Benjamin J. Whitaker

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The definition of ‘life’ has invoked innumerable vigorous discussions, ranging from the religious to the scientific, philosophical and metaphysical, and still today no universally acceptable definition is available. This controversy is inescapable because of the absence of a theory of the nature of living systems1. There is, however, an urgent practical(More)
A representation of the search space in optical pulse shaping problems employing an acousto-optic programmable dispersive filter (AOPDF) is presented for use in closed-loop learning experiments where the optimal spectral phase function to some control problem is determined by an iterative learning algorithm. The representation allows the algorithm to select(More)
The proposal and subsequent global use of an Internet standard based on chemical primary Multipurpose Internet Mail Extensions (chemical MIME) media type is reviewed. Examples of the configuration of this standard for use with Internet-based electronic mail and World Wide Web clients are shown. The longterm objectives of the integration and interoperability(More)
We propose an Internet based standard based on primary chemical MIME types to be used in conjuction with the WorldWide Web information delivery system. W e show how this allows the user to have access to and control of molecular structural and spectroscopic information transparently integrated into scientific publications. W e illustrate this with examples(More)
We experimentally investigate the transition to synchronization in a population of photochemical oscillators with weak global coupling. Above a critical coupling strength the oscillators join a one-phase group or two-phase clusters. The number of oscillators in each cluster depends on the initial phase distribution, and irregular switching of oscillators(More)
Rotational wave packet revivals on an excited electronic state have been measured by femtosecond time-resolved photoelectron imaging for the first time. The first full revival at 82 ps of S1 (n,pi*) pyrazine was clearly observed in the time dependencies of the photoelectron intensity and the photoelectron angular distribution (PAD). The PAD, measured for(More)
Temperature and concentration fields have been investigated in the cylindrical combustion chamber of a rapid compression machine (RCM) by schlieren photography, chemiluminescent imaging and planar laser induced fluorescence of acetone and of formaldehyde in a 2-dimensional sheet across the diameter. The timescale of particular interest was up to 10 ms after(More)
We measure the photoionization cross-section of vibrationally excited levels in the S 2 state of azulene by femtosecond pump-probe spectroscopy. At the wavelengths studied (349-265 nm in the pump) the transient signals exhibit two distinct and well-defined behaviours: (i) Short-term (on the order of a picosecond) polarization dependent transients and (ii)(More)
This paper investigates the origin of a quantum interference observed when NO(2) is dissociatively ionized by short pulses of ultraviolet light. We describe time-resolved measurements of NO(+), O(+), and NO(2)(+) ions produced following the interaction of NO(2) with a approximately 70 fs duration pulse centered close to 400 nm and a subsequent time-delayed(More)