Search NASA⌕ Search

SEARCH · Search NASA

Results for “sample activation”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Emerging flux in active regions

The rates at which flux emerges in active and quiet solar regions within the sunspot belts are compared. The emerging flux regions (EFRs) were identified by the appearance of arch filament structures in H-alpha. All EFRs in high resolution films of active regions made at Big Bear in 1978 were counted. The comparable rate of flux emergence in quiet regions was obtained from SGD data and independently from EFRs detected outside the active region perimeter on the same films. The rate of flux emergence is 10 times higher in active regions than in quiet regions. A sample of all active regions in 31 days of 1983 gave a ratio of 7.5. Possible mechanisms which might funnel new magnetic flux to regions of strong magnetic field are discussed.

Liggett, M.↗
NASA NTRS1989

On the ratio of the infrared-to-ultraviolet continuum to the X-rays in quasars and active galaxies

A sample of 122 quasars and Seyfert galaxies was analyzed and it was found that the NIR 7500 A rest frame luminosity is more linearly related to the X-ray luminosity than is the optical luminosity. It is also found that the mean spectral slope between 7500 and 4200 A in the rest frame monotonically flattens with luminosity over more than three orders of magnitude. The present results support models which attribute the IR and X-ray continua to linked nonthermal processes such as synchrotron self-Compton, while the blue-UV bump comes from a different source, such as an accretion disk.

Mushotzky, R. F.↗
DOE OSTI2016

Development of a Low-Level Ar-37 Calibration Standard

Argon-37 is an important environmental signature of an underground nuclear explosion. Producing and quantifying low-level 37Ar standards is an important step in the development of sensitive field measurement instruments for use during an On-Site Inspection, a key provision of the Comprehensive Nuclear-Test-Ban Treaty. This paper describes progress at Pacific Northwest National Laboratory (PNNL) in the development of a process to generate and quantify low-level 37Ar standard material, which can then be used to calibrate sensitive field systems at activities consistent with soil background levels. The 37Ar used for our work was generated using a laboratory-scale, high-energy neutron source to irradiate powdered samples of calcium carbonate. Small aliquots of 37Ar were then extracted from the head space of the irradiated samples. The specific activity of the head space samples, mixed with P10 (90% stable argon:10% methane by mole fraction) count gas, is then derived using the accepted Length-Compensated Internal-Source Proportional Counting method. Due to the low activity of the samples, a set of three Ultra-Low Background Proportional-Counters designed and fabricated at PNNL from radio-pure electroformed copper was used to make the measurements in PNNL’s shallow underground counting laboratory. Very low background levels (<10 counts/day) have been observed in the spectral region near the 37Ar emission feature at 2.8 keV. Two separate samples from the same irradiation were measured. The first sample was counted for 12 days beginning 28 days after irradiation, the second sample was counted for 24 days beginning 70 days after irradiation (the half-life of 37Ar is 35.0 days). Both sets of measurements were analyzed and yielded very similar results for the starting activity (~0.1 Bq) and activity concentration (0.15 mBq/ccSTP argon) after P10 count gas was added. A detailed uncertainty model was developed based on the ISO Guide to the Expression of Uncertainty in Measurement. This paper presents a discussion of the measurement analysis, along with assumptions and uncertainty estimates.

Absolute radiation measurement↗
NASA NTRS1998

A Multiplicity Survey of Chromospherically Active and Inactive Stars

Surveys of the three samples of solar-type stars, segregated by chromospheric emission level, were made to determine their multiplicity fractions and to investigate the evolution of multiplicity with age. In total, 245 stars were searched for companions with DeltaV <= 3.0 and separations of 0.035" to 1.08" using optical speckle interferometry, By incorporating the visual micrometer survey for duplicity of the LamontHussey Observatory, the angular coverage was extended to 5.0" with no change in in the DeltaV limit. This magnitude difference allows mass ratios of 0.63 and larger to be detected throughout a search region of 2-127 AU for the stars observed. The 84 primaries observed in the chromospherically active sample are presumably part of a young population and are found to have a multiplicity fraction of 17.9% +/- 4.6%. The sample of 118 inactive, presumably older, primaries were selected and observed using identical methods and are found to have a multiplicity fraction of only 8.5% +/- 2.7%. Given the known link between chromospheric activity and age, these results tentatively imply a decreasing stellar multiplicity fraction from 1 to 4 Gyr, the approximate ages of the two samples. Finally, only two of the 14 very active primaries observed were found to have a companion meeting the survey detection parameters. In this case, many of the systems are either very young, or close, RS CVn type multiples that are unresolvable using techniques employed here.

