A computational method for simulating dispersed two-phase flows using the PDF approach

The thesis presents a Probability Density Function (PDF)-derived Eulerian/Eulerian model for the prediction of dispersed two-phase (solid/gas) flows. Continuum equations for the dispersed phase are formulated from the Kinetic Model (KM) PDF transport equations. The Kinetic stresses of the dispersed phase are determined from an algebraic stress model (ASM) together with a KM-based transport equation for the fluctuating kinetic energy. The continuum equations for the continuous phase are assumed to be the same as those in the Eulerian two-fluid model except for the interfacial momentum and energy transfer terms. Closures for these terms are derived from the PDF KM and mirror their counterparts in the dispersed phase equations. Also, the carrier phase turbulence is modelled by the standard k-ε model. These transport equations are solved using the numerical framework of an existing two-fluid approach. Furthermore, the current two-fluid model practice of applying wall functions to impose boundary conditions is adapted for application to the particulate phase. Such wall functions are calculated from the PDF KM itself. In this approach, the PDF equations are pre-integrated using the fully developed flow assumption along the wall to relate wall fluxes to values of the relevant variables in the interior of the flow. Such integration is utilised to create a wall functions database for a range of mean flow conditions. The model is validated against a range of both unbounded and bounded flow cases. Comparisons are made with experimental data as well as the results of other computational methods. It was found that the proposed model performs very well in capturing particulate behaviour and improves, in certain aspects, on the performance of traditional two-fluid models while retaining the practicality of the latter model for industrial applications. In particular, a reasonable capture of the particulate dispersion was observed within jet flows. Improvements were also seen in the prediction of mass flux distribution in shear layers and an accurate capture of near-wall mass distributions in bounded flows

Extropy: Complementary Dual of Entropy

This article provides a completion to theories of information based on entropy, resolving a longstanding question in its axiomatization as proposed by Shannon and pursued by Jaynes. We show that Shannon's entropy function has a complementary dual function which we call "extropy." The entropy and the extropy of a binary distribution are identical. However, the measure bifurcates into a pair of distinct measures for any quantity that is not merely an event indicator. As with entropy, the maximum extropy distribution is also the uniform distribution, and both measures are invariant with respect to permutations of their mass functions. However, they behave quite differently in their assessments of the refinement of a distribution, the axiom which concerned Shannon and Jaynes. Their duality is specified via the relationship among the entropies and extropies of course and fine partitions. We also analyze the extropy function for densities, showing that relative extropy constitutes a dual to the Kullback-Leibler divergence, widely recognized as the continuous entropy measure. These results are unified within the general structure of Bregman divergences. In this context they identify half the $L_2$ metric as the extropic dual to the entropic directed distance. We describe a statistical application to the scoring of sequential forecast distributions which provoked the discovery.Comment: Published at http://dx.doi.org/10.1214/14-STS430 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Vitrification of day 7 hatching blastocyst using hemistraw resulting in a full term delivery: a case study

This is probably the first report of a successful delivery following transfer of a vitrified-warmed day 7 slow growing hatching blastocyst using hemistraw-vitriplug as an embryo carrier system. Case Report: A 26 years old Indian woman underwent controlled ovarian stimulation using short antagonist protocol and on day 11 after hCG administration, sixteen mature oocytes obtained were fertilized by ICSI procedure. On day 5, after transfer of two expanded blastocysts, three supernumerary embryos were still in the expanding stages, therefore, continued to culture in vitro. On day 7, one of them grew to be a hatching blastocyst which was cryopreserved with caution by ultra-rapid vitrification using hemistraw (HS) as carrier system. After 5 months, the vitrified slow growing day 7 hatching blastocyst was warmed and transferred in a natural cycle resulting in successful pregnancy. The women delivered a healthy male baby weighing 2820 grams at 36 weeks of gestation by caesarean section with no obvious anomalies detected. This report concludes that a day 7 hatching blastocyst can be successfully vitrified using HS and have pregnancy potential after warming

Field Guide to Nonindigenous Marine Fishes of Florida

The purpose of this field guide is to provide information on nonindigenous (i.e., non-native) fishes that have been observed in Florida’s marine waters. Introductions of non-native marine fishes into Florida’s waters could be intentional or unintentional, and are likely from a variety of sources, including aquarium releases, escape from aquaculture, loss due to extreme weather events (e.g., flooding from hurricanes), and possibly transfer with ballast water or hull-fouling. Presently the lionfishes (Pterois volitans and P. miles) are the only non-native marine fish species known to be established along the coast of Florida. All other marine fishes in this guide (except the euryhaline species, see below) have infrequent occurrences, occur singly or in small groups, and have not yet become self-sustaining populations. Aquarium releases are one of the major pathways whereby nonindigenous fishes gain access to new environments (Ruiz et al. 1997; Fuller et al. 1999). Most of the nonindigenous marine fishes found in Florida’s waters are thought to be aquarium fishes that either were illegally released into the ocean or escaped captivity (e.g., during severe storm/flooding events). Indeed, south Florida is a hotspot for nonindigenous marine aquarium fishes (Semmens et al. 2004). Increased public awareness of the problems caused by released or escaped aquarium fishes may aid in stemming the frequency of releases. For example, HabitattitudeTM (www.habitattitude.net) is a national public awareness and partnership campaign that encourages aquarists and water gardeners to prevent the release of unwanted aquarium plants, fish and other animals. It prompts hobbyists to adopt alternative actions when dealing with these aquatic plants and animals. (PDF file contains 133 pages.

