Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Department of Mechanical Engineering-Engineering Mechanics (10)
- Additive manufacturing (4)
- Department of Electrical and Computer Engineering (4)
- Optimal control (4)
- Circular economy (3)
-
- Department of Materials Science and Engineering (3)
- Distributed manufacturing (3)
- 3D printing (2)
- Controls (2)
- Electronic Cooling (2)
- Extruder (2)
- Hybrid Electric Vehicle (2)
- Model Predictive Control (2)
- Open hardware (2)
- Optimization (2)
- Polymers (2)
- Recycling (2)
- System Identification (2)
- Upcycle (2)
- Waste plastic (2)
- Wave energy conversion (2)
- 3-D printing (1)
- 3D printed buoy (1)
- 3D-printing (1)
- AC power system (1)
- ALE (1)
- ARPA-E (1)
- Acoustic Vector Sensor (1)
- Acoustics (1)
- Active and reactive power-sharing (1)
- Publication
- Publication Type
Articles 1 - 30 of 58
Full-Text Articles in Engineering
Me-Em Enewsbrief, December 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Me-Em Enewsbrief, December 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Department of Mechanical Engineering-Engineering Mechanics eNewsBrief
No abstract provided.
Multi-Resonant Feedback Control Of Multiple Degree-Of-Freedom Wave Energy Converters, Ossama Abdelkhalik, Shangyan Zou, Rush D. Robinett Iii, David G. Wilson, Giorgio Bacelli, Ryan G. Coe, Umesh Korde
Multi-Resonant Feedback Control Of Multiple Degree-Of-Freedom Wave Energy Converters, Ossama Abdelkhalik, Shangyan Zou, Rush D. Robinett Iii, David G. Wilson, Giorgio Bacelli, Ryan G. Coe, Umesh Korde
Michigan Tech Patents
Multi-resonant control of a 3 degree-of-freedom (heave-pitch-surge) wave energy converter enables energy capture that can be in the order of three times the energy capture of a heave-only wave energy converter. The invention uses a time domain feedback control strategy that is optimal based on the criteria of complex conjugate control. The multi-resonant control can also be used to shift the harvested energy from one of the coupled modes to another, enabling the elimination of one of the actuators otherwise required in a 3 degree-of-freedom wave energy converter. This feedback control strategy does not require wave prediction; it only requires …
Droop Control In Dq Coordinates For Fixed Frequency Inverter-Based Ac Microgrids, Mohamed Toub, Mehrzad Mohammadi Bijaieh, Wayne Weaver, Rush D. Robinett Iii, Mohamed Maaroufi, Ghassane Aniba
Droop Control In Dq Coordinates For Fixed Frequency Inverter-Based Ac Microgrids, Mohamed Toub, Mehrzad Mohammadi Bijaieh, Wayne Weaver, Rush D. Robinett Iii, Mohamed Maaroufi, Ghassane Aniba
Michigan Tech Publications
This paper presents a proof-of-concept for a novel dq droop control technique that applies DC droop control methods to fixed frequency inverter-based AC microgrids using the dq0 transformation. Microgrids are usually composed of distributed generation units (DGUs) that are electronically coupled to each other through power converters. An inherent property of inverter-based microgrids is that, unlike microgrids with spinning machines, the frequency of the parallel-connected DGUs is a global variable independent from the output power since the inverters can control the output waveform frequency with a high level of precision. Therefore, conventional droop control methods that distort the system frequency …
Open Source Waste Plastic Granulator, Arvind Ravindran, Sean Scsavnicki, Walker Nelson, Peter Gorecki, Jacob Franz, Shane Oberloier, Theresa K. Meyer, Andrew Barnard, Joshua M. Pearce
Open Source Waste Plastic Granulator, Arvind Ravindran, Sean Scsavnicki, Walker Nelson, Peter Gorecki, Jacob Franz, Shane Oberloier, Theresa K. Meyer, Andrew Barnard, Joshua M. Pearce
Michigan Tech Publications
In order to accelerate deployment of distributed recycling by providing low-cost feed stocks of granulated post-consumer waste plastic, this study analyzes an open source waste plastic granulator system. It is designed, built, and tested for its ability to convert post-consumer waste, 3D printed products and waste into polymer feedstock for recyclebots of fused particle/granule printers. The technical specifications of the device are quantified in terms of power consumption (380 to 404 W for PET and PLA, respectively) and particle size distribution. The open source device can be fabricated for less than $2000 USD in materials. The experimentally measured power use …
