Noffke, Nora
2015-02-01
Sandstone beds of the Mars have been interpreted as evidence of an ancient playa lake environment. On Earth, such environments have been sites of colonization by microbial mats from the early Archean to the present time. Terrestrial microbial mats in playa lake environments form microbialites known as microbially induced sedimentary structures (MISS). On Mars, three lithofacies of the Gillespie Lake Member sandstone display centimeter- to meter-scale structures similar in macroscopic morphology to terrestrial MISS that include "erosional remnants and pockets," "mat chips," "roll-ups," "desiccation cracks," and "gas domes." The microbially induced sedimentary-like structures identified in Curiosity rover mission images do not have a random distribution. Rather, they were found to be arranged in spatial associations and temporal successions that indicate they changed over time. On Earth, if such MISS occurred with this type of spatial association and temporal succession, they would be interpreted as having recorded the growth of a microbially dominated ecosystem that thrived in pools that later dried completely: erosional pockets, mat chips, and roll-ups resulted from water eroding an ancient microbial mat-covered sedimentary surface; during the course of subsequent water recess, channels would have cut deep into the microbial mats, leaving erosional remnants behind; desiccation cracks and gas domes would have occurred during a final period of subaerial exposure of the microbial mats. In this paper, the similarities of the macroscopic morphologies, spatial associations, and temporal succession of sedimentary structures on Mars to MISS preserved on Earth has led to the following hypothesis: The sedimentary structures in the Mars are ancient MISS produced by interactions between microbial mats and their environment. Proposed here is a strategy for detecting, identifying, confirming, and differentiating possible MISS during current and future Mars missions.
Directory of Open Access Journals (Sweden)
Benzerara K.
2014-02-01
Full Text Available Microbialites are sedimentary formations that are found throughout the geological record and are usually considered as one of the oldest traces of life on Earth. Although they have been known for more than a century and hold as an emblematic object in Earth Sciences, we yet do not understand in details how they form and how microbial processes impact their chemistry, structure and macroscopic morphology. Here, we show recent advances achieved owing to funding provided by the EPOV program on the formation of modern microbialites in the crater Lake Alchichica (Mexico. We first show that very diverse microbial communities populate these microbialites, including diverse microbial groups able to induce carbonate precipitation. We demonstrate that this microbial diversity can be preserved for several years in laboratory aquaria offering a nice opportunity for future studies to assess the relationships between biodiversity and microbialite formation. We then detail the textural modifications affecting cyanobacterial cells during the first steps of fossilization as captured in Alchichica microbialites. Finally, we report the discovery of a new deepbranching cyanobacterium species, Candidatus Gloeomargarita lithophora, able to form intracellular Ca-, Mg-, Sr- and Ba-rich carbonates and discuss the implications for the interpretation of the fossil record.
Yang, H.; Chen, Z.; Wang, Y. B.; Ou, W.; Liao, W.; Mei, X.
2013-12-01
The Permian-Triassic (P-Tr) carbonate successions are often characterized by the presence of microbialite buildups worldwide. The widespread microbialites are believed as indication of microbial proliferation immediately after the P-Tr mass extinction. The death of animals representing the primary consumer trophic structure of marine ecosystem in the P-Tr crisis allows the bloom of microbes as an important primary producer in marine trophic food web structure. Thus, the PTB microbialite builders have been regarded as disaster taxa of the P-Tr ecologic crisis. Microbialite ecosystems were suitable for most organisms to inhabit. However, increasing evidence show that microbialite dwellers are also considerably abundant and diverse, including mainly foraminifers Earlandia sp. and Rectocornuspira sp., lingulid brachiopods, ostrocods, gastropods, and microconchids. In particular, ostracods are extremely abundant in this special ecosystem. Microconchid-like calcareous tubes are also considerably abundant. Here, we have sampled systematically a PTB microbialite deposit from the Dajiang section, southern Guizhou Province, southwest China and have extracted abundant isolated specimens of calcareous worm tubes. Quantitative analysis enables to investigate stratigraphic and facies preferences of microconchids in the PTB microbialites. Our preliminary result indicates that three microconchid species Microconchus sp., Helicoconchus elongates and Microconchus aberrans inhabited in microbialite ecosystem. Most microconchilds occurred in the upper part of the microbialite buildup and the grainstone-packstone microfacies. Very few microconchilds were found in the rocks bearing well-developed microbialite structures. Their stratigraphic and environmental preferences indicate proliferation of those metazoan organisms is coupled with ebb of the microbialite development. They also proliferated in some local niches in which microbial activities were not very active even if those
Mata, S A; Bottjer, D J
2012-01-01
Widespread development of microbialites characterizes the substrate and ecological response during the aftermath of two of the 'big five' mass extinctions of the Phanerozoic. This study reviews the microbial response recorded by macroscopic microbial structures to these events to examine how extinction mechanism may be linked to the style of microbialite development. Two main styles of response are recognized: (i) the expansion of microbialites into environments not previously occupied during the pre-extinction interval and (ii) increases in microbialite abundance and attainment of ecological dominance within environments occupied prior to the extinction. The Late Devonian biotic crisis contributed toward the decimation of platform margin reef taxa and was followed by increases in microbialite abundance in Famennian and earliest Carboniferous platform interior, margin, and slope settings. The end-Permian event records the suppression of infaunal activity and an elimination of metazoan-dominated reefs. The aftermath of this mass extinction is characterized by the expansion of microbialites into new environments including offshore and nearshore ramp, platform interior, and slope settings. The mass extinctions at the end of the Triassic and Cretaceous have not yet been associated with a macroscopic microbial response, although one has been suggested for the end-Ordovician event. The case for microbialites behaving as 'disaster forms' in the aftermath of mass extinctions accurately describes the response following the Late Devonian and end-Permian events, and this may be because each is marked by the reduction of reef communities in addition to a suppression of bioturbation related to the development of shallow-water anoxia. © 2011 Blackwell Publishing Ltd.
Hernández Velázquez, J D; Barroso-Flores, J; Gama Goicochea, A
2016-11-23
Two of the most commonly encountered friction-reducing agents used in plastic sheet production are the amides known as erucamide and behenamide, which despite being almost identical chemically, lead to markedly different values of the friction coefficient. To understand the origin of this contrasting behavior, in this work we model brushes made of these two types of linear-chain molecules using quantum mechanical numerical simulations under the density functional theory at the B97D/6-31G(d,p) level of theory. Four chains of erucamide and behenamide were linked to a 2 × 10 zigzag graphene sheet and optimized both in vacuum and in continuous solvent using the SMD implicit solvation model. We find that erucamide chains tend to remain closer together through π-π stacking interactions arising from the double bonds located at C13-C14, a feature behenamide lacks, and thus a more spread configuration is obtained with the latter. It is argued that this arrangement of the erucamide chains is responsible for the lower friction coefficient of erucamide brushes, compared with behenamide brushes, which is a macroscopic consequence of cooperative quantum mechanical interactions. While only quantum level interactions are modeled here, we show that behenamide chains are more spread out in the brush than erucamide chains as a consequence of those interactions. The spread-out configuration allows more solvent particles to penetrate the brush, leading in turn to more friction, in agreement with macroscopic measurements and mesoscale simulations of the friction coefficient reported in the literature.
Modern carbonate microbialites from an asbestos open pit pond, Yukon, Canada.
Power, I M; Wilson, S A; Dipple, G M; Southam, G
2011-03-01
Microbialites were discovered in an open pit pond at an abandoned asbestos mine near Clinton Creek, Yukon, Canada. These microbialites are extremely young and presumably began forming soon after the mine closed in 1978. Detailed characterization of the periphyton and microbialites using light and scanning electron microscopy was coupled with mineralogical and isotopic analyses to investigate the mechanisms by which these microbialites formed. The microbialites are columnar in form (cm scale), have an internal spherulitic fabric (mm scale), and are mostly made of aragonite, which is supersaturated in the subsaline pond water. Initial precipitation is seen as acicular aragonite crystals nucleating onto microbial biomass and detrital particles. Continued precipitation entombs benthic diatoms (e.g. Brachysira vitrea), filamentous algae (e.g. Oedogonium sp.), dinoflagellates, and cyanobacteria. The presence of phototrophs at spherulite centers strongly suggests that these microbes play an important initial role in aragonite precipitation. Substantial growth of individual spherulites occurs abiotically through periodic precipitation of aragonite that forms concentric laminations around spherulite centers while pauses in spherulite growth allow for colonization by microbes. Aragonite associated with biomass (δ(13)C = -4.6‰ VPDB) showed a (13)C-enrichment of 0.8‰ relative to aragonite exhibiting no biomass (δ(13)C = -5.4‰ VPDB), which suggests a modest removal of isotopically light dissolved inorganic carbon by phototrophs. The combination of a low sedimentation rate, high calcification rate, and low microbial growth rate appears to result in the formation of these microbialites. The formation of microbialites at an historic mine site demonstrates that an anthropogenically constructed environment can foster microbial carbonate formation. © 2011 Blackwell Publishing Ltd.
Exploring Biogeochemistry and Microbial Diversity of Extant Microbialites in Mexico and Cuba
Valdespino-Castillo, Patricia M.; Hu, Ping; Merino-Ibarra, Martín; López-Gómez, Luz M.; Cerqueda-García, Daniel; González-De Zayas, Roberto; Pi-Puig, Teresa; Lestayo, Julio A.; Holman, Hoi-Ying; Falcón, Luisa I.
2018-01-01
Microbialites are modern analogs of ancient microbial consortia that date as far back as the Archaean Eon. Microbialites have contributed to the geochemical history of our planet through their diverse metabolic capacities that mediate mineral precipitation. These mineral-forming microbial assemblages accumulate major ions, trace elements and biomass from their ambient aquatic environments; their role in the resulting chemical structure of these lithifications needs clarification. We studied the biogeochemistry and microbial structure of microbialites collected from diverse locations in Mexico and in a previously undescribed microbialite in Cuba. We examined their structure, chemistry and mineralogy at different scales using an array of nested methods including 16S rRNA gene high-throughput sequencing, elemental analysis, X-Ray fluorescence (XRF), X-Ray diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), Fourier Transformed Infrared (FTIR) spectroscopy and Synchrotron Radiation-based Fourier Transformed Infrared (SR-FTIR) spectromicroscopy. The resulting data revealed high biological and chemical diversity among microbialites and specific microbe to chemical correlations. Regardless of the sampling site, Proteobacteria had the most significant correlations with biogeochemical parameters such as organic carbon (Corg), nitrogen and Corg:Ca ratio. Biogeochemically relevant bacterial groups (dominant phototrophs and heterotrophs) showed significant correlations with major ion composition, mineral type and transition element content, such as cadmium, cobalt, chromium, copper and nickel. Microbial-chemical relationships were discussed in reference to microbialite formation, microbial metabolic capacities and the role of transition elements as enzyme cofactors. This paper provides an analytical baseline to drive our understanding of the links between microbial diversity with the chemistry of their lithified precipitations. PMID
Directory of Open Access Journals (Sweden)
Richard Allen White III
2015-09-01
Full Text Available Within the subarctic climate of Clinton Creek, Yukon, Canada, lies an abandoned and flooded open-pit asbestos mine that harbors rapidly growing microbialites. To understand their formation we completed a metagenomic community profile of the microbialites and their surrounding sediments. Assembled metagenomic data revealed that bacteria within the phylum Proteobacteria numerically dominated this system, although the relative abundances of taxa within the phylum varied among environments. Bacteria belonging to Alphaproteobacteria and Gammaproteobacteria were dominant in the microbialites and sediments, respectively. The microbialites were also home to many other groups associated with microbialite formation including filamentous cyanobacteria and dissimilatory sulfate-reducing Deltaproteobacteria, consistent with the idea of a shared global microbialite microbiome. Other members were present that are typically not associated with microbialites including Gemmatimonadetes and iron-oxidizing Betaproteobacteria, which participate in carbon metabolism and iron cycling. Compared to the sediments, the microbialite microbiome has significantly more genes associated with photosynthetic processes (e.g., photosystem II reaction centers, carotenoid and chlorophyll biosynthesis and carbon fixation (e.g., CO dehydrogenase. The Clinton Creek microbialite communities had strikingly similar functional potentials to non-lithifying microbial mats from the Canadian High Arctic and Antarctica, but are functionally distinct, from non-lithifying mats or biofilms from Yellowstone. Clinton Creek microbialites also share metabolic genes (R2 0.900. These metagenomic profiles from an anthropogenic microbialite-forming ecosystem provide context to microbialite formation on a human-relevant timescale.
Petryshyn, V A; Lim, D; Laval, B L; Brady, A; Slater, G; Tripati, A K
2015-01-01
Quantitative tools for deciphering the environment of microbialite formation are relatively limited. For example, the oxygen isotope carbonate-water geothermometer requires assumptions about the isotopic composition of the water of formation. We explored the utility of using 'clumped' isotope thermometry as a tool to study the temperatures of microbialite formation. We studied microbialites recovered from water depths of 10-55 m in Pavilion Lake, and 10-25 m in Kelly Lake, spanning the thermocline in both lakes. We determined the temperature of carbonate growth and the (18)O/(16)O ratio of the waters that microbialites grew in. Results were then compared to current limnological data from the lakes to reconstruct the history of microbialite formation. Modern microbialites collected at shallow depths (11.7 m) in both lakes yield clumped isotope-based temperatures of formation that are within error of summer water temperatures, suggesting that clumped isotope analyses may be used to reconstruct past climates and to probe the environments in which microbialites formed. The deepest microbialites (21.7-55 m) were recovered from below the present-day thermoclines in both lakes and yield radioisotope ages indicating they primarily formed earlier in the Holocene. During this time, pollen data and our reconstructed water (18)O/(16)O ratios indicate a period of aridity, with lower lake levels. At present, there is a close association between both photosynthetic and heterotrophic communities, and carbonate precipitation/microbialite formation, with biosignatures of photosynthetic influences on carbonate detected in microbialites from the photic zone and above the thermocline (i.e., depths of generally <20 m). Given the deeper microbialites are receiving <1% of photosynthetically active radiation (PAR), it is likely these microbialites primarily formed when lower lake levels resulted in microbialites being located higher in the photic zone, in warm surface waters. © 2014 John
Castro-Contreras, Set I.; Gingras, Murray K.; Pecoits, Ernesto; Aubet, Natalie R.; Petrash, Daniel; Castro-Contreras, Saulo M.; Dick, Gregory; Planavsky, Noah J.; Konhauser, Kurt O.
2014-01-01
Microbialites provide some of the oldest direct evidence of life on Earth. They reached their peak during the Proterozoic and declined afterward. Their decline has been attributed to grazing and/or burrowing by metazoans, to changes in ocean chemistry, or to competition with other calcifying organisms. The freshwater microbialites at Laguna Bacalar (Mexico) provide an opportunity to better understand microbialite growth in terms of interaction between grazing organisms versus calcium carb...
Centeno, Carla M; Mejía, Omar; Falcón, Luisa I
2016-09-01
Community structure and composition are dictated by evolutionary and ecological assembly processes which are manifested in signals of, species diversity, species abundance and species relatedness. Analysis of species coexisting relatedness, has received attention as a tool to identify the processes that influence the composition of a community within a particular habitat. In this study, we tested if microbialite genetic composition is dependent on random events versus biological/abiotical factors. This study was based on a large genetic data set of two hypervariable regions (V5 and V6) from previously generated barcoded 16S rRNA amplicons from nine microbialite communities distributed in Northeastern, Central and Southeastern Mexico collected in May and June of 2009. Genetic data of the most abundant phyla (Proteobacteria, Planctomycetes, Verrucomicrobia, Bacteroidetes, and Cyanobacteria) were investigated in order to state the phylogenetic structure of the complete communities as well as each phylum. For the complete dataset, Webb NTI index showed positive and significant values in the nine communities analysed, where values ranged from 31.5 in Pozas Azules I to 57.2 in Bacalar Pirate Channel; meanwhile, NRI index were positive and significant in six of the nine communities analysed with values ranging from 18.1 in Pozas Azules I to 45.1 in Río Mesquites. On the other hand, when comparing each individual phylum, NTI index were positive and significant in all groups, except in Cyanobacteria for which positive and significant values were only found in three localities; finally, NRI index was significant in only a few of the comparisons performed. The results suggest that habitat filtering is the main process that drives phylogenetic structure in bacterial communities associated to microbialites with the exception of Cyanobacteria where different lineages can contribute to microbialite formation and growth.
Last, Fawn M.; Last, William M.; Halden, Norman M.
2010-03-01
Manito Lake is a large, perennial, Na-SO 4 dominated saline to hypersaline lake located in the northern Great Plains of western Canada. Significant water level decrease over the past several decades has led to reduction in volume and surface area, as well as an increase in salinity. The salinity has increased from 10 ppt to about 50 ppt TDS. This decrease in water level has exposed large areas of nearshore microbialites. These organogenic structures range in size from several cm to over a meter and often form large bioherms several meters high. They have various external morphologies, vary in mineralogical composition, and show a variety of internal fabrics from finely laminated to massive. In addition to microbiolities and bioherms, the littoral zone of Manito Lake contains a variety of carbonate hardgrounds, pavements, and cemented clastic sediments. Dolomite and aragonite are the most common minerals found in these shoreline structures, however, calcite after ikaite, monohydrocalcite, magnesian calcite, and hydromagnesite are also present. The dolomite is nonstoichiometric and calcium-rich; the magnesian calcite has about 17 mol% MgCO 3. AMS radiocarbon dating of paired organic matter and endogenic carbonate material confirms little or no reservoir affect. Although there is abundant evidence for modern carbonate mineral precipitation and microbialite formation, most of the larger microbialites formed between about 2300 and 1000 cal BP, whereas the hardgrounds, cements, and laminated crusts formed about 1000-500 cal BP.
Questioning the Origin of the Great Salt Lake "Microbialites"
Frantz, C.; Matyjasik, M.; Newell, D. L.; Vanden Berg, M. D.; Park, C.
2017-12-01
The Great Salt Lake (GSL) of Utah contains abundant carbonate mounds that have been described in the literature as "biostromes", "bioherms", "stromatolites", and "microbialites". The structures are commonly cited as being rare examples of modern lacustrine microbialites, which implies that they are actively-forming and biogenic. Indeed, at least in some regions of the lake, the mounds are covered in a mixed community of cyanobacteria, algae, insect larval casings, microbial heterotrophs, and other organisms that is thought to contribute significantly to benthic primary productivity in GSL. However, the presence of a modern surface microbial community does not implicate a biogenic or modern origin for the mounds. The few studies to date GSL microbialites indicate that they are ancient, with radiocarbon calendar ages in the late Pleistocene and Holocene ( 13 - 3 cal ka). However, could they still be actively growing, and are the surface microbial communities playing a role? Here, we present results of a suite geochemical measurements used to constrain parameters—including groundwater seepage—influencing carbonate saturation and precipitation in the vicinity of one currently-submerged "microbialite reef" on the northern shore of Antelope Island in the South Arm of GSL. Our data suggests that calcium-charged brackish groundwater input to the lake through a permeable substratum in this location results in locally supersaturated conditions for aragonite, which could lead to modern, abiogenic mineralization. In addition, a series of laboratory experiments suggest that the modern surface microbial communities that coat the mounds do not appreciably facilitate carbonate precipitation in simulated GSL conditions, although they may serve as a template for precipitation when local waters become supersaturated.
Lim, D. S. S.; Hawes, I.; Mackey, T. J.; Brady, A. L.; Biddle, J.; Andersen, D. T.; Belan, M.; Slater, G.; Abercromby, A.; Squyres, S. W.; Delaney, M.; Haberle, C. W.; Cardman, Z.
2014-12-01
Pavilion Lake in British Columbia, Canada is an ultra-oligotrophic lake that has abundant microbialite growth. Recent research has shown that photoautotrophic microbial communities are important to modern microbialite development in Pavilion Lake. However, questions remain as to the relationship between changing light levels within the lake, variation in microbialite macro-structure, microbial consortia, and the preservation of associated biosignatures within the microbialite fabrics. The 2014 Pavilion Lake Research Project (PLRP) field program was focused on data gathering to understand these complex relationships by determining if a) light is the immediate limit to photosynthetic activity and, if so, if light is distributed around microbialites in ways that are consistent with emergent microbialite structure; and b) if at more local scales, the filamentous pink and green cyanobacterial nodular colonies identified in previous PLRP studies are centers of photosynthetic activity that create pH conditions suitable for carbonate precipitation. A diver-deployed pulse-amplitude modulated (PAM) fluorometer was used to collect synoptic in situ measurements of fluorescence yield and irradiance and across microbialites, focusing on comparing flat and vertical structural elements at a range of sites and depths. As well, we collected time series measurements of photosynthetic activity and irradiance at a set depth of 18 m across three different regions in Pavilion Lake. Our initial findings suggest that all microbialite surfaces are primarily light-limited regardless of depth or location within the lake. Shore based PAM fluorometry and microelectrode profiling of diver-collected samples suggest that pink and green nodules have different photosynthetic properties and pH profiles, and that nodular growth is likely to be the primary route of calcification due to the gelatinous covering the nodule creates. On-going tests for molecular signatures and isotopic shifts will allow for
Directory of Open Access Journals (Sweden)
Cristian eComan
2015-03-01
Full Text Available Modern mineral deposits play an important role in evolutionary studies by providing clues to the formation of ancient lithified microbial communities. Here we report the presence of microbialite-forming microbial mats in different microenvironments at 32ºC, 49ºC and 65ºC around the geothermal spring from an abandoned oil drill in Ciocaia, Romania. The mineralogy and the macro- and microstructure of the microbialites were investigated, together with their microbial diversity based on a 16S rRNA gene amplicon sequencing approach. The calcium carbonate is deposited mainly in the form of calcite. At 32ºC and 49ºC, the microbialites show a laminated structure with visible microbial mat-carbonate crystal interactions. At 65ºC, the mineral deposit is clotted, without obvious organic residues. Partial 16S rRNA gene amplicon sequencing showed that the relative abundance of the phylum Archaea was low at 32ºC (1%. The dominant bacterial groups at 32ºC were Cyanobacteria, Gammaproteobacteria, Firmicutes, Bacteroidetes, Chloroflexi, Thermi, Actinobacteria, Planctomycetes and Defferibacteres. At 49ºC, there was a striking dominance of the Gammaproteobacteria, followed by Firmicutes, Bacteroidetes, and Armantimonadetes. The 65ºC sample was dominated by Betaproteobacteria, Firmicutes, [OP1], Defferibacteres, Thermi, Thermotogae, [EM3] and Nitrospirae. Several groups from Proteobacteria and Firmicutes, together with Halobacteria and Melainabacteria were described for the first time in calcium carbonate deposits. Overall, the spring from Ciocaia emerges as a valuable site to probe microbes-minerals interrelationships along thermal and geochemical gradients.
Energy Technology Data Exchange (ETDEWEB)
Machado, A.S., E-mail: alemachado@lin.ufrj.br [Laboratório de Geologia Sedimentar—IGEO, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil); Laboratório de Instrumentação Nuclear—COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil); Dal Bó, P.F.F. [Laboratório de Geologia Sedimentar—IGEO, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil); Lima, I. [Laboratório de Instrumentação Nuclear—COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil); Borghi, L. [Laboratório de Geologia Sedimentar—IGEO, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil); Lopes, R. [Laboratório de Instrumentação Nuclear—COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil)
2015-06-01
The objective of the present study is to apply the micro-CT technique to assess recent microbialite samples from a hypersaline coastal lagoon in the Rio de Janeiro State. The study comprises structural assessment, mineralogical characterization and porosity distribution of each sample. Micro-CT is increasingly present in geological reservoir analyses, and has advantages over other laboratory techniques since it is non-invasive and allows 2D/3D visualization of inner structures without previous preparation method, such as slabbing, polishing, thinning or impregnation. This technique renders structural analyses which can be spatially resolved to a scale of micrometers. Results show that micro-CT technique is also adequate for the characterization of carbonate microbialites, providing excellent high resolution 3D images, that enabled to distinguish different mineralogies and porosity distribution beyond it is inner structure.
International Nuclear Information System (INIS)
Machado, A.S.; Dal Bó, P.F.F.; Lima, I.; Borghi, L.; Lopes, R.
2015-01-01
The objective of the present study is to apply the micro-CT technique to assess recent microbialite samples from a hypersaline coastal lagoon in the Rio de Janeiro State. The study comprises structural assessment, mineralogical characterization and porosity distribution of each sample. Micro-CT is increasingly present in geological reservoir analyses, and has advantages over other laboratory techniques since it is non-invasive and allows 2D/3D visualization of inner structures without previous preparation method, such as slabbing, polishing, thinning or impregnation. This technique renders structural analyses which can be spatially resolved to a scale of micrometers. Results show that micro-CT technique is also adequate for the characterization of carbonate microbialites, providing excellent high resolution 3D images, that enabled to distinguish different mineralogies and porosity distribution beyond it is inner structure
Johnson, D B; Beddows, P A; Flynn, T M; Osburn, M R
2018-05-01
Laguna Bacalar is a sulfate-rich freshwater lake on the Yucatan Peninsula that hosts large microbialites. High sulfate concentrations distinguish Laguna Bacalar from other freshwater microbialite sites such as Pavilion Lake and Alchichica, Mexico, as well as from other aqueous features on the Yucatan Peninsula. While cyanobacterial populations have been described here previously, this study offers a more complete characterization of the microbial populations and corresponding biogeochemical cycling using a three-pronged geobiological approach of microscopy, high-throughput DNA sequencing, and lipid biomarker analyses. We identify and compare diverse microbial communities of Alphaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria that vary with location along a bank-to-bank transect across the lake, within microbialites, and within a neighboring mangrove root agglomeration. In particular, sulfate-reducing bacteria are extremely common and diverse, constituting 7%-19% of phylogenetic diversity within the microbialites, and are hypothesized to significantly influence carbonate precipitation. In contrast, Cyanobacteria account for less than 1% of phylogenetic diversity. The distribution of lipid biomarkers reflects these changes in microbial ecology, providing meaningful biosignatures for the microbes in this system. Polysaturated short-chain fatty acids characteristic of cyanobacteria account for Bacalar microbialites. By contrast, even short-chain and monounsaturated short-chain fatty acids attributable to both Cyanobacteria and many other organisms including types of Alphaproteobacteria and Gammaproteobacteria constitute 43%-69% and 17%-25%, respectively, of total abundance in microbialites. While cyanobacteria are the largest and most visible microbes within these microbialites and dominate the mangrove root agglomeration, it is clear that their smaller, metabolically diverse associates are responsible for significant biogeochemical cycling in this
Fang, Yuheng; Chen, Zhong-Qiang; Kershaw, Stephen; Yang, Hao; Luo, Mao
2017-05-01
A previously unknown microbialite bed in the Permian-Triassic (P-Tr) boundary beds of Zuodeng section, Tiandong County, Guangxi, South China comprises a thin (5 cm maximum thickness) stromatolite in the lower part and the remaining 6 m is thrombolite. The Zuodeng microbialite has a pronounced irregular contact between the latest Permian bioclastic limestone and microbialite, as in other sites in the region. The stromatolite comprises low-relief columnar and broad domal geometries, containing faint laminations. The thrombolite displays an irregular mixture of sparitic dark coloured altered microbial fabric and light coloured interstitial sediment in polished blocks. Abundant microproblematic calcimicrobe structures identified here as Gakhumella are preserved in dark coloured laminated areas of the stromatolite and sparitic areas in thrombolites (i.e. the calcimicrobial part, not the interstitial sediment) and are orientated perpendicular to stromatolitic laminae. Each Gakhumella individual has densely arranged segments, which form a column- to fan-shaped structure. Single segments are arch-shaped and form a thin chamber between segments. Gakhumella individuals in the stromatolite and thrombolite are slightly different from each other, but are readily distinguished from the Gakhumella- and Renalcis-like fossils reported from other P-Tr boundary microbialites in having a smaller size, unbranching columns and densely arranged, arch-shaped segments. Renalcids usually possess a larger body size and branching, lobate outlines. Filament sheath aggregates are also observed in the stromatolite and they are all orientated in one direction. Both Gakhumella and filament sheath aggregates may be photosynthetic algae, which may have played an important role in constructing the Zuodeng microbialites. Other calcimicrobes in the Zuodeng microbialite are spheroids, of which a total of five morphological types are recognized from both stromatolite and thrombolite: (1) sparry calcite
Johnson, Markes E.; Ledesma-Vázquez, Jorge; Backus, David H.; González, Maria R.
2012-07-01
Examples of two closed lagoons with extensive growth of Recent microbialites showing variable surface morphology and internal structure are found on Isla Angel de la Guarda in the Gulf of California. Comparable lagoonal microbialites also occur ashore from Ensenada El Quemado on the adjacent peninsular mainland of Baja California. The perimeters of all three lagoons feature crusted structures indicative of thrombolites with a knobby surface morphology 2 cm to 3 cm in relief and internal clotting without any sign of laminations. Outward from this zone, thrombolitic construction thins to merge with a white calcified crust below which a soft substratum of dark organic material 4 cm to 6 cm in thickness is concealed. The substratum is laminated and heavily mucilaginous, as observed along the edges of extensive shrinkage cracks in the overlying crust. The thrombolitic crust is anchored to the shore, while the thinner crust and associated stromatolitic mats float on the surface of the lagoons. Laboratory cultures of the dark organic material yielded the solitary cyanobacterium Chroococcidiopsis as the predominant taxon interspersed with filamentous forms. In decreasing order of abundance, other morphotypes present include Phormidium, Oscillatoria, Geitlerinema, Chroococus, and probably Spirulina. The larger of the two island lagoons follows an east-west azimuth and covers 0.225 km2, while the smaller lagoon has a roughly north-south axis and covers only 0.023 km2. The salinity of water in the smaller lagoon was measured as148 ppt. Pliocene strata along the edge of the smaller modern lagoon include siltstone bearing calcified platelets suggestive of a microbial origin. Dry lagoons abandoned during the later Quaternary occur inland at higher elevations on the island, but retain no fossils except for sporadic white crusts cemented on cobbles around distinct margins. Raised Quaternary lagoons parallel to the big lagoon on Isla Angel de la Guarda are partly obscured by flood
Benssaou, Mohammed; Hamoumi, Naima
2004-02-01
Three microbialite forms are recognized in the Lower-Cambrian succession of Irherm area in the western Anti-Atlas (Morocco). Stromatolites, which correspond to non-calcified shallow marine laminated microbialites, are well developed in the basal Lower-Cambrian succession. Occurrence of calcified microbial thrombolites, in the middle part of this succession, reflects an increasing sea level from the peritidal zone to the subtidal environment. In the upper part of this succession, a second increasing water depth event and the development of branching archaeocyathan reefal framework lead to dendritic microbialite emergence. To cite this article: M. Benssaou, N. Hamoumi, C. R. Geoscience 336 (2004).
Microbialites and global environmental change across the Permian-Triassic boundary: a synthesis.
Kershaw, S; Crasquin, S; Li, Y; Collin, P-Y; Forel, M-B; Mu, X; Baud, A; Wang, Y; Xie, S; Maurer, F; Guo, L
2012-01-01
Permian-Triassic boundary microbialites (PTBMs) are thin (0.05-15 m) carbonates formed after the end-Permian mass extinction. They comprise Renalcis-group calcimicrobes, microbially mediated micrite, presumed inorganic micrite, calcite cement (some may be microbially influenced) and shelly faunas. PTBMs are abundant in low-latitude shallow-marine carbonate shelves in central Tethyan continents but are rare in higher latitudes, likely inhibited by clastic supply on Pangaea margins. PTBMs occupied broadly similar environments to Late Permian reefs in Tethys, but extended into deeper waters. Late Permian reefs are also rich in microbes (and cements), so post-extinction seawater carbonate saturation was likely similar to the Late Permian. However, PTBMs lack widespread abundant inorganic carbonate cement fans, so a previous interpretation that anoxic bicarbonate-rich water upwelled to rapidly increase carbonate saturation of shallow seawater, post-extinction, is problematic. Preliminary pyrite framboid evidence shows anoxia in PTBM facies, but interbedded shelly faunas indicate oxygenated water, perhaps there was short-term pulsing of normally saturated anoxic water from the oxygen-minimum zone to surface waters. In Tethys, PTBMs show geographic variations: (i) in south China, PTBMs are mostly thrombolites in open shelf settings, largely recrystallised, with remnant structure of Renalcis-group calcimicrobes; (ii) in south Turkey, in shallow waters, stromatolites and thrombolites, lacking calcimicrobes, are interbedded, likely depth-controlled; and (iii) in the Middle East, especially Iran, stromatolites and thrombolites (calcimicrobes uncommon) occur in different sites on open shelves, where controls are unclear. Thus, PTBMs were under more complex control than previously portrayed, with local facies control playing a significant role in their structure and composition. © 2011 Blackwell Publishing Ltd.
Rizzo, Vincenzo; Cantasano, Nicola
2017-10-01
The study analyses possible parallels of the microbialite-known structures with a set of similar settings selected by a systematic investigation from the wide record and data set of images shot by NASA rovers. Terrestrial cases involve structures both due to bio-mineralization processes and those induced by bacterial metabolism, that occur in a dimensional field longer than 0.1 mm, at micro, meso and macro scales. The study highlights occurrence on Martian sediments of widespread structures like microspherules, often organized into some higher-order settings. Such structures also occur on terrestrial stromatolites in a great variety of `Microscopic Induced Sedimentary Structures', such as voids, gas domes and layer deformations of microbial mats. We present a suite of analogies so compelling (i.e. different scales of morphological, structural and conceptual relevance), to make the case that similarities between Martian sediment structures and terrestrial microbialites are not all cases of `Pareidolia'.
Occurrence and genesis of Quaternary microbialitic tufa at Hammam Al Ali, Oman
Khalaf, Fikry I.
2017-05-01
Remnants of late Quaternary microbialitic tufa occurs within a shallow depression in the Hammam Al Ali hot spring area, which is located approximately 14.5 km to the southwest of Muscat, Oman. The tufa precipitated from hot spring water supersaturated with respect to calcium carbonate and is mostly of a porous phytogenic type, with occasional detrital and stromatolitic types. Microscopic and nanoscopic examination revealed that the tufa deposits developed through two successive processes of calcite precipitation, biotic and abiotic, preceded by limited precipitation of unstable aragonite. It is suggested that biologically mediated precipitation results in the construction of incomplete skeletal calcite crystals. The latter provide a base for classical physiochemical precipitation and, eventually, the development of complete sparry calcite crystals. The initiation of dendritic calcite crystals in the stromatolitic tufa as incomplete biogenic skeletal crystals and their characteristic growth pattern indicates that the tufa represents a clear example of hot spring calcitic microbialite.
Freshwater Microbialites of Pavilion Lake, British Columbia, Canada: A Limnological Investigation
Lim, D. S. S.; McKay, C. P.; Laval, B.; Bird, J.; Cady, S.
2004-01-01
Pavillion Lake is 5.7km long and an average of 0.8 km in width, and is located in Marble Canyon in the interior of British Columbia, Canada. It is a slightly alkaline, freshwater lake with a maximum-recorded depth of 65m. The basin walls of Pavilion Lake are lined with microbialite structures that are oriented perpendicularly to the shoreline, and which are found from depths of 5 meters to the bottom of the photic zone (light levels 1% of ambient; approximately 30m depth). These structures are speculated to have begun formation nearly 11,000 years ago, after the glacial retreat of the Cordilleran Ice Sheet. They are likely a distinctive assemblage of freshwater calcite microbialites, which display micromorphologies possibly related to the ancient Epiphyton and Girvanella classes of calcareous organosedimentary structures.
Ionescu, D; Spitzer, S; Reimer, A; Schneider, D; Daniel, R; Reitner, J; de Beer, D; Arp, G
2015-03-01
Microbialite-forming microbial mats in a hypersaline lake on the atoll of Kiritimati were investigated with respect to microgradients, bulk water chemistry, and microbial community composition. O2, H2S, and pH microgradients show patterns as commonly observed for phototrophic mats with cyanobacteria-dominated primary production in upper layers, an intermediate purple layer with sulfide oxidation, and anaerobic bottom layers with sulfate reduction. Ca(2+) profiles, however, measured in daylight showed an increase of Ca(2+) with depth in the oxic zone, followed by a sharp decline and low concentrations in anaerobic mat layers. In contrast, dark measurements show a constant Ca(2+) concentration throughout the entire measured depth. This is explained by an oxygen-dependent heterotrophic decomposition of Ca(2+)-binding exopolymers. Strikingly, the daylight maximum in Ca(2+) and subsequent drop coincides with a major zone of aragonite and gypsum precipitation at the transition from the cyanobacterial layer to the purple sulfur bacterial layer. Therefore, we suggest that Ca(2+) binding exopolymers function as Ca(2+) shuttle by their passive downward transport through compression, triggering aragonite precipitation in the mats upon their aerobic microbial decomposition and secondary Ca(2+) release. This precipitation is mediated by phototrophic sulfide oxidizers whose action additionally leads to the precipitation of part of the available Ca(2+) as gypsum. © 2014 John Wiley & Sons Ltd.
Macroscopic theory of superconductors
International Nuclear Information System (INIS)
Carr, W.J. Jr.
1981-01-01
A macroscopic theory for bulk superconductors is developed in the framework of the theory for other magnetic materials, where ''magnetization'' current is separated from ''free'' current on the basis of scale. This contrasts with the usual separation into equilibrium and nonequilibrium currents. In the present approach magnetization, on a large macroscopic scale, results from the vortex current, while the Meissner current and other surface currents are surface contributions to the Maxwell j. The results are important for the development of thermodynamics in type-II superconductors. The advantage of the description developed here is that magnetization becomes a local concept and its associated magnetic field can be given physical meaning
Macroscopic magnetic Self assembly
Löthman, Per Arvid
2018-01-01
Exploring the macroscopic scale's similarities to the microscale is part and parcel of this thesis as reflected in the research question: what can we learn about the microscopic scale by studying the macroscale? Investigations of the environment in which the self-assembly takes place, and the
Nuclear fission as a macroscopic quantum tunneling
International Nuclear Information System (INIS)
Takigawa, N.
1995-01-01
We discuss nuclear fission from the point of view of a macroscopic quantum tunneling, one of whose major interests is to study the effects of environments on the tunneling rate of a macroscopic variable. We show that a vibrational excitation of the fissioning nucleus significantly enhances the fission rate. We show this effect by two different methods. The one is to treat the vibrational excitation as an environmental degree of freedom, the other treats the fission as a two dimensional quantum tunneling. (author)
Macroscopic Optomechanically Induced Transparency
Pate, Jacob; Castelli, Alessandro; Martinez, Luis; Thompson, Johnathon; Chiao, Ray; Sharping, Jay
Optomechanically induced transparency (OMIT) is an effect wherein the spectrum of a cavity resonance is modified through interference between coupled excitation pathways. In this work we investigate a macroscopic, 3D microwave, superconducting radio frequency (SRF) cavity incorporating a niobium-coated, silicon-nitride membrane as the flexible boundary. The boundary supports acoustic vibrational resonances, which lead to coupling with the microwave resonances of the SRF cavity. The theoretical development and physical understanding of OMIT for our macroscopic SRF cavity is the same as that for other recently-reported OMIT systems despite vastly different optomechanical coupling factors and device sizes. Our mechanical oscillator has a coupling factor of g0 = 2 π . 1 ×10-5 Hz and is roughly 38 mm in diameter. The Q = 5 ×107 for the SRF cavity allows probing of optomechanical effects in the resolved sideband regime.
Superposition and macroscopic observation
International Nuclear Information System (INIS)
Cartwright, N.D.
1976-01-01
The principle of superposition has long plagued the quantum mechanics of macroscopic bodies. In at least one well-known situation - that of measurement - quantum mechanics predicts a superposition. It is customary to try to reconcile macroscopic reality and quantum mechanics by reducing the superposition to a mixture. To establish consistency with quantum mechanics, values for the apparatus after a measurement are to be distributed in the way predicted by the superposition. The distributions observed, however, are those of the mixture. The statistical predictions of quantum mechanics, it appears, are not borne out by observation in macroscopic situations. It has been shown that, insofar as specific ergodic hypotheses apply to the apparatus after the interaction, the superposition which evolves is experimentally indistinguishable from the corresponding mixture. In this paper an idealized model of the measuring situation is presented in which this consistency can be demonstrated. It includes a simplified version of the measurement solution proposed by Daneri, Loinger, and Prosperi (1962). The model should make clear the kind of statistical evidence required to carry of this approach, and the role of the ergodic hypotheses assumed. (Auth.)
Directory of Open Access Journals (Sweden)
Purificacion eLopez-Garcia
2015-08-01
Full Text Available Cyanobacteria are thought to play a key role in carbonate formation due to their metabolic activity, but other organisms carrying out oxygenic photosynthesis (photosynthetic eukaryotes or other metabolisms (e.g. anoxygenic photosynthesis, sulfate reduction, may also contribute to carbonate formation. To obtain more quantitative information than that provided by more classical PCR-dependent methods, we studied the microbial diversity of microbialites from the Alchichica crater lake (Mexico by mining for 16S/18S rRNA genes in metagenomes obtained by direct sequencing of environmental DNA. We studied samples collected at the Western (AL-W and Northern (AL-N shores of the lake and, at the latter site, along a depth gradient (1, 5, 10 and 15 m depth. The associated microbial communities were mainly composed of bacteria, most of which seemed heterotrophic, whereas archaea were negligible. Eukaryotes composed a relatively minor fraction dominated by photosynthetic lineages, diatoms in AL-W, influenced by Si-rich seepage waters, and green algae in AL-N samples. Members of the Gammaproteobacteria and Alphaproteobacteria classes of Proteobacteria, Cyanobacteria and Bacteroidetes were the most abundant bacterial taxa, followed by Planctomycetes, Deltaproteobacteria (Proteobacteria, Verrucomicrobia, Actinobacteria, Firmicutes and Chloroflexi. Community composition varied among sites and with depth. Although cyanobacteria were the most important bacterial group contributing to the carbonate precipitation potential, photosynthetic eukaryotes, anoxygenic photosynthesizers and sulfate reducers were also very abundant. Cyanobacteria affiliated to Pleurocapsales largely increased with depth. Scanning electron microscopy (SEM observations showed considerable areas of aragonite-encrusted Pleurocapsa-like cyanobacteria at microscale. Multivariate statistical analyses showed a strong positive correlation of Pleurocapsales and Chroococcales with aragonite formation at
Sulfur Isotope Trends in Archean Microbialite Facies Record Early Oxygen Production and Consumption
Zerkle, A.; Meyer, N.; Izon, G.; Poulton, S.; Farquhar, J.; Claire, M.
2014-12-01
The major and minor sulfur isotope composition (δ34S and Δ33S) of pyrites preserved in ~2.65-2.5 billion-year-old (Ga) microbialites record localized oxygen production and consumption near the mat surface. These trends are preserved in two separate drill cores (GKF01 and BH1-Sacha) transecting the Campbellrand-Malmani carbonate platform (Ghaap Group, Transvaal Supergroup, South Africa; Zerkle et al., 2012; Izon et al., in review). Microbialite pyrites possess positive Δ33S values, plotting parallel to typical Archean trends (with a Δ33S/δ34S slope of ~0.9) but enriched in 34S by ~3 to 7‰. We propose that these 34S-enriched pyrites were formed from a residual pool of sulfide that was partially oxidized via molecular oxygen produced by surface mat-dwelling cyanobacteria. Sulfide, carrying the range of Archean Δ33S values, could have been produced deeper within the microbial mat by the reduction of sulfate and elemental sulfur, then fractionated upon reaction with O2 produced by oxygenic photosynthesis. Preservation of this positive 34S offset requires that: 1) sulfide was only partially (50-80%) consumed by oxidation, meaning H2S was locally more abundant (or more rapidly produced) than O2, and 2) the majority of the sulfate produced via oxidation was not immediately reduced to sulfide, implying either that the sulfate pool was much larger than the sulfide pool, or that the sulfate formed near the mat surface was transported and reduced in another part of the system. Contrastingly, older microbialite facies (> 2.7 Ga; Thomazo et al., 2013) appear to lack these observed 34S enrichments. Consequently, the onset of 34S enrichments could mark a shift in mat ecology, from communities dominated by anoxygenic photosynthesizers to cyanobacteria. Here, we test these hypotheses with new spatially resolved mm-scale trends in sulfur isotope measurements from pyritized stromatolites of the Vryburg Formation, sampled in the lower part of the BH1-Sacha core. Millimeter
Nuclear physics: Macroscopic aspects
International Nuclear Information System (INIS)
Swiatecki, W.J.
1993-12-01
A systematic macroscopic, leptodermous approach to nuclear statics and dynamics is described, based formally on the assumptions ℎ → 0 and b/R << 1, where b is the surface diffuseness and R the nuclear radius. The resulting static model of shell-corrected nuclear binding energies and deformabilities is accurate to better than 1 part in a thousand and yields a firm determination of the principal properties of the nuclear fluid. As regards dynamics, the above approach suggests that nuclear shape evolutions will often be dominated by dissipation, but quantitative comparisons with experimental data are more difficult than in the case of statics. In its simplest liquid drop version the model exhibits interesting formal connections to the classic astronomical problem of rotating gravitating masses
Directory of Open Access Journals (Sweden)
Yin-Ye Wu
2017-04-01
Full Text Available With oil and gas exploration transferring to deeper and more ancient marine strata, more researches have been conducted about the Meso–Neoproterozoic and Cambrian microbial carbonate rocks by petroleum geologists. The Cambrian deposits experienced the first transgression of the Paleozoic, with shallow marine facies depositing in most areas, which are favorable for different kinds of biological reproduction. The Lower Cambrian in Beijing area is lithologically dominated by purple red shales interbedded with limestones, the Middle Cambrian is mainly composed of thick oolitic limestones, and the Upper Cambrian consists of thin limestones and flat-pebble conglomerates. Two beds of microbial carbonate rocks were discovered in the Cambrian outcrops in the vicinity of Beijing. One is from the Zhangxia Formation of Middle Cambrian, and the other is from the Gushan Formation of Upper Cambrian. The microbialites are characterized by combination of multiple stromatolites forming different bioherms. The bioherms are mostly in oval shape and with different sizes, which are 3–4 m long, and 1–3 m high. The surrounding strata beneath the bioherms are oolitic limestones. A central core of flat-pebble conglomerates occurred within each bioherm. Wavy or columnar stromatolites grow on the basis of flat-pebble conglomerates, with dentate erosional surfaces. The bioherm carbonate rocks are interpreted as products from a deep ramp sedimentary environment where potential oil and gas reservoirs can be found. The analysis of sedimentological characteristics of bioherm carbonate rocks and its lithofacies palaeogeography has significant implication for petroleum exploration. Research on geological record of microbialites is beneficial to investigating the Earth evolution, biodiversity, palaeoenvironment and palaeoclimate change, as well as biological extinction event during geological transitions. It also gives warning to human beings of modern biological crisis.
Seismic scanning tunneling macroscope - Theory
Schuster, Gerard T.
2012-09-01
We propose a seismic scanning tunneling macroscope (SSTM) that can detect the presence of sub-wavelength scatterers in the near-field of either the source or the receivers. Analytic formulas for the time reverse mirror (TRM) profile associated with a single scatterer model show that the spatial resolution limit to be, unlike the Abbe limit of λ/2, independent of wavelength and linearly proportional to the source-scatterer separation as long as the point scatterer is in the near-field region; if the sub-wavelength scatterer is a spherical impedance discontinuity then the resolution will also be limited by the radius of the sphere. Therefore, superresolution imaging can be achieved as the scatterer approaches the source. This is analogous to an optical scanning tunneling microscope that has sub-wavelength resolution. Scaled to seismic frequencies, it is theoretically possible to extract 100 Hz information from 20 Hz data by imaging of near-field seismic energy.
Seismic scanning tunneling macroscope - Theory
Schuster, Gerard T.; Hanafy, Sherif M.; Huang, Yunsong
2012-01-01
We propose a seismic scanning tunneling macroscope (SSTM) that can detect the presence of sub-wavelength scatterers in the near-field of either the source or the receivers. Analytic formulas for the time reverse mirror (TRM) profile associated with a single scatterer model show that the spatial resolution limit to be, unlike the Abbe limit of λ/2, independent of wavelength and linearly proportional to the source-scatterer separation as long as the point scatterer is in the near-field region; if the sub-wavelength scatterer is a spherical impedance discontinuity then the resolution will also be limited by the radius of the sphere. Therefore, superresolution imaging can be achieved as the scatterer approaches the source. This is analogous to an optical scanning tunneling microscope that has sub-wavelength resolution. Scaled to seismic frequencies, it is theoretically possible to extract 100 Hz information from 20 Hz data by imaging of near-field seismic energy.
Macroscopic effects in attosecond pulse generation
International Nuclear Information System (INIS)
Ruchon, T; Varju, K; Mansten, E; Swoboda, M; L'Huillier, A; Hauri, C P; Lopez-Martens, R
2008-01-01
We examine how the generation and propagation of high-order harmonics in a partly ionized gas medium affect their strength and synchronization. The temporal properties of the resulting attosecond pulses generated in long gas targets can be significantly influenced by macroscopic effects, in particular by the intensity in the medium and the degree of ionization which control the dispersion. Under some conditions, the use of gas targets longer than the absorption length can lead to the generation of compressed attosecond pulses. We show these macroscopic effects experimentally, using a 6 mm-long argon-filled gas cell as the generating medium
Macroscopic effects in attosecond pulse generation
Energy Technology Data Exchange (ETDEWEB)
Ruchon, T; Varju, K; Mansten, E; Swoboda, M; L' Huillier, A [Department of Physics, Lund University, PO Box 118, SE-221 00 Lund (Sweden); Hauri, C P; Lopez-Martens, R [Laboratoire d' Optique Appliquee, Ecole Nationale Superieure des Techniques Avancees (ENSTA)-Ecole Polytechnique CNRS UMR 7639, 91761 Palaiseau (France)], E-mail: anne.lhuillier@fysik.lth.se
2008-02-15
We examine how the generation and propagation of high-order harmonics in a partly ionized gas medium affect their strength and synchronization. The temporal properties of the resulting attosecond pulses generated in long gas targets can be significantly influenced by macroscopic effects, in particular by the intensity in the medium and the degree of ionization which control the dispersion. Under some conditions, the use of gas targets longer than the absorption length can lead to the generation of compressed attosecond pulses. We show these macroscopic effects experimentally, using a 6 mm-long argon-filled gas cell as the generating medium.
Microscopic and macroscopic bell inequalities
International Nuclear Information System (INIS)
Santos, E.
1984-01-01
The Bell inequalities, being derived for micro-systems, cannot be tested by (macroscopic) experiments without additional assumptions. A macroscopic definition of local realism is proposed which might be the starting point for deriving Bell inequalities testable without auxiliary assumptions. (orig.)
Quantum equilibria for macroscopic systems
International Nuclear Information System (INIS)
Grib, A; Khrennikov, A; Parfionov, G; Starkov, K
2006-01-01
Nash equilibria are found for some quantum games with particles with spin-1/2 for which two spin projections on different directions in space are measured. Examples of macroscopic games with the same equilibria are given. Mixed strategies for participants of these games are calculated using probability amplitudes according to the rules of quantum mechanics in spite of the macroscopic nature of the game and absence of Planck's constant. A possible role of quantum logical lattices for the existence of macroscopic quantum equilibria is discussed. Some examples for spin-1 cases are also considered
Quantum equilibria for macroscopic systems
Energy Technology Data Exchange (ETDEWEB)
Grib, A [Department of Theoretical Physics and Astronomy, Russian State Pedagogical University, St. Petersburg (Russian Federation); Khrennikov, A [Centre for Mathematical Modelling in Physics and Cognitive Sciences Vaexjoe University (Sweden); Parfionov, G [Department of Mathematics, St. Petersburg State University of Economics and Finances (Russian Federation); Starkov, K [Department of Mathematics, St. Petersburg State University of Economics and Finances (Russian Federation)
2006-06-30
Nash equilibria are found for some quantum games with particles with spin-1/2 for which two spin projections on different directions in space are measured. Examples of macroscopic games with the same equilibria are given. Mixed strategies for participants of these games are calculated using probability amplitudes according to the rules of quantum mechanics in spite of the macroscopic nature of the game and absence of Planck's constant. A possible role of quantum logical lattices for the existence of macroscopic quantum equilibria is discussed. Some examples for spin-1 cases are also considered.
Superconductivity and macroscopic quantum phenomena
International Nuclear Information System (INIS)
Rogovin, D.; Scully, M.
1976-01-01
It is often asserted that superconducting systems are manifestations of quantum mechanics on a macroscopic scale. In this review article it is demonstrated that this quantum assertion is true within the framework of the microscopic theory of superconductivity. (Auth.)
Macroscopic constraints on string unification
International Nuclear Information System (INIS)
Taylor, T.R.
1989-03-01
The comparison of sting theory with experiment requires a huge extrapolation from the microscopic distances, of order of the Planck length, up to the macroscopic laboratory distances. The quantum effects give rise to large corrections to the macroscopic predictions of sting unification. I discus the model-independent constraints on the gravitational sector of string theory due to the inevitable existence of universal Fradkin-Tseytlin dilatons. 9 refs
Interpretation of macroscopic quantum phenomena
International Nuclear Information System (INIS)
Baumann, K.
1986-01-01
It is argued that a quantum theory without observer is required for the interpretation of macroscopic quantum tunnelling. Such a theory is obtained by augmenting QED by the actual electric field in the rest system of the universe. An equation of the motion of this field is formulated form which the correct macroscopic behavior of the universe and the validity of the Born interpretation is derived. Care is taken to use mathematically sound concepts only. (Author)
Arp, Gernot; Thiel, Volker; Reimer, Andreas; Michaelis, Walter; Reitner, Joachim
1999-07-01
Calcium carbonate precipitation and microbialite formation at highly supersaturated mixing zones of thermal spring waters and alkaline lake water have been investigated at Pyramid Lake, Nevada. Without precipitation, pure mixing should lead to a nearly 100-fold supersaturation at 40°C. Physicochemical precipitation is modified or even inhibited by the properties of biofilms, dependent on the extent of biofilm development and the current precipitation rate. Mucus substances (extracellular polymeric substances, EPS, e.g., of cyanobacteria) serve as effective Ca 2+-buffers, thus preventing seed crystal nucleation even in a highly supersaturated macroenvironment. Carbonate is then preferentially precipitated in mucus-free areas such as empty diatom tests or voids. After the buffer capacity of the EPS is surpassed, precipitation is observed at the margins of mucus areas. Hydrocarbon biomarkers extracted from (1) a calcifying Phormidium-biofilm, (2) the stromatolitic carbonate below, and (3) a fossil `tufa' of the Pleistocene pinnacles, indicate that the cyanobacterial primary producers have been subject to significant temporal changes in their species distribution. Accordingly, the species composition of cyanobacterial biofilms does not appear to be relevant for the formation of microbial carbonates in Pyramid Lake. The results demonstrate the crucial influence of mucus substances on carbonate precipitation in highly supersaturated natural environments.
Macroscopic and non-linear quantum games
International Nuclear Information System (INIS)
Aerts, D.; D'Hooghe, A.; Posiewnik, A.; Pykacz, J.
2005-01-01
Full text: We consider two models of quantum games. The first one is Marinatto and Weber's 'restricted' quantum game in which only the identity and the spin-flip operators are used. We show that this quantum game allows macroscopic mechanistic realization with the use of a version of the 'macroscopic quantum machine' described by Aerts already in 1980s. In the second model we use non-linear quantum state transformations which operate on points of spin-1/2 on the Bloch sphere and which can be used to distinguish optimally between two non-orthogonal states. We show that efficiency of these non-linear strategies out-perform any linear ones. Some hints on the possible theory of non-linear quantum games are given. (author)
Special relativity - the foundation of macroscopic physics
International Nuclear Information System (INIS)
Dixon, W.G.
1978-01-01
This book aims to show that an understanding of the basic laws of macroscopic systems can be gained more easily within relativistic physics than within Newtonian physics. The unity of dynamics, thermodynamics and electromagnetism under the umbrella of special relativity is examined under chapter headings entitled: the physics of space and time, affine spaces in mathematics and physics, foundations of dynamics, relativistic simple fluids, and, electrodynamics of polarizable fluids. (U.K.)
Testing quantum behaviour at the macroscopic level
International Nuclear Information System (INIS)
Ghirardi, G.C.
1994-07-01
We reconsider recent proposals to test macro realism versus quantum mechanics in experiments involving noninvasive measurement processes on a Squid. In spite of the fact that we are able to prove that the proposed experiments do not represent a test of macro realism but simply of macroscopic quantum coherence we call attention to their extreme conceptual relevance. We also discuss some recent criticisms which have been raised against the considered proposal and we show that they are not relevant. (author). 12 refs
Microbialite Biosignature Analysis by Mesoscale X-ray Fluorescence (μXRF) Mapping.
Tice, Michael M; Quezergue, Kimbra; Pope, Michael C
2017-11-01
As part of its biosignature detection package, the Mars 2020 rover will carry PIXL, the Planetary Instrument for X-ray Lithochemistry, a spatially resolved X-ray fluorescence (μXRF) spectrometer. Understanding the types of biosignatures detectable by μXRF and the rock types μXRF is most effective at analyzing is therefore an important goal in preparation for in situ Mars 2020 science and sample selection. We tested mesoscale chemical mapping for biosignature interpretation in microbialites. In particular, we used μXRF to identify spatial distributions and associations between various elements ("fluorescence microfacies") to infer the physical, biological, and chemical processes that produced the observed compositional distributions. As a test case, elemental distributions from μXRF scans of stromatolites from the Mesoarchean Nsuze Group (2.98 Ga) were analyzed. We included five fluorescence microfacies: laminated dolostone, laminated chert, clotted dolostone and chert, stromatolite clast breccia, and cavity fill. Laminated dolostone was formed primarily by microbial mats that trapped and bound loose sediment and likely precipitated carbonate mud at a shallow depth below the mat surface. Laminated chert was produced by the secondary silicification of microbial mats. Clotted dolostone and chert grew as cauliform, cryptically laminated mounds similar to younger thrombolites and was likely formed by a combination of mat growth and patchy precipitation of early-formed carbonate. Stromatolite clast breccias formed as lag deposits filling erosional scours and interstromatolite spaces. Cavities were filled by microquartz, Mn-rich dolomite, and partially dolomitized calcite. Overall, we concluded that μXRF is effective for inferring genetic processes and identifying biosignatures in compositionally heterogeneous rocks. Key Words: Stromatolites-Biosignatures-Spectroscopy-Archean. Astrobiology 17, 1161-1172.
Thermodynamical properties and thermoelastic coupling of complex macroscopic structure
International Nuclear Information System (INIS)
Fabbri, M.; Sacripanti, A.
1996-11-01
Gross qualitative/quantitative analysis about thermodynamical properties and thermoelastic coupling (or elastocaloric effect) of complex macroscopic structure (running shoes) is performed by infrared camera. The experimental results showed the achievability of a n industrial research project
Macroscopic models for traffic safety.
Oppe, S.
1988-01-01
Recently there has been an increased interest in the application of macroscopic models for the description of developments in traffic safety. A discussion was started on the causes of the sudden decrease in the number of fatal and injury accidents after 1974. Before that time these numbers had
Schneider, Dominik; Arp, Gernot; Reimer, Andreas; Reitner, Joachim; Daniel, Rolf
2013-01-01
On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰). Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster), which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria), Chloroflexi (Anaerolineae and Caldilineae), purple non-sulfur bacteria (Alphaproteobacteria), purple sulfur bacteria (Chromatiales), anaerobic Bacteroidetes (Marinilabiacae), Nitrospirae (OPB95), Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata) to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B) with increasing depth.
Directory of Open Access Journals (Sweden)
Dominik Schneider
Full Text Available On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰. Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster, which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria, Chloroflexi (Anaerolineae and Caldilineae, purple non-sulfur bacteria (Alphaproteobacteria, purple sulfur bacteria (Chromatiales, anaerobic Bacteroidetes (Marinilabiacae, Nitrospirae (OPB95, Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B with increasing depth.
Macroscopic nonclassical-state preparation via postselection
Montenegro, Víctor; Coto, Raúl; Eremeev, Vitalie; Orszag, Miguel
2017-11-01
Macroscopic quantum superposition states are fundamental to test the classical-quantum boundary and present suitable candidates for quantum technologies. Although the preparation of such states has already been realized, the existing setups commonly consider external driving and resonant interactions, predominantly by considering Jaynes-Cummings-like and beam-splitter-like interactions, as well as the nonlinear radiation pressure interaction in cavity optomechanics. In contrast to previous works on the matter, we propose a feasible probabilistic scheme to generate a macroscopic mechanical qubit, as well as phononic Schrödinger's cat states with no need of any energy exchange with the macroscopic mechanical oscillator. Essentially, we investigate an open dispersive spin-mechanical system in the absence of any external driving under nonideal conditions, such as the detrimental effects due to the oscillator and spin energy losses in a thermal bath at nonzero temperature. In our work, we show that the procedure to generate the mechanical qubit state is solely based on spin postselection in the weak to moderate coupling regime. Finally, we demonstrate that the mechanical superposition is related to the amplification of the mean values of the mechanical quadratures as they maximize the quantum coherence.
Scanner-based macroscopic color variation estimation
Kuo, Chunghui; Lai, Di; Zeise, Eric
2006-01-01
Flatbed scanners have been adopted successfully in the measurement of microscopic image artifacts, such as granularity and mottle, in print samples because of their capability of providing full color, high resolution images. Accurate macroscopic color measurement relies on the use of colorimeters or spectrophotometers to provide a surrogate for human vision. The very different color response characteristics of flatbed scanners from any standard colorimetric response limits the utility of a flatbed scanner as a macroscopic color measuring device. This metamerism constraint can be significantly relaxed if our objective is mainly to quantify the color variations within a printed page or between pages where a small bias in measured colors can be tolerated as long as the color distributions relative to the individual mean values is similar. Two scenarios when converting color from the device RGB color space to a standardized color space such as CIELab are studied in this paper, blind and semi-blind color transformation, depending on the availability of the black channel information. We will show that both approaches offer satisfactory results in quantifying macroscopic color variation across pages while the semi-blind color transformation further provides fairly accurate color prediction capability.
Pathways toward understanding Macroscopic Quantum Phenomena
International Nuclear Information System (INIS)
Hu, B L; Subaşi, Y
2013-01-01
measure of quantumness here and pick out these somewhat counter-intuitive examples to show that there are blind spots worthy of our attention and issues which we need to analyze closer. Our purpose is to try to remove the stigma that quantum only pertains to micro, in order to make way for deeper probes into the conditions whereby quantum features of macroscopic systems manifest.
Single-Phase Bundle Flows Including Macroscopic Turbulence Model
Energy Technology Data Exchange (ETDEWEB)
Lee, Seung Jun; Yoon, Han Young [KAERI, Daejeon (Korea, Republic of); Yoon, Seok Jong; Cho, Hyoung Kyu [Seoul National University, Seoul (Korea, Republic of)
2016-05-15
To deal with various thermal hydraulic phenomena due to rapid change of fluid properties when an accident happens, securing mechanistic approaches as much as possible may reduce the uncertainty arising from improper applications of the experimental models. In this study, the turbulence mixing model, which is well defined in the subchannel analysis code such as VIPRE, COBRA, and MATRA by experiments, is replaced by a macroscopic k-e turbulence model, which represents the aspect of mathematical derivation. The performance of CUPID with macroscopic turbulence model is validated against several bundle experiments: CNEN 4x4 and PNL 7x7 rod bundle tests. In this study, the macroscopic k-e model has been validated for the application to subchannel analysis. It has been implemented in the CUPID code and validated against CNEN 4x4 and PNL 7x7 rod bundle tests. The results showed that the macroscopic k-e turbulence model can estimate the experiments properly.
