bluuebunny/crossref_metadata_2025 huggingface dataset:
THE REFORMATION OF ENGLISH ADMINISTRATIVE LAW? “RIGHTS”, RHETORIC AND REALITY
Authors: Varuhas Jason N.E.
Published: July 2013

This article examines and responds to a doctrinal claim, made by an increasing number of commentators, that English administrative law is in the midst of a “reformation” or “reinvention”, with the notion of “rights” at the heart of this radical recalibration. The article is critical of such claims on several grounds. First, these claims are steeped in ambiguity, such that the nature and doctrinal scope of the claimed metamorphosis are not clear. Second, these commentators have not undertaken the sort of detailed doctrinal analysis which is required to make credible claims about the development of the law, meaning their broad claims have a strong propensity to mislead, and pass over the nuances and complexities of doctrine. An analysis of significant features of doctrine tends to tell against a wholesale recalibration of administrative law around rights, and indicates an increasingly pluralistic rather than unitary legal order. Third, despite the centrality of the idea of “rights” to their claims, these commentators do not squarely address what they mean by “rights”, in general using the term indiscriminately, and thereby plunging their claims into uncertainty. The article demonstrates the importance of conceptual clarity in analysing “rights”-based developments through a doctrinal analysis of “rights” in administrative law, conducted through the prism of W.N. Hohfeld's analytical scheme.
New species ofStygiopontius(Copepoda: Siphonostomatoida: Dirivultidae) from a deep-sea hydrothermal volcano in the New Ireland Fore-Arc system (Papua New Guinea)
Authors: Ivanenko Viatcheslav N. , Ferrari Frank D.
Published: July 2013

A male of the new speciesStygiopontius senckenbergibelonging to the family Dirivultidae Humes & Dojiri, 1980 (Copepoda: Siphonostomatoida) and endemic to deep-sea hydrothermal vents, is described from a raised fault block structure south of Edison seamount of the New Ireland Fore-Arc system (Papua New Guinea). The copepods were collected in by box-corer during cruise SO-133 of the RV ‘Sonne’ at a depth of 1610–1625 m, 3°19′S 152°35′E. The new species belongs to a group of eight species that are separate from 21 congeners on the basis of setation of legs 1 and 4: the coxa of leg 1 has an inner seta (absent on the others) and the third exopodal segment of leg 4 has three outer spines (instead of two spines). The new species shares withS. pectinatusHumes, 1987 a pectinate maxilliped but differs from it in lacking two pectinate, terminal claw-like setae on the endopod of the antenna.
COMMENTS ON “ORDERING PROPERTIES OF ORDER STATISTICS FROM HETEROGENEOUS POPULATIONS”
Authors: Li Xiaohu , You Yinping
Published: July 2013

Balakrishnan and Zhao does an excellent job in this issue at reviewing the recent advances on stochastic comparison between order statistics from independent and heterogeneous observations with proportional hazard rates, gamma distribution, geometric distribution, and negative binomial distributions, the relation between various stochastic order and majorization order of concerned heterogeneous parameters is highlighted. Some examples are presented to illustrate main results while pointing out the potential direction for further discussion.
Height Aiding, C/N0 Weighting and Consistency Checking for GNSS NLOS and Multipath Mitigation in Urban Areas
Authors: Groves Paul D , Jiang Ziyi
Published: July 2013

Multiple global navigation satellite system (GNSS) constellations can dramatically improve the signal availability in dense urban environments. However, accuracy remains a challenge because buildings block, reflect and diffract the signals. This paper investigates three different techniques for mitigating the impact of non-line-of-sight (NLOS) reception and multipath interference on position accuracy without using additional hardware, testing them using data collected at multiple sites in central London. Aiding the position solution using a terrain height database was found to have the biggest impact, improving the horizontal accuracy by 35% and the vertical accuracy by a factor of 4. An 8% improvement in horizontal accuracy was also obtained from weighting the GNSS measurements in the position solution according to the carrier-power-to-noise-density ratio (C/N0). Consistency checking using a conventional sequential elimination technique was found to degrade horizontal positioning performance by 60% because it often eliminated the wrong measurements in cases when multiple signals were affected by NLOS reception or strong multipath interference. A new consistency checking method that compares subsets of measurements performed better, but was still equally likely to improve or degrade the accuracy. This was partly because removing a poor measurement can result in adverse signal geometry, degrading the position accuracy. Based on this, several ways of improving the reliability of consistency checking are proposed.
GPS Satellite State Vector Determination in ECI Coordinate System using the Civil Navigation Message
Authors: Kim Ghangho , Jeon Sanghoon , Kee Changdon , No Tae Soo , Kwon Kiho , Choi Seungwoon
Published: July 2013

