Distribution by Scientific Domains

Terms modified by Anomalous

  • anomalous behavior
  • anomalous behaviour
  • anomalous difference
  • anomalous diffraction
  • anomalous dispersion
  • anomalous dispersion data
  • anomalous dispersion experiment
  • anomalous dispersion phasing
  • anomalous origin
  • anomalous pulmonary venous connection
  • anomalous pulmonary venous drainage
  • anomalous pulmonary venous return
  • anomalous result
  • anomalous scatterer
  • anomalous scattering
  • anomalous scattering signal
  • anomalous signal
  • anomalous value

  • Selected Abstracts

    Anomalous Left Anterior Descending Coronary Artery from the Pulmonary Artery, Unroofed Coronary Sinus, Patent Foramen Ovale, and a Persistent Left-sided SVC in a Single Patient: A Harmonious Quartet of Defects

    Andrew J. Klein MD
    ABSTRACT Unroofing of the coronary sinus without complex structural heart defects is a rare congenital defect often seen in conjunction with a persistent left-sided superior vena cava. Anomalous origin of the left anterior descending artery from the pulmonary artery with normal origin of the left circumflex coronary artery is an even rarer congenital cardiac defect. We report a case of a 54-year-old woman presenting with mild dyspnea on exertion who was found on invasive and noninvasive evaluations to have a unique combination of defects,unroofed coronary sinus, persistent left-sided superior vena cava, patent foramen ovale, and anomalous origin of the left anterior descending artery from the pulmonary artery without evidence of previous coronary ischemia. [source]

    Congenital Left Ventricular Splint in an Adult Patient with Unrepaired Anomalous Left Coronary Artery from the Pulmonary Artery

    Adam M. Sabbath MD
    ABSTRACT A 24-year-old woman presented with a recent increase in dyspnea on exertion and development of presyncope. The patient stated that she has reproducible episodes of dizziness and near fainting when she climbs a flight of stairs and activity is limited to a slow gait. [source]

    Respiratory Syncytial Viral Infection in an Infant with Unrepaired Anomalous Left Coronary Artery from the Pulmonary Artery

    Karen McClard MD
    ABSTRACT Abnormal origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare coronary anomaly in children that requires necessary and urgent repair. We report a child who was hospitalized with respiratory failure due respiratory syncytial viral (RSV) infection and was subsequently diagnosed with ALCAPA. Aggressive treatment for RSV included synagis and nebulized ribavirin prior to surgical repair. After waiting 4 weeks for the RSV infection to resolve, she underwent successful left coronary artery reimplantation on hospital day 27 and has regained normal left ventricular size and function. [source]

    Anterior Aortic Reimplantation of Anomalous Left Coronary Artery from the Pulmonary Artery (ALCAPA) Originating from the Nonfacing Sinus in an Adult

    Panagiotis G. Sfyridis M.D.
    Intraoperative findings and surgical technique are discussed.,(J Card Surg 2010;25:214-217) [source]

    Management of Anomalous Left Circumflex Artery Encircling the Aortic Annulus in a Patient Undergoing Multivalvular Surgery

    Javier G. Castillo M.D.
    In patients undergoing aortic valve replacement, this finding becomes crucial because the left circumflex is at risk of injury during the procedure. The scenario is even more complex in patients undergoing multi-valve surgery. We report the diagnosis and successful operative strategy in a patient with anomalous left circumflex arising from the proximal right sinus of Valsalva undergoing double aortic and tricuspid valve surgery for active bacterial endocarditis. [source]

    Crystallization and preliminary X-ray analysis of FliJ, a cytoplasmic component of the flagellar type III protein-export apparatus from Salmonella sp.

    Tatsuya Ibuki
    The axial component proteins of the bacterial flagellum are synthesized in the cytoplasm and then translocated into the central channel of the flagellum by the flagellar type III protein-export apparatus for self-assembly at the distal growing end of the flagellum. FliJ is an essential cytoplasmic component of the export apparatus. In this study, Salmonella FliJ with an extra three residues (glycine, serine and histidine) attached to the N-terminus as the remainder of a His tag (GSH-FliJ) was purified and crystallized. Crystals were obtained by the sitting-drop vapour-diffusion technique using PEG 300 as a precipitant. GSH-FliJ crystals grew in the hexagonal space group P6122 or P6522. While the native crystals diffracted to 3.3,Å resolution, the diffraction resolution limit of mercury derivatives was extended to 2.1,Å. Anomalous and isomorphous difference Patterson maps of the mercury-derivative crystal showed significant peaks in their Harker sections, indicating the usefulness of the derivative data for structure determination. [source]

