Granular materials are in abundance both in nature and in industry. They are of considerable interest to both the engineering and physics communities, due to their practical importance and many unsolved scientific challenges. This thesis is concerned with the “pressure dip” phenomenon underneath a granular pile (commonly known as the “sandpile problem”) which has attracted great attention in the past few decades. Underneath a sandpile that is formed by funnel feeding, a significant minimum (dip) in the vertical base pressure is often found below the apex where a maximum pressure is intuitively expected. Despite a large amount of work undertaken, a comprehensive understanding of this phenomenon remains elusive. This thesis presents an extensive study investigating the underlying mechanism of this phenomenon and also its implications on pressures in silos. The study started with a laboratory test programme of conical mini iron pellet piles. The results confirmed that the pressure dip is a robust phenomenon. It was shown that, under certain deposition radius with uniform deposition across the deposition area, a dip emerges firstly in a ring shape when the radius of the formed pile is small and comparable to the deposition radius. With the increase of the pile radius upon further deposition, the dip ring gradually evolves to a central dip as the pressure at outer radius eventually overtakes that in the centre. The magnitude of the dip was found to be significantly affected by the deposition rate but almost unaffected by the deposition height.

Background: Jump height, utilization of the stretch-shortening cycle (SSC) and knee stability is key qualifications and important factors for athletic performance. This is usually practiced with the help of plyometric training. However, plyometric training is considered as an exercise with high-impact that adds stress on the body. Trampoline training is an activity with a growing number of adolescent’s performers, and with the ability to train the same qualities that plyometric training. However, few studies have investigated trampoline trainings effect on jump height, utilization of the SSC and the knee stability in comparison to ordinary plyometric exercises. Aim: The aim of the study was to investigate whether the jump height in a countermovement jump (CMJ) and a squat jump (SJ), the use of SSC and knee stability at landing is different in adolescents who are training using a trampoline and adolescents training using plyometric exercises. Methods: Thirty (n=30) participants, 19 handball players and 11 trampoline practitioners, aged 14-18 years, completed this cross-sectional study. This study involved three tests, a CMJ and a SJ for measuring the jump height and SSCand a double leg drop jump test for measuring the knee stability. Results: The result showed a significant difference in relative jump value between the groups, were the handball group showed a higher value in the CMJ and the SJ compared to the trampoline group. In the utilization of the SSC there were no significant difference between the groups. The result showed that there was a significant difference between the groups knee stability, were the handball group showed a greater knee degrees of varus compared to the trampoline group. Conclusion: Findings from this study suggests that adolescents might benefit from performing plyometric training to achieve a greater jump height and trampoline training to achieve a greater knee stability. Both activities had the same effect on the utilization of theSSC. More studies are needed, including a more homogenous group with larger sample sizes, to support the present results and investigate whether the results are reliable.

Modelling of selected forest geometric parameters from airborne laser scanning data Abstract The main aim of this work is to approximate the shape of a tree crown with mathematically describable 3D shape based on airborne laser scanning (ALS) data. And consequently derive geometrical parameters describing the tree from this model. Included in the work is a custom designed algorithm based on angular segmentation. Measured results of this algorithm are then compared to an algorithm based on RANSAC and field measurement. The first part of this work describes airborne laser scanning, its use to derive characteristics of forest stands and individual trees and the theory of tree crown modelling. The next part contains a description of both algorithms and presentation of results and field measurements. The conclusion summarizes and evaluates the outputs of the custom angular segmentation algorithm and discusses its possible modifications. Keywords: airborne laser scanning, tree height, crown width, crown height, crown cover, crown volume, crown shape, RANSAC

The aim of this work is to design automatic detection of spot heights from airborne laser scanning data and its generalization. The first part is about the idea of spot height: the importance of spot heights for altimetry representation on maps and suggestions concerning the scatter of spot heights on maps. In the following part, different approaches for terrain critical points extraction (peaks, depressions, passes) from digital terrain models are described as suitable places for spot heights location. Further, we introduce a description of geomorphological characteristics of these points by which is possible to identify its significance and generalize them. In accordance to analysis of Základní mapa ČR and recommendation for spot heights location described in literature we designed own method of automatic generation and generalization spot heights from digital terrain models. This method were implemented and there is a description of the test data and results on the real data DMR 5G of the algorithm in the end of the work. Powered by TCPDF (www.tcpdf.org)

