To investigate the liquefaction mitigation capability of Rammed Aggregate Piers® (RAP) in silty sand, blast liquefaction testing was performed at a soil profile treated with a full-scale RAP group relative to an untreated soil profile. The RAP group consisted of 16 piers in a 4x4 arrangement at 2 m center-to-center spacing extending to a depth of 9.5 m. Blasting around the untreated area induced liquefaction (ru ≈1.0) from 3 m to 11 m depth, producing several large sand boils, and causing settlement of 10 cm. In contrast, installation of the RAP group reduced excess pore water pressure (ru ≈0.75), eliminated sand ejecta, and reduced average settlement to between 2 to 5 cm when subjected to the same blast charges. Although the liquefaction-induced settlement in the untreated area could be accurately estimated using the CPT-based settlement approach proposed by Zhang et al. (2002), settlement in the RAP treated area was significantly overestimated with the same approach even after considering RAP treatment-induced densification. Analyses indicate that settlement after RAP treatment could be successfully estimated from elastic compression of the sand and RAP acting as a composite material. The composite reinforced soil mass, surrounded by liquefied soil, transferred load to the base of the RAP group inducing settlement in the non-liquefied sand below the group. This test program identifies a mechanism that explains how settlement was reduced for the RAP group despite the elevated ru values in the silty sands that are often difficult to improve with vibratory methods.

L’auto-cicatrisation des fissures des matériaux cimentaires présente un intérêt important pour améliorer leur durabilité (propriétés de transfert par exemple). L’impact du laitier de haut-fourneau sur ce phénomène a été peu étudié bien qu’il ait été observé sur des ouvrages du Génie Civil. Dans cette étude, la cinétique et l’amplitude de l’auto-cicatrisation ont été suivies par des essais non destructifs : la tomographie aux rayons X et la perméabilité à l’air, pour une fissuration créée à 7 jours et à 28 jours. Les résultats montrent que le laitier de haut-fourneau possède un potentiel d’auto-cicatrisation intéressant pouvant dépasser les résultats obtenus pour les formulations de référence sans laitier. Ce bon potentiel dépend des caractéristiques physicochimiques des matériaux brutes et du potentiel d’hydratation de la formulation au cours du temps. De plus pour suivre l’auto-cicatrisation, un nouvel essai a été mis en place afin de fissurer les éprouvettes de mortier par retrait gêné et d’étudier l’auto-cicatrisation d’une fissure naturelle. Cet essai s’est avéré efficace sur la formulation de référence. Une caractérisation des produits de cicatrisation par MEB-EDS témoigne de la formation de nouveaux produits dans les fissures et de l’impact important des conditions de stockage sur le type de produits formés: des C-S-H pour un stockage sous eau et des carbonates de calcium pour un stockage en chambre humide (CO2 + eau). Les résultats de migration aux chlorures de nano-indentation montrent que ces produits de cicatrisation possèdent de bonnes propriétés de durabilité et des propriétés mécaniques à l’échelle microscopique intéressantes (pour le carbonate de calcium). Enfin, une modélisation du phénomène d’auto-cicatrisation est proposée au moyen du code de calcul de géochimie PHREEQC. L’étude a révélé le potentiel intéressant de PHREEQC pour modéliser l’auto-cicatrisation et en faire un outil de prédiction du phénomène. / Self-healing of cementitious materials presents great interest to improve the durability of concrete structure (transfer properties for example). The impact of blast-furnace slag on this phenomenon is not yet clear even if the self-healing of concrete with blast-furnace slag was observed in building sites. To understand the blast-furnace slag influence, non-destructive methods were used to follow self-healing: X-ray tomography and gas permeability test. All specimens were cracked at 7 days and 28 days. The results show that the blast furnace slag has an interesting self-healing potential that can exceed the reference formulation results. This good potential depends on the physico-chemical characteristics of the raw materials and the hydration potential of the formulation over time. In addition to follow the self-healing, a new trial was set up to crack mortar specimens by restrained shrinkage and study the self-healing of a natural crack. In addition to follow the self-healing, a new trial was set up to crack mortar specimens by restrained shrinkage and study the self-healing of a natural crack. This test has proven effective over the reference formulation.The SEM with EDS analysis showed the formation of new products in the crack and the impact of storage conditions on these products : C-S-H for specimens stored in water and calcium carbonate for specimens stored in a damp chamber (CO2 + water). Migration chlorures and nano-indentation tests results showed that self-healing products had interesting durability properties and micro-mechanical properties (for calcium carbonate). Finally, self-healing modelling is proposed by means of geochemistry PHREEQC calculation code. The study revealed interesting potential PHREEQC to model self- healing phenomenon and make it a of predictive tool.

