Experimental study on fluidization of micronic powders

The fluidization behavior of yttrium oxide (Y2O3) powders of high density and micronic diameter belonging to the group C of Geldart’s classification has been investigated. Large interparticle forces lead to bed cracking, slugging and channelling, and cause the powder not to fluidize consistently. Different fluidization technologies have been tested, such as mechanical agitated fluidization, vibrated fluidization and addition of easyto-fluidize large particles to fine particles. The quality of fluidization has been studied through pressure drop diagrams for decreasing gas velocities and for various fixed bed heights to column diameter ratios. In the case of stirred fluidization, several stirrer geometries have been tested (helix, turbine, etc.). However, the fluidization has not been satisfactory. By adding larger particles to fine powders, convenient fluidization conditions have been obtained. An inertia effect proportional to the initial bed weight seems to contribute to fluidization. Some evaluation of interparticle forces governing the tested mixture of fine/large particles has been performed by studying the influence of mass percentage of fine particles on the Hausner ratio and the angle of repose. Fluidization under vibration allows to partly overcome the adhesion forces between powders. The fluidization behavior has been improved for the highest vibration strengths

High temperature annealing of micrometric Zn2SiO4:Mn phosphor powders in fluidized bed

Micrometric Zn1.8Mn0.2SiO4 phosphor powders prepared by spray pyrolysis have been annealed between 900 and 1200°C under ambient air atmosphere to exalt their luminescence properties. Two original gas-solid fluidization processes have been tested in order to limit sintering phenomena, and the post-treated products have been compared with those annealed using a conventional process in crucible. The crystallinity, the size distribution, the outer morphology and the luminescence properties of powders before and after treatment have been analysed. Massive sintering phenomena occur in crucible from 1000°C, whereas the original granulometry and spherical morphology are preserved till 1100°C in fluidized bed. The luminescence efficiencies are comparable for the three processes and maximal after annealing at 1200°C. It has been established that residual ZnO and manganese ions at oxidation state higher than 2, still present after treatment at 1100°C, are detrimental to good luminescence efficiency. Both disappear from samples post-treated at 1200°C

The Social and Cultural Alienation of First and Second Generation Immigrant Youths: Interrogating Mainstream Bullying Discourse

Bullying is a multidirectional and a multileveled social problem, which affects every member of a community, thus it requires a diverse and multidisciplinary method to be addressed. Even though immigrant youths are as much prone to this phenomenon, if not more, as their native-born peers, the advertisements, media and news outlets have portrayed youth bullying as a white subject. The socio-cultural differences, past experiences of political, social and domestic violence, and the difficulties of integration and accommodation with the unfamiliar lifestyle of the new country heavily affect the vulnerability of the ignored young immigrant populations. If the bullying experts, bullying prevention activists and the justice system brackets their prejudices and look at every incident involving youths violent carefully and analytically, regardless of the victims socio-cultural backgrounds and the colour of their skin, it might uncover many other fatal bullying cases. In this thesis, I would like to have a closer look at three students fatal cases: Kiranjit Nijjar, Hamid Aminzada, and Zaid Youssef and Michael Menjivar, as examples of this faulty view on the characteristics of the bully and the bullied

Law Without Lawyers: Examining the Limitations of Consumer-Centric Legal Tech Services

The legal field is undergoing a disruptive change with the emergence of technology- based legal services aimed directly at serving the consumer, bypassing the need for a human lawyer. Specialized legal technologies powered by Artificial Intelligence (AI) or enabled by blockchain are leading to what is being referred to as new law, new ways of interpreting, implementing, and enforcing the law. Raymond Brescia has termed this transformative period in legal history as the third wave of lawyering. This wave is characterized by a new world of law without lawyers, comparable to the banking revolution, where mobile apps and online banking platforms replaced traditional tellers. There is an emergence of a legal ecosystem where conventional legal practices coexist alongside technology-driven legal services. These legal techs hold the promise of enhancing legal and justice inclusion by providing cheaper, more convenient, and more accessible legal services compared to traditional law firms and lawyers. This paper examines the emerging legal tech field, focusing on the business- to-consumer (B2C) category.B2C legal tech refers to tools designed to provide legal services and information directly to consumers without requiring the involvement of a human lawyer. This paper explores the factors driving these disruptive changes in legal services and evaluates some of the limitations of legal tech in meeting clients’ legal needs. The author concludes that B2C legal tech is gaining traction. However, the author avers that these technologies have limitations in fully meeting the needs of their users; therefore, lawyers still play an essential role in the legal ecosystem. As legal tech continues to gain traction, specific measures need to be implemented to address some of their limitations and ensure the seamless integration of these technologies into the legal field. This paper contributes to the ongoing discourse on the future of the legal profession in the era of technological advancement