Title: Comparison of respiratory function in school age children Objectives: The main aims of this study were to estimate influence of age, anthropometric measures, and a type of physical activity on forced vital capacity (FVC), and additionally to create reference values of FVC for children aged 5 to 10 years. Methods: 281 girls and 345 boys were enrolled in this cross-sectional study. Data were obtained during the sport propagation event called Sportacek 2016. Descriptive statistics and regression models were carried out in data processing. Results: Statistically significant influence of body height as well as influence of physical activity in boys' gymnastics on FVC was found. Keywords: respiration, dependence, body height, forced vital capacity

Le but de ce travail est de réaliser une étude approfondie des caractéristiques morphologiques des footballeurs algériens de 15-16 ans en vue d’améliorer les processus de détection et de formation de l’élite nationale. Pour cela, cette thèse repose sur deux études qui permettent d’une part de tracer le profil type des jeunes footballeurs Algériens et d’autre part d’évaluer l’influence de la maturation précoce ou tardive sur la sélection en équipe nationale. L’objectif de la première étude est la détermination du profil morphologique des jeunes footballeurs algériens de 15-16 ans où nous avons pris un échantillon de 146 joueurs ayant une moyenne d’âge de (15,61 ans ± 0,49), dont 25 font partie de l’équipe nationale (U-17) et 121 évoluant dans les quatre régions du pays (Est, Ouest, Centre et Sud). Nous nous sommes basés sur la méthode anthropométrique afin de pouvoir déterminer les différences morphologiques existantes entre les joueurs suivant le niveau de pratique et les compartiments de jeu. La comparaison entre les sélections par régions et les données de l’équipe nationale, nous renseigne sur la différence du niveau du développement morphologique existant. Ce dernier est en faveur de la sélection nationale, exception faite pour la sélection Est qui s’en rapproche. Selon les postes de jeu, nous constatons que résultats des jeunes footballeurs algériens de moins de 17 ans, sont conforment aux exigences du football par poste de jeu, définis par plusieurs auteurs. Cette étude, par rapport aux données internationales exploitées, met en évidence des différences significatives pour les indices du développement physique, ce qui confirme la faiblesse de nos jeunes joueurs. L’analyse en composantes principales a permis de choisir 20 paramètres, estimés comme les plus représentatifs du développement morphologique de nos jeunes joueurs. Cette sélection de paramètres nous a permis de dégager un profil type du jeune footballeur algérien. Le deuxième volet de notre étude s’articule autour de l’influence de l'âge, des dimensions corporelles et des stades de maturation sur la sélection des jeunes footballeurs algériens âgés de moins de 17 ans en équipe nationale en comparant leurs résultats a ceux des équipes régionales du pays. Quatre-vingt onze jeunes footballeurs algériens (28 internationaux et 63 régionaux) ont été étudiés (âge moyen = 16,6 ans). L’âge du pic de croissance (PHV) a été déterminé selon l'équation de Mirwald et al. (2002). Les deux groupes sont d'âge chronologique similaire mais les joueurs appartenant à l'équipe nationale sont significativement plus matures que les joueurs de la sélection régionale (P <0,01). […] Les présents résultats démontrent que dans le football, le développement physique avancé est un avantage certain pour accéder aux meilleures équipes, […] que le développement morphologique précoce est une caractéristique importante que les entraîneurs détectent de façon plus ou moins consciente dans leur recherche des «jeunes talents». D’un point de vue général, ce travail souligne l’importance de l’élaboration du profil morphologique du jeune footballeur algérien de 15-16 ans pour servir de base de référence aux entraineurs et aux scientifiques. L’influence de la croissance et de la maturation sur la performance étant un fait avéré, une des principales conditions de l’efficacité du système de détection et de préparation de nos jeunes footballeurs consisterait en un contrôle rigoureux de l’âge biologique. Une classification rationnelle, prenant compte les stades de maturation et le développement harmonieux des qualités physiques, permettrait de résoudre correctement les questions posées par la sélection sportive et l’orientation des jeunes footballeurs à savoir, la déperdition des talents et les blessures. Une des perspectives de ce travail sera de rechercher les causes physiologiques des lacunes morphologiques du jeune footballeur algérien qui font obstacle au bon déroulement de son processus de formation. / The aim of this work is to perform a comprehensive study of morphological characteristics of Algerian soccer players’ aged 15-16 years to improve the detection process of the national elite. To do this, this thesis is based on two studies that allow one hand to trace the typical profile of young Algerians soccer players and secondly to assess the influence of early and late maturation on selection for of national team.The objective of the first study is to determine the morphological profile of young Algerian soccer players aged 15-16 years where we took a sample of 146 players with an average age (15.61 years ± 0.49), 25 of which are part of the national team (U-17) and 121 stocks in the four regions (Eastern, Western, Central and South). We relied on anthropometric method in order to determine the morphological differences existing between players depending on the level of practice and compartments. The comparison between selections by region and data from the national team, tells us about existing differences in level of morphological development, except for East regional selection. Depending on the position of play, we find that outcomes for young Algerian soccer players less than 17 years shall comply with the requirements of the post football game, set by several authors. This study, compared to international data used, highlights significant differences in the indices of physical development, which confirms the weakness of our young players. Principal component analysis allowed the selection of 20 parameters, estimated as the most representative of the morphological development of our young players. With this selection of parameters we have identified a typical profile of young Algerian soccer players.The second part of our study focuses on the influence of age, body dimensions and stage of maturation on the selection of young Algerian soccer players aged Under-17 national team, by comparing their results to those of regional teams. Ninety-one young Algerian soccer players (28 international and 63 regional) were studied (mean age = 16.6 years). The age of peak height velocity (PHV) was determined by the equation of Mirwald et al. (2002). The two groups are similar chronological age but the players belonging to the national team are significantly more mature than the regional one (P <0.01). [...] These results show that in football, developing advanced physics is an advantage to access the best teams, [...] that the early morphological development is an important feature that coaches detect more or less conscious in their search for "young talent".From a general point of view, this work highlights the importance of the assessment of the morphological profile of young Algerian soccer players aged 15-16 to serve as a baseline for coaches and scientists. The influence of growth and maturation performance is a fact, one of the main conditions for the effectiveness of the detection system and preparing our young players would be a strict monitoring of biological age. A rational classification, taking into account the stages of maturation and harmonious development of physical qualities, would properly resolve the loss of talent and injuries. A perspective of this work is to investigate the physiological causes of morphological gaps of the young Algerian soccer players who impede the smooth functioning of its training process.

