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Articles 1261 - 1290 of 4850

Full-Text Articles in Engineering

Fundamental Investigation Of Magnesium Corrosion Using Experiments And Simulation, Dila Ram Banjade Jul 2018

Fundamental Investigation Of Magnesium Corrosion Using Experiments And Simulation, Dila Ram Banjade

Theses and Dissertations

Magnesium (Mg) is the lightest of all structural metals and has tremendous potential for applications in the lightweight industry. However, the corrosion of Mg is a significant barrier towards its wider use. Despite years of research, the fundamental understanding of Mg corrosion still remains short. The enhanced hydrogen evolution reaction (HER) with anodic polarization, the modeling of galvanic corrosion and the impact of hydrogen bubbles for galvanically coupled Mg are important aspects of Mg corrosion that need to be understood before any mitigation measures can be taken. The results presented in this work provide a key step in that direction. …


Integrated Scheduling And Control In Discrete-Time With Dynamic Parameters And Constraints, Logan Beal, Damon Petersen, David R. Grimsman, Sean Warnick, John Hedengren Jul 2018

Integrated Scheduling And Control In Discrete-Time With Dynamic Parameters And Constraints, Logan Beal, Damon Petersen, David R. Grimsman, Sean Warnick, John Hedengren

Faculty Publications

Integrated scheduling and control (SC) seeks to unify the objectives of the various layers of optimization in manufacturing. This work investigates combining scheduling and control using a nonlinear discrete-time formulation, utilizing the full nonlinear process model throughout the entire horizon. This discrete-time form lends itself to optimization with time-dependent constraints and costs. An approach to combined SC is presented, along with sample pseudo-binary variable functions to ease the computational burden of this approach. An initialization strategy using feedback linearization, nonlinear model predictive control, and continuous-time scheduling optimization is presented. The formulation is applied with a generic continuous stirred tank reactor …


Total Hemispherical Apparent Radiative Properties Of The Infinite V-Groove With Diffuse Reflection, Rydge B. Mulford, Nathan S. Collins, Michael S. Farnsworth, Matthew R. Jones, Brian D. Iverson Jul 2018

Total Hemispherical Apparent Radiative Properties Of The Infinite V-Groove With Diffuse Reflection, Rydge B. Mulford, Nathan S. Collins, Michael S. Farnsworth, Matthew R. Jones, Brian D. Iverson

Faculty Publications

Dynamic control of radiative surface properties enables optimization of thermal management systems for spacecraft, radiative cooling systems and other applications [1-3]. Various methods of altering the absorption or emission from a surface have been investigated [4-6]. Use of origami-inspired, tessellated surfaces to control apparent radiative surface properties is a promising technology [7-9]. Realizing the full potential of tessellated surfaces to dynamically control apparent radiative surface properties requires convenient methods of calculating apparent properties as a function of tessellation geometry and intrinsic radiative surface properties. This paper focuses on the use of geometry to affect total, hemispherical properties of V-grooves comprised …


A Framework And Exploration Of A Cybersecurity Education Escape Room, Justin Charles Snyder Jul 2018

A Framework And Exploration Of A Cybersecurity Education Escape Room, Justin Charles Snyder

Theses and Dissertations

This thesis presents a review of educational-escape-room literature followed by a design-oriented framework (the Snyder Escape Room Framework or SERF) and demonstrates the potential efficacy of escape-rooms in cybersecurity education. Several authors have proposed frameworks and guidelines for game and educational design regarding escape rooms. This work coalesces some of those ideas into a more substantial and comprehensive framework (SERF) that designers can use when developing educational escape rooms. The Snyder Escape Room Framework provides heuristics for goals and objectives, players, activities, context, trajectory design, and evaluation. Additionally, this work describes and analyzes the novel prototyped BYU GCC escape room …


Evaluation Of Processing Variables In Polymer Projection Sintering, Justin Nussbaum, Nathan B. Crane Jun 2018

Evaluation Of Processing Variables In Polymer Projection Sintering, Justin Nussbaum, Nathan B. Crane

Faculty Publications

Purpose – Projection sintering, a system for selectively sintering large areas of polymer powder simultaneously with a high power projector is introduced. The paper evaluates the suitability of laser sintering process parameters for projection sintering as it uses substantially lower intensities, longer exposure times, and larger areas than conventional laser sintering (LS).