Design Of Hydroxyapatite/Magnetite (Hap/Fe3o4) Based Composites Reinforced With Zno And Mgo For Biomedical Applications, D. Katundi, E. Bayraktar, F. Gatamorta, I. Miskioglu
Design Of Hydroxyapatite/Magnetite (Hap/Fe3o4) Based Composites Reinforced With Zno And Mgo For Biomedical Applications, D. Katundi, E. Bayraktar, F. Gatamorta, I. Miskioglu
Michigan Tech Publications
Hydroxyapatite (HAP-- Ca 10(PO4 )6 (OH)2 ) is a biocompatible and bioactive material that is widely used for biomedical applications, especially in bone replacements. It has good load carrying capacity; however, it lacks antibacterial property. New bio-composites based on bovine hydroxyapatite doped with, magnetite iron oxide (HAP/ Fe3 O4 ) matrix reinforced with ZnO and MgO nanoparticles are proposed for biomedical applications that provide improved antibacterial activity with potential to be used in magnetic therapy. Microwave sintering was used to manufacture the composites. The microstructure evolution in these composites were studied by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy …
Multi-Resonant Feedback Control Of A Single Degree-Of-Freedom Wave Energy Converter, David G. Wilson, Rush D. Robinett Iii, Ossama Abdelkhalik, Jiajun Song, Giorgio Bacelli
Multi-Resonant Feedback Control Of A Single Degree-Of-Freedom Wave Energy Converter, David G. Wilson, Rush D. Robinett Iii, Ossama Abdelkhalik, Jiajun Song, Giorgio Bacelli
Michigan Tech Patents
A multi-resonant wide band controller decomposes the wave energy converter control problem into sub-problems; an independent single-frequency controller is used for each sub-problem. Thus, each sub-problem controller can be optimized independently. The feedback control enables actual time-domain realization of multi-frequency complex conjugate control. The feedback strategy requires only measurements of the buoy position and velocity. No knowledge of excitation force, wave measurements, nor wave prediction is needed. As an example, the feedback signal processing can be carried out using Fast Fourier Transform with Hanning windows and optimization of amplitudes and phases. Given that the output signal is decomposed into individual …
Model Predictive Control Of Parametric Excited Pitch-Surge Modes In Wave Energy Converters, Ossama Abdelkhalik, Rush D. Robinett Iii, Shangyan Zou, David G. Wilson, Giorgio Bacelli, Umesh Korde, Ryan G. Coe
Model Predictive Control Of Parametric Excited Pitch-Surge Modes In Wave Energy Converters, Ossama Abdelkhalik, Rush D. Robinett Iii, Shangyan Zou, David G. Wilson, Giorgio Bacelli, Umesh Korde, Ryan G. Coe
Michigan Tech Patents
A parametric excitation dynamic model is used for a three degrees-of-freedom (3-DOF) wave energy converter. Since the heave motion is uncoupled from the pitch and surge modes, the pitch-surge equations of motion can be treated as a linear time varying system, or a linear system with parametric excitation. In such case the parametric exciting frequency can be tuned to twice the natural frequency of the system for higher energy harvesting. A parametric excited 3-DOF wave energy converter can harvest more power, for both regular and irregular waves, compared to the linear 3-DOF. For example, in a Bretschneider wave, the harvested …
Optimal And Decentralized Control Strategies For Inverter-Based Ac Microgrids, Michael D. Cook, Eddy H. Trinklein, Gordon Parker, Rush D. Robinett Iii, Wayne Weaver
Optimal And Decentralized Control Strategies For Inverter-Based Ac Microgrids, Michael D. Cook, Eddy H. Trinklein, Gordon Parker, Rush D. Robinett Iii, Wayne Weaver
Michigan Tech Publications
This paper presents two control strategies: (i) An optimal exergy destruction (OXD) controller and (ii) a decentralized power apportionment (DPA) controller. The OXD controller is an analytical, closed-loop optimal feedforward controller developed utilizing exergy analysis to minimize exergy destruction in an AC inverter microgrid. The OXD controller requires a star or fully connected topology, whereas the DPA operates with no communication among the inverters. The DPA presents a viable alternative to conventional P−ω/Q−V droop control, and does not suffer from fluctuations in bus frequency or steady-state voltage while taking advantage of distributed storage assets necessary for the high penetration of …
Me-Em Enewsbrief, September 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Me-Em Enewsbrief, September 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Department of Mechanical Engineering-Engineering Mechanics eNewsBrief
No abstract provided.
