Novel Evaluation Methods for Complex Systems via Adaptive Sequential Exploration of Variables Interactions

The complex and coupled behavior of variables in the currently developing Generation IV reactors and Small Modular Reactors is becoming a major incentive to seek efficient design methods. This research develops and validates new methods to evaluate systems with various degrees of variables’ interactions using basic knowledge in variables’ directions of effect and an adaptive number of experiments. The methods replace the commonly used assumption of negligible interactions with a broader assumption of monotonic variables’ effects. The assumption was evaluated using studies of other physical systems’ regularities, and is expected to be significantly present in physical systems. Four methods were developed and analyzed in this dissertation. Three of the introduced methods utilized an adaptive sequential spanning tree concept with a method specific criterion to construct piecewise multidimensional surfaces or subtrees. Each method then used a specific approach to project the results within the subtrees. The fourth method is an expansion to an existing method to explore any order of interactions through the introduction of a new domain of parameters. Three of the four methods significantly outperformed the common orthogonal arrays methods that rely on a uniform distribution of experiments in the design domain. Two of the three methods significantly outperformed the third method and were used in the dissertation’s application. The strength of the applicable methods was demonstrated through their application to two examples from literature, each of which has a different degree of variables’ monotonic behavior. The most applicable method of the two most effective methods was used to decouple the effects of fourteen variables on six performance characteristics in the design of a Small Modular Reactor version of the Advanced Pressurized Water Reactor AP1000. The methods’ application succeeded in finding the most important main effects and interactions of each performance characteristic. The performance of the methods’ application to three performance characteristics was compared to the performance of fractional factorial designs. The methods were found to significantly reduce the projection error when the assumption of variables’ monotonic behavior is valid

Nπ raspršenje i elektromagnetske popravke u proširenom linearnom sigma modelu

Recent analysis of pion-nucleon scattering and nucleon magnetic moments are investigated in an extended linear sigma model. The field equations are solved in the mean-field approximation. Good results have been obtained in comparison with previous work and experimental data.Proučavamo nedavne analize raspršenja pion–nukleon i magnetske momente nukleona u proširenom linearnom sigma modelu. Jednadžbe polja riješili smo u približenju srednjeg polja. Postigli smo bolji sklad s eksperimentalnim podacima nego raniji radovi

Nπ raspršenje i elektromagnetske popravke u proširenom linearnom sigma modelu

Recent analysis of pion-nucleon scattering and nucleon magnetic moments are investigated in an extended linear sigma model. The field equations are solved in the mean-field approximation. Good results have been obtained in comparison with previous work and experimental data.Proučavamo nedavne analize raspršenja pion–nukleon i magnetske momente nukleona u proširenom linearnom sigma modelu. Jednadžbe polja riješili smo u približenju srednjeg polja. Postigli smo bolji sklad s eksperimentalnim podacima nego raniji radovi

Comment on ``Structure of exotic nuclei and superheavy elements in a relativistic shell model''

A recent paper [M. Rashdan, Phys. Rev. C 63, 044303 (2001)] introduces the new parameterization NL-RA1 of the relativistic mean-field model which is claimed to give a better description of nuclear properties than earlier ones. Using this model ^{298}114 is predicted to be a doubly-magic nucleus. As will be shown in this comment these findings are to be doubted as they are obtained with an unrealistic parameterization of the pairing interaction and neglecting ground-state deformation.Comment: 2 pages REVTEX, 3 figures, submitted to comment section of Phys. Rev. C. shortened and revised versio

Isolation of Cronobacter spp. (formerly Enterobacter sakazakii) from infant food, herbs and environmental samples and the subsequent identification and confirmation of the isolates using biochemical, chromogenic assays, PCR and 16S rRNA sequencing