Design/methodology/approach – The tradeoffs in sintering outcomes are evaluated by creating single layer components with varied exposure times and optical intensities. Some of these components were cross-sectioned and evaluated for degree of densification while the single layer thickness and the maximum tensile force was measured for the rest. …


One-Dimensional Turbulence Modeling For Cylindrical And Spherical Flows: Model Formulation And Application, David O. Lignell, Victoria B. Lansinger, Juan Medina, Marten Klein, Alan R. Kerstein, Heiko Schmidt, Marco Fistler, Michael Oevermann Jun 2018

One-Dimensional Turbulence Modeling For Cylindrical And Spherical Flows: Model Formulation And Application, David O. Lignell, Victoria B. Lansinger, Juan Medina, Marten Klein, Alan R. Kerstein, Heiko Schmidt, Marco Fistler, Michael Oevermann

Faculty Publications

The one-dimensional turbulence (ODT) model resolves a full range of time and length scales and is computationally efficient. ODT has been applied to a wide range of complex multi-scale flows, such as turbulent combustion. Previous ODT comparisons to experimental data have focused mainly on planar flows. Applications to cylindrical flows, such as round jets, have been based on rough analogies, e.g., by exploiting the fortuitous consistency of the similarity scalings of temporally developing planar jets and spatially developing round jets. To obtain a more systematic treatment, a new formulation of the ODT model in cylindrical and spherical coordinates is presented …


From Holographic Video Monitors To Optogenetic Probes: How Advancements To Leaky-Mode Modulator Technology Are Saving The World, Stephen Dalton Mclaughlin Jun 2018

From Holographic Video Monitors To Optogenetic Probes: How Advancements To Leaky-Mode Modulator Technology Are Saving The World, Stephen Dalton Mclaughlin

Theses and Dissertations

The research presented in this dissertation focuses on improvements made to lithium niobate leaky-mode modulators for both holographic video and optogenetic applications. The specific improvements found herein are: (1) characterization of leaky-mode modulators to decrease driver bandwidth to match that of commodity graphics processing units, (2) the implementation of surface relief gratings as input couplers to replace rutile prism coupling, (3) the addition of backside surface relief gratings to create an orthogonal output face for the leaky-mode modulator, and (4) the creation of superimposed surface relief gratings in lithium niobate to enable multiple wavelength coupling at a single input angle. …


Increased Energy Yield Through Fast Pyrolysis: Empowering Malawian Villages, Diehl Mutamba Jun 2018

Increased Energy Yield Through Fast Pyrolysis: Empowering Malawian Villages, Diehl Mutamba

Undergraduate Honors Theses

Biomass contributes to several renewable energy technologies. This project will explore the use of fast pyrolysis to produce fuels by designing an apparatus for fast pyrolysis. Malawian people harvest firewood from the forests, which is a major contributor to deforestation. Furthermore, they convert some of it to charcoal with about 10-15% efficiency to sell to city dwellers. The project will enable herbaceous fuels to replace wood, increase charcoal yields and create new products. Firewood and charcoal produce smoke and carbon monoxide (CO) that compromises the villagers’ health.

This project will address deforestation problems, improve sustainability, decrease health hazards and improve …


Test Method For Predicting Failure Modes In Protective Films, Aubrey Jeanette Decker Jun 2018

Test Method For Predicting Failure Modes In Protective Films, Aubrey Jeanette Decker

Theses and Dissertations

In the business of packaging engineering, a large consumption of time is placed on evaluating new materials to provide cost savings to a company. This evaluation is made by using test methods such as those found in ASTM D4169-16, which helps to simulate shipping and distribution conditions. A key problem is that this test method can take up to multiple months, and sometimes years to complete. The apparatus created in this study allows for a comparison to be made between currently used films and prospective films in approximately ten hours. This allows for a prescreening of new films to be …


Hardware And Software Improvements To A Low-Cost Holographic Video Monitor, Andrew August Henrie Jun 2018

Hardware And Software Improvements To A Low-Cost Holographic Video Monitor, Andrew August Henrie

