102 research outputs found
Modelling of Melt Pressure Development in Polymer Extrusion: Effects of Process Settings and Screw Geometry
Monitoring and Modelling of the Effects of Process Settings and Screw Geometry on Melt Pressure Generation in Polymer Extrusion
Quantitative myocardial perfusion in mice based on the signal intensity of flow sensitized CMR
Remanufacturing using End-of-Life Vehicles and Electrical and Electronic Equipment Polymer Recyclates - A Paradigm for Assessing the Value Proposition
Over 400 million tonnes of plastics are produced on earth every year and are the most used materials on the globe. As a result, polymeric material-based waste has been accumulating, and now can be found not only in designated waste tips on land, but also as pollution all over the world. Therefore, it is timely to accelerate global recycling plans to minimize the use of natural resources. At present, end-of-life vehicles (EOLV) and electrical and electronic equipment (EEE) are two major sources of waste. Such waste includes a combination of polymers, which are hard to separate. Because the properties of blends of polymer are not well-understood, the recycling opportunities for such wastes are hindered. Hence, this paper aims to extend the knowledge concerning the re-processing of such recycled polymers, as a first step towards developing a more effective circular manufacturing economy. Three types of recycled polymers were tested under various processing conditions, and the effects of six different process parameters were investigated, including chip size and morphology. The results confirm that properties and processing behaviour of recycled materials can be highly variable, and hence difficult to predict. This highlights the importance of better selection and screening of scrap polymers, to remove undesirable content from the material batch. Knowing the exact constituents of each batch of material to be recycled means that appropriate process settings can be selected, to achieve better material properties in the recycled end product. In addition, energy and materials costs can be reduced by optimizing process parameters such as the set temperatures, pressures, and product dimensions. Tests carried out with different recycled polymer chip sizes indicate that size grading would be worthwhile, as would the reforming of chips to flattened discs or strings. Such additional processing could represent considerable value proposition to the recycled material preparation industry
The effect of melt viscosity on thermal efficiency for single screw extrusion of HDPE
YesIn this work, a highly instrumented single screw extruder has been used to study the effect of polymer rheology on the thermal efficiency of the extrusion process. Three different molecular weight grades of high density polyethylene (HDPE) were extruded at a range of conditions. Three geometries of extruder screws were used at several set temperatures and screw rotation speeds. The extruder was equipped with real-time quantification of energy consumption; thermal dynamics of the process were examined using thermocouple grid sensors at the entrance to the die. Results showed that polymer rheology had a significant effect on process energy consumption and thermal homogeneity of the melt. Highest specific energy consumption and poorest homogeneity was observed for the highest viscosity grade of HDPE. Extruder screw geometry, set extrusion temperature and screw rotation speed were also found to have a direct effect on energy consumption and melt consistency. In particular, specific energy consumption was lower using a barrier flighted screw compared to single flighted screws at the same set conditions. These results highlight the complex nature of extrusion thermal dynamics and provide evidence that rheological properties of the polymer can significantly influence the thermal efficiency of the process. (C) 2014 The Authors. Published by Elsevier B.V. All rights reserved
Design and Implementation of a Web Application for an E-Plant Store
With the advancement of technology in every industry, finding items with a few clicks is now simpler. Most people do not have enough knowledge about planting and its advantages of it. Therefore, this platform will be very helpful for those who sell and buy plants. Customers cannot compare prices or pay online when it comes to markets or plant nurseries. So, in this case, Plantae.lk offers various opportunities to customers. They can inspect, get details, compare plantsâ pricing, and make online payments easily. In this competitive business world, customer satisfaction is extremely important. We want each customer to have a pleasant shopping experience. With that intention, customer support service offers technical advice and guidance when it is needed. This web application also consists of detailed gardening advice. The major goal of this web application is to provide a better business experience for both seller and consumer.([1])([2]
Exophiala jeanselmei causing subcutaneous phaeohyphomycosis in a healthy adult in Sri Lanka: A case report
Phaeohyphomycosis is a chronic infection caused by filamentous dematiaceous fungi and it embraces a wide range of clinical presentations. Subcutaneous phaeohyphomycosis is caused by traumatic implantation of aetiological fungi in subcutaneous tissue and is usually reported in agricultural workers in the tropics. Subcutaneous phaeohyphomycosis presents with various skin manifestations and is often misdiagnosed by clinicians. Exophiala sp is a common aetiological agent of post traumatic subcutaneous phaeohyphomycosis. We present a middle aged farmer who presented with a subcutaneous nodule in his dominant hand. This swelling was initially diagnosed as a ganglion but turned out to be an abscess caused by Exophiala jeanselmei and the patient was cured by complete surgical excision without antifungal therapy. This case report aims to contribute to knowledge on this uncommon entity, in order to help practitioners to correctly diagnose and treat subcutaneous phaeohyphomycosis. </p
A prognostic index predicting survival in transformed Waldenström macroglobulinemia
Histological transformation into diffuse large B-cell lymphoma is a rare complication in patients with Waldenström macroglobulinemia (WM) usually associated with a poor prognosis. The objective of this study was to develop and validate a prognostic index for survival in transformed WM patients. Through this multicenter, international collaborative effort, we developed a scoring system based on data from 133 patients with transformed WM who were evaluated between 1995 and 2016 (training cohort). Univariate and multivariate analyses were used to propose a prognostic index with 2-year survival after transformation as an end-point. For external validation, a data set of 67 patients was used to evaluate the performance of the model (validation cohort). By multivariate analysis, three adverse covariates were identified as independent predictors of 2-year survival after transformation: elevated serum LDH (2 points), platelet count < 100 x 109/L (1 point) and any previous treatment for WM (1 point). Three risk groups were defined: low-risk (0-1 point, 24% of patients), intermediate-risk (2-3 points, 59%, hazard ratio (HR) = 3.4) and high-risk (4 points, 17%, HR = 7.5). Two-year survival rates were 81%, 47%, and 21%, respectively (P < 0.0001). This model appeared to be a better discriminant than the International Prognostic Index (IPI) and the revised IPI (R-IPI). We validated this model in an independent cohort. This easy-to-compute scoring index is a robust tool that may allow identification of groups of transformed WM patients with different outcomes and could be used for improving the development of risk-adapted treatment strategies
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