158 research outputs found
Elastomeric microsystems fabricated using transfer printing
No full textTransfer printing, a method to transfer microscale objects using polymeric stamps, has been studied extensively over the past decade as an enabling technology for the micro and nanofabrication of novel flexible electronics. This dissertation focuses on the adoption of transfer printing towards the fabrication of unusual elastomeric microsystems for sensing, actuation, energy harvesting and robotic micromanipulation. Conventionally, microsystems are constructed by rigid materials such as semiconductors, metals, and dielectric materials with a set of well-established processing methods such as thin film deposition, lithography, etching, chemical-mechanical planarization. Soft materials such as elastomers are in general not compatible with these semiconductor processes which involve harsh environments (high temperature, corrosive chemicals, ion radiations, etc.). In this dissertation, transfer printing is utilized such that the rigid and soft materials are prepared under their optimal conditions and integrated mechanically by transfer printing. Functional devices such as responsive surfaces and vibration energy harvesters are constructed to demonstrate the benefits of the unconventional elastomeric microsystem. Such devices outperform rigid systems regarding large deformation capability and providing additional design and functionalities that are not possible with rigid components alone.
As the first example, responsive surfaces with hybrid elastomer-silicon microstructure is fabricated using transfer printing. The elastomer-silicon hybrid microstructure can be actuated using external mechanical, electrical, or magnetic stimuli to realize tunable functions including tunable topography, wettability, optical transmission, structural coloration, etc. As the second example, elastomeric microsystems with tunable and broadband resonators are constructed for broadband vibration energy harvesting and self-powered motion sensing. In addition to the demonstration of functional elastomeric microstructures and devices, this thesis also contributes to the fundamental study of transfer printing process including the positioning error during transfer printing, the joining strength of material pairs after thermal processing, and thermal stress and deformation due to thermal processing.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2020-08-01The student, Zining Yang, accepted the attached license on 2018-07-03 at 12:28.The student, Zining Yang, submitted this Dissertation for approval on 2018-07-03 at 12:46.This Dissertation was approved for publication on 2018-07-10 at 11:49.DSpace SAF Submission Ingestion Package generated from Vireo submission #12719 on 2018-09-27 at 11:35:43Made available in DSpace on 2018-09-27T16:47:21Z (GMT). No. of bitstreams: 3
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Previous issue date: 2018-07-10Embargo set by: Seth Robbins for item 107884
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Chemical and rheological properties of polymer modified bitumen incorporating bio-oil derived from waste cooking oil
No full textThe chemical and rheological properties of polymer modified bitumen incorporating bio-oil derived from waste cooking oil (WCO) were investigated in this paper. At first, the chemical composition and mixing mechanism of the experimental materials were analysed from the perspective of functional group, and the influence of bio-oil on the activation energy was also researched. Then, the effect of bio-oil on the rotational viscosities of polymer modified bitumen and construction temperatures of corresponding mixtures was studied. Finally, the shear and bending rheological properties of polymer modified bitumen containing bio-oil were investigated. The results show that the bio-oil and styrene–butadiene–styrene (SBS) modified bitumen is mainly physically mixed, the addition of bio-oil decreases the activation energy of SBS modified bitumen. Additionally, the SBS modified bitumen containing bio-oil has lower viscosity values, and corresponding mixtures also have lower construction temperatures. Furthermore, the addition of bio-oil in SBS modified bitumen reduces the shear modulus and increases the bending creep compliance, which means bio-oil has positive effect on the low-temperature thermal cracking resistance performance while sacrificing the high-temperature rutting resistance performance to some extent. Therefore, the incorporation of WCO-based bio-oil in polymer modified bitumen is a promising technique to be used in cold regions where the low-temperature problems are more crucial.Accepted Author ManuscriptPavement Engineerin
Environmental Impact Assessment Law in China's courts: A study of 107 judicial decisions
No full textThe article explores the practices of Environmental Impact Assessment (EIA) Law in China's courts by examining 107 judicial decisions. Each of the 107 judicial decisions has been analyzed to determine the time/location of the decision, what type of EIA document was referred to, what specific claim was made by the plaintiffs, and what the court's ruling was on the case. The results indicate that: unlike in Germany or Japan, all kinds of EIA decisions made by environment protect bureaus (EPBs) in China were widely taken as justiciable, and China's courts generally allowed local residents to have standing and thus challenge the EPBs' decisions made during the EIA process. On the other hand, the research also shows the EPBs overwhelmingly prevailed in those EIA lawsuits. It is also found that China's reviewing judges were highly self-restrained, giving obvious deference to the technocrat with the substantial contents of EIA documents. Also, the concept of "flaw" was created when it came to procedural issues. These two factors, among others, were both helping the EPBs' prevailing successes. (C) 2015 Elsevier Inc All rights [email protected]