Theses and Dissertations

The "Mark V" Holographic Video Monitor ("HoloMonitor") is a continuation of effort and accomplishments to produce a low-cost device capable of reproducing true full-color horizontal-parallax-only computer-generated holograms at typical video frame-rates. While other devices around the world may have greater capabilities, these devices are currently confined to laboratory settings due to their sheer complexity and expense. The aim of this project is to provide researchers and "tinkerers" with a device capable of recreating holographic effects in full color, respectable resolution, in real time, and at a comparatively low cost. The "Mark V" HoloMonitor is a closer representation of a consumer …


Crash Severity Distributions For Life-Cycle Benefit-Cost Analysis Of Safety-Related Improvements On Utah Roadways, Conor Judd Seat Jun 2018

Crash Severity Distributions For Life-Cycle Benefit-Cost Analysis Of Safety-Related Improvements On Utah Roadways, Conor Judd Seat

Theses and Dissertations

The Utah Department of Transportation developed life-cycle benefit-cost analysis spreadsheets that allow engineers and analysts to evaluate multiple safety countermeasures. The spreadsheets have included the functionality to evaluate a roadway based on the 11 facility types from the Highway Safety Manual (HSM) with the use of crash severity distributions. The HSM suggests that local agencies develop crash severity distributions based on their local crash data. The Department of Civil and Environmental Engineering at Brigham Young University worked with the Statistics Department to develop crash severity distributions for the facility types from the HSM.The primary objective of this research was to …


High Throughput Fpga Configuration Using A Custom Dma Configuration Controller, Peter William Zabriskie Jun 2018

High Throughput Fpga Configuration Using A Custom Dma Configuration Controller, Peter William Zabriskie

Theses and Dissertations

SRAM-based Field Programmable Gate Arrays (FPGAs) must be programmed with configuration data every time they are powered on. In addition to initially programming an FPGA, there are many other applications that require access to FPGA configuration memory such as partial reconfiguration, fault injection, and memory scrubbing. This thesis describes a system that provides high-speed, programmable configuration management for Xilinx FPGAs through external interfaces. This system is an improvement upon the JTAG Configuration Manager (JCM) previously created at BYU. The JCM consists of a custom I/O board paired with a MicroZed development board which includes a Xilinx ZYNQ SoC. This platform …


Using Quantitative Mri To Measure Cartilage Health, Laurel Jane Hales Jun 2018

Using Quantitative Mri To Measure Cartilage Health, Laurel Jane Hales

Theses and Dissertations

Osteoarthritis (OA) is one of the leading causes of disability world-wide. It affects 12% of all Americans ages 25-74 [1]. One of the challenges with OA, is that there are currently no clinically viable methods to measure the health of the cartilage before cartilage loss. There are no ways to replace or heal the cartilage after it has been lost. It is known that the early stages of OA involve a decrease in the amount of glycosaminoglycans (GAG), one of the main molecules in cartilage. This decrease in GAG leads to a change in the fixed charge density of the …


Adjustment Of Rapidscat Backscatter Measurements For Improved Radar Images, Garrett Scott Mcdonald Jun 2018

Adjustment Of Rapidscat Backscatter Measurements For Improved Radar Images, Garrett Scott Mcdonald

Theses and Dissertations

RapidScat is a spaceborne wind scatterometer mounted on the International Space Station (ISS). The RapidScat mission lasted from September 2014 to November 2016. RapidScat enables the measurement of diurnal patterns of sigma-0 measurements. This capability is possible because of the non-sun-synchronous orbit of the ISS, in which the local time of day (LTOD) of sigma-0 measurements gradually shifts over time in any given location. The ISS platform is a relatively unstable platform for wind scatterometers. Because of the varying attitude of the ISS, RapidScat experiences a constant variation of its pointing vector. Variations of the pointing vector cause variations in …


Parametric Study On Multi-Story, Partially Grouted, Perforated, Masonry Shear Walls By Finite Element Analysis, Kyle Henry Chavez Jun 2018

Parametric Study On Multi-Story, Partially Grouted, Perforated, Masonry Shear Walls By Finite Element Analysis, Kyle Henry Chavez

Theses and Dissertations

In this study, parameters related to material properties, geometry, and external stimuli were examined individually to determine their influence on multi-story, partially grouted, perforated (openings), masonry shear walls using a finite element software FormWorks. The parameters studied were: the strength of grouted masonry prisms f'm,grouted; the strength of un-grouted (hollow) masonry prisms f'm,ungrouted; the ratio of mortar shear strength to masonry compressive strength; vertical and horizontal reinforcement ratios in terms of size and spacing of reinforcement; axial load; aspect ratio; and openings that were vertically and horizontally altered. To perform this study, finite element models were …


