2,697 research outputs found
Determination of wind from NIMBUS 6 satellite sounding data
Objective methods of computing upper level and surface wind fields from NIMBUS 6 satellite sounding data are developed. These methods are evaluated by comparing satellite derived and rawinsonde wind fields on gridded constant pressure charts in four geographical regions. Satellite-derived and hourly observed surface wind fields are compared. Results indicate that the best satellite-derived wind on constant pressure charts is a geostrophic wind derived from highly smoothed fields of geopotential height. Satellite-derived winds computed in this manner and rawinsonde winds show similar circulation patterns except in areas of small height gradients. Magnitudes of the standard deviation of the differences between satellite derived and rawinsonde wind speeds range from approximately 3 to 12 m/sec on constant pressure charts and peak at the jet stream level. Fields of satellite-derived surface wind computed with the logarithmic wind law agree well with fields of observed surface wind in most regions. Magnitudes of the standard deviation of the differences in surface wind speed range from approximately 2 to 4 m/sec, and satellite derived surface winds are able to depict flow across a cold front and around a low pressure center
Modulated voltage metastable ionization detector
The output current from a metastable ionization detector (MID) is applied to a modulation voltage circuit. An adjustment is made to balance out the background current, and an output current, above background, is applied to an input of a strip chart recorder. For low level concentrations, i.e., low detected output current, the ionization potential will be at a maximum and the metastable ionization detector will operate at its most sensitive level. When the detected current from the metastable ionization detector increases above a predetermined threshold level, a voltage control circuit is activated which turns on a high voltage transistor which acts to reduce the ionization potential. The ionization potential applied to the metastable ionization detector is then varied so as to maintain the detected signal level constant. The variation in ionization potential is now related to the concentration of the constituent and a representative amplitude is applied to another input of said strip chart recorder
Active Analytics: Adapting Web Pages Automatically Based on Analytics Data
Web designers are expected to perform the difficult task of adapting a site’s design to fit changing usage trends. Web analytics tools give designers a window into website usage patterns, but they must be analyzed and applied to a website\u27s user interface design manually. A framework for marrying live analytics data with user interface design could allow for interfaces that adapt dynamically to usage patterns, with little or no action from the designers. The goal of this research is to create a framework that utilizes web analytics data to automatically update and enhance web user interfaces. In this research, we present a solution for extracting analytics data via web services from Google Analytics and transforming them into reporting data that will inform user interface improvements. Once data are extracted and summarized, we expose the summarized reports via our own web services in a form that can be used by our client side User Interface (UI) framework. This client side framework will dynamically update the content and navigation on the page to reflect the data mined from the web usage reports. The resulting system will react to changing usage patterns of a website and update the user interface accordingly. We evaluated our framework by assigning navigation tasks to users on the UNF website and measuring the time it took them to complete those tasks, one group with our framework enabled, and one group using the original website. We found that the group that used the modified version of the site with our framework enabled was able to navigate the site more quickly and effectively
A comparative analysis of rawinsonde and NIMBUS 6 and TIROS N satellite profile data
Comparisons are made between rawinsonde and satellite profiles in seven areas for a wide range of surface and weather conditions. Variables considered include temperature, dewpoint temperature, thickness, precipitable water, lapse rate of temperature, stability, geopotential height, mixing ratio, wind direction, wind speed, and kinematic parameters, including vorticity and the advection of vorticity and temperature. In addition, comparisons are made in the form of cross sections and synoptic fields for selected variables. Sounding data from the NIMBUS 6 and TIROS N satellites were used. Geostrophic wind computed from smoothed geopotential heights provided large scale flow patterns that agreed well with the rawinsonde wind fields. Surface wind patterns as well as magnitudes computed by use of the log law to extrapolate wind to a height of 10 m agreed with observations. Results of this study demonstrate rather conclusively that satellite profile data can be used to determine characteristics of large scale systems but that small scale features, such as frontal zones, cannot yet be resolved
Preliminary results of spectral reflectance studies of tycho crater
