Characterization of acoustic signals due to surface discharges on H.V. glass insulators using wavelet radial basis function neural networks

A hybrid model incorporating wavelet and radial basis function neural network is presented which is used to detect, identify and characterize the acoustic signals due to surface discharge activity and hence differentiate abnormal operating conditions from the normal ones. The tests were carried out on cleaned and polluted high voltage glass insulators by using surface tracking and erosion test procedure of international electrotechnical commission 60587. A laboratory experiment was conducted by preparing the prototypes of the discharges. This study suggests a feature extraction and classification algorithm for surface discharge classification, which when combined together reduced the dimensionality of the feature space to a manageable dimension, by “marrying” the wavelet to radial basis function neural network very high levels of classification are achieved. Wavelet signal treatment toolbox is used to recover the surface discharge acoustic signals by eliminating the noisy portion and to reduce the dimension of the feature input vector. A radial basis function neural network classifier was used to classify the surface discharge and assess the suitability of this feature vector in classification. This learning method is proved to be effective by applying the wavelet radial basis function neural network in the classification of surface discharge fault data set. The test results show that the proposed approach is efficient and reliable.     

The human gallbladder increases cholesterol solubility in bile by differential lipid absorption: a study using a new in vitro model of isolated intra-arterially perfused gallbladder

In this study, we first developed and validated a new in vitro isolated, intra-arterially perfused, gallbladder model and then applied the method to investigate the absorption of biliary lipids by the gallbladder wall and the effect of this process on the composition of human bile. Oxygenated and glucose-added buffer was perfused through the cystic artery to maintain organ viability. A standard pooled natural bile, radiolabeled with H3-cholesterol and C14-palmitoyl-linoleoyl-phosphatidylcholine, was instilled in the lumen via a cystic duct catheter. Changes in bile volume and lipid concentrations were monitored at time intervals to evaluate the disappearance of lipids from bile caused by gallbladder absorptive function. Organ viability was demonstrated by stable lactate dehydrogenase (LDH) organ release and oxygen consumption throughout the experiments. In the pig, disappearance rates of lipids from bile were similar in vitro and in vivo, demonstrating the validity of the isolated in vitro model for functional studies. By applying our in vitro isolated preparation to the human gallbladder, we found that 23% of cholesterol and 32% of phosphatidylcholine, but only 9% of bile salts, disappeared from bile in 5 hours. As a consequence, at the end of the experiments, cholesterol (P < .05) and phospholipid (P < .05) molar percentages were significantly reduced, while the bile salt (P < .05) molar percentage was significantly increased with respect to values at the beginning of the studies. Our findings are of pathophysiological relevance and support the concept that the human gallbladder modifies the relative composition of biliary lipids in such a way as to increase cholesterol solubility in bile.     

Chemoprevention trial of contralateral breast cancer with fenretinide. Rationale, design, methodology, organization, data management, statistics and accrual

The Fenretinide (4-HPR) Breast Cancer Study is a randomized multicenter clinical trial originally designed and conducted by the investigators of the Istituto Nazionale Tumori of Milan. The study is sponsored by the National Cancer Institute of Bethesda and by the Italian National Research Council. The trial was designed to evaluate the effectiveness of the synthetic retinoid 4-HPR, at a dose of 200 mg per os every day for 5 years, in reducing the incidence of contralateral breast cancer in a population of patients previously operated on for breast cancer. Between 1987 and 1993, the Istituto Nazionale Tumori of Milan and 9 other collaborating Centers enrolled 2,972 women between the ages of 30 and 70 years who had been previously operated on for T1-T2 N- M0 breast cancer. This paper describes the rationale, design, methodology, organization, data management, statistics and accrual of the participating population.     

The Jordan River Basin: 2. Potential Future Allocations to the Co-riparians

Abstract

The Jordan River drains parts of four States and one territory (Lebanon, Syria, Israel, Jordan and Palestine), and is an important regional source of water. A previous paper in this series discussed the flow allocations from the Jordan River to the co-riparians which were proposed in the Johnston Plan of 1955, noting that recently declassified documents shed new light on the allocation proposed for Israel. The present paper discusses potential future allocations of water from the Jordan River basin to the co-riparians, providing alternative methods of calculating these using basic principles which are considered to generally reflect customary international water law. It is concluded that whilst certain of the downstream co-riparians are undoubtedly “water-stressed” an acceptable solution to the allocation of water within the region is attainable. However, this will depend on coupling the allocation of the existing resources to the strategic development of additional fresh water resources in the region, which will also encourage the joint management of the resulting system.     