Laurent, Gindre-Chanu; Edoardo, Perri; Ian, Sharp R.; Peacock, D. C. P.; Roger, Swart; Ragnar, Poulsen; Hercinda, Ferreira; Vladimir, Machado
2016-08-01
Ephemeral evaporitic conditions developed within the uppermost part of the transgressive Late Sag sequence in the Namibe Basin (SW Angola), leading to the formation of extensive centimetre- to metre-thick sulphate-bearing deposits and correlative microbialitic carbonates rich in pseudomorphs after evaporite crystals. The onshore pre-salt beds examined in this study are located up to 25 m underneath the major mid-Aptian evaporitic succession, which is typified at the outcrop by gypsiferous Bambata Formation and in the subsurface by the halite-dominated Loeme Formation. Carbonate-evaporite cycles mostly occur at the top of metre-thick regressive parasequences, which progressively onlap and overstep landward the former faulted (rift) topography, or fill major pre-salt palaeo-valleys. The sulphate beds are made up of alabastrine gypsum associated with embedded botryoidal nodules, dissolution-related gypsum breccia, and are cross-cut by thin satin-spar gypsum veins. Nodular and fine-grained fabrics are interpreted as being diagenetic gypsum deposits resulting from the dissolution and recrystallisation of former depositional subaqueous sulphates, whereas gypsum veins and breccia result from telogenetic processes. The carbonates display a broader diversity of facies, characterised by rapid lateral variations along strike. Thin dolomitic and calcitic bacterial-mediated filamentous microbialitic boundstones enclose a broad variety of evaporite pseudomorphs and can pass laterally over a few metres into sulphate beds. Dissolution-related depositional breccias are also common and indicate early dissolution of former evaporite layers embedded within the microbialites. Sulphate and carbonate units are interpreted as being concomitantly deposited along a tide-dominated coastal supra- to intertidal- sabkha and constitute high-frequency hypersaline precursor events, prior to the accumulation of the giant saline mid-Aptian Bambata and Loeme Formations. Petrographic and geochemical
Macroscopic quantum tunneling of the magnetic moment
Tejada, J.; Hernandez, J. M.; del Barco, E.
1999-05-01
In this paper we review the work done on magnetic relaxation during the last 10 years on both single-domain particles and magnetic molecules and its contribution to the discovery of quantum tunneling of the magnetic moment (Chudnovsky and Tejada, Macroscopic Quantum tunneling of the Magnetic moment, Cambridge University press, Cambridge, 1998). We present first the theoretical expressions and their connection to quantum relaxation and secondly, we show and discuss the experimental results. Finally, we discuss very recent hysteresis data on Mn 12Ac molecules at extremely large sweeping rate for the external magnetic field which suggest the existence of quantum spin—phonon avalanches.
On the problem of contextuality in macroscopic magnetization measurements
International Nuclear Information System (INIS)
Soeda, Akihito; Kurzyński, Paweł; Ramanathan, Ravishankar; Grudka, Andrzej; Thompson, Jayne; Kaszlikowski, Dagomir
2013-01-01
We show that sharp measurements of total magnetization cannot be used to reveal contextuality in macroscopic many-body systems of spins of arbitrary dimension. We decompose each such measurement into set of projectors corresponding to well-defined value of total magnetization. We then show that such sets of projectors are too restricted to construct Kochen–Specker sets.
Plasmonic direct writing lithography with a macroscopical contact probe
Huang, Yuerong; Liu, Ling; Wang, Changtao; Chen, Weidong; Liu, Yunyue; Li, Ling
2018-05-01
In this work, we design a plasmonic direct writing lithography system with a macroscopical contact probe to achieve nanometer scale spots. The probe with bowtie-shaped aperture array adopts spring hinge and beam deflection method (BDM) to realize near-field lithography. Lithography results show that a macroscopical plasmonic contact probe can achieve a patterning resolution of around 75 nm at 365 nm wavelength, and demonstrate that the lithography system is promising for practical applications due to beyond the diffraction limit, low cost, and simplification of system configuration. CST calculations provide a guide for the design of recording structure and the arrangement of placing polarizer.
Modification of the Charlesby law. Pt. 2. Macroscopic sensitivity
International Nuclear Information System (INIS)
Schiltz, A.; Weil, A.; Paniez, P.
1984-01-01
In part II, results are presented showing that for doses below macroscopic sensitivity, Qsub(sm), degradation due to fluence of the particles seems to be non-uniform over the entire area. In the light of this, a modification of the Charlesby's law is proposed providing a solution to the problems considered in part I [fr
Macroscopic and microscopic magnetism of metal-metalloid amorphous alloys
International Nuclear Information System (INIS)
Vasconcellos, M.A.Z.; Fichtner, P.F.P.; Livi, F.P.; Costa, M.I. da; Baibich, M.N.
1984-01-01
In this paper is investigated the interrelation between macroscopic and microscopic magnetic phenomena using experimetnal data from Moessbauer effect and the magnetization of layers of amorphous (Fe 1-x Ni x ) 80 B 20 . The Moessbauer effect measurement show a distribution of hyperfine fields in Fe site as well as a likely distribution of isomeric shifts (M.W.O.) [pt
Rank distributions: A panoramic macroscopic outlook
Eliazar, Iddo I.; Cohen, Morrel H.
2014-01-01
This paper presents a panoramic macroscopic outlook of rank distributions. We establish a general framework for the analysis of rank distributions, which classifies them into five macroscopic "socioeconomic" states: monarchy, oligarchy-feudalism, criticality, socialism-capitalism, and communism. Oligarchy-feudalism is shown to be characterized by discrete macroscopic rank distributions, and socialism-capitalism is shown to be characterized by continuous macroscopic size distributions. Criticality is a transition state between oligarchy-feudalism and socialism-capitalism, which can manifest allometric scaling with multifractal spectra. Monarchy and communism are extreme forms of oligarchy-feudalism and socialism-capitalism, respectively, in which the intrinsic randomness vanishes. The general framework is applied to three different models of rank distributions—top-down, bottom-up, and global—and unveils each model's macroscopic universality and versatility. The global model yields a macroscopic classification of the generalized Zipf law, an omnipresent form of rank distributions observed across the sciences. An amalgamation of the three models establishes a universal rank-distribution explanation for the macroscopic emergence of a prevalent class of continuous size distributions, ones governed by unimodal densities with both Pareto and inverse-Pareto power-law tails.
Macroscopic transport by synthetic molecular machines
Berna, J; Leigh, DA; Lubomska, M; Mendoza, SM; Perez, EM; Rudolf, P; Teobaldi, G; Zerbetto, F
Nature uses molecular motors and machines in virtually every significant biological process, but demonstrating that simpler artificial structures operating through the same gross mechanisms can be interfaced with - and perform physical tasks in - the macroscopic world represents a significant hurdle
Macroscopic quantum waves in non local theories
International Nuclear Information System (INIS)
Ventura, I.
1979-01-01
By means of an expansion in the density, it is shown that Macroscopic Quantum Waves also apear in non local theories. This result reinforces the conjecture that these waves should exist in liquid 4 He. (Author) [pt
Macroscopic quantum waves in non local theories
International Nuclear Information System (INIS)
Ventura, I.
1979-01-01
By means of an expansion in the density, it is shown that Macroscopic Quantum Waves also appear in non local theories. This result reinforces the conjecture that these waves should exist in liquid 4 He [pt
Assessments of macroscopicity for quantum optical states
DEFF Research Database (Denmark)
Laghaout, Amine; Neergaard-Nielsen, Jonas Schou; Andersen, Ulrik Lund
2015-01-01
With the slow but constant progress in the coherent control of quantum systems, it is now possible to create large quantum superpositions. There has therefore been an increased interest in quantifying any claims of macroscopicity. We attempt here to motivate three criteria which we believe should...... enter in the assessment of macroscopic quantumness: The number of quantum fluctuation photons, the purity of the states, and the ease with which the branches making up the state can be distinguished. © 2014....
Directory of Open Access Journals (Sweden)
Jörg C. Frommlet
2018-05-01
Full Text Available Dinoflagellates in the genus Symbiodinium exhibit a variety of life styles, ranging from mutualistic endosymbioses with animal and protist hosts to free-living life styles. In culture, Symbiodinium spp. and naturally associated bacteria are known to form calcifying biofilms that produce so-called symbiolites, i.e., aragonitic microbialites that incorporate Symbiodinium as endolithic cells. In this study, we investigated (i how algal growth and the combined physiological activity of these bacterial-algal associations affect the physicochemical macroenvironment in culture and the microenvironment within bacterial-algal biofilms, and (ii how these interactions induce the formation of symbiolites. In batch culture, calcification typically commenced when Symbiodinium spp. growth approached stationary phase and when photosynthetic activity and its influence on pH and the carbonate system of the culture medium had already subsided, indicating that symbiolite formation is not simply a function of photosynthetic activity in the bulk medium. Physical disturbance of bacteria-algal biofilms, via repeated detaching and dispersing of the developing biofilm, generally impeded symbiolite formation, suggesting that the structural integrity of biofilms plays an important role in generating conditions conducive to calcification. Microsensor measurements of pH and O2 revealed a biofilm microenvironment characterized by high photosynthetic rates and by dynamic changes in photosynthesis and respiration with light intensity and culture age. Ca2+ microsensor measurements confirmed the significance of the biofilm microenvironment in inducing calcification, as photosynthesis within the biofilm induced calcification without the influence of batch culture medium and under environmentally relevant flow conditions. Furthermore, first quantitative data on calcification from 26 calcifying cultures enabled a first broad comparison of Symbiodinium-induced bacterial
Cloud Macroscopic Organization: Order Emerging from Randomness
Yuan, Tianle
2011-01-01
Clouds play a central role in many aspects of the climate system and their forms and shapes are remarkably diverse. Appropriate representation of clouds in climate models is a major challenge because cloud processes span at least eight orders of magnitude in spatial scales. Here we show that there exists order in cloud size distribution of low-level clouds, and that it follows a power-law distribution with exponent gamma close to 2. gamma is insensitive to yearly variations in environmental conditions, but has regional variations and land-ocean contrasts. More importantly, we demonstrate this self-organizing behavior of clouds emerges naturally from a complex network model with simple, physical organizing principles: random clumping and merging. We also demonstrate symmetry between clear and cloudy skies in terms of macroscopic organization because of similar fundamental underlying organizing principles. The order in the apparently complex cloud-clear field thus has its root in random local interactions. Studying cloud organization with complex network models is an attractive new approach that has wide applications in climate science. We also propose a concept of cloud statistic mechanics approach. This approach is fully complementary to deterministic models, and the two approaches provide a powerful framework to meet the challenge of representing clouds in our climate models when working in tandem.
Investigation of dissipative forces near macroscopic media
International Nuclear Information System (INIS)
Becker, R.S.
1982-12-01
The interaction of classical charged particles with the fields they induce in macroscopic dielectric media is investigated. For 10- to 1000-eV electrons, the angular perturbation of the trajectory by the image potential for surface impact parameters of 50 to 100 A is shown to be of the order of 0.001 rads over a distance of 100 A. The energy loss incurred by low-energy particles due to collective excitations such as surface plasmons is shown to be observable with a transition probability of 0.01 to 0.001 (Becker, et al., 1981b). The dispersion of real surface plasmon modes in planar and cylindrical geometries is discussed and is derived for pinhole geometry described in terms of a single-sheeted hyperboloid of revolution. An experimental apparatus for the measurement of collective losses for medium-energy electrons translating close to a dielectric surface is described and discussed. Data showing such losses at electron energies of 500 to 900 eV in silver foils containing many small apertures are presented and shown to be in good agreement with classical stopping power calculations and quantum mechanical calculations carried out in the low-velocity limit. The data and calculations are compared and contrasted with earlier transmission and reflection measurements, and the course of further investigation is discussed
Role of stochastic fluctuations in the charge on macroscopic particles in dusty plasmas
International Nuclear Information System (INIS)
Vaulina, O.S.; Nefedov, A.P.; Petrov, O.F.; Khrapak, S.A.
1999-01-01
The currents which charge a macroscopic particle placed in a plasma consist of discrete charges; hence, the charge can undergo random fluctuations about its equilibrium value. These random fluctuations can be described by a simple model which, if the mechanisms for charging of macroscopic particles are known, makes it possible to determine the dependence of the temporal and amplitude characteristics of the fluctuations on the plasma parameters. This model can be used to study the effect of charge fluctuations on the dynamics of the macroscopic particles. The case of so-called plasma-dust crystals (i.e., highly ordered structures which develop because of strong interactions among macroscopic particles) in laboratory gaseous discharge plasmas is considered as an example. The molecular dynamics method shows that, under certain conditions, random fluctuations in the charge can effectively heat a system of macroscopic particles, thereby impeding the ordering process
Macroscopic averages in Qed in material media
International Nuclear Information System (INIS)
Dutra, S.M.; Furuya, K.
1997-01-01
The starting point of macroscopic theories of quantum electrodynamics in material media is usually the classical macroscopic Maxwell equations that are then quantized. Such approach however, is based on the assumption that a macroscopic description is attainable, i.e., it assumes that we can describe the effect of the atoms of material on the field only in terms of a dielectric constant in the regime where the field has to be treated quantum mechanically. The problem we address is whether this assumption is valid at all and if so, under what conditions. We have chosen a simple model, which allows us to start from first principles and determine the validity of these approximations, without simply taking them for granted as in previous papers
Conversion of light into macroscopic helical motion
Iamsaard, Supitchaya; Aßhoff, Sarah J.; Matt, Benjamin; Kudernac, Tibor; Cornelissen, Jeroen J. L. M.; Fletcher, Stephen P.; Katsonis, Nathalie
2014-03-01
A key goal of nanotechnology is the development of artificial machines capable of converting molecular movement into macroscopic work. Although conversion of light into shape changes has been reported and compared to artificial muscles, real applications require work against an external load. Here, we describe the design, synthesis and operation of spring-like materials capable of converting light energy into mechanical work at the macroscopic scale. These versatile materials consist of molecular switches embedded in liquid-crystalline polymer springs. In these springs, molecular movement is converted and amplified into controlled and reversible twisting motions. The springs display complex motion, which includes winding, unwinding and helix inversion, as dictated by their initial shape. Importantly, they can produce work by moving a macroscopic object and mimicking mechanical movements, such as those used by plant tendrils to help the plant access sunlight. These functional materials have potential applications in micromechanical systems, soft robotics and artificial muscles.
Nonequilibrium work relation in a macroscopic system
International Nuclear Information System (INIS)
Sughiyama, Yuki; Ohzeki, Masayuki
2013-01-01
We reconsider a well-known relationship between the fluctuation theorem and the second law of thermodynamics by evaluating stochastic evolution of the density field (probability measure valued process). In order to establish a bridge between microscopic and macroscopic behaviors, we must take the thermodynamic limit of a stochastic dynamical system following the standard procedure in statistical mechanics. The thermodynamic path characterizing a dynamical behavior in the macroscopic scale can be formulated as an infimum of the action functional for the stochastic evolution of the density field. In our formulation, the second law of thermodynamics can be derived only by symmetry of the action functional without recourse to the Jarzynski equality. Our formulation leads to a nontrivial nonequilibrium work relation for metastable (quasi-stationary) states, which are peculiar in the macroscopic system. We propose a prescription for computing the free energy for metastable states based on the resultant work relation. (paper)
Macroscopic phase separation in high-temperature superconductors
Wen, Hai-Hu
2000-01-01
High-temperature superconductivity is recovered by introducing extra holes to the Cu-O planes, which initially are insulating with antiferromagnetism. In this paper I present data to show the macroscopic electronic phase separation that is caused by either mobile doping or electronic instability in the overdoped region. My results clearly demonstrate that the electronic inhomogeneity is probably a general feature of high-temperature superconductors. PMID:11027323
Extension of Seismic Scanning Tunneling Macroscope to Elastic Waves
Tarhini, Ahmad
2017-11-06
The theory for the seismic scanning tunneling macroscope is extended from acoustic body waves to elastic body-wave propagation. We show that, similar to the acoustic case, near-field superresolution imaging from elastic body waves results from the O(1/R) term, where R is the distance between the source and near-field scatterer. The higher-order contributions R−n for n>1 are cancelled in the near-field region for a point source with normal stress.
Extension of Seismic Scanning Tunneling Macroscope to Elastic Waves
Tarhini, Ahmad; Guo, Bowen; Dutta, Gaurav; Schuster, Gerard T.
2017-01-01
The theory for the seismic scanning tunneling macroscope is extended from acoustic body waves to elastic body-wave propagation. We show that, similar to the acoustic case, near-field superresolution imaging from elastic body waves results from the O(1/R) term, where R is the distance between the source and near-field scatterer. The higher-order contributions R−n for n>1 are cancelled in the near-field region for a point source with normal stress.
A Review on Macroscopic Pedestrian Flow Modelling
Directory of Open Access Journals (Sweden)
Anna Kormanová
2013-12-01
Full Text Available This paper reviews several various approaches to macroscopic pedestrian modelling. It describes hydrodynamic models based on similarity of pedestrian flow with fluids and gases; first-order flow models that use fundamental diagrams and conservation equation; and a model similar to LWR vehicular traffic model, which allows non-classical shocks. At the end of the paper there is stated a comparison of described models, intended to find appropriate macroscopic model to eventually be a part of a hybrid model. The future work of the author is outlined.
Macroscopic fundamental strings in cosmology
Energy Technology Data Exchange (ETDEWEB)
Aharonov, Y; Englert, F; Orloff, J
1987-12-24
We show that, when D greater than or equal to 4, theories of closed strings of closed strings in D, non-compact space-time dimensions exhibit a phase transition. The high-temperature phase is characterized by a condensate of arbitrarily long strings with Hausdorff dimension two (area filling curves). We suggest that this stringy phase is the ancestor of the adiabatic era. Fundamental strings could then both drive the inflation and seed, in a way reminiscent of the cosmic string mechanism, the large structures in the universe.
Macroscopic (and microscopic massless modes
Directory of Open Access Journals (Sweden)
Michael C. Abbott
2015-05-01
Full Text Available We study certain spinning strings exploring the flat directions of AdS3×S3×S3×S1, the massless sector cousins of su(2 and sl(2 sector spinning strings. We describe these, and their vibrational modes, using the D(2,1;α2 algebraic curve. By exploiting a discrete symmetry of this structure which reverses the direction of motion on the spheres, and alters the masses of the fermionic modes s→κ−s, we find out how to treat the massless fermions which were previously missing from this formalism. We show that folded strings behave as a special case of circular strings, in a sense which includes their mode frequencies, and we are able to recover this fact in the worldsheet formalism. We use these frequencies to calculate one-loop corrections to the energy, with a version of the Beisert–Tseytlin resummation.
The mirrors model: macroscopic diffusion without noise or chaos
International Nuclear Information System (INIS)
Chiffaudel, Yann; Lefevere, Raphaël
2016-01-01
Before stating our main result, we first clarify through classical examples the status of the laws of macroscopic physics as laws of large numbers. We next consider the mirrors model in a finite d-dimensional domain and connected to particles reservoirs at fixed chemical potentials. The dynamics is purely deterministic and non-ergodic but takes place in a random environment. We study the macroscopic current of particles in the stationary regime. We show first that when the size of the system goes to infinity, the behaviour of the stationary current of particles is governed by the proportion of orbits crossing the system. This allows us to formulate a necessary and sufficient condition on the distribution of the set of orbits that ensures the validity of Fick’s law. Using this approach, we show that Fick’s law relating the stationary macroscopic current of particles to the concentration difference holds in three dimensions and above. The negative correlations between crossing orbits play a key role in the argument. (letter)
Macroscopic optical response and photonic bands
International Nuclear Information System (INIS)
Pérez-Huerta, J S; Luis Mochán, W; Ortiz, Guillermo P; Mendoza, Bernardo S
2013-01-01
We develop a formalism for the calculation of the macroscopic dielectric response of composite systems made of particles of one material embedded periodically within a matrix of another material, each of which is characterized by a well-defined dielectric function. The nature of these dielectric functions is arbitrary, and could correspond to dielectric or conducting, transparent or opaque, absorptive and dispersive materials. The geometry of the particles and the Bravais lattice of the composite are also arbitrary. Our formalism goes beyond the long-wavelength approximation as it fully incorporates retardation effects. We test our formalism through the study of the propagation of electromagnetic waves in two-dimensional photonic crystals made of periodic arrays of cylindrical holes in a dispersionless dielectric host. Our macroscopic theory yields a spatially dispersive macroscopic response which allows the calculation of the full photonic band structure of the system, as well as the characterization of its normal modes, upon substitution into the macroscopic field equations. We can also account approximately for the spatial dispersion through a local magnetic permeability and analyze the resulting dispersion relation, obtaining a region of left handedness. (paper)
Berkeley Experiments on Superfluid Macroscopic Quantum Effects
International Nuclear Information System (INIS)
Packard, Richard
2006-01-01
This paper provides a brief history of the evolution of the Berkeley experiments on macroscopic quantum effects in superfluid helium. The narrative follows the evolution of the experiments proceeding from the detection of single vortex lines to vortex photography to quantized circulation in 3He to Josephson effects and superfluid gyroscopes in both 4He and 3He
Macroscopic sizes of field of superrelativistic charges
International Nuclear Information System (INIS)
Strel'tsov, V.N.
1995-01-01
Based on the equation of Lienard-Wiechert equipotentials, it is shown that the field of superrelativistic charges reaches macroscopic sizes (e.g., R || = 2 m at E e = 50 GeV). This phenomenon serves an initial cause of the known considerable growth of formation length at high energies. 3 refs., 1 tab
On quantum mechanics for macroscopic systems
International Nuclear Information System (INIS)
Primas, H.
1992-01-01
The parable of Schroedinger's cat may lead to several up-to date questions: how to treat open systems in quantum theory, how to treat thermodynamically irreversible processes in the quantum mechanics framework, how to explain, following the quantum theory, the existence, phenomenologically evident, of classical observables, what implies the predicted existence by the quantum theory of non localized macroscopic material object ?
Macroscopic quantum electrodynamics of high-Q cavities
International Nuclear Information System (INIS)
Khanbekyan, Mikayel
2009-01-01
In this thesis macroscopic quantum electrodynamics in linear media was applied in order to develop an universally valid quantum theory for the description of the interaction of the electromagnetic field with atomic sources in high-Q cavities. In this theory a complete description of the characteristics of the emitted radiation is given. The theory allows to show the limits of the applicability of the usually applied theory. In order to establish an as possible generally valid theory first the atom-field interaction was studied in the framework of macroscopic quantum electrodynamics in dispersive and absorptive media. In order to describe the electromagnetic field from Maxwell's equations was started, whereby the noise-current densities, which are connected with the absorption of the medium, were included. The solution of these equations expresses the electromagnetic field variables by the noise-current densities by means of Green's tensor of the macroscopic Maxwell equations. The explicit quantization is performed by means of the noise-current densities, whereby a diagonal Hamiltonian is introduced, which then guarantees the time development according to Maxwell's equation and the fulfillment of the fundamental simultaneous commutation relations of the field variables. In the case of the interaction of the medium-supported field with atoms the Hamiltonian must be extended by atom-field interactions energies, whereby the canonical coupling schemes of the minimal or multipolar coupling can be used. The dieelectric properties of the material bodies as well as their shape are coded in the Green tensor of the macroscopic Maxwell equations. As preparing step first the Green tensor was specified in order to derive three-dimensional input-output relations for the electromagnetic field operators on a plane multilayer structure. Such a general dewscription of the electromagnetic field allows the inclusion both of dispersion and absorption of the media and the possible
Seismic scanning tunneling macroscope - Elastic simulations and Arizona mine test
Hanafy, Sherif M.; Schuster, Gerard T.
2012-01-01
Elastic seismic simulations and field data tests are used to validate the theory of a seismic scanning tunneling macroscope (SSTM). For nearfield elastic simulation, the SSTM results show superresolution to be better than λ/8 if the only scattered data are used as input data. If the direct P and S waves are muted then the resolution of the scatterer locations are within about λ/5. Seismic data collected in an Arizona tunnel showed a superresolution limit of at least λ/19. These test results are consistent with the theory of the SSTM and suggest that the SSTM can be a tool used by geophysicists as a probe for near-field scatterers.
Bimodality in macroscopic dynamics of nuclear fission
International Nuclear Information System (INIS)
Bastrukov, S.I.; Salamatin, V.S.; Strteltsova, O.I.; Molodtsova, I.V.; Podgainy, D.V.; )
2000-01-01
The elastodynamic collective model of nuclear fission is outlined whose underlying idea is that the stiff structure of nuclear shells imparts to nucleus properties typical of a small piece of an elastic solid. Emphasis is placed on the macroscopic dynamics of nuclear deformations resulting in fission by two energetically different modes. The low-energy S-mode is the fission due to disruption of elongated quadrupole spheroidal shape. The characteristic features of the high-energy T-mode of division by means of torsional shear deformations is the compact scission configuration. Analytic and numerical estimates for the macroscopic fission-barrier heights are presented, followed by discussion of fingerprints of the above dynamical bimodality in the available data [ru
Macroscopic Quantum Resonators (MAQRO): 2015 update
International Nuclear Information System (INIS)
Kaltenbaek, Rainer; Aspelmeyer, Markus; Kiesel, Nikolai; Barker, Peter F.; Bose, Sougato; Bassi, Angelo; Bateman, James; Bongs, Kai; Cruise, Adrian Michael; Braxmaier, Claus; Brukner, Caslav; Christophe, Bruno; Rodrigues, Manuel; Chwalla, Michael; Johann, Ulrich; Cohadon, Pierre-Francois; Heidmann, Antoine; Lambrecht, Astrid; Reynaud, Serge; Curceanu, Catalina; Dholakia, Kishan; Mazilu, Michael; Diosi, Lajos; Doeringshoff, Klaus; Peters, Achim; Ertmer, Wolfgang; Rasel, Ernst M.; Gieseler, Jan; Novotny, Lukas; Rondin, Loic; Guerlebeck, Norman; Herrmann, Sven; Laemmerzahl, Claus; Hechenblaikner, Gerald; Hossenfelder, Sabine; Kim, Myungshik; Milburn, Gerard J.; Mueller, Holger; Paternostro, Mauro; Pikovski, Igor; Pilan Zanoni, Andre; Riedel, Charles Jess; Roura, Albert; Schleich, Wolfgang P.; Schmiedmayer, Joerg; Schuldt, Thilo; Schwab, Keith C.; Tajmar, Martin; Tino, Guglielmo M.; Ulbricht, Hendrik; Ursin, Rupert; Vedral, Vlatko
2016-01-01
Do the laws of quantum physics still hold for macroscopic objects - this is at the heart of Schroedinger's cat paradox - or do gravitation or yet unknown effects set a limit for massive particles? What is the fundamental relation between quantum physics and gravity? Ground-based experiments addressing these questions may soon face limitations due to limited free-fall times and the quality of vacuum and microgravity. The proposed mission Macroscopic Quantum Resonators (MAQRO) may overcome these limitations and allow addressing such fundamental questions. MAQRO harnesses recent developments in quantum optomechanics, high-mass matter-wave interferometry as well as state-of-the-art space technology to push macroscopic quantum experiments towards their ultimate performance limits and to open new horizons for applying quantum technology in space. The main scientific goal is to probe the vastly unexplored 'quantum-classical' transition for increasingly massive objects, testing the predictions of quantum theory for objects in a size and mass regime unachievable in ground-based experiments. The hardware will largely be based on available space technology. Here, we present the MAQRO proposal submitted in response to the 4th Cosmic Vision call for a medium-sized mission (M4) in 2014 of the European Space Agency (ESA) with a possible launch in 2025, and we review the progress with respect to the original MAQRO proposal for the 3rd Cosmic Vision call for a medium-sized mission (M3) in 2010. In particular, the updated proposal overcomes several critical issues of the original proposal by relying on established experimental techniques from high-mass matter-wave interferometry and by introducing novel ideas for particle loading and manipulation. Moreover, the mission design was improved to better fulfill the stringent environmental requirements for macroscopic quantum experiments. (orig.)
Macroscopic Quantum Resonators (MAQRO): 2015 update
Energy Technology Data Exchange (ETDEWEB)
Kaltenbaek, Rainer [University of Vienna, Vienna Center for Quantum Science and Technology, Vienna (Austria); Aspelmeyer, Markus; Kiesel, Nikolai [University of Vienna, Vienna Center for Quantum Science and Technology, Vienna (Austria); Barker, Peter F.; Bose, Sougato [University College London, Department of Physics and Astronomy, London (United Kingdom); Bassi, Angelo [University of Trieste, Department of Physics, Trieste (Italy); INFN - Trieste Section, Trieste (Italy); Bateman, James [University of Swansea, Department of Physics, College of Science, Swansea (United Kingdom); Bongs, Kai; Cruise, Adrian Michael [University of Birmingham, School of Physics and Astronomy, Birmingham (United Kingdom); Braxmaier, Claus [University of Bremen, Center of Applied Space Technology and Micro Gravity (ZARM), Bremen (Germany); Institute of Space Systems, German Aerospace Center (DLR), Bremen (Germany); Brukner, Caslav [University of Vienna, Vienna Center for Quantum Science and Technology, Vienna (Austria); Austrian Academy of Sciences, Institute of Quantum Optics and Quantum Information (IQOQI), Vienna (Austria); Christophe, Bruno; Rodrigues, Manuel [The French Aerospace Lab, ONERA, Chatillon (France); Chwalla, Michael; Johann, Ulrich [Airbus Defence and Space GmbH, Immenstaad (Germany); Cohadon, Pierre-Francois; Heidmann, Antoine; Lambrecht, Astrid; Reynaud, Serge [ENS-PSL Research University, Laboratoire Kastler Brossel, UPMC-Sorbonne Universites, CNRS, College de France, Paris (France); Curceanu, Catalina [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Dholakia, Kishan; Mazilu, Michael [University of St. Andrews, School of Physics and Astronomy, St. Andrews (United Kingdom); Diosi, Lajos [Wigner Research Center for Physics, P.O. Box 49, Budapest (Hungary); Doeringshoff, Klaus; Peters, Achim [Humboldt-Universitaet zu Berlin, Institut fuer Physik, Berlin (Germany); Ertmer, Wolfgang; Rasel, Ernst M. [Leibniz Universitaet Hannover, Institut fuer Quantenoptik, Hannover (Germany); Gieseler, Jan; Novotny, Lukas; Rondin, Loic [ETH Zuerich, Photonics Laboratory, Zuerich (Switzerland); Guerlebeck, Norman; Herrmann, Sven; Laemmerzahl, Claus [University of Bremen, Center of Applied Space Technology and Micro Gravity (ZARM), Bremen (Germany); Hechenblaikner, Gerald [Airbus Defence and Space GmbH, Immenstaad (Germany); European Southern Observatory (ESO), Garching bei Muenchen (Germany); Hossenfelder, Sabine [KTH Royal Institute of Technology and Stockholm University, Nordita, Stockholm (Sweden); Kim, Myungshik [Imperial College London, QOLS, Blackett Laboratory, London (United Kingdom); Milburn, Gerard J. [University of Queensland, ARC Centre for Engineered Quantum Systems, Brisbane (Australia); Mueller, Holger [University of California, Department of Physics, Berkeley, CA (United States); Paternostro, Mauro [Queen' s University, Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Belfast (United Kingdom); Pikovski, Igor [Harvard-Smithsonian Center for Astrophysics, ITAMP, Cambridge, MA (United States); Pilan Zanoni, Andre [Airbus Defence and Space GmbH, Immenstaad (Germany); CERN - European Organization for Nuclear Research, EN-STI-TCD, Geneva (Switzerland); Riedel, Charles Jess [Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada); Roura, Albert [Universitaet Ulm, Institut fuer Quantenphysik, Ulm (Germany); Schleich, Wolfgang P. [Universitaet Ulm, Institut fuer Quantenphysik, Ulm (Germany); Texas A and M University Institute for Advanced Study (TIAS), Institute for Quantum Science and Engineering (IQSE), and Department of Physics and Astronomy, College Station, TX (United States); Schmiedmayer, Joerg [Vienna University of Technology, Vienna Center for Quantum Science and Technology, Institute of Atomic and Subatomic Physics, Vienna (Austria); Schuldt, Thilo [Institute of Space Systems, German Aerospace Center (DLR), Bremen (Germany); Schwab, Keith C. [California Institute of Technology, Applied Physics, Pasadena, CA (United States); Tajmar, Martin [Technische Universitaet Dresden, Institut fuer Luft- und Raumfahrttechnik, Dresden (Germany); Tino, Guglielmo M. [Universita di Firenze, Dipartimento di Fisica e Astronomia and LENS, INFN, Sesto Fiorentino, Firenze (Italy); Ulbricht, Hendrik [University of Southampton, Physics and Astronomy, Southampton (United Kingdom); Ursin, Rupert [Austrian Academy of Sciences, Institute of Quantum Optics and Quantum Information (IQOQI), Vienna (Austria); Vedral, Vlatko [University of Oxford, Atomic and Laser Physics, Clarendon Laboratory, Oxford (United Kingdom); National University of Singapore, Center for Quantum Technologies, Singapore (SG)
2016-12-15
Do the laws of quantum physics still hold for macroscopic objects - this is at the heart of Schroedinger's cat paradox - or do gravitation or yet unknown effects set a limit for massive particles? What is the fundamental relation between quantum physics and gravity? Ground-based experiments addressing these questions may soon face limitations due to limited free-fall times and the quality of vacuum and microgravity. The proposed mission Macroscopic Quantum Resonators (MAQRO) may overcome these limitations and allow addressing such fundamental questions. MAQRO harnesses recent developments in quantum optomechanics, high-mass matter-wave interferometry as well as state-of-the-art space technology to push macroscopic quantum experiments towards their ultimate performance limits and to open new horizons for applying quantum technology in space. The main scientific goal is to probe the vastly unexplored 'quantum-classical' transition for increasingly massive objects, testing the predictions of quantum theory for objects in a size and mass regime unachievable in ground-based experiments. The hardware will largely be based on available space technology. Here, we present the MAQRO proposal submitted in response to the 4th Cosmic Vision call for a medium-sized mission (M4) in 2014 of the European Space Agency (ESA) with a possible launch in 2025, and we review the progress with respect to the original MAQRO proposal for the 3rd Cosmic Vision call for a medium-sized mission (M3) in 2010. In particular, the updated proposal overcomes several critical issues of the original proposal by relying on established experimental techniques from high-mass matter-wave interferometry and by introducing novel ideas for particle loading and manipulation. Moreover, the mission design was improved to better fulfill the stringent environmental requirements for macroscopic quantum experiments. (orig.)
Microscopic and macroscopic models for pedestrian crowds
Makmul, Juntima
2016-01-01
This thesis is concerned with microscopic and macroscopic models for pedes- trian crowds. In the first chapter, we consider pedestrians exit choices and model human behaviour in an evacuation process. Two microscopic models, discrete and continuous, are studied in this chapter. The former is a cellular automaton model and the latter is a social force model. Different numerical test cases are investigated and their results are compared. In chapter 2, a hierarchy of models for...
Macroscopic acoustoelectric charge transport in graphene
Bandhu, L.; Lawton, L. M.; Nash, G. R.
2013-09-01
We demonstrate macroscopic acoustoelectric transport in graphene, transferred onto piezoelectric lithium niobate substrates, between electrodes up to 500 μm apart. Using double finger interdigital transducers we have characterised the acoustoelectric current as a function of both surface acoustic wave intensity and frequency. The results are consistent with a relatively simple classical relaxation model, in which the acoustoelectric current is proportional to both the surface acoustic wave intensity and the attenuation of the wave caused by the charge transport.
Thermomechanical macroscopic model of shape memory alloys
International Nuclear Information System (INIS)
Volkov, A.E.; Sakharov, V.Yu.
2003-01-01
The phenomenological macroscopic model of the mechanical behaviour of the titanium nickelide-type shape memory alloys is proposed. The model contains as a parameter the average phase shear deformation accompanying the martensite formation. It makes i possible to describe correctly a number of functional properties of the shape memory alloys, in particular, the pseudoelasticity ferroplasticity, plasticity transformation and shape memory effects in the stressed and unstressed samples [ru
Macroscopic behaviour of a charged Boltzmann gas
International Nuclear Information System (INIS)
Banyai, L.; Gartner, P.; Protopopescu, V.
1980-08-01
We consider a classical charged gas (with self-consistent Coulomb interaction) described by a solvable linearized Boltzman equation with thermaljzation on unifopmly distributed scatterers. It is shown that jf one scales the time t, the reciprocal space coordinate k vector and the Debye length l as lambda 2 t, k vector/lambda, lambda l respectively, in the lambda→infinity limit the charge density is equal to the solution of the corresponding diffusion-conduction (macroscopic) equation. (author)
Active Polar Two-Fluid Macroscopic Dynamics
Pleiner, Harald; Svensek, Daniel; Brand, Helmut R.
2014-03-01
We study the dynamics of systems with a polar dynamic preferred direction. Examples include the pattern-forming growth of bacteria (in a solvent, shoals of fish (moving in water currents), flocks of birds and migrating insects (flying in windy air). Because the preferred direction only exists dynamically, but not statically, the macroscopic variable of choice is the macroscopic velocity associated with the motion of the active units. We derive the macroscopic equations for such a system and discuss novel static, reversible and irreversible cross-couplings connected to this second velocity. We find a normal mode structure quite different compared to the static descriptions, as well as linear couplings between (active) flow and e.g. densities and concentrations due to the genuine two-fluid transport derivatives. On the other hand, we get, quite similar to the static case, a direct linear relation between the stress tensor and the structure tensor. This prominent ``active'' term is responsible for many active effects, meaning that our approach can describe those effects as well. In addition, we also deal with explicitly chiral systems, which are important for many active systems. In particular, we find an active flow-induced heat current specific for the dynamic chiral polar order.
Experimental demonstration of macroscopic quantum coherence in Gaussian states
DEFF Research Database (Denmark)
Marquardt, C.; Andersen, Ulrik Lund; Leuchs, G.
2007-01-01
We witness experimentally the presence of macroscopic coherence in Gaussian quantum states using a recently proposed criterion [E. G. Cavalcanti and M. D. Reid, Phys. Rev. Lett. 97 170405 (2006)]. The macroscopic coherence stems from interference between macroscopically distinct states in phase...
The macroscopic harmonic oscillator and quantum measurements
International Nuclear Information System (INIS)
Hayward, R.W.
1982-01-01
A quantum mechanical description of a one-dimensional macroscopic harmonic oscillator interacting with its environment is given. Quasi-coherent states are introduced to serve as convenient basis states for application of a density matrix formalism to characterize the system. Attention is given to the pertinent quantum limits to the precision of measurement of physical observables that may provide some information on the nature of a weak classical force interacting with the oscillator. A number of ''quantum nondemolition'' schemes proposed by various authors are discussed. (Auth.)
Compressor Has No Moving Macroscopic Parts
Gasser, Max
1995-01-01
Compressor containing no moving macroscopic parts functions by alternating piston and valve actions of successive beds of magnetic particles. Fabricated easily because no need for precisely fitting parts rotating or sliding on each other. Also no need for lubricant fluid contaminating fluid to be compressed. Compressor operates continuously, eliminating troublesome on/off cycling of other compressors, and decreasing consumption of energy. Phased cells push fluid from bottom to top, adding increments of pressure. Each cell contains magnetic powder particles loose when electromagnet coil deenergized, but tightly packed when coil energized.
Micro- and macroscopic photonic control of matter
Ryabtsev, Anton
parameters. In order for measurements not to be skewed, these interactions need to be taken into account and mitigated at the time of the experiment or handled later in data analysis and simulations. Experimental results are presented in four chapters. Chapter 2 describes two topics: (1) single-shot real-time monitoring and correction of spectral phase drifts, which commonly originate from temperature and pointing fluctuations inside the laser cavity when the pulses are generated; (2) an all-optical method for controlling the dispersion of femtosecond pulses using other pulses. Chapter 3 focuses on the effects of the propagation media--how intense laser pulses modify media and how, in turn, the media modifies them back--and how these effects can be counteracted. Self-action effects in fused silica are discussed, along with some interesting and unexpected results. A method is then proposed for mitigating self-action processes using binary modulation of the spectral phases of laser pulses. Chapter 4 outlines the design of two laser systems, which are specifically tailored for particular spectroscopic applications and incorporate the comprehensive pulse control described in previous chapters. Chapter 5 shows how control of spatial beam characteristics can be applied to measurements of the mechanical motion of microscale particles and how it can potentially be applied to molecular motion. It also describes an experiment on laser-induced flow in air in which attempts were made to control the macroscopic molecular rotation of gases. My research, with a pulse shaper as the enabling tool, provides important insights into ultrafast scientific studies by making femtosecond laser research more predictable, reliable and practical for measurement and control. In the long term, some of the research methods in this thesis may help the transition of femtosecond lasers from the laboratory environment into clinics, factories, airports, and other everyday settings.
Macroscopic reality and the dynamical reduction program
International Nuclear Information System (INIS)
Ghirardi, G.C.
1995-10-01
With reference to recently proposed theoretical models accounting for reduction in terms of a unified dynamics governing all physical processes, we analyze the problem of working out a worldview accommodating our knowledge about natural phenomena. We stress the relevant conceptual differences between the considered models and standard quantum mechanics. In spite of the fact that both theories describe individual physical systems within a genuine Hilbert space framework, the nice features of spontaneous reduction theories drastically limit the class of states which are dynamically stable. This allows one to work out a description of the world in terms of a mass density function in ordinary configuration space. A topology based on this function and differing radically from the one characterizing the Hilbert space is introduced and in terms of it the idea of similarity of macroscopic situations is made precise. Finally it is shown how the formalism and the proposed interpretation yield a natural criterion for establishing the psychophysical parallelism. The conclusion is that, within the considered theoretical models and at the nonrelativistic level, one can satisfy all sensible requirements for a consistent, unified, and objective description of reality at the macroscopic level. (author). 16 refs
Macroscopic description of isoscalar giant multipole resonances
International Nuclear Information System (INIS)
Nix, J.R.; Sierk, A.J.
1980-01-01
On the basis of a simple macroscopic model, we calculate the isoscalar giant-resonance energy as a function of mass number and multipole degree. The restoring force is determined from the distortion of the Fermi surface, and the inertia is determined for the incompressible, irrotational flow of nucleons with unit effective mass. With no adjustable parameters, the resulting closed expression reproduces correctly the available experimental data, namely the magnitude and dependence upon mass number of the giant quadrupole energy and the magnitude of the giant octupole energy for 208 Pb. We also calculate the isoscalar giant-resonance width as a function of mass number and multipole degree for various macroscopic damping mechanisms, including two-body viscosity, one-body dissipation, and modified one-body dissipation. None of these damping mechanisms reproduces correctly all features of the available experimental data, namely the magnitude and dependence upon mass number of the giant quadrupole width and the magnitude of the giant octupole width for 208 Pb
Macroscopic quantum tunneling in Mn12-acetat
International Nuclear Information System (INIS)
Beiter, J.; Reissner, M.; Hilscher, G.; Steiner, W.; Pajic, D.; Zadro, K.; Bartel, M.; Linert, W.
2004-01-01
Molecules provide the exciting opportunity to study magnetism on the passage from atomic to macroscopic level. One of the most interesting effects in such mesoscopic systems is the appearance of quantum tunnelling of magnetization (MQT) at low temperatures. In the last decade molecular chemistry has had a large impact in this field by providing new single molecule magnets. They consist of small clusters exhibiting superparamagnetic behavior, similar to that of conventional nanomagnetic particles. The advantage of these new materials is that they form macroscopic samples consisting of regularly arranged small identical high-spin clusters which are widely separated by organic molecules. The lack of distributions in size and shape of the magnetic clusters and the very weak intercluster interaction lead in principle to only one barrier for the spin reversal. We present detailed magnetic investigations on a Mn 12 -ac single crystal. In this compound the tetragonal ordered clusters consist of a central tetrahedron of four Mn 4+ (S = 3/2) atoms surrounded by eight Mn 3+ (S = 2) atoms with antiparallel oriented spins, leading to an overall spin moment of S = 10. In the hysteresis loops nine different jumps at regularly spaced fields are identified in the investigated temperature range (1.5 < T < 3 K). At these fields the relaxation of moment due to thermal activation is superimposed by strong quantum tunnelling. In lowering the temperature the time dependence changes from thermally activated to thermally assisted tunnelling. (author)
Macroscopic effects of the quantum trace anomaly
International Nuclear Information System (INIS)
Mottola, Emil; Vaulin, Ruslan
2006-01-01
The low energy effective action of gravity in any even dimension generally acquires nonlocal terms associated with the trace anomaly, generated by the quantum fluctuations of massless fields. The local auxiliary field description of this effective action in four dimensions requires two additional scalar fields, not contained in classical general relativity, which remain relevant at macroscopic distance scales. The auxiliary scalar fields depend upon boundary conditions for their complete specification, and therefore carry global information about the geometry and macroscopic quantum state of the gravitational field. The scalar potentials also provide coordinate invariant order parameters describing the conformal behavior and divergences of the stress tensor on event horizons. We compute the stress tensor due to the anomaly in terms of its auxiliary scalar potentials in a number of concrete examples, including the Rindler wedge, the Schwarzschild geometry, and de Sitter spacetime. In all of these cases, a small number of classical order parameters completely determine the divergent behaviors allowed on the horizon, and yield qualitatively correct global approximations to the renormalized expectation value of the quantum stress tensor
Measurement contextuality is implied by macroscopic realism
International Nuclear Information System (INIS)
Chen Zeqian; Montina, A.
2011-01-01
Ontological theories of quantum mechanics provide a realistic description of single systems by means of well-defined quantities conditioning the measurement outcomes. In order to be complete, they should also fulfill the minimal condition of macroscopic realism. Under the assumption of outcome determinism and for Hilbert space dimension greater than 2, they were all proved to be contextual for projective measurements. In recent years a generalized concept of noncontextuality was introduced that applies also to the case of outcome indeterminism and unsharp measurements. It was pointed out that the Beltrametti-Bugajski model is an example of measurement noncontextual indeterminist theory. Here we provide a simple proof that this model is the only one with such a feature for projective measurements and Hilbert space dimension greater than 2. In other words, there is no extension of quantum theory providing more accurate predictions of outcomes and simultaneously preserving the minimal labeling of events through projective operators. As a corollary, noncontextuality for projective measurements implies noncontextuality for unsharp measurements. By noting that the condition of macroscopic realism requires an extension of quantum theory, unless a breaking of unitarity is invoked, we arrive at the conclusion that the only way to solve the measurement problem in the framework of an ontological theory is by relaxing the hypothesis of measurement noncontextuality in its generalized sense.
Macroscopic reality and the dynamical reduction program
Energy Technology Data Exchange (ETDEWEB)
Ghirardi, G C
1995-10-01
With reference to recently proposed theoretical models accounting for reduction in terms of a unified dynamics governing all physical processes, we analyze the problem of working out a worldview accommodating our knowledge about natural phenomena. We stress the relevant conceptual differences between the considered models and standard quantum mechanics. In spite of the fact that both theories describe individual physical systems within a genuine Hilbert space framework, the nice features of spontaneous reduction theories drastically limit the class of states which are dynamically stable. This allows one to work out a description of the world in terms of a mass density function in ordinary configuration space. A topology based on this function and differing radically from the one characterizing the Hilbert space is introduced and in terms of it the idea of similarity of macroscopic situations is made precise. Finally it is shown how the formalism and the proposed interpretation yield a natural criterion for establishing the psychophysical parallelism. The conclusion is that, within the considered theoretical models and at the nonrelativistic level, one can satisfy all sensible requirements for a consistent, unified, and objective description of reality at the macroscopic level. (author). 16 refs.
Macroscopic Theory for Evolving Biological Systems Akin to Thermodynamics.
Kaneko, Kunihiko; Furusawa, Chikara
2018-05-20
We present a macroscopic theory to characterize the plasticity, robustness, and evolvability of biological responses and their fluctuations. First, linear approximation in intracellular reaction dynamics is used to demonstrate proportional changes in the expression of all cellular components in response to a given environmental stress, with the proportion coefficient determined by the change in growth rate as a consequence of the steady growth of cells. We further demonstrate that this relationship is supported through adaptation experiments of bacteria, perhaps too well as this proportionality is held even across cultures of different types of conditions. On the basis of simulations of cell models, we further show that this global proportionality is a consequence of evolution in which expression changes in response to environmental or genetic perturbations are constrained along a unique one-dimensional curve, which is a result of evolutionary robustness. It then follows that the expression changes induced by environmental changes are proportionally reduced across different components of a cell by evolution, which is akin to the Le Chatelier thermodynamics principle. Finally, with the aid of a fluctuation-response relationship, this proportionality is shown to hold between fluctuations caused by genetic changes and those caused by noise. Overall, these results and support from the theoretical and experimental literature suggest a formulation of cellular systems akin to thermodynamics, in which a macroscopic potential is given by the growth rate (or fitness) represented as a function of environmental and evolutionary changes.
Parametric equations for calculation of macroscopic cross sections
International Nuclear Information System (INIS)
Botelho, Mario Hugo; Carvalho, Fernando
2015-01-01
Neutronic calculations of the core of a nuclear reactor is one thing necessary and important for the design and management of a nuclear reactor in order to prevent accidents and control the reactor efficiently as possible. To perform these calculations a library of nuclear data, including cross sections is required. Currently, to obtain a cross section computer codes are used, which require a large amount of processing time and computer memory. This paper proposes the calculation of macroscopic cross section through the development of parametric equations. The paper illustrates the proposal for the case of macroscopic cross sections of absorption (Σa), which was chosen due to its greater complexity among other cross sections. Parametric equations created enable, quick and dynamic way, the determination of absorption cross sections, enabling the use of them in calculations of reactors. The results show efficient when compared with the absorption cross sections obtained by the ALPHA 8.8.1 code. The differences between the cross sections are less than 2% for group 2 and less than 0.60% for group 1. (author)
Parameterized representation of macroscopic cross section for PWR reactor
International Nuclear Information System (INIS)
Fiel, João Cláudio Batista; Carvalho da Silva, Fernando; Senra Martinez, Aquilino; Leal, Luiz C.
2015-01-01
Highlights: • This work describes a parameterized representation of the homogenized macroscopic cross section for PWR reactor. • Parameterization enables a quick determination of problem-dependent cross-sections to be used in few group calculations. • This work allows generating group cross-section data to perform PWR core calculations without computer code calculations. - Abstract: The purpose of this work is to describe, by means of Chebyshev polynomials, a parameterized representation of the homogenized macroscopic cross section for PWR fuel element as a function of soluble boron concentration, moderator temperature, fuel temperature, moderator density and 235 92 U enrichment. The cross-section data analyzed are fission, scattering, total, transport, absorption and capture. The parameterization enables a quick and easy determination of problem-dependent cross-sections to be used in few group calculations. The methodology presented in this paper will allow generation of group cross-section data from stored polynomials to perform PWR core calculations without the need to generate them based on computer code calculations using standard steps. The results obtained by the proposed methodology when compared with results from the SCALE code calculations show very good agreement
Reversible optical control of macroscopic polarization in ferroelectrics
Rubio-Marcos, Fernando; Ochoa, Diego A.; Del Campo, Adolfo; García, Miguel A.; Castro, Germán R.; Fernández, José F.; García, José E.
2018-01-01
The optical control of ferroic properties is a subject of fascination for the scientific community, because it involves the establishment of new paradigms for technology1-9. Domains and domain walls are known to have a great impact on the properties of ferroic materials1-24. Progress is currently being made in understanding the behaviour of the ferroelectric domain wall, especially regarding its dynamic control10-12,17,19. New research is being conducted to find effective methodologies capable of modulating ferroelectric domain motion for future electronics. However, the practical use of ferroelectric domain wall motion should be both stable and reversible (rewritable) and, in particular, be able to produce a macroscopic response that can be monitored easily12,17. Here, we show that it is possible to achieve a reversible optical change of ferroelectric domains configuration. This effect leads to the tuning of macroscopic polarization and its related properties by means of polarized light, a non-contact external control. Although this is only the first step, it nevertheless constitutes the most crucial one in the long and complex process of developing the next generation of photo-stimulated ferroelectric devices.
Catalytic Growth of Macroscopic Carbon Nanofibers Bodies with Activated Carbon
Abdullah, N.; Rinaldi, A.; Muhammad, I. S.; Hamid, S. B. Abd.; Su, D. S.; Schlogl, R.
2009-06-01
Carbon-carbon composite of activated carbon and carbon nanofibers have been synthesized by growing Carbon nanofiber (CNF) on Palm shell-based Activated carbon (AC) with Ni catalyst. The composites are in an agglomerated shape due to the entanglement of the defective CNF between the AC particles forming a macroscopic body. The macroscopic size will allow the composite to be used as a stabile catalyst support and liquid adsorbent. The preparation of CNT/AC nanocarbon was initiated by pre-treating the activated carbon with nitric acid, followed by impregnation of 1 wt% loading of nickel (II) nitrate solutions in acetone. The catalyst precursor was calcined and reduced at 300° C for an hour in each step. The catalytic growth of nanocarbon in C2H4/H2 was carried out at temperature of 550° C for 2 hrs with different rotating angle in the fluidization system. SEM and N2 isotherms show the level of agglomeration which is a function of growth density and fluidization of the system. The effect of fluidization by rotating the reactor during growth with different speed give a significant impact on the agglomeration of the final CNF/AC composite and thus the amount of CNFs produced. The macrostructure body produced in this work of CNF/AC composite will have advantages in the adsorbent and catalyst support application, due to the mechanical and chemical properties of the material.
Partitioning a macroscopic system into independent subsystems
Delle Site, Luigi; Ciccotti, Giovanni; Hartmann, Carsten
2017-08-01
We discuss the problem of partitioning a macroscopic system into a collection of independent subsystems. The partitioning of a system into replica-like subsystems is nowadays a subject of major interest in several fields of theoretical and applied physics. The thermodynamic approach currently favoured by practitioners is based on a phenomenological definition of an interface energy associated with the partition, due to a lack of easily computable expressions for a microscopic (i.e. particle-based) interface energy. In this article, we outline a general approach to derive sharp and computable bounds for the interface free energy in terms of microscopic statistical quantities. We discuss potential applications in nanothermodynamics and outline possible future directions.
Quantum teleportation between stationary macroscopic objects
Energy Technology Data Exchange (ETDEWEB)
Bao, Xiao-Hui; Yuan, Zhen-Sheng; Pan, Jian-Wei [Physikalisches Institut, Universitaet Heidelberg (Germany); Hefei National Laboratory for Physical Sciences at Microscale, Department of Modern Physics, University of Science and Technology of China, Hefei (China); Xu, Xiao-Fan [Physikalisches Institut, Universitaet Heidelberg (Germany); Li, Che-Ming [Physikalisches Institut, Universitaet Heidelberg (Germany); Department of Physics, National Center for Theoretical Sciences, National Cheng Kung University, Tainan (China)
2010-07-01
Quantum teleportation is a process to transfer a quantum state of an object without transferring the state carrier itself. So far, most of the teleportation experiments realized are within the photonic regime. For the teleportation of stationary states, the largest system reported is a single ion. We are now performing an experiment to teleport the state of an macroscopic atomic cloud which consists about 10{sup 6} single atoms. In our experiment two atomic ensembles are utilized. In the first ensemble A we prepare the collective atomic state to be teleported using the quantum feedback technique. The second ensemble B is utilized to generate entanglement between it collective state with a scattered single-photon. Teleportation is realized by converting the atomic state of A to a single-photon and making a Bell state measurement with the scattered single-photon from ensemble B.
Macroscopic balance model for wave rotors
Welch, Gerard E.
1996-01-01
A mathematical model for multi-port wave rotors is described. The wave processes that effect energy exchange within the rotor passage are modeled using one-dimensional gas dynamics. Macroscopic mass and energy balances relate volume-averaged thermodynamic properties in the rotor passage control volume to the mass, momentum, and energy fluxes at the ports. Loss models account for entropy production in boundary layers and in separating flows caused by blade-blockage, incidence, and gradual opening and closing of rotor passages. The mathematical model provides a basis for predicting design-point wave rotor performance, port timing, and machine size. Model predictions are evaluated through comparisons with CFD calculations and three-port wave rotor experimental data. A four-port wave rotor design example is provided to demonstrate model applicability. The modeling approach is amenable to wave rotor optimization studies and rapid assessment of the trade-offs associated with integrating wave rotors into gas turbine engine systems.
Macroscopic quantum tunneling in a dc SQUID
International Nuclear Information System (INIS)
Chen, Y.C.
1986-01-01
The theory of macroscopic quantum tunneling is applied to a current-biased dc SQUID whose dynamics can be described by a two-dimensional mechanical system with a dissipative environment. Based on the phenomenological model proposed by Caldeira and Leggett, the dissipative environment is represented by a set of harmonic oscillators coupling to the system. After integrating out the environmental degrees of freedom, an effective Euclidean action is found for the two-dimensional system. The action is used to provide the quantum tunneling rate formalism for the dc SQUID. Under certain conditions, the tunneling rate reduces to that of a single current-biased Josephson junction with an adjustable effective critical current
Macroscopic Floquet topological crystalline steel and superconductor pump
Rossi, Anna M. E. B.; Bugase, Jonas; Fischer, Thomas M.
2017-08-01
The transport of a macroscopic steel sphere and a superconducting sphere on top of two-dimensional periodic magnetic patterns is studied experimentally and compared with the theory and with experiments on topological transport of magnetic colloids. Transport of the steel and superconducting sphere is achieved by moving an external permanent magnet on a closed loop around the two-dimensional crystal. The transport is topological, i.e., the spheres are transported by a primitive unit vector of the lattice when the external magnet loop winds around specific directions. We experimentally determine the set of directions the loops must enclose for nontrivial transport of the spheres into various directions. We show that the loops can be used to sort steel and superconducting spheres. We show that the topological transport is robust with respect to the scale of the system and therefore speculate on its down scalability to the molecular scale.
Fault detection by surface seismic scanning tunneling macroscope: Field test
Hanafy, Sherif M.
2014-08-05
The seismic scanning tunneling macroscope (SSTM) is proposed for detecting the presence of near-surface impedance anomalies and faults. Results with synthetic data are consistent with theory in that scatterers closer to the surface provide brighter SSTM profiles than those that are deeper. The SSTM profiles show superresolution detection if the scatterers are in the near-field region of the recording line. The field data tests near Gulf of Aqaba, Haql, KSA clearly show the presence of the observable fault scarp, and identify the subsurface presence of the hidden faults indicated in the tomograms. Superresolution detection of the fault is achieved, even when the 35 Hz data are lowpass filtered to the 5-10 Hz band.
Fault detection by surface seismic scanning tunneling macroscope: Field test
Hanafy, Sherif M.; Schuster, Gerard T.
2014-01-01
The seismic scanning tunneling macroscope (SSTM) is proposed for detecting the presence of near-surface impedance anomalies and faults. Results with synthetic data are consistent with theory in that scatterers closer to the surface provide brighter SSTM profiles than those that are deeper. The SSTM profiles show superresolution detection if the scatterers are in the near-field region of the recording line. The field data tests near Gulf of Aqaba, Haql, KSA clearly show the presence of the observable fault scarp, and identify the subsurface presence of the hidden faults indicated in the tomograms. Superresolution detection of the fault is achieved, even when the 35 Hz data are lowpass filtered to the 5-10 Hz band.
Models for universal reduction of macroscopic quantum fluctuations
International Nuclear Information System (INIS)
Diosi, L.
1988-10-01
If quantum mechanics is universal, then macroscopic bodies would, in principle, possess macroscopic quantum fluctuations (MQF) in their positions, orientations, densities etc. Such MQF, however, are not observed in nature. The hypothesis is adopted that the absence of MQF is due to a certain universal mechanism. Gravitational measures were applied for reducing MQF of the mass density. This model leads to classical trajectories in the macroscopic limit of translational motion. For massive objects, unwanted macroscopic superpositions of quantum states will be destroyed within short times. (R.P.) 34 refs
Rakociński, Michał; Racki, Grzegorz
2016-01-01
Microbial carbonates, consisting of abundant girvanellid oncoids, are described from cephalopod-crinoid and crinoid-brachiopod coquinas (rudstones) occurring in the lowermost Famennian of the Holy Cross Mountains, Poland. A Girvanella-bearing horizon (consist with numerous girvanellid oncoids) has been recognised at the Psie Górki section, and represents the northern slope succession of the drowned Dyminy Reef. This occurrence of microbialites in the aftermath of the Frasnian-Famennian event is interpreted as the result of opportunistic cyanobacteria blooms, which, as 'disaster forms', colonised empty shallow-water ecological niches during the survival phase following the Frasnian metazoan reef collapse, due to collapsed activity of epifaunal, grazing, and/or burrowing animals. The anachronistic lithofacies at Psie Górki is linked with catastrophic mass mortality of the cephalopod and crinoid-brachiopod communities during the heavy storm events. This mass occurrence of girvanellid oncoids, along with Frutexites-like microbial shrubs and, at least partly, common micritisation of some skeletal grains, records an overall increase in microbial activity in eutrophic normal marine environments. Microbial communities in the Holy Cross Mountains are not very diverse, being mainly represented by girvanellid oncoids, and stand in contrast to the very rich microbial communities known from the Guilin area (China), Canning Basin (Australia) and the Timan-northern Ural area (Russia). The association from Poland is similar to more diverse microbial communities represented by oncoids, trombolites and stromatolites, well known from the Canadian Alberta basin.
Distinct molecular features of different macroscopic subtypes of colorectal neoplasms.
Directory of Open Access Journals (Sweden)
Kenichi Konda
Full Text Available Colorectal adenoma develops into cancer with the accumulation of genetic and epigenetic changes. We studied the underlying molecular and clinicopathological features to better understand the heterogeneity of colorectal neoplasms (CRNs.We evaluated both genetic (mutations of KRAS, BRAF, TP53, and PIK3CA, and microsatellite instability [MSI] and epigenetic (methylation status of nine genes or sequences, including the CpG island methylator phenotype [CIMP] markers alterations in 158 CRNs including 56 polypoid neoplasms (PNs, 25 granular type laterally spreading tumors (LST-Gs, 48 non-granular type LSTs (LST-NGs, 19 depressed neoplasms (DNs and 10 small flat-elevated neoplasms (S-FNs on the basis of macroscopic appearance.S-FNs showed few molecular changes except SFRP1 methylation. Significant differences in the frequency of KRAS mutations were observed among subtypes (68% for LST-Gs, 36% for PNs, 16% for DNs and 6% for LST-NGs (P<0.001. By contrast, the frequency of TP53 mutation was higher in DNs than PNs or LST-Gs (32% vs. 5% or 0%, respectively (P<0.007. We also observed significant differences in the frequency of CIMP between LST-Gs and LST-NGs or PNs (32% vs. 6% or 5%, respectively (P<0.005. Moreover, the methylation level of LINE-1 was significantly lower in DNs or LST-Gs than in PNs (58.3% or 60.5% vs. 63.2%, P<0.05. PIK3CA mutations were detected only in LSTs. Finally, multivariate analyses showed that macroscopic morphologies were significantly associated with an increased risk of molecular changes (PN or LST-G for KRAS mutation, odds ratio [OR] 9.11; LST-NG or DN for TP53 mutation, OR 5.30; LST-G for PIK3CA mutation, OR 26.53; LST-G or DN for LINE-1 hypomethylation, OR 3.41.We demonstrated that CRNs could be classified into five macroscopic subtypes according to clinicopathological and molecular differences, suggesting that different mechanisms are involved in the pathogenesis of colorectal tumorigenesis.