A closed form of an algorithm to determine a Global Positioning System (GPS) satellite's position, velocity and acceleration is proposed, and an Earth Centred Earth Fixed (ECEF) to Earth Centred Inertial (ECI) transformation result using the Civil Navigation (CNAV) message is presented in this paper. To obtain the closed form of the GPS satellite velocity and acceleration determination algorithm using the CNAV, we analytically differentiated the IS-GPS-200F position determination function. The calculated data are transformed from the International Terrestrial Reference Frame (ITRF) to the Geocentric Celestial Reference Frame (GCRF) using an equinox-based transform algorithm that is defined in the IAU-2000 resolution system using the Earth Orientation Parameter (EOP) data. To verify the correctness of the proposed velocity and acceleration determination algorithm, the analytical results are compared to the numerical result. The equinox-based transformation result is compared to simple rotation about the z-axis, which does not use the EOP. The results show that by using the proposed algorithm and the equinox-based transformation together, the user can obtain more accurate navigation data in the ECI frame.
The effect of ambient air temperature and precipitation on monthly counts of salmonellosis in four regions of Kazakhstan, Central Asia, in 2000–2010
Authors: GRJIBOVSKI A. M. , KOSBAYEVA A. , MENNE B.
Published: July 2013

We studied associations between monthly counts of laboratory-confirmed cases of salmonellosis, ambient air temperature and precipitation in four settings in Kazakhstan. We observed a linear association between the number of cases of salmonellosis and mean monthly temperature during the same months only in Astana: an increase of 1°C was associated with a 5·5% [95% confidence interval (CI) 2·2–8·8] increase in the number of cases. A similar association, although not reaching the level of significance was observed in the Southern Kazakhstan region (3·5%, 95% CI −2·1 to 9·1). Positive association with precipitation with lag 2 was found in Astana: an increase of 1 mm was associated with a 0·5% (95% CI 0·1–1·0) increase in the number of cases. A similar association, but with lag 0 was observed in Southern Kazakhstan region (0·6%, 95% CI 0·1–1·1). The results may have implications for the future patterns of salmonellosis in Kazakhstan with regard to climate change.
Diet-related practices and BMI are associated with diet quality in older adults
Authors: Ford Dara W , Hartman Terryl J , Still Christopher , Wood Craig , Mitchell Diane , Hsiao Pao Ying , Bailey Regan , Smiciklas-Wright Helen , Coffman Donna L , Jensen Gordon L
Published: July 2013

Objective

To assess the association of diet-related practices and BMI with diet quality in rural adults aged ≥74 years.

Design

Cross-sectional. Dietary quality was assessed by the twenty-five-item Dietary Screening Tool (DST). Diet-related practices were self-reported. Multivariate linear regression models were used to analyse associations of DST scores with BMI and diet-related practices after controlling for gender, age, education, smoking and self- v. proxy reporting.

Setting

Geisinger Rural Aging Study (GRAS) in Pennsylvania, USA.

Subjects

A total of 4009 (1722 males, 2287 females; mean age 81·5 years) participants aged ≥74 years.

Results

Individuals with BMI < 18·5 kg/m2 had a significantly lower DST score (mean 55·8, 95 % CI 52·9, 58·7) than those individuals with BMI = 18·5–24·9 kg/m2 (mean 60·7, 95 % CI 60·1, 61·5; P = 0·001). Older adults with higher, more favourable DST scores were significantly more likely to be food sufficient, report eating breakfast, have no chewing difficulties and report no decline in intake in the previous 6 months.

Conclusions

The DST may identify potential targets for improving diet quality in older adults including promotion of healthy BMI, breakfast consumption, improving dentition and identifying strategies to decrease concern about food sufficiency.
Increased collagen deposition in the heart of chronically hypoxic ovine fetuses
Authors: Thompson J. A. , Piorkowska K. , Gagnon R. , Richardson B. S. , Regnault T. R. H.
Published: July 2013

This study determined the effect of chronic intrauterine hypoxia on collagen deposition in the fetal sheep heart. Moderate or severe hypoxia was induced by placental embolization in chronically catheterized fetal sheep for 15 days starting at gestational day 116 ± 2 (term ∼147 days). The fetal right and left ventricle were evaluated for collagen content using a Sirius red dye and for changes in signaling components of pathways involved in collagen synthesis and remodeling using quantitative polymerase chain reaction and Western blot. In severely hypoxic fetuses (n = 6), there was a two-fold increase (P < 0.05) in the percentage staining for collagen in the right ventricle, compared with control (n = 6), whereas collagen content was not altered in the moderate group (n = 4). Procollagen I and III mRNA levels were increased in the right ventricle, two-fold (P < 0.05) and three-fold (P < 0.05), respectively, in the severe group relative to control. These changes were paralleled by a two-fold increase (P < 0.05) in mRNA levels of the pro-fibrotic cytokine, transforming growth factor β (TGF-β1), in the right ventricle. In the right ventricle, the mRNA levels of matrix metalloproteinase 2 (MMP-2) and its activator, membrane-type MMP (MTI-MMP) were increased five-fold (P = 0.06) and three-fold (P < 0.05), respectively, relative to control. Protein levels of TGF-β were increased in the left ventricle (P < 0.05). Thus, up-regulated collagen synthesis leading to increased collagen content occurs in the chronically hypoxic fetal heart and may contribute to the right ventricular diastolic and systolic dysfunction reported in human intrauterine growth restriction fetuses.
Adenosine‐A3 receptors in neutrophil microdomains promote the formation of bacteria‐tethering cytonemes
Authors: Corriden Ross , Self Tim , Akong‐Moore Kathryn , Nizet Victor , Kellam Barrie , Briddon Stephen J , Hill Stephen J
Published: July 2013

