Ethics and social networking sites: A disclosive analysis of Facebook

Paper has been accepted for publication in Information, Technology and People.Purpose: This paper provides insights into the moral values embodied by a popular social networking site (SNS), Facebook. We adopt the position that technology as well as humans has a moral character in order to disclose ethical concerns that are not transparent to users of the site. Design/methodology/approach: This study is based upon qualitative field work, involving participant observation, conducted over a two year period. Findings: Much research on the ethics of information systems has focused on the way that people deploy particular technologies, and the consequences arising, with a view to making policy recommendations and ethical interventions. By focusing on technology as a moral actor with reach across and beyond the Internet, we reveal the complex and diffuse nature of ethical responsibility in our case and the consequent implications for governance of SNS. Research limitations/implications: We situate our research in a body of work known as disclosive ethics and argue for an ongoing process of evaluating SNS to reveal their moral importance. Along with other authors in the genre, our work is largely descriptive, but we engage with prior research by Brey and Introna to highlight the scope for theory development. Practical implications: Governance measures that require the developers of social networking sites to revise their designs fail to address the diffuse nature of ethical responsibility in this case. Such technologies need to be opened up to scrutiny on a regular basis to increase public awareness of the issues and thereby disclose concerns to a wider audience. We suggest that there is value in studying the development and use of these technologies in their infancy, or if established, in the experiences of novice users. Furthermore, flash points in technological trajectories can prove useful sites of investigation. Originality/value: Existing research on social networking sites either fails to address ethical concerns head on or adopts a tool view of the technologies so that the focus is on the ethical behaviour of users. We focus upon the agency, and hence the moral character, of technology to show both the possibilities for, and limitations of, ethical interventions in such cases

Photon induced secondary electron emission

Numerical models for predicting photon-induced secondary electron emission are presented. The results are compared with experimental measurements made using a Co-60 gamma ray source

A 100 GHz coplanar strip circuit tuned with a sliding planar backshort

A means of mechanically altering the electrical length of a planar transmission line would greatly enhance the use of integrated circuit technology at millimeter and submillimeter wavelengths. Such a mechanically adjustable planar RF tuning element, successfully demonstrated at 100 GHz, is described here. It consists of a thin metallic sheet, with appropriately sized and spaced holes, which slides along on top of a dielectric-coated coplanar-strip transmission line. Multiple RF reflections caused by this structure add constructively, resulting in a movable RF short circuit, with |s11|≫APX=/-0.3 dB, which can be used to vary the electrical length of a planar tuning stub. The sliding short is used here to produce a 2-dB improvement in the response of a diode detector. This tuning element can be integrated with planar circuits to compensate for the effect of parasitic reactance inherent in various devices including semiconductor diodes and superconductor-insulator-superconductor (SIS) junctions

An experimental study of surface pressure fluctuations in a separating turbulent boundary layer

Measurements of streamwise velocity fluctuation and surface pressure fluctuation spectra and wavespeeds are reported for a well-documented separating turbulent boundary layer. Because a portion of the acoustic pressure fluctuations is the same across the nominally two-dimensional turbulent flow, it is possible to decompose two microphone signals and obtain directly the turbulent flow contributions to the surface pressure spectra. The rms surface pressure fluctuation p' and spectra phi(omega) increase through the adverse pressure gradient attached flow region and the detached flow zone and scale on the maximum turbulent shearing stress tau(M); p'/tau(M) increases to the detachment location and decreases downstream due to the rapid movement of the pressure-fluctuation-producing motions away from the wall after the beginning of intermittent backflow. At lower frequencies for the attached flow phi(omega) is approximately omega to the -0.7 while phi(omega) is approximately omega to the -3 at higher frequencies. After the beginning of intermittent backflow, phi(omega) varies with omega at low frequencies and omega to the -3 at high frequencies; farther downstream the lower frequency range varies with omega to the 2.4. The surface pressure fluctuation celerity for the attached flow increases with frequency and agrees with the semi-logarithmic overlap equation of Panton and Linebarger. After the beginning of the separation process, the wavespeed decreases because of the oscillation of the instantaneous wavespeed direction and the streamwise coherence decreases drastically

Geoids in General Relativity: Geoid Quasilocal Frames

We develop, in the context of general relativity, the notion of a geoid -- a surface of constant "gravitational potential". In particular, we show how this idea naturally emerges as a specific choice of a previously proposed, more general and operationally useful construction called a quasilocal frame -- that is, a choice of a two-parameter family of timelike worldlines comprising the worldtube boundary of the history of a finite spatial volume. We study the geometric properties of these geoid quasilocal frames, and construct solutions for them in some simple spacetimes. We then compare these results -- focusing on the computationally tractable scenario of a non-rotating body with a quadrupole perturbation -- against their counterparts in Newtonian gravity (the setting for current applications of the geoid), and we compute general-relativistic corrections to some measurable geometric quantities.Comment: 24 pages, 8 figures; v2: reference added; v3: introduction clarified, reference adde

Optical studies of the pre-breakdown mechanism in dielectronic liquids.

PhDThe work described in this thesis provides an optical study of pre-breakdown events in liquid dielectrics. A small scale rig employing a 50SI test cell with viewing windows, as part of a high voltage co-axial line, enabled short rise time pulses to be applied to a non-uniform test gap. For the liquid dielectric, changes of refractive index resulting from applied voltage were rendered visible by means of a Schlieren optical system. A high speed image converter camera enabled rapidly changing pre-breakdown phenomena to be photographically recorded at framing speeds up to 107 per second. Scattered light photographs were taken by orthogonal flash illumination under both pulse and direct voltage conditions, allowing large format macrophotography. Using a piezoelectric transducer placed within the test cell, and a photomultiplier to view the gap region, a relationship has also been established between the generation of mechanical waves, light scintillation and conduction current pulses. From the photographic records and conventional parameter measurements there exists strong evidence for the presence of a gaseous phase in processes leading to the electrical breakdown of liquid dielectrics even under pulse conditions