399 research outputs found
The Box Problem
The box problem is taken from Calculus 1, where a student is asked to maximize the volume of a box constructed from a rectangular piece of cardboard with squares removed at the corners. We are interested in what the width and length need to be in order to have at least a rational answer for the optimum height. In 2000, Cuoco used Eisenstein triples to find the dimensions. Hotchkiss expanded on Cuoco\u27s work in 2002 and used an elliptical equation to find the dimensions needed for the box. This paper answers two open questions posed by Hotchkiss: proving that the smallest possible distinct dimensions that produce an integral solution are 5 and 8. Also the minimum distnct dimensions are examined in general
A study of the effectiveness of self-management as a form of behavior modification
Behavior management is a major concern among educators. Effective practices for managing behavior are constantly being studied and tested. This research study focuses on self-management as an effective form of behavior modification in an inclusive classroom. This study is to determine if a self-management form of behavior modification will increase self-awareness which will in turn decrease disruptive behavior in the classroom. An intervention is implemented to determine its effect on the behaviors being studied. A goal of this study is also to contribute more findings on the effectiveness of self-management to the current research
Experimental thermal mechanics of deployable boom structures
An apparatus was developed for thermal distortion measurements on deployable boom structures. The calibration procedure and thermal static bending plus twist measurements are considered. The thermal mechanics test facility is described. A table is presented for several examples of spacecraft applications of thermal static distortion measurements on 3-m deployable booms
Method of bonding metals with a radio-opaque adhesive/sealant for void detection and product made
A method and structure for providing radio-opaque polymer compounds for use in metal bonding and sealing. A powder filler comprising a high atomic number metal or compound thereof is incorporated into a polymer compound to render it more radio-opaque than the surrounding metal structures. Voids or other discontinuities in the radio-opaque polymer compound can then be detected by x-ray inspection or other non-destructive radiographic procedure
Hydrogen Sulfide Increases Nitric Oxide Production from Endothelial Cells by an Akt-Dependent Mechanism
Hydrogen sulfide (H2S) and nitric oxide (NO) are both gasotransmitters that can elicit synergistic vasodilatory responses in the in the cardiovascular system, but the mechanisms behind this synergy are unclear. In the current study we investigated the molecular mechanisms through which H2S regulates endothelial NO production. Initial studies were performed to establish the temporal and dose-dependent effects of H2S on NO generation using EPR spin trapping techniques. H2S stimulated a twofold increase in NO production from endothelial nitric oxide synthase (eNOS), which was maximal 30 min after exposure to 25–150 μM H2S. Following 30 min H2S exposure, eNOS phosphorylation at Ser 1177 was significantly increased compared to control, consistent with eNOS activation. Pharmacological inhibition of Akt, the kinase responsible for Ser 1177 phosphorylation, attenuated the stimulatory effect of H2S on NO production. Taken together, these data demonstrate that H2S up-regulates NO production from eNOS through an Akt-dependent mechanism. These results implicate H2S in the regulation of NO production in endothelial cells, and suggest that deficiencies in H2S signaling can directly impact processes regulated by NO
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Head Observation Organizer (HObO)
The Head Observation Organizer, HObO, is a computer program that stores and manages measured ground-water levels. HObO was developed to help ground-water modelers compile, manage, and document water-level data needed to calibrate ground-water models. Well-construction and water-level data from the U.S. Geological Survey National Water Database (NWIS) easily can be imported into HObO from the NWIS web site (NWISWeb). The water-level data can be flagged to determine which data will be included in the calibration data set. The utility program HObO_NWISWeb was developed to simplify the down loading of well and water-level data from NWISWeb. An ArcGIS NWISWeb Extension was developed to retrieve site information from NWISWeb. A tutorial is presented showing the basic elements of HObO
