Engineering Commons^™

A New Capacity Controller For A Direct Expansion Air Conditioning System For Operational Safety And Efficiency., Yudong Xia, Huaxia Yan, Shiming Deng, Ming-Yin Chan

Faculty of Science & Technology (THEi)

For achieving a balance between the operational safety and efficiency of a variable speed direct expansion air conditioning system, a new capacity controller that can not only simultaneously control indoor air temperature and humidity, but also select an optimized degree of superheat setting to properly balance the operational safety and efficiency has been developed, by adding a control module to a previously developed capacity controller. The core of the control module was an artificial neural network based model representing the known relationship between the inherent operational characteristics and operational stability of a variable speed direct expansion air conditioning system. Using …

Investigation On Solar Assisted Liquid Desiccant Dehumidifier And Evaporative Cooling System For Fresh Air Treatment., Yi Chen, Hongxing Yang, Yimo Luo

Faculty of Science & Technology (THEi)

The widely used semi-centralized air conditioning (A/C) system consisting of independent fresh air system and fan coil system suffers from huge energy consumption, especially for fresh air treatment. Therefore, a liquid desiccant dehumidifier and regenerative indirect evaporative cooling (LDD-RIEC) system is proposed for fresh air treatment. The fresh air is handled by the LDD-RIEC system in which no electricity-intensive compressor involves. The hot and humid fresh air is firstly dehumidified by LDD and then sensibly cooled by RIEC. The thermal energy captured by solar collectors is used for desiccant solution regeneration. Indoor return air is cooled by fan coils of …

Development And Experimental Study Of A Novel Plate Dehumidifier Made Of Anodized Aluminum., Tao Wen, Lin Lu, Chuanshuai Dong, Yimo Luo

Faculty of Science & Technology (THEi)

The falling film dehumidifier is a key component in the liquid desiccant cooling system (LDCS). However, the most commonly used metals, such as steel and aluminum, can hardly resist the erosion of liquid desiccant. It greatly limits the fabrication of compact dehumidifiers and hinders the promotion of LDCS. The present study introduced a novel falling film dehumidifier which was made by the metal of anodized aluminum. Experiments were carried out to compare the dehumidification performance between ordinary aluminum dehumidifier and anodized one. The influences of air temperature, mass flow rate, inlet humidity and solution temperature, mass flow rate, temperature on …

The Rock 2018, School Of Engineering And Computer Science

The Rock

No abstract provided.

Rapid And Damage-Free Outgassing Of Implanted Helium From Amorphous Silicon Oxycarbide, Qing Su, Hepeng Ding, Lloyd Price, Lin Shao, Jonathan A. Hinks, Graeme Greaves, Stephen E. Donnelly, Michael J. Demkowicz, Michael Nastasi

Nebraska Center for Energy Sciences Research: Publications

Damage caused by implanted helium (He) is a major concern for material performance in future nuclear reactors. We use a combination of experiments and modeling to demonstrate that amorphous silicon oxycarbide (SiOC) is immune to He-induced damage. By contrast with other solids, where implanted He becomes immobilized in nanometer-scale precipitates, He in SiOC remains in solution and outgasses from the material via atomic-scale diffusion without damaging its free surfaces. Furthermore, the behavior of He in SiOC is not sensitive to the exact concentration of carbon and hydrogen in this material, indicating that the composition of SiOC may be tuned to …

Visible Light Crosslinkable Human Hair Keratin Hydrogels, Kan Yue, Yanhui Liu, Batzaya Byambaa, Vaishali Singh, Wanjun Liu, Xiuyu Li, Yunxia Sun, Yu Shrike Zhang, Ali Tamayol, Peihua Zhang, Kee Woei Ng, Nasim Annabi, Ali Khademhosseini

