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Detailed Observations (detailed + observation)
Selected AbstractsAssembled structures of nanocrystals in polymer/calcium carbonate thin-film composites formed by the cooperation of chitosan and poly(aspartate)JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2006Ayae Sugawara Abstract Assembled structures of calcium carbonate (CaCO3) nanocrystals have been examined for polymer/CaCO3 thin-film composites synthesized through a self-organization process inspired by biomineralization. For the crystallization of CaCO3, a thin-film matrix of chitosan has been used as a polymeric substrate. When the matrix is immersed into a supersaturated aqueous solution of CaCO3 containing 1.4 × 10,3 wt % poly(aspartate) (PAsp), thin-film crystals of CaCO3 are formed spontaneously. Three kinds of disklike films have been observed under a polarizing optical microscope. Electron diffraction analyses of each film have revealed that one is aragonite, displaying radial orientation of the c axes, and the others are vaterite, exhibiting different orientations. Detailed observation by scanning electron microscopy has clarified that these films are assemblies of crystalline particles 10,20 nm in size. The thin-film composites have been obtained over a PAsp concentration range of 4.4 × 10,4 to 1.0 × 10,2 wt %. Vaterite formation becomes dominant when the concentration of PAsp is increased. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5153,5160, 2006 [source] Predation by seals on salmonids in two Scottish estuariesFISHERIES MANAGEMENT & ECOLOGY, Issue 3 2001T. J. Carter Detailed observations of the behaviour of harbour seals, Phoca vitulina L., at sites within the estuaries of the Rivers Dee and Don, in north-eastern Scotland, were made over two full years between 1993 and 1996. Small numbers of grey seals, Halichoerus grypus Fab., were also present. The presence of seals within the estuaries was strongly related to season, with maximum numbers observed in winter and early spring; seals were virtually absent in June and July. The River Don was used largely as a haul-out site, while the River Dee was used predominantly as a foraging site, although it was not possible to determine whether the same seals were using the two estuaries. More seals were hauled-out on the River Don during twilight and dark than in daylight. The seals were observed to eat mostly salmonids, Salmo salar L. and S. trutta L., unidentified roundfish and flounder, Pleuronectes flesus L. The otoliths identified in scats collected at the mouth of the River Don belonged to marine species indicating that the seals were also feeding outside the estuaries. A minimum estimate is given of the numbers of large salmonids eaten in each river during the course of the year. Although no information was available on the numbers of salmonids using the rivers or the reproductive status of the fish eaten by the seals, as a cause of mortality, seal predation on large salmonids in estuaries is apparently an order of magnitude less important than mortality caused by angling within the river. [source] We're Decent People: Constructing and Managing Family Identity in Rural Working-Class CommunitiesJOURNAL OF MARRIAGE AND FAMILY, Issue 2 2004Margie L. Kiter Edwards Using grounded theory methodology, I establish family identity management as an important type of invisible work that connects women's household-based domestic activities with community members' perceptions and treatment of them and their family members. Detailed observations of household routines and family interactions, as well as in-depth interviews with working-class women living in two rural trailer park communities, provide insight into the meanings women assign to this labor, and their motivations for performing this work. I describe the strategies that women use to accomplish the work, examine how the work supports family life and child development, and explain how the residential environment influences the organization and accomplishment of this work. [source] The structure and mechanical properties of amorphous and nanocrystalline Fe,Si,B alloysJOURNAL OF MICROSCOPY, Issue 1 2006A. SYPIE Summary This article describes the results of investigations of the microstructure of failure surfaces and the mechanism of deformation of an amorphous Fe80Si11B9 alloy, nanocrystallized with the use of Nd:YAG pulsed laser heating. The research included ,in situ' tensile testing in a scanning electron microscope. Mechanical properties were also measured on an Instron-type machine for the amorphous and nanocrystalline alloys. The mechanical tensile tests performed on the amorphous and nanocrystalline samples showed a ductile fracture surface with very high fracture stress. Detailed observations of the flow deformation and fractures revealed the relationship between the quenched-in crystalline and mechanical behaviour. [source] 81 Recent introduction of polysiphonia morrowii (ceramiales, rhodophyta) to punta arenas, chileJOURNAL OF PHYCOLOGY, Issue 2003M.S. Kim Polysiphonia morrowii (Rhodomelaceae, Rhodophyta) is abundant intertidally in spring in the Northwest Pacific. The species occurs in a large part of the North Sea and in Thau Lagoon, France, showing disjointed distributions, where the alga has been probably introduced recently. Using plastid protein-coding rbcL sequence data from specimens of P. morrowii and putatively related taxa, collected in Korea, Japan and Far-east