Bubble Nucleation In Superhydrophobic Microchannels Due To Subcritical Heating, Adam Cowley, Daniel Maynes, Julie Crockett, Brian D. Iverson Jun 2018

Bubble Nucleation In Superhydrophobic Microchannels Due To Subcritical Heating, Adam Cowley, Daniel Maynes, Julie Crockett, Brian D. Iverson

Faculty Publications

This work experimentally studies the effects of single wall heating on laminar flow in a high-aspect ratio superhydrophobic microchannel. When water that is saturated with air is used as the working liquid, the non-wetted cavities on the superhydrophobic surfaces act as nucleation sites and allow air to effervesce out of the water and onto the surface when heated. Previous works in the literature have only considered the opposite case where the water is undersaturated and absorbs air out the cavities for a microchannel setting. The microchannel considered in this work consists of a rib/cavity structured superhydrophobic surface and a glass …


Art To Engineering: Curved Folding And Developable Surfaces In Mechanism And Deployable Structure Design, Todd G. Nelson Jun 2018

Art To Engineering: Curved Folding And Developable Surfaces In Mechanism And Deployable Structure Design, Todd G. Nelson

Theses and Dissertations

This work investigates how curved-crease origami and the developable surfaces which compose it can be transitioned to engineering design. Methods for creating flexible, tailorable-property surfaces that function as thick panels in place of paper are presented. Concepts from curved-crease origami and developable surfaces that can describe and extend engineering applications are discussed and demonstrated. These concepts are particularly beneficial to applications where curved surfaces are integral to the function, deployability is desired, and planar manufacturing could be beneficial.The first part of this work uses arrays of compliant elements to create flexible-tailorable property surfaces. The key feature to these arrays is …


Development Of A Vortex Particle Code For The Modeling Of Wake Interaction In Distributed Propulsion, Eduardo Alvarez, Andrew Ning Jun 2018

Development Of A Vortex Particle Code For The Modeling Of Wake Interaction In Distributed Propulsion, Eduardo Alvarez, Andrew Ning

Faculty Publications

Recent developments in electric aircraft technology have enabled the use of distributed propulsion for the next generation of vertical lift vehicles. However, the ability to rapidly assess the performance of these design concepts, with sufficient fidelity, is a current weakness of this nascent industry. This paper explores the capacity of the viscous Vortex Particle Method (VPM) to model wake interactions found in distributed propulsion. The elements of the vortex particle method are summarized, and a new approach for the calculation of vortex stretching through the complex-step derivative approximation is presented. Preliminary validation is performed on vortex ring cases resembling the …


Camera View Planning For Structure From Motion: Achieving Targeted Inspection Through More Intelligent View Planning Methods, Trent James Okeson Jun 2018

Camera View Planning For Structure From Motion: Achieving Targeted Inspection Through More Intelligent View Planning Methods, Trent James Okeson

Theses and Dissertations

Remote sensors and unmanned aerial vehicles (UAVs) have the potential to dramatically improve infrastructure health monitoring in terms of accuracy of the information and frequency of data collection. UAV automation has made significant progress but that automation is also creating vast amounts of data that needs to be processed into actionable information. A key aspect of this work is the optimization (not just automation) of data collection from UAVs for targeted planning of mission objectives. This work investigates the use of camera planning for Structure from Motion for 3D modeling of infrastructure. Included in this thesis is a novel multi-scale …


Universal Airfoil Parametrization Using B-Splines, Dev Rajnarayan, Andrew Ning, Judd Mehr Jun 2018

Universal Airfoil Parametrization Using B-Splines, Dev Rajnarayan, Andrew Ning, Judd Mehr

Faculty Publications

In this paper, we apply well-known techniques for parametric curves to the definition and deformation of airfoil sections. While it has already been shown that many versions of Kulfan’s Class Shape Transformation (CST) are exactly equivalent to Bézier curves, we show here that all NACA 4-digit thickness distributions and the PARSEC parametrization of Sobiezcky are also higher-order Bézier curves. As with CST, Béziers and B-Splines provide direct control over aerodynamically meaningful features such as nose radius and boat-tail angle, but also provide more a intuitive parametrization of the rest of the airfoil surface. We show the efficacy of B-Spline-based parametrizations …