BACKGROUND: Cronobacter spp. (formerly Enterobacter sakazakii), are a group of Gram-negative pathogens that have been implicated as causative agents of meningitis and necrotizing enterocolitis in infants. The pathogens are linked to infant formula; however, they have also been isolated from a wide range of foods and environmental samples. RESULTS: In this study, 233 samples of food, infant formula and environment were screened for the presence of Cronobacter spp. in an attempt to find its source. Twenty nine strains were isolated from samples of spices, herbs, infant foods, and dust obtained from household vacuum cleaners. Among the 76 samples of infant food, infant formula, milk powder and non-milk dairy products tested, only one sample of infant food contained Cronobacter spp. (1.4%). The other Cronobacter spp. isolates recovered include two from household vacuum dust, and 26 from 67 samples of herbs and spices. Among the food categories analyzed, herbs and spices harbored the highest number of isolates, indicating plants as a possible reservoir of this pathogen. Initial screening with API 20E test strips yielded 42 presumptive isolates. Further characterization using 3 chromogenic media (α-MUG, DFI and EsPM) and 8 sets of PCR primers detecting ITS (internal transcribed spacer sequences), 16S rRNA, zpx, gluA, gluB, OmpA genes followed by nucleotide sequencing of some PCR amplicons did not confirm the identity of all the isolates as none of the methods proved to be free of both false positives or false negatives. The final confirmation step was done by 16S rRNA sequence analysis identifying only 29 of the 42 isolates as Cronobacter spp. CONCLUSION: Our studies showed that Cronobacter spp. are highly diverse and share many phenotypic traits with other Enterobacteriaceae members highlighting the need to use several methods to confirm the identity of this pathogen. None of the biochemical, chromogenic or PCR primers proved to be a reliable method for confirmation of the identity of the isolates as all of them gave either false positives or false negatives or both. It is therefore concluded that 16S rRNA sequencing is pivotal to confirm the identity of the isolates

Characterization of surface proteins of Cronobacter muytjensii using monoclonal antibodies and MALDI-TOF Mass spectrometry

<p>Abstract</p> <p>Background</p> <p><it>Cronobacter </it>spp. is a newly emerging pathogen that causes meningitis in infants and other diseases in elderly and immunocompromised individuals. This study was undertaken to investigate surface antigenic determinants in <it>Cronobacter </it>spp. using monoclonal antibodies (MAbs) and MALDI-TOF Mass spectrometry.</p> <p>Results</p> <p>Spleenocytes from mice that were immunized with heat-killed (20 min, 80°C) <it>Cronobacter </it>cells were fused with SP2 myeloma cells. Five desirable MAbs (A1, B5, 2C2, C5 and A4) were selected. MAbs A1, B5, 2C2 and C5 were of IgG2a isotype while A4 was an IgM. Specificity of the MAbs was determined by using immunoblotting with outer membrane protein preparations (OMPs) extracted from 12 <it>Cronobacter </it>and 6 non-<it>Cronobacter </it>bacteria. All MAbs recognized proteins with molecular weight ranging between 36 and 49 kDa except for one isolate (44) in which no OMPs were detected. In addition, MAbs recognized two bands (38-41 kDa) in four of the non-<it>Cronobacter </it>bacteria. Most of the proteins recognized by the MAbs were identified by MALDI-TOF peptide sequencing and appeared to be heterogeneous with the identities of some of them are still unknown. All MAbs recognized the same epitope as determined by an additive Index ELISA with their epitopes appeared to be conformational rather than sequential. Further, none of the MAbs recognized purified LPS from <it>Cronobacter </it>spp. Specificity of the MAbs toward OMPs was further confirmed by transmission electron microscopy.</p> <p>Conclusions</p> <p>Results obtained in this study highlight the immunological cross-reactivity among <it>Cronobacter </it>OMPs and their <it>Enterobacteriaceae </it>counterparts. Nevertheless, the identity of the identified proteins appeared to be different as inferred from the MALDI-TOF sequencing and identification.</p

Development and testing of open-jet wind tunnel for quadrotor flight testing

Station keeping of a hovering quadrotor under various turbulent wind condition has gained much attention these days due to its potential application in complex environments. Various types of control algorithm have been developed to increase the performance of the quadrotor under such wind conditions. These need to be tested and verified by flying the quadrotor itself. One of the quick and low-cost solutions would be to set up a test rig by modifying an existing wind tunnel to recreate such wind conditions. In order to cater such experiments, in Universiti Putra Malaysia (UPM), an open-jet wind tunnel was attached to an existing open-loop wind tunnel, which initially has a test area of 1 meter by 1-meter size. By attaching the open-jet wind tunnel which has a diverged shape, the test section area is increased up to 2 meters in diameter size, ensuring sufficient space for manoeuvring and hovering the experimental quadrotor. A settling chamber is attached before the test section to characterize the output wind. The maximum wind speed at the opening is 8 m/s. The extended wind tunnel's flow characteristics are analyzed by anemometer for velocity distribution in four different distance from the opening. It has been found that the wind velocity distribution and turbulent intensity simulate the outdoor wind turbulent condition to test a quadrotor hovering control algorithm