bluuebunny/crossref_metadata_2025 huggingface dataset:
A point is normal for almost all mapsβx+αmod 1 or generalizedβ-transformations
Authors: FALLER B. , PFISTER C.-E.
Published: February 2009

We consider the mapTα,β(x):=βx+α mod 1, which admits a unique probability measureμα,βof maximal entropy. Forx∈[0,1], we show that the orbit ofxisμα,β-normal for almost all (α,β)∈[0,1)×(1,∞) (with respect to Lebesgue measure). Nevertheless, we construct analytic curves in [0,1)×(1,∞) along which the orbit ofx=0 isμα,β-normal at no more than one point. These curves are disjoint and fill the set [0,1)×(1,∞). We also study the generalizedβ-transformations (in particular, the tent map). We show that the critical orbitx=1 is normal with respect to the measure of maximal entropy for almost allβ.
Mill, Sentimentalism and the Problem of Moral Authority
Authors: CALLCUT DANIEL
Published: February 2009

Mill's aim in chapter 3 ofUtilitarianismis to show that his revisionary moral theory can preserve the kind of authority typically and traditionally associated with moral demands. One of his main targets is the idea that if people come to believe that morality is rooted in human sentiment then they will feel less bound by moral obligation. Chapter 3 emphasizes two claims: (1) The main motivation to ethical action comes from feelings and not from beliefs and (2) Ethical feelings are highly malleable. I provide a critical examination of Mill's use of these claims to support his argument that Utilitarianism can preserve morality's authority. I show how the two claims, intended to form a significant rebuttal to the worry about Utilitarianism, can in fact be combined to raise powerful skeptical concerns. I explain how Mill evades the skepticism, and why contemporary philosophers who lack Millian optimism about human nature find it harder to avoid the skeptical outcome.
Virtue, Satisfaction and Welfare Enhancement
Authors: DOVIAK DANIEL
Published: February 2009

In ‘Is Virtue Its Own Reward?’ Wayne Sumner argues that (1) as a matter of necessity, virtue is intrinsically prudentially rewarding, and (2) if all else is equal, the virtuous will fare better than the non-virtuous. In this article, I reproduce and criticize those arguments. I offer several objections to the argument for the first thesis; each objection makes the same basic point: contrary to what Sumner assumes, certain contingent facts over and above a person's being virtuous have to obtain if virtue is to issue in any prudential reward. I object to Sumner's second thesis by arguing that moral neutrality can be at least as welfare-enhancing as moral virtuosity. Finally, I argue that even if virtue were intrinsically rewarding in the way Sumner envisions, it would still be impossible to determine a priori whether adopting a virtuous lifestyle would be prudentially rational.
The Epistemic and Informational Requirements of Utilitarianism
Authors: BREAKEY HUGH
Published: February 2009

A recurring objection confronting utilitarianism is that its dictates require information that lies beyond the bounds of human epistemic wherewithal. Utilitarians require reliable knowledge of the social consequences of various policies, and of people's preferences and utilities. Agreeing partly with the sceptics, I concur that the general rules of thumb offered by social science do not provide sufficient justification for the utilitarian legislator to rationally recommend a particular political regime, such as liberalism. Actual data about human preference-structures and utilities is required to bridge this evidentiary gap. I offer two arguments to support the availability of such information. First, I contend that ordinary human beings have a clear method of epistemic access to reliable information about commensurable preference-structures. Second, in an attempt to shift the onus of philosophic argument, I show that the utilitarian legislator's requirements do not differ in kind from those implicitly called upon by the sceptical deontic liberal.
The Rejection of Scalar Consequentialism
Authors: LAWLOR ROB
Published: February 2009

In ‘The Scalar Approach to Utilitarianism’ Alastair Norcross argues that scalar consequentialism is the most plausible form of consequentialism, but his arguments are flawed: he is simply mistaken when he suggests that there is a problem with deriving absolutes like right and wrong from gradable properties such as goodness; he cannot justify his claim that the choice of a threshold will always be arbitrary; and his ‘no significant difference’ argument only shows that the consequentialist doesn'tcareabout permissibility. Furthermore, I argue that, although Norcross was right to claim that a scalar theory can be action-guiding (to an extent), he was mistaken to think that ‘Abolishing the notion of “ought” will not seriously undermine the action-guiding nature of morality.’ If anything can be said in favour of scalar consequentialism, it is only that it is the mosthonestform of consequentialism, because it doesn't pretend to care about permissibility.
Slime cells on the surface ofEragrostisseeds maintain a level of moisture around the grain to enhance germination
Authors: Kreitschitz Agnieszka , Tadele Zerihun , Gola Edyta M.
Published: February 2009