A uniform reduction equivalence for process calculi
No full textWe present a new uniform definition of reduction-based semantics for different process calculi, called indexed reduction equivalence (or congruence). We prove that early bisimulation coincides with indexed reduction equivalence for pi-calculus, context bisimulation coincides with indexed reduction equivalence for higher order pi-calculus and indexed reduction congruence is strictly finer than contextual barbed congruence for Safe Mobile Ambients.Computer Science, Software EngineeringComputer Science, Theory & MethodsSCI(E)CPCI-S(ISTP)
Configuration Synthesis and Performance Analysis of Finger Soft Actuator
No full textCompared with the traditional rigid finger actuator, the soft actuator has the advantages of light weight and good compliance. This type of finger actuator can be used for data acquisition or finger rehabilitation training, and it has broad application prospects. The motion differences between the soft actuator and finger may cause extrusion deformation at the binding point, and the binding forces along nonfunctional direction may reduce drive efficiency. In order to reduce the negative deformation of soft structure and improve comfort, the configuration synthesis and performance analysis of the finger soft actuator were conducted for the present work. The configuration synthesis method for soft actuator was proposed based on the analysis of the physiological structure of the finger, and the soft actuator can make the human-machine closed-loop structure including n joints (n=1, 2, 3) meet the requirement of DOF (degrees of freedom). Then the typical feasible configurations were enumerated. The different typical configurations were analyzed and compared based on the establishment of mathematical models and simulation analysis. Results show that the configuration design method is feasible. This study offers a theoretical basis for designing the configuration of finger soft actuator
Multi-View Cosine Similarity Learning with Application to Face Verification
No full textAn instance can be easily depicted from different views in pattern recognition, and it is desirable to exploit the information of these views to complement each other. However, most of the metric learning or similarity learning methods are developed for single-view feature representation over the past two decades, which is not suitable for dealing with multi-view data directly. In this paper, we propose a multi-view cosine similarity learning (MVCSL) approach to efficiently utilize multi-view data and apply it for face verification. The proposed MVCSL method is able to leverage both the common information of multi-view data and the private information of each view, which jointly learns a cosine similarity for each view in the transformed subspace and integrates the cosine similarities of all the views in a unified framework. Specifically, MVCSL employs the constraints that the joint cosine similarity of positive pairs is greater than that of negative pairs. Experiments on fine-grained face verification and kinship verification tasks demonstrate the superiority of our MVCSL approach
Preparation Method of Corn Stalk Fiber Material and Its Performance Investigation in Asphalt Concrete
No full textIn this study, a bioresource material, corn stalks, were converted by a combination of physical and chemical methods into a corn stalk fiber material that can be utilized in an asphalt pavement. Firstly, corn stalk fiber was produced with different comminution times, mass fractions of sodium hydroxide solution, reaction times, and reaction temperatures. An orthogonal experimental method was employed to determine the optimal production process. The results show that the optimal comminution time was 3.5 min, and corn stalk should be reacted with a sodium hydroxide solution at 80 °C for 30 min to obtain the best corn stalk fiber product. The mass ratios of corn stalk fibers, sodium hydroxide, and water should be 8:1:200. After an evaluation of the physical and mechanical properties of the corn stalk fibers, asphalt binders, and mixtures, it was concluded that this kind of corn stalk fiber can be a good substitute of pavement fiber
Research on innovative preparation and performance of semi flexible pavement materials
No full textSemi-flexible concrete has been utilized in highway engineering due to its exceptional pavement performance. This study investigates the proportions of semi-flexible grout, the porosity of asphalt mixture, and the performance of semi-flexible concrete. Initially, 18 sets of semi-flexible grouting materials were proposed through an orthogonal test, resulting in the following material ratio: (cement: mineral powder): water cement ratio: sand cement ratio: Swelling agent: water reducer: flocculant = (0.85:0.15):0.45:0.2:0.04:0.001:0.005. Subsequently, the impact of the 2.36 mm sieve passing rate on the air void of SFAC-13 and SFAC-16 mixtures was analyzed, and a relationship between them was established. Observation of the semi-flexible concrete section and analysis of the grouting rate indicated that the developed grouting material effectively fills the gaps in the asphalt mixture. Lastly, the pavement performance of semi-flexible concrete was compared with SMA-13 asphalt mixture. The results demonstrate that semi-flexible composite concrete exhibits outstanding dynamic modulus, crack resistance, deformation resistance, water stability, and low-temperature performance. Moreover, the material properties of SFAC-13 are akin to those of SFAC-16
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