An evaluation of the interfacial bond properties between carbon phenolic and glass phenolic composites

The effects of moisture and surface finish on the mechanical and physical properties of the interfacial bond between the carbon/phenolic (C/P) and glass/phenolic (G/P) composite materials are presented. Four flat panel laminates were fabricated using the C/P and G/P materials. Of the four laminates, one panel was fabricated in which the C/P and G/P materials were cured simultaneously. It was identified as the cocure. The remaining laminates were processed with an initial simultaneous cure of the three C/P billets. Two surface finishes, one on each half, were applied to the top surface. Prior to the application and cure of the G/P material to the machined surface of the three C/P panels, each was subjected to the specific environmental conditioning. Types of conditioning included: (1) nominal fabrication environment, (2) a prescribed drying cycle, and (3) a total immersion in water at 160 F. Physical property tests were performed on specimens removed from the C/P materials of each laminate for determination of the specific gravity, residual volatiles and and resin content. Comparisons of results with shuttle solid rocket motor (SRM) nozzle material specifications verified that the materials used in fabricating the laminates met acceptance criteria and were representative of SRM nozzle materials. Mechanical property tests were performed at room temperature on specimens removed from the G/P, the C/P and the interface between the two materials for each laminate. The double-notched shear strength test was used to determine the ultimate interlaminar shear strength. Results indicate no appreciable difference in the C/P material of the four laminates with the exception of the cocure laminate, where 20 percent reduction in the strength was observed. The most significant effect and the ultimate strength was significantly reduced in the wet material. No appreciable variation was noted between the surface finishes in the wet laminate

Calcium signaling components and their effect on synaptic morphology during neuronal development

Along with regulating synaptic transmission, voltage-gated calcium channel (VGCC) function is responsible for a myriad of cellular outputs, ranging from gene expression to shaping synaptic morphology. Despite the morphological role of VGCCs, the proteins working downstream of VGCCs to regulate synaptic morphology remain mostly unknown, and their identification would provide insight into the shaping of synapses through calcium signaling. Chapter I introduces the Caenorhabditis elegans VGCC subunits unc-2 and unc-36 as regulators of D-type GABAergic neuromuscular junction morphology. In addition to synaptic defects found in single mutants, loss-of-function mutations in VGCC subunits, independent of neurotransmission, suppressed the enlarged synaptic areas resulting from mutations in the extracellular matrix protein nidogen (nid-1). Furthermore, time-lapse microscopy revealed UNC-2 function was required for proper synaptic dynamics that occurred during the L4 larval stage of organismal growth. Specifically, the dynamics observed in wild-type animals were slowed or absent in unc-2 mutants. Since wild-type synapses undergo enlargement - increasing to areas similar to nid-1 - and subsequently divide into two smaller puncta, we conclude UNC-2 is responsible for a temporal switch between synaptic stability and growth to add synapses during development. In chapter III, I detail the characterization of the calm-1 (ortholog of calmyrin), a gene encoding an EF hand protein that was identified in a nid-1 suppressor screen. Double mutant analysis between calm-1 and VGCC subunits suggests calm-1 acts downstream of VGCCs to regulate synaptic morphology. This result is the first to find a calmyrin protein that affects synapse morphology downstream of VGCCs. A calcium-dependent CALM-1 pulldown identified the intracellular scaffolding protein RACK-1 as a protein that may be targeted via VGCC/CALM-1 signaling. Similar to nid-1, rack-1 mutants displayed abnormally shaped synaptic areas that were suppressed by calm-1 mutants. In conclusion, my genetic analyses suggest synaptic growth through VGCCs is normally inhibited by NID-1. But this inhibition is relieved during development to allow synaptogenesis to occur, commensurate with increases in organismal size, from the expansion and budding of existing synaptic connections. Thus, the cycling between synaptic adhesion and growth allows for a rapid and localized mechanism to add new synapses

A History [of] Department of Education and Teacher Training at South Dakota State College

Section I: Beginnings and up to 1918.Section II: Development of the Department -- 1918-1923Section III: (A Separate) -- History and Development of Teacher Training in Agriculture at State College --1918-1954 Section IV History of Education and Psychology Department at South Dakota State College 1930-1957Supplementary Part of Section IV LCSH:South Dakota State University. Division of Education -- HistoryAgricultural education -- South Dakota -- HistoryTeachers -- Training of -- South Dakota -- Histor

The Road to Realizing In-Space Manufacturing

Additive Manufacturing in space offers tremendous potential for dramatic paradigm shift in the development and manufacturing of space architectures. Additive Manufacturing in space offers the potential for mission safety risk reduction for low Earth orbit and deep space exploration; new paradigms for maintenance, repair, and logistics. Leverage ground-based technology developments, process characterization, and material properties databases. Investments are required primarily in the microgravity environment. We must do the foundational work. It's not sexy, but it is required