Russia, and Chile, we tested the taxonomic position of each taxon. Pairwise divergence and topology of the sequences indicate that the Chilean taxon was identical to P. morrowii and was clearly separated from other related taxa from Chile. The results suggest that P. morrowii is recently anthropogenically introduced from the Northwest Pacific to Chile by boat or by transport with aquacultured organisms. Detailed observations of field-collected material will probably enable a more realistic evaluation of distribution of P. morrowii to be made in the Pacific Ocean. [source] S,N curve characteristics and subsurface crack initiation behaviour in ultra-long life fatigue of a high carbon-chromium bearing steelFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 12 2001K. Shiozawa The S,N curve obtained from cantilever-type rotary bending fatigue tests using hour-glass-shaped specimens of high carbon-chromium bearing steel clearly distinguished the fracture modes into two groups each having a different crack origin. One was governed by crystal slip on the specimen surface, which occurred in the region of short fatigue life and a high stress amplitude level. The other was governed by a non-metallic inclusion at a subsurface level which occurred in the region of long fatigue life and low stress amplitude. The inclusion developed a fish-eye fracture mode that was distributed over a wide range of stress amplitude not only below the fatigue limit defined as the threshold for fracture due to the surface slip mode but also above the fatigue limit. This remarkable shape of the S,N curve was different from the step-wise one reported in previous literature and is characterized as a duplex S,N curve composed of two different S,N curves corresponding to the respective fracture modes. From detailed observations of the fracture surface and the fatigue crack origin, the mechanisms for the internal fracture mode and the characteristics of the S,N curve are discussed. [source] Image analysis of Daphnia populations: non-destructive determination of demography and biomass in culturesFRESHWATER BIOLOGY, Issue 10 2002Per J. Færøvig SUMMARY 1. An image analysis technique was developed for the semiautomatic determination of abundance, size distribution and biomass in Daphnia cultures. This allowed detailed observations of growth, demography and biomass accumulation in live populations, avoiding artifacts caused by subsampling and sampling losses. 2. The image analysis method gave fast, non-destructive and reliable individual counts, even in cultures with high density and a large fraction of juveniles. 3. In Daphnia, animal width changes with nutritional status and growth within instar, while length changes only at the moult. Thus, estimation of individual biomass using an ellipsoidal model based on animal width gave improved biomass calculations compared to manual counting, sizing, and length : weight regressions. 4. The power of the image analysis technique for assessing population growth and size structure was demonstrated in two 40-day experiments, with Daphnia magna feeding on the green algae Selenastrum capricornutum in a two-stage chemostat system. [source] The surface radiation budget over North America: gridded data assessment and evaluation of regional climate modelsINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 15 2009Marko Markovic Abstract While surface station observations of downwelling radiation offer accuracy at high temporal resolution, they do not easily allow an evaluation of model surface radiation budgets (SRB) over a wide geographical area. We evaluate three gridded SRB data sets against detailed observations from six surface radiation sites from the US surface radiation (SURFRAD) network. We subsequently use the most accurate surrogate observational data set for evaluation of model-simulated SRB. The data sets assessed are: ERA40,reanalysis of European Centre for Medium-Range Weather Forecasts (ECMWF), North American Regional Reanalysis (NARR),regional reanalysis of National Centres for Environmental Prediction (NCEP) and the surface radiative budget (SRB) from the International Satellite Cloud Climatology Project (ISCCP). Due to varying constraints with respect to temporal coverage of each data set, the evaluation period used in this study is 1996,2001, inclusive. The ERA40 downwelling longwave radiation (DLR) appears the most accurate surrogate observation, while both ERA40 and ISCCP show accurate results when the incoming shortwave radiation (ISR) is considered across the annual cycle. Winter DLR is less accurate in ISCCP with a positive bias and lack of very low (<200 Wm,2) flux values. The NARR SRB shows a large positive bias in the ISR throughout the annual cycle, linked to a significant underestimate of cloud cover. The ERA40 data are subsequently used to evaluate the simulated SRB in three regional climate models across North America. With respect to solar radiation, cloud cover biases are seen to be crucial, while for longwave fluxes both cloud fraction and in-cloud water content are important to simulate correctly. Inclusion of trace gases beyond H2O, CO2 and O3 appears necessary for an accurate calculation of clear-sky longwave radiation. Error compensation frequently occurs between the various components contributing to a model total-sky SRB. This is important to consider when trying to identify the underlying causes of errors in the simulated total SRB. Copyright © 2009 Royal Meteorological