he mobile social networking revolution is upon us and could have as profound an effect in enriching local social interaction as the Internet has had in enriching online information access and discourse. The key observation in this article is that the explosive phenomenon of online social networks can be harnessed using mobile devices to answer the compelling question that frequently appears in local social contexts: "Who's that?" It is often the case that people want to find out more about those who are around them; for example, who is that speaking to a group of people in a corner of the room, or who is that who just walked into the room? Standard solutions include asking those around you, looking at name tags, introducing yourself, and so on, none of which leverage the power of technology to help answer these compelling questions and thereby enrich the social interaction.Online social networks have exploded in popularity [1-3]. As of December 2007, Facebook had over 59 million users [4]. It is estimated that over 85 percent of four-year college students have a Facebook profile, presenting a very usable penetration rate and providing an incredible resource for applications that might leverage this data. These online social networks provide a wealth of personal contextual information, including name, picture, contact information, gender, relationship status/interests, activities/hobbies, musical preferences, literature interests, group membership, and, of course, friendship information concerning user interconnection. Social networks provide a variety of mechanisms for users to share these rich sets of contextual data with other users, including searching for other users with similar interests, as well as a means to establish and maintain communication with other users. Social networks can be seen as a natural evolution of the Internet, where the first big wave facilitated a person's access to information; for example, Web servers and peer-topeer networks providing news and information content, as well as ways to buy products, whereas this next big wave is focused on facilitating person-to-person communication.WhozThat is motivated by the idea that bringing this rich contextual information from online social networks into the real world of local human interactions substantially enriches local social interaction. Imagine if you knew more about the people around you in a social gathering, such that you could more easily strike up a conversation with someone with whom you were interested in talking. By being informed via mobile technology of the identity of the person with whom you are seeking to interact and consulting information obtained from that person's public social networking profile, you could more easily initiate a conversation, perhaps introducing yourself and saying, "I noticed we have a shared interest in this hobby or that cause." The ability of mobile social networking (MoSoNet) technology to substantially lower the barriers to social discourse by minimizing unfamiliarity could revolutionize human soc...

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Diode laser brazing of aluminium alloy (A5052) to interstitial free steel (IF steel) or type 304 stainless steel (SUS304) was conducted using aluminium filler metal (BA4047) with Nocolock flux. The processing parameters of laser power, wire feed rate and travel speed were varied. The strength of lap joints of A5052 on steels was evaluated by tensile shear test. The joint strength of A5052/steels was increased with increasing laser power and reached the maximum strength, more than approximately 80% of the A5052 base metal strength, at a laser power of 1300 W. Voids and incomplete penetration of filler metal were observed at the A5052/braze layer interface when the laser power was below 1100 W. The Fe–Al intermetallic compounds were formed at the steel/braze layer interfaces and grew drastically when the laser power exceeded 1300 W. Superior brazability of A5052/steels was found at brazing conditions corresponding to a temperature of filler metal droplet of 1050–1250 K.

Microcracking behaviour in the gas tungsten arc multipass weld metal of alloy 690 was investigated. The majority of microcracks occurred within about 300 mm from the fusion line of the subsequent weld bead and propagated along the solidification boundaries in the multipass weld metal. The morphology of the crack surface indicated the characteristic texture of ductility dip cracking. The microcracking susceptibility of the reheated weld metal was evaluated via the spot Varestraint test using three different filler metals having varying contents of impurity elements such as P and S. Microcracking occurring in the spot Varestraint tests consisted predominantly of ductility dip cracking, with a small amount of liquation cracking. The ductility dip cracking temperature range was about 1350-1600 K in the weld metal FF1, and narrowed in the order of weld metals FF1.FF3.FF5. The ductility dip cracking susceptibility was reduced with decreasing contents of impurity elements in the filler metal. It was concluded that the amount of (PzS) in the filler metal should be reduced as much as possible (to about 30 ppm in total) to suppress microcracking in the multipass weldment.

Thermodynamic calculations have been used to construct time temperature sensitization (TTS) diagrams for AISI 304 stainless steels (SS). The quantitative Stawstrom and Hillert model, which is based on chromium diffusion control of sensitization, was used to calculate the TTS diagrams. Electrochemical potentiokinetic reactivation (EPR) tests were performed on these steels, with various nitrogen additions, to obtain the experimental TTS curves. The calculated and experimental TTS diagrams have been compared to better understand nitrogen addition effects on the sensitization kinetics of AISI 304 SS. These results indicate that nitrogen additions below 0.16 wt% retard the sensitization kinetics; one possible mechanism by which this is achieved is an increase in chromium concentration adjacent to the grain boundaries, which decreases the chromium concentration gradient between the austenite matrix and the graín boundaries and hence retards carbide growth.