    El Niño, climate change, and Southern African climate

    ENVIRONMETRICS, Issue 4 2001
    Simon J. Mason
    Abstract The El Niño phenomenon involves a large-scale warming of the equatorial eastern and central Pacific Ocean. Recent developments in the El Niño,Southern Oscillation (ENSO) phenomenon have raised concerns about climate change. In this review paper, these recent developments are critically assessed and forecasts of possible future changes are reviewed. Since the late-1970s, El Niño episodes have been unusually recurrent, while the frequency of strong La Niña events has been low. Prolonged/recurrent warm event conditions of the first half of the 1990s were the result of the persistence of an anomalously warm pool near the date line, which, in turn, may be part of an abrupt warming trend in tropical sea-surface temperatures that occurred in the late-1970s. The abrupt warming of tropical sea-surface temperatures has been attributed to the enhanced-greenhouse effect, but may be indicative of inter-decadal variability: earlier changes in the frequency of ENSO events and earlier persistent El Niño and La Niña sequences have occurred. Most forecasts of ENSO variability in a doubled-CO2 climate suggest that the recent changes in the tropical Pacific are anomalous. Of potential concern, however, is a possible reduction in the predictability of ENSO events given a warmer background climate. El Niño events usually are associated with below-normal rainfall over much of southern Africa. Mechanisms for this influence on southern African climate are discussed, and the implications of possible changes in ENSO variability on the climate of the region are assessed. Recent observed changes in southern African climate and their possible relationships with trends in ENSO variability are investigated. The El Niño influence on rainfall over southern Africa occurs largely because of a weakening of tropical convection over the subcontinent. A warming of the Indian Ocean during El Niño events appears to be important in providing a teleconnection from the equatorial Pacific Ocean. The abrupt warming of the tropical Pacific and Indian oceans in the late-1970s is probably partly responsible for increasing air temperatures over southern Africa, and may have contributed to a prolongation of predominantly dry conditions. A return to a wet phase appears to have occurred, despite the persistence of anomalously high sea-surface temperatures associated with the late-1970s warming, and a record-breaking El Niño in 1997/98. Copyright © 2001 John Wiley & Sons, Ltd. [source]

    Singing in the Face of Danger: the Anomalous Type II Vocalization of the Splendid Fairy-Wren

    ETHOLOGY, Issue 3 2001
    Bethanne Zelano
    Males of certain species of fairy-wrens (Aves: Maluridae) emit a unique vocalization, the Type II vocalization, in response to the calls of potential predators. We conducted field observations and playback experiments to identify the contexts in which the Type II vocalization is emitted by splendid fairy-wren (Malurus splendens) males, and to examine social and genetic factors that influence its occurrence. In field observations and controlled playback experiments, Type II vocalizations were elicited most consistently by calls of the predatory gray butcherbird (Cracticus torquatus). Some vocalizations from other avian species also elicited Type II vocalizations, and the majority of these were vocalizations from avian predators. Splendid fairy-wrens are cooperative breeders, and males that responded with Type II vocalizations to playbacks of butcherbird calls tended to be primary rather than secondary males, had larger cloacal protuberances, and were older than those that did not respond. In addition, secondary males that were sons of resident females were more likely than non-sons to respond with a Type II vocalization. In another playback experiment, females responded similarly to the Type I song and Type II vocalizations of their mates. Although the Type II vocalization is emitted primarily in response to predator calls, it is inconsistent with an alarm call explanation. Patterns of reproductive success among Type II calling males suggest that it does not function as an honest signal of male quality. At present, the function of the vocalization remains anomalous, but indirect fitness benefits may play a role in its explanation. [source]


