Chiral Perturbation Theory for Tensor Mesons

Interactions of $a_2, K^*_2, f_2$ and $f_2'$ tensor-mesons with low-energy $\pi, K, \eta, \eta'$ pseudo-scalar mesons are constrained by chiral symmetry. We derive a chiral Lagrangian of tensor mesons in which the tensor mesons are treated as heavy non-relativistic matter fields. Using $1/N_c$ counting, we derive relations among unknown couplings of the chiral Lagrangian. Chiral perturbation theory is applied to the tensor-meson mass matrix. At one-loop there are large corrections to the individual tensor meson masses, but the singlet-octet mixing angle remains almost unchanged. We argue that all heavy mesons of spin $\ge 1$ share common feature of chiral dynamics.Comment: Latex, 9 pages, no figure

Backscatter-immune, polarization managed, all fiber Sagnac sensing interferometer

We propose a new all fiber Mach-Zehnder-Sagnac hybrid interferometer topology for precision sensing. This configuration utilizes a high coherence laser source, mitigates the effects of Rayleigh backscatter and polarization wander, while eliminating scale factor drift. We also present preliminary experimental results, using telecommunications grade single mode fiber and fiber couplers, to demonstrate its principle of operation

Digitally range-gated optical frequency domain reflectometry

We present a new optical frequency domain reflectometry technique which permits high frequency sweep repetition rates without sacrificing range. This technique could thus be adapted for remote and distributed acoustic sensing over long lengths of fibre

In Vitro Scaffold Construction for a Bio-artificial Liver

The main focus of this investigation is to design a scaffold that will accommodate a growing Bio-Artificial Liver (BAL) with oxygen. The two design objectives are to find the maximum length and the distance between the artificial capillaries of the scaffold to provide adequate oxygen supply above 1.98 x 10-19 g/um3 to prevent hypoxia to the growing liver tissues. By utilizing industrial modeling software, FIDAP and GAMBIT, a model of a single capillary with liver tissue attached directly was constructed to simulate the oxygen delivery by means of diffusion and convection from the capillary wall to the tissue and the uptake by metabolism. From the results obtained, it was concluded that diffusion, not convection of the oxygen flow within the capillary was the dominant process of oxygen transport throughout the tissue. The maximum distance traveled into the tissue with capillary length of 60 ?m was 147 ?m from the capillary at the inlet side of the tissue while diffusion at the outlet tissue was at a modest 108 ?m. These values are unacceptable for the feasible construction of oxygen transport system solely based on diffusion. Thus, this investigation concludes that novel methods of greater complexity are needed to construct a more efficient and economically applicable oxygen delivery system for the mass production of bio-organs

Pico-strain multiplexed fiber optic sensor array operating down to infra-sonic frequencies

An integrated sensor system is presented which displays passive long range operation to 100 km at pico-strain (pε) sensitivity to low frequencies (4 Hz) in wavelength division multiplexed operation with negligible cross-talk (better than −75 dB). This has been achieved by prestabilizing and multiplexing all interrogation lasers for the sensor array to a single optical frequency reference. This single frequency reference allows each laser to be locked to an arbitrary wavelength and independently tuned, while maintaining suppression of laser frequency noise. With appropriate packaging, such a multiplexed strain sensing system can form the core of a low frequency accelerometer or hydrophone array

Polarization speed meter for gravitational-wave detection

We propose a modified configuration of an advanced gravitational-wave detector that is a speed-meter-type interferometer with improved sensitivity with respect to quantum noise. With the addition of polarization-controlling components to the output of an arm cavity Michelson interferometer, an orthogonal polarization state of the interferometer can be used to store signal, returning it later with opposite phase to cancel position information below the storage bandwidth of the opposite mode. This modification provides an alternative to an external kilometer-scale Fabry-Pérot cavity, as presented in earlier work of Purdue and Chen [Phys. Rev. D 66, 122004 (2002)]. The new configuration requires significantly less physical infrastructure to achieve speed meter operation. The quantity of length and alignment degrees of freedom is also reduced. We present theoretical calculations to show that such a speed meter detector is capable of beating the strain sensitivity imposed by the standard quantum limit over a broad range of frequencies for Advanced Laser Interferometer Gravitational-wave Observatory-like parameters. The benefits and possible difficulties of implementing such a scheme are outlined. We also present results for tuning of the speed meter by adjusting the degree of polarization coupling, a novel possibility that does not exist in previously proposed designs, showing that there is a smooth transition from speed meter operation to that of a signal-recycling Michelson behavior

Biodegradable electroactive polymers for electrochemically-triggered drug delivery

We report biodegradable electroactive polymer (EAP)-based materials and their application as drug delivery devices. Copolymers composed of oligoaniline-based electroactive blocks linked to either polyethylene glycol or polycaprolactone blocks via ester bonds were synthesized in three steps from commercially available starting materials and isolated without the need for column chromatography. The physicochemical and electrochemical properties of the polymers were characterized with a variety of techniques. The ability of the polymers to deliver the anti-inflammatory drug dexamethasone phosphate on the application of electrochemical stimuli was studied spectroscopically. Films of the polymers were shown to be degradable and cell adhesive in vitro. Such EAP-based materials have prospects for integration in implantable fully biodegradable/bioerodible EAP-based drug delivery devices that are capable of controlling the chronopharmacology of drugs for future clinical application