The A3‐adenosine receptor (A3AR) has recently emerged as a key regulator of neutrophil behaviour. Using a fluorescent A3AR ligand, we show that A3ARs aggregate in highly polarized immunomodulatory microdomains on human neutrophil membranes. In addition to regulating chemotaxis, A3ARs promote the formation of filipodia‐like projections (cytonemes) that can extend up to 100 μm to tether and ‘reel in’ pathogens. Exposure to bacteria or an A3AR agonist stimulates the formation of these projections and bacterial phagocytosis, whereas an A3AR‐selective antagonist inhibits cytoneme formation. Our results shed new light on the behaviour of neutrophils and identify the A3AR as a potential target for modulating their function.
Host genetic background impacts modulation of the TLR4 pathway by RON in tissue‐associated macrophages
Authors: Chaudhuri Amitabha , Wilson Nicholas S , Yang Becky , Paler Martinez Andres , Liu Jinfeng , Zhu Catherine , Bricker Nicole , Couto Suzana , Modrusan Zora , French Dorothy , Cupp James , Ashkenazi Avi
Published: July 2013

Toll‐like receptors (TLRs) enable metazoans to mount effective innate immune responses to microbial and viral pathogens, as well as to endogenous host‐derived ligands. It is understood that genetic background of the host can influence TLR responsiveness, altering susceptibility to pathogen infection, autoimmunity and cancer. Macrophage stimulatory protein (MSP), which activates the receptor tyrosine kinase recepteur d'origine nantais (RON), promotes key macrophage functions such as motility and phagocytic activity. MSP also acts via RON to modulate signaling by TLR4, which recognizes a range of pathogen or endogenous host‐derived molecules. Here, we show that RON exerts divergent control over TLR4 activity in macrophages from different mouse genetic backgrounds. RON potently modulated the TLR4 response in macrophages from M2‐prone FVB mice, as compared with M1‐skewed C57Bl6 mice. Moreover, global expression analysis revealed that RON suppresses the TLR4‐dependent type‐I interferon gene signature only in FVB macrophages. This leads to attenuated production of the potent inflammatory mediator, tumor necrosis factor‐α. Eliminating RON kinase activity markedly decreased carcinogen‐mediated tumorigenesis in M2/Th2‐biased FVB mice. We propose that host genetic background influences RON function, thereby contributing to the variability in TLR4 responsiveness in rodents and, potentially, in humans. These findings provide novel insight into the complex interplay between genetic context and immune function.
Joint single transmit and receive antenna selection for MIMO cognitive radios without channel state information
Authors: Li Jing , Zhang Qi , Li Quanzhong , Luo Liping , Qin Jiayin
Published: July 2013

For multiple‐input multiple‐output cognitive radios, a single transmit and receive antenna selection scheme is proposed for when the channel state information from a cognitive transmitter to a cognitive receiver is unknown to the transmitter. In the proposed scheme, the transmit antenna at the cognitive transmitter that maximises the transmit power and the receive antenna at the cognitive receiver that maximises the signal‐to‐interference‐and‐noise ratio are selected. Also derived is the exact closed‐form outage probability considering the peak interference power constraint, the peak transmit power constraint, and interference from the primary transmitter to the cognitive receiver.
Method for picosecond time interval measurements based on frequency‐switching sinusoidal shape
Authors: Ripamonti G. , Caponio F.
Published: July 2013

If the wave output by a voltage controlled oscillator (VCO) has the property of having no phase jump also when its frequency is swiftly changed, the measures of the phase before and after a fast frequency change can be used for calculating the time at which such event has occurred. Based on this property, a precise time measurement instrument has been designed and built. A non‐optimised version has better than 100ps resolution full width at half maximum, is VCO drift compensated and is able to time events against a stable clock running at 312.5MHz. The VCO frequency of the prototype jumps from 47 to 59MHz. The analogue hardware is fairly limited. Applications may range from particle timing to time resolved fluorescence spectroscopy to range finding through time‐of‐flight methods.
PWM interface for piezoelectric energy harvesting
Authors: Vasic D. , Yao Y.
Published: July 2013

A wideband electric interface based on pulse width modulation (PWM) for a piezoelectric energy harvester is investigated. The switching interfaces are used to increase the output power of energy harvesting devices for a wide frequency range. It is shown that the energy harvesting technique can effectively enable harvested power to be the maximum possible value for a dynamic electromechanical system for all excitation frequencies. The proposed wideband interface is composed of a full‐bridge converter with PWM modulation. The piezoelectric voltage is adaptive to the vibration. In the final experiment, the PWM interface harvested more energy in the case of multi‐frequency vibration.
Influence of age, gender and delay on overtaking dynamics
Authors: Llorca Carlos , García Alfredo , Moreno Ana Tsui , Pérez‐Zuriaga Ana María
Published: July 2013