    EVOLUTION, Issue 3 2000
    Stephen C. Weeks
    Abstract., Androdioecy is an uncommon form of reproduction in which males coexist with hermaphrodites. Androdioecy is thought to be difficult to evolve in species that regularly inbreed. The freshwater shrimp Eulimnadia texana has recently been described as both androdioecious and highly selfing and is thus anomalous. Inbreeding depression is one factor that may maintain males in these populations. Here we examine the extent of "late" inbreeding depression (after sexual maturity) in these clam shrimp using two tests: (1) comparing the fitness of shrimp varying in their levels of individual heterozygosity from two natural populations that differ in overall genetic diversity; and (2) specifically outcrossing and selfing shrimp from these same populations and comparing fitness of the resulting offspring. The effects of inbreeding differed within each population. In the more genetically diverse population, fecundity, size, and mortality were significantly reduced in inbred shrimp. In the less genetically diverse population, none of the fitness measures was significantly lowered in selfed shrimp. Combining estimates of early inbreeding depression from a previous study with current estimates of late inbreeding depression suggests that inbreeding depression is substantial (,= 0.68) in the more diverse population and somewhat lower (,= 0.50) in the less diverse population. However, given that males have higher mortality rates than hermaphrodites, neither estimate of inbreeding depression is large enough to account for the maintenance of males in either population by inbreeding depression alone. Thus, the stability of androdioecy in this system is likely only if hermaphrodites are unable to self-fertilize many of their own eggs when not mated to a male or if male mating success is generally high (or at least high when males are rare). Patterns of fitness responses in the two populations were consistent with the hypothesis that inbreeding depression is caused by partially recessive deleterious alleles, although a formal test of this hypothesis still needs to be conducted. [source]

    Redox control of N:P ratios in aquatic ecosystems

    GEOBIOLOGY, Issue 2 2009
    T. M. QUAN
    ABSTRACT The ratio of dissolved fixed inorganic nitrogen to soluble inorganic phosphate (N:P) in the ocean interior is relatively constant, averaging ~16 : 1 by atoms. In contrast, the ratio of these two elements spans more than six orders of magnitude in lakes and other aquatic environments. To understand the factors influencing N:P ratios in aquatic environments, we analyzed 111 observational datasets derived from 35 water bodies, ranging from small lakes to ocean basins. Our results reveal that N:P ratios are highly correlated with the concentration of dissolved O2 below ~100 µmol L,1. At higher concentrations of O2, N:P ratios are highly variable and not correlated with O2; however, the coefficient of variation in N:P ratios is strongly related to the size of the water body. Hence, classical Redfield ratios observed in the ocean are anomalous; this specific elemental stoichiometry emerges not only as a consequence of the elemental ratio of the sinking flux of organic matter, but also as a result of the size of the basins and their ventilation. We propose that the link between N:P ratios, basin size and oxygen levels, along with the previously determined relationship between sedimentary ,15N and oxygen, can be used to infer historical N:P ratios for any water body. [source]

    Crustal underplating and its implications for subsidence and state of isostasy along the Ninetyeast Ridge hotspot trail

    Ingo Grevemeyer
    Recent seismic field work has revealed high lower-crustal velocities under Ninetyeast Ridge, Indian Ocean, indicating the presence of crustal underplating (Grevemeyer et al. 2000). We used results from Ocean Drilling Program (ODP) drill cores and cross-spectral analysis of gravity and bathymetric data to study the impact of the underplating body on the subsidence history and the mode of isostatic compensation along Ninetyeast Ridge. Compared with the adjacent Indian basin, the subsidence of Ninetyeast Ridge is profoundly anomalous. Within the first few millions of years after crustal emplacement the ridge subsided rapidly. Thereafter, however, subsidence slowed down significantly. The most reliable model of isostasy suggests loading of a thin elastic plate on and beneath the seafloor. Isostatic compensation of subsurface loading occurs at a depth of about 25 km, which is in reasonably good agreement with seismic constraints. Subsurface loading is inherently associated with buoyant forces acting on the lithosphere. The low subsidence may therefore be the superposition of cooling of the lithosphere and uplift due to buoyant material added at the base of the crust. A model including prolonged crustal growth in the form of subcrustal plutonism may account for all observations. [source]

    Still the Anomalous Democracy?

    Institutions in Italy, Politics
    Until the early 1990s, the Italian political system was regarded as anomalous among advanced democracies because of its failure to achieve alternation in government. Since then, that problem has been overcome, but Italy has been popularly viewed as continuing to be different to other democracies because it is ,in transition' between regimes. However, this position itself is becoming increasingly difficult to sustain because of the length of time of this so-called transition. Rather than focus on what is rather an abstract debate, it may be more fruitful to analyse what, in substance, is distinctive about Italian politics in this period: the manner in which a debate over fundamental institutional (including electoral) reform has become entangled in day-to-day politics. This can best be exemplified through an analysis of two key electoral consultations held in 2006: the national elections and the referendum on radically revising the Italian Constitution. [source]

    The River Arno catchment, northern Tuscany: chemistry of waters and sediments from the River Elsa and River Era sub-basins, and sulphur and oxygen isotopes of aqueous sulphate