During this thesis work a coupled thermo-mechanical finite element model (FEM) was builtto simulate hot rolling in the blooming mill at Sandvik Materials Technology (SMT) inSandviken. The blooming mill is the first in a long line of processes that continuously or ingotcast ingots are subjected to before becoming finished products. The aim of this thesis work was twofold. The first was to create a parameterized finiteelement (FE) model of the blooming mill. The commercial FE software package MSCMarc/Mentat was used to create this model and the programing language Python was used toparameterize it. Second, two different pass schedules (A and B) were studied and comparedusing the model. The two pass series were evaluated with focus on their ability to healcentreline porosity, i.e. to close voids in the centre of the ingot. This evaluation was made by studying the hydrostatic stress (σm), the von Mises stress (σeq)and the plastic strain (εp) in the centre of the ingot. From these parameters the stress triaxiality(Tx) and the hydrostatic integration parameter (Gm) were calculated for each pass in bothseries using two different transportation times (30 and 150 s) from the furnace. The relationbetween Gm and an analytical parameter (Δ) was also studied. This parameter is the ratiobetween the mean height of the ingot and the contact length between the rolls and the ingot,which is useful as a rule of thumb to determine the homogeneity or penetration of strain for aspecific pass. The pass series designed with fewer passes (B), many with greater reduction, was shown toachieve better void closure theoretically. It was also shown that a temperature gradient, whichis the result of a longer holding time between the furnace and the blooming mill leads toimproved void closure.

