The use of mathematical modelling in fire safety engineering

Fire is a form of uncontrolled combustion which generates heat, smoke, toxic and irritant gases. All of these products are harmful to man and account for the heavy annual cost of 800 lives and £1,000,000,000 worth of property damage in Britain alone. The new discipline of Fire Safety Engineering has developed as a means of reducing these unacceptable losses. One of the main tools of Fire Safety Engineering is the mathematical model and over the past 15 years a number of mathematical models have emerged to cater for the needs of this discipline. Part of the difficulty faced by the Fire Safety Engineer is the selection of the most appropriate modelling tool to use for the job. To make an informed choice it is essential to have a good understanding of the various modelling approaches, their capabilities and limitations. In this paper some of the fundamental modelling tools used to predict fire and evacuation are investigated as are the issues associated with their use and recent developments in modelling technology.

Multi-Disciplinary Applications of Oceanographic Geophysical Data Collection

Thesis (Ph.D.)--University of Washington, 2016-08

Development and characterization of Poly(L-lactic acid) (PLLA) platforms for bone tissue engineering

The development of scaffolds based on biomaterials is a promising strategy for Tissue Engineering and cellular regeneration. This work focuses on Bone Tissue Engineering, the aim is to develop electrically tailored biomaterials with different crystalline and electric features, and study their impacts onto cell biological behavior, so as to predict the materials output in the enhancement of bone tissue regeneration. It is accepted that bone exhibits piezoelectricity, a property that has been proved to be involved in bone growth/repair mechanism regulation. In addition electrical stimulations have been proved to influence bone growth and repair. Piezoelectric materials are therefore widely investigated for a potential use in bone tissue engineering. The main goal is the development of novel strategies to produce and employ piezoelectric biomaterials, with detailed knowledge of mechanisms involved in cell-material interaction. In the current work, poly (L-lactic) acid (PLLA), a synthetic semi-crystalline polymer, exhibiting biodegradibility, biocompatibility and piezoelectricity is studied and proposed as a promoter of enhanced tissue regeneration. PLLA has already been approved for implantation in human body by the Food and Drug Administration (FDA), and at the moment it is being used in several clinical strategies. The present study consists of first preparing films with different degrees of crystallinity and characterizing these PLLA films, in terms of surface and structural properties, and subsequently assessing the behavior of cells in terms of viability, proliferation, morphology and mineralization for each PLLA configuration. PLLA films were prepared using the solvent cast technique and submitted to different thermal treatments in order to obtain different degrees of crystallinity. Those platforms were then electrically poled, positively and negatively, by corona discharge in order to tailor their electrical properties. The cellular assays were conducted by using two different osteoblast cell lines grown directly onto the PLLA films:Human osteoblast Hob, a primary cell culture and Human osteosarcoma MG-63 cell line. This thesis gives also a comprehensive introduction to the area of Bone Tissue Engineering and provides a review of the work done in this field in the past until today, in that same field, including the one related with bone’s piezoelectricity. Then the experimental part deals with the effects of the crystallinity degrees and of the polarization in terms of surface properties and cellular bio assays. Three different degrees of crystallinity, and three different polarization conditions were prepared; which results in 9 different configurations under investigation.

New tools for cognitive and motor rehabilitation: development and clinical validation

Nervous system disorders are associated with cognitive and motor deficits, and are responsible for the highest disability rates and global burden of disease. Their recovery paths are vulnerable and dependent on the effective combination of plastic brain tissue properties, with complex, lengthy and expensive neurorehabilitation programs. This work explores two lines of research, envisioning sustainable solutions to improve treatment of cognitive and motor deficits. Both projects were developed in parallel and shared a new sensible approach, where low-cost technologies were integrated with common clinical operative procedures. The aim was to achieve more intensive treatments under specialized monitoring, improve clinical decision-making and increase access to healthcare. The first project (articles I – III) concerned the development and evaluation of a web-based cognitive training platform (COGWEB), suitable for intensive use, either at home or at institutions, and across a wide spectrum of ages and diseases that impair cognitive functioning. It was tested for usability in a memory clinic setting and implemented in a collaborative network, comprising 41 centers and 60 professionals. An adherence and intensity study revealed a compliance of 82.8% at six months and an average of six hours/week of continued online cognitive training activities. The second project (articles IV – VI) was designed to create and validate an intelligent rehabilitation device to administer proprioceptive stimuli on the hemiparetic side of stroke patients while performing ambulatory movement characterization (SWORD). Targeted vibratory stimulation was found to be well tolerated and an automatic motor characterization system retrieved results comparable to the first items of the Wolf Motor Function Test. The global system was tested in a randomized placebo controlled trial to assess its impact on a common motor rehabilitation task in a relevant clinical environment (early post-stroke). The number of correct movements on a hand-to-mouth task was increased by an average of 7.2/minute while the probability to perform an error decreased from 1:3 to 1:9. Neurorehabilitation and neuroplasticity are shifting to more neuroscience driven approaches. Simultaneously, their final utility for patients and society is largely dependent on the development of more effective technologies that facilitate the dissemination of knowledge produced during the process. The results attained through this work represent a step forward in that direction. Their impact on the quality of rehabilitation services and public health is discussed according to clinical, technological and organizational perspectives. Such a process of thinking and oriented speculation has led to the debate of subsequent hypotheses, already being explored in novel research paths.