Diagnosis of bladder tumours in patients with macroscopic haematuria
DEFF Research Database (Denmark)
Gandrup, Karen L; Løgager, Vibeke B; Bretlau, Thomas
2015-01-01
patients underwent CTU, MRU and flexible cystoscopy. Two uroradiologists individually reviewed the images without any clinical information, using a questionnaire. Patient records and pathology reports were also reviewed. RESULTS: At flexible cystoscopy, MRU and CTU, 32, 19 and 15 bladder lesions were...... identified, respectively. Histopathology showed that 13 of the 29 biopsied lesions were transitional cell carcinomas. Compared with the histopathology, the sensitivity and specificity for detection of tumours by CTU and MRU were 61.5% and 94.9%, and 79.9% and 93.4%, respectively. False-positive detection...... of bladder tumours, compared with histopathology, was reported in seven CTUs and nine MRUs, whereas the number of false-negative findings was five for CTUs and three for MRUs. CONCLUSIONS: Split-bolus CTU or MRU cannot replace cystoscopy in cases of macroscopic haematuria. MRU has a higher sensitivity than...
Polynomial parameterized representation of macroscopic cross section for PWR reactor
International Nuclear Information System (INIS)
Fiel, Joao Claudio B.
2015-01-01
The purpose of this work is to describe, by means of Tchebychev polynomial, a parameterized representation of the homogenized macroscopic cross section for PWR fuel element as a function of soluble boron concentration, moderator temperature, fuel temperature, moderator density and 235 U 92 enrichment. Analyzed cross sections are: fission, scattering, total, transport, absorption and capture. This parameterization enables a quick and easy determination of the problem-dependent cross-sections to be used in few groups calculations. The methodology presented here will enable to provide cross-sections values to perform PWR core calculations without the need to generate them based on computer code calculations using standard steps. The results obtained by parameterized cross-sections functions, when compared with the cross-section generated by SCALE code calculations, or when compared with K inf , generated by MCNPX code calculations, show a difference of less than 0.7 percent. (author)
The N-salicylidene aniline mesogen: Microscopic and macroscopic properties
International Nuclear Information System (INIS)
Nesrullazade, A.
2004-01-01
The vast majority of compounds exhibiting Iiquid crystalline phases may be regarded as having a rigid molecular central group with one or two flexible terminal alkyl or alkyloxy chains. The N-saIicyIidene anilines are very interesting and important materials both from fundamental and application points of view. These materials are on the one hand the ligands used to obtain metal containing complexes and on the other hand they are materials having the thermotropic mesomorphism. In this work we present investigations of microscopic and macroscopic properties of the 4-(Octyloxy)-N-(4-hexylphenyl)-2-hydrobenzaIimine (8SA) compound which was synthesized by our group. The 8SA compound shows the smectic C and nematic mesophases. These mesophases are enantiotropic and display specific confocal and schlieren textures, respectively. Thermotropic and thermodynamical properties of the straight and reverse phase transitions between smectic C and nematic mesophases and between nematic mesophase and isotropic liquid have been investigated
Non-Poissonian photon statistics from macroscopic photon cutting materials.
de Jong, Mathijs; Meijerink, Andries; Rabouw, Freddy T
2017-05-24
In optical materials energy is usually extracted only from the lowest excited state, resulting in fundamental energy-efficiency limits such as the Shockley-Queisser limit for single-junction solar cells. Photon-cutting materials provide a way around such limits by absorbing high-energy photons and 'cutting' them into multiple low-energy excitations that can subsequently be extracted. The occurrence of photon cutting or quantum cutting has been demonstrated in a variety of materials, including semiconductor quantum dots, lanthanides and organic dyes. Here we show that photon cutting results in bunched photon emission on the timescale of the excited-state lifetime, even when observing a macroscopic number of optical centres. Our theoretical derivation matches well with experimental data on NaLaF 4 :Pr 3+ , a material that can cut deep-ultraviolet photons into two visible photons. This signature of photon cutting can be used to identify and characterize new photon-cutting materials unambiguously.
Searching for the nanoscopic–macroscopic boundary
Energy Technology Data Exchange (ETDEWEB)
Velásquez, E.A. [GICM and GES Groups, Instituto de Física-FCEN, Universidad de Antioquia UdeA, Calle 70 No. 52-21 Medellín (Colombia); Grupo de Investigación en Modelamiento y Simulación Computacional, Universidad de San Buenaventura Sec. Medellín, A.A. 5222, Medellín (Colombia); Altbir, D. [Departamento de Física, Universidad de Santiago de Chile (USACH), CEDENNA, Santiago (Chile); Mazo-Zuluaga, J. [GICM and GES Groups, Instituto de Física-FCEN, Universidad de Antioquia UdeA, Calle 70 No. 52-21 Medellín (Colombia); Duque, L.F. [GICM and GES Groups, Instituto de Física-FCEN, Universidad de Antioquia UdeA, Calle 70 No. 52-21 Medellín (Colombia); Grupo de Física Teórica, Aplicada y Didáctica, Facultad de Ciencias Exactas y Aplicadas Instituto Tecnológico Metropolitano, Medellín (Colombia); Mejía-López, J., E-mail: jmejia@puc.cl [Facultad de Física, Pontificia Universidad Católica de Chile, CEDENNA, Santiago (Chile)
2013-12-15
Several studies have focused on the size-dependent properties of elements, looking for a unique definition of the nanoscopic–macroscopic boundary. By using a novel approach consisting of an energy variational method combined with a quantum Heisenberg model, here we address the size at which the ordering temperature of a magnetic nanoparticle reaches its bulk value. We consider samples with sizes in the range 1–500 nm, as well as several geometries and crystalline lattices and observe that, contrarily to what is commonly argued, the nanoscopic-microscopic boundary depends on both factors: shape and crystalline structure. This suggests that the surface-to-volume ratio is not the unique parameter that defines the behavior of a nanometric sample whenever its size increases reaching the bulk dimension. Comparisons reveal very good agreement with experimental evidence with differences less than 2%. Our results have broad implications for practical issues in measurements on systems at the nanometric scale. - Highlights: • A novel quantum-Heisenberg variational energy method is implemented. • The asymptotic behavior toward the thermodynamic limit is explored. • An important dependence of the nano-bulk boundary on the geometry is found. • And also an important dependence on the crystalline lattice. • We obtain a very good agreement with experimental evidence with differences <2%.
Adiabatic process reversibility: microscopic and macroscopic views
International Nuclear Information System (INIS)
Anacleto, Joaquim; Pereira, Mario G
2009-01-01
The reversibility of adiabatic processes was recently addressed by two publications. In the first (Miranda 2008 Eur. J. Phys. 29 937-43), an equation was derived relating the initial and final volumes and temperatures for adiabatic expansions of an ideal gas, using a microscopic approach. In that relation the parameter r accounts for the process reversibility, ranging between 0 and 1, which corresponds to the free and reversible expansion, respectively. In the second (Anacleto and Pereira 2009 Eur. J. Phys. 30 177-83), the authors have shown that thermodynamics can effectively and efficiently be used to obtain the general law for adiabatic processes carried out by an ideal gas, including compressions, for which r≥1. The present work integrates and extends the aforementioned studies, providing thus further insights into the analysis of the adiabatic process. It is shown that Miranda's work is wholly valid for compressions. In addition, it is demonstrated that the adiabatic reversibility coefficient given in terms of the piston velocity and the root mean square velocity of the gas particles is equivalent to the macroscopic description, given just by the quotient between surroundings and system pressure values. (letters and comments)
Theory of superfluidity macroscopic quantum waves
International Nuclear Information System (INIS)
Ventura, I.
1978-10-01
A new description of superfluidity is proposed, based upon the fact that Bogoliubov's theory of superfluidity exhibits some so far unsuspected macroscopic quantum waves (MQWs), which have a topological nature and travel within the fluid at subsonic velocities. To quantize the bounded quasi-particles the field theoretic version of the Bohr-Sommerfeld quantization rule, is employed and also resort to a variational computation. In an instantaneous configuration the MQWs cut the condensate into blocks of phase, providing, by analogy with ferromagnetism, a nice explanation of what could be the lambda-transition. A crude estimate of the critical temperature gives T sub(c) approximately equal to 2-4K. An attempt is made to understand Tisza's two-fluid model in terms of the MQWs, and we rise the conjecture that they play an important role in the motion of second. We present also a qualitative prediction concerning to the behavior of the 'phononroton' peak below 1.0K, and propose two experiments to look for MQWs [pt
The Proell Effect: A Macroscopic Maxwell's Demon
Rauen, Kenneth M.
2011-12-01
Maxwell's Demon is a legitimate challenge to the Second Law of Thermodynamics when the "demon" is executed via the Proell effect. Thermal energy transfer according to the Kinetic Theory of Heat and Statistical Mechanics that takes place over distances greater than the mean free path of a gas circumvents the microscopic randomness that leads to macroscopic irreversibility. No information is required to sort the particles as no sorting occurs; the entire volume of gas undergoes the same transition. The Proell effect achieves quasi-spontaneous thermal separation without sorting by the perturbation of a heterogeneous constant volume system with displacement and regeneration. The classical analysis of the constant volume process, such as found in the Stirling Cycle, is incomplete and therefore incorrect. There are extra energy flows that classical thermo does not recognize. When a working fluid is displaced across a regenerator with a temperature gradient in a constant volume system, complimentary compression and expansion work takes place that transfers energy between the regenerator and the bulk gas volumes of the hot and cold sides of the constant volume system. Heat capacity at constant pressure applies instead of heat capacity at constant volume. The resultant increase in calculated, recyclable energy allows the Carnot Limit to be exceeded in certain cycles. Super-Carnot heat engines and heat pumps have been designed and a US patent has been awarded.
Breukink, S O; Grond, A J K; Pierie, J P E N; Hoff, C; Wiggers, T; Meijerink, W J H J
2005-03-01
Next to surgical margins, yield of lymph nodes, and length of bowel resected, macroscopic completeness of mesorectal excision may serve as another quality control of total mesorectal excision (TME). In this study, the macroscopic completeness of laparoscopic TME was evaluated. A series of 25 patients with rectal cancer were managed laparoscopically (LTME) and included in this study. The pathologic specimens of the LTME group were prospectively examined and matched with a historical group of resection specimens from patients who had undergone open TME (OTME). The two groups were matched for gender and type of resection (low anterior or abdominoperineal resection). Special care was given to the macroscopic judgment concerning the completeness of the mesorectum. A three-grade scoring system showed no differences between the LTME and OTME groups. The current study supports the hypothesis that oncologic resection using laparoscopic TME is feasible and adequate.
Hybrid methods for witnessing entanglement in a microscopic-macroscopic system
International Nuclear Information System (INIS)
Spagnolo, Nicolo; Vitelli, Chiara; Paternostro, Mauro; De Martini, Francesco; Sciarrino, Fabio
2011-01-01
We propose a hybrid approach to the experimental assessment of the genuine quantum features of a general system consisting of microscopic and macroscopic parts. We infer entanglement by combining dichotomic measurements on a bidimensional system and phase-space inference through the Wigner distribution associated with the macroscopic component of the state. As a benchmark, we investigate the feasibility of our proposal in a bipartite-entangled state composed of a single-photon and a multiphoton field. Our analysis shows that, under ideal conditions, maximal violation of a Clauser-Horne-Shimony-Holt-based inequality is achievable regardless of the number of photons in the macroscopic part of the state. The difficulty in observing entanglement when losses and detection inefficiency are included can be overcome by using a hybrid entanglement witness that allows efficient correction for losses in the few-photon regime.
Hybrid methods for witnessing entanglement in a microscopic-macroscopic system
Energy Technology Data Exchange (ETDEWEB)
Spagnolo, Nicolo [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Vitelli, Chiara [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Paternostro, Mauro [School of Mathematics and Physics, Queen' s University, BT 7 1NN Belfast (United Kingdom); De Martini, Francesco [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Accademia Nazionale dei Lincei, via della Lungara 10, I-00165 Roma (Italy); Sciarrino, Fabio [Dipartimento di Fisica, Sapienza Universita di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche (INO-CNR), largo E. Fermi 6, I-50125 Firenze (Italy)
2011-09-15
We propose a hybrid approach to the experimental assessment of the genuine quantum features of a general system consisting of microscopic and macroscopic parts. We infer entanglement by combining dichotomic measurements on a bidimensional system and phase-space inference through the Wigner distribution associated with the macroscopic component of the state. As a benchmark, we investigate the feasibility of our proposal in a bipartite-entangled state composed of a single-photon and a multiphoton field. Our analysis shows that, under ideal conditions, maximal violation of a Clauser-Horne-Shimony-Holt-based inequality is achievable regardless of the number of photons in the macroscopic part of the state. The difficulty in observing entanglement when losses and detection inefficiency are included can be overcome by using a hybrid entanglement witness that allows efficient correction for losses in the few-photon regime.
Departure of microscopic friction from macroscopic drag in molecular fluid dynamics
Energy Technology Data Exchange (ETDEWEB)
Hanasaki, Itsuo [Institute of Engineering, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588 (Japan); Fujiwara, Daiki; Kawano, Satoyuki, E-mail: kawano@me.es.osaka-u.ac.jp [Graduate School of Engineering Science, Osaka University, Machikaneyama-cho 1-3, Toyonaka, Osaka 560-8531 (Japan)
2016-03-07
Friction coefficient of the Langevin equation and drag of spherical macroscopic objects in steady flow at low Reynolds numbers are usually regarded as equivalent. We show that the microscopic friction can be different from the macroscopic drag when the mass is taken into account for particles with comparable scale to the surrounding fluid molecules. We illustrate it numerically by molecular dynamics simulation of chloride ion in water. Friction variation by the atomistic mass effect beyond the Langevin regime can be of use in the drag reduction technology as well as the electro or thermophoresis.
Classical behaviour of macroscopic bodies and quantum measurements
International Nuclear Information System (INIS)
Ghirardi, G.; Rimini, A.; Weber, T.
1986-01-01
This report describes a recent attempt of giving a consistent and unified description of microscopic and macroscopic phenomena. The model presented in this paper exhibits the nice features of leaving unaltered the quantum description of microsystems and of accounting for the classical behaviour of the macroscopic objects when their dynamical evolution is consistently deduced from the dynamics of their elementary constituents
Macroscopic quantum tunnelling in a current biased Josephson junction
International Nuclear Information System (INIS)
Martinis, J.M.; Devoret, M.H.; Clarke, J.; Urbina, C.
1984-11-01
We discuss in this work an attempt to answer experimentally the question: do macroscopic variables obey quantum mechanics. More precisely, this experiment deals with the question of quantum-mechanical tunnelling of a macroscopic variable, a subject related to the famous Schrodinger's cat problem in the theory of measurement
Energetic macroscopic representation and inversion-based control of a CVT-based HEV
Chouhou, M.; Grée, F.; Jivan, C.; Bouscayrol, A.; Hofman, T.
2014-01-01
A Continuous Variable Transmission (CVT) is introduced in the simulation model of a Hybrid Electric Vehicle (HEV). The CVT-based vehicle simulation and its control are deduced from the Energetic Macroscopic Representation (EMR). Simulations are provided to show the interest of the CVT in term of
Energetic macroscopic representation and inversion- based control of a CVT-based HEV
Chouhou, M.; Grée, F.; Jivan, C.; Bouscayrol, A.; Hofman, T.
2013-01-01
A Continuous Variable Transmission (CVT) is introduced in the simulation model of a Hybrid Electric Vehicle (HEV). The CVT-based vehicle simulation and its control are deduced from the Energetic Macroscopic Representation (EMR). Simulations are provided to show the interest of the CVT in term of
Self-similar drag reduction in plug-flow of suspensions of macroscopic fibers
Gillissen, J.J.J.; Hoving, J.P.
2012-01-01
Pipe flow experiments show that turbulent drag reduction in plug-flow of concentrated suspensions of macroscopic fibers is a self-similar function of the wall shear stress over the fiber network yield stress. We model the experimental observations, by assuming a central fiber network plug, whose
Towards a theory of macroscopic gravity
International Nuclear Information System (INIS)
Zalaletdinov, R.M.
1993-01-01
By averaging out Cartan's structure equations for a four-dimensional Riemannian space over space regions, the structure equations for the averaged space have been derived with the procedure being valid on an arbitrary Riemannian space. The averaged space is characterized by a metric, Riemannian and non-Riemannian curvature 2-forms, and correlation 2-, 3- and 4-forms, an affine deformation 1-form being due to the non-metricity of one of two connection 1-forms. Using the procedure for the space-time averaging of the Einstein equations produces the averaged ones with the terms of geometric correction by the correlation tensors. The equations of motion for averaged energy momentum, obtained by averaging out the coritracted Bianchi identifies, also include such terms. Considering the gravitational induction tensor to be the Riemannian curvature tensor (the non-Riemannian one is then the field tensor), a theorem is proved which relates the algebraic structure of the averaged microscopic metric to that of the induction tensor. It is shown that the averaged Einstein equations can be put in the form of the Einstein equations with the conserved macroscopic energy-momentum tensor of a definite structure including the correlation functions. By using the high-frequency approximation of Isaacson with second-order correction to the microscopic metric, the self-consistency and compatibility of the equations and relations obtained are shown. Macrovacuum turns out to be Ricci non-flat, the macrovacuum source being defined in terms of the correlation functions. In the high-frequency limit the equations are shown to become Isaacson's ones with the macrovacuum source becoming Isaacson's stress tensor for gravitational waves. 17 refs
Macroscopic quantum electrodynamics of high-Q cavities
Energy Technology Data Exchange (ETDEWEB)
Khanbekyan, Mikayel
2009-10-27
In this thesis macroscopic quantum electrodynamics in linear media was applied in order to develop an universally valid quantum theory for the description of the interaction of the electromagnetic field with atomic sources in high-Q cavities. In this theory a complete description of the characteristics of the emitted radiation is given. The theory allows to show the limits of the applicability of the usually applied theory. In order to establish an as possible generally valid theory first the atom-field interaction was studied in the framework of macroscopic quantum electrodynamics in dispersive and absorptive media. In order to describe the electromagnetic field from Maxwell's equations was started, whereby the noise-current densities, which are connected with the absorption of the medium, were included. The solution of these equations expresses the electromagnetic field variables by the noise-current densities by means of Green's tensor of the macroscopic Maxwell equations. The explicit quantization is performed by means of the noise-current densities, whereby a diagonal Hamiltonian is introduced, which then guarantees the time development according to Maxwell's equation and the fulfillment of the fundamental simultaneous commutation relations of the field variables. In the case of the interaction of the medium-supported field with atoms the Hamiltonian must be extended by atom-field interactions energies, whereby the canonical coupling schemes of the minimal or multipolar coupling can be used. The dieelectric properties of the material bodies as well as their shape are coded in the Green tensor of the macroscopic Maxwell equations. As preparing step first the Green tensor was specified in order to derive three-dimensional input-output relations for the electromagnetic field operators on a plane multilayer structure. Such a general dewscription of the electromagnetic field allows the inclusion both of dispersion and absorption of the media and the
Susilaningsih, E.; Wulandari, C.; Supartono; Kasmui; Alighiri, D.
2018-03-01
This research aims to compose learning material which contains definitive macroscopic, microscopic and symbolic to analyze students’ conceptual understanding in acid-base learning materials. This research was conducted in eleven grade, natural science class, senior high school 1 (SMAN 1) Karangtengah, Demak province, Indonesia as the low level of students’ conceptual understanding and the high level of students’ misconception. The data collecting technique is by test to assess the cognitive aspect, questionnaire to assess students’ responses to multi representative learning materials (definitive, macroscopic, microscopic, symbolic), and observation to assess students’ macroscopic aspects. Three validators validate the multi-representative learning materials (definitive, macroscopic, microscopic, symbolic). The results of the research show that the multi-representative learning materials (definitive, macroscopic, microscopes, symbolic) being used is valid in the average score 62 of 75. The data is analyzed using the descriptive qualitative method. The results of the research show that 72.934 % students understand, 7.977 % less understand, 8.831 % do not understand, and 10.256 % misconception. In comparison, the second experiment class shows 54.970 % students understand, 5.263% less understand, 11.988 % do not understand, 27.777 % misconception. In conclusion, the application of multi representative learning materials (definitive, macroscopic, microscopic, symbolic) can be used to analyze the students’ understanding of acid-base materials.
Thermal activation and macroscopic quantum tunneling in a DC SQUID
International Nuclear Information System (INIS)
Sharifi, F.; Gavilano, J.L.; VanHarlingen, D.J.
1989-01-01
The authors report measurements of the transition rate from metastable minima in the two-dimensional 1 of a dc SQUID as a function of applied flux temperature. The authors observe a crossover from energy-activated escape to macroscopic quantum tunneling at a critical temperature. The macroscopic quantum tunneling rate is substantially reduced by damping, and also broadens the crossover region. Most interestingly, the authors observe thermal rates that are suppressed from those predicted by the two-dimensional thermal activation model. The authors discuss possible explanations for this based on the interaction of the macroscopic degree of freedom in the device and energy level effects
Testing quantum mechanics against macroscopic realism using the output of χ(2) nonlinearity
International Nuclear Information System (INIS)
Podoshvedov, Sergey A.; Kim, Jaewan
2006-01-01
We suggest an all-optical scheme to generate entangled superposition of a single photon with macroscopic entangled states for testing macroscopic realism. The scheme consists of source of single photons, a Mach-Zehnder interferometer in routes of which a system of coupled-down converters with type-I phase matching is inserted, and a beam splitter for the other auxiliary modes of the scheme. We use quantization of the pumping modes, depletion of the coherent states passing through the system, and interference effect in the pumping modes in the process of erasing which-path information of the single-photon on exit from the Mach-Zehnder interferometer. We show the macroscopic fields of the output superposition are distinguishable states. This scheme generates macroscopic entangled state that violates Bell's inequality. Moreover, the detailed analysis concerning change of amplitudes of entangled superposition by means of repeating this process many times is accomplished. We show our scheme works without photon number resolving detection and it is robust to detector inefficiency
Measurement-Induced Macroscopic Superposition States in Cavity Optomechanics
DEFF Research Database (Denmark)
Hoff, Ulrich Busk; Kollath-Bönig, Johann; Neergaard-Nielsen, Jonas Schou
2016-01-01
A novel protocol for generating quantum superpositions of macroscopically distinct states of a bulk mechanical oscillator is proposed, compatible with existing optomechanical devices operating in the bad-cavity limit. By combining a pulsed optomechanical quantum nondemolition (QND) interaction...
Dynamical fusion thresholds in macroscopic and microscopic theories
International Nuclear Information System (INIS)
Davies, K.T.R.; Sierk, A.J.; Nix, J.R.
1983-01-01
Macroscopic and microscopic results demonstrating the existence of dynamical fusion thresholds are presented. For macroscopic theories, it is shown that the extra-push dynamics is sensitive to some details of the models used, e.g. the shape parametrization and the type of viscosity. The dependence of the effect upon the charge and angular momentum of the system is also studied. Calculated macroscopic results for mass-symmetric systems are compared to experimental mass-asymmetric results by use of a tentative scaling procedure, which takes into account both the entrance-channel and the saddle-point regions of configuration space. Two types of dynamical fusion thresholds occur in TDHF studies: (1) the microscopic analogue of the macroscopic extra push threshold, and (2) the relatively high energy at which the TDHF angular momentum window opens. Both of these microscopic thresholds are found to be very sensitive to the choice of the effective two-body interaction
Directory of Open Access Journals (Sweden)
Xingtuan Yang
2015-05-01
Full Text Available A direct numerical simulation study of the characteristics of macroscopic and microscopic rotating motions in swirling jets confined in a rectangular flow domain is carried out. The different structures of vortex cores for different swirl levels are illustrated. It is found that the vortex cores of low swirl flows are of regular cylindrical-helix patterns, whereas those of the high swirl flows are characterized by the formation of the bubble-type vortex breakdown followed by the radiant processing vortex cores. The results of mean velocity fields show the general procedures of vortex origination. Moreover, the effects of macroscopic and microscopic rotating motions with respect to the mean and fluctuation fields of the swirling flows are evaluated. The microscopic rotating effects, especially the effects with respect to the turbulent fluctuation motion, are increasingly intermittent with the increase in the swirl levels. In contrast, the maximum value of the probability density functions with respect to the macroscopic rotating effects of the fluctuation motion occurs at moderate swirl levels since the macroscopic rotating effects are attenuated by the formation of the bubble vortex breakdown with a region of stagnant fluids at supercritical swirl levels.
General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures
Energy Technology Data Exchange (ETDEWEB)
Liu, Yen, E-mail: yen.liu@nasa.gov; Vinokur, Marcel [NASA Ames Research Center, Moffett Field, California 94035 (United States); Panesi, Marco; Sahai, Amal [University of Illinois, Urbana-Champaign, Illinois 61801 (United States)
2015-04-07
This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model’s accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy
General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures
Liu, Yen; Panesi, Marco; Sahai, Amal; Vinokur, Marcel
2015-04-01
This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model's accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy
General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures.
Liu, Yen; Panesi, Marco; Sahai, Amal; Vinokur, Marcel
2015-04-07
This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model's accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy
General multi-group macroscopic modeling for thermo-chemical non-equilibrium gas mixtures
International Nuclear Information System (INIS)
Liu, Yen; Vinokur, Marcel; Panesi, Marco; Sahai, Amal
2015-01-01
This paper opens a new door to macroscopic modeling for thermal and chemical non-equilibrium. In a game-changing approach, we discard conventional theories and practices stemming from the separation of internal energy modes and the Landau-Teller relaxation equation. Instead, we solve the fundamental microscopic equations in their moment forms but seek only optimum representations for the microscopic state distribution function that provides converged and time accurate solutions for certain macroscopic quantities at all times. The modeling makes no ad hoc assumptions or simplifications at the microscopic level and includes all possible collisional and radiative processes; it therefore retains all non-equilibrium fluid physics. We formulate the thermal and chemical non-equilibrium macroscopic equations and rate coefficients in a coupled and unified fashion for gases undergoing completely general transitions. All collisional partners can have internal structures and can change their internal energy states after transitions. The model is based on the reconstruction of the state distribution function. The internal energy space is subdivided into multiple groups in order to better describe non-equilibrium state distributions. The logarithm of the distribution function in each group is expressed as a power series in internal energy based on the maximum entropy principle. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients succinctly to any order. The model’s accuracy depends only on the assumed expression of the state distribution function and the number of groups used and can be self-checked for accuracy and convergence. We show that the macroscopic internal energy transfer, similar to mass and momentum transfers, occurs through nonlinear collisional processes and is not a simple relaxation process described by, e.g., the Landau-Teller equation. Unlike the classical vibrational energy
Theory and feasibility tests for a seismic scanning tunnelling macroscope
Schuster, Gerard T.
2012-09-01
We propose a seismic scanning tunnelling macroscope (SSTM) that can detect subwavelength scatterers in the near-field of either the source or the receivers. Analytic formulas for the time reverse mirror (TRM) profile associated with a single scatterer model show that the spatial resolution limit to be, unlike the Abbe limit of λ/2, independent of wavelength and linearly proportional to the source-scatterer separation as long as the scatterer is in the near-field region. This means that, as the scatterer approaches the source, imaging of the scatterer with super-resolution can be achieved. Acoustic and elastic simulations support this concept, and a seismic experiment in an Arizona tunnel shows a TRM profile with super-resolution adjacent to the fault location. The SSTM is analogous to the optical scanning tunnelling microscopes having subwavelength resolution. Scaled to seismic frequencies, it is theoretically possible to extract 100 Hz information from 20 Hz data by the imaging of near-field seismic energy.
Feedback Gating Control for Network Based on Macroscopic Fundamental Diagram
Directory of Open Access Journals (Sweden)
YangBeibei Ji
2016-01-01
Full Text Available Empirical data from Yokohama, Japan, showed that a macroscopic fundamental diagram (MFD of urban traffic provides for different network regions a unimodal low-scatter relationship between network vehicle density and network space-mean flow. This provides new tools for network congestion control. Based on MFD, this paper proposed a feedback gating control policy which can be used to mitigate network congestion by adjusting signal timings of gating intersections. The objective of the feedback gating control model is to maximize the outflow and distribute the allowed inflows properly according to external demand and capacity of each gating intersection. An example network is used to test the performance of proposed feedback gating control model. Two types of background signalization types for the intersections within the test network, fixed-time and actuated control, are considered. The results of extensive simulation validate that the proposed feedback gating control model can get a Pareto improvement since the performance of both gating intersections and the whole network can be improved significantly especially under heavy demand situations. The inflows and outflows can be improved to a higher level, and the delay and queue length at all gating intersections are decreased dramatically.
Gravitational wave echoes from macroscopic quantum gravity effects
Energy Technology Data Exchange (ETDEWEB)
Barceló, Carlos [Instituto de Astrofísica de Andalucía (IAA-CSIC),Glorieta de la Astronomía, 18008 Granada (Spain); Carballo-Rubio, Raúl [The Cosmology & Gravity Group and the Laboratory for Quantum Gravity & Strings,Department of Mathematics & Applied Mathematics, University of Cape Town,Private Bag, Rondebosch 7701 (South Africa); Garay, Luis J. [Departamento de Física Teórica II,Universidad Complutense de Madrid, 28040 Madrid (Spain); Instituto de Estructura de la Materia (IEM-CSIC),Serrano 121, 28006 Madrid (Spain)
2017-05-10
New theoretical approaches developed in the last years predict that macroscopic quantum gravity effects in black holes should lead to modifications of the gravitational wave signals expected in the framework of classical general relativity, with these modifications being characterized in certain scenarios by the existence of dampened repetitions of the primary signal. Here we use the fact that non-perturbative corrections to the near-horizon external geometry of black holes are necessary for these modifications to exist, in order to classify different proposals and paradigms with respect to this criterion and study in a neat and systematic way their phenomenology. Proposals that lead naturally to the existence of echoes in the late-time ringdown of gravitational wave signals from black hole mergers must share the replacement of black holes by horizonless configurations with a physical surface showing reflective properties in the relevant range of frequencies. On the other hand, proposals or paradigms that restrict quantum gravity effects on the external geometry to be perturbative, such as black hole complementarity or the closely related firewall proposal, do not display echoes. For the sake of completeness we exploit the interplay between the timescales associated with the formation of firewalls and the mechanism behind the existence of echoes in order to conclude that even unconventional distortions of the firewall concept (such as naked firewalls) do not lead to this phenomenon.
Bahniuk, A. M.; Vasconcelos, C.; McKenzie, J. A.; Franca, A. B.; Matsuda, N.; Eiler, J.
2010-12-01
Recent studies of the sedimentological, stratigraphic and geochemical aspects of carbonate microbialites have been carried out to characterize the paleoenvironmental and hydrological conditions of deposition for the Aptian Codó Formation (Parnaíba Basin) and the time-equivalent Santana Formation (Araripe Basin). This environmental interpretation is of interest because these sediments record the early stages of the opening of the Equatorial Atlantic Ocean, as well as being potentially important reservoir rock. Specifically, clumped isotope thermometry has been applied to evaluate the growth temperatures of carbonate components in selected samples from both outcrop and drill core. Preliminary results of clumped isotope measurements provide paleotemperatures derived for dense stromatolitic fabrics drilled from outcrop samples of the Codó Formation which vary between 29 and 33°C. In contrast, the micritic matrix of the drill core samples of the Codó Formation indicates a temperature range from 30 to 48°C. The lower values for the outcrop samples may represent a primary or early diagenetic temperature signal preserved in the rock. Moreover, the micritic matrix from the Santana Formation drill core samples indicates paleotemperatures ranging from 40 to 68°C, which are slightly higher than those for all measured samples of the Codó Formation. We propose that the higher paleotemperatures for all drill core samples denote a diagenetic effect that occurred with sediment lithification processes during burial; that is, isotopic reequilibration at depth is reflected in the higher measured paleotemperatures. Increased paleotemperatures are probably present in some carbonate fabrics of the outcrop samples of the Codo Formation, which also underwent lithification, but this signal was missed by our inability to micro-sample primary or early diagenetic stromatolitic fabrics. Assuming that the outcrop samples of the Codó Formation preserve an original stable isotope signal
Microscopic to macroscopic depletion model development for FORMOSA-P
International Nuclear Information System (INIS)
Noh, J.M.; Turinsky, P.J.; Sarsour, H.N.
1996-01-01
Microscopic depletion has been gaining popularity with regard to employment in reactor core nodal calculations, mainly attributed to the superiority of microscopic depletion in treating spectral history effects during depletion. Another trend is the employment of loading pattern optimization computer codes in support of reload core design. Use of such optimization codes has significantly reduced design efforts to optimize reload core loading patterns associated with increasingly complicated lattice designs. A microscopic depletion model has been developed for the FORMOSA-P pressurized water reactor (PWR) loading pattern optimization code. This was done for both fidelity improvements and to make FORMOSA-P compatible with microscopic-based nuclear design methods. Needless to say, microscopic depletion requires more computational effort compared with macroscopic depletion. This implies that microscopic depletion may be computationally restrictive if employed during the loading pattern optimization calculation because many loading patterns are examined during the course of an optimization search. Therefore, the microscopic depletion model developed here uses combined models of microscopic and macroscopic depletion. This is done by first performing microscopic depletions for a subset of possible loading patterns from which 'collapsed' macroscopic cross sections are obtained. The collapsed macroscopic cross sections inherently incorporate spectral history effects. Subsequently, the optimization calculations are done using the collapsed macroscopic cross sections. Using this approach allows maintenance of microscopic depletion level accuracy without substantial additional computing resources
Proposed test of macroscopic quantum contextuality
International Nuclear Information System (INIS)
Cabello, Adan
2010-01-01
We show that, for any system with a number of levels which can be identified with n qubits, there is an inequality for the correlations between three compatible dichotomic measurements which must be satisfied by any noncontextual theory, but is violated by any quantum state. Remarkably, the violation grows exponentially with n, and the tolerated error per correlation also increases with n, showing that state-independent quantum contextuality is experimentally observable in complex systems.
Macroscopic quantum effects in nonlinear optical patterns
International Nuclear Information System (INIS)
Gatti, A.; Lugiato, L.A.; Oppo, G.L.; Barnett, S.M.; Marzoli, I.
1998-01-01
We display the results of the numerical simulations of a set of Langevin equations, which describe the dynamics of a degenerate optical parametric oscillator in the Wigner representation. The scan of the threshold region shows the gradual transformation of a quantum image into a classical roll pattern. Thus the quantum image behaves as a precursor of the roll pattern which appear above threshold. In the fax field, suitable spatial correlation functions of intensity and field quadratures show unambiguously the quantum nature of fluctuations that generate the image, leading to effects of quantum noise reduction below the shot noise level and to the formulation of an EPR paradox. (author)
Extended Macroscopic Study of Dilute Gas Flow within a Microcavity
Directory of Open Access Journals (Sweden)
Mohamed Hssikou
2016-01-01
Full Text Available The behaviour of monatomic and dilute gas is studied in the slip and early transition regimes using the extended macroscopic theory. The gas is confined within a two-dimensional microcavity where the longitudinal sides are in the opposite motion with constant velocity ±Uw. The microcavity walls are kept at the uniform and reference temperature T0. Thus, the gas flow is transported only by the shear stress induced by the motion of upper and lower walls. From the macroscopic point of view, the regularized 13-moment equations of Grad, R13, are solved numerically. The macroscopic gas proprieties are studied for different values of the so-called Knudsen number (Kn, which gives the gas-rarefaction degree. The results are compared with those obtained using the classical continuum theory of Navier-Stokes and Fourier (NSF.
Bell-inequality tests with macroscopic entangled states of light
Energy Technology Data Exchange (ETDEWEB)
Stobinska, M. [Max Planck Institute for the Science of Light, Erlangen (Germany); Institute for Theoretical Physics II, Erlangen-Nuernberg University, Erlangen (Germany); Sekatski, P.; Gisin, N. [Group of Applied Physics, University of Geneva, Geneva (Switzerland); Buraczewski, A. [Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw (Poland); Leuchs, G. [Max Planck Institute for the Science of Light, Erlangen (Germany); Institute for Optics, Information and Photonics, Erlangen-Nuernberg University, Erlangen (Germany)
2011-09-15
Quantum correlations may violate the Bell inequalities. Most experimental schemes confirming this prediction have been realized in all-optical Bell tests suffering from the detection loophole. Experiments which simultaneously close this loophole and the locality loophole are highly desirable and remain challenging. An approach to loophole-free Bell tests is based on amplification of the entangled photons (i.e., on macroscopic entanglement), for which an optical signal should be easy to detect. However, the macroscopic states are partially indistinguishable by classical detectors. An interesting idea to overcome these limitations is to replace the postselection by an appropriate preselection immediately after the amplification. This is in the spirit of state preprocessing revealing hidden nonlocality. Here, we examine one of the possible preselections, but the presented tools can be used for analysis of other schemes. Filtering methods making the macroscopic entanglement useful for Bell tests and quantum protocols are the subject of an intensive study in the field nowadays.
Decoherence bypass of macroscopic superpositions in quantum measurement
International Nuclear Information System (INIS)
Spehner, Dominique; Haake, Fritz
2008-01-01
We study a class of quantum measurement models. A microscopic object is entangled with a macroscopic pointer such that a distinct pointer position is tied to each eigenvalue of the measured object observable. Those different pointer positions mutually decohere under the influence of an environment. Overcoming limitations of previous approaches we (i) cope with initial correlations between pointer and environment by considering them initially in a metastable local thermal equilibrium, (ii) allow for object-pointer entanglement and environment-induced decoherence of distinct pointer readouts to proceed simultaneously, such that mixtures of macroscopically distinct object-pointer product states arise without intervening macroscopic superpositions, and (iii) go beyond the Markovian treatment of decoherence. (fast track communication)
He, Q Y; Reid, M D
2013-01-01
Experiments have reported the entanglement of two spatially separated macroscopic atomic ensembles at room temperature (Krauter et al 2011 Phys. Rev. Lett. 107 080503; Julsgaard et al 2001 Nature 413 400). We show how an Einstein-Podolsky-Rosen (EPR) paradox is realizable with this experiment. Our proposed test involves violation of an inferred Heisenberg uncertainty principle, which is a sufficient condition for an EPR paradox. This is a stronger test of nonlocality than entanglement. Our pr...
Magnetic properties and macroscopic heterogeneity of FeCoNbB Hitperms
Energy Technology Data Exchange (ETDEWEB)
Butvin, Pavol [Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava (Slovakia)], E-mail: fyzipbut@savba.sk; Butvinova, Beata [Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava (Slovakia); Sitek, Jozef; Degmova, Jarmila [Department of Nuclear Physics and Technology, FEI, Slovak University of Technology, Ilkovicova 3, 812 19 Bratislava (Slovakia); Vlasak, Gabriel; Svec, Peter; Janickovic, Dusan [Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava (Slovakia)
2008-03-15
Nanocrystalline ribbons of Fe{sub 81-x}Co{sub x}Nb{sub 7}B{sub 12} (where x ranges from 0 to 40.5 at%) Hitperm alloys have been investigated as to their basic magnetic properties and the influence of the macroscopic heterogeneity. Different crystalline share at surfaces compared with the volume average is observed by conversion electron Moessbauer spectroscopy (CEMS) and Moessbauer spectroscopy (MS), respectively. This marks the presence of macroscopic heterogeneity in these Hitperms. The heterogeneity is generally more significant in Ar-annealed samples than in the vacuum-annealed ones. The characteristic slant hysteresis loops (hard-ribbon-axis) are seen as a rule with few exceptions. An inspection of hysteresis loop response of resin potted samples shows that the surfaces bi-axially squeeze the ribbon interior in heterogeneous Hitperms when the ribbons cool down after annealing. Certain compositions show macroscopic viscous flow prior to crystallization so the heterogeneity gets another chance to induce anisotropy during annealing. The induction attains 1.5 T but saturates poorly due to the heterogeneity and the ensuing anisotropy. Moreover the heterogeneity appears to hamper the crystallization within the ribbon interior. Unlike Finemets, the density of these Hitperms show no pronounced trend with annealing.
Magnetic properties and macroscopic heterogeneity of FeCoNbB Hitperms
Butvin, Pavol; Butvinová, Beata; Sitek, Jozef; Degmová, Jarmila; Vlasák, Gabriel; Švec, Peter; Janičkovič, Dušan
Nanocrystalline ribbons of Fe 81-xCo xNb 7B 12 (where x ranges from 0 to 40.5 at%) Hitperm alloys have been investigated as to their basic magnetic properties and the influence of the macroscopic heterogeneity. Different crystalline share at surfaces compared with the volume average is observed by conversion electron Mössbauer spectroscopy (CEMS) and Mössbauer spectroscopy (MS), respectively. This marks the presence of macroscopic heterogeneity in these Hitperms. The heterogeneity is generally more significant in Ar-annealed samples than in the vacuum-annealed ones. The characteristic slant hysteresis loops (hard-ribbon-axis) are seen as a rule with few exceptions. An inspection of hysteresis loop response of resin potted samples shows that the surfaces bi-axially squeeze the ribbon interior in heterogeneous Hitperms when the ribbons cool down after annealing. Certain compositions show macroscopic viscous flow prior to crystallization so the heterogeneity gets another chance to induce anisotropy during annealing. The induction attains 1.5 T but saturates poorly due to the heterogeneity and the ensuing anisotropy. Moreover the heterogeneity appears to hamper the crystallization within the ribbon interior. Unlike Finemets, the density of these Hitperms show no pronounced trend with annealing.
Statistical thermodynamics understanding the properties of macroscopic systems
Fai, Lukong Cornelius
2012-01-01
Basic Principles of Statistical PhysicsMicroscopic and Macroscopic Description of StatesBasic PostulatesGibbs Ergodic AssumptionGibbsian EnsemblesExperimental Basis of Statistical MechanicsDefinition of Expectation ValuesErgodic Principle and Expectation ValuesProperties of Distribution FunctionRelative Fluctuation of an Additive Macroscopic ParameterLiouville TheoremGibbs Microcanonical EnsembleMicrocanonical Distribution in Quantum MechanicsDensity MatrixDensity Matrix in Energy RepresentationEntropyThermodynamic FunctionsTemperatureAdiabatic ProcessesPressureThermodynamic IdentityLaws of Th
Fluctuations in macroscopically agitated plasma:quasiparticles and effective temperature
International Nuclear Information System (INIS)
Sosenko, P.P.; Gresillon, D.
1994-01-01
Fluctuations in the plasma, in which macroscopic fluid-like motion is agitated due to large-scale and low-frequency electro-magnetic fields, are studied. Such fields can be produced by external factors or internally, for example due to turbulence. Fluctuation spectral distributions are calculated with regard to the renormalization of the transition probability for a test-particle and of the test-particle shielding. If the correlation length for the random fluid-like motion is large as compared to the fluctuation scale lengths, then the fluctuation spectral distributions can be explained in terms of quasiparticles originating from macroscopic plasma agitation and of an effective temperature
Macroscopic and radiographic examination of proximal root surface caries
International Nuclear Information System (INIS)
Nordenram, G.; Bergvist, A.; Johnson, G.; Henriksen, C.O.; Anneroth, G.
1988-01-01
The purpose of the study was to compare macroscopic and radiographic examination of proximal root surface caries of extracted teeth from patients aged 65-95 years. Although the study conditions for macroscopic and radiographic diagnosis favored more sensitive evaluations than routine clinical conditions, there was a 24% disagreement in diagnosis. This finding indicates that under routine clinical conditions it is difficult to register with certainty all superficial root carious lesions. Even in the absence of clinically detectable root surface caries, preventive measures should be considered for elderly people with exposed root surfaces
On creating macroscopically identical granular systems with different numbers of particles
van der Meer, Devaraj; Rivas, Nicolas
2015-11-01
One of the fundamental differences between granular and molecular hydrodynamics is the enormous difference in the total number of constituents. The small number of particles implies that the role of fluctuations in granular dynamics is of paramount importance. To obtain more insight in these fluctuations, we investigate to what extent it is possible to create identical granular hydrodynamic states with different number of particles. A definition is given of macroscopically equivalent systems, and the dependency of the conservation equations on the particle size is studied. We show that, in certain cases, and by appropriately scaling the microscopic variables, we are able to compare systems with significantly different number of particles that present the same macroscopic phenomenology. We apply these scalings in simulations of a vertically vibrated system, namely the density inverted granular Leidenfrost state and its transition to a buoyancy-driven convective state.
He, Q. Y.; Reid, M. D.
2013-06-01
Experiments have reported the entanglement of two spatially separated macroscopic atomic ensembles at room temperature (Krauter et al 2011 Phys. Rev. Lett. 107 080503; Julsgaard et al 2001 Nature 413 400). We show how an Einstein-Podolsky-Rosen (EPR) paradox is realizable with this experiment. Our proposed test involves violation of an inferred Heisenberg uncertainty principle, which is a sufficient condition for an EPR paradox. This is a stronger test of nonlocality than entanglement. Our proposal would enable the first definitive confirmation of quantum EPR paradox correlations between two macroscopic objects at room temperature. This is a necessary intermediate step towards a nonlocal experiment with causal measurement separations. As well as having fundamental significance, the realization of an atomic EPR paradox could provide a resource for novel applications in quantum technology.
International Nuclear Information System (INIS)
He, Q Y; Reid, M D
2013-01-01
Experiments have reported the entanglement of two spatially separated macroscopic atomic ensembles at room temperature (Krauter et al 2011 Phys. Rev. Lett. 107 080503; Julsgaard et al 2001 Nature 413 400). We show how an Einstein–Podolsky–Rosen (EPR) paradox is realizable with this experiment. Our proposed test involves violation of an inferred Heisenberg uncertainty principle, which is a sufficient condition for an EPR paradox. This is a stronger test of nonlocality than entanglement. Our proposal would enable the first definitive confirmation of quantum EPR paradox correlations between two macroscopic objects at room temperature. This is a necessary intermediate step towards a nonlocal experiment with causal measurement separations. As well as having fundamental significance, the realization of an atomic EPR paradox could provide a resource for novel applications in quantum technology. (paper)
Macroscopic morphology of radiation damage in copper
International Nuclear Information System (INIS)
Black, K.E.
1977-01-01
This Thesis describes the damage produced in copper single crystals when they are irradiated with neutrons from a nuclear reactor, and shows that the morphology of the damage is dependent on the temperature of irradiation. The production of point defects in the initial stages of the bombardment and their subsequent diffusion is described in Chapter One. Chapter Two describes the techniques used to etch and thus make visible the damage regions. The defect clusters were examined with a microscope. A typical selection of micrographs of the damage is presented and discussed in Chapter Three. In the final chapter, Chapter Four, the results of the present work are discussed in the light of work done by other research workers. The Thesis ends with a brief suggestion for future work to be carried out on neutron irradiated copper single crystals
Entanglement criteria for microscopic-macroscopic systems
International Nuclear Information System (INIS)
Spagnolo, Nicolo; Vitelli, Chiara; Sciarrino, Fabio; De Martini, Francesco
2010-01-01
We discuss the conclusions that can be drawn on a recent experimental micro-macro entanglement test [De Martini, Sciarrino, and Vitelli, Phys. Rev. Lett. 100, 253601 (2008)]. The system under investigation is generated through optical parametric amplification of one photon belonging to an entangled pair. The adopted entanglement criterion makes it possible to infer the presence of entanglement before losses that occur on the macrostate under a specific assumption. In particular, an a priori knowledge of the system that generates the micro-macro pair is necessary to exclude a class of separable states that can reproduce the obtained experimental results. Finally, we discuss the feasibility of a micro-macro ''genuine'' entanglement test on the analyzed system by considering different strategies, which show that in principle a fraction ε, proportional to the number of photons that survive the lossy process, of the original entanglement persists in any loss regime.
Scaling from single molecule to macroscopic adhesion at polymer/metal interfaces.
Utzig, Thomas; Raman, Sangeetha; Valtiner, Markus
2015-03-10
Understanding the evolution of macroscopic adhesion based on fundamental molecular interactions is crucial to designing strong and smart polymer/metal interfaces that play an important role in many industrial and biomedical applications. Here we show how macroscopic adhesion can be predicted on the basis of single molecular interactions. In particular, we carry out dynamic single molecule-force spectroscopy (SM-AFM) in the framework of Bell-Evans' theory to gain information about the energy barrier between the bound and unbound states of an amine/gold junction. Furthermore, we use Jarzynski's equality to obtain the equilibrium ground-state energy difference of the amine/gold bond from these nonequilibrium force measurements. In addition, we perform surface forces apparatus (SFA) experiments to measure macroscopic adhesion forces at contacts where approximately 10(7) amine/gold bonds are formed simultaneously. The SFA approach provides an amine/gold interaction energy (normalized by the number of interacting molecules) of (36 ± 1)k(B)T, which is in excellent agreement with the interaction free energy of (35 ± 3)k(B)T calculated using Jarzynski's equality and single-molecule AFM experiments. Our results validate Jarzynski's equality for the field of polymer/metal interactions by measuring both sides of the equation. Furthermore, the comparison of SFA and AFM shows how macroscopic interaction energies can be predicted on the basis of single molecular interactions, providing a new strategy to potentially predict adhesive properties of novel glues or coatings as well as bio- and wet adhesion.
Microscopic Simulation and Macroscopic Modeling for Thermal and Chemical Non-Equilibrium
Liu, Yen; Panesi, Marco; Vinokur, Marcel; Clarke, Peter
2013-01-01
This paper deals with the accurate microscopic simulation and macroscopic modeling of extreme non-equilibrium phenomena, such as encountered during hypersonic entry into a planetary atmosphere. The state-to-state microscopic equations involving internal excitation, de-excitation, dissociation, and recombination of nitrogen molecules due to collisions with nitrogen atoms are solved time-accurately. Strategies to increase the numerical efficiency are discussed. The problem is then modeled using a few macroscopic variables. The model is based on reconstructions of the state distribution function using the maximum entropy principle. The internal energy space is subdivided into multiple groups in order to better describe the non-equilibrium gases. The method of weighted residuals is applied to the microscopic equations to obtain macroscopic moment equations and rate coefficients. The modeling is completely physics-based, and its accuracy depends only on the assumed expression of the state distribution function and the number of groups used. The model makes no assumption at the microscopic level, and all possible collisional and radiative processes are allowed. The model is applicable to both atoms and molecules and their ions. Several limiting cases are presented to show that the model recovers the classical twotemperature models if all states are in one group and the model reduces to the microscopic equations if each group contains only one state. Numerical examples and model validations are carried out for both the uniform and linear distributions. Results show that the original over nine thousand microscopic equations can be reduced to 2 macroscopic equations using 1 to 5 groups with excellent agreement. The computer time is decreased from 18 hours to less than 1 second.
Nuclear magnetic resonance studies of macroscopic morphology and dynamics
International Nuclear Information System (INIS)
Barrall, G.A.; Lawrence Berkeley Lab., CA
1995-09-01
Nuclear magnetic resonance techniques are traditionally used to study molecular level structure and dynamics with a noted exception in medically applied NMR imaging (MRI). In this work, new experimental methods and theory are presented relevant to the study of macroscopic morphology and dynamics using NMR field gradient techniques and solid state two-dimensional exchange NMR. The goal in this work is not to take some particular system and study it in great detail, rather it is to show the utility of a number of new and novel techniques using ideal systems primarily as a proof of principle. By taking advantage of the analogy between NMR imaging and diffraction, one may simplify the experiments necessary for characterizing the statistical properties of the sample morphology. For a sample composed of many small features, e.g. a porous medium, the NMR diffraction techniques take advantage of both the narrow spatial range and spatial isotropy of the sample's density autocorrelation function to obtain high resolution structural information in considerably less time than that required by conventional NMR imaging approaches. The time savings of the technique indicates that NMR diffraction is capable of finer spatial resolution than conventional NMR imaging techniques. Radio frequency NMR imaging with a coaxial resonator represents the first use of cylindrically symmetric field gradients in imaging. The apparatus as built has achieved resolution at the micron level for water samples, and has the potential to be very useful in the imaging of circularly symmetric systems. The study of displacement probability densities in flow through a random porous medium has revealed the presence of features related to the interconnectedness of the void volumes. The pulsed gradient techniques used have proven successful at measuring flow properties for time and length scales considerably shorter than those studied by more conventional techniques
Macroscopic quantum systems and gravitational phenomena
International Nuclear Information System (INIS)
Pikovski, I.
2014-01-01
Low-energy quantum systems are studied theoretically in light of possible experiments to test the interplay between quantum theory and general relativity. The research focus in this thesis is on quantum systems which can be controlled with very high precision and which allow for tests of quantum theory at novel scales in terms of mass and size. The pulsed regime of opto-mechanics is explored and it is shown how short optical pulses can be used to prepare and characterize quantum states of a massive mechanical resonator, and how some phenomenological models of quantum gravity can be probed. In addition, quantum interferometry with photons and matter-waves in the presence of gravitational time dilation is considered. It is shown that time dilation causes entanglement between internal states and the center-of-mass position and that it leads to decoherence of all composite quantum systems. The results of the thesis show that the interplay between quantum theory and general relativity affects even low-energy quantum systems and that it offers novel phenomena which can be probed in experiments. (author) [de
Vascular flora and macroscopic fauna on the Fernow Experimental Forest
Darlene M. Madarish; Jane L. Rodrigue; Mary Beth Adams
2002-01-01
This report is the first comprehensive inventory of the vascular flora and macroscopic fauna known to occur within the Fernow Experimental Forest in north-central West Virignia. The compendium is based on information obtained from previous surveys, current research, and the personal observations of USDA Forest Service personnel and independent scientists. More than 750...
Photoinduced macroscopic chiral structures in a series of azobenzene copolyesters
DEFF Research Database (Denmark)
Nedelchev, L.; Nikolova, L.; Matharu, A.
2002-01-01
A study of the propagation of elliptically polarized light and the resulting formation of macroscopic chiral structures in a series of azobenzene side-chain copolyesters, in which the morphology is varied from liquid crystalline to amorphous, is reported. Real-time measurements are presented...
Charge of a macroscopic particle in a plasma sheath
International Nuclear Information System (INIS)
Samarian, A.A.; Vladimirov, S.V.
2003-01-01
Charging of a macroscopic body levitating in a rf plasma sheath is studied experimentally and theoretically. The nonlinear charge vs size dependence is obtained. The observed nonlinearity is explained on the basis of an approach taking into account different plasma conditions for the levitation positions of different particles. The importance of suprathermal electrons' contribution to the charging process is demonstrated
Macroscopic Fundamental Diagram for pedestrian networks : Theory and applications
Hoogendoorn, S.P.; Daamen, W.; Knoop, V.L.; Steenbakkers, Jeroen; Sarvi, Majid
2017-01-01
The Macroscopic Fundamental diagram (MFD) has proven to be a powerful concept in understanding and managing vehicular network dynamics, both from a theoretical angle and from a more application-oriented perspective. In this contribution, we explore the existence and the characteristics of the
Emergence of an urban traffic macroscopic fundamental diagram
DEFF Research Database (Denmark)
Ranjan, Abhishek; Fosgerau, Mogens; Jenelius, Erik
2016-01-01
This paper examines mild conditions under which a macroscopic fundamental diagram (MFD) emerges, relating space-averaged speed to occupancy in some area. These conditions are validated against empirical data. We allow local speedoccupancy relationships and, in particular, require no equilibrating...
Stereodynamics: From elementary processes to macroscopic chemical reactions
Energy Technology Data Exchange (ETDEWEB)
Kasai, Toshio [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Graduate School of Science, Department of Chemistry, Osaka University, Toyonaka, 560-0043 Osaka (Japan); Che, Dock-Chil [Graduate School of Science, Department of Chemistry, Osaka University, Toyonaka, 560-0043 Osaka (Japan); Tsai, Po-Yu [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Lin, King-Chuen [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Palazzetti, Federico [Scuola Normale Superiore, Pisa (Italy); Dipartimento di Chimica Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Aquilanti, Vincenzo [Dipartimento di Chimica Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Roma (Italy); Instituto de Fisica, Universidade Federal da Bahia, Salvador (Brazil)
2015-12-31
This paper aims at discussing new facets on stereodynamical behaviors in chemical reactions, i.e. the effects of molecular orientation and alignment on reactive processes. Further topics on macroscopic processes involving deviations from Arrhenius behavior in the temperature dependence of chemical reactions and chirality effects in collisions are also discussed.
Macroscopic realism and quantum measurement: measurers as a natural kind
International Nuclear Information System (INIS)
Jaeger, Gregg
2014-01-01
The notion of macroscopic realism has been used in attempts to achieve consistency between physics and everyday experience and to locate some boundary between the realms of classical mechanics and quantum meachanics. Its ostensibly underlying conceptual components, realism and macroscopicity, have most often appeared in the foundations of physics in relation to quantum measurement: reality became a prominent topic of discussion in quantum physics after the notion of element of reality was defined and used by Einstein, Podolsky and Rosen in that context, and macroscopicity is often explicitly assumed to be an essential property of any measuring apparatus. However, macroscopicity turns out to be a rather vaguer and less consistently understood notion than typically assumed by physicists who have not explicitly explored the notion themselves. For this reason, it behooves those investigating the foundations of quantum mechanics from a realist perspective to look for alternative notions for grounding quantum measurement. Here, the merits of treating the measuring instrument as a ‘natural kind’ as a means of avoiding anthropocentrism in the foundations of quantum measurement are pointed out as a means of advancing quantum measurement theory. (paper)
Microstructure and macroscopic properties of polydisperse systems of hard spheres
Ogarko, V.
2014-01-01
This dissertation describes an investigation of systems of polydisperse smooth hard spheres. This includes the development of a fast contact detection algorithm for computer modelling, the development of macroscopic constitutive laws that are based on microscopic features such as the moments of the
Macroscopic domain formation in the platelet plasma membrane
DEFF Research Database (Denmark)
Bali, Rachna; Savino, Laura; Ramirez, Diego A.
2009-01-01
There has been ample debate on whether cell membranes can present macroscopic lipid domains as predicted by three-component phase diagrams obtained by fluorescence microscopy. Several groups have argued that membrane proteins and interactions with the cytoskeleton inhibit the formation of large d...
Macroscopic charge quantization in single-electron devices
Burmistrov, I.S.; Pruisken, A.M.M.
2010-01-01
In a recent paper by the authors [I. S. Burmistrov and A. M. M. Pruisken, Phys. Rev. Lett. 101, 056801 (2008)] it was shown that single-electron devices (single-electron transistor or SET) display "macroscopic charge quantization" which is completely analogous to the quantum Hall effect observed on
Macroscopic quantum phenomena from the large N perspective
International Nuclear Information System (INIS)
Chou, C H; Hu, B L; Subasi, Y
2011-01-01
Macroscopic quantum phenomena (MQP) is a relatively new research venue, with exciting ongoing experiments and bright prospects, yet with surprisingly little theoretical activity. What makes MQP intellectually stimulating is because it is counterpoised against the traditional view that macroscopic means classical. This simplistic and hitherto rarely challenged view need be scrutinized anew, perhaps with much of the conventional wisdoms repealed. In this series of papers we report on a systematic investigation into some key foundational issues of MQP, with the hope of constructing a viable theoretical framework for this new endeavour. The three major themes discussed in these three essays are the large N expansion, the correlation hierarchy and quantum entanglement for systems of 'large' sizes, with many components or degrees of freedom. In this paper we use different theories in a variety of contexts to examine the conditions or criteria whereby a macroscopic quantum system may take on classical attributes, and, more interestingly, that it keeps some of its quantum features. The theories we consider here are, the O(N) quantum mechanical model, semiclassical stochastic gravity and gauge / string theories; the contexts include that of a 'quantum roll' in inflationary cosmology, entropy generation in quantum Vlasov equation for plasmas, the leading order and next-to-leading order large N behaviour, and hydrodynamic / thermodynamic limits. The criteria for classicality in our consideration include the use of uncertainty relations, the correlation between classical canonical variables, randomization of quantum phase, environment-induced decoherence, decoherent history of hydrodynamic variables, etc. All this exercise is to ask only one simple question: Is it really so surprising that quantum features can appear in macroscopic objects? By examining different representative systems where detailed theoretical analysis has been carried out, we find that there is no a priori
The origins of macroscopic quantum coherence in high temperature superconductivity
International Nuclear Information System (INIS)
Turner, Philip; Nottale, Laurent
2015-01-01
Highlights: • We propose a new theoretical approach to superconductivity in p-type cuprates. • Electron pairing mechanisms in the superconducting and pseudogap phases are proposed. • A scale free network of dopants is key to macroscopic quantum coherence. - Abstract: A new, theoretical approach to macroscopic quantum coherence and superconductivity in the p-type (hole doped) cuprates is proposed. The theory includes mechanisms to account for e-pair coupling in the superconducting and pseudogap phases and their inter relations observed in these materials. Electron pair coupling in the superconducting phase is facilitated by local quantum potentials created by static dopants in a mechanism which explains experimentally observed optimal doping levels and the associated peak in critical temperature. By contrast, evidence suggests that electrons contributing to the pseudogap are predominantly coupled by fractal spin waves (fractons) induced by the fractal arrangement of dopants. On another level, the theory offers new insights into the emergence of a macroscopic quantum potential generated by a fractal distribution of dopants. This, in turn, leads to the emergence of coherent, macroscopic spin waves and a second associated macroscopic quantum potential, possibly supported by charge order. These quantum potentials play two key roles. The first involves the transition of an expected diffusive process (normally associated with Anderson localization) in fractal networks, into e-pair coherence. The second involves the facilitation of tunnelling between localized e-pairs. These combined effects lead to the merger of the super conducting and pseudo gap phases into a single coherent condensate at optimal doping. The underlying theory relating to the diffusion to quantum transition is supported by Coherent Random Lasing, which can be explained using an analogous approach. As a final step, an experimental program is outlined to validate the theory and suggests a new
Triboelectricity: macroscopic charge patterns formed by self-arraying ions on polymer surfaces.
Burgo, Thiago A L; Ducati, Telma R D; Francisco, Kelly R; Clinckspoor, Karl J; Galembeck, Fernando; Galembeck, Sergio E
2012-05-15
Tribocharged polymers display macroscopically patterned positive and negative domains, verifying the fractal geometry of electrostatic mosaics previously detected by electric probe microscopy. Excess charge on contacting polyethylene (PE) and polytetrafluoroethylene (PTFE) follows the triboelectric series but with one caveat: net charge is the arithmetic sum of patterned positive and negative charges, as opposed to the usual assumption of uniform but opposite signal charging on each surface. Extraction with n-hexane preferentially removes positive charges from PTFE, while 1,1-difluoroethane and ethanol largely remove both positive and negative charges. Using suitable analytical techniques (electron energy-loss spectral imaging, infrared microspectrophotometry and carbonization/colorimetry) and theoretical calculations, the positive species were identified as hydrocarbocations and the negative species were identified as fluorocarbanions. A comprehensive model is presented for PTFE tribocharging with PE: mechanochemical chain homolytic rupture is followed by electron transfer from hydrocarbon free radicals to the more electronegative fluorocarbon radicals. Polymer ions self-assemble according to Flory-Huggins theory, thus forming the experimentally observed macroscopic patterns. These results show that tribocharging can only be understood by considering the complex chemical events triggered by mechanical action, coupled to well-established physicochemical concepts. Patterned polymers can be cut and mounted to make macroscopic electrets and multipoles.
Comparison of collisionless macroscopic models and application to the ion-electron instability
International Nuclear Information System (INIS)
Ahedo, E.; Lapuerta, V.
