Flowback of solids through distribution plates of gas fluidized beds and associated phenomena

This work is concerned with a study of certain phenomena related to the performance and design of distributors in gas fluidized beds with particular regard to flowback of solid particles. The work to be described is divided into two parts. I. In Part one, a review of published material pertaining to distribution plates, including details from the patent specifications, has been prepared. After a chapter on the determination of the incipient fluidizing velocity, the following aspects of multi-orifice distributor plates in gas fluidized beds have been studied: (i) The effect of the distributor on bubble formation related to the way in which even distribution of bubbles on the top surface of the fluidized bed is obtained, e.g. the desirable pressure drop ratio ?PD/?PB for the even distribution of gas across the bed. Ratios of distributor pressure drop ?PD to bed pressure drop at which stable fluidization occurs show reasonable agreement with industrial practice. There is evidence that larger diameter beds tend to be less stable than smaller diameter beds when these are operated with shallow beds. Experiments show that in the presence of the bed the distributor pressure drop is reduced relative to the pressure drop without the bed, and this pressure drop in the former condition is regarded as the appropriate parameter for the design of the distributor. (ii) Experimental measurements of bubble distribution at the surface has been used to indicate maldistribution within the bed. Maldistribution is more likely at low gas flow rates and with distributors having large fractional free area characteristics (i.e. with distributors having low pressure drops). Bubble sizes obtained from this study, as well as those of others, have been successfully correlated. The correlation produced implies the existence of a bubble at the surface of an orifice and its growth by the addition of excess gas from the fluidized bed. (iii) For a given solid system, the amount of defluidized particles stagnating on the distributor plate is influenced by the orifice spacing, bed diameter and gas flow rate, but independent of the initial bed height and the way the orifices are arranged on the distributor plate. II. In Part two, solids flowback through single and multi-orifice distributors in two-dimensional and cylindrical beds of solids fluidized with air has been investigated. Distributors equipped with long cylindrical nozzles have also been included in the study. An equation for the prediction of free flowback of solids through multi-orifice distributors has been derived. Under fluidized conditions two regimes of flowback have been differentiated, namely Jumping and weeping. Data in the weeping regime have been successfully correlated. The limiting gas velocity through the distributor orifices at which flowback is completely excluded is found to be indepnndent of bed height, but a function of distributor design and physical properties of gas and solid used. A criterion for the prediction of this velocity has been established. The decisive advantage of increasing the distributor thickness or using nozzles to minimize solids flowback in fluidized beds has been observed and the opportunity taken to explore this poorly studied subject area. It has been noted, probably for the first time, that with long nozzles, there exists a critical nozzle length above which uncontrollable downflow of solids occurs. A theoretical model for predicting the critical length of a bundle of nozzles in terms of gas velocity through the nozzles has been set up. Theoretical calculations compared favourably with experiments.

Vínculo empregatício: interpretação judicial do direito fundamental à relação de emprego protegida e seus efeitos

The Federal Constitution, in Article 1, sections III and IV, lifted the work as the foundation of the Federative Republic of Brazil, including work as a social guarantee in Article 6, listing in its Article 7 minimal guarantees role with respect to social rights of workers. Although elevated to constitutional rights, these social rights of workers have in the judicial interpretation of the characteristic elements of the employment relationship, sometimes a mismatch with the legal and constitutional order, when, in deciding not ponder such elements, causing damage economic and social benefits to all workers, thus affecting the very constitutional basis of worker protection, there is therefore situations in which there must be part of unavailability of rights by the employee. Therefore, identifying the characteristic elements of employment, means allow immediate legal finding about possible illegality perpetrated by the employer, precisely because the sentence recognizes be merely declaratory noting, therefore, the elements that make up the juridical system normative in order to establish the characterization of employment in step with the effective observance and guarantee of social rights and therefore the employer's performance limiter as pertains to hiring and employee dismissal. This point is it's main element of this work, which is fundamental for the exegesis of the theme to limit the autonomy of the will. There is no denying, therefore, the need to extend the effects of these guarantees in the employment contract. In this context, therefore, jumping the guarantees of employees, embodied in particular in the Consolidation of Labor Laws, and especially in the Federal Constitution and international protection instruments to ensure the fundamental right to secure employment relationship, where technological advancement, social and economic, reflect directly, such as the parassubordinação, and claiming more and more systematic resolutions, especially when evidence gaps' values, which elevate the debate about the need for increased use of precedents of order to support the judgments, often beset with aspects of unconstitutionality, all in compliance with the integration of standards, seeking legal enforcement of this bond and providing legal certainty, there emerged, so the essence of the theme: discuss to what extent the distortion of employment limits the effectiveness of social rights and what its legal effects, since the constitutional standard for social guarantees protects equally worker admission.

