Evaluation, design, and construction of the Wallace Astrophysical Observatory Camera for astronomical observations

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, June 2009."May 2008." Cataloged from PDF version of thesis.Includes bibliographical references (p. 53-54).The goal of this thesis is to upgrade the scientific capabilities of the 24" Cassegrain reflector telescope at the George R. Wallace, Jr. Astrophysical Observatory (Wallace Observatory), part of Massachusetts Institute of Technology (MIT). The upgrade consists of evaluating, designing and constructing the Wallace Astrophysical Observatory Camera (WAOcam), optimized for 24" telescope. A full 3D model of the 24" telescope and dome was created to find the size restrictions for WAOcam. An optical model was also developed to maximize the field of view of the camera detector. WAOcam was designed using SolidWorks (3D modeling Software), the parts files from the designing process were also used to machine the instrument. The manufacturing of the WAOcam involved using the following: Computer Numerical Control (CNC) lathe, CNC mill, drill press, and a Waterjet (cutting machine). The manufacturing process also required learning of Omax (software for the Waterjet) and MasterCam 9.1 (software for the CNC lathe and CNC mill). The resulting product is WAOcam, which consists of three modules: 1) vacuum dewar (houses a CCD detector), 2) shutter (controls when light hits the camera detector), and 3) filter wheel (modifies the light before hitting the detector). The remaining work left on the WAOcam is the installation of two additional modules: 1) a four port instrument rotator and 2) a field rotator. This upgrade will allow for occultation observations, strip scanning surveys, and Kuiper Belt Object (KBOs) astrometry to be obtained using the 24" telescope.by Folkers Eduardo Rojas.S.B

Heat extraction for the CSPonD thermal storage unit

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, February 2011."February 2011." Cataloged from PDF version of thesis.Includes bibliographical references (p. 78).Three coiled tube heat exchanger prototypes were designed to extract heat from containers holding 0.5 kg, 2.3 kg, and 10.5 kg of Sodium Nitrate-Potassium Nitrate salt. All of the prototypes were left with an open surface free to undergo radiation losses and surface convection. The first objective was to measure the power extraction over time for each prototype. Coiled tube heat exchangers were modeled as a tube with a constant wall temperature. Air is used as the working fluid, with a maximum Reynolds number of 2000 at a maximum flow rate of 10 standard liters per minute (SLPM) at air flow temperatures above 900°C. The accuracy of the power extraction model for the three prototypes in increasing order: 46 %, 35 %, and 43 % of the measured data. The duration of power extraction with an open top container for the first (P-1), second (P-l1), and third (P-II) prototype respectively are: 14 min, 29 min, 45 min producing an average power of 22 W, 23 W, and 22 W respectively. To compare across the prototypes, the data provided is for bath bulk temperatures starting at 330°C and ending at 275' C. Prototype three produced 25 W for 123 minutes for the same temperature change in the bulk temperature (330° to 275°C) with the lights off and a thermal lid, to reduce radiation and surface convection losses. The thermal lid improved the extraction duration by a factor of four. The second objective was to characterize the thermal loss rate (W) of the each prototype. The thermal loss rate model is accurate within 28.9 % (P-1), 28.7 % (P-11), and 24.7 % (P-III) of the measured values. There is evidence of convection cells in prototype two and three. A high temperature Particle Image Velocimetry (PIV) system has been proposed to measure the magnitude of the convection cells, and a proof of concept setup has been tested. Particles native to the molten salt are illuminated using a Class 3b laser (power <5mW). The laser beam is converted into a plane using a polypropylene conical centrifuge tube filled with water.by Folkers Eduardo Rojas.S.M

HAWK for rapidly controlling a free flowing oil well

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014."June 2014." Cataloged from PDF version of thesis.Includes bibliographical references (pages 189-195).To mitigate the impact of a Blowout Preventer (BOP) failure, this work proposes a method and machine that can create a gradual flow reduction to zero in an offshore well by introducing a mechanical plug inside the BOP. The backup safety tool, referred to as the Hampering Active Wellbore Kit (HAWK), is a machine that gradually introduces a continuous medium (e.g. wire) from a spool through the choke/kill lines of a failed BOP to gradually stem the flow through the BOP. The machine can couple to a standard choke/kill line on the BOP and can co-exist with the BOP or be deployed at the time of an accident. This work presents the design theory for wire feeding in order to form an entanglement, and the mechanism by which to accomplish the reliable feeding of the continuous structure. The efficacy of the entanglement is evaluated by comparing flow rates of a single experimental wellbore before and after the introduction of the mechanical plug.by Folkers Eduardo Rojas.Ph. D

Rapidly scalable mechanical ventilator for the COVID-19 pandemic

The SARS-CoV-2 pandemic is straining healthcare systems worldwide, and a global ventilator shortage is fueling the dire situation. As a response, the MIT E-Vent Team (S1) manufactured a scalable ventilator prototype for mass production and demonstrated basic clinical feasibility