Engineering Commons^™

1/Fnoise Modelling And Characterization For Cmos Quanta Image Sensors, Wei Deng, Eric R. Fossum

Dartmouth Scholarship

This work fits the measured in-pixel source-follower noise in a CMOS Quanta Image Sensor (QIS) prototype chip using physics-based 1/f noise models, rather than the widely-used fitting model for analog designers. This paper discusses the different origins of 1/f noise in QIS devices and includes correlated double sampling (CDS). The modelling results based on the Hooge mobility fluctuation, which uses one adjustable parameter, match the experimental measurements, including the variation in noise from room temperature to –70 °C. This work provides useful information for the implementation of QIS in scientific applications and suggests that even lower read noise is attainable …

Human-Centered Data Visualizations And Web Layouts For Life-Cycle Assessment Design Guides, Jonathan Klein

ENGS 86 Independent Projects (AB Students)

User tests with 30 Dartmouth Engineering and STEM undergraduates were performed to investigate preferences toward a set of data visualizations and web layouts showing life-cycle assessment data and corresponding uncertainty. The data was collected and synthesized from academic papers, corporate manufacturers, and self-generated using the LCA software Sustainable Minds. A variety of visualizations were produced to accurately and aesthetically represent the data graphically, and especially understand how non-technical audiences interact with different displays of uncertainty, which is a key component of data visualization that is lacking from most LCA design guides. Web layouts were produced to present key information about …

Group Iv Environmentally Benign, Inexpensive Semiconductor Nanomaterials For Solar Cells, Lisa Je

ENGS 86 Independent Projects (AB Students)

Modern solar cells are composed of silicon, cadmium tellurium, and copper indium gallium diselenide. While these materials are efficient, elements such as cadmium and indium are rare and expensive. To make this renewable energy source more inexpensive and sustainable, the Liu Optics lab is substituting expensive rare earth metals for more commonly found transition state metals. Work has been done to replace the solar cell layers composed of cadmium and gallium to replace them with glass, silicon, and/or thin films. Common metals such as germanium and tin are investigated and characterized to provide a platform for solar cell components.

Developing A Control System To Better Understand The Effects Of Pyruvate Decarboxylase Activity On Clostridium Thermocellum Metabolism, Nicholas Cervenka

ENGS 88 Honors Thesis (AB Students)

In order for cellulosic biofuels from Clostridium thermocellum to be commercially viable, the ethanol yield and titer of the microbe must be increased. To accomplish this, it has been suggested to introduce the Pyruvate Decarboxylase (PDC) enzyme into C. thermocellum. In order to demonstrate effects on ethanol production by PDC prior to genetic modification, a cell free system (CFS) has been developed. A purified enzyme system was developed with the CFS to function as a control. Using the purified enzyme system, PDC from Saccharomyces cerevisiae was demonstrated to be a good candidate for further testing in the CFS.

Shape Effects Of Gold Coated Silica Nanoparticles For Localized Plasmonic Resonance Based Biosensing, Russell Beckerman

ENGS 88 Honors Thesis (AB Students)

Gold coated silica (Au@SiO₂) nanoparticles are promising optical transducers for biosensors due to localized surface plasmonic resonance (LSPR) sensitivity to changes in refractive index. This study investigates the effects of shape, size, and structure on LSPR sensitivity of Au@SiO₂ nanoparticles of spherical, rod, and ellipsoid geometries. Finite-difference time domain simulations in CST were used to examine these key parameters of interest and guided particle synthesis. Simulation and experiments show rod-shaped Au@SiO₂ nanoparticles had maximum sensitivity of 969nm/RIU, an improvement over most particles in current literature. This study examines a method for enhanced LSPR-biosensors that leverages advances …

Bandpass: A Smart Resistance Exercise Band To Monitor Strength, Suehayla Mohieldin

ENGS 88 Honors Thesis (AB Students)