Mason, Brian D.↗
DOE OSTI2020

Groundwater Monitoring Report, U.S. Department of Energy Y-12 National Security Complex, Oak Ridge, Tennessee

This report contains the groundwater and surface water monitoring data obtained during calendar year (CY) 2019 at the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) on the DOE Oak Ridge Reservation (ORR) in Oak Ridge, Tennessee. The monitoring data were obtained from wells, springs, and surface water sampling locations in three hydrogeologic regimes at Y-12. The Bear Creek Hydrogeologic Regime (Bear Creek Regime) encompasses a section of Bear Creek Valley (BCV) between the west end of Y-12 and the west end of the Bear Creek Watershed (directions are in reference to the Y-12 grid system, shown as Plant North. The Upper East Fork Poplar Creek Hydrogeologic Regime (East Fork Regime) encompasses the Y-12 industrial facilities and support structures in BCV. The Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime) encompasses a section of Chestnut Ridge directly south of Y-12. Background information in Section 2 of this report outlines the hydrogeologic framework for groundwater and surface water quality monitoring at Y-12 and includes an overview of the groundwater contamination in each hydrogeologic regime. Section 3 provides details regarding the groundwater and surface water sampling and analysis activities implemented under the Y-12 GWPP, including sampling locations and frequency, sample collection and handling, field measurements and laboratory analytes, quality assurance (QA)/quality control (QC) sampling, data management, and data quality assessment (DQA). However, the equivalent QA/QC or DQA information for the groundwater and surface water data associated with the monitoring programs implemented by UCOR are not included in this report and instead are deferred to referenced programmatic plans and reports issued by OREM and UCOR. Section 4 of this report presents a summary evaluation of the CY 2019 monitoring data with regard to the respective objectives of surveillance monitoring and exit pathway/perimeter monitoring. The evaluation is based primarily on the analytical results for the following principal groundwater contaminants at Y-12: nitrate, uranium, gross alpha activity, gross beta activity, and volatile organic compounds (VOCs). Section 5 summarizes the most significant findings with respect to the principal contaminants along with recommendations for any proposed changes to the ongoing groundwater and surface water quality monitoring performed under the Y-12 GWPP. Technical reports and plans cited in the narrative sections of the report are listed in Section 6. Narrative sections of this report reference several appendices. Figures (maps and diagrams) and data tables (excluding data summary tables incorporated in the narrative sections) are in Appendix A and Appendix B, respectively. Appendix C contains construction details for each well sampled during CY 2019 by either the Y-12 GWPP or UCOR, along with schematic diagrams for wells equipped with Westbay™ multiport sampling equipment or Barcad® pump systems. Appendix D supports the background summary discussion in Section 2 and provides more detailed information about the hydrogeologic framework for groundwater and surface water monitoring at Y-12, including the primary sources of groundwater contamination in each hydrogeologic regime. Results for all field measurements and laboratory analyses obtained by the Y-12 GWPP and UCOR are presented in Appendix E, which also includes the sample numbers for the QA/QC samples associated with groundwater and surface water monitoring performed by the Y-12 GWPP.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2010

Visual Sample Plan (VSP) Statistical Software as Related to the CTBTO’s On-Site Inspection Procedure