    Gianni Cortecci
    Abstract Within the hydrologic balance of the River Arno catchment (northern Tuscany), the Rivers Elsa and Era are important tributaries entering the main river from the left bank in the lower part of the watershed. Waters and bed sediments were sampled in June 2000 during low discharges in the Rivers Elsa and Era, as well as in major tributary streams. Water samples were analysed for major chemistry and sulphur isotope composition of sulphate, and sediment samples were analysed for major composition and selected trace elements of environmental concern (Zn, Cu, Pb, Cr and Ni). The main results for the waters are: (1) Na and Cl in solution show consistent downstream positive trends in the main rivers, thus supporting progressive contributions of anthropogenic salts; the highest concentration values are observed in tributaries; (2) as shown by sulphur isotopes, sulphate in solution is mainly controlled by dissolution of evaporites (Elsa basin) or oxidation of reduced organic/biogenic sulphur (Era basin), with anthropogenic contributions in most streams not higher than 10% in both the basins. A ,34S signature in the range ,2 to +3, is estimated for pollutant sulphate in the basins studied. The main results for the sediments are: (1) major chemistry is essentially controlled by the lithotypes drained by the waters; (2) pollution by heavy metals does not reach high levels; (3) compared with local fine-grained rocks, copper is more frequently anomalous, whereas lead and zinc show only occasional anomalies; (4) local high concentrations of chromium and nickel can be attributed to upstream occurrences of ophiolites. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Anomalous Defects and Dynamic Failure of Armor Ceramics

    M.P. Bakas
    The ballistic performance of state-of-the-art silicon carbide armor material can exhibit a fairly wide variability in certain test configurations, which, it is proposed, may be due to the presence of large (>0.1 mm), rare defects, termed, herein, "anomalous" defects. SiC rubble resulting from ballistic tests was examined, as were quasi-static test samples. Ballistic fragment fracture surfaces revealed large carbonaceous defects that seemed to affect fracture path and mode. Low-strength biaxial flexure samples demonstrated similar defects (>0.1 mm) as failure origins. Carbonaceous defects similar in appearance but smaller in size were also found at the fracture origins of SiC bend bars. Frequently, alumina inclusions were found within the carbonaceous discontinuities. These alumina inclusions may cause the graphitic regions to form during sintering. The random distribution of such large, rare carbonaceous discontinuities from sample-to-sample, as well as batch-to-batch variability, may explain high ballistic variability for SiC armor ceramics. [source]

    Classification of synchronous oceanic and atmospheric El Niño-Southern Oscillation (ENSO) events for palaeoclimate reconstruction

    Joëlle L. Gergis
    Abstract Since the mid-1970s, ENSO has changed in character to a predominance of El Niño conditions, the extreme phase of which appears coincidental with increases in global temperature records. Instrumental time series (<150 years) are too short to adequately address the significance of late twentieth-century ENSO variability, thus, multi-century palaeoclimate reconstructions derived from long proxy records are sought. Despite the global influence exerted by ENSO on society, limited consensus exists within the scientific community as to which index best defines the timing, duration and strength of events. Here we address issues associated with the complexity of ENSO characterisation by comparing the ,event capture' ability of two currently used indices of ENSO. It is suggested that the use of a sole ENSO index is undesirable as a given index is only indicative of one physical aspect of the phenomenon, and as such is unlikely to be representative of the wider interactions experienced in the coupled ocean-atmospheric system. In an attempt to describe more of the nature and evolution of ENSO events, the Coupled ENSO Index (CEI) classification scheme was devised to identify synchronous oceanic (Niño 3.4 SST) and atmospheric (Southern Oscillation Index) anomalies associated with ENSO for the instrumental period (1871,2003). The CEI is of practical relevance to the ENSO community as it provides an amplitude preserving instrumental baseline for the calibration of proxy records to reconstruct both components of the ENSO system. Analysis of the nature of instrumental ENSO events from the CEI suggests that the frequency and intensity of post-1970 ENSO events (when 50% of all extreme events identified occur) appears the most anomalous in the context of at least the past century. It is hoped that the CEI will facilitate palaeo-ENSO research to systematically resolve the long-term context of past ENSO behaviour to assess whether the apparently anomalous nature of late twentieth-century variability is unprecedented within existing palaeoclimate archives. Copyright © 2005 Royal Meteorological Society. [source]

    Trend and variability of China precipitation in spring and summer: linkage to sea-surface temperatures