Overtaking is one of the most dangerous manoeuvres on two‐lane rural highways. The most influential factors are related to drivers, so ITS and assistance systems are not yet common. This research is based on experimental data of overtaking manoeuvres collected using an instrumented passenger car, equipped with four cameras, laser rangefinders and a global positioning service (GPS) tracker. This vehicle was driven along four different road segments in the surroundings of Valencia (Spain) at a speed slightly slower than the operating speed of each segment. Overtaking time and speeds were measured. Unlike previous work, the influence of human factor was also considered. Age and gender of overtaking driver, as well as time spent following were used to characterise this influence. More than 200 manoeuvres were recorded and the influence of driver characteristics and delay on gap acceptance, manoeuvre duration and speed differences have been analysed. Results show differences in behaviour between age and gender groups, since young male overtaking drivers have shown a more aggressive behaviour. Overtaking times were around 1 s lower than other drivers, whereas average speed difference was 4 km/h higher. Collected data and their analysis have provided a basis to review design criteria and to develop future assistance systems.
Gender and age‐related differences in the perception of in‐vehicle mobile phone usage among Portuguese drivers
Authors: Ferreira Ana L. , Bianchi Piccinini Giulio F. , Rôla Susana , Simões Anabela
Published: July 2013

It has already been proved that the use of the mobile phone while driving has a negative impact on the driving performance, increasing the risk of being involved in a car accident. However, in order to plan adequate corrective actions, there is the need to know more about people's usage of mobile phone while driving and what are drivers' opinions about the risk represented by that action. The aim of the present study was three‐fold: to investigate the patterns of use of the mobile phone while driving by gender and age, to find out the prevalence of hands‐free systems use by gender and age and, finally, to understand the perceived hazard in using the mobile phone while driving by gender and age. A sample of 769 Portuguese drivers answered a web‐based survey developed in the frame of the European project INTERACTION. The answers revealed that the rate of mobile phone use among Portuguese drivers is very high. In addition, results showed that drivers perceived talking on a hands‐free mobile phone while driving as much less dangerous compared with speaking on a hand‐held mobile phone. Based on those results, further research is suggested.
ITS‐based Cooperative Services development framework for improving safety of vulnerable road users
Authors: Sánchez Nuria , Alfonso Jorge , Torres Juan , Menéndez José Manuel
Published: July 2013

Innovative advanced systems have been proposed for improving the safety and efficiency in the mobility of road users in Europe. Particularly for road transport, new ITS‐based Cooperative Services for preventing accidents in critical points and situations are emerging where road users, vehicles and a sensorised integrative infrastructure are the main actors. With this motivation, and taking into account the road infrastructure's capability to incorporate new Cooperative Systems technology, this study aims to provide a first set of guidelines for speeding up the convergence process among a broad set of multi‐heterogeneous sensor data fusion, high level situation understanding and assessment, and communications capabilities, all of them necessary for the development of advanced ITS safety‐related services previously mentioned. Analysis is focused on vulnerable road users (VRUs) and on how this kind of services will contribute to provide more intelligent and safer urban traffic environments. A typical scenario involving VRU is studied as a preliminary analysis of the impact that these systems have on the safety of a specific group of road users. Some of the underlying principles of the proposed architecture will be validated in a field operational test FP7 European project.
Automatic impedance matching and antenna tuning using quantum genetic algorithms for wireless and mobile communications
Authors: Tan Yanghong , Sun Yichuang , Lauder David
Published: July 2013

In this study an adaptive impedance tuning scheme based on the quantum genetic algorithm (QGA) is proposed. A low‐pass passive LC impedance matching network is used and tuned by a QGA controller. The tuning algorithm iterates until the matching point is reached. Simulations and results of the QGA tuning method are presented for 1.8 and 2.4 GHz of mobile and wireless communications with different antenna impedances. Comparison of the proposed QGA tuning method with conventional genetic algorithm‐based tuning method is also given, which shows that the QGA tuning algorithm is much faster. The proposed QGA method can also be used for tuning a radiofrequency band by tuning the impedance matching network to the band centre frequency. Simulation results for the universal mobile telecommunications system band of 60 MHz width and Industrial, Scientific and Medical band of 200 MHz width all show good performances.
64.8 GHz Wireless personal area network characterisation using single‐carrier frequency domain equalisation for indoor channels
Authors: Sobaihi Khaled , Hammoudeh Akram , Scammell David
Published: July 2013

Single‐carrier transmission with frequency domain equalisation (SC‐FDE) is one of the candidates for the next generation indoor wireless personal area networks operating at millimetre waves in the frequency band around 60 GHz. In this study, a 64.8 GHz SC‐FDE wireless mobile radio system is presented and its back‐to‐back performance verified. The transceiver employs fractionally spaced minimum mean‐square‐error frequency domain equalisation, that is, compliant with the IEEE 802.15.3c millimetre‐wave standard. Results of experiments, undertaken at 64.8 GHz in a number of indoor environments, to characterise the effectiveness of the SC‐FDE technique to mitigate the effects of multipath propagation are presented for line‐of‐sight and non‐line‐of‐sight scenarios. Bit‐error‐rate performance for 16‐quadrature amplitude modulation 100 Mb/s transmission is given as a function of signal‐to‐noise ratio for a combination of omnidirectional and directional antennas at both terminals and compared with that obtained in additive white Gaussian noise channel.
Investigation of the electric field inside differential antenna‐in‐package
Authors: Han Guorui , Yan Liyun , Han Liping , Yin Wangbao , Zhang Wenmei
Published: July 2013

