We constructed a cw Ti:Al(2)O(3) master oscillator-dye preamplifier-Ti:Al(2)O(3) power amplifier system that generates <2-ns, 100-mJ pulses. The system is tunable from 750 to 890 nm and has a repetition rate of 30 Hz. The output pulse has a near Fourier-transform-limited bandwidth of ~240 MHz. Backward stimulated Brillouin scattering is used to control the growth of amplified spontaneous emissi...

Helium accumulation negatively impacts structural materials used in neutron-irradiated environments, such as fission and fusion reactors. Next-generation fission and fusion reactors will require structural materials, such as steels, that are resistant to large neutron doses yet see service temperatures in the range most affected by helium embrittlement. Previous work has indicated the difficult...

Efficiency is a primary concern in wireless communications and many other industries. Most often, this sought after efficiency comes at a financial cost. The cellular industry is no different from other business in its efforts to reduce cost by maximizing efficiency. In the cellular industry, a large portion of the costs are attributed to base stations. The base station is the infrastructure th...

An array of fused silica waveguiding channels with randomly distributed transverse sizes in a disordered microstructure fiber is shown to allow a highly efficient broadly tunable frequency conversion of low-energy ultrashort laser pulses. Dispersion can be switched in such waveguide arrays by coupling the pump field into waveguiding wires with different diameters. Microstructure-fiber-integrate...

Reducing instruction memory requirements by improving code density using compression techniques has been the aim of much recent work on embedded devices. Previous work has been successful in improving compression ratios with modest decompression overhead for general purpose RISC architectures. However, most traditional compression techniques fail to produce good results for tightly encoded VLIW...

We have studied terahertz ~THz! emission from InAs and GaAs in a magnetic field, and find that the emitted radiation is produced by coupled cyclotron-plasma charge oscillations. Ultrashort pulses of THz radiation were produced at semiconductor surfaces by photoexcitation with a femtosecond Ti-sapphire laser. We recorded the integrated THz power and the THz emission spectrum as a function of mag...

INTRODUCTION Instrument separation is a serious concern in endodontics. Stainless steel instruments usually deform before they separate whereas Nickel Titanium instruments do not show any sign of deformation. AIM of the present study was to compare the cyclic rotations needed to fracture three different rotary nickel titanium endodontic instruments namely Profile, K3 Endo, RaCe in simulated c...

During orthodontic tooth movement, the mechanical behaviour of the extracellular matrix of the periodontal ligament (PDL) determines the cellular processes involved in turnover of the PDL and alveolar bone. This mechanical behaviour is the basis for finite element (FE) models and FE analyses. Five young adult male beagle dogs were used to test the null hypothesis that the mechanical behaviour o...

BACKGROUND Fiber-reinforced polymer composite (FRPC) archwires could provide an esthetic solution to conventional orthodontic archwires. This study was carried out with the following aims: (1) to compare the sliding friction of FRPC archwire with nickel titanium archwire using various archwire-bracket combinations and (2) to determine the correlation between surface roughness and friction of th...