Development of new film thickness models for hot mix asphalt

The current standard model for calculating film thickness is not sufficiently detailed to adequately reflect differences in hot mix asphalt mixtures; and therefore, has limited value as a tool to evaluate research or mix designs. Modifications to the model (or replacement of the model) would give practitioners a better tool to assess the durability potential of a hot mix asphalt mixture;Durability is an important characteristics of hot mix asphalt that must get adequate attention to insure long-term performance of hot mix asphalt. Film thickness is one mixture parameter used to characterize a mixture\u27s potential durability. The standard film thickness model is only a nominal approximation that applies 1940\u27s technology;This study develops two film thickness models that more accurately reflect the relationship of the asphalt binder coating to other mixture parameters. The INDEX Model uses basic weight and volume relationships on each aggregate source in the mixture to improve the surface area value used in the standard model. The VIRTUAL Model uses three-dimensional concepts to redefine film thickness as the spatial relationship between aggregate particles and air voids. The VIRTUAL Model allows the practitioner to compute the film thickness at any level of field compacted density;The study examines the historical development and application of the standard film thickness model. The proposed film thickness models account for the individual aggregate source gradations, specific gravities, and particle shape that comprise the hot mix asphalt blend. The study provides a practical approach to the significant contribution of the mineral filler as both an aggregate and asphalt binder extender. These parameters were not adequately accounted for prior to this study;These new film thickness models provide the asphalt community with improved approaches to calculating film thickness that better reflect the unique properties of each hot mix asphalt mixture. Based on the analysis in this study, future studies of hot mix asphalt durability will have a more accurate perception of film thickness to compare differences in hot mix asphalt durability

Fractal and compositional analysis of soil aggregation

A soil aggregate is made of closely packed sand, silt, clay, and organic particles building up soil structure. Soil aggregation is a soil quality index integrating the chemical, physical, and biological processes involved in the genesis of soil structure and tilth. Aggregate size distribution is determined by sieving a fixed amount of soil mass under mechanical stress and is commonly synthesized by the mean weight diameter (MWD) and fractal dimensions such as the fragmentation fractal dimensions (D f). A fractal is a rough object that can be broken down into a number of reduced-size copies of the original object. Equations have been developed to compute bounded and unbounded scaling factors as measures of fractal dimensions based on assumptions about average diameter, bulk density, shape and probability of failure of sieved particles. The log-log relationship between particle diameter and cumulative number or mass of aggregates or soil particles above a given diameter often shows more or less uniform fractal patterns. Multi-fractal (slopes showing several D f values ≤ 3) and non fractal patterns or incomplete fragmentation ( D f 3) have been reported. Scaling factors are curve- fitting parameters that are very sensitive to the choice of the fractal domain about breakpoints. Compositional data analysis using sequential binary partitions for isometric log ratio (ilr) coordinates with orthonormal basis provides a novel approach that avoids the assumptions and dimensional constraints of fractal analysis. Our objective was to compare MWD, fractal scaling factors and ilr coordinates using published data. In the first dataset, MWD was found to be biased by excessively high weight being given to the largest aggregate-size. Eight ilr coordinates contrasting micro- vs. macro-aggregates were related to fragmentation fractal dimensions, most of which were below 2 or above 3, a theoretical impossibility for geometric fractals. The critical ilr value separating scaling factors 3 and > 3 was close to zero. In a second dataset, the Aitchison distance computed across ilr coordinates proved to be a useful measure of the degree of soil aggregation, agradation or degradation against a reference composition such as that of primary particles, bare fallow or permanent grass. The individual contributions of ilr coordinates to the Aitchison distance can be interpreted in terms of sign and amplitude and be related to soil properties and processes mediated by soil aggregation

Freeze Extrusion Fabrication of 13-93 Bioactive Glass Scaffolds for Bone Repair

There is an increasing demand for synthetic scaffolds with the requisite biocompatibility, internal architecture, and mechanical properties for the bone repair and regeneration. In this work, scaffolds of a silicate bioactive glass (13-93) were prepared by a freeze extrusion fabrication (FEF) method and evaluated in vitro for potential applications in bone repair and regeneration. The process parameters for FEF production of scaffolds with the requisite microstructural characteristics, as well as the mechanical and cell culture response of the scaffolds were evaluated. After binder burnout and sintering (60 min at 700°C), the scaffolds consisted of a dense glass network with interpenetrating pores (porosity ≈ 50%; pore width = 100-500 μm). These scaffolds had a compressive strength of 140 ± 70 MPa, which is comparable to the strength of human cortical bone and far higher than the strengths of bioactive glass and ceramic scaffolds prepared by more conventional methods. The scaffolds also supported the proliferation of osteogenic MLO-A5 cells, indicating their biocompatibility. Potential application of these scaffolds in the repair and regeneration of load-bearing bones, such as segmental defects in long bones, is discussed

Enhancing Concrete Barrier Reflectivity With A Focus On Recycled Glass Aggregate Replacement

Increased accident rates during the nighttime and wet weather conditions on the United States highways necessitate the enhancement of highway concrete barrier visibility. The visibility of these delineators is dependent on their reflectivity. Several methods are proposed that stand to increase the reflectivity of these concrete barriers, such as the use of white cement versus gray cement and the attachment of raised pavement markers to the side of the barriers. The incorporation of recycled glass into the concrete mixture is one of the proposed methods that was put through further laboratory study. The aim of the laboratory testing was to identify proper mixing proportions that mitigate the potential for the alkali-silica reaction (ASR) in recycled glass aggregate concretes without producing any negative effects on the compressive strength of the concrete. The retroreflectivity of these concrete mixtures was also evaluated and is presented in this report

