bluuebunny/crossref_metadata_2025 huggingface dataset:
The challenge of political change: urban history in the 1990s
Authors: Lees Lynn Hollen
Published: February 2009

Urban history is a rapidly expanding, flourishing field in Europe. Nevertheless, urban scholars would do well to re-examine the paradigms within which they have been working as the field today lacks central questions and general interpretive models. Moreover, the common focus on urban biography or upon one region within a single nation-state has become increasingly outmoded, given the international scale of economic processes and migration flows. More attention to topics treated within a European-wide or even international context is needed. In addition, urban history as currently defined is tilted towards social and economic concerns to the neglect of the political arena.
Urban hierarchies, typologies and classification in early medieval India: c. 750–1200
Authors: Thakur Renu
Published: February 2009

Architectural treatises and inscriptional evidence from buildings, artefacts and monuments are used to identify the different terms ascribed to urban settlements in medieval India. These sources reveal the diversity of terms used to describe towns and cities, and accordingly the diversity of functions associated with them. The linguistic variations employed indicate how urban functions changed over time, and convey contemporary perceptions of an urban hierarchy based on a functional classification or typology of towns.
Fellowship and family: oddfellows' lodges in Preston and Lancaster, c. 1830-c. 1890
Authors: D'cruze Shani , Turnbull Jean
Published: February 2009

Oddfellows' lodges in mid-nineteenth-century Lancaster and Preston offer fresh perspectives on affiliated friendly societies. These societies combined fraternal good fellowship with a hierarchical organization which operated on the assumption that members were breadwinners supporting dependants in nuclear family households. Despite the skilled or artisan occupational status of many oddfellows, their domestic economies often relied on more than one wage and complex household structures. Since oddfellows' households also clustered in certain neighbourhoods, social associations established by lodge membership overlapped with local networks. By considering these lodges less as bounded institutional entities and more as focuses for intersecting social networks where mores of respectablity and social identity were worked out, relations of gender and community as well as class, can be brought to bear on a historical appreciation of this topic.
Urban renewal and citizenship: the quality of life in British cities, 1890-1990
Authors: Meller Helen
Published: February 2009

This paper juxtaposes two key themes: the concept of citizenship and ideas on urban renewal over the past century. The aim is to explore the interaction of cultural changes and the physical environment of cities. The concept of citizenship represents a cultural response to social change which itself has changed dramatically over the past century. Urban renewal has taken many forms. Yet behind all the growing technical expertise in dealing with the physical environment, there are specific social responses to the city which legitimize action. By looking at citizenship and urban renewal together, it is possible to establish a perspective on how the urban environment has been manipulated over the past century, often in ways which have barely interfaced with the social demands of many sections of the community.
An eighteenth-century revolution? Investigating urban growth in north-west England, 1664–1801
Authors: Stobart Jon
Published: February 2009

The briefest inspection of the English urban hierarchy during the long eighteenth century reveals this as a period of immense change. However, regional analysis of the temporal and spatial patterns of these pre-census developments relies on using a variety of non-demographic sources to produce a series of urban demographic ‘snap-shots’ of the urban population. Employing this ‘demographic photography’ in early modern northwest England allows detailed investigation of the dynamics of the entire urban system. This reveals the deep roots of urban development in the region and points to an eighteenth-century urban revolution. Towns grew faster than the overall population, but this growth was unevenly distributed; both large and small towns exhibited strong and weak growth, making changes in the urban hierarchy inevitable and far-reaching. The most notable trend was the changing geography of the system: Cheshire towns grew far less rapidly than their increasingly industrial neighbours in Lancashire and the urban locus underwent a definite shift northwards. The fact that the urban patterns of growth appear to have preceded the period of maximum industrial growth by some forty to fifty years forces us to rethink the relationship between industrial and urban development.
German cities in the late early modern era: some problems and prospects
Authors: Friedrichs Christopher R.
Published: February 2009

Sources of information abound for the study of German urban demography in the ‘late’ early modern era – the period from about 1600 to 1800. Yet we are still a long way from a comprehensive grasp of urbanpopulation trends. Frequently-cited figures for the total population of German cities are often based on the uncritical replication of casual estimates. Intensive case studies which exploit the full range of available sources are more reliable, yet only the smallest towns can be subjected to the process of ‘total reconstitution’. A true understanding of German urban demography in the early modern era may come less from the endless accumulation of data than from a thoughtful comparison of findings from different cities.
Cities in the suburbs: heterogeneous communities on the US urban fringe, 1920–60
Authors: Borchert James
Published: February 2009

While the scholarly literature largely ignores issues of suburban population size, density and heterogeneity, during the 1920s a number of large, densely-settled, heterogeneous suburbs emerged on the fringe of the largest US cities. The article identifies forty-one of these potential ‘city suburbs’ which are defined as communities having minimum thresholds of 25,000 population and residential densities of 6,000 per square mile. City suburbs may have claimed nearly 25 per cent of the suburban populations of the nation's ten largest metropolitan districts. Drawing largely on data for midwestern cities, city suburbs are further identified through their diverse populations by class, ethnicity and race; varied housing stocks and economic activities including retailing, professional services and manufacturing; and political independence from their central city. Nearly equally divided between residential and industrial suburbs, the former, including Oak Park, Illinois, ‘fit’ traditional middle-class suburban descriptions while neighbouring Cicero represented workingclass, industrial communities.
Urban history and historical epidemiology: the case of London, 1860–1920
Authors: Luckin Bill , Mooney Graham
Published: February 2009