Augmented Design Capabilities For Origami Tessellations, Janette Darlene Herron Jun 2018

Augmented Design Capabilities For Origami Tessellations, Janette Darlene Herron

Theses and Dissertations

Applying engineering principles to tessellation origami-based designs enables the control of certain design properties, such as flexibility, bending stiffness, mechanical advantage, shape conformance, and deployment motion. The ability to control these and other properties will enable augmented design capabilities in environments which currently limit the design to specific materials, including space, medicine, harsh environments, and scaled environments (such as MEMS applications). Other applications will be able to achieve more complex motions or better satisfy design and performance requirements.This research demonstrates augmented design capabilities of origami tessellations in engineering design in rigid-foldable and non-rigid-foldable applications. First, a method to determine Poisson's …


Suitability Of The Kalina Cycle For Power Conversion From Pressurized Water Reactors, Jack Ryan Webster Jun 2018

Suitability Of The Kalina Cycle For Power Conversion From Pressurized Water Reactors, Jack Ryan Webster

Theses and Dissertations

The primary objective of this work is to determine the Kalina cycle's suitability for thermal power conversion from a pressurized water reactor. Several previous papers have examined this application, but these either lack proof of concept or make unfeasible assumptions. This work expands current knowledge by simulating the Kalina cycle and comparing it to current pressurized water reactor Rankine cycles in order to identify which is more efficient. Prerequisite to the modeling is a simulation tool capable of modeling the thermodynamics of ammonia/water mixtures. Instead of using an existing program, a new one called Clearwater is used. This tool is …


A Systematic Process For Implementing Mass Customization In Residential Preconstruction, Spencer J. Blaylock Jun 2018

A Systematic Process For Implementing Mass Customization In Residential Preconstruction, Spencer J. Blaylock

Theses and Dissertations

According to production process theory, customization is directly related to cost and inversely related to volume, efficiency, and productivity. However, customers generally desire products that are individually tailored to their wants and needs. For this reason, as residential contractors grow, they struggle to meet customers' demands for flexibility. This struggle to increase customization is not unique to the construction industry and many other industries have studied this problem in depth. While the inverse relationship between customization and cost is generally true, mass customization can enable increased customization with limited or no increased cost. The residential construction process employs many mass …


Real-Time Feedback For In-Class Introductory Computer Programming Exercises, Ariana Dawn Sellers Jun 2018

Real-Time Feedback For In-Class Introductory Computer Programming Exercises, Ariana Dawn Sellers

Theses and Dissertations

Computer programming is a difficult subject to master. Introductory programming courses often have low retention and high failure rates. Part of the problem is identifying if students understand the lecture material. In a traditional classroom, a professor can gauge a class's understanding on questions asked during lecture. However, many struggling students are unlikely to speak up in class. To address this problem, recent research has focused on gathering compiler data from programming exercises to identify at-risk students in these courses. These data allow professors to intervene with individual students who are at risk and, after analyzing the data for a …


Baseline Effects Of Lysophosphatidylcholine And Nerve Growth Factor In A Rat Model Of Sciatic Nerve Regeneration After Crush Injury, Ryan L. Wood, Keaton S. Karlinsey, Austin D. Thompson, Mark N. Rigby, Greggory D. Boatright, William G. Pitt, Beverly L. Roeder, Scott C. Steffersen, Alonzo D. Cook May 2018

Baseline Effects Of Lysophosphatidylcholine And Nerve Growth Factor In A Rat Model Of Sciatic Nerve Regeneration After Crush Injury, Ryan L. Wood, Keaton S. Karlinsey, Austin D. Thompson, Mark N. Rigby, Greggory D. Boatright, William G. Pitt, Beverly L. Roeder, Scott C. Steffersen, Alonzo D. Cook

Faculty Publications

Schwann cells play a major role in helping heal injured nerves. They help clear debris, produce neurotrophins, upregulate neurotrophin receptors, and form bands of Büngner to guide the healing nerve. But nerves do not always produce enough neurotrophins and neurotrophin receptors to repair themselves. Nerve growth factor (NGF) is an important neurotrophin for promoting nerve healing and lysophosphatidylcholine (LPC) has been shown to stimulate NGF receptors (NGFR). This study tested the administration of a single intraneural injection of LPC (1 mg/mL for single LPC injection and 10 mg/mL for multiple LPC injections) at day 0 and one (day 7), two …