Life Cycle Energy Assesment of Advanced Fiber Reinforced Composite Design and Manufacturing Methodologies

Automotive industry at large is focused on vehicle light-weighting since a 6%-8% increase in fuel efficiency can be achieved with a 10% reduction in vehicle weight [1]. With the growing demand for cost-effective and sustainable light weighting of automobile structures, interest has increased in the application of fiber reinforced plastic (FRP) composites for use in the Body-in-White (BiW), which can account for up to 40% of the total vehicle weight. Traditional FRP composite manufacturing processes like vacuum assisted resin transfer molding, autoclave consolidation or use of automated fiber placement have been successfully used for marine and aerospace applications. However, these processes are not suitable for the automotive industry due to the low production rate, need for highly skilled labor for manufacturing and quality control, and poor joining with traditional structural materials like steel. This necessitates the use of higher throughput outof-autoclave (OOA) processes like high pressure resin transfer molding (HP-RTM), wet compression molding (WCM) or even fiber reinforced thermoplastics (FR-TP) forming. The transition to these OOA processes face two major challenges: a) the time-consuming iterative design and thermal profiling process required for metal tools which increases cost; and b) the lack of a low-cost, scalable, and sustainable multi-material joining pathways that can enable integration of FRP composite parts with traditional metal structures. This is because existing composite joining methods necessitate significant redesign of existing OEM infrastructure, incur high capital costs, and produce weak joints between metal and composite components. iii To address the first challenge, a new paradigm where additive manufacturing of thermoplastic filament reinforced with continuous fiber is used to develop a low-cost and sustainable composite tool, is investigated. Furthermore, additive manufacturing can enable faster tool design turn-around times and allows for designing of complex tool geometries with embedded sensors and conformal cooling channels. This opens greater avenues for process and design optimization and will enable manufacturers to gain a better understanding of the process based on sensor data gathered in real time from the embedded sensors. To address the later challenge, a highly integrated multi-material, FRP-intensive BiW design was developed using unique multi-material transition joints which retain existing OEM joining infrastructure [2]. It incorporates multi-material transition joints where continuous dry fibers are laid through machined looped channels in a metal substrate and additional metal layers are additively manufactured on top of the looped fiber and metal substrate to embed the fibers within the metal and create a strong metal – fiber mechanical interlocking bond. The fibers are then infused with a thermoset matrix that fills out the loops as well, forming a string FRP-metal transition [3]. Thus, the resulting CFRP component with metal tabs can be spot welded to other metal components without piercing, drilling, or punching holes - significantly increasing the mechanical performance of the multi-material joints. To ascertain the advantages of these multi-material designs and the use of state-of-the-art additively manufactured smart tools, their life cycle impact must be investigated and compared with existing technology. The results from the LCA can provide vital understanding of the energy requirements of the new processes methodologies and can help iv quantify the benefits offered by transitioning to this new proposed paradigm of composite design and manufacturing from a sustainability and emission reduction standpoint. To best of the authors knowledge there have been no studies that address the LCA for each of the proposed solutions. Thus, this work, conducts two comparative life cycle analyses on the proposed additively manufactured smart composite tool for OOA processes and for the multi-material designs for automotive structural components. Different scenarios are studied for both the LCAs to consider the existing FRP production processes as well as the production process of traditional materials

Sarcasm Detection in English and Arabic Tweets Using Transformer Models

This thesis describes our approach toward the detection of sarcasm and its various types in English and Arabic Tweets through methods in deep learning. There are five problems we attempted: (1) detection of sarcasm in English Tweets, (2) detection of sarcasm in Arabic Tweets, (3) determining the type of sarcastic speech subcategory for English Tweets, (4) determining which of two semantically equivalent English Tweets is sarcastic, and (5) determining which of two semantically equivalent Arabic Tweets is sarcastic. All tasks were framed as classification problems, and our contributions are threefold: (a) we developed an English binary classifier system with RoBERTa, (b) an Arabic binary classifier with XLM-RoBERTa, and (c) an English multilabel classifier with BERT. Pre-processing steps are taken with labeled input data prior to tokenization, such as extracting and appending verbs/adjectives or representative/significant keywords to the end of an input tweet to help the models better understand and generalize sarcasm detection. We also discuss the results of simple data augmentation techniques to improve the quality of the given training dataset as well as an alternative approach to the question of multilabel sequence classification. Ultimately, our systems place us in the top 14 participants for each of the five tasks in a sarcasm detection competition