Advocating a closer relationship between urban and epidemiological history, the paper concentrates, firstly, on a critical overview of the McKeown thesis. It next identifies components from the work of John Landers as a means of constructing a structural model of mortality experienced during the period under review. The paper goes on to examine the manner in which this model might be applied to London during an era in which the classic killing infections of the mid-nineteenth century were gradually replaced by non-infectious causes of death. Returning, by way of conclusion, to the theme of an integration of urban and epidemiological methodologies, attention is drawn to the explanatory potential of a fully historical economy of health and disease.
Councillors and commerce in Liverpool, 1650–1750
Authors: Power Michael
Published: February 2009

Liverpool grew remarkably in the century after 1650 outpacing long-established ports like Bristol and Hull. In part this was due to advantages of location, in part to the ambitions of its merchants. The council opened a wet dock in 1715, a pioneering project which gave the port an unusual trading advantage. This paper explains that event by tracing the emergence of merchants on the council in the late seventeenth century and, by analysing port book evidence, argues that they assumed a trading dominance in the town which was especially strong about 1700. Their powerful position on the council was, in part, the result of a new town charter of 1695. Political and economic factors worked together to propel the town towards its spectacular eighteenth-century economic development.
Putting order into the cities: the evolution of ‘policy science’ in eighteenth-century Spain
Authors: Fraile Pedro
Published: February 2009

Urban growth revealed problems associated with the administration of mid-sixteenth-century cities. In the Mediterranean area, and especially in Spain and France, a discrete discourse emerged in the late seventeenth century as to how towns and cities should be organized and administered. Contained in numerous tracts and manuals were ‘policy science’ recommendations to deal with environmental health and related matters. This article examines the evolution of ‘policy science’ in Spain which achieved its greatest prominence during Carlos III's reign (1759–88). It is a field of study which offers insights into urban customs, behaviour and beliefs, and had important implications for the subsequent morphology of the Spanish city.
Representing Cape Town on the eve of apartheid
Authors: Bickford-Smith Vivian
Published: February 2009

This article attempts a detailed social portrait of Cape Town on the eve of apartheid. In the process it provides a rare cross-racial study of a twentieth-century South African city. The first section reveals a complex place already distinguished by considerable segregation and predictable social inequalities, both between and within racial and ethnic categories. Yet such findings are at odds with popular memories of a golden age – marked by tolerance, greater cohesion and security. So the second section explores and explains the differences. It finds that memories cannot simply be dismissed as myths.
Mutual aid and civil society: friendly societies in nineteenth-century Bristol
Authors: Gorsky Martin
Published: February 2009

Recent work on ‘civil society’ has made claims for the past capacity of mutual aid associations to generate ‘social capital’: self-help, trust, solidarity. Friendly societies in nineteenth-century Bristol are examined to test these claims. Their origins and growth are explored, as well as their membership and social, convivial and medical roles. Solidarities of class and neighbourhood are set against evidence of exclusion and division. Trust and close personal ties proved insufficient to avert the actuarial risks that threatened financial security.
Glasgow's public parks and the community, 1850–1914: a case study in Scottish civic interventionism
Authors: Maver Irene
Published: February 2009

From the mid-nineteenth century Glasgow's civic leaders recognized the effect that the rapidly deteriorating urban fabric was having on perceptions of the city, and began to construct a more positive identity, intended to inspire faith in municipal government. The landscape played a crucial part in selling this ideal. Parks were used as visible evidence of civic beneficence, and (deriving much influence from evangelical Presbyterianism) also served as a potent symbol of regeneration. However, while this paper considers the success of public parks in boosting Glasgow's image between 1850 and 1914, it also examines the complex material motivations originally underlying civic involvement, the impact of the environment in determining parks' policy and the influence of other British and European cities in shaping ideas.
‘The world economy is everywhere’: urban history and the world system
Authors: King A. D.
Published: February 2009

Even without the urban riots of 1980–1, there would be little disagreement that one, if not the major change in British cities since the war has been in the ethnic composition of their populations. The Black and Asian population of Britain, estimated at some 2.1 million in mid 1980 by the Office of Population Censuses and Surveys, and forming 3.9 per cent of the total population, compared with under 1.4 million (2.5 per cent) in 1971 and some 200,000 in 1951. The concentration of this population into four or five major conurbations where, until economic crisis brought unemployment, there was a high demand for labour, means that anywhere between 1 in 10 to 1 in 20 inhabitants of many towns is of so-called ‘New Commonwealth’ and Pakistan origin; in certain London boroughs, depending on definition, the figure might be 30 per cent.
The new urban history and its alternatives: some reflections on recent U.S. scholarship on the twentieth-century city
Authors: Mohl Raymond A.
Published: February 2009