Docking Control Of An Autonomous Underwater Vehicle Using Reinforcement Learning, Enrico Anderlini, Gordon Parker, Giles Thomas
Docking Control Of An Autonomous Underwater Vehicle Using Reinforcement Learning, Enrico Anderlini, Gordon Parker, Giles Thomas
Michigan Tech Publications
To achieve persistent systems in the future, autonomous underwater vehicles (AUVs) will need to autonomously dock onto a charging station. Here, reinforcement learning strategies were applied for the first time to control the docking of an AUV onto a fixed platform in a simulation environment. Two reinforcement learning schemes were investigated: one with continuous state and action spaces, deep deterministic policy gradient (DDPG), and one with continuous state but discrete action spaces, deep Q network (DQN). For DQN, the discrete actions were selected as step changes in the control input signals. The performance of the reinforcement learning strategies was compared …
Stability Analysis On Nonequilibrium Supersonic Boundary Layer Flow With Velocity-Slip Boundary Conditions, Xin He, Chunpei Cai
Stability Analysis On Nonequilibrium Supersonic Boundary Layer Flow With Velocity-Slip Boundary Conditions, Xin He, Chunpei Cai
Michigan Tech Publications
This paper presents our recent work on investigating velocity slip boundary conditions’ effects on supersonic flat plate boundary layer flow stability. The velocity-slip boundary conditions are adopted and the flow properties are obtained by solving boundary layer equations. Stability analysis of two such boundary layer flows is performed by using the Linear stability theory. A global method is first utilized to obtain approximate discrete mode values. A local method is then utilized to refine these mode values. All the modes in these two scenarios have been tracked upstream-wisely towards the leading edge and also downstream-wisely. The mode values for the …
Pseudo-Spectral Method To Control Three-Degree-Of-Freedom Wave Energy Converters, Ossama Abdelkhalik, Giorgio Bacelli, Shangyan Zou, Rush D. Robinett Iii, David G. Wilson, Ryan G. Coe
Pseudo-Spectral Method To Control Three-Degree-Of-Freedom Wave Energy Converters, Ossama Abdelkhalik, Giorgio Bacelli, Shangyan Zou, Rush D. Robinett Iii, David G. Wilson, Ryan G. Coe
Michigan Tech Patents
The invention provides optimal control of a three-degree-of-freedom wave energy converter using a pseudo-spectral control method. The three modes are the heave, pitch and surge. A dynamic model is characterized by a coupling between the pitch and surge modes, while the heave is decoupled. The heave, however, excites the pitch motion through nonlinear parametric excitation in the pitch mode. The invention can use a Fourier series as basis functions to approximate the states and the control. For the parametric excited case, a sequential quadratic programming approach can be implemented to numerically solve for the optimal control. The numerical results show …
Generating Electrospray From A Ferrofluid, Lyon Bradley King
Generating Electrospray From A Ferrofluid, Lyon Bradley King
Michigan Tech Patents
An electrospray device for generating electrospray from a ferrofluid. The electrospray device includes an emitter, an extraction electrode, and a magnet. The emitter is configured to receive a ferrofluidic liquid. The extraction electrode includes an aperture and is positioned a first distance from the emitter. The magnet generates a magnetic field in a first direction toward the emitter. The magnetic field causes Rosensweig instability in the ferrofluidic liquid, and generates a ferrofluidic peak in the ferrofluidic liquid. The magnet is positioned a second distance from the emitter, and the emitter is positioned between the extraction electrode and the magnet. The …
Mapping Modeled Exposure Of Wildland Fire Smoke For Human Health Studies In California, Patricia Koman, Michael Billmire, Kirk Baker, Ricardo De Majo, Frank Anderson, Sumi Hoshiko, Brian Thelen, Nancy H. F. French
Mapping Modeled Exposure Of Wildland Fire Smoke For Human Health Studies In California, Patricia Koman, Michael Billmire, Kirk Baker, Ricardo De Majo, Frank Anderson, Sumi Hoshiko, Brian Thelen, Nancy H. F. French
Michigan Tech Publications
Wildland fire smoke exposure affects a broad proportion of the U.S. population and is increasing due to climate change, settlement patterns and fire seclusion. Significant public health questions surrounding its effects remain, including the impact on cardiovascular disease and maternal health. Using atmospheric chemical transport modeling, we examined general air quality with and without wildland fire smoke PM2.5. The 24-h average concentration of PM2.5 from all sources in 12-km gridded output from all sources in California (2007–2013) was 4.91 μg/m3. The average concentration of fire-PM2.5 in California by year was 1.22 μg/m3 (~25% …
Me-Em Enewsbrief, June 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Me-Em Enewsbrief, June 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Department of Mechanical Engineering-Engineering Mechanics eNewsBrief
No abstract provided.
