scholarly journals Thermoplastic Pultrusion: A Review

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 180
Author(s):  
Kirill Minchenkov ◽  
Alexander Vedernikov ◽  
Alexander Safonov ◽  
Iskander Akhatov

Pultrusion is one of the most efficient methods of producing polymer composite structures with a constant cross-section. Pultruded profiles are widely used in bridge construction, transportation industry, energy sector, and civil and architectural engineering. However, in spite of the many advantages thermoplastic composites have over the thermoset ones, the thermoplastic pultrusion market demonstrates significantly lower production volumes as compared to those of the thermoset one. Examining the thermoplastic pultrusion processes, raw materials, mechanical properties of thermoplastic composites, process simulation techniques, patents, and applications of thermoplastic pultrusion, this overview aims to analyze the existing gap between thermoset and thermoplastic pultrusions in order to promote the development of the latter one. Therefore, observing thermoplastic pultrusion from a new perspective, we intend to identify current shortcomings and issues, and to propose future research and application directions.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Youjing Li ◽  
Fen Li ◽  
Ying Yang ◽  
Baocai Ge ◽  
Fanzhu Meng

Abstract In view of the serious environmental pollution, which is the greatest problem the world is facing, and the continuous consumption of raw materials, it is imminent to search for green and sustainable resources. Lignin is an organic polymer that exists widely in nature, and if it can be transformed from traditional low-value waste product with low range of applications to functional materials with high application prospects, it can be of great significance to alleviate environmental pollution and shortage of fossil resources. One of the functional applications of lignin involves its use to fabricate composite with other polymeric materials, which can then be used to prepare membrane materials. This review summarizes the recent research and application progress of combining lignin with polypropylene, polyvinyl alcohol, starch, cellulose, chitosan, and other polymeric materials to prepare composite membranes; and summarizes the future development direction of lignin-based composite membranes. We hope this review may provide a new perspective to the understanding of lignin-based composite membranes and a useful reference for future research.


2021 ◽  
Vol 11 (15) ◽  
pp. 7016
Author(s):  
Pawel S. Dabrowski ◽  
Cezary Specht ◽  
Mariusz Specht ◽  
Artur Makar

The theory of cartographic projections is a tool which can present the convex surface of the Earth on the plane. Of the many types of maps, thematic maps perform an important function due to the wide possibilities of adapting their content to current needs. The limitation of classic maps is their two-dimensional nature. In the era of rapidly growing methods of mass acquisition of spatial data, the use of flat images is often not enough to reveal the level of complexity of certain objects. In this case, it is necessary to use visualization in three-dimensional space. The motivation to conduct the study was the use of cartographic projections methods, spatial transformations, and the possibilities offered by thematic maps to create thematic three-dimensional map imaging (T3DMI). The authors presented a practical verification of the adopted methodology to create a T3DMI visualization of the marina of the National Sailing Centre of the Gdańsk University of Physical Education and Sport (Poland). The profiled characteristics of the object were used to emphasize the key elements of its function. The results confirmed the increase in the interpretative capabilities of the T3DMI method, relative to classic two-dimensional maps. Additionally, the study suggested future research directions of the presented solution.


2021 ◽  
Vol 54 (4) ◽  
pp. 1-34
Author(s):  
Pengzhen Ren ◽  
Yun Xiao ◽  
Xiaojun Chang ◽  
Po-yao Huang ◽  
Zhihui Li ◽  
...  

Deep learning has made substantial breakthroughs in many fields due to its powerful automatic representation capabilities. It has been proven that neural architecture design is crucial to the feature representation of data and the final performance. However, the design of the neural architecture heavily relies on the researchers’ prior knowledge and experience. And due to the limitations of humans’ inherent knowledge, it is difficult for people to jump out of their original thinking paradigm and design an optimal model. Therefore, an intuitive idea would be to reduce human intervention as much as possible and let the algorithm automatically design the neural architecture. Neural Architecture Search ( NAS ) is just such a revolutionary algorithm, and the related research work is complicated and rich. Therefore, a comprehensive and systematic survey on the NAS is essential. Previously related surveys have begun to classify existing work mainly based on the key components of NAS: search space, search strategy, and evaluation strategy. While this classification method is more intuitive, it is difficult for readers to grasp the challenges and the landmark work involved. Therefore, in this survey, we provide a new perspective: beginning with an overview of the characteristics of the earliest NAS algorithms, summarizing the problems in these early NAS algorithms, and then providing solutions for subsequent related research work. In addition, we conduct a detailed and comprehensive analysis, comparison, and summary of these works. Finally, we provide some possible future research directions.