    Fanglin Yang
    Abstract Observational records in the past 50 years show an upward trend of boreal-summer precipitation over central eastern China and a downward trend over northern China. During boreal spring, the trend is upward over southeastern China and downward over central eastern China. This study explores the forcing mechanism of these trends in association with the global sea-surface temperature (SST) variations on the interannual and interdecadal time scales. Results based on singular value decomposition (SVD) analyses show that the interannual variability of China precipitation in boreal spring and summer can be well defined by two centres of action for each season, which are covarying with two interannual modes of SSTs. The first SVD modes of precipitation in spring and summer, which are centred in southeastern China and northern China respectively, are linked to an El Niño,southern oscillation (ENSO)-like mode of SSTs. The second SVD modes of precipitation in both seasons are confined to central eastern China, and are primarily linked to SST variations over the warm pool and the Indian Ocean. Features of the anomalous 850 hPa winds and 700 hPa geopotential height corresponding to these modes support a physical mechanism that explains the causal links between the modal variations of precipitation and SSTs. On the decadal and longer time scale, similar causal links are found between the same modes of precipitation and SSTs, except for the case of springtime precipitation over central eastern China. For this case, while the interannual mode of precipitation is positively correlated with the interannual variations of SSTs over the warm pool and Indian Ocean, the interdecadal mode is negatively correlated with a different SST mode, i.e. the North Pacific mode. The latter is responsible for the observed downward trend of springtime precipitation over central eastern China. For all other cases, both the interannual and interdecadal variations of precipitation can be explained by the same mode of SSTs. The upward trend of springtime precipitation over southeastern China and downward trend of summertime precipitation over northern China are attributable to the warming trend of the ENSO-like mode. The recent frequent summertime floods over central eastern China are linked to the warming trend of SSTs over the warm pool and Indian Ocean. Copyright © 2004 Royal Meteorological Society [source]

    An Odd Thing Happened on the Way to Balancing: East Asian States' Reactions to China's Rise

    Steve Chan
    Are East Asian states reacting to China's rise according to balance-of-power expectations? This review discusses the pertinent debate and presents overtime data germane to this question. It raises several issues of theoretical argumentation and historical purview pertaining to this debate, and concludes that the conduct of China's neighbors thus far is anomalous from the traditional balance-of-power perspective. [source]

    On Spiritual Edgework: The Logic of Extreme Ritual Performances

    Religion as a social form is constructed to provide adherents with a sense of empowerment and control. Rituals that involve a risk of physical or psychological injury or even death therefore would appear anomalous and indeed are frequently the objects of social scientific and journalistic denigration. Firewalking and serpent handling exemplify such rituals. I argue that these two radical ritual practices, which I term spiritual edgework, provide a valuable sociological window on how radical ritual practices are socially constructed. The social construction process involves the identification of a mythically relevant edge that offers: both contingency and certainty; individual and collective preparation for the impending edgework during which tensions are elevated for later ritual resolution; a ritualized process for successfully navigating the edge; and postedgework accounts that neutralize potential disconfirming injuries or deaths. [source]

    Why are very large herbivores absent from Australia?

    A new theory of micronutrients
    Abstract Aim We propose a Megacatalyst Theory, based on the pivotal role of the micronutrients iodine (I), cobalt (Co) and selenium (Se), in answer to the body size anomaly of herbivores on different continents, and the previously unexplained absence of megaherbivores in certain environments. Location It is anomalous that megaherbivores are absent from Australia while present in even dry and nutrient-poor parts of southern Africa, and that they have been exterminated from the Americas, but not south-east Asia. Methods We hypothesize that I, Co and Se are micronutrients in quantity, but megacatalysts in effect, determining maximum body size and pace of life, hence whether energy is used by animals or fire. The Megacatalyst Theory suggests that the greater the reproductive rate and brain size relative to body size, the greater the probable demand for I, Co and Se. Results Balanced supply of I, Co and Se, within narrow tolerances, is elusive because of disparate cycles: I gravitates towards the sea, whereas Co and Se are concentrated in ultramafics and organic shales, respectively. Sufficiency of these micronutrients, at less than toxic concentrations, is vital for rapid metabolism and growth, particularly of the nervous system. Iodine controls thermogenesis, Co controls the gut fermentation supplying herbivores, and Se controls biochemical damage where both processes occur rapidly. The supply of Co allows vegetation to be metabolized instead of combusted, by promoting digestion of fibre by gut microbes. Herbivores demand I, Co and Se in greater concentrations than palatable plants necessarily contain, as an increasing proportion of energy is fermented from fibre with increasing body size. Economy of scale is limited by loss of I in urine (partly compensated by thyroid size), Co in faeces (partly compensated by gut compartments), and Se both ways. Main conclusions The larger the herbivore species, the more it may depend on supplementation in order to survive predation by humans. As body mass increases, Co becomes deficient before I, because it is essential for rumination, and cannot be absorbed by the skin. Moderate uplift of a fairly flat landscape sustainably supplies I from mineralized springs, and Co from rocks (and Se from both), avoiding the excess of I in the sea and the excess of Co on high mountains. Iodine and Se leached to groundwater under dry climates are inaccessible to herbivores on a continent as flat as Australia, where even kangaroos have limited fecundity and intelligence compared to southern African ruminants of similar body mass. Where springs and associated earth-licks were available in the late Pleistocene, megaherbivores could evolve to survive the era of domestication. [source]

