Initial Investigation of Analytic Hierarchy Process to Teach Creativity in Design and Engineering

This paper investigates the use of Analytic Hierarchy Process to teach design creativity and innovation in undergraduate engineering students. Examples are included to assess its effectiveness in the classroom. The purpose of this research is to investigate the suitability of the Analytic Hierarchy Process (AHP) to teach design innovation and creativity in undergraduate engineering classrooms. AHP is a very structured, multi-criteria, decision-making process and traditionally has been used to solve complex problem sets. This investigation takes a fresh look at how AHP provides the framework to engage and encourage students to think creatively and innovatively in design and engineering. This paper presents several separate case studies that incorporate the AHP technique in the classroom to teach design innovation and creativity to undergraduate engineering students, including introduction at the freshmen engineering level. These case studies include: the design of a robotic water vehicle; the design of a coffee maker; and the design of a website. These diverse case studies explore the suitability of this decision-making technique across abroad range of design problems to assess how AHP can be utilized to give students a better understanding of the design process, to foster a personal motivation towards creative and innovative thinking and to equip students with a strategy for creative problem solving theycan use through their engineering careers. Students who participated in the case studies completed questionnaires to assess the application of AHP and its effectiveness to understand the problem and to reach a creative and innovative solution. Based on the results of these student questionnaires, there is positive evidence that AHP can be utilized to remove barriers that inhibit creativity and to foster an environment for students to achieve more design creativity and innovation in engineering classrooms. This study has implications to change the pedagogical approach used to teach engineering design and provides a methodology for design creativity that students will carry with them throughout their career

Preparation of ZrB2-ZrC-SiC-ZrO2 nanopowders with in-situ grown homogeneously dispersed SiC nanowires

To explore the application of SiC nanowires (SiCnws) in ZrB2 based ceramic materials, a facile approach is reported to in situ synthesize homogeneously dispersed SiCnws in ZrB2-ZrC-SiC-ZrO2 nanopowders by pyrolyzing a B-Si-Zr containing sol precursor impregnated in polyurethane sponge. The sponge was used to provide porous skeletons for the growth of SiC nanowires and facilitate their uniform distribution in the powders. After heat-treatment of the precursor with a Si/Zr atomic ratio of 10 at 1500 °C for 2 h, ZrB2-ZrC-SiC-ZrO2 ceramic powders were obtained with an even and fine particle size of ~100 nm. The SiCnws were in a diameter of ~100 nm with a controllable length varying from tens to hundreds of microns by increasing the silicon content in the precursor. Moreover, the produced SiCnws were in high purity, and homogeneously dispersed in the hybrid nanopowders. The study can open up a feasible route to overcome the critical fabrication process in SiCnws reinforced ceramic matrix composites

Study on the Electrospun CNTs/Polyacrylonitrile-Based Nanofiber Composites

CNTs/PAN nanofibers were electrospun from PAN-based solution for the preparation of carbon nanofiber composites. The as-spun polyacrylonitrile-based nanofibers were hot-stretched by weighing metal in a temperature controlled oven. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the morphology of the nanofibers, which indicated that carbon nanotubes were dispersed well in the composites and were completely wrapped by PAN matrix. Because of the strong interfacial interaction between CNTs and PAN, the CNTs/PAN application performance will be enhanced correspondingly, such as the mechanical properties and the electrical conductivity. It was concluded that the hot-stretched CNTs/PAN nanofibers can be used as a potential precursor to produce high-performance carbon composites

Exceptional point-based ultrasensitive surface acoustic wave gas sensor

Exceptional points (EPs) refer to degeneracies in non-Hermitian systems where two or more eigenvalues and their corresponding eigenvectors coalesce. Recently, there has been growing interest in harnessing EPs to enhance the responsivity of sensors. Significant improvements in the sensitivity of sensors in optics and electronics have been developed. In this work, we present a novel ultrasensitive surface acoustic wave (SAW) gas sensor based on EP. We demonstrate its ability to significantly respond to trace amount of hydrogen sulfide (H2S) gas by tuning additional loss to approach the EP, thereby enhancing the responsivity compared to the conventional delay line gas sensors. In addition to high sensitivity, our sensor is robust to temperature variation and exclusive to H2S gas. We propose an innovative method for designing a new generation of ultrasensitive gas sensor

“She uses men to boost her career” : Chinese digital cultures and gender stereotypes of female academics in Zhihu discourses