Electrochem ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 149-184
Author(s):  
Francisco T. T. Cavalcante ◽  
Italo R. R. de A. Falcão ◽  
José E. da S. Souza ◽  
Thales G. Rocha ◽  
Isamayra G. de Sousa ◽  
...  

Among the many biological entities employed in the development of biosensors, enzymes have attracted the most attention. Nanotechnology has been fostering excellent prospects in the development of enzymatic biosensors, since enzyme immobilization onto conductive nanostructures can improve characteristics that are crucial in biosensor transduction, such as surface-to-volume ratio, signal response, selectivity, sensitivity, conductivity, and biocatalytic activity, among others. These and other advantages of nanomaterial-based enzymatic biosensors are discussed in this work via the compilation of several reports on their applications in different industrial segments. To provide detailed insights into the state of the art of this technology, all the relevant concepts around the topic are discussed, including the properties of enzymes, the mechanisms involved in their immobilization, and the application of different enzyme-derived biosensors and nanomaterials. Finally, there is a discussion around the pressing challenges in this technology, which will be useful for guiding the development of future research in the area.


2014 ◽  
Vol 5 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Sean Upton-McLaughlin

Purpose – The purpose of this paper was to explore the Chinese concept of suzhi and how it relates to behavioral standards within mainland Chinese society and the workplace. The article provides a general discussion of suzhi and its inherent elements to act as a foundation for the education of expatriate managers and executives and for future research by Chinese human resource management (HRM) scholars. Design/methodology/approach – This paper draws on the author's first-hand experience and observations from five years of living and working abroad in mainland China with Chinese companies and executives. Findings – The concept of suzhi in China is a reflection of multiple behavioral standards throughout China. And while suzhi's roots are in ancient Chinese culture and Confucianism, it is also subject to influence and change. Practical implications – The paper may serve as a foundation both for expatriate managers seeking to improve HRM practices in foreign companies in China and future scholars who wish to conduct further research on suzhi and Chinese behavioral standards as they can be applied to the workplace. Originality/value – This is an attempt to enlighten expatriate managers and executives in China on the concept of suzhi and its implication for HRM in China.


2021 ◽  
pp. 152483802110131
Author(s):  
Ilana Seff

In light of the many robust quantitative data sets that include information on attitudes and behaviors related to intimate partner violence (IPV), and in an effort to expand the evidence base around social norms and IPV, many researchers construct proxy measures of norms within and across groups embedded in the data. While this strategy has become increasingly popular, there is no standardized approach for assessing and constructing these norm proxies, and no review of these approaches has been undertaken to date. This study presents the results of a systematic review of methods used to construct quantitative proxy measures for social norms related to IPV. PubMed, Embase, Popline, and Scopus, and PsycINFO were searched using Boolean search techniques. Inclusion criteria comprised studies published since 2000 in English that either (i) examined a norm proxy related to gender or IPV or (ii) analyzed the relationship between a norm proxy and perpetration of, experiences of, or attitudes toward IPV. Studies that employed qualitative methods or that elicited direct measures of descriptive or injunctive norms were not included. Twenty-six studies were eligible for review. Evidence from this review highlights inconsistencies in how proxies are constructed, how they are assessed to ensure valid representation of norms, and how researchers acknowledge their respective method’s limitations. Key processes and reflections employed by some of the studies are identified and recommended for future research inquiries.


2021 ◽  
Author(s):  
Oliver Barima ◽  

Digital computing and allied communication tools have been phenomenal, but they are fast reaching their technical limits and also their capacity to solve certain extant complex problems. Quantum computing has now emerged with a touted potential to deal with aspects of the latter complex problems and also significantly transform extant computing and communication methods. Yet, little studies exist in the Architectural, Engineering and Construction (AEC) industry related literature on quantum computing to boost awareness and also explore its prospective impact on the AEC industry. This study discusses the underpinning basic concepts, technologies and trends in the quantum computing domain to build awareness to boost Architecture, Engineering and Construction (AEC) industry capacity on the topic. The research dissects the challenges in this novel area. And also examines the near-term practical opportunities and potential impact of quantum computing on the AEC industry. The study concludes with suggestions for practice and future research.


