Paired kitchen-living room dust samples from 30 UK houses were collected for the analysis of BFRs, including PBDEs, HBCDDs and PBEB, EH-TBB, BTBPE, BEH-TEBP, DBDPE. Ninety-six plastic kitchen utensils were collected, screened for Br concentration by X-ray fluorescence spectromet…
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We investigate generalizations of coherent states as a means of representing the dynamics of excitations of the superconducting ground state. We also analyse the propagation of generalized coherent state wave packets under the Bogoliubov-de Gennes Hamiltonian. The excitations of…
A low energy gamma ray telescope, and the results of its observations are described. The telescope consisted of four sodium iodide crystals, each of 120 cm(2) area, occulted by lead discs. Charged particles are rejected using scintillation, anti-coincidence shields. The telescop…
Pulsed nuclear magnetic resonance has been used for the investigation of YHx where x = 1.72, 1.81, 1.92 and 1.98, YD1.88, YH1.98 doped with 20, 50, 100, 200 and 915 ppm Gd, TiH1.74 doped with150, 500 and 104 ppm Mn and [Pd0.92y0.08]H0.51 • The Proton relaxation times T1 and T2 h…
89Y MAS NMR has been used to study the effects of substitution for Cu in YBa2(Cul_xMx)3O7 (M=V,Fe,Co,Ni,Zn,Al and Ga) and YBa2(Cu1,_yMy)4O8 (M=Zn and Fe). Substituted YBa2(Cu1_xMx)3O7 and YBa2(Cu1-yMy)4O8 samples have been characterized by means of XRD and A.C. susceptibility me…
The Electrochemical Polarisation, Photocurrent Spectroscopy and Extended X-ray Absorption Fine Structure (EXAFS) techniques have been used to study the passive film on pure iron and iron alloy samples containing up to 25% chromium. The material used in this work was prepared bot…
Au/PbSn joints are widely used in the microelectronics industry. Intermetallic formation in Au/60Sn-40wt. %Pb and in Au/62Sn-36Pb-2wt. %Ag systems has been studied in the temperature range 80°C-160°C using diffusion couples. Interdiffusion between Au films and 60Sn-40wt. %Pb sol…
The strength of the geomagnetic field is a subject of both scientific and public interest, with the decay over the past 160 years leading to speculation as to whether we are entering a geomagnetic reversal. Prior to 1840, there was no capability for direct measurements of geomag…
A few percent of nitrogen (N) or bimuth (Bi) incorporation in GaAs compound semiconductors have proved to lower significantly its bandgap. This unusual bandgap reduction is of interest for numerous applications such as long wave-length lasers, solar cells etc. However, the addit…
This thesis presents results of lattice QCD computations of the K → π semi-leptonic (Kl3) and pion electromagnetic form factors using partially twisted boundary conditions. These form factors parameterize low-energynon-perturbative strong interaction effects and cannot therefore…
The term `laser cooling' is applied to the use of optical means to cool the motional energies of either atoms and molecules, or micromirrors. In the literature, these two strands are kept largely separate; both, however suffer from severe limitations. Laser cooling of atoms and …
X-ray spectral variability is a powerful probe of the relationship between the accretion disc and corona in accreting compact objects. In this thesis, I present the use of variability techniques to disentangle the different variable components of X-ray spectra. By examining corr…
The Silicon Photomultiplier (SIPM) is a novel photon sensing device, with potential applications in particle physics, astronomy and general gamma-ray spectroscopy. Various SiPM designs were evaluated for these roles by coupling them to a range of scintillators, including LSO, Na…
Cold atom samples, at temperatures of the order 100 uK, are useful for a wide reaching array of new and exciting technological and scientific endeavours. Atoms are conventionally cooled by Doppler cooling, which relies on the continuous absorption and reemission of photons in a …
The first experimental confirmation that femtosecond plasmon pulses can be generated, transmitted and modulated along a metal/dielectric waveguide is achieved. The ultrafast optical modulation of plasmons is accomplished by optical excitation of the aluminium plasmonic waveguide…
Passive acoustics provides a powerful tool for marine mammal research and mitigation of the risk posed by high energy anthropogenic acoustic activities through monitoring animal positions. Animal vocalisations can be detected and utilised in poor visibility conditions and while …
In this thesis, I investigate cladding-pumped Raman fibre lasers and amplifiers. Such devices, offering a novel way to generate Raman gain, combine the advantages of the hugely successful cladding-pumped rare-earth doped fibre lasers with those of stimulated Raman scattering. Th…
The aim of the work presented in this thesis is to investigate adaptively shaped advanced ultrafast laser sources in the near-(NIR) and the mid-infrared (MIR) regimes. The setup involves shaping a NIR pulse using an adaptively controlled liquid crystal spatial light modulator (L…
This thesis presents a series of experimental studies based on using liquid crystals (LC) with planar optical lightwave components. Adaptive optical devices have been fabricated by combining LCs with direct UV written buried channel waveguide and Bragg grating structures. It has…
The main aim of this project was to characterise electrical and optical effects in hybrid liquid crystals. Hybrid form of liquid crystals was achieved by using photoconducting alignment layers in liquid crystals cells and also by including ferroelectric, inorganic nanoparticles …