Realization of an electromechanical nano-string device

Electromechanics is the field of studying the interaction between microwave resonators and mechanical oscillators. It has been an interesting topic in the recent decade due to its numerous potential applications in science and technology, including ground-state cooling of macroscopic objects, quantum sensing, quantum memory, and quantum transduction. This thesis presents a comprehensive analysis of a project focused on simulating, designing, and modeling electromechanical devices with the ultimate objective of achieving their successful implementation. Through the thesis, after an overview of the theoretical model of electromechanics, I will introduce our design for the device and explain how we simulated it to optimize its characteristics. Next, I will discuss the nanofabrication process we have developed for the device, along with the fundamental aspects of the characterization method and setup. Subsequently, I will present the theoretical model I have developed based on electromechanics. This model has significant potential to open up new avenues for future research, building upon the foundation laid by the current project.Comment: Master's thesi

From Data to Decision: An Implementation Model for the Use of Evidence-based Medicine, Data Analytics, and Education in Transfusion Medicine Practice

Healthcare in the United States is underperforming despite record increases in spending. The causes are as myriad and complex as the suggested solutions. It is increasingly important to carefully assess the appropriateness and cost-effectiveness of treatments especially the most resource-consuming clinical interventions. Healthcare reimbursement models are evolving from fee-for-service to outcome-based payment. The Patient Protection and Affordable Care Act has added new incentives to address some of the cost, quality, and access issues related to healthcare, making the use of healthcare data and evidence-based decision-making essential strategies. However, despite the great promise of these strategies, the transition to data-driven, evidence-based medical practice is complex and faces many challenges. This study aims to bridge the gaps that exist between data, knowledge, and practice in a healthcare setting through the use of a comprehensive framework to address the administrative, cultural, clinical, and technical issues that make the implementation and sustainability of an evidence-based program and utilization of healthcare data so challenging. The study focuses on promoting evidence-based medical practice by leveraging a performance management system, targeted education, and data analytics to improve outcomes and control costs. The framework was implemented and validated in transfusion medicine practice. Transfusion is one of the top ten coded hospital procedures in the United States. Unfortunately, the costs of transfusion are underestimated and the benefits to patients are overestimated. The particular aim of this study was to reduce practice inconsistencies in red blood cell transfusion among hospitalists in a large urban hospital using evidence-based guidelines, a performance management system, recurrent reporting of practice-specific information, focused education, and data analytics in a continuous feedback mechanism to drive appropriate decision-making prior to the decision to transfuse and prior to issuing the blood component. The research in this dissertation provides the foundation for implementation of an integrated framework that proved to be effective in encouraging evidence-based best practices among hospitalists to improve quality and lower costs of care. What follows is a discussion of the essential components of the framework, the results that were achieved and observations relative to next steps a learning healthcare organization would consider

A Knapsack Problem Approach For Achieving Efficient Energy Consumption in Smart Grid for Endusers’ Life Style

In order to achieve an efficient energy consumption level in the residential sector of a smart grid, the end-users are equipped with various smart home energy controller technologies. The devices are provided to inform the consumers about their consumption pattern by showing or sending different kinds of consumptional information to them. This kind of information is provided to assist them in making decisions about altering their consumption behaviour or to urge them to modify their life style during peak hours. We propose that the energy home controllers should offer preferred and optimal scenarios to support end-users when making a decision about their consumption. Effective scenarios should emerge from consumer's life style and preferences. In this paper, we will apply AHP methodology to quantify the consumer's preferences for using appliances during peak periods when the price has increased, and use the Knapsack problem approach to achieve the optimal solution for managing the appliances. With this approach, not only will the cost of electricity not escalate during peak hours, but also user preferences, satisfaction and minimum change to current life style will be considered

Gradient-based constitutive model to predict size effect in the response of SMA thin films

For sufficiently small dimensions, the response of shape memory alloy (SMA) actuators is not independent of the sample size. The response of SMA single crystal micro/nanopillars is shown to depend on the size of the specimen. An increase in the critical stresses for the start and finish of austenite to martensite transformation is seen when reducing the diameter into the submicron region. In addition, the damping observed in a pseudoelastic cycle of a nanopillar is much higher than that of a counterpart SMA bulk specimen. This phenomenon is furthermore observed in SMA wires where the critical stresses for the start of martensite and austenite transformations are -reported to increase for diameters \u3c100 µm. Finally, the hardness of SMA thin films obtained from micro- or -nanoindentation experiments was shown to depend on the indentation depth demonstrating an increased hardness for smaller indentation depths. SMAs have recently been used as a promising and high performance -material for application in micro–electro–mechanical systems in the form of thin films/beams. Nano/microindentation experiments, on the other hand, are one the major experimental routines to establish properties of SMA thin film actuators. Assessing the functionality of such microactuators requires numerical modeling tools that can take into account the observed size effect. Size effect in the SMA response cannot be simulated using conventional constitutive theories, which lack an intrinsic length scale in their constitutive modeling. To enable such a property, a new nonlocal thermodynamically consistent constitutive model is developed, which in addition to conventional internal variables of martensitic volume fraction and transformation strain, contains the spatial gradient of martensitic volume fraction as an internal variable. This allows the introduction of energetic and dissipative length scales in the model. The transformation surface in such a theory will be obtained from the solution of a partial differential equation. In conventional formulations, transformation surface is an algebraic equation. A boundary value problem, in this case, contains the equilibrium equation with its standard boundary conditions as well as the PDE for the transformation and associated martensitic volume fraction. The developed gradient theory is used to analytically simulate the uniaxial stretching of SMA wires, pure bending of SMA beams, and compression response of SMA micro/nanopillars. SMA beams with larger thickness show a response closer to the classical (local) model prediction, which in the nondimentional sense, is independent of the thickness of the beam. In addition, the nano/microindentation process was studied using the developed constitutive model. The response of the SMA structures using the developed gradient theory depends on the size, being stiffer for smaller dimensions and harder for smaller indentation depths

Some reflections on the building and calibration of useful network models

Over the past 10 years or so in the UK much effort has gone into the construction of computerised network models of water supply and distribution networks. At best such models offer an approximation of reality, their performance in simulation being constrained, in many cases, by the uncertainties present in the data upon which they were compiled. Most notable are the problems of demand specification, including leakage evaluation. In the UK this exercise is compounded by the unmetered nature of most domestic consumption. Reconciliation of the output of this process is invariably and inextricably linked to such matters as flow-meter accuracy, network and district metered area (DMA) connectivity, and monitored pressure regime, as well as precision in property allocation and quality of billing records. For large networks the task of the modeller is most arduous since the exercise of pipe calibration, leading to production of the 'verified' model, is itself highly dependent upon the distribution of flows generated in the network. The paper elaborates on these problems and introduces outlines for systematic treatments of the data reconciliation processes, with the aim of producing usable models which 'best' represent reality from the information available