A Sustainable Industrial Waste Management Solution: Application Of Silica Fume To Enhance Asphalt Binder Rheological Properties

This thesis investigates the practical feasibility of using silica fume, an industrial waste material, to enhance the rheological properties of asphalt binder. It has been widely reported that asphalt binder oxidation reduces the service life of asphalt pavement by negatively impacting its rheological properties. When asphalt binder is oxidized, its viscoelastic properties are diminished; this can be evidenced by the reduction in asphalt phase angle as measured through dynamic shear and torsion tests. This can lead to a more brittle pavement, which is more prone to cracks due to thermal stress and traffic loading and leads to premature pavement failure. In this thesis, the effectiveness of the application of silica-fume-based additives to reduce asphalt oxidative aging is investigated. It is hypothesized that fine-graded silica fume with nano- to micro-level particle size can be used to reduce asphalt oxidation. To test this hypothesis, various percentages of silica fume were introduced to base binders; then a series of experiments in binder and mixture level was conducted to evaluate the effects of silica fume addition

A Sustainable Industrial Waste Management Solution: Application Of Silica Fume To Enhance Asphalt Binder Rheological Properties

This thesis investigates the practical feasibility of using silica fume, an industrial waste material, to enhance the rheological properties of asphalt binder. It has been widely reported that asphalt binder oxidation reduces the service life of asphalt pavement by negatively impacting its rheological properties. When asphalt binder is oxidized, its viscoelastic properties are diminished; this can be evidenced by the reduction in asphalt phase angle as measured through dynamic shear and torsion tests. This can lead to a more brittle pavement, which is more prone to cracks due to thermal stress and traffic loading and leads to premature pavement failure. In this thesis, the effectiveness of the application of silica-fume-based additives to reduce asphalt oxidative aging is investigated. It is hypothesized that fine-graded silica fume with nano- to micro-level particle size can be used to reduce asphalt oxidation. To test this hypothesis, various percentages of silica fume were introduced to base binders; then a series of experiments in binder and mixture level was conducted to evaluate the effects of silica fume addition

Characterization of early graft damage after pancreatic transplantation

Kein Inhaltsverzeichnis

Limits to ion energy control in high density glow discharges: Measurement of absolute metastable ion concentrations

Unprecedented demands for uniformity, throughput, anisotropy, and damage control in submicron pattern transfer are spurring development of new, low pressure, high charge density plasma reactors. Wafer biasing, independent of plasma production in these new systems is intended to provide improved ion flux and energy control so that selectivity can be optimized and damage can be minimized. However, as we show here, an inherent property of such discharges is the generation of significant densities of excited, metastable ionic states that can bombard workpiece surfaces with higher translational and internal energy. Absolute metastable ion densities are measured using the technique of self-absorption, while the corresponding velocity distributions and density scaling with pressure and electron density are measured using laser-induced fluorescence. For a low pressure, helicon-wave excited plasma, the metastable ion flux is at least 24% of the total ion flux to device surfaces. Because the metastable ion density scales roughly as the reciprocal of the pressure and as the square of the electron density, the metastable flux is largest in low pressure, high charge density plasmas. This metastable ion energy flux effectively limits ion energy and flux control in these plasma reactors, but the consequences for etching and deposition of thin films depend on the material system and remain an open question

Latent Autoimmune Diabetes in Adults in the United Arab Emirates: Clinical Features and Factors Related to Insulin-Requirement