Resistance exercise bands are being incorporated into clinical weight loss programs, particularly for older adults, as resistance training can mitigate the trajectory of muscle mass and bone density loss that can occur while dieting. However, adherence to home-based treatments cannot be reliably ascertained by clinicians as there is no method for clinicians to monitor patient compliance outside of the clinic. BANDPASS, a smart resistance band used for exercise, was developed to bridge the gap between clinicians and patients, allowing for easy remote monitoring of patients’ exercise performance. The device integrates a 10kΩ linear potentiometer to TheraBand® tubing. When the user …

A Physical And Computational Reverse-Engineering Approach To Determine Dimensional Change And Its Relationship To Oxidation In Retrieved Orthopedic Implants, Josephine Kalshoven

ENGS 88 Honors Thesis (AB Students)

Oxidation of the Ultra-High Molecular Weight Polyethylene (UHMWPE) tibial inserts of total knee arthroplasty devices is a major factor underlying multiple modes of failure for these devices, including delamination, wear, and fracture. Previous research has demonstrated that oxidation of UHMWPE is driven by a high concentration of free radicals in the polyethylene. However, even new devices created with undetectable amounts of free radicals are oxidizing in vivo. One theory is that, in the absence of residual free radicals, oxidation is facilitated by absorbed species (e.g. lipids, ROS) delivered or exacerbated by contact stress. However, no method exists to comprehensively …

Evaluating The Potential For Renewable Energy Technology At Us Ski Resorts, Tyler Farrell

ENGS 86 Independent Projects (AB Students)

The ski industry is one of the most at-risk industries as a result of climate change. Warming temperatures and decreasing snowfall are contributing to a decline in skier visitations, shorter seasons, and higher energy costs. Currently, only 3 of 478 ski resorts in the United States rely on 100% renewable energy sources. The intent of this paper is to understand what the issues and barriers are to renewable energy development at ski resorts, and what technologies are feasible and appropriate for this industry to develop. While the renewable energy industry faces many issues and barriers, the ski industry faces its …

Development Of An Rfid Tracking System For Coarse Sediment Transport In A Flume Setting, Peter Mahoney Jr.

ENGS 88 Honors Thesis (AB Students)

Development of an RFID Tracking System for Coarse Sediment Transport in a Flume Setting

Peter E. Mahoney

Professor Carl Renshaw

Understanding how sediment moves through a fluvial system has important implications for the study of river systems, sediment flux, and flood events. Over the past decade, RFID (radio frequency identification) technology has emerged as a useful method for tracking the movement and transport of coarse sediment clasts. This approach has been used to measure the transport of large clasts in mid-sized streams, ephemeral channels, and laboratory flume settings. However, this research utilized finite transport of sediment and focused on accurately …

Surface Engineering Of Annealed High Entropy Alloys Towards Thermodynamically Stable, Anti-Oxidation, Solar Selective Absorbers, Sheppard R. Somers

ENGS 88 Honors Thesis (AB Students)

Concentrating solar power (CSP) systems require receivers that maintain their physical properties at the high operating temperature and are absorbent. The high entropy alloy Fe28.2Ni18.8Mn32.9Al14.1Cr6 (HEA) investigated in this thesis fills these needs by harnessing the HEA’s oxidation process to create a selective solar absorbing layer that grows at a parabolic rate at CSP operating temperatures. Results of this research demonstrate that annealing processes of HEA can yield over 90% solar thermal efficiency by engineering the surface oxidation to be both physically and optically optimized for absorption.

Spatial Frequency Domain Imaging Of Short-Wave Infrared Fluorescence For Biomedical Applications, Joseph P. Leonor

ENGS 88 Honors Thesis (AB Students)

Fluorescence imaging has become a standard in many clinical applications, such as tumor and vasculature imaging. One application that is becoming more prominent in cancer treatment is fluorescence-guided surgery (FGS). Currently, FGS allows surgeons the ability to visually navigate tumors and tissue structures intraoperatively. As a result, they can remove tumor more efficiently while maintaining critical structures within the patient, creating better outcomes and lower recovery times. However, background fluorescence and inability to localize depth create challenges when determining resection boundaries.

