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Articles 2701 - 2730 of 2828

Full-Text Articles in Engineering

Analysis Of Phase Ii Metabolites Of Methamphetamine By Solid-Phase Extraction And Liquid Chromatography With Tandem Mass Spectrometric Detection, Jordan Carbary, Howard P. Hendrickson May 2009

Analysis Of Phase Ii Metabolites Of Methamphetamine By Solid-Phase Extraction And Liquid Chromatography With Tandem Mass Spectrometric Detection, Jordan Carbary, Howard P. Hendrickson

Biological and Agricultural Engineering Undergraduate Honors Theses

Methamphetamine (METH) abuse is one of the most serious health problems in the United States and Europe due to its addictive properties and potential neurotoxic effects [1, 2, 3]. METH abuse appears to have stabilized or decreased slightly in the general populations, however abuse in certain populations is increasing [4, 5]. Treatments for drug abuse are often tested in animal behavioral pharmacology models. One of the first in vivo tests conducted in animals is to follow the concentration of the drug and its metabolites as a function of time. In this way, one can determine how long a potential medication …

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A Computational Model Of Breast Ducts, Jordan Greenlee Jan 2009

A Computational Model Of Breast Ducts, Jordan Greenlee

Inquiry: The University of Arkansas Undergraduate Research Journal

Ductal Carcinoma represents almost 75% of breast cancer. In this specific type of cancer. malignant cells in the breast ducts invade the surrounding healthy tissue. Almost all researchers who are investigating microwave modality in the area of breast cancer detection employ oversimplified models of the internal structure of the breast. Use of engineered or biologically inaccurate models can render inaccurate results. Therefore. a mathematical biological model was implemented in this work aiming to bridge the gap between physiologists and engineers. The result show that the proposed breast duct model has the capability of modeling the breast ducts of different kinds …

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Mapping Reality Into Virtual Worlds, Josh Mcfarlane Dec 2008

Mapping Reality Into Virtual Worlds, Josh Mcfarlane

Computer Science and Computer Engineering Undergraduate Honors Theses

As virtual worlds become more prevalent, they become increasingly useful as a means of information dissemination. This thesis examines the possible connections between real world objects and their virtual world counterparts. We look at how, by attaching sensors to an object, or by using a smart object with embedded sensors, the information can be relayed to a server. From this information, it will be possible to create a duplicate object in the virtual world and have it mirror the real world object in terms of state and movement. Almost all current solutions for remotely viewing a room or area are …

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Steganography In Ipv6, Barret Miller Dec 2008

Steganography In Ipv6, Barret Miller

Computer Science and Computer Engineering Undergraduate Honors Theses

Steganography is the process of hiding a secret message within another message such that it is difficult to detect the presence of the secret message. In other words, the existence of the secret message is hidden. A covert channel refers to the actual medium that is used to communicate the information such as a message, image, or file. This honors thesis uses steganography within the source address fields of Internet Protocol Version 6 (IPv6) packets to create a covert channel through which clandestine messages are passed from one party to another. A fully functional computer program was designed and written …

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A Study Of Switched-Capacitor Filters, Kacie Thomas Dec 2008

A Study Of Switched-Capacitor Filters, Kacie Thomas

Electrical Engineering Undergraduate Honors Theses

This paper presents the basic principles of the switched-capacitor circuit. In order to become more acquainted with the workings and design of filters and switched-capacitor filters specifically, an example filter was designed based on a set of parameters. It was constructed starting in the passive stage, then the active stage and finally the switched-capacitor filter was generated. All of these circuits were also simulated using SwitcherCAD and Saber. Then, a switched-capacitor filter designed by Auburn University was redesigned using the same process as the example circuit. It was also simulated in all three stages. The results from this design are …

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Key Factors In Tag Recognition For Rfid System, Nachiketa Das Aug 2008

Key Factors In Tag Recognition For Rfid System, Nachiketa Das

Computer Science and Computer Engineering Undergraduate Honors Theses

The research effort described here was a study of factors that affect the efficiency of a Radio Frequency Identification (RFID) system in reading a certain type of commonly used passive RFID tag ('Squiggle' by Alien Technologies). The two sets of experiments conducted under this study focus on two response variables namely: readability and read rate. The factors in focus are distance between antenna and tags, the number and combinations of tags simultaneously read by the system and position of the tags left or right of the center of the antenna. Two separate experimental setups as explained in the following sections …

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Microwave Dielectroscopy Of Breast Tissue Phantoms In The 5.8-40 Ghz Range, Binh Tran Aug 2008