Department of Mechanical and Materials Engineering: Faculty Publications

Keratins extracted from human hair have emerged as a promising biomaterial for various biomedical applications, partly due to their wide availability, low cost, minimal immune response, and the potential to engineer autologous tissue constructs. However, the fabrication of keratin-based scaffolds typically relies on limited crosslinking mechanisms, such as via physical interactions or disulfide bond formation, which are time-consuming and result in relatively poor mechanical strength and stability. Here, we report the preparation of photocrosslinkable keratin-polyethylene glycol (PEG) hydrogels via the thiol-norbornene “click” reaction, which can be formed within one minute upon irradiation of visible light. The resulting keratin-PEG hydrogels showed …

Multivariate Analysis Of Students Perception On Teaching With Client Based And Non-Client Based Team Projects, Philip Appiah-Kubi

Engineering Management and Systems Faculty Publications

The classroom experience has evolved from traditional lecture, PowerPoint and whiteboards to a more active environment where students and instructors work together on hands-on activities to achieve the course objectives. Various names have been given to this pedagogy; experiential learning, project based learning (client based versus non-client based), active learning, and problem based learning are a handful of names used to describe this evolving pedagogy. The main challenge faced by educators in educating undergraduate students to be independent thinkers and problem solvers has been the driving force fueling the shift in pedagogy. This research looks into student’s perception on project …

John Frank Stevens: Panama Canal Mastermind And Pioneering Railroad Pathfinder, J. David Rogers, Lawrence M. Magura

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

John Frank Stevens began his civil engineering career as a rodman on a survey crew in Maine in 1872. He soon moved to Minneapolis, where he apprenticed himself, eventually becoming Assistant City Engineer. In 1876 he began working for railroads in the western United States. In 1882 Stevens began working for a contractor laying tracks for the Canadian Pacific Railroad in Saskatchewan. The next spring he became assistant engineer of location for the Canadian Pacific, completing the first transcontinental line linking Montreal with Vancouver in 1888. In 1889 James Jerome Hill retained Stevens as chief pathfinder for the new Great …

Mech 237-101-103: Strength Of Materials, Elizabeth Castro

Civil and Environmental Engineering Syllabi

No abstract provided.

Performance Trades For Multiantenna Gnss Multisensor Attitude Determination Systems, Nathan A. Tehrani, Jason N. Gross

Faculty & Staff Scholarship

We present various performance trades for multiantenna global navigation satellite system (GNSS) multisensor attitude estimation systems. In particular, attitude estimation performance sensitivity to various error sources and system configurations is assessed. This study is motivated by the need for system designers, scientists, and engineers of airborne astronomical and remote sensing platforms to better determine which system configuration is most suitable for their specific application. In order to assess performance trade-offs, the attitude estimation performance of various approaches is tested using a simulation that is based on a stratospheric balloon platform. For GNSS errors, attention is focused on multipath, receiver measurement …

Further Development Of A Thermal Comfort Based Fuzzy Logic Controller For A Direct Expansion Air Conditioning System, Huaxia Yan, Yan Pan, Zhao Li, Shiming Deng

Faculty of Science & Technology (THEi)

The primary purpose of A/C is offering occupants with acceptable indoor thermal comfort levels. Thermal comfort is a complicated result of non-linear interactions between six parameters. However, many of current A/C systems solely control air temperature. Whenever anyone of the five parameters other than temperature varies significantly, an occupant may feel thermally uncomfortable. To address the issue, a comprehensive thermal comfort index should be used as regulator in A/C systems. One fuzzy logic controller is available. However, the approach to the fuzzy logic controller is complicated. In this paper, one previous established fuzzy logic controller is simplified for its real …

Impact Of Sustainable Product Design On Elderly Ergonomics, Tris Kee, Alex King

Faculty of Design & Environment (THEi)

No abstract provided.