The preliminary analysis and interpretation of near infrared spectra obtained for both the interior and exterior deposits associated with the Tycho crater is presented. Specific objectives were: (1) to determine the composition and stratigraphy of the highland crust in the Tycho target site; (2) to determine the likely composition of the primary ejecta which may be present in ray deposits; (3) to investigate the nature of spectral units defined in previous studies; (4) to further investigate the nature and origin of both the bright and dark haloes around the rim crest; and (5) to compare the compositions determined for the Tycho units with those of the Aristarchus crater as well as typical highland deposits. The spectra obtained for the interior areas exhibit similar spectral features. These include relatively strong 1 micron absorption bands whose minima are centered between 0.97 and 0.99 microns and shallow to intermediate continuum slopes. The spectra generally exhibit indications of a 1.3 micron feature consistent with the presence of Fe(2+) bearing plagioclase feldspar. The strong 1 micron absorption features indicate a dominant high Ca clinopyroxene component. Results obtained from the ejecta deposits show that the spectrum of the inner, bright halo is almost identical with those obtained for interior units. The spectrum of the dark halo exhibits a wide, relatively shallow absorption feature centered at 1.01 microns, a 1.3 micron absorption, and a steep continuum slope. This spectrum is interpreted as indicating the presence of pyroxene, Fe-bearing feldspar, and a significant component of Fe-bearing impact melt glass. Finally, the spectra of spots inside Tycho show similarity with certain spectra for Aristarchus. However, the suite of spectra obtained for Tycho exhibits a different trend in terms of band center versus width
Chemical quality parameters and anthocyanin pattern of red-fleshed Weirouge apples
Red-fleshed ‘Weirouge’ apples were investigated with respect to their chemical quality parameters including anthocyanins and colour. Anthocyanin concentrations were considerably higher than previously reported for common red-peeled apples. Due to its high malic acid content, the cultivar ‘Weirouge’ was characterised by a high colour brilliance. Among the anthocyanins, cyanidin-3-maloyl-galactoside and 5-carboxy-pyrano-cyanidin-hexoside not previously found in apples were tentatively identified by HPLC-MS3. Highest anthocyanin and total phenolics contents were found in the peel corresponding with the respective antioxidant capacities as determined using the FRAP and TEAC assays, respectively
Validation and application of a standardized procedure for evaluating freshness of Citrus juices based on pectin methylesterase activity quantitation
A method developed for freshness authentication of freshly squeezed Citrus juices (FSCJ) was evaluated for routine application. It involved titrimetric assessment of pectin methylesterase (PE) activity after enzyme extraction from pulp-standardized juice samples. Standard test conditions enabled reliable discrimination between FSCJ and chilled Citrus juices that had comparative advantages due to extended shelf life. Unlike the latter, FSCJ always displayed PE activities in the linear range between the limit of identification (LOI, 0.42 units g-1 of juice) and the maximum activity found for FSCJ (1.94 units -1), equivalent to 0.0035-0.016 units during titration. However, for model samples having activities < LOI due to production by respective dilution of FSCJ, the responses abruptly fell to unspecific levels below the limit of detection (LOD, 0.21 units g-1). Accuracy was substantiated by 100 -106 % recovery for model juices with PE activities of 0.87 -1.22 units g-1 resulting from FSCJ dilution or PE standard addition, but it was lower (76 - 80 %) near LOI. The average of the mean activities, which were detected by 3 analysts with intraassay precision ≤ 8.4 %, varied with relative standard deviations of 8.2 % for FSCJ and 3.9 % for a sample of the same juice diluted to 60 % (w/w), thus proving reproducibility. FSCJ batches were unambiguously distinguished from four commercial chilled juices, because the activities detected for the latter were by far ≤ LOD and thus confirmed labeled mild preservation
Comparison of morphological and chemical fruit traits from different pitaya genotypes (Hylocereus sp.) grown in Costa Rica
Physico-chemical parameters of the fruits of five Hylocereus genotypes grown in their natural habitat in Costa Rica were determined and their morphological traits were assessed. Besides, overall dimensions, shape, weight, flesh fraction, skin thickness, seed content and juice yield were recorded. Chemical analyses comprised pH, total soluble solids, titratable acidity, proline and pectin content, formol number and density of the juices. In addition, the major sugars glucose, fructose and sucrose, as well as organic acids were quantified by HPLC. Moreover, skin and flesh firmness were assessed. Significant differences were observed between genotypes concerning fruit weight and dimensions, skin thickness, proportion of flesh and amount of seeds. Whereas lowest pH values were determined in the juices from ‘San Ignacio’, highest malic acid contents in ‘Rosa’ and maximal total soluble solids were found in juices from ‘Nacional’ fruits. Furthermore, differences between genotypes concerning density, pectin and glucose contents of the juices were noted
Evaluation of the antioxidant capacity of betalainic fruits and vegetables
The present investigation determined total phenolics, ascorbic acid, betalain contents and the corresponding antioxidant capacities of betalain-bearing fruits and vegetables. In addition to differently coloured Swiss chard petioles (Beta vulgaris L. ssp. cicla [L.] Alef. cv. ‘Bright Lights’) and hypocotyls of white, yellow, and red beetroot varieties (Beta vulgaris L. ssp. vulgaris, cv. ‘Albina Vereduna’, cv. ‘Burpee’s Golden’, and cv. ‘Rote Kugel 2’), juices from cactus pears (Opuntia ficus-indica [L.] Mill. cv. ‘Gialla’ and cv. ‘Rossa’) and pitaya fruits (Hylocereus polyrhizus [Weber] Britton & Rose, H. undatus [Haworth] Britton & Rose, Selenicereus megalanthus [K. Schumann ex Vaupel] Moran) were included in this study. Antioxidant capacities were determined by application of the TEAC and FRAP assays, respectively, resulting in differing rankings of the commodities investigated. In both test systems, highest antioxidant capacity was shown for red beetroot extract while for the remaining samples no straightforward order could be established
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