Partial oxidation of methane over the perovskite oxides

Ba0.5Sr0.5Co0.8Fe0.2O3-delta and Ba0.5Sr0.5Co0.8Ti0.2O3-delta oxides were synthesized by a combined EDTA-citrate complexing method. The catalytic behavior of these two oxides with the perovskite structure was studied during the reaction of methane oxidation. The pre-treatment with methane has different effect on the catalytic activities of both the oxides. The methane pre-treatment has not resulted in the change of the catalytic activity of BSCFO owing to its excellent reversibility of the perovskite structure resulting from the excellent synergistic interaction between Co and Fe in the oxide. However, the substitution with Ti on Fe-site in the lattice makes the methane pre-treatment have an obvious influence on the activity of the formed BSCTO oxide.

Uniformly convergent finite element methods for singularly perturbed parabolic partial differential equations

This thesis is concerned with uniformly convergent finite element methods for numerically solving singularly perturbed parabolic partial differential equations in one space variable. First, we use Petrov-Galerkin finite element methods to generate three schemes for such problems, each of these schemes uses exponentially fitted elements in space. Two of them are lumped and the other is non-lumped. On meshes which are either arbitrary or slightly restricted, we derive global energy norm and L2 norm error bounds, uniformly in the diffusion parameter. Under some reasonable global assumptions together with realistic local assumptions on the solution and its derivatives, we prove that these exponentially fitted schemes are locally uniformly convergent, with order one, in a discrete L∞norm both outside and inside the boundary layer. We next analyse a streamline diffusion scheme on a Shishkin mesh for a model singularly perturbed parabolic partial differential equation. The method with piecewise linear space-time elements is shown, under reasonable assumptions on the solution, to be convergent, independently of the diffusion parameter, with a pointwise accuracy of almost order 5/4 outside layers and almost order 3/4 inside the boundary layer. Numerical results for the above schemes are presented. Finally, we examine a cell vertex finite volume method which is applied to a model time-dependent convection-diffusion problem. Local errors away from all layers are obtained in the l2 seminorm by using techniques from finite element analysis.

Parallel algorithms of the Purcell method for direct solution of linear systems

In this paper, we first demonstrate that the classical Purcell's vector method when combined with row pivoting yields a consistently small growth factor in comparison to the well-known Gauss elimination method, the Gauss–Jordan method and the Gauss–Huard method with partial pivoting. We then present six parallel algorithms of the Purcell method that may be used for direct solution of linear systems. The algorithms differ in ways of pivoting and load balancing. We recommend algorithms V and VI for their reliability and algorithms III and IV for good load balance if local pivoting is acceptable. Some numerical results are presented.

A molecular method for the identification of resting eggs of acartiid copepods in the Thau lagoon, France

Acartia and Paracartia species, often known to co-occur, can exhibit complex life cycles, including the production of resting eggs. Studying and understanding their population dynamics is hindered by the inability to identify eggs and early developmental stages using morphological techniques. We have developed a simple molecular technique to distinguish between the three species of the Acartiidae family (Acartia clausi, A. discaudata and Paracartia grani) that co-occur in the Thau lagoon (43�250N; 03�400E) in southern France. Direct amplification of a partial region of the mitochondrial cytochrome oxidase I gene by polymerase chain reaction and subsequent restriction fragment length polymorphism results in a unique restriction profile for each species. The technique is capable of determining the identity of individual eggs, including resting eggs retrieved from sediment samples, illustrating its application in facilitating population dynamic studies of this ubiquitous and important member of the zooplankton community.

Speech Recognition with unknown partial feature corruption - a review of the union model

This paper provides a summary of our studies on robust speech recognition based on a new statistical approach – the probabilistic union model. We consider speech recognition given that part of the acoustic features may be corrupted by noise. The union model is a method for basing the recognition on the clean part of the features, thereby reducing the effect of the noise on recognition. To this end, the union model is similar to the missing feature method. However, the two methods achieve this end through different routes. The missing feature method usually requires the identity of the noisy data for noise removal, while the union model combines the local features based on the union of random events, to reduce the dependence of the model on information about the noise. We previously investigated the applications of the union model to speech recognition involving unknown partial corruption in frequency band, in time duration, and in feature streams. Additionally, a combination of the union model with conventional noise-reduction techniques was studied, as a means of dealing with a mixture of known or trainable noise and unknown unexpected noise. In this paper, a unified review, in the context of dealing with unknown partial feature corruption, is provided into each of these applications, giving the appropriate theory and implementation algorithms, along with an experimental evaluation.