2018 ◽  
Vol 31 (3) ◽  
pp. 34-53 ◽  
Author(s):  
Yu Jia ◽  
Nianxin Wang ◽  
Shilun Ge

The purpose of this article is to portray the knowledge evolution paths of business-IT alignment (BITA) research and identify a set of important papers in the development of BITA, and elucidate the intellectual structure of this field. This study collected 309 papers published during the period 1983-2015 from the Web of Science (WOS) database. Using a variety of bibliometric and visualization analytic techniques such as citation analysis, co-citation analysis and main path analysis, this article (1) delineates the significant knowledge flows of BITA research and identifies 15 important papers in this field; (2) graphically maps the influential countries, institutions, and journals of BITA research; (3) identifies four major research themes: BITA model, measurement, antecedents, and dynamics, and visualizing the relationships among them. Based on these findings, recommendations for the future research directions have suggested. This article provides IT practitioners, executives, and scholars with a new perspective to get a better understanding of BITA.


2019 ◽  
Vol 25 (6) ◽  
pp. 1228-1250 ◽  
Author(s):  
Lidia Sanchez-Ruiz ◽  
Beatriz Blanco ◽  
Emma Diaz

Purpose The purpose of this paper is to define a general and common construct in order to measure the level of difficulty companies experience when they implement continuous improvement (CI). Additionally, a rank of barriers is obtained together with a rank of companies. Design/methodology/approach In order to achieve the objective, first, a literature review is carried out to specify the domain of the construct; second, a sample of items is selected; third a survey is carried out in companies that have already implemented CI initiatives, the results being thus limited to this population; fourth, measures are purified by analysing the reliability and validity of the measurements, and finally results are obtained. The Rasch measurement theory will be used to provide a new perspective on a mature research topic. Findings It can be concluded that a new valid construct has been defined together with a rank of CI barriers, being lack of time the main barrier. A rank of companies is also obtained which is a first step in the development of future research studies. Practical implications Managers are provided with a better understanding of the barriers that can obstruct CI implementation. Thus, the rank of CI barriers guides managers through the most common and important obstacles so that they will be able to plan better CI strategies. In addition, the rank of companies allows each company to undertake a benchmarking exercise. Originality/value This work proposes a new way of analysing the difficulty in implementing CI as a continuum, rather than as independent barriers. From a theoretical point of view, it defines a new construct and offers a rank of CI barriers together with a rank of companies based on their level of difficulty when implementing CI initiatives. This is something new, as previous studies were mainly focussed on the items side. From a practical point of view, this study offers the surveyed companies the opportunity to see how they are positioned with respect to the other companies. Moreover, this rank of companies is the foundation on which to develop further studies with a practical orientation in the future.


Robotica ◽  
2004 ◽  
Vol 22 (5) ◽  
pp. 533-545 ◽  
Author(s):  
M. Benosman ◽  
G. Le Vey

A survey of the field of control for flexible multi-link robots is presented. This research area has drawn great attention during the last two decades, and seems to be somewhat less “attractive” now, due to the many satisfactory results already obtained, but also because of the complex nature of the remaining open problems. Thus it seems that the time has come to try to deliver a sort of “state of the art” on this subject, although an exhaustive one is out of scope here, because of the great amount of publications. Instead, we survey the most salient progresses – in our opinion – approximately during the last decade, that are representative of the essential different ideas in the field. We proceed along with the exposition of material coming from about 119 included references. We do not pretend to deeply present each of the methods quoted hereafter; however, our goal is to briefly introduce most of the existing methods and to refer the interested reader to more detailed presentations for each scheme. To begin with, a now well-established classification of the flexible arms control goals is given. It is followed by a presentation of different control strategies, indicating in each case whether the approach deals with the one-link case, which can be successfully treated via linear models, or with the multi-link case which necessitates nonlinear, more complex, models. Some possible issues for future research are given in conclusion.


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