The JavaScript programming language is widely used for web programming and, increasingly, for general purpose computing. As such, improving the correctness, security and performance of JavaScript applications has been the driving force for research in type systems, static analysis and compiler techniques for this language. Many of these techniques aim to reign in some of the most dynamic features of the language, yet little seems to be known about how programmers actually utilize the language or these features. In this paper we perform an empirical study of the dynamic behavior of a corpus of widely-used JavaScript programs, and analyze how and why the dynamic features are used. We report on the degree of dynamism that is exhibited by these JavaScript programs and compare that with assumptions commonly made in the literature and accepted industry benchmark suites.

This paper introduces an electrical four-point measurement method enabling thermal and electrical conductivity measurements of nanoscale materials. The method was applied to determine the thermal and electrical conductivity of reduced graphene oxide flakes. The dielectrophoretically deposited samples exhibited thermal conductivities in the range of 0.14-2.87 W m(-1) K(-1) and electrical conductivities in the range of 6.2 x 10(2)-6.2 x 10(3) Omega(-1) m(-1). The measured properties of each flake were found to be dependent on the duration of the thermal reduction and are in this sense controllable.

During debugging, a developer must repeatedly and manually reproduce faulty behaviors in order to inspect different facets of the program's execution. Existing tools for reproducing such behaviors prevent the use of debugging aids such as breakpoints and logging, and are not designed for interactive, random-access exploration of recorded behavior. This paper presents Timelapse, a tool for quickly recording, reproducing, and debugging interactive behaviors in web applications. Developers can use Timelapse to browse, visualize, and seek within recorded program executions while simultaneously using familiar debugging tools such as breakpoints and logging. Testers and end-users can use Timelapse to demonstrate failures in situ and share recorded behaviors with developers, improving bug report quality by obviating the need for detailed reproduction steps. Timelapse is built on Dolos, a novel record/replay infrastructure that ensures deterministic execution by capturing and reusing program inputs both from the user and from external sources such as the network. Dolos introduces negligible overhead and does not interfere with breakpoints and logging. In a small user evaluation, participants used Timelapse to accelerate existing reproduction activities, but were not significantly faster or more successful in completing the larger tasks at hand. Together, the Dolos infrastructure and Timelapse developer tool support systematic bug reporting and debugging practices.

In the last few years, the creation of new 1D single crystalline molecular materials has attracted much attention due to promising applications in fields such as optics and electronics. [1][2][3][4] Much research effort is currently devoted to obtain long nanowires and nanotubes in a reproducible manner. Most approaches to influence the morphology of nanostructures are based on modifications of the chemical composition of the building blocks and optimization of preparative conditions, such as concentrations, solvents, and temperature. Furthermore, in order to obtain high-quality homogeneous micro-and nanostructures from molecular units in solution, a number of deposition techniques has been developed including zone-casting, self-assembled monolayers (SAMs), Langmuir-Blodgett (LB) films, stamping, electrochemical methods, and thermal evaporation.[5] Although these techniques and their combination facilitate the fabrication of soft-matter devices with low manufacturing costs, large-area coverage on surfaces, and high molecular order, it is still challenging to obtain anisotropic structures and to influence the crystalline structure.Recent studies, however, have indicated that microfluidic systems could provide unique advantages in order to promote the formation of micro-and nanometer-scaled structures. In particular, the formation of crystals and nanoparticles was achieved in microchannels in superior quality due to the excellent handling of small fluid volumes of nano-and even picolitres. [6,7]