objective of this thesis is to contribute to the understanding of the behavior of the liquid metal eutectic gallium/indium (EGaIn) in composite systems and provide a platform for the development of functional hybrid nanocomposites. Contributions are regarding (i) the investigation of the electromechanical coupling performance of EGaIn as electrodes in a soft electrostatic transducer and (ii) the effectiveness of organic surfactants to stabilize EGaIn nanoparticles in organic solvents. For the first portion, a completely soft dielectric elastomer actuator (DEA) using EGaIn electrodes was fabricated and evaluated. Experimental actuation of the DEA showed high agreement with a generalized NeoHookean constitutive law, assuming uniaxial pre-stretch and considering the device saddle deformation. The expected conductive behavior of the liquid alloy was confirmed, and further efforts have focused on the development and stabilization of EGaIn nanodroplets, which do not exhibit the problems associated with larger pools of EGaIn (such as leakage) and can be applied to soft multifunctional materials. A computational procedure was developed for calculating suspended EGaIn nanoparticle mass in order to determine reaction yields using applied Mie theory and optical characterization techniques (dynamic light scattering and UV/Vis spectrophotometry). This method calculated total mass to within 20% when applied to a known system. A systematic study evaluating particle yield as a function of aliphatic surfactant composition and concentration (and solvent type) revealed a pronounced dependence of nanodroplet formation on the solvent type as well as surfactant structure. Ethanol (EtOH) was found to be the most effective solvent for the formation and stabilization of EGaIn nanodroplets, in which only thiol-based surfactants were found to improve nanodroplet yield. Results suggest a stabilization mechanism other than the expected self-assembled monolayer (SAM) formation. The research has been extended to alternative (e.g. plant based) surfactant systems.

Products from iron and copper mining are among Sweden’s top exports. However, as the metals are excavated, they often end up in the aquatic environment where they can cause toxicity. To implement the Water Framework Directive (WFD) within the European Union, all member states must classify their waters and set local environmental quality standards (EQS). These EQS are used to set the maximum concentration of a metal allowed in water and can be set both by the Swedish EPA and EU. The WFD EQS are to be based on the bioavailable metal fraction, as compared to the total metal concentration as have been used previously. As a tool in setting EQS, bioavailability models, like the biotic ligand model (BLM), have been proposed. BLMs can calculate toxicity endpoints based on water chemistry and organismal response and these predictions can be used for regional EQS values. However, BLMs are often calibrated toward hard waters with neutral or high pH, containing low concentrations of natural organic material (NOM), a water chemistry most commonly found in the central and southern parts of Europe. The overarching aim of this doctoral thesis was, therefore, to assess the regulatory applicability of Cu BLMs for Swedish conditions. Results from Paper I and II show that for at least 50% of Fennoscandinavian (Sweden, Finland and Norway) freshwater bodies, the models are not fully applicable. This due to crucial model input parameters being outside of the current calibration range of the Cu BLM. Papers II and III further showed that BLM calculated results differed from measured Cu toxicity to daphnids and algae, indicating that model-based EQS will not be protective for these organisms. Moreover, Paper III showed that Al had an impact on Cu speciation and, hence, toxicity. In conclusion, the present thesis shows that several available Cu BLMs are not yet fully applicable for Swedish or Scandinavian freshwater bodies due to incomplete parameterisation of the models.  To improve the applicability of the models, there is a need to calibrate the models for soft freshwater bodies and include Al and NOM properties as input parameters. / Produkter från metallindustrin är bland Sveriges viktigaste exportprodukter. Metallutvinning leder dock till utsläpp som kan hamna i den akvatiska miljön och där orsaka toxicitet. Europeiska Unionens Vattendirektiv syftar till att alla medlemsstater ska klassificera sina vatten och ta fram miljökvalitetsnormer. Dessa normer ska baseras på den biotillgängliga fasen av metaller istället för den totala som tidigare. Biotiska ligand modeller (BLM) har förts fram som verktyg i denna process. BLM kan beräkna utsläppsnivåer för sötvatten baserat på rådande vattenkemi samt vattenorganismers känslighet och ger användaren en specifikt anpassad rekommendation (LC/EC50, NOEC, PNEC o.s.v.). Dock är dessa modeller ofta kalibrerade för en vattenkemi gällande i de centrala och södra delarna av Europa. I Sverige är det vanligt med sura mjuka vatten, vilka har en högre koncentration av biotillgängliga metaller vilka kan orsaka toxicitet. Det övergripande syftet med denna doktorsavhandling var att undersöka hur dagens BLM för koppar (Cu) fungerar för svenska sötvatten. Resultaten från Artikel I och II visar att en stor del av de Fennoskandinaviska vatten som testats faller utanför kalibreringsintervallet för BLM. Vidare visar Artikel III och IV att de testade modellerna inte på ett korrekt sätt kunde uppskatta toxicitet för alger och vattenloppor, vilket innebär att de inte räknar ut skyddande rekommendationer för dessa arter. Det var även tydligt i Artikel IV att aluminium (Al) påverkar kopparspecieringen och genom detta även koppars toxicitet. Sammanfattningsvis visar denna avhandling att flera tillgängliga BLM inte är helt applicerbara i mjuka vatten, ofta p.g.a. opassande intervall för de kemiska parametrarna. För att förbättra tillämpbarheten av BLMs i Sverige krävs det att modellerna dels kalibreras för den rådande vattenkemin och dels att Al och NOMs egenskaper inkluderas.

