Validating delta-filters for resonant bar detectors of improved bandwidth foreseeing the future coincidence with interferometers

The classical delta filters used in the current resonant bar experiments for detecting GW bursts are viable when the bandwidth of resonant bars is few Hz. In that case, the incoming GW burst is likely to be viewed as an impulsive signal in a very narrow frequency window. After making improvements in the read-out with new transducers and high sensitivity dc-SQUID, the Explorer-Nautilus have improved the bandwidth ($\sim 20$ Hz) at the sensitivity level of $10^{-20}/\sqrt{Hz}$. Thus, it is necessary to reassess this assumption of delta-like signals while building filters in the resonant bars as the filtered output crucially depends on the shape of the waveform. This is presented with an example of GW signals -- stellar quasi-normal modes, by estimating the loss in SNR and the error in the timing, when the GW signal is filtered with the delta filter as compared to the optimal filter.Comment: 7 pages, presented in Amaldi6, accepted for publication in Journal of Physics: Conference Serie

A VALIDATED STABILITY INDICATING RP-HPLC METHOD FOR ESTIMATION OF TOLFENAMIC ACID IN PRESENCE OF ITS PHARMACOPOEIAL IMPURITIES

Objective: The proposed research work was conducted to develop a single reverse-phase high-performance chromatography (RP-HPLC) method capable of separating two Pharmacopoeial related impurities as well as degradation product of Tolfenamic acid (TA). The drug was subjected to various stress conditions recommended under ICH Q1A (R2) guidelines. Methods: The desired separation of two Pharmacopoeial impurities and one degradant generated under oxidative stress was carried out using Sunfire ODS C-18 (250 x 4.6 mm, 5 µm) column maintained at 40 °C. Isocratic elution was carried out using acetonitrile and ammonium dihydrogen orthophosphate buffer (10 mmol, pH 2.5) in the ratio of 80:20 v/v. The detection was carried out at 205 nm using flow rate of 1 ml/min. The developed method was validated as per ICH Q2 (R1) guidelines for specificity, linearity, accuracy, precision, Limit of detection (LOD), Limit of Quantification (LOQ) and robustness. Results: Linearity response of TA was found at a concentration range of 10-100µg/ml, with a correlation coefficient of 0.9987. The Pharmacopoeial impurity A and impurity B showed linearity results at concentration of 0.1-1µg/ml, with correlation coefficient of 0.9984 for Impurity A and 0.9989 for Impurity B. The % recovery during accuracy studies for TA and the two impurities were within the acceptance range of 95-105%. LOD and LOQ for TA were found to be 4.561µg/ml and 133.771µg/ml respectively. For impurity A, LOD and LOQ were found to be 0.035 µg/ml and 0.106 µg/ml and for Impurity B, LOD and LOQ were 0.042 µg/ml and 0.128 µg/ml. With slight variation of organic phase in mobile phase and flow rate the method exhibited good robustness. Under forced degradation studies the drug was found stable under hydrolytic, photolytic and thermal stress conditions, but was found susceptible for degradation under oxidative stress with appearance of a degradant peak. From on the RRT values of Pharmacopoeial impurities and the formed degradant it was inferred that the developed method is selective for the drug in the presence of impurities or degradants. Conclusion: The developed stability-indicating method is found to be simple, rapid, accurate, precise and robust as compared to other proposed methods while determining TA in presence of its Pharmacopoeial impurities and degradation products. Hence the developed method can be used for analysis of stability samples of TA in presence of its related impurities

Caffeine, Its Basicity, Acidity, Hydrolysis & Spectrophotometric Assay

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Comment on ``One-Dimensional Disordered Bosonic Hubbard Model: A Density-Matrix Renormalization Group Study"

We present the phase diagram of the system obtained by continuous-time worldline Monte Carlo simulations, and demonstrate that the actual phase diagram is in sharp contrast with that found in Phys. Rev. Lett., 76 (1996) 2937.Comment: 1 page, LaTex, 1 figur

Evaluation of Effectiveness of Wavelet Based Denoising Schemes Using ANN and SVM for Bearing Condition Classification

