Positional dependence of material flow in friction stir welding: analysis of joint line remnant and its relevance to dissimilar metal welding

Understanding material flow in friction stir welding is important for production of sound dissimilar metal welding that control the intermixing of two alloys being welded and consequent formation of new constituents which influences the weld properties. In the present experimental investigation material flow patterns are visualised using dissimilar and similar aluminium alloys using a simple innovative ,experiment. The experimental results reveal that only a portion of material transported from the leading edge undergoes chaotic flow and the remaining is deposited systematically in the trailing edge of the weld. Using this information it is shown that the formation of a friction stir welding defect, joint line remnant, does not occur only when the weld interface is on the advancing side. The material flow visualisation study has been utilised to analyse the mechanism of weld formation and its usefulness in improving fatigue properties and for dissimilar metal welds.

Druvan - Den personalekonomiska nyttan av mångdimensionell företagshälsovårds- och personalutvecklingsverksamhet baserad på Metal Age-konceptet i Dragsfjärds kommun (2002-2005)

Under åren 2002-2005 förverkligades Druvan-projektet i Dragsfjärds kommun, vilket innebar en dramatisk ökning av företagshälsovårdsinsatserna. Företagshälsovårdsutgifterna ökade från 20 € per anställd till över 400 €. Den totala satsningen på personalens hälsa ökade ännu mer. Innehållet i Druvan baserade sig på den s.k. Metal Age-metoden. Metoden går ut på att arbetsgemenskapen tillsammans identifierar utvecklingsbehov och –åtgärder. Projektet ledde till en stor mängd utvecklingsåtgärder och därpå följande effekter på personalens hälsa, trivsel och samarbete. Som en del av åtgärderna utarbetade kommunen en personalrapport för de aktuella åren. Under projekttiden utvecklades personalens arbetsförmåga betydligt gynnsammare än förväntat. Den ekonomiska analysen visade att det investerade kapitalet gav en avkastning på 46%. Nyttan uppkom som resultat av minskad sjukfrånvaro och färre förtidspensioneringar. Druvan-projektet stöder de tidigare bedömningarna, enligt vilka det finns ett klart utrymme för att öka satsningarna på företagshälsovård i vårt land. Detta gäller speciellt arbetsplatser vars satsningar på företagshälsovård är betydligt under genomsnittet. Dragsfjärds kommun har beslutat göra Druvan till en bestående struktur inom kommunen. Guy Ahonen är professor i Knowledge Management, speciellt personalekonomi vid institutionen för företagsledning och organisation vid Hanken. Ove Näsman är ledande företagsläkare vid Dalmed OyAb i Dalsbruk i sydvästra Finland. Båda har forskat i årtionden kring effekterna av ökat välbefinnande i arbetet.

Room temperature ferromagnetism in ZnO (core)/graphite (shell) nanowires fabricated by a one-step method

ZnO (core)/graphitic (shell) nanowires were successfully fabricated by a one-step method. Morphology of the as-grown nanowires was studied in detail by scanning electron microscopy, transmission electron microscopy (TEM), and energy dispersive X-ray analysis (EDS). High resolution TEM micrographs and selected area electron diffraction patterns reveal the core/shell morphology of the nanowires that grew along the c-axis of ZnO. EDS study of the nanowires confirms that there are no impurities within the detectable limit. Superconducting quantum interference device magnetometer measurements show room temperature ferromagnetic ordering in these core/shell nanowires. (C) 2010 Elsevier Ltd. All rights reserved.

Surface Ligand Population Controlled Oriented Attachment: A Case of CdS Nanowires

using two types of organic ligands having similar chemical structure but different physical properties and varying their dynamic population at the surface of zinc blende seed nanocrystals, self-assembled zinc blende semicircular-shaped bent nanowires of CdS are synthesized via a colloidal synthetic approach. It is found that the hydrophobic tail interaction of long-chain ligands puts strain on these thin nanowires (< 2 nm diameter) and bend them to some extent, forming strained nanowires.