Fast Paced, Low Cost Projects at MSFC

What does an orbiting microsatellite, a robotic lander and a ruggedized camera and telescope have in common? They are all fast paced, low cost projects managed by Marshall Space Flight Center (MSFC) teamed with successful industry partners. MSFC has long been synonymous with human space flight large propulsion programs, engineering acumen and risk intolerance. However, there is a growing portfolio/product line within MSFC that focuses on these smaller, fast paced projects. While launching anything into space is expensive, using a managed risk posture, holding to schedule and keeping costs low by stopping at egood enough f were key elements to their success. Risk is defined as the possibility of loss or failure per Merriam Webster. The National Aeronautics and Space Administration (NASA) defines risk using procedural requirement 8705.4 and establishes eclasses f to discern the acceptable risk per a project. It states a Class D risk has a medium to significant risk of not achieving mission success. MSFC, along with industry partners, has created a niche in Class D efforts. How did the big, cautious MSFC succeed on these projects that embodied the antithesis of its heritage in human space flight? A key factor toward these successful projects was innovative industry partners such as Dynetics Corporation, University of Alabama in Huntsville (UAHuntsville), Johns Hopkins Applied Physics Laboratory (JHU APL), Teledyne Brown Engineering (TBE), Von Braun Center for Science and Innovation (VCSI), SAIC, and Jacobs. Fast Affordable Satellite Technology (FastSat HSV01) is a low earth orbit microsatellite that houses six instruments with the primary scientific objective of earth observation and technology demonstration. The team was comprised of Dynetics, UAHuntsvile, SAIC, Goddard Space Flight Center (GSFC) and VCSI with the United States Air Force Space Test Program as the customer. The team completed design, development, manufacturing, environmental test and integration in one year. FastSat HSV01 also deployed a Poly Picosatellite Orbital Deployer (PPOD) for a separate nano ]satellite class spacecraft (Cubesat: Nano Sail Demonstration) in partnership with Ames Research Center. The Robotic lunar lander is a MSFC JHU APL partnership that led to the development of a flexible architecture for landers to support robotic missions to a wide range of lunar and asteroid destinations. The team started with the goal of meeting NASA agency directives that led to the creation of a test bed focusing on GN&C and software to demonstrate the descent and landing on any airless body for the final 30 to 60 meters. The team created a complex technology demonstration as well as Guidance Control and Navigation (GN&C) algorithms providing autonomous control of the lander. The team uses a green propellant of 90% hydrogen peroxide and has completed 18 successful test flights. The International Space Station (ISS) SERVIR Environmental Research and Visualization System (ISERV) is a technology demonstration payload to assist the SERVIR project with environmental monitoring for disaster relief and humanitarian efforts. The ISERV project was a partnership with TBE. The ISERV payload consists of a commercial off the shelf camera, telescope, and MSFC developed power distribution box and interfaces on ISS with the Window Observational Research Facility in the US Lab. MSFC has identified three key areas that enabled the low cost mission success to include culture, partnering, and cost/schedule control. This paper will briefly discuss these three Class D efforts, FastSat HSV-01, the Robotic Lunar Lander and the ISERV camera system, the lessons learned, their successes and challenges

Overview of Flight Certification Methodology for Additive Manufacturing

No abstract availabl

Caenorhabditis elegans voltage-gated calcium channel subunits UNC-2 and UNC-36 and the calcium-dependent kinase UNC-43/CaMKII regulate neuromuscular junction morphology

The conserved Caenorhabditis elegans proteins NID-1/nidogen and PTP-3A/LAR-RPTP function to efficiently localize the presynaptic scaffold protein SYD-2/α-liprin at active zones. Loss of function in these molecules results in defects in the size, morphology and spacing of neuromuscular junctions

Archaeological Investigations within San Pedro Springs Park (41BX19), San Antonio, Bexar County, Texas

