39 research outputs found

    The Law of Worker Ownership

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    This article discusses Canadian, U.K., U.S., French, and Swedish models of worker ownership and the legal principles which apply to them. Based on the evidence that, in contrast to other traditional forms of workplace organization, worker participation in ownership and management gives rise to greater efficiency and productivity, lower employee absentee rates, greater job satisfaction, reduced need for managerial supervision, the lowest cost per job created and a democratic workplace, the article argues for comprehensive legislation to address the relevant issues surrounding worker ownership, so that worker co-operatives and other forms of worker ownership can reach their full potential in Canada

    The Citizen and neighborhood renewal : a collection of working papers on planning with people in the inner city

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    Report: ii, 328 p., maps, digital fileThis report is designed primarily to be of assistance to those involved in the act of renewing or developing our cities, whether elected politician, civic administrator, professional advisor, community organizer or ordinary citizen. It will hopefully provide suggestions that can be immediately applied and used in developing new polid.es, planning projects or carrying out programs. It is intended as a guide, a manual, a catalogue on how to better plan and design city neighbourhoods

    Turning data into information that improves teaching and learning: the WA experience

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    This paper looks at some examples of the way in which the Western Australian Department of Education and Training is presenting student performance data and transforming it into information to assist teachers to modify their teaching practices and improve the learning of their students

    Water distribution network modelling: From steady state to waterhammer

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    grantor: University of TorontoIt is both difficult and costly for water utilities to update and maintain accurate data bases for steady state, extended time period, and waterhammer simulation models. Clearly, one comprehensive model, capable of both steady and unsteady, long-term simulation, is desirable. Compared to three individual simulation models, a comprehensive model reduces memory and run time requirements, requires only one data set, and encourages more reliable record keeping. The major objectives of this thesis are (1) to create a single algorithm for quasi-steady state, rigid water column, and waterhammer analyses of water distribution networks, (2) to develop boundary conditions that interface with each of the quasi-steady state, rigid water column, and waterhammer solution procedures, (3) to identify an accurate, efficient, and general framework for solving linked boundary conditions of relevance to any or all of the key flow regimes, and (4) to demonstrate the correctness of the 'multi-flow' regime model. Although further work is necessary to refine this model for commercial use, it is considered that these objectives have been achieved. The comprehensive model contains several new features: an automatic pipe classification system for selecting, at the beginning of a simulation, one of waterhammer, rigid water column, or quasi-steady state analysis; a direct valve closure algorithm that avoids iteration to preserve nodal continuity required by graph-theoretically based models; an explicit pump power failure solution procedure that allows efficient numerical calculation of complex and variable speed pumping arrangements; and a coupling of rigid water column and waterhammer network solvers permits more efficient modelling of complex boundary devices in waterhammer analysis. Several numerical experiments demonstrate the comprehensive model and show good agreement with known network solutions. In particular, slow valve closure and pump speed change examples demonstrate the suitability and reliability of the rigid water column analysis component for slow transient events. A pump power failure example shows the waterhammer analysis component to be accurate for rapid transient events. The last numerical experiment shows that the comprehensive model can accurately and efficiently capture the long-term transient response of a water distribution network by selectively using quasi-steady state, rigid water column, and waterhammer analyses.Ph.D

    The Law of Worker Ownership

    No full text
    This article discusses Canadian, U.K., U.S., French, and Swedish models of worker ownership and the legal principles which apply to them. Based on the evidence that, in contrast to other traditional forms of workplace organization, worker participation in ownership and management gives rise to greater efficiency and productivity, lower employee absentee rates, greater job satisfaction, reduced need for managerial supervision, the lowest cost per job created and a democratic workplace, the article argues for comprehensive legislation to address the relevant issues surrounding worker ownership, so that worker co-operatives and other forms of worker ownership can reach their full potential in Canada

    Extended thermodynamics derivation of energy dissipation in unsteady pipe flow

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    Extended irreversible thermodynamics (EIT) provides a framework for deriving extensions to phenomenological equations (e.g., Newton's law of viscosity, Fick's law of mass transport, and Darcy's law for porous media flow) for problems involving high frequencies (i.e., rapid transients). In this paper, a phenomenological equation is derived for energy loss in 1D unsteady pipe flow using an EIT formalism. The resulting wall shear stress is equal to the sum of (1) the steady-state shear stress; (2) a term that is proportional to the local (i.e., temporal) acceleration; and (3) a term that is proportional to the product of the velocity and the convective (i.e., spatial) acceleration. The form of this FIT-based wall shear stress formula shows that EIT provides a physical basis for instantaneous acceleration based unsteady friction formulas. It also illustrates the limitations and underlying assumptions of these models. For example, instantaneous acceleration based unsteady friction formulas are limited to fast transients (i.e., transients in which the water hammer timescale is significantly smaller than the diffusion timescale). A characteristics solution for unsteady pipe flow is proposed in which the phenomenological equation is used to model energy dissipation. Comparison of numerical test results with measured data from upstream and downstream valve closure laboratory experiments shows excellent agreement

    A review of water hammer theory and practice

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    Hydraulic transients in closed conduits have been a subject of both theoretical study and intense practical interest for more than one hundred years. While straightforward in terms of the one-dimensional nature of pipe networks, the full description of transient fluid flows pose interesting problems in fluid dynamics. For example, the response of the turbulence structure and strength to transient waves in pipes and the loss of flow axisymmetry in pipes due to hydrodynamic instabilities are currently not understood. Yet, such understanding is important for modeling energy dissipation and water quality in transient pipe flows. This paper presents an overview of both historic developments and present day research and practice in the field of hydraulic transients. In particular, the paper discusses mass and momentum equations for one-dimensional Flows, wavespeed, numerical solutions for one-dimensional problems, wall shear stress models; two-dimensional mass and momentum equations, turbulence models, numerical solutions for two-dimensional problems, boundary conditions, transient analysis software, and future practical and research needs in water hammer. The presentation emphasizes the assumptions and restrictions involved in various governing equations so as to illuminate the range of applicability as well as the limitations of these equations. Understanding the limitations of current models is essential for (i) interpreting their results, (ii) judging the reliability of the data obtained from them, (iii) minimizing misuse of water-hammer models in both research and practice, and (iv) delineating the contribution of physical processes from the contribution of numerical artifacts to the results of water hammer models. There are 134 refrences cited in this review article. Copyright ┬ę 2005 by ASME
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