Impact Of Antenna Mutual Coupling, Propagation, And Nonreciprocity On Propagation-Based Key Establishment, Attiya Mahmood May 2018

Impact Of Antenna Mutual Coupling, Propagation, And Nonreciprocity On Propagation-Based Key Establishment, Attiya Mahmood

Theses and Dissertations

Propagation-based key establishment is a physical layer method for generating encryption keys based on two radios observing a reciprocal propagation channel. This work explores the impact of mutual coupling when communicating nodes are equipped with multiple antennas, multipath richness in the propagation environment, and practical limitations caused by the nonreciprocal nature of RF circuits on key establishment. First, network theory is used to formulate a model of a realistic communication system which incorporates transmit sources and receive loads, impedance matching networks, low-noise amplifiers (LNAs), mutually coupled antenna arrays, and a passive eavesdropper. Afterwards, a detailed analysis is performed to quantify …


Applying Attribute-Based Encryption In Two-Way Radio Talk Groups: A Feasibility Study, Michael Andreas Gough May 2018

Applying Attribute-Based Encryption In Two-Way Radio Talk Groups: A Feasibility Study, Michael Andreas Gough

Theses and Dissertations

In two-way radio systems, talk groups are used to organize communication. Some situations may call for creating a temporary talk group, but there are no straightforward ways to do this. Making a new talk group requires programming radios off-line. Temporary groups can be created, but this requires inputting radio IDs which is tedious on a radio's limited controls. By describing group members using attributes, ciphertext-policy attribute-based encryption (CP-ABE) can be used to quickly create sub-groups of a talk group. This scheme requires fewer button presses and messages sent in the new talk group are kept secret. CP-ABE can be used …


Addressing The Regulator's Dilemma: A Self Drive Framework For Balancing Safety And Innovation, Craig Maughan May 2018

Addressing The Regulator's Dilemma: A Self Drive Framework For Balancing Safety And Innovation, Craig Maughan

Brigham Young University Prelaw Review

Policymakers are tasked with creating regulations that responsibly oversee the growth and deployment of emerging technologies. I argue that the SELF DRIVE Act, currently being deliberated in Congress, offers one such intelligent regulatory structure for autonomous vehicles: it prioritizes public safety over adherence to outdated requirements, giving innovators greater freedom to field-test new designs. More importantly, I examine how key principles of the SELF DRIVE Act should be applied to other emerging technologies currently facing regulatory roadblock. Specifically, I suggest the drone industry be subject to regulatory changes that incentivize safety, allow exploration, and anticipate future growth. Such regulations allow …


Autonomous Cars And The Anonymous Threat: The Immediate Need For Cybersecurity Legislation For Self-Driving Vehicles, Forrest Albiston May 2018

Autonomous Cars And The Anonymous Threat: The Immediate Need For Cybersecurity Legislation For Self-Driving Vehicles, Forrest Albiston

Brigham Young University Prelaw Review

This paper addresses the immediate need for cybersecurity regulations on self-driving cars. The focus of this paper is to discuss the urgency of these laws and put forth the SPY Car Act of 2017 as a solution with some edits. This Act will help ensure the safety of US citizens and will also benefit businesses.


Design Of A Low-Cost Capillary Electrophoresis Laser-Induced Fluorescence System: Lessons Learned When Trying To Build The Lowest Possible Cost System, Steven James Perry May 2018

Design Of A Low-Cost Capillary Electrophoresis Laser-Induced Fluorescence System: Lessons Learned When Trying To Build The Lowest Possible Cost System, Steven James Perry

Theses and Dissertations

Capillary electrophoresis laser-induced fluorescence (CE-LIF) is widely used to detect both the presence and concentration of fluorescently labeled biomolecules. In CE-LIF, a plug of sample fluid is electrophoretically driven down a microchannel using a high voltage applied between the opposite ends of the microchannel. Molecules of different sizes and charge states travel at different velocities down the channel. Laser light with a wavelength in the excitation band of the fluorophores is focused near the end of the channel. As each species of molecule passes through the laser spot, the fluorophores emit a fluorescence signal which is measured with an optical …