Specific and sensitive detection of Nosema bombi (Microsporidia : Nosematidae) in bumble bees (Bombus spp.; Hymenoptera : Apidae) by PCR of partial rRNA gene sequences

A polymerase chain reaction (PCR) based method was developed for the specific and sensitive diagnosis of the microsporidian parasite Nosema bombi in bumble bees (Bombus spp.). Four primer pairs, amplifying ribosomal RNA (rRNA) gene fragments, were tested on N. bombi and the related microsporidia Nosema apis and Nosema ceranae, both of which infect honey bees. Only primer pair Nbombi-SSU-Jf1/Jr1 could distinguish N. bombi (323 bp amplicon) from these other bee parasites. Primer pairs Nbombi-SSU-Jf1/Jr1 and ITS-f2/r2 were then tested for their sensitivity with N. bombi spore concentrations from 107 down to 10 spores diluted in 100 mu l of either (i) water or (ii) host bumble bee homogenate to simulate natural N. bombi infection (equivalent to the DNA from 10(6) spores down to 1 spore per PCR). Though the N. bombi-specific primer pair Nbombi-SSU-Jf1/Jr1 was relatively insensitive, as few as 10 spores per extract (equivalent to 1 spore per PCR) were detectable using the N. bombi-non-specific primer pair ITS-f2/r2, which amplifies a short fragment of similar to 120 bp. Testing 99 bumble bees for N. bombi infection by light microscopy versus PCR diagnosis with the highly sensitive primer pair ITS-f2/r2 showed the latter to b more accurate. PCR diagnosis of N. bombi using a combination of two primer pairs (Nbombi-SSU-Jf1/Jr1 and ITS-f2/r2) provides increased specificity, sensitivity, and detection of all developmental stages compared with light microscopy. (c) 2005 Elsevier Inc. All rights reserved.

The circle in the relationship between space and body. Photo-essay based on Isidro Blasco and the BAPNE method

This article demonstrates a visual study on the educational space in which the teaching of body percussion is carried out in universities. The methodological framework is chosen by the Visual Arts Based Educational Research, using the work of an artist as a conceptual and methodological model. The research remains notable (1) due to the theoretical reference to the BAPNE method, (2) due to the visual reference to the work of Isidro Blasco – especially with the piece “Shanghai Planet 2009” - ;(3) due to the parallelisms established between the object of study in this investigation -the spatial analysis- and the focuses of interest revealed by the art critics in relation to the work of this artist. By means of a visual speech formed with 7 photo-collages the relationship between body and educational space is visualized in the basic disposition of circular learning. The visual constructions by way of photo-collage and their aesthetic charge brings us closer to the intimacy of the educational space, in the style in which it is distributed to the students in the music classroom, the materialization of interpersonal relationships, the occupied and empty volumes.

Some thoughts on Juan Antonio Ramírez´s iconologic-paranoid method for the study of Dali´s works

In 1990, Juan Antonio Ramírez made known his iconological paranoiac method to the academic world. It is a system devised to study Dalí´s work, born of happy matrimony between the catalonian artist´s critical paranoiac method and the first iconographic school of Warburg and Panofsky. What, at first sight, seemed to be an extravagant methodology with little academic credibility, turned out to be, by going forward in time, an effective research method when analyzing Dali´s initial works. It is no wonder that, at the beginning of XXI century, this hybridization between Dalí´s and Panofsky’s methods, were regarded as a strange and nonsensical idea. Nevertheless, twenty years after, blatant examples have been noted, which endorse the advantages of this new system for “iconographic” study. As usual, this new contribution by Juan Antonio Ramirez to art history methodology is called upon to have a successful future survival, in forthcoming generations. This article, attempts to analyze this method, inquiring into the validity, effectiveness and practical utility.

Robust face recognition with partial occlusion, illumination variation and limited training data by optimal feature selection

This study investigates face recognition with partial occlusion, illumination variation and their combination, assuming no prior information about the mismatch, and limited training data for each person. The authors extend their previous posterior union model (PUM) to give a new method capable of dealing with all these problems. PUM is an approach for selecting the optimal local image features for recognition to improve robustness to partial occlusion. The extension is in two stages. First, authors extend PUM from a probability-based formulation to a similarity-based formulation, so that it operates with as little as one single training sample to offer robustness to partial occlusion. Second, they extend this new formulation to make it robust to illumination variation, and to combined illumination variation and partial occlusion, by a novel combination of multicondition relighting and optimal feature selection. To evaluate the new methods, a number of databases with various simulated and realistic occlusion/illumination mismatches have been used. The results have demonstrated the improved robustness of the new methods.

Motor skill deficits in children with partial hearing

AIM:
We examined the effect of partial hearing, including cochlear implantation, on the development of motor skills in children (aged 6-12y).

METHOD:
Three independent groups of children were selected: a partial hearing group (n=25 [14 males, 11 females]; mean age 8y 8mo, SD 1y 10mo), a nonverbal IQ-matched group (n=27 [15 males, 12 females]; mean age 9y, SD 1y 6mo), and an age-matched group (n=26 [8 males, 18 females]; mean age 8y 8mo, SD 1y 7mo) from three schools with special units for children with partial hearing. All children with partial hearing had a bilateral hearing loss >60 decibels. Motor and balance skills were assessed using the Movement Assessment Battery for Children (MABC) and two protocols from the NeuroCom Balance Master clinical procedures.