2001-01-01
In a first part, different macroscopic models of linear Landau damping are compared using a concise one-dimensional (1-D) collisionless formulation. The three-moment model of Chang and Callen (CC) [Phys. Fluids B 4, 1167 (1992)] with two closure relations (complex in the Fourier space) for the viscous stress and the heat conduction is found to be equivalent to the two-moment model of Stubbe-Sukhorukov (SS) [Phys. Plasmas 6, 2976 (1999)], which uses a single (complex) closure relation for the pressure. The comparison of the respective closure relations favors clearly the SS pressure law, which associates an anomalous resistivity to the Landau damping. In a second part, a macroscopic interpretation, with the SS model, of the ion-electron instability shows its resistive character for low and intermediate drift velocities, and the transition to the reactive Buneman limit. The pressure law for the electrons is found to verify a simple law, whereas approximate laws are discussed for the ion pressure. These laws are used to close a macroscopic model for stability analyses of nonhomogeneous plasma structures, where SS and CC models are not applicable easily
Zeroual, Abdelhafid
2017-08-19
Monitoring vehicle traffic flow plays a central role in enhancing traffic management, transportation safety and cost savings. In this paper, we propose an innovative approach for detection of traffic congestion. Specifically, we combine the flexibility and simplicity of a piecewise switched linear (PWSL) macroscopic traffic model and the greater capacity of the exponentially-weighted moving average (EWMA) monitoring chart. Macroscopic models, which have few, easily calibrated parameters, are employed to describe a free traffic flow at the macroscopic level. Then, we apply the EWMA monitoring chart to the uncorrelated residuals obtained from the constructed PWSL model to detect congested situations. In this strategy, wavelet-based multiscale filtering of data has been used before the application of the EWMA scheme to improve further the robustness of this method to measurement noise and reduce the false alarms due to modeling errors. The performance of the PWSL-EWMA approach is successfully tested on traffic data from the three lane highway portion of the Interstate 210 (I-210) highway of the west of California and the four lane highway portion of the State Route 60 (SR60) highway from the east of California, provided by the Caltrans Performance Measurement System (PeMS). Results show the ability of the PWSL-EWMA approach to monitor vehicle traffic, confirming the promising application of this statistical tool to the supervision of traffic flow congestion.
Zeroual, Abdelhafid; Harrou, Fouzi; Sun, Ying; Messai, Nadhir
2017-01-01
Monitoring vehicle traffic flow plays a central role in enhancing traffic management, transportation safety and cost savings. In this paper, we propose an innovative approach for detection of traffic congestion. Specifically, we combine the flexibility and simplicity of a piecewise switched linear (PWSL) macroscopic traffic model and the greater capacity of the exponentially-weighted moving average (EWMA) monitoring chart. Macroscopic models, which have few, easily calibrated parameters, are employed to describe a free traffic flow at the macroscopic level. Then, we apply the EWMA monitoring chart to the uncorrelated residuals obtained from the constructed PWSL model to detect congested situations. In this strategy, wavelet-based multiscale filtering of data has been used before the application of the EWMA scheme to improve further the robustness of this method to measurement noise and reduce the false alarms due to modeling errors. The performance of the PWSL-EWMA approach is successfully tested on traffic data from the three lane highway portion of the Interstate 210 (I-210) highway of the west of California and the four lane highway portion of the State Route 60 (SR60) highway from the east of California, provided by the Caltrans Performance Measurement System (PeMS). Results show the ability of the PWSL-EWMA approach to monitor vehicle traffic, confirming the promising application of this statistical tool to the supervision of traffic flow congestion.
On quantum effects in the dynamics of macroscopic test masses
International Nuclear Information System (INIS)
Mueller-Ebhardt, Helge
2009-01-01
This thesis provides theoretically a link between the increase of the sensitivity of gravitational-wave detectors and the possibility of preparing macroscopic quantum states in such detectors. In the first part of this thesis, we theoretically explore the quantum measurement noise of an optical speed meter topology, the Sagnac interferometer, equipped with an additional detuned cavity at the output port. This detuned signal-recycling technique was already investigated when applying it to a Michelson interferometer and is used in the gravitational-wave detector GEO600. Together with the quantum noise analysis of the simple Sagnac interferometer, it is the basis of our study: we optimize the Sagnac interferometer's sensitivity towards the detection of a certain gravitational-wave source in the vicinity of a realistic classical noise environment. Motivated by the fact that the Michelson interferometer, as a position meter, with detuned signal-recycling can transduce the gravitational-wave strain into real mirror motion, we compare the transducer effect in a speed and in a position meter. Furthermore, we theoretically investigate the conditional output squeezing of a cavity which is detuned with respect to its carrier and its subcarrier. Therewith we pursue the theoretical analysis of the ponderomotive squeezer. With the knowledge gained in the first part about the quantum measurement process in laser interferometers, the second part of this thesis comprises a theoretical analysis of the conditonal state in positon and momentum of the interferometer's test masses. We motivate not to obtain the conditional states from a stochastic master equation but with the help of the so-called Wiener filtering method. Using this method, we calculate the most general expression for the conditional covariance matrix of the Gaussian state of a test mass under any linear Markovian measurement process. Then we specify to the interferometry and theoretically show under which circumstances
Wave speeds in the macroscopic extended model for ultrarelativistic gases
Energy Technology Data Exchange (ETDEWEB)
Borghero, F., E-mail: borghero@unica.it [Dip. Matematica e Informatica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy); Demontis, F., E-mail: fdemontis@unica.it [Dip. Matematica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy); Pennisi, S., E-mail: spennisi@unica.it [Dip. Matematica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy)
2013-11-15
Equations determining wave speeds for a model of ultrarelativistic gases are investigated. This model is already present in literature; it deals with an arbitrary number of moments and it was proposed in the context of exact macroscopic approaches in Extended Thermodynamics. We find these results: the whole system for the determination of the wave speeds can be divided into independent subsystems which are expressed by linear combinations, through scalar coefficients, of tensors all of the same order; some wave speeds, but not all of them, are expressed by square roots of rational numbers; finally, we prove that these wave speeds for the macroscopic model are the same of those furnished by the kinetic model.
Analysis and Enhancements of a Prolific Macroscopic Model of Epilepsy
Directory of Open Access Journals (Sweden)
Christopher Fietkiewicz
2016-01-01
Full Text Available Macroscopic models of epilepsy can deliver surprisingly realistic EEG simulations. In the present study, a prolific series of models is evaluated with regard to theoretical and computational concerns, and enhancements are developed. Specifically, we analyze three aspects of the models: (1 Using dynamical systems analysis, we demonstrate and explain the presence of direct current potentials in the simulated EEG that were previously undocumented. (2 We explain how the system was not ideally formulated for numerical integration of stochastic differential equations. A reformulated system is developed to support proper methodology. (3 We explain an unreported contradiction in the published model specification regarding the use of a mathematical reduction method. We then use the method to reduce the number of equations and further improve the computational efficiency. The intent of our critique is to enhance the evolution of macroscopic modeling of epilepsy and assist others who wish to explore this exciting class of models further.
Problems related to macroscopic electric fields in the magnetosphere
International Nuclear Information System (INIS)
Faelthammar, C.
1977-01-01
The macroscopic electric fields in the magnetosphere originate from internal as well as external sources. The fields are intimately coupled with the dynamics of magnetospheric plasma convection. They also depend on the complicated electrical properties of the hot collisionless plasma. Macroscopic electric fields are responsible for some important kinds of energization of charged particles that take place in the magnetosphere and affect not only particles of auroral energy but also, by multistep processes, trapped high-energy particles. A particularly interesting feature of magnetospheric electric fields is that they can have substantial components along the geomagnetic field, as has recently been confirmed by observations. Several physical mechanisms have been identified by which such electric fields can be supported even when collisions between particles are negligible. Comments are made on the magnetic mirror effect, anomalous resistivity, the collisionless thermoelectric effect, and electric double layers, emphasizing key features and differences and their significance in the light of recent observational data
Macroscopic balance equations for two-phase flow models
International Nuclear Information System (INIS)
Hughes, E.D.
1979-01-01
The macroscopic, or overall, balance equations of mass, momentum, and energy are derived for a two-fluid model of two-phase flows in complex geometries. These equations provide a base for investigating methods of incorporating improved analysis methods into computer programs, such as RETRAN, which are used for transient and steady-state thermal-hydraulic analyses of nuclear steam supply systems. The equations are derived in a very general manner so that three-dimensional, compressible flows can be analysed. The equations obtained supplement the various partial differential equation two-fluid models of two-phase flow which have recently appeared in the literature. The primary objective of the investigation is the macroscopic balance equations. (Auth.)
Negative heat capacity at phase-separation in macroscopic systems
Gross, D. H. E.
2005-01-01
Systems with long-range as well with short-range interactions should necessarily have a convex entropy S(E) at proper phase transitions of first order, i.e. when a separation of phases occurs. Here the microcanonical heat capacity c(E)= -\\frac{(\\partial S/\\partial E)^2}{\\partial^2S/\\partial E^2} is negative. This should be observable even in macroscopic systems when energy fluctuations with the surrounding world can be sufficiently suppressed.
A macroscopic model for magnetic shape-memory single crystals
Czech Academy of Sciences Publication Activity Database
Bessoud, A. L.; Kružík, Martin; Stefanelli, U.
2013-01-01
Roč. 64, č. 2 (2013), s. 343-359 ISSN 0044-2275 R&D Projects: GA AV ČR IAA100750802; GA ČR GAP201/10/0357 Institutional support: RVO:67985556 Keywords : magnetostriction * evolution Subject RIV: BA - General Mathematics Impact factor: 1.214, year: 2013 http://library.utia.cas.cz/separaty/2012/MTR/kruzik-a macroscopic model for magnetic shape- memory single crystals.pdf
Toward a superconducting quantum computer. Harnessing macroscopic quantum coherence.
Tsai, Jaw-Shen
2010-01-01
Intensive research on the construction of superconducting quantum computers has produced numerous important achievements. The quantum bit (qubit), based on the Josephson junction, is at the heart of this research. This macroscopic system has the ability to control quantum coherence. This article reviews the current state of quantum computing as well as its history, and discusses its future. Although progress has been rapid, the field remains beset with unsolved issues, and there are still many new research opportunities open to physicists and engineers.
Pseudo-Goldstone bosons and new macroscopic forces
International Nuclear Information System (INIS)
Hill, C.T.; Ross, G.G.
1988-01-01
Pseudoscalar Goldstone bosons may readily be associated with weakly, explicitly broken symmetries giving them mixed CP quantum numbers. In general this leads to scalar couplings to nucleons and leptons, which produces coherent long range forces. This can naturally accommodate detectable long range macroscopic forces mediated by bosons completely consistent with conventional cosmological limits, e.g., new interactions with the range of present 'fifth force' searches which probe a scale of new physics of f ≅ 10 14 GeV. (orig.)
Macroscopic quantum mechanics: theory and experimental concepts of optomechanics
International Nuclear Information System (INIS)
Chen Yanbei
2013-01-01
Rapid experimental progress has recently allowed the use of light to prepare macroscopic mechanical objects into nearly pure quantum states. This research field of quantum optomechanics opens new doors towards testing quantum mechanics, and possibly other laws of physics, in new regimes. In the first part of this article, I will review a set of techniques of quantum measurement theory that are often used to analyse quantum optomechanical systems. Some of these techniques were originally designed to analyse how a classical driving force passes through a quantum system, and can eventually be detected with an optimal signal-to-noise ratio—while others focus more on the quantum-state evolution of a mechanical object under continuous monitoring. In the second part of this article, I will review a set of experimental concepts that will demonstrate quantum mechanical behaviour of macroscopic objects—quantum entanglement, quantum teleportation and the quantum Zeno effect. Taking the interplay between gravity and quantum mechanics as an example, I will review a set of speculations on how quantum mechanics can be modified for macroscopic objects, and how these speculations—and their generalizations—might be tested by optomechanics. (invited review)
Macroscopic phase-resetting curves for spiking neural networks
Dumont, Grégory; Ermentrout, G. Bard; Gutkin, Boris
2017-10-01
The study of brain rhythms is an open-ended, and challenging, subject of interest in neuroscience. One of the best tools for the understanding of oscillations at the single neuron level is the phase-resetting curve (PRC). Synchronization in networks of neurons, effects of noise on the rhythms, effects of transient stimuli on the ongoing rhythmic activity, and many other features can be understood by the PRC. However, most macroscopic brain rhythms are generated by large populations of neurons, and so far it has been unclear how the PRC formulation can be extended to these more common rhythms. In this paper, we describe a framework to determine a macroscopic PRC (mPRC) for a network of spiking excitatory and inhibitory neurons that generate a macroscopic rhythm. We take advantage of a thermodynamic approach combined with a reduction method to simplify the network description to a small number of ordinary differential equations. From this simplified but exact reduction, we can compute the mPRC via the standard adjoint method. Our theoretical findings are illustrated with and supported by numerical simulations of the full spiking network. Notably our mPRC framework allows us to predict the difference between effects of transient inputs to the excitatory versus the inhibitory neurons in the network.
Macroscopic phase-resetting curves for spiking neural networks.
Dumont, Grégory; Ermentrout, G Bard; Gutkin, Boris
2017-10-01
The study of brain rhythms is an open-ended, and challenging, subject of interest in neuroscience. One of the best tools for the understanding of oscillations at the single neuron level is the phase-resetting curve (PRC). Synchronization in networks of neurons, effects of noise on the rhythms, effects of transient stimuli on the ongoing rhythmic activity, and many other features can be understood by the PRC. However, most macroscopic brain rhythms are generated by large populations of neurons, and so far it has been unclear how the PRC formulation can be extended to these more common rhythms. In this paper, we describe a framework to determine a macroscopic PRC (mPRC) for a network of spiking excitatory and inhibitory neurons that generate a macroscopic rhythm. We take advantage of a thermodynamic approach combined with a reduction method to simplify the network description to a small number of ordinary differential equations. From this simplified but exact reduction, we can compute the mPRC via the standard adjoint method. Our theoretical findings are illustrated with and supported by numerical simulations of the full spiking network. Notably our mPRC framework allows us to predict the difference between effects of transient inputs to the excitatory versus the inhibitory neurons in the network.
Stochastic and Macroscopic Thermodynamics of Strongly Coupled Systems
Directory of Open Access Journals (Sweden)
Christopher Jarzynski
2017-01-01
Full Text Available We develop a thermodynamic framework that describes a classical system of interest S that is strongly coupled to its thermal environment E. Within this framework, seven key thermodynamic quantities—internal energy, entropy, volume, enthalpy, Gibbs free energy, heat, and work—are defined microscopically. These quantities obey thermodynamic relations including both the first and second law, and they satisfy nonequilibrium fluctuation theorems. We additionally impose a macroscopic consistency condition: When S is large, the quantities defined within our framework scale up to their macroscopic counterparts. By satisfying this condition, we demonstrate that a unifying framework can be developed, which encompasses both stochastic thermodynamics at one end, and macroscopic thermodynamics at the other. A central element in our approach is a thermodynamic definition of the volume of the system of interest, which converges to the usual geometric definition when S is large. We also sketch an alternative framework that satisfies the same consistency conditions. The dynamics of the system and environment are modeled using Hamilton’s equations in the full phase space.
Macroscopic description of the limb muscles of Tupinambis merianae
Directory of Open Access Journals (Sweden)
Juliana Barbosa Casals
2012-03-01
Full Text Available Tegu lizard (Tupinambis merianae belongs to the Teiidae family. It is distributed throughout the Americas, with many species, including Brazilian ones. They are from the Tupinambis genus, the largest representatives of the Teiidae family. For this study three animals (run over coming from donation were used. The dissected lizards were fixed in 10%, formaldehyde, and the macroscopic analysis was carried out in a detailed and photo documented way, keeping the selected structures “in situ”. This paper had as its main aim contributing to the macroscopic description of the chest myology, as well as the thoracic and pelvic limbs of the lizard T. merianae. The results obtained from this research were compared to authors who have studied animals from the same Reptilia class. Thus, we conclude that our macroscopic results are similar to those already described by the researchers Hildebrand (1995, Moro and Abdala (2004 and Abdala and Diogo (2010. We should highlight that the knowledge on anatomy has importance and applications to various areas within Biology, contributing in a substantial way to the areas of human health and technology.
Kruyt, Nicolaas P.; Gutkowski, Witold; Rothenburg, L.; Kowalewski, Tomasz A.
2004-01-01
Using Discrete Element Method (DEM) simulations with varying interparticle friction coefficient, the relation between interparticle friction coefficient and macroscopic continuum friction and dissipation is investigated. As expected, macroscopic friction and dilatancy increase with interparticle
Kobayashi, Tsunehiro
1996-01-01
Quantum macroscopic motions are investigated in the scheme consisting of N-number of harmonic oscillators in terms of ultra-power representations of nonstandard analysis. Decoherence is derived from the large internal degrees of freedom of macroscopic matters.
Directory of Open Access Journals (Sweden)
O. V. Sokolova
2014-01-01
Full Text Available The differential diagnosis of alcoholic and dilated cardiomyopathy according to the macroscopic data is represented in the article. The identity of macroscopic changes of heart, related to alcoholic and dilated cardiomyopathy, cannot diagnose these diseases based on the macroscopic characteristics; especially if there are no other visceral manifestations typical for chronic alcoholism.
Kurihara, Takayuki; Watanabe, Hiroshi; Nakajima, Makoto; Karube, Shutaro; Oto, Kenichi; Otani, YoshiChika; Suemoto, Tohru
2018-03-01
We exploit an intense terahertz magnetic near field combined with femtosecond laser excitation to break the symmetry of photoinduced spin reorientation paths in ErFeO3 . We succeed in aligning macroscopic magnetization reaching up to 80% of total magnetization in the sample to selectable orientations by adjusting the time delay between terahertz and optical pump pulses. The spin dynamics are well reproduced by equations of motion, including time-dependent magnetic potential. We show that the direction of the generated magnetization is determined by the transient direction of spin tilting and the magnetic field at the moment of photoexcitation.
Macroscopic polarization in crystalline dielectrics: the geometric phase approach
International Nuclear Information System (INIS)
Resta, R.
1994-01-01
The macroscopic electric polarization of a crystal is often defined as the dipole of a unit cell. In fact, such a dipole moment is ill defined, and the above definition is incorrect. Looking more closely, the quantity generally measured is differential polarization, defined with respect to a ''reference state'' of the same material. Such differential polarizations include either derivatives of the polarization (dielectric permittivity, Born effective charges, piezoelectricity, pyroelectricity) or finite differences (ferroelectricity). On the theoretical side, the differential concept is basic as well. Owing to continuity, a polarization difference is equivalent to a macroscopic current, which is directly accessible to the theory as a bulk property. Polarization is a quantum phenomenon and cannot be treated with a classical model, particularly whenever delocalized valence electrons are present in the dielectric. In a quantum picture, the current is basically a property of the phase of the wave functions, as opposed to the charge, which is a property of their modulus. An elegant and complete theory has recently been developed by King-Smith and Vanderbilt, in which the polarization difference between any two crystal states--in a null electric field--takes the form of a geometric quantum phase. This gives a comprehensive account of this theory, which is relevant for dealing with transverse-optic phonons, piezoelectricity, and ferroelectricity. Its relation to the established concepts of linear-response theory is also discussed. Within the geometric phase approach, the relevant polarization difference occurs as the circuit integral of a Berry connection (or ''vector potential''), while the corresponding curvature (or ''magnetic field'') provides the macroscopic linear response
Eliyawati; Rohman, I.; Kadarohman, A.
2018-05-01
This research aims to investigate the effect of learning multimedia on students’ understanding of macroscopic, sub-microscopic, and symbolic levels in electrolyte and nonelectrolyte topic. The quasi-experimental with one group pre-test post-test design was used. Thirty-five students were experimental class and another thirty-five were control class. The instrument was used is three representation levels. The t-test was performed on average level of 95% to identify the significant difference between experimental class and control class. The results show that the normalized gain average of experimental class is 0.75 (high) and the normalized gain average of control class is 0.45 (moderate). There is significant difference in students’ understanding in sub-microscopic and symbolic levels and there is not significant difference of students’ understanding in macroscopic level between experimental class and control class. The normalized gain of students’ understanding of macroscopic, sub-microscopic and symbolic in experimental class are 0.6 (moderate), 0.75 (high), and 0.64 (moderate), while the normalized gain of students’ understanding of macroscopic, sub-microscopic and symbolic in control class are 0.49 (moderate), 0.39 (high), and 0.3 (moderate). Therefore, it can be concluded that learning multimedia can help in improving students’ understanding especially in sub-microscopic and symbolic levels.
Macroscopic influence on the spontaneous symmetry breaking in quantum field
International Nuclear Information System (INIS)
Kirzhnitz, D.A.
1977-01-01
Major results of investigations concerning macroscopic influence (heating, compression, external field and current) on elementary particle systems with spontaneous symmetry breaking are briefly reviewed. The study of this problem has been stimulated by recent progress in the unified renormalizable theory of elementary particles. Typically it appears that at some values of external parameters a phase transition with symmetry restoration takes place. There exists a profound and far going analogy with phase transition in many-body physics especially with superconductivity phenomenon. Some applications to cosmology are also considered
Macroscopic relationship in primal-dual portfolio optimization problem
Shinzato, Takashi
2018-02-01
In the present paper, using a replica analysis, we examine the portfolio optimization problem handled in previous work and discuss the minimization of investment risk under constraints of budget and expected return for the case that the distribution of the hyperparameters of the mean and variance of the return rate of each asset are not limited to a specific probability family. Findings derived using our proposed method are compared with those in previous work to verify the effectiveness of our proposed method. Further, we derive a Pythagorean theorem of the Sharpe ratio and macroscopic relations of opportunity loss. Using numerical experiments, the effectiveness of our proposed method is demonstrated for a specific situation.
The Two-Time Interpretation and Macroscopic Time-Reversibility
Directory of Open Access Journals (Sweden)
Yakir Aharonov
2017-03-01
Full Text Available The two-state vector formalism motivates a time-symmetric interpretation of quantum mechanics that entails a resolution of the measurement problem. We revisit a post-selection-assisted collapse model previously suggested by us, claiming that unlike the thermodynamic arrow of time, it can lead to reversible dynamics at the macroscopic level. In addition, the proposed scheme enables us to characterize the classical-quantum boundary. We discuss the limitations of this approach and its broad implications for other areas of physics.
GRUCAL, a computer program for calculating macroscopic group constants
International Nuclear Information System (INIS)
Woll, D.
1975-06-01
Nuclear reactor calculations require material- and composition-dependent, energy averaged nuclear data to describe the interaction of neutrons with individual isotopes in material compositions of reactor zones. The code GRUCAL calculates these macroscopic group constants for given compositions from the material-dependent data of the group constant library GRUBA. The instructions for calculating group constants are not fixed in the program, but will be read at the actual execution time from a separate instruction file. This allows to accomodate GRUCAL to various problems or different group constant concepts. (orig.) [de
Conductance fluctuations in a macroscopic 3-dimensional Anderson insulator
International Nuclear Information System (INIS)
Sanquer, M.
1990-01-01
We report magnetoconductance experiment on a amorphous Y x -Si 1-x alloy (∼0.3). which is an Anderson insulator where spin-orbit scattering is strong. Two principal and new features emerge from the data: the first one is an halving of the localization length by the application of a magnetic field of about 2.5 Teslas. This effect is predicted by a new approach of transport in Anderson insulators where basic symetry considerations are the most important ingredient. The second one is the observation of reproducible conductance fluctuations at very low temperature in this macroscopic 3 D amorphous material
A simple vibrating sample magnetometer for macroscopic samples
Lopez-Dominguez, V.; Quesada, A.; Guzmán-Mínguez, J. C.; Moreno, L.; Lere, M.; Spottorno, J.; Giacomone, F.; Fernández, J. F.; Hernando, A.; García, M. A.
2018-03-01
We here present a simple model of a vibrating sample magnetometer (VSM). The system allows recording magnetization curves at room temperature with a resolution of the order of 0.01 emu and is appropriated for macroscopic samples. The setup can be mounted with different configurations depending on the requirements of the sample to be measured (mass, saturation magnetization, saturation field, etc.). We also include here examples of curves obtained with our setup and comparison curves measured with a standard commercial VSM that confirms the reliability of our device.
Macroscopic quantum tunneling of a Bose-Einstein condensate through double Gaussian barriers
Maeda, Kenji; Urban, Gregor; Weidemüller, Matthias; Carr, Lincoln D.
2015-05-01
Macroscopic quantum tunneling is one of the great manifestations of quantum physics, not only showing passage through a potential barrier but also emerging in a many-body wave function. We study a quasi-1D Bose-Einstein condensate of Lithium, confined by two Gaussian barriers, and show that in an experimentally realistic potential tens of thousands of atoms tunnel on time scales of 10 to 100 ms. Using a combination of variational and WKB approximations based on the Gross-Pitaevskii or nonlinear Schrödinger equation, we show that many unusual tunneling features appear due to the nonlinearity, including the number of trapped atoms exhibiting non-exponential decay, severe distortion of the barriers by the mean field, and even formation of a triple barrier in certain regimes. In the first 10ms, nonlinear many-body effects make the tunneling rates significantly larger than background loss rates, from 10 to 70 Hz. Thus we conclude that macroscopic quantum tunneling can be observed on experimental time scales. Funded by NSF, AFOSR, the Alexander von Humboldt foundation, and the Heidelberg Center for Quantum Dynamics.
International Nuclear Information System (INIS)
Stenlund, B.; Marions, O.; Engstroem, K.F.; Goldie, I.; Soedersjukhuset, Stockholm; Karolinska Sjukhuset, Stockholm
1988-01-01
In a total of 108 acromioclavicular articulations from cadavers the osteoarthrotic changes were studied. The articulations were macroscopically and radiographically ranked according to their grade of osteoarthrosis. The two ranking lines were correlated statistically and showed a rank correlation of 0.741. In 38 articulations tomography was also carried out. These articulations were classified into five grades of osteoarthrosis and the macroscopic, conventional radiographic and tomographic gradings were compared. The correlation coefficient for tomography versus macroscopy was 0.714. Tomography versus standard radiography showed a correlation of 0.767 and standard radiography versus macroscopy a correlation of 0.841. The standard radiographic investigation reveals moderate and severe osteoarthrotic changes in the acromioclavicular joint but cannot depict smaller changes. Tomography does not seem to improve the specificity. There is a need for a better radiologic technique in the examination of the acromioclavicular joint. Radiography during some kind of loading might be a practical way of improving the specificity and make it possible to show early osteoarthrosis in the acromioclavicular articulation. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Stenlund, B.; Marions, O.; Engstroem, K.F.; Goldie, I.
In a total of 108 acromioclavicular articulations from cadavers the osteoarthrotic changes were studied. The articulations were macroscopically and radiographically ranked according to their grade of osteoarthrosis. The two ranking lines were correlated statistically and showed a rank correlation of 0.741. In 38 articulations tomography was also carried out. These articulations were classified into five grades of osteoarthrosis and the macroscopic, conventional radiographic and tomographic gradings were compared. The correlation coefficient for tomography versus macroscopy was 0.714. Tomography versus standard radiography showed a correlation of 0.767 and standard radiography versus macroscopy a correlation of 0.841. The standard radiographic investigation reveals moderate and severe osteoarthrotic changes in the acromioclavicular joint but cannot depict smaller changes. Tomography does not seem to improve the specificity. There is a need for a better radiologic technique in the examination of the acromioclavicular joint. Radiography during some kind of loading might be a practical way of improving the specificity and make it possible to show early osteoarthrosis in the acromioclavicular articulation.
International Nuclear Information System (INIS)
Masouleh, M.N.; Haghdoost, I.S.; Heydari, G.A.C.; Raissi, A.; Mohitmafi, S.
2011-01-01
This study was designed for evaluation of the difference between the ability of greater omentum graft with or without macroscopic fat deposition in acceleration of bone healing process. Adult female New Zealand white rabbits (n=15) were randomly divided into three equal groups. In groups A and B, the drilled hole on the left radius was filled by the omentum without and with macroscopic fat deposition, respectively while drilled hole on the right radius left intact for consideration as control. In group C, the drilled hole on the left and right radius was filled by the omentum sample with and without macroscopic fat deposition, respectively. Experimental bone defects on the radiuses were secured by the pieces of greater omentum, with or without macroscopic fat deposition, which obtained as an autogenous graft from each rabbit in accompany with control samples. Standardized serial radiography for evaluation of bone healing was performed and the difference in bone healing process in three groups of study was determined. According to the obtained data, the radius bones which filled by omentum without macroscopic fat deposition showed faster healing process than the radius bones which filled by omentum with macroscopic fat deposition (P<0.05). (author)
On the macroscopic modeling of dilute emulsions under flow in the presence of particle inertia
Mwasame, Paul M.; Wagner, Norman J.; Beris, Antony N.
2018-03-01
Recently, Mwasame et al. ["On the macroscopic modeling of dilute emulsions under flow," J. Fluid Mech. 831, 433 (2017)] developed a macroscopic model for the dynamics and rheology of a dilute emulsion with droplet morphology in the limit of negligible particle inertia using the bracket formulation of non-equilibrium thermodynamics of Beris and Edwards [Thermodynamics of Flowing Systems: With Internal Microstructure (Oxford University Press on Demand, 1994)]. Here, we improve upon that work to also account for particle inertia effects. This advance is facilitated by using the bracket formalism in its inertial form that allows for the natural incorporation of particle inertia effects into macroscopic level constitutive equations, while preserving consistency to the previous inertialess approximation in the limit of zero inertia. The parameters in the resultant Particle Inertia Thermodynamically Consistent Ellipsoidal Emulsion (PITCEE) model are selected by utilizing literature-available mesoscopic theory for the rheology at small capillary and particle Reynolds numbers. At steady state, the lowest level particle inertia effects can be described by including an additional non-affine inertial term into the evolution equation for the conformation tensor, thereby generalizing the Gordon-Schowalter time derivative. This additional term couples the conformation and vorticity tensors and is a function of the Ohnesorge number. The rheological and microstructural predictions arising from the PITCEE model are compared against steady-shear simulation results from the literature. They show a change in the signs of the normal stress differences that is accompanied by a change in the orientation of the major axis of the emulsion droplet toward the velocity gradient direction with increasing Reynolds number, capturing the two main signatures of particle inertia reported in simulations.
On monogamy of non-locality and macroscopic averages: examples and preliminary results
Directory of Open Access Journals (Sweden)
Rui Soares Barbosa
2014-12-01
Full Text Available We explore a connection between monogamy of non-locality and a weak macroscopic locality condition: the locality of the average behaviour. These are revealed by our analysis as being two sides of the same coin. Moreover, we exhibit a structural reason for both in the case of Bell-type multipartite scenarios, shedding light on but also generalising the results in the literature [Ramanathan et al., Phys. Rev. Lett. 107, 060405 (2001; Pawlowski & Brukner, Phys. Rev. Lett. 102, 030403 (2009]. More specifically, we show that, provided the number of particles in each site is large enough compared to the number of allowed measurement settings, and whatever the microscopic state of the system, the macroscopic average behaviour is local realistic, or equivalently, general multipartite monogamy relations hold. This result relies on a classical mathematical theorem by Vorob'ev [Theory Probab. Appl. 7(2, 147-163 (1962] about extending compatible families of probability distributions defined on the faces of a simplicial complex – in the language of the sheaf-theoretic framework of Abramsky & Brandenburger [New J. Phys. 13, 113036 (2011], such families correspond to no-signalling empirical models, and the existence of an extension corresponds to locality or non-contextuality. Since Vorob'ev's theorem depends solely on the structure of the simplicial complex, which encodes the compatibility of the measurements, and not on the specific probability distributions (i.e. the empirical models, our result about monogamy relations and locality of macroscopic averages holds not just for quantum theory, but for any empirical model satisfying the no-signalling condition. In this extended abstract, we illustrate our approach by working out a couple of examples, which convey the intuition behind our analysis while keeping the discussion at an elementary level.
Macroscopic superposition states and decoherence by quantum telegraph noise
Energy Technology Data Exchange (ETDEWEB)
Abel, Benjamin Simon
2008-12-19
In the first part of the present thesis we address the question about the size of superpositions of macroscopically distinct quantum states. We propose a measure for the ''size'' of a Schroedinger cat state, i.e. a quantum superposition of two many-body states with (supposedly) macroscopically distinct properties, by counting how many single-particle operations are needed to map one state onto the other. We apply our measure to a superconducting three-junction flux qubit put into a superposition of clockwise and counterclockwise circulating supercurrent states and find this Schroedinger cat to be surprisingly small. The unavoidable coupling of any quantum system to many environmental degrees of freedom leads to an irreversible loss of information about an initially prepared superposition of quantum states. This phenomenon, commonly referred to as decoherence or dephasing, is the subject of the second part of the thesis. We have studied the time evolution of the reduced density matrix of a two-level system (qubit) subject to quantum telegraph noise which is the major source of decoherence in Josephson charge qubits. We are able to derive an exact expression for the time evolution of the reduced density matrix. (orig.)
An exploration for the macroscopic physical meaning of entropy
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
The macroscopic physical meaning of entropy is analyzed based on the exergy (availability) of a combined system (a closed system and its environment), which is the maximum amount of useful work obtainable from the system and the environment as the system is brought into equilibrium with the environment. The process the system experiences can be divided in two sequent sub-processes, the process at constant volume, which represents the heat interaction of the system with the environment, and the adiabatic process, which represents the work interaction of the system with the environment. It is shown that the macroscopic physical meaning of entropy is a measure of the unavailable energy of a closed system for doing useful work through heat interaction. This statement is more precise than those reported in prior literature. The unavailability function of a closed system can be defined as T0S and p0V in volume constant process and adiabatic process, respectively. Their changes, that is, AiTgS) and A (p0V) represent the unusable parts of the internal energy of a closed system for doing useful work in corresponding processes. Finally, the relation between Clausius entropy and Boltzmann entropy is discussed based on the comparison of their expressions for absolute entropy.
Estimating minimum polycrystalline aggregate size for macroscopic material homogeneity
International Nuclear Information System (INIS)
Kovac, M.; Simonovski, I.; Cizelj, L.
2002-01-01
During severe accidents the pressure boundary of reactor coolant system can be subjected to extreme loadings, which might cause failure. Reliable estimation of the extreme deformations can be crucial to determine the consequences of severe accidents. Important drawback of classical continuum mechanics is idealization of inhomogenous microstructure of materials. Classical continuum mechanics therefore cannot predict accurately the differences between measured responses of specimens, which are different in size but geometrical similar (size effect). A numerical approach, which models elastic-plastic behavior on mesoscopic level, is proposed to estimate minimum size of polycrystalline aggregate above which it can be considered macroscopically homogeneous. The main idea is to divide continuum into a set of sub-continua. Analysis of macroscopic element is divided into modeling the random grain structure (using Voronoi tessellation and random orientation of crystal lattice) and calculation of strain/stress field. Finite element method is used to obtain numerical solutions of strain and stress fields. The analysis is limited to 2D models.(author)
A Macroscopic Multifractal Analysis of Parabolic Stochastic PDEs
Khoshnevisan, Davar; Kim, Kunwoo; Xiao, Yimin
2018-05-01
It is generally argued that the solution to a stochastic PDE with multiplicative noise—such as \\dot{u}= 1/2 u''+uξ, where {ξ} denotes space-time white noise—routinely produces exceptionally-large peaks that are "macroscopically multifractal." See, for example, Gibbon and Doering (Arch Ration Mech Anal 177:115-150, 2005), Gibbon and Titi (Proc R Soc A 461:3089-3097, 2005), and Zimmermann et al. (Phys Rev Lett 85(17):3612-3615, 2000). A few years ago, we proved that the spatial peaks of the solution to the mentioned stochastic PDE indeed form a random multifractal in the macroscopic sense of Barlow and Taylor (J Phys A 22(13):2621-2626, 1989; Proc Lond Math Soc (3) 64:125-152, 1992). The main result of the present paper is a proof of a rigorous formulation of the assertion that the spatio-temporal peaks of the solution form infinitely-many different multifractals on infinitely-many different scales, which we sometimes refer to as "stretch factors." A simpler, though still complex, such structure is shown to also exist for the constant-coefficient version of the said stochastic PDE.
Macroscopic Biological Characteristics of Individualized Therapy in Chinese Mongolian Osteopathy
Namula, Zhao; Mei, Wang; Li, Xue-en
Objective: Chinese Mongolian osteopathy has been passed down from ancient times and includes unique practices and favorable efficacy. In this study, we investigate the macroscopic biological characteristics of individualized Chinese Mongolian osteopathy, in order to provide new principle and methods for the treatment of bone fracture. Method: With a view to provide a vital link between nature and humans, the four stages of Chinese Mongolian osteopathy focus on the unity of the mind and body, the limbs and body organs, the body and its functions, and humans and nature. Results: We discuss the merits of individualized osteopathy in terms of the underlying concepts, and evaluate the approaches and principles of traditional medicine, as well as biomechanics. Conclusions: Individualized Mongolian osteopathy targets macroscopic biological components including dynamic reduction, natural fixation, and functional healing. Chinese Mongolian osteopathy is a natural, ecological and non-invasive osteopathy that values the link between nature and humans, including the unity of mind and body. The biological components not only serve as a foundation for Chinese Mongolian osteopathy but are also important for the future development of modern osteopathy, focusing on individualization, actualization and integration.
Macroscopic superposition states and decoherence by quantum telegraph noise
International Nuclear Information System (INIS)
Abel, Benjamin Simon
2008-01-01
In the first part of the present thesis we address the question about the size of superpositions of macroscopically distinct quantum states. We propose a measure for the ''size'' of a Schroedinger cat state, i.e. a quantum superposition of two many-body states with (supposedly) macroscopically distinct properties, by counting how many single-particle operations are needed to map one state onto the other. We apply our measure to a superconducting three-junction flux qubit put into a superposition of clockwise and counterclockwise circulating supercurrent states and find this Schroedinger cat to be surprisingly small. The unavoidable coupling of any quantum system to many environmental degrees of freedom leads to an irreversible loss of information about an initially prepared superposition of quantum states. This phenomenon, commonly referred to as decoherence or dephasing, is the subject of the second part of the thesis. We have studied the time evolution of the reduced density matrix of a two-level system (qubit) subject to quantum telegraph noise which is the major source of decoherence in Josephson charge qubits. We are able to derive an exact expression for the time evolution of the reduced density matrix. (orig.)
Inverted rank distributions: Macroscopic statistics, universality classes, and critical exponents
Eliazar, Iddo; Cohen, Morrel H.
2014-01-01
An inverted rank distribution is an infinite sequence of positive sizes ordered in a monotone increasing fashion. Interlacing together Lorenzian and oligarchic asymptotic analyses, we establish a macroscopic classification of inverted rank distributions into five “socioeconomic” universality classes: communism, socialism, criticality, feudalism, and absolute monarchy. We further establish that: (i) communism and socialism are analogous to a “disordered phase”, feudalism and absolute monarchy are analogous to an “ordered phase”, and criticality is the “phase transition” between order and disorder; (ii) the universality classes are characterized by two critical exponents, one governing the ordered phase, and the other governing the disordered phase; (iii) communism, criticality, and absolute monarchy are characterized by sharp exponent values, and are inherently deterministic; (iv) socialism is characterized by a continuous exponent range, is inherently stochastic, and is universally governed by continuous power-law statistics; (v) feudalism is characterized by a continuous exponent range, is inherently stochastic, and is universally governed by discrete exponential statistics. The results presented in this paper yield a universal macroscopic socioeconophysical perspective of inverted rank distributions.
A Macroscopic Multifractal Analysis of Parabolic Stochastic PDEs
Khoshnevisan, Davar; Kim, Kunwoo; Xiao, Yimin
2018-04-01
It is generally argued that the solution to a stochastic PDE with multiplicative noise—such as \\dot{u}= 1/2 u''+uξ, where {ξ} denotes space-time white noise—routinely produces exceptionally-large peaks that are "macroscopically multifractal." See, for example, Gibbon and Doering (Arch Ration Mech Anal 177:115-150, 2005), Gibbon and Titi (Proc R Soc A 461:3089-3097, 2005), and Zimmermann et al. (Phys Rev Lett 85(17):3612-3615, 2000). A few years ago, we proved that the spatial peaks of the solution to the mentioned stochastic PDE indeed form a random multifractal in the macroscopic sense of Barlow and Taylor (J Phys A 22(13):2621-2626, 1989; Proc Lond Math Soc (3) 64:125-152, 1992). The main result of the present paper is a proof of a rigorous formulation of the assertion that the spatio-temporal peaks of the solution form infinitely-many different multifractals on infinitely-many different scales, which we sometimes refer to as "stretch factors." A simpler, though still complex, such structure is shown to also exist for the constant-coefficient version of the said stochastic PDE.
Microscopic and macroscopic models for the onset and progression of Alzheimer's disease
International Nuclear Information System (INIS)
Bertsch, Michiel; Franchi, Bruno; Tesi, Maria Carla; Tosin, Andrea
2017-01-01
In the first part of this paper we review a mathematical model for the onset and progression of Alzheimer’s disease (AD) that was developed in subsequent steps over several years. The model is meant to describe the evolution of AD in vivo . In Achdou et al (2013 J. Math. Biol . 67 1369–92) we treated the problem at a microscopic scale, where the typical length scale is a multiple of the size of the soma of a single neuron. Subsequently, in Bertsch et al (2017 Math. Med. Biol . 34 193–214) we concentrated on the macroscopic scale, where brain neurons are regarded as a continuous medium, structured by their degree of malfunctioning. In the second part of the paper we consider the relation between the microscopic and the macroscopic models. In particular we show under which assumptions the kinetic transport equation, which in the macroscopic model governs the evolution of the probability measure for the degree of malfunctioning of neurons, can be derived from a particle-based setting. The models are based on aggregation and diffusion equations for β -Amyloid (A β from now on), a protein fragment that healthy brains regularly produce and eliminate. In case of dementia A β monomers are no longer properly washed out and begin to coalesce forming eventually plaques. Two different mechanisms are assumed to be relevant for the temporal evolution of the disease: (i) diffusion and agglomeration of soluble polymers of amyloid, produced by damaged neurons; (ii) neuron-to-neuron prion-like transmission. In the microscopic model we consider mechanism (i), modelling it by a system of Smoluchowski equations for the amyloid concentration (describing the agglomeration phenomenon), with the addition of a diffusion term as well as of a source term on the neuronal membrane. At the macroscopic level instead we model processes (i) and (ii) by a system of Smoluchowski equations for the amyloid concentration, coupled to a kinetic-type transport equation for the distribution
Microscopic and macroscopic models for the onset and progression of Alzheimer's disease
Bertsch, Michiel; Franchi, Bruno; Carla Tesi, Maria; Tosin, Andrea
2017-10-01
In the first part of this paper we review a mathematical model for the onset and progression of Alzheimer’s disease (AD) that was developed in subsequent steps over several years. The model is meant to describe the evolution of AD in vivo. In Achdou et al (2013 J. Math. Biol. 67 1369-92) we treated the problem at a microscopic scale, where the typical length scale is a multiple of the size of the soma of a single neuron. Subsequently, in Bertsch et al (2017 Math. Med. Biol. 34 193-214) we concentrated on the macroscopic scale, where brain neurons are regarded as a continuous medium, structured by their degree of malfunctioning. In the second part of the paper we consider the relation between the microscopic and the macroscopic models. In particular we show under which assumptions the kinetic transport equation, which in the macroscopic model governs the evolution of the probability measure for the degree of malfunctioning of neurons, can be derived from a particle-based setting. The models are based on aggregation and diffusion equations for β-Amyloid (Aβ from now on), a protein fragment that healthy brains regularly produce and eliminate. In case of dementia Aβ monomers are no longer properly washed out and begin to coalesce forming eventually plaques. Two different mechanisms are assumed to be relevant for the temporal evolution of the disease: (i) diffusion and agglomeration of soluble polymers of amyloid, produced by damaged neurons; (ii) neuron-to-neuron prion-like transmission. In the microscopic model we consider mechanism (i), modelling it by a system of Smoluchowski equations for the amyloid concentration (describing the agglomeration phenomenon), with the addition of a diffusion term as well as of a source term on the neuronal membrane. At the macroscopic level instead we model processes (i) and (ii) by a system of Smoluchowski equations for the amyloid concentration, coupled to a kinetic-type transport equation for the distribution function of the
Gunji, Yukio-Pegio; Shinohara, Shuji; Haruna, Taichi; Basios, Vasileios
2017-02-01
To overcome the dualism between mind and matter and to implement consciousness in science, a physical entity has to be embedded with a measurement process. Although quantum mechanics have been regarded as a candidate for implementing consciousness, nature at its macroscopic level is inconsistent with quantum mechanics. We propose a measurement-oriented inference system comprising Bayesian and inverse Bayesian inferences. While Bayesian inference contracts probability space, the newly defined inverse one relaxes the space. These two inferences allow an agent to make a decision corresponding to an immediate change in their environment. They generate a particular pattern of joint probability for data and hypotheses, comprising multiple diagonal and noisy matrices. This is expressed as a nondistributive orthomodular lattice equivalent to quantum logic. We also show that an orthomodular lattice can reveal information generated by inverse syllogism as well as the solutions to the frame and symbol-grounding problems. Our model is the first to connect macroscopic cognitive processes with the mathematical structure of quantum mechanics with no additional assumptions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Stochastic space interval as a link between quantum randomness and macroscopic randomness?
Haug, Espen Gaarder; Hoff, Harald
2018-03-01
For many stochastic phenomena, we observe statistical distributions that have fat-tails and high-peaks compared to the Gaussian distribution. In this paper, we will explain how observable statistical distributions in the macroscopic world could be related to the randomness in the subatomic world. We show that fat-tailed (leptokurtic) phenomena in our everyday macroscopic world are ultimately rooted in Gaussian - or very close to Gaussian-distributed subatomic particle randomness, but they are not, in a strict sense, Gaussian distributions. By running a truly random experiment over a three and a half-year period, we observed a type of random behavior in trillions of photons. Combining our results with simple logic, we find that fat-tailed and high-peaked statistical distributions are exactly what we would expect to observe if the subatomic world is quantized and not continuously divisible. We extend our analysis to the fact that one typically observes fat-tails and high-peaks relative to the Gaussian distribution in stocks and commodity prices and many aspects of the natural world; these instances are all observable and documentable macro phenomena that strongly suggest that the ultimate building blocks of nature are discrete (e.g. they appear in quanta).
Directory of Open Access Journals (Sweden)
Chiara Biscarini
2013-01-01
Full Text Available The numerical simulation of fast-moving fronts originating from dam or levee breaches is a challenging task for small scale engineering projects. In this work, the use of fully three-dimensional Navier-Stokes (NS equations and lattice Boltzmann method (LBM is proposed for testing the validity of, respectively, macroscopic and mesoscopic mathematical models. Macroscopic simulations are performed employing an open-source computational fluid dynamics (CFD code that solves the NS combined with the volume of fluid (VOF multiphase method to represent free-surface flows. The mesoscopic model is a front-tracking experimental variant of the LBM. In the proposed LBM the air-gas interface is represented as a surface with zero thickness that handles the passage of the density field from the light to the dense phase and vice versa. A single set of LBM equations represents the liquid phase, while the free surface is characterized by an additional variable, the liquid volume fraction. Case studies show advantages and disadvantages of the proposed LBM and NS with specific regard to the computational efficiency and accuracy in dealing with the simulation of flows through complex geometries. In particular, the validation of the model application is developed by simulating the flow propagating through a synthetic urban setting and comparing results with analytical and experimental laboratory measurements.
Induction of novel macroscopic properties by local symmetry violations in spin-spiral multiferroics
Meier, D.; Leo, N.; Becker, P.; Bohaty, L.; Ramesh, R.; Fiebig, M.
2011-03-01
Incommensurate (IC) structures are omnipresent in strongly correlated electron systems as high-TC superconductors, CMR manganites, as well as multiferroics. In each case they are origin of a pronounced symmetry reduction reflecting the complexity of the underlying microscopic interactions. Macroscopically, this can lead to new phases and possibilities to gain control of the host material. Here we report how the IC nature of a spin-spiral multiferroic induces new physical properties by renormalizing the relevant length scales of the system. Local symmetry violations directly manifest in the macroscopic response of the material and co-determine the multiferroic order giving rise to additional domain states. These usually hidden degrees of freedom become visible when non-homogenous fields are applied and condition for instance the second harmonic generation. Our study shows that incommensurabilities play a vital role in the discussion of the physical properties of multiferroics -- they represent a key ingredient for further enhancing the functionality of this class of materials. This work was supported by the DFG through the SFB 608. D.M. thanks the AvH for financial support.
Time-dependent entropy evolution in microscopic and macroscopic electromagnetic relaxation
International Nuclear Information System (INIS)
Baker-Jarvis, James
2005-01-01
This paper is a study of entropy and its evolution in the time and frequency domains upon application of electromagnetic fields to materials. An understanding of entropy and its evolution in electromagnetic interactions bridges the boundaries between electromagnetism and thermodynamics. The approach used here is a Liouville-based statistical-mechanical theory. I show that the microscopic entropy is reversible and the macroscopic entropy satisfies an H theorem. The spectral entropy development can be very useful for studying the frequency response of materials. Using a projection-operator based nonequilibrium entropy, different equations are derived for the entropy and entropy production and are applied to the polarization, magnetization, and macroscopic fields. I begin by proving an exact H theorem for the entropy, progress to application of time-dependent entropy in electromagnetics, and then apply the theory to relevant applications in electromagnetics. The paper concludes with a discussion of the relationship of the frequency-domain form of the entropy to the permittivity, permeability, and impedance
Directory of Open Access Journals (Sweden)
R. A. Bosch
2008-09-01
Full Text Available In a two-stage compression and acceleration system, where each stage compresses a chirped bunch in a magnetic chicane, wakefields affect high-current bunches. The longitudinal wakes affect the macroscopic energy and current profiles of the compressed bunch and cause microbunching at short wavelengths. For macroscopic wavelengths, impedance formulas and tracking simulations show that the wakefields can be dominated by the resistive impedance of coherent edge radiation. For this case, we calculate the minimum initial bunch length that can be compressed without producing an upright tail in phase space and associated current spike. Formulas are also obtained for the jitter in the bunch arrival time downstream of the compressors that results from the bunch-to-bunch variation of current, energy, and chirp. Microbunching may occur at short wavelengths where the longitudinal space-charge wakes dominate or at longer wavelengths dominated by edge radiation. We model this range of wavelengths with frequency-dependent impedance before and after each stage of compression. The growth of current and energy modulations is described by analytic gain formulas that agree with simulations.
Energy Technology Data Exchange (ETDEWEB)
Wagner, J.N., E-mail: Julia.Wagner@kit.edu [KNMF, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Hofmann, M. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), TU München, Lichtenbergstr. 1, 85747 Garching (Germany); Wimpory, R. [Helmholtz-Zentrum Berlin für Materialien und Energie, D-14109 Berlin Wannsee (Germany); Krempaszky, C. [Christian-Doppler-Labor für Werkstoffmechanik von Hochleistungslegierungen, TU München, Boltzmannstr. 15, 85747 Garching (Germany); Lehrstuhl für Werkstoffkunde und Werkstoffmechanik, TU München, Boltzmannstr. 15, 85747 Garching (Germany); Stockinger, M. [Böhler Schmiedetechnik GmbH and Co KG, Mariazeller Straße 25, 8605 Kapfenberg (Austria)
2014-11-17
Knowledge of the macroscopic residual stresses in components of complex high performance alloys is crucial when it comes to considering the safety and manufacturing aspects of components. Diffraction experiments are one of the key methods for studying residual stresses. However a component of the residual strain determined by diffraction experiments, known as microstrain or intergranular residual strain, occurs over the length scale of the grains and thus plays only a minor role for the life time of such components. For the reliable determination of macroscopic strains (with the minimum influence of these intergranular residual strains), the ISO standard recommends the use of particular Bragg reflections. Here we compare the build-up of intergranular strain of two different precipitation hardened IN 718 (INCONEL 718) samples, with identical chemical composition. Since intergranular strains are also affected by temperature, results from room temperature measurement are compared to results at T=550 °C. It turned out that microstructural parameters, such as grain size or type of precipitates, have a larger effect on the intergranular strain evolution than the influence of temperature at the measurement temperature of T=550 °C. The results also show that the choice of Bragg reflections for the diffractometric residual stress analysis is dependent not only on its chemical composition, but also on the microstructure of the sample. In addition diffraction elastic constants (DECs) for all measured Bragg reflections are given.
Macroscopic Modeling of Transport Phenomena in Direct Methanol Fuel Cells
DEFF Research Database (Denmark)
Olesen, Anders Christian
An increasing need for energy efficiency and high energy density has sparked a growing interest in direct methanol fuel cells for portable power applications. This type of fuel cell directly generates electricity from a fuel mixture consisting of methanol and water. Although this technology...... surpasses batteries in important areas, fundamental research is still required to improve durability and performance. Particularly the transport of methanol and water within the cell structure is difficult to study in-situ. A demand therefore exist for the fundamental development of mathematical models...... for studying their transport. In this PhD dissertation the macroscopic transport phenomena governing direct methanol fuel cell operation are analyzed, discussed and modeled using the two-fluid approach in the computational fluid dynamics framework of CFX 14. The overall objective of this work is to extend...
Generation of macroscopic singlet states in atomic ensembles
Tóth, Géza; Mitchell, Morgan W.
2010-05-01
We study squeezing of the spin uncertainties by quantum non-demolition (QND) measurement in non-polarized spin ensembles. Unlike the case of polarized ensembles, the QND measurements can be performed with negligible back-action, which allows, in principle, perfect spin squeezing as quantified by Tóth et al (2007 Phys. Rev. Lett. 99 250405). The generated spin states approach many-body singlet states and contain a macroscopic number of entangled particles even when individual spin is large. We introduce the Gaussian treatment of unpolarized spin states and use it to estimate the achievable spin squeezing for realistic experimental parameters. Our proposal might have applications for magnetometry with a high spatial resolution or quantum memories storing information in decoherence free subspaces.
Macroscopic chirality of a liquid crystal from nonchiral molecules
International Nuclear Information System (INIS)
Jakli, A.; Nair, G. G.; Lee, C. K.; Sun, R.; Chien, L. C.
2001-01-01
The transfer of chirality from nonchiral polymer networks to the racemic B2 phase of nonchiral banana-shaped molecules is demonstrated. This corresponds to the transfer of chirality from an achiral material to another achiral material. There are two levels of chirality transfers. (a) On a microscopic level the presence of a polymer network (chiral or nonchiral) favors a chiral state over a thermodynamically stable racemic state due to the inversion symmetry breaking at the polymer-liquid crystal interfaces. (b) A macroscopically chiral (enantimerically enriched) sample can be produced if the polymer network has a helical structure, and/or contains chemically chiral groups. The chirality transfer can be locally suppressed by exposing the liquid crystal to a strong electric field treatment
Modeling Macroscopic Shape Distortions during Sintering of Multi-layers
DEFF Research Database (Denmark)
Tadesse Molla, Tesfaye
as to help achieve defect free multi-layer components. The initial thickness ratio between the layers making the multi-layer has also significant effect on the extent of camber evolution depending on the material systems. During sintering of tubular bi-layer structures, tangential (hoop) stresses are very...... large compared to radial stresses. The maximum value of hoop stress, which can generate processing defects such as cracks and coating peel-offs, occurs at the beginning of the sintering cycle. Unlike most of the models defining material properties based on porosity and grain size only, the multi...... (firing). However, unintended features like shape instabilities of samples, cracks or delamination of layers may arise during sintering of multi-layer composites. Among these defects, macroscopic shape distortions in the samples can cause problems in the assembly or performance of the final component...
DEFF Research Database (Denmark)
2014-01-01
The anti-reenactment 'Show-Bix &' consists of 5 dias projectors, a dial phone, quintophonic sound, and interactive elements. A responsive interface will enable the Dias projectors to show copies of original dias slides from the Show-Bix piece ”March på Stedet”, 265 images in total. The copies are...
2008-09-01
measured during operation without breaking the gas environment. For this study, coatings were deposited on 304 stainless steel spheres and rectangular...activated behavior in macroscopic tribology is reserved for systems with stable interfaces and ultra-low wear, and athermal behavior is characteristic to...efforts to measure and under- stand tribological behavior at cryogenic temperatures; to date, results of these efforts show either no trend or con- flicting
Zalaletdinov, R. M.
1998-04-01
The averaging problem in general relativity is briefly discussed. A new setting of the problem as that of macroscopic description of gravitation is proposed. A covariant space-time averaging procedure is described. The structure of the geometry of macroscopic space-time, which follows from averaging Cartan's structure equations, is described and the correlation tensors present in the theory are discussed. The macroscopic field equations (averaged Einstein's equations) derived in the framework of the approach are presented and their structure is analysed. The correspondence principle for macroscopic gravity is formulated and a definition of the stress-energy tensor for the macroscopic gravitational field is proposed. It is shown that the physical meaning of using Einstein's equations with a hydrodynamic stress-energy tensor in looking for cosmological models means neglecting all gravitational field correlations. The system of macroscopic gravity equations to be solved when the correlations are taken into consideration is given and described.
Directory of Open Access Journals (Sweden)
Song Wenyu
2017-06-01
Full Text Available In the current study, a macroscopic lattice Boltzmann model for simulating the heat and moisture transport phenomenon in unsaturated porous media during the freezing process was proposed. The proposed model adopted percolation threshold to reproduce the extra resistance in frozen fringe during the freezing process. The freezing process in Kanagawa sandy loam soil was demonstrated by the proposed model. The numerical result showed good agreement with the experimental result. The proposed model also offered higher computational efficiency and better agreement with the experimental result than the existing numerical models. Lattice Boltzmann method is suitable for simulating complex heat and mass transfer process in porous media at macroscopic scale under proper dimensionless criterion, which makes it a potentially powerful tool for engineering application.
DEFF Research Database (Denmark)
Sandvik, Kjetil; Laursen, Ditte
2014-01-01
User interaction with radio and television programmes is not a new thing. However, with new cross-media production concepts such as X Factor and Voice, this is changing dramatically. The second-screen logic of these productions encourages viewers, along with TV’s traditional one-way communication...... mode, to communicate on interactive (dialogue-enabling) devices such as laptops, smartphones and tablets. Using the TV show Voice as our example, this article shows how the technological and situational set-up of the production invites viewers to engage in new ways of interaction and communication...
Moore, Mitzi Ruth
1992-01-01
Proposes having students perform skits in which they play the roles of the science concepts they are trying to understand. Provides the dialog for a skit in which hot and cold gas molecules are interviewed on a talk show to study how these properties affect wind, rain, and other weather phenomena. (MDH)
Corbee, R J
2014-12-01
Obesity is an important disease with a high prevalence in cats. Because obesity is related to several other diseases, it is important to identify the population at risk. Several risk factors for obesity have been described in the literature. A higher incidence of obesity in certain cat breeds has been suggested. The aim of this study was to determine whether obesity occurs more often in certain breeds. The second aim was to relate the increased prevalence of obesity in certain breeds to the official standards of that breed. To this end, 268 cats of 22 different breeds investigated by determining their body condition score (BCS) on a nine-point scale by inspection and palpation, at two different cat shows. Overall, 45.5% of the show cats had a BCS > 5, and 4.5% of the show cats had a BCS > 7. There were significant differences between breeds, which could be related to the breed standards. Most overweight and obese cats were in the neutered group. It warrants firm discussions with breeders and cat show judges to come to different interpretations of the standards in order to prevent overweight conditions in certain breeds from being the standard of beauty. Neutering predisposes for obesity and requires early nutritional intervention to prevent obese conditions. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.
Honored Teacher Shows Commitment.
Ratte, Kathy
1987-01-01
Part of the acceptance speech of the 1985 National Council for the Social Studies Teacher of the Year, this article describes the censorship experience of this honored social studies teacher. The incident involved the showing of a videotape version of the feature film entitled "The Seduction of Joe Tynan." (JDH)
Energy Technology Data Exchange (ETDEWEB)
Asai, Hidehiro, E-mail: hd-asai@aist.go.jp [Electronics and Photonics Research Institute (ESPRIT), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Ota, Yukihiro [CCSE, Japan Atomic Energy Agency, Kashiwa, Chiba 277-8587 (Japan); Kawabata, Shiro [Electronics and Photonics Research Institute (ESPRIT), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Nori, Franco [CEMS, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)
2014-09-15
Highlights: • We study MQT in Josephson junctions composed of multi-gap superconductors. • We derive a formula of the MQT escape rate for multiple phase differences. • We investigate the effect of inter-band phase fluctuation on MQT. • The MQT escape rate is significantly enhanced by the inter-band phase fluctuation. - Abstract: We theoretically investigate macroscopic quantum tunneling (MQT) in a hetero Josephson junction formed by a conventional single-gap superconductor and a multi-gap superconductor. In such Josephson junctions, phase differences for each tunneling channel are defined, and the fluctuation of the relative phase differences appear which is referred to as Josephson–Leggett’s mode. We take into account the effect of the fluctuation in the tunneling process and calculate the MQT escape rate for various junction parameters. We show that the fluctuation of relative phase differences drastically enhances the escape rate.
Macroscopic self-consistent model for external-reflection near-field microscopy
International Nuclear Information System (INIS)
Berntsen, S.; Bozhevolnaya, E.; Bozhevolnyi, S.
1993-01-01
The self-consistent macroscopic approach based on the Maxwell equations in two-dimensional geometry is developed to describe tip-surface interaction in external-reflection near-field microscopy. The problem is reduced to a single one-dimensional integral equation in terms of the Fourier components of the field at the plane of the sample surface. This equation is extended to take into account a pointlike scatterer placed on the sample surface. The power of light propagating toward the detector as the fiber mode is expressed by using the self-consistent field at the tip surface. Numerical results for trapezium-shaped tips are presented. The authors show that the sharper tip and the more confined fiber mode result in better resolution of the near-field microscope. Moreover, it is found that the tip-surface distance should not be too small so that better resolution is ensured. 14 refs., 10 figs
Build-up of macroscopic eigenstates in a memory-based constrained system
International Nuclear Information System (INIS)
Labousse, M; Perrard, S; Couder, Y; Fort, E
2014-01-01
A bouncing drop and its associated accompanying wave forms a walker. Based on previous works, we show in this article that it is possible to formulate a simple theoretical framework for the walker dynamics. It relies on a time scale decomposition corresponding to the effects successively generated when the memory effects increase. While the short time scale effect is simply responsible for the walker's propulsion, the intermediate scale generates spontaneously pivotal structures endowed with angular momentum. At an even larger memory scale, if the walker is spatially confined, the pivots become the building blocks of a self-organization into a global structure. This new theoretical framework is applied in the presence of an external harmonic potential, and reveals the underlying mechanisms leading to the emergence of the macroscopic spatial organization reported by Perrard et al (2014 Nature Commun. 5 3219). (paper)
Macroscopic Quantum States and Quantum Phase Transition in the Dicke Model
International Nuclear Information System (INIS)
Lian Jin-Ling; Zhang Yuan-Wei; Liang Jiu-Qing
2012-01-01
The energy spectrum of Dicke Hamiltonians with and without the rotating wave approximation for an arbitrary atom number is obtained analytically by means of the variational method, in which the effective pseudo-spin Hamiltonian resulting from the expectation value in the boson-field coherent state is diagonalized by the spin-coherent-state transformation. In addition to the ground-state energy, an excited macroscopic quantum-state is found corresponding to the south- and north-pole gauges of the spin-coherent states, respectively. Our results of ground-state energies in exact agreement with various approaches show that these models exhibit a zero-temperature quantum phase transition of the second order for any number of atoms, which was commonly considered as a phenomenon of the thermodynamic limit with the atom number tending to infinity. The critical behavior of the geometric phase is analyzed. (general)
Sanlı, Ceyda; Saitoh, Kuniyasu; Luding, Stefan; van der Meer, Devaraj
2014-09-01
When a densely packed monolayer of macroscopic spheres floats on chaotic capillary Faraday waves, a coexistence of large scale convective motion and caging dynamics typical for glassy systems is observed. We subtract the convective mean flow using a coarse graining (homogenization) method and reveal subdiffusion for the caging time scales followed by a diffusive regime at later times. We apply the methods developed to study dynamic heterogeneity and show that the typical time and length scales of the fluctuations due to rearrangements of observed particle groups significantly increase when the system approaches its largest experimentally accessible packing concentration. To connect the system to the dynamic criticality literature, we fit power laws to our results. The resultant critical exponents are consistent with those found in densely packed suspensions of colloids.