Microwave Dielectroscopy Of Breast Tissue Phantoms In The 5.8-40 Ghz Range, Binh Tran

Electrical Engineering Undergraduate Honors Theses

Based on the high contrast in dielectric properties between the low-water-contain sample and the high-water-content one, we can determine whether the tissue sample is cancerous or normal. In order to make the measurement repeatable and convenient, some phantom materials, which have the same dielectric properties of human tissues, have been prepared. These phantom tissues are made from gelatin, water with honey syrup and Sodium Chloride (NaCl). In this project, we are going to measure and compare the dielectric properties of different types of phantom tissues by using focused beam antennas. The purpose of this project is to perform a systematic …

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Service Oriented Transitive Closure Solution, Jonathan Baran Aug 2008

Service Oriented Transitive Closure Solution, Jonathan Baran

Computer Science and Computer Engineering Undergraduate Honors Theses

The goal of this project is a service based solution that utilizes parallel and distributed processing algorithms to solve the transitive closure problem for a large dataset. A dataset may be view conceptually as a table in a database, with a physical structure representing a file containing a sequence of records and fields. Two records are said to be transitively related if and only if they are directly related due to sharing of one or more specific fields, or a sequence may be made from one record to the other under the condition that all intermediate entries are related the …

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Oil Recovery Through Deemulsification Research : Separation Of Water From Emulsified Oil, Aaron Russell, Matthew S. Clay, Christopher A. Cox, Jessica E. Nichols, Summer Scott, Sirikarn Surawanvijit Aug 2008

Oil Recovery Through Deemulsification Research : Separation Of Water From Emulsified Oil, Aaron Russell, Matthew S. Clay, Christopher A. Cox, Jessica E. Nichols, Summer Scott, Sirikarn Surawanvijit

Chemical Engineering Undergraduate Honors Theses

In an effort to improve the environment, there is a need to recover and reuse the oil and water components of lubricating emulsions used in copper drawing and rolling processes. The Freeport-McMoRan Copper and Gold Inc. copper rod mill located in El Paso, TX was chosen as the site location for this project. It is one of the largest rolling and drawing operation facilities in the world, and it meets the established criteria set by Project ORDER. A large facility generates an average of 8,400 gallons of spent lubricant per day. The WERC emulsion sample contains 98 v% water and …

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Design Of A Temperature Profiling System For Use In Thermal Processing Of Food Products, Linda Tarantino Aug 2008

Design Of A Temperature Profiling System For Use In Thermal Processing Of Food Products, Linda Tarantino

Biological and Agricultural Engineering Undergraduate Honors Theses

The purpose of this study was to develop a thermal inspection system on a full scale meat and poultry product line. The system must withstand the production and sanitation environments and adapt to the many different products and conditions present on a common product line. By using this device, food processors will be able to measure the internal temperature of the product during its entire cooking process. This will provide certainty to food processors if the product reached the required internal temperature by USDA standards as well as proof of their processes.

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Developing Subgrade Inputs For Mechanistic-Empirical Pavement Design, Meagan Berlau May 2008

Developing Subgrade Inputs For Mechanistic-Empirical Pavement Design, Meagan Berlau

Computer Science and Computer Engineering Undergraduate Honors Theses

The Resilient Modulus (MR) of a subgrade soil is an essential input into the flexible pavement design models contained in the American Association of State Highway and Transportation Official’s new pavement design guide, the MechanisticEmpirical Pavement Design Guide (MEPDG). For most inputs required for pavement design, there are three levels of input that can be used within the MEPDG system. Level One requires the engineer to enter a value for subgrade Resilient Modulus based on the results of Resilient Modulus tests conducted in the laboratory. Level Two allows the user to input values for other soil property tests including California …

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Location-Based Hashing For Querying And Searching, Felix Ching May 2008

Location-Based Hashing For Querying And Searching, Felix Ching

Computer Science and Computer Engineering Undergraduate Honors Theses

The rapidly growing information technology in modern days demands an efficient searching scheme to search for desired data. Locality Sensitive Hashing (LSH) is a method for searching similar data in a database. LSH achieves high accuracy and precision for locating desired data, but consumes a significant amount of memory and time. Based on LSH, this thesis presents two novel schemes for efficient and accurate data searching: Locality Sensitive Hashing-SmithWaterman (LSH-SmithWaterman) and Secure Min-wise Locality Sensitive Hashing (SMLSH). Both methods dramatically reduce the memory and time consumption and exhibit high accuracy in data searching. Simulation results demonstrate the efficiency of the …

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Visualization Of An Approach To Data Clustering, Marisabel Guevara May 2008

