A study of accuracy in selected numerical-analysis integration techniques

Report discusses several methods of performing numerical integration with computer. When data can be expressed as state vector that is dependent variable in a differential equation, self-starting integrators can be used to predict future data

Space shuttle navigation filter development

Problems encountered in developing a high speed trajectory data processor for the shuttle ascent and entry phases are described. The development of a 19 state acceleration filter for the processor is reported

Refraction corrections for surveying

Optical measurements of range and elevation angle are distorted by the earth's atmosphere. High precision refraction correction equations are presented which are ideally suited for surveying because their inputs are optically measured range and optically measured elevation angle. The outputs are true straight line range and true geometric elevation angle. The 'short distances' used in surveying allow the calculations of true range and true elevation angle to be quickly made using a programmable pocket calculator. Topics covered include the spherical form of Snell's Law; ray path equations; and integrating the equations. Short-, medium-, and long-range refraction corrections are presented in tables

Least squares polynomial fits and their accuracy

Equations are presented which attempt to fit least squares polynomials to tables of date. It is concluded that much data are needed to reduce the measurement error standard deviation by a significant amount, however at certain points great accuracy is attained

Inversion and approximation of Laplace transforms

A method of inverting Laplace transforms by using a set of orthonormal functions is reported. As a byproduct of the inversion, approximation of complicated Laplace transforms by a transform with a series of simple poles along the left half plane real axis is shown. The inversion and approximation process is simple enough to be put on a programmable hand calculator

The Synthesis of Benzyloxy Substituted DP-PPV and Examination of the Horner-Wadsworth-Emmons Reaction in the Synthesis of DP-PPV

In the interest of the synthesis of polymers that have the potential to possess inherent light-emitting properties (LEDs) the synthesis of a novel 1,4-bis(chloromethyl)-benzene monomer, 5-benzyloxy-1,4-dichloromethyl-2,3-diphenyl benzene 78 was carried out. Monomer 78 was polymerized via the Gilch polymerization method to yield, poly(5-benzyloxy-2,3-diphenyl phenylene vinylene) 80. Polymer 80 was characterized by TGA (5% weight loss at 267°, GPC (weight average molecular weight of 7136 Da, number average molecular weight of 6603 Da) , UV-Vis and fluorescence studies (absorbance maximum at 406 nm, emission maximum at 510 nm). The Horner-Wadsworth-Emmons variant of the Wittig was applied in the synthesis of poly(2,3-diphenyl-1,4-phenylenevinylene) (DP-PPV) 3 from 2,3-diphenylterephthalaldehyde 6 and 1,4-bis(diethoxyphosphorylmethyl)-2,3-diphenyl benzene 79, which was synthesized via the Michaelis-Arbuzov reaction. Four trials were carried out to determine an optimal method for the order of addition of the monomers and base. Of these, trial 4, which yielded polymer 3d, was found to the most optimal. Polymer 3d was characterized by TGA (5% weight loss of 319°), UV-Vis and fluorescence studies (absorbance maximum at 430 nm, emission maximum at 496 nm when excited at 416 or 424 nm)

The Synthesis of Benzyloxy Substituted DP-PPV and Examination of the Horner-Wadsworth-Emmons Reaction in the Synthesis of DP-PPV

In the interest of the synthesis of polymers that have the potential to possess inherent light-emitting properties (LEDs) the synthesis of a novel 1,4-bis(chloromethyl)-benzene monomer, 5-benzyloxy-1,4-dichloromethyl-2,3-diphenyl benzene 78 was carried out. Monomer 78 was polymerized via the Gilch polymerization method to yield, poly(5-benzyloxy-2,3-diphenyl phenylene vinylene) 80. Polymer 80 was characterized by TGA (5% weight loss at 267°, GPC (weight average molecular weight of 7136 Da, number average molecular weight of 6603 Da) , UV-Vis and fluorescence studies (absorbance maximum at 406 nm, emission maximum at 510 nm). The Horner-Wadsworth-Emmons variant of the Wittig was applied in the synthesis of poly(2,3-diphenyl-1,4-phenylenevinylene) (DP-PPV) 3 from 2,3-diphenylterephthalaldehyde 6 and 1,4-bis(diethoxyphosphorylmethyl)-2,3-diphenyl benzene 79, which was synthesized via the Michaelis-Arbuzov reaction. Four trials were carried out to determine an optimal method for the order of addition of the monomers and base. Of these, trial 4, which yielded polymer 3d, was found to the most optimal. Polymer 3d was characterized by TGA (5% weight loss of 319°), UV-Vis and fluorescence studies (absorbance maximum at 430 nm, emission maximum at 496 nm when excited at 416 or 424 nm)

Development of single-cell protectors for sealed silver-zinc cells

Three design approaches to cell-level protection were developed, fabricated, and tested. These systems are referred to as the single-cell protector (SCP), multiplexed-cell protector(MCP). To evaluate the systems 18-cell battery packs without cell level control were subjected to cycle life test. A total of five batteries were subjected to simulate synchronous orbit cycling at 40% depth of discharge at 22C. Batteries without cell-level protection failed between 345 and 255 cycles. Cell failure in the cell level protected batteries occurred between 412 and 540. It was determined that the cell-level monitoring and protection is necessary to attain the long cycle life of a AgZn battery. The best method of providing control and protection of the AgZn cells depends on the specific application and capability of the user

Observations of MMOD Impact Damage to the ISS

This paper describes meteoroid and orbital debris (MMOD) damage observations on the International Space Station (ISS). Several hundred MMOD damage sites on ISS have been documented using imagery taken from ISS windows. MMOD damage sites visible from ISS windows are typically larger approximately 5mm diameter and greater due to the larger viewer-to-surface distance. Closer inspection of these surfaces by astronauts during spacewalks reveals many smaller features that are typically less distinct. Characterization of these features as MMOD or non- MMOD is difficult, but can be partially accomplished by matching physical characteristics of the damage against typical MMOD impact damage observed on ground-based impact tests. Numerous pieces of space-exposed ISS hardware were returned during space shuttle missions. Subsequent ground inspection of this hardware has also contributed to the database of ISS MMOD impact damage. A handful of orbital replacement units (ORUs) from the ISS active thermal control and electrical power subsystems were swapped out and returned during the Space Shuttle program. In addition, a reusable logistics module was deployed on ISS for a total 59.4 days on 11 shuttle missions between 2001 and 2011 and then brought back in the shuttle payload bay. All of this returned hardware was subjected to detailed post-flight inspections for MMOD damage, and a database with over 1,400 impact records has been collected. A description of the largest observed damage features is provided in the paper. In addition, a discussion of significant MMOD impact sites with operational or design aspects is presented. MMOD impact damage to the following ISS modules/subsystems is described: (1) Solar Arrays, (2) US and Russian windows, (3) Extravehicular Activity (EVA) handrails, (4) Radiators, and (5) Russian Functional Cargo Block (FGB) module