An overview of burst, buckling, durability and corrosion analysis of lightweight FRP composite pipes and their applicability

© 2019 Elsevier Ltd. All rights reserved.The main aim of this review article was to address the performance of filament wound fibre reinforced polymer (FRP) composite pipes and their critical properties, such as burst, buckling, durability and corrosion. The importance of process parameters concerning merits and demerits of the manufacturing methods was discussed for the better-quality performance. Burst analysis revealed that the winding angle of ±55° was observed to be optimum with minimum failure mechanisms, such as matrix cracking, whitening, leakage and fracture. The reduction of buckling effect was reported in case of lower hoop stress value in the hoop to axial stress ratio against axial, compression and torsion. A significant improvement in energy absorption was observed in the hybrid composite pipes with the effect of thermal treatment. However, the varying winding angle in FRP pipe fabrication was reported as an influencing factor affecting all the aforementioned properties. Almost 90% of the reviewed studies was done using E-glass/epoxy materials for the composite pipe production. By overcoming associated limitations, such as replacing synthetic materials, designing new material combinations and cost-benefit analysis, the production cost of the lightweight FRP composite pipes can be decreased for the real-time applications.Peer reviewe

Hållbara evenemang : med fokus på Göteborg och Co

 In this paper we will investigate sustainable events. The aim is to gain a deeper understanding of how thoughtful Goteborg & Co work socially and ecologically sustainable with their events. What will be investigated is what positive and negative effects that can occur with events based on the two sustainability aspects. Through in-depth interviews we have gained an idea of ​​the organizers' role in sustainability. The theories underlying the investigation have touched on sustainability concepts in events, ISO 20121, and strategies for achieving sustainable events. The empirical material is based on deep interviews with selected respondents from environmental management as well as Goteborg & Co. Further in the analysis and conclusion we have come to the conclusion that sustainability is extremely important. Organizers are working on sustainability in their events, partly because it promotes the marketing concept and partly to reduce environmental impact by raising awareness among visitors to think more sustainable. The authors conclude that the organizers are on track but that there is still sustainability work that the events need to improve. We have also noted that both small and large festivals should invest more in working sustainably to achieve sustainable long-term success.Studien undersöker hållbara evenemang. Syftet är att få en djupare förståelse kring hur genomtänkt Göteborg & Co arbetar socialt samt ekologiskt hållbart med sina evenemang. Det som kommer att undersökas är vilka positiva och negativa effekter som kan uppstå med evenemangen utifrån de två hållbarhetsaspekterna. Genom djupintervjuer har vi fått en uppfattning om arrangörernas roll inom hållbarhetsarbetet. Teorierna som ligger till grund för undersökningen har berört hållbarhetsbegrepp inom evenemang, ISO 20121 samt strategier för att uppnå hållbara evenemang. Det empiriska materialet är baserat på djupintervjuer med utvalda respondenter från Miljöförvaltningen samt Göteborg & Co.Vidare i analysen och slutsatsen har studien visat att hållbarhet är enormt viktigt. Arrangörerna arbetar med hållbarhet i deras evenemang, dels för att det främjar marknadsföringskonceptet och dels för att minska miljöpåverkan genom att öka medvetandet hos besökarna att tänka mer hållbart.Författarna drar slutsatsen att arrangörerna på god väg, men att det fortfarande finns hållbarhets arbeten som  evenemangen behöver förbättra sig inom. Vi har även noterat att både små och stora festivaler bör satsa mer på att arbeta hållbart för att uppnå hållbar framgång på lång sikt

RNN-GWR: A geographically weighted regression approach for frequently updated data