For antenna‐in‐package (AiP), there will be an interaction between the antenna and packaged components and this interaction always takes place in the zone of the near field. So, it is necessary to study an electric field inside the package cavity and how to reduce it. In this study, the finite difference time domain model for the differential AiP is presented. Based on it, the distributions of the electric field inside the package cavity with the whole ground and gridded ground are analysed separately. The near fields EX and EY are far less than EZ and approach to zero. Also, the maximum EZ appears at the edge of cavity and it is 57 dB V/m. According to this feature, a new package configuration reducing near field is presented. The measured and simulated results show that the new packaging structure can decrease the electric field inside the package cavity to about 20 dB V/m.
Compact, two‐element array with high broadside directivity
Authors: Tang Ming‐Chun , Ziolkowski Richard W.
Published: July 2013

A combination of two high directivity, electrically small, slot‐modified conducting disc‐augmented Egyptian axe dipole (EAD) antennas is investigated to achieve interesting broadside radiation properties, including a high broadside directivity and front‐to‐back ratio. Their array arrangement is guided by a simple two‐element dipole model. The parasitic conducting disc associated with each EAD antenna is modified only slightly from their original single‐element dimensions to preserve nearly complete matching to their sources, to accommodate the coupling between the two elements and to maximise the array pattern characteristics. Parameter studies lead to a final design, whose simulation results demonstrate that the two‐element array has outstanding performance characteristics, including a 9.98 dB broadside directivity, an 88.19% radiation efficiency, a 20.03 dB front‐to‐back‐ratio, a − 22.42 dB mutual coupling level, more than a 30 dB level of polarisation purity, and good impedance matching to their respective 50 Ω sources, despite each antenna being electrically small, that is, ka < 1, and the distance between the centre of each element being only slightly larger than a half wavelength.
Design and analysis of broadband high‐gain and omnidirectional printed antenna with radiated loads
Authors: Shu Lin , Xi Liu , Xinru Ma
Published: July 2013

A novel coplanar waveguide planar antenna, which is broadband, high‐gain and omnidirectional, is proposed and analysed. The antenna radiation efficiency is improved by introducing a kind of monopole radiator as a non‐consumption radiated terminal load. The out‐of‐roundness of the antenna's H‐plane (x–z plane) is decreased by introducing horizontal stubs as non‐effective radiated loads. The simulated and experimental results indicate that the operating band of the proposed antenna is 4.65–5.61 GHz with a reflection coefficient less than − 10 dB (relative bandwidth 18.7%), the out‐of‐roundness of the radiation pattern in the horizontal plane (H‐plane or x–z plane) is less than 1.5 dB and the maximum gain achievable in the elevation plane (E‐plane or x–y plane) is more than 5.0 dB in the operating band. The pattern bandwidth well matches the impedance bandwidth. Moreover, the gain per wavelength of the novel antenna exceeds 3.0 dB, which is beneficial for antenna miniaturisation.
On Emergence and Forcing in Information Systems Grounded Theory Studies: The Case of Strauss and Corbin
Authors: Seidel Stefan , Urquhart Cathy
Published: July 2013

Grounded theory method (GTM), which has been increasingly used in the information systems (IS) field, is a contested method. GTM has even been viewed as a family of methods by Antony Bryant and Kathy Charmaz in the respected ‘Handbook of Grounded Theory’. One debate that is of particular relevance is about the metaphor of ‘emergence’ and the most basic rule of GTM - that researchers should not force preconceived conceptualizations on data. This debate has its origins in a dispute between the two co-founders of grounded theory, Barney Glaser and Anselm Strauss. Glaser criticized Strauss for the introduction of the stage of axial coding and the use of one single coding paradigm. In his view, the paradigm is too rigid, forces data, hinders emergence, and leads to conceptual description instead of grounded theory. It is perhaps surprising then, that this debate has so far been conducted without any empirical evidence in support of the proposition that the Strauss and Corbin version of grounded theory might result in forcing. In this article, we analyse IS studies in top journals where Straussian grounded theory procedures - which have found most adherents in the IS discipline - are utilized. We provide detailed insights into the use and the impact of axial coding and the coding paradigm. We find that the researchers’ use of Straussian coding procedures in the IS field is on a level that is conscious and deliberative. We relate our findings to the broader debate about the contested nature of GTM, and find that axial coding and the coding paradigm are an exemplar that shows that GTM is an evolving method that is subject to idiosyncratic interpretations and flexible deployment. Our findings, we argue, are in line with the more recent development of constructivist grounded theory that holds that grounded theories are not discovered, they are constructed, based on conscious decisions and interpretive acts. We also put forward three propositions, and five guidelines, intended to assist IS researchers in constructing grounded theories using Straussian coding procedures, while adhering to the primacy of avoiding preconceptions.
Structural and magnetic properties of La0.7Sr0.3Mn1−xNixO3 (x ≤ 0.4)
Authors: Creel Thomas F. , Yang Jinbo , Kahveci Mehmet , Malik Satish K. , Quezado S. , Pringle O. A. , Yelon William B. , James William J.
Published: July 2013

