COMMITMENTS AND CAPABILITIES: THE ROYAL NAVY IN THE 21ST CENTURY

The size of the British Royal Navy (RN) has decreased significantly over the last century. Recent policy documents have outlined plans for new warship construction as well as an increase in maritime strategic commitments, raising the question of whether the RN’s means are sufficient to achieve the government’s desired ends. This work compares the current and future capabilities of the Royal Navy against Britain’s renewed global ambitions, to determine if the new policy is over-ambitious. It also identifies possible pitfalls that the RN may encounter as it reorients itself over the next decade. The three main findings can be summarized as follows: (1) the RN can meet its current and future commitments if the stated force structure plans are followed; (2) there is significant strategic risk associated with failure to follow-through on these plans, and finally (3) close cooperation with Britain’s allies (both in NATO and globally) will continue to be an important supporting element of RN policy. This thesis recommends expanding new frigate construction following completion of the current contracts, ensuring renewed naval diplomacy produces meaningful benefits to offset its political and economic costs, and continuing the RN’s strong track record of close integration with allies worldwide.Lieutenant, United States NavyApproved for public release. Distribution is unlimited

A new Raman technique of superior spectral resolution

Raman-active vibrational modes are coherently excited by the transient stimulated Raman process. A subsequent delayed probe of relatively long duration interacts with the freely relaxing vibrations. Raman spectra are generated with higher resolution and more accurate peak positions than in conventional Raman spectroscopy. In liquid cyclohexane four new Raman lines were readily detected in the frequency range 2870–2920 cm−1

Narrowing of spectral lines beyond the natural or dephasing line width

Transient excitation and gated or delayed observation provides a narrowing of the inherent line width of the transition. Possible experimental one- and two-photon systems are discussed and the loss of signal with line narrowing is calculated. The general case of lines broadened by dephasing processes is treated. Contact is made with the line narrowing in recent Raman type experiments

Magnetotransport in Sr3PbO antiperovskite with three-dimensional massive Dirac electrons

Novel topological phenomena are anticipated for three-dimensional (3D) Dirac electrons. The magnetotransport properties of cubic ${\rm Sr_{3}PbO}$ antiperovskite, theoretically proposed to be a 3D massive Dirac electron system, are studied. The measurements of Shubnikov-de Haas oscillations and Hall resistivity indicate the presence of a low density ($\sim 1 \times 10^{18}$ ${\rm cm^{-3}}$) of holes with an extremely small cyclotron mass of 0.01-0.06$m_{e}$. The magnetoresistance $\Delta\rho_{xx}(B)$ is linear in magnetic field $B$ with the magnitude independent of temperature. These results are fully consistent with the presence of 3D massive Dirac electrons in ${\rm Sr_{3}PbO}$. The chemical flexibility of the antiperovskites and our findings in the family member, ${\rm Sr_{3}PbO}$, point to their potential as a model system in which to explore exotic topological phases

Generation of femtosecond light pulses in the near infrared around λ = 850 nm

Femtosecond light pulses tunable between 840 nm and 880 nm are generated in a synchronously pumped ring dye laser. The laser emits nearly bandwidth-limited pulses (Δv tp = 0.45) with pulse durations down to 65 fs. At a pumping power of 450 mW of a mode-locked Ar-ion laser (λ = 514 nm) the infrared femtosecond dye laser has an output of up to 15 mW

Excited-state reaction dynamics of bacteriorhodopsin studied by femtosecond spectroscopy

The photodynamics of bacteriorhodopsin were studied by transient absorption and gain measurements after excitation with femtosecond pulses at 620 nm. With probing pulses at longer wavelengths (λ > 770 nm) the previously reported formation of the J intermediate (with a time constant of 500±100 fs) was confirmed. With probing pulses around 700 nm, a faster process with a relaxation time of 200±70 fs was observed. The data analysis strongly suggests that this kinetic constant describes the reactive motion of the polyatomic molecule on its excited-state potential energy surface, i.e. one observes directly the incipient isomerization of the retinal molecule. The minimum of the S1 potential energy surface reached in 200 fs lies approximately 13300 cm−1 above the ground state of bacteriorhodopsin and from this minimum the intermediate J is formed with a time constant of 500 fs

The influence of phase-modulation on femtosecond time-resolved coherent Raman spectroscopy

The influence of phase-modulation on femtosecond time-resolved coherent Raman scattering is investigated theoretically and experimentally. The coherent Raman signal taken as a function of the spectral position shows unexpected temporal oscillations close to time zero. A theoretical analysis of the coherent Raman scattering process indicates that the femtosecond light pulses are amplitude and phase modulated. The pulses are asymmetric in time with more slowly decaying trailing wings. The phase of the pulse amplitude contains quadratic and higher-order contributions

Distribution of Neuropeptide F-Like Immunoreactivity in the Eastern Subterranean Termite, Reticulitermes flavipes

The nervous system and gut of worker, soldier and alate castes of the eastern subterranean termite, Reticulitermes flavipes Kollar (Isoptera: Rhinotermitidae) were examined for immunoreactivity to an antiserum to Helicoverpa zea (Boddie) (Leipidoptera: Noctuidae) MP-I (QAARPRF-NH2), a truncated form of neuropeptide F. More than 145 immunostained axons and cell bodies were seen in the brain and all ganglia of the ventral nerve cord. Immunoreactive axons exiting the brain projected anteriorly to the frontal ganglion and posteriorly to the corpora cardiaca and corpora allata. In the stomatogastric nervous system, immunoreactive axons were observed over the surface of the foregut, salivary glands, midgut and rectum. These axons originated in the brain and from 15–25 neurosecretory cells on the foregut. Staining patterns were consistent between castes, with the exception of immunostaining observed in the optic lobes of alates. At least 600 immunoreactive endocrine cells were evenly distributed in the midguts of all castes with higher numbers present in the worker caste. Immunostaining of cells in the nervous system and midgut was blocked by preabsorption of the antiserum with Hez MP-I but not by a peptide having only the RF-NH2 in common. This distribution suggests NPF-like peptides coordinate feeding and digestion in all castes of this termite species