Disaster support and recovery generally involve highly irregular and dangerous environments. Modular robots are a salient solution to support search and rescue efforts but are still limited to do their reliance on a rigid structure design. To enhance flexibility and resilience to damage, a soft-body interconnection mechanism for self-reconfigurable modular robotic systems has been developed. The soft-body interconnection mechanism utilizes elastomeric polymers instead of a rigid body. Hence, it is capable of deforming under extreme loads without damage. This thesis presents the work completed towards the realization of a soft-body interconnection mechanism. The functional requirements of the soft-body mechanism were broken down into two separate modules for extension and capture. An initial simulation demonstrated the inability of using a simulated model made of hypo-elastic materials as a basis for design. Hence, an iterative design process was used to develop an initial extension and capture soft-body mechanisms that conformed to the desired performance parameters. An empirical study which varied multiple structural parameters was then completed with the initial extension and capture soft-body mechanisms as a basis for the modified designs. The data from the study was correlated with measured performance data with resulted in diagrams useful for the optimal design of soft-body extension and capture mechanisms. The use of the diagrams for design was demonstrated in the design and development of a soft-body interconnection mechanism for an in-house designed small hard shell modular robot system.

A thesis submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Medicine in Therapeutic Radiology. / Soft tissue sarcomas of the extremities were previously treated either with wide excision alone, leading to a 30 to 50% local recurrence rate, or amputation, which although lead to a recurrence rate of less than 5%, caused significant physical and psychological morbidity. In addition to the :risk of local recurrence, distant metaatases occur in 30 to 50% of high grade lesions.(Abbreviation abstract) / Andrew Chakane 2018

acase@tulane.edu / Soft tissue mechanics attempts to describe biological tissues such as skin, tendon, and the reproductive organs using concepts found in mechanical engineering. By approaching soft tissues using this framework, the complex biomechanical response of such tissues, which have been implicated in the development of disease and injury, can be ascertained and quantified. Robust mechanical tests, in which tissue stress-strain behavior is characterized, are needed in order to inform constitutive models of healthy and diseased tissue. The overall objective of this thesis was to design, construct, program, and validate a planar biaxial device capable of testing soft tissues. Improvements and redesigns were made to the device to better suit the nature of testing required for soft tissue. Custom grips, modules, and software were developed and fabricated to facilitate accurate biaxial mechanical tests. Optimized for testing of small soft tissues, the biaxial device is an evolution of the standard approach towards mechanical testing. The overall device and the individual systems were validated internally and externally. Pilot studies were conducted on murine skin, compared to existing data from literature, and observed to correspond with known stress-strain and load-displacement properties. Further, experimental protocols were developed to evaluate the biaxial behavior of soft tissues, including cervical, uterine, vaginal, and uterosacral ligament tissue. Studies were described in which experimental data could be used to establish structure-function relationships describing reproductive tissue. Results from these studies could be used to elucidate the underlying mechanical etiologies of preterm birth and pelvic organ prolapse. / 1 / Jonathan Nguyen