We have studied the structural and magnetic properties of La0.7Sr0.3Mn1−xNixO3 (x = 0.05, 0.1, 0.20, 0.30, and 0.40) perovskites using x-ray and neutron diffraction and magnetic measurements. Our data consist of neutron (λ = 1.479 Å) and x-ray (λ = 1.5481 Å; Cu Kα) powder diffraction and magnetization measurements. We previously suggested these systems transition from ferromagnetic to antiferromagnetic ordering with the intermediate concentrations containing coexisting domains of ferromagnetically and antiferromagnetically ordered states. Upon further detailed examination, we find that the samples are homogeneous and that neutron data can be fitted to a single long-range magnetically ordered state. The compositional dependent changes are driven by a shift in the dominant near neighbor interaction from ferromagnetic to antiferromagnetic. In the intermediate compositions, peaks previously identified as due to antiferromagnetic ordering, in fact arise from charge ordering; the system remains in a ferromagnetic state where the Ni moments are antiparallel to the Mn moments. This interpretation supersedes multiphase and spin glass models for these complex systems.
Water polarization induced by thermal gradients: The extended simple point charge model (SPC/E)
Authors: Armstrong J. A. , Bresme F.
Published: July 2013

We investigate the non-equilibrium response of extended simple point charge (SPC/E) water to thermal gradients. Using non-equilibrium molecular dynamics simulations, we show that SPC/E water features the thermo-polarization orientation effect, namely, water becomes polarized as a response to a thermal gradient. The polarization field increases linearly with the thermal gradient, in agreement with predictions of non-equilibrium thermodynamics theory. This observation confirms the generality of the thermo-polarization effect, first reported using the Modified Central Force Model (MCFM), and shows this physical effect is present irrespective of the water model details, in particular, dipole moment magnitude and model flexibility. The magnitude of the effect is the same for both models, although the sign of the electrostatic field is reversed in going from the MCFM to the SPC/E model. We further analyze the impact that the molecular geometry and mass distribution has on the magnitude of the polarization. Our results indicate that the thermo-polarization effect should be observed in a wide range of polar fluids, including fluids where hydrogen bonding is not present. Using various molecular models, we show that the polarization of these fluids under appropriate thermodynamic conditions can be of the same order or stronger than in water.
First-principle interaction potentials for metastable He(3S) and Ne(3P) with closed-shell molecules: Application to Penning-ionizing systems
Authors: Hapka Michał , Chałasiński Grzegorz , Kłos Jacek , Żuchowski Piotr S.
Published: July 2013

We present new interaction potential curves, calculated from first-principles, for the He(3S, 1s12s1)⋯H2 and He(3S)⋯Ar systems, relevant in recent Penning ionization experiments of Henson et al. [Science 338, 234 (2012)10.1126/science.1229141]. Two different approaches were applied: supermolecular using coupled cluster (CC) theory and perturbational within symmetry-adapted perturbation theory (SAPT). Both methods gave consistent results, and the potentials were used to study the elastic scattering and determine the positions of shape resonances for low kinetic energy (up to 1 meV). We found a good agreement with the experiment. In addition, we investigated two other dimers composed of metastable Ne (3P, 2p53s1) and ground state He and Ar atoms. For the Ne(3P)⋯He system, a good agreement between CC and SAPT approaches was obtained. The Ne(3P)⋯Ar dimer was described only with SAPT, as CC gave divergent results. Ne* systems exhibit extremely small electronic orbital angular momentum anisotropy of the potentials. We attribute this effect to screening of an open 2p shell by a singly occupied 3s shell.
A joint theoretical and experimental study for elastic electron scattering from 1,4-dioxane
Authors: Palihawadana P. , Sullivan J. P. , Buckman S. J. , Mašín Z. , Gorfinkiel J. D. , Blanco F. , García G. , Brunger M. J.
Published: July 2013

We present results of measurements and calculations of elastic electron scattering from 1,4-dioxane in the energy range of 0–1000 eV. Absolute differential and integral elastic cross sections have been measured using a crossed electron-molecule beam spectrometer and the relative flow technique, at four energies in the 10–30 eV range and for scattered electrons in the angular range 20°–129°. The measured cross sections are compared with results from R-matrix computations, at the static exchange plus polarization level, calculated at energies between 0–20 eV, and with calculations employing the independent atom model with the screening corrected additivity rule (IAM-SCAR). Those latter computations were conducted at energies between 1 and 1000 eV. Agreement between the measured and R-matrix cross sections was typically found to be good at all common energies, whereas agreement with IAM-SCAR was satisfactory only at 30 eV. To the best of our knowledge, the present results are the first absolute data to be published in the literature for this scattering system.
A connection between the structural α-relaxation and the β-relaxation found in bulk metallic glass-formers
Authors: Ngai K. L. , Wang Z. , Gao X. Q. , Yu H. B. , Wang W. H.
Published: July 2013

New metallic glasses containing La or Ce have been introduced having dynamic properties bordering on two extremes of conventional metallic glasses. This provides opportunity to test if the trends or correlations established before in molecular and polymeric glass-formers also exist in the broader family of metallic glasses. Due to the drastically different chemical and physical structures of metallic glass-formers than soft matter, there is no guarantee that any correlation found in the latter will hold in the former. If the trends and correlations are found, the result brings metallic glasses closer to the much wider classes of glass-formers in the similarity of properties. In non-metallic glass-formers, a general and fundamental connection has been established between the non-exponentiality parameter of the structural α-relaxation and the separation between its relaxation time τα and the β-relaxation time τβ. In this paper, we explore the experimental data of metallic glass-formers and show the correlation applies. An explanation of this correlation is given by the Coupling Model. The establishment of the correlation may facilitate the understanding of the roles played by the β-relaxation in macroscopic properties of metallic glasses including the relations to shear transformation zone, ductile-brittle transition in deformation, crystallization, and diffusion.
Quantum gates in hyperfine levels of ultracold alkali dimers by revisiting constrained-phase optimal control design
Authors: Jaouadi A. , Barrez E. , Justum Y. , Desouter-Lecomte M.
Published: July 2013

