Hot corrosion Type II of FeCr‐based model alloys for boiler and heat exchanger applications

The hot corrosion Type II of the alloys FeCr20, FeCr20Ni10, FeCr20Ni20, and FeCr20Co10 is investigated at 700°C in air + 0.5% SO₂ with deposits consisting of Na₂SO₄ and a eutectic mixture of Na₂SO₄ and MgSO₄ for 24, 100, and 300 h. The alloying elements nickel and cobalt have a positive influence when tests are conducted using a MgSO₄‐Na₂SO₄ deposit. In this case, they reduce the metal loss and increase the time to the propagation stage. In contrast, when the alloys are exposed with a Na₂SO₄ deposit, these alloying elements increase the metal loss and allow for the transition to the propagation stage because they can form molten phases with the Na₂SO₄. During the incubation stage an oxide scale forms on the FeCr20 alloy, which is thicker than the one formed during exposure without a deposit, and iron oxides are observed, which precipitate in the deposit. The propagation stage occurs by a dissolution and precipitation mechanism forming localized pitting attack. Iron is the main species that dissolves and precipitates, while chromium remains mainly as an oxide beneath the initial surface. The additional elements are found in the pit and in the salt deposit.     

Chemical composition of eight edible mushrooms

A comparative analysis of crude protein, crude ash, phosphorus (P), potassium (K) and calcium (Ca) contents of 57 samples of eight common edible mushroom species was made. The most important protein sources were: Marasmius oreades and Lepista nebularis. Species of the Boletaceae formed an intermediate group, while relatively proteinless species were: Armillariella mellea and Cratarellus cornucopioides. The lowest crude protein content was established in Cantharellus cibarius. The ash contents varied more widely. The greatest P contents were measured in Lepista nebularis and Marasmius oreades but most mushrooms contained 6-7 gP/kg. The analysed mushroom samples contained 30-40 gK/kg dry weight and 0,2-0,3 gCa/kg. These analyses are important from the point of view of the nutritional role of mushrooms.     

One-step synthesis of functional Co nanoparticles for surface-initiated polymerization

Much effort is conducted to construct artificial objects that are capable of converting chemical or electromagnetic energy into a specific, predetermined motion on the nanoscale. We present results on the synthesis of core–shell nanoparticles capable to be set in rotation by the application of electromagnetic fields. The nanorotors implied in the study are based on the cobalt nanospheres decorated with a stabilizing brush shell composed of poly(?-caprolactone) that is attached by surface-initiated polymerization. The functional cores used as macroinitiators can be fabricated alternatively by a two-step or a one-step process.     

Surface Treatments of Automotive Parts – Research and Applications

Surface treatments used in daily manufacturing of parts for the automotive industry are selected to serve functional and decorative requirements achieved of mass production. Increased loads (mechanical, thermal etc.), longer life time, weight reduction, friction reduction, and corrosion resistance are demanded for modern automotive systems. Within the last decade, improved and new deposition techniques were developed in PVD, PECVD, thermochemical heat treatment and thermal spraying. These new treatments are becoming more and more common in powertrain and engine applications. Generating optimized surfaces for different types of substrate materials (e.g. Al‐ alloys, case hardened steels etc.) and geometries (e.g. bores) also impacts the running costs. Due to the new developments within these competing surface treatments, it becomes more and more common to substitute traditional treatment‐substrate‐systems with advanced treatments. Both the application potential and selected examples of different surface treatments will be shown. Aspects of the internal coating of bores inside the engine by plasma spraying, features of the corrosion protection of parts for the powertrain by the IONITOX process and piston ring treatments are discussed in more detail.     

Web-based education experiences

The World Wide Web has the potential to revolutionize instruction and increase educational opportunities across corporate, government and educational sectors. Not only will the Web enable distance learning and peer-to-peer connectivity, but it will also enhance student feedback and let instructors understand whether and how long students have studied a particular lesson. It also has the potential to reduce training costs. The authors discuss the creation of an online learning environment considering practical and pedagogical issues