Influence of the cutting edge micro-geometry of PCBN tools on the flank wear in orthogonal quenched and tempered turning M2 steel

Quenched and tempered high-speed steels obtained by powder metallurgy are commonly used in automotive components, such as valve seats of combustion engines. In order to machine these components, tools with high wear resistance and appropriate cutting edge geometry are required. This work aims to investigate the influence of the edge preparation of polycrystalline cubic boron nitride (PCBN) tools on the wear behavior in the orthogonal longitudinal turning of quenched and tempered M2 high-speed steels obtained by powder metallurgy. For this research, PCBN tools with high and low-CBN content have been used. Two different cutting edge geometries with a honed radius were tested: with a ground land (S shape) and without it (E shape). Also, the cutting speed was varied from 100 to 220 m/min. A rigid CNC lathe was used. The results showed that the high-CBN, E-shaped tool presented the longest life for a cutting speed of 100 m/min. High-CBN tools with a ground land and honed edge radius (S shaped) showed edge damage and lower values of the tool’s life. Low-CBN, S-shaped tools showed similar results, but with an inferior performance when compared with tools with high CBN content in both forms of edge preparation.

Tissue engineering: technological advances to improve its applications in reconstructive surgery

Background. Tremendous advances in biomaterials science and nanotechnologies, together with thorough research on stem cells, have recently promoted an intriguing development of regenerative medicine/tissue engineering. The nanotechnology represents a wide interdisciplinary field that implies the manipulation of different materials at nanometer level to achieve the creation of constructs that mimic the nanoscale-based architecture of native tissues. Aim. The purpose of this article is to highlight the significant new knowledges regarding this matter. Emerging acquisitions. To widen the range of scaffold materials resort has been carried out to either recombinant DNA technology-generated materials, such as a collagen-like protein, or the incorporation of bioactive molecules, such as RDG (arginine-glycine-aspartic acid), into synthetic products. Both the bottom-up and the top-down fabrication approaches may be properly used to respectively obtain sopramolecular architectures or, instead, micro-/nanostructures to incorporate them within a preexisting complex scaffold construct. Computer-aided design/manufacturing (CAD/CAM) scaffold technique allows to achieve patient-tailored organs. Stem cells, because of their peculiar properties - ability to proliferate, self-renew and specific cell-lineage differentiate under appropriate conditions - represent an attractive source for intriguing tissue engineering/regenerative medicine applications. Future research activities. New developments in the realization of different organs tissue engineering will depend on further progress of both the science of nanoscale-based materials and the knowledge of stem cell biology. Moreover the in vivo tissue engineering appears to be the logical step of the current research.

Degenerate mixtures of rubidium and ytterbium for engineering open quantum systems

In the last two decades, experimental progress in controlling cold atoms and ions now allows us to manipulate fragile quantum systems with an unprecedented degree of precision. This has been made possible by the ability to isolate small ensembles of atoms and ions from noisy environments, creating truly closed quantum systems which decouple from dissipative channels. However in recent years, several proposals have considered the possibility of harnessing dissipation in open systems, not only to cool degenerate gases to currently unattainable temperatures, but also to engineer a variety of interesting many-body states. This thesis will describe progress made towards building a degenerate gas apparatus that will soon be capable of realizing these proposals. An ultracold gas of ytterbium atoms, trapped by a species-selective lattice will be immersed into a Bose-Einstein condensate (BEC) of rubidium atoms which will act as a bath. Here we describe the challenges encountered in making a degenerate mixture of rubidium and ytterbium atoms and present two experiments performed on the path to creating a controllable open quantum system. The first experiment will describe the measurement of a tune-out wavelength where the light shift of $\Rb{87}$ vanishes. This wavelength was used to create a species-selective trap for ytterbium atoms. Furthermore, the measurement of this wavelength allowed us to extract the dipole matrix element of the $5s \rightarrow 6p$ transition in $\Rb{87}$ with an extraordinary degree of precision. Our method to extract matrix elements has found use in atomic clocks where precise knowledge of transition strengths is necessary to account for minute blackbody radiation shifts. The second experiment will present the first realization of a degenerate Bose-Fermi mixture of rubidium and ytterbium atoms. Using a three-color optical dipole trap (ODT), we were able to create a highly-tunable, species-selective potential for rubidium and ytterbium atoms which allowed us to use $\Rb{87}$ to sympathetically cool $\Yb{171}$ to degeneracy with minimal loss. This mixture is the first milestone creating the lattice-bath system and will soon be used to implement novel cooling schemes and explore the rich physics of dissipation.