Photocatalytic degradation of phenol by base metal-substituted orthovanadates

Base metal (Cr, Mn, Fe, Ni, Cu) substituted CeVO4 compounds were synthesized by the solution combustion technique. These compounds were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis spectroscopy, transmission electron microscopy and BET surface area analyzer. The characterization indicated that the base metals were substituted in the ionic state in all the compounds. These compounds were used for the photocatalytic degradation of phenol and the degradation rates obtained in the presence of these compounds werecompared against that obtained with the commercial Degussa P-25 TiO2 catalyst. Fe and Cr substituted CeVO4 showed photocatalytic activity that was comparable with that of Degussa P-25 TiO2. The concentration of toxic intermediates was high when the reaction was carried out in presence of Degussa P-25 TiO2 but it was found to be insignificant when the reaction was carried out in presence of base metal-substituted CeVO4. The effect of % Fe-substitution (varied from 1 to 5 at%) in CeVO4 on the photocatalytic activity was also investigated and it was observed that 1 at% Fe-substituted compound showed the highest activity. A mathematical model describing the kinetics of the photocatalytic degradation of phenol was developed on the basis of the catalyst structure and taking into account the formation of all the possible intermediates. The variation of the concentration of phenol and the intermediates was described by the model and the reaction rateconstants were determined. (C) 2010 Elsevier B.V. All rights reserved.

Synthesis of metal oxide nanorods using carbon nanotubes as templates

Nanorods of several oxides, with diameters in the range of 10-200 nm and lengths upto a few microns, have been prepared by templating against carbon nanotubes. The oxides include V2O5, WO3, MoO3 and Sb2O5 as well as metallic MoO2, RuO2 and IrO2. The nanorods tend to be single-crystalline structures. Nanotube structures have also been obtained in MoO3 and RuO2.

Metal-ion-ligand interactions in thermotropic liquid crystals

The interactions of lithium perchlorate with ligands such as dimethyl sulphoxide, acetonitrile, pyridine and the Schiff base liquid crystals are investigated. The experiments open a new field for the study of metal-ion-ligand interactions in thermotropic liquid crystals.

Growth and characterization of germanium nanowires by electron beam evaporation

Germanium nanowires were grown on Au coated Si substrates at 380 degrees C in a high vacuum (5 x 10(-5) Torr) by e-beam evaporation of Germanium (Ge). The morphology observation by a field emission scanning electron microscope (FESEM) shows that the grown nanowires are randomly oriented with an average length and diameter of 600 nm and 120 nm respectively for a deposition time of 60 min. The nanowire growth ratewas measured to be similar to 10 nm/min. Transmission electron microscope (TEM) studies revealed that the Ge nanowires were single crystalline in nature and further energy dispersive X-ray analysis(EDAX) has shown that the tip of the grown nanowires was capped with Au nanoparticles, this shows that the growth of the Ge nanowires occurs by the vapour liquid solid (VLS) mechanism. HRTEM studies on the grown Ge nanowire show that they are single crystalline in nature and the growth direction was identified to be along [110]. (C) 2010 Elsevier B.V. All rights reserved.

Quinone studies. Part III. Metal ion-catalysed oxidation of halophenols and halonaphthols by peroxidisulphate

Oxidation of representative halophenols and halonaphthols by peroxidisulphate has been examined. The influence of metallic ions, viz. Cu2+, Fe3+, Ag+, on the above reaction has been studied. Cu2+ ion-catalyzed oxidation gives halo-1, 4-quinones in excellent yield. Potassium bis(biureto)cuprate(III) complex also oxidises halophenols to halo-1, 4-quinones.

Oxide-based bifunctional oxygen electrode for rechargeable metal/air batteries

Statistical methods for optimizing the morphology of oxide-based, bifunctional oxygen electrodes for use in rechargeable metal/air batteries are examined with regard to binder composition, compaction time, and compaction load. Results show that LaNiO3 with PTFE binder in a nickel mesh envelope provides a satisfactory electrode.