For the finite element (FE) simulation of relatively thin organs under complex dynamic loadings that are relevant in the biomedical engineering field, shell elements, compared to volume elements, have the potential to capture the whole thickness of the organ at once. Shell elements, are also known to feature efficiently large critical time steps, ensuring competitive computational times in dynamic structural analysis projects. As an improvement to the tools available for modelling and analysis, a new general nonlinear thick continuum-based (CB) shell FE embedded in an updated Lagrangian formulation and an explicit time integration scheme was recently developed. It can account for irregular and complex geometries, and hyper-elastic, large, nearly incompressible anisotropic 3D deformations characteristic of soft tissues. The original proof of concept was developed in MATLAB, which despite known advantages, is very slow. As a result, computational times, even for simple problems, have not been competitive. Therefore, the present work focused on re-writing the code in an efficient programming language with execution speed in mind in order to compete with the available elements which, in spite of having inferior capabilities, have better running times. In addition, a programming algorithm was needed to improve running time. Once it was implemented, the running time was reduced in half on a benchmark problem. Optimization was then exploited to introduce workarounds and design improvements that reduced running time further to 95% of its original value. The new version of the code was implemented in C++ and reached the goal of reducing running time while maintaining the expected functionality.

“soft power is the ability to get what a country wants through attraction rather than coercion or payment.” - Joseph S. Nye Jr. From Nye’s original soft power idea, the term now has been increasingly attached to China’s conduct of its diplomacy in various parts of the globe from Southeast Asia to Africa and South America. This research examines China’s soft power in Southeast Asia and its effectiveness relative to the pursuit and advancement of the country’s regional objectives and aspirations. The primary consideration here would be the US approach towards the region and how, if any, this has affected Southeast Asian governments’ reception and perception of China’s drive for increased influence and potential domination of regional affairs. Striking a comparison between Beijing’s standing in Southeast Asia before and after its soft power application would likely provide a logical explanation on the effectiveness of its intensified diplomacy in attracting regional countries. Also of particular importance to this research would be the US policy towards the region and the underlying rationale behind its stance, as well as Southeast Asia’s attitude regarding Washington’s regional approach. Undoubtedly, America’s image in the region has been tainted by the previous governments’ missteps and unpopular actions, but there is no denying that Southeast Asian governments still rely on the US military apparatus for regional stability and security. This has been made more complex by China’s growing penetration in Southeast Asia, but might as well provide enough reason for the US to engage Southeast Asia a lot more. Knowing the political, economic and historical correlation of individual regional countries vis-à-vis the US and China might shed some light as to their mindset relative to the competition of these two external powers for increased influence in Southeast Asia. Being the US’ most reliable ally in Southeast Asia, the Philippines offers the most compelling case for this study. How the Philippines react, and what other factors influence its behavior, as far its relations with both the US and China provides some relevant information in the overall calculation of Beijing’s attractiveness among regional countries. Particularly relevant to this estimation is determining China’s rationale behind its goal of attaining unparalleled relations with the Philippines as well as Manila’s motivation in reciprocating Beijing’s offer of friendship. Equally important is the evolution of the Philippine-US relations and what drives these two countries to reinvigorate their security partnership, previously the cornerstone of American military supremacy in Southeast Asia, amid China’s charm offensive. In the end, this study finds that it appears that the Philippines’ strategy vis-à-vis its relations with both the US and China has been to secure the best possible concessions from both countries while playing a delicate balancing game to accommodate their intensified competition for influence in the country. Although there have been remarkable improvement in relations between the Philippines and China, privately Manila is still uneasy with the potential security repercussions that Beijing’s rise might engender in the long run, especially with regards to their conflicting claims over the SCS. As it seems, the Philippines’ increased confidence in dealing with China can be rooted on its ability to keep the American military deeply engaged in the country. As has been notable in the Philippine experience, Southeast Asia appeared determined to sustain the power equilibrium with regards to external powers, and all indications point to China as the concentration of this strategy. The ASEAN recognized that Beijing’s soft power has already put it in a position to compete with Washington for increased influence in the region. Southeast Asia wants to accommodate this, but judged that it would be safer to include other powers in the equation to ensure that the ASEAN still has control in managing these powers’ engagement. Having said this, while there is no doubt that China’s soft power has served its regional purpose well, Southeast Asia’s desire to sustain the regional balance of power, apparently with the US still at the top, would continue to put some limits to Beijing’s charm offensive in the region.