The virtual class as a knowledge democratization model

This paper presents the conceptualization and use of a virtual classroom in the course EIF-200 Fundamentos de Informática, first course in the Information Systems Engineering career of the Universidad Nacional of Costa Rica. The virtual classroom is seen as a complement to the class and is conceived as a space that allows to centralize teaching resources, thereby promoting the  democratization of knowledge among students and teachers. Furthermore, this concept of virtual classroom helps to reduce the culture of individualism, present many times in university teaching practices, and contributes to create new opportunities to learn from other colleagues within a culture of reflection, analysis and respectful dialogue aimed to improve the teaching practices.

Vocational training and knowledge development: a deeper understanding

Construction management research literature has identified the importance of understanding the practical realities of skills and training provision and the role of reflective practice in the development of knowledge. This paper examines vocational training of experienced site staff in the development of their knowledge through SVQ training to investigate the primary factors for successful learning in site-based construction staff with a supervisory/management role. Using semi-structured interviews the impact of vocational training on individual candidates and other sitebased staff are investigated. The paper explores, through the reflections of 26 SVQ candidates (20 SVQ3 and 6 SVQ4), a deeper understanding of how site supervisors and site managers learn through the SVQ process and develop tacit knowledge through formal reflection. Reflective practice develops practical wisdom (Phronesis). The investigation explains aspects of practical wisdom and how knowledge, practice and skills are developed through vocational training. There is a clear perception by those completing the qualification that it has enabled them to perform their job better identifying numerous examples relating to problem solving, critical thinking, making decisions and leadership. It has been found that Phronesis is evident on a day-to-day basis on site activities developed through reflective practice in personal development. The reflective practice in developing knowledge also builds, within individuals, a better understanding of themselves and their capabilities through the learning achieved in the SVQ. Future work is identified around analysing the role of the assessor in facilitating Phronesis in the SVQ context.

Handling Heterogeneity in Collaborative Networked Surgical Simulators

Stand-alone and networked surgical virtual reality based simulators have been proposed as means to train surgical skills with or without a supervisor nearby the student or trainee -- However, surgical skills teaching in medicine schools and hospitals is changing, requiring the development of new tools to focus on: (i) importance of mentors role, (ii) teamwork skills and (iii) remote training support -- For these reasons, a surgical simulator should not only allow the training involving a student and an instructor that are located remotely, but also the collaborative training of users adopting different medical roles during the training sesión -- Collaborative Networked Virtual Surgical Simulators (CNVSS) allow collaborative training of surgical procedures where remotely located users with different surgical roles can take part in the training session -- To provide successful training involving good collaborative performance, CNVSS should handle heterogeneity factors such as users’ machine capabilities and network conditions, among others -- Several systems for collaborative training of surgical procedures have been developed as research projects -- To the best of our knowledge none has focused on handling heterogeneity in CNVSS -- Handling heterogeneity in this type of collaborative sessions is important because not all remotely located users have homogeneous internet connections, nor the same interaction devices and displays, nor the same computational resources, among other factors -- Additionally, if heterogeneity is not handled properly, it will have an adverse impact on the performance of each user during the collaborative sesión -- In this document, the development of a context-aware architecture for collaborative networked virtual surgical simulators, in order to handle the heterogeneity involved in the collaboration session, is proposed -- To achieve this, the following main contributions are accomplished in this thesis: (i) Which and how infrastructure heterogeneity factors affect the collaboration of two users performing a virtual surgical procedure were determined and analyzed through a set of experiments involving users collaborating, (ii) a context-aware software architecture for a CNVSS was proposed and implemented -- The architecture handles heterogeneity factors affecting collaboration, applying various adaptation mechanisms and finally, (iii) A mechanism for handling heterogeneity factors involved in a CNVSS is described, implemented and validated in a set of testing scenarios

Comunicação e dinâmicas de trabalho em equipa no desenvolvimento de projetos multimédia: estudo realizado no contexto de desenvolvimento de uma aplicação digital móvel interativa