Eragrostisis a cosmopolitan genus of the familyPoaceae. Several wild species, includingE. pilosa(L.) Beauv., are harvested for food, but the only cultivated crop-species is tef [E. tef(Zucc.) Trotter]. Despite its importance as a staple food and its plasticity to diverse environmental conditions, little is known about the structural and physiological strategies that adapt tef seeds to endure diverse and variable moisture regimes. Here, we report the presence of slime cells, a type of modified epidermal cell, covering the fruit of tef and its wild relative,E. pilosa. The slime produced byEragrostisbelongs to the ‘true’ slime type, since it is exclusively composed of pectins. Pectin forms uniform layers on the cell wall inner surface, which are confined by a thin cellulose layer to prevent release into the cell lumen. In the presence of water, pectins quickly hydrate, causing swelling of the slime cells. This is followed by their detachment, which may be controlled by a thin cuticle layer on the fruit surface. The ability of slime to absorb and maintain moisture around the grain is thought to be an adaptive feature forEragrostisgrowing in dry habitats. This retention of water by slime may create conditions that are suitable for rapid germination.
Sensitivity cycling and its ecological role in seeds with physical dormancy
Authors: Jayasuriya K.M.G. Gehan , Baskin Jerry M. , Baskin Carol C.
Published: February 2009

Cycling of physically dormant (PY) seeds between states insensitive and sensitive to dormancy-breaking factors in the environment has recently been demonstrated inFabaceaeandConvolvulaceae, and it may be a common phenomenon in seeds with water-impermeable seed coats. In contrast to seeds of many species with physiological dormancy (PD), those with PY cannot cycle between dormancy and non-dormancy (ND). In this paper, we evaluate the role of sensitivity cycling in controlling the timing of germination of seeds with PY in nature, and show that sensitivity cycling in seeds with PY serves the same ecological role as dormancy cycling in seeds with PD. Thus, sensitivity cycling in seeds with PY ensures that germination in nature occurs only at (a) time(s) of the year when environmental conditions for growth are, and are likely to remain, suitable long enough for the plant to complete its life cycle or to form a perennating structure. Further, we describe the experimental procedures necessary to determine whether sensitivity cycling is occurring, and discuss briefly the possible relevance of sensitivity cycling to dormancy classification.
Smoke-water-induced changes of expression pattern in Grand Rapids lettuce achenes
Authors: Soós Vilmos , Juhász Angela , Light Marnie E. , Van Staden Johannes , Balázs Ervin
Published: February 2009

Aerosol smoke and smoke-water can break dormancy and promote seed germination of many plant species. In this study we investigated changes in gene expression after imbibition of light-sensitiveLactuca sativaL. cv. ‘Grand Rapids’ achenes with dilute smoke-water compared to water control samples kept in the dark or continuous light, using the fluorescent differential display technique. Although no difference was detected in the smoke-water versus water control samples germinated in light, smoke-water treatment resulted in the differential display of several expressed sequence tags (ESTs) when compared to water control samples kept in the dark. The most pronounced fragments isolated correspond to known genes related to germination, with functions in cell wall expansion, regulation of translation, the cell division cycle, carbohydrate metabolism and abscisic acid (ABA) regulation. Real-time polymerase chain reaction (PCR) validation revealed that the transcript abundance of the genes,HVA22, short-chain dehydrogenase/reductase and late embryogenesis abundant protein, are upregulated after smoke treatment when compared to control achenes kept in the light. The results indicate that smoke has a dual effect. On the one hand, the smoke can induce genes that may be linked to ABA action, whereas, on the other hand, it elicits a faster germination rate by inducing a similar pattern in gene expression as light treatment. Smoke effects could be manifested mainly through the induction of the cell division cycle, cell wall extension and storage mobilization.
Effect of medium conditioned with rat hepatoma BRL cells on ‘2-cell block’ of random-bred mouse embryos culturedin vitro
Authors: Kobayashi Masayuki , Terawaki Yoshinori , Saito Koichi , Kasuga Kano , Kojima Ikuo
Published: February 2009

The phenomenon of developmental arrest at the 2-cell stage of zygotes obtained from certain mouse strains duringin vitroculture is known as the 2-cell block. The effect of conditioned medium (CM) with rat hepatoma BRL cells on the 2-cell block of CD-1 mouse zygotes was investigated in comparison with that of CM with rat hepatoma Reuber H-35 cells. In control medium with EDTA, 75.4% of 2-cell embryos developed to the 4- to 8-cell stages. In the same conditions, the BRLMr<10000 fraction inhibited the development of 2-cell embryos to the 4- to 8-cell stages (57.7%), although the inhibition by this fraction was weaker than by the ReuberMr<10000 fraction (19.8%). As a result of reversed-phase column chromatography, a 2-cell stage specific inhibitor of the cleavage of mouse embryos (Fr.B-25), which separated into theMr<10000 fraction of the Reuber CM, was detected at a low level in the BRLMr<10000 fraction. On the other hand, theMr>10000 fraction of BRL CM accelerated the development of the embryos (90.3%). This beneficial effect was also evident even in the absence of EDTA. RT-PCR analysis revealed that mRNAs encoding the β-A or β-B subunit of activins (Mr~29000), which are well characterized cytokines that act as releasers of the 2-cell block, were expressed in BRL cells. These results indicate that BRL cells synthesize Fr.B-25 at low levels, and that activins contained in the BRL CM probably contributed to overcoming the 2-cell block of CD-1 zygotes culturedin vitro.
A tractable hybrid DDN–POMDP approach to affective dialogue modeling for probabilistic frame-based dialogue systems
Authors: BUI TRUNG H. , POEL MANNES , NIJHOLT ANTON , ZWIERS JOB
Published: February 2009

