Nonlinear temperature dependent failure analysis of finite width composite laminates

A quasi-three dimensional, nonlinear elastic finite element stress analysis of finite width composite laminates including curing stresses is presented. Cross-ply, angle-ply, and two quasi-isotropic graphite/epoxy laminates are studied. Curing stresses are calculated using temperature dependent elastic properties that are input as percent retention curves, and stresses due to mechanical loading in the form of an axial strain are calculated using tangent modulii obtained by Ramberg-Osgood parameters. It is shown that curing stresses and stresses due to tensile loading are significant as edge effects in all types of laminate studies. The tensor polynomial failure criterion is used to predict the initiation of failure. The mode of failure is predicted by examining individual stress contributions to the tensor polynomial

Evaluating Machine Learning Models for Semantic Segmentation over Cloud Images for Classification

Due to the increasing number of available approaches nowadays, choosing the most accurate image semantic segmentation model has become hard. The purpose of this research is to find the best-performing image semantic segmentation model for Cloud classification. For the purpose of this study, a data set of cloud images from the Max Planck Institute for meteorology is used. These images were taken from the by two NASA space satellite.Three main models UNet, PSPNet and FPN were used in combination of 4 differ-ent encoder Inception-ResNet-v2, MobileNet-v2, ResNet-34, and ResNet 101. After training all the models in the Mississippi Center for Super Computing, the results were plotted. Over-all the models turned out broadly similar to each other. Even so, the FPN model with the MobileNet-v2 encoder backbone stood out first followed by the UNet model with the Inception-ResNet-v2 encoder backbone in second place

Compressive X-ray phase tomography based on the transport of intensity equation

We develop and implement a compressive reconstruction method for tomographic recovery of refractive index distribution for weakly attenuating objects in a microfocus X-ray system. This is achieved through the development of a discretized operator modeling both the transport of intensity equation and X-ray transform that is suitable for iterative reconstruction techniques

An exploratory study of culturally responsive teaching practices for students who are ELLs

"July, 2011"Title from PDF of title page (University of Missouri--Columbia, viewed on May 18, 2012).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Erica LembkeVita.The purpose of this study was to explore whether certain teacher characteristics impacted teachers' perceived importance and reported use of culturally responsive practices within their classrooms. The numbers of ELLs in US classrooms has increased substantially over the past three decades and districts are mandated by federal law to provide these students appropriate high quality instruction for their language learning needs, as well as their academic achievement. Researchers suggest that teachers need to be culturally responsive while trying to meet the needs of ELLs and this study examined what teacher characteristics contributed to the use of culturally responsive practices within classrooms. The study was conducted in three school districts in a mid-western state and findings indicated that the most important predictor of teachers' perceived importance and reported use of culturally responsive practices in the classroom was teacher attitudes towards ELLs. Implications for current practice and future research are discussed.Includes bibliographical reference

Dependence of Self-Assembled Peptide Hydrogel Network Structure on Local Fibril Nanostructure

Physically cross-linked, fibrillar hydrogel networks are formed by the self-assembly of β-hairpin peptide molecules with varying degrees of strand asymmetry. The peptide registry in the self-assembled state can be used as a design element to generate fibrils with twisting, nontwisting, or laminated morphology. The mass density of the networks varies significantly, and can be directly related to the local fibrillar morphology as evidenced by small angle neutron scattering (SANS) and in situ substantiation using cryogenic transmission electron microscopy (cryo-TEM) under identical concentrations and conditions. Similarly, the density of the network is dependent on changes in the peptide concentration. Bulk rheological properties of the hydrogels can be correlated to the fibrillar nanostructure, with the stiffer, laminated fibrils forming networks with a higher G′ as compared to the flexible, singular fibrillar networks