Different techniques, such as spatially modulating the illumination and imaging at longer light wavelengths, have been developed to accurately …

Feasibility Study Of Dartmouth's Renewable Energy Future, Lily R. Hanig

ENGS 88 Honors Thesis (AB Students)

This is a feasibility study of Dartmouth's Renewable Energy propositions. This study analyzes the carbon offsets of implementing a 13 MW solar PV system at Oak Hill. This study used the Energy Database to calculate the carbon emissions of the college for 2010 (the baseline year) and 2018. It also projected carbon emissions for the year 2025 assuming the Oak Hill solar PV system is implemented as outlined and the biomass plant is implemented with similar fuel ratios to nearby biomass plant projects. It was found that Dartmouth should sufficiently make its carbon emissions reductions goals for 2025.

Mascoma River Greenway Extension, Isalys Quiñones

ENGS 86 Independent Projects (AB Students)

In July of 2018, the Mascoma River Greenway (MRG), a 2.2-mile rail trail extending from Downtown Lebanon, NH to Glen Road in West Lebanon, NH, was completed with the help of the MRG Coalition, the Friends of the Northern Rail Trail, Lebanon Recreation and Parks, and members of the City of Lebanon. Initially, this trail was proposed to extend from Downtown Lebanon to Downtown West Lebanon and White River Junction (WRJ). With pushback from the State of New Hampshire to lease the City of Lebanon recreational usage to the New Hampshire State Department of Transportation (NHDOT) owned rail corridor, the …

Modeling The Economic Machine Using Bayesian Inference And Statistical Networks, And Optimal Portfolio Construction Using Operations Research, Richard Yang

ENGS 88 Honors Thesis (AB Students)

In this paper, we propose a network-based model to attempt to connect modern macroeconomic theory with real world economic observations and trends. We find that by extending macroeconomic theory with credit leveraging/deleveraging thresholds, we are able to explain economic cycles in addition to long-term growth. Furthermore, we specifically explore the growth-inflation view of the macro economy as a basis for optimal portfolio construction and efficient asset trading. Connecting our network-based macroeconomic model and our optimal portfolio construction algorithm, we create a novel macroeconomic asset-trading framework.

Biomedical Engineering Or Biomedical Optics: Will The Real Discipline Please Stand Up?, Brian W. Pogue

Dartmouth Scholarship

This editorial reflects on the shape of biomedical engineering as a discipline, and its relation to biomedical optics.

Comparing Past Board Assembly Inemi Roadmaps To Technology Outcomes, Annaka Rose Balch

ENGS 86 Independent Projects (AB Students)

This project compares past board assembly roadmaps with actual technological outcomes, examining the progression of predictions across seven significant aspects of board assembly covered in the 1994, 2002, 2007, 2013 and 2017 roadmaps: 1) Conversion Costs, 2) NPI Cycle Time, 3) Component Trends, 4) Solder Paste, 5) Bar Solder, 6) Wave Solder Flux and 7) Die Attach Adhesives. It should be noted that there are discrepancies between these roadmaps—from general outline to the many aspects of board assembly that are investigated. This project aims to bridge these discrepancies in a comprehensive fashion to better inform iNEMI and identify possible areas …

Soundboard: Planar Tracking For Instrument Control, Peter O'Sullivan

ENGS 86 Independent Projects (AB Students)

The Soundboard is the central component of Syrinx, a synthesizer instrument invented by Spencer Topel. A generated audio signal is transduced through the Soundboard, and by manually adjusting the positioning of its top metal plane, the user can manipulate the encased soundwaves before they are transduced back into a signal and output. My task for this project was to add controller functionality to the Soundboard component by implementing control voltages that carry information about its planar tilt, yaw, and altitude. These voltages can be used to modulate various digital parameters and further affect the sonic output of the instrument. Further, …

