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Full-Text Articles in Mechanical Engineering

Synthesis And Connection Of Iridium Hydrogen Evolution Catalyst To Chlorella Vulgaris Photosystem I For Light-Driven Hydrogen Evolution, Anna Ramirez Dec 2019

Synthesis And Connection Of Iridium Hydrogen Evolution Catalyst To Chlorella Vulgaris Photosystem I For Light-Driven Hydrogen Evolution, Anna Ramirez

Honors Program Theses and Projects

Hydrogen gas has been shown to be a promising energy source as options other than fossil fuels are being looked at in the face of anthropogenic climate change. It is known that anthropogenic climate change is caused by the production of greenhouse gases being let into the atmosphere, specifically a common reason for this is the burning of fossil fuels for energy. The overall goal of this project is to design a biochemical hybrid system that will be used to make H 2 gas and does not require the use of fossil fuels. Burning hydrogen as fuel produces only water …


College Of Engineering Senior Design Competition Fall 2019, University Of Nevada, Las Vegas Dec 2019

College Of Engineering Senior Design Competition Fall 2019, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …


Thermodynamic Model Of Co2 Deposition In Cold Climates, Sandra K. S. Boetcher, Ted Von Hippel, Matthew J. Traum Dec 2019

Thermodynamic Model Of Co2 Deposition In Cold Climates, Sandra K. S. Boetcher, Ted Von Hippel, Matthew J. Traum

Publications

A thermodynamic model, borrowing ideas from psychrometric principles, of a cryogenic direct-air CO2-capture system utilizing a precooler is used to estimate the optimal CO2 removal fraction to minimize energy input per tonne of CO2. Energy costs to operate the system scale almost linearly with the temperature drop between the ingested air and the cryogenic desublimation temperature of CO2, driving siting to the coldest accessible locations. System performance in three Arctic/Antarctic regions where the proposed system can potentially be located is analyzed. Colder ambient temperatures provide colder system input air temperature yielding lower CO2 removal energy requirements. A case is also …


Energy And Exergy Analysis Of A Novel Multiple-Effect Vapor Chamber Distillation System For High-Salinity Wastewater Treatment, Hamidreza Shabgard, Ramkumar Parthasarathy, Ben Xu Dec 2019

Energy And Exergy Analysis Of A Novel Multiple-Effect Vapor Chamber Distillation System For High-Salinity Wastewater Treatment, Hamidreza Shabgard, Ramkumar Parthasarathy, Ben Xu

Mechanical Engineering Faculty Publications and Presentations

A novel modular thermally-driven multiple-effect vapor chamber distillation (MVCD) system is presented for compact and portable desalination applications. The MVCD system consists of several vapor chambers connected in series with the condenser section of the upstream vapor chambers serving as the evaporator section of the following effect. A heat transfer model accounting for the major thermal resistances was developed to predict the heat transfer and distilled water production rates. A mass transfer analysis was performed to evaluate the effect of the accumulation of the non-condensable gasses within the chambers. An exergy analysis was also conducted to quantify the efficiency of …


Pressure Effect On An Ocean-Based Humidification-Dehumidification Desalination Process, Yingchen Yang Oct 2019

Pressure Effect On An Ocean-Based Humidification-Dehumidification Desalination Process, Yingchen Yang

Mechanical Engineering Faculty Publications and Presentations

A new humidification-dehumidification (HDH) desalination process is proposed and analyzed. Being ocean based, the process does not produce any brine. It is largely powered jointly by solar energy, wind energy, and various types of ocean energies in a nearly natural way. A vacuum pump is employed to drive the air circulation throughout the HDH process. It is the only unit that consumes electricity. The HDH process is analyzed under various conditions, including using a low pressure (as low as to 0.2 atm) for humidification and the ambient pressure for dehumidification, running the entire HDH process around a low pressure (as …


Designing An Accessible Wave Energy Conversion Device For Powering Ocean Sensors, Sophie Coppieters ‘T Wallant Oct 2019

Designing An Accessible Wave Energy Conversion Device For Powering Ocean Sensors, Sophie Coppieters ‘T Wallant

Independent Study Project (ISP) Collection

Currently, less than 5% of our oceans are comprehensively monitored and much more ocean data is needed to facilitate understanding of ocean physics, carbon cycling, and ocean ecosystems. Today, most autonomous ocean sensors are powered by primary battery, which have both limited capacity and lifetime. The goal of this research is to design a small, accessible renewable wave energy device to power autonomous free-floating ocean sensors. By designing a cheap, accessible, and simple wave energy converter, this work hopes to make ocean sensor deployment easier and cheaper for researchers, increase the lifetime of autonomous ocean sensors, and reduce the reliance …


Assessing The Implications Of A Tidal Barrage Power Plant In Hvalfjörður, Iceland, Olive M. Colangelo Oct 2019

Assessing The Implications Of A Tidal Barrage Power Plant In Hvalfjörður, Iceland, Olive M. Colangelo