Mass equidistribution of Hilbert modular eigenforms

Let F be a totally real number field, and let f traverse a sequence of non-dihedral holomorphic eigencuspforms on GL(2)/F of weight (k_1,...,k_n), trivial central character and full level. We show that the mass of f equidistributes on the Hilbert modular variety as max(k_1,...,k_n) tends to infinity. Our result answers affirmatively a natural analogue of a conjecture of Rudnick and Sarnak (1994). Our proof generalizes the argument of Holowinsky-Soundararajan (2008) who established the case F = Q. The essential difficulty in doing so is to adapt Holowinsky's bounds for the Weyl periods of the equidistribution problem in terms of manageable shifted convolution sums of Fourier coefficients to the case of a number field with nontrivial unit group.Comment: 40 pages; typos corrected, nearly accepted for

Evaluation and Testing of Brick Dust as a Pozzolanic Additive to Lime Mortars for Architectural Conservation

The purpose of this research is to identify an optimal methodology for determining whether a given brick dust will produce a pozzolanic reaction when combined with lime. This property will be referred to as pozzolanicity. The research required a review of the properties of pozzolanic materials, the nature of the pozzolanic reaction, and a review of existing methods for determining pozzolanicity. A testing program performed at the Architectural Conservation Laboratory at the University of Pennsylvania was designed and executed to evaluate methods for testing pozzolanicity of brick dust to determine their efficacy. An evaluation of the tests was the final result of the research, along with recommendations for ways in which this immensely valuable resource can be tested and utilized economically and sustainably for conservation work in the future

Modelling a fluidized wet granulation process

Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, 2020, Universidade de Lisboa, Faculdade de Farmácia.Tradicionalmente, a produção de medicamentos pela indústria farmacêutica é realizada em modo descontínuo sendo o produto acabado libertado após a sua verificação, também designado por quality-by-testing. Este fato decorre em parte devido ao elevado nível de regulação, o que, no passado, juntamente com outros fatores, dificultou a transição para processos contínuos e novos paradigmas de avaliação da qualidade. Atualmente, a transição para processos de produção em contínuo começou a ser incentivada pelas autoridades reguladoras, sendo que estes processos serão vantajosos não só para a indústria, por aumentar a eficiência dos processos de produção, mas também para os consumidores, fornecendo uma maior consistência na qualidade dos produtos fabricados. A Food and Drug Administration (FDA) e a European Medicines Agency (EMA), assim como as novas guidelines do Conselho Internacional para Harmonização de Requisitos Técnicos de Produtos Farmacêuticos para Uso Humano (ICH). incentivam agora o desenvolvimento de processos de produção de medicamentos baseados no conceito de Quality-By-Design (QbD). Permitindo implementar processos contínuos de produção baseando-se num conhecimento aprofundado das principais variáveis que influenciam o processo de fabrico, de forma a conceber um produto de qualidade e, tendo em conta que a qualidade não deve ser testada no produto final, mas sim desenvolvida desde a primeira etapa de produção. Com o conceito de QbD em mente, foi decidido, neste estudo, desenvolver um design space (DS) para um processo de granulação, uma vez que se trata de um processo importante na produção de várias formas farmacêuticas. Para isso, estudou-se uma combinação de variáveis e parâmetros do processo que demostram resultar num produto de qualidade, ou seja, dentro das especificações que foram estabelecidas. As variáveis escolhidas para este estudo incluíram a formulação e parâmetros identificados como críticos do processo. Para alcançar este objetivo, foi utilizado um método de delineamento experimental de forma a definir os ensaios a realizar. Os grânulos foram testados de acordo com vários parâmetros de qualidade de forma a estabelecer o DS. De modo a testar a influência do processo de granulação na forma farmacêutica final, foi decidido também proceder à produção de comprimidos, que foram também testados.Traditionally the production of medicines by the pharmaceutical industry is done in batches with the finished product released after verification, also known as quality-by-testing. This is due to the fact that it is an industry with tight regulations that, in the past, together with other factors, made the transition to continuous processes, as well as quality control methods difficult. Currently, the transition to continuous processes has been encouraged by regulatory authorities as these processes will be advantageous not only for the industry, as it increases the efficiency of the processes, but also for the consumers, providing higher quality to the manufactured product. Food and Drug Administration (FDA) and the European Medicines Agency (EMA), as well as the new guidelines from the International Council for Harmonization of Technical Requirements for Pharmaceutical Products for Human Use (ICH) now encourage the development of drug manufacturing processes based on the concept of quality-bydesign(QbD), with the opportunity of implementing continuous production processes based on an in-depth knowledge of the main variables that influence the manufacturing process, in order to design a quality product, with the notion that quality cannot be tested on a product but developed from the ground up starting with the first step of production. With the concept of QbD in mind, it was decided, in this study, to develop a design space (DS) for a granulation process, an important process in the production of various pharmaceutical forms, studying a combination of variables and process parameters that guarantee to result in a product with quality, that is, within the specifications that were decided. The variables chosen for this process included the formulation and critical parameters of the process. To achieve this objective, experimental design was used in order to establish the most important tests. The granules were tested in various experiments suitable to our variables in order to establish the DS. In order to test the influence of the granulation process on the final pharmaceutical form, it was also decided to proceed with the production of tablets, which were also tested.Com o patrocínio da Faculdade de Farmácia da Universidade de Lisboa

Linked Open Data - Creating Knowledge Out of Interlinked Data: Results of the LOD2 Project

Database Management; Artificial Intelligence (incl. Robotics); Information Systems and Communication Servic