In the event of a potential nuclear weapons test the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is commissioned to conduct an on-site investigation (OSI) of the suspected test site in an effort to find confirmatory evidence of the nuclear test. The OSI activities include collecting air, surface soil, and underground samples to search for indications of a nuclear weapons test - these indicators include radionuclides and radioactive isotopes Ar and Xe. This report investigates the capability of the Visual Sample Plan (VSP) software to contribute to the sampling activities of the CTBTO during an OSI. VSP is a statistical sampling design software, constructed under data quality objectives, which has been adapted for environmental remediation and contamination detection problems for the EPA, US Army, DoD and DHS among others. This report provides discussion of a number of VSP sample designs, which may be pertinent to the work undertaken during an OSI. Examples and descriptions of such designs include hot spot sampling, combined random and judgment sampling, multiple increment sampling, radiological transect surveying, and a brief description of other potentially applicable sampling methods. Further, this work highlights a potential need for the use of statistically based sample designs in OSI activities. The use of such designs may enable canvassing a sample area without full sampling, provide a measure of confidence that radionuclides are not present, and allow investigators to refocus resources in other areas of concern.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2018

Discovery of Potent and Selective Periphery-Restricted Quinazoline Inhibitors of the Cyclic Nucleotide Phosphodiesterase PDE1

Herein we disclose the discovery and X-ray cocrystal data of potent, selective quinazoline inhibitors of PDE1. Inhibitor $(S)$-3 readily attains free plasma concentrations above PDE1 IC50 values and has restricted brain access. The racemic compound 3 inhibits >75% of PDE hydrolytic activity in soluble samples of human myocardium, consistent with heightened PDE1 activity in this tissue. These compounds represent promising new tools to probe the value of PDE1 inhibition in the treatment of cardiovascular disease.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Measurements of short-lived fission product yields from photofission of 238 U using 13.0 MeV monoenergetic photons

Photon-induced fission product yield (FPY) measurements were conducted on the isotope 238U. Fission was induced using Eγ = 13.0 MeV monoenergetic photons produced by the Triangle Universities Nuclear Laboratory’s (TUNL’s) High Intensity γ-ray Source (HIγS) facility. Short-lived FPYs were measured by performing cyclic activation of the sample using a rapid target transfer system. Following activation, the 238U target was rapidly (0.4 s) transferred to a counting station consisting of two well-shielded high-purity germanium (HPGe) detectors. The irradiation-counting cycle was repeated until the summed data had sufficient statistical accuracy. Twenty-eight unique fission products with half-lives ranging from 1 s to 450 s were identified, and their cumulative FPYs determined. Furthermore, the results are compared with previous independent FPY measurements using inverse kinematics. Good agreement between the data sets is found despite the different excitation energy distributions of the fissioning nucleus in the experiments.

Physics - Nuclear physics and radiation physics↗
NASA NTRS2004

Simulation of Wind Profile Perturbations for Launch Vehicle Design

Ideally, a statistically representative sample of measured high-resolution wind profiles with wavelengths as small as tens of meters is required in design studies to establish aerodynamic load indicator dispersions and vehicle control system capability. At most potential launch sites, high- resolution wind profiles may not exist. Representative samples of Rawinsonde wind profiles to altitudes of 30 km are more likely to be available from the extensive network of measurement sites established for routine sampling in support of weather observing and forecasting activity. Such a sample, large enough to be statistically representative of relatively large wavelength perturbations, would be inadequate for launch vehicle design assessments because the Rawinsonde system accurately measures wind perturbations with wavelengths no smaller than 2000 m (1000 m altitude increment). The Kennedy Space Center (KSC) Jimsphere wind profiles (150/month and seasonal 2 and 3.5-hr pairs) are the only adequate samples of high resolution profiles approx. 150 to 300 m effective resolution, but over-sampled at 25 m intervals) that have been used extensively for launch vehicle design assessments. Therefore, a simulation process has been developed for enhancement of measured low-resolution Rawinsonde profiles that would be applicable in preliminary launch vehicle design studies at launch sites other than KSC.

