Cerium Effect on the Phase Composition and Crystallization Behavior of Aluminum Casting Alloys Based on the Al–Mg–Si System

Russian Journal of Non-Ferrous Metals - Using a Thermo-Calc software package (TCAl4.0 database), unexplored data concerning the phase composition and crystallization behavior of...     

Ensuring Strength in Laser Welds Made Using the Dispersion-Hardened EP693 Nickel Alloy

Russian Journal of Non-Ferrous Metals - The process of making a weld using the heat-resistant EP693 alloy (Ni–Cr–W–Co–Co–Mo system) to make assemblies and components...     

Production of Powdered α-Fe2O3 with Multilevel Gradient Porosity

Russian Journal of Non-Ferrous Metals - This article discusses methods for producing a material with gradient multilevel porosity by sintering layer-by-layer distributed α-Fe2O3 nanopowders...     

OPTIMAL MAINTENANCE SCHEDULING FOR WATER DISTRIBUTION SYSTEMS

The scheduling of maintenance for water distribution systems is a complex task encompassing a wide range of alternatives. The methodology presented in this paper can consider the major piping alternatives of replacing and cleaning, and relining. It also considers the potential of pumping improvements while accounting for the costs of maintenance, failure and operations for a multiple-period planning horizon. To solve the problem a nonlinear optimization model is linked with a network simulation model. The application showed that the procedure can determine solutions in reasonable times.     

Interobjectivity in architectural research and theory: towards a meta-theory of materiality and the effects of architecture and everyday life

The aim of this article is to introduce a meta-theoretical discussion in architectural research about materiality and its effect on everyday life and use. Taking a relational perspective, I distinguish between three different perspectives on materialities as described in theories in recent decades. From these perspectives I develop three possible conceptualisations of interobjectivity. The first perspective sees interobjectivity as collaboratively constructed ‘cross-road effects’. The second perspective sees interobjectivity as the process of stitching together material heterogeneities. The third perspective sees interobjectivity as the radiance of a persistent identity through different contexts. These three perspectives each contribute to the ways architectural objects and spaces interact and produce effects. These effects are often discussed within separate paradigms. Putting them together as different modalisations of interobjectivity enables a much richer empirical analysis, where the notion of ‘material effects’ can be differentiated and compared.     

Copper accumulation in soils from two different‐aged apricot orchards in Central Otago,New Zealand

In recent years there has been a move in New Zealand to convert small, uneconomic orchards to other agricultural uses. Overseas research has demonstrated that copper from fungicide sprays often accumulates in the soils of orchards and can cause certain problems for plant growth and livestock. To date, no assessments appear to have been made of the degree of copper accumulation in such older orchards in New Zealand. This study presents the results of an assessment of two well‐established apricot orchards in the Central Otago region of South Island, New Zealand.

Two aspects of the results are surprising. The first is the relatively low levels of copper in the soil when compared with results from another orchard in the region. That orchard is 18 years old and mean soil copper has already reached 100.0 μg/g, indicating a much faster rate of accumulation than in the two orchards in the current study. The second unexpected result is that the younger orchard has a significantly higher level of copper than the older orchard. Reasons for these findings are discussed in relation to apparent differences in soil properties.     

Environmental studies on impacts of dredging

The coastal zone acts as a major interface between the ocean and continents. Harbours located in this zone face grave problems from sedimentation, which is a global issue for most of the harbours of the world. Dredging which counter acts sedimentation, brings about innumerable environmental impacts — both positive and negative. As a case study, this paper reports the impacts of dredging conducted at Cochin harbour which is the second largest port along the west coast of India; this port is a nodal center in trade and commerce connecting south east Asia to European sector. The harbour operation mainly depends on maintenance form of dredging bringing about impacts which have both direct and indirect effects in the long term. The important parameters selected for this study are salinity, current, extinction coefficient, turbidity, nutrients, chlorophyll and bottom fauna. An assessment is made on both positive and negative impacts which indicate rise in turbidity, changes in nutrient content and biota. The current practice on dredging is conducive to harbour operations, regulating the material made available to the near shore areas and highlights the possible venues for utilization of spoil for reclamation of land and wetland development. A flow chart identifies the areas vulnerable to impacts arising out of dredging and its consequential environmental issues.     

Energy decay characteristics of a non-circular supersonic jet

In this paper, we study the energy decay characteristics of the nozzle at supersonic velocity. We have taken three types of configuration: circular, square and elliptical. The results are compared to the circular exit design. The experimental data are compared in relation to the pressure ratio. The throat area assumed to be constant. The supersonic potential core length of the different orientations is calculated. From the results, we have found that the exit geometry plays an important role in mixing promotion. The core length of a non-circular jet is less intense than a circular jet. The core length of the nozzle is the same in both under and overexpanded case. In addition to that, there is no sign of axis switching due to weak shock. The results are obtained in two different categories, total pressure data and numerical simulation. An empirical relation is used to investigate the core length experimentally.     

Estimating using cost significant global cost models

Cost significant models have been suggested as one way of overcoming criticisms of the amount of detail contained within the traditional bill of quantities. Recent research into these models reveals a lack of formal rules for the selection of work packages to be used within the models, and a potential to overestimate the cost of projects. This paper presents a methodology for selecting work packages, and recommends a refinement to the technique that reduces the variability in estimates produced using cost significance. Estimates are produced using both the traditional method of producing cost significant models, and a refined global cost methodology. Both techniques are tested against unpriced bills to measure the difference in results, with significant improvements being achieved with the new technique.