Resumo: O experimento foi conduzido na UNESP - Campus de Botucatu, Faculdade de Medicina Veterinária e Zootecnia. O delineamento experimental foi em blocos ao acaso num arranjo fatorial com três cultivares de Brachiaria brizantha (Marandu, Xaraés e BRS Piatã) e duas alturas de resíduo (15 e 25 cm), no total de seis tratamentos com quatro repetições (parcelas de 20 m2). O período de avaliação foi de um ano (01/12/2007 a 10/12/2008), com a realização de oito cortes, sendo três na primavera, três no verão, um no outono e um no inverno. A produção de massa seca (MS) da Xaraés foi maior no verão e na primavera em relação à Marandu. No somatório do ano a produtividade de MS da Xaraés foi 27,07% superior à Marandu, alcançando valor elevado (20.023 kg/ha), o que demonstra o potencial de utilização deste genótipo, principalmente em sistemas de produção de bovinos de corte mais intensivos. A produção de MS da Piatã nas estações do ano foi semelhante à Marandu, totalizando 17.572 e 15.757 kg/ha, respectivamente. Os dados de produção indicam que a Piatã apresentou a melhor distribuição da forragem produzida ao longo do ano. A produção de forragem das cultivares foi maior na altura do resíduo de 15 cm no verão e inverno, e não diferiu nas alturas de manejo no outono e primavera, demonstrando exigências diferentes de manejo do capim ao longo do ano. Os resultados obtidos confirmam a recomendação e a importância da cultivar Piatã como alternativa de utilização e diversificação das pastagens nos sistemas produtivos. / Abstract: The experiment was conducted in the School of Veterinary Medicine and Animal Science of UNESP - Botucatu Campus. The experimental design was a complete randomized blocks in a factorial arrangement with three cultivars of Brachiaria brizantha (Marandu, Xaraés and BRS Piatã) and two stubble heights (15 and 25 cm), in the total six treatments with four replications (20 m² plots). The evaluation period was of one year (12/01/2007 to 12/10/2008) with eight cuts: three in the spring, three in the summer, one in the fall and one in the winter. The production of dry matter (DM) of Xaraés in summer and spring were higher than Marandu with a total of 27.07% higher DM than Marandu. The total DM production was 20,023 kg/ha, demonstrating the potential of use of the Xaraés cultivar, especially in more intensive systems of beef cattle production. DM production of Piatã in the seasons was similar to Marandu, totalizing 17,572 and 15,757 kg/ha, respectively. The production data indicate that Piatã cultivar had the best distribution of forage produced during the year. The forage production of cultivars was higher in the stubble height of 15 cm in summer and winter, and did not differ for two heights of management in the fall and spring, showing different requirements of grass management during the year. The results confirm the recommendation and the importance of Piatã cultivar as an alternative of use and diversification of pastures in the production systems. / Orientador: Ciniro Costa / Coorientador: Paulo Roberto de Lima Meirelles / Banca: Heraldo César Gonçalves / Banca: Roberto Antonio Rodella / Banca: Cacilda Borges do Valle / Banca: Valdo Rodrigues Hering / Doutor

Teleskophandtaget på en resväska är troligen det användaren är i kontakt med mest och kanske även det som berörs först vid val av resväska. Det gör att det har en viktig roll i att förmedla en uppfattning om resväskans kvalitet. Detta projekt har initierats av företaget Thule Sweden AB som arbetar med transportlösningar för personliga föremål, däribland exempelvis resväskor som är det affärsområde projektet tillhörde. Projektet syftar till att utveckla deras befintliga teleskophandtag till att erbjuda större valfrihet i höjdjustering. Thule kännetecknas av, och strävar efter, att ta fram funktionella och genomtänkta lösningar med hög kvalitet och säkerhet. De tror att utveckling av teleskophandtaget kan höja kvalitetsuppfattning av resväskan i stort. Projektet har genomförts som ett examensarbete för maskiningenjörsutbildningen på Mittuniversitetet i Östersund. I rapporten redovisas de delar av produktutvecklingsprocessen projektet innefattat och alla resultat från de olika metoder som använts. Processen delades in i de tre faserna: produktspecificering, konceptgenerering samt konceptutvärdering. Resultatet av projektet blev två konceptuella lösningar till låsmekanismer för steglös höjdjustering. Dessa anpassades för integrering i Thules befintliga teleskophandtag. Den ena av mekanismerna bygger på mekanisk låsning och den andra på friktionslåsning. Med anledning av att koncepten skiljer sig åt i teknik samt att Thule ansåg att båda hade intressanta egenskaper valdes båda till slutkoncept. Lösningarna presenteras både i form av digitala solidmodeller och 3Dprintade prototyper. De båda konceptuella lösningarna behöver utvärderas vidare bland annat genom att undersöka om det är möjligt att skapa ett tillräckligt högt motstånd med friktionslösningen samt om det är möjligt att minska vikten hos den mekaniska lösningen. Den viktigaste slutsatsen av projektet är att det bör vara fullt möjligt att utveckla ett steglöst teleskophandtag som passar Thules varumärkesmässiga profil och som faktiskt höjer kvalitetskänslan. / The telescope handle on a suitcase is probably what the user is in contact with most and perhaps also what is touched first when choosing a suitcase. This means that it has an important role to play in conveying a conception of the suitcase quality. This project has been initiated by the company Thule Sweden AB, which works with transport solutions for personal items, including, among other things suitcases that are the business area the project belonged to. The project aims to develop their existing telescopic handles to offer greater freedom of choice in height adjustment. Thule is characterized by, and strives for, to develop functional and well-thought-out solutions with high quality and safety. They believe that the development of the telescopic handle can increase the quality perception of the suitcase in general. The project has been carried out as a degree project for the mechanical engineering program at the Mid Sweden University in Östersund. In the report, the parts of the product development process are included in the project and all results from the various methods used. The process was divided into the three phases: product specification, concept generation and concept evaluation. The result of the project was two conceptual solutions for locking mechanisms for continuous height adjustment. These were adapted for integration in Thule's existing telescopic handles. One of the mechanisms is based on mechanical locking and the other on friction locking. Due to the fact that the concepts differ in technology and that Thule considered that both had interesting properties, both were chosen as final concepts. The solutions are presented both in the form of digital solid models and 3D-printed prototypes. The two conceptual solutions need to be further evaluated, among other things by examining whether it is possible to create a sufficiently high locking resistance with the friction solution and whether it is possible to reduce the weight of the mechanical solution. The most important conclusion of the project is that it should be possible to develop a continuous height adjustable telescopic handle that fits Thule's brand profile and which actually increases the feeling of quality. / <p>Betyg: 2019-08-15</p>