An investigation of lower limb joint powers as a predictive measure of countermovement vertical jump height.

Measuring and tracking athletic performance is crucial to an athlete’s development and the countermovement vertical jump is often used to measure athletic performance, particularly lower limb power. The linear power developed in the lower limb is estimated through jump height. However, the relationship between angular power, produced by the joints of the lower limb, and jump height is not well understood. This study examined the contributions of the kinetic value of angular power, and its kinematic component, angular velocity, of the lower limb joints to jump height in the countermovement vertical jump. Kinematic and kinetic data were gathered from twenty varsity-level basketball and volleyball athletes as they performed six maximal effort jumps in four arm swing conditions: no-arm involvement, single-non-dominant arm swing, single-dominant arm swing, and two-arm swing. The displacement of the whole body centre of mass, peak joint powers, peak angular velocity, and locations of the peaks as a percentage of the jump’s takeoff period, were computed. Linear regressions assessed the relationship of the variables to jump height. Results demonstrated that knee peak power (p = 0.001, ß = 0.363, r = 0.363), its location within takeoff period (p = 0.023, ß = -0.256, r = 0.256), and peak knee peak angular velocity (p = 0.005, ß = 0.310, r = 0.310) were moderately linked to increased jump height. Additionally, the location, within the takeoff period, of the peak angular velocities of the hip (p = 0.003, ß = -0.318, r = 0.419) and ankle (p = 0.011, ß = 0.270, r = 0.419) were positively linked to jump height. These results highlight the importance of training the velocity and timing of joint motion beyond traditional power training protocols as well as the importance of further investigation into appropriate testing protocol that is sensitive to the contributions by individual joints in maximal effort jumping.

Footbridge system identification using wireless inertial measurement units for force and response measurements

With the main focus on safety, design of structures for vibration serviceability is often overlooked or mismanaged, resulting in some high profile structures failing publicly to perform adequately under human dynamic loading due to walking, running or jumping. A standard tool to inform better design, prove fitness for purpose before entering service and design retrofits is modal testing, a procedure that typically involves acceleration measurements using an array of wired sensors and force generation using a mechanical shaker. A critical but often overlooked aspect is using input (force) to output (response) relationships to enable estimation of modal mass, which is a key parameter directly controlling vibration levels in service.

This paper describes the use of wireless inertial measurement units (IMUs), designed for biomechanics motion capture applications, for the modal testing of a 109 m footbridge. IMUs were first used for an output-only vibration survey to identify mode frequencies, shapes and damping ratios, then for simultaneous measurement of body accelerations of a human subject jumping to excite specific vibrations modes and build up bridge deck accelerations at the jumping location. Using the mode shapes and the vertical acceleration data from a suitable body landmark scaled by body mass, thus providing jumping force data, it was possible to create frequency response functions and estimate modal masses.

The modal mass estimates for this bridge were checked against estimates obtained using an instrumented hammer and known mass distributions, showing consistency among the experimental estimates. Finally, the method was used in an applied research application on a short span footbridge where the benefits of logistical and operational simplicity afforded by the highly portable and easy to use IMUs proved extremely useful for an efficient evaluation of vibration serviceability, including estimation of modal masses.

Barn utforskar sin förskolegård : Förskolebarns perspektiv på sin utemiljö

Vårt intresse för utemiljön uppstod då vi såg, genom erfarenheter av arbete på förskolor, att många förskolegårdar inte alltid tilltalade barnen. Några gårdar såg inte inspirerande ut och barnen visste inte vet vad de skulle göra. Syftet med studien är att skapa kunskap om hur barn utforskar sin förskolegård och vad som styr deras val av hur de placerar sig själva på gården när de leker. Utifrån en etnografisk, induktiv studie, vill vi lyfta fram vad barnen berättar om sin förskolegård. Vi har utgått från barndomsgeografi vilken ses inom forskningen som en del av barndomssociologin. Barndomen ses här som socialt konstruerad och frågor uppkommer om vilka platser som betraktas som bra för barn. Vi har sett utifrån våra samtalspromenader och observationer att barnen använder sig av olika rörelsestrategier såsom att klättra i träden, åka rutschkana och gunga samt att de använder sig av fysiska aktiviteter som till exempel att bygga kojor, samla naturmaterial och hoppar i lövhögar men att de även styrs av sin nyfikenhet och plötsligt kan stanna till för att titta på insekter etc. när de utforskar områden på gården. Resultaten av vår studie visar att rörelse är något som barnen ofta berättar om att de ägnar sig åt på sin förskolegård.

