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991.
Bryan Haslam Long-Fang Tsai Ryan R. Anderson Seunghyun Kim Weisheng Hu Gregory P. Nordin 《Biomicrofluidics》2015,9(4)
A new microfluidic pump, termed a reflow pump, is designed to operate with a sub-μl sample volume and transport it back and forth between two pneumatically actuated reservoirs through a flow channel typically containing one or more sensor surfaces. The ultimate motivation is to efficiently use the small sample volume in conjunction with convection to maximize analyte flux to the sensor surface(s) in order to minimize sensor response time. In this paper, we focus on the operational properties of the pumps themselves (rather than the sensor surfaces), and demonstrate both two-layer and three-layer polydimethylsiloxane reflow pumps. For the three-layer pump, we examine the effects of reservoir actuation pressure and actuation period, and demonstrate average volumetric flow rates as high as 500 μl/min. We also show that the two-layer design can pump up to 93% of the sample volume during each half period and demonstrate integration of a reflow pump with a single-chip microcantilever array to measure maximum flow rate. 相似文献
992.
Herein, we demonstrate a novel method for the generation of monodisperse cell-like structures containing a biocompatible hydrogel matrix surrounded by a membrane responsive to chemical cues. Specifically, we employ droplet-based microfluidics to generate PEG-PLA polymersomes encapsulating alginate in liquid form. We investigate alginate core gelation by creating an osmotic pressure gradient across the polymeric membrane that, through expansion, allows the passage of calcium ions. The effects of calcium concentration on the core gelation are explored. 相似文献
993.
Ewout Timmerman Joel De Water Kim Kachel Machar Reid Damian Farrow Geert Savelsbergh 《Journal of sports sciences》2015,33(10):1093-1100
The influence of scaling court-size and net height on children’s tennis performance was examined. Sixteen boys (9.7 ± 0.5 years) had to perform a 30-min match in four different conditions, where court-size and/or net height were scaled by using a scaling ratio based on the differences in temporal demands between the children and the adult game. These 30-min matches were analysed using Tennis Analyst (FairPlay Ltd., Jindalee, QLD, Australia) software to determine typical tennis match performance characteristics. Children hit more winners, more forced errors, played more volleys, struck more shots from a comfortable height and played in a more forward court position when the net was scaled. Scaling both the court and net lead to a faster children’s game, more closely approximating what is typical of the adult game. The differences between the typical tennis performance variables recorded suggested that scaling the net led to a more aggressive way of playing. Further, children enjoyed playing on the standard court–scaled net condition more than standard adult conditions. It is suggested that optimising the scaling of net height may be as critical as other task constraints, such as racquet length or court-size, as it leads to a more engaging learning environment for experienced children. 相似文献
994.
This paper develops a framework for analyzing the competitive implications of innovation. The framework is based on the concept of transilience — the capacity of an innovation to influence the established systems of production and marketing. Application of the concept results in a categorization of innovation into four types. Examples from the technical history of the US auto industry are used to illustrate the concepts and their applicability. The analysis shows that the categories of innovation are closely linked to different patterns of evolution and to different managerial environments. Special emphasis is placed on the role of incremental technical change in shaping competition and on the possibilities for a technology based reversal in the process of industrial maturity. 相似文献
995.
Using an Assistive Technology Toolkit to Promote Inclusion 总被引:1,自引:0,他引:1
Although the use of assistive technology for young children is increasing, the lack of awareness and the lack of training
continue to act as major barriers to providers using assistive technology. This article describes an assistive technology
toolkit designed for use with young children with disabilities that can be easily assembled and implemented by early childhood
professionals. Specifically, we will describe assistive technology tools that support young children’s participation in their
daily activities that involve movement and sensory needs, communication, and interaction with materials and offer strategies
on how to implement these devices. An assembled toolkit that allows young children with disabilities immediate access to experiences
that lead to acquisition of skills they need to learn and grow is discussed. 相似文献
996.
Rahman Tazizur Kim Yang Sok Noh Mijin Lee Choong Kwon 《Educational technology research and development : ETR & D》2021,69(2):1325-1351
Educational technology research and development - Social-Media-Based Learning (SMBL) is the use of social-media-based platforms, such as Twitter, Google Plus, Facebook, and YouTube, for learning... 相似文献
997.
Kim Yanghee Tscholl Michael 《Educational technology research and development : ETR & D》2021,69(4):2059-2081
Educational technology research and development - This study examined the affordances of an embodied humanoid robot to engage children in play and learning from the perspective of embodied... 相似文献
998.
In existing unsupervised methods, Latent Semantic Analysis (LSA) is used for sentence selection. However, the obtained results are less meaningful, because singular vectors are used as the bases for sentence selection from given documents, and singular vector components can have negative values. We propose a new unsupervised method using Non-negative Matrix Factorization (NMF) to select sentences for automatic generic document summarization. The proposed method uses non-negative constraints, which are more similar to the human cognition process. As a result, the method selects more meaningful sentences for generic document summarization than those selected using LSA. 相似文献
999.
Pilkee Kim Eng Hui Ong King Ho Holden Li Yong-Jin Yoon Sum Huan Gary Ng Khuntontong Puttachat 《Biomicrofluidics》2016,10(2)
Blood plasma contains biomarkers and substances that indicate the physiological state of an organism, and it can be used to diagnose various diseases or body condition. To improve the accuracy of diagnostic test, it is required to obtain the high purity of blood plasma. This paper presents a low-cost, disposable microfluidics device for blood plasma extraction using magnetophoretic behaviors of blood cells. This device uses alternating magnetophoretic capture modes to trap and separate paramagnetic and diamagnetic cells away from blood plasma. The device system is composed of two parts, a disposable microfluidics chip and a non-disposable (reusable) magnetic field source. Such modularized device helps the structure of the disposable part dramatically simplified, which is beneficial for low-cost mass production. A series of numerical simulation and parametric study have been performed to describe the mechanism of blood cell separation in the microchannel, and the results are discussed. Furthermore, experimental feasibility test has been carried out in order to demonstrate the blood plasma extraction process of the proposed device. In this experiment, pure blood plasma has been successfully extracted with yield of 21.933% from 75 μl 1:10 dilution of deoxygenated blood. 相似文献
1000.
Instagram and other photo-based social networking sites have emerged as a popular medium. Previous studies mainly focused on social media texts, but the current study deals with the relationships between the characteristics of Instagram users and the features of their photos. The Big Five personality traits and gender were employed as the variables for user characteristics. Content category, the number of faces, the emotions on the faces, and the pixel derived features were employed as the variables for photo characteristics. An online survey of 179 university students was conducted to measure user characteristics, and 25,394 photos in total were downloaded and analyzed from the respondents’ Instagram accounts. Results suggested that content category is associated with extraversion and gender of users. The number of faces is associated with extraversion, agreeableness, and openness of users. Extraversion, agreeableness, and openness of users were partly associated with emotions expressed on the faces in their photos. Correlations were observed among some pixel features and extraversion, agreeableness, conscientiousness, and gender of users. It was also observed that the Big Five personality traits, except for gender, can be predicted by above variables. Implications and limitations are discussed and suggestions for future research are suggested. 相似文献