Mechanical Properties And Applications Of Recycled Polycarbonate Particle Material Extrusion-Based Additive Manufacturing, Matthew J. Reich, Aubrey Woern, Nagendra Gautam Tanikella, Joshua M. Pearce
Mechanical Properties And Applications Of Recycled Polycarbonate Particle Material Extrusion-Based Additive Manufacturing, Matthew J. Reich, Aubrey Woern, Nagendra Gautam Tanikella, Joshua M. Pearce
Michigan Tech Publications
Past work has shown that particle material extrusion (fused particle fabrication (FPF)/fused granular fabrication (FGF)) has the potential for increasing the use of recycled polymers in 3D printing. This study extends this potential to high-performance (high-mechanical-strength and heat-resistant) polymers using polycarbonate (PC). Recycled PC regrind of approximately 25 mm2 was 3D printed with an open-source Gigabot X and analyzed. A temperature and nozzle velocity matrix was used to find useful printing parameters, and a print test was used to maximize the output for a two-temperature stage extruder for PC. ASTM type 4 tensile test geometries as well as ASTM-approved …
Agent-Based Microgrid Architecture For Generation Following Protocols, Steven Goldsmith
Agent-Based Microgrid Architecture For Generation Following Protocols, Steven Goldsmith
Michigan Tech Patents
A system for predicting power and loads over a single, relatively short time horizon. More specifically, a system comprising a Storage Agent (S-agent) Cohort within a grid control society, wherein the system expands G and L intra-cohort protocols to allow the S-cohort to participate in power management of the grid by scheduling storage components in source or load roles as determined by the time-varying state of the power imbalance and by the risk-adjusting capacity margin relationship between the G and L cohorts.
Open Source Completely 3-D Printable Centrifuge, Salil S. Sule, Aliaksei Petsiuk, Joshua M. Pearce
Open Source Completely 3-D Printable Centrifuge, Salil S. Sule, Aliaksei Petsiuk, Joshua M. Pearce
Michigan Tech Publications
Centrifuges are commonly required devices in medical diagnostics facilities as well as scientific laboratories. Although there are commercial and open source centrifuges, the costs of the former and the required electricity to operate the latter limit accessibility in resource-constrained settings. There is a need for low-cost, human-powered, verified, and reliable lab-scale centrifuges. This study provides the designs for a low-cost 100% 3-D printed centrifuge, which can be fabricated on any low-cost RepRap-class (self-replicating rapid prototyper) fused filament fabrication (FFF)- or fused particle fabrication (FPF)-based 3-D printer. In addition, validation procedures are provided using a web camera and free and open …
Capillary Penetration Method For Measuring Wetting Properties Of Carbon Ionomer Films For Proton Exchange Membrane Fuel Cell (Pemfc) Applications, Sofyane Abbou, Kazuya Tajiri, K. T. Alofari, Ezequiel F. Medici, A. T. Haug, Jeffrey S. Allen
Capillary Penetration Method For Measuring Wetting Properties Of Carbon Ionomer Films For Proton Exchange Membrane Fuel Cell (Pemfc) Applications, Sofyane Abbou, Kazuya Tajiri, K. T. Alofari, Ezequiel F. Medici, A. T. Haug, Jeffrey S. Allen
Michigan Tech Publications
In this work, capillary rise experiments were performed to assess the wetting properties of carbon-ionomer (CI) films. The samples were attached to a micro-balance and then immersed into liquid water to (i) measure the mass gain from the liquid uptake and (ii) estimate the (external) contact angle to water (typical value around 140°). The results showed that drying the CI films under low vacuum significantly impacted the CI film wettability. The influence of the ionomer content on the CI films’ wettability was investigated with various ionomer to carbon (I/C) ratios: 0.8, 1.0, 1.2 and 1.4. No significant variation of the …
A Discrete Curvature Estimation Based Low-Distortion Adaptive Savitzky-Golay Filter For Ecg Denoising, Hui Huang, Shiyan Hu, Ye Sun
A Discrete Curvature Estimation Based Low-Distortion Adaptive Savitzky-Golay Filter For Ecg Denoising, Hui Huang, Shiyan Hu, Ye Sun
Department of Mechanical Engineering-Engineering Mechanics Publications
