bluuebunny/crossref_metadata_2025 huggingface dataset:
‘THE HONEST TRADESMAN’S HONOUR’: OCCUPATIONAL AND SOCIAL IDENTITY IN SEVENTEENTH-CENTURY ENGLAND
Authors: Hailwood Mark
Published: November 2014

This paper starts from the proposition that historians of identity in the early modern period have paid insufficient attention to the significance of occupations and work. It demonstrates one possible approach to this topic by exploring the social identity of a particular occupational group – tradesmen – through a study of a particular source – printed broadside ballads. A number of important conclusions result: it argues that historians have overstated the dominance of craft-specific consciousness in the formation of early modern work-based identity (a term that is offered as a more helpful alternative to that of occupational identity), and suggests that broad-based identifiers such as ‘tradesman’ had a real purchase in contemporary discourse. It also considers the extent to which broader changes in the seventeenth-century economy – especially growing commercialisation and the increasing complexity of credit relations – affected the identity of the tradesman. Although the tension between the hard-working tradesman and the prodigal gentleman in ballad portraits suggests a growing social confidence on the part of the former, the marketplace is depicted to be as much a threat as an opportunity for tradesmen given the fragility of credit relationships. Moreover, the paper examines the gender dimensions of this occupational identity, arguing that a ‘female voice’ was central to ballad discussions of masculine ideals, and that the tradesman's patriarchal authority was generally portrayed as insecure. At its heart, the paper is an exploration of the intersection of class, gender and occupational identities in a period of economic change.
Assessing Cerebrovascular Reactivity Abnormality by Comparison to a Reference Atlas
Authors: Sobczyk Olivia , Battisