Radiometric Research Articles

Intercomparison of NO2 photolysis frequency measurements by actinic flux spectroradiometry and chemical actinometry during JCOM97

A first intercomparison of JNO2 measurements by actinic flux spectroradiometry (SR) and chemical actinometry (CA) was performed in summer 1997 in Jülich, Germany. During this experiment (JCOM97) a large set of data was collected with a time resolution of ∼ 1 min, showing a high linear correlation (R = 0.998) in JNO2. Linear regression indicates a good absolute agreement with the CA being 6% higher than SR if the quantum yield recommended by NASA/JPL (1997) and recently published data of the NO2 absorption spectrum (σNO2) is used for the evaluation of the SR‐data. The influence of using previously published σNO2 data is discussed. Overall the comparison suggests that JNO2 can be measured by either CA or SR with an accuracy of better than 10%.

Grenzen der radiometrischen 230Th/U-Altersbestimmung der Sauerwasserkalkvorkommen (Travertine) in Stuttgart

Grenzen der radiometrischen 230Th/U-Altersbestimmung der Sauerwasserkalkvorkommen (Travertine) in Stuttgart

Introduction to Radiometry and Photometry [Book Review

Introduction to Radiometry and Photometry [Book Review

BIOCHRONOLOGY OF THE PLEISTOCENE MAMMAL FAUNA FROM PONTE GALERIA (ROME) AND REMARKS ON THE MIDDLE GALERIAN FAUNAS

Taking into account the fossil mammal material recently discovered at Cava di Breccia (sands outcropping at Ponte Galeria, Rome), the revised fossils from the area and the updated stratigraphical settings of the Ponte Galeria Formation (Rome), the Authors discuss the biochronology of the Middle Galerian faunal assemblages with a new definition of its Faunal Units. 1) The mammal fauna of Isernia in our opinion is strongly conditioned by palaeoenvironmental factors and by human influence. The occurrence at Isernia La Pineta of the rodent Arvicola cantiana, which was widespread in Western Europe from 0.6 MA, does not match with the biochronology of the fauna and with the absolute dating (0.736 MA). A new radiometric dating will be useful to determine the age of the Isernia La Pineta local fauna, which can be considered younger than 0.736 MA on the basis of its faunal assemblage. 2) The age of the faunal assemblage of Ponte Galeria is between 0.8 and 0.75 MA, approximately in correspondence with the Brunhes-Matuyama paleomagnetic reversal event. The first occurrence of Bos galerianus and Megaloceros savini testifies a faunal renewal in comparison with the faunal assemblage of Slivia. The megacerine cervids from Ponte Galeria are more primitive than those from Isernia La Pineta and Venosa-Notarchirico. The Ponte Galeria local fauna has to be considered as a distinct Faunal Unit, younger than Slivia F.U. and older than the Isernia La Pineta fauna. SHORT NOTE

THE MINDYAK PALAEOZOIC LHERZOLITE OPHIOLITE, SOUTHERN URALS: GEOCHEMISTRY AND GEOCHRONOLOGY

The Mindyak ophiolite, Southern Urals, preserves metamorphic garnet- and amphibole-bearing blocks, along with a diverse assemblage of ocean crust-derived clasts, in a serpentinite tectonic breccia in contact with its spinel-plagioclase/spinel lherzolite mantle and wehrlite/clinopyroxenite transition zone sequences. On the basis of petrological and geochemical data we suggest that the mantle section preserves variably depleted lherzolites generated by a two-stage process involving melting followed by magma-mantle interaction in a supra-subduction zone setting. The garnetiferous rocks are interpreted as high-temperature metamorphosed, rodingitized ocean crust gabbros that subsequently underwent later stage low-temperature retrogression. Previously determined radiometric U-Pb and Pb-Pb dates of 410–415 Ma, at the Silurian-Devonian boundary, for the peak metamorphic event affecting the metagabbros are confirmed with new Sm-Nd radiometric data. The complex, multistage evolution of the garnet metagabbros and their preservation in the Mindyak lherzolitic ophiolite massif give insights into processes from plate divergence and ocean formation, to plate convergence and, ultimately, to preservation in the Uralian orogeny.