We propose a novel approach to developing a tractable affective dialogue model for probabilistic frame-based dialogue systems. The affective dialogue model, based on Partially Observable Markov Decision Process (POMDP) and Dynamic Decision Network (DDN) techniques, is composed of two main parts: the slot-level dialogue manager and the global dialogue manager. It has two new features: (1) being able to deal with a large number of slots and (2) being able to take into account some aspects of the user's affective state in deriving the adaptive dialogue strategies. Our implemented prototype dialogue manager can handle hundreds of slots, where each individual slot might have hundreds of values. Our approach is illustrated through a route navigation example in the crisis management domain. We conducted various experiments to evaluate our approach and to compare it with approximate POMDP techniques and handcrafted policies. The experimental results showed that the DDN–POMDP policy outperforms three handcrafted policies when the user's action error is induced by stress as well as when the observation error increases. Further, performance of the one-step look-ahead DDN–POMDP policy after optimizing its internal reward is close to state-of-the-art approximate POMDP counterparts.
HUMANITARIAN LAW AND LITERATURE: FROM UTOPIA TO SLAUGHTERHOUSE-FIVE
Authors: Bring Ove
Published: February 2009

The article identifies humanitarian law related thought in some works of world literature. A starting point is Thomas More'sUtopia(1516). Since Judge T. Meron has dealt extensively with Shakespeare from a similar perspective, the works referred to in the article (exceptUtopia) are all post-Shakespearean. The exposé ends with Kurt Vonnegut'sSlaughterhouse Five(1969) and some dry comments on the bombing of Dresden in that book.
INTERNATIONAL CRIMINAL COURTS ROUND-UP
Authors: Guellai Amna , Rojo Enrique Carnero
Published: February 2009

The International Criminal Courts Round-Up reports on the most interesting judgements and decisions rendered by international(ized) criminal courts and tribunals during the reporting period. In addition, important developments within the various organs of the courts are highlighted, such as the appointment of new judges and significant amendments to the procedural rules of the courts. The Round-Up presently covers issues concerning the International Criminal Court, the International Criminal Tribunal for the former Yugoslavia, the International Criminal Tribunal for Rwanda and the Special Court for Sierra Leone.
THE ‘LONG YEAR’: EMERGING INTERNATIONAL EFFORTS TO ADDRESS THE HUMANITARIAN IMPACTS OF CLUSTER MUNITIONS, 2006-2007
Authors: Borrie John
Published: February 2009

Cluster munitions are a class of weapon originating from the Second World War, and concerns about the hazards they pose to civilians, both at time of use and post-conflict, have been raised since the 1960s. However, attempts to specifically address the humanitarian impacts of cluster munitions through international legal means gained little traction until a turning-point period from late 2006 to the end of 2007. Remarkably, by the end of this period not one – but two – multilateral negotiating processes were underway to develop international legally binding arrangements on cluster munitions.
Aliens are us. An innovative course in astrobiology
Authors: Oliveira Carlos F. , Barufaldi James P.
Published: February 2009

We live in a scientific world; paradoxically, the scientific literacy of the population is minimal at best. Science is an ongoing process, a human endeavour; paradoxically, students tend to believe that science is a finished enterprise. Many non-science major students are not motivated in science classes; paradoxically, there is a public fascination with the possibility of life in the Universe, which is nowadays a scientific endeavour. An astrobiology course was developed at the Center for Science and Mathematics Education at The University of Texas at Austin to address these paradoxes and includes the following objectives: (a) to improve scientific literacy; (b) to demonstrate that science is a work in progress; (c) to enhance the inherent interdisciplinary aspect of science; (d) to demonstrate that science is embedded in society and relates with several social sciences; (e) to improve the content knowledge about the nature of science; (f) to illustrate how engaging learning science can be; and (g) to draw from the intrinsic motivation already incorporated in the general population. The course has been offered, taught and revised for the past three years. The informal course student feedback has been very positive and encouraging. The purpose of this paper is to provide a general overview of the course. In addition, the course's background, content, themes and mode of delivery are outlined, discussed and analysed in this paper. This paper subscribes to an educational philosophy that focuses on the multidisciplinary nature of science and includes critical thinking-based teaching strategies using the dynamic discipline of astrobiology.
EDITORIAL
Authors: MCCLARY SUSAN
Published: February 2009

John Dryden famously bowdlerized Shakespeare, whose plays violated his reason-governed tastes. That the author of such verse as ‘Happy, happy, happy pair! / None but the brave, / None but the brave, / None but the brave deserves the fair’ (Alexander’s Feast) should have found the rather stronger temperament and the complex plot ambiguities of his predecessor indigestible should come as no surprise. Because our educational processes have long since held up Shakespeare as the pinnacle of English-language literature, we tend to find Dryden’s fastidious attitude somewhat quaint – if, indeed, we remember it at all.
JOHANN SIGISMUND COUSSER, WILLIAM III AND THE SERENATA IN EARLY EIGHTEENTH-CENTURY DUBLIN
Authors: OWENS SAMANTHA
Published: February 2009