Visualization Of An Approach To Data Clustering, Marisabel Guevara

Computer Science and Computer Engineering Undergraduate Honors Theses

Using visualization and clustering goals as guidelines, this thesis explores a graphic implementation of a data clustering technique that repositions vertices by applying physical laws of charges and springs to the components of the graph. The resulting visualizations are evidence of the success of the approach as well as of the data sets that lend themselves to a clustering routine. Due to the visual product of the implementation, the algorithm is most useful as an aid in understanding the grouping pattern of a data set. Either for a rapid analysis or to assist in presentation, the visual result of the …

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Measurement Of Absolute Argon Excited State Populations And Electron Energy Distribution Functions In An Ar-A-Si Plasma, Katherine Herring May 2008

Measurement Of Absolute Argon Excited State Populations And Electron Energy Distribution Functions In An Ar-A-Si Plasma, Katherine Herring

Electrical Engineering Undergraduate Honors Theses

Deposition systems utilizing plasma are used for a variety of tasks, including tool coatings and creating thin-film materials. In order to have repeatable results, the internal conditions of a plasma chamber need to be known. This project centered on the use of data from optical emissions and a Langmuir probe from an argon plasma amorphous silicon depositing system. An electron energy distribution function (EEDF) was obtained from manipulation of the Langmuir probe data. This EEDF was then input to an argon collisional-radiative model (CRM) to obtain the electron population of the 4p level of the argon plasma. Through an absolute …

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Dna Comparison Chip: Circuit Design And Evaluation, Tushar Bajaj May 2008

Dna Comparison Chip: Circuit Design And Evaluation, Tushar Bajaj

Electrical Engineering Undergraduate Honors Theses

The purpose of this project was to: First, design a microchip that is capable of comparing strings of DNA sequences. Second, evaluate the functioning of such a microchip and how it can implemented in various real world applications. Physically, this microchip will act as an attachment to any computer. The computer will send two strings of DNA sequences-one library string and one pattern string-and the chip will output the number of matches that exist between the two strings (at a given position of the pattern string with respect to the library string). The circuit design is based on a 600 …

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A Comparison Of Nondestructive Testing Backcalculation Techniques For Rigid And Flexible Pavements, Trenton Ellis May 2008

A Comparison Of Nondestructive Testing Backcalculation Techniques For Rigid And Flexible Pavements, Trenton Ellis

Civil Engineering Undergraduate Honors Theses

In designing new pavements, engineers rely on many different measures to characterize the average traffic, climate and soil conditions of the region. Of those, soil conditions are the most elusive, but are also the most crucial for designing a pavement of proper thickness and stiffness. This problem is compounded when the design is for an overlay instead of a new pavement. For overlay designs, engineers require a quantitative characterization of the strength of the existing pavement as well as the underlying soil. Especially for new Mechanistic-Empirical design procedures, direct measures and/or estimates of pavement stiffness are essential inputs. A variety …

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Pitch Correction On The Human Voice, Suzanne Ownbey May 2008

Pitch Correction On The Human Voice, Suzanne Ownbey

Computer Science and Computer Engineering Undergraduate Honors Theses

Singing is an excellent way to achieve fame, granted one can sing on key. Alternatively, a person who does not inherently have this ability or want to spend the time practicing to achieve it could use a programmatic solution to pitch correction. Proprietary products already exist that can correct the pitch of a singer, but the average mediocre singer may not be willing or able to purchase them. The focus of this research is to use the basic frequency altering algorithm of resampling, which alters the length of the wave to correct the pitch of a note. Small parts of …

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Multiuav2 Agent Swarming For Distributed Atr Simulation, Kyle White May 2008

Multiuav2 Agent Swarming For Distributed Atr Simulation, Kyle White

Computer Science and Computer Engineering Undergraduate Honors Theses

Traditional automatic target recognition (ATR) is performed by unmanned aerial vehicles (UAVs) depending on a central control tower to provide the high level organization of the system. The UAVs fly through a region of interest to identify targets and relay all communication through a central control tower. The centralized approach to ATR has limited fault-tolerance, scalability with regards to the number of UAVs, and susceptibility to malicious attacks on the central tower [2]. A swarm-driven alternative [1] is extended with a communication control scheme to address fault-tolerance and scalability while utilizing the higher onboard processing power now available for UAVs …

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A Timer Module For An 8051 Microcontroller, Troy England May 2008

A Timer Module For An 8051 Microcontroller, Troy England

Electrical Engineering Undergraduate Honors Theses

A timer module for an 8051 Microcontroller is designed from the ground up. It could potentially be integrated into a larger 8051 for use in lunar and Martian missions. It follows through a synchronous digital design flow from HDL code through layout verification. The timer shows functionality at 100MHz with some minor glitches.