Title: Investigation Of Oxidative Reduction Reactions In Carbon-Based Electrocatalysts Presentation, Andrew Mason, Siamak Nejati, Shayan Kaviani

UCARE: Research Products

The expense of commonly used electrocatalysts such as Platinum and Palladium, make many battery technologies and electrochemical reactions cost-prohibitive. A new group of promising low-cost catalysts is doped carbon complexes. These materials need further development to reach the same activity as traditional catalysts. But by examining the Oxidative Reduction Reactions (ORR) of various carbon complexes, desirable characteristics and geometries can be identified and enhanced. For this comparative analysis, a series of Carbon Nanotube (CNT) and Graphene Complexes were tested.

Engineering Hyaluronic Acid Carbon Nanotube Nanofibers: A Peripheral Nerve Interface To Electrically Stimulate Regeneration, Elisabeth M. Steel

Wayne State University Dissertations

Peripheral nerve injuries annually affect hundreds of thousands of people globally. Current treatments like the gold standard autograft and commercially available nerve guide conduits (NGC) are insufficient to repair long gap peripheral nerve injuries. NGCs can aid recovery but lack key microenvironment cues that promote nerve regeneration. We hypothesized that providing topographical, mechanical, and electrical guidance cues through a nanofibrous composite biopolymer would result in improved neuron growth metrics using an in vitro model. We embedded hydrophilic carbon nanotubes (CNT) within hyaluronic acid (HA) nanofibers by electrospinning. The aims of this study were (1) to define the topographical, nanomechanical, and …

The Social, Educational, And Market Scenario For Nzeb In Europe, Evangelia Topriska, Maria Kolokotroni, Daniela Melandri, Simon Mcguinness, Andrei Ceclan, Georgios C. Christoforidis, Fazio Vittoria, Maria Hadjpannayi, Patrick Hendrick, Marija Kacarska, López Lopez, Kaj Leonhart Petersen, Jutta Steinbrecher

Articles

Nearly Zero Energy Buildings (nZEB) are a significant part of the energy efficiency strategy of the European Union. As buildings represent approximately 40% of the final energy use in Europe, the reduction of their energy demand is key for a sustainable future. This paper takes a qualitative approach and presents data about professional and market barriers, as well as the educational market in relation to the implementation of nZEB policies for new and retrofit buildings in 11 European countries. Different levels of policy enactments and market penetration are reported and are generally found to be more advanced in western and …

Exercise Machine Generator, Duane Harbick

All Undergraduate Projects

Exercise “spinning bikes” and bicycle training stands are common ways to maintain fitness and train for cycling. This exercise necessitates the user putting work into the machine by means of pedaling. In many instances the work put into exercise bikes and training stands is not taken advantage of. The objective of this project is an attempt to make use of some of the energy that a person would usually expend during exercise by building a generator that interfaces with multiple spinning bikes and training stands. It uses a synchronous pulley system to interface with the exercise machine and spin a …

Asme Rc Baja Challenge: Suspension And Steering, Hunter W. Jacobson

All Undergraduate Projects

The American Society of Mechanical Engineers (ASME) usually hosts an RC Baja challenge each year, testing a RC car in three events: slalom, acceleration and Baja. Although ASME will not be holding an event this year, CWU will be holding a similar event with three RC Baja car teams from CWU. The RC car that is tested in these events is designed and manufactured typically in teams of two. The RC car that each team submits must be able to complete these events while also remaining competitive. One part of great importance for the RC car is the suspension and …

Easy Install Outboard Motor Mount, Doug Dunbar

All Undergraduate Projects

The boating industry can be expensive for the typical weekend boater. That is, keeping, maintaining, and using a boat and all of its various accessories is a constant cost for the owner. In the Midwest and inland it is necessary to store boats and outboard boat motors out of the inclement weather and harsh conditions of seasonal change. Specifically, removing or installing an expensive and awkward outboard motor can be both dangerous financially and physically (damage or injury). It is not uncommon for motors to cost several thousand dollars.