    Management of Anomalous Left Circumflex Artery Encircling the Aortic Annulus in a Patient Undergoing Multivalvular Surgery

    Javier G. Castillo M.D.
    In patients undergoing aortic valve replacement, this finding becomes crucial because the left circumflex is at risk of injury during the procedure. The scenario is even more complex in patients undergoing multi-valve surgery. We report the diagnosis and successful operative strategy in a patient with anomalous left circumflex arising from the proximal right sinus of Valsalva undergoing double aortic and tricuspid valve surgery for active bacterial endocarditis. [source]

    Percutaneous Transluminal Angioplasty of the Anomalous Circumflex Artery

    The technical experience reported in the literature concerning angioplasty in patients with anomalous origin of the left circumflex artery is limited. Balloon angioplasty seems to be a favorable approach for revascularization in these vessels, and major determinants of successful angioplasty are angiographic knowledge of their course and structure, appropriate selection of guiding catheter, and the possibility of advancing the balloon into the anomalous vessel. Five consecutive patients with severe atherosclerotic lesions on the anomalous left circumflex artery who underwent coronary angioplasty of the anomalous vessel are reported. Angiographic and clinical success were achieved in three patients with balloon alone and in one with stent implantation. (J Interven Cardiol 2001;14:11,16) [source]

    Public (Interest) or Private (Gain)?

    The Curious Case of Network Rail's Status
    This paper develops Whitehouse's 2003 examination of the creation of Network Rail, a case study of New Labour's attempt to operationalize the ,third way'. Significant changes have occurred since 2003 which make Network Rail's position as a private company with private sector debt appear increasingly anomalous. These changes include: the reclassification of the debt of another rail company from private to public, and the introduction of,imputed debt'into public sector debt measurement; new funding arrangements for Network Rail which make it heavily dependent on public support; and important rail regulatory policy changes. The paper analyses these changes, and revisits White-house's conclusions. In particular, this paper challenges Whitehouse's contention that Network Rail's creation led to the de facto renationalization of the railway infrastructure at a reduced public cost. The paper demonstrates that Network Rail is a very expensive mechanism for channelling public money to private companies, and argues that the Labour government's attempt to maintain the company's private sector status as part of its third way approach is ultimately untenable. [source]

    Kinetics of adsorption of 2-CEES and HD on impregnated silica nanoparticles under static conditions

    AICHE JOURNAL, Issue 5 2009
    Amit Saxena
    Abstract Silica nanoparticles of high surface area (887.3 m2/g) were synthesized using aerogel route and, thereafter, impregnated with those reactive chemicals, which have already been proven to be effective against sulfur mustard (HD). Thus, developed adsorbents were tested for their potential by conducting studies on kinetics of adsorption of 2-chloroethylethyl sulfide (2-CEES) and HD under static conditions. Kinetics of adsorption was studied using linear driving force model and Fickian diffusion model. The kinetic parameters such as equilibration constant, equilibration capacity, diffusional exponent, and adsorbate-adsorbent interaction constant were also determined. Trichloroisocyanuric acid impregnated silica nanoparticles (10% w/w) showed the maximum uptake of 2-CEES (1824 mg/g) and HD (1208 mg/g). Values of diffusional exponent indicated the mechanisms to be Fickian and anomalous. Chemical interaction seemed to be another mechanism involved in the toxicant uptake rate. Hydrolysis, dehydrochlorination, and oxidation reactions were found to be the route of degradation of toxicants. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]


