Trace element analysis of Cretan wines and wine products

The object of this research is to investigate the ways and the degree of contamination of Cretan grapes from the area of Chania and their alcoholic products, with the elements aluminium, arsenic, cadmium, copper, chromium, iron, lead, manganese, nickel and zinc. Fifteen samples of grapes were collected and used for the production of experimental wines from rinsed and unrinsed grapes. A microwave furnace was used for the digestion and dissolution of the experimental wines, the precipitates that originated in these wines, as well as the wines of the corresponding producers. The analyses of all mentioned samples as well as 34 local alcoholic distillates were performed using total reflection X-ray fluorescence and graphite furnace atomic absorption spectrometry. The concentrations for all the elements that were determined were almost in all cases, well below the maximum permissible levels by the Greek and the European Union legislation.     

Tunnel fire and life safety within the world road association (PIARC)

This paper presents the global activities of the World Road Association (PIARC) in the area of fire and life safety in road tunnels. It traces the organizational structure in the form of technical committees, its publications, current activities and concludes with a summary as to the position of the organization with regard to fire and life safety in tunnels.     

Finite element three-dimensional elastic-plastic creep analysis

This paper presents a continued development of computationally efficient finite element methods for accurately predicting the isothermal three-dimensional elastic-plastic creep responses of thick and thin shell structures subjected to mechanical and thermal loads. This work is applicable to a wide range of engineering structures and most recently has been used in the elastic-plastic creep analyses of high-temperature nuclear reactor components and rotating turbine blades.Previous work in this area for elastic-plastic analysis has been demonstrated by Levy et al. In that reference, use of a variable number of stress points within an element to describe elastic-plastic behaviour was demonstrated. These ideas have been extended for combined plasticity and creep behaviour. Thus, within an element, the order of the allowable total kinematic strain distribution is dependent on the number of element nodes (assumed displacement distribution), and the order of the allowable plastic strain distribution (and hence the elastic-plastic boundaries) and/or creep strain distribution is dependent on the number and location of the stress points used to numerically integrate the inelastic effects. This allows for an accurate representation of the elastic-plastic creep behaviour within an element. This higher inelastic representation results in the use of a minimum number of degrees of freedom for a given nonlinear analysis, which is particularly important for combined creep and plasticity behaviour and for cyclic loading, where computer times can be prohibitive.The basic numerical solution procedure for the elastic-plastic creep analysis is an incremental predictor-corrector iterative scheme combined with the ‘initial strain’ approach. Attention has been given to the time step increment strategy for combined plasticity and creep as this governs efficiency and accuracy.The methods have been implemented into the three-dimensional solid element module (HEX) of the Grumman PLANS finite element program.Sample problems are used to demonstrate and investigate the accuracy and efficiency of these methods. Sample problems include combined plasticity and creep analysis of a simple rod under time varying load, stress-relaxation of a simple rod, thermal stress-relaxation of a plate subjected to a temperature variation across the width, and creep analysis of an internally loaded thick-walled pressure vessel.     

Gravity driven counterflow through an open door in a sealed room

Flow measurements using tracer gas techniques were made on the exterior doorway of a test house for indoor-outdoor temperature differences of 0.5–45 K. The time for door opening and closing was constant at 3.75 s, and fully open hold time varied from 0.5 s to 120 s. Predictions of a variable density steady flow model were in good agreement with the measurements when adjustments were made for the time-varying size of the opening and for the effect of cross-stream mixing between the incoming and outgoing air streams. The flow rate is shown to be governed by an effective density very close to the average of inflow and outflow densities, and the control condition at the doorway is fixed by the jet-like behavior of the inflow stream. Dependence of cross-stream mixing on interfacial stability caused the orifice and coefficient to increase from 0.4 to 0.6 as temperature difference increased. This varying orifice coefficient is well represented by the combination of a discharge coefficient for streamline contraction combined with a mixing coefficient which accounts for mixing between the inflow and outflow.     

Separation of physical loading from photosynthesis/respiration processes in rivers by mass balance

Diurnal variations in physical and chemical concentrations, including nutrients, are observed in river ecosystems. Understanding these cycles and separating the effects of physical loading (from point and non-point sources) and biogeochemical processes are necessary for water management and the TMDL process. A chloride mass balance approach is used to separate the relative influences of physical loading and biogeochemical processes in the Bow River through Calgary, Canada, which has a significant influence on the river water chemistry. Sampling campaigns were conducted in December 2005, when minimal photosynthesis and respiration occur, and in July 2006, when river discharge is high and some photosynthesis and respiration activity is present. Samples in each campaign were collected at point source input and output along the river reach through the city every hour for a 24-hour period, allowing for time of travel. The two wastewater treatment facilities within the city contributed the majority of physical mass loading to the river, with temporal variations in effluent discharge, chloride, and nutrient concentrations. Wastewater effluent chloride to nutrient (as well as other parameter relationships) concentrations also varied diurnally. An hourly chloride mass balance was achieved, within 0.5% (average, S.D.=4.4) for December and 7.7% (average, S.D.=4.2) for July, between estimated cumulative sum values from all inputs and measured values at the river output downgradient of the city, allowing for the investigation of other parameter conservativeness. Some slight diurnal variations associated with photosynthesis and respiration were observed even with limited productivity in the river. Nitrate mass fluxes appeared to be most strongly influenced by photosynthesis and respiration processes, with phosphate being less influenced. Ammonia mass fluxes appeared to be most strongly influenced by wastewater effluent loading. Physical loading can mask or enhance biogeochemical diurnal fluctuations, creating errors in river process interpretations. Chloride was a useful tracer in the mass balance to distinguish between and assist in separating physical loading and biogeochemical processes in the river.     

Object–Oriented Enterprise Modeling and Simulation of AEC Projects

In this paper we describe an object–oriented framework for developing enterprise models of Architecture, Engineering, Construction projects, and a methodology for formalizing these models such that they can be used for discrete event simulation of information processing and coordination in project execution. The simulation results can be used to predict the probable effects of carrying out proposed changes in planning and managing projects.
In our enterprise modeling framework we represent engineering design projects in terms of deliverables (requirements and solutions), plans (activities and process relations), and organization (participants and organizational relations). The resulting project model is the starting point for identifying coordination requirements between project team participants. Our methodology uses matrix techniques derived from qualtiy function deployment (QFD) to identify interactions between project requirements and solutions and calculate measures of product complexity . We then describe information flow between project activities in a similar matrix and calculate measures of process uncertainty . Finally, we identify the responsibilities of project team members and use a matrix to point out organizational interdependencies .
We apply our framework and methodology to model and simulate engineering design for a major extension of an electrical power substation. Our simulation results demonstrate how project performance is contingent on the fit between the project policies and the objectives and preferences of the project team.