The purpose of this project was to research, design, and implement …

Cwu Bottle Opener Manufacturing, Austin Sanford

All Undergraduate Projects

Previous students from the Mechanical Engineering Technology program came up with a method to help raise funds and awareness for the program. The idea was to manufacture and sell CWU bottle openers. However, a more efficient manufacturing method was needed. The aspect of the process that would have the most impact on the manufacturing time and material efficiency was the CNC machining of the parts. There were many potential variables to change to improve the process, but the main changes were to the cutter speeds and stock material size. Consequently, the changes made to stock material size reduced the number …

Asme R/C Baja Car, Torrie Large

All Undergraduate Projects

How does one build a car? Do they start with the tires and build inward or do they develop separate aspects at the same time? This remote-controlled car was designed and built with the intention of competing in the annual Baja Competition. There are three competitions: sprinting, slalom, and an obstacle course. The suspension system of this car must be designed to support the car for both the physical build and the competitiveness. It must do this without interfering with the drive train and steering mechanism designed by Doug Erickson. The suspension system employs suspension arms attached to the chassis …

Seawater Distiller (Solar Collector For Heating Seawater), Ali Alismail

All Undergraduate Projects

Many people in the world globally have limited or no access to clean drinking water. Unclean drinking water is a major cause of deadly diseases such as typhoid, cholera, and other water-borne diseases. The motivation of this report aims to document a senior project to satisfy for the award of MET by CWU. The aim was to design and manufacture a solar thermal collector capable of heating water using solar energy. The solar collector was developed by designing and fabricating a parabolic reflective surface. The reflective surface was manufactured from a reflective stainless-steel sheet. The advantages of using a parabolic …

Cassette Lockring Removal Tool, Kyle Wright

All Undergraduate Projects

Removal of a bicycle cassette requires additional tools to hold the cassette in place while loosening the cassette lockring. Typically a tool called a chain whip is used to stabilize the cassette, but is difficult to quickly and correctly apply to the cassette. Due to the need for an additional tool to hold the cassette, the user is faced with utilizing both hands while still needing to somehow hold the wheel in place. The lockring is torqued relatively tight and the overall combination of force, ergonomics, and number of tools required makes the task difficult to perform quickly. The objective …

H.F. Hauff Pruner Cutting Blades, Wyley Stewart

All Undergraduate Projects

Apple orchards are a critical component of agriculture in the United States, and keeping the apple trees in the best shape for optimum growth and production is hard work. Neil Hauff, an agriculture industry expert, challenged students at CWU to engineer a power assisted tree pruner. Across the country, apple orchards need pruned every season. The pruning of the trees is strenuous manual labor that requires many man hours. The proposed solution is to create a power assisted tree pruner that would minimize the amount of work needed to trim each tree branch. This project has been separated into three …

Flow Control Of Tandem Cylinders Using Plasma Actuators, Jonah Larsen

Honors Undergraduate Theses

The flow over a set of tandem cylinders at a moderate Reynolds numbers (Re), and with different separation lengths has been studied. Two dimensional (2D) and three-dimensional (3D) plasma actuators were used to control the flow over the leading cylinder to change the vortex shedding, and subsequently the flow on the second cylinder. The 3D plasma actuator was segmented along the length of the cylinder with a spacing of λ = 4 while the 2D actuator simply ran straight down the span of the cylinder. Particle image velocimetry (PIV) measurements were used to investigate the flow along the central plane …

Mechanical Properties Of The Skeleton Of Acropora Cervicornis, Bridget Masa

Honors Undergraduate Theses

This research explores the instantaneous mechanical behavior of the skeleton of the critically endangered staghorn coral Acropora cervicornis. Both bleached and sanded skeletons were used in this experiment. The Raman spectroscopy test showed that there was no significant change in the Raman shift between the three branches tested. The shifts were nearly identical to Raman shifts of calcium carbonate. Vickers hardness test found that 1 Bleached had the average hardness of 3.44 GPa with a standard deviation of 0.12 GPa. The sanded sample also had a similar value of 3.54 GPa with a standard deviation of 0.13 GPa. Samples from …