PRELIMINARY RE-OS ISOTOPIC DATA IN PGE RICH CHROMITITE LAYERS OF LUANGA ULTRAMAFIC LAYERED INTRUSION – CARAJAS (PARÀ STATE), BRAZIL

The Luanga layered complex intruded a greenstone belt sequence (Rio Novo Formation) at 2760 Ma (Rb-Sr radiometric dating; Suita and Nilson, 1991). This age is confirmed by relationships with the Lower Proterozoic age of the covering sequence (Salobo and Rio Fresco Units). Lithostratigraphic data based on outcrops and three drillholes confirm the layered nature of the intrusion made up of dunite, peridotite, pyroxenite, norite and gabbro layers from the bottom to the top. Chromitite layers and seams, occur in three well defined horizons located in plagioclase pyroxenites and at the transition zone between dunite and peridotite. The massive chromitite layers show thicknesses between 2 m and a few centimetres. The massive chromitite displays an equigranular texture, with single grains ranging from 0.5 to 2 mm in size. The fresh chromitite layers show: atoll-like texture with olivine and orthopyroxene inside and outside chromite rings, pseudomyrmekitic intergrowth of silicates and chromite. Relationships of the two dominant PGMs (braggite and sperrylite) with the silicates and chromite suggest that PGM crystallization predates the almost contemporaneous precipitation of silicates and chromite. Weathering processes changed only in part the primary composition and mineralogy of the chromitite, for this reason it was possible to select well preserved primary minerals and mineral assemblages for analyses with microprobe, fire assay and neutron activation and mass spectrometry. The chemistry of the chromitite layers is typical of chromites generated by fractionation and cumulus processes, with widely ranging, but generally high Al2O3 and low Cr2O3 contents. PGE chondritic profiles display a PPGE enrichment in all the three horizons (Table 1), (Diella et al., 1995). Preliminary Re–Os isotopic data were obtained on two selected massive chromitite samples from the PGE richer (Lu3) and the relatively PGE poorer (Lu 6) chromitite horizons. These two samples show respectively the highest and the lowest PGE contents of all data collected. Isotopic analyses were performed with the Carius tube isotope dilution procedure, using the PGE standard “WPR- 1” provided by the Canadian Certified Reference Materials Project. Isotopic data (Table 2), in form of 187Os/188Os, were transformed into 187Os/186Os by using a 188Os/186Os ratio of 8,302 (Luck and Allegre, 1983). Initial 187Os/186Os ratios and gOs were determined by considering an age of emplacement of Luanga complex at 2700 Ma. Reliabilty of data is confirmed by very low 2s values for both samples. Isotopic analyses were performed with the Carius tube isotope dilution procedure, using the PGE standard “WPR- 1” provided by the Canadian Certified Reference Materials Project. Isotopic data, in form of 187Os/188Os, were transformed into 187Os/186Os by using a 188Os/186Os ratio of 8,302 (Luck and Allegre, 1983). Initial 187Os/186Os ratios and gOs were determined by considering an age of emplacement of Luanga complex at 2700 Ma. Reliability of data is confirmed by very low 2s values for both samples. Our data were compared with those of other chromitites from layered complexes as Stillwater (A, B, G, I, K chromitites; Marcantonio et al., 1993) and Bushveld (UG1, UG2 chromitites; Hulbert and Gregoire, 1993) and PGE-rich Merensky Reef of Bushveld (Fig. 1). Luanga chromitites show high ratios, similar to those of Merensky Reef, and much higher than CHUR at 2700 Ma. It is possible to state that the mantle-melt system at Luanga underwent some modification and cannot be thought as due to a process of melting of a primary fertile undisturbed mantle. At this stage different processes able to increase (187Os/186Os)i can be envisaged: anomaly in the source due to the presence of a metasomatized mantle, strong differentiation during fractionation or crustal contamination.