Faculty of Engineering and Built Enviroment School of Mining Engineering 0315711f musakale@egoli.min.wits.ac.za / Rockfalls are a significant risk in open pit mines. Once movement of a rock perched on the top of a slope (bench) has been initiated, the most important factor controlling its fall trajectory is the geometry of the slope (bench). The best possible knowledge of rockfall trajectories and energies is important in order to determine accurate risk zoning and for the design and construction of adequate defence systems near the threatened areas. This study attempts to determine the influence of bench geometries, and the coefficient of restitution of rock, on rockfall behaviour. A study of literature was carried out to review previous studies and other relevant information on rockfalls and their analysis. The literature may be divided into two categories: experimental methods involving physical modelling, and computer models involving rockfall analyses using computers analysis methods. Rockfall computer simulation is considered to be applicable, quick to carry out and reproducible. The accuracy of the results depends on the knowledge of site conditions and slope geometry. The use of the Modified Ritchie criterion for the design of catch benches in open pit mines was also investigated. The assessment of bounce height, maximum run-out distance and kinetic energy achieved during the fall of rocks on the catch bench were the bases of the evaluation of the results obtained in this project. The computer program, Rocfall Version 4, was used for the purposes of the research. The following parameter variables were considered in the analyses: three types of rock; slopes with three stack configurations; four bench heights; and four bench face angles. The results show that, for all stack configurations and rock types, the maximum runout distance and maximum bounce height increase as functions of bench height at a specific bench face angle. A single bench configuration provides a maximum run-out distance of falling rocks larger than the value determined using the Modified Ritchie criterion for all rock types and bench face angles. Multiple bench stack configurations provide maximum run-out distances less than the value determined using the Modified Ritchie criterion only for the 90o bench face angle in all rock types; those with 60o, 70o and 80o bench face angle provide a larger maximum run-out distance. Therefore, the validity of the Modified Ritchie criterion for the design of catch bench widths in open pit mines with inclined benches must be questioned. According to Ritchie’s study (1963), rocks that fall in trajectory (free fall) seldom give high bounces after impact on a catch bench. This project shows that this finding is valid for rocks with low coefficients of normal restitution. Rocks with lower coefficients of normal restitution provide larger run-out distances with flatter bench face angles compared with rocks with higher coefficients. In contrast, rocks with higher coefficients provide larger run-out distances than those with lower coefficients for steeper angles. The consideration of the influence of geometry (shape) of falling rocks on rockfall behaviour showed that, for a flatter slope, as could logically be expected, the maximum run-out distance is greatest for rounder rocks and smallest for flatter slabby iv rocks. This is due to the fact that on a flatter slope, the mode of falling of rounder rocks is rolling down the slope. This mode provides essentially no resistance to motion, resulting in largest maximum run-out distance. In contrast, for long flat slabs, the mode of movement will be sliding, which results in a smaller maximum run-out distance. The maximum run-out distance as function of rock shape reduces as the normal coefficient of restitution increases. For all rock types, the maximum bounce height reduces as a function of the friction angle for flatter slopes. This is due to the fact that rocks are in contact with the slope during the rockfall. As the coefficient of normal restitution increases, an increase in the maximum bounce height results.