70,884 research outputs found
SAM-2 ground-truth plan: Correlative measurements for the Stratospheric Aerosol Measurement-2 (SAM 2) sensor on the Nimbus G satellite
The SAM-2 will fly aboard the Nimbus-G satellite for launch in the fall of 1978 and measure stratospheric vertical profiles of aerosol extinction in high latitude bands. The plan gives details of the location and times for the simultaneous satellite/correlative measurements for the nominal launch time, the rationale and choice of the correlative sensors, their characteristics and expected accuracies, and the conversion of their data to extinction profiles. The SAM-2 expected instrument performance and data inversion results are presented. Various atmospheric models representative of polar stratospheric aerosols are used in the SAM-2 and correlative sensor analyses
Niche tracking and rapid establishment of distributional equilibrium in the house sparrow show potential responsiveness of species to climate change.
The ability of species to respond to novel future climates is determined in part by their physiological capacity to tolerate climate change and the degree to which they have reached and continue to maintain distributional equilibrium with the environment. While broad-scale correlative climatic measurements of a species' niche are often described as estimating the fundamental niche, it is unclear how well these occupied portions actually approximate the fundamental niche per se, versus the fundamental niche that exists in environmental space, and what fitness values bounding the niche are necessary to maintain distributional equilibrium. Here, we investigate these questions by comparing physiological and correlative estimates of the thermal niche in the introduced North American house sparrow (Passer domesticus). Our results indicate that occupied portions of the fundamental niche derived from temperature correlations closely approximate the centroid of the existing fundamental niche calculated on a fitness threshold of 50% population mortality. Using these niche measures, a 75-year time series analysis (1930-2004) further shows that: (i) existing fundamental and occupied niche centroids did not undergo directional change, (ii) interannual changes in the two niche centroids were correlated, (iii) temperatures in North America moved through niche space in a net centripetal fashion, and consequently, (iv) most areas throughout the range of the house sparrow tracked the existing fundamental niche centroid with respect to at least one temperature gradient. Following introduction to a new continent, the house sparrow rapidly tracked its thermal niche and established continent-wide distributional equilibrium with respect to major temperature gradients. These dynamics were mediated in large part by the species' broad thermal physiological tolerances, high dispersal potential, competitive advantage in human-dominated landscapes, and climatically induced changes to the realized environmental space. Such insights may be used to conceptualize mechanistic climatic niche models in birds and other taxa
Application of an optimal estimation inverse method to GPS/MET bending angle observations
Palmer et al. [2000] describes an optimal estimation inverse method for radio occultation (RO) bending angle measurements to retrieve simultaneously temperature, humidity, and surface pressure; outlines quality control procedures for retrieved profiles; and investigates the results from numerical simulations. Here we present retrievals that use bending angle observations from the Global Positioning System Meteorology (GPS/MET) satellite instrument and a priori information from the European Centre for Medium-Range Weather Forecasts analyses. Retrieved profiles are compared with correlative radiosondes, United Kingdom Meterological Office (UKMO) model analyses, and retrievals from the conventional inverse method. Retrieved temperature profiles are generally colder than analyses but agree with the conventional inverse method to within 1 K. Water vapor retrievals are generally drier than the UKMO analyses and wetter than the radiosonde profiles. Quality of retrieved surface pressure values are related to the extent to which RO observations reach into the troposphere. Low-latitude retrievals make large adjustments to surface pressure and tropospheric temperatures, which are directly linked to the lack of water vapor above 300 hPa in the inverse model, consistent with previous studies. A study of individual occultations at low and high latitude shows that the optimal retrievals are able to resolve small-scale atmospheric structure exhibited by the conventional inverse method and collocated radiosondes, not shown by analyses
THE PERSISTENCE OF CORRELATIVE WATER RIGHTS IN COLONIAL AUSTRALIA: A THEORETICAL CONTRADICTION?