Electrocardiogram (ECG) sensing is an important application for the diagnosis of cardiovascular diseases. Recently, driven by the emerging technology of wearable electronics, massive wearable ECG sensors are developed, which however brings additional sources of noise contamination on ECG signals from these wearable ECG sensors. In this paper, we propose a new low-distortion adaptive Savitzky-Golay (LDASG) filtering method for ECG denoising based on discrete curvature estimation, which demonstrates better performance than the state of the art of ECG denoising. The standard Savitzky-Golay (SG) filter has a remarkable performance of data smoothing. However, it lacks adaptability to signal variations and thus often …
A Novel Correlation Model For Horizontal Axis Wind Turbines Operating At High-Interference Flow Regimes, Anurag Rajan, Fernando L. Ponta
A Novel Correlation Model For Horizontal Axis Wind Turbines Operating At High-Interference Flow Regimes, Anurag Rajan, Fernando L. Ponta
Department of Mechanical Engineering-Engineering Mechanics Publications
Driven by economics-of-scale factors, wind-turbine rotor sizes have increased formidably in recent years. Larger rotors with lighter blades of increased flexibility will experiment substantially higher levels of deformation. Future turbines will also incorporate advanced control strategies to widen the range of wind velocities over which energy is captured. These factors will extend turbine operational regimes, including flow states with high interference factors. In this paper we derive a new empirical relation to both improve and extend the range of Blade Element Momentum (BEM) models, when applied to high interference-factor regimes. In most BEM models, these flow regimes are modeled using …
Me-Em Enewsbrief, March 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Me-Em Enewsbrief, March 2019, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Department of Mechanical Engineering-Engineering Mechanics eNewsBrief
No abstract provided.
A Hamiltonian Surface-Shaping Approach For Control System Analysis And The Design Of Nonlinear Wave Energy Converters, Shadi Darani, Ossama Abdelkhalik, Rush D. Robinett Iii, David Wilson
A Hamiltonian Surface-Shaping Approach For Control System Analysis And The Design Of Nonlinear Wave Energy Converters, Shadi Darani, Ossama Abdelkhalik, Rush D. Robinett Iii, David Wilson
Department of Mechanical Engineering-Engineering Mechanics Publications
The dynamic model of Wave Energy Converters (WECs) may have nonlinearities due to several reasons such as a nonuniform buoy shape and/or nonlinear power takeoff units. This paper presents the Hamiltonian Surface-Shaping (HSS) approach as a tool for the analysis and design of nonlinear control of WECs. The Hamiltonian represents the stored energy in the system and can be constructed as a function of the WEC’s system states, its position, and velocity. The Hamiltonian surface is defined by the energy storage, while the system trajectories are constrained to this surface and determined by the power flows of the applied non-conservative …
Optimal Control Of Wave Energy Converters, Ossama Abdelkhalik, Rush D. Robinett Iii, Shangyan Zou, Giorgio Bacelli, David G. Wilson, Umesh Korde
Optimal Control Of Wave Energy Converters, Ossama Abdelkhalik, Rush D. Robinett Iii, Shangyan Zou, Giorgio Bacelli, David G. Wilson, Umesh Korde
Michigan Tech Patents
A wave energy converter and method for extracting energy from water waves maximizes the energy extraction per cycle by estimating an excitation force of heave wave motion on the buoy, computing a control force from the estimated excitation force using a dynamic model, and applying the computed control force to the buoy to extract energy from the heave wave motion. Analysis and numerical simulations demonstrate that the optimal control of a heave wave energy converter is, in general, in the form of a bang-singular-bang control; in which the optimal control at a given time can be either in the singular …
Comprehensive Parameters Identification And Dynamic Model Validation Of Interior-Mount Line-Start Permanent Magnet Synchronous Motors, Luqman S. Maraaba, Zakariya M. Al-Hamouz, Absulaziz S. Milhem, Ssennoga Twaha