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Optical Properties Of Colloidal Core/Shell Nanocrystals, Abhishek Joshi May 2008

Optical Properties Of Colloidal Core/Shell Nanocrystals, Abhishek Joshi

Electrical Engineering Undergraduate Honors Theses

Recently, colloidal core/shell nanocrystals have found use in several applications such as solar cells, light emitting diodes, fluorescent dies, etc. In this thesis, optical properties of colloidal CdSe/ZnS core/shell nanocrystals were studied. The samples were prepared such that the nanocrystals were embedded in a UV curable resin. Once the samples were cured, they were placed in different spectrophotometers to measure the absorbance and the photoluminescence (PL) spectrum. The effect on the absorbance and PL spectra was investigated by using nanocrystal samples of different quantum dot sizes and by changing the temperature of the samples. It was found that the energy …

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Simulation Of Multicultural Factors In Terrorism Networks, Jared Townsley May 2008

Simulation Of Multicultural Factors In Terrorism Networks, Jared Townsley

Industrial Engineering Undergraduate Honors Theses

As globalization extends its influence to the far corners of the world, rapid developments and changes are taking place economically, socially, and environmentally. Cultural differences between and within organizations have become significant during the past few years as politics and marketplaces expand globally to include multiple nationalities, beliefs, and value systems. Unfortunately, terrorism has also felt the effects of globalization as organizations such as Al-Qaeda seek to expand their influence worldwide. Although a considerable amount of research has been conducted to identify key cultural factors that play major roles within organizations, simulation models that attempt to quantify cultural effects are …

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Exploring The Potential For Electromangetophoretic Separation, Thomas Lewis May 2008

Exploring The Potential For Electromangetophoretic Separation, Thomas Lewis

Chemical Engineering Undergraduate Honors Theses

Current research in mircofluidic technology is underway to develop automatic micro-analyzing chips for medical diagnostic testing. Diagnostic testing often requires separation of specific biological particles from a sample, and many of these molecules contain electric or magnetic properties. This project investigates the potential for separation in electromagnetophoretic and magnetophoretic microfluidic technology. In electromagnetophoresis, the Lorentz force acting on a current carrying medium in a homogeneous magnetic field creates a pressure gradient in the fluid, resulting in an applied force to particles present in the separation medium. This force causes the particle to have a velocity component that is perpendicular to …

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Evaluating Arkansas Roadway Intersection Accidents Using Traffic Safety Analysis Methods: Generalized Estimating Equations And Roadway Observation, Jacob Mercer May 2008

Evaluating Arkansas Roadway Intersection Accidents Using Traffic Safety Analysis Methods: Generalized Estimating Equations And Roadway Observation, Jacob Mercer

Industrial Engineering Undergraduate Honors Theses

Considerable research has been made in recent years to evaluate road traffic safety. This is especially true with the United States, whose international rank in public safety is rapidly declining. In 2004, Arkansas ranked as the third highest in traffic fatalities among all the states. These are striking numbers that reflect the lack of attention that the state has received in terms of evaluating road traffic safety. Historically, this safety is measure by one of two methods: Statistical analyses of historical data or hands-on, observational analyses of present safety conditions. Rarely in research are both methods used within the same …

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A Study Of Inhomogeneity Effects On Packed High Performance Liquid Chromatography Columns, Tyler House May 2008

A Study Of Inhomogeneity Effects On Packed High Performance Liquid Chromatography Columns, Tyler House

Chemical Engineering Undergraduate Honors Theses

The packing quality of a High Performance Liquid Chromatography column has significant impact on the resulting separations. In practice, problems in a packing occur through normal usage of a column. Resulting chromatograms from inhomogeneities exhibit varying problems such as extreme tailing and double peaks. Early detection of such problems is critical to fixing problems before their effect harms efficiency, but a fully developed theory of how inhomogeneities affect separations does not exist. The purpose of this work was to experimentally characterize HPLC column inhomogeneities and to begin preliminary simulations of HPLC columns with the computer simulation package STAR-CD. To do …

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Conversion Of Biomass Resource To Useful Forms Of Energy And Other Products, Steven Jennings May 2008

Conversion Of Biomass Resource To Useful Forms Of Energy And Other Products, Steven Jennings