A DoG based Approach for Fingerprint Image Enhancement

Fingerprints have been the most accepted tool for personal identification since many decades. It is also an invaluable tool for law enforcement and forensics for over a century, motivating the research in Automated fingerprint-based identification, an application of biometric system. The matching or identification accuracy using fingerprints has been shown to be very high. The theory on the uniqueness of fingerprint minutiae leads to the steps in studying the statistics of extracting the minutiae features reliably. Fingerprint images obtained through various sources are rarely of perfect quality. They may be degraded or noisy due to variations in skin or poor scanning technique or due to poor impression condition. Hence enhancement techniques are applied on fingerprint images prior to the minutiae point extraction to get sure of less spurious and more accurate minutiae points from the reliable minutiae location. This thesis focuses on fingerprint image enhancement techniques through histogram equalization applied locally on the degraded image. The proposed work is based on the Laplacian pyramid framework that decomposes the input image into a number of band-pass images to improve the local contrast, as well as the local edge information. The resultant image is passed through the regular methodologies of fingerprint, like ridge orientation, ridge frequency calculation, filtering, binarization and finally the morphological operation thinning. Experiments using different texture of images are conducted to enhance the images and to show a comparative result in terms of number of minutiae extracted from them along with the spurious and actual number existing in each enhanced image. Experimental results out performs well to overcome the counterpart of enhancement technique

Statistical approaches to harness high throughput sequencing data in diverse biological systems

The development of novel statistical approaches to questions specific to biological systems of interest is becoming more valuable as we tackle increasingly complex problems. This thesis explores three distinct biological systems in which high throughput sequencing data is utilised, varying in research area, organism, number of sequencing platforms and datasets integrated, and structure such as matched samples; showcasing the variety of study designs and thus the need for tailored statistical approaches. First, we characterise allelic imbalance from RNA-Seq data including stringent filtering criteria and a count based likelihood ratio test. This work identified genes of particular importance in livestock genomics such as those related to energy use. Second, we outline a novel methodology to identify highly expressed genes and cells for single cell RNA-Seq data. We derive a gamma-normal mixture model to identify lowly and highly expressed components, and use this to identify novel markers for olfactory sensory neuron (OSN) maturity across publicly available mouse neuron datasets. In addition we estimate single cell networks and find that mature OSN single cell networks are more centralised than immature OSN single cell networks. Third, we develop two novel frameworks for relating information from Whole Exome DNA-Seq and RNA-Seq data when i) samples are matched and when ii) samples are not necessary matched between platforms. In the latter case, we relate functional somatic mutation driver gene scores to transcriptional network correlation disturbance using a permutation testing framework, identifying potential candidate genes for targeted therapies. In the former case, we estimate directed mutation-expression networks for each cancer using linear models, providing a useful exploratory tool for identifying novel relationships among genes. This thesis demonstrates the importance of tailored statistical approaches to further understanding across many biological systems

Crystallization of microscopic Y2O3 powders by different techniques of fluidization at high temperature

Ahigh temperature fluidized bed reactor (HTFBR)working at 900 to 1200 ◦Chas been developed to crystallize microscopic yttria (Y2O3) powders synthesized by spray pyrolysis. Such crystallization is classically performed in crucible or in moving belt furnaces. In order to demonstrate the advantages of the fluidized bed process over the conventional static mode treatments, a comparative study of the main characteristics of particles after heat treatment in a crucible and in the HTFBR has been performed. The high interparticle forces existing in such Geldart group C powders made it necessary to activate their fluidization. Following previous results, two activated fluidization processes were studied: addition of coarse powders to fine particles and vibrated fluidization. The hydrodynamic behavior of these fluidized beds was analyzed through pressure drop measurements. Convenient fluidization conditions were obtained for the two activated fluidization processes, leading to isothermal beds. The size distribution, the crystallinity and the outer morphology of particles before and after thermal treatments were analyzed and compared for the three processes tested. Some pre-sintering phenomena occurred at 1200 ◦C, which were clearly more intense in crucible than in activated fluidization. The crystallinity of the samples treated was equivalent for the three methods of thermal treatment. The interest of fluidization processes to post-treat microscopic particles is thus fully demonstrated