Adelfang, S. I.↗
DOE OSTI2013

2012 Groundwater Monitoring and Inspection Report Gnome-Coach, New Mexico, Site

Gnome-Coach was the site of a 3-kiloton underground nuclear test conducted in 1961. Surface and subsurface contamination resulted from the underground nuclear testing, post-test drilling, and a groundwater tracer test performed at the site. Surface reclamation and remediation began after the underground testing. A Completion Report was prepared, and the State of New Mexico is currently proceeding with a conditional certificate of completion for the surface. Subsurface corrective action activities began in 1972 and have generally consisted of annual sampling and monitoring of wells near the site. In 2008, the annual site inspections were refined to include hydraulic head monitoring and collection of samples from groundwater monitoring wells onsite using the low-flow sampling method. These activities were conducted during this monitoring period on January 18, 2012. Analytical results from this sampling event indicate that concentrations of tritium, strontium-90, and cesium-137 were generally consistent with concentrations from historical sampling events. The exceptions are the decreases in concentrations of strontium-90 in samples from wells USGS-4 and USGS-8, which were more than 2.5 times lower than last year's results. Well USGS-1 provides water for livestock belonging to area ranchers, and a dedicated submersible pump cycles on and off to maintain a constant volume in a nearby water tank. Water levels in wells USGS-4 and USGS-8 respond to the on/off cycling of the water supply pumping from well USGS-1. Well LRL-7 was not sampled in January, and water levels were still increasing when the transducer data were downloaded in September. A seismic reflection survey was also conducted this year. The survey acquired approximately 13.9 miles of seismic reflection data along 7 profiles on and near the site. These activities were conducted from February 23 through March 10, 2012. The site roads, monitoring well heads, and the monument at surface ground zero were in good condition at the time of the site inspection. However, it was reported in September 2012 that the USGS-1 well head had been damaged by a water truck in April 2012.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Closure Report for Corrective Action Unit 413: Clean Slate II Plutonium Dispersion (TTR) Tonopah Test Range, Nevada, Revision 0

This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 413: Clean Slate II Plutonium Dispersion (TTR), located on the Tonopah Test Range, Nevada. CAU 413 consists of the release of radionuclides to the surface and shallow subsurface from the conduct of the Clean Slate II storage-transportation test conducted on May 31, 1963. The purpose of this CR is to provide documentation and justification for the clean closure of CAU 413 under the FFACO without further corrective action. This justification is based on historical knowledge of the site, previous site investigations, closure activities conducted at the site, and the results of verification samples. Clean closure activities included excavating and disposing of radiologically contaminated soil and debris in the vicinity of ground zero, and collecting verification samples to support the corrective action of clean closure. Results confirmed that further corrective action is not required at CAU 413. Based on the corrective action activities conducted, clean closure of the site is complete; the closure objectives established in the CADD/CAP have been achieved; and no further corrective action at the site is required.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Post-Closure Inspection, Sampling, and Maintenance Report for the Salmon, Mississippi, Site Calendar Year 2012

This report summarizes the 2012 annual inspection, sampling, measurement, and maintenance activities performed at the Salmon, Mississippi, Site (Salmon site). The draft Long-Term Surveillance and Maintenance Plan for the Salmon Site, Lamar County, Mississippi (DOE 2007) specifies the submittal of an annual report of site activities with the results of sample analyses. A revised plan is in preparation. The Long-Term Surveillance Plan for the Salmon, Mississippi, Site is intended for release in 2013. The Salmon site consists of 1,470 acres. The site is located in Lamar County, Mississippi, approximately 10 miles west of Purvis, Mississippi, and about 21 miles southwest of Hattiesburg, Mississippi The State of Mississippi owns the surface real estate subject to certain restrictions related to subsurface penetration. The State is the surface operator; the Mississippi Forestry Commission is its agent. The federal government owns the subsurface real estate (including minerals and some surface features), shares right-of-entry easements with the State, and retains rights related to subsurface monitoring. The U.S. Department of Energy (DOE) Office of Legacy Management (LM), a successor agency to the U.S. Atomic Energy Commission, is responsible for the long-term surveillance of the subsurface real estate

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2012

Post-Closure Inspection, Sampling, and Maintenance Report for the Salmon, Mississippi, Site Calendar Year 2011

