451 research outputs found
(POSTER) Design of an Extruder Cooling Line
Extruder Cooling Line
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Trine University’s School of Engineering and Technology offers a plastics minor with an assortment of machines and tools for the students to gain experience using in a lab environment. One machine is a plastic extruder that mixes polymer pellets and any filler the students wish to add and extrudes the hot material through a die forming a 2D profile part. The current setup has no cooling unit at the die end, so when the hot plastic is extruded it falls straight down into a five gallon plastic bucket where the material coils and sticks together while cooling. The time to cool fully is much longer than desired and makes achieving a standard sample difficult. The design team is tasked with designing a simple cooling system that catches the extruded plastic upon emerging from the die and cools it to a temperature which is safe to handle. A mechanism to pull and guide the plastic is also required and must match the speed of the extruder. With these requirements, the design team came up with the overall design of a liquid trough system supported by a frame with a mechanical puller device to guide the extruded polymer and provide sufficient cooling. The two main factors of the project were cost and overall size. Existing cooling lines are expensive and are designed more for manufacturing in a large scale industrial environment with constant use, while the department only uses the extruder a few times a year for laboratory activities. The device will allow students in the plastics minor to use the extruder and safely cool the plastic and achieve more uniform samples while saving the university money
Hand and wrist problems in general practice : diagnosis and prognosis
Horst, H.E. van der [Promotor]Windt, D.A.W.M. van der [Copromotor
Landbouwonderwijs in Drente : kwantitatieve en kwalitatieve analyse van de belangstelling van de boerenzoons voor het landbouwdagonderwijs
Dynamics of natural populations of the dertitivorous mudsnail Potamopyrgus antipodarum (Gray) (Hydrobiidae) in two interconnected Lakes differing in trophic state
Here we investigate the allocation of resources between growth and reproduction by surveying the dynamics of natural populations of the aquatic detritivorous mudsnail Potamopyrgus antipodarum from two interconnected lakes that differ in trophic state. The size distributions and reproductive output of the snail populations was analyzed monthly by field surveys spanning 3Â years, and in a controlled microcosm experiment to evaluate the reproductive potential under laboratory conditions. Snails in the meso-oligotrophic lake showed reduced growth and a smaller size compared to snails in the eutrophic lake. However, the numbers of eggs and nearly-neonates per adult snail did not differ significantly between the two populations. It is speculated that P. antipodarum populations living under meso-oligotrophic conditions may consistently invest more internal energy in reproduction at the expense of growth and that food quantity may be an important driver for macro-invertebrate resource allocation in detrital food webs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/2193-1801-3-736) contains supplementary material, which is available to authorized users
Structural similarity analysis of midfacial fractures:a feasibility study
The structural similarity index metric is used to measure the similarity between two images. The aim here was to study the feasibility of this metric to measure the structural similarity and fracture characteristics of midfacial fractures in computed tomography (CT) datasets following radiation dose reduction, iterative reconstruction (IR) and deep learning reconstruction. Zygomaticomaxillary fractures were inflicted on four human cadaver specimen and scanned with standard and low dose CT protocols. Datasets were reconstructed using varying strengths of IR and the subsequently applying the PixelShine™ deep learning algorithm as post processing. Individual small and non-dislocated fractures were selected for the data analysis. After attenuating the osseous anatomy of interest, registration was performed to superimpose the datasets and subsequently to measure by structural image quality. Changes to the fracture characteristics were measured by comparing each fracture to the mirrored contralateral anatomy. Twelve fracture locations were included in the data analysis. The most structural image quality changes occurred with radiation dose reduction (0.980036±0.011904), whilst the effects of IR strength (0.995399±0.001059) and the deep learning algorithm (0.999996±0.000002) were small. Radiation dose reduction and IR strength tended to affect the fracture characteristics. Both the structural image quality and fracture characteristics were not affected by the use of the deep learning algorithm. In conclusion, evidence is provided for the feasibility of using the structural similarity index metric for the analysis of structural image quality and fracture characteristics
Schatting van de toxiciteit van enkele polychloordibenzo-p-dioxinen, polychloordibenzofuranen en polychloorbifenylen in Nederlandse paling in relatie tot de overige componenten uit deze groepen verbindingen
Schatting van de toxiciteit van enkele polychloordibenzo-p-dioxinen, polychloordibenzofuranen en polychloorbifenylen in Nederlandse paling in relatie tot de overige componenten uit deze groepen verbindingen
Iterative reconstruction and deep learning algorithms for enabling low-dose computed tomography in midfacial trauma
OBJECTIVES: The objective of this study was to quantitatively assess the image quality of Advanced Modeled Iterative Reconstruction (ADMIRE) and the PixelShine (PS) deep learning algorithm for the optimization of low-dose computed tomography protocols in midfacial trauma. STUDY DESIGN: Six fresh frozen human cadaver head specimens were scanned by computed tomography using both standard and low-dose scan protocols. Three iterative reconstruction strengths were applied to reconstruct bone and soft tissue data sets and these were subsequently applied to the PS algorithm. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated for each data set by using the image noise measurements of 10 consecutive image slices from a standardized region of interest template. RESULTS: The low-dose scan protocol resulted in a 61.7% decrease in the radiation dose. Radiation dose reduction significantly reduced, and iterative reconstruction and the deep learning algorithm significantly improved, the CNR for bone and soft tissue data sets. The algorithms improved image quality after substantial dose reduction. The greatest improvement in SNRs and CNRs was found using the iterative reconstruction algorithm. CONCLUSION: Both the ADMIRE and PS algorithms significantly improved image quality after substantial radiation dose reduction
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