The spaceborne data processing of the "Kyi" multi-channel radiometric complex

Main problems of on-line data processing for the “Kyi” microwave radiometric complex are considered. A structural algorithm of data processing for the spaceborne segment of the computational complex is presented.

Radiometry at infrared wavelengths for agricultural applications

Les mesures de radiation thermique aux longueurs d'ondes infrarouges (7 a 14 μm) fournissent une riche information concernant la surface des terres. Ces observations sont utilisees en premier lieu pour determiner la temperature de surface, puisque l'emissivite en est generalement proche. Dans ce cas il arrive par hasard que le pic dans l'emission thermique se trouve dans la fenetre de transmission atmospherique. En outre il y a des variations de l'emissivite des mineraux et des sols dans la bande 7 a 14 μm, qui peuvent etre interpretees dans des buts d'identification. On a trouve que l'emissivite des canopees de la vegetation etait proche de la valeur un, avec une petite variation spectrale. On discute des applications de la temperature de surface derivee a l'etude de l'equilibre energetique de surface et a l'estimation des flux d'energie envoye par la surface des terres. Les concepts de base de l'equilibre energetique a la surface des terres sont presentes avec un exemple qui montre comment les temperatures de brillance de surface teledetectees peuvent etre utilisees pour estimer la chaleur sensible et l'utilisation de l'eau par la plante. L'exemple est tire de l'experience Mousson 90 qui a ete faite au-dessus d'une ligne de partage des eaux en region aride, dans l'etat d'Arizona. Dans ce cas, les temperatures de surface provenant du detecteur infrarouge thermique de l'avion et les caracteristiques de la vegetation et de l'utilisation des terres provenant de l'image Landsat TM ont ete utilisees dans un modele a deux sources pour predire les flux de chaleur de surface. Les resultats concordent assez bien avec les mesures de terrain faites durant les trois jours d'observation.

Temporal study of the activity of matrix metalloproteinases and their endogenous inhibitors during wound healing.

The restoration of functional connective tissue is a major goal of the wound healing process. This regenerative event requires the deposition and accumulation of collagenous and noncollagenous matrix molecules as well as the remodelling of extracellular matrix (ECM) by matrix metalloproteinases (MMPs). In this study, we have utilized substrate gel electrophoresis, radiometric enzyme assays, and Western blot analyses to determine the temporal pattern of appearance and activity of active and latent MMPs and their inhibitors during the entire healing process in a partial thickness wound model. Through the use of substrate gel electrophoresis, we studied the appearance of proteolytic bands whose molecular weight was consistent with their being members of the MMP family of enzymes. Proteolytic bands whose molecular weight is consistent with both the active and latent forms of MMP-2 (72 kDa, Type IV gelatinase) were detected in wound fluid of days 1-7 after wounding. The number of active MMP-2 species detectable in wound fluid was greatest during days 4-6 after wounding. The most prominent proteolytic band detected each day migrated with a molecular weight consistent with it being the latent form of MMP-9 (92 kDa, Type V pro-collagenase). In contrast to MMP-2, the active form of this enzyme was never detected. The presence of MMP-1 (interstitial collagenase) was detected by immunoblot in the wound fluid from days 1-6 post-injury. Using a radiometric enzyme assay for collagenase inhibitory activity we have also determined the time course of activity of endogenous matrix metalloproteinase inhibitors. We have correlated these data to the known cellular events occurring in the wound during this time period as well. This study establishes a prototypical pattern of MMP appearance in normal wound healing. It may also provide potential intervention sites for the therapeutic use of inhibitors of aberrant MMP activities which characterize chronic wounds.