Surfactant Driven Assembly Of Freeze-Casted, Polymer-Derived Ceramic Nanoparticles On Grapehene Oxide Sheets For Lithium-Ion Battery Anodes, Ali Zein Khater

Honors Undergraduate Theses

Traditional Lithium-Ion Batteries (LIBs) are a reliable and cost-efficient choice for energy storage. LIBs offer high energy density and low self-discharge. Recent developments in electric-based technologies push for replacing historically used Lead-Acid batteries with LIBs. However, LIBs do not yet meet the demands of modern technology. Silicon and graphene oxide (GO) have been identified as promising replacements to improve anode materials. Graphene oxide has a unique sheet-like structure that provides a mechanically stable, light weight material for LIB anodes. Due to its structure, reduced graphene oxide (rGO) is efficiently conductive and resistive to environmental changes. On the other hand, silicon-based …

A Machine Learning Approach To Assess The Separation Of Seismocardiographic Signals By Respiration, Brian Solar

Honors Undergraduate Theses

The clinical usage of Seismocardiography (SCG) is increasing as it is being shown to be an effective non-invasive measurement for heart monitoring. SCG measures the vibrational activity at the chest surface and applications include non-invasive assessment of myocardial contractility and systolic time intervals. Respiratory activity can also affect the SCG signal by changing the hemodynamic characteristics of cardiac activity and displacing the position of the heart. Other clinically significant information, such as systolic time intervals, can thus manifest themselves differently in an SCG signal during inspiration and expiration. Grouping SCG signals into their respective respiratory cycle can mitigate this issue. …

Safety Assessment And Risk Estimation For Unmanned Aerial Vehicles Operating In National Airspace System, Xuejun Zhang, Yang Liu, Yu Zhang, Xiangmin Guan, Daniel Delahaye, Li Tang

Civil and Environmental Engineering Faculty Publications

This paper proposes an effective approach for modelling and assessing the risks associated with unmanned aerial vehicles (UAVs) integrated into national airspace system (NAS). Two critical hazards with UAV operations are considered and analyzed, which are ground impacts and midair collisions. Threats to fatalities that result from the two hazards are the focus in the proposed method. In order to realize ground impact assessment, a multifactor risk model is designed by calculating system reliability required to meet a target level of safety for different UAV categories. Both fixed-wing and rotary-wing UAVs are taken into account under a real scenario that …

Oil Droplet Transport Under Non-Breaking Waves: An Eulerian Rans Approach Combined With A Lagrangian Particle Dispersion Model, Roozbeh Golshan, Michel C. Boufadel, Victor A. Rodriguez, Xiaolong Geng, Feng Gao, Thomas King, Brian Robinson, Andres E. Tejada-Martinez

Civil and Environmental Engineering Faculty Publications

Oil droplet transport under a non-breaking deep water wave field is investigated herein using Computational Fluid dynamics (CFD). The Reynolds-averaged Navier–Stokes (RANS) equations were solved to simulate regular waves in the absence of wind stress, and the resulting water velocities agreed with Stokes theory for waves. The RANS velocity field was then used to predict the transport of buoyant particles representing oil droplets under the effect of non-locally generated turbulence. The RANS eddy viscosity exhibited an increase with depth until reaching a maximum at approximately a wave height below the mean water level. This was followed by a gradual decrease …

A Systems Analysis Of Factors Influencing Household Solar Pv Adoption In Santiago, Chile, Jeffrey Walters, Jessica Kaminsky, Lawrence Gottschamer

Civil and Environmental Engineering Faculty Publications

Societal uptake of household solar photovoltaic (PV) technology is the result of a complex and interdependent array of technical, social, political and economic factors. This novel study employs a systems lens to examine both technical and non-technical barriers to renewables, with a focus on interactions that are empirically influential on PV uptake. Using local solar expert stakeholder input into a participatory systems approach, this study provides a structural analysis of factors influencing household solar adoption. The approach is applied and assessed for household solar PV systems in Santiago, Chile, to gain insight into the interconnected factors driving technology adoption. Barriers …