    R. A. McTavish
    In early electron spin resonance (ESR) analysis of North Sea wells, maturation of organic matter (OM) was expressed in terms of maximum palaeotemperature (MPT) based on North American calibrations that did not consider the influences of kerogen composition or overpressure. In the North Sea, the MPTs were anomalous in overpressured sequences and relative to other indices of OM maturation such as vitrinite reflectance, so the ESR method was abandoned there in geochemical studies. However, early empirical study of North Sea ESR data indicated that, in relation to functions that linked temperature and pore pressure, some ESR parameters were predictable without reference to MPTs. In order to re-evaluate ESR parameters as indices of OM maturation, the physical factors (temperature and pressure) which affect OM maturation are related in the present paper to the ESR parameters "g" (spectral position) and Ng (spin density) at six well locations in the northern North Sea. A third ESR parameter, W (line width), is not an effective guide to maturation levels due to its complex relationship to the physical factors and kerogen types. However, cross-plots of W versus "g" and Ng appear to be as effective as pyrolysis for kerogen typing. Levels of maturation investigated in the North Sea wells range through the equivalent vitrinite reflectance values of about 0.50,1.50%. The values of "g" and Ng have been differentiated for kerogen type, but undifferentiated values of "g" have also been studied. Regression analysis has shown that there are linear relationships between the ESR parameters "g" and Ng, and the physical factors present-day temperature (To), "effective" temperature (Te), and differential pressure (Pd). Correlation coefficients for both "g" (undifferentiated and differentiated) and Ng (differentiated) relative to the physical factors are high; the highest values are for "g" and Ng relative to Te and Pd (r =,0.950 for "g" differentiated or undifferentiated, r = 0.944,0.976 for Ng differentiated, respectively). However, correlation coefficients were lower for "g" and Ng relative to To. More frequent high correlation coefficients and larger sample populations suggest that "g" (undifferentiated) is a more reliable index of OM maturation than Ng(differentiated). However, the estimation of levels of OM maturation is improved if both indices are used together. The ESR method appears to be effective both for estimating levels of OM maturation and for kerogen typing. It has a number of potential advantages over other geochemical methods: firstly, it is more sensitive for estimating OM maturation than most other methods; secondly, it can be used to analyze organic matter which is as old as Proterozoic; thirdly, it does not destroy the samples analyzed. [source]

    Anomalous behavior of the second and third harmonics generated by femtosecond Cr:forsterite laser pulses in SiC,polymer nanocomposite materials as functions of the SiC nanopowder content

    S. O. Konorov
    Abstract Femtosecond pulses of 1.25 µm Cr:forsterite laser radiation were used to study second- and third-harmonic generation in silicon carbide nanopowders embedded in a poly(methyl methacrylate) (PMMA) film. Harmonic generation processes extend the analytical and sensing abilities of light-scattering techniques, including Raman spectroscopy, offering a convenient and efficient approach to the analysis of nanocomposite materials where nanoparticles tend to agglomerate, masking informative features in Raman spectra. The second- and third-harmonic yields are shown to display an anomalous, counterintuitive behavior as functions of the SiC nanopowder content in a polymer film. Whereas harmonic generation in polymer films with a high content of SiC nanocrystals is quenched by the absorption of agglomerating nanoparticles, the influence of absorption is less detrimental in nanocomposite films with a lower SiC content, leading to the growth of the second- and third-harmonic yields. Nanocomposite films with a lower SiC content are also characterized by a higher breakdown threshold, allowing pump pulses with higher fluences to be applied for more efficient harmonic generation. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    Rights-based justifications for the tort of unlawful interference with economic relations

    LEGAL STUDIES, Issue 2 2008
    JW Neyers
    The tort of unlawful interference with economic relations is anomalous since it allows a plaintiff to sue a defendant for a loss that is occasioned by an unlawful act committed by that defendant against a third party. This parasitic liability is seemingly in violation of the basic tort law principle that in order to make out a claim what the plaintiff must show is a violation of her own rights, not merely a wrong to someone else. Thus, it appears that the tort is an instance of damnum absque injuria. This paper examines whether this is in fact the case by examining if there are any rights-based theories that can explain the tort in a way that is consistent with basic private law principle. In other words, is it possible to find an independent right of the defendant that has somehow been violated, one which explains why the defendant is able to sue in their own right? Upon examination, it appears that the ,right to trade', ,remoteness' and ,abuse of right' theories are largely incapable of providing such an explanation since they display many seemingly insurmountable problems of coherence and fit with the existing case-law. More promising are the arguments that the tort is a justified exception to basic principle or that it is an example of public rights being vindicated in private law, yet each of these theories is also problematic in some respects. The overall thesis of the paper is that the tort of unlawful interference with economic relations is radically under-theorised and that it, and the other economic torts, could benefit tremendously from more intense academic examination. [source]