Os projetos multimédia são uma forma única de desenvolver produtos e serviços inovadores, com recurso a um conjunto distintivo de membros de equipa, conhecimentos e metodologias. Grande parte dos estudos desenvolvidos em torno do conceito de desenvolvimento ágil são orientados para a área da engenharia de software, não sendo, muitas vezes, ajustados às particularidades dos projetos multimédia. Ainda que seja possível desenvolver e gerir projetos multimédia com recurso a métodos ágeis, é fundamental aprofundar o conhecimento nesta área apresentando estudos que comprovem a efetiva adequação das metodologias ágeis a esta tipologia projetual. O trabalho desenvolvido nesta dissertação pretendeu, não só analisar e compreender as metodologias, instrumentos e ferramentas de desenvolvimento ágil, considerando as particularidades da área da multimédia, como também analisar dados recolhidos num contexto real de desenvolvimento, observando práticas e eventos de um projeto específico; tais dados foram confrontados com metodologias existentes, de modo a permitir o desenho e a proposta de uma metodologia de suporte ao desenvolvimento ágil de um projeto multimédia. Os dados foram recolhidos em quatro fases e com objetivos distintos: conhecer o projeto e os elementos envolvidos; observar dinâmicas de trabalho em equipa; recolher informações sobre eventos de interação e partilha, organização hierárquica, controlo e monitorização e tomada de decisão e, por fim, recolher a opinião dos envolvidos sobre a proposta da metodologia de suporte. Esta proposta de metodologia constituiu, portanto, o principal resultado do estudo, apontando para a necessidade de (i) recorrer a uma ferramenta online de suporte à gestão de tempo e tarefas, (ii) utilizar uma ferramenta de partilha que permita um acesso constante por todos os elementos da equipa e (iii) promover reuniões periódicas, com ordem de trabalho definida.

Experiences of African American male engineering students: a qualitative analysis

Prior to the 1970s, African Americans were essentially invisible in the science and engineering academic and professional communities (Babco, 2001a). The few who did earn degrees in these fields, obtained them primarily from historically Black colleges and universities (HBCUs), and these institutions also served as the primary employer for these graduates in science and engineering (Hines, 1997; Babco, 2001a, 2001b). Since the 1970s, African Americans have made considerable progress, but still are not on a level playing field with White males in terms of opportunities for preparation of science and engineering careers or for employment and advancement in those careers. The purpose of this study was to explore second and third-year African American male engineering students’ perceptions and examine what experiences have contributed to their access to and persistence in engineering. A qualitative research design was employed to gather data necessary to answer the research questions. Eight second and third-year African American male engineering students from Research University (pseudonym) participated in interviews with the researcher. The data from the interviews was used to consider the themes that emerged from the participants. The findings from this study suggest that African American male engineering students at Research University have specific experiences that influence their persistence and academic achievement. Themes identified from the interview data include: (1) pre-college experiences; (2) participation in academic and social networks; (3) institutional programming and organizational support; (4) personal accountability and motivation; and (5) goals outside of engineering. As a result of this research, several future implications are highlighted. These include acknowledging the value of diversity, continued support through organizations, and increased knowledge of best practices.

The role of networking and social media tools during job search: an information behaviour perspective.

The paper presents a critical analysis of the extant literature pertaining to the networking behaviours of young jobseekers in both offline and online environments. A framework derived from information behaviour theory is proposed as a basis for conducting further research in this area. Method. Relevant material for the review was sourced from key research domains such as library and information science, job search research, and organisational research. Analysis. Three key research themes emerged from the analysis of the literature: (1) social networks, and the use of informal channels of information during job search, (2) the role of networking behaviours in job search, and (3) the adoption of social media tools. Tom Wilson’s general model of information behaviour was also identified as a suitable framework to conduct further research. Results. Social networks have a crucial informational utility during the job search process. However, the processes whereby young jobseekers engage in networking behaviours, both offline and online, remain largely unexplored. Conclusion. Identification and analysis of the key research themes reveal opportunities to acquire further knowledge regarding the networking behaviours of young jobseekers. Wilson’s model can be used as a framework to provide a holistic understanding of the networking process, from an information behaviour perspective.

Tacit knowledge sharing: the determination of a methodological approach to explore the intangible.

Introduction. Research design should take into account both (a) the specific nature of the object under scrutiny, and (b) approaches to its study in the past. This is to ensure that informed decisions are made regarding research design in future empirical studies. Here these factors are taken into account with reference to methodological choice for a doctoral study on tacit knowledge sharing, and the extent to tacit knowledge sharing may be facilitated by online tools. The larger study responds to calls for the two domains of knowledge management and human information behaviour to be considered together in terms of their research approaches and theory development. Method. Relevant literature – both domain-specific (knowledge management) and general (research methods in social science) - was identified and analysed to identify the most appropriate approaches for an empirical study of tacit knowledge sharing. Analysis. The analysis shows that there are a number of challenges associated with studying an intangible entity such as tacit knowledge. Quantitative, qualitative and mixed methods have been adopted in prior work on this theme, each with their own strengths and weaknesses. Results. The analysis has informed a decision to adopt a research approach that deploys mixed methods for an inductive case study to extend knowledge of the influence of online tools on tacit knowledge sharing. Conclusion. This work intends to open the debate on methodological choice and routes to implementation for studies that are subject to practical constraints imposed by the context in which they are situated.