Historians came late to the study of the American city. They lagged far behind scholars in other disciplines who, by the turn of the twentieth century, had begun to apply the tools of the social sciences to the examination of urban America and its problems. American urban history as a distinctive field of scholarly inquiry does not date much earlier than 1940, when Arthur M. Schlesinger, sr, published his landmark article on ‘The City in American History.’ Interest in the field grew rather slowly, however, and by the mid-1950s only a half-dozen or so universities offered courses in the subject. Progress in urban history research was also somewhat less than dynamic, the chief accomplishments being several fine urban biographies and a handful of monographs, notably the works of Carl Bridenbaugh on the colonial seaport towns, Oscar Handlin's study of Boston's immigrants, and Richard C. Wade's book,The Urban Frontier(1959).
Conference reports
Authors: Daunton Martin
Published: February 2009

The opening lecture of the conference was on a Scottish theme to complement the Scottish venue. Professor JOHN BUTT (Strathclyde) spoke on ‘Working-class housing in the Scottish cities 1900–51’. He began with a fairly traditional picture of working-class housing, which seemed to suggest that it was almost synonymous with slum-dwelling. He also outlined the system of house-letting which operated in Glasgow at the turn of the century, and suggested the impact on the housing market. This system was based upon yearly lets expiring at one date for all but thebottom of the market, where monthly lets were the norm. The main agitation for a change in the letting system came from the mostly ‘respectable’ tenants who occupied yearly-let property, as opposed to the slum-dwellers who rented on a monthly basis. (Regular attenders at the Urban History Group conferences will remember that these themes were discussed in the paper presented by Nick Morgan and Martin Daunton to the Loughborough meeting in 1981; they will also form a major element in Dr Englander's forthcoming book on Landlord and Tenant in Urban Britain 1838–1918.) Professor Butt went on to argue that during the rent strikes of the First World War, it is possible to see a clear distinction between the ‘landlord class’ and the ‘employer class’, the latter not always supporting the view of the former. The final part of the lecture considered the provision of new housing for the working classes after 1918. Detailed figures were provided to support the contention that the building industry and building supplies trade in Scotland were incapable of meeting the demand for new housing from the public sector during the 1930s. He illustrated his argument with specific examples of corporation house-building in Aberdeen, Glasgow, Dundee and Edinburgh.
Moving on from holes and corners: recent currents in urban archaeology
Authors: Robertson J. C.
Published: February 2009

Urban archaeology offers distinctive readings of urban histories: we have too few of those to ignore fresh insights. Half a dozen recent books offer a sample from a fertile field. The pressures of modern urban development, with the fundamental incompatibility of today's foundations with the ‘soft fill’ of archaeological deposits, have obliged urban archaeology to be a public discipline. Urban archaeology has stayed in the limelight, not only through sympathetic coverage on television and radio over continuing crises, like the recent unpredicted discoveries at the Rose Playhouse site, but also through popular books — like Richard Hall's glossy paperback on York's Coppergate excavations. Much of this material, however, does more than demonstrate how far passion can make urban excavations into journalistic copy. Methodologies, research priorities and interpretations are all subject to argument. Urban archaeology offers an approach to the urban past, but it is also an urban phenomenon in its own right.
The spatial configuration of class solidarity in London's West End 1792–1939
Authors: Atkins P. J.
Published: February 2009

For more than two hundred years after the Glorious Revolution, the British aristocracy gained control of ‘every aspect of government, both executive and legislative. They dominated the Cabinet, the highest ranks of the armed forces, the civil service and, to a lesser extent, the judiciary’. During the eighteenth and early nineteenth centuries there was a shift in their centre of gravity from that of a rural elite, to a group whose influence was mediated increasingly through the manipulation of the levers of power embedded in the urban system. This urbanization of their consciousness was coupled with, and partly responsible for, a scale jump in their collectivity. By 1850 it was no longer true that ‘society’ owed its allegiance to the local ‘county’ circles. Bush suggests that for the aristocratic class there developed in the nineteenth century a nationwide, shared ethos and culture. This was fostered on the proverbial playing fields of the nascent public schools, but it is the thesis of this paper that the spatiality of the West End of London was also a major factor in what amounts to a process of class formation for the disparate social factions which were eventually moulded into a coalition of the British ruling classes. Such was the binding quality of the social cement manufactured in the West End that it was able to withstand the aggressive solvent of industrial capitalism for something approaching a century.
Small-town conflict in the later Middle Ages: events at Shipston-on-Stour
Authors: Dyer Christopher
Published: February 2009

The seventeenth-century Worcestershire antiquarian Thomas Habington knew of great agitations around 1400 at Shipston-on-Stour, a manor of Worcester Cathedral Priory. He reported that after an arbitration of 1405–6 ‘the discontented tenants not satisfied broke out against their lord again, but all these being long since buried, shall not be revived by my pen, which shall never prejudice or blot any with infamy’. This article will rescue the rebels from the oblivion to which Habington sought to condemn them. This is not just to correct his bias (as a recusant he sympathized with Benedictine monks; as a member of the gentry he disliked disturbance of the social order), but more to use the Shipston story to investigate general problems of urban conflict in the Middle Ages.
Planning versus administration: The Independent City Planning Commission in Cincinnati, 1918–1940
Authors: Burnham Robert A.
Published: February 2009