This paper analyses whether the evolution of water law in the Australian colony of New South Wales (NSW) contradicts theoretical models that suggest in arid countries correlative, land based water rights will be replaced with individual ownership. Evidence from NSW shows a series of Supreme Court decisions between 1850-1870 adopted correlative riparian rights thereby implying that common law was inefficient. However, further consideration of factors that gave rise to these decisions suggests the value of water was higher when used in unity because of the arid climate and non-consumptive nature of water use in the pastoral industry. The findings suggest that where intensity of water use is low, economic development is dominated by industries requiring low levels of capital investment, and acute water scarcity prevails, correlative water rights are efficient.water rights, common law
Correlative analyses for Homestake neutrino data
We present results from linear correlative analyses between Homestake data and several solar-activity parameters in the period 1970-1992. Our findings support the hypothesis that the observed neutrino flux exhibits a significative correlation with some solar-activity parameters, particularly with those related with the heliomagnetic
field
Combination of Imaging Infrared Spectroscopy and X-ray Computed Microtomography for the Investigation of Bio-and Physicochemical processes in Structured Soils
Soil is a heterogeneous mixture of various organic and inorganic parent materials. Major soil functions are driven by their quality, quantity and spatial arrangement, resulting in soil structure. Physical protection of organic matter (OM) in this soil structure is considered as a vital mechanism for stabilizing organic carbon turnover, an important soil function in times of climate change. Herein, we present a technique for the correlative analysis of 2D imaging visible light near-infrared spectroscopy and 3D X-ray computed microtomography (mCT) to investigate the interplay of biogeochemical properties and soil structure in undisturbed soil samples. Samples from the same substrate but different soil management and depth (no-tilled topsoil, tilled topsoil and subsoil) were compared in order to evaluate this method in a diversely structured soil. Imaging spectroscopy is generally used to qualitatively and quantitatively identify OM with high spatial resolution, whereas 3D X-ray mCT provides high resolution information on pore characteristics. The unique combination of these techniques revealed that, in undisturbed samples, OM can be found mainly at greater distances from macropores and close to biopores. However, alterations were observed because of disturbances by tillage. The correlative application of imaging infrared spectroscopic and X-ray mCT analysis provided new insights into the biochemical processes affected by soil structural changes
Mechanical Properties of Microstructural Components of Inorganic Materials
Disertační práce se zabývá studiem strukturních a mechanických vlastností anorganických materiálů. Cílem je nalezení jednotlivých fází ve zkoumaném materiálu a hlavně lokalizace (mechanicky) nejslabšího místa, jeho ovlivnění a následně výroba materiálu o lepších mechanických vlastnostech. Z důvodu velkého množství použitých metod je základní teorie vložena vždy na začátku příslušné kapitoly. Taktéž z důvodu značného množství výsledků jsou na konci kapitol uvedeny dílčí závěry. Práce je rozdělena na tři části, kdy první se zabývá seznámením s možnostmi modelování mikro-mechanických vlastností a provedením experimentů umožňujících posouzení rozsahu platnosti některého modelu. V druhé části je provedeno shrnutí současných možností indentačních zkoušek pro měření mechanických vlastností strukturních složek betonu a praktické zvládnutí metodiky vhodné k užití pro výzkum materiálů zkoumaných domovským pracovištěm. V třetí části je navržena metoda identifikace nejslabších článků struktury anorganických pojiv a její ověření na konkrétním materiálu zkoumaném na domovském pracovišti. V této dizertační práci jsou použity tyto metody: kalorimetrie, ultrazvukové testování, jednoosá pevnost v tlaku, nanoindentace, korelativní mikroskopie a rastrovací elektronová mikroskopie s energiově disperzním spektrometrem. Dílčími výsledky jsou kompletní charakterizace cementových materiálů, upřesnění stávajících poznatků a nalezení optimálního postupu pro charakterizaci. Hlavním výsledkem je inovativní přístup vedoucí k pozitivnímu ovlivnění materiálu.The doctoral thesis deals with study of structural and mechanical properties of inorganic materials. Goal is to find the weakest (mechanically) phases and interfaces of material. By affecting these structures it should be possible consequently produce a material with better mechanical properties. Due to the large amount of used methods the basic theory is discussed always in the beginning of relevant chapter. Similarly, due to the considerable amount of results every chapter includes partial conclusions. The work is divided in three parts. The first deals with the introduction of the possibilities of modeling micro-mechanical properties and performing of experiments that allow assessment of the scope of some model. In second part itis performed an overview of current possibilities of indentation tests for measuring mechanical properties of structural components of concrete and the practical managing of methods suitable for use for materials research examined at our faculty. In third part the method of identifying the weakest points in structure of inorganic binders is proposed and validation on the particular material examined at our faculty is performed. The methods used in this doctoral thesis are: calorimetry, ultrasonic testing, uniaxial compression, nanoindentation, correlative microscopy and scanning electron microscopy with energy dispersive spectrometer. Partial results are a complete characterization of cementitious materials, specification of existing knowledge and finding the optimal procedure for characterization. The main result is an innovative approach that leads to a positive effect on the material.
Probert, Philomen. 2015. Early Greek Relative Clauses. Oxford: Oxford University Press. ISBN 870-0-19-871382-1
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