O treino pliométrico na melhoria da capacidade de salto no âmbito das aulas de técnica de dança moderna no 3º ciclo da Escola de Dança Ana Mangericão

Relatório Final de Estágio apresentado à Escola Superior de Dança, com vista à obtenção do grau de Mestre em Ensino de Dança.

Artificial Skin - Culturing of Different Skin Cell Lines for Generating an Artificial Skin Substitute on Cross-Weaved Spider Silk Fibres

Background: In the field of Plastic Reconstructive Surgery the development of new innovative matrices for skin repair is in urgent need. The ideal biomaterial should promote attachment, proliferation and growth of cells. Additionally, it should degrade in an appropriate time period without releasing harmful substances, but not exert a pathological immune response. Spider dragline silk from Nephila spp meets these demands to a large extent. Methodology/Principal Findings: Native spider dragline silk, harvested directly out of Nephila spp spiders, was woven on steel frames. Constructs were sterilized and seeded with fibroblasts. After two weeks of cultivating single fibroblasts, keratinocytes were added to generate a bilayered skin model, consisting of dermis and epidermis equivalents. For the next three weeks, constructs in co-culture were lifted on an originally designed setup for air/liquid interface cultivation. After the culturing period, constructs were embedded in paraffin with an especially developed program for spidersilk to avoid supercontraction. Paraffin cross-sections were stained in Haematoxylin & Eosin (H&E) for microscopic analyses. Conclusion/Significance: Native spider dragline silk woven on steel frames provides a suitable matrix for 3 dimensional skin cell culturing. Both fibroblasts and keratinocytes cell lines adhere to the spider silk fibres and proliferate. Guided by the spider silk fibres, they sprout into the meshes and reach confluence in at most one week. A well-balanced, bilayered cocultivation in two continuously separated strata can be achieved by serum reduction, changing the medium conditions and the cultivation period at the air/liquid interphase. Therefore spider silk appears to be a promising biomaterial for the enhancement of skin regeneration.

Swimming training repercussion on metabolic and structural bone development: benefits of the incorporation of whole body vibration or pilometric training; the RENACIMIENTO project

Introduction: Enviromental factors such as exercise participation and nutrition have often been linked to bone improvements. However, not all sports have the same effects, being non-osteogenic sports such as swimming defined as negative or neutral sports to practice regarding bone mass by some authors, similarly exercise-diet interaction in especific groups is still not clear. Objective: To present the methodology of the RENACIMENTO project that aims to evaluate body composition and more specifically bone mass by several techniques in adolescent swimmers and to observe the effects and perdurability of whole body vibration (WBV) and jumping intervention (JIN) on body composition and fitness on this population and explore posible diet interactions. Design: Randomized controlled trial. Methods: 78 swimmers (12-17 y) and 26 sex- and age-matched controls will participate in this study. Dual energy X-ray, peripheral Quantitative Computed Tomography, Quantitative Ultrasound, Bioelectrical Impedance Analysis, and anthropometry measurements will be performed in order to evaluate body composition. Physical activity, nutrition, pubertal development and socio-economical status may act as confounders of body composition and therefore will also be registered. Several fitness factors regarding strength, endurance, performance and others will also be registered to evaluate differences with controls and act as confounders. A 7-month WBV therapy will be performed by 26 swimmers consisting of a training of 15 minutes 3 times per week. An 8 month JIM will also be performed by 26 swimmers 3 times per week. The remaining 26 swimmers will continue their normal swimming training. Four evaluations will be performed, the first one in order to describe differences between swimmers and controls. The second one to describe the effects of the interventions and the third and fourth evaluations to describe the perdurability of the effects of the WBV and JIN. Conclusion: The RENACIMIENTO project will allow to answer several questions regarding body composition, fitness, bone mass and interaction with diet of adolescent swimmers, describe swimming as a positive, negative or neutral sport to practice regarding these parameters and elucidate the effects and perdurability of WBV and JIM on body composition.

A review of risk factors for hamstring injury in soccer: a biomechanical approach

The aim has been to review the literature about the risk factors of hamstring injury in soccer from a biomechanical point of view. METHODOLOGY. Data bases of bibliography references were Medline, Scopus and SportDiscuss. RESULTS AND DISCUSSION. Many prospective studies have shown that the previous injury is the greatest risk factor of sustaining the injury. However the primary causes of the injury are unclear in soccer. A lack of hamstring flexibility has been one of the main injury risk factors with controversies on the results. Imbalance of isokinetic force is a risk factor but electrical coactivation of all muscles participating during knee flexion and extension are unknown in football. While the importance of lumbopelvic-hamstrings muscles synchronization during running seems to be crucial for understanding the risk of injury, no research has been developed in this topic in football. CONCLUSIONS. More research using new data recording procedures as Dynamic Scanners, Surface EMG, Inverse Dynamic Analysis are needed. The analysis of more specific movements as running, kicking or jumping is clearly required. Managers, coaches, physical trainers, physiotherapists, sport physicians and researchers should work together in order to improve the injury prevention and rehabilitation programs of football players. Key Words: sports biomechanics, soccer, hamstring injury, risk factors