Among the holdings of Hamburg’s Staats- und Universitätsbibliothek Carl von Ossietzky is an anonymous fifty-two-page score headed ‘Serenata à 4’, described in the corresponding catalogue entry by its former owner, German musicologist Friedrich Chrysander (1826–1901), as a ‘cantata for the funeral of the English king William III of Orange, 1702’. But both the work’s text and the recent identification of the manuscript as being in the hand of Johann Sigismund Cousser (1660–1727) call for a reassessment of this serenata’s provenance, situating it in either England or Ireland between Cousser’s arrival in London on Christmas Day 1704 and the end of Queen Anne’s reign in 1714. Over the course of the two decades he resided in Ireland, from 4 July 1707 until his death, Cousser was responsible for the composition and musical direction of one ode and more than twenty serenatas, the majority of which were commissioned by the viceregal court at Dublin Castle for state celebrations of the reigning monarch’s birthday. Taking printed librettos, contemporary newspaper reports, Cousser’s own commonplace book and two further surviving manuscript scores as its primary evidence, this study seeks to establish a likely location and occasion for the performance of the ‘William III’ serenata within Dublin’s musical life during the early eighteenth century. In their choice of terminology, compositional style and performance practices, Cousser’s serenatas, which may have incorporated elements of theatrical staging and dancing, reveal his extensive Continental experience, and they can be seen to have functioned in part as an operatic substitute, presumably reflecting the limited financial resources of Dublin high society.
Thermal perturbations caused by large impacts and consequences for mantle convection
Authors: Watters W. A. , Zuber M. T. , Hager B. H.
Published: February 2009

We examine the effects of thermal perturbations on a convecting layer of incompressible fluid with uniform viscosity in the limit of infinite Prandtl number, for two upper boundary conditions (free‐ and no‐slip) and heat sources (100% volumetric heating and 100% bottom heating) in 2‐D Cartesian finite element simulations. Small, low‐temperature perturbations are swept into nearby downflows and have almost no effect on the ambient flow field. Large, high‐temperature perturbations are rapidly buoyed and flattened, and spread along the layer's upper boundary as a viscous gravity current. The spreading flow severs and displaces downwellings in its path, and also thins and stabilizes the upper thermal boundary layer (TBL), preventing new instabilities from growing until the spreading motion stops. A return flow driven by the spreading current displaces the roots of plumes toward the center of the spreading region and inhibits nascent plumes in the basal TBL. When spreading halts, the flow field is reorganized as convection reinitiates. We obtain an expression for the spreading time scale, ts, in terms of the Rayleigh number and a dimensionless perturbation temperature (Θ), as well as a size (Λ), and a condition that indicates when convection is slowed at a system‐wide scale. We also describe a method for calculating the heat deposited by shock waves at the increased temperatures and pressures of terrestrial mantles, and supply estimates for projectile radii in the range 200 to 900 km and vertical incident velocities in the range 7 to 20 km s−1. We also consider potential applications of this work for understanding the history of early Mars.
Canopy‐scale kinetic fractionation of atmospheric carbon dioxide and water vapor isotopes
Authors: Lee Xuhui , Griffis Tim J. , Baker John M. , Billmark Kaycie A. , Kim Kyounghee , Welp Lisa R.
Published: February 2009

The carbon and oxygen isotopes of CO2 and the oxygen isotopes of H2O are powerful tracers for constraining the dynamics of carbon uptake and water flux on land. The role of land biota in the atmospheric budgets of these isotopes has been extensively explored through the lens of leaf‐scale observations. At the ecosystem scale, kinetic fractionation is associated with molecular and turbulent diffusion. Intuitively, air turbulence, being nondiscriminative in diffusing materials, should act to erase the kinetic effect. Using the first canopy‐scale isotopic flux measurements, we show just the opposite: that in the terrestrial environment, air turbulence enhances the effect, rather than suppressing it. The sensitivity of kinetic fractionation to turbulence is striking in situations where the canopy resistance is comparable to or lower than the aerodynamic resistance. Accounting for turbulent diffusion greatly improves land surface model predictions of the isoforcing of 18O‐CO2 and transpiration enrichment of leaf water in 18O‐H2O in field conditions. Our results suggest that variations in surface roughness across the landscape can contribute to spatial variations in the composition of atmospheric 18O‐CO2 and that temporal trends in wind circulation on land can play a role in the interannual variability of atmospheric 18O‐CO2. In comparison, air turbulence has a limited effect on the isoforcing of 13C‐CO2.
A dynamically‐based method for forecasting tropical cyclogenesis location in the Atlantic sector using global model products
Authors: Wang Zhuo , Montgomery Michael T. , Dunkerton Timothy J.
Published: February 2009

A real‐time forecast method is developed for prediction of the tropical cyclogenesis location over the Atlantic using global model operational products. The method is based on the marsupial theory for tropical cyclogenesis proposed in a recent observational study. A moisture front is usually found ahead of the precursor wave trough, which separates the relatively dry air outside of the wave pouch (a region of closed circulation) from the relatively moist air inside the wave pouch. The propagation speed of the pouch can be determined by tracking the propagation of this moisture front, and the intersection of the critical surface and the trough axis pinpoints the predicted genesis location. Using the global model operational products the genesis location can be predicted up to three days in advance with an error less than 200 km, which can provide useful guidance for forecasters and flight planning.
Sea surface temperature control on the stable isotopic composition of rainfall in Panama
Authors: Lachniet Matthew S.
Published: February 2009