Reliable spectroradiometry, by Henry J. Kostkowski

Reliable spectroradiometry, by Henry J. Kostkowski

Full-wave detection against half-wave detection in radiometry

Half-wave detection which is used in practice in radiometers does not allow the achievement of potential sensitivity. A comparison of the output signal-to-noise ratios for both full-wave and half-wave detectors shows that considerable gain could be obtained with the full-wave detector.

BIOCHRONOLOGY OF SELECTED MAMMALS, MOLLUSCS AND OSTRACODS FROM THE MIDDLE PLIOCENE TO THE LATE PLEISTOCENE IN ITALY. THE STATE OF THE ART

The Authors have elaborated four range charts of mammalian (large and micro), molluscs and fresh-water and brackish ostracodes faunas, for the selected Plio-Pleistocene fossiliferous localities of the Italy. A new Mammal Age (Aurelian) correlatable to late Middle and Late Pleistocene has been defined. Inside this age two Faunal Units (Torre in Pietra and Vitinia) have been defined as characteristic for Early and Middle Aurelian, while no gisements have been chosen for the late Aurelian. Biochronological units are calibrated on magnetostratigraphic and isotopic scales and by radiometric datings.

大阪東南部，二上層群の中新世火山岩の放射年代

大阪東南部，二上層群の中新世火山岩の放射年代

Geochronologic, petrologic and kinematic constraints on the evolution of the Err-Platta boundary, part of a fossil continent-ocean suture in the Alps (eastern Switzerland)

The boundary between the Austroalpine Err nappe and the Penninic Platta unit represents part of a Late Cretaceous continent-ocean suture preserved in the highest stockwerk of the Tertiary Alpine orogen. Subduction and nappe stacking (D1) and subsequent extensional uplift (D2) along part of this suture are dated with the K-Ar method on two generations of syn-kinematic white mica in the Err nappe and with Ar-Ar step-heating of syn- to post-kinematic riebeckitic amphiboles in the Platta nappe. The first generation of white micas associated with isoclinal folds and W-directed mylonitic thrusting along nappe contacts yields a 76 to 89 Ma age range, whereas the second generation of white micas that grew during tight folding and top-to-the-E extensional D2 shearing yields 67 to 80 Ma ages. The K-Ar white mica ages are interpreted as ages of formation at the approximately 300°C temperature of lower green-schist facies regional metamorphism in the southern part of the Err nappe. The two amphibole samples from the Platta nappe yield 69 and 73 Ma Ar-Ar ages, interpreted as syn-D2 formational ages. The Si-content of the white micas in chlorite-K-feldspar-quartz-bearing meta-radiolarites in the southern part of the Err nappe indicate a pressure decrease from D1 to D2 deformation, probably accompanied by an increase in temperature. This can be related to D2 extensional uplift accommodated along reactivated D1 nappe contacts in the footwall of the Julier-Bernina nappe. When combined with stratigraphic evidence, the radiometric ages and deformation-crystallization relations indicate clockwise P-T paths for the Err, Platta, and Margna nappes: Suturing of the Austroalpine continental and Liguro-Piemontese oceanic crust began with near surface thrusting and flysch sedimentation between 88 and 100 Ma and culminated with D1 folding and nappe stacking under high P/T greenschist facies conditions sometime during the period 80 to 88 Ma. The unroofing of this suture was a multi-stage process involving Late Cretaceous D2 extension under greenschist facies conditions, Early Tertiary D3 thrusting under lower anchizonal conditions, and mid-Tertiary D4 normal faulting above the uplifting Lepontine dome.