RESULTS:
The mean standardized total MABC score of the children with partial hearing (95% confidence interval [CI] 71.8-88.7) was significantly lower than both the age-matched (95% CI 95.8-111.4; p<0.01) and the IQ-matched (95% CI 87.6-103.0; p=0.03) comparison groups. The children with partial hearing had particular difficulties with balance, most notably during tests of intersensory demand. However, subgroup analyses revealed that the effect of cochlear implantation was clearly dependent on the nature of the task.

INTERPRETATION:
Children with partial hearing are at high risk of clinical levels of motor deficit, with balance difficulties providing support for conventional vestibular deficit theory. However, the effect of cochlear implantation suggests that other sensory systems may be involved. A broader ecological perspective, which takes into account factors external to the child, may prove a useful framework for future research.

Approximating the Set of Local Minima in Partial RNA Folding Landscapes

Motivation: We study a stochastic method for approximating the set of local minima in partial RNA folding landscapes associated with a bounded-distance neighbourhood of folding conformations. The conformations are limited to RNA secondary structures without pseudoknots. The method aims at exploring partial energy landscapes pL induced by folding simulations and their underlying neighbourhood relations. It combines an approximation of the number of local optima devised by Garnier and Kallel (2002) with a run-time estimation for identifying sets of local optima established by Reeves and Eremeev (2004).

Results: The method is tested on nine sequences of length between 50 nt and 400 nt, which allows us to compare the results with data generated by RNAsubopt and subsequent barrier tree calculations. On the nine sequences, the method captures on average 92% of local minima with settings designed for a target of 95%. The run-time of the heuristic can be estimated by O(n2D?ln?), where n is the sequence length, ? is the number of local minima in the partial landscape pL under consideration and D is the maximum number of steepest descent steps in attraction basins associated with pL.

Contribution of process variables to the entrapment efficiency of propranolol hydrochloride within ethylcellulose microspheres prepared by the solvent evaporation method as evaluated using a factorial design

The effects of the process variables, pH of aqueous phase, rate of addition of organic, polymeric, drug-containing phase to aqueous phase, organic:aqueous phase volume ratio and aqueous phase temperature on the entrapment of propranolol hydrochloride in ethylcellulose (N4) microspheres prepared by the solvent evaporation method were examined using a factorial design. The observed range of drug entrapment was 1.43 +/- 0.02%w/w (pH 6, 25 degrees C, phase volume ratio 1:10, fast rate of addition) to 16.63 +/- 0.92%w/w (pH 9, 33 degrees C, phase volume ratio 1:10, slow rate of addition) which corresponded to mean entrapment efficiencies of 2.86 and 33.26, respectively. Increased pH, increased temperature and decreased rate of addition significantly enhanced entrapment efficiency. However, organic:aqueous phase volume ratio did not significantly affect drug entrapment. Statistical interactions were observed between pH and rate of addition, pH and temperature, and temperature and rate of addition. The observed interactions involving pH are suggested to be due to the abilities of increased temperature and slow rate of addition to sufficiently enhance the solubility of dichloromethane in the aqueous phase, which at pH 9, but not pH 6, allows partial polymer precipitation prior to drug partitioning into the aqueous phase. The interaction between temperature and rate of addition is due to the relative lack of effect of increased temperature on drug entrapment following slow rate of addition of the organic phase. In comparison to the effects of pH on drug entrapment, the contributions of the other physical factors examined were limited.

GPU Acceleration of Partial Differential Equation Solvers

Differential equations are often directly solvable by analytical means only in their one dimensional version. Partial differential equations are generally not solvable by analytical means in two and three dimensions, with the exception of few special cases. In all other cases, numerical approximation methods need to be utilized. One of the most popular methods is the finite element method. The main areas of focus, here, are the Poisson heat equation and the plate bending equation. The purpose of this paper is to provide a quick walkthrough of the various approaches that the authors followed in pursuit of creating optimal solvers, accelerated with the use of graphical processing units, and comparing them in terms of accuracy and time efficiency with existing or self-made non-accelerated solvers.

Partial volume correction using bimodal contrast agents in PET-MRI

Tese de mestrado integrado em Engenharia Biomédica e Biofísica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2014

Invariant discretizations of partial differential equations

Un algorithme permettant de discrétiser les équations aux dérivées partielles (EDP) tout en préservant leurs symétries de Lie est élaboré. Ceci est rendu possible grâce à l'utilisation de dérivées partielles discrètes se transformant comme les dérivées partielles continues sous l'action de groupes de Lie locaux. Dans les applications, beaucoup d'EDP sont invariantes sous l'action de transformations ponctuelles de Lie de dimension infinie qui font partie de ce que l'on désigne comme des pseudo-groupes de Lie. Afin d'étendre la méthode de discrétisation préservant les symétries à ces équations, une discrétisation des pseudo-groupes est proposée. Cette discrétisation a pour effet de transformer les symétries ponctuelles en symétries généralisées dans l'espace discret. Des schémas invariants sont ensuite créés pour un certain nombre d'EDP. Dans tous les cas, des tests numériques montrent que les schémas invariants approximent mieux leur équivalent continu que les différences finies standard.