This report summarizes the 2011 annual inspection, sampling, measurement, and maintenance activities performed at the Salmon, Mississippi, Site (Salmon site1). The draft Long-Term Surveillance and Maintenance Plan for the Salmon Site, Lamar County, Mississippi (DOE 2007) specifies the submittal of an annual report of site activities with the results of sample analyses. The Salmon site consists of 1,470 acres. The site is located in Lamar County, Mississippi, approximately 10 miles west of Purvis, Mississippi, and about 21 miles southwest of Hattiesburg, Mississippi.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2011

Post-Closure Inspection, Sampling, and Maintenance Report for the Salmon, Mississippi, Site Calendar Year 2010

This report summarizes the annual inspection, sampling, measurement, and maintenance activities performed at the Salmon, Mississippi, Site in calendar year 2010. The draft Long-Term Surveillance and Maintenance Plan for the Salmon Site, Lamar County Mississippi (DOE 2007) specifies the submittal of an annual report of site activities with the results of sample analyses. The Salmon, MS, Site is a federally owned site located in Lamar County, MS, approximately 12 miles west of Purvis, MS, and about 21 miles southwest of Hattiesburg, MS (Figure 1). The U.S. Department of Energy (DOE), a successor agency to the U.S. Atomic Energy Commission (AEC), is responsible for the long-term surveillance and maintenance of the 1,470-acre site. DOE's Office of Legacy Management (LM) is the operating agent for the surface and subsurface real estate.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Supported molybdenum oxides for the aldol condensation reaction of acetaldehyde

The (retro-)aldol condensation reaction is an important chemical transformation in the upgrading of biomass-derived compounds into fuels and valuable specialty chemicals. In this study, we found that supported molybdenum oxide (MoO x ) catalysts were active and selective for the aldol condensation of acetaldehyde to crotonaldehyde under steady-state reactor conditions. Through a combination of transmission electron microscopy (TEM), ultraviolet–visible (UV–VIS) diffuse reflectance spectroscopy, Fourier transform infrared (FTIR) spectroscopy of adsorbed pyridine, and steady-state reactor testing, we determined that highly dispersed MoO x has a strong interaction with a γ-Al 2 O 3 support resulting in optimal catalyst performance at low weight loadings. In contrast, MoO x particles supported on SiO 2 have a weaker interaction with the support, resulting in a monotonic relationship between Mo loading and aldol condensation activity. The Lewis acid site density and strength are important parameters for predicting aldol condensation activity across all samples. The concentration of weak acid sites had a poor correlation with aldol condensation activity, most likely because these sites are too weak to activate acetaldehyde for the reaction. Medium and strong acid sites both had good correlations to aldol condensation activity. Results from X-ray absorption near edge structure (XANES) and acetaldehyde temperature programmed desorption (TPD) indicated that partially reduced MoO x was more active for aldol condensation, but pretreatment in reducing or oxidizing environments had no significant effect on steady-state catalytic activity. Finally, characterization of spent catalyst samples through temperature programmed oxidation (TPO) and thermogravimetric analysis (TGA) revealed that catalysts with high densities of strong acid sites tended to form more carbonaceous deposits on the surface over the course of the reaction.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Materials and Methods for Streamlined Laboratory Analysis of Environmental Samples, FY 2016 Report