We simulate the implementation of a 3-qubit quantum Fourier transform gate in the hyperfine levels of ultracold polar alkali dimers in their first two lowest rotational levels. The chosen dimer is 41K87Rb supposed to be trapped in an optical lattice. The hyperfine levels are split by a static magnetic field. The pulses operating in the microwave domain are obtained by optimal control theory. We revisit the problem of phase control in information processing. We compare the efficiency of two optimal fields. The first one is obtained from a functional based on the average of the transition probabilities for each computational basis state but constrained by a supplementary transformation to enforce phase alignment. The second is obtained from a functional constructed on the phase sensitive fidelity involving the sum of the transition amplitudes without any supplementary constrain.
Efficient and accurate surface hopping for long time nonadiabatic quantum dynamics
Authors: Kelly Aaron , Markland Thomas E.
Published: July 2013

The quantum-classical Liouville equation offers a rigorous approach to nonadiabatic quantum dynamics based on surface hopping type trajectories. However, in practice the applicability of this approach has been limited to short times owing to unfavorable numerical scaling. In this paper we show that this problem can be alleviated by combining it with a formally exact generalized quantum master equation treatment. This allows dramatic improvements in the efficiency of the approach in nonadiabatic regimes, making it computationally tractable to treat the quantum dynamics of complex systems for long times. We demonstrate our approach by applying it to a model of condensed phase charge transfer where our method is shown to be numerically exact in regimes where fewest-switches surface hopping and mean field approaches fail to obtain either the correct rates or long-time populations.
Kelvin probe force microscopy and electrostatic force microscopy responses to the polarization in a ferroelectric thin film: Theoretical and experimental investigations
Authors: Cuniot-Ponsard M.
Published: July 2013

The ability of non-contact electric modes (Kelvin probe force microscopy (KPFM) and electrostatic force microscopy (EFM)) to provide quantitative information about the remnant polarization in a ferroelectric thin film is theoretically and experimentally investigated. The theoretical relationship between the microscopic signal and the polarization in the film is established: it is linear in the KPFM mode and parabolic in the EFM mode. The KPFM and EFM signals are predicted tip-shape, tip-surface distance, and poled area dimensions dependent so that an absolute value of the polarization cannot be extracted. Nevertheless provided these parameters are held constant, KPFM theoretically enables to investigate quantitatively the polarization dependence on any parameter relative to the film preparation conditions or to the poling process. It does not enable to investigate its dependence on poled area geometry. Based on these conclusions, experimental KPFM investigations have been carried out on a ferroelectric strontium barium niobate (SrxBa1−xNb2O6, SBN:100x) epitaxial thin film deposited on a platinum covered MgO substrate. Poled areas are created in the film by moving the biased tip in contact with the surface. KPFM images are dominated by the written polarization and not by injected or attracted extrinsic charges. The experimental decay of the KPFM signal with increasing tip-surface distance confirms the contribution of the volume of the lever/tip to the KPFM response. The spontaneous evolution of the written polarization as well as the polarization dependence on poling voltage and poling duration are investigated using KPFM, with the poled area dimensions as a parameter. For comparison, the macroscopic remnant polarization in the SBN film has been measured versus poling field from hysteresis cycles drawn using a macroscopic Pt dot as top contact. The significant difference observed between macroscopic and microscopic results can be accounted for by using a simple model of the inhomogeneous electric field generated by a poling tip. KPFM measurements do not alter the initial polarization of the film and can provide essential qualitative and quantitative information on the polarization in a ferroelectric thin film.
Dielectric breakdown and failure of anodic aluminum oxide films for electrowetting systems
Authors: Mibus M. , Jensen C. , Hu X. , Knospe C. , Reed M. L. , Zangari G.
Published: July 2013

We study electrical properties and breakdown phenomena in metal/aluminum oxide/metal and electrolyte/aluminum oxide/metal contacts, with the aim to achieve a better understanding of failure modes and improve the performance of model electrowetting systems. Electrical conduction in anodic aluminum oxide dielectrics is dominated by the presence of electrically active trapping sites, resulting in various conduction mechanisms being dominant within distinct voltage ranges until hard breakdown occurs. Breakdown voltage depends on its polarity, due to the formation of a p-i-n junction within the oxide; such asymmetric behavior tends to disappear at larger oxide thickness. Electrolyte/dielectric contacts present an even more pronounced asymmetry in breakdown characteristics: a cathodic bias results in breakdown at low voltage, while under anodic bias high field ionic conduction starts before breakdown occurs. These phenomena are interpreted in terms of electrochemical reactions occurring at the surface: cathodic processes contribute to oxide dissolution and failure, while anodic processes result in additional oxide growth before breakdown.
Quasifinite representations of classical Lie subalgebras of $W_{\bm\infty ,\,p}$W∞,p
Authors: García José I. , Liberati José I.
Published: July 2013