Portrayed by the media as the story of “how a female PhD juggles intimate relationship with four male PhD academics”, the LM incident, named after the female main character of the story, was a high-profile case, which provoked public debates on Chinese social media in 2019. In this article, we explore how the stereotyping of female PhDs plays out in Chinese Internet users’ discussions about the LM incident. We collected a total of 632 relevant posts from the most popular Chinese community question-answering (CQA) site – Zhihu and analysed them by drawing on critical discourse analysis (CDA). The research findings reveal how a sexualised portrayal of female PhDs, which is dramatically “different” from the traditional, asexual stereotypes of well-educated women, is established in Zhihu users’ postings. Many Zhihu users, including both women and men, mobilise an overwhelmingly sexualised portrayal of female PhDs, which speaks to the normalisation of patriarchal discourses in the status quo of Chinese academia and beyond. The research findings shed light on post-socialist gender politics, which facilitates the perpetuation of gender essentialism in China in the post-reform era

Multiscale modeling for the heterogeneous strength of biodegradable polyesters

A heterogeneous method of coupled multiscale strength model is presented in this paper for calculating the strength of medical polyesters such as polylactide (PLA), polyglycolide (PGA) and their copolymers during degradation by bulk erosion. The macroscopic device is discretized into an array of mesoscopic cells. A polymer chain is assumed to stay in one cell. With the polymer chain scission, it is found that the molecular weight, chain recrystallization induced by polymer chain scissions, and the cavities formation due to polymer cell collapse play different roles in the composition of mechanical strength of the polymer. Therefore, three types of strength phases were proposed to display the heterogeneous strength structures and to represent different strength contribution to polymers, which are amorphous phase, crystallinity phase and strength vacancy phase, respectively. The strength of the amorphous phase is related to the molecular weight; strength of the crystallinity phase is related to molecular weight and degree of crystallization; and the strength vacancy phase has negligible strength. The vacancy strength phase includes not only the cells with cavity status but also those with an amorphous status, but a molecular weight value below a threshold molecular weight. This heterogeneous strength model is coupled with micro chain scission, chain recrystallization and a macro oligomer diffusion equation to form a multiscale strength model which can simulate the strength phase evolution, cells status evolution, molecular weight, degree of crystallinity, weight loss and device strength during degradation. Different example cases are used to verify this model. The results demonstrate a good fit to experimental data

High-performance potassium poly(heptazine imide) films for photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting is an appealing approach by which to convert solar energy into hydrogen fuel. Polymeric semiconductors have recently attracted intense interest of many scientists for PEC water splitting. The crystallinity of polymer films is regarded as the main factor that determines the conversion efficiency. Herein, potassium poly(heptazine) imide (K-PHI) films with improved crystallinity were in situ prepared on a conductive substrate as a photoanode for solar-driven water splitting. A remarkable photocurrent density of ca. 0.80 mA cm-2 was achieved under air mass 1.5 global illumination without the use of any sacrificial agent, a performance that is ca. 20 times higher than that of the photoanode in an amorphous state, and higher than those of other related polymeric photoanodes. The boosted performance can be attributed to improved charge transfer, which has been investigated using steady state and operando approaches. This work elucidates the pivotal importance of the crystallinity of conjugated polymer semiconductors for PEC water splitting and other advanced photocatalytic applications

An iterative approach of protein function prediction

Background: Current approaches of predicting protein functions from a protein-protein interaction (PPI) dataset are based on an assumption that the available functions of the proteins (a.k.a. annotated proteins) will determine the functions of the proteins whose functions are unknown yet at the moment (a.k.a. un-annotated proteins). Therefore, the protein function prediction is a mono-directed and one-off procedure, i.e. from annotated proteins to un-annotated proteins. However, the interactions between proteins are mutual rather than static and mono-directed, although functions of some proteins are unknown for some reasons at present. That means when we use the similarity-based approach to predict functions of un-annotated proteins, the un-annotated proteins, once their functions are predicted, will affect the similarities between proteins, which in turn will affect the prediction results. In other words, the function prediction is a dynamic and mutual procedure. This dynamic feature of protein interactions, however, was not considered in the existing prediction algorithms.Results: In this paper, we propose a new prediction approach that predicts protein functions iteratively. This iterative approach incorporates the dynamic and mutual features of PPI interactions, as well as the local and global semantic influence of protein functions, into the prediction. To guarantee predicting functions iteratively, we propose a new protein similarity from protein functions. We adapt new evaluation metrics to evaluate the prediction quality of our algorithm and other similar algorithms. Experiments on real PPI datasets were conducted to evaluate the effectiveness of the proposed approach in predicting unknown protein functions.Conclusions: The iterative approach is more likely to reflect the real biological nature between proteins when predicting functions. A proper definition of protein similarity from protein functions is the key to predicting functions iteratively. The evaluation results demonstrated that in most cases, the iterative approach outperformed non-iterative ones with higher prediction quality in terms of prediction precision, recall and F-value