Comprehensive Parameters Identification And Dynamic Model Validation Of Interior-Mount Line-Start Permanent Magnet Synchronous Motors, Luqman S. Maraaba, Zakariya M. Al-Hamouz, Absulaziz S. Milhem, Ssennoga Twaha
School of Technology Publications
The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of …
Mechanical Engineering Technology Newsletter 2019, Department Of Manufacturing And Mechanical Engineering Technology, Michigan Technological University
Mechanical Engineering Technology Newsletter 2019, Department Of Manufacturing And Mechanical Engineering Technology, Michigan Technological University
Department of Manufacturing and Mechanical Engineering Technology Newsletters
Table of Contents
- Where Racing Will Take Him
- Irwin Wins Center for Teaching and Learning Instructional Award
- Five MET Students Inducted into Epsilon Pi Tau Honor Society
- 2018 and 2019 Scholarship Awards
- 2018 Bob Mark Business Model Competition
- Senior Design Projects
- What's New?
High Injection Pressure Dme Ignition And Combustion Processes: Experiment And Simulation, Xiucheng Zhu
High Injection Pressure Dme Ignition And Combustion Processes: Experiment And Simulation, Xiucheng Zhu
Dissertations, Master's Theses and Master's Reports
With nearly smokeless combustion, Dimethyl Ether (DME) can be pressurized and used as a liquid fuel for compression-ignition (CI) combustion. However, due to its lower heating value and liquid density compared with diesel fuel, DME has a smaller energy content per unit volume. To obtain an equivalent energy content of diesel, approximately 1.86 times more quantity of DME is required. This can be addressed by a larger nozzle size or higher injection pressure. However, the effect of high injection pressure on DME spray combustion characteristics have not yet been well understood. In order to fill this gap, spray and combustion …
Me-Em 2018-19 Annual Report, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Me-Em 2018-19 Annual Report, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Department of Mechanical Engineering-Engineering Mechanics Annual Reports
Table of Contents
- Faculty Research
- Enrollment & Degrees
- Department News
- Graduates
- Faculty & Staff
- Alumni
- Donors
- Contracts & Grants
- Patents & Publications
Optimization And Comparison Of Over-Expanded And Other High Efficiency Four-Stroke Spark-Ignited Boosted Engines, Zhuyong Yang
Optimization And Comparison Of Over-Expanded And Other High Efficiency Four-Stroke Spark-Ignited Boosted Engines, Zhuyong Yang
Dissertations, Master's Theses and Master's Reports
Recent fuel economy and emission regulations are the major concern of the research and development of modern internal combustion engine. Such technologies include variable valve timing (VVT), direct injection (DI), turbocharging, downsizing, and over-expanded cycle are used by many manufacturers to improve engine fuel economy or increase power density.
Current Atkinson cycle technology in the production engine is mainly realized by an advanced valvetrain system to reduce the effective compression ratio while maintaining the same expansion ratio. Another approach to realize over-expanded cycle engine is to utilize a multi-link cranktrain mechanism. Although the Atkinson cycle was originally patented in the …
3d Printing In Low Resource Healthcare Settings: Analysis Of Potential Implementations, Alenna Beroza
3d Printing In Low Resource Healthcare Settings: Analysis Of Potential Implementations, Alenna Beroza
Dissertations, Master's Theses and Master's Reports
3D printing has gained significant momentum in the past ten years, and its unique advantages make it especially ideal for use in low resource healthcare settings, where many designs have already been successfully implemented. Yet, little has been studied on how 3D printing can be sustainably and functionally implemented in low resource healthcare systems as a manufacturing practice. In this report, three business models are proposed for this implementation: In-House Operator, Independent Operator, and Print Farm. These models were then tested over four months in Kisumu county, Kenya, at two workshops and seven public hospitals. I worked with local medical …