Dynamics of Microfluidic Aqueous Two-Phase Compound Droplets

Master'sMASTER OF ENGINEERIN

A comparative study of using two numerical strategies to simulate the biochemical processes in microbially induced calcite precipitation

In this study, we carried out a comparative study of two different numerical strategies for the modeling of the biogeochemical processes in microbially induced calcite precipitation (MICP) process. A simplified MICP model was used, which is based on the mass transport theory. Two numerical strategies, namely the operator splitting (OS) and the global implicit (GI) strategies, were adopted to solve the coupled reactive mass transport problems. These two strategies were compared in the aspects of numerical accuracy, convergence property and computational efficiency by solving the presented MICP model. To look more into the details of the model, sensitivity analysis of some important modeling parameters was also carried out in this paper

Potato: A Data-Oriented Programming 3D Simulator for Large-Scale Heterogeneous Swarm Robotics

Large-scale simulation with realistic nonlinear dynamic models is crucial for algorithms development for swarm robotics. However, existing platforms are mainly developed based on Object-Oriented Programming (OOP) and either use simple kinematic models to pursue a large number of simulating nodes or implement realistic dynamic models with limited simulating nodes. In this paper, we develop a simulator based on Data-Oriented Programming (DOP) that utilizes GPU parallel computing to achieve large-scale swarm robotic simulations. Specifically, we use a multi-process approach to simulate heterogeneous agents and leverage PyTorch with GPU to simulate homogeneous agents with a large number. We test our approach using a nonlinear quadrotor model and demonstrate that this DOP approach can maintain almost the same computational speed when quadrotors are less than 5,000. We also provide two examples to present the functionality of the platform.Comment: 4 pages, 5 figures, accepted by ICRA 2023 Workshop on "The Role of Robotics Simulators for Unmanned Aerial Vehicles

Fluorescence resonance energy transfer-based visualization and actuation of molecular signaling transductions for controlling cellular behaviors

Understanding and engineering of complex biological systems are key challenges to the scientific community for addressing health problems, especially diseases. Studies of biological systems can vary in scale from molecules, cells, to entire organisms. Cells, as the basic building blocks of life, compose various biological entities of higher order and precisely control both structures and functions. Therefore, it is of vital importance to understand how cell functions and behaviors are regulated in order to engineer and manipulate cell behaviors. Recently, advances in molecular imaging technologies and synthetic biology approaches have enabled us to better detect and manipulate cell signals and behaviors, and provide a broad set of tools to influence and revolutionize basic research, medicine and therapy. In my dissertation, a general high-throughput platform has been established to systematically optimize biosensors and a new Src biosensor with high sensitivity has been developed accordingly. Combining fluorescence/Förster resonance energy transfer microscopy and laser scissors technology, the signaling transmission between neighboring cells and the underlying mechanism could thus be revealed, which could provide a cell model to understand intercellular communications and wound healing process. Furthermore, I have successfully developed, characterized and demonstrated specific molecular machineries to program cell behaviors by rewiring molecular signaling pathways, specifically immune responses in immune cells against cancer cells. These new tools and understanding may open a new avenue towards cancer therapy and lead to potential therapeutic strategies

Fluorescence resonance energy transfer-based visualization and actuation of molecular signaling transductions for controlling cellular behaviors

Understanding and engineering of complex biological systems are key challenges to the scientific community for addressing health problems, especially diseases. Studies of biological systems can vary in scale from molecules, cells, to entire organisms. Cells, as the basic building blocks of life, compose various biological entities of higher order and precisely control both structures and functions. Therefore, it is of vital importance to understand how cell functions and behaviors are regulated in order to engineer and manipulate cell behaviors. Recently, advances in molecular imaging technologies and synthetic biology approaches have enabled us to better detect and manipulate cell signals and behaviors, and provide a broad set of tools to influence and revolutionize basic research, medicine and therapy. In my dissertation, a general high-throughput platform has been established to systematically optimize biosensors and a new Src biosensor with high sensitivity has been developed accordingly. Combining fluorescence/Förster resonance energy transfer microscopy and laser scissors technology, the signaling transmission between neighboring cells and the underlying mechanism could thus be revealed, which could provide a cell model to understand intercellular communications and wound healing process. Furthermore, I have successfully developed, characterized and demonstrated specific molecular machineries to program cell behaviors by rewiring molecular signaling pathways, specifically immune responses in immune cells against cancer cells. These new tools and understanding may open a new avenue towards cancer therapy and lead to potential therapeutic strategies

Riley Oxidation of Heterocyclic Intermediates on Paths to Hydroporphyrins—A Review

Riley oxidation of advanced heterocyclic intermediates (dihydrodipyrrins and tetrahydrodipyrrins) is pivotal in routes to synthetic hydroporphyrins including chlorins, bacteriochlorins, and model (bacterio)chlorophylls. Such macrocycles find wide use in studies ranging from energy sciences to photomedicine. The key transformation (–CH3 → –CHO) is often inefficient, however, thereby crimping the synthesis of hydroporphyrins. The first part of the review summarizes 12 representative conditions for Riley oxidation across diverse (non-hydrodipyrrin) substrates. An interlude summarizes the proposed mechanisms and provides context concerning the nature of various selenium species other than SeO2. The second part of the review comprehensively reports the conditions and results upon Riley oxidation of 45 1-methyltetrahydrodipyrrins and 1-methyldihydrodipyrrins. A comparison of the results provides insights into the tolerable structural features for Riley oxidation of hydrodipyrrins. In general, Riley oxidation of dihydrodipyrrins has a broad scope toward substituents, but proceeds in only modest yield. Too few tetrahydrodipyrrins have been examined to draw conclusions concerning scope. New reaction conditions or approaches will be required to achieve high yields for this critical transformation in the synthesis of hydroporphyrins

Luminous efficacy and color rendering index of high power white LEDs packaged by using red phosphor

We packaged a series of high power white LEDs by covering the blue LED chips with yellow phosphor, red phosphor and the two phosphors mixed by appropriate mass ratio, respectively, and discussed the excitation and emission spectrum of yellow phosphor and red phosphor and the characteristics of the LEDs. We found that the luminous efficacy of the white LEDs covered with the two phosphors mixed by appropriate mass ratio was lower than that of the white LEDs covered with yellow phosphor, but the color rendering index was improved observabl