Unprecedented solar water splitting of dendritic nanostructured Bi2O3 films by combined oxygen vacancy formation and Na2MoO4 doping

We demonstrate the synergetic effect of Na₂MoO₄-doping and vacuum-annealing on dendritic nanostructured bismuth oxide (Bi₂O₃) thin films prepared by electrodeposition for visible-light-assisted photoelectrochemical (PEC) water oxidation. After evaluating various extents of Na₂MoO₄-doping as well as vacuum-annealing temperatures, it was evidenced that both Na₂MoO₄-doping and vacuum-annealing significantly improved the efficiency and PEC water oxidation performance. Compared to the undoped Bi₂O₃ photoanode, the optimized Na₂MoO₄-doped Bi₂O₃, after vacuum-annealing, resulted in more than 25-fold enhancement in the photoanodic current density to 1.06 mA/cm² at 1.23 V_RHE under AM1.5 G illumination. The PEC enhancement is credited mainly to the increased PEC surface active sites in the Na₂MoO₄-doped vacuum annealed sample. Confirmed by combined XPS and Mott-Schottky (M ? S) analysis, vacuum annealing resulted in surface oxygen vacancies that can contribute to the photocatalytic activity. Besides, Na₂MoO₄-doping resulted in reduced dimensions of the dendritic structure, revealed by FE-SEM and XRD measurements, resulting in larger surface area and, therefore, larger surface/electrolyte contact. This dual strategy (metal doping + vacuum annealing) can be generalized to assemble photoanodes of other materials used for the production of solar fuels. Our results make a valuable step towards efficient Bi₂O₃/BiVO₄ pn heterojunctions.     

Analysis of the reliability of the local effect model for the use in carbon ion treatment planning systems

In radiotherapy with carbon ions, biological effects of treatments have to be predicted. For this purpose, one of the most used models is the local effect model (LEM) developed at the Gesellschaft für Schwerionenforschung (GSI), Germany. At the Istituto Nazionale di Fisica Nucleare, Italy, the reliability of the last published version of LEM (LEM III) in reproducing radiobiological data has been checked under both monoenergetic and spread-out Bragg peak (SOBP) carbon-ion irradiation. The reproduction of the monoenergetic measurements with the LEM was rather successful for some cell lines, while it failed for the less-radioresistant ones. The SOBP experimental trend was predicted by the LEM, but a large shift between model curves and measured points was observed.     

A direct method for the characterization and computation of bifurcation points with corank 2

We will consider an extension of a direct method due to Griewank and Reddien for the characterization and computation of double singular points with corank 2. Singular points which satisfy certain type of symmetry will also be considered. The method used will produce an extended system which does not introduce the null vectors as variables, but gives a good idea bout them. Several numerical examples are presented to demonstrate that the method is efficient.     

Formation,growth, and transport of soot in a three-dimensional turbulent non-premixed jet flame

The formation, growth, and transport of soot is investigated via large scale numerical simulation in a three-dimensional turbulent non-premixed n-heptane/air jet flame at a jet Reynolds number of 15,000. For the first time, a detailed chemical mechanism, which includes the soot precursor naphthalene and a high-order method of moments are employed in a three-dimensional simulation of a turbulent sooting flame. The results are used to discuss the interaction of turbulence, chemistry, and the formation of soot. Compared to temperature and other species controlled by oxidation chemistry, naphthalene is found to be affected more significantly by the scalar dissipation rate. While the mixture fraction and temperature fields show fairly smooth spatial and temporal variations, the sensitivity of naphthalene to turbulent mixing causes large inhomogeneities in the precursor fields, which in turn generate even stronger intermittency in the soot fields. A strong correlation is apparent between soot number density and the concentration of naphthalene. On the contrary, while soot mass fraction is usually large where naphthalene is present, pockets of fluid with large soot mass are also frequent in regions with very low naphthalene mass fraction values. From the analysis of Lagrangian statistics, it is shown that soot nucleates and grows mainly in a layer close to the flame and spreads on the rich side of the flame due to the fluctuating mixing field, resulting in more than half of the total soot mass being located at mixture fractions larger than 0.6. Only a small fraction of soot is transported towards the flame and is completely oxidized in the vicinity of the stoichiometric surface. These results show the leading order effects of turbulent mixing in controlling the dynamics of soot in turbulent flames. Finally, given the difficulties in obtaining quantitative data in experiments of turbulent sooting flames, this simulation provides valuable data to guide the development of models for Large Eddy Simulation and Reynolds Average Navier Stokes approaches.