The University of Texas at San Antonio Center for Archaeological Research (UTSA-CAR) contracted with Adams Environmental, Inc. to provide archaeological services to Capital Improvement Management (CIMS) of the City of San Antonio (COSA) related to the archaeological investigation of selected areas of San Pedro Springs Park in San Antonio, Bexar County, Texas. The CAR conducted archaeological testing at this National Register Site, 41BX19, from early December 2013 to mid-January of 2014. The goals of archaeological investigations were to identify and investigate any proto-historic and historic archaeological deposits associated with Colonial Period occupants of the area, including evidence of the first acequia and associated dam, and the location of the first presidio and villa. In addition, CAR was tasked with the investigation of any prehistoric cultural deposits encountered. This project was performed by staff archaeologists from the CAR. It was conducted under Texas Antiquities Permit No. 6727, with Dr. Steve Tomka serving as Principal Investigator (PI), and Kristi Nichols and Stephen Smith serving as Project Archaeologists. Dr. Tomka departed from UTSA shortly after the completion of fieldwork. At that time, Dr. Raymond Mauldin of CAR assumed PI responsibilities for the project. One hundred and eleven shovel tests, eleven 1-x-1 m test units, two 50-x-50 cm units, two backhoe trenches, and several auger holes were excavated during this effort. Minimal artifactual evidence of colonial occupants was noted during the archaeological investigations. Several Native American bone tempered sherds that could reflect either Late Prehistoric Leon Plain or Goliad ware were recovered. However, no Spanish Majolicas or lead glazed wares were uncovered, and no gunflints were identified in the lithic assemblage. Due to various utility lines and other obstructions, backhoe trenches to search for the acequia and associated dam could not be excavated. It is likely that areas proposed for investigation of the acequia and associated dam have been disturbed by aforementioned utility lines as well as earlier construction within the park. No evidence of the specific location of the first presidio or villa was located. Shovel testing and test units revealed the presence of historic and prehistoric use of the park, though mixing of historic and prehistoric material, as well as other disturbances (e.g., rodents), was common in the deposits. However, there was an increase in prehistoric material with depth as revealed in shovel testing results. Shovel testing located Feature 1, a burned rock feature that possibly was associated with a sheet midden, as well as several areas with high densities of prehistoric materials. Test excavations, based on these shovel tests, suggest that Feature 1 is a discrete feature that lies below a widespread, low-density distribution of burned rock. Shovel testing also identified a high-density cluster of lithic, bone, and burned rock. The excavation of a 1-x-1 m test unit (TU 4) in this area produced over 4,000 pieces of debitage, with over 50% of this total coming from three levels. Burned rock, a variety of tools, faunal material, and charcoal were present throughout these levels. Temporal placement of deposits relied on artifact typologies (e.g., ceramic types, lithic projectile points, lithic tool types) as well as two charcoal and four bone collagen radiocarbon dates. Artifact typologies suggest occupation as early as the Early Archaic as reflected by a possible Guadalupe tool. A series of Late Archaic Points (Castroville, Frio, Marcos, and Montell) and Late Prehistoric point forms (Edwards, Perdiz, and Scallorn) are present from several areas. In addition, a possible Middle Archaic La Jita point was recovered. The bone tempered Native American wares could date as early as AD 1250, though they could also reflect proto-historic or colonial age materials. Other ceramics primarily suggest a mid-nineteenth- to midtwentieth- century occupation. Using the midpoints of the 1-sigma distribution, calibrated radiocarbon dates show use of San Pedro Park from as early as 100 AD (CAR 345; 1905 +/- 22 Radiocarbon Years Before Present [RCYBP]) to as recently as the early twentieth century. The more recent end of that range is a function of two late dates from two different areas of the park. The first of these is on a bison bone (CAR 344) that returned a date of 158 +/- 23 RCYBP. The second is on a bone consistent with a bison-sized animal (CAR 346) that produced a date of 155 +/- 23 RCYBP. The corrected, calibrated dates for these two samples range from AD 1670 to the early 1940s using the 1-sigma spread. The wide range of these dates is related to the flat calibration curve late in time. However, the most probable date range (ca. 36% probability) for these two dates is between AD 1729 and 1779, with a roughly 48% probability that they date prior to AD 1779. Limited testing suggests that, with a few specific exceptions, the upper 30-40 cm of San Pedro Park is extensively disturbed. However, though some disturbances are present, at least three areas have materials in what appears to be good context. These include material dating to the Late Archaic, Late Prehistoric, and possibly the Proto-historic or Colonial Period. Based on historic maps, previous work, and the current investigation, CAR proposes a series of management areas for San Pedro Park. If work in these management areas follows these suggestions for various limits on subsurface impacts, CAR recommends that renovation activities within the park be allowed to proceed. The Texas Historical Commission (THC), in a letter dated February 4, 2015, agreed with these recommendations. Finally, CAR provides several recommendations for public education facilities within the park. In accordance with the THC Permit specifications and the Scope of Work for this project, all field notes, analytical notes, photographs, and other project related documents, along with a copy of the final report, will be curated at the CAR. After quantification and completion of analysis, and in consultation with THC and the COSA Office of Historic Preservation, artifacts possessing little scientific value were discarded pursuant to Chapter 26.27(g)(2) of the Antiquities Code of Texas. Artifact classes discarded specific to this project included samples of burned rock and snail shell, all unidentifiable metal, soil samples, and recent (post-1950) material

Federal Programs that Support Makers

No abstract availabl

Taking Additive Manufacturing to the Next Level: Ensuring Quality Control for Future Spaceflight

No abstract availabl