Regimes alimentares no cavalo de desporto : a utilização de alimentos compostos complementares na suplementação das dietas

Dissertação de Mestrado em Engenharia Zootécnica / Produção Animal

Investigating stratification, language diversity and mathematics classroom interaction

Research on the socio-political dimensions of language diversity in mathematics classrooms is under-theorised and largely focuses on language choice. These dimensions are, however, likely to influence mathematics classroom interaction in many other ways than participants’ choice of language. To investigate these influences, I propose that the notions ofheteroglossia, orders of indexicality and scale-jumping, can provide new theoretical tools with which to understand the links between classroom interaction and broader social patterns of marginalisation. To illustrate the utility of these ideas, I include some analysis of an episode observed in a sheltered elementary school second language mathematics classroom in Canada.

A influência de um protocolo de treino pliométrico na força explosiva em jovens atletas de voleibol feminino

Projeto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciado em Fisioterapia

Percentiles de salto con contramovimiento en escolares de Bogotá, Colombia: Estudio FUPRECOL

Objetivo: Determinar la distribución por percentiles de salto con contramovimiento (CMJ) en una población escolar de Bogotá, Colombia, perteneciente al estudio Fuprecol. Métodos: Estudio transversal realizado entre 2846 niños y 2754 adolescentes, entre 9 a 17 años de edad, pertenecientes a 18 instituciones educativas oficiales de Bogotá, Colombia. Se evaluó el CMJ, de acuerdo, con lo establecido por la batería de condición física, Fuprecol. Se calcularon, los percentiles (P3, P10, P25, P50, P75, P90 y P97), y curvas centiles por el método LMS, según su sexo y edad. Se realizó una comparación entre los valores de la CMJ observados con estándares internacionales. Resultados: La muestra estuvo constituida por 5.600 niños y adolescentes entre 9 y 17 años; el promedio de edad fue 12,6 ± 2,4 años. En el CMJ, los valores altos, los obtuvieron los niños, franja en la que la media osciló entre 25,1 cm a los 9 años, y 38,6 cm a los 17; para las niñas, la media fluctuó entre 23,2 cm a los 9 años, y 28,6 a los 17; en ambos sexos esos valores aumentan proporcional a la edad. Conclusiones: Se registran percentiles del CMJ de acuerdo con la edad y el sexo, que podrán ser usados como referencia en la evaluación del salto vertical desde edades tempranas.

Normative reference of standing long jump for Colombian schoolchildren aged 9-17.9 years: The FUPRECOL study

El propósito del presente estudio era generar los valores normativos de salto largo para niños de 9-17.9 años, e investigar las diferencias de sexo y grupo de edad

Clínica e cirurgia de equinos

O presente relatório de conclusão do curso de Mestrado Integrado em Medicina Veterinária da Universidade de Évora é baseado no estágio curricular realizado no hospital de equinos “Pferdeklinik in Kirchheim” na Alemanha e em clínica ambulatória com a Dra. Rita Rocha Pires na zona da Grande Lisboa e no concurso de saltos de obstáculos internacional de Vilamoura. O presente relatório é dividido em duas partes. A primeira parte apresenta a casuística nos dois locais do estágio e descreve alguns dos casos clínicos e cirúrgicos acompanhados nas diferentes áreas da clínica de equinos. A segunda parte aborda uma monografia sobre as vantagens e desvantagens de diferentes tipos de tratamento de fraturas completas do terceiro osso do metacarpo/tarso e apresenta um caso clinico de fratura cominutiva do terceiro osso do metatarso, o qual foi acompanhado durante o estágio na Alemanha; EQUINE CLINICS AND SURGERY ABSTRACT: The present report is based on the curricular internship, integrated on the Master´s degree in veterinary medicine at the University of Évora, which took place at the equine hospital “Pferdeklinik in Kirchheim” in Germany and at outpatient clinic with Dr. Rita Rocha Pires in the Greater Lisbon area and at the international show jumping competition in Vilamoura. This report is divided into two sections. The first section presents the casuistry at the two internship sites and describes some of the clinical and surgical cases followed in different areas of equine clinics. The second section develops a monograph on the advantages and disadvantages of different types of treatment for complete third metacarpal/tarsal bone fractures and presents a clinical case of a comminuted third metatarsal bone fracture, which was accompanied during the internship in Germany.