The capability to easily and inexpensively fabricate microfluidic devices with negligible dependence on specialized laboratory equipment continues to be one of the primary forces driving the widespread use of plastic-based devices. These devices are typically produced as replicas of a rigid mold or master incorporating a negative image of the desired structures. The negative image is typically constructed from either thick photoresists or etched silicon substrates using conventional photolithographic fabrication processes. While these micromachining techniques are effective in constructing masters with micron-sized features, the need to produce masters rapidly in order to design, fabricate, and test microfluidic devices, is a major challenge in microfluidic technology. In this research, we use inexpensive photosensitized copper clad circuit board substrates to produce master molds using conventional printed circuit technology. The techniques provide the benefits of parallel fabrication associated with photolithography without the need for cleanroom facilities, thereby offering a degree of speed and simplicity that allows microfluidic master molds to be constructed in approximately 30 minutes in any laboratory. These techniques are used to produce a variety of microfluidic channel networks using PDMS (polydimethylsiloxane) and melt-processable plastic materials.

To allow faster and more reliable wireless communication a technique is to use multiple antennas in the transmitter and receiver. This technique is called MIMO. The usage of MIMO adds complexity to the receiver that must determine what the transmitter actually sent. This thesis focuses on hardware implementation suitable for an FPGA of a detection algorithm called SUMIS. A background to detection and SUMIS in particular is given as a theoretical aid for a better understanding of how an algorithm like this can be implemented. An introduction to hardware and digital design is also presented. A subset of the operations in the SUMIS algorithm such as matrix inversion and sum of logarithmic values are analyzed and suitable hardware architectures are presented. These operations are implemented in RTL hardware using VHDL targeted for an FPGA, Virtex-6 from Xilinx. The accuracy of the implemented operations is investigated showing promising results alongside of a presentation of the necessary resource usage. Finally other approaches to hardware implementation of detection algorithms are discussed and more suitable approaches for a future implementation of SUMIS are commented on. The key aspects are flexibility through software reprogrammability and area efficiency by designing a custom processor architecture.

In recent years there has been much interest in the self-assembly of materials. Much of this research has been focused on the self-assembly of particles in solution (colloids), typically on the order of nanometres or micrometres in size. While it is easy to imagine the self-assembly of either irregularly shaped particles, or particles under an anisotropic potential, a novel class of colloids with engineerable isotropic interactions have achieved this aim. With the use of Self-Consistent Field Theory (SCFT), a mean-field model first developed for polymer melt systems, we develop a model for a system of particles of two species. One species experiences a long-range repulsive and short-range attractive interaction. The other is inert, acting as a solvent in which the former is suspended. Using this method, we calculated the equilibrium morphologies of the system for various parameters including the total volume fraction of one species relative to the other, the strengths and ranges of both the attractive and repulsive components of the interaction, and the relative particle sizes. In this way, we are able to loosely mimic the polymer-coated colloidal systems that are one of the current subjects of self-assembly research. By reducing our model to a simplified, isotropic interaction, we are able to show that the self-assembly of such systems is the result of the nature of the interaction and not any anisotropy within the model. We have also shown that the phase progressions of this system exhibit remarkable agreement with those of diblock copolymer melt systems despite significant differences in the molecules of these two systems.