The climate dynamical controls on rainfall oxygen isotope values (δ18Orain) are poorly constrained in most areas. In Central America, rainfall variations are associated with sea surface temperature anomalies in the Pacific and Atlantic Oceans, yet the response inδ18Orainhas not been adequately investigated. Analysis of a 30‐year time series ofδ18Orainin Panama was used to test the hypothesis thatδ18Orainvariations are forced by anomalies in rainfall and sea surface temperatures (SSTAs) in the bordering tropical oceans. The results show thatδ18Orainvalues in Panama are positively (negatively) correlated with SSTAs in the Pacific Ocean (Caribbean Sea). The data are consistent with a dominant 'amount effect' whereby lowestδ18O values are associated with a northerly position of the Intertropical Convergence Zone when regional rainfall is high. The source effect (Caribbean vs. Pacific), as constrained by wind direction, does not appear to be an important control on the temporal variations inδ18Orain.
From concentric eyewall to annular hurricane: A numerical study with the cloud‐resolved WRF model
Authors: Zhou Xiaqiong , Wang Bin
Published: February 2009

Observations show that concentric eyewalls may lead to the formation of an annular hurricane (AH), but available radar and satellite images provide very limited information. By using the cloud‐resolved Weather Research and Forecasting (WRF) model, the transformation from a non‐AH to an AH through a concentric eyewall replacement cycle is simulated under a resting environment. The simulated hurricane experiences three distinct stages: the formation of a secondary eyewall, the eyewall replacement and the formation of an AH. The simulated eyewall succession and accompanying intensity change are qualitatively consistent with observations. The bottom‐up mixing of the elevated PV in the concentric eyewalls leads to the formation of an AH. The time of the transition from concentric eyewalls to the AH is less than 24 hours, suggesting that the concentric eyewall replacement is an efficient route to AH formation. The results demonstrate potential capability of the WRF model to predict concentric eyewall cycles, the formation of AHs and associated intensity changes.
Porosimetry of vesicular volcanic products by a water‐expulsion method and the relationship of pore characteristics to permeability
Authors: Yokoyama Tadashi , Takeuchi Shingo
Published: February 2009

Porosimetry of vesicular volcanic products was conducted by a water‐expulsion method to investigate the relationship between pore characteristics and gas permeability. The pores in a rock were categorized as total, connected, transport, dead‐end, and isolated pores. Gas flow takes place only through the transport pores but the pores that do not provide a flow path are included in both total and connected porosities. Permeability correlated weakly with total porosity, connected porosity, and transport porosity. The characteristic maximum pore‐throat radius rch (m) was also determined. Both rch and transport porosity correlated well with permeability k1 (m2) according to the following form of the Kozeny‐Carman relation: k1 = 0.0022ϕtrarch2. Permeability is thus strongly dependent on pore size, and estimation of pore size is essential for understanding the permeabilities of vesicular volcanic products.
Anthropogenic aerosols observed in Asian continental outflow at Jeju Island, Korea, in spring 2005
Authors: Sahu L. K. , Kondo Y. , Miyazaki Y. , Kuwata M. , Koike M. , Takegawa N. , Tanimoto H. , Matsueda H. , Yoon S. C. , Kim Y. J.
Published: February 2009

Anthropogenic aerosols were measured together with CO at Gosan (33°17′N, 126°10′E) on Jeju Island, South Korea, between 17 March and 5 April 2005. Outflow of these aerosols from the Asian continent was associated with a high‐pressure system centered over the northern region of China and Mongolia. Air masses are classified into five distinct categories on the basis of origin: marine, free troposphere, Yellow Sea, Korea, and China. The concentrations of aerosols and CO show large variations because of the alternation of air masses, while wet scavenging of aerosols was another important factor during precipitation events at Gosan. The average mass concentrations of black carbon (BC), organic carbon (OC), water‐soluble organic carbon (WSOC), and sulfate (SO42−) aerosols were 1.2 ± 0.8 μgC m−3, 4.2 ± 1.6 μgC m−3, 1.3 ± 1.0 μgC m−3, and 4.0 ± 3.4 μg m−3, respectively. Almost all species concentrations were highest in Chinese air masses, while they were lowest in marine air masses. The observed ΔBC/ΔCO slope of 9.7 ng m−3 ppbv−1 in Chinese outflow agrees reasonably with the estimates of the BC/CO emission ratios over northeastern China. The transport efficiencies of SOx (SO2 + SO42−) are calculated to be 40–45% from the observed SOx‐CO correlation. The relationships of the SO42−/BC and WSOC/BC ratios with transport time from the continent suggest that a majority of SO42− and WSOC aerosols were formed by about 1.5 days after the air masses left the East Asian continent.
Optical properties of atmospheric aerosols obtained by in situ and remote measurements during 2006 Campaign of Air Quality Research in Beijing (CAREBeijing‐2006)
Authors: Jung Jinsang , Lee Hanlim , Kim Young J. , Liu Xingang , Zhang Yuanhang , Hu Min , Sugimoto Nobuo
Published: February 2009