Society [source] Enactment, Sensemaking and Decision Making: Redesign Processes in the 1976 Reorganization of US IntelligenceJOURNAL OF MANAGEMENT STUDIES, Issue 2 2000James Douglas Orton Weick's theories of organizing and sensemaking help enrich the assumptions in the organization design school. This study builds on Weick's theories of sensemaking to illustrate how three fundamental organization design assumptions , dominant variables, causal laws and executive dictates , were found to be restrictive in the explanation of redesign processes in the 1976 reorganization of the US intelligence community. The assumption of dominant variables was challenged by the appearance of a multitude of events, or enactments, which were selected by organization members for further attention. The assumption of causal laws was challenged by the appearance of individual-level cause maps which were filtered, through sensemaking processes, into organization-level workable realities. The assumption of executive dictates was challenged by the appearance of attempts to punctuate redesign processes as organizational decisions. The study suggests value in moving from simple organization design assumptions to more reliable findings drawn from detailed observations of redesign processes. [source] Physical properties of meteorites,Applications in space missions to asteroidsMETEORITICS & PLANETARY SCIENCE, Issue 6 2008T. KOHOUT However, more detailed observations indicate that differences exist in composition between asteroids and meteorites resulting in difficulties when searching for meteorite-asteroid match. We show that among other physical parameters the magnetic susceptibility of an asteroid can be determined remotely from the magnetic induction by solar wind using an orbiting spacecraft or directly using the AC coil on the lander, or it can be measured in samples returned to the laboratory. The shape corrected value of the true magnetic susceptibility of an asteroid can be compared to those of meteorites in the existing database, allowing closer match between asteroids and meteorites. The database of physical properties contains over 700 samples and was recently enlarged with measurements of meteorites in European museums using mobile laboratory facility. [source] Collecting, shipping, storing, and imaging snow crystals and ice grains with low-temperature scanning electron microscopy ,MICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2003Eric F. Erbe Abstract Methods to collect, transport, and store samples of snow and ice have been developed that enable detailed observations of these samples with a technique known as low-temperature scanning electron microscopy (LTSEM). This technique increases the resolution and ease with which samples of snow and ice can be observed, studied, and photographed. Samples are easily collected in the field and have been shipped to the electron microscopy laboratory by common air carrier from distances as far as 5,000 miles. Delicate specimens of snow crystals and ice grains survive the shipment procedures and have been stored for as long as 3 years without undergoing any structural changes. The samples are not subjected to the melting or sublimation artifacts. LTSEM allows individual crystals to be observed for several hours with no detectable changes. Furthermore, the instrument permits recording of photographs containing the parallax information necessary for three-dimensional imaging of the true shapes of snowflakes, snow crystals, snow clusters, ice grains, and interspersed air spaces. This study presents detailed descriptions of the procedures that have been used successfully in the field and the laboratory to collect, ship, store, and image snow crystals and ice grains. Microsc. Res. Tech. 62:19,32, 2003. Published 2003 Wiley-Liss, Inc. [source] Isolate specificity of quantitative trait loci for partial resistance of barley to Puccinia hordei confirmed in mapping populations and near-isogenic linesNEW PHYTOLOGIST, Issue 3 2008Thierry C. Marcel Summary ,,Partial resistance is considered race-nonspecific and durable, consistent with the concept of ,horizontal' resistance. However, detailed observations of partial resistance to leaf rust (Puccinia hordei) in barley (Hordeum vulgare) revealed small cultivar × isolate interactions, suggesting a minor-gene-for-minor-gene interaction model, similar to so-called ,vertical' resistance. ,,Three consistent quantitative trait loci (QTLs), labelled Rphq2, Rphq3 and Rphq4, that were detected in the cross susceptible L94 × partially resistant Vada have been incorporated into the L94 background to obtain near-isogenic lines (NILs). Three isolates were used to map QTLs on seedlings of the L94 × Vada population and to evaluate the effect of each QTL on adult plants of the respective NILs under field conditions. ,,Rphq2 had a strong effect in seedlings but almost no effect in adult plants, while Rphq3 was effective in seedlings and in adult plants against all three isolates. However, Rphq4 was effective in seedlings and in adult plants against two isolates but ineffective in both development stages against the third, demonstrating a clear and reproducible isolate-specific effect. The resistance governed by the three QTLs was not associated with a hypersensitive reaction. ,,Those results confirm the minor-gene-for-minor-gene model suggesting specific interactions between QTLs for partial resistance and P. hordei isolates. [source] | |||||||||||||||||||