the prevalent method of irrigation in paddy fields in iran is continuous ponding, which changes to intermittent method at the time of water shortage. soil cracks are the main problem in intermittent irrigation. in this study, effects of adding rice straw on some soil physical characteristics and cracks were studied in paddy soils of the guilan province of iran. the experiment was performed as s...

The aim of the presented study was to estimate the influence of the traits of hoof measurement in dairy cows on claw disorders, lameness, and locomotion scores were determined. Data on claw health and measurement trait of claws were collected from 68 primiparous cows housed in tie stalls and from 76 primiparous cows housed in free stalls. Data were collected during professional claw trimming. T...

Foreign object damage (FOD) occurs when hard, millimeter-sized objects such as gravel or sand and even the pieces of the engine components are ingested into aircraft jet engines. Particles impacting blades produce small indentation craters which can become sites for fatigue crack initiation, severely limiting the lifetime of the blade. In this study, the impact on the edge of a thin plate is in...

In this paper, it has been attempted to evaluate the performance of asphalt overlays which were reinforced with geogrid, modified by sasobit and combination of them on rehabilitation of reflective cracking. The laboratory tests under dynamic loading in bending mode were conducted to investigate reflective cracking retardation compared to reference samples. The results illustrated that in a cert...

A novel method for preparing and testing bending specimens in-situ the TEM has been developed. This method provides high visibility of the crack front and its associated plastic zone. This is significant because energy release rates can now be calculated at many points throughout the test based on crack tip opening displacement (CTOD), crack opening angle (COA), and crack advance. Further refin...

In this work, the plastic deformation mechanisms responsible for mechanical properties and fracture toughness in nanotwinned (NT) magnesium is studied by molecular dynamics (MD) simulation. The influence of twin boundary (TBs) spacing and crack position on deformation behaviors are investigated. The microstructure evolution at the crack tip are not exactly the same for the left edge crack (LEC)...

A new species of abertellid sand dollar, Abertella miskellyi n. sp., is described from the Miocene Camarones Formation of Patagonia, southern Argentina. The new taxon corroborates the existence of the genus in South America, given that Abertella is most common in the southeastern USA and the eastern coast of Central America. It is characterized by a unique basicoronal circle, in which the inter...

Centuries ago, European builders developed a reliable means of installing tile for high-traffic, high-use applications which relied on the laying of a sand strata between the structural substrate and the mortar-bed/tile composite top layer. Due to space (height) requirements and other concerns, the sand strata method for tile installation is, for all practical purposes, extinct. Modern theory, ...

modelling of crack propagation by finite element method under mixed mode conditions is of prime importance in fracture mechanics. this paper describes an application of finite element method to the analysis of mixed mode crack growth in linear elastic fracture mechanics. crack growth process is simulated by an incremental crack-extension analysis based on the maximum principal stress criterion,...