City planning has become such an acknowledged function of city government that today we tend to take the city planning commission for granted as a logical part of the city government. Pioneers in the city planning movement in the United States at the turn of the century, however, had yet to decide upon the proper vehicle for carrying out city planning. Although in the early years of the movement a variety of methods were tried, including private planning associations, planning conducted by a committee of city council, and city planning conducted by a single city official, the most common agency of planning to emerge out of this period was the city planning commission.
Geometry of the Hikurangi subduction thrust and upper plate, North Island, New Zealand
Authors: Barker Daniel H. N. , Sutherland Rupert , Henrys Stuart , Bannister Stephen
Published: February 2009

We use 2800 line km of seismic reflection data to map the offshore character and geometry of the Hikurangi subduction thrust and outer forearc wedge to depths of ∼15 km. For 200 km along‐strike south of Hawke Bay, the subduction thrust is relatively smooth, dips less than 8°, and the wedge is characterized by accretion of young sediment and topographic slopes of less than 3°. In Hawke Bay and north for 200 km, a kink in the subduction thrust is apparent, with a downdip increase in dip to angles greater than 8° at depths of 10–15 km; there is a corresponding steepening of the topographic slope to greater than 3° outboard of the kink and the wedge is characterized by lithified sedimentary rock and slope failure. The kink in the subduction thrust is a locus of inherent weakness in the subducting slab; we suggest its occurrence relates to a northward increase in subduction rate that controls initial slab dehydration and fluid release rates and hence intraslab deformation patterns. The subduction thrust geometry, in combination with a northward increase in subducting plate roughness and decrease in the amount of sediment accreted, causes the observed spatial change in character of the subduction thrust and forearc wedge.
Array rotation aperture synthesis for short‐range imaging at millimeter wavelengths
Authors: Lucotte B. M. , Grafulla‐González B. , Harvey A. R.
Published: February 2009

Millimeter‐wave interferometric synthetic aperture imagers are currently being developed for short‐range applications such as concealed weapons detection. In contrast to the traditional snapshot imaging approach, we investigate the potential of mechanical scanning between the scene and the array in order to reduce the number of antennas and correlators. We assess the trade‐off between this hardware reduction, the radiometric sensitivity and the imaging frame rate of the system. We show that rotational scanning achieves a more uniform coverage of the (u, v) plane than the more conventional linear scanning. We use a genetic algorithm to optimize two‐dimensional arrays for maximum uniform (u, v) coverage after a rotational mechanical scan and demonstrates improvements in the array point spread function. Imaging performance is assessed with simulated millimeter‐wave scenes. Results show an increased image quality is achieved with the optimized array compared with a conventional power law Y‐shaped array. Finally we discuss the increased demands on system stability and calibration that the increased acquisition time of the proposed technique places.
Global Methan Emissions From Wetlands, Rice Paddies, and Lakes
Authors: Zhuang Qianlai , Melack John M. , Zimov Sergey , Walter Katey M. , Butenhoff Christopher L. , Khalil M. Aslam K.
Published: February 2009

The current concentration of atmospheric methane is 1774±1.8 parts per billion, and it accounts for 18% of total greenhouse gas radiative forcing [Forster et al., 2007]. Atmospheric methane is 22 times more effective, on a per‐unit‐mass basis, than carbon dioxide in absorbing long‐wave radiation on a 100‐year time horizon, and it plays an important role in atmospheric ozone chemistry (e.g., in the presence of nitrous oxides, tropospheric methane oxidation will lead to the formation of ozone). Wetlands are a large source of atmospheric methane, Arctic lakes have recently been recognized as a major source [e.g., Walter et al., 2006], and anthropogenic activities—such as rice agriculture—also make a considerable contribution.
Magnetic and magnetorheological characterization of a polymer liquid crystal ferronematic
Authors: Santiago-Quiñones Darlene I. , Acevedo Aldo , Rinaldi Carlos
Published: February 2009

Cobalt ferrite (CoFe2O4) nanoparticles (∼12nm diameter) were suspended in the polymer liquid crystal hydroxypropyl cellulose (HPC)∕m-cresol to obtain a new type of ferronematic. Suspension of these particles in 35%wt HPC in m-cresol did not affect the appearance of the liquid crystalline phase as evidenced by small angle x-ray scattering. Magnetic measurements performed on the 35%wt HPC∕m-cresol∕CoFe2O4 ferronematic showed the appearance of ferromagnetic behavior and magnetic hysteresis. In addition, rheometry of the samples showed magnetorheological effect upon application of a dc magnetic field, with the ferronematic having the largest response.
Artificial neural network based torque calculation of switched reluctance motor without locking the rotor
Authors: Kucuk Fuat , Goto Hiroki , Guo Hai-Jiao , Ichinokura Osamu
Published: February 2009