DEFF Research Database (Denmark)
Wang, D. H.; Kou, R.; Gil, M. P.
2005-01-01
properties of the electrodes, such as electrochemical active area and methanol oxidation, have also been studied. Compared with conventional polycrystalline Pt electrodes, these novel nanowire network electrodes possess high electrochemical active areas and demonstrate higher current densities and a lower...... onset potential for methanol electro-oxidation. Enzymatic Pt nanowire-network-based sensors show higher sensitivity for glucose detection than that using conventional polycrystalline Pt electrode. Such macroscopic nanowire network electrodes provide ideal platforms for sensing and other device......Abstract: Novel platinum nanowire network electrodes have been fabricated through electrodeposition using mesoporous silica thin films as templates. These electrodes were characterized by X-ray diffraction, transmission electron microscope, and scanning electron microscope. The electrochemical...
Directory of Open Access Journals (Sweden)
Zhenqing Wang
2013-01-01
Full Text Available The effect of nanosilica contents on mechanical properties of the epoxy matrix with some nanoparticle aggregations was studied in macroscopic experiments and nanoscale simulation, particularly with regard to the effective modulus and ultimate stress. Three analytical models were used to obtain the effective elastic modulus of nanoparticle-reinforced composites. Based on Monte-Carlo method, the special program for the automatic generation of 2D random distribution particles without overlapping was developed for nanocomposite modeling. Weight fractions of nanoparticles were converted to volume fractions, in order to coordinate the content unit in the simulation. In numerical analysis, the weak interface strengthening and toughening mechanism was adopted. Virtual crack closure technique (VCCT and extended finite element method (XFEM were used to simulate phenomena of nanoparticle debonding and matrix crack growth. Experimental and simulation results show a good agreement with each other. By way of simulation, the weak interface toughening and strengthening mechanism of nanocomposites is confirmed.
International Nuclear Information System (INIS)
Asai, Hidehiro; Ota, Yukihiro; Kawabata, Shiro; Nori, Franco
2014-01-01
Highlights: • We study MQT in Josephson junctions composed of multi-gap superconductors. • We derive a formula of the MQT escape rate for multiple phase differences. • We investigate the effect of inter-band phase fluctuation on MQT. • The MQT escape rate is significantly enhanced by the inter-band phase fluctuation. - Abstract: We theoretically investigate macroscopic quantum tunneling (MQT) in a hetero Josephson junction formed by a conventional single-gap superconductor and a multi-gap superconductor. In such Josephson junctions, phase differences for each tunneling channel are defined, and the fluctuation of the relative phase differences appear which is referred to as Josephson–Leggett’s mode. We take into account the effect of the fluctuation in the tunneling process and calculate the MQT escape rate for various junction parameters. We show that the fluctuation of relative phase differences drastically enhances the escape rate
Dynamic Chiral Magnetic Effect and Faraday Rotation in Macroscopically Disordered Helical Metals.
Ma, J; Pesin, D A
2017-03-10
We develop an effective medium theory for electromagnetic wave propagation through gapless nonuniform systems with a dynamic chiral magnetic effect. The theory allows us to calculate macroscopic-disorder-induced corrections to the values of optical, as well as chiral magnetic conductivities. In particular, we show that spatial fluctuations of the optical conductivity induce corrections to the effective value of the chiral magnetic conductivity. The absolute value of the effect varies strongly depending on the system parameters, but yields the leading frequency dependence of the polarization rotation and circular dichroism signals. Experimentally, these corrections can be observed as features in the Faraday rotation angle near frequencies that correspond to the bulk plasmon resonances of a material. Such features are not expected to be present in single-crystal samples.
Macroscopic objects in quantum mechanics: A combinatorial approach
International Nuclear Information System (INIS)
Pitowsky, Itamar
2004-01-01
Why do we not see large macroscopic objects in entangled states? There are two ways to approach this question. The first is dynamic. The coupling of a large object to its environment cause any entanglement to decrease considerably. The second approach, which is discussed in this paper, puts the stress on the difficulty of observing a large-scale entanglement. As the number of particles n grows we need an ever more precise knowledge of the state and an ever more carefully designed experiment, in order to recognize entanglement. To develop this point we consider a family of observables, called witnesses, which are designed to detect entanglement. A witness W distinguishes all the separable (unentangled) states from some entangled states. If we normalize the witness W to satisfy tr(Wρ)≤1 for all separable states ρ, then the efficiency of W depends on the size of its maximal eigenvalue in absolute value; that is, its operator norm parallel W parallel . It is known that there are witnesses on the space of n qubits for which parallel W parallel is exponential in n. However, we conjecture that for a large majority of n-qubit witnesses parallel W parallel ≤O(√(n log n)). Thus, in a nonideal measurement, which includes errors, the largest eigenvalue of a typical witness lies below the threshold of detection. We prove this conjecture for the family of extremal witnesses introduced by Werner and Wolf [Phys. Rev. A 64, 032112 (2001)
Communication: On the diffusion tensor in macroscopic theory of cavitation
Shneidman, Vitaly A.
2017-08-01
The classical description of nucleation of cavities in a stretched fluid relies on a one-dimensional Fokker-Planck equation (FPE) in the space of their sizes r, with the diffusion coefficient D(r) constructed for all r from macroscopic hydrodynamics and thermodynamics, as shown by Zeldovich. When additional variables (e.g., vapor pressure) are required to describe the state of a bubble, a similar approach to construct a diffusion tensor D ^ generally works only in the direct vicinity of the thermodynamic saddle point corresponding to the critical nucleus. It is shown, nevertheless, that "proper" kinetic variables to describe a cavity can be selected, allowing to introduce D ^ in the entire domain of parameters. In this way, for the first time, complete FPE's are constructed for viscous volatile and inertial fluids. In the former case, the FPE with symmetric D ^ is solved numerically. Alternatively, in the case of an inertial fluid, an equivalent Langevin equation is considered; results are compared with analytics. The suggested approach is quite general and can be applied beyond the cavitation problem.
Macroscopic multigroup constants for accelerator driven system core calculation
International Nuclear Information System (INIS)
Heimlich, Adino; Santos, Rubens Souza dos
2011-01-01
The high-level wastes stored in facilities above ground or shallow repositories, in close connection with its nuclear power plant, can take almost 106 years before the radiotoxicity became of the order of the background. While the disposal issue is not urgent from a technical viewpoint, it is recognized that extended storage in the facilities is not acceptable since these ones cannot provide sufficient isolation in the long term and neither is it ethical to leave the waste problem to future generations. A technique to diminish this time is to transmute these long-lived elements into short-lived elements. The approach is to use an Accelerator Driven System (ADS), a sub-critical arrangement which uses a Spallation Neutron Source (SNS), after separation the minor actinides and the long-lived fission products (LLFP), to convert them to short-lived isotopes. As an advanced reactor fuel, still today, there is a few data around these type of core systems. In this paper we generate macroscopic multigroup constants for use in calculations of a typical ADS fuel, take into consideration, the ENDF/BVI data file. Four energy groups are chosen to collapse the data from ENDF/B-VI data file by PREPRO code. A typical MOX fuel cell is used to validate the methodology. The results are used to calculate one typical subcritical ADS core. (author)
Zero time tunneling: macroscopic experiments with virtual particles
Directory of Open Access Journals (Sweden)
Nimtz Günter
2015-01-01
Full Text Available Feynman introduced virtual particles in his diagrams as intermediate states of an interaction process. They represent necessary intermediate states between observable real states. Such virtual particles were introduced to describe the interaction process between an electron and a positron and for much more complicated interaction processes. Other candidates for virtual particles are evanescent modes in optics and in elastic fields. Evanescent modes have a purely imaginary wave number, they represent the mathematical analogy of the tunneling solutions of the Schrödinger equation. Evanescent modes exist in the forbidden frequency bands of a photonic lattice and in undersized wave guides, for instance. The most prominent example for the occurrence of evanescent modes is the frustrated total internal reflection (FTIR at double prisms. Evanescent modes and tunneling lie outside the bounds of the special theory of relativity. They can cause faster than light (FTL signal velocities. We present examples of the quantum mechanical behavior of evanescent photons and phonons at a macroscopic scale. The evanescent modes of photons are described by virtual particles as predicted by former QED calculations.
The universe as an ultimate macroscopic quantum phenomenon?
International Nuclear Information System (INIS)
Hu, Bei-Lok
2005-01-01
Full text: We explore two unconventional proposals on the meaning of quantum gravity and the quantum properties of spacetime. The first is an older proposal of mine that general relativity is the hydrodynamic limit of some fundamental theories of the microscopic structure of spacetime and matter, a more specific derivative of the idea of Sakharov. The latter is a more recent thought of mine on the possibility that spacetime is a condensate (Bose or Fermi). These proposals have implications radically different from the conventional views. For the former, spacetime described by a differentiable manifold is regarded as an emergent entity and the metric or connection forms are collective variables valid only at the low energy, long wavelength limit of the micro-theories of spacetime and matter. This view would render irrelevant the traditional efforts to find ways to quantize general relativity, because it would only give us the equivalent of phonon physics, not a theory of electrons or photons, QED. In the second proposal, even without the knowledge of what the 'atom of spacetime' is, the mere thought that spacetime at all energies below the Planck scale, including today's, is quantum rather than classical, has many challenging consequences. We discuss the implications of this view pertaining to issues in gravitation and cosmology, as well as to macroscopic quantum coherence phenomena. (author)
Quantum-limited heat conduction over macroscopic distances
Partanen, Matti; Tan, Kuan Yen; Govenius, Joonas; Lake, Russell E.; Mäkelä, Miika K.; Tanttu, Tuomo; Möttönen, Mikko
2016-05-01
The emerging quantum technological apparatuses, such as the quantum computer, call for extreme performance in thermal engineering. Cold distant heat sinks are needed for the quantized electric degrees of freedom owing to the increasing packaging density and heat dissipation. Importantly, quantum mechanics sets a fundamental upper limit for the flow of information and heat, which is quantified by the quantum of thermal conductance. However, the short distance between the heat-exchanging bodies in the previous experiments hinders their applicability in quantum technology. Here, we present experimental observations of quantum-limited heat conduction over macroscopic distances extending to a metre. We achieved this improvement of four orders of magnitude in the distance by utilizing microwave photons travelling in superconducting transmission lines. Thus, it seems that quantum-limited heat conduction has no fundamental distance cutoff. This work establishes the integration of normal-metal components into the framework of circuit quantum electrodynamics, which provides a basis for the superconducting quantum computer. Especially, our results facilitate remote cooling of nanoelectronic devices using faraway in situ-tunable heat sinks. Furthermore, quantum-limited heat conduction is important in contemporary thermodynamics. Here, the long distance may lead to ultimately efficient mesoscopic heat engines with promising practical applications.
Macroscopic local-field effects on photoabsorption processes
International Nuclear Information System (INIS)
Ma Xiaoguang; Gong Yubing; Wang Meishan; Wang Dehua
2008-01-01
The influence of the local-field effect on the photoabsorption cross sections of the atoms which are embedded in the macroscopic medium has been studied by a set of alternative expressions in detail. Some notes on the validity of some different local-field models used to study the photoabsorption cross sections of atoms in condensed matter have been given for the first time. Our results indicate that the local fields can have substantial and different influence on the photoabsorption cross section of atoms in condensed matter for different models. Clausius-Mossotti model and Onsager model have proved to be more reasonable to describe the local field in gas, liquid, or even some simple solid, while Glauber-Lewenstein model probably is wrong in these conditions except for the ideal gas. A procedure which can avoid the errors introduced by Kramers-Kronig transformation has been implemented in this work. This procedure can guarantee that the theoretical studies on the local field effects will not be influenced by the integral instability of the Kramers-Kronig transformation
Three lectures on macroscopic aspects of nuclear dynamics
International Nuclear Information System (INIS)
Swiatecki, W.J.
1979-03-01
These lectures concentrate on macroscopic aspects of nuclear dynamics, those aspects that come into prominence when the number of nucleons, A, is large, A >> 1. An attempt is made to set up a theory of the dynamics of nuclear shape changes, for small (sub-sonic) collective velocities. To set up the equations of motion one needs three forces: conservative, dissipative, and inertial. The first lecture deals with statics, i.e., it discusses methods of treating the Potential Energy Function of nuclear systems. From the Potential Energy the conservative forces that drive the time evolution of a nuclear configuration can be deduced. The division of the underlying potential energy into Local, Proximity, and Global terms is stressed. The second lecture deals with dynamical aspects, especially with the nuclear Dissipation Function, which describes how dissipative frictional forces oppose the conservative driving forces. The underlying physics is the approximate validity of the Independent-Particle model. This, combined with the Randomization Hypothesis, leads to simple formulas that suggest that dissipative forces may often overshadow the inertial forces. The third lecture outlines the kind of dynamics that results from the balance of these forces, and describes a number of applications to nuclear fission and heavy-ion collisions of this New Dynamics. Particularly simple equations of motion are set up, and some of the consequences are explored. 18 references, 31 figures, 3 tables
Validity of macroscopic concepts for fluids on a microscopic scale
International Nuclear Information System (INIS)
Alder, B.J.; Alley, W.E.; Pollock, E.L.
1981-01-01
By Fourier decomposition of the appropriate fluctuation it is possible within the regime of linear response to extend the concept of both thermodynamic quantities and transport coefficients to their dependence on both wavelength and frequency. Experimentally these generalized macroscopic properties are accessible through neutron diffraction and, as examples, the dependence of the sound speed on wavelength and the diffusion coefficient on time are discussed. Through the molecular dynamics computer method the dependence of the viscosity on wavelength is calculated and applied with spectacular success to predict the dependence of the friction coefficient on the size of a Brownian particle all the way to atomic dimensions. On the other hand, the dielectric constant continuum concept, as applied to a charge or dipole in a cavity, generally fails to predict even the correct field at large distance from the charge. Avoiding the introduction of a cavity cures that problem, but the generalized dielectric constant fails badly in predicting the field at shorter distances from the charge. (orig.)
International Nuclear Information System (INIS)
1988-01-01
The Energy Show is a new look at the problems of world energy, where our supplies come from, now and in the future. The programme looks at how we need energy to maintain our standards of living. Energy supply is shown as the complicated set of problems it is - that Fossil Fuels are both raw materials and energy sources, that some 'alternatives' so readily suggested as practical options are in reality a long way from being effective. (author)
Endler, Margit; Saltvedt, Sissel; Papadogiannakis, Nikos
2016-05-01
Retained placenta is a potentially fatal obstetric disorder due to postpartum hemorrhage, its pathophysiology is however unknown. We aimed to assess if retained placenta was associated with increased macroscopic and histological signs of placental maternal underperfusion, a pattern otherwise seen in preeclampsia and other disorders of defective placentation. This was a case-control study of retained (n = 49) and non-retained (n = 47) placentas, collected from full-term singleton and otherwise healthy pregnancies, carried out at a tertiary level obstetric department. Macroscopic and histological analysis was performed. Signs of maternal placental underperfusion and signs of placental inflammation, fetal vascular thrombo-occlusive disease and increased placental attachment were recorded in a primary and secondary analysis respectively. Variables were compared groupwise using unconditional logistic regression or comparison of median or mean values. Compared to non-retained placentas retained placentas had a significantly smaller surface area (p = 0.05), were more oblong in shape (OR 5.24 95% CI:1.34-20.21) and showed overall more signs of maternal underperfusion (OR 2.52 95% CI: 1.07-5.87). There was no significant difference in signs of placental inflammation, fetal vascular thrombo-occlusive disease or placenta accreta but basal plate myometrial fibers were more common among retained placentas. In regard to shape, surface area and histological signs of maternal placental underperfusion, retained placentas showed a histological pattern similar to that seen in preeclamptic placentas. Copyright © 2016 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Zhu, Yuping; Gu, Yunling; Liu, Hongguang
2015-01-01
Directional solidification technology has been widely used to improve the properties of polycrystalline Ni 2 MnGa materials. Mechanical training can adjust the internal organizational structures of the materials, reduce the stress of twin boundaries motion, and then result in larger strain at lower outfield levels. In this paper, we test the microscopic structure of Ni 2 MnGa polycrystalline ferromagnetic shape memory alloy produced by directional solidification and compress it along two axes successively for mechanical training. The influences of pre-compressive stresses on the temperature-induced strains are analyzed. The macroscopic mechanical behaviors show anisotropy. According to the generating mechanism of the macroscopic strain, a three-dimensional constitutive model is established. Based on thermodynamic method, the kinetic equations of the martensitic transformation and inverse transformation are presented considering the driving force and energy dissipation. The prediction curves of temperature-induce strains along two different directions are investigated. And the results coincide well with the experiment data. It well explains the macroscopic anisotropy mechanical behaviors and fits for using in engineering
Leinonen, Risto; Asikainen, Mervi A.; Hirvonen, Pekka E.
2015-01-01
This study concentrates on evaluating the consistency of upper-division students' use of the second law of thermodynamics at macroscopic and microscopic levels. Data were collected by means of a paper and pencil test (N = 48) focusing on the macroscopic and microscopic features of the second law concerned with heat transfer processes. The data…
Quantum mechanics versus macroscopic realism: Is the flux there when nobody looks
International Nuclear Information System (INIS)
Leggett, A.J.; Garg, A.
1985-01-01
It is shown that, in the contect of an idealized ''macroscopic quantum coherence'' experiment, the prediction of quantum mechanics are incompattible with the conjunction of two general assimptions which are designated ''macroscopic realism'' and ''noninvasive measurability at the macroscopiclevel.'' The conditions under which quantum mechanics can be tested against these assumptions in a realistic experiment are discussed
Macroscopic erosion of divertor and first wall armour in future tokamaks
Würz, H.; Bazylev, B.; Landman, I.; Pestchanyi, S.; Safronov, V.
2002-12-01
Sputtering, evaporation and macroscopic erosion determine the lifetime of the 'in vessel' armour materials CFC, tungsten and beryllium presently under discussion for future tokamaks. For CFC armour macroscopic erosion means brittle destruction and dust formation whereas for metallic armour melt layer erosion by melt motion and droplet splashing. Available results on macroscopic erosion from hot plasma and e-beam simulation experiments and from tokamaks are critically evaluated and a comprehensive discussion of experimental and numerical macroscopic erosion and its extrapolation to future tokamaks is given. Shielding of divertor armour materials by their own vapor exists during plasma disruptions. The evolving plasma shield protects the armour from high heat loads, absorbs the incoming energy and reradiates it volumetrically thus reducing drastically the deposited energy. As a result, vertical target erosion by vaporization turns out to be of the order of a few microns per disruption event and macroscopic erosion becomes the dominant erosion source.
Macroscopic erosion of divertor and first wall armour in future tokamaks
International Nuclear Information System (INIS)
Wuerz, H.; Bazylev, B.; Landman, I.; Pestchanyi, S.; Safronov, V.
2002-01-01
Sputtering, evaporation and macroscopic erosion determine the lifetime of the 'in vessel' armour materials CFC, tungsten and beryllium presently under discussion for future tokamaks. For CFC armour macroscopic erosion means brittle destruction and dust formation whereas for metallic armour melt layer erosion by melt motion and droplet splashing. Available results on macroscopic erosion from hot plasma and e-beam simulation experiments and from tokamaks are critically evaluated and a comprehensive discussion of experimental and numerical macroscopic erosion and its extrapolation to future tokamaks is given. Shielding of divertor armour materials by their own vapor exists during plasma disruptions. The evolving plasma shield protects the armour from high heat loads, absorbs the incoming energy and reradiates it volumetrically thus reducing drastically the deposited energy. As a result, vertical target erosion by vaporization turns out to be of the order of a few microns per disruption event and macroscopic erosion becomes the dominant erosion source
Directory of Open Access Journals (Sweden)
Denise Koufogiannakis
2009-06-01
Full Text Available When Su Cleyle and I first decided to start Evidence Based Library and Information Practice, one of the things we agreed upon immediately was that the journal be open access. We knew that a major obstacle to librarians using the research literature was that they did not have access to the research literature. Although Su and I are both academic librarians who can access a wide variety of library and information literature from our institutions, we belong to a profession where not everyone has equal access to the research in our field. Without such access to our own body of literature, how can we ever hope for practitioners to use research evidence in their decision making? It would have been contradictory to the principles of evidence based library and information practice to do otherwise.One of the specific groups we thought could use such an open access venue for discovering research literature was school librarians. School librarians are often isolated and lacking access to the research literature that may help them prove to stakeholders the importance of their libraries and their role within schools. Certainly, school libraries have been in decline and the use of evidence to show value is needed. As Ken Haycock noted in his 2003 report, The Crisis in Canada’s School Libraries: The Case for Reform and Reinvestment, “Across the country, teacher-librarians are losing their jobs or being reassigned. Collections are becoming depleted owing to budget cuts. Some principals believe that in the age of the Internet and the classroom workstation, the school library is an artifact” (9. Within this context, school librarians are looking to our research literature for evidence of the impact that school library programs have on learning outcomes and student success. They are integrating that evidence into their practice, and reflecting upon what can be improved locally. They are focusing on students and showing the impact of school libraries and
Macroscopic behavior and microscopic magnetic properties of nanocarbon
Energy Technology Data Exchange (ETDEWEB)
Lähderanta, E., E-mail: Erkki.Lahderanta@lut.fi [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Ryzhov, V.A. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Petersburg Nuclear Physics Institute, NRC “Kurchatov Institute”, Orlova Coppice, Gatchina, Leningrad province 188300 (Russian Federation); Lashkul, A.V. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Galimov, D.M. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); South Ural State University, 454080 Chelyabinsk (Russian Federation); Titkov, A.N. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); A. F. Ioffe Physico-Technical Institute, 194021 St. Petersburg (Russian Federation); Matveev, V.V. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Saint-Petersburg State University, Saint-Petersburg 198504 (Russian Federation); Mokeev, M.V. [Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg (Russian Federation); Kurbakov, A.I. [Petersburg Nuclear Physics Institute, NRC “Kurchatov Institute”, Orlova Coppice, Gatchina, Leningrad province 188300 (Russian Federation); Lisunov, K.G. [Lappeenranta University of Technology, PO Box 20, FIN-53851 Lappeenranta (Finland); Institute of Applied Physics ASM, Academiei Str., 5, MD 2028 Kishinev (Moldova, Republic of)
2015-06-01
Here are presented investigations of powder and glass-like samples containing carbon nanoparticles, not intentionally doped and doped with Ag, Au and Co. The neutron diffraction study reveals an amorphous structure of the samples doped with Au and Co, as well as the magnetic scattering due to a long-range FM order in the Co-doped sample. The composition and molecular structure of the sample doped with Au is clarified with the NMR investigations. The temperature dependence of the magnetization, M (T), exhibits large irreversibility in low fields of B=1–7 mT. M (B) saturates already above 2 T at high temperatures, but deviates from the saturation behavior below ~50 (150 K). Magnetic hysteresis is observed already at 300 K and exhibits a power-law temperature decay of the coercive field, B{sub c} (T). The macroscopic behavior above is typical of an assembly of partially blocked magnetic nanoparticles. The values of the saturation magnetization, M{sub s}, and the blocking temperature, T{sub b}, are obtained as well. However, the hysteresis loop in the Co-doped sample differs from that in other samples, and the values of B{sub c} and M{sub s} are noticeably increased. - Highlights: • We have investigated powder and glassy samples with carbon nanoparticles. • They include an undoped sample and those doped with Ag, Au and Co. • Neutron diffraction study reveals amorphous structure of Au- and Co-doped samples. • Composition and molecular structure of Au-doped sample was investigated with NMR. • Magnetic behavior is typical of an assembly of partially blocked magnetic nanoparticles.
Macroscopic behavior and microscopic magnetic properties of nanocarbon
International Nuclear Information System (INIS)
Lähderanta, E.; Ryzhov, V.A.; Lashkul, A.V.; Galimov, D.M.; Titkov, A.N.; Matveev, V.V.; Mokeev, M.V.; Kurbakov, A.I.; Lisunov, K.G.
2015-01-01
Here are presented investigations of powder and glass-like samples containing carbon nanoparticles, not intentionally doped and doped with Ag, Au and Co. The neutron diffraction study reveals an amorphous structure of the samples doped with Au and Co, as well as the magnetic scattering due to a long-range FM order in the Co-doped sample. The composition and molecular structure of the sample doped with Au is clarified with the NMR investigations. The temperature dependence of the magnetization, M (T), exhibits large irreversibility in low fields of B=1–7 mT. M (B) saturates already above 2 T at high temperatures, but deviates from the saturation behavior below ~50 (150 K). Magnetic hysteresis is observed already at 300 K and exhibits a power-law temperature decay of the coercive field, B c (T). The macroscopic behavior above is typical of an assembly of partially blocked magnetic nanoparticles. The values of the saturation magnetization, M s , and the blocking temperature, T b , are obtained as well. However, the hysteresis loop in the Co-doped sample differs from that in other samples, and the values of B c and M s are noticeably increased. - Highlights: • We have investigated powder and glassy samples with carbon nanoparticles. • They include an undoped sample and those doped with Ag, Au and Co. • Neutron diffraction study reveals amorphous structure of Au- and Co-doped samples. • Composition and molecular structure of Au-doped sample was investigated with NMR. • Magnetic behavior is typical of an assembly of partially blocked magnetic nanoparticles
Proton irradiation effects on beryllium – A macroscopic assessment
Energy Technology Data Exchange (ETDEWEB)
Simos, Nikolaos, E-mail: simos@bnl.gov [Nuclear Sciences & Technology Department, Brookhaven National Laboratory, Upton, NY, 11973 (United States); Elbakhshwan, Mohamed [Nuclear Sciences & Technology Department, Brookhaven National Laboratory, Upton, NY, 11973 (United States); Zhong, Zhong [Photon Sciences, NSLS II, Brookhaven National Laboratory, Upton, NY, 11973 (United States); Camino, Fernando [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973 (United States)
2016-10-15
Beryllium, due to its excellent neutron multiplication and moderation properties, in conjunction with its good thermal properties, is under consideration for use as plasma facing material in fusion reactors and as a very effective neutron reflector in fission reactors. While it is characterized by unique combination of structural, chemical, atomic number, and neutron absorption cross section it suffers, however, from irradiation generated transmutation gases such as helium and tritium which exhibit low solubility leading to supersaturation of the Be matrix and tend to precipitate into bubbles that coalesce and induce swelling and embrittlement thus degrading the metal and limiting its lifetime. Utilization of beryllium as a pion production low-Z target in high power proton accelerators has been sought both for its low Z and good thermal properties in an effort to mitigate thermos-mechanical shock that is expected to be induced under the multi-MW power demand. To assess irradiation-induced changes in the thermal and mechanical properties of Beryllium, a study focusing on proton irradiation damage effects has been undertaken using 200 MeV protons from the Brookhaven National Laboratory Linac and followed by a multi-faceted post-irradiation analysis that included the thermal and volumetric stability of irradiated beryllium, the stress-strain behavior and its ductility loss as a function of proton fluence and the effects of proton irradiation on the microstructure using synchrotron X-ray diffraction. The mimicking of high temperature irradiation of Beryllium via high temperature annealing schemes has been conducted as part of the post-irradiation study. This paper focuses on the thermal stability and mechanical property changes of the proton irradiated beryllium and presents results of the macroscopic property changes of Beryllium deduced from thermal and mechanical tests.
Innovations in macroscopic evaluation of pancreatic specimens and radiologic correlation
Directory of Open Access Journals (Sweden)
Charikleia Triantopoulou
2016-01-01
Full Text Available The purpose of this study was to evaluate the feasibility of a novel dissection technique of surgical specimens in different cases of pancreatic tumors and provide a radiologic pathologic correlation. In our hospital, that is a referral center for pancreatic diseases, the macroscopic evaluation of the pancreatectomy specimens is performed by the pathologists using the axial slicing technique (instead of the traditional procedure with longitudinal opening of the main pancreatic and/or common bile duct and slicing along the plane defined by both ducts. The specimen is sliced in an axial plane that is perpendicular to the longitudinal axis of the descending duodenum. The procedure results in a large number of thin slices (3–4 mm. This plane is identical to that of CT or MRI and correlation between pathology and imaging is straightforward. We studied 70 cases of suspected different solid and cystic pancreatic tumors and we correlated the tumor size and location, the structure—consistency (areas of necrosis—hemorrhage—fibrosis—inflammation, the degree of vessels’ infiltration, the size of pancreatic and common bile duct and the distance from resection margins. Missed findings by imaging or pitfalls were recorded and we tried to explain all discrepancies between radiology evaluation and the histopathological findings. Radiologic-pathologic correlation is extremely important, adding crucial information on imaging limitations and enabling quality assessment of surgical specimens. The deep knowledge of different pancreatic tumors’ consistency and way of extension helps to improve radiologists’ diagnostic accuracy and minimize the radiological-surgical mismatching, preventing patients from unnecessary surgery.
NMR studies of macroscopic and microscopic properties of liquid crystals
International Nuclear Information System (INIS)
Hughes, J.R.
1998-03-01
The work presented is concerned with studies of orientational order in liquid crystals and the behaviour of certain mesophases. The experimental technique used in common with all the work is deuterium NMR spectroscopy. Much of the work involves studies of the orientational order of deuteriated solute molecules dissolved in liquid crystal solvents. Chapter 1 gives an introduction to liquid crystals followed by a quantitative description of orientational order. Deuterium NMR in liquid crystals is described and an outline of the molecular field theory behind the orientational order of a rigid, biaxial solute in a uniaxial mesophase is given. In Chapter 2 a novel type of mesophase induction is studied using NMR, where a solute induces up to two extra phases in a discotic mesogen depending on its concentration. The purpose of this work is to try to gain an understanding into the mechanism of the phase induction involved. Chapter 3 is concerned primarily with the macroscopic behaviour of the nematic phase formed by a semi-rigid main-chain polymer in solution. Of particular interest is the study of the reorientation of the monodomain, once the director has been rotated with respect to the magnetic field of the NMR spectrometer. A mesogen which has been claimed to exhibit a biaxial nematic phase is studied in Chapter 4, in order to determine the symmetry of the phase using NMR. Finally, Chapter 5 deals with the differing behaviour of a liquid crystal monomer and its dimer dissolved in common nematic solvents in order to determine whether this agrees with molecular field theory. (author)
King, Simon; Dimech, Margaret; Johnstone, Susan
2016-06-01
We examined whether introduction of a structured macroscopic reporting template for rectal tumour resection specimens improved the completeness and efficiency in collecting key macroscopic data elements. Fifty free text (narrative) macroscopic reports retrieved from 2012 to 2014 were compared with 50 structured macroscopic reports from 2013 to 2015, all of which were generated at John Hunter Hospital, Newcastle, NSW. The six standard macroscopic data elements examined in this study were reported in all 50 anatomical pathology reports using a structured macroscopic reporting dictation template. Free text reports demonstrated significantly impaired data collection when recording intactness of mesorectum (p<0.001), relationship to anterior peritoneal reflection (p=0.028) and distance of tumour to the non-peritonealised circumferential margin (p<0.001). The number of words used was also significantly (p<0.001) reduced using pre-formatted structured reports compared to free text reports. The introduction of a structured reporting dictation template improves data collection and may reduce the subsequent administrative burden when macroscopically evaluating rectal resections. Copyright © 2016 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.
Innovations in macroscopic evaluation of pancreatic specimens and radiologic correlation
International Nuclear Information System (INIS)
Triantopoulou, Charikleia; Papaparaskeva, Kleo; Agalianos, Christos; Dervenis, Christos
2016-01-01
•The axial slicing technique offers many advantages in accurate estimation of tumors extend and staging.•Cross-sectional axial imaging is the best technique for accurate radiologic-pathologic correlation.•Correlation may explain any discrepancies between radiological and histopathological findings.•Pathology correlation may offer a better understanding of the missed findings by imaging or pitfalls The axial slicing technique offers many advantages in accurate estimation of tumors extend and staging. Cross-sectional axial imaging is the best technique for accurate radiologic-pathologic correlation. Correlation may explain any discrepancies between radiological and histopathological findings. Pathology correlation may offer a better understanding of the missed findings by imaging or pitfalls The purpose of this study was to evaluate the feasibility of a novel dissection technique of surgical specimens in different cases of pancreatic tumors and provide a radiologic pathologic correlation. In our hospital, that is a referral center for pancreatic diseases, the macroscopic evaluation of the pancreatectomy specimens is performed by the pathologists using the axial slicing technique (instead of the traditional procedure with longitudinal opening of the main pancreatic and/or common bile duct and slicing along the plane defined by both ducts). The specimen is sliced in an axial plane that is perpendicular to the longitudinal axis of the descending duodenum. The procedure results in a large number of thin slices (3–4 mm). This plane is identical to that of CT or MRI and correlation between pathology and imaging is straightforward. We studied 70 cases of suspected different solid and cystic pancreatic tumors and we correlated the tumor size and location, the structure—consistency (areas of necrosis—hemorrhage—fibrosis—inflammation), the degree of vessels’ infiltration, the size of pancreatic and common bile duct and the distance from resection margins
Polymorphic phase transitions: Macroscopic theory and molecular simulation.
Anwar, Jamshed; Zahn, Dirk
2017-08-01
Transformations in the solid state are of considerable interest, both for fundamental reasons and because they underpin important technological applications. The interest spans a wide spectrum of disciplines and application domains. For pharmaceuticals, a common issue is unexpected polymorphic transformation of the drug or excipient during processing or on storage, which can result in product failure. A more ambitious goal is that of exploiting the advantages of metastable polymorphs (e.g. higher solubility and dissolution rate) while ensuring their stability with respect to solid state transformation. To address these issues and to advance technology, there is an urgent need for significant insights that can only come from a detailed molecular level understanding of the involved processes. Whilst experimental approaches at best yield time- and space-averaged structural information, molecular simulation offers unprecedented, time-resolved molecular-level resolution of the processes taking place. This review aims to provide a comprehensive and critical account of state-of-the-art methods for modelling polymorph stability and transitions between solid phases. This is flanked by revisiting the associated macroscopic theoretical framework for phase transitions, including their classification, proposed molecular mechanisms, and kinetics. The simulation methods are presented in tutorial form, focusing on their application to phase transition phenomena. We describe molecular simulation studies for crystal structure prediction and polymorph screening, phase coexistence and phase diagrams, simulations of crystal-crystal transitions of various types (displacive/martensitic, reconstructive and diffusive), effects of defects, and phase stability and transitions at the nanoscale. Our selection of literature is intended to illustrate significant insights, concepts and understanding, as well as the current scope of using molecular simulations for understanding polymorphic
Observation of squeezed light and quantum description of the macroscopical body movement
International Nuclear Information System (INIS)
Bykov, V.P.
1992-01-01
The possibility of a nondemolition measurement (observation) of macroscopical objects in widely distributed quantum mechanical states arises from the fact of the squezzed light observation. Macroscopical bodies -bodies of classical mechanics - are usually in states with narrow wave packets. It is shown that the absence of macroscopical bodies in widely distributed states is due to the focusing influence of the body's gravity field on its wave packet. An evidence that the gravity is essential in the classic limit of quantum mechanics is given. (author). 14 refs, 7 figs
From Microscopic to Macroscopic Descriptions of Cell Migration on Growing Domains
Baker, Ruth E.; Yates, Christian A.; Erban, Radek
2009-01-01
are studied, and correspondence with a macroscopic-level PDE describing the evolution of cell density is demonstrated. The individual-based models are formulated in terms of random walkers on a lattice. Domain growth provides an extra mathematical challenge
New nuclear data set ABBN-90 and its testing on macroscopic experiments
International Nuclear Information System (INIS)
Kosh'cheev, V.N.; Manturov, G.N.; Nikolaev, M.N.; Rineyskiy, A.A.; Sinitsa, V.V.; Tsyboolya, A.M.; Zabrodskaya, S.V.
1993-01-01
The new group constant set ABBN-90 is developed now. It based on the FOND-2 evaluated neutron data library processed with the code GRUCON. Some results of the testing ABBN-90 set in different macroscopic experiments are presented. (author)
Relationship Between Filler-Matrix Interface and Macroscopical Properties of Polymer Nanocomposites
Ventura, Isaac Aguilar
2017-01-01
The macroscopic properties of Multiwall Carbon Nanotube (MWCNT) polymer nano-composites and multiscale composites have been studied from a multifunctional standpoint. The objective is to understand and correlate the mechanisms in which the addition
Equation-Free Analysis of Macroscopic Behavior in Traffic and Pedestrian Flow
DEFF Research Database (Denmark)
Marschler, Christian; Sieber, Jan; Hjorth, Poul G.
2014-01-01
Equation-free methods make possible an analysis of the evolution of a few coarse-grained or macroscopic quantities for a detailed and realistic model with a large number of fine-grained or microscopic variables, even though no equations are explicitly given on the macroscopic level. This will fac......Equation-free methods make possible an analysis of the evolution of a few coarse-grained or macroscopic quantities for a detailed and realistic model with a large number of fine-grained or microscopic variables, even though no equations are explicitly given on the macroscopic level....... This will facilitate a study of how the model behavior depends on parameter values including an understanding of transitions between different types of qualitative behavior. These methods are introduced and explained for traffic jam formation and emergence of oscillatory pedestrian counter flow in a corridor...
Polyelectrolyte surfactant aggregates and their deposition on macroscopic surfaces
International Nuclear Information System (INIS)
Voisin, David
2002-01-01
cationically modified guar gums (of varying charge density) with two anionic surfactants: sodium lauryl (or dodecyl) ether sulfate [SLES] and sodium dodecyl sulfate [SDS], for various concentrations of the polyelectrolyte and added sodium chloride, at room temperature. The addition of sodium chloride has only a minor net effect on the CFC, but increases the CSC significantly. The interactions between the cationic polyelectrolyte and the surfactant have been studied in the one-phase regions, i.e. below the CFC and above the CSC, using different techniques. Surface tension, electrophoresis, light scattering and viscosimetry have been employed. In the two-phase region, the sedimented floe phase has been analysed and the flocculation has been investigated. Rheology of the floe phase has been studied, after a mild compression by centrifugation. The initial rate of flocculation has been determined, using stop-flow equipment. The growth and the structure of the flocs have been investigated by light scattering. The open-network flocs of polyelectrolyte-surfactant particles grow to ∼10's μm in size, prior to their eventual settling out. Other colloidal particles can be trapped within these large flocs, and the flocs can be used to transport these particles to a macroscopic surface. The deposition and the removal of such composite flocs on glass surfaces, under flow, have been studied using a flow cell device coupled with an optical microscope. Scanning electron microscopy and atomic force microscopy have also been employed. (author)
Polyelectrolyte surfactant aggregates and their deposition on macroscopic surfaces
Energy Technology Data Exchange (ETDEWEB)
Voisin, David
2002-07-01
the CSC have been determined for mixtures of cationically modified guar gums (of varying charge density) with two anionic surfactants: sodium lauryl (or dodecyl) ether sulfate [SLES] and sodium dodecyl sulfate [SDS], for various concentrations of the polyelectrolyte and added sodium chloride, at room temperature. The addition of sodium chloride has only a minor net effect on the CFC, but increases the CSC significantly. The interactions between the cationic polyelectrolyte and the surfactant have been studied in the one-phase regions, i.e. below the CFC and above the CSC, using different techniques. Surface tension, electrophoresis, light scattering and viscosimetry have been employed. In the two-phase region, the sedimented floe phase has been analysed and the flocculation has been investigated. Rheology of the floe phase has been studied, after a mild compression by centrifugation. The initial rate of flocculation has been determined, using stop-flow equipment. The growth and the structure of the flocs have been investigated by light scattering. The open-network flocs of polyelectrolyte-surfactant particles grow to {approx}10's {mu}m in size, prior to their eventual settling out. Other colloidal particles can be trapped within these large flocs, and the flocs can be used to transport these particles to a macroscopic surface. The deposition and the removal of such composite flocs on glass surfaces, under flow, have been studied using a flow cell device coupled with an optical microscope. Scanning electron microscopy and atomic force microscopy have also been employed. (author)
Effect of isovector coupling channel on the macroscopic part of the nuclear binding energy
International Nuclear Information System (INIS)
Haddad, S.
2011-04-01
The effect of the isovector coupling channel on the macroscopic part of the nuclear binding energy is determined utilizing the relativistic density dependent Thomas-Fermi approach for the calculation of the macroscopic part of the nuclear binding energy, and the dependency of this effect on the numbers of neutrons and protons is studied. The isovector coupling channel leads to increased nuclear binding energy, and this effect sharpens with growing excess of the number of neutrons on the number of protons. (author)
Experimental observation of the quantum behavior of a macroscopic degree of freedom
International Nuclear Information System (INIS)
Devoret, M.H.; Martinis, J.M.; Esteve, D.
1986-08-01
At Berkeley a series of experiments have been performed, that demonstrates the quantum behavior of one macroscopic degree of freedom, namely the phase difference across a current biased Josephson junction. Here we will focus on the praticalities involved in such a demonstration. The emphasis is put on the particular procedures used to solve the two problems of noise shielding and parameter determination. To begin, a short description of the macroscopic system investigated, the current biased Josephson junction is given
Yan, Zhifeng; Liu, Chongxuan; Liu, Yuanyuan; Bailey, Vanessa L.
2017-11-01
Biofilms are critical locations for biogeochemical reactions in the subsurface environment. The occurrence and distribution of biofilms at microscale as well as their impacts on macroscopic biogeochemical reaction rates are still poorly understood. This paper investigated the formation and distributions of biofilms in heterogeneous sediments using multiscale models and evaluated the effects of biofilm heterogeneity on local and macroscopic biogeochemical reaction rates. Sediment pore structures derived from X-ray computed tomography were used to simulate the microscale flow dynamics and biofilm distribution in the sediment column. The response of biofilm formation and distribution to the variations in hydraulic and chemical properties was first examined. One representative biofilm distribution was then utilized to evaluate its effects on macroscopic reaction rates using nitrate reduction as an example. The results revealed that microorganisms primarily grew on the surfaces of grains and aggregates near preferential flow paths where both electron donor and acceptor were readily accessible, leading to the heterogeneous distribution of biofilms in the sediments. The heterogeneous biofilm distribution decreased the macroscopic rate of biogeochemical reactions as compared with those in homogeneous cases. Operationally considering the heterogeneous biofilm distribution in macroscopic reactive transport models such as using dual porosity domain concept can significantly improve the prediction of biogeochemical reaction rates. Overall, this study provided important insights into the biofilm formation and distribution in soils and sediments as well as their impacts on the macroscopic manifestation of reaction rates.
Theory of macroscopic quantum tunneling in high-T c cuprate
International Nuclear Information System (INIS)
Kawabata, Shiro; Tanaka, Yukio; Kashiwaya, Satoshi; Asano, Yasuhiro
2006-01-01
To reveal macroscopic quantum tunneling (MQT) in high-T c superconductor Josephson junctions is an important issue since there is a possibility to fabricate a superconducting quantum bit by use of high T c junctions. Using the functional integral and the instanton theory, we analytically obtain the MQT rate (the inverse lifetime of the metastable state) for the c-axis twist Josephson junctions. In the case of the zero twist angle, the system shows the super-Ohmic dissipation due to the presence of the nodal quasiparticle tunneling. Therefore, the MQT rate is suppressed compared with the finite twist angle cases. Furthermore, the effect of the zero energy bound states (ZES) on the MQT in the in-plane junctions is theoretically investigated. We obtained the analytical formula of the MQT rate and showed that the presence of the ZES at the normal/superconductor interface leads to a strong Ohmic quasiparticle dissipation. Therefore, the MQT rate is noticeably inhibited compared with the c-axis junctions in which the ZES are completely absent
Tracer sorption and macroscopic transport in clay nano-pores: a lattice-Boltzmann study
International Nuclear Information System (INIS)
Levesque, Maximilien; Rotenberg, Benjamin; Duvail, Magali; Benichou, Olivier; Voituriez, Raphael; Pagonabarraga, Ignacio; Frenkel, Daan
2012-01-01
Document available in extended abstract form only. The Agence Nationale pour la gestion des Dechets Radioactifs (ANDRA) has been entrusted to find a safe solution for disposing of existing and future nuclear wastes. A prototype site has been considered for the waste disposal in a deep underground sedimentary geological formation. It is composed of clay minerals chosen, among other reasons, for their remarkable ability to limit radionuclide transport. Clay minerals are complex charged porous media characterized by heterogeneities at several length scales. They naturally occur as an assembly of few nano-meter-sized particles connected to form 10 to 100 nm interparticle pores containing water and ions. This intrinsically multi-scale structure, that gives the material its remarkable properties, makes the description of sorption and transport phenomena of transported ions particularly challenging. Experimental studies of water and ion transport through clays mostly consist in evaluating macroscopic effective transport coefficients like permeability or conductivity. They showed that the main transport mechanism is an effective diffusion that not only depends on particle charge but also on its chemical nature, or specificity. The goal of assessing the performance of clays as confinement barriers, particularly in the context of the geological disposal of nuclear waste, requires not only quantitative prediction of the retention and transport of species but also an understanding of the microscopic mechanisms underlying them. A successful approach has been to use numerical simulations via the Lattice-Boltzmann method (LB). It consists in making evolve populations describing the fluid at a level which is consistent with time and length-scales involved in transport properties, while still including a microscopic description of the phenomena. The transport of charged ions at the pore scale has recently been included in LB. In this method, the evolution of a tracer population is
Physically-based modeling of the cyclic macroscopic behaviour of metals
International Nuclear Information System (INIS)
Sauzay, M.; Evrard, P.; Steckmeyer, A.; Ferrie, E.
2010-01-01
Grain size seems to have only a minor influence on the cyclic strain strain curves (CSSCs) of metallic polycrystals of medium to high stacking fault energy (SFE). That is why many authors tried to deduce the macroscopic CSSCs curves from the single crystals ones. Either crystals oriented for single slip or crystals oriented for multiple slip could be considered. In addition, a scale transition law should be used (from the grain scale to the macroscopic scale). Authors generally used either the Sachs rule (homogeneous single slip) or the Taylor one (homogeneous plastic strain, multiple slip). But the predicted macroscopic CSSCs do not generally agree with the experimental data for metals and alloys, presenting various SFE values. In order to avoid the choice of a particular scale transition rule, many finite element (FE) computations have been carried out using meshes of polycrystals including more than one hundred grains without texture. This allows the study of the influence of the crystalline constitutive laws on the macroscopic CSSCs. Activation of a secondary slip system in grains oriented for single slip is either allowed or hindered (slip planarity), which affects strongly the macroscopic CSSCs. The more planar the slip, the higher the predicted macroscopic stress amplitudes. If grains oriented for single slip obey slip planarity and two crystalline CSSCs are used (one for single slip grains and one for multiple slip grains), then the predicted macroscopic CSSCs agree well with experimental data provided the SFE is not too low (316L, copper, nickel, aluminium). Finally, the incremental self-consistent Hill-Hutchinson homogenization model is used for predicting CSS curves and partially validated with respect to the curves computed by the FE method. (authors)
International Nuclear Information System (INIS)
Pang Xiaofeng; Deng Bo
2008-01-01
Influences of magnetic field on microscopic structures and macroscopic properties of water are studied by the spectrum techniques of infrared, Raman, visible, ultraviolet lights and X-ray. From these investigations, we know that the magnetic fields change the distribution of molecules and electrons, cause displacements and polarization of molecules and atoms, result in changes of dipole-moment transition and vibrational states of molecules and variation of transition probability of electrons, but does not alter the constitution of molecules and atoms. These are helpful in seeking the mechanism of magnetization of water. Meanwhile, we also measure the changed rules of the surface tension force, soaking effect or angle of contact, viscosity, rheology features, refraction index, dielectric constant and electric conductivity of magnetized water relative to that of pure water. The results show that the magnetic fields increase the soaking degree and hydrophobicity of water to materials, depress its surface-tension force, diminish the viscosity of war, enhance the feature of plastic flowing of water, and increase the refraction index, dielectric constant and electric conductivity of water after magnetization. These changes are caused by the above changes of microscopic structures under the action of magnetic field. Therefore, our studies are significant in science and has practical value of applications
Probing the surface properties of a polymer glass with macroscopic friction
International Nuclear Information System (INIS)
Bureau, Lionel
2007-01-01
We show how macroscopic friction can be used as a sensitive probe of chain dynamics at the surface of a glassy polymer. We present experiments in which a smooth poly(methylmethacrylate) (PMMA) solid slides on flat surfaces presenting different densities of pinning sites available for polymer/substrate bond formation. These experiments indicate that: (i) at high pinning level, frictional dissipation occurs through the sudden flips of molecular-sized bistable regions localized in a nm-thick layer of confined chains, which responds to shear as an elasto-plastic solid, and (ii) in situations of weak pinning, dissipation appears to be governed by a process akin to that proposed for rubber friction. This suggests that some 'glass-to-rubber' transition occurs at the polymer surface when its interaction with the substrate goes from strong to weak. The temperature-dependence of friction provides further support for the presence of a nm-thick layer at the polymer surface, which exhibits a rubberlike response in situation of weak interaction with the countersurface. This behavior results from the interplay between viscous flow in this surface layer, and shear induced depinning of adsorbed surface chains. Moreover, a quantitative analysis of the results indicates that the pinning dynamics of polymer chains is controlled by localized β rotational motions at the interface
Two-dimensional macroscopic quantum tunneling in multi-gap superconductor Josephson junctions
International Nuclear Information System (INIS)
Asai, Hidehiro; Kawabata, Shiro; Ota, Yukihiro; Machida, Masahiko
2014-01-01
Low-temperature characters of superconducting devices yield definite probes for different superconducting phenomena. We study the macroscopic quantum tunneling (MQT) in a Josephson junction, composed of a single-gap superconductor and a two-gap superconductor. Since this junction has two kinds to the superconducting phase differences, calculating the MQT escape rate requires the analysis of quantum tunneling in a multi-dimensional configuration space. Our approach is the semi-classical approximation along a 1D curve in a 2D potential- energy landscape, connecting two adjacent potential (local) minimums through a saddle point. We find that this system has two plausible tunneling paths; an in-phase path and an out-of-phase path. The former is characterized by the Josephson-plasma frequency, whereas the latter is by the frequency of the characteristic collective mode in a two-band superconductor, Josephson- Leggett mode. Depending on external bias current and inter-band Josephson-coupling energy, one of them mainly contributes to the MQT. Our numerical calculations show that the difference between the in-phase path and the out-of-phase path is manifest, with respect to the bias- current-dependence of the MQT escape rate. This result suggests that our MQT setting be an indicator of the Josephson-Leggett mode
Langevin dynamics encapsulate the microscopic and emergent macroscopic properties of midge swarms
2018-01-01
In contrast to bird flocks, fish schools and animal herds, midge swarms maintain cohesion but do not possess global order. High-speed imaging techniques are now revealing that these swarms have surprising properties. Here, I show that simple models found on the Langevin equation are consistent with this wealth of recent observations. The models predict correctly that large accelerations, exceeding 10 g, will be common and they predict correctly the coexistence of core condensed phases surrounded by dilute vapour phases. The models also provide new insights into the influence of environmental conditions on swarm dynamics. They predict that correlations between midges increase the strength of the effective force binding the swarm together. This may explain why such correlations are absent in laboratory swarms but present in natural swarms which contend with the wind and other disturbances. Finally, the models predict that swarms have fluid-like macroscopic mechanical properties and will slosh rather than slide back and forth after being abruptly displaced. This prediction offers a promising avenue for future experimentation that goes beyond current quasi-static testing which has revealed solid-like responses. PMID:29298958
Gong, Jian; Viswanathan, Sandeep; Rothamer, David A; Foster, David E; Rutland, Christopher J
2017-10-03
Motivated by high filtration efficiency (mass- and number-based) and low pressure drop requirements for gasoline particulate filters (GPFs), a previously developed heterogeneous multiscale filtration (HMF) model is extended to simulate dynamic filtration characteristics of GPFs. This dynamic HMF model is based on a probability density function (PDF) description of the pore size distribution and classical filtration theory. The microstructure of the porous substrate in a GPF is resolved and included in the model. Fundamental particulate filtration experiments were conducted using an exhaust filtration analysis (EFA) system for model validation. The particulate in the filtration experiments was sampled from a spark-ignition direct-injection (SIDI) gasoline engine. With the dynamic HMF model, evolution of the microscopic characteristics of the substrate (pore size distribution, porosity, permeability, and deposited particulate inside the porous substrate) during filtration can be probed. Also, predicted macroscopic filtration characteristics including particle number concentration and normalized pressure drop show good agreement with the experimental data. The resulting dynamic HMF model can be used to study the dynamic particulate filtration process in GPFs with distinct microstructures, serving as a powerful tool for GPF design and optimization.
International Nuclear Information System (INIS)
Cleland, A.N.
1991-01-01
Experiments investigated the process of macroscopic quantum tunneling in a moderately-damped, resistively shunted, Josephson junction are described, followed by a discussion of experiments performed on very-small-capacitance normal-metal tunnel junctions. The experiments on the resistively-shunted Josephson junction were designed to investigate a quantum process, that of the tunneling of the Josephson-phase variable under a potential barrier, in a system in which dissipation plays a major role in the dynamics of motion. All the parameters of the junction were measured using the classical phenomena of thermal activation and resonant activation. Theoretical predictions are compared with the experimental results, showing good agreement with no adjustable parameters. The experiments on small-capacitance tunnel junctions extend the measurements on the large-area Josephson junctions from the region in which the phase variable has a fairly well-defined value, i.e. its wave function has a narrow width, to the region where its value is almost completely unknown. The charge on the junction becomes well-defined and is predicted to quantize the current through the junction, giving rise to the Coulomb blockade at low bias
Macroscopic Spatial Complexity of the Game of Life Cellular Automaton: A Simple Data Analysis
Hernández-Montoya, A. R.; Coronel-Brizio, H. F.; Rodríguez-Achach, M. E.
In this chapter we present a simple data analysis of an ensemble of 20 time series, generated by averaging the spatial positions of the living cells for each state of the Game of Life Cellular Automaton (GoL). We show that at the macroscopic level described by these time series, complexity properties of GoL are also presented and the following emergent properties, typical of data extracted complex systems such as financial or economical come out: variations of the generated time series following an asymptotic power law distribution, large fluctuations tending to be followed by large fluctuations, and small fluctuations tending to be followed by small ones, and fast decay of linear correlations, however, the correlations associated to their absolute variations exhibit a long range memory. Finally, a Detrended Fluctuation Analysis (DFA) of the generated time series, indicates that the GoL spatial macro states described by the time series are not either completely ordered or random, in a measurable and very interesting way.
Martín-Pacheco, Ana; Del Río Castillo, Antonio Esaú; Martín, Cristina; Herrero, María Antonia; Merino, Sonia; García Fierro, José Luis; Díez-Barra, Enrique; Vázquez, Ester
2018-05-17
Fluorescence based on quantum confinement is a property restricted to the nanoscopic range. The incorporation of nanoparticles in a three-dimensional polymeric network could afford macroscopic scaffolds that show nanoscopic properties. Moreover, if these scaffolds are based on strong bonds, the stability of the resulting materials can be preserved, thus enhancing their final applications. We report for the first time the preparation of a graphene quantum dot (GQD) composite based on a cationic covalent network. This new material has unusual features: (i) the final composite remains stable after several swelling-deswelling cycles, thus demonstrating strong interactions between GQDs and the polymeric material, and therefore it could be used as a portable system. (ii) Fluorescence emission in the composite and in solution is quasi-independent to the excitation wavelength. (iii) However, and in contrast to the behavior observed in GQD solutions, the fluorescence of the composite remains unaltered over a wide pH range and in the presence of different ions commonly found in tap water. (iv) Fluorescence quenching is only observed as a consequence of molecules that bear aromatic systems, and this could be applied to the preparation of in situ water sensors.
Exploring the safety in numbers effect for vulnerable road users on a macroscopic scale.
Tasic, Ivana; Elvik, Rune; Brewer, Simon
2017-12-01
A "Safety in Numbers" effect for a certain group of road users is present if the number of crashes increases at a lower rate than the number of road users. The existence of this effect has been invoked to justify investments in multimodal transportation improvements in order to create more sustainable urban transportation systems by encouraging walking, biking, and transit ridership. The goal of this paper is to explore safety in numbers effect for cyclists and pedestrians in areas with different levels of access to multimodal infrastructure. Data from Chicago served to estimate the expected number of crashes on the census tract level by applying Generalized Additive Models (GAM) to capture spatial dependence in crash data. Measures of trip generation, multimodal infrastructure, network connectivity and completeness, and accessibility were used to model travel exposure in terms of activity, number of trips, trip length, travel opportunities, and conflicts. The results show that a safety in numbers effect exists on a macroscopic level for motor vehicles, pedestrians, and bicyclists. Copyright © 2017 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Hecher, Johannes; Zehetmayer, Martin; Weber, Harald W
2014-01-01
We present a study of the real-space flux-line lattice (FLL) of pristine and neutron irradiated conventional type-II superconductors using scanning tunnelling microscopy. Our work is focused on the magnetic field range, where the critical current density shows a second peak as a result of neutron irradiation. Scanning tunnelling microscopy images, including more than 2000 flux lines, are used to evaluate various microscopic parameters describing the disorder of the FLL, such as the defect density, the nearest neighbour distances and correlation functions. These parameters are compared with the macroscopic critical current density of the samples. The results show a direct correlation of the micro- and macroscopic properties. We observe a clear transition from an ordered to a disordered lattice at the onset of the second peak. Moreover, we discuss the defects of the FLL and their accumulation to large clusters in the second peak region. (papers)
DEFF Research Database (Denmark)
Riis, R G C; Gudbergsen, H; Simonsen, O
2017-01-01
the DCE-MRI variable MExNvoxel (surrogate of the volume and degree of synovitis) and the macroscopic score showed correlations above the pre-specified threshold for acceptance with histological inflammation. The maximum R2-value obtained in Model 1 was R2 = 0.39. In Model 2, where the CE......-MRI-variables were added, the highest R2 = 0.52. In Model 3, a four-variable model consisting of the gender, one CE-MRI and two DCE-MRI-variables yielded a R2 = 0.71. CONCLUSION: DCE-MRI is correlated with histological synovitis in end-stage KOA and the combination of CE and DCE-MRI may be a useful, non......-enhanced magnetic resonance imaging (CE-MRI) and dynamic contrast-enhanced (DCE)-MRI prior to (TKR) and correlated with microscopic and macroscopic assessments of synovitis obtained intraoperatively. Multiple bivariate correlations were used with a pre-specified threshold of 0.70 for significance. Also, multiple...
Directory of Open Access Journals (Sweden)
Marta Galanti
2016-08-01
Full Text Available Describing particle transport at the macroscopic or mesoscopic level in non-ideal environments poses fundamental theoretical challenges in domains ranging from inter and intra-cellular transport in biology to diffusion in porous media. Yet, often the nature of the constraints coming from many-body interactions or reflecting a complex and confining environment are better understood and modeled at the microscopic level.In this paper we review the subtle link between microscopic exclusion processes and the mean-field equations that ensue from them in the continuum limit. We show that in an inhomogeneous medium, i.e. when jumps are controlled by site-dependent hopping rates, one can obtain three different nonlinear advection-diffusion equations in the continuum limit, suitable for describing transport in the presence of quenched disorder and external fields, depending on the particular rule embodying site inequivalence at the microscopic level. In a situation that might be termed point-like scenario, when particles are treated as point-like objects, the effect of crowding as imposed at the microscopic level manifests in the mean-field equations only if some degree of inhomogeneity is enforced into the model. Conversely, when interacting agents are assigned a finite size, under the more realistic extended crowding framework, exclusion constraints persist in the unbiased macroscopic representation.
Energy Technology Data Exchange (ETDEWEB)
Poloski, Adam P.; Daniel, Richard C.; Rector, David R.; Bredt, Paul R.; Buck, Edgar C.; Berg, John C.; Saez, Avelino E.
2006-09-29
Hanford TRU tank sludges are complex mixtures of undissolved minerals and salt solids in an aqueous phase of high ionic strength. They show complex rheological behavior resulting from interactions at the macroscopic level, such as interparticle friction between grains in the coarse fraction, as well as from interactions at the nano-scale level, such as the agglomeration of colloidal particles. An understanding of how phenomena such as interparticle friction and aggregate stability under shear will allow better control of Hanford TRU tank sludges being processed for disposal. The project described in this report had two objectives. The first was to understand the physical properties and behavior of the Hanford transuranic (TRU) tank sludges under conditions that might exist during retrieval, treatment, packaging, and transportation for disposal at the Waste Isolation Pilot Plant (WIPP). The second objective was to develop a fundamental understanding of sludge physical properties by correlating the macroscopic behavior with interactions occurring at the particle/colloidal scale. These objectives were accomplished by: 1) developing continuum models for coarse granular slurries and 2) studying the behavior of colloidal agglomerates under shear and under irradiation.
The effect of interlayer adhesion on the mechanical behaviors of macroscopic graphene oxide papers.
Gao, Yun; Liu, Lu-Qi; Zu, Sheng-Zhen; Peng, Ke; Zhou, Ding; Han, Bao-Hang; Zhang, Zhong
2011-03-22
High mechanical performances of macroscopic graphene oxide (GO) papers are attracting great interest owing to their merits of lightweight and multiple functionalities. However, the loading role of individual nanosheets and its effect on the mechanical properties of the macroscopic GO papers are not yet well understood. Herein, we effectively tailored the interlayer adhesions of the GO papers by introducing small molecules, that is, glutaraldehyde (GA) and water molecules, into the gallery regions. With the help of in situ Raman spectroscopy, we compared the varied load-reinforcing roles of nanosheets, and further predicted the Young's moduli of the GO papers. Systematic mechanical tests have proven that the enhancement of the tensile modulus and strength of the GA-treated GO paper arose from the improved load-bearing capability of the nanosheets. On the basis of Raman and macroscopic mechanical tests, the influences of interlayer adhesions on the fracture mechanisms of the strained GO papers were inferred.
International Nuclear Information System (INIS)
Czubek, J.A.; Burda, J.; Drozdowicz, K.; Igielski, A.; Kowalik, W.; Krynicka-Drozdowicz, E.; Woznicka, U.
1986-03-01
Preparation of rock samples for the measurement of the thermal neutron macroscopic absorption cross-section in small cylindrical two-region systems by a pulsed technique is presented. Requirements which should be fulfilled during the preparation of the samples due to physical assumptions of the method are given. A cylindrical vessel is filled with crushed rock and saturated with a medium strongly absorbing thermal neutrons. Water solutions of boric acid of well-known macroscopic absorption cross-section are used. Mass contributions of the components in the sample are specified. This is necessary for the calculation of the thermal neutron macroscopic absorption cross-section of the rock matrix. The conditions necessary for assuring the required accuracy of the measurement are given and the detailed procedure of preparation of the rock sample is described. (author)
Mechanical Behaviour of Materials Volume 1 Micro- and Macroscopic Constitutive Behaviour
François, Dominique; Zaoui, André
2012-01-01
Advances in technology are demanding ever-increasing mastery over the materials being used: the challenge is to gain a better understanding of their behaviour, and more particularly of the relations between their microstructure and their macroscopic properties. This work, of which this is the first volume, aims to provide the means by which this challenge may be met. Starting from the mechanics of deformation, it develops the laws governing macroscopic behaviour – expressed as the constitutive equations – always taking account of the physical phenomena which underlie rheological behaviour. The most recent developments are presented, in particular those concerning heterogeneous materials such as metallic alloys, polymers and composites. Each chapter is devoted to one of the major classes of material behaviour. As the subtitles indicate, Volume 1 deals with micro- and macroscopic constitutive behaviour and Volume 2 with damage and fracture mechanics. A third volume will be devoted to exercises and the...