Critical requirements for a posteriori track recorder neutron dosimetry at Hiroshima and Nagasaki

International programs have been carried out over the last four decades to quantify the exposure of atom bomb survivors from Hiroshima and Nagasaki. Unfortunately, the quest for accurate gamma-ray and neutron exposure doses of atom bomb survivors has proven illusive. In the most recent of these programs, designated as Dosimetry System 1986 (DS86), a serious and persistent discrepancy has arisen between neutron transport calculations and radiometric (RM) neutron dosimetry for the Hiroshima site, which has been called the DS86 neutron dosimetry enigma. A recently completed in-depth analysis demonstrates that a simple single factor panacea does not exist to explain the DS86 neutron dosimetry enigma. Careful treatment of a number of specific experimental and calculational effects is required before any progress can be achieved. Within this perspective, the applicability of solid state track recorder (SSTR) neutron dosimetry for the Hiroshima and Nagasaki sites is examined as an independent alternative to radiometric (RM) neutron dosimetry. The utility of the SSTR method for the Hiroshima and Nagasaki sites is analyzed in light of: (i) the current status of the DS86 neutron dosimetry enigma; and (ii) SSTR characteristics that are specifically germane to the Hiroshima and Nagasaki sites. On this basis, critical SSTR requirements are identified, recommended ways of meeting these critical requirements are advanced and the domain of applicability of SSTR neutron dosimetry at the Hiroshima site is estimated.

Physics‐based vision: Principles and practice, radiometry, edited by Lawrence B. Wolff, Steven A. Shafer, and Glenn E. Healey, Jones and Bartlett, Boston, MA, 1992, Hardbound, 408 pp., $59.95

Physics‐based vision: Principles and practice, radiometry, edited by Lawrence B. Wolff, Steven A. Shafer, and Glenn E. Healey, Jones and Bartlett, Boston, MA, 1992, Hardbound, 408 pp., $59.95

Integration Technique of Multi-source Information Dominated by Aerial Radiometric Measure-ment and Its Application

This paper aims at exploring a digital image integration technique for multi-geoscience in formation dominated by airborne gamma-ray data, especially deeply discussing the method to secondly develop those aerial data by combining digital image processing system with the colored mapping system. Utilizing this technique , we have analyzed the geologic environment of uranium mineralization of Lianshanguan area > Liaoning Province, provided some important background information for further seeking of minerals. Meanwhile , experimental studies have been made to predict uranium mineralization , and evident results aquired. Practise shows that this new technique offers prospecting significance for mineral seeking and great practical value in survey of uranium resources.

An Experiment for the Radiometric Calibration of the ERS-1 SAR

RESUMEQuatre gros reflecteurs diedres de precision ont ete mis en service pour un essai d'etalonnage d'un radar a antenne synthetique monte a bord du satellite ERS-1. Cet article presente les resultats d'une evaluation de la performance de ces reflecteurs ainsi que d'un radome concu pour permettre l'utilisation des cibles dans toutes les conditions atmospheriques. La precision de la section efficace en radar des reflecteurs est superieure a ± 0,3 dB et la stabilite de ces derniers est d'environ du meme ordre. Le radome a produit une attenuation du signal de l'ordre de 0,3 dB environ, bien que cette valeur ait augmente en presence de gouttelettes a sa surface. Des ecarts allant jusqu'a 2 dB dans la reponse des reflecteurs ont ete observes. On a demontre que ces ecarts etaient dus a des changements dans la puissance de crete des impulsions. L'effet produit par les sols denudes et par les prairies, soit les deux types de sol utilises aux fins de cette experience, a ete compare. On a constate que les prairies...

Microwave systems applications in deep space telecommunications and navigation: Space Exploration Initiative architectures

The US Space Exploration Initiative (SEI) calls for the charting of a new and evolving manned course to the Moon, Mars, and beyond. The fundamental SEI support objectives are to provide the mission with means to monitor and control mission elements, acquire engineering, science, and navigation data, compute state vectors and navigate, and move these data efficiently and automatically between mission nodes for timely analysis and decision-making. Microwave links provide the means to communicate between system nodes, and the essential radio metrics to navigate; later, these probably will be augmented with optical links. The general mission telecommunications and navigation support requirements and resulting architectures for SEI mission support are described, and then the implications of these on the role of microwave technology in these architectures, particularly for Mars exploration support, are discussed. >

Recording sample activity in aerosol radiometry

Recording sample activity in aerosol radiometry