Feedback of motor torque is required in most of switched reluctance (SR) motor applications in order to control torque and its ripple. An SR motor shows highly nonlinear property which does not allow calculating torque analytically. Torque can be directly measured by torque sensor, but it inevitably increases the cost and has to be properly mounted on the motor shaft. Instead of torque sensor, finite element analysis (FEA) may be employed for torque calculation. However, motor modeling and calculation takes relatively long time. The results of FEA may also differ from the actual results. The most convenient way seems to calculate torque from the measured values of rotor position, current, and flux linkage while locking the rotor at definite positions. However, this method needs an extra assembly to lock the rotor. In this study, a novel torque calculation based on artificial neural networks (ANNs) is presented. Magnetizing data are collected while a 6/4 SR motor is running. They need to be interpolated for torque calculation. ANN is very strong tool for data interpolation. ANN based torque estimation is verified on the 6/4 SR motor and is compared by FEA based torque estimation to show its validity.
Ferromagnetism of manganese-doped indium tin oxide films deposited on polyethylene naphthalate substrates
Authors: Nakamura Toshihiro , Isozaki Shinichi , Tanabe Kohei , Tachibana Kunihide
Published: February 2009

Mn-doped indium tin oxide (ITO) films were deposited on polyethylene naphthalate (PEN) substrates using radio-frequency magnetron sputtering. The magnetic, electrical, and optical properties of the films deposited on PEN substrates were investigated by comparing with the properties of films grown on glass substrates at the same growth conditions. Thin films on PEN substrates exhibited low electrical resistivity of the order of 10−4 Ω cm and high optical transmittance between 75% and 90% in the visible region. Ferromagnetic hysteresis loops were observed at room temperature for the samples grown on PEN substrates. Mn-doped ITO films can be one of the most promising candidates of transparent ferromagnetic materials for flexible spintronic devices.
Pseudoheating of protons in the presence of Alfvénic turbulence
Authors: Wang C. B. , Wu C. S.
Published: February 2009

The possibility of heating of protons via Alfvén waves is a topic that stimulates much discussion in both plasma physics and astrophysics. Conventional thinking is that dissipation is essential for heating. In two recent discussions it is shown that turbulent Alfvén waves can enhance stochastic particle motion via scattering. This process can lead to a higher proton temperature. In this Letter two essential points are stressed: First, there is no dissipation; second, physically the temperature increment is “apparent” rather than genuine, and consequently the heating is spurious. If the turbulent wave field should diminish, the proton temperature returns to its original value. The purpose of this communication is to elucidate and explain the above points.
Molecular orientation studies by pulsed electron-electron double resonance experiments
Authors: Marko A. , Margraf D. , Yu H. , Mu Y. , Stock G. , Prisner T.
Published: February 2009

Pulsed electron-electron double resonance (PELDOR) has proven to be a valuable tool to measure the distribution of long range distances in noncrystalline macromolecules. These experiments commonly use nitroxide spin labels as paramagnetic markers that are covalently attached to the macromolecule at specific positions. Unless these spin labels are flexible in such a manner that they exhibit an almost random orientation, the PELDOR signals will—apart from the interspin distance—also depend on the orientation of the spin labels. This effect needs to be considered in the analysis of PELDOR signals and can, moreover, be used to obtain additional information on the structure of the molecule under investigation. In this work, we demonstrate that the PELDOR signal can be represented as a convolution of a kernel function containing the distance distribution function and an orientation intensity function. The following strategy is proposed to obtain both functions from the experimental data. In a first step, the distance distribution function is estimated by the Tikhonov regularization, using the average over all PELDOR time traces with different frequency offsets and neglecting angular correlations of the spin labels. Second, the convolution relation is employed to determine the orientation intensity function, using again the Tikhonov regularization. Adopting small nitroxide biradical molecules as simple examples, it is shown that the approach works well and is internally consistent. Furthermore, independent molecular dynamics simulations are performed and used to calculate PELDOR signals, distance distributions, and orientational intensity functions. The calculated and experimental results are found to be in excellent overall agreement.
Intensity analysis and energy-level modeling of Nd3+ in Nd3+:Y2O3 nanocrystals in polymeric hosts
Authors: Nash Kelly L. , Dennis Robert C. , Gruber John B. , Sardar Dhiraj K.
Published: February 2009

Optical absorption and emission intensities are investigated for Nd3+ in nanocrystalline Nd3+:Y2O3. Room temperature absorption intensities of Nd3+(4f3) transitions in synthesized Nd3+:Y2O3 nanocrystals have been analyzed using the Judd–Ofelt (J-O) approach to obtain the phenomenological intensity parameters. The J-O intensity parameters are used to calculate the spontaneous emission probabilities, radiative lifetimes, and branching ratios of the Nd3+ transitions from the upper multiplet manifolds to the corresponding lower-lying multiplet manifolds L2S+1J of Nd3+(4f3). The emission cross sections and room temperature fluorescence lifetimes of the important intermanifold F43/2→I4J (J=9/2,11/2,13/2,15/2) transitions have been determined. We also compare the spectra of the Nd3+:Y2O3 nanocrystals to those of the nanocrystals embedded in polymeric matrices of epoxy and chitosan, and we find similarities in terms of the detailed Stark energy levels of the Nd3+ ion in the Y2O3 nanocrystalline host. The 300 K spectra are analyzed for the energy (Stark) level transitions between the L2S+1J multiplet manifolds of Nd3+(4f3). The results of this study are also compared with a crystal-field splitting analysis reported earlier for single-crystal Nd3+:Y2O3 grown by a modified flame fusion method. We find that the spectroscopic properties of our nanocrystals embedded in polymeric hosts compare favorably with other ceramic and single-crystal forms of Nd3+:Y2O3 currently available.
All-inorganic spin-cast nanoparticle solar cells with nonselective electrodes
Authors: Anderson I. E. , Breeze A. J. , Olson J. D. , Yang L. , Sahoo Y. , Carter S. A.
Published: February 2009