The wavelet based denoising has proven its ability to denoise the bearing vibration signals by improving the signal-to-noise ratio (SNR) and reducing the root-mean-square error (RMSE). In this paper seven wavelet based denoising schemes have been evaluated based on the performance of the Artificial Neural Network (ANN) and the Support Vector Machine (SVM), for the bearing condition classification. The work consists of two parts, the first part in which a synthetic signal simulating the defective bearing vibration signal with Gaussian noise was subjected to these denoising schemes. The best scheme based on the SNR and the RMSE was identified. In the second part, the vibration signals collected from a customized Rolling Element Bearing (REB) test rig for four bearing conditions were subjected to these denoising schemes. Several time and frequency domain features were extracted from the denoised signals, out of which a few sensitive features were selected using the Fisher’s Criterion (FC). Extracted features were used to train and test the ANN and the SVM. The best denoising scheme identified, based on the classification performances of the ANN and the SVM, was found to be the same as the one obtained using the synthetic signal

Best chirplet chain: near-optimal detection of gravitational wave chirps

The list of putative sources of gravitational waves possibly detected by the ongoing worldwide network of large scale interferometers has been continuously growing in the last years. For some of them, the detection is made difficult by the lack of a complete information about the expected signal. We concentrate on the case where the expected GW is a quasi-periodic frequency modulated signal i.e., a chirp. In this article, we address the question of detecting an a priori unknown GW chirp. We introduce a general chirp model and claim that it includes all physically realistic GW chirps. We produce a finite grid of template waveforms which samples the resulting set of possible chirps. If we follow the classical approach (used for the detection of inspiralling binary chirps, for instance), we would build a bank of quadrature matched filters comparing the data to each of the templates of this grid. The detection would then be achieved by thresholding the output, the maximum giving the individual which best fits the data. In the present case, this exhaustive search is not tractable because of the very large number of templates in the grid. We show that the exhaustive search can be reformulated (using approximations) as a pattern search in the time-frequency plane. This motivates an approximate but feasible alternative solution which is clearly linked to the optimal one. [abridged version of the abstract]Comment: 23 pages, 9 figures. Accepted for publication in Phys. Rev D Some typos corrected and changes made according to referee's comment

Quality and Reporting of Diagnostic Accuracy Studies in TB, HIV and Malaria: Evaluation Using QUADAS and STARD Standards

BackgroundPoor methodological quality and reporting are known concerns with diagnostic accuracy studies. In 2003, the QUADAS tool and the STARD standards were published for evaluating the quality and improving the reporting of diagnostic studies, respectively. However, it is unclear whether these tools have been applied to diagnostic studies of infectious diseases. We performed a systematic review on the methodological and reporting quality of diagnostic studies in TB, malaria and HIV.MethodsWe identified diagnostic accuracy studies of commercial tests for TB, malaria and HIV through a systematic search of the literature using PubMed and EMBASE (2004–2006). Original studies that reported sensitivity and specificity data were included. Two reviewers independently extracted data on study characteristics and diagnostic accuracy, and used QUADAS and STARD to evaluate the quality of methods and reporting, respectively.FindingsNinety (38%) of 238 articles met inclusion criteria. All studies had design deficiencies. Study quality indicators that were met in less than 25% of the studies included adequate description of[...] and description of the team executing the test and management of indeterminate/outlier results (both 17%). The use of STARD was not explicitly mentioned in any study. Only 22% of 46 journals that published the studies included in this review required authors to use STARD

Endoscopic ultrasound guided radiofrequency ablation, for pancreatic cystic neoplasms and neuroendocrine tumors