Chemical Engineering Undergraduate Honors Theses

The United States is facing increasing pressure to find renewable energy sources due to rising energy costs. With world energy demand at an all time high, renewable energy has been thrust into the forefront of research as a means to mitigate this looming crisis. Throughout the United States, there is a large quantity of agricultural biomass that could be used to generate energy and lessen the dependence on diminishing resources. Specifically, animal feeding operations (AFOs) such as dairies generate large amounts of cow manure, which, when improperly handled, causes both air and water pollution. Currently, most manure is temporarily stockpiled …

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The Effect Of Water Extracted Silibinin On Reactive Oxygen Species (Ros) Production Of Macrophages, Julie Abbott, Sunny Wallace, Ed Clausen, Danielle Carrier May 2008

The Effect Of Water Extracted Silibinin On Reactive Oxygen Species (Ros) Production Of Macrophages, Julie Abbott, Sunny Wallace, Ed Clausen, Danielle Carrier

Biological and Agricultural Engineering Undergraduate Honors Theses

The world is actively looking for technology to produce sustainable liquid fuels to replace our reliance on petroleum-based fuels. Biomass can be converted either through the thermochemical or saccharification platforms into fuels such as ethanol or butanol. In addition to converting the biomass into liquid fuels, valuable phytochemicals can be extracted prior, during, or after the conversion. Extracting useful phytochemicals, as a part of the overall conversion of biomass to fuels, is included in the concept of the biobased biorefinery. However, the key to effectively and economically extract phytochemicals from biomass is the ability to couple the extraction to the …

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Kinetics Determination Of Soybean Oil Transesterification In The Design Of A Continuous Biodiesel Production Process, Irwin Jacob, Ed Clausen, Danielle Julie Carrier May 2008

Kinetics Determination Of Soybean Oil Transesterification In The Design Of A Continuous Biodiesel Production Process, Irwin Jacob, Ed Clausen, Danielle Julie Carrier

Biological and Agricultural Engineering Undergraduate Honors Theses

One-step batch transesterification consisting of three stepwise reversible reactions of pure soybean oil with methanol was conducted at two different mixing speeds (600 and 300 rpm) to produce soybean oil fatty acid methyl esters (biodiesel). In both batch reactions, sodium methoxide (1.09 wt% based on soybean oil) was used as the catalyst, the reaction temperature was 60oC, and the methanol-to-oil molar ratio was 6:1. The objectives were to determine and/or investigate: 1) the mechanism and order of the reaction, 2) the reaction rate constants, 3) the effect of changes in mixing intensity on the reaction rate, 4) the comparison of …

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A Review Of Variable Valve Timing Devices, Paul Shelton May 2008

A Review Of Variable Valve Timing Devices, Paul Shelton

Mechanical Engineering Undergraduate Honors Theses

Variable valve timing (VVT) has evolved from simple, manual controlled engine management to automatic, electronic works of engineering. Starting from the need for more power and extending into fuel efficiency and low emissions, VVT has evolved from the constant changing of needs. This paper summarizes various devices used to control the timing of valves from the early 1920s up until 2007.

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Restart Capabilities Of Hybrid Rocket Motor Utilizing Gaseous Propane And Oxygen Injection System, Joseph Gracy May 2008

Restart Capabilities Of Hybrid Rocket Motor Utilizing Gaseous Propane And Oxygen Injection System, Joseph Gracy

Mechanical Engineering Undergraduate Honors Theses

Hybrid rockets have become an increasingly popular application in professional and amateur rocketry for their outstanding performance and reliability. An issue pressing the marketability and functionality of these rockets is the ability to restart with an exclusive system after primary ignition. Research and development of a system that can be used reliably in either application to achieve restart under various conditions has been made recently using dual injection of GOX and C3H8 using a 200kV ignition system while implementing a polymethylmethacrylate (PMMA) formable polymer as primary fuel. The system used a manual valve arrangement for control. The design features most …

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Development Of Miniature Hybrid Rockets For Orbital Upkeep And Transfer Applications In Nano/Pico-Satellites, Derek Willingham May 2008

Development Of Miniature Hybrid Rockets For Orbital Upkeep And Transfer Applications In Nano/Pico-Satellites, Derek Willingham

Mechanical Engineering Undergraduate Honors Theses

This research has developed and constructed a successful miniature hybrid rocket test assembly for research into hybrid rocket scaling issues. It is hoped that such systems will find eventual integration into small satellites. The test assembly houses 3" fuel grains and provides an inlet for gaseous oxidizer. Although far from complete, preliminary data were taken with PMMA and GOx and some useful conclusions were drawn that will benefit future research into this topic. Fuel grains with combustion chambers whose diameters range from 1/16" to 3/8" were tested at different flow rates and thrust data gathered. Maximum flow information was gathered …

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