The science and technology of condensed matter physics - from atomic imaging to space research

Various areas of our ongoing condensed matter physics research which involve both fundamental physics and advanced technology are described. The research topics include studies of the vortex dynamics and pairing symmetry of high-temperature superconductors; development of precision clocks using high-Q superconducting microwave cavities; state-of-the-art measurements of the density and critical phenomena of liquid helium near phase transitions and under microgravity; as well as the physics and device applications of various magnetoresistive perovskites. The experimental scope encompasses techniques from atomic imaging to space research, and the important interplay of fundamental science and frontier technology in our research is also addressed

Investigations of urethral sphincter activity in mice with bladder hyperalgesia before and after drug administration of gabapentin.

PurposeThis study investigated the effect of gabapentin on lower urinary tract dysfunction focusing on urethral activities and cystitis-induced hyperalgesia in a mouse model of painful bladder syndrome/interstitial cystitis (PBS/IC). The electromyography (EMG) of external urethral sphincter (EUS) was difficult to obtain, but contained useful information to examine the drug effect in mice.MethodsFemale C57BL/6J mice were intraperitoneally (ip) administration with either saline or 200 mg/kg of cyclophosphamide (CYP) 48 h before experimental evaluation. Cystitis mice were treated with administration of gabapentin (25 or 50 mg/kg, ip). Cystometry and EUS EMG were obtained and analyzed during continuous bladder infusion. The visceral pain-related visceromotor reflex (VMR) was recorded in response to isotonic bladder distension.ResultsCystitis mice showed shorter inter-contraction intervals and increased occurrence of non-voiding contractions during bladder infusion, with increased VMR during isotonic bladder distension, indicating cystitis-induced bladder hyperalgesia. Gabapentin (50 mg/kg) suppressed effects of CYP on cystometry, but not on EUS EMG activity, during bladder infusion. The effect on urodynamic recordings lasted 4 h. VMR was significantly reduced by gabapentin.ConclusionsThe present study showed that CYP-induced cystitis in mice is a model of visceral hyperalgesia affecting detrusor contractions, not urethral activations. The technique of using EUS EMG to evaluate the drug effects on urethral activities is novel and useful for future investigations. Gabapentin can be as a potential treatment for detrusor overactivity and PBS/IC

Fuzzy multi criteria evaluation for performance of bus companies

A multi criteria decision making in ranking the bus companies using fuzzy rule is proposed. The proposed method uses the application of fuzzy sets and approximate reasoning in deciding the ranking of the performance of several bus companies. The proposed method introduces data normalization using similarity function which dampens extreme values that exist in the data. The use of the model is suitable in evaluating situation that involves subjectivity, vagueness and imprecise information. Experimental results are comparable to several previous methods

Time Response of Water-based Liquid Scintillator from X-ray Excitation

Water-based liquid scintillators (WbLS) present an attractive target medium for large-scale detectors with the ability to enhance the separation of Cherenkov and scintillation signals from a single target. This work characterizes the scintillation properties of WbLS samples based on LAB/PPO liquid scintillator (LS). X-ray luminescence spectra, decay profiles, and relative light yields are measured for WbLS of varying LS concentration as well as for pure LS with a range of PPO concentrations up to 90 g/L. The scintillation properties of the WbLS are related to the precursor LAB/PPO: starting from 90 g/L PPO in LAB before synthesis, the resulting WbLS have spectroscopic properties that instead match 10 g/L PPO in LAB. This could indicate that the concentration of active PPO in the WbLS samples depends on their processing.Comment: 6 pages, 7 figures, 2 tables. Submitted to Materials Advances, a journal of the Royal Society of Chemistr

Variational problems with singular perturbation

In this paper, we construct the local minimum of a certain variational problem which we take in the form $\mathrm{inf}\int_\Omega\left\{\frac{\epsilon}{2}kg^2|\nabla w|^2+\frac{1}{4\epsilon}f^2g^4(1-w^2)^2\right\}\,\mathrm{d}x$, where $\epsilon$ is a small positive parameter and $\Omega\subset\mathbb{R}^n$ is a convex bounded domain with smooth boundary. Here $f,g,k\in C^3(\Omega)$ are strictly positive functions in the closure of the domain $\bar{\Omega}$. If we take the inf over all functions $H^1(\Omega)$, we obtain the (unique) positive solution of the partial differential equation with Neumann boundary conditions (respectively Dirichlet boundary conditions). We wish to restrict the inf to the local (not global) minimum so that we consider solutions of this Neumann problem which take both signs in $\Omega$ and which vanish on $(n-1)$ dimensional hypersurfaces $\Gamma_\epsilon\subset\Omega$. By using a $\Gamma$-convergence method, we find the structure of the limit solutions as $\epsilon\to0$ in terms of the weighted geodesics of the domain $\Omega$