Functionalized Plasmonic Gold Nanorods On Chip For Circulating Tumor Dna Point Mutation Detection, George Cheng

ENGS 86 Independent Projects (AB Students)

Nanosensors utilizing the phenomenon of localized surface plasmon resonance (LSPR) have been gaining in popularity due to improved sensitivity and wider dynamic range of optical sensors. Liquid biopsy is a minimally invasive method of analyzing disease dynamics and many technologies have been developed for research laboratory settings. However, there remains a need to simplify the workflow and expand these technologies into point-of-care clinical settings. Functionalized gold nanoparticles dispersed on-chip represent a promising solution to this problem and could also be easily multiplexed to detect many different biomarkers on a single-chip. We are focused on the KRAS G12V point mutation of …

Characterizing Short-Wave Infrared Fluorescence Of Conventional Near-Infrared Fluorophores, Brook K. Byrd, Margaret R. Folaron, Joseph P. Leonor, Rendall R. Strawbridge, Xu Cao, Petr Bruza, Scott C. Davis

Dartmouth Scholarship

The observed behavior of short-wave infrared (SWIR) light in tissue, characterized by relatively low scatter and subdiffuse photon transport, has generated considerable interest for the potential of SWIR imaging to produce high-resolution, subsurface images of fluorescence activity in vivo. These properties have important implications for fluorescence-guided surgery and preclinical biomedical research. Until recently, translational efforts have been impeded by the conventional understanding that fluorescence molecular imaging in the SWIR regime requires custom molecular probes that do not yet have proven safety profiles in humans. However, recent studies have shown that two readily available near-infrared (NIR-I) fluorophores produce measurable SWIR fluorescence, …

Making Personal Goals More Achievable, Adam Carlson

ENGS 86 Independent Projects (AB Students)

Achieving long-term goals has a large impact on one’s life. However, this success requires focused, consistent work even when the achievement is not imminent. Presently, we turn to calendars and task management applications for help. But, these tools quickly become cluttered making it difficult to visualize progress. I created an iPhone application which emphasizes long-term thinking. First-time users must provide three long-term goals with deadlines. Then, they have the opportunity to add smaller, to-do items to their week. For each item, the user must specify a long-term goal to which it is associated. The long-term association ensures users stay focused.

Diagnostic Performance Of Receptor-Specific Surgical Specimen Staining Correlates With Receptor Expression Level, Jasmin M. Schaefer, Connor W. Barth, Scott C. Davis, Summer L. Gibbs

Dartmouth Scholarship

Intraoperative margin assessment is imperative to cancer cure but is a continued challenge to successful surgery. Breast conserving surgery is a relevant example, where a cosmetically improved outcome is gained over mastectomy, but re-excision is required in >25  %   of cases due to positive or closely involved margins. Clinical translation of margin assessment modalities that must directly contact the patient or required administered contrast agents are time consuming and costly to move from bench to bedside. Tumor resections provide a unique surgical opportunity to deploy margin assessment technologies including contrast agents on the resected tissues, substantially shortening the path to …

Ensuring Scientific Publishing Credibility In Translational Biomedical Optics., Brian W. Pogue

Dartmouth Scholarship

Optics has consistently been the largest singular technology sector used in medicine, and major advances in biomedical optics are documented daily in peer-reviewed publications. However, the academic stature of this field can be damaged by weaknesses in scientific publishing, where a “credibility crisis” has emerged as a popularized and increasingly studied dialogue. While there are still relatively few overt cases of fraud or erroneous research, more insidious aspects are seen in papers with results that have either low statistical power, selective reporting of observations, or data or computer codes that cannot be independently verified. Interestingly, the same solutions that improve …