Spin-cast all-inorganic nanoparticle solutions have been used to make a CdTe/CdSe solar cell with an efficiency of up to 2.6% using air stable electrodes and without an additional alumina layer. The type of junction as well as the nonselective nature of the electrodes of these devices are explored.
Cylindrically symmetric viscous fluid universe in Lyra geometry
Authors: Pradhan Anirudh
Published: February 2009

A new class of cylindrically symmetric homogeneous cosmological models for viscous fluid distribution is obtained in the context of Lyra’s geometry. We have obtained solutions by considering the time dependent displacement field. To get the deterministic solutions of Einstein’s modified field equations, the free gravitational field is assumed to be of type D which is of the next order in the hierarchy of Petrov classification. It has been found that the displacement vector β(t) behaves like cosmological term Λ in the normal gauge treatment and the solutions are consistent with the observations. The displacement vector β(t) affects entropy. Some physical and geometrical properties of the models are discussed.
Aging investigation of biocompatible magnetic fluids modulated by sample dilution
Authors: Oliveira F. M. L. , Canizares A. P. , Figueiredo L. C. , Neto K. Skeff , Morais P. C.
Published: February 2009

In this study static magnetic birefringence (SMB) was used to investigate the effects of aging of two biocompatible magnetic fluid (BMF) samples after dilution with pure water. The two BMF samples are based on dimercaptosuccinic-coated maghemite nanoparticles, with very similar average core diameters (7.2 and 7.9 nm) but presenting different dimercaptosuccinic acid surface grafting coefficients. Stock samples were submitted to different degrees of dilution and left to age on shelve before recording the SMB signal. Changes in the diluted and aged samples were evaluated via the average Q-cluster size value (⟨Q⟩) and Q-cluster size-dispersion value (σQ) related to a log-normal distribution function P(Q). The ⟨Q⟩ and σQ values were obtained from the analysis of the SMB signal. We found strong evidences that the higher the dilution and the higher the surface grafting coefficient the lower both the ⟨Q⟩ and σQ values.
A one-dimensional free energy surface does not account for two-probe folding kinetics of protein α3D
Authors: Liu Feng , Dumont Charles , Zhu Yongjin , DeGrado William F. , Gai Feng , Gruebele Martin
Published: February 2009

We present fluorescence-detected measurements of the temperature-jump relaxation kinetics of the designed three-helix bundle protein α3D taken under solvent conditions identical to previous infrared-detected kinetics. The fluorescence-detected rate is similar to the IR-detected rate only at the lowest temperature where we could measure it (326 K). The fluorescence-detected rate decreases by a factor of 3 over the 326–344 K temperature range, whereas the IR-detected rate remains nearly constant over the same range. To investigate this probe dependence, we tested an extensive set of physically reasonable one-dimensional (1D) free energy surfaces by Langevin dynamics simulation. The simulations included coordinate- and temperature-dependent roughness, diffusion coefficients, and IR/fluorescence spectroscopic signatures. None of these can reproduce the IR and fluorescence data simultaneously, forcing us to the conclusion that a 1D free energy surface cannot accurately describe the folding of α3D. This supports the hypothesis that α3D has a multidimensional free energy surface conducive to downhill folding at 326 K, and that it is already an incipient downhill folder with probe-dependent kinetics near its melting point.
High resolution in situ magneto-optic Kerr effect and scanning tunneling microscopy setup with all optical components in UHV
Authors: Lehnert A. , Buluschek P. , Weiss N. , Giesecke J. , Treier M. , Rusponi S. , Brune H.
Published: February 2009

A surface magneto-optic Kerr effect (MOKE) setup fully integrated in an ultrahigh vacuum chamber is presented. The system has been designed to combine in situ MOKE and scanning tunneling microscopy. Magnetic fields up to 0.3 T can be applied at any angle in the transverse plane allowing the study of in-plane and out-of-plane magnetization. The setup performance is demonstrated for a continuous film of 0.9 monolayers (ML) Co/Rh(111) with in-plane easy axis and for a superlattice of nanometric double layer Co islands on Au(11,12,12) with out-of-plane easy axis. For Co/Au(11,12,12) we demonstrate that the magnetic anisotropy energies deduced from thermally induced magnetization reversal and from applying a torque onto the magnetization by turning the field are the same. For the presented setup we establish a coverage detection limit of 0.5 ML for transverse and 0.1 ML for polar MOKE. For island superlattices with the density of Co/Au(11,12,12), the latter limit corresponds to islands composed of about 50 atoms. The detection limit can be further reduced when optimizing the MOKE setup for either one of the two Kerr configurations.
Voltage thresholdlike evidence during thermal-electric field induction of second order nonlinearity in soda-lime glasses
Authors: Moura A. L. , Nascimento E. M. , Araujo M. T. , Vermelho M. V. D. , Aitchison J. S.
Published: February 2009