AIMS: To describe and to characterize clinical features of latent autoimmune diabetes in adults (LADA) compared to type 1 and type 2 diabetes in the UAE. METHODS: In this cross-sectional study a dataset including 18,101 subjects with adult-onset (>30 years) diabetes was accessed. 17,072 subjects fulfilled the inclusion/exclusion criteria. Data about anthropometrics, demographics, autoantibodies to Glutamic Acid Decarboxylase (GADA) and to Islet Antigen 2 (anti-IA2), HbA1c, cholesterol and blood pressure were extracted. LADA was diagnosed according to GADA and/or anti-IA2 positivity and time to insulin therapy. RESULTS: 437 (2.6%) patients were identified as LADA and 34 (0.2%) as classical type 1 diabetes in adults. Mean age at diagnosis, BMI, waist circumference, systolic blood pressure and HbA1c significantly differed between, LADA, type 2 and type 1 diabetes, LADA showing halfway features between type 2 and type 1 diabetes. A decreasing trend for age at diagnosis and waist circumference was found among LADA subjects when subdivided by positivity for anti-IA2, GADA or for both antibodies (p=0.013 and p=0.011 for trend, respectively). There was a gradual downward trend in autoantibody titre in LADA subjects requiring insulin within the first year from diagnosis to subjects not requiring insulin after 10 years of follow-up (p<0.001). CONCLUSIONS: This is the first study describing the clinical features of LADA in the UAE, which appear to be different from both type 1 and type 2 diabetes. Furthermore, we showed that the clinical phenotype of LADA is dependent on different patterns of antibody positivity, influencing the time to insulin requirement

Evolution of Preprofessional Pharmacy Curricula

Objectives. To examine changes in preprofessional pharmacy curricular requirements and trends, and determine rationales for and implications of modifications. Methods. Prerequisite curricular requirements compiled between 2006 and 2011 from all doctor of pharmacy (PharmD) programs approved by the Accreditation Council of Pharmacy Education were reviewed to ascertain trends over the past 5 years. An online survey was conducted of 20 programs that required either 3 years of prerequisite courses or a bachelor’s degree, and a random sample of 20 programs that required 2 years of prerequisites. Standardized telephone interviews were then conducted with representatives of 9 programs. Results. In 2006, 4 programs required 3 years of prerequisite courses and none required a bachelor’s degree; by 2011, these increased to 18 programs and 7 programs, respectively. Of 40 programs surveyed, responses were received from 28 (70%), 9 (32%) of which reported having increased the number of prerequisite courses since 2006. Reasons given for changes included desire to raise the level of academic achievement of students entering the PharmD program, desire to increase incoming student maturity, and desire to add clinical sciences and experiential coursework to the pharmacy curriculum. Some colleges and schools experienced a temporary decrease in applicants. Conclusions. The preprofessional curriculum continues to evolve, with many programs increasing the number of course prerequisites. The implications of increasing prerequisites were variable and included a perceived increase in maturity and quality of applicants and, for some schools, a temporary decrease in the number of applicants

Image processing techniques for improved porosity estimation

The work reported here is on the first phase of the development of an automated image analysis package. It is intended that the initial application should be to the problem of porosity estimation in powder metals. Although a great deal of work has been concentrated recently on using ultrasonic velocity changes and attenuation for porosity estimation, the problem can also be addressed through acoustical imaging

LEARNING ARITHMETIC READ-ONCE FORMULAS*

Abstract. A formula is read-once if each variable appears at most once in it. An arithmetic read-once formula is one in which the operators are addition, subtraction, multiplication, and division. We present polynomial time algorithms for exact learning of arithmetic read-once formulas over a field. We present a membership and equivalence query algorithm that identifies arithmetic read-once formulas over an arbitrary field. We present a randomized membership query algorithm (i.e., a randomized black box interpolation algorithm) that identifies such formulas over finite fields with at least 2n + 5 elements (where n is the number of variables) and over infinite fields. We also show the existence of nonuniform deterministic membership query algorithms for arbitrary read-once formulas over fields of characteristic 0, and division-free read-once formulas over fields that have at least 2n + elements. For our algorithms, we assume we are able to perform efficiently arithmetic operations on field elements and compute square roots in the field. It is shown that the ability to compute square roots is necessary in the sense that the problem of computing n square roots in a field can be reduced to the problem of identifying an arithmetic formula over n variables in that field. Our equivalence queries are of a slightly nonstandard form, in which counterexamples are required not to be inputs on which the formula evaluates to 0/0. This assumption is shown to be necessary for fields of size o(n! log n) in the sense that we prove there exists no polynomial time identification algorithm that uses only membership and standard equivalence queries