Smolina, Irina Yu.
2015-10-01
Mechanical properties of a cable are of great importance in design and strength calculation of flexible cables. The problem of determination of elastic properties and rigidity characteristics of a cable modeled by anisotropic helical elastic rod is considered. These characteristics are calculated indirectly by means of the parameters received from statistical processing of experimental data. These parameters are considered as random quantities. With taking into account probable nature of these parameters the formulas for estimation of the macroscopic elastic moduli of a cable are obtained. The calculating expressions for macroscopic flexural rigidity, shear rigidity and torsion rigidity using the macroscopic elastic characteristics obtained before are presented. Statistical estimations of the rigidity characteristics of some cable grades are adduced. A comparison with those characteristics received on the basis of deterministic approach is given.
A strict experimental test of macroscopic realism in a superconducting flux qubit.
Knee, George C; Kakuyanagi, Kosuke; Yeh, Mao-Chuang; Matsuzaki, Yuichiro; Toida, Hiraku; Yamaguchi, Hiroshi; Saito, Shiro; Leggett, Anthony J; Munro, William J
2016-11-04
Macroscopic realism is the name for a class of modifications to quantum theory that allow macroscopic objects to be described in a measurement-independent manner, while largely preserving a fully quantum mechanical description of the microscopic world. Objective collapse theories are examples which aim to solve the quantum measurement problem through modified dynamical laws. Whether such theories describe nature, however, is not known. Here we describe and implement an experimental protocol capable of constraining theories of this class, that is more noise tolerant and conceptually transparent than the original Leggett-Garg test. We implement the protocol in a superconducting flux qubit, and rule out (by ∼84 s.d.) those theories which would deny coherent superpositions of 170 nA currents over a ∼10 ns timescale. Further, we address the 'clumsiness loophole' by determining classical disturbance with control experiments. Our results constitute strong evidence for the superposition of states of nontrivial macroscopic distinctness.
Theory and feasibility tests for a seismic scanning tunnelling macroscope
Schuster, Gerard T.; Hanafy, Sherif; Huang, Yunsong
2012-01-01
scatterer model show that the spatial resolution limit to be, unlike the Abbe limit of λ/2, independent of wavelength and linearly proportional to the source-scatterer separation as long as the scatterer is in the near-field region. This means that
Fritsche, Hans-Martin; Novara, Giacomo; Burger, Maximilian; Gupta, Amit; Matsumoto, Kazumasa; Kassouf, Wassim; Sircar, Kanishka; Zattoni, Filiberto; Walton, Tom; Tritschler, Stefan; Baba, Shiro; Bastian, Patrick J; Martínez-Salamanca, Juan I; Seitz, Christian; Otto, Wolfgang; Wieland, Wolf Ferdinand; Karakiewicz, Pierre I; Ficarra, Vincenzo; Hartmann, Arndt; Shariat, Shahrokh F
2012-09-01
Macroscopic sessile tumor architecture was associated with adverse outcomes after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). Before inclusion in daily clinical decision-making, the prognostic value of tumor architecture needs to be validated in an independent, external dataset. We tested whether macroscopic tumor architecture improves outcome prediction in an international cohort of patients. We retrospectively studied 754 patients treated with RNU for UTUC without neoadjuvant chemotherapy at 9 centers located in Asia, Canada, and Europe. Tumor architecture was macroscopically categorized as either papillary or sessile. Univariable and multivariable Cox regression analyses were used to address recurrence-free (RFS) and cancer-specific survival (CSS) estimates. Macroscopic sessile architecture was present in 20% of the patients. Its prevalence increased with advancing pathologic stage and it was significantly associated with established features of biologically aggressive UTUC, such as tumor grade, lymph node metastasis, lymphovascular invasion, and concomitant CIS (all P values architecture were 85% and 90%, compared with 58% and 66% for those with macroscopic sessile architecture, respectively (P values architecture was an independent predictor of both RFS (hazard ratio {HR}: 1.5; P = 0.036) and CSS (HR: 1.5; P = 0.03). We confirmed the independent prognostic value of macroscopic tumor architecture in a large, independent, multicenter UTUC cohort. It should be reported in every pathology report and included in post-RNU predictive models in order to refine current clinical decision making regarding follow-up protocol and adjuvant therapy. Copyright © 2012 Elsevier Inc. All rights reserved.
Macroscopic behavior of fast reactor fuel subjected to simulated thermal transients
International Nuclear Information System (INIS)
Fenske, G.R.; Emerson, J.E.; Savoie, F.E.
1983-06-01
High-speed cinematography has been used to characterize the macroscopic behavior of irradiated and unirradiated fuel subjected to thermal transients prototypical of fast reactor transients. The results demonstrate that as the cladding melts, the fuel can disperse via spallation if the fuel contains in excess of approx. 16 μmoles/gm of fission gas. Once the cladding has melted, the macroscopic behavior (time to failure and dispersive nature) was strongly influenced by the presence of volatile fission products and the heating rate
Generating macroscopic chaos in a network of globally coupled phase oscillators
So, Paul; Barreto, Ernest
2011-01-01
We consider an infinite network of globally coupled phase oscillators in which the natural frequencies of the oscillators are drawn from a symmetric bimodal distribution. We demonstrate that macroscopic chaos can occur in this system when the coupling strength varies periodically in time. We identify period-doubling cascades to chaos, attractor crises, and horseshoe dynamics for the macroscopic mean field. Based on recent work that clarified the bifurcation structure of the static bimodal Kuramoto system, we qualitatively describe the mechanism for the generation of such complicated behavior in the time varying case. PMID:21974662
Tetè, Stefano; Zizzari, Vincenzo; De Carlo, Alessandro; Sinjari, Bruna; Gherlone, Enrico
2012-04-01
The purpose of this study is to evaluate macroscopic and microscopic appearance of a new implant design, with particular emphasis given to the type of prosthesis connection. Two dental implants of the same type (Torque Type(®), WinSix(®), BioSAFin. S.r.l. - Ancona, Italy), with sandblasted and acid etched surfaces (Micro Rough Surface(®)), but differing from each other for the prosthesis connection system, were examined by scanning electron microscope (SEM) analysis at different magnifications: TTI implant, with a hexagonal internal connection, and TTX implant, with a hexagonal external connection. SEM analysis showed that the Torque Type(®) implant is characterized by a truncated cone shape with tapered tips. The implant body showed a double loop thread and double pitch with blunt tips. For both types of connection, the implant neck was 0.7 mm in height with a 3% taper. This implant design may be able to guarantee osteotomic properties at the time of insertion in a surgical site suitably prepared, a facilitated screwing, thanks to the thread pitch and to the broad and deep draining grooves, thereby ensuring a good primary stability. The different connection design appears defined and precise, in order to ensure a good interface between the fixture and the prosthetic components. Therefore, this design appears to be particularly suitable in cases where a good primary stability is necessary and a precise coupling between endosseous and prosthetic components, as it allows an easy insertion of the fixture even in conditions of reduced bone availability, and in cases of immediately loaded full-arch rehabilitations.
Macroscopic tunneling, decoherence and noise-induced activation
Energy Technology Data Exchange (ETDEWEB)
Lombardo, Fernando C; Monteoliva, Diana; Villar, Paula I [Departamento de Fisica Juan Jose Giambiagi, Facultad de Ciencias Exactas y Naturales, UBA, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina)
2007-05-15
We study the effects of the environment at zero temperature on tunneling in an open system described by a static double-well potential. We show that the evolution of the system in an initial Schroedinger cat state, can be summarized in terms of three main physical phenomena, namely decoherence, quantum tunneling and noise-induced activation. Using large-scale numerical simulations, we obtain a detailed picture of the main stages of the evolution and of the relevant dynamical processes.
International Nuclear Information System (INIS)
Everitt, M.J.; Clark, T.D.; Stiffell, P.B.; Prance, R.J.; Prance, H.; Vourdas, A.; Ralph, J.F.
2004-01-01
In this paper we explore the quantum behavior of a superconducting quantum-interference device (SQUID) ring which has a significant Josephson coupling energy. We show that the eigenfunctions of the Hamiltonian for the ring can be used to create macroscopic quantum superposition states of the ring. We also show that the ring potential may be utilized to squeeze coherent states. With the SQUID ring as a strong contender as a device for manipulating quantum information, such properties may be of great utility in the future. However, as with all candidate systems for quantum technologies, decoherence is a fundamental problem. In this paper we apply an open systems approach to model the effect of coupling a quantum-mechanical SQUID ring to a thermal bath. We use this model to demonstrate the manner in which decoherence affects the quantum states of the ring
Energy Technology Data Exchange (ETDEWEB)
Lacroix, D
2001-07-01
In this work, we introduce a method to reduce the microscopic mean-field theory to a classical macroscopic dynamics at the initial stage of fusion reaction. We show that TDHF (Time-dependent Hartree-Fock) could be a useful tool to infer information on the fusion barrier as well as on one-body dissipation effect. We apply the reduction of information to the case of head-on reaction between a {sup 16}O and {sup 16,22,24,28}O in order to quantify the effect of neutron skin on fusion. We show that the precise determination of fusion barrier requires, in addition to the relative distance between center of mass, the introduction of an additional collective coordinate that explicitly breaks the neutron-proton symmetry. With this additional collective variable, we obtain a rather precise determination of the barrier position, height and diffuseness as well as one-body friction. (author)
Quantitative macroscopic anatomy of the giraffe (Giraffa camelopardalis) digestive tract
DEFF Research Database (Denmark)
Sauer, Cathrine; Bertelsen, Mads Frost; Lund, Peter
2016-01-01
Quantitative data on digestive anatomy of the world’s largest ruminant, the giraffe, are scarce. Data were collected from a total of 25 wild caught and 13 zoo housed giraffes. Anatomical measures were quantified by dimension, area or weight, and analyzed by allometric regression. The majority...... of measures scaled positively and isometrically to body mass. Giraffes had lower tissue weight of all stomach compartments and longer large intestinal length than cattle. When compared to other ruminants, the giraffe digestive tract showed many of the convergent morphological adaptations attributed...
Macroscopic results for a novel oxygenated silicon material
International Nuclear Information System (INIS)
Watts, S.J.; Da Via', C.; Karpenko, A.
2002-01-01
High-resistivity FZ silicon diodes have been processed in order to increase their oxygen dimer (O 2i ) concentration. Deep level transient spectroscopy measurements have been performed after proton irradiation showing that the formation of the VO centre is suppressed. The substrates had a starting resistivity of 2-4 kΩ cm, with an oxygen concentration of 10 15 and 10 17 cm -3 . Results for doping changes, leakage current and annealing behaviour after irradiation with 24 GeV/c protons are shown
Macroscopic results for a novel oxygenated silicon material
Watts, S J; Karpenko, A
2002-01-01
High-resistivity FZ silicon diodes have been processed in order to increase their oxygen dimer (O sub 2 sub i) concentration. Deep level transient spectroscopy measurements have been performed after proton irradiation showing that the formation of the VO centre is suppressed. The substrates had a starting resistivity of 2-4 k OMEGA cm, with an oxygen concentration of 10 sup 1 sup 5 and 10 sup 1 sup 7 cm sup - sup 3. Results for doping changes, leakage current and annealing behaviour after irradiation with 24 GeV/c protons are shown.
EVAPORITE MICROBIAL FILMS, MATS, MICROBIALITES AND STROMATOLITES
Energy Technology Data Exchange (ETDEWEB)
Brigmon, R; Penny Morris, P; Garriet Smith, G
2008-01-28
Evaporitic environments are found in a variety of depositional environments as early as the Archean. The depositional settings, microbial community and mineralogical composition vary significantly as no two settings are identical. The common thread linking all of the settings is that evaporation exceeds precipitation resulting in elevated concentrations of cations and anions that are higher than in oceanic systems. The Dead Sea and Storrs Lake are examples of two diverse modern evaporitic settings as the former is below sea level and the latter is a coastal lake on an island in the Caribbean. Each system varies in water chemistry as the Dead Sea dissolved ions originate from surface weathered materials, springs, and aquifers while Storrs Lake dissolved ion concentration is primarily derived from sea water. Consequently some of the ions, i.e., Sr, Ba are found at significantly lower concentrations in Storrs Lake than in the Dead Sea. The origin of the dissolved ions are ultimately responsible for the pH of each system, alkaline versus mildly acidic. Each system exhibits unique biogeochemical properties as the extreme environments select certain microorganisms. Storrs Lake possesses significant biofilms and stromatolitic deposits and the alkalinity varies depending on rainfall and storm activity. The microbial community Storrs Lake is much more diverse and active than those observed in the Dead Sea. The Dead Sea waters are mildly acidic, lack stromatolites, and possess a lower density of microbial populations. The general absence of microbial and biofilm fossilization is due to the depletion of HCO{sub 3} and slightly acidic pH.
Bell inequalities and experiments on quantum correlations for macroscopic distances
International Nuclear Information System (INIS)
Grib, A.A.
1984-01-01
Recently in different laboratories experiments checking the validity of Bell's inequalities were made. These inequalities give the answer to the qUestion which interpretation of quantum mechanics is correct: either Einstein's interpretation according to which properties of quantum system exist as elements of physical reality independently from their observation or Copenhagen's interpretation due to Bohr and Fock according to which quantUm properties described by noncommuting operators don't exist independently from measurement. Experiments are classified on three groups: Those with optical photons with γ-quanta and with nucleons. The experiments undoubtedly show that Bell's inequalities are not satisfied, so the Copenhagen's interpretation of quantum mehanics and the principle of relativity to the means of measurement of properties of the microsystem give the only non-contradicting-to-experiment description of quantum phenomena
Macroscopic quantum phenomena in strongly correlated fermionic systems
International Nuclear Information System (INIS)
Rech, J.
2006-06-01
It took several years after the idea of a zero-temperature phase transition emerged to realize the impact of such a quantum critical point over a large region of the phase diagram. Observed in many experimental examples, this quantum critical regime is not yet understood in details theoretically, and one needs to develop new approaches. In the first part, we focused on the ferromagnetic quantum critical point. After constructing a controlled approach allowing us to describe the quantum critical regime, we show through the computation of the static spin susceptibility that the ferromagnetic quantum critical point is unstable, destroyed internally by an effective dynamic long-range interaction generated by the Landau damping. In the second part, we revisit the exactly screened single impurity Kondo model, using a bosonic representation of the local spin and treating it in the limit of large spin degeneracy N. We show that, in this regime, the ground-state is a non-trivial Fermi liquid, unlike what was advocated by previous similar studies. We then extend our method to encompass the physics of two coupled impurities, for which our results are qualitatively comparable to the ones obtained from various approaches carried out in the past. We also develop a Luttinger-Ward formalism, enabling us to cure some of the drawbacks of the original method used to describe the single impurity physics. Finally, we present the main ideas and the first results for an extension of the method towards the description of a Kondo lattice, relevant for the understanding of the quantum critical regime of heavy fermion materials. (authors)
International Nuclear Information System (INIS)
Belo, Thiago F.; Fiel, Joao Claudio B.
2015-01-01
Nuclear reactor core analysis involves neutronic modeling and the calculations require problem dependent nuclear data generated with few neutron energy groups, as for instance the neutron cross sections. The methods used to obtain these problem-dependent cross sections, in the reactor calculations, generally uses nuclear computer codes that require a large processing time and computational memory, making the process computationally very expensive. Presently, analysis of the macroscopic cross section, as a function of nuclear parameters, has shown a very distinct behavior that cannot be represented by simply using linear interpolation. Indeed, a polynomial representation is more adequate for the data parameterization. To provide the cross sections of rapidly and without the dependence of complex systems calculations, this work developed a set of parameterized cross sections, based on the Tchebychev polynomials, by fitting the cross sections as a function of nuclear parameters, which include fuel temperature, moderator temperature and density, soluble boron concentration, uranium enrichment, and the burn-up. In this study is evaluated the problem-dependent about fission, scattering, total, nu-fission, capture, transport and absorption cross sections for a typical PWR fuel element reactor, considering burn-up cycle. The analysis was carried out with the SCALE 6.1 code package. The results of comparison with direct calculations with the SCALE code system and also the test using project parameters, such as the temperature coefficient of reactivity and fast fission factor, show excellent agreements. The differences between the cross-section parameterization methodology and the direct calculations based on the SCALE code system are less than 0.03 percent. (author)
Directory of Open Access Journals (Sweden)
V. Couvreur
2012-08-01
Full Text Available Many hydrological models including root water uptake (RWU do not consider the dimension of root system hydraulic architecture (HA because explicitly solving water flow in such a complex system is too time consuming. However, they might lack process understanding when basing RWU and plant water stress predictions on functions of variables such as the root length density distribution. On the basis of analytical solutions of water flow in a simple HA, we developed an "implicit" model of the root system HA for simulation of RWU distribution (sink term of Richards' equation and plant water stress in three-dimensional soil water flow models. The new model has three macroscopic parameters defined at the soil element scale, or at the plant scale, rather than for each segment of the root system architecture: the standard sink fraction distribution SSF, the root system equivalent conductance K_{rs} and the compensatory RWU conductance K_{comp}. It clearly decouples the process of water stress from compensatory RWU, and its structure is appropriate for hydraulic lift simulation. As compared to a model explicitly solving water flow in a realistic maize root system HA, the implicit model showed to be accurate for predicting RWU distribution and plant collar water potential, with one single set of parameters, in dissimilar water dynamics scenarios. For these scenarios, the computing time of the implicit model was a factor 28 to 214 shorter than that of the explicit one. We also provide a new expression for the effective soil water potential sensed by plants in soils with a heterogeneous water potential distribution, which emerged from the implicit model equations. With the proposed implicit model of the root system HA, new concepts are brought which open avenues towards simple and mechanistic RWU models and water stress functions operational for field scale water dynamics simulation.
International Nuclear Information System (INIS)
Cleland, A.N.
1991-04-01
Experiments investigating the process of macroscopic quantum tunneling in a moderately-damped, resistively shunted, Josephson junction are described, followed by a discussion of experiments performed on very small capacitance normal-metal tunnel junctions. The experiments on the resistively-shunted Josephson junction were designed to investigate a quantum process, that of the tunneling of the Josephson phase variable under a potential barrier, in a system in which dissipation plays a major role in the dynamics of motion. All the parameters of the junction were measured using the classical phenomena of thermal activation and resonant activation. Theoretical predictions are compared with the experimental results, showing good agreement with no adjustable parameters; the tunneling rate in the moderately damped (Q ∼ 1) junction is seen to be reduced by a factor of 300 from that predicted for an undamped junction. The phase is seen to be a good quantum-mechanical variable. The experiments on small capacitance tunnel junctions extend the measurements on the larger-area Josephson junctions from the region in which the phase variable has a fairly well-defined value, i.e. its wavefunction has a narrow width, to the region where its value is almost completely unknown. The charge on the junction becomes well-defined and is predicted to quantize the current through the junction, giving rise to the Coulomb blockade at low bias. I present the first clear observation of the Coulomb blockade in single junctions. The electrical environment of the tunnel junction, however, strongly affects the behavior of the junction: higher resistance leads are observed to greatly sharpen the Coulomb blockade over that seen with lower resistance leads. I present theoretical descriptions of how the environment influences the junctions; comparisons with the experimental results are in reasonable agreement
Directory of Open Access Journals (Sweden)
Stuart eHughes
2011-08-01
Full Text Available Although EEG alpha ( (8-13 Hz rhythms are often considered to reflect an ‘idling’ brain state, numerous studies indicate that they are also related to many aspects of perception. Recently, we outlined a potential cellular substrate by which such aspects of perception might be linked to basic rhythm mechanisms. This scheme relies on a specialized subset of rhythmically bursting thalamocortical (TC neurons (high-threshold bursting cells in the lateral geniculate nucleus (LGN which are interconnected by gap junctions (GJs. By engaging GABAergic interneurons, that in turn inhibit conventional relay-mode TC neurons, these cells can lead to an effective temporal framing of thalamic relay-mode output. Although the role of GJs is pivotal in this scheme, evidence for their involvement in thalamic rhythms has thus far mainly derived from experiments in in vitro slice preparations. In addition, direct anatomical evidence of neuronal GJs in the LGN is currently lacking. To address the first of these issues we tested the effects of the GJ inhibitors, carbenoxolone (CBX and 18-glycyrrhetinic acid (18-GA, given directly to the LGN via reverse microdialysis, on spontaneous LGN and EEG rhythms in behaving cats. We also examined the effect of CBX on rhythm-related LGN unit activity. Indicative of a role for thalamic GJs in these activities, 18-GA and CBX reversibly suppressed both LGN and EEG rhythms, with CBX also decreasing neuronal synchrony. To address the second point, we used electron microscopy to obtain definitive ultrastructural evidence for the presence of GJs between neurons in the cat LGN. As interneurons show no phenotypic evidence of GJ coupling (i.e. dye-coupling and spikelets we conclude that these GJs must belong to TC neurons. The potential significance of these findings for relating macroscopic changes in rhythms to basic cellular processes is discussed.
Modeling ancient Egyptian mummification on fresh human tissue: macroscopic and histological aspects.
Papageorgopoulou, Christina; Shved, Natallia; Wanek, Johann; Rühli, Frank J
2015-06-01
Many studies have been concerned with the ancient Egyptian mummification method; nevertheless, little effort has been made to explore it experimentally. The goal of this study is to apply evidence-based diagnostic criteria and state-of-the art methodology in order to improve knowledge on soft tissues preservation and postmortem alterations. Two human lower limbs (LL) from a female donor were (1) "naturally" mummified by dry heat and (2) artificially in natron. At specific time intervals a macroscopic and radiological examination of the LL was performed and skin and muscle samples were taken for histological and biomolecular analysis. Temperature, humidity, pH, and weight of the LL were systematically measured. The mummification by dry heat was stopped after 7 days due to unexpected lack of mummification progress. The mummification in natron was completed successfully after 208 days. The humidity, the external temperature, and the pH were proven with Pearson correlation and principal component analysis as important factors for the mummification process. The steady removal of water from the tissues through the natron has prevented the putrefaction. This is also evident in the absence of bacteria or fungi through the microbiological analysis. The histological analysis revealed very good preservation of the skin and the muscle tissues. In the muscular sample certain degree of structural disintegration can be seen, particularly affecting the epimysium whilst in the skin samples the epidermis, especially the stratum corneum, is mostly affected. The samples show better preservation compared with ancient Egyptian sections and other mummified tissues from historic or forensic context. © 2015 Wiley Periodicals, Inc.
Directory of Open Access Journals (Sweden)
S Senoussi
2006-09-01
Full Text Available We report systematic investigations of the magnetic superconducting properties of the new superconducting materials (NS: New high temperature superconductors (HTS, Organic superconductors (OS, fullerenes, carbon nanotubes, MgB2 etc. We show that, contrary to conventional superconductors where the superconducting state can be coherent over several tenths of km, the macroscopic coherence range lc of the NS is often as short as 0.1 to 10 µm typically. As a consequence, the magnetic properties are dominated by granular-like effects as well as Josephson coupling between grains. Here, we concentrate on HTS ceramics and organic superconductors exclusively. In the first case we observe three distinct regimes: (i At very low field (H < 5 Oe to say all the grains are coupled via Josephson effect and lc can be considered as infinite. (2 At intermediate field (5 < H < 50 Oe, typically the grains are gradually decoupled by H and/or T. (iii At higher fields all the grains are decoupled and lc roughly coincides with the diameter of the metallurgical grains. The case of OS is more subtle and is connected with a kind of order-disorder transition that occurs in most of them. For instance, in this study, we exploit quenched disorder (after crossing such a transition in the -(BEDT-TTF2Cu[N(CN2]Br layered organic superconductor to get new insights on both the superconducting state (T £ 11.6 K and the glassy transition at Tg, by studying the superconducting properties as functions of annealing time and annealing temperature around the glassy transition. Our main result is that the data can be described by a percolation molecular cluster model in which the topology and the growth of the molecular clusters obey an Ising spin-glass-like model with Tg ≈ 80 K for the hydrogenated compound and Tg ≈ 55 K for the fully deuterated one.
Histomorphometry and macroscopic intestinal lesions in broilers infected with Eimeria acervulina.
Assis, R C L; Luns, F D; Beletti, M E; Assis, R L; Nasser, N M; Faria, E S M; Cury, M C
2010-03-25
This study aimed at measuring intestinal villi and assessing the intestinal absorptive area in broilers infected with Eimeria acervulina under different treatments to control coccidiosis. The experiment was divided into two stages, carried out in successive housings, raised in the same environment (or aviary). In the first stage, on 25 May 2008, fifty 12-day-old birds were orally inoculated with 3 x 10(3) oocysts of E. acervulina. In the second stage, on July 2008, other 50 birds were allocated on litter contaminated by the feces of birds on the first housing (natural infection by oocysts present in the reused litter). The experiment was arranged in a complete randomized design with five treatments and three replicates of 10 chicks per treatment. Broiler chicks were housed at 1 day of age and autopsies were performed at 21 days of age. Three 2-cm-long segments of the duodenum were excised from each bird and fixed in 10% buffered formalin. A total of 30 slides were prepared for each treatment, totaling 150 evaluated histological sections using H&E staining. Villus morphology was carried out by the HL Image 97 software. The intestinal absorptive area was calculated and macroscopic lesions were classified according to standard lesion scores. Results showed that intestinal villus measurements and absorptive area are directly affected by E. acervulina and that there is direct and positive correlation between the macro and microscopic findings observed in intestinal coccidiosis. E. acervulina causes shortening of villi and reduction in the intestinal absorptive area, affecting broiler growth. The prevention method of litter fermentation during the interval between housings and oral administration of Diclazuril can reduce the severity of intestinal lesions by E. acervulina in broilers impairing oocyst virulence or viability.
International Nuclear Information System (INIS)
Bechade, J.L.; Toualbi, L.; Bosonnet, S.; Carlan, Y. de; Castelnau, O.
2014-01-01
To improve the efficiency of components operating at high temperatures, many efforts are deployed to develop new materials. Oxide Dispersion Strengthened (ODS) materials could be used for heat exchangers or cladding tubes for the new GENIV nuclear reactors. This type of materials are composed with a metallic matrix (usually iron base alloy for nuclear applications or nickel base alloy for heat exchangers) reinforced by a distribution of nano-oxides. They are obtained by powder metallurgy and mechanical alloying. The creep resistance of these materials is excellent, and they usually exhibit a high tensile strength at room temperature. Depending on the cold working and/or the heat treatments, several types of microstructure can be obtained: recrystallised, stress relieved. One of the key challenges is to transform ODS materials into thin tubes (up to 500 microns thick) within a robust fabrication route while keeping the excellent mechanical properties. To prevent cracking during the process or to obtain a final product with low residual stresses, it is important to quantify the effect of the heat treatments on the release of internal stresses. The aim of this study is to show how residual stresses can be determined on different thin tubes using two complementary approaches: (i) macroscopic stresses determination in the tube using beam theory (small cuts along the longitudinal and circumferential directions and measurements of the deflection), (ii) stress determination from x-ray diffraction analyses (surface analyses, using 'sin"2ψ' method with different hypothesis). Depending on the material and the heat treatment, residual stresses vary dramatically and can reach 800 MPa which is not far from the yield stress; comparisons between both methods are performed and suggestions are given in order to optimize the thermo-mechanical treatment of thin ODS tubes. (authors)
Energy Technology Data Exchange (ETDEWEB)
Belo, Thiago F.; Fiel, Joao Claudio B., E-mail: thiagofbelo@hotmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)
2015-07-01
Nuclear reactor core analysis involves neutronic modeling and the calculations require problem dependent nuclear data generated with few neutron energy groups, as for instance the neutron cross sections. The methods used to obtain these problem-dependent cross sections, in the reactor calculations, generally uses nuclear computer codes that require a large processing time and computational memory, making the process computationally very expensive. Presently, analysis of the macroscopic cross section, as a function of nuclear parameters, has shown a very distinct behavior that cannot be represented by simply using linear interpolation. Indeed, a polynomial representation is more adequate for the data parameterization. To provide the cross sections of rapidly and without the dependence of complex systems calculations, this work developed a set of parameterized cross sections, based on the Tchebychev polynomials, by fitting the cross sections as a function of nuclear parameters, which include fuel temperature, moderator temperature and density, soluble boron concentration, uranium enrichment, and the burn-up. In this study is evaluated the problem-dependent about fission, scattering, total, nu-fission, capture, transport and absorption cross sections for a typical PWR fuel element reactor, considering burn-up cycle. The analysis was carried out with the SCALE 6.1 code package. The results of comparison with direct calculations with the SCALE code system and also the test using project parameters, such as the temperature coefficient of reactivity and fast fission factor, show excellent agreements. The differences between the cross-section parameterization methodology and the direct calculations based on the SCALE code system are less than 0.03 percent. (author)
Macroscopic placental changes associated with fetal and maternal events in diabetes mellitus
Directory of Open Access Journals (Sweden)
Ana Karina Marques Salge
2012-10-01
Full Text Available OBJECTIVES: The current study sought to identify macroscopic placental changes associated with clinical conditions in women with or without diabetes and their newborns. METHODS: The study population consisted of 62 pregnant women clinically diagnosed with diabetes and 62 healthy women (control group. RESULTS: Among the subjects with diabetes, 43 women (69.3% were diagnosed with gestational diabetes mellitus, 15 had diabetes mellitus I (24.2%, and four had diabetes mellitus II (6.5%. The mean age of the women studied was 28.5 ± 5.71 years, and the mean gestational age of the diabetic women was 38.51 weeks. Of the 62 placentas from diabetic pregnancies, 49 (79% maternal surfaces and 59 (95.2% fetal surfaces showed abnormalities, including calcium and fibrin deposits, placental infarction, hematoma, and fibrosis. A statistical association was found between newborn gender and fetal and maternal placental changes (p = 0.002. The mean weight of the newborns studied was 3,287 ± 563 g for women with diabetes mellitus, 3,205 ± 544 g for those with gestational diabetes mellitus, 3,563 ± 696 g forthose with diabetes mellitus II, and 3,095 ± 451 g forthose with diabetes mellitus I. CONCLUSIONS: Infarction, hematoma, calcification, and fibrin were found on the maternal and fetal placental surfaces in women with diabetes. Women with gestational diabetes and post-term infants had more calcium deposits on the maternal placental surface as compared to those with type I and type II diabetes.
Local and Macroscopic Properties of Stripe Ordered Conductors
International Nuclear Information System (INIS)
Kivelson, Steven A.
2011-01-01
The tendency of many strongly correlated electron systems to form locally inhomogeneous structures is now well established. This introduces new emergent length scales into the electronic structure. In the research supported by this grant, we examined some of the consequences of this new length scale. In particular, we showed that in the limit where the inhomogeneous structures are strong and of certain forms (we considered a checkerboard lattice as a concrete example), it is possible to examine how strong repulsive interactions give rise to a substantial superconducting pairing scale. Interestingly, even though the interactions are purely repulsive, there is a crossover as a function of U, much like the one that occurs in the attractive Hubbard model, from a region with relatively strong pairing, but with a small Tc due to the small superfluid stiffness, to a region with in which Tc tends to zero as the pairing scale vanishes. However, in contrast to the attractive model, in the repulsive checkerboard model, the pairing scale vanishes at a finite critical value of U=Uc, where the superfluid stiffness is largest, and drops with decreasing U. The other point of contrast is that the superconducting state has d-wave symmetry for the repulsive model.
Macroscopic treatment of radio emission from cosmic ray air showers based on shower simulations
Werner, Klaus; Scholten, Olaf
We present a macroscopic calculation of coherent electro-magnetic radiation from air showers initiated by ultra-high energy cosmic rays, based on currents obtained from Monte Carlo simulations of air showers in a realistic geo-magnetic field. We can clearly relate the time signal to the time
International Nuclear Information System (INIS)
Strasburg, Sean; Davidson, Ronald C.
2000-01-01
The macroscopic warm-fluid model developed by Lund and Davidson [Phys.Plasmas 5, 3028 (1998)] is used in the smooth-focusing approximation to investigate detailed stability properties of an intense charged particle beam with pressure anisotropy, assuming small-amplitude electrostatic perturbations about a waterbag equilibrium
Effect of the isovector coupling channel on the macroscopic part of ...
Indian Academy of Sciences (India)
Physics Department, Atomic Energy Commission of Syria, P.O. Box 6091, Damascus, Syria. E-mail: pscientific@aec.org.sy. MS received 10 June 2012; revised 18 October 2012; accepted 12 December 2012. Abstract. The effect of isovector coupling channel on the macroscopic part of the nuclear binding energy is studied ...
On the inclusion of macroscopic theory in Monte Carlo simulation using game theory
International Nuclear Information System (INIS)
Tatarkiewicz, J.
1980-01-01
This paper presents the inclusion of macroscopic damage theory into Monte Carlo particle-range simulation using game theory. A new computer code called RADDI was developed on the basis of this inclusion. Results of Monte Carlo damage simulation after 6.3 MeV proton bombardment of silicon are compared with experimental data of Bulgakov et al. (orig.)
Study using macroscopic autoradiography of the distribution of vanadium 48 in the rat and mouse
International Nuclear Information System (INIS)
Serhrouchni, M.
1982-07-01
Study of vanadium 48 distribution in the laboratory animal by macroscopic autoradiography. Vanadium 48 bioavailability is zero after oral administration and good after pulmonary administration. It is distributed throughout the body with a particular affinity for bone and teeth. Study of perinatal metabolism [fr
Macroscopic modeling for heat and water vapor transfer in dry snow by homogenization.
Calonne, Neige; Geindreau, Christian; Flin, Frédéric
2014-11-26
Dry snow metamorphism, involved in several topics related to cryospheric sciences, is mainly linked to heat and water vapor transfers through snow including sublimation and deposition at the ice-pore interface. In this paper, the macroscopic equivalent modeling of heat and water vapor transfers through a snow layer was derived from the physics at the pore scale using the homogenization of multiple scale expansions. The microscopic phenomena under consideration are heat conduction, vapor diffusion, sublimation, and deposition. The obtained macroscopic equivalent model is described by two coupled transient diffusion equations including a source term arising from phase change at the pore scale. By dimensional analysis, it was shown that the influence of such source terms on the overall transfers can generally not be neglected, except typically under small temperature gradients. The precision and the robustness of the proposed macroscopic modeling were illustrated through 2D numerical simulations. Finally, the effective vapor diffusion tensor arising in the macroscopic modeling was computed on 3D images of snow. The self-consistent formula offers a good estimate of the effective diffusion coefficient with respect to the snow density, within an average relative error of 10%. Our results confirm recent work that the effective vapor diffusion is not enhanced in snow.
How can macroscopically normal peritoneum contribute to the pathogenesis of endometriosis?
Fassbender, Amelie; Overbergh, Lut; Verdrengh, Eefje; Kyama, Cleophas M; Vodolazakaia, Alexandra; Bokor, Attila; Meuleman, Christel; Peeraer, Karen; Tomassetti, Carla; Waelkens, Etienne; Mathieu, Chantal; D'Hooghe, Thomas
2011-09-01
This study indicates that the immunobiology of macroscopically normal peritoneum is relevant to understand the pathogenesis of endometriosis. Peritoneal interleukin 6, interleukin 12, and ferritin were differentially expressed in women with and without endometriosis. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
Macroscopic quantum coherence in a magnetic nanoparticle above the surface of a superconductor
Chudnovsky; Friedman
2000-12-11
We study macroscopic quantum tunneling of the magnetic moment in a single-domain particle placed above the surface of a superconductor. Such a setup allows one to manipulate the height of the energy barrier, preserving the degeneracy of the ground state. The tunneling amplitude and the effect of the dissipation in the superconductor are computed.
Macroscopic Quantum Coherence in a Magnetic Nanoparticle Above the Surface of a Superconductor
Energy Technology Data Exchange (ETDEWEB)
Chudnovsky, Eugene M.; Friedman, Jonathan R.
2000-12-11
We study macroscopic quantum tunneling of the magnetic moment in a single-domain particle placed above the surface of a superconductor. Such a setup allows one to manipulate the height of the energy barrier, preserving the degeneracy of the ground state. The tunneling amplitude and the effect of the dissipation in the superconductor are computed.
Macroscopic Quantum Coherence in a Magnetic Nanoparticle Above the Surface of a Superconductor
International Nuclear Information System (INIS)
Chudnovsky, Eugene M.; Friedman, Jonathan R.
2000-01-01
We study macroscopic quantum tunneling of the magnetic moment in a single-domain particle placed above the surface of a superconductor. Such a setup allows one to manipulate the height of the energy barrier, preserving the degeneracy of the ground state. The tunneling amplitude and the effect of the dissipation in the superconductor are computed
Energy Technology Data Exchange (ETDEWEB)
Gonnelli, Eduardo; Diniz, Ricardo [Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP Travessa R-400, 05508-900, Cidade Universitaria, Sao Paulo (Brazil)
2013-05-06
The neutron lifetimes of the core, reflector, and global were experimentally obtained through macroscopic neutron noise in the IPEN/MB-01 reactor for five levels of subcriticality. The theoretical Auto Power Spectral Densities were derived by point kinetic equations taking the reflector effect into account, and one of the approaches consider an additional group of delayed neutrons.
Bilateral subacromial bursitis with macroscopic rice bodies: Ultrasound, CT and MR appearance
International Nuclear Information System (INIS)
Law, T.C.; Chong, S.F.; Lu, P.P.; Mak, K.H.
1998-01-01
The radiological findings of ultrasound, CT and MR of a case of bilateral subacromial bursitis with macroscopic rice bodies is described. MRI is the investigation of choice and the intravenous gadolinium-enhanced usefulness was noted. The previous literature is also reviewed. Copyright (1998) Blackwell Science Pty Ltd
Bilateral subacromial bursitis with macroscopic rice bodies: Ultrasound, CT and MR appearance
Energy Technology Data Exchange (ETDEWEB)
Law, T.C.; Chong, S.F.; Lu, P.P. [Kwong Wah Hospital (Hong Kong). Department of Radiology; Mak, K.H. [Kwong Wah Hospital (Hong Kong). Department of Orthopaedics and Traumatology
1998-05-01
The radiological findings of ultrasound, CT and MR of a case of bilateral subacromial bursitis with macroscopic rice bodies is described. MRI is the investigation of choice and the intravenous gadolinium-enhanced usefulness was noted. The previous literature is also reviewed. Copyright (1998) Blackwell Science Pty Ltd 5 refs., 1 tab., 4 figs.
Sanli, Ceyda; Saitoh, K.; Luding, Stefan; van der Meer, Roger M.
2014-01-01
When a densely packed monolayer of macroscopic spheres floats on chaotic capillary Faraday waves, a coexistence of large scale convective motion and caging dynamics typical for glassy systems is observed. We subtract the convective mean flow using a coarse graining (homogenization) method and reveal
Are the toroidal shapes of heavy-ion reactions seen in macroscopic drop collisions?
International Nuclear Information System (INIS)
Menchaca R, A.; Borunda, M.; Hidalgo, S.S.; Huidobro, F.; Michaelian, K.; Perez, A.; Rodriguez, V.
1996-01-01
Experiments involving the collisions of water, and mineral oil, drops are reported. The aim is to search for toroidal configurations predicted by, both, macroscopic fluid dynamic and nuclear models. Instead, we find the formation of thin liquid sheets surrounded by a somewhat thicker rim presenting a fingering instability. (Author)
On the origin and elimination of macroscopic defects in MBE films
Wood, C. E. C.; Rathbun, L.; Ohno, H.; DeSimone, D.
1981-02-01
Spitting of group III metal droplets from Knudsen type effusion cells has been found culpable for a genre of problematical macroscopic surface topographical defects observed in the growth of semiconductor films by molecular beam epitaxy. Successful precautions are described which virtually eliminate the problem.
Lability of Nanoparticulate Metal Complexes at a Macroscopic Metal Responsive (Bio)interface
Duval, Jérôme F.L.; Town, Raewyn M.; Leeuwen, Van Herman P.
2018-01-01
The lability of metal complexes expresses the extent of the dissociative contribution of the complex species to the flux of metal ions toward a macroscopic metal-responsive (bio)interface, for example, an electrodic sensor or an organism. While the case of molecular ligands is well-established, it
Pinning of a curved flux line by macroscopic inclusions in a type II superconductor
International Nuclear Information System (INIS)
Shehata, L.N.; Saif, A.G.
1983-08-01
The pinning force is calculated as a function of the distance between a curved (or straight) flux line and the centre of a macroscopic superconducting (or normal) ellipsoidal inclusion. When the ellipsoidal tends to a spherical inclusion the results agree with those previously obtained. (author)
Pollen and macroscopic analyses of sediments from two lakes in the High Tatra mountains, Slovakia
Czech Academy of Sciences Publication Activity Database
Rybníčková, Eliška; Rybníček, Kamil
2006-01-01
Roč. 15, - (2006), s. 345-356 ISSN 0939-6314 R&D Projects: GA ČR(CZ) GA206/96/0531; GA ČR GA206/02/0568 Institutional research plan: CEZ:AV0Z60050516 Keywords : Pollen analyses * macroscopic analyses * high mointain lakes Subject RIV: EF - Botanics Impact factor: 0.649, year: 2006
Macroscopic networks in the human brain: mapping connectivity in healthy and damaged brains
Nijhuis, E.H.J.
2013-01-01
The human brain contains a network of interconnected neurons. Recent advances in functional and structural in-vivo magnetic resonance neuroimaging (MRI) techniques have provided opportunities to model the networks of the human brain on a macroscopic scale. This dissertation investigates the
Putting Personal Knowledge Management under the Macroscope of Informing Science
Directory of Open Access Journals (Sweden)
Ulrich Schmitt
2015-08-01
Full Text Available The paper introduces a novel Personal Knowledge Management (PKM concept and prototype system. The system’s objective is to aid life-long-learning, resourcefulness, creativity, and teamwork of individuals throughout their academic and professional life and as contributors and beneficiaries of organizational and societal performance. Such a scope offers appealing and viable opportunities for stakeholders in the educational, professional, and developmental context. To further validate the underlying PKM application design, the systems thinking techniques of the transdiscipline of Informing Science (IS are employed. By applying Cohen’s IS-Framework, Leavitt’s Diamond Model, the IS-Meta Approach, and Gill’s and Murphy’s Three Dimensions of Design Task Complexity, the more specific KM models and methodologies central to the PKMS concept are aligned, introduced, and visualized. The extent of this introduction offers an essential overview, which can be deepened and broadened by using the cited URL and DOI links pointing to the available resources of the author’s prior publications. The paper emphasizes the differences of the proposed meme-based PKM System compared to its traditional organizational document-centric counterparts as well as its inherent complementing synergies. As a result, it shows how the system is closing in on Vannevar Bush’s still unfulfilled vison of the ‘Memex’, an as-close-as-it-gets imaginary ancestor celebrating its 70th anniversary as an inspiring idea never realized. It also addresses the scenario recently put forward by Levy which foresees a decentralizing revolution of knowledge management that gives more power and autonomy to individuals and self-organized groups. Accordingly, it also touches on the PKM potential in terms of Kuhn’s Scientific Revolutions and Disruptive Innovations.
Energy Technology Data Exchange (ETDEWEB)
Sanguineti, Giuseppe, E-mail: sanguineti@ifo.it [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy); Arcidiacono, Fabio [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy); Landoni, Valeria [Department of Physics, Regina Elena National Cancer Institute, Rome (Italy); Saracino, Bianca Maria; Farneti, Alessia; Arcangeli, Stefano; Petrongari, Maria Grazia; Gomellini, Sara [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy); Strigari, Lidia [Department of Physics, Regina Elena National Cancer Institute, Rome (Italy); Arcangeli, Giorgio [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy)
2016-10-01
Purpose: To assess the macroscopic hematuria rates within a single-institution randomized phase 3 trial comparing dose-escalated, conventionally fractionated radiation therapy (CFRT) and moderately hypofractionated radiation therapy (MHRT) for localized prostate cancer. Methods and Materials: Patients with intermediate- to high-risk localized prostate cancer were treated with conformal RT and short-course androgen deprivation. Both the prostate and the entire seminal vesicles were treated to 80 Gy in 40 fractions over 8 weeks (CFRT) or 62 Gy in 20 fractions over 5 weeks (MHRT). The endpoint of the present study was the development of any episode or grade of macroscopic hematuria. The median follow-up period was 93 months (range 6-143). Results: Macroscopic hematuria was reported by 25 of 168 patients (14.9%). The actuarial estimate of hematuria at 8 years was 17.0% (95% confidence interval [CI] 10.7%-23.3%). The number of patients with hematuria was 6 and 19 in the CFRT and MHRT arms, respectively, for an actuarial 8-year estimate of 9.7% and 24.3%, respectively (hazard ratio 3.468, 95% CI 1.385-8.684; P=.008). Overall, 8 of 25 patients were found to have biopsy-proven urothelial carcinoma (3 in the CFRT arm and 5 in the MHRT arm; P=.27). Thus, the 8-year actuarial incidence of macroscopic hematuria (after censoring urothelial cancer–related episodes) was 4.1% and 18.2% after CFRT and MHRT, respectively (hazard ratio 4.961, 95% CI 1.426-17.263; P=.012). The results were confirmed by multivariate analysis after accounting for several patient-, treatment-, and tumor-related covariates. Conclusions: MHRT was associated with a statistically significant increased risk of macroscopic hematuria compared with CFRT.
International Nuclear Information System (INIS)
Sanguineti, Giuseppe; Arcidiacono, Fabio; Landoni, Valeria; Saracino, Bianca Maria; Farneti, Alessia; Arcangeli, Stefano; Petrongari, Maria Grazia; Gomellini, Sara; Strigari, Lidia; Arcangeli, Giorgio
2016-01-01
Purpose: To assess the macroscopic hematuria rates within a single-institution randomized phase 3 trial comparing dose-escalated, conventionally fractionated radiation therapy (CFRT) and moderately hypofractionated radiation therapy (MHRT) for localized prostate cancer. Methods and Materials: Patients with intermediate- to high-risk localized prostate cancer were treated with conformal RT and short-course androgen deprivation. Both the prostate and the entire seminal vesicles were treated to 80 Gy in 40 fractions over 8 weeks (CFRT) or 62 Gy in 20 fractions over 5 weeks (MHRT). The endpoint of the present study was the development of any episode or grade of macroscopic hematuria. The median follow-up period was 93 months (range 6-143). Results: Macroscopic hematuria was reported by 25 of 168 patients (14.9%). The actuarial estimate of hematuria at 8 years was 17.0% (95% confidence interval [CI] 10.7%-23.3%). The number of patients with hematuria was 6 and 19 in the CFRT and MHRT arms, respectively, for an actuarial 8-year estimate of 9.7% and 24.3%, respectively (hazard ratio 3.468, 95% CI 1.385-8.684; P=.008). Overall, 8 of 25 patients were found to have biopsy-proven urothelial carcinoma (3 in the CFRT arm and 5 in the MHRT arm; P=.27). Thus, the 8-year actuarial incidence of macroscopic hematuria (after censoring urothelial cancer–related episodes) was 4.1% and 18.2% after CFRT and MHRT, respectively (hazard ratio 4.961, 95% CI 1.426-17.263; P=.012). The results were confirmed by multivariate analysis after accounting for several patient-, treatment-, and tumor-related covariates. Conclusions: MHRT was associated with a statistically significant increased risk of macroscopic hematuria compared with CFRT.
Directory of Open Access Journals (Sweden)
Risto Leinonen
2015-09-01
Full Text Available [This paper is part of the Focused Collection on Upper Division Physics Courses.] This study concentrates on evaluating the consistency of upper-division students’ use of the second law of thermodynamics at macroscopic and microscopic levels. Data were collected by means of a paper and pencil test (N=48 focusing on the macroscopic and microscopic features of the second law concerned with heat transfer processes. The data analysis was based on a qualitative content analysis where students’ responses to the macroscopic- and microscopic-level items were categorized to provide insight into the consistency of the students’ ideas; if students relied on the same idea at both levels, they ended up in the same category at both levels, and their use of the second law was consistent. The most essential finding is that a majority of students, 52%–69% depending on the physical system under evaluation, used the second law of thermodynamics consistently at macroscopic and microscopic levels; approximately 40% of the students used it correctly in terms of physics while others relied on erroneous ideas, such as the idea of conserving entropy. The most common inconsistency harbored by 10%–15% of the students (depending on the physical system under evaluation was students’ tendency to consider the number of accessible microstates to remain constant even if the entropy was stated to increase in a similar process; other inconsistencies were only seen in the answers of a few students. In order to address the observed inconsistencies, we would suggest that lecturers should utilize tasks that challenge students to evaluate phenomena at macroscopic and microscopic levels concurrently and tasks that would guide students in their search for contradictions in their thinking.
Simos, N.; Zhong, Z.; Dooryhee, E.; Ghose, S.; Gill, S.; Camino, F.; Şavklıyıldız, İ.; Akdoğan, E. K.
2017-06-01
The study revealed that loss of ductility in an amorphous Fe-alloy coating on a steel substrate composite structure was essentially prevented from occurring, following radiation with modest neutron doses of ∼2 × 1018 n/cm2. At the higher neutron dose of ∼2 × 1019, macroscopic stress-strain analysis showed that the amorphous Fe-alloy nanostructured coating, while still amorphous, experienced radiation-induced embrittlement, no longer offering protection against ductility loss in the coating-substrate composite structure. Neutron irradiation in a corrosive environment revealed exemplary oxidation/corrosion resistance of the amorphous Fe-alloy coating, which is attributed to the formation of the Fe2B phase in the coating. To establish the impact of elevated temperatures on the amorphous-to-crystalline transition in the amorphous Fe-alloy, electron microscopy was carried out which confirmed the radiation-induced suppression of crystallization in the amorphous Fe-alloy nanostructured coating.
International Nuclear Information System (INIS)
Simos, N.; Zhong, Z.; Dooryhee, E.; Ghose, S.; Gill, S.
2017-01-01
Here, this study revealed that loss of ductility in an amorphous Fe-alloy coating on a steel substrate composite structure was essentially prevented from occurring, following radiation with modest neutron doses of ~2 x 10 18 n/cm 2 . At the higher neutron dose of ~2 x 10 19 , macroscopic stress-strain analysis showed that the amorphous Fe-alloy nanostructured coating, while still amorphous, experienced radiation-induced embrittlement, no longer offering protection against ductility loss in the coating-substrate composite structure. Neutron irradiation in a corrosive environment revealed exemplary oxidation/corrosion resistance of the amorphous Fe-alloy coating, which is attributed to the formation of the Fe 2 B phase in the coating. To establish the impact of elevated temperatures on the amorphous-to-crystalline transition in the amorphous Fe-alloy, electron microscopy was carried out which confirmed the radiation-induced suppression of crystallization in the amorphous Fe-alloy nanostructured coating.
Albéric, Marie; Dean, Mason N.; Gourrier, Aurélien; Wagermaier, Wolfgang; Dunlop, John W. C.; Staude, Andreas; Fratzl, Peter; Reiche, Ina
2017-01-01
Macroscopic, periodic, dark and bright patterns are observed on sections of elephant tusk, in the dentin part (ivory). The motifs—also called Schreger pattern—vary depending on the orientation in the tusk: on sections perpendicular to the tusk axis, a checkerboard pattern is present whereas on sections longitudinal to it, alternating stripes are observed. This pattern has been used to identify elephant and mammoth ivory in archeological artifacts and informs on the continuous tissue growth mechanisms of tusk. However, its origin, assumed to be related to the 3D structure of empty microtubules surrounded by the ivory matrix has yet to be characterized unequivocally. Based on 2D observations of the ivory microtubules by means of a variety of imaging techniques of three different planes (transverse, longitudinal and tangential to the tusk axis), we show that the dark areas of the macroscopic pattern are due to tubules oblique to the surface whereas bright areas are related to tubules parallel to it. The different microstructures observed in the three planes as well as the 3D data obtained by SR-μCT analysis allow us to propose a 3D model of the microtubule network with helical tubules phase-shifted in the tangential direction. The phase shift is a combination of a continuous phase shift of π every 1 mm with a stepwise phase shift of π/2 every 500 μm. By using 3D modeling, we show how the 3D helical model better represents the experimental microstructure observed in 2D planes compared to previous models in the literature. This brings new information on the origin of the unique Schreger pattern of elephant ivory, crucial for better understanding how archaeological objects were processed and for opening new routes to rethink how biological materials are built. PMID:28125603
Energy Technology Data Exchange (ETDEWEB)
Zhu, Yuping, E-mail: zhuyuping@126.com; Gu, Yunling; Liu, Hongguang
2015-02-25
Directional solidification technology has been widely used to improve the properties of polycrystalline Ni{sub 2}MnGa materials. Mechanical training can adjust the internal organizational structures of the materials, reduce the stress of twin boundaries motion, and then result in larger strain at lower outfield levels. In this paper, we test the microscopic structure of Ni{sub 2}MnGa polycrystalline ferromagnetic shape memory alloy produced by directional solidification and compress it along two axes successively for mechanical training. The influences of pre-compressive stresses on the temperature-induced strains are analyzed. The macroscopic mechanical behaviors show anisotropy. According to the generating mechanism of the macroscopic strain, a three-dimensional constitutive model is established. Based on thermodynamic method, the kinetic equations of the martensitic transformation and inverse transformation are presented considering the driving force and energy dissipation. The prediction curves of temperature-induce strains along two different directions are investigated. And the results coincide well with the experiment data. It well explains the macroscopic anisotropy mechanical behaviors and fits for using in engineering.
International Nuclear Information System (INIS)
Ghirardi, G.C.; Rimini, A.; Weber, T.
1987-06-01
It is shown that the assumption of a stochastic localization process for the quantum wave function is essentially different from the suppression of coherence over macroscopic distances arising from the interaction with the environment and allows for a conceptually complete derivation of the classical behaviour of macroscopic bodies. (author). 4 refs
International Nuclear Information System (INIS)
Méndez Romero, Alejandra; Verheij, Joanne; Dwarkasing, Roy S.; Seppenwoolde, Yvette; Redekop, William K.; Zondervan, Pieter E.; Nowak, Peter J.C.M.; Ijzermans, Jan N.M.; Levendag, Peter C.; Heijmen, Ben J.M.; Verhoef, Cornelis
2012-01-01
Purpose: To compare pathology macroscopic tumor dimensions with magnetic resonance imaging (MRI) measurements and to establish the microscopic tumor extension of colorectal liver metastases. Methods and Materials: In a prospective pilot study we included patients with colorectal liver metastases planned for surgery and eligible for MRI. A liver MRI was performed within 48 hours before surgery. Directly after surgery, an MRI of the specimen was acquired to measure the degree of tumor shrinkage. The specimen was fixed in formalin for 48 hours, and another MRI was performed to assess the specimen/tumor shrinkage. All MRI sequences were imported into our radiotherapy treatment planning system, where the tumor and the specimen were delineated. For the macroscopic pathology analyses, photographs of the sliced specimens were used to delineate and reconstruct the tumor and the specimen volumes. Microscopic pathology analyses were conducted to assess the infiltration depth of tumor cell nests. Results: Between February 2009 and January 2010 we included 13 patients for analysis with 21 colorectal liver metastases. Specimen and tumor shrinkage after resection and fixation was negligible. The best tumor volume correlations between MRI and pathology were found for T1-weighted (w) echo gradient sequence (r s = 0.99, slope = 1.06), and the T2-w fast spin echo (FSE) single-shot sequence (r s = 0.99, slope = 1.08), followed by the T2-w FSE fat saturation sequence (r s = 0.99, slope = 1.23), and the T1-w gadolinium-enhanced sequence (r s = 0.98, slope = 1.24). We observed 39 tumor cell nests beyond the tumor border in 12 metastases. Microscopic extension was found between 0.2 and 10 mm from the main tumor, with 90% of the cases within 6 mm. Conclusions: MRI tumor dimensions showed a good agreement with the macroscopic pathology suggesting that MRI can be used for accurate tumor delineation. However, microscopic extensions found beyond the tumor border indicate that caution is needed
Kornecki, Martin; Strube, Jochen
2018-03-16
Productivity improvements of mammalian cell culture in the production of recombinant proteins have been made by optimizing cell lines, media, and process operation. This led to enhanced titers and process robustness without increasing the cost of the upstream processing (USP); however, a downstream bottleneck remains. In terms of process control improvement, the process analytical technology (PAT) initiative, initiated by the American Food and Drug Administration (FDA), aims to measure, analyze, monitor, and ultimately control all important attributes of a bioprocess. Especially, spectroscopic methods such as Raman or near-infrared spectroscopy enable one to meet these analytical requirements, preferably in-situ. In combination with chemometric techniques like partial least square (PLS) or principal component analysis (PCA), it is possible to generate soft sensors, which estimate process variables based on process and measurement models for the enhanced control of bioprocesses. Macroscopic kinetic models can be used to simulate cell metabolism. These models are able to enhance the process understanding by predicting the dynamic of cells during cultivation. In this article, in-situ turbidity (transmission, 880 nm) and ex-situ Raman spectroscopy (785 nm) measurements are combined with an offline macroscopic Monod kinetic model in order to predict substrate concentrations. Experimental data of Chinese hamster ovary cultivations in bioreactors show a sufficiently linear correlation (R² ≥ 0.97) between turbidity and total cell concentration. PLS regression of Raman spectra generates a prediction model, which was validated via offline viable cell concentration measurement (RMSE ≤ 13.82, R² ≥ 0.92). Based on these measurements, the macroscopic Monod model can be used to determine different process attributes, e.g., glucose concentration. In consequence, it is possible to approximately calculate (R² ≥ 0.96) glucose concentration based on online cell
Directory of Open Access Journals (Sweden)
Martin Kornecki
2018-03-01
Full Text Available Productivity improvements of mammalian cell culture in the production of recombinant proteins have been made by optimizing cell lines, media, and process operation. This led to enhanced titers and process robustness without increasing the cost of the upstream processing (USP; however, a downstream bottleneck remains. In terms of process control improvement, the process analytical technology (PAT initiative, initiated by the American Food and Drug Administration (FDA, aims to measure, analyze, monitor, and ultimately control all important attributes of a bioprocess. Especially, spectroscopic methods such as Raman or near-infrared spectroscopy enable one to meet these analytical requirements, preferably in-situ. In combination with chemometric techniques like partial least square (PLS or principal component analysis (PCA, it is possible to generate soft sensors, which estimate process variables based on process and measurement models for the enhanced control of bioprocesses. Macroscopic kinetic models can be used to simulate cell metabolism. These models are able to enhance the process understanding by predicting the dynamic of cells during cultivation. In this article, in-situ turbidity (transmission, 880 nm and ex-situ Raman spectroscopy (785 nm measurements are combined with an offline macroscopic Monod kinetic model in order to predict substrate concentrations. Experimental data of Chinese hamster ovary cultivations in bioreactors show a sufficiently linear correlation (R2 ≥ 0.97 between turbidity and total cell concentration. PLS regression of Raman spectra generates a prediction model, which was validated via offline viable cell concentration measurement (RMSE ≤ 13.82, R2 ≥ 0.92. Based on these measurements, the macroscopic Monod model can be used to determine different process attributes, e.g., glucose concentration. In consequence, it is possible to approximately calculate (R2 ≥ 0.96 glucose concentration based on online cell
Interpreting the macroscopic pointer by analysing the elements of reality of a Schrödinger cat
Reid, M. D.
2017-10-01
We examine Einstein-Podolsky-Rosen’s (EPR) steering nonlocality for two realisable Schrödinger cat-type states where a meso/macroscopic system (called the ‘cat’-system) is entangled with a microscopic spin-1/2 system. We follow EPR’s argument and derive the predictions for ‘elements of reality’ that would exist to describe the cat-system, under the assumption of EPR’s local realism. By showing that those predictions cannot be replicated by any local quantum state description of the cat-system, we demonstrate the EPR-steering of the cat-system. For large cat-systems, we find that a local hidden state model is near-satisfied, meaning that a local quantum state description exists (for the cat) whose predictions differ from those of the elements of reality by a vanishingly small amount. For such a local hidden state model, the EPR-steering of the cat vanishes, and the cat-system can be regarded as being in a mixture of ‘dead’ and ‘alive’ states despite it being entangled with the spin system. We therefore propose that a rigorous signature of the Schrödinger cat-type paradox is the EPR-steering of the cat-system and provide two experimental signatures. This leads to a hybrid quantum/classical interpretation of the macroscopic pointer of a measurement device and suggests that many Schrödinger cat-type paradoxes may be explained by microscopic nonlocality.
Transport processes in macroscopically disordered media from mean field theory to percolation
Snarskii, Andrei A; Sevryukov, Vladimir A; Morozovskiy, Alexander; Malinsky, Joseph
2016-01-01
This book reflects on recent advances in the understanding of percolation systems to present a wide range of transport phenomena in inhomogeneous disordered systems. Further developments in the theory of macroscopically inhomogeneous media are also addressed. These developments include galvano-electric, thermoelectric, elastic properties, 1/f noise and higher current momenta, Anderson localization, and harmonic generation in composites in the vicinity of the percolation threshold. The book describes how one can find effective characteristics, such as conductivity, dielectric permittivity, magnetic permeability, with knowledge of the distribution of different components constituting an inhomogeneous medium. Considered are a wide range of recent studies dedicated to the elucidation of physical properties of macroscopically disordered systems. Aimed at researchers and advanced students, it contains a straightforward set of useful tools which will allow the reader to derive the basic physical properties of compli...
Flux dynamics and magnetovoltage measurements in a macroscopic cylindrical hole drilled in BSCCO
Energy Technology Data Exchange (ETDEWEB)
Yetis, H.; Altinkok, A.; Olutas, M. [Abant Izzet Baysal University, Department of Physics, Turgut Gulez Research Laboratory, 14280 Bolu (Turkey); Kilic, A. [Abant Izzet Baysal University, Department of Physics, Turgut Gulez Research Laboratory, 14280 Bolu (Turkey)], E-mail: kilic_a@ibu.edu.tr; Kilic, K. [Abant Izzet Baysal University, Department of Physics, Turgut Gulez Research Laboratory, 14280 Bolu (Turkey)
2007-10-01
Slow transport relaxation measurements (V-t curves) and magnetovoltage measurements (V-H curves) were carried out in a polycrystalline sample of Bi{sub 1.7}Pb{sub 0.3}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (BSCCO) with a macroscopic cylindrically drilled hole (CH). The time evolution of quenched state in V-t curves was interpreted in terms of enhancement of the superconducting order parameter and the relaxation of moving entity. Upon cycling of the external magnetic field with different sweep rates, unusual counter clockwise hysteresis effects and asymmetry in V-H curves are observed in BSCCO sample with CH, which can also be correlated to the trapping of the macroscopic flux bundles in CH.
Flux dynamics and magnetovoltage measurements in a macroscopic cylindrical hole drilled in BSCCO
International Nuclear Information System (INIS)
Yetis, H.; Altinkok, A.; Olutas, M.; Kilic, A.; Kilic, K.