    Compositions and taxonomy of 15 unusual carbonaceous chondrites

    Won Hie CHOE
    1152 (anomalous CV3); Pecora Escarpment (PCA) 91008 (anomalous, metamorphosed CM); Queen Alexandra Range 99038 (type 2 ungrouped); Sahara 00182 (type 3 ungrouped, possibly related to HaH 073 and/or to C-L 001); and WIS 91600 (mildly metamorphosed, anomalous, CM-like chondrite, possibly a member of a new grouplet that includes Belgica-7904, Dhofar 225, and Y-86720). Many of these meteorites show fractionated abundance patterns, especially among the volatile elements. Impact volatilization and dehydration as well as elemental transport caused by terrestrial weathering are probably responsible for most of these compositional anomalies. The metamorphosed CM chondrites comprise two distinct clusters on the basis of their ,17O values: approximately ,4, for PCA 91008, GRO 95566, DaG 978, and LEW 85311, and approximately 0, for Belgica-7904 and WIS 91600. These six meteorites must have been derived from different asteroidal regions. [source]

    Probability density of the multipole vectors for a Gaussian cosmic microwave background

    Mark R. Dennis
    ABSTRACT We review Maxwell's multipole vectors, and elucidate some of their mathematical properties, with emphasis on the application of this tool to the cosmic microwave background (CMB). In particular, for a completely random function on the sphere (corresponding to the statistically isotropic Gaussian model of the CMB), we derive the full probability density function of the multipole vectors. This function is used to analyse the internal configurations of the third-year Wilkinson Microwave Anisotropy Probe quadrupole and octopole, and we show that the observations are consistent with the Gaussian prediction. A particular aspect is the planarity of the octopole, which we find not to be anomalous. [source]

    Anomalous charge relaxation in channels of pentacene-based organic field-effect transistors: a charge transient spectroscopy study

    I. Thurzo
    Abstract Two types of Si/SiO2/pentacene organic field-effect transistors (OFET) with bottom Au-source (S) and , drain (D) electrodes were examined by charge transient spectroscopy (QTS), applying pulsed bias ,UDS to the channel of an OFET with floating gate electrode. The transient charge Q (t ), flowing through the channel after the removal of the bias pulse, was processed at a constant temperature by a three-channel correlator yielding the signal ,Q = Q (t1) , 3/2Q (2t1) + 1/2Q (4t1), the scanned delay t1 being related to the trailing edge of the bias pulse. Most of the QTS spectra were characterized by peaks of ,Q (t1) with FWHM corresponding to discrete time constants ,m , t1m, while scanning t1 from 2 ,s to 0.1 s. The common feature of the QTS spectra was a linear dependence of the peak height ,Qm on ,UDS for both polarities of the latter, thereby resembling what is expected for dielectric relaxation (polarization). Some devices showed anomalous (reversed) sign of the signal with respect to the polarity of ,UDS, or even features like transitions from the correct sign to the reversed one. In order to customize the anomalies, a model is presented which ignores injection of excess charge carriers and takes into account two contributions to the total transient charge: a/space charge of intrinsic charge carriers piled up at the blocking Au-electrodes during the pulse, relaxing with the dielectric relaxation time ,D = ,0,r/, (, being conductivity of the organics); b/orientation of molecular dipoles (,dip) in the relaxing electric field of the space charge. It is the dipolar component that is responsible for the anomalous charge flow direction manifested by the signal reversal. The origin of the permanent dipole moment of the otherwise non-polar pentacene molecules may be either attached excess or missing atoms (vacancies) of the defect molecules [J. E. Northrup and M. L. Chabinyc, Phys. Rev. B 68, 041202 (2003)]. In cases of non-blocking contacts the dipolar relaxation would lead to QTS peaks of correct sign, to be distinguished from possibly non-negligible contribution of the dielectric relaxation in the semiconductor. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Anomalous capacitance,voltage characteristics of Pt,AlGaN/GaN Schottky diodes exposed to hydrogen

    Yoshihiro Irokawa
    Abstract We have investigated the interaction of hydrogen with Pt-AlGaN/GaN Schottky barrier diodes (SBDs) using a low-frequency capacitance-voltage (C-V) technique. At a frequency of 1kHz, the C-V curve in hydrogen shifts toward negative bias values as compared with that in nitrogen. As the frequency decreases from 1kHz to 1Hz, the capacitance in hydrogen significantly increases and the fluctuations of the capacitance are observed. These C-V characteristics are quite anomalous and have not been reported yet, suggesting the formation of interfacial polarization which could be attributable to hydrogen-related dipoles. The fluctuation of the capacitance may be related to the alignment of the dipoles. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]