Life of Pennzane and 815Z-Lubricated Instrument Bearings Cleaned with Non-CFC Solvents
This report takes the form of two papers: (1) "Life of Pennzane and 815Z-Lubricated Instrument Bearings cleaned with Non-CFC Solvents" and (2) a published paper, entitled "Instrument bearing life with NON-CFC cleaners". Abstract for paper # 1 : Bearings used in spacecraft mechanisms have historically been cleaned with chlorofluorocarbon CFC-1 13 (Freon) solvents and lubricated with a perfluorinated polyalkylether (PFPE) oils like 815-Z. Little full-scale bearing life test data exists to evaluate the effects of the newer class environmental-friendly bearing cleaners or improved synthetic hydrocarbon space oils like Pennzane. To address the lack of data, a cooperative, bearing life test program was initiated between NASA, Lockheed Martin and MPB. The objective was to obtain comparative long-term, life test data for flight-quality bearings, cleaned with non-CFC solvents versus CFC-1 13 under flight-like conditions with two space oils. A goal was to gain a better understanding of the lubricant surface chemistry effects with such solvents. A second objective was to obtain well-controlled, full-scale bearing life test data with a relatively new synthetic oil (Pennzane), touted as an improvement to Bray 815Z, an oil with considerable space flight history. The second paper, which serves as an attachment, is abstracted below: Bearings used in spacecraft mechanisms have historically been cleaned with chlorofluorocarbon CFC-113 (Freon) solvents and lubricated with a perfluorinated polyalkylether (PFPE) oils like 815-Z. Little full-scale bearing life test data exists to evaluate the effects of the newer class environmental-friendly bearing cleaners or improved synthetic hydrocarbon space oils like Pennzane. To address the lack of data, a cooperative, bearing life test program was initiated between NASA, Lockheed Martin and MPB. The objective was to obtain comparative long-term, life test data for flight-quality bearings, cleaned with non-CFC solvents versus CFC-1 13 under flight-like conditions with two space oils. A goal was to gain a better understanding of the lubricant surface chemistry effects with such solvents. A second objective was to obtain well-controlled, full-scale bearing life test data with a relatively new synthetic oil (Pennzane), touted as an improvement to Bray 815Z, an oil with considerable space flight history
Juan Ramón Jiménez: entre el cielo y el mar
This essay examines the importance and value of the literary work of Juan Ramón Jiménez in twentieth-century Spanish poetry. It emphasizes the enormous innovation of a brilliant cycle of poetry that extends from Sonetos espirituales to Piedra y cielo and that recognizes Diario de un poeta reciencasado as the center of a new poetic world. It studies the key significance of the Diario as an epoch-making contribution to the poetry of its time and as an indispensable book for understanding the later work of the Nobel Laureate in exile. This essay gives special attention to the unity and coherence of his work, in its constant evolution and renovation. The two poles of nearly sacred orientation and inspiration, Moguer and Zenobia, constitute the center of the drama in the Diario and appear again as important themes in Dios deseado y deseante. Juan Ramón's entire work, as he himself has pointed out, can be seen as the poet's religious progress toward the encounter with his god.En este ensayo se examina Ia importancia y el valor de la obra de Juan Ramón Jiménez en la poesía hispánica del siglo XX. En particular, se destaca la enorme innovación de un ciclo de poesía brillante que se extiende desde Sonetos espirituales hasta Piedra y cielo, y que reconoce Diario de un poeta reciéncasado como centro de un nuevo mundo poético. Se estudia el significado capital del Diario como obra que hace época en Ia poesía de su tiempo y como libro indispensable para entender la obra posterior del Nobel en el exilio. Se subraya, sobre todo, una impresionante coherencia y unidad de su obra en su constante evolución y renovación. Los dos polos de orientación e inspiración casi sagrados, Moguer y Zenobia, constituyen el centro del drama en el Diario y vuelven a aparecer como temas importantes en Dios deseado y deseante. Toda Ia obra de Juan Ramón, como el mismo ha señalado, se puede ver como un avance religioso del poeta hacia el encuentro con su dios
El sufijo "-al" en el español de Guatemala
En este número no se incluyeron resúmenes ni palabras clave.
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