nanofilms. Moreover, the mechanical attributes of the oxide skin enable high surface conformation by exhibiting liquid-like behavior. We measured an adhesion energy of 0.238 ± 0.008 J m^–2 between a liquid-gallium droplet and smooth flat glass, which is close to the measurements of thin-sheet nanomaterials such as graphene on silicon dioxide