AIM: To outline the feasibility, safety, adverse events and early results of endoscopic ultrasound (EUS)-radiofrequency ablation (RFA) in pancreatic neoplasms using a novel probe. METHODS: This is a multi-center, pilot safety feasibility study. The intervention described was radiofrequency ablation (RF) which was applied with an innovative monopolar RF probe (1.2 mm Habib EUS-RFA catheter) placed through a 19 or 22 gauge fine needle aspiration (FNA) needle once FNA was performed in patients with a tumor in the head of the pancreas. The Habib™ EUS-RFA is a 1 Fr wire (0.33 mm, 0.013") with a working length of 190 cm, which can be inserted through the biopsy channel of an echoendoscope. RF power is applied to the electrode at the end of the wire to coagulate tissue in the liver and pancreas. RESULTS: Eight patients [median age of 65 (range 27-82) years; 7 female and 1 male] were recruited in a prospective multicenter trial. Six had a pancreatic cystic neoplasm (four a mucinous cyst, one had intraductal papillary mucinous neoplasm and one a microcystic adenoma) and two had a neuroendocrine tumors (NET) in the head of pancreas. The mean size of the cystic neoplasm and NET were 36.5 mm (SD ± 17.9 mm) and 27.5 mm (SD ± 17.7 mm) respectively. The EUS-RFA was successfully completed in all cases. Among the 6 patients with a cystic neoplasm, post procedure imaging in 3-6 mo showed complete resolution of the cysts in 2 cases, whilst in three more there was a 48.4% reduction [mean pre RF 38.8 mm (SD ± 21.7 mm) vs mean post RF 20 mm (SD ± 17.1 mm)] in size. In regards to the NET patients, there was a change in vascularity and central necrosis after EUS-RFA. No major complications were observed within 48 h of the procedure. Two patients had mild abdominal pain that resolved within 3 d. CONCLUSION: EUS-RFA of pancreatic neoplasms with a novel monopolar RF probe was well tolerated in all cases. Our preliminary data suggest that the procedure is straightforward and safe. The response ranged from complete resolution to a 50% reduction in size

Effect of Newtonian and non-Newtonian flow in subject specific carotid artery

Advances in the numerical simulation techniques has immensely helped in the demonstrating the importance of blood flow through elastic arteries and evaluating the disease progression and flow dynamics of cardiovascular diseases such as atherosclerosis. The present work deals with a case study of a patient diagnosed with partial narrowing of entire cervical segment of Internal Carotid Artery (ICA), while Common Carotid Artery (CCA) and External Carotid Artery (ECA) appears to be normal. Subject specific 3D carotid bifurcation CAD model is generated based on CT-angio scan data using MIMICS-14.0 and numerical analysis is performed using Computational Fluid Dynamics (CFD) in ANSYS-CFX-14.0. Pulsatile blood flow through the subject-specific artery is investigated to study the influence of rheology on the haemodynamics in the blood flow. The simulation results obtained through Carreau-Yasuda and Newtonian models are investigated. Flow behaviour observed during peak systole exhibits significant difference in the spatial parameters between both the Newtonian and nonNewtonians models. The comparison of local shear stress magnitude in CCA, ICA and ECA demonstrates that WSS is highly influenced by the shear thinning property of blood. This variation is also observed artery branches with reduced lumen diameter, lumen narrowing due to stenosis and in the bifurcation zone

Self Injection length in La0.7 Ca0.3 Mno3-YBa 2Cu3O7-d ferromagnet- superconductor multi layer thin films

We have carried out extensive studies on the self-injection problem in barrierless heterojunctions between La0.7Ca0.3MnO3 (LCMO) and YBa2Cu3O7-d (YBCO). The heterojunctions were grown in situ by sequentially growing LCMO and YBCO films on LaAlO3 (LAO) substrate using a pulsed laser deposition (PLD) system. YBCO micro-bridges with 64 microns width were patterned both on the LAO (control) and LCMO side of the substrate. Critical current, Ic, was measured at 77K on both the control side as well as the LCMO side for different YBCO film thickness. It was observed that while the control side showed a Jc of ~2 x 10E6 A/ cm2 the LCMO side showed about half the value for the same thickness (1800 A). The difference in Jc indicates that a certain thickness of YBCO has become 'effectively' normal due to self-injection. From the measurement of Jc at two different thickness' (1800 A and 1500 A) of YBCO both on the LAO as well as the LCMO side, the value of self-injection length (at 77K) was estimated to be ~900 A self-injection length has been quantified. A control experiment carried out with LaNiO3 deposited by PLD on YBCO did not show any evidence of self-injection.Comment: 6 pages, one figure in .ps forma