Indiana University-Purdue University Indianapolis (IUPUI) / Social support is a powerful therapeutic against fear and anxiety and is utilized in many psychotherapies. The concept that a familiar or friendly presence helps a person learn to overcome anxiety has been well-known for decades, yet, the basic neural mechanisms that regulate this psychosocial learning remain unknown. A first step towards elucidating these basic mechanisms is the development of a valid preclinical animal model. However, preclinical behavioral models exploring the use of a social presence in reducing anxiety have not been fully characterized. Therefore, it was our goal to identify a useful way in which to study the mechanisms of how a social presence can induce anxiolysis (the reduction of anxiety). We accomplished this goal by characterizing and validating a preclinical model, as well as demonstrating that the model was capable of measuring deficits in rats given a mild traumatic brain injury. To this end, we identified an existing, but uncharacterized model, the social interaction-habituation model, as an effective model of social familiarity-induced anxiolysis (SoFiA), which demonstrates socially enhanced safety learning, or psychosocial learning. We find that as social familiarity develops across time, anxiolysis develops. We identified that the use of a Bright Light Challenge is a useful anxiogenic stimulus to use during SI-habituation training. The anxiolysis acquired following SI-habituation testing is partner specific, and can be blocked by an inhibition of the medical prefrontal cortex, while it can be enhanced by D-cycloserine. We found that this model identified deficits in SoFiA acquisition in rodents exposed to a mild traumatic brain injury, which, in humans, has been linked to psychosocial deficits. This work is a step in creating ways in which we can study and better understand the regulatory processes of emotions mediated by social behavior.

No description available.

This research developed the quasi-static and dynamic equipment and protocols for tests of both Very-High-Strength Concrete (VHSC) and High-Strength High-Ductility Concrete (HSHDC) to predict blast performance. VHSC was developed for high compressive strength (> 200 MPa). Using VHSC as the baseline material, HSHDC was developed and exhibits comparable compressive strength (> 150 MPa) and high tensile ductility (> 3% tensile strain). This research investigated quasi-static material properties including compression, tension, and flexure (third-point and pressure loadings). Additionally, dynamic blast load simulator (shock tube) tests were performed on simply-supported one-way panels in flexure. Subsequently, the material response in flexure was predicted using the Wall Analysis Code (WAC). Although VHSC has a higher peak flexural strength capacity, HSHDC exhibits higher ductility through multiple parallel micro-cracks transverse to loading. The equipment and test protocols proved to be successful in providing ways to test scaled concrete specimens quasi-statically and dynamically.

Military personnel often experience mild traumatic brain injury (mTBI) from exposure to improvised explosive devices (IEDs). Soldiers typically endure blast trauma from the IED pressure wave as well as blunt trauma from ensuing head impacts. Researchers have not reached a consensus on whether the biomechanical response from blunt or blast trauma plays a more dominant role in mTBI because the specific biomechanical sources of injury are often undetermined. Consequently, the goal of this dissertation was to conduct three separate studies in order to characterize the mechanical behavior of the brain after exposure to mTBI conditions. For Study 1, mild blunt and blast trauma were induced in Sprague-Dawley rats using a custom-built device. In-house diffusion tensor imaging (DTI) software was used to make 3-D reconstructions of white matter fiber tracts before and after injury (1, 4, and 7 days). Axonal integrity was characterized by examining the fiber count, fiber length, and fractional anisotropy (FA). In-house image analysis software also quantified the microstructural variations in Hematoxylin and Eosin (H&E) stained brain sections, where significant differences in parameters such as the area fraction (AF) and nearest neighbor distance (NND) correlated to voids that formed after water diffused extracellularly from axons. Study 2 employed a computational approach involving the development of a finite element (FE) model for the rat head followed by the simulation of blunt and blast trauma, respectively. FE parameters such as von Mises stress, pressure, and maximum principal strain were analyzed at various locations including the skull, cerebral cortex, corpus callosum, and hypothalamus to compare injury cases. Study 3 involved interruption mechanical testing of porcine brain, a suitable animal surrogate of human brain. Compression, tension, and shear experiments were performed at a strain rate of 0.1 s-1 to examine the differential mechanical response. Microstructural changes in H&E stained brain sections were analyzed with in-house image analysis software to quantify differences among stress states at strains of 0.15, 0.30, and 0.40. Studies 1 and 2 confirmed that the brain behaves differently in response to blunt and blast trauma, respectively, while Study 3 further demonstrated the stress state dependent behavior of brain tissue.