In order to investigate the optical properties of atmospheric aerosol in the urban area of Beijing, in situ and remote measurements of particulate pollutants were conducted at an urban site (39.98°N, 116.35°E, ∼20 m above ground level) in Beijing during the Campaign of Air Quality Research in Beijing (CAREBeijing) campaign from 16 August to 10 September 2006. During the intensive measurement period, average PM2.5 mass concentration and light extinction coefficient (bext) were measured to be 102.1 ± 55.0 μg m−3 and 880.7 ± 685.9 Mm−1, respectively. Average mass scattering efficiency of PM10 and PM2.5 particle were found to be 2.5 ± 1.1 and 3.4 ± 1.2 m2 g−1, respectively. Average single scattering albedo (SSA) of dry PM10 was characterized to be 0.82 ± 0.09. It was found that SSA decreased to lower values of ∼0.75 during the relatively clean condition while it increased up to ∼0.86 during polluted condition mainly owing to the increases of ammonium sulfate, ammonium nitrate, and organic mass by carbon's contributions to PM mass concentrations. Pollution episodes in Beijing were strongly related to wind speed and wind direction. Stagnant weather conditions with southerly wind and low wind speed accelerated the accumulation of the pollutants in Beijing, which led to severe haze. It has been found that high PM2.5/AOT (aerosol optical thickness) ratio of 228.2 μg m−3 was observed when air mass was transported from western or northern China while significantly lower PM2.5/AOT of 107.6 μg m−3 was observed when it was affected mostly by local air pollutants in Beijing.
Probabilistic description of topographic slope and aspect
Authors: Vico G. , Porporato A.
Published: February 2009

Local topographic features such as slope and aspect play a crucial role in a number of morphological, ecological, and hydrological processes. We propose a simple yet realistic probabilistic description of local slope and aspect as a function of properties of the field of elevation changes. We consider different classes of models of elevation changes and obtain the theoretical distribution of slope and aspect. We relate the features of the obtained distributions to large‐scale landscape structures, such as regional trends and anisotropy. We find that the theoretical distribution of slope is strongly impacted by the parameters used to represent the distribution of elevation changes, while large‐scale features play a secondary role. Conversely, the distribution of aspect is also controlled by regional trends and anisotopy, even when they are weak. The proposed statistical description of slope and aspect is applied to assess the effects of topographic features on direct solar radiation mean and standard deviation. The main control on direct solar radiation is exerted by the partial derivative variance. We consider four different landscapes across the continental United States and compare the proposed theoretical description of slope and aspect distributions to the observed histograms.
Simulation of the spatiotemporal aspects of land erodibility in the northeast Lake Eyre Basin, Australia, 1980–2006
Authors: Webb Nicholas P. , McGowan Hamish A. , Phinn Stuart R. , McTainsh Grant H. , Leys John F.
Published: February 2009

This paper explores spatiotemporal patterns in land erodibility in the northeast portion of the Lake Eyre Basin, Australia, using the Australian Land Erodibility Model (AUSLEM) in simulations from 1980 to 2006. First, spatial patterns in land erodibility are examined. We then present an analysis of seasonal and interannual variations in land erodibility. Patterns in land erodibility change are compared to rainfall variability, the El Niño–Southern Oscillation (ENSO) and Pacific (inter‐) Decadal Oscillation (PDO). Land erodibility is found to peak in the study area between early spring (September, October, November) and late summer (January, February, March), and reach a minimum over winter (June, July, August). Weak correlations are found between modeled land erodibility, rainfall, ENSO, and the PDO. The results indicate a complex landscape response to climate variability, with land erodibility dynamics being affected by antecedent rainfall and vegetation conditions which generate lag responses in land erodibility change. The research highlights the importance of developing methods for monitoring conditions driving variations in wind erosion at the landscape scale to enhance land management policy in arid and semiarid landscapes at a time of uncertain future climate changes.
Ductile shear zones related to crustal shortening and domain boundary evolution in the central Fennoscandian Shield
Authors: Högdahl Karin , Sjöström Håkan , Bergman Stefan
Published: February 2009

The Paleoproterozoic part of the Fennoscandian Shield is composed of crustal components formed in different tectonic settings and generally separated by well‐defined shear zone systems. An anomalous transitional boundary has been investigated by integrating structural analysis and geochronology with published geophysical data. The nature of this boundary is interpreted to be a consequence of an apparent stacking in the lower and middle crust initiating 1.87–1.86 Ga dextral shear along the Gävle‐Rättvik Zone (GRZ) and adjacent shear zones, resulting in an arcuate northern boundary of the Bergslagen province. This boundary coincides with geophysical anomalies and temporal and metamorphic breaks. Owing to continuous convergence the pure‐shear overprint component increased on the GRZ and caused a shift of dextral shear to the Hagsta Gneiss Zone with recorded shear at 1809 ± 2 Ma. Most likely, both these structures are related to coeval shear zones farther to the east as a part of an ∼1500 km long crustal, or possibly terrane, boundary.
Experiments in a high‐amplitude Kinoshita meandering channel: 2. Implications of bend orientation on bed morphodynamics
Authors: Abad Jorge D. , Garcia Marcelo H.
Published: February 2009