GoFFish: A Sub-Graph Centric Framework for Large-Scale Graph Analytics

Large scale graph processing is a major research area for Big Data exploration. Vertex centric programming models like Pregel are gaining traction due to their simple abstraction that allows for scalable execution on distributed systems naturally. However, there are limitations to this approach which cause vertex centric algorithms to under-perform due to poor compute to communication overhead ratio and slow convergence of iterative superstep. In this paper we introduce GoFFish a scalable sub-graph centric framework co-designed with a distributed persistent graph storage for large scale graph analytics on commodity clusters. We introduce a sub-graph centric programming abstraction that combines the scalability of a vertex centric approach with the flexibility of shared memory sub-graph computation. We map Connected Components, SSSP and PageRank algorithms to this model to illustrate its flexibility. Further, we empirically analyze GoFFish using several real world graphs and demonstrate its significant performance improvement, orders of magnitude in some cases, compared to Apache Giraph, the leading open source vertex centric implementation.Comment: Under review by a conference, 201

Analysis of physics research output of SP Pune University during the period 1990-2014

The paper analyzes the research contributions by the faculty members of the Department of Physics, Savitribai Phule Pune University (SPPU), Pune, Maharashtra, India for the period 1990-2014. Bibliographic and citation data were retrieved from Scopus database. Query statements covering all variations in the name of SPPU were used to search the database. Scopus indexed 1629 publications with 22618 citations for the period. Author keywords in Scopus database indicate that faculty members are working in core areas of physics as well as interdisciplinary subjects like chemistry, instrumentation sciences, engineering, etc. The year-wise analysis shows that research productivity of faculty member increased over the period. Faculty members published their research in core physics journals among which Journal of Applied Physics (72 papers) is the most preferred journal. The faculty members of the University have collaborated with scientists from USA, UK, Germany and Japan. At the national level, the University physicists have collaborated most with Bhabha Atomic Research Centre

CMOS x-rays detector array based on scintillating light guides

This paper describes a pixel imaging array consisting in 400µm x 400µm photodiodes fabricated in CMOS technology. An array of scintillating CsI:Tl crystals is placed above the photodiodes. These crystals are encapsulated in aluminum walls, forming a light path that guides the visible light produced by the scintillating crystal into the photodiodes. In This way, the x-ray energy is first converted into visible light which is then detected by the photodiode at the end of each light guide. The scintillator is 800 µm thick, absorbing almost all 20keV x-ray photons. Usually, the spatial resolution of the scintillating x-ray detectors is identical to the scintillator thickness. By using the light guides, the scintillator thickness can be increased without decreasing the spatial resolution. The increase of the scintillator thickness is desirable in order to increase the x-rays absorption efficiency. Tests carried out on the system show very promising results near 20keV

Primary succession on a seasonal tropical rocky shore: The relative roles of spatial heterogeneity and herbivory

Hong Kong is within the tropics and has a seasonal climate. In winter, shores support patches of ephemeral macroalgae and areas of seemingly bare rock close to crevices where molluscan herbivores are abundant. Using a factorial design of herbivore exclusions in areas far and close to crevices, the development of algal assemblages was monitored in mid-shore, cleared areas, in winter. To estimate the role of herbivore mucus deposition, half the treatments received a mucus application. Algal development was estimated from macroalgal and biofilm development and chlorophyll a levels. In all areas, biofilms (diatoms, unicellular cyanobacteria) developed rapidly in herbivore exclusions followed by ephemeral macroalgae (Enteromorpha spp. and Porphyra suborbiculata). In herbivore access treatments, however, the algal assemblage was influenced by treatment location; few macroalgae developed in areas close to crevices, and the rock was dominated by cyanobacteria. A negative relationship between macroalgae and biofilms suggested that ephemeral algae were competitively dominant. In areas distant from herbivore refuges, ephemeral macroalgae did develop, illustrating that the effectiveness of molluscan herbivores was limited to 50 to 100 cm from these refuges. The absence of large herbivorous fish, and the sparse numbers of herbivorous crabs at this site, means that algae can achieve a spatial escape from consumption, and where this occurs competition between producers is important in assemblage development. Mucus appeared to play a limited role, only sometimes stimulating initial stages of unicellular cyanobacteria and macroalgae. With the onset of summer, macroalgae died back, and rock space became available for colonization. Unicellular cyanobacteria developed rapidly but were replaced in all treatments by the encrusting macroalga, Hapalospongidion gelatinosum, which dominated treatments until the end of the experiment. On seasonal, tropical shores processes influencing community structure can, therefore, be temporally variable and their relative importance, even at the same shore level, can change with season.published_or_final_versio