The International Atomic Energy Agency (IAEA) relies upon laboratory analysis of environmental samples (typically referred to as “swipes”) collected during on-site inspections of safeguarded facilities to support the detection and deterrence of undeclared activities. Unfortunately, chemical processing and assay of the samples is slow and expensive. A rapid, effective, and simple extraction process and analysis method is needed to provide certified results with improved timeliness at reduced costs (principally in the form of reduced labor), while maintaining or improving sensitivity and efficacy. To address these safeguard needs the Pacific Northwest National Laboratory (PNNL) explored and demonstrated improved methods for environmental sample (ES) analysis. Improvements for both bulk and particle analysis were explored. To facilitate continuity and adoption, the new sampling materials and processing methods will be compatible with existing IAEA protocols for ES analysis. PNNL collaborated with Oak Ridge National Laboratory (ORNL), which performed independent validation of the new bulk analysis methods and compared performance to traditional IAEA’s Network of Analytical Laboratories (NWAL) protocol. ORNL efforts are reported separately. This report describes PNNL’s FY 2016 progress, which was focused on analytical application supporting environmental monitoring of uranium enrichment plants and nuclear fuel processing. In the future the technology could be applied to other safeguard applications and analytes related to fuel manufacturing, reprocessing, etc. PNNL’s FY 2016 efforts were broken into two tasks and a summary of progress, accomplishments and highlights are provided below. Principal progress and accomplishments on Task 1, Optimize Materials and Methods for ICP-MS Environmental Sample Analysis, are listed below. • Completed initial procedure for rapid uranium extraction from ES swipes based upon carbonate-peroxide chemistry (delivered to ORNL for evaluation). • Explored improvements to carbonate-peroxide rapid uranium extraction chemistry. • Evaluated new sampling materials and methods (in collaboration with ORNL). • Demonstrated successful ES extractions from standard and novel swipes for a wide range uranium compounds of interest including UO 2 F 2 and UO 2 (NO 3 ) 2 , U 3 O 8 and uranium ore concentrate. • Completed initial discussions with commercial suppliers of PTFE swipe materials. • Submitted one manuscript for publication. Two additional drafts are being prepared. Principal progress and accomplishments on Task 2, Optimize Materials and Methods for Direct SIMS Environmental Sample Analysis, are listed below. • Designed a SIMS swipe sample holder that retrofits into existing equipment and provides simple, effective, and rapid mounting of ES samples for direct assay while enabling automation and laboratory integration. • Identified preferred conductive sampling materials with better performance characteristics. • Ran samples on the new PNNL NWAL equivalent Cameca 1280 SIMS system. • Obtained excellent agreement between isotopic ratios for certified materials and direct SIMS assay of very low levels of LEU and HEU UO 2 F 2 particles on carbon fiber sampling material. Sample activities range from 1 to 500 CPM (uranium mass on sample is dependent upon specific isotope ratio but is frequently in the subnanogram range). • Found that the presence of the UF molecular ions, as measured by SIMS, provides chemical information about the particle that is separate from the uranium isotopics and strongly suggests that those particles originated from an UF6 enrichment activity. • Submitted one manuscript for publication. Another manuscript is in preparation.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2019

Fischer-Tropsch synthesis: Direct cobalt nitrate reduction of promoted Co/TiO 2 catalysts

The effect of the direct reduction of cobalt nitrate versus the more conventional calcination/reduction treatment has been investigated. Porosity properties of the catalysts are not significantly modified by avoiding the calcination step, as similar BET surface area, pore volume and pore diameter are obtained for the activated catalysts. In contrast, the cobalt reducibility decreases, but smaller cobalt particles size and higher dispersion are obtained. The reduction phenomena occurring for the uncalcined catalysts are more complex because of the additional nitrate decomposition steps. TPR-MS and TPR-XANES point out that CoO x intermediate species are formed during the reductive nitrate decomposition. However, these species are oxidized by NO X (formed by nitrate decomposition) to spinel type Co 3 O 4 , which is then converted to CoO prior to the final reduction step to Co 0 . The addition of promoters (Pt, Re, Ru, Ag) improves the cobalt reducibility, especially by shifting the final reduction step (i.e., CoO to Co 0 ) to lower temperature. FT activity testing data show that activated uncalcined catalysts have higher CO conversion following the initial decline and leveling off period relative to the activated calcined catalyst. We find that the best performance is achieved with uncalcined Pt-12%Co/TiO 2 . This catalyst has the highest CO steady state conversion, which is 1.2 times higher than the Pt-promoted calcined catalyst. Moreover, its deactivation rate is 0.13%/h compared to 0.2%/h for the corresponding calcined catalyst. The difference in the catalytic activity is even higher for the un-promoted samples, where the activated uncalcined catalyst has almost double the CO conversion as compared to its calcined counterpart. Finally, the addition of other promoters such as Ru, Re and Ag has no significant effect on catalytic activity.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