Results 41 to 50 of about 29,239 (203)

Establishing the Strength Characteristics of the Lifting-Leveling Device Structures of the VPO-3-3000 Machines for the Track Straightening

Communications, 2020
This article deals with replacement of the magnetic grippers on the VPO-3-3000 machines with roller grippers. The novelty lies in establishment of dependences characterizing stress and strain in elements of the lifting and straightening devices and in ...
Adil Kadyrov, Akbope Karsakov, Bakytzhan Donenbayev, Kyrmyzy Balabekova   +3 more
doaj   +1 more source

Intercomparison of carbon‐13 and carbon‐14 tracer approaches for estimating marine calcification and net primary production

Limnology and Oceanography: Methods, EarlyView.
Abstract Accurate measurements of phytoplankton net primary production (NPP) and calcification are essential for quantifying marine carbon cycling, yet in situ calcification rates remain poorly constrained. We compared 13C‐ and 14C‐based tracer methods for NPP in laboratory cultures of the diatom Chaetoceros tenuissimus and the coccolithophore ...
Chloe L. Smith, Austin Grubb, Kay D. Bidle, Kimberlee Thamatrakoln, Adam V. Subhas   +4 more
wiley   +1 more source

Track behaviour: the importance of the sleeper to ballast interface

, 2008
The aim of this research is to develop a fuller understanding of the mechanical behaviour of thesleeper/ballast interface, related in particular, to the forces applied by high speed tilting trains onlow radius curves.
Le Pen, Louis
core   +1 more source

Method‐dependent differences in zooplankton abundance and size metrics: Microscopy vs. ZooScan

Limnology and Oceanography: Methods, EarlyView.
Abstract Image‐based approaches such as ZooScan are increasingly used for high‐throughput zooplankton monitoring. However, quantitative evaluations of methodological differences relative to conventional microscopy remain limited. In this study, zooplankton abundance and size‐based metrics obtained from microscopy and ZooScan image analysis were ...
Young Seok Jeong, Min‐Chul Jang, Min Ho Seo, Dong‐Hun Lee, Ho Young Soh   +4 more
wiley   +1 more source

Desempenho operacional de trator com e sem o acionamento da tração dianteira auxiliar Operational performance of a tractor with and without the use of wheel assist drive

Pesquisa Agropecuária Brasileira, 1999
Entre os fatores que podem influenciar o desempenho de tração do trator agrícola, destacam-se a pressão de inflação e a carga sobre o rodado motriz. Neste trabalho, o objetivo foi avaliar, em situação de campo, a influência dos fatores inflação (sob ...
Kiyoshi Yanai, Gastão Moraes da Silveira, Kleber Pereira Lanças, Ila Maria Corrêa, José Valdemar Gonzalez Maziero   +4 more
doaj   +1 more source

Linear Mechatronic Modeling of Rectangular Tank Sloshing Dynamics

International Journal of Mechanical System Dynamics, EarlyView.
ABSTRACT Sloshing dynamics in partially filled tanks can strongly influence system‐level behavior when fluid motion couples with rigid‐body dynamics. This paper presents a linear and acausal two‐dimensional sloshing model for rectangular tanks, based on the reformulation of established sloshing theory within a modular, multi‐domain modeling framework ...
Magnus Steinstø, Eilif Pedersen
wiley   +1 more source

Field survey and evaluation method for fouled ballast using transmitted sound characteristics

Transportation Engineering
As railway ballast crushing and refining progress with time, and the content of fine grains increases, the saturation of ballast increases during rainfall. The decrease in drainage and strength increase the likelihood for ballast to settle.
Takahisa Nakamura, Takahiro Kageyama
doaj   +1 more source

Sampling Methodologies and Approaches for Ballast Water Management Compliance Monitoring

Promet (Zagreb), 2011
The human-mediated transfer of harmful organisms via shipping, especially via ballast water transport, has raised considerable attention especially in the last decade due to the negative associated impacts.
Stephan Gollasch, Matej David
doaj   +1 more source

An Anisotropic Constitutive Model for Crushable Geomaterials Based on Non‐Stationary Critical State Line Concept

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT In this paper, the dependencies of granular soil behaviour on particle crushing and fabric anisotropy are formulated within a novel model based on bounding surface plasticity theory enriched by the non‐stationary critical state line (NCSL) concept.
Hesam Dejaloud, Hamed Taghavizade, Mohammad Rezania   +2 more
wiley   +1 more source

Experimental and Numerical Investigation on Ballast Flight from Perspective of Individual Particles

Applied Sciences, 2019
Ballast flight significantly affects the safe operation of high-speed railway. A wind tunnel experiment and computational fluid dynamics simulation were performed to investigate the occurrence and development mechanism of ballast flight from the ...
Hao Yin, Liang Gao
doaj   +1 more source