2007-01-01
Slow transport relaxation measurements (V-t curves) and magnetovoltage measurements (V-H curves) were carried out in a polycrystalline sample of Bi 1.7 Pb 0.3 Sr 2 Ca 2 Cu 3 O x (BSCCO) with a macroscopic cylindrically drilled hole (CH). The time evolution of quenched state in V-t curves was interpreted in terms of enhancement of the superconducting order parameter and the relaxation of moving entity. Upon cycling of the external magnetic field with different sweep rates, unusual counter clockwise hysteresis effects and asymmetry in V-H curves are observed in BSCCO sample with CH, which can also be correlated to the trapping of the macroscopic flux bundles in CH
Linking stress with macroscopic and microscopic leaf response in trees: New diagnostic perspectives
Energy Technology Data Exchange (ETDEWEB)
Guenthardt-Goerg, Madeleine S. [Swiss Federal Institute for Forest, Snow and Landscape Research, WSL, Zuercherstrasse 111, CH-8903 Birmensdorf (Switzerland)]. E-mail: madeleine.goerg@wsl.ch; Vollenweider, Pierre [Swiss Federal Institute for Forest, Snow and Landscape Research, WSL, Zuercherstrasse 111, CH-8903 Birmensdorf (Switzerland)
2007-06-15
Visible symptoms in tree foliage can be used for stress diagnosis once validated with microscopical analyses. This paper reviews and illustrates macroscopical and microscopical markers of stress with a biotic (bacteria, fungi, insects) or abiotic (frost, drought, mineral deficiency, heavy metal pollution in the soil, acidic deposition and ozone) origin helpful for the validation of symptoms in broadleaved and conifer trees. Differentiation of changes in the leaf or needle physiology, through ageing, senescence, accelerated cell senescence, programmed cell death and oxidative stress, provides additional clues raising diagnosis efficiency, especially in combination with information about the target of the stress agent at the tree, leaf/needle, tissue, cell and ultrastructural level. Given the increasing stress in a changing environment, this review discusses how integrated diagnostic approaches lead to better causal analysis to be applied for specific monitoring of stress factors affecting forest ecosystems. - Macroscopic leaf symptoms and their microscopic analysis as stress bioindications.
Linking stress with macroscopic and microscopic leaf response in trees: New diagnostic perspectives
International Nuclear Information System (INIS)
Guenthardt-Goerg, Madeleine S.; Vollenweider, Pierre
2007-01-01
Visible symptoms in tree foliage can be used for stress diagnosis once validated with microscopical analyses. This paper reviews and illustrates macroscopical and microscopical markers of stress with a biotic (bacteria, fungi, insects) or abiotic (frost, drought, mineral deficiency, heavy metal pollution in the soil, acidic deposition and ozone) origin helpful for the validation of symptoms in broadleaved and conifer trees. Differentiation of changes in the leaf or needle physiology, through ageing, senescence, accelerated cell senescence, programmed cell death and oxidative stress, provides additional clues raising diagnosis efficiency, especially in combination with information about the target of the stress agent at the tree, leaf/needle, tissue, cell and ultrastructural level. Given the increasing stress in a changing environment, this review discusses how integrated diagnostic approaches lead to better causal analysis to be applied for specific monitoring of stress factors affecting forest ecosystems. - Macroscopic leaf symptoms and their microscopic analysis as stress bioindications
All-carbon nanotube diode and solar cell statistically formed from macroscopic network
Institute of Scientific and Technical Information of China (English)
Albert G. Nasibulin[1,2,3; Adinath M. Funde[3,4; Ilya V. Anoshkin[3; Igor A. Levitskyt[5,6
2015-01-01
Schottky diodes and solar cells are statistically created in the contact area between two macroscopic films of single-walled carbon nanotubes （SWNTs） at the junction of semiconducting and quasi-metallic bundles consisting of several high quality tubes. The n-doping of one of the films allows for photovoltaic action, owing to an increase in the built-in potential at the bundle-to-bundle interface. Statistical analysis demonstrates that the Schottky barrier device contributes significantly to the I-V characteristics, compared to the p-n diode. The upper limit of photovoltaic conversion efficiency has been estimated at N20%, demonstrating that the light energy conversion is very efficient for such a unique solar cell. While there have been multiple studies on rectifying SWNT diodes in the nanoscale environment, this is the first report of a macroscopic all-carbon nanotube diode and solar cell.
Automatic macroscopic characterization of diesel sprays by means of a new image processing algorithm
Rubio-Gómez, Guillermo; Martínez-Martínez, S.; Rua-Mojica, Luis F.; Gómez-Gordo, Pablo; de la Garza, Oscar A.
2018-05-01
A novel algorithm is proposed for the automatic segmentation of diesel spray images and the calculation of their macroscopic parameters. The algorithm automatically detects each spray present in an image, and therefore it is able to work with diesel injectors with a different number of nozzle holes without any modification. The main characteristic of the algorithm is that it splits each spray into three different regions and then segments each one with an individually calculated binarization threshold. Each threshold level is calculated from the analysis of a representative luminosity profile of each region. This approach makes it robust to irregular light distribution along a single spray and between different sprays of an image. Once the sprays are segmented, the macroscopic parameters of each one are calculated. The algorithm is tested with two sets of diesel spray images taken under normal and irregular illumination setups.
Flux dynamics and magnetovoltage measurements in a macroscopic cylindrical hole drilled in BSCCO
Yetiş, H.; Altinkok, A.; Olutaş, M.; Kiliç, A.; Kiliç, K.
2007-10-01
Slow transport relaxation measurements (V-t curves) and magnetovoltage measurements (V-H curves) were carried out in a polycrystalline sample of Bi1.7Pb0.3Sr2Ca2Cu3Ox (BSCCO) with a macroscopic cylindrically drilled hole (CH). The time evolution of quenched state in V-t curves was interpreted in terms of enhancement of the superconducting order parameter and the relaxation of moving entity. Upon cycling of the external magnetic field with different sweep rates, unusual counter clockwise hysteresis effects and asymmetry in V-H curves are observed in BSCCO sample with CH, which can also be correlated to the trapping of the macroscopic flux bundles in CH.
Measurements of effective total macroscopic cross sections and effective energy of continuum beam
Energy Technology Data Exchange (ETDEWEB)
Kobayashi, Hisao [Rikkyo Univ., Yokosuka, Kanagawa (Japan). Inst. for Atomic Energy
1998-03-01
Two practically useful quantities are introduced in this study to characterize a continuum neutron beam and to describe transmission phenomena of the beam in field of quantitative neutron radiography: an effective energy instead of a peak energy or a mean energy of the spectrum and an effective total macroscopic (ETM) cross section instead of a total macroscopic (TM) cross section defined at the monochromatic energy. The effective energy was evaluated by means of energy dependence of ETM cross section. To realize the method a beam quality indicator (BQI) has been proposed recently. Several effective energies were measured for non-filtered, filtered neutron beams, and outputs of neutron guide tubes in world by the BQI. A thermal neutron beam and three beams modulated by Pb filters with different thicknesses are studied to measure ETM cross sections for various materials and summarized in a table. Validity of the effective energy determined by the BQI is discussed relating with ETM cross sections of materials. (author)
Macroscopic proof of the Jarzynski–Wójcik fluctuation theorem for heat exchange
International Nuclear Information System (INIS)
Sughiyama, Yuki; Abe, Sumiyoshi
2008-01-01
In a recent work, Jarzynski and Wójcik (2004 Phys. Rev. Lett. 92 230602) have shown by using the properties of Hamiltonian dynamics and a statistical mechanical consideration that heat exchange through contact between two systems initially prepared at different temperatures obeys a fluctuation theorem. Here, another proof is presented, in which only macroscopic thermodynamic quantities are employed. The detailed balance condition is found to play an essential role. As a result, the theorem is found to hold under very general conditions
Macroscopic angular-momentum stages of Bose-Einstein condensates in toroidal traps
International Nuclear Information System (INIS)
Benakli, M.; Raghavan, S.; Smerzi, A.; Fantoni, S.; Shenoy, S.R.
2001-03-01
We study the stability of a rotating repulsive-atom Bose-Einstein condensate in a toroidal trap. The resulting macroscopic angular-momentum states with integer vorticity l spread radially, lowering rotational energies. These states are robust against vorticity-lowering decays, with estimated metastability barriers capable of sustaining large angular momenta (1 < or ∼ 10) for typical parameters. We identify the centrifugally squashed l-dependent density profile as a possible signature of condensate rotation and superfluidity. (author)
Quantum description of microscopic and macroscopic systems: Old problems and recent investigations
International Nuclear Information System (INIS)
Ghirardi, G.C.
1986-04-01
We review some open problems and some proposed solutions which are encountered in the quantum description of the microscopic systems, of the macroscopic ones, and of the interactions between these two types of objects. We describe a recent attempt allowing a unified description of all phenomena, reproducing the quantum mechanical situation for microscopic systems and inducing in a completely consistent way the classical behaviour of macro object and the phenomena of wave packet reduction in the system-apparatus interaction. (author)
Solano, Javier; Duarte, José; Vargas, Erwin; Cabrera, Jhon; Jácome, Andrés; Botero, Mónica; Rey, Juan
2016-10-01
This paper addresses the Energetic Macroscopic Representation EMR, the modelling and the control of photovoltaic panel PVP generation systems for simulation purposes. The model of the PVP considers the variations on irradiance and temperature. A maximum power point tracking MPPT algorithm is considered to control the power converter. A novel EMR is proposed to consider the dynamic model of the PVP with variations in the irradiance and the temperature. The EMR is evaluated through simulations of a PVP generation system.
Time-dependent mechanical behavior of human amnion: Macroscopic and microscopic characterization
2014-01-01
© 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Characterizing the mechanical response of the human amnion is essential to understand and to eventually prevent premature rupture of fetal membranes. In this study a large set of macroscopic and microscopic mechanical tests have been carried out on fresh unfixed amnion to gain insight into the time dependent material response and the underlying mechanisms. Creep and relaxation responses of amnion were characterized in...
Levitation of Bose-Einstein condensates induced by macroscopic non-adiabatic quantum tunneling
Nakamura, Katsuhiro; Kohi, Akihisa; Yamasaki, Hisatsugu; Perez-Garcia, Victor M.
2006-01-01
We study the dynamics of two-component Bose-Einstein condensates trapped in different vertical positions in the presence of an oscillating magnetic field. It is shown here how tuning appropriately the oscillation frequency of the magnetic field leads to the levitation of the system against gravity. This phenomenon is a manifestation of a macroscopic non-adiabatic tunneling in a system with internal degrees of freedom.
International Nuclear Information System (INIS)
Shenoy, S.R.; Karlsruhe Univ.
1983-07-01
A two-dimensional NXN array of coupled Josephson junctions, each of size tau 0 and Josephson length lambdasub(JO)>>tau 0 , is shown to exhibit macroscopic weak superconductivity. The Josephson phase coherence here extends across the array, vanishing discontinuously at the Kosterlitz-Thouless transition temperature. The transverse size Ntau 0 must be smaller than a few times the effective Josephson screening length lambdasub(J)sup(eff) proportional to lambdasub(JO), for a sharp transition to be seen. (author)
International Nuclear Information System (INIS)
Velotta, R.; Avaldi, L.; Camilloni, R.; Giammanco, F.; Spinelli, N.; Stefani, G.
1996-01-01
The macroscopic electric field resulting from the space charge produced in electron-impact experiments has been characterized by using secondary electrons of well-defined energy (e.g., Auger or autoionizing electrons) as a probe. It is shown that the measurement of the kinetic-energy shifts suffered by secondary electrons is a suitable tool for the analysis of the self-generated electric field in a low-density plasma. copyright 1996 The American Physical Society
International Nuclear Information System (INIS)
Medina, V.F.O.
1995-01-01
The document is a study on the relationship between irradiation dose and the macroscopic and microscopic parameters and chromosomal aberrations in the onions. The data were analyzed using analysis of variance or F-test to determine significant differences among treatments as affected by does of radiation followed by Duncan's Multiple Range Test (DMRT). LSD test was also used in comparing means when the F-ratio was significant. 23 refs.; 19 figs.; tabs
León M., Eric; Sato S., Alberto; Navarrete Z., Miluska; Cisneros S., Jannet
2011-01-01
The anatomical description of the reproductive tract of the female llama was studied in four animals. Macroscopically, the reproductive system is morphologically similar to the cow. However, the difference is the absence of intercornual ligament and cotyledons, and the presence of an intercornual septum, as in the alpaca. The distribution of the arteries and veins that irrigated and drained the blood to and from the pelvic cavity and reproductive system presented a vascular distribution almos...
State-space based analysis and forecasting of macroscopic road safety trends in Greece.
Antoniou, Constantinos; Yannis, George
2013-11-01
In this paper, macroscopic road safety trends in Greece are analyzed using state-space models and data for 52 years (1960-2011). Seemingly unrelated time series equations (SUTSE) models are developed first, followed by richer latent risk time-series (LRT) models. As reliable estimates of vehicle-kilometers are not available for Greece, the number of vehicles in circulation is used as a proxy to the exposure. Alternative considered models are presented and discussed, including diagnostics for the assessment of their model quality and recommendations for further enrichment of this model. Important interventions were incorporated in the models developed (1986 financial crisis, 1991 old-car exchange scheme, 1996 new road fatality definition) and found statistically significant. Furthermore, the forecasting results using data up to 2008 were compared with final actual data (2009-2011) indicating that the models perform properly, even in unusual situations, like the current strong financial crisis in Greece. Forecasting results up to 2020 are also presented and compared with the forecasts of a model that explicitly considers the currently on-going recession. Modeling the recession, and assuming that it will end by 2013, results in more reasonable estimates of risk and vehicle-kilometers for the 2020 horizon. This research demonstrates the benefits of using advanced state-space modeling techniques for modeling macroscopic road safety trends, such as allowing the explicit modeling of interventions. The challenges associated with the application of such state-of-the-art models for macroscopic phenomena, such as traffic fatalities in a region or country, are also highlighted. Furthermore, it is demonstrated that it is possible to apply such complex models using the relatively short time-series that are available in macroscopic road safety analysis. Copyright © 2013 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Gao Chongshou; Wang Chengshing
1993-01-01
A macroscopic damping model is proposed to calculate the zero degree energy distribution in ultra-relativistic heavy ion collisions. The main features of the measured distributions are reproduced, good agreement is obtained in the middle energy region while overestimation results on the high energy side. The average energy loss coefficient of incident nucleons, varying in the reasonable region 0.2-0.6, depends on beam energy and target size
From Microscopic to Macroscopic Descriptions of Cell Migration on Growing Domains
Baker, Ruth E.
2009-10-28
Cell migration and growth are essential components of the development of multicellular organisms. The role of various cues in directing cell migration is widespread, in particular, the role of signals in the environment in the control of cell motility and directional guidance. In many cases, especially in developmental biology, growth of the domain also plays a large role in the distribution of cells and, in some cases, cell or signal distribution may actually drive domain growth. There is an almost ubiquitous use of partial differential equations (PDEs) for modelling the time evolution of cellular density and environmental cues. In the last 20 years, a lot of attention has been devoted to connecting macroscopic PDEs with more detailed microscopic models of cellular motility, including models of directional sensing and signal transduction pathways. However, domain growth is largely omitted in the literature. In this paper, individual-based models describing cell movement and domain growth are studied, and correspondence with a macroscopic-level PDE describing the evolution of cell density is demonstrated. The individual-based models are formulated in terms of random walkers on a lattice. Domain growth provides an extra mathematical challenge by making the lattice size variable over time. A reaction-diffusion master equation formalism is generalised to the case of growing lattices and used in the derivation of the macroscopic PDEs. © 2009 Society for Mathematical Biology.
Information and self-organization a macroscopic approach to complex systems
Haken, Hermann
1988-01-01
Complex systems are ubiquitous, and practically all branches of science ranging from physics through chemistry and biology to economics and sociology have to deal with them. In this book we wish to present concepts and methods for dealing with complex systems from a unifying point of view. Therefore it may be of inter est to graduate students, professors and research workers who are concerned with theoretical work in the above-mentioned fields. The basic idea for our unified ap proach sterns from that of synergetics. In order to find unifying principles we shall focus our attention on those situations where a complex system changes its macroscopic behavior qualitatively, or in other words, where it changes its macroscopic spatial, temporal or functional structure. Until now, the theory of synergetics has usually begun with a microscopic or mesoscopic description of a complex system. In this book we present an approach which starts out from macroscopic data. In particular we shall treat systems that acquir...
International Nuclear Information System (INIS)
Chen, P.J.
1986-01-01
Microscopically, when the molecules of certain materials are under the influence of external stimuli such as mechanical and electrical forces, several processes can happen. In particular, the centers of charge of the positive and negative ions of a molecule may displace with respect to each other. This notion leads to the macroscopic concept of polarization which has been exploited in the classical studies of piezoelectric and ferroelectric materials. In addition, the ions of the molecule may also rotate angularly relative to one another. Here an entirely new macroscopic concept of body couple which differs from the classical concept is introduced. It is shown that the simplest representations of the proposed constitutive relations lead to an equation within the context of the classical bending theory of thin plates whose solution is in remarkable agreement with recent experimental results concerning the bending of thin virgin ferroelectric ceramic discs under the action of small d.c. voltages. These experimental results cannot be explained by the classical notion of polarization. Therefore, the concept of macroscopic body couple introduced here is a fundamental feature which must be taken into account in the considerations of electromechanical interactions
A constitutive model and numerical simulation of sintering processes at macroscopic level
Wawrzyk, Krzysztof; Kowalczyk, Piotr; Nosewicz, Szymon; Rojek, Jerzy
2018-01-01
This paper presents modelling of both single and double-phase powder sintering processes at the macroscopic level. In particular, its constitutive formulation, numerical implementation and numerical tests are described. The macroscopic constitutive model is based on the assumption that the sintered material is a continuous medium. The parameters of the constitutive model for material under sintering are determined by simulation of sintering at the microscopic level using a micro-scale model. Numerical tests were carried out for a cylindrical specimen under hydrostatic and uniaxial pressure. Results of macroscopic analysis are compared against the microscopic model results. Moreover, numerical simulations are validated by comparison with experimental results. The simulations and preparation of the model are carried out by Abaqus FEA - a software for finite element analysis and computer-aided engineering. A mechanical model is defined by the user procedure "Vumat" which is developed by the first author in Fortran programming language. Modelling presented in the paper can be used to optimize and to better understand the process.
Sialic acid-triggered macroscopic properties switching on a smart polymer surface
Xiong, Yuting; Li, Minmin; Wang, Hongxi; Qing, Guangyan; Sun, Taolei
2018-01-01
Constructing smart surfaces with responsive polymers capable of dynamically and reversibly changing their chemical and physical properties by responding to the recognition of biomolecules remains a challenging task. And, the key to achieving this purpose relies on the design of polymers to precisely interact with the target molecule and successfully transform the interaction signal into tunable macroscopic properties, further achieve special bio-functions. Herein, inspired by carbohydrate-carbohydrate interaction (CCI) in life system, we developed a three-component copolymer poly(NIPAAm-co-PT-co-Glc) bearing a binding unit glucose (Glc) capable of recognizing sialic acid, a type of important molecular targets for cancer diagnosis and therapy, and reported the sialic acid triggered macroscopic properties switching on this smart polymer surface. Detailed mechanism studies indicated that multiple hydrogen bonding interactions between Glc unit and Neu5Ac destroyed the initial hydrogen bond network of the copolymer, leading to a reversible "contraction-to-swelling" conformational transition of the copolymer chains, accompanied with distinct macroscopic property switching (i.e., surface wettability, morphology, stiffness) of the copolymer film. And these features enabled this copolymer to selectively capture sialic acid-containing glycopeptides from complex protein samples. This work provides an inspiration for the design of novel smart polymeric materials with sensitive responsiveness to sialic acid, which would promote the development of sialic acid-specific bio-devices and drug delivery systems.
Directory of Open Access Journals (Sweden)
Aunyachulee Ganogpichayagrai
2016-01-01
Full Text Available Thai mango cultivars are classified into six groups plus one miscellaneous group according to germplasm database for mango. Characterization is important for conservation and the development of Thai mango cultivars. This study investigated macroscopic, microscopic leaf characteristics, and genetic relationship among 17 cultivars selected from six groups of mango in Thailand. Selected mango samples were obtained from three different locations in Thailand (n = 57. They were observed for their leaf and fruit macroscopic characteristics. Leaf measurement for the stomatal number, veinlet termination number, and palisade ratio was evaluated under a microscope attached with digital camera. DNA fingerprint was performed using CTAB extraction of DNA and inter-simple sequence repeat (ISSR amplification. Forty-five primers were screened; then, seven primers that amplified the reproducible band patterns were selected to amplified and generate dendrogram by Unweighted Pair-Group Method with Arithmetic Average. These selected 17 Thai mango cultivars had individually macroscopic characteristics based on fruits and leaves. For microscopic characteristics, the stomatal number, veinlet termination number, and palisade ratio were slightly differentiable. For genetic identification, 78 bands of 190-2660 bps were amplified, of which 82.05% were polymorphic. The genetic relationship among these cultivars was demonstrated and categorized into two main clusters. It was shown that ISSR markers could be useful for Thai mango cultivar identification.
International Nuclear Information System (INIS)
Huang Shaoming; Dai Liming
2002-01-01
By pyrolysis of iron phthalocyanine (FePc), either in a patterned or non-patterned fashion, under an Ar/H 2 atmosphere, we have demonstrated the large-scale production of aligned carbon nanotubes perpendicular to the substrate surface useful for building devices with three-dimensional structures. Depending on the particular pyrolytic conditions used, carbon nanotubes with a wide range of microscopic structures having curved, helical, coiled, branched, and tube-within-tube shapes have also been prepared by the pyrolysis of FePc. This, coupled with several microfabrication methods (photolithography, soft-lithography, self-assembling, micro-contact transfer, etc.), has enabled us to produce carbon nanotube arrays of various macroscopic architectures including polyhedral, flower-like, dendritic, circular, multilayered, and micropatterned geometries. In this article, we summarize our work on the preparation of FePc-generated carbon nanotubes with the large variety of microscopic and macroscopic structures and give a brief overview on the perspectives of making carbon nanotubes with tailor-made microscopic/macroscopic structures, and hence well-defined physicochemical properties, for specific applications
International Nuclear Information System (INIS)
Wieland, E.; Bonhoure, I.; Tits, J.; Scheidegger, A.M.; Bradbury, M.H.
2002-01-01
The uptake of safety-relevant radionuclides was studied using a combination of macroscopic (wet chemistry) and spectroscopic (X-ray absorption fine structure (XAFS) spectroscopy) techniques with the aim of gaining a mechanistic understanding of the uptake processes on hardened cement paste (HCP) and deducing robust sets of sorption values. HCP contains impurities of metal cations in the ppb to ppm concentration range. As a consequence, the inventories of stable isotopes are expected to be significant in a cementitious near-field and may even exceed the radionuclide inventories of the waste matrix for many safety-relevant radioelements. In view of the significant inventories of stable isotopes, it is suggested that isotopic exchange - replacement of stable isotopes by their radioactive counterparts in the cement matrix - is an important immobilisation process in HCP. However, it is not a priori known what proportion of each elemental inventory is available for isotopic exchange. Wet chemistry studies with Cs and Sr show that the total inventory of these elements is reversibly bound and that their partitioning between HCP and pore water can be modelled using the distribution values deduced from studies of the corresponding tracers ( 137 Cs and 85 Sr). This finding corroborates the relevance of isotopic exchange in cementitious systems. Wet chemistry investigations need to be complemented by spectroscopic techniques, e.g., XAFS, in order to gain a mechanistic understanding of the chemical processes by which waste ions become immobilised in cement-based matrices. XAFS can be used to obtain information at the atomic/molecular level, i.e., the type, number and distance of neighbouring atoms. XAFS studies on cementitious systems are still rather rare, and therefore information on the potential and limitations of this technique is sparse. Mechanistic aspects of the immobilisation processes are discussed for some safety-relevant radionuclides (e.g. Ni and Sr) using the
Singh, A.; Holt, R. M.; Ramarao, B.; Clemo, T.
2011-12-01
Three radioactive waste disposal landfills at the Waste Control Specialists (WCS) facility in Andrews County, Texas are constructed below grade, within the low-permeability Dockum Group mudrocks (Cooper Canyon Formation) of Triassic age. Recent site investigations at the WCS disposal facilities indicate the presence of a trapped and compressed gas phase in the mudrocks. The Dockum is a low-permeability medium with vertical and horizontal effective hydraulic conductivities of 1.2E-9 cm/s and 2.9E-7 cm/s. The upper 300+ feet of the Dockum is in the unsaturated zone, with an average saturation of 0.87 and average capillary pressure of 2.8 MPa determined from core samples. Air entry pressures on core samples range from from 0.016 to 9.8 MPa, with a mean of 1.0 MPa. Heat dissipation sensors, thermocouple psychrometers, and advanced tensiometers installed in Dockum borehole arrays generally show capillary pressures one order of magnitude less than those measured on core samples. These differences with core data are attributed to the presence of a trapped and compressed gas phase within Dockum materials. In the vicinity of an instrumented borehole, the gas phase pressure equilibrates with atmospheric pressure, lowering the capillary pressure. We have developed a new macroscopic invasion percolation (MIP) model to illustrate the origin of the trapped gas phase in the Dockum rocks. An MIP model differs from invasion percolation (IP) through the definition of macro-scale capillarity. Individual pore throats and necks are not considered. Instead, a near pore-scale block is defined and characterized by a local threshold spanning pressure (a local block-scale breakthrough pressure) that represents the behavior of the subscale network. The model domain is discretized into an array of grid blocks with assigned spanning pressures. An invasion pressure for each block is then determined by the sum of spanning pressure, buoyance forces, and viscous forces. An IP algorithm sorts the
DEFF Research Database (Denmark)
Andersen, Steffen; Harrison, Glenn W.; Lau, Morten I.
2008-01-01
We review the use of behavior from television game shows to infer risk attitudes. These shows provide evidence when contestants are making decisions over very large stakes, and in a replicated, structured way. Inferences are generally confounded by the subjective assessment of skill in some games......, and the dynamic nature of the task in most games. We consider the game shows Card Sharks, Jeopardy!, Lingo, and finally Deal Or No Deal. We provide a detailed case study of the analyses of Deal Or No Deal, since it is suitable for inference about risk attitudes and has attracted considerable attention....
Measuring performance at trade shows
DEFF Research Database (Denmark)
Hansen, Kåre
2004-01-01
Trade shows is an increasingly important marketing activity to many companies, but current measures of trade show performance do not adequately capture dimensions important to exhibitors. Based on the marketing literature's outcome and behavior-based control system taxonomy, a model is built...... that captures a outcome-based sales dimension and four behavior-based dimensions (i.e. information-gathering, relationship building, image building, and motivation activities). A 16-item instrument is developed for assessing exhibitors perceptions of their trade show performance. The paper presents evidence...
Tokyo Motor Show 2003; Tokyo Motor Show 2003
Energy Technology Data Exchange (ETDEWEB)
Joly, E.
2004-01-01
The text which follows present the different techniques exposed during the 37. Tokyo Motor Show. The report points out the great tendencies of developments of the Japanese automobile industry. The hybrid electric-powered vehicles or those equipped with fuel cells have been highlighted by the Japanese manufacturers which allow considerable budgets in the research of less polluting vehicles. The exposed models, although being all different according to the manufacturer, use always a hybrid system: fuel cell/battery. The manufacturers have stressed too on the intelligent systems for navigation and safety as well as on the design and comfort. (O.M.)
Reality show: um paradoxo nietzschiano
Directory of Open Access Journals (Sweden)
Ilana Feldman
2011-01-01
Full Text Available
O fenômeno dos reality shows - e a subseqüente relação entre imagem e verdade - assenta-se sobre uma série de paradoxos. Tais paradoxos podem ser compreendidos à luz do pensamento do filósofo alemão Friedrich Nietzsche, que, através dos usos de formulações paradoxais, concebia a realidade como um mundo de pura aparência e a verdade como um acréscimo ficcional, como um efeito. A ficção é então tomada, na filosofia de Nietzsche, não em seu aspecto falsificante e desrealizador - como sempre pleiteou nossa tradição metafísica -, mas como condição necessária para que certa espécie de invenção possa operar como verdade. Sendo assim, a própria expressão reality show, através de sua formulação paradoxal, engendra explicitamente um mundo de pura aparência, em que a verdade, a parte reality da proposição, é da ordem do suplemento, daquilo que se acrescenta ficcionalmente - como um adjetivo - a show. O ornamento, nesse caso, passa a ocupar o lugar central, apontando para o efeito produzido: o efeito-de-verdade. Seguindo, então, o pensamento nietzschiano e sua atualização na contemporaneidade, investigaremos de que forma os televisivos “shows de realidade” operam paradoxalmente, em consonância com nossas paradoxais práticas culturais.
Tieleman, D.P; Berendsen, H.J.C.
1996-01-01
We compared molecular dynamics simulations of a bilayer of 128 fully hydrated phospholipid (DPPC) molecules, using different parameters and macroscopic boundary conditions. The same system was studied under constant pressure, constant volume, and constant surface tension boundary conditions, with
International Nuclear Information System (INIS)
Zhang Aixia; Xue Jukui
2012-01-01
We propose a scheme to reveal the interplay between dipole–dipole interaction (DDI), inter-level coupling and macroscopic phase transitions in dipolar condensates. By considering a macroscopic sample of dipolar bosons in triple-well potentials, DDI-induced coupling between the inter-level physics and the macroscopic phase transitions is presented. When the DDI exceeds certain thresholds, the degeneracy of the two lowest energy levels and the excitation of new eigenstates occur, respectively. Interestingly, these thresholds give the boundaries of various quantum phase transitions. That is, the quantum phase transitions are the consequence of the levels' degeneracy and the new eigenstates' excitation. Furthermore, DDI-induced long-range macroscopic Josephson oscillations are observed and long-range coherent quantum transportation is achieved. Our results give clear proof of the interplay between the multi-level physics and quantum phase transitions, and also provide a way for designing the long-range coherent quantum transportation. (paper)
Elze, J; Liebler-Tenorio, E; Ziller, M; Köhler, H
2013-07-01
The objective of this study was to identify the most reliable approach for prevalence estimation of Mycobacterium avium ssp. paratuberculosis (MAP) infection in clinically healthy slaughtered cattle. Sampling of macroscopically suspect tissue was compared to systematic sampling. Specimens of ileum, jejunum, mesenteric and caecal lymph nodes were examined for MAP infection using bacterial microscopy, culture, histopathology and immunohistochemistry. MAP was found most frequently in caecal lymph nodes, but sampling more tissues optimized the detection rate. Examination by culture was most efficient while combination with histopathology increased the detection rate slightly. MAP was detected in 49/50 animals with macroscopic lesions representing 1.35% of the slaughtered cattle examined. Of 150 systematically sampled macroscopically non-suspect cows, 28.7% were infected with MAP. This indicates that the majority of MAP-positive cattle are slaughtered without evidence of macroscopic lesions and before clinical signs occur. For reliable prevalence estimation of MAP infection in slaughtered cattle, systematic random sampling is essential.
Energy Technology Data Exchange (ETDEWEB)
Dal Pra, Alan [Bern University Hospital, Inselspital Bern, Department of Radiation Oncology, Bern (Switzerland); Panje, Cedric; Glatzer, Markus; Putora, Paul Martin [Kantonsspital St. Gallen, Department of Radiation Oncology, St. Gallen (Switzerland); Zilli, Thomas [Hospitaux Universitaires de Geneve, Department of Radiation Oncology, Geneve (Switzerland); Arnold, Winfried [Luzerner Kantonsspital, Department of Radiation Oncology, Luzerner (Switzerland); Brouwer, Kathrin [Stadtspital Triemli, Department of Radiation Oncology, Zuerich (Switzerland); Garcia, Helena [Universitaetsspital Zuerich, Department of Radiation Oncology, Zuerich (Switzerland); Gomez, Silvia [Kantonsspital Aarau, Department of Radiation Oncology, Aarau (Switzerland); Herrera, Fernanda [Centre Hospitalier Universitaire Vaudois, Department of Radiation Oncology, Lausanne (Switzerland); Kaouthar, Khanfir [Hopital du Valais, Department of Radiation Oncology, Sion (Switzerland); Papachristofilou, Alexandros [Universitaetsspital Basel, Department of Radiation Oncology, Basel (Switzerland); Pesce, Gianfranco [EOC Bellinzona, Department of Radiation Oncology, Bellinzona (Switzerland); Reuter, Christiane [Kantonsspital Muensterlingen, Department of Radiation Oncology, Muensterlingen (Switzerland); Vees, Hansjoerg [Klinik Hirslanden, Department of Radiation Oncology, Zuerich (Switzerland); Zwahlen, Daniel Rudolf [Kantonsspital Graubuenden, Department of Radiation Oncology, Chur (Switzerland); Engeler, Daniel [Kantonsspital St. Gallen, Department of Urology, St. Gallen (Switzerland)
2018-01-15
Although salvage radiotherapy (SRT) for PSA recurrence after radical prostatectomy provides better oncological outcomes when delivered early, in the absence of detectable disease many patients are treated for macroscopic locally recurrent tumors. Due to limited data from prospective studies, we hypothesized an important variability in the SRT management of these patients. Our aim was to investigate current practice patterns of SRT for local macroscopic recurrence after radical prostatectomy. A total of 14 Swiss radiation oncology centers were asked to complete a survey on treatment specifications for macroscopic locally recurrent disease including information on pretherapeutic diagnostic procedures, dose prescription, radiation delivery techniques and androgen deprivation therapy (ADT). Treatment recommendations on ADT were analyzed using the objective consensus methodology. The majority of centers recommended pretreatment magnetic resonance imaging (MRI) of the pelvis and choline positron emission tomography (PET). The median prescribed dose to the prostate bed was 66 Gy (range 65-72 Gy) with a boost to the macroscopic lesion used by 79% of the centers with a median total dose of 72 Gy (range 70-80 Gy). Intensity-modulated rotational techniques were used by all centers and daily cone beam computed tomography (CT) was recommended by 43%. The use of concomitant ADT for any macroscopic recurrence was recommended by 43% of the centers while the remaining centers recommended it only for high-risk disease, which was not consistently defined. We observed a high variability of treatment paradigms when SRT is indicated for macroscopic local recurrences after prostatectomy. These data reflect the need for more standardized approaches and ultimately further research in this field. (orig.) [German] Obwohl die Evidenz fuer eine fruehzeitige Salvage-Radiotherapie (SRT) bei einem PSA-Rezidiv nach radikaler Prostatektomie spricht, werden viele Patienten erst bei einem
Energy Technology Data Exchange (ETDEWEB)
Yan, Zhifeng [Institute of Surface-Earth System Science, Tianjin University, Tianjin China; Pacific Northwest National Laboratory, Richland WA USA; Liu, Chongxuan [Pacific Northwest National Laboratory, Richland WA USA; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen China; Liu, Yuanyuan [Pacific Northwest National Laboratory, Richland WA USA; School of Earth Science and Engineering, Nanjing University, Nanjing China; Bailey, Vanessa L. [Pacific Northwest National Laboratory, Richland WA USA
2017-11-01
Biofilms are critical locations for biogeochemical reactions in the subsurface environment. The occurrence and distribution of biofilms at microscale as well as their impacts on macroscopic biogeochemical reaction rates are still poorly understood. This paper investigated the formation and distributions of biofilms in heterogeneous sediments using multiscale models, and evaluated the effects of biofilm heterogeneity on local and macroscopic biogeochemical reaction rates. Sediment pore structures derived from X-ray computed tomography were used to simulate the microscale flow dynamics and biofilm distribution in the sediment column. The response of biofilm formation and distribution to the variations in hydraulic and chemical properties was first examined. One representative biofilm distribution was then utilized to evaluate its effects on macroscopic reaction rates using nitrate reduction as an example. The results revealed that microorganisms primarily grew on the surfaces of grains and aggregates near preferential flow paths where both electron donor and acceptor were readily accessible, leading to the heterogeneous distribution of biofilms in the sediments. The heterogeneous biofilm distribution decreased the macroscopic rate of biogeochemical reactions as compared with those in homogeneous cases. Operationally considering the heterogeneous biofilm distribution in macroscopic reactive transport models such as using dual porosity domain concept can significantly improve the prediction of biogeochemical reaction rates. Overall, this study provided important insights into the biofilm formation and distribution in soils and sediments as well as their impacts on the macroscopic manifestation of reaction rates.
Gecko toe and lamellar shear adhesion on macroscopic, engineered rough surfaces.
Gillies, Andrew G; Henry, Amy; Lin, Hauwen; Ren, Angela; Shiuan, Kevin; Fearing, Ronald S; Full, Robert J
2014-01-15
The role in adhesion of the toes and lamellae - intermediate-sized structures - found on the gecko foot remains unclear. Insight into the function of these structures can lead to a more general understanding of the hierarchical nature of the gecko adhesive system, but in particular how environmental topology may relate to gecko foot morphology. We sought to discern the mechanics of the toes and lamellae by examining gecko adhesion on controlled, macroscopically rough surfaces. We used live Tokay geckos, Gekko gecko, to observe the maximum shear force a gecko foot can attain on an engineered substrate constructed with sinusoidal patterns of varying amplitudes and wavelengths in sizes similar to the dimensions of the toes and lamellae structures (0.5 to 6 mm). We found shear adhesion was significantly decreased on surfaces that had amplitudes and wavelengths approaching the lamella length and inter-lamella spacing, losing 95% of shear adhesion over the range tested. We discovered that the toes are capable of adhering to surfaces with amplitudes much larger than their dimensions even without engaging claws, maintaining 60% of shear adhesion on surfaces with amplitudes of 3 mm. Gecko adhesion can be predicted by the ratio of the lamella dimensions to surface feature dimensions. In addition to setae, remarkable macroscopic-scale features of gecko toes and lamellae that include compliance and passive conformation are necessary to maintain contact, and consequently, generate shear adhesion on macroscopically rough surfaces. Findings on the larger scale structures in the hierarchy of gecko foot function could provide the biological inspiration to drive the design of more effective and versatile synthetic fibrillar adhesives.
Can We Advance Macroscopic Quantum Systems Outside the Framework of Complex Decoherence Theory?
Brezinski, Mark E; Rupnick, Maria
2016-01-01
Macroscopic quantum systems (MQS) are macroscopic systems driven by quantum rather than classical mechanics, a long studied area with minimal success till recently. Harnessing the benefits of quantum mechanics on a macroscopic level would revolutionize fields ranging from telecommunication to biology, the latter focused on here for reasons discussed. Contrary to misconceptions, there are no known physical laws that prevent the development of MQS. Instead, they are generally believed universally lost in complex systems from environmental entanglements (decoherence). But we argue success is achievable MQS with decoherence compensation developed, naturally or artificially, from top-down rather current reductionist approaches. This paper advances the MQS field by a complex systems approach to decoherence. First, why complex system decoherence approaches (top-down) are needed is discussed. Specifically, complex adaptive systems (CAS) are not amenable to reductionist models (and their master equations) because of emergent behaviour, approximation failures, not accounting for quantum compensatory mechanisms, ignoring path integrals, and the subentity problem. In addition, since MQS must exist within the context of the classical world, where rapid decoherence and prolonged coherence are both needed. Nature has already demonstrated this for quantum subsystems such as photosynthesis and magnetoreception. Second, we perform a preliminary study that illustrates a top-down approach to potential MQS. In summary, reductionist arguments against MQS are not justifiable. It is more likely they are not easily detectable in large intact classical systems or have been destroyed by reductionist experimental set-ups. This complex systems decoherence approach, using top down investigations, is critical to paradigm shifts in MQS research both in biological and non-biological systems. PMID:29200743
Elucidation of molecular kinetic schemes from macroscopic traces using system identification.
Directory of Open Access Journals (Sweden)
Miguel Fribourg
2017-02-01
Full Text Available Overall cellular responses to biologically-relevant stimuli are mediated by networks of simpler lower-level processes. Although information about some of these processes can now be obtained by visualizing and recording events at the molecular level, this is still possible only in especially favorable cases. Therefore the development of methods to extract the dynamics and relationships between the different lower-level (microscopic processes from the overall (macroscopic response remains a crucial challenge in the understanding of many aspects of physiology. Here we have devised a hybrid computational-analytical method to accomplish this task, the SYStems-based MOLecular kinetic scheme Extractor (SYSMOLE. SYSMOLE utilizes system-identification input-output analysis to obtain a transfer function between the stimulus and the overall cellular response in the Laplace-transformed domain. It then derives a Markov-chain state molecular kinetic scheme uniquely associated with the transfer function by means of a classification procedure and an analytical step that imposes general biological constraints. We first tested SYSMOLE with synthetic data and evaluated its performance in terms of its rate of convergence to the correct molecular kinetic scheme and its robustness to noise. We then examined its performance on real experimental traces by analyzing macroscopic calcium-current traces elicited by membrane depolarization. SYSMOLE derived the correct, previously known molecular kinetic scheme describing the activation and inactivation of the underlying calcium channels and correctly identified the accepted mechanism of action of nifedipine, a calcium-channel blocker clinically used in patients with cardiovascular disease. Finally, we applied SYSMOLE to study the pharmacology of a new class of glutamate antipsychotic drugs and their crosstalk mechanism through a heteromeric complex of G protein-coupled receptors. Our results indicate that our methodology
Maximum Entropy Methods as the Bridge Between Microscopic and Macroscopic Theory
Taylor, Jamie M.
2016-09-01
This paper is concerned with an investigation into a function of macroscopic variables known as the singular potential, building on previous work by Ball and Majumdar. The singular potential is a function of the admissible statistical averages of probability distributions on a state space, defined so that it corresponds to the maximum possible entropy given known observed statistical averages, although non-classical entropy-like objective functions will also be considered. First the set of admissible moments must be established, and under the conditions presented in this work the set is open, bounded and convex allowing a description in terms of supporting hyperplanes, which provides estimates on the development of singularities for related probability distributions. Under appropriate conditions it is shown that the singular potential is strictly convex, as differentiable as the microscopic entropy, and blows up uniformly as the macroscopic variable tends to the boundary of the set of admissible moments. Applications of the singular potential are then discussed, and particular consideration will be given to certain free-energy functionals typical in mean-field theory, demonstrating an equivalence between certain microscopic and macroscopic free-energy functionals. This allows statements about L^1-local minimisers of Onsager's free energy to be obtained which cannot be given by two-sided variations, and overcomes the need to ensure local minimisers are bounded away from zero and +∞ before taking L^∞ variations. The analysis also permits the definition of a dual order parameter for which Onsager's free energy allows an explicit representation. Also, the difficulties in approximating the singular potential by everywhere defined functions, in particular by polynomial functions, are addressed, with examples demonstrating the failure of the Taylor approximation to preserve relevant shape properties of the singular potential.
Levrero-Florencio, Francesc; Pankaj, Pankaj
2018-01-01
Realistic macro-level finite element simulations of the mechanical behavior of trabecular bone, a cellular anisotropic material, require a suitable constitutive model; a model that incorporates the mechanical response of bone for complex loading scenarios and includes post-elastic phenomena, such as plasticity (permanent deformations) and damage (permanent stiffness reduction), which bone is likely to experience. Some such models have been developed by conducting homogenization-based multiscale finite element simulations on bone micro-structure. While homogenization has been fairly successful in the elastic regime and, to some extent, in modeling the macroscopic plastic response, it has remained a challenge with respect to modeling damage. This study uses a homogenization scheme to upscale the damage behavior from the tissue level (microscale) to the organ level (macroscale) and assesses the suitability of different damage constitutive laws. Ten cubic specimens were each subjected to 21 strain-controlled load cases for a small range of macroscopic post-elastic strains. Isotropic and anisotropic criteria were considered, density and fabric relationships were used in the formulation of the damage law, and a combined isotropic/anisotropic law with tension/compression asymmetry was formulated, based on the homogenized results, as a possible alternative to the currently used single scalar damage criterion. This computational study enhances the current knowledge on the macroscopic damage behavior of trabecular bone. By developing relationships of damage progression with bone's micro-architectural indices (density and fabric) the study also provides an aid for the creation of more precise macroscale continuum models, which are likely to improve clinical predictions.
Macroscopic Study of the Isthmus of the Thyroid Gland in Bangladeshi People: A Postmortem Study
Directory of Open Access Journals (Sweden)
Fakhrul Amin Mohammad Hasanul Banna
2017-01-01
Full Text Available Background: The position and size of isthmus of thyroid gland varies considerably in human with age, sex, physiologic state, race and geographical location and sometimes the isthmus may be absent. So this study was designed to find out the macroscopic differences in isthmus of thyroid gland of different age and sex groups in Bangladeshi people. Objective: To record the macroscopic characteristics of isthmus of thyroid gland with advancing age in both sexes with a view to help establishing normal standard of Bangladeshi people. Materials and Methods: This descriptive cross-sectional study was carried out on 54 autopsied human thyroid glands aged 5 to 65 years. Thyroid glands were collected from unclaimed dead bodies autopsied in the morgue of Sylhet M. A. G. Osmani Medical College, Sylhet. The collected specimens were divided into groups –– A (20 years and below, B (21 to 50 years and C (50 years and above. All specimens were examined morphologically by careful gross dissection method. Results: The isthmus was absent in 5.56% cases. In most of the cases (35.29% it was against the 1st–4th tracheal rings. There was significant difference in length between Group A and Group C (p<0.05 and in breadth between Group A and Group C and between Group B and Group C (p<0.05. No significant difference was found in length, breadth and thickness of isthmus of the thyroid gland between males and females. Conclusion: The presence or absence, positional change and variation in gross dimension of isthmus of thyroid gland were evident in human. The macroscopic difference was found with increasing age but not with sex.
Macroscopic and microscopic findings in avascular necrosis of the femoral head.
Kamal, Diana; Alexandru, D O; Kamal, C K; Streba, C T; Grecu, D; Mogoantă, L
2012-01-01
The avascular necrosis of the femoral head is an illness induced by the cutoff of blood flow to the femoral head and it affects mostly young adults between the ages of 30 and 50 years, raising therapeutic and diagnostic issues. Many risk factors are incriminated in the development of avascular necrosis of the femoral head like: trauma, chronic alcohol consumption, smoking, administration of corticosteroid drugs, most of the cases are considered to be idiopathic. The main goal of our paper is to describe the macroscopic and microscopic variations of the bone structure, which occur in patients with avascular necrosis of the femoral head. The biological material needed for our study was obtained following hip arthroplasty surgery in 26 patients between the ages of 29 and 59 years, which previously were diagnosed with avascular necrosis of the femoral head and admitted in the Orthopedics Department of the Emergency County Hospital of Craiova (Romania) between 2010 and 2011. From a macroscopic point of view, we found well defined areas of necrosis, most of which were neatly demarcated of the adjacent viable tissue by hyperemic areas, loss of shape and contour of the femoral head and transformations of the articular cartilage above the area of necrosis. When examined under the microscope, we found vast areas of fibrosis, narrow bone trabeculae, obstructed blood vessels or blood vessels with clots inside, hypertrophic fat cells, bone sequestration but also small cells and pyknotic nuclei. The microscopic and macroscopic findings on the femoral head sections varied with the patients and the stage of the disease.
Macroscopic effects in electromagnetically-induced transparency in a Doppler-broadened system
International Nuclear Information System (INIS)
Pei Li-Ya; Qu Yi-Zhi; Niu Jin-Yan; Wang Ru-Quan; Wu Ling-An; Fu Pan-Ming; Zuo Zhan-Chun
2015-01-01
We study the electromagnetically-induced transparency (EIT) in a Doppler-broadened cascaded three-level system. We decompose the susceptibility responsible for the EIT resonance into a linear and a nonlinear part, and the EIT resonance reflects mainly the characteristics of the nonlinear susceptibility. It is found that the macroscopic polarization interference effect plays a crucial role in determining the EIT resonance spectrum. To obtain a Doppler-free spectrum there must be polarization interference between atoms of different velocities. A dressed-state model, which analyzes the velocities at which the atoms are in resonance with the dressed states through Doppler frequency shifting, is employed to explain the results. (paper)
GRUCAL: a program system for the calculation of macroscopic group constants
International Nuclear Information System (INIS)
Woll, D.
1984-01-01
Nuclear reactor calculations require material- and composition-dependent, energy-averaged neutron physical data in order to decribe the interaction between neutrons and isotopes. The multigroup cross section code GRUCAL calculates these macroscopic group constants for given material compositions from the material-dependent data of the group constant library GRUBA. The instructions for calculating group constants are not fixed in the program, but are read in from an instruction file. This makes it possible to adapt GRUCAL to various problems or different group constant concepts
On the inherent self-excited macroscopic randomness of chaotic three-body system
Liao, Shijun; Li, Xiaoming
2014-01-01
What is the origin of macroscopic randomness (uncertainty)? This is one of the most fundamental open questions for human being. In this paper, 10000 samples of reliable (convergent), multiple-scale (from 1.0E-60 to 100) numerical simulations of a chaotic three-body system indicate that, without any external disturbance, the microscopic inherent uncertainty (in the level of 1.0E-60) due to physical fluctuation of initial positions of the three-body system enlarges exponentially into macroscopi...
New limits on the detection of a composition-dependent macroscopic force
International Nuclear Information System (INIS)
Boynton, P.; Aronson, S.
1990-01-01
We report here on a continuing experimental search for a macroscopic, composition dependent force coupling to ordinary matter. Within the phenomenological framework commonly employed -- a Yukawa representation of the interaction potential, and composition specified as some linear combination of baryon and lepton numbers -- the Index 3 experiment sets the most stringent upper limits yet on the interaction strength for coupling from B-2L to B-L, and for an interaction range from 200 m to 10 km. It is also the first null result to conflict with the marginal detection reported for the Index 1 experiment for all relevant values of the composition and range parameters
Quantum teleportation from light beams to vibrational states of a macroscopic diamond
Hou, P.-Y.; Huang, Y.-Y.; Yuan, X.-X.; Chang, X.-Y.; Zu, C.; He, L.; Duan, L.-M.
2016-01-01
With the recent development of optomechanics, the vibration in solids, involving collective motion of trillions of atoms, gradually enters into the realm of quantum control. Here, building on the recent remarkable progress in optical control of motional states of diamonds, we report an experimental demonstration of quantum teleportation from light beams to vibrational states of a macroscopic diamond under ambient conditions. Through quantum process tomography, we demonstrate average teleportation fidelity (90.6±1.0)%, clearly exceeding the classical limit of 2/3. The experiment pushes the target of quantum teleportation to the biggest object so far, with interesting implications for optomechanical quantum control and quantum information science. PMID:27240553
Macroscopic quantum tunneling in 1 μm Nb junctions below 100mK
International Nuclear Information System (INIS)
Voss, R.F.; Webb, R.A.
1981-01-01
The transition probabilities out of the superconducting state of low current density 1 μm Nb Josephson junctions with capacitance < 0.15 pF have been measured as a function of temperature T down to 3 mK. Below 100 mK the distribution widths become independent of T. Junctions with critical currents that differ by an order of magnitude have the same dependence of relative width on T. The low T results are interpreted in terms of quantum tunneling of the (macroscopic) junction phase. The observed low temperature widths are smaller than expected indicating the necessity of corrections to the simple WKB tunneling rates. (orig.)
Welch, Kyle J; Hastings-Hauss, Isaac; Parthasarathy, Raghuveer; Corwin, Eric I
2014-04-01
We have constructed a macroscopic driven system of chaotic Faraday waves whose statistical mechanics, we find, are surprisingly simple, mimicking those of a thermal gas. We use real-time tracking of a single floating probe, energy equipartition, and the Stokes-Einstein relation to define and measure a pseudotemperature and diffusion constant and then self-consistently determine a coefficient of viscous friction for a test particle in this pseudothermal gas. Because of its simplicity, this system can serve as a model for direct experimental investigation of nonequilibrium statistical mechanics, much as the ideal gas epitomizes equilibrium statistical mechanics.
Quantum laws of the microworld and the wealth of macroscopic structures
International Nuclear Information System (INIS)
Noga, M.
2000-01-01
The reasons are highlighted why classical physics was unable to explain the formation of any collective self-organized arrangement such as magnetism and how the wealth of macroscopic self-organized structures emerges spontaneously from quantum theory applied to the given physical system. This is demonstrated on the simplest multi-electron system, viz. the model of a metal as electron gas with Coulomb interaction with a background of homogeneously distributed positive charge possessing a constant density so as to ensure charge neutrality of the system
Experimental study of macroscopic quantum tunnelling in Bi2212 intrinsic Josephson junctions
International Nuclear Information System (INIS)
Matsumoto, Tetsuro; Kashiwaya, Hiromi; Shibata, Hajime; Kashiwaya, Satoshi; Kawabata, Shiro; Eisaki, Hiroshi; Yoshida, Yoshiyuki; Tanaka, Yukio
2007-01-01
The quantum dynamics of Bi 2 Sr 2 CaCu 2 O 8+δ intrinsic Josephson junctions (IJJs) is studied based on escape rate measurements. The saturations observed in the escape temperature and in the width of the switching current below 0.5 K (= T * ) indicate the transition of the switching mechanism from thermal activation to macroscopic quantum tunnelling. It is shown that the switching properties are consistently explained in terms of the underdamped Josephson junction with a quality factor of 70 ± 20 in spite of possible damping due to the nodal quasiparticles of d-wave superconductivity. The present result gives the upper limit of the damping of IJJs
Determination of crystallographic and macroscopic orientation of planar structures in TEM
DEFF Research Database (Denmark)
Huang, X.; Liu, Q.
1998-01-01
With the aid of a double-tilt holder in a transmission electron microscope (TEM), simple methods are described for determination of the crystallographic orientation of a planar structure and for calculation of the macroscopic orientation of the planar structure. The correlation between a planar...... structure and a crystallographic plane can be found by comparing the differences in their trace directions on the projection plane and inclination angles with respect to that plane. The angles between the traces of planar structures and the sample axis measured from the TEM micrographs, which have been...
International Nuclear Information System (INIS)
De Martini, Francesco; Sciarrino, Fabio; Spagnolo, Nicolo
2009-01-01
The high resilience to decoherence shown by a recently discovered macroscopic quantum superposition (MQS) generated by a quantum-injected optical parametric amplifier and involving a number of photons in excess of 5x10 4 motivates the present theoretical and numerical investigation. The results are analyzed in comparison with the properties of the MQS based on |α> and N-photon maximally entangled states (NOON), in the perspective of the comprehensive theory of the subject by Zurek. In that perspective the concepts of 'pointer state' and 'environment-induced superselection' are applied to the new scheme.
Tetè, Stefano; Zizzari, Vincenzo; De Carlo, Alessandro; Sinjari, Bruna; Gherlone, Enrico
2012-01-01
The purpose of this study is to evaluate macroscopic and microscopic appearance of a new implant design, with particular emphasis given to the type of prosthesis connection. Two dental implants of the same type (Torque Type®, WinSix®, BioSAFin. S.r.l. - Ancona, Italy), with sandblasted and acid etched surfaces (Micro Rough Surface®), but differing from each other for the prosthesis connection system, were examined by scanning electron microscope (SEM) analysis at different magnifications: TTI...
Micciché, Maurizio; Arzt, Eduard; Kroner, Elmar
2014-05-28
The goal of our study is to better understand the design parameters of bioinspired dry adhesives inspired by geckos. For this, we fabricated single macroscopic pillars of 400 μm diameter with different aspect ratios and different tip shapes (i.e., flat tips, spherical tips with different radii, and mushroom tips with different diameters). Tilt-angle-dependent adhesion measurements showed that although the tip shape of the pillars strongly influences the pull-off force, the pull-off strength is similar for flat and mushroom-shaped tips. We found no tilt-angle dependency of adhesion for spherical tip structures and, except for high tilt angle and low preload experiments, no tilt-angle effect for mushroom-tip pillars. For flat-tip pillars, we found a strong influence of tilt angle on adhesion, which decreased linearly with increasing aspect ratio. The experiments show that for the tested aspect ratios between 1 and 5, a linear decrease of tilt-angle dependency is found. The results of our studies will help to design bioinspired adhesives for application on smooth and rough surfaces.
Energy Technology Data Exchange (ETDEWEB)
Vega, H.J. de [Sorbonne Universites, Universite Pierre et Marie Curie UPMC Paris VI, LPTHE CNRS UMR 7589, Paris Cedex 05 (France); Sanchez, N.G. [Observatoire de Paris PSL Research University, Sorbonne Universites UPMC Paris VI, Observatoire de Paris, LERMA CNRS UMR 8112, Paris (France)
2017-02-15
The Thomas-Fermi approach to galaxy structure determines self-consistently and non-linearly the gravitational potential of the fermionic warm dark matter (WDM) particles given their quantum distribution function f(E). This semiclassical framework accounts for the quantum nature and high number of DM particles, properly describing gravitational bounded and quantum macroscopic systems as neutron stars, white dwarfs and WDM galaxies. We express the main galaxy magnitudes as the halo radius r{sub h}, mass M{sub h}, velocity dispersion and phase space density in terms of the surface density which is important to confront to observations. From these expressions we derive the general equation of state for galaxies, i.e., the relation between pressure and density, and provide its analytic expression. Two regimes clearly show up: (1) Large diluted galaxies for M{sub h} >or similar 2.3 x 10{sup 6} M {sub CircleDot} and effective temperatures T{sub 0} > 0.017 K described by the classical self-gravitating WDM Boltzman gas with a space-dependent perfect gas equation of state, and (2) Compact dwarf galaxies for 1.6 x 10{sup 6} M {sub CircleDot} >or similar M{sub h} >or similar M{sub h,min} ≅ 3.10 x 10{sup 4} (2 keV/m){sup (16)/(5)} M {sub CircleDot}, T{sub 0} < 0.011 K described by the quantum fermionic WDM regime with a steeper equation of state close to the degenerate state. In particular, the T{sub 0} = 0 degenerate or extreme quantum limit yields the most compact and smallest galaxy. In the diluted regime, the halo radius r{sub h}, the squared velocity v{sup 2}(r{sub h}) and the temperature T{sub 0} turn to exhibit square-root of M{sub h} scaling laws. The normalized density profiles ρ(r)/ρ(0) and the normalized velocity profiles v{sup 2}(r)/v{sup 2}(0) are universal functions of r/r{sub h} reflecting the WDM perfect gas behavior in this regime. These theoretical results contrasted to robust and independent sets of galaxy data remarkably reproduce the observations. For
Rovers, Stefan A; Kemmere, Maartje F; Keurentjes, Jos T F; Hoogenboom, Richard
2017-09-15
A system for multiple on-demand drug release has been prepared that can be activated with an alternating magnetic field as external trigger. The core/shell samples have been developed based on a macroscopic spherical iron core coated with a thermoresponsive polymer, poly(styrene-stat-butyl methacrylate), containing ibuprofen as a model drug. During exposure of the samples to the magnetic field (ON state), the release rate of ibuprofen is significantly increased, up to 35 times the release rate without the magnetic field (OFF state). Using one sample or two samples in line with the magnetic field does not influence the ON/OFF ratio of the system, showing the possibility of using multiple samples to increase and tune the drug dose. Increasing the concentration of ibuprofen in the polymer layer is shown to increase the release rate in both the ON and OFF states. Increasing the size of the iron core and, consequently, decreasing the polymer thickness, was found to only increase the release rate during exposure resulting in higher ON/OFF ratios. The developed on demand drug delivery systems represents a promising development towards on demand drug delivery implants. During my chemical engineering studies, it was only during my master thesis work that I decided to continue with PhD research as I really enjoyed doing original research. When coming to the end of my PhD research under supervision of Prof. Ulrich S. Schubert, I developed the ambition to pursue an academic career. Fortunately, I got the opportunity to stay with Prof. Schubert as project leader for the Dutch Polymer Institute (DPI). Within this position, I supervised ten researchers and was able to start developing my independent research lines. Despite that I now advise students to not stay in the same laboratory, this first position allowed me to gain some initial independence and to publish a large number of papers that has been a great benefit in my further career. After two and a half years I needed a new
Huang, Shiping
2017-11-13
The evolution of the contact area with normal load for rough surfaces has great fundamental and practical importance, ranging from earthquake dynamics to machine wear. This work bridges the gap between the atomic scale and the macroscopic scale for normal contact behavior. The real contact area, which is formed by a large ensemble of discrete contacts (clusters), is proven to be much smaller than the apparent surface area. The distribution of the discrete contact clusters and the interaction between them are key to revealing the mechanism of the contacting solids. To this end, Green's function molecular dynamics (GFMD) is used to study both how the contact cluster evolves from the atomic scale to the macroscopic scale and the interaction between clusters. It is found that the interaction between clusters has a strong effect on their formation. The formation and distribution of the contact clusters is far more complicated than that predicted by the asperity model. Ignorance of the interaction between them leads to overestimating the contacting force. In real contact, contacting clusters are smaller and more discrete due to the interaction between the asperities. Understanding the exact nature of the contact area with the normal load is essential to the following research on friction.
Energy Technology Data Exchange (ETDEWEB)
Wiesand-Valk, B. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung
2000-07-01
This paper deals with the correlations between microstructural disorder, that means statistical distribution of phases and local material properties, and macroscopic failure of disordered multiphase materials. On a microscopic level the microstructural disorder leads to randomly distributed local damage before failure (in brittle materials to microcracks) and eventually to localisation of damage. On a macroscopic level the value and scatter of fracture strength and its dependence on specimen size are essentially determined by the microstructural disorder. The failure behaviour is treated by using the discrete chain-of-bundles-model, which treats the details of the microstructure not explicitly but as locally distributed fluctuations of characteristical material parameters. The model has been verified by comparing with experimental results for four intermetallic titanium aluminides and its validity has been demonstrated. (orig.) [German] Die Arbeit behandelt die Zusammenhaenge zwischen der Stochastizitaet des Gefueges, das heisst, einer statistischen Verteilung von Phasen und lokalen Materialeigenschaften und dem makroskopischen Versagen von ungeordneten mehrphasigen Werkstoffen. Auf mikroskopischer Ebene fuehrt die Stochastizitaet des Gefueges vor dem Versagen zu lokalen Schaedigungen (in sproeden Werkstoffen zu Mikrorissen) und schliesslich (abhaengig vom Grad der Unordnung) zur Lokalisierung des Bruchgeschehens. Makroskopisch werden die Groesse und Streuung von Bruchfestigkeitswerten und ihre Probengroessenabhaengigkeit durch die mikrostrukturelle Unordnung wesentlich bestimmt. Dieses Versagensverhalten wird in dem diskreten Chain-of-Bundles-Modell beschrieben, das die Details der Mikrostruktur nicht explizit sondern als lokale statistische Schwankungen von charakteristischen Werkstoffparametern erfasst. Am Beispiel von vier ausgewaehlten Titan-Aluminiden wird das Modell validiert und verifiziert. (orig.)
Electricity in foams: from one soapy interface to the macroscopic material
Biance, Anne-Laure
2017-11-01
Liquid foams (a dispersion of gas bubbles in a soapy solution) destabilize with time due to coarsening, coalescence and gravity driven drainage. We propose here to inhibit (or trigger) the foam destabilization by applying an electric field to the material. This effect is investigated at the different scales of the system: one soapy interface, one liquid film, the macroscopic foam. The generation of an electroosmotic flow near a soapy liquid/gas interface raises many issues. How does the flow affect surfactant repartition? Is there a Marangoni stress at the interface? At the scale of one soap film, how the electric field affects the film stability and deformation? In a macroscopic foam, one can wonder whether the electric field can indeed reverse gravity driven drainage and increase foam lifetime? These different issues are considered by developing new experimental techniques allowing us to probe surfactant repartition at liquid interfaces, soap film thicknesses and liquid foam properties when an electric field is applied. The results will be presented together with a comprehensive picture of the mechanisms arising at each scale of the material, to conclude with the potential use of electricity in liquid foams to control destabilization. Collaborators: Baptiste Blanc, Oriane Bonhomme, Laurent Joly, Christophe Ybert.