We show that there are exactly two anti-involutions σ± of the algebra of differential operators on the circle that are a multiple of p(t∂t) preserving the principal gradation (\documentclass[12pt]{minimal}\begin{document}$p\in \mathds {C}[x]$\end{document}p∈C[x] non-constant). We classify the irreducible quasifinite highest weight representations of the central extension \documentclass[12pt]{minimal}\begin{document}$\widehat{\mathcal {D}}_p^{\pm }$\end{document}D̂p± of the Lie subalgebra fixed by −σ±. The most important cases are the subalgebras \documentclass[12pt]{minimal}\begin{document}$\widehat{\mathcal {D}}_x^{\pm }$\end{document}D̂x± of W∞ that are obtained when p(x) = x. In these cases, we realize the irreducible quasifinite highest weight modules in terms of highest weight representation of the central extension of the Lie algebra of infinite matrices with finitely many nonzero diagonals over the algebra \documentclass[12pt]{minimal}\begin{document}$\mathds {C}[u]/(u^{m+1})$\end{document}C[u]/(um+1) and its classical Lie subalgebras of C and D types.
Method to characterize dielectric properties of powdery substances
Authors: Tuhkala M. , Juuti J. , Jantunen H.
Published: July 2013

An open ended coaxial cavity method for dielectric characterization of powdery substance operating at 4.5 GHz in TEM mode is presented. Classical mixing rules and electromagnetic modeling were utilized with measured effective permittivities and Q factors to determine the relative permittivity and dielectric loss tangent of different powders with εr up to 30. The modeling enabled determination of the correction factor for the simplified equation for the relative permittivity of an open ended coaxial resonator and mixing rules having the best correlation with experiments. SiO2, Al2O3, LTCC CT 2000, ZrO2, and La2O3 powders were used in the experiments. Based on the measured properties and Bruggeman symmetric and Looyenga mixing rules, the determined dielectric characteristics of the powders exhibited good correlation with values in the literature. The presented characterization method enabled the determination of dielectric properties of powdery substances within the presented range, and therefore could be applied to various research fields and applications where dielectric properties of powders need to be known and controlled.
Excellent retention characteristics of nanocomposite gate insulator consisting of fullerene-containing polystyrene
Authors: Nakajima Anri , Fujii Daiki , Uchino Masatoshi
Published: July 2013

Nanocomposite gate insulators were fabricated with functionalized fullerene in a gate insulating polymer [polystyrene (PS) or poly 4-vinyl phenol (PVP)]. An extremely long retention time was obtained for the gate insulating PS, although a larger absolute value of the programming voltage was necessary for the same flatband-voltage shift compared with PVP. The current–voltage characteristics suggested that the level of the lowest-unoccupied molecular orbital of PS was much higher than that of PVP and that this was the reason for the excellent retention characteristics of the fullerene-containing PS. Optimizing the concentration of fullerene molecules in PS will enable fabrication of a practical nanocomposite gate insulator for organic nonvolatile flash memory.
Low-frequency narrow-band acoustic filter with large orifice
Authors: Ma Guancong , Yang Min , Yang Zhiyu , Sheng Ping
Published: July 2013

Conventional means of attenuating airborne sound usually require blocking the air medium with a solid material. By exploiting properties of membrane-type acoustic metamaterials (MAMs), we demonstrate large transmission loss to be achievable across a sizable orifice through which air can freely flow. We find that interaction of resonating field of the MAMs with the continuous sound field passing through the orifice is responsible for such phenomenon. The narrow-band characteristic of this effect can be used for acoustic filtering of noise with a particular narrow frequency band.
Temperature-dependent strain localization and texture evolution of highly nanotwinned Cu
Authors: Furnish T. A. , Lohmiller J. , Gruber P. A. , Barbee T. W. , Hodge A. M.
Published: July 2013

Strong differences in the plastic strain and texture development in high purity nanotwinned copper foils deformed to failure in tension at ambient and liquid nitrogen (LN) temperatures have been observed. High energy microdiffraction patterns for the room temperature (RT) sample showed two distinct deformation regions relative to its fracture surface: d < 500 μm and d > 500 μm; while for the sample deformed at 77 K, three distinct regions were observed: d < 120 μm, 120 μm < d < 1550 μm, and d > 1550 μm. The localized plastic deformation in the RT tensile test and the increased ductile deformation at LN temperature are discussed in terms of the dualistic nanotwins plus micro-scale columnar grain structure.
Enabling an environment for solar and wind energy deployment in the Macedonian agricultural sector
Authors: Markovska Natasa , Krkoleva Aleksandra , Taseska Verica , Borozan Vesna , Pop-Jordanov Jordan
Published: July 2013

The paper deals with the possibility for cross-cutting the agricultural and energy sector, aiming toward better utilisation of the available renewable energy sources. An integrated methodological framework is proposed in order to formulate the possible solutions to the core question, which is “who does what” to improve the utilization of renewable energy potential in the agricultural sector. The methodology includes mainly stakeholder analyses (focusing on importance, knowledge, position, and interests of each stakeholder), as well as problem and objective tree analyses. It is applied for the case of solar and wind energy deployment in the Macedonian agricultural sector. The creation of “enabling environment” is a complex process which involves different stakeholders, with specific roles and assignments, but acting in partnership with one another. Implicitly, some recommendations in a form of priority actions with roles and responsibilities assigned to various stakeholders are proposed in the paper.