Geographically weighted regression (GWR) is a local spatial regression technique to model varying relationships in many application domains, such as ecology, environmental management, public health, meteorology, and tourism. In the literature, most of the studies dealing with GWR do not take into account if the dataset is frequently updated and so these techniques are not efficient to handle such datasets. In this study, to handle frequently updated data on given locations, a computationally efficient GWR approach, RNN-GWR, which utilizes reverse nearest neighbor (RNN) strategy, is proposed. The performance of the proposed RNN-GWR approach is compared with the performances of a Naive-GWR and FastGWR approaches. Experimental evaluations show that the proposed approach is computationally efficient than the other approaches on handling frequently updated data. (c) 2020 Elsevier B.V. All rights reserved

Hållbara evenemang : med fokus på Göteborg och Co

In this paper we will investigate sustainable events. The aim is to gain a deeper understanding of how thoughtful Goteborg & Co work socially and ecologically sustainable with their events. What will be investigated is what positive and negative effects that can occur with events based on the two sustainability aspects. Through in-depth interviews we have gained an idea of ​​the organizers' role in sustainability. The theories underlying the investigation have touched on sustainability concepts in events, ISO 20121, and strategies for achieving sustainable events. The empirical material is based on deep interviews with selected respondents from environmental management as well as Goteborg & Co. Further in the analysis and conclusion we have come to the conclusion that sustainability is extremely important. Organizers are working on sustainability in their events, partly because it promotes the marketing concept and partly to reduce environmental impact by raising awareness among visitors to think more sustainable. The authors conclude that the organizers are on track but that there is still sustainability work that the events need to improve. We have also noted that both small and large festivals should invest more in working sustainably to achieve sustainable long-term success

A Novel YOLOv5 Deep Learning Model for Handwriting Detection and Recognition

Computer Vision (CV) has become an essential field in Artificial Intelligence applications. Object detection and recognition (ODR) is one of the fundamental tasks of computer vision implementations. However, developing an efficient ODR model is still a significant problem. The model's execution time and speed are the most critical features during the inference or detection and recognition process, which need to be improved using the latest object detection architectures. In this paper, the handwritten detection and recognition (HDR) model is developed based on previously known algorithms with their efficiency, such as Faster R-CNN and YOLOv4 in the first hand. On the other hand, two new models capable of detecting and recognizing handwritten digits using the latest ODR algorithm are proposed, one based on the latest YOLO family architecture (YOLOv5-HDR) with high speed and accuracy and the other using the transformers architecture (DETR). To the best of our knowledge, this is the first study to achieve a details comparison between YOLOv5 and transformers-based models in handwritten digit detection. Finally, the detailed performance analysis achieved by the paper proves that the YOLOv4-based model achieved the testing inference 13% faster than Faster R-CNN. However, the proposed YOLOv5-based model outperformed the YOLOv4 and the transformers-based one as it increased the testing execution time 25% faster than the YOLOv4, three times faster than the DETR model. A further adversarial attack test has been conducted to ensure the robust performance of the proposed model. Furthermore, numerical experiment results and their analyses demonstrate the robustness and effectiveness of the proposed YOLOv5-based model being the most stable for handwritten digit detection and recognition tasks

Investigation of Mechanical Properties of Carbon Nanotubes / High Density Polyethylene Composites Produced by Extrusion Method "Investigation of Mechanical Properties of Carbon Nanotubes / High Density Polyethylene Composites Investigation of Mechanical P

Abstract In this study, mechanical properties of multiwalled carbon nanotubes / high density polyethylene (MWCNT/HDPE) nanocomposite materials produced by method of injection molding have been investigated experimentally. Multi-walled carbon nanotubes (MWCNTs) have been incorporated into a high-density polyethylene (HDPE) matrix using twin screw extrusion and injection technique. High density polyethylene, which was reinforced with different percentages (1%, 3% and 5%) of carbon nanotubes, was produced in the form of tensile test bars and then tested. The tensile tests were performed according to ASTM D 638 test standards. The increase in tensile strength as a result of the added carbon nanotube was studied. After the experiments, changes of mechanism at fracture surfaces were examined. Experiments were repeated three times. As a result, it could be inferred that minimum percentage of carbon nanotubes reinforcement should be between 1% -3%