Comparative Study of DEM and Experimental Results of Flow Patterns in a Ploughshare Mixer

Author(s):  
B. F. C. Laurent ◽  
P. W. Cleary
2020 ◽  
Vol 75 (5) ◽  
pp. 507-511
Author(s):  
Y. El-Ouardi ◽  
A. Dadouch ◽  
A. Aknouch ◽  
M. Mouhib ◽  
A. Maghnouj ◽  
...  

Author(s):  
Kaushik Kumar ◽  
J. Paulo Davim

The usage of composite material has been increasing day by day over the years due to the excellent properties being offered by them such as lower volume-to-weight ratio, improved toughness, recyclable, environment friendly and also due to their short cycle productivity, easiness in fabrication, long lasting life span etc. This work presents study of mechanical and tribological behaviour of ABS polymer matrix filled with micron-sized inorganic and Natural / Green fillers. The main purpose behind this work is to compare the performance of composites with different class of fillers. The experimental results unveil that the composite with inorganic fillers perform better than with natural based fillers.


1999 ◽  
Vol 4 (1) ◽  
Author(s):  
SHEILA CANEVESE RAHAL ◽  
MANOEL ÁLVARO GUIMARÃES ◽  
JOSÉ VICENTE FORTES ◽  
HÉLIO LANGONI ◽  
PEDRO HELIO LUCCHIARI

"Linhas de pesca"* em diâmetros de 0,15mm; 0,20mm; 0,25mm; 0,30mm foram divididas em quatro grupos, contendo dez amostras de cada diâmetro: grupo I - controle; grupo II - linhas colocadas em frasco com pastilhas de formalina; grupo III - um ciclo de autoclavagem (30 minutos à 121 C, seguido por 10 minutos de secagem à 37 C em estufa); grupo IV - dois ciclos de autoclavagens. Foram avaliadas quanto: comprimento, calibre, resistência no nó e alongamento. Comparativamente foram examinados fios de náilon cirúrgico nas numerações 0, 1-0, 2-0, 3-0, 4-0 e 5-0 (10 amostras de cada um). Pelos resultados da análise estastística, verificou-se que a esterilização pelo calor úmido exerceu um efeito adverso na resistência da "linha de pesca". Por outro lado não houve diferenças na resistência, calibre e alongamento da "linha de pesca" entre o primeiro e segundo ciclo de autoclavagem. As “linhas” mantidas em pastilhas de formalina mantiveram na sua maioria suas características originais de resistência, comprimento, diâmetro e alongamento quando comparada ao grupo controle, entretanto, cabe lembrar que o formaldeído é considerado irritante para pele e membrana mucosa. Foi possível concluir que a "linha de pesca" apresenta características semelhantes ao fio cirúrgico, podendo ser mantida em pastilhas de formalina ou esterilizada em autoclave, lembrando que a autoclavagem altera algumas de suas propriedades físicas. Abstract A comparative study has been carried out between fishing lines and nylon thread in regard to their applicability as surgical thread. Four groups of 10 fishing lines in each of the following diameters = 0.15, 0.20, 0.25 and 0.30 mm = were subjected to the following treatments: group I, control; group II sterilized with formalin tablets; group III, autoclaved 30 minutes at 121oC; group IV, autoclaved twice 30 minutes at 121oC. The following parameters were then considered: length, caliber, resistance at the knot, and elongation. Ten samples of each surgical 0, 1.0, 2.0, 3.0, 4.0 and 5.0 nylon threads were used in comparatively similar experiments as the ones carried out with the fishing lines. According to the statistical analyses of the experimental results, it has been found that the sterilization by means of the humid heat exerts an adverse effect on the resistance of the fishing line. However, no differences were found between the effect displayed by two cycles sterilization compared with the fishing lines subjected to only one cycle. The threads maintained in formalin kept the majority of their original properties of resistance, length, diameter and elongation when compared with the control group. It is known, however that formaldehyde is an irritant chemical towards the skin and the mucous membranes. It was possible to conclude: a. fishing lines display characteristics similar to that ones of the nylon surgical thread; b. they can be maintained in formalin solution; c. autoclave sterilization alters some of their physical properties.


2018 ◽  
Vol 220 ◽  
pp. 05003 ◽  
Author(s):  
Constantin Daniel Comeaga ◽  
Dragos Ovezea ◽  
Cristinel Ilie

The article presents a comparative study regarding the design and experimental results for a miniature electromagnetic actuator with a modified design comparing with the classical type, including a mobile array of micro-magnets and a fixed coil in two configurations (planar spiral multi-layered and cylindrical). Previous work on design, modeling and simulation of this type of actuator indicated the optimum design and conducted to dimensions and material parameters. Different types of actuators were produced and experimentally tested, showing good results but also some drawbacks. Three of these design solutions are presented together with the static voltage-deflection and electrical impedances curves, experimentally derived. The results confirmed the feasibility of two actuating solution, showing good linearity and possibility to control the position at h accuracy and indicated improving directions.


2020 ◽  
Vol 68 (3) ◽  
pp. 223-230
Author(s):  
Mikolas Kesely

AbstractThe paper describes a mathematical and physical modelling of flow of complex slurries in pipelines, i.e. a flow of slurries composed of solids covering a very broad range of particle sizes that overlaps more than one flow patterns – non-Newtonian, pseudohomogeneous, heterogeneous and fully-stratified. A typical examples are residual products (“tailings”) from mining industry with normal average particle sizes of 20 to 100 μm or more. Experimental results of flows of complex slurries composing of non-Newtonian carrier fluid and three fractions of glass particles in 50 mm pipe are presented. Depending on the particle size, particles show different flow patterns and therefore considerable differences in pressure drops. Fine particles tend behave as a homogeneous matter, while coarser particles exhibit heterogeneous behaviour and even coarser particles form a sliding bed. A mathematical 3-component predictive model for turbulent flow of complex slurries is presented based on well-established semi-empirical formulae developed originally for flows with Newtonian carrier. The predicted values of pressure drops show very reasonable agreement with experimental results and indicate suitability of the model for engineering practice.


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