Energy Technology Data Exchange (ETDEWEB)
Moy, Charles K.S., E-mail: charles.moy@sydney.edu.au [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Ranzi, Gianluca [ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Petersen, Timothy C. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); Ringer, Simon P. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia)
2011-05-15
One major concern since the development of the field ion microscope is the mechanical strength of the specimens. The macroscopic shape of the imaging tip greatly influences field-induced stresses and there is merit in further study of this phenomenon from a classical perspective. Understanding the geometrical, as opposed to localized electronic, factors that affect the stress might improve the quality and success rate of atom probe experiments. This study uses macroscopic electrostatic principles and finite element modelling to investigate field-induced stresses in relation to the shape of the tip. Three two-dimensional idealized models are considered, namely hyperbolic, parabolic and sphere-on-orthogonal-cone; the shapes of which are compared to experimental tips prepared by electro-polishing. Three dimensional morphologies of both a nano-porous and single-crystal aluminium tip are measured using electron tomography to quantitatively test the assumption of cylindrical symmetry for electro-polished tips. The porous tip was prepared and studied to demonstrate a fragile specimen for which such finite element studies could determine potential mechanical failure, prior to any exhaustive atom probe investigation. -- Research highlights: {yields} We use electrostatic principles and finite element to model field-induced stresses. {yields} We study two-dimensional idealized needle-shaped field emitters. {yields} Stress distribution of hyperbolic, parabolic and sphere-on-orthogonal-cone tips mapped. {yields} Electron tomography to obtain the morphology of three-dimensional aluminium tips. {yields} Studies of the morphology of the porous tip demonstrate a fragile specimen.
International Nuclear Information System (INIS)
Savvakis, C.; Tsimillis, K.; Petropoulos, J.H.
1982-01-01
The adsorption and gas-phase or surface diffusion properties of a series of microporous pellets made by the compaction of very fine graphite powder are reported. The overall degree of compaction of the powder was very nearly the same in all cases, but the mode of compaction was varied. The resulting variation in the macroscopic structural inhomogeneity of the pellets (examined in some detail in a parallel study) has been shown to affect both adsorption and diffusion properties. The effect on adsorption properties was modest but definite and can be accounted for by the dependence of the extent of adsorption on pore size. On the other hand, the experimental gas-phase and surface diffusion coefficients were strongly dependent on macroscopic structure. The dependence of the surface diffusion coefficient was particularly marked and is of special interest: such effects have not, so far, been taken into account in interpretations of experimental data, although they can be predicted theoretically. Previous analyses of the structure dependence of experimental gas-phase and surface diffusion coefficients are thus subject to revision in the light of the present conclusions. (author)
Gautier, G; Kelders, L; Groby, J P; Dazel, O; De Ryck, L; Leclaire, P
2011-09-01
Wave propagation in macroscopically inhomogeneous porous materials has received much attention in recent years. The wave equation, derived from the alternative formulation of Biot's theory of 1962, was reduced and solved recently in the case of rigid frame inhomogeneous porous materials. This paper focuses on the solution of the full wave equation in which the acoustic and the elastic properties of the poroelastic material vary in one-dimension. The reflection coefficient of a one-dimensional macroscopically inhomogeneous porous material on a rigid backing is obtained numerically using the state vector (or the so-called Stroh) formalism and Peano series. This coefficient can then be used to straightforwardly calculate the scattered field. To validate the method of resolution, results obtained by the present method are compared to those calculated by the classical transfer matrix method at both normal and oblique incidence and to experimental measurements at normal incidence for a known two-layers porous material, considered as a single inhomogeneous layer. Finally, discussion about the absorption coefficient for various inhomogeneity profiles gives further perspectives. © 2011 Acoustical Society of America
Energy Technology Data Exchange (ETDEWEB)
Bagdatlioglu, Cem, E-mail: cemb@utexas.edu; Schneider, Erich
2016-06-15
Highlights: • Describes addition of spatially dependent power sharing to a previous methodology. • The methodology is used for calculating the input and output isotopics and burnup. • Generalizes to simulate reactors with strong spatial and flux heterogeneities. • Presents cases where the old approach would not have been sufficient. - Abstract: This paper describes the addition of spatially dependent power sharing to a methodology used for calculating the input and output isotopics and burnup of nuclear reactors within a nuclear fuel cycle simulator. Neutron balance and depletion calculations are carried out using pre-calculated fluence-based libraries. These libraries track the transmutation and neutron economy evolution of unit masses of nuclides available in input fuel. The work presented in the paper generalizes the method to simulate reactors that contain more than one type of fuel as well as strong spatial and flux heterogeneities, for instance breeders with a driver–blanket configuration. To achieve this, spatial flux calculations are used to determine the fluence-dependent relative average fluxes inside macroscopic spatial regions. These fluxes are then used to determine the average power of macroscopic spatial regions as well as to more accurately calculate region-specific transmutation rates. The paper presents several cases where the fluence based approach alone would not have been sufficient to determine results.
Light induced electrical and macroscopic changes in hydrogenated polymorphous silicon solar cells
Directory of Open Access Journals (Sweden)
Roca i Cabarrocas P.
2012-07-01
Full Text Available We report on light-induced electrical and macroscopic changes in hydrogenated polymorphous silicon (pm-Si:H PIN solar cells. To explain the particular light-soaking behavior of such cells – namely an increase of the open circuit voltage (Voc and a rapid drop of the short circuit current density (Jsc – we correlate these effects to changes in hydrogen incorporation and structural properties in the layers of the cells. Numerous techniques such as current-voltage characteristics, infrared spectroscopy, hydrogen exodiffusion, Raman spectroscopy, atomic force microscopy, scanning electron microscopy and spectroscopic ellipsometry are used to study the light-induced changes from microscopic to macroscopic scales (up to tens of microns. Such comprehensive use of complementary techniques lead us to suggest that light-soaking produces the diffusion of molecular hydrogen, hydrogen accumulation at p-layer/substrate interface and localized delamination of the interface. Based on these results we propose that light-induced degradation of PIN solar cells has to be addressed from not only as a material issue, but also a device point of view. In particular we bring experimental evidence that localized delamination at the interface between the p-layer and SnO2 substrate by light-induced hydrogen motion causes the rapid drop of Jsc.
CH-π Interaction Driven Macroscopic Property Transition on Smart Polymer Surface
Li, Minmin; Qing, Guangyan; Xiong, Yuting; Lai, Yuekun; Sun, Taolei
2015-10-01
Life systems have evolved to utilize weak noncovalent interactions, particularly CH-π interaction, to achieve various biofunctions, for example cellular communication, immune response, and protein folding. However, for artificial materials, it remains a great challenge to recognize such weak interaction, further transform it into tunable macroscopic properties and realize special functions. Here we integrate monosaccharide-based CH-π receptor capable of recognizing aromatic peptides into a smart polymer with three-component “Recognition-Mediating-Function” design, and report the CH-π interaction driven surface property switching on smart polymer film, including wettability, adhesion, viscoelasticity and stiffness. Detailed studies indicate that, the CH-π interaction induces the complexation between saccharide unit and aromatic peptide, which breaks the initial amphiphilic balance of the polymer network, resulting in contraction-swelling conformational transition for polymer chains and subsequent dramatic switching in surface properties. This work not only presents a new approach to control the surface property of materials, but also points to a broader research prospect on CH-π interaction at a macroscopic level.
Macroscopic description of complex adaptive networks coevolving with dynamic node states
Wiedermann, Marc; Donges, Jonathan F.; Heitzig, Jobst; Lucht, Wolfgang; Kurths, Jürgen
2015-05-01
In many real-world complex systems, the time evolution of the network's structure and the dynamic state of its nodes are closely entangled. Here we study opinion formation and imitation on an adaptive complex network which is dependent on the individual dynamic state of each node and vice versa to model the coevolution of renewable resources with the dynamics of harvesting agents on a social network. The adaptive voter model is coupled to a set of identical logistic growth models and we mainly find that, in such systems, the rate of interactions between nodes as well as the adaptive rewiring probability are crucial parameters for controlling the sustainability of the system's equilibrium state. We derive a macroscopic description of the system in terms of ordinary differential equations which provides a general framework to model and quantify the influence of single node dynamics on the macroscopic state of the network. The thus obtained framework is applicable to many fields of study, such as epidemic spreading, opinion formation, or socioecological modeling.
On Macroscopic Quantum Phenomena in Biomolecules and Cells: From Levinthal to Hopfield
Directory of Open Access Journals (Sweden)
Dejan Raković
2014-01-01
Full Text Available In the context of the macroscopic quantum phenomena of the second kind, we hereby seek for a solution-in-principle of the long standing problem of the polymer folding, which was considered by Levinthal as (semiclassically intractable. To illuminate it, we applied quantum-chemical and quantum decoherence approaches to conformational transitions. Our analyses imply the existence of novel macroscopic quantum biomolecular phenomena, with biomolecular chain folding in an open environment considered as a subtle interplay between energy and conformation eigenstates of this biomolecule, governed by quantum-chemical and quantum decoherence laws. On the other hand, within an open biological cell, a system of all identical (noninteracting and dynamically noncoupled biomolecular proteins might be considered as corresponding spatial quantum ensemble of these identical biomolecular processors, providing spatially distributed quantum solution to a single corresponding biomolecular chain folding, whose density of conformational states might be represented as Hopfield-like quantum-holographic associative neural network too (providing an equivalent global quantum-informational alternative to standard molecular-biology local biochemical approach in biomolecules and cells and higher hierarchical levels of organism, as well.
Macroscopic Rock Texture Image Classification Using a Hierarchical Neuro-Fuzzy Class Method
Directory of Open Access Journals (Sweden)
Laercio B. Gonçalves
2010-01-01
Full Text Available We used a Hierarchical Neuro-Fuzzy Class Method based on binary space partitioning (NFHB-Class Method for macroscopic rock texture classification. The relevance of this study is in helping Geologists in the diagnosis and planning of oil reservoir exploration. The proposed method is capable of generating its own decision structure, with automatic extraction of fuzzy rules. These rules are linguistically interpretable, thus explaining the obtained data structure. The presented image classification for macroscopic rocks is based on texture descriptors, such as spatial variation coefficient, Hurst coefficient, entropy, and cooccurrence matrix. Four rock classes have been evaluated by the NFHB-Class Method: gneiss (two subclasses, basalt (four subclasses, diabase (five subclasses, and rhyolite (five subclasses. These four rock classes are of great interest in the evaluation of oil boreholes, which is considered a complex task by geologists. We present a computer method to solve this problem. In order to evaluate system performance, we used 50 RGB images for each rock classes and subclasses, thus producing a total of 800 images. For all rock classes, the NFHB-Class Method achieved a percentage of correct hits over 73%. The proposed method converged for all tests presented in the case study.
Impact of local diffusion on macroscopic dispersion in three-dimensional porous media
Dartois, Arthur; Beaudoin, Anthony; Huberson, Serge
2018-02-01
While macroscopic longitudinal and transverse dispersion in three-dimensional porous media has been simulated previously mostly under purely advective conditions, the impact of diffusion on macroscopic dispersion in 3D remains an open question. Furthermore, both in 2D and 3D, recurring difficulties have been encountered due to computer limitation or analytical approximation. In this work, we use the Lagrangian velocity covariance function and the temporal derivative of second-order moments to study the influence of diffusion on dispersion in highly heterogeneous 2D and 3D porous media. The first approach characterizes the correlation between the values of Eulerian velocity components sampled by particles undergoing diffusion at two times. The second approach allows the estimation of dispersion coefficients and the analysis of their behaviours as functions of diffusion. These two approaches allowed us to reach new results. The influence of diffusion on dispersion seems to be globally similar between highly heterogeneous 2D and 3D porous media. Diffusion induces a decrease in the dispersion in the direction parallel to the flow direction and an increase in the dispersion in the direction perpendicular to the flow direction. However, the amplification of these two effects with the permeability variance is clearly different between 2D and 3D. For the direction parallel to the flow direction, the amplification is more important in 3D than in 2D. It is reversed in the direction perpendicular to the flow direction.
A macroscopic cross-section model for BWR pin-by-pin core analysis
International Nuclear Information System (INIS)
Fujita, Tatsuya; Endo, Tomohiro; Yamamoto, Akio
2014-01-01
A macroscopic cross-section model used in boiling water reactor (BWR) pin-by-pin core analysis is studied. In the pin-by-pin core calculation method, pin-cell averaged cross sections are calculated for many combinations of core state and depletion history variables and are tabulated prior to core calculations. Variations of cross sections in a core simulator are caused by two different phenomena (i.e. instantaneous and history effects). We treat them through the core state variables and the exposure-averaged core state variables, respectively. Furthermore, the cross-term effect among the core state and the depletion history variables is considered. In order to confirm the calculation accuracy and discuss the treatment of the cross-term effect, the k-infinity and the pin-by-pin fission rate distributions in a single fuel assembly geometry are compared. Some cross-term effects could be negligible since the impacts of them are sufficiently small. However, the cross-term effects among the control rod history (or the void history) and other variables have large impacts; thus, the consideration of them is crucial. The present macroscopic cross-section model, which considers such dominant cross-term effects, well reproduces the reference results and can be a candidate in practical applications for BWR pin-by-pin core analysis on the normal operations. (author)
Sun, Jun; Xing, Zhaoyu; Xing, Wei; Zheng, Linfeng; Chen, Jie; Fan, Min; Chen, Tongbing; Zhang, Zhuoli
2016-03-01
To evaluate the value of combining the detection of intratumoral macroscopic fat and hemorrhage in the differentiation of the benign from malignant solid renal masses.Conventional magnetic resonance imaging (MRI), chemical shift (CS)-MRI, and susceptibility-weighted imaging were performed in 152 patients with 152 solid renal masses, including 48 benign and 104 malignant masses all pathologically confirmed. The presence of macroscopic fat detected by CS-MRI and hemorrhage detected by susceptibility-weighted imaging were evaluated in all masses. The rates of macroscopic fat and hemorrhage observed between benign and malignant masses were compared by a χ test. All masses found to contain macroscopic fat with or without hemorrhage were considered to be benign. The remaining masses (without macroscopic fat) found not to contain hemorrhage were considered to be benign. Only those found to contain hemorrhage alone were considered to be malignant. The evaluation indexes for differentiating and forecasting the benign and malignant masses were calculated.Significant differences in the rate of macroscopic fat (observed in 85.42% of benign masses vs. 0% of malignant masses) and hemorrhage (observed in 4.17% of benign masses vs. 95.19% of malignant masses) were measured in the benign and malignant groups (P benign and malignant masses were 96.05%, 95.19%, and 97.92%, respectively, and the accuracy and error rate of forecasting the benign and malignant masses were 95.39% and 4.61%, respectively.Combining the detection intratumoral macroscopic fat and hemorrhage can be used to differentiate the benign from malignant solid renal masses.
Directory of Open Access Journals (Sweden)
Xiaohui Lin
2017-01-01
Full Text Available Connected-vehicles network provides opportunities and conditions for improving traffic signal control, and macroscopic fundamental diagrams (MFD can control the road network at the macrolevel effectively. This paper integrated proposed real-time access to the number of mobile vehicles and the maximum road queuing length in the Connected-vehicles network. Moreover, when implementing a simple control strategy to limit the boundary flow of a road network based on MFD, we determined whether the maximum queuing length of each boundary section exceeds the road-safety queuing length in real-time calculations and timely adjusted the road-network influx rate to avoid the overflow phenomenon in the boundary section. We established a road-network microtraffic simulation model in VISSIM software taking a district as the experimental area, determined MFD of the region based on the number of mobile vehicles, and weighted traffic volume of the road network. When the road network was tending to saturate, we implemented a simple control strategy and our algorithm limits the boundary flow. Finally, we compared the traffic signal control indicators with three strategies: (1 no control strategy, (2 boundary control, and (3 boundary control with limiting queue strategy. The results show that our proposed algorithm is better than the other two.
Directory of Open Access Journals (Sweden)
Veronika Chaloupková
2018-02-01
Full Text Available Via image-based macroscopic, analysis of a briquettes’ surface structure, particle size, and distribution was determined to better understand the behavioural pattern of input material during agglomeration in the pressing chamber of a briquetting machine. The briquettes, made of miscanthus, industrial hemp and pine sawdust were produced by a hydraulic piston press. Their structure was visualized by a stereomicroscope equipped with a digital camera and software for image analysis and data measurements. In total, 90 images of surface structure were obtained and quantitatively analysed. Using Nikon Instruments Software (NIS-Elements software, the length and area of 900 particles were measured and statistically tested to compare the size of the particles at different surface locations. Results showed statistically significant differences in particles’ size distribution: larger particles were generally on the front side of briquettes and vice versa, smaller particles were on the rear side. As well, larger particles were centred in the middle of cross sections and the smaller particles were centred on the bottom of the briquette.
Wong, Lih-Ming; Chum, Jia-Min; Maddy, Peter; Chan, Steven T F; Travis, Douglas; Lawrentschuk, Nathan
2010-07-01
Macroscopic hematuria is a common symptom and sign that is challenging to quantify and describe. The degree of hematuria communicated is variable due to health worker experience combined with lack of a reliable grading tool. We produced a reliable, standardized visual scale to describe hematuria severity. Our secondary aim was to validate a new laboratory test to quantify hemoglobin in hematuria specimens. Nurses were surveyed to ascertain current hematuria descriptions. Blood and urine were titrated at varying concentrations and digitally photographed in catheter bag tubing. Photos were processed and printed on transparency paper to create a prototype swatch or card showing light, medium, heavy and old hematuria. Using the swatch 60 samples were rated by nurses and laymen. Interobserver variability was reported using the generalized kappa coefficient of agreement. Specimens were analyzed for hemolysis by measuring optical density at oxyhemoglobin absorption peaks. Interobserver agreement between nurses and laymen was good (kappa = 0.51, p visual scale to grade and communicate hematuria with adequate interobserver agreement is feasible. The test for optical density at oxyhemoglobin absorption peaks is a new method, validated in our study, to quantify hemoglobin in a hematuria specimen. Copyright (c) 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Hongzhan Xie
2015-06-01
Full Text Available The objective of this study was to investigate the macroscopic spray characteristics of different 0%–100% blends of biodiesel derived from drainage oil and diesel (BD0, BD20, BD50, BD80, BD100, such as spray tip penetration, average tip velocity at penetration, spray angle, average spray angle, spray evolution process, spray area and spray volume under different injection pressures (60, 70, 80, 90, 100 MPa and ambient pressures (0.1, 0.3, 0.5, 0.7, 0.9 MPa using a common rail system equipped with a constant volume chamber. The characteristic data was extracted from spray images grabbed by a high speed visualization system. The results showed that the ambient pressure and injection pressure had significant effects on the spray characteristics. As the ambient pressure increased, the spray angle increased, while the spray tip penetration and the peak of average tip velocity decreased. As the injection pressure increased, the spray tip penetration, spray angle, spray area and spray volume increased. The increasing blend ratio of biodiesel brought about a shorter spray tip penetration and a smaller spray angle compared with those of diesel. This is due to the comparatively higher viscosity and surface tension of biodiesel, which enhanced the friction effect between fuel and the injector nozzle surface and inhibited the breakup of the liquid jet.
Scierski, Wojciech; Polok, Aleksandra; Namysłowski, Grzegorz; Nozyński, Jerzy; Turecka, Lucyna; Urbaniec, Natalia; Pamuła, Elzbieta
2009-09-01
The surgical treatment of large cartilage defects in the region of head and neck is often impossible because of the atrophy of surrounding tissues and lack of suitable material for reconstruction. In the surgical treatment many of methods and reconstructive materials have been used. For many years the suitable synthetic material for the cartilage defects reconstruction has been searched for. Was to evaluate two different biomaterials with proper mechanical and biological features for the cartilage replacement. Two type of biomaterials in this study were used: resorbable polymer - poly(L-lactide-co-glycolide) (PLG) acting as a supportive matrix. A thin layer of sodium hyaluronate (Hyal) was also deposited on the surface as well in the pore walls of PLG scaffolds in order to provide biologically active molecules promoting differentiation and regeneration of the tissue. The studies were performed on the 50 animals--rabbits divided into 2 groups. The animals were operated in the general anaesthesia. The incision was done along the edge of the rabbit's auricle. Perichondrium and cartilage of the auricle on the surface 4 x 3 cm were prepared. Subperichondrically 1 x 1 cm fragment of the cartilage was removed by the scissors. This fragment was then replaced by the biomaterials: PLG in first group of 25 rabbits and PLG-Hyal in second group 25 rabbits. The tissues were sutured with polyglycolide Safil 3-0. The animals obtained Enrofloxacin for three days after the operation. Then 1, 4 and 12 weeks after the surgery the animals were painlessly euthanized by an overdose of Morbital. Implants and surrounding tissues were excised and observed macroscopically and using an optical microscope. In all the observation periods we observed proper macroscopic healing process of biomaterials. We didn't stated strong inflammatory process and necrosis around the implanted biomaterials. The histological and macroscopic examinations indicated that both materials developed in this study have
Dalgicdir, Cahit; Globisch, Christoph; Peter, Christine; Sayar, Mehmet
2015-08-01
Secondary amphiphilicity is inherent to the secondary structural elements of proteins. By forming energetically favorable contacts with each other these amphiphilic building blocks give rise to the formation of a tertiary structure. Small proteins and peptides, on the other hand, are usually too short to form multiple structural elements and cannot stabilize them internally. Therefore, these molecules are often found to be structurally ambiguous up to the point of a large degree of intrinsic disorder in solution. Consequently, their conformational preference is particularly susceptible to environmental conditions such as pH, salts, or presence of interfaces. In this study we use molecular dynamics simulations to analyze the conformational behavior of two synthetic peptides, LKKLLKLLKKLLKL (LK) and EAALAEALAEALAE (EALA), with built-in secondary amphiphilicity upon forming an alpha-helix. We use these model peptides to systematically study their aggregation and the influence of macroscopic and molecular interfaces on their conformational preferences. We show that the peptides are neither random coils in bulk water nor fully formed alpha helices, but adopt multiple conformations and secondary structure elements with short lifetimes. These provide a basis for conformation-selection and population-shift upon environmental changes. Differences in these peptides' response to macroscopic and molecular interfaces (presented by an aggregation partner) can be linked to their inherent alpha-helical tendencies in bulk water. We find that the peptides' aggregation behavior is also strongly affected by presence or absence of an interface, and rather subtly depends on their surface charge and hydrophobicity.
International Nuclear Information System (INIS)
Guodong Sheng; Jiang Sheng; Shitong Yang; Ju Hu; Xiangke Wang
2011-01-01
The effects of pH, ionic strength, competing ions and initial metal concentrations on the uptake behavior and mechanism of radioactive Ni(II) onto MnO 2 was investigated using a combination of classical macroscopic methods and the extended X-ray absorption fine structure (EXAFS) spectroscopy technique. The results indicated that the uptake of Ni(II) on MnO 2 is obviously dependent on pH but independent of ionic strength, which suggested that the uptake of Ni(II) onto MnO 2 is attributed to an inner-sphere surface complex rather than an outer-sphere surface complex. EXAFS analysis shows that the hydrated Ni(II) is adsorbed through six-fold coordination with an average Ni-O interatomic distance of 2.04 ± 0.01 A. It can be inferred from the EXAFS analysis that the inner-sphere surface complex of Ni(II) onto MnO 2 is involved in both edge-sharing and corner-sharing linkages. Both the macroscopic uptake data and the molecular level evidence of Ni(II) surface speciation at the MnO 2 -water interfaces should be factored into better prediction of the bioavailability and mobility of Ni(II) in soil and water environment. (author)
Directory of Open Access Journals (Sweden)
Cahit Dalgicdir
2015-08-01
Full Text Available Secondary amphiphilicity is inherent to the secondary structural elements of proteins. By forming energetically favorable contacts with each other these amphiphilic building blocks give rise to the formation of a tertiary structure. Small proteins and peptides, on the other hand, are usually too short to form multiple structural elements and cannot stabilize them internally. Therefore, these molecules are often found to be structurally ambiguous up to the point of a large degree of intrinsic disorder in solution. Consequently, their conformational preference is particularly susceptible to environmental conditions such as pH, salts, or presence of interfaces. In this study we use molecular dynamics simulations to analyze the conformational behavior of two synthetic peptides, LKKLLKLLKKLLKL (LK and EAALAEALAEALAE (EALA, with built-in secondary amphiphilicity upon forming an alpha-helix. We use these model peptides to systematically study their aggregation and the influence of macroscopic and molecular interfaces on their conformational preferences. We show that the peptides are neither random coils in bulk water nor fully formed alpha helices, but adopt multiple conformations and secondary structure elements with short lifetimes. These provide a basis for conformation-selection and population-shift upon environmental changes. Differences in these peptides' response to macroscopic and molecular interfaces (presented by an aggregation partner can be linked to their inherent alpha-helical tendencies in bulk water. We find that the peptides' aggregation behavior is also strongly affected by presence or absence of an interface, and rather subtly depends on their surface charge and hydrophobicity.
International Nuclear Information System (INIS)
Mazzarella, G.; Toigo, F.; Salasnich, L.; Parola, A.
2011-01-01
We consider a bosonic Josephson junction made of N ultracold and dilute atoms confined by a quasi-one-dimensional double-well potential within the two-site Bose-Hubbard model framework. The behavior of the system is investigated at zero temperature by varying the interatomic interaction from the strongly attractive regime to the repulsive one. We show that the ground state exhibits a crossover from a macroscopic Schroedinger-cat state to a separable Fock state through an atomic coherent regime. By diagonalizing the Bose-Hubbard Hamiltonian we characterize the emergence of the macroscopic cat states by calculating the Fisher information F, the coherence by means of the visibility α of the interference fringes in the momentum distribution, and the quantum correlations by using the entanglement entropy S. Both Fisher information and visibility are shown to be related to the ground-state energy by employing the Hellmann-Feynman theorem. This result, together with a perturbative calculation of the ground-state energy, allows simple analytical formulas for F and α to be obtained over a range of interactions, in excellent agreement with the exact diagonalization of the Bose-Hubbard Hamiltonian. In the attractive regime the entanglement entropy attains values very close to its upper limit for a specific interaction strength lying in the region where coherence is lost and self-trapping sets in.
Guiding effect of bent macroscopic quartz tube for high current electron beam
International Nuclear Information System (INIS)
Zhang Mingwu; Chen Jing; Wu Yehong; Yang Bian; Wang Wei; Xue Yingli; Yu Deyang; Cai Xiaohong
2012-01-01
By using an incident electron beam with the high current and high energy, the guiding effect of the bent macroscopic quartz tube for the electron beam has been investigated. The angular distributions of outgoing electrons depending on the current and energy of incident electrons were measured. The dependences of electron transmitted fraction on energy and current of incident electrons are also shown. As the incident electron energy increasing, the electron transmitted fraction increases, but it decreases while the incident electron current increasing. The results have been compared with the present data. This work presents, the process of guiding electrons is essentially different from that of guiding highly charged ions, the guiding electron beam was caused by both elastic and inelastic collisions between electrons and inner walls of quartz tube, rather than self-organized charging effect on the surface of inner wall of quartz tube. (authors)
Influence of microscopic inhomogeneity on macroscopic transport current of Ag/Bi2223 tapes
International Nuclear Information System (INIS)
Ogawa, Kazuhiro; Osamura, Kozo
2004-01-01
In Ag/Bi2223 tapes, inhomogeneities such as spatially distributed weak links or non-superconducting oxides are inevitably introduced because of the complicated manufacturing process and thermodynamic instability. In order to clarify the effect of the difference in such microscopic inhomogeneites on the macroscopic current transport properties, we carried out a numerical analysis. By changing volume fraction (V f ) of the Bi2223 phase and the shape of local distribution of critical current at each weak link, it is revealed that I-V characteristics are largely affected by the breadth of local distributions with different dependence on V f of Bi2223 and calculated results can be analyzed by Weibull distribution function with some parameters including the information of two-dimensional distribution
Directory of Open Access Journals (Sweden)
Shota Ushiba
2014-01-01
Full Text Available We study the alignment of single-wall carbon nanotubes (SWCNTs in bubble imprints through polarized Raman microscopy. A hemispherical bubble containing SWCNTs is pressed against a glass substrate, resulting in an imprint of the bubble membrane with a coffee ring on the substrate. We find that macroscopic ensembles of aligned SWCNTs are obtained in the imprints, in which there are three patterns of orientations: (i azimuthal alignment on the coffee ring, (ii radial alignment at the edge of the membrane, and (iii random orientation at the center of the membrane. We also find that the alignment of SWCNTs in the imprints can be manipulated by spinning bubbles. The orientation of SWCNTs on the coffee ring is directed radially, which is orthogonal to the case of unspun bubbles. This approach enables one to align SWCNTs in large quantities and in a short time, potentially opening up a wide range of CNT-based electronic and optical applications.
Sibley, David; Nold, Andreas; Kalliadasis, Serafim
2015-11-01
Density Functional Theory (DFT), a statistical mechanics of fluids approach, captures microscopic details of the fluid density structure in the vicinity of contact lines, as seen in computations in our recent study. Contact lines describe the location where interfaces between two fluids meet solid substrates, and have stimulated a wealth of research due to both their ubiquity in nature and technological applications and also due to their rich multiscale behaviour. Whilst progress can be made computationally to capture the microscopic to mesoscopic structure from DFT, complete analytical results to fully bridge to the macroscale are lacking. In this work, we describe our efforts to bring asymptotic methods to DFT to obtain results for contact angles and other macroscopic quantities in various parameter regimes. We acknowledge financial support from European Research Council via Advanced Grant No. 247031.
Finite element simulation of nanoindentation tests using a macroscopic computational model
International Nuclear Information System (INIS)
Khelifa, Mourad; Fierro, Vanessa; Celzard, Alain
2014-01-01
The aim of this work was to develop a numerical procedure to simulate nanoindentation tests using a macroscopic computational model. Both theoretical and numerical aspects of the proposed methodology, based on the coupling of isotropic elasticity and anisotropic plasticity described with the quadratic criterion of Hill are presented to model this behaviour. The anisotropic plastic behaviour accounts for the mixed nonlinear hardening (isotropic and kinematic) under large plastic deformation. Nanoindentation tests were simulated to analyse the nonlinear mechanical behaviour of aluminium alloy. The predicted results of the finite element (FE) modelling are in good agreement with the experimental data, thereby confirming the accuracy level of the suggested FE method of analysis. The effects of some technological and mechanical parameters known to have an influence during the nanoindentation tests were also investigated.
International Nuclear Information System (INIS)
Mauk, B.H.; Meng, C.I.
1986-01-01
As an illustration of the operation of macroscopic ion acceleration processes within the earth's magnetosphere, the paper reviews processes thought to be associated with the formation of the earth's ring-current populations. Arguing that the process of global, quasi-curl-free convection cannot explain particle characteristics observed in the middle (geosynchronous) to outer regions, it is concluded that the transport and energization of the seed populations that give rise to the ring-current populations come about in two distinct stages involving distinct processes. Near and outside the geostationary region, the energization and transport are always associated with highly impulsive and relatively localized processes driven by inductive electric fields. The subsequent adiabatic earthward transport is driven principally by enhanced, curl-free global convection fields. 58 references
Macroscopic QED in linearly responding media and a Lorentz-Force approach to dispersion forces
Energy Technology Data Exchange (ETDEWEB)
Raabe, Christian
2008-07-08
In this thesis, a very general quantization scheme for the macroscopic electromagnetic field in arbitrary linearly responding media is presented. It offers a unified approach to QED in such media. Applying the quantization scheme, a theory of the dispersion forces on the basis of the Lorentz force is developed. By regarding the dispersion force as the (ground-state or thermal-state) expectation value of the Lorentz force that acts on appropriately defined charge and current densities, Casimir, Casimir-Polder, and van der Waals forces are united in a very natural way that makes transparent their common physical basis. Application of the theory to planar structures yields generalizations of well-known Lifschitz and Casimir-type formulas. (orig.)
Babin, Anatoli
2016-01-01
In this monograph, the authors present their recently developed theory of electromagnetic interactions. This neoclassical approach extends the classical electromagnetic theory down to atomic scales and allows the explanation of various non-classical phenomena in the same framework. While the classical Maxwell–Lorentz electromagnetism theory succeeds in describing the physical reality at macroscopic scales, it struggles at atomic scales. Here, quantum mechanics traditionally takes over to describe non-classical phenomena such as the hydrogen spectrum and de Broglie waves. By means of modifying the classical theory, the approach presented here is able to consistently explain quantum-mechanical effects, and while similar to quantum mechanics in some respects, this neoclassical theory also differs markedly from it. In particular, the newly developed framework omits probabilistic interpretations of the wave function and features a new fundamental spatial scale which, at the size of the free electron, is much lar...
A Macroscopic Performance Analysis of NASA’s Northrop Grumman RQ-4A
Directory of Open Access Journals (Sweden)
Enric Pastor
2018-01-01
Full Text Available This paper presents the process of identification, from a macroscopic point of view, of the Northrop Grumman RQ-4A Global Hawk Remote-Piloted Aircraft System from real, but limited flight information. Performance parameters and operational schemes will be extracted by analyzing available data from two specific science flights flown by the Global Hawk back in 2010. Each phase of the flight, take-off, climb, cruise climb, descent and landing, is analyzed from various points of view: speed profile, altitude, climb/descent ratios and rate of turn. The key performance parameters derived from individual flights will be confirmed by performing a wider statistical validation with additional flight trajectories. Derived data are exploited to validate a simulated RQ-4A vehicle employed in extensive real-time air traffic management simulated integration exercises and to complement the development of a future RQ-4A trajectory predictor.
Molecular dynamics simulations of irradiation cascades in alpha-zirconium under macroscopic strain
Energy Technology Data Exchange (ETDEWEB)
Di, Sali [Department of Mechanical and Materials Engineering, Queen’s University, Kingston, ON, Canada K7L 3N6 (Canada); Yao, Zhongwen, E-mail: yaoz@me.queensu.ca [Department of Mechanical and Materials Engineering, Queen’s University, Kingston, ON, Canada K7L 3N6 (Canada); Daymond, Mark R. [Department of Mechanical and Materials Engineering, Queen’s University, Kingston, ON, Canada K7L 3N6 (Canada); Gao, Fei [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)
2013-05-15
Numerous computer simulation studies have been performed on the radiation damage of zirconium. In contrast to most of the work in the literature which has focused on the effects of temperature and recoil energy on defect production and defect clustering, we have developed a computational model to consider the influence of elastic strain field on the formation of defects and their clusters, as strain is commonly present in a real reactor environment. In this work, irradiation induced displacement cascades in alpha-zirconium experiencing a macroscopic strain have been studied by molecular dynamics (MD) simulations using a many-body interatomic potential. The external strain mainly affects the size of defect clusters rather than the total number of defects. The sizes of interstitial and vacancy clusters respond differently to the external strain conditions.
Macroscopic angular momentum states of Bose-Einstein condensates in toroidal traps
International Nuclear Information System (INIS)
Benakli, M.; Raghavan, S.; Fantoni, S.; Shenoy, S.R.; Smerzi, A.
1997-11-01
We consider a Bose-Einstein condensate (BEC) of N atoms of repulsive interaction ∼ U 0 , in an elliptical trap, axially pierced by a Gaussian-intensity laser beam, forming an effective (quasi-2D) toroidal trap with minimum at radial distance ρ = ρ p . The macroscopic angular momentum states Ψ l (ρ,θ) ∼ √NΦ l (ρ)e ilθ for integer l spread up to ρ max ∼ (NU 0 ) 1/4 >> ρ p . The spreading lowers rotational energies, so estimated low metastability barriers can support large l max ∼ (NU 0 ) 1/4 , l (ρ) 2 -Φ 0 (ρ) 2 is a signature of BEC rotation. Results are insensitive to off-axis laser displacements ρ 0 , for ρ 0 ρ max << 1. (author)
Penetration of fast projectiles into resistant media: From macroscopic to subatomic projectiles
Gaite, José
2017-09-01
The penetration of a fast projectile into a resistant medium is a complex process that is suitable for simple modeling, in which basic physical principles can be profitably employed. This study connects two different domains: the fast motion of macroscopic bodies in resistant media and the interaction of charged subatomic particles with matter at high energies, which furnish the two limit cases of the problem of penetrating projectiles of different sizes. These limit cases actually have overlapping applications; for example, in space physics and technology. The intermediate or mesoscopic domain finds application in atom cluster implantation technology. Here it is shown that the penetration of fast nano-projectiles is ruled by a slightly modified Newton's inertial quadratic force, namely, F ∼v 2 - β, where β vanishes as the inverse of projectile diameter. Factors essential to penetration depth are ratio of projectile to medium density and projectile shape.
International Nuclear Information System (INIS)
Miyazaki, T.; Koyama, T.; Kobayashi, S.
1996-01-01
A new experimental method to determine the phase boundary and phase equilibrium is accomplished by - means of analytical transmission electron microscopy for alloys with a macroscopic composition gradient. The various phase boundaries, i.e. the coherent binodal and spinodal lines, incoherent binodal line and order/disorder transformation line are distinctly determined for the Cu-Ti alloy and the other alloy systems. Furthermore, the equilibrium compositions at the interface of precipitate/matrix can experimentally be obtained for various particle sizes, and thus the Gibbs-Thomson's relation is verified. It is expected that the composition gradient method proposed in the present will become an important experimental method of the microstructural characterization
Directory of Open Access Journals (Sweden)
Laurent Dewasme
2017-02-01
Full Text Available Hybridoma cells are commonly grown for the production of monoclonal antibodies (MAb. For monitoring and control purposes of the bioreactors, dynamic models of the cultures are required. However these models are difficult to infer from the usually limited amount of available experimental data and do not focus on target protein production optimization. This paper explores an experimental case study where hybridoma cells are grown in a sequential batch reactor. The simplest macroscopic reaction scheme translating the data is first derived using a maximum likelihood principal component analysis. Subsequently, nonlinear least-squares estimation is used to determine the kinetic laws. The resulting dynamic model reproduces quite satisfactorily the experimental data, as evidenced in direct and cross-validation tests. Furthermore, model predictions can also be used to predict optimal medium renewal time and composition.
Directory of Open Access Journals (Sweden)
Ahmad Arabi Shamsabadi
2016-04-01
Full Text Available This paper presents an experimental study of the self-initiation reaction of n-butyl acrylate (n-BA in free-radical polymerization. For the first time, the frequency factor and activation energy of the monomer self-initiation reaction are estimated from measurements of n-BA conversion in free-radical homo-polymerization initiated only by the monomer. The estimation was carried out using a macroscopic mechanistic mathematical model of the reactor. In addition to already-known reactions that contribute to the polymerization, the model considers a n-BA self-initiation reaction mechanism that is based on our previous electronic-level first-principles theoretical study of the self-initiation reaction. Reaction rate equations are derived using the method of moments. The reaction-rate parameter estimates obtained from conversion measurements agree well with estimates obtained via our purely-theoretical quantum chemical calculations.
Damping width of giant dipole resonances of cold and hot nuclei: A macroscopic model
International Nuclear Information System (INIS)
Mughabghab, S.F.; Sonzogni, A.A.
2002-01-01
A phenomenological macroscopic model of the giant dipole resonance (GDR) damping width of cold and hot nuclei with ground-state spherical and near-spherical shapes is developed. The model is based on a generalized Fermi liquid model which takes into account the nuclear surface dynamics. The temperature dependence of the GDR damping width is accounted for in terms of surface and volume components. Parameter-free expressions for the damping width and the effective deformation are obtained. The model is validated with GDR measurements of the following nuclides: 39,40 K, 42 Ca, 45 Sc, 59,63 Cu, 109-120 Sn, 147 Eu, 194 Hg, and 208 Pb, and is compared with the predictions of other models
Macroscopic optical constants of a cloud of randomly oriented nonspherical scatterers
International Nuclear Information System (INIS)
Borghese, F.; Denti, P.; Saija, R.; Toscano, G.; Sindoni, O.I.
1984-01-01
A method to calculate the macroscopic optical constants of a low-density medium consisting of a cloud of identical nonspherical scatterers is presented. The scatterers in the medium are clusters of dielectric spheres and the electromagnetic field scattered by each of the clusters is obtained as a superposition of multipole fields, as previously proposed by the authors. The transformation properties of the spherical multipoles under rotation allow the orientation-dependent terms in the expression for the forward-scattering amplitude of each of the clusters to be factored out. In this way the sum of the scattering amplitudes of the clusters with different orientations, needed to calculate the optical response of the medium, is greatly facilitated and admits a simple analytic expression in the case of randomly oriented clusters. Results of calculations of the optical constants for a few model media are presented
[Scholarships for a science in crisis: the JAE as sponsor for macroscopic anatomy (1912-1931)].
Velasco Morgado, Raúl
2010-01-01
Beside the creation of national research institutions, the patronage work of the JAE (through scholarships and recognition given to Spanish scientists in the first third of the 20th century) was important in opening the door to the silver age of Spanish science. In the morphologic sciences, macroscopic anatomy was an almost closed science and in crisis with regard to the microscopic sciences and embryology. Despite this setting, the JAE chose to promote this science, importing European anatomical pedagogy and including the technologies and philosophy of the new dynamic anatomy under way on the continent. In this paper, we analyze the grantholders listed in the JAE archives and the studies that they published by them. We conclude that the utilization of these grants played an important role in promoting the international exchange necessary for the reform of a science in crisis, with anatomical pedagogy and technology being the major protagonists of this renewal.
A dualism in entanglement and testing quantum identicity of macroscopic objects
International Nuclear Information System (INIS)
Bose, S.; Home, D.
2005-01-01
Full text: Identical quantum objects are known to behave very differently from their classical counterparts by exhibiting bosonic/fermionic statistics. We present another consequence of the impossibility of distinguishing identical quantum objects through their superselected innate attributes. If two quantum objects distinguished through a dynamical variable A are entangled in another dynamical variable B, then (under certain conditions) they are also entangled in variable A when distinguished from each other by variable B. This dualism is independent of and more general than quantum statistics. We formulate a general scheme to test this dualism through polarization entangled photons. The dualism enables one to use prior entanglement to avoid scattering while probing the identicity of two mutually interacting, even macroscopic objects. It thus opens the way for studying the quantum to classical transition of identicity. (author)
Directory of Open Access Journals (Sweden)
Carlos Alberto Venegas Cortes
2006-06-01
Full Text Available In order to answer the problem of what could be the most appropriate innovative didactic to improve the learning process of equine encephalon anatomy in the School of Veterinary Medicine of La Salle University, this project began to design, apply and evaluate a didactic prototype Computerized Educative Media CEM in macroscopic anatomy of equine encephalon, to improve the «significant learning» in this subject. The project was developed in three phases regarding the Galviz software engineering, as well as the selected environment for learning, within the framework of the conceptual Novak maps, the significant learning of Ausubel, and the test of usability adapted and applied to the anatomy students, as a MEC evaluation.
Quantum hologram of macroscopically entangled light via the mechanism of diffuse light storage
International Nuclear Information System (INIS)
Gerasimov, L V; Sokolov, I M; Kupriyanov, D V; Havey, M D
2012-01-01
In this paper, we consider a quantum memory scheme for light diffusely propagating through a spatially disordered atomic gas. A unique characteristic is enhanced trapping of the signal light pulse by quantum multiple scattering, which can be naturally integrated with the mechanism of stimulated Raman conversion into a long-lived spin coherence. Then, the quantum state of the light can be mapped onto the disordered atomic spin subsystem and can be stored in it for a relatively long time. The proposed memory scheme can be applicable for storage of the macroscopic analogue of the Ψ (−) Bell state and the prepared entangled atomic state performs its quantum hologram, which suggests the possibility of further quantum information processing. (paper)
Macroscopic-microscopic energy of rotating nuclei in the fusion-like deformation valley
International Nuclear Information System (INIS)
Gherghescu, R.A.; Royer, Guy
2000-01-01
The energy of rotating nuclei in the fusion-like deformation valley has been determined within a liquid drop model including the proximity energy, the two-center shell model and the Strutinsky method. The potential barriers of the 84 Zr, 132 Ce, 152 Dy and 192 Hg nuclei have been determined. A first minimum having a microscopic origin and lodging the normally deformed states disappears with increasing angular momenta. The microscopic and macroscopic energies contribute to generate a second minimum where superdeformed states may survive. It becomes progressively the lowest one at intermediate spins. At higher angular momenta, the minimum moves towards the foot of the external fission barrier leading to hyperdeformed quasi-molecular states. (author)
Hu, Ying; Li, Zhe; Lan, Tian; Chen, Wei
2016-12-01
Photoactuators with integrated optical-to-mechanical energy conversion capacity have attracted growing research interest in the last few decades due to their unique features of remote control and their wide applications ranging from bionic robots, biomedical devices, and switches to motors. For the photoactuator design, the energy conversion route and structure assembly are two important parts, which directly affect the performance of the photoactuators. In particular, the architectural designs at the molecular, nano-, micro-, and macro- level, are found to play a significant role in accumulating molecular-scale strain/stress to macroscale strain/stress. Here, recent progress on photoactuators based on photochemical and photothermal effects is summarized, followed by a discussion of the important assembly strategies for the amplification of the photoresponsive components at nanoscale to macroscopic scale motions. The application advancement of current photoactuators is also presented. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Wave dynamics in an extended macroscopic traffic flow model with periodic boundaries
Wang, Yu-Qing; Chu, Xing-Jian; Zhou, Chao-Fan; Yan, Bo-Wen; Jia, Bin; Fang, Chen-Hao
2018-06-01
Motivated by the previous traffic flow model considering the real-time traffic state, a modified macroscopic traffic flow model is established. The periodic boundary condition is applied to the car-following model. Besides, the traffic state factor R is defined in order to correct the real traffic conditions in a more reasonable way. It is a key step that we introduce the relaxation time as a density-dependent function and provide corresponding evolvement of traffic flow. Three different typical initial densities, namely the high density, the medium one and the low one, are intensively investigated. It can be found that the hysteresis loop exists in the proposed periodic-boundary system. Furthermore, the linear and nonlinear stability analyses are performed in order to test the robustness of the system.
Macroscopic Model and Simulation Analysis of Air Traffic Flow in Airport Terminal Area
Directory of Open Access Journals (Sweden)
Honghai Zhang
2014-01-01
Full Text Available We focus on the spatiotemporal characteristics and their evolvement law of the air traffic flow in airport terminal area to provide scientific basis for optimizing flight control processes and alleviating severe air traffic conditions. Methods in this work combine mathematical derivation and simulation analysis. Based on cell transmission model the macroscopic models of arrival and departure air traffic flow in terminal area are established. Meanwhile, the interrelationship and influential factors of the three characteristic parameters as traffic flux, density, and velocity are presented. Then according to such models, the macro emergence of traffic flow evolution is emulated with the NetLogo simulation platform, and the correlativity of basic traffic flow parameters is deduced and verified by means of sensitivity analysis. The results suggest that there are remarkable relations among the three characteristic parameters of the air traffic flow in terminal area. Moreover, such relationships evolve distinctly with the flight procedures, control separations, and ATC strategies.
Kim, Jihwan; Kim, Bum-Kyu; Kim, Hong-Seok; Hwang, Ahreum; Kim, Bongsoo; Doh, Yong-Joo
2017-11-08
We report on the fabrication and electrical transport properties of superconducting junctions made of β-Ag 2 Se topological insulator (TI) nanowires in contact with Al superconducting electrodes. The temperature dependence of the critical current indicates that the superconducting junction belongs to a short and diffusive junction regime. As a characteristic feature of the narrow junction, the critical current decreases monotonously with increasing magnetic field. The stochastic distribution of the switching current exhibits the macroscopic quantum tunneling behavior, which is robust up to T = 0.8 K. Our observations indicate that the TI nanowire-based Josephson junctions can be a promising building block for the development of nanohybrid superconducting quantum bits.
Information and Self-Organization A Macroscopic Approach to Complex Systems
Haken, Hermann
2006-01-01
This book presents the concepts needed to deal with self-organizing complex systems from a unifying point of view that uses macroscopic data. The various meanings of the concept "information" are discussed and a general formulation of the maximum information (entropy) principle is used. With the aid of results from synergetics, adequate objective constraints for a large class of self-organizing systems are formulated and examples are given from physics, life and computer science. The relationship to chaos theory is examined and it is further shown that, based on possibly scarce and noisy data, unbiased guesses about processes of complex systems can be made and the underlying deterministic and random forces determined. This allows for probabilistic predictions of processes, with applications to numerous fields in science, technology, medicine and economics. The extensions of the third edition are essentially devoted to an introduction to the meaning of information in the quantum context. Indeed, quantum inform...
Macroscopic QED in linearly responding media and a Lorentz-Force approach to dispersion forces
International Nuclear Information System (INIS)
Raabe, Christian
2008-01-01
In this thesis, a very general quantization scheme for the macroscopic electromagnetic field in arbitrary linearly responding media is presented. It offers a unified approach to QED in such media. Applying the quantization scheme, a theory of the dispersion forces on the basis of the Lorentz force is developed. By regarding the dispersion force as the (ground-state or thermal-state) expectation value of the Lorentz force that acts on appropriately defined charge and current densities, Casimir, Casimir-Polder, and van der Waals forces are united in a very natural way that makes transparent their common physical basis. Application of the theory to planar structures yields generalizations of well-known Lifschitz and Casimir-type formulas. (orig.)
Clinical significance of macroscopic completeness of mesorectal resection in rectal cancer.
Leite, J S; Martins, S C; Oliveira, J; Cunha, M F; Castro-Sousa, F
2011-04-01
Local recurrence after resection of rectal cancer is usually regarded as being due to a 'failure' of surgery. The completeness of resection of the mesorectum has been proposed as an indicator of the 'quality' of the resection. We determined the prognostic value of macroscopic evaluation of rectal cancer resection specimens and the circumferential resection margin (CRM) after curative surgery. From 1999 to 2006, the macroscopic quality of the mesorectum and the CRM were prospectively assessed in 127 patients who underwent rectal cancer resection with curative intent (R0+R1). Chemoradiotherapy was administered for 61 tumours staged as locally advanced tumours (T3, T4 and N+). Univariate analysis of time to local recurrence and cancer-free survival were tested (Kaplan-Meier) and multivariate analysis calculated with a Cox regression model. The mesorectum was incomplete in 34 (26.8%) patients. At a median follow up of 34 months (range, 9-96 months), in the group with an adequate mesorectal excision, the cumulative risk of local recurrence at 5 years was 10%. This was 25% if the mesorectum was incomplete (P CRM and the mesorectal score as independent factors for local recurrence, and T and N status and the mesorectal score as independent factors for disease-free survival. The outcome of surgical treatment of rectal cancer is related to the completeness of mesorectal excision. It is a more discriminative prognostic factor than the classic tumour-node-metastasis (TNM) system. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and Ireland.
Value of conventional cytology in the presence of macroscopic lesions of the anal canal
Directory of Open Access Journals (Sweden)
Lêda Pereira de Barcellos
2014-01-01
Full Text Available Objectives: To verify the value of conventional cytology for the diagnosis of macroscopic le- sions of the anal canal and to describe the limitations of the samples. Method: We evaluated 395 conventional cytology samples obtained by brushing the anal canal of patients (predominantly male, HIV-positive and compared them to the presence of macroscopic lesions of the anal canal observed under anorectal examination. Results: Of the total, 91.6% of samples were classified as adequate. Cellular elements repre- sentative of the anal transformation zone were observed in 63.5% of samples. Sensitivity in the presence or absence of cellularity was 80% and 31%, respectively. Conclusion: The study demonstrates the feasibility of using conventional anal cytology in outpatients. Resumo: Objetivo: verificar o valor da citologia convencional no diagnóstico de lesões macroscópicas do canal anal e descrever as limitações das amostras obtidas. Método: avaliamos 395 exames citológicos convencionais obtidos por escovado do canal anal de pacientes predominantemente do sexo masculino, soropositivos para HIV, e com- paramos com a presença de lesões macroscópicas do canal anal constatadas ao exame proctológico. Resultado: o percentual de amostras adequadas foi de 91,6%, e os elementos celulares re- presentativos da zona de transformação anal foram observados em 63,5% das amostras. Encontramos sensibilidade de 80% e 31% na presença ou ausência desta celularidade, res- pectivamente. Conclusão: O estudo demonstra a possibilidade de utilização da citologia anal convencional no rastreio de lesões macroscópicas do canal anal em pacientes ambulatoriais. Keywords: HPV Prevention of anal neoplasia Conventional cytology, Palavras-chave: HPV Prevenção de neoplasia anal Citologia convencional
Vaddiraju, S; Wang, Y; Qiang, L; Burgess, D J; Papadimitrakopoulos, F
2012-10-16
Biofouling and tissue inflammation present major challenges toward the realization of long-term implantable glucose sensors. Following sensor implantation, proteins and cells adsorb on sensor surfaces to not only inhibit glucose flux but also signal a cascade of inflammatory events that eventually lead to permeability-reducing fibrotic encapsulation. The use of drug-eluting hydrogels as outer sensor coatings has shown considerable promise to mitigate these problems via the localized delivery of tissue response modifiers to suppress inflammation and fibrosis, along with reducing protein and cell absorption. Biodegradable poly (lactic-co-glycolic) acid (PLGA) microspheres, encapsulated within a poly (vinyl alcohol) (PVA) hydrogel matrix, present a model coating where the localized delivery of the potent anti-inflammatory drug dexamethasone has been shown to suppress inflammation over a period of 1-3 months. Here, it is shown that the degradation of the PLGA microspheres provides an auxiliary venue to offset the negative effects of protein adsorption. This was realized by: (1) the creation of fresh porosity within the PVA hydrogel following microsphere degradation (which is sustained until the complete microsphere degradation) and (2) rigidification of the PVA hydrogel to prevent its complete collapse onto the newly created void space. Incubation of the coated sensors in phosphate buffered saline (PBS) led to a monotonic increase in glucose permeability (50%), with a corresponding enhancement in sensor sensitivity over a 1 month period. Incubation in serum resulted in biofouling and consequent clogging of the hydrogel microporosity. This, however, was partially offset by the generated macroscopic porosity following microsphere degradation. As a result of this, a 2-fold recovery in sensor sensitivity for devices with microsphere/hydrogel composite coatings was observed as opposed to similar devices with blank hydrogel coatings. These findings suggest that the use of
Klymko, Katherine; Geissler, Phillip L.; Whitelam, Stephen
2016-08-01
Colloidal particles of two types, driven in opposite directions, can segregate into lanes [Vissers et al., Soft Matter 7, 2352 (2011), 10.1039/c0sm01343a]. This phenomenon can be reproduced by two-dimensional Brownian dynamics simulations of model particles [Dzubiella et al., Phys. Rev. E 65, 021402 (2002), 10.1103/PhysRevE.65.021402]. Here we use computer simulation to assess the generality of lane formation with respect to variation of particle type and dynamical protocol. We find that laning results from rectification of diffusion on the scale of a particle diameter: oppositely driven particles must, in the time taken to encounter each other in the direction of the drive, diffuse in the perpendicular direction by about one particle diameter. This geometric constraint implies that the diffusion constant of a particle, in the presence of those of the opposite type, grows approximately linearly with the Péclet number, a prediction confirmed by our numerics over a range of model parameters. Such environment-dependent diffusion is statistically similar to an effective interparticle attraction; consistent with this observation, we find that oppositely driven nonattractive colloids display features characteristic of the simplest model system possessing both interparticle attractions and persistent motion, the driven Ising lattice gas [Katz, Leibowitz, and Spohn, J. Stat. Phys. 34, 497 (1984), 10.1007/BF01018556]. These features include long-ranged correlations in the disordered regime, a critical regime characterized by a change in slope of the particle current with the Péclet number, and fluctuations that grow with system size. By analogy, we suggest that lane formation in the driven colloid system is a phase transition in the macroscopic limit, but that macroscopic phase separation would not occur in finite time upon starting from disordered initial conditions.
Energy Technology Data Exchange (ETDEWEB)
Mares, Tennille E. [Department of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Moore, Tim A. [Department of Geological Sciences, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Solid Energy NZ Ltd., P.O. Box 1303, Christchurch (New Zealand)
2008-10-02
Secondary biogenic gas content can be related to textural characteristics in Eocene age subbituminous coals from the Huntly coalfield, New Zealand. However, the relationships between the two major coal seams in the basin are considerably different despite their close stratigraphic proximity (less than 25 m). In this study, 163 coal samples were collected and desorbed from eight drill holes. Gas adsorption capacity and proximate analyses were conducted as well as macroscopic logging for coal type and vitrain banding characteristics. Vitrain bands were quantitatively point counted and the longest dimension of the shortest axis measured. Three coal types were recognized: bright luster non-banded, bright moderately banded and bright highly banded. Vitrain band thickness, converted to the phi (- log{sub 2}) scale, was found to increase across the coal types with the thickest bands being associated with the most banded coal type. Overall, when normalized by seam and location, the dataset reveals a relationship between coal type and gas content with the non-banded coal type having the highest gas contents and conversely, the coal types with the most vitrain bands having the lowest gas contents. However, when the seams are considered separately, it can be seen that in the stratigraphically higher Renown coal seam, gas has an indirect association with increasing band thickness, in agreement with the overall trend, while the stratigraphically lower Kupakupa coal seam appears to have a direct relationship. Interestingly the Renown seam, which has a greater percentage of non-banded material, generally has a greater methane adsorption capacity as well as a greater gas content compared to the Kupakupa seam. It is believed these differences are related to macroscopic texture and that the differing proportions of the coal types between the two seams has a fundamental effect on microporosity, ultimately controlling the available surface area for gas adsorption. (author)
International Nuclear Information System (INIS)
Liu Jiming; Shi Benyun
2012-01-01
Supply disruptions on one node of a distribution network may spread to other nodes, and potentially bring various social and economic impacts. To understand the performance of a distribution network in the face of supply disruptions, it would be helpful for policy makers to quantitatively evaluate the robustness of the network, i.e., its ability of maintaining a supply–demand balance on individual nodes. In this paper, we first define a notion of network entropy to macroscopically characterize distribution robustness with respect to the dynamics of energy flows. Further, we look into how microscopic evaluation based on a failure spreading model helps us determine the extent to which disruptions on one node may affect the others. We take the natural gas distribution network in the USA as an example to demonstrate the introduced concepts and methods. Specifically, the proposed macroscopic and microscopic evaluations provide us a means of precisely identifying transmission bottlenecks in the U.S. interstate pipeline network, ranking the effects of supply disruptions on individual nodes, and planning geographically advantageous locations for natural gas storage. These findings can offer policy makers, planners, and network managers with further insights into emergency planning as well as possible design improvement. - Highlights: ► This paper evaluates distribution robustness by defining a notion of network entropy. ► The disruption impacts on individual node are evaluated by a failure spreading model. ► The robustness of the U.S. natural gas distribution network is studied. ► Results reveal pipeline bottlenecks, the node rank, and potential storage locations. ► Possible strategies for mitigating the impacts of supply disruptions are discussed.
Helzel, Christiane; Tzavaras, Athanasios
2016-01-01
We consider a kinetic model, which describes the sedimentation of rod-like particles in dilute suspensions under the influence of gravity, presented in Helzel and Tzavaras (submitted for publication). Here we restrict our considerations to shear flow and consider a simplified situation, where the particle orientation is restricted to the plane spanned by the direction of shear and the direction of gravity. For this simplified kinetic model we carry out a linear stability analysis and we derive two different nonlinear macroscopic models which describe the formation of clusters of higher particle density. One of these macroscopic models is based on a diffusive scaling, the other one is based on a so-called quasi-dynamic approximation. Numerical computations, which compare the predictions of the macroscopic models with the kinetic model, complete our presentation.
Helzel, Christiane
2016-07-22
We consider a kinetic model, which describes the sedimentation of rod-like particles in dilute suspensions under the influence of gravity, presented in Helzel and Tzavaras (submitted for publication). Here we restrict our considerations to shear flow and consider a simplified situation, where the particle orientation is restricted to the plane spanned by the direction of shear and the direction of gravity. For this simplified kinetic model we carry out a linear stability analysis and we derive two different nonlinear macroscopic models which describe the formation of clusters of higher particle density. One of these macroscopic models is based on a diffusive scaling, the other one is based on a so-called quasi-dynamic approximation. Numerical computations, which compare the predictions of the macroscopic models with the kinetic model, complete our presentation.
Directory of Open Access Journals (Sweden)
Timo Rahko
1990-08-01
Full Text Available The histological structure and secretory function of the common bile duct (ductus hepaticus communis has not been previously described in reindeer. Macroscopical studies were thus performed in 25 reindeer to reveal the morphology and topography of the ductus hepaticus communis and adjoining organs. Histologic structure of the common bile duct was investigated in 20 animals. Our studies showed that the ductus hepaticus communis and pancreaticus join about 2 cm before the duodenal opening to form the common duct. The common bile duct is an elastic tube about 3 to 5 cm long and 2 to 3 mm thick partly surrounded by fat and pancreatic tissues. The wall of the duct, being about 1 mm thick by light microscopy, consisted of folded mucosa surrounded by connective tissue fibres and a serosal layer. Distally, also muscular bands were seen. In some areas separate leucocytes and even lymphatic nodules were present. Surprisingly pancreatic acini occurred in certain areas of the wall, even in close contact to subepithelial tissues. Mucosal epithelium consisted of surface and glandular epithelial cells with mucous secretion. Numerous intraepithelial globule leucocytes were identifiable within the lamina epithelialis.Tutkimus yhteisen sappikäytävän rakenteesta porolla.Abstract in Finnish / Yhteenveto: Yhteisen sappikäytävän (ductus hepaticus communis histologista rakennetta ja eritystoimintaa ei ole aikaisemmin kuvattu porolla. Makroskooppisia tutkimuksia suoritettiin 25 porolla yhteisen sappikäytävän rakenteen ja topografian selvittämiseksi. Seinämän histologinen rakenne selvitettiin 20 porolla. Tutkimukset osoittivat, että porolla ductus hepaticus communis ja ductus pancreaticus yhtyvät noin 2 cm ennen ohutsuolta muodostaakseen yhteisen tiehyeen. Ductus hepaticus communis on noin 3-5 cm pitkä ja 2-3 mm:n läpimittainen käytävä. Se on elastinen ja osit-tain rasva- ja haimakudoksen ympäröimä. Seinämä on mikroskooppisesti noin 1 mm paksu
Rathke, Hendrik; Hamm, Bernd; Guettler, Felix; Lohneis, Philipp; Stroux, Andrea; Suttmeyer, Britta; Jonczyk, Martin; Teichgräber, Ulf; de Bucourt, Maximilian
2015-12-01
. Hyperacute MRI after ex vivo intervention may result in the underestimation of the real expansion of the produced necrosis zone. This must be kept in mind when using MRI for validating ablation success directly after RFA. One reason for the discrepancy between macroscopic and MRI appearance immediately after RFA may be that the transitional zone shows no or only partially visible MR signal change.
Agent-Based and Macroscopic Modeling of the Complex Socio-Economic Systems
Directory of Open Access Journals (Sweden)
Aleksejus Kononovičius
2013-08-01
Full Text Available Purpose – The focus of this contribution is the correspondence between collective behavior and inter-individual interactions in the complex socio-economic systems. Currently there is a wide selection of papers proposing various models for the both collective behavior and inter-individual interactions in the complex socio-economic systems. Yet the papers directly relating these two concepts are still quite rare. By studying this correspondence we discuss a cutting edge approach to the modeling of complex socio-economic systems. Design/methodology/approach – The collective behavior is often modeled using stochastic and ordinary calculus, while the inter-individual interactions are modeled using agent-based models. In order to obtain the ideal model, one should start from these frameworks and build a bridge to reach another. This is a formidable task, if we consider the top-down approach, namely starting from the collective behavior and moving towards inter-individual interactions. The bottom-up approach also fails, if complex inter-individual interaction models are considered, yet in this case we can start with simple models and increase the complexity as needed. Findings – The bottom-up approach, considering simple agent-based herding model as a model for the inter-individual interactions, allows us to derive certain macroscopic models of the complex socio-economic systems from the agent-based perspective. This provides interesting insights into the collective behavior patterns observed in the complex socio-economic systems. Research limitations/implications –The simplicity of the agent-based herding model might be considered to be somewhat limiting. Yet this simplicity implies that the model is highly universal. It reproduces universal features of social behavior and also can be further extended to fit different socio-economic scenarios. Practical implications – Insights provided in this contribution might be used to modify existing