Alien Registration- Levine, Lena F. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/25314/thumbnail.jp

Fatigue reliability and post-fracture residual capacity of a two-girder steel bridge

2016 Fall.Includes bibliographical references.Due to the immense and always increasing traffic volume, bridges are permanently subjected to repetitive loadings. These high numbers of cyclic loads can cause the initiation of fatigue cracks. If these flaws remain undetected they may become through-thickness cracks and further propagate, if left unrepaired, until they eventually lead to fracture of the entire member. The criticality of a full member fracture is not well defined nor agreed upon. Previous failure cases have demonstrated the ability of two-girder steel bridges to withstand full girder fracture of one of the two girders without structural collapse. Other cases, however, have shown the criticality of a complete girder failure on complete system collapse. Due to uncertainties in bridge redundancy and the ability to develop alternative load path, the American Association of State Highway and Transportation Officials (AASHTO) attempts to prevent fracture or collapse by classifying bridges with respect to their redundancy into fracture critical bridges (FCB) and decreasing their inspection periods. However, this leads to higher construction and maintenance costs for the owners of FCBs. Clearly, the level of uncertainty in bridge performance when one of its two girders suffer complete fracture should be represented in a probabilistic manner to evaluate the probability of fatigue crack growth and system collapse. To that end, thesis uses probabilistic analysis to assess the crack propagation behavior in a girder of a two-girder steel bridge by conducting finite element Monte Carlo simulations. The simulations account for the scatter in the load and the resistance by treating those uncertainties as random variables with predefined statistical distributions. Additionally, the post fracture redundancy is evaluated by comparing the resulting equivalent plastic strain to the failure strain of steel. The results show that the bridge provides sufficient redundancy to redistribute the load after full depth fracture a FC member. Furthermore, the results of the probabilistic analyses provide a basis for choosing the inspection intervals for FCBs

External control strategies for self-propelled particles: optimizing navigational efficiency in the presence of limited resources

We experimentally and numerically study the dependence of different navigation strategies regarding the effectivity of an active particle to reach a predefined target area. As the only control parameter, we vary the particle's propulsion velocity depending on its position and orientation relative to the target site. By introducing different figures of merit, e.g. the time to target or the total consumed propulsion energy, we are able to quantify and compare the efficiency of different strategies. Our results suggest, that each strategy to navigate towards a target, has its strengths and weaknesses and none of them outperforms the other in all regards. Accordingly, the choice of an ideal navigation strategy will strongly depend on the specific conditions and the figure of merit which should be optimized

GRAVITY: The AO-Assisted, Two-Object Beam-Combiner Instrument

We present the proposal for the infrared adaptive optics (AO) assisted, two-object, high-throughput, multiple-beam-combiner GRAVITY for the VLTI. This instrument will be optimized for phase-referenced interferometric imaging and narrow-angle astrometry of faint, red objects. Following the scientific drivers, we analyze the VLTI infrastructure, and subsequently derive the requirements and concept for the optimum instrument. The analysis can be summarized with the need for highest sensitivity, phase referenced imaging and astrometry of two objects in the VLTI beam, and infrared wavefront-sensing. Consequently our proposed instrument allows the observations of faint, red objects with its internal infrared wavefront sensor, pushes the optical throughput by restricting observations to K-band at low and medium spectral resolution, and is fully enclosed in a cryostat for optimum background suppression and stability. Our instrument will thus increase the sensitivity of the VLTI significantly beyond the present capabilities. With its two fibers per telescope beam, GRAVITY will not only allow the simultaneous observations of two objects, but will also push the astrometric accuracy for UTs to 10 micro-arcsec, and provide simultaneous astrometry for up to six baselines.Comment: 12 pages, to be published in the Proceedings of the ESO Workshop on "The Power of Optical/IR Interferometry: Recent Scientific Results and 2nd Generation VLTI Instrumentation", eds. F. Paresce, A. Richichi, A. Chelli and F. Delplancke, held in Garching, Germany, 4-8 April 200

NaFe3+EDTA as a food fortificant: influence on zinc, calcium and copper metabolism in the rat

The general acceptance of NaFe3+EDTA for food Fe fortification has been partly restricted by concern over the influence of EDTA on the metabolism of other nutritionally important trace elements and minerals. We have investigated the influence of NaFe3+EDTA, and of increasing dietary levels of Na2EDTA, on Zn, Cu and Ca metabolism in rats fed on Zn-sufficient and Zn-deficient soya-bean-isolate- based diets. With the Zn-deficient diets, changing the dietary Fe compound from FeSO4 to NaFe3+- EBTA significantly (P < 0·05) increased mean apparent Zn absorption from 50·2 to 67·4%. urinary Zn excretion from 2·0 to 4·0% of intake, and Zn retention from 48·2 to 63·4%. Increasing the dietary EDTA level to 1000 mg/kg further increased Zn absorption to 78·1%, urinary Zn excretion to 15·6% of intake and Zn retention to 62·5%. Increased Zn retention was accompanied by a significant increase in weight gain indicating that the extra Zn was available for normal metabolic processes. With rats fed on the Zn-sufficient diet, NaFe3+EDTA and Na2EDTA similarly increased the absorption, urinary excretion and retention of Zn but to a lesser extent. NaFe3+EDTA, however, had no influence on the absorption, urinary excretion and retention of Cu and Ca, and additional Na2EDTA caused only minor increases in Cu absorption and retention and in the urinary excretion of Ca. We conclude that using NaFe3+EDTA as a food fortificant would have no detrimental effect on the metabolism of Zn, Cu and Ca and, in some situations, could improve Zn absorption and retention from low-bioavailability diet

