21,008 research outputs found
Finitely generated soluble groups and their subgroups
We prove that every finitely generated soluble group which is not virtually
abelian has a subgroup of one of a small number of types.Comment: 16 page
Weak shock waves in the ionosphere
Weak shock waves in ionosphere and simple model of chemistry of ionospheric D laye
Machinery Transportation Management: Case Study of 'Plant-trailer' H&S Incidents
Purpose – The purpose of this paper is to investigate causal agents of health and safety (H&S)incidents among “plant-trailers” (as used by construction and utility contractors to transport mechanical machinery); including the relationship(s) of such incidents to routine safety inspections and, plant maintenance functions.
Design/methodology/approach – H&S plant-trailer incident data, from a collaborating UK-based case study utility company are analysed using inductive, interpretative and descriptive statistical methods.
Findings – Principal incident occurrences relate to trailer wheels, wheel bearings, tyres and braking systems. All forms of incidents observed harbour significant risk and especially, if they occur during travel on public highways. Derived recommendations for incident mitigation and Control, suggest a requirement for improved human behaviour, machinery inspection regimes and maintenance systems.
Research limitations/implications – The findings will be valuable to academia as a basis for advancing this new research subject, both empirically and internationally. Direction is offered in this respect.
Practical implications – Recommendations will be of practical relevance to machinery management practitioners generally and to plant-trailer stakeholders more Specifically. For the latter, the study encourages introspective consideration of plant-trailer H&S systems.
Originality/value – No previous research has targeted these issues relating to plant-trailers.
Keywords Risk, Inspection, Maintenance, Machinery, H&S, Trailers
Paper type Case stud
Eye-controlled ''teletypewriter''
Oculometer provides dynamic measurement of subject's look direction, and its outputs can be used to generate visual display of his look pattern and/or to cause equipment operation associated with his lookpoint at given times. Measured eye-direction information could be used as control input at man/machine interface
Distribution Functions of the Nucleon and Pion in the Valence Region
We provide an experimental and theoretical perspective on the behavior of
unpolarized distribution functions for the nucleon and pion on the
valence-quark domain; namely, Bjorken-x \gtrsim 0.4. This domain is key to much
of hadron physics; e.g., a hadron is defined by its flavor content and that is
a valence-quark property. Furthermore, its accurate parametrization is crucial
to the provision of reliable input for large collider experiments. We focus on
experimental extractions of distribution functions via electron and muon
inelastic scattering, and from Drell-Yan interactions; and on theoretical
treatments that emphasize an explanation of the distribution functions,
providing an overview of major contemporary approaches and issues.
Valence-quark physics is a compelling subject, which probes at the heart of our
understanding of the Standard Model. There are numerous outstanding and
unresolved challenges, which experiment and theory must confront. In connection
with experiment, we explain that an upgraded Jefferson Lab facility is
well-suited to provide new data on the nucleon, while a future electron ion
collider could provide essential new data for the mesons. There is also great
potential in using Drell-Yan interactions, at FNAL, J-PARC and GSI, to push
into the large-x domain for both mesons and nucleons. We argue furthermore that
explanation, in contrast to modeling and parametrization, requires a widespread
acceptance of the need to adapt theory: to the lessons learnt already from the
methods of nonperturbative quantum field theory; and a fuller exploitation of
those methods.Comment: Review article: 133 double-spaced pages, 44 figures, 6 table
Study of vortex valve for medium temperature solid propellants
Fluid state vortex valve secondary injection control system shows considerable promise for future application to solid propellant rocket engine thrust vector control. The single axis injection system tested would be capable of providing secondary injection thrust vector control using 2000 deg F gas
The development and empirical testing of a pressure/ response model of green supply chain management amongst a cross-sectoral sample of members of The Chartered Institute of Purchasing and Supply.
This study develops and empirically tests a model of factors determining green supply chain management practices in organisations. Previous research on aspects of green supply chain management is dominated by anecdotal, sector
specific studies that examine specific aspects of the supply chain, such as purchasing or logistics. Many argue this field is embryonic and lacking a structured integrative framework of research. This study addresses this gap by focussing on a whole supply chain approach that provides a synthesis of previous research to develop a model of green supply chain management. The data from a cross-sectoral survey of 149 members the Chartered Institute of Purchasing and Supply is used to test this model, using a variety of multivariate techniques.
The model identifies environmental attitude as the primary determinant of green supply chain management practices, influenced to a lesser extent by external legislative factors. The influence of organisational contingencies on this model is also explored, and size identified as the only contingency that influences the relationships in this model. The dominant influence of environmental attitude
suggests that within organisations there are internal factors, or individuals, that may push forward the green agenda, and those initiatives that focus on changing the environmental attitude/ culture of an organisation might be the most effective at improving environmental performance.
This study suggests that factors previously identified as important within green supply chain management, such as supply chain or competitive pressures, are less influential than expected. However, future research should seek to
compare the findings from this study with a larger, cross-sectoral sample that includes diverse organisations from different nations, sectors and levels of channel power
Apparatus for recording oscillation properties of a Penning ionization gauge at very high frequencies
Recording equipment for very high frequency oscillations in Penning ionization gaug
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