1,629,059 research outputs found

    Calibration of planetary brightness temperature spectra at near-millimeter and submillimeter wavelengths with a Fourier-transform spectrometer

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    A medium-resolution Fourier-transform spectrometer for ground-based observation of astronomical sources at near-millimeter and submillimeter wavelengths is described. The steps involved in measuring and calibrating astronomical spectra are elaborated. The spectrometer is well suited to planetary spectroscopy, and initial measurements of the intrinsic brightness temperature spectra of Uranus and Neptune at wavelengths of 1.0 to 1.5 mm are presented

    Titanium-Oxygen Reactivity Study

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    A program has been conducted at Astronautics to investigate the likelihood of occurrence of the catastrophic oxidation of titanium alloy sheet under conditions which simulate certain cases of accidental failure of the metal while it is in contact with liquid or gaseous oxygen. Three methods of fracturing the metal were used; they consisted of mechanical puncture, tensile fracture of welded joints, and perforation by very high velocity particles. The results of the tests which have been conducted provide further evidence of the reactivity of titanium with liquid and gaseous oxygen. The evidence indicates that the rapid fracturing of titanium sheet while it is in contact with oxygen initiates the catastrophic oxidation reaction. Initiation occurred when the speed of the fracture was some few feet per second, as in both the drop-weight puncture tests and the static tensile fracture tests of welded joints, as well as when the speed was several thousand feet per second, as in the simulated micrometeoroid penetration tests. The slow propagation of a crack, however, did not initiate the reaction. It may logically be concluded that the localized frictional heat of rapid fracture and/or spontaneous oxidation (exothermic) of minute particles emanating from the fracture cause initiation of the reaction. Under conditions of slow fracture, however, the small heat generated may be adequately dissipated and the reaction is not initiated. A portion of the study conducted consisted of investigating various means by which the reaction might be retarded or prevented. Providing a "barrier" at the titanium-oxygen interface consisting of either aluminum metal or a coating of a petroleum base corrosion inhibitor appeared to be only partially effective in retarding the reaction. The accidental puncturing or similar rupturing of thin-walled pressurized oxygen tanks on missiles and space vehicle will usually constitute loss of function, and may sometimes cause their catastrophic destruction by explosive decompression regardless of the type of material used for their construction. In the case of tanks constructed of titanium alloys the added risk is incurred of catastrophic burning of the tanks. In view of this it is recommended that thin-walled tanks constructed of titanium alloys should not be used to contain liquid or gaseous oxygen

    Doping-Induced Spectral Shifts in Two Dimensional Metal Oxides

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    Doping of strongly layered ionic oxides is an established paradigm for creating novel electronic behavior. This is nowhere more apparent than in superconductivity, where doping gives rise to high temperature superconductivity in cuprates (hole-doped) and to surprisingly high Tc in HfNCl (Tc=25.5K, electron-doped). First principles calculations of hole-doping of the layered delafossite CuAlO2 reveal unexpectedly large doping-induced shifts in spectral density, strongly in opposition to the rigid band picture that is widely used as an accepted guideline. These spectral shifts, of similar origin as the charge transfer used to produce negative electron affinity surfaces and adjust Schottky barrier heights, drastically alter the character of the Fermi level carriers, leading in this material to an O-Cu-O molecule-based carrier (or polaron, at low doping) rather than a nearly pure-Cu hole as in a rigid band picture. First principles linear response electron-phonon coupling (EPC) calculations reveal, as a consequence, net weak EPC and no superconductivity rather than the high Tc obtained previously using rigid band expectations. These specifically two-dimensional dipole-layer driven spectral shifts provides new insights into materials design in layered materials foe functionalities besides superconductivity.Comment: 6 pages, 8 figures,1 tabl

    Protein sterilization method of firefly luciferase using reduced pressure and molecular sieves

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    The sterilization of the protein fruitfly luciferase under conditions that prevent denaturation is examined. Denaturation is prevented by heating the protein in contact with molecular seives and under a reduced pressure of the order of 0.00005 millimeters of mercury

    Voltage regulator/amplifier is self-regulated

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    Signal modulated, self-regulating voltage regulator/amplifier controls the output b-plus voltage in modulated regulator systems. It uses self-oscillation with feedback to a control circuit with a discontinuous amplitude action feedback loop

    Stratification of centrifuged amoeba nuclei investigated by electron microscopy

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    Study establishes a relationship between radioresistance and the nucleolar stratification characteristics of various amoeba species. Two species of fresh water amoeba are studied with the electron microscope. The report discusses the nature of nucleolar layers and their possible relationship to the differences in radiosensitivity of the two amoeba species

    Cable insulation cut-through tester

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    Device accurately measures cut-through load within specified time or time when cut-through occurs at specific load. Tests are performed at ambient conditions or in an environmental chamber

    Hybrid coordinate formulation used for the design of attitude control systems for flexible spacecraft

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    Formulation combines certain advantages of discrete and distributed coordinates by using both simultaneously. In report summarizing method, theoretical development is extended as necessary for applications of practical interest. Explicit analyses are presented in sufficient detail to establish utility in flexible space vehicle control system of hybrid coordinate formulation

    Conflict Management. The Contribution of the Christian Church

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    It is true now that man lives in a world of conflict. Conflict is an ever-present process in human relations. Conflict situations indeed appear frequently in daily, public and private life. Conflict may occur within and among families, groups, communities or nations; and they may be fuelled by ethnic, racial, religious, or economic differences, or may arise from differences in ideologies, values and beliefs. Conflict may be on a small or large scale. Conflict charge the people with tensions, threats, fears, anxieties and uncertainties. What makes a society ideal is the extent to which the conflicting interests and needs in a society are constructively managed so that violence does not threaten its continued existence. Since it is obvious that conflicts in any given society is inevitable, management and resolution of conflict is the very essence of talking about conflict. This is what this work is set to achieve and to offer suggestions on how to manage and resolve conflict thereby reducing its negative and destructive effects. This work showed the church has the potential to contribute to the management and resolution of conflicts in Nigeria
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