Thermal-electric field poling of soda-lime glasses with modulated applied voltage based on the peculiar dependence of the electroluminescence activation energy is investigated. The second order nonlinearity (SON) stability upon infrared laser pump has show an abrupt change for poling voltage of ∼900V. The contributions to the onset of the SON are treated concerning the general random-energy model for ionic transport in ionic glasses. Corona effect and electroluminescence in thermal-electric field poling in soda-lime glasses are also investigated. The corona and electroluminescence spectra exhibit noticeable difference only in the 185–300nm region where the former is absent.
On Greenwald density limit in H-mode
Authors: Tokar M. Z.
Published: February 2009

The experimental Greenwald density limit in tokamak H-mode is explained from the requirements that in the edge transport barrier the radial pressure gradient does not exceed the ballooning stability threshold and the plasma collisionality corresponds to the transition from the plateau regime of neoclassical transport to the Pfirsch–Schlüter one, where the edge temperature and plasma energy content decrease dramatically with increasing density.
Multiple deformation mechanisms of Ti–22.4Nb–0.73Ta–2.0Zr–1.34O alloy
Authors: Yang Y. , Li G. P. , Cheng G. M. , Li Y. L. , Yang K.
Published: February 2009

Ti–22.4Nb–0.73Ta–2.0Zr–1.34O (at. %) alloy after cold compression to ∼5.2% strain was investigated. The alloy exhibited multiple plastic deformation mechanisms, including the stress-induced α″ martensitic (SIM α″) and ω phase transformations, 1/2⟨111⟩ dislocations slipping on the {112}β planes as well as {332}⟨113⟩β and {112}⟨111⟩β twinning, which have not previously been reported to coexist in a titanium alloy. It was also found that β phase with the {200} planes vertical to the compression direction was almost completely consumed away by a β→SIM α″ transformation, and a (100) texture of SIM α″ formed.
A comparative study of organic single-crystal transistors gated with various ionic-liquid electrolytes
Authors: Ono S. , Miwa K. , Seki S. , Takeya J.
Published: February 2009

We report on a comparative study of rubrene single-crystal field-effect transistors with various ionic-liquid electrolytes used for gate insulators. A systematic correlation is found that mobility of the field-effect transistors increases with decreasing electrostatic capacitance of the electric double layers, as the result of highly reproducible comparisons among tens of samples with the variation of anions in the purified ionic liquids. By optimizing the gating ionic liquid, the highest mobility of the electrolyte-gated organic transistors elevated up to 9.5 cm2/V s, which is only a fraction of the value of intrinsic material property, demonstrating an excellent field-effect switching operation.
Mode locking of a GaInN semiconductor laser with an internal saturable absorber
Authors: Yoshita Masahiro , Kuramoto Masaru , Ikeda Masao , Yokoyama Hiroyuki
Published: February 2009

We demonstrated the mode locking of an external-cavity 404 nm GaInN semiconductor laser diode with an internal saturable absorber layer for the first time. Stable passive mode locking was confirmed at a repetition rate of 840 MHz. Furthermore, hybrid mode-locking operation incorporating rf current modulation generated optical pulses of 20 ps duration and 0.4 W peak power.
Chemical sensing in slotted photonic crystal heterostructure cavities
Authors: Di Falco A. , O’Faolain L. , Krauss T. F.
Published: February 2009

We fabricated slotted photonic crystal waveguides and cavities supporting resonant modes in air. Their peculiar geometry enables the detection of refractive index changes in a given analyte with high sensitivity because of the large overlap between the optical mode and the analyte. This yields a high figure of merit for the sensitivity of the device and we are able to report values of S=Δλ/Δn over 1500. By applying a photonic crystal heterostructure to the slotted geometry, we are able to create high quality-factor cavities essential for realizing low detection limits up to Q=50 000.
Enhanced resolution and high aspect-ratio semiconductor nanopatterning by metal overcoating
Authors: Hayat Alex , Berkovitch Nikolai , Orenstein Meir
Published: February 2009

We present a focused ion beam semiconductor nanopatterning technique enabling high resolution and high-aspect ratios. Undesired semiconductor material removal due to residual lower-intensity ion beam tails is prevented by a 20 nm slow-etch-rate TiO2 layer acting as an effective saturated-absorber dynamic mask. Resulting semiconductor features smaller than 30 nm and deeper than 350 nm correspond to aspect ratio higher than 10, while for larger features the aspect ratio can be as high as 15. The experimentally demonstrated results are in good agreement with the theoretical predictions. A transmission spectrum of a microcavity realized by this method conforms to numerical calculation results.
Tunneling spectroscopy in core/shell structured Fe/MgO nanospheres
Authors: Martínez-Boubeta C. , Balcells Ll. , Monty C. , Ordejon P. , Martínez B.
Published: February 2009