Experiments carried out under flat smooth bed condition in a periodic, asymmetric, Kinoshita meandering channel showed that bend skewness controls the three‐dimensional mean flow (e.g., primary and secondary flow) and turbulence structure (e.g., location of shear layers and turbulent shear stresses). In this paper, similar hydraulic conditions are used to perform movable‐bed experiments with uniform sediment size in order to study the effect of bend orientation on bed morphodynamics. Two main differences between the upstream‐ and downstream‐skewed meander configurations are found: (1) for the case of bends oriented upstream valley, the bed forms are produced just upstream of the bend apex, whereas for the case of bends oriented downstream valley they are observed around the upstream inflection point, and (2) the downstream‐skewed condition produces the deepest scour region, which is located downstream of the bend apex. A comparison with observations at two bends on the Wabash River, Illinois, shows some remarkable similarities with the bed morphology observed in the Kinoshita channel. Further analysis of the bed form celerity, bed load transport during evolution, and superimposition of migrating bed forms and their implications on bend migration are presented.
Estimating uncertainty of streamflow simulation using Bayesian neural networks
Authors: Zhang Xuesong , Liang Faming , Srinivasan Raghavan , Van Liew Michael
Published: February 2009

Recent studies have shown that Bayesian neural networks (BNNs) are powerful tools for providing reliable hydrologic prediction and quantifying the prediction uncertainty. The reasonable estimation of the prediction uncertainty, a valuable tool for decision making to address water resources management and design problems, is influenced by the techniques used to deal with different uncertainty sources. In this study, four types of BNNs with different treatments of the uncertainties related to parameters (neural network's weights) and model structures were applied for uncertainty estimation of streamflow simulation in two U.S. Department of Agriculture Agricultural Research Service watersheds (Little River Experimental Watershed in Georgia and Reynolds Creek Experimental Watershed in Idaho). An advanced Markov chain Monte Carlo algorithm, evolutionary Monte Carlo, was used to train the BNNs and to estimate uncertainty limits of streamflow simulation. The results obtained in these two case study watersheds show that the 95% uncertainty limits estimated by different types of BNNs are different from each other. The BNNs that only consider the parameter uncertainty with noninformative prior knowledge contain the least number of observed streamflow data in their 95% uncertainty bound. By considering variable model structure and informative prior knowledge, the BNNs can provide more reasonable quantification of the uncertainty of streamflow simulation. This study stresses the need for improving understanding and quantifying methods of different uncertainty sources for effective estimation of uncertainty of hydrologic simulation using BNNs.
Laboratory experiments on dispersive transport across interfaces: The role of flow direction
Authors: Berkowitz Brian , Cortis Andrea , Dror Ishai , Scher Harvey
Published: February 2009

We present experimental evidence of asymmetrical dispersive transport of a conservative tracer across interfaces between different porous materials. Breakthrough curves are measured for tracer pulses that migrate in a steady state flow field through a column that contains adjacent segments of coarse and fine porous media. The breakthrough curves show significant differences in behavior, with tracers migrating from fine medium to coarse medium arriving significantly faster than those from coarse medium to fine medium. As the flow rate increases, the differences between the breakthrough curves diminish. We argue that this behavior indicates the occurrence of significant, time‐dependent tracer accumulation in the resident concentration profile across the heterogeneity interface. Conventional modeling using the advection‐dispersion equation is demonstrated to be unable to capture this asymmetric behavior. However, tracer accumulation at the interface has been observed in particle‐tracking simulations, which may be related to the asymmetry in the observed breakthrough curves.
Who Influences Whom? Analyzing Workplace Referents’ Social Influence on it Adoption and Non-Adoption
Authors: Eckhardt Andreas , Laumer Sven , Weitzel Tim
Published: February 2009

Technology adoption research has long struggled to incorporate normative beliefs from sources in the social environment of adopters into adoption models. We study the role of social influence from different workplace referent groups, like superiors and colleagues from the same or the IT department, on the intention to adopt. An empirical analysis, using data from 152 firms, based on the Unified Theory of Acceptance and Use of Technology and related approaches reveals that social influence on adoption significantly differs with regard to both source (peer groups) and sink (adopters and non-adopters) of the influence. The results imply that a single cumulative subjective norm measure might be too naive and that future research might considerably improve our understanding of IT adoption and non-adoption by revealing the differential impact of various peer groups on adoption intention, and also on its antecedents.
Fabry–Pérot-type enhancement in plasmonic visible nanosource
Authors: Consonni Marianne , Hazart Jérôme , Lérondel Gilles
Published: February 2009

Starting from thin film planar technology, we designed and fabricated a visible optical source that produces a localized bright spot with nanometric dimensions. The structure consists of exciting surface plasmons through the illumination of a subwavelength hole in a silver film and in confining them at the vicinity of the aperture by surrounding the hole of Bragg mirrors resonant with the plasmons generated. Both finite element method computations and experimental results evidence the performances of this device that could find applications, for example, in nanolithography or optical data storage.
Adaptive interferometry with photorefractive crystals
Authors: Kamshilin Alexei A. , Romashko Roman V. , Kulchin Yuri N.
Published: February 2009

This work presents a review of progress and development in the field of adaptive laser interferometry. This method enables highly precise and reliable measurement of various physical parameters under unstable environmental conditions, which makes it very attractive for numerous industrial applications.
Multiple NMR spin echoes in magnets: The echo structure and potential applications
Authors: Akhalkatsi A. M. , Gavasheli T. A. , Gegechkori T. O. , Mamniashvili G. I. , Shermadini Z. G. , Clark W. G.
Published: February 2009