The Experiences of Highly Educated Nigerian Immigrants in the United States

As the Child of Brain Drainers ( Highly educated immigrants that moved from a developing country to a developed country) and a soon to be highly educated African immigrant, I often ponder the effects of immigration on the families of those who immigrated as well as countries within the African continent. Oftentimes, African countries are perceived as stagnant places where progress may seem impossible because of corruption, poverty and their failing economies. Therefore, for an African to immigrate to a western country is not something unusual; this seems to be a common pattern. The narrative seems to be that if you have a chance to leave the continent, you should. It seems to be something so normal that we rarely question why people immigrate. The objective of this paper is to explore the push and pull factors of the emigration to the United States of highly educated Nigerian immigrants and their families, a subgroup of African immigrants. Push factors are the reasons why immigrants are leaving their countries of birth. Pull factors are the reasons why immigrants move to the receiving civilizations or the destination countries. This paper will also describe the experiences of highly educated (People with a bachelor\u27s degree or more) Nigerian born citizens living in the United States, speak of the effects of the increasing immigration of African immigrants or the brain drain (Void created in developing countries when many highly educated and skilled people immigrate out), highlight some of the expectations of highly educated immigrants, and speak of the effects of the increasing immigration of African immigrants on Nigeria\u27s brain drain

A Multi-Method Examination of Homicide Investigations on Case Outcomes

Approximately a third of homicide cases go unsolved each year. Research focused on understanding what affects homicide clearance rates is often methodologically underdeveloped and has produced mixed findings. These deficiencies compromise the ability of researchers to provide important guidance to police practitioners seeking to develop best practices. Under-specified modeling and limited access to accurate sources of homicide investigation data are two potential and interconnected reasons for the inconsistencies found in previous studies. The purpose of this study was to expand the literature on homicide case outcomes as follows: 1) to organize predictors into five substantive domains (involved subjects, event circumstances, case dynamics, ecological characteristics, and investigator factors) and operationalize multiple measures of each as viable predictors of clearance outcomes; 2) to explore the utility of using original and verified police data with a larger number of nuanced data points than previously documented in modeling efforts; and 3) to forward a unique multi-method account of the factors that predict homicide case outcomes that can be readily replicated in future studies. Data were collected from one Southern metropolitan police department\u27s 2009 to 2011 homicide investigations (N = 252). Access to official homicide case files allowed for key subject, incident, and evidentiary information to be obtained. Critical investigation details and context were added to the case file data via interviews and survey administration efforts involving the lead detectives that worked the cases. The dataset was further supplemented with Census data. Subsequent analyses included examination of the data quality and multivariate logistic regressions. A comparison of the dataset after the first stage of data collection to the final product was conducted to understand the extent to which the dataset were improved. The multi-method process resulted in more precision to the data recorded from case files, significant reductions in missing data, and heightened detail on key variables. Consequently those data allowed for specification of a multivariate model that included multiple measures from all of the homicide investigation domains. Those results suggest the expanded data more accurately captured the factors that predict clearance outcomes as measures within all five domains were significant predictors of investigation closure

Open Space Concepts for the Conversion of Former Railroad Land in the Spartan Keyes Neighborhood San José, CA

This project aims to analyze the feasibility of converting an abandoned brownfield in the Spartan- Keyes neighborhood, which happens to be a former railroad right-of-way, into an open space such as a linear park, plaza, or community garden. In order to create a vibrant development that provides safety and economic growth, the open space can include some local commercial uses such as coffee shops or can be open to food trucks or mobile vendors. A new linear park in the Spartan Keyes neighborhood can not only meet the community’s need for open space, but also can provide many social and ecological benefits for the neighborhood. There are different reasons preventing the former railroad site from being developed as a park or open space, such as cleanup and purchasing costs, shape of the parcel, safety constraints, and soil contamination. This study will attempt to provide a better knowledge of the reasons preventing this particular parcel from being redeveloped as well as recommendations to address those constraints. This document can be used to convince the City of San José and the County of Santa Clara to provide funding for the redevelopment of this abandoned railroad parcel. The end results of this study will provide the Spartan Keyes neighborhood leaders with evidence to support their desire of redeveloping the abandoned railroad parcel into a linear park