Bending and Breaking of Stripes in a Charge-Ordered Manganite

In complex electronic materials, coupling between electrons and the atomic lattice gives rise to remarkable phenomena, including colossal magnetoresistance and metal-insulator transitions. Charge-ordered phases are a prototypical manifestation of charge-lattice coupling, in which the atomic lattice undergoes periodic lattice displacements (PLDs). Here we directly map the picometer scale PLDs at individual atomic columns in the room temperature charge-ordered manganite Bi$_{0.35}$Sr$_{0.18}$Ca$_{0.47}$MnO$_3$ using aberration corrected scanning transmission electron microscopy (STEM). We measure transverse, displacive lattice modulations of the cations, distinct from existing manganite charge-order models. We reveal locally unidirectional striped PLD domains as small as $\sim$5 nm, despite apparent bidirectionality over larger length scales. Further, we observe a direct link between disorder in one lattice modulation, in the form of dislocations and shear deformations, and nascent order in the perpendicular modulation. By examining the defects and symmetries of PLDs near the charge-ordering phase transition, we directly visualize the local competition underpinning spatial heterogeneity in a complex oxide.Comment: Main text: 20 pages, 4 figures. Supplemental Information: 27 pages, 14 figure

Analisis Penggunaan Metode Altman dalam Memprediksi Kebangkrutan Perusahaan (Studi pada Perusahaan Plastik dan Kemasan yang Terdaftar di Bursa Efek Indonesia Periode Tahun 2012-2014)

This study aims to determine the implementation of Altman\u27s (Z-score) analysis in predicting bancruptcy the plastic and packaging companies that is listed at Indonesia Stock Exchange (IDX) study period of 2012-2014. Data analysis used the method of Altman by used ratio of net working capital to total assets, retained earnings to total assets, earning before interest and tax to total assets, market value of equity to total debt, and sales to total assets. After get the Z-score result, then be classified according to the point of cut-off.This study used secondary data, financial reports (annual report). As for data listed in Indonesia Stock Exchange (IDX) for 3 years from 2012-2014. This study is descriptive research in methods of data collection by documentation, by taking data of the company financial statement. Sampling used a purposive sampling technique with researched 11 compenies for three years.This analysis showed that there were four companies which predicted potentially into bancruptcy next year if there is no progress in its financial position and operating result. They are PT Alam Karya Unggul Tbk, PT Berlina Tbk, PT Indopoly Swakarsa Industry Tbk and PT Siwani Makmur Tbk. While there were five companies which predicted into grey area. They are PT Argha Karya Prima Industry Tbk, PT Asiaplast Industries Tbk, PT Lotte Chemical Titan Tbk, PT Trias Sentosa Tbk and PT Yana Prima Hasta Persada Tbk. There is only two companies in good condition, they are PT Champion Pacific Indonesia Tbk and PT Sekawan Inti Pratama Tbk

The Genetic Relationship between Leishmania aethiopica and Leishmania tropica Revealed by Comparing Microsatellite Profiles

Background Leishmania (Leishmania) aethiopica and L. (L.) tropica cause cutaneous leishmaniases and appear to be related. L. aethiopica is geographically restricted to Ethiopia and Kenya; L. tropica is widely dispersed from the Eastern Mediterranean, through the Middle East into eastern India and in north, east and south Africa. Their phylogenetic inter- relationship is only partially revealed. Some studies indicate a close relationship. Here, eight strains of L. aethiopica were characterized genetically and compared with 156 strains of L. tropica from most of the latter species' geographical range to discern the closeness. Methodology/Principal Findings Twelve unlinked microsatellite markers previously used to genotype strains of L. tropica were successfully applied to the eight strains of L. aethiopica and their microsatellite profiles were compared to those of 156 strains of L. tropica from various geographical locations that were isolated from human cases of cutaneous and visceral leishmaniasis, hyraxes and sand fly vectors. All the microsatellite profiles were subjected to various analytical algorithms: Bayesian statistics, distance-based and factorial correspondence analysis, revealing: (i) the species L. aethiopica, though geographically restricted, is genetically very heterogeneous; (ii) the strains of L. aethiopica formed a distinct genetic cluster; and (iii) strains of L. aethiopica are closely related to strains of L. tropica and more so to the African ones, although, by factorial correspondence analysis, clearly separate from them. Conclusions/Significance The successful application of the 12 microsatellite markers, originally considered species-specific for the species L. tropica, to strains of L. aethiopica confirmed the close relationship between these two species. The Bayesian and distance-based methods clustered the strains of L. aethiopica among African strains of L. tropica, while the factorial correspondence analysis indicated a clear separation between the two species. There was no correlation between microsatellite profiles of the eight strains of L. aethiopica and the type of leishmaniasis, localized (LCL) versus diffuse cutaneous leishmaniasis (DCL), displayed by the human cases