[pt] O alto forno é um reator metalúrgico cujo objetivo consiste na produção de ferro-gusa. O consumo de combustível/redutor no processo de redução de minério de ferro em altos fornos, representa mais de 50 por cento do custo do gusa. No sentido de aumentar a produtividade e reduzir o consumo de combustível/redutor são empregadas técnicas de injeção de combustíveis auxiliares pelas ventaneiras dos altos fornos. A combustão de gás natural (GN) injetado nas ventaneiras produz grande quantidade de hidrogênio, esse gás é melhor redutor se comparado ao monóxido de carbono, pois ele possui velocidade de reação maior com os óxidos de ferro e, além disso, a geração de CO2 no processo de redução é diminuída quando comparado ao uso do carvão pulverizado (PCI), que é atualmente o material de injeção mais usado no Brasil. Este trabalho propõe a simulação da combustão de GN injetado pelas ventaneiras de um alto forno, utilizando o software CHEMKIN. As simulações provenientes deste software são amplamente utilizadas para otimização da combustão, sendo possível explorar rapidamente o impacto das variáveis de projeto sobre o desempenho do processo. Os resultados provenientes dessa simulação computacional em condições típicas de alto forno permitiram a previsão da temperatura de chama adiabática e a quantificação dos gases redutores de óxidos de ferro: H2 e CO. A partir da variação dos parâmetros de processo foi possível obter resultados úteis para a tomada de decisão, visando controlar e otimizar o processo. / [en] The blast furnace is a metallurgical reactor whose goal is to produce pig iron. The fuel / reductant in the reduction of iron ore in the blast furnace process, represents more than 50 percent of the cost of the iron. In order to increase the productivity of the blast furnace and reduce fuel consumption / reducer injection techniques are employed by tuyeres of materials that act as fuel / reducer. The combustion of natural gas injected into the tuyeres produces large amounts of hydrogen, which replaces part of the carbon monoxide as reducing gas in the tank. The hydrogen gas is better compared to the reductant carbon monoxide, because it has reaction rate with the iron oxides and, moreover, the CO2 generation in the process of reduction is decreased when compared to the use of pulverized coal (PCI), which is currently the material most commonly used injection by tuyeres in Brazil. This paper proposes the simulation of combustion of natural gas injected into the tuyeres of a blast furnace, using the CHEMKIN software package. Simulations from this software are widely used for optimization of combustion, which can quickly explore the impact of design variables on the performance of the process, using accurate models of chemical kinetics. The computer simulation results from the combustion of natural gas at typical conditions of blast furnaces allowed the prediction of the adiabatic flame temperature and the reaching of the reducing gases of iron oxides: H2 and CO. From the variation of process parameters was possible to obtain useful results in order to control and optimize the process.

No description available.

Similarity searches are an essential component to most bioinformatic applications. They form the bases of structural motif identification, gene identification, and insights into functional associations. With the rapid increase in the available genetic data through a wide variety of databases, similarity searches are an essential tool for accessing these data in an informative and productive way. In our chapter, we provide an overview of similarity searching approaches, related databases, and parameter options to achieve the best results for a variety of applications. We then provide a worked example and some notes for consideration. Homology detection is one of the most basic and fundamental problems at the heart of bioinformatics. It is central to problems currently under intense investigation in protein structure prediction, phylogenetic analyses, and computational drug development. Currently discriminative methods for homology detection, which are not readily interpretable, are substantially more powerful than their more interpretable counterparts, particularly when sequence identity is very low. Here I present a computational graph-based framework for homology inference using physiochemical amino acid properties which aims to both reduce the gap in accuracy between discriminative and generative methods and provide a framework for easily identifying the physiochemical basis for the structural similarity between proteins. The accuracy of my method slightly improves on the accuracy of PSI-BLAST, the most popular generative approach, and underscores the potential of this methodology given a more robust statistical foundation.

<p>  </p> <p>The design of blast-resistant structures is critical for defense related facilities and industries. An emerging option for these applications is Steel-plate composite (SC) systems. SC systems include a steel module and concrete infill. Steel modules can include but are not limited to steel faceplates, tie bars, tie plates, diaphragm plates, and steel headed stud anchors. SC technologies have been adopted as a structural system in the design of nuclear powerplant containment vessels and high-rise buildings. These applications have benefitted from the inherent ductility and modular construction that SC systems provide.</p> <p>When designing structures to resist blast and impact, the desired behavior is for the structure to demonstrate ductility. Previous research has explored the behavior of a variety of SC elements; however, limited research on the behavior of L-joint connections exists. For L-joint connections to demonstrate ductile behavior, it is suggested that the joint that connects SC components- SC beams, columns, or slabs- be stronger than the connected elements. L-joint connections with joints stronger than the connected SC elements are considered full strength connections. As such, the connected elements reach their maximum bending moments and demonstrate ductile behavior. This study proposes a design philosophy for achieving full-strength L-joint connections using a diagonal steel reinforcing plate in the joint. This study evaluated the behavior of L-joint connections with joint reinforcement through large-scale experimental testing and subsequent benchmarked finite element analyses. The inclusion of a diagonal plate contributes to the L-joint connections ability to resist joint failure and develop a greater moment capacity in the SC members. This finding was also validated through finite element analyses comparing the specimen behavior with and without the joint reinforcement. The specimen without joint reinforcement experienced joint shear failure in the concrete while the experimental specimens were able to demonstrate ductile behavior prior to failure. </p>