The results of a NMR study of the nature of main multiple nuclear spin-echo components in lithium ferrite are presented. It is shown that the strongly relaxing echo component in lithium ferrite is formed by the stimulated mechanism similar to the one observed in this material earlier for a single-pulse echo.
Magnetic glassy behavior in ferroelectric relaxor type solid solutions: Magnetoelectric relaxor
Authors: Cheng Z. X. , Wang X. L. , Alvarez G. , Dou S. X. , Zhang S. J. , Shrout T. R.
Published: February 2009

Perovskite solid solution ceramics with compositions of 0.9Pb(Fe0.5Nb0.5)O3–0.1PbTiO3, 0.6Pb(Ni1∕3Nb2∕3)O3–0.4PbTiO3, and 0.6Pb(Co1∕3Nb2∕3)O3–0.4PbTiO3 were synthesized by the traditional solid state reaction method. Ferroelectric measurements revealed that these samples have well saturated polarization-electrical field loops. Dielectric measurements showed that abnormal dielectric peaks at their Curie temperature were frequency dependent. Both characteristics indicate that these samples are relaxor type ferroelectric materials. Field cooled and zero field cooled magnetization measurements revealed that the 0.6Pb(Ni1∕3Nb2∕3)O3–0.4PbTiO3 and 0.6Pb(Co1∕3Nb2∕3)O3–0.4PbTiO3 samples are paramagnetic down to 5K, while the 0.9Pb(Fe0.5Nb0.5)O3–0.1PbTiO3 sample shows an antiferromagnetic-like ordering starting from around 40K. Furthermore, a weak ferromagnetism is observed in the 0.9Pb(Fe0.5Nb0.5)O3–0.1PbTiO3 sample, as evidenced by the magnetic hysteresis loop measured at 10K. The ac susceptibility measurement of this sample showed that the peak position around 40K is strongly dependent on frequency, indicating a glassy or relaxor type bahavior below that temperature. Therefore, relaxor type ferroelectric and magnetic 0.9Pb(Fe0.5Nb0.5)O3–0.1PbTiO3 is a magnetoelectric relaxor.
Formation and control of internal spin-wave channels in arrays of densely packed Permalloy nanowires
Authors: Topp Jesco , Podbielski Jan , Heitmann Detlef , Grundler Dirk
Published: February 2009

Broadband spin-wave spectroscopy is performed on two arrays of long 300-nm-wide Ni20Fe80 wires which exhibit two different edge-to-edge separations a of 700 and 200nm. When the in-plane field H⃗ is applied a few degrees off from the hard axis direction, an intermediate field regime is found where the central region and the edges of a wire are magnetized in different directions. Here, resonances are pronounced and reflect spin waves confined on the sub-100nm scale within a wire. For small a, the confinement effect is found to occur over a broad regime of H. These results are relevant for high-density integration of magnonic waveguides.
Alkanethiol induced changes in the magnetotransport properties of Co∕Au bilayers
Authors: Knaus B. , Garzon S. , Crawford T. M.
Published: February 2009

We demonstrate that chemisorption of a dodecanethiol (C12H25SH) self-assembled monolayer on the surface of a Au film alters the coercivity Hc of an underlying Co film, as measured using the planar Hall effect. Changes in Hc occur over a time scale of hours, and only when the thiolated devices are biased with perpendicular magnetic fields. While vacuum-stored samples show larger changes in Hc than those stored under ambient conditions, sample-sample variability persists. We hypothesize that the coercivity shifts are caused by magnetostatic fields originating at the Au-thiol interface, which affect the Co domain structure during magnetization reversal.
Paramagnetic spin dynamics in the nonhomogeneous crystals of low-doped lanthanum manganites
Authors: Auslender M. , Shames A. I. , Rozenberg E. , Gorodetsky G. , Mukovskii Ya. M.
Published: February 2009

The X-band electron paramagnetic resonance (EPR) technique and the model analysis of the EPR linewidth versus temperature were employed to characterize the dopant distribution in a number of La-manganite crystals, low doped with Ca, Sr, and Ba. Such distribution appears to be inhomogeneous in accordance with the results of previous study of EPR susceptibility. The technological originated competition between the quenching and annealing effects during the cooling of the crystals from the high temperatures seems to be the reason of their inherent inhomogeneity. It depends strongly on the dopant nature and, in the crystal doped with 15% of Ba, the inhomogeneity is small as compared to those in the Ca- and Sr-doped samples. It is emphasized that such chemical disorder influences strongly the crystal structure, magnetic state, and transport of these objects.
A novel simulation of air∕liquid bearings based on lattice Boltzmann method
Authors: Kim Dehee , Kim Woo Tae , Kim Hyung Min , Chen Haigang , Jain Parag , Jhon Myung S.
Published: February 2009

A novel three dimensional (3D) simulation tool based on lattice Boltzmann method (LBM), which is more efficient than the conventional computational fluid dynamics approach, was developed to analyze the head∕disk interface (HDI) dynamics. For handling general geometrical structures, Taylor series expansion and least squares based LBM was employed to simulate the flow conditions under a model slider. Truncated power-law and Bird–Carreau models were incorporated to capture the non-Newtonian fluid flow behavior of lubricant liquid film undergoing extremely high shear rates by modifying the relaxation time as a function of shear rate. After the benchmark study of two dimensional∕3D Poiseuille flows, pressure and shear profiles under the model slider were calculated for different constitutive relationships. The results indicate that our LBM techniques could be an attractive computational tool for next generation HDI design.