Proposed Delivery And Return Water Temperatures For Dartmouth College Hot Water Network, Storm Mata

ENGS 86 Independent Projects (AB Students)

This study aimed to verify the viability of the planned hot water heating network at Dartmouth, and determine the necessary hot water radiator areas needed to satisfy the empirically-determined heat demand for buildings on campus, using 5 year of steam con- sumption data. In order to verify viability, the pressure and temperature of the delivery steam and return condensate of the current heating network were used to find the amount of heat delivered per pound of steam to campus. The above-mentioned steam consump- tion data were then used to find the max heat demand for the past five years and …

Correcting Human Errors In Rock Climbing, Regina Yan

ENGS 86 Independent Projects (AB Students)

In the sport of rock climbing, improper belay technique resulting from the belayer standing too far from the wall is a main source of accidents and injuries from lead climbing. This project aimed to correct human errors in lead belaying and climbing. The resulting product was the Belay Belt, a device that successfully measured the belayer’s distance from the wall and alerted the belayer when he or she exceeded a safe distance threshold.

Microfluidic Pcr On Gold Nanorods For Combined Screening And Detection Of Ctdna, Cathy Li

ENGS 86 Independent Projects (AB Students)

Microfluidics and liquid biopsy on chip are growing in popularity as a method of detection and analysis used in point of care devices. The advantages of liquid biopsy include minimal invasiveness, low cost, shorter time from analysis to results, and less consumption of sample and reagents. Liquid biopsy has shown the ability to detect small concentrations of a biomarker of interest. However, some biomarkers, such as circulating tumor deoxyribose nucleic acid (DNA), exist in very small concentrations that make detection challenging. The integration of miniaturized polymerase chain reaction (PCR) with liquid biopsy techniques is a promising solution. Gold nanoparticles are …

Pairing A Robot To A Virtual Entity To Provide Haptic Feedback In Virtual Reality, Tristan G. Fogt

ENGS 88 Honors Thesis (AB Students)

Virtual reality (VR) environments are most commonly used for entertainment and gaming, though are also employed in rehabilitative and professional contexts. Virtual reality systems currently have highly convincing visual and aural feedback, allowing for a superficially immersive experience for the user. However, these systems lack haptic feedback, breaking the immersive experience as soon as the user tries to interact with a virtual object or entity physically, which severely limits the uses of VR.

To solve this, instead of the conventional approach of trying to simulate feeling something that isn’t actually there, a physical robot was created to exist in real …

Impact In Practice, Maria Garman

ENGS 88 Honors Thesis (AB Students)

Medial Tibial Stress Syndrome (Shin splits) is an overuse injury caused by repetitive impact. If ignored it can lead to stress reactions and then stress fractures in the shins. This nagging injury is something that plagues many track athletes especially as they start to wear their competition shoes more frequently at practice to work on technical aspects of their events.

This paper investigates the relationship between ground reaction forces experienced by the athletes in each stride and what shoes they are wearing on their feet. Due to the fact that repetitive impact is a cause for shin splints, the conclusion …

Abso2luteu-Net: Tissue Oxygenation Calculation Using Photoacoustic Imaging And Convolutional Neural Networks, Kevin Hoffer-Hawlik, Geoffrey P. Luke

ENGS 88 Honors Thesis (AB Students)

Photoacoustic (PA) imaging uses incident light to generate ultrasound signals within tissues. Using PA imaging to accurately measure hemoglobin concentration and calculate oxygenation (sO₂) requires prior tissue knowledge and costly computational methods. However, this thesis shows that machine learning algorithms can accurately and quickly estimate sO₂. absO₂luteU-Net, a convolutional neural network, was trained on Monte Carlo simulated multispectral PA data and predicted sO₂ with higher accuracy compared to simple linear unmixing, suggesting machine learning can solve the fluence estimation problem. This project was funded by the Kaminsky Family Fund and the Neukom Institute.