We report on tunneling conductance properties of a single Fe island enclosed by an epitaxial MgO shell. The results obtained show clear oscillations in the current-voltage curves that, along with the theoretical modeling, allow determining the electronic density of states of the iron core. Moreover, the correlation of these results with the temperature dependence of the electrical conductivity of assemblies of Fe/MgO nanocrystals provides evidence of the Δ1 symmetry-sensitive tunneling across a crystalline magnesia barrier.
In situ extended x-ray absorption fine structure study of initial processes in CdSe nanocrystals formation using a microreactor
Authors: Uehara M. , Sun Z. H. , Oyanagi H. , Yamashita K. , Fukano A. , Nakamura H. , Maeda H.
Published: February 2009

The nucleation process of CdSe nanocrystals is studied by fluorescence-detected extended x-ray absorption fine structure (EXAFS) using a microreactor and synchrotron radiation. Detailed analysis of in situ Se K-edge EXAFS data measured along a microreactor channel revealed a strong position-dependence which displays a rapid increase in the CdSe phase with time at the initial stage. The results indicate that the CdSe nucleation completes within several seconds starting from trioctylphosphine Se solution and dodecylamine surfactant at 240 °C. This shows the promising capability of in situ EXAFS combined with a microreactor to investigate the nucleation process of nanocrystals synthesized in a solvent.
Controlled Synthesis of One-Dimensional Single-Crystal Co3O4 Nanowires
Authors: Du Jin , Chai Lanlan , Wang Gongming , Li Kai , Qian Yitai
Published: February 2009

Uniform Co3O4 nanowires with diameters of ~80 nm and lengths of 10–20 μm have been prepared by a hydrothermal reaction and sequential decomposition of the intermediate product. Transmission electron microscopy characterization and selected-area electron diffraction patterns show that the nanowires elongate along the [110] direction. The amount of CO(NH2)2 employed and the heating rate of calcination have a key effect on the morphology of the product. In addition, analysis of the optical properties indicates a blue shift of the bandgaps and reveals the semiconductive nature of the products.
Attempts to Mimic Key Bond-Forming Events Associated with the Proposed Biogenesis of the Pentacyclic Lamellarins
Authors: Axford Lorraine C. , Holden Kate E. , Hasse Katrin , Banwell Martin G. , Steglich Wolfgang , Wagler Jörg , Willis Anthony C.
Published: February 2009

The pyrrole-tethered veratroles 16 and 27 each engage in PIFA-induced oxidative cyclization reactions to give compounds 22 and 29, respectively, which incorporate a key tricyclic fragment associated with the title natural products. In contrast, the corresponding catechols 11 and 12 only produce polymeric materials on subjection to analogous reaction conditions. Efforts to study lactone ring formation by the oxidative cyclization of catechol 30 and veratrole 38 have been thwarted by an inability to prepare the former substrate and decomposition of the latter. The reported conversions 44 → 45 and 46 → 47 suggest that a C2-carboxy group attached to the pyrrole ring can ‘direct’ the oxidative cyclization of N-tethered aryl groups. The acquisition of compound 22 by the means described herein provides an adventitious and concise route to the racemic modification of the pyrrolo[2,1-a]isoquinoline alkaloid crispine A (52).
Synthesis of Succinimidoalkylbenzaldehyde Analogues: Potential Bifunctional Linkers for Bioconjugation
Authors: Crosby Ian T. , Pietersz Geoffrey A. , Ripper Justin A.
Published: February 2009

A series of novel 4-substituted benzaldehydes containing a succinimide moiety were synthesized as potential bifunctional linkers for the purpose of binding therapeutic drugs to antibodies raised against cancer cells. These potential benzaldehyde linkers varied in the nature of the para functionality so as to provide a range of potential acid labilities. Synthesis of the linkers involved a Williamson ether formation to make the ether linker 1, a Sonagoshira palladium-catalyzed coupling to synthesize the skeleton of the alkyl linker 2, and formation of an amide bond directly from a methyl ester gave the 4-substituted amide linker 3. As an example of the type of acetal that can be produced using these linkers, uridine was used as an analogue of the cytotoxic compound 5-fluorouridine to give the cyclic acetals 19–21.
Mg2Cl5 - and Mg3Cl7 - Superhalogen Anions
Authors: Anusiewicz Iwona
Published: February 2009

The vertical electron detachment energies of Mg2Cl5– and Mg3Cl7– superhalogen anions were calculated at the outer valence Green function level with 6–311+G(3df) basis sets. These species were found to form rather unusual geometrical structures, each of which corresponds to a stable anionic state exhibiting superhalogen nature. The global minimum structure of Mg2Cl5– was found to possess D3h symmetry, which can be described as a system in which two central magnesium atoms are linked via a symmetrical triangle formed by three chlorine atoms, whereas the lowest-energy structure for Mg3Cl7– was found to have C3v symmetry, which can be viewed as a fragment of chloromagnesite crystal lattice. Extremely large electron binding energies of these anions (exceeding 6.5 eV in all cases) were predicted and discussed.