Nanocrystalline samples of highly pure lead oxide were prepared by the sol-gel route of synthesis. X-ray diffraction and transmission electron microscopic techniques confirmed the nanocrystallinity of the samples, and the average sizes of the crystallites were found within 20 nm to 35 nm. The nanocrystallites exhibited specific anomalous properties, among which a prominent one is the increased lattice parameters and unit cell volumes. The optical band gaps also increased when the nanocrystallites became smaller in size. The latter aspect is attributable to the onset of quantum confinement effects, as seen in a few other metal oxide nanoparticles. Positron annihilation was employed to study the vacancy type defects, which were abundant in the samples and played crucial roles in modulating their properties. The defect concentrations were significantly larger in the samples of smaller crystallite sizes. The results suggested the feasibility of tailoring the properties of lead oxide nanocrystallites for technological applications, such as using lead oxide nanoparticles in batteries for better performance in discharge rate and resistance. It also provided the physical insight into the structural build-up process when crystallites were formed with a finite number of atoms, whose distributions were governed by the site stabilization energy.
Software development is information-dense knowledge work that requires collaboration with other developers and awareness of artifacts such as work items, pull requests, and file changes. With the speed of development increasing, information overload, and information discovery are challenges for people developing and maintaining these systems. Finding information about similar code changes and experts is difficult for software engineers, especially when they work in large software systems or have just recently joined a project. In this paper, we build a large-scale data platform named Nalanda platform to address the challenges of information overload and discovery. Nalanda contains two subsystems: (1) a large-scale socio-technical graph system, named Nalanda graph system, and (2) a large-scale index system, named Nalanda index system that aims at satisfying the information needs of software developers.To show the versatility of the Nalanda platform, we built two applications: (1) a software analytics application with a news feed named MyNalanda that has Daily Active Users (DAU) of 290 and Monthly Active Users (MAU) of 590, and (2) a recommendation system for related work items and pull requests that accomplished similar tasks (artifact recommendation) and a recommendation system for subject matter experts (expert recommendation), augmented by the Nalanda socio-technical graph. Initial studies of the two applications found that developers and engineering managers are favorable toward continued use of the news feed application for information discovery. The studies also found that developers agreed that
Software development is information-dense knowledge work that requires collaboration with other developers and awareness of artifacts such as work items, pull requests, and files. With the speed of development increasing, information overload is a challenge for people developing and maintaining these systems. In this paper, we build a large scale socio-technical graph to address challenges of information overload and discovery, with an initial focus on artifacts central to the software development and delivery process. The Nalanda graph is an enterprise scale graph with data from 6,500 repositories, with 37,410,706 nodes and 128,745,590 edges. On top of this, we built software analytics applications including a newsfeed named MyNalanda, and based on organic growth alone, it has Daily Active Users (DAU) of 290 and Monthly Active Users (MAU) of 590. A preliminary user study shows that 74% of developers and engineering managers surveyed are favorable toward continued use of the platform for information discovery. This work provides a view into a new large-scale socio-technical graph and the technical choices made for this approach, the implications for information discovery and overload among developers and managers, and the implications of future development on the Nalanda graph.
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