A study of planetary-approach orbit- determination policies using Mariner IV DOPPLER data
Planetary approach orbit determination target errors using Mariner IV Doppler tracking data
DOPPLER RADAR↗
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The superior conjunction of Mariner IV
Radio communication system instrumentation for Mariner IV space probe, and received spectrograms
SPECTROGRAM↗
The problem of using Mariner IV IONOSPHERIC densities to deduce a model of the Martian atmospheric structure
Martian atmosphere model deduced from Mariner IV IONOSPHERE electron density measurements
MARINER IV SPACE PROBE↗
Cosmic ray observations in 1964-1965 with Mariner IV
Design of particle detector used in Mariner IV COSMIC ray observations
PARTICLE DETECTOR↗
Mariner IV midcourse propulsion system impulse and accuracy prediction.
Mariner IV midcourse 50-lb thrust pressure- controlled monopropellant hydrazine propellant system, predicting impulse and velocity error as function of burn time
MARINER IV SPACE PROBE↗
Thermal scale modeling of the Mariner IV SPACECRAFT.
Half-scale thermal model of Mariner IV SPACECRAFT tested in simulated solar environment
MARINER IV SPACE PROBE↗
Mariner IV space data automation system /SDAS/ computer reliability.
Mariner IV Space Data Automation System /SDAS/ computer reliability design, pellet component concept, testing, interconnection and welding techniques
FAILURE MODE↗
The Mariner Venus 67 spacecraft and its evolution from Mariner IV.
Mariner IV spacecraft modification for Venus mission, discussing extent of changes
MARINER IV SPACE PROBE↗
A quasi-global analysis of tropospheric water vapor content and its temporal variations from radiation data of the meteorological satellite Tiros IV.
Radiation data measured by Tiros IV satellite for determination of global distribution of atmospheric water vapor
ATMOSPHERIC RADIATION↗
The integration of scientific instruments into Mariner IV.
Scientific instrument integration into Mariner IV spacecraft and prelaunch testing for flexible performance
PRELAUNCH TESTING↗
The Mariner IV Canopus sensor.
Canopus star sensor used for roll control of Mariner IV spacecraft
GUIDANCE SENSOR↗
The Mariner IV photographs of Mars.
Mariner IV photographs of Mars, discussing mission objectives, functioning of camera system and interpretation of pictures
MARS SURFACE↗
Radio occultation measurement of the Martian atmosphere over two regions by the Mariner IV SPACE probe.
Radio occultation measurement of Martian atmosphere over two regions by Mariner IV SPACE probe
MARINER IV SPACE PROBE↗
Ground instrumentation for Mariner IV OCCULTATION experiment.
Ground instrumentation system for Mariner IV OCCULTATION experiment, using Doppler frequency perturbation method for Mars atmospheric parameters determination
OCCULTATION↗
Control and measurement of temperatures of Mariner IV.
Control and measurement of temperatures of Mariner IV
SPACECRAFT CONTROL↗
Mariner IV midcourse propulsion system impulse and accuracy prediction.
Mariner IV midcourse 50-lb thrust pressure- controlled monopropellant hydrazine propellant system, predicting impulse and velocity error as function of burn time
SPECIFIC IMPULSE↗
Aqueous Zr/Hf IV ‐Oxo Cluster Speciation and Separation
Abstract Many industrial separations of chemically‐similar elements are achieved by solvent extraction, exploiting differences in speciation and solubility across aqueous‐organic interfaces. We recently identified [OM 4 (OH) 6 (SCN) 12 ] 4− (OM 4 , M=Zr/Hf IV ) tetrahedral oxoclusters as the main species in industrial processes that produce nuclear‐grade Zr and Hf from crude ore. However, isostructural/isoelectronic OM 4 ‐oxoclusters do not explain selective extraction of Hf into the organic phase. Here we have characterized heterometal Hf−Zr clusters in solution and the solid‐state yielding key information about their fundamentally different chemistry that engenders separation. Clusters prepared with both ammonium (industrial process) and tetramethylammonium counter cations revealed that 1) heterometal clusters (instead of a mixture of homometal clusters) assemble, and 2) Hf‐rich OM 4 selectively precipitates over Zr‐rich OM 4 , providing a separation process that does not require an organic extractant. Mass spectrometry, small‐angle X‐ray scattering, solution‐state 1 H nuclear magnetic resonance (NMR) spectroscopy, and solid‐state 17 O NMR evidence both mixed‐metal speciation and selective Hf‐precipitation. Raman spectroscopy suggests greater Zr‐ligand lability than Hf‐ligand lability, consistent with higher aqueous solubility of Zr‐rich clusters, enabling both extraction and precipitation‐based separation. Fundamentally, we also identify a key difference between these chemically similar elements that has enabled diversification of Zr‐polyoxocation chemistry over the last decade, while Hf‐polyoxocation chemistry lags.
Roseborough, Alexander [Department of Chemistry Or↗