Substance without citation: evaluating the online impact of grey literature

Individuals and organisations producing information or knowledge for others sometimes need to be able to provide evidence of the value of their work in the same way that scientists may use journal impact factors and citations to indicate the value of their papers. There are many cases, however, when organisations are charged with producing reports but have no real way of measuring their impact, including when they are distributed free, do not attract academic citations and their sales cannot be tracked. Here, the web impact report (WIRe) is proposed as a novel solution for this problem. A WIRe consists of a range of web-derived statistics about the frequency and geographic location of online mentions of an organisation’s reports. WIRe data is typically derived from commercial search engines. This article defines the component parts of a WIRe and describes how to collect and analyse the necessary data. The process is illustrated with a comparison of the web impact of the reports of a large UK organisation. Although a formal evaluation was not conducted, the results suggest that WIRes can indicate different levels of web impact between reports and can reveal the type of online impact that the reports have.     

Evaluating altmetrics

The rise of the social web and its uptake by scholars has led to the creation of altmetrics, which are social web metrics for academic publications. These new metrics can, in theory, be used in an evaluative role, to give early estimates of the impact of publications or to give estimates of non-traditional types of impact. They can also be used as an information seeking aid: to help draw a digital library user’s attention to papers that have attracted social web mentions. If altmetrics are to be trusted then they must be evaluated to see if the claims made about them are reasonable. Drawing upon previous citation analysis debates and web citation analysis research, this article discusses altmetric evaluation strategies, including correlation tests, content analyses, interviews and pragmatic analyses. It recommends that a range of methods are needed for altmetric evaluations, that the methods should focus on identifying the relative strengths of influences on altmetric creation, and that such evaluations should be prioritised in a logical order.     

Fast Simulation of Laplacian Growth

Laplacian instability is the physical mechanism driving pattern formation in many disparate natural phenomena. Current algorithms for simulating this instability are slow and memory intensive. A new algorithm, based on the dielectric breakdown model from physics, is more than three orders of magnitude faster than previous methods and decreases memory use by two orders of magnitude. Our algorithm admits a spherical harmonic solution, letting it account for arbitrary boundary data, such as an environment map     

Studying the bulk dynamic strength of a quartz glass by laser-induced breakdown

Methods and results of the investigation of pulsed pressures excited in the bulk of a quartz glass by focused nanosecond laser pulses (λ=1.06 μm, τ_0.5≈12.5 ns) are described. The experiments were performed in a wide range of laser power densities, which allowed the generation of pulsed pressures to be studied for both thermomechanical effect and optical damage in the bulk of glass. We have measured displacement of the free sample surface (laser interferometry), determined optical damage thresholds, and performed fractographic analysis of the fracture zones. The results revealed nonlinear thermomechanical response and allowed us to estimate the change in the optical absorption and temperature of the material near the optical damage threshold. Quantitative data are obtained on the relative efficiency of pulsed pressure production during the thermomechanical effect and optical damage. Data on the dynamic strength of a quartz glass are obtained for the first time in the absence of a damaged surface layer. Using the proposed method, it is possible to determine the energy consumption for the fracture of brittle materials. High sensitivity of the method of laser-induced breakdown allows this technique to be used for studying the influence of microstructure on the mechanical and optical properties of transparent media.     

The movement of a metal disk toward pulsed laser radiation

It is shown in works [1–5] that the electron heat transfer mechanism yields the dominating value and duration of the tensile phase in pulses of the elastic stresses excited by pulse laser heating. This leads to a nonzero average mechanical momentum and the possibility of the movement of heat conducting objects toward the pulse heat source. In this work, we present the results of an experimental study of the movement of a pendulum—an aluminum disk 20 mm in diameter and 0.85 mm thick—toward pulse laser radiation.     

Ultimate bearing capacity of footings on coal ash

Coal ash is recognized as an alternative fill material to the conventional natural soils near a coal fired thermal power station where its large deposits are available. This paper presents experimental investigations on footings on coal ash subjected to loads. A series of laboratory model tests on varying sizes of footings were conducted. The conventional bearing capacity evaluation methods applied for natural soils do not consider progressive failure. These effects are explained based on the non-linear strength behavior of the granular soil and occurrence of progressive failure. The classical bearing capacity theory was applied in relation to the relative dilatancy of coal ash to describe this phenomenon. Few novel observations presented here show that the extent of progressive failure of ash fills is a compressed function of material characteristics of the ash, size and depth of footing and the settlement ratio.