Effect of Copper on Corrosion of Forged AlSi1MgMn Automotive Suspension Components

Recently, modifications in the alloy composition and the manufacturing process cycle were proposed to achieve a more uniform structure with no evidence of coarse grains across the section of the AlSi1MgMn alloys. Cu was added to the AlSi1MgMn alloy to improve its age hardening capacity without a separate solution heat treatment. However, Cu addition degrades the corrosion resistance of this alloy due to the formation of Al-Cu precipitates along the grain boundaries that are cathodic with respect to the aluminum matrix and thus encourage intergranular corrosion. The present work was undertaken to identify the impact of Cu addition on the corrosion properties of AlSi1MgMn alloys with different Cu contents. A series of AlSi1MgMn alloys with 0.06-0.89 wt.% Cu were tested in order to identify an optimum level of Cu addition.     

Using economic valuation techniques to inform water resources management: a survey and critical appraisal of available techniques and an application

The need for economic analysis for the design and implementation of efficient water resources management policies is well documented in the economics literature. This need is also emphasised in the European Union's recent Water Framework Directive (2000/60/EC), and is relevant to the objectives of Euro-limpacs, an EU funded project which inter alia, aims to provide a decision-support system for valuing the effects of future global change on Europe's freshwater ecosystems. The purpose of this paper is to define the role of economic valuation techniques in assisting in the design of efficient, equitable and sustainable policies for water resources management in the face of environmental problems such as pollution, intensive land use in agriculture and climate change. The paper begins with a discussion of the conceptual economic framework that can be used to inform water policy-making. An inventory of the available economic valuation methods is presented and the scope and suitability of each for studying various aspects of water resources are critically discussed. Recent studies that apply these methods to water resources are reviewed. Finally, an application of one of the economic valuation methods, namely the contingent valuation method, is presented using a case study of the Cheimaditida wetland in Greece.     

Friction stir welding of twin-roll cast EN AW 3003 plates

Twin-roll cast EN AW 3003 plates were butt-welded with friction stir welding and their structural features were identified. Sound welds were obtained in twin-roll cast EN AW 3003 plates at tool rotation speeds higher than 500 rpm. The ultimate tensile strength of the welded plates was 134 ± 3 MPa, comparable to the ultimate tensile strength of the original plate, at 146 MPa. The stirring action of the pin fractured the interdendritic network and coarse eutectic cells, replacing the dendritic features of the base plate with a uniform dispersion of very fine intermetallic particles across the stir zone. The thermal and mechanical cycles introduced during FSW relaxed the supersaturation of the cast plate, leading to the precipitation of intermetallic particles. This precipitation activity produced a particle population gradient that peaks inside the stir zone and dictates the etching response across the plate section. The material in direct contact with the rotating pin is severely deformed and is exposed to frictional heating and inevitably undergoes dynamic recrystallization. The very fine grain structure thus obtained suffers abnormal grain growth when annealed at high temperatures due to the effective pinning of the grain boundaries by the fine particles.     

Internal cooling to produce aluminium alloy slurries for rheocasting

Rheocasting is becoming the choice of the casting industry which relies on the semi-solid processing for high integrity structural parts. It is thus of great technological interest to identify simple methods to prepare slurries at reduced cost. The potential of internal cooling to produce slurries for rheocasting was investigated in the present work for several aluminium casting alloys which are technologically important for aluminium foundries. Alloys quenched directly from the liquid state were predominantly dendritic while the slurry samples quenched after an initial fraction of solid phase was first formed, were dominated by α-Al rosettes and globules. The solidification of the remaining liquid phase occurred through the growth of the α-Al rosettes and globules which have formed during internal cooling before quenching.     

Hydrogen supply chain and challenges in large-scale LH2 storage and transportation

Hydrogen is considered to be one of the fuels of future and liquid hydrogen (LH2) technology has great potential to become energy commodity beyond LNG. However, for commercial widespread use and feasibility of hydrogen technology, it is of utmost importance to develop cost-effective and safe technologies for storage and transportation of LH2 for use in stationary applications as well as offshore transportation. This paper reviews various aspects of global hydrogen supply chain starting from several ways of production to storage and delivery to utilization. While each these aspects contribute to the overall success and efficiency of the global supply chain, storage and delivery/transport are the key enablers for establishing global hydrogen technology, especially while current infrastructure and technology are being under development. In addition, while all storage options have their own advantages/disadvantages, the LH2 storage has unique advantages due to the familiarity with well-established LNG technology and existing hydrogen technology in space programs. However, because of extremely low temperature constraints, commercialization of LH2 technology for large-scale storage and transportation faces many challenges, which are discussed in this paper along with the current status and key gaps in the existing technology.     

Effects of marination, cooking and storage on physico-chemical and microbiological properties of ready to eat trout döner kebab

The aim of this work was to investigate the use of rainbow trout (Oncorhynchus mykiss) in ready to eat döner kebab production and determine the effects of marination, cooking and storage conditions (4 and ?18 °C) on physico-chemical and microbiological properties of döner kebab. The raw trout meat, raw, cooked and stored döner kebab samples were subjected to moisture, protein, fat, ash, color, pH, cholesterol, biogenic amines, lipid oxidation, fatty acids profile, texture, microbiological and sensory analysis. The results indicated that the major fatty acids in trout döner kebab were palmitic, stearic, oleic, omega-3 and omega-6 fatty acids and unsaturated fatty acids were higher than saturated fatty acids (p < 0.05). Low biogenic amine and cholesterol contents were determined in döner kebab. It was found that ?18 °C of storage temperature was more effective than 4 °C for inhibition of lipid oxidation and microbial growth in trout döner kebab (p < 0.05). While cooking affected parameters evaluated (p < 0.05), marination did not have any significant effect. The study results indicated that using rainbow trout meat in döner kebab production could be beneficial to provide healthy meat products without posing any acceptability problems in terms of quality factors. This is the first paper to be reported on physico-chemical and microbiological properties of döner kebab produced with rainbow trout and effects of marination, cooking and different storage temperatures on these physico-chemical and microbiological properties.     

Restoration of the bake hardening response in a naturally aged twin-roll cast AlMgSi automotive sheet

Reversion treatments at 225 °C for several minutes were effective in improving the bake hardening response of the naturally aged twin-roll cast AlMgSi sheet which, when processed without reversion, failed to meet in-service strength requirements with a rather poor bake hardening response.     

Current trends in traditional Turkish meat products and cuisine

This study reports on the results of research and technological improvements achieved during the past decade in the field of traditional Turkish meat products having economic value. Traditional Turkish meat products discussed are sucuk (dry, uncooked, cured, and fermented sausage), past?rma (seasoned, air-dried, cured, pressed, and non-fermented beef cut), döner kebab (meat block roasted with slow rotation in front of a vertically positioned heat source), kavurma (a deep fried, diced meat, stored in the solidified animal fat), and çi? köfte (raw meat balls). These products are produced and consumed all around the world. Research on these products has been focused on issues such as chemical and microbiological analysis of commercial products, quality and safety improvements, additives, new and/or alternative processing methods, and health. Research results indicate that possible foodborne illnesses and quality problems are major concerns and further research, a broad control system, changes such as adding natural antimicrobial and antioxidants and process modifications are needed to improve safety and quality of these products. Some changes such as intensive poultry contributions to commercial production, safety and quality concerns about traditional meat products are pointed out, as well as the trends in a research and development, technological circumstances are discussed.