Results 81 to 90 of about 1,172 (264)
American Journal of Agricultural Economics, EarlyView.Abstract Our general interest is in global trade loss from livestock pathogens, specifically exports. We adopt a causal inference approach that considers animal disease outbreaks over time as non‐staggered binary treatments with the potential for switching in (infection) and out of treatment (recovery) within the sample period. The outcome evolution of
Mohammad Maksudur Rahman +1 more
wiley +1 more source
The role of venture‐financed startups in innovation for US agriculture
American Journal of Agricultural Economics, EarlyView.Abstract To evaluate the role played by startup companies in the innovation ecosystem of US agriculture, we compile a unique dataset of 6024 new entrants founded 1987–2019 that details their financing lifecycles, annual economic performance, and patenting activities.
Gregory D. Graff +2 more
wiley +1 more source
Design of converging stepped spillways
, 2008 Roller compacted concrete (RCC) stepped spillways are growing in popularity for providing overtopping protection for aging watershed dams with inadequate auxiliary spillway capacity and for the construction of new dams. Unobtainable land rights, topographic features, and land use changes caused by urbanization limit the ability to construct new dams or
Hunt, Sherry Lynn, author +1 more
openaire +1 more source
Hydraulic study of two phase flow on low-gradient stepped spillways [PDF]
مهندسی منابع آب, 2016 Recently, low gradient stepped spillways, which can be constructed on the embankment dams, have been getting high attention owing to their easy implementation.
Ali Akbar Hekmatzadeh +2 more
doaj
Two-Dimensional Modeling of the Two-Phase Flow over Stepped Spillways [PDF]
مهندسی منابع آب, 2013 Different measures may be taken into account in order to reduce the destructive effects of flow over spillways, one of which is the application of stepped spillways in an attempt to dissipate the flow energy.
A. Golzar, M. Ghaeini
doaj
Influence of a Modified Weir Profile on Velocity Field and Dissipation Rate in Stepped Spillways: A Comparative Study Using Physical Models and Computational Fluid Dynamics [PDF]
Journal of Applied Fluid MechanicsStepped spillways are specialized hydraulic structures crafted to optimize the effective dissipation of hydraulic energy along stepped chutes. The central objective is to scrutinize and improve the mitigation of flow separation occurring from the ogee ...
H. Souli, J. Ahattab, S. Bensallam
doaj +1 more source
Energy dissipation evaluation for stepped spillway using a fuzzy inference system [PDF]
, 2020 Alireza Mojtahedi +2 more
openalex +1 more source
British Educational Research Journal, EarlyView.Abstract Quality in early childhood education and care (ECEC) is a contested concept and has generally been conceptualised by inter‐related indicators such as staff qualifications, educational environment, policy or child‐to‐staff ratios. There has been a more limited emphasis on how young children might perceive and experience quality.
Nikki Fairchild, Éva Mikuska
wiley +1 more source
Numerical investigation of air-entrainment in skimming flow over stepped spillways
Theoretical and Applied Mechanics Letters, 2016 As a widely used flood energy dissipator, the stepped spillway can significantly dissipate the kinetic or hydraulic energy due to the air-entrainment in skimming flow over the steps.
Jiemin Zhan, Jianbo Zhang, Yejun Gong
doaj +1 more source