Independent Study Project (ISP) Collection

As climate change continues to threaten the future state of our world, we are searching for measures to take for mitigation. Among these measures, the most talked about method is the development of renewable energies. Great amounts of attention is paid to solar and wind power, but relatively little effort is given to researching the possibilities of ocean energy, particularly tidal barrage energy. This study assesses the possibility of a tidal barrage plant in Hvalfjörður, Iceland. This hypothetical power plant in Hvalfjörður would have an installed capacity of 840MWh and could produce 613GWh per year. This is less than 0.01% …


Energy Transformation And Conservation Investigation, Mike Jackson, Holly Haney Jul 2019

Energy Transformation And Conservation Investigation, Mike Jackson, Holly Haney

High School Lesson Plans

Students will use a thermoelectric generator module to analyze the relationship between thermal and electrical energies. Using data collection sensors and analysis software, students will investigate the relationship between the temperature gradient across a thermoelectric generator module and the resulting electrical potential. Students will then use their data and analysis to solve problems relating to waste thermal energy in electrical systems and communicate their work to their peers and teacher.


College Of Engineering Senior Design Competition Spring 2019, University Of Nevada, Las Vegas May 2019

College Of Engineering Senior Design Competition Spring 2019, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …


Design Of A Portable Biogas Purification And Storage System, Anikumar Kosna, Bade Shrestha Mar 2019

Design Of A Portable Biogas Purification And Storage System, Anikumar Kosna, Bade Shrestha

Faculty Research and Creative Activities Award (FRACAA)

The objective of this study is to propose and design a commercial portable purification and storage system to commercialize biogas (which mainly consists of 45 - 75 % of methane and 15 - 16% of carbon dioxide), produced from household/non-commercial biogas plants. The selection of purification process is based on the portability of the purification system.


A Total Life Cycle Approach For Developing Predictive Design Methodologies To Optimize Product Performance, Buddhika M. Hapuwatte, Ibrahim S. Jawahir Jan 2019

A Total Life Cycle Approach For Developing Predictive Design Methodologies To Optimize Product Performance, Buddhika M. Hapuwatte, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Sustainable products must be designed by considering how design decisions impact their total life cycle (TLC) sustainability content. Even more so important when designing products to incorporate the technological elements of sustainable manufacturing, the 6Rs (Reduce, Reuse, Recycle, Recover, Redesign and Remanufacture), to achieve Circular Economy (CE). This paper presents the preliminary work of an ongoing research project on developing a novel framework incorporating predictive models with TLC considerations. This unique approach develops and integrates models with associated risks, and optimizes for maximizing the sustainability benefits due to design decisions. Such predictive capability is extremely useful for process planning, where …


Process Sustainability Evaluation For Manufacturing Of A Component With The 6r Application, Ana E. Bonilla Hernández, Tao Lu, Tomas Beno, Claes Fredriksson, Ibrahim S. Jawahir Jan 2019

Process Sustainability Evaluation For Manufacturing Of A Component With The 6r Application, Ana E. Bonilla Hernández, Tao Lu, Tomas Beno, Claes Fredriksson, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

Sustainability in manufacturing can be evaluated at product, process and system levels. The 6R methodology for sustainability enhancement in manufacturing processes includes: reduced use of materials, energy, water and other resources; reusing of products/components; recovery and recycling of materials/components; remanufacturing of products; and redesigning of products to utilize recovered materials/resources. Although manufacturing processes can be evaluated by their productivity, quality and cost, process sustainability assessment makes it a complete evaluation. This paper presents a 6R-based evaluation method for sustainable manufacturing in terms of specific metrics within six major metrics clusters: environmental impact, energy consumption, waste management, cost, resource utilization and …


Sustainable Production Through Balancing Trade-Offs Among Three Metrics In Flow Shop Scheduling, Amin Abedini, Wei Li, Fazleena Badurdeen, Ibrahim S. Jawahir Jan 2019

Sustainable Production Through Balancing Trade-Offs Among Three Metrics In Flow Shop Scheduling, Amin Abedini, Wei Li, Fazleena Badurdeen, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

In sustainable manufacturing, inconsistencies exist among objectives defined in triple-bottom-lines (TBL) of economy, society, and environment. Analogously, inconsistencies exist in flow shop scheduling among three objectives of minimizing total completion time (TCT), maximum completion time (MCT), and completion time variance (CTV), respectively. For continuous functions, the probability is zero to achieve the objectives at their optimal values, so is it at their worst values. Therefore, with inconsistencies among individual objectives of discrete functions, it is more meaningful and feasible to seek a solution with high probabilities that system performance varies within the …


Designing And Redesigning Products, Processes, And Systems For A Helical Economy, Ryan Bradley, Ibrahim S. Jawahir Jan 2019

Designing And Redesigning Products, Processes, And Systems For A Helical Economy, Ryan Bradley, Ibrahim S. Jawahir

Institute for Sustainable Manufacturing Faculty Publications

The Circular Economy (CE) concept has promised to unlock trillions of dollars in business value while driving a significant reduction in the world’s resource consumption and anthropogenic emissions. However, CE mainly lives in ambiguity in the manufacturing domain because CE does not address the changes needed across all of the fundamental elements of manufacturing: products, processes, and systems. Conceptually, CE is grounded in the concept of closed-loop material flows that fit within ecological limits. This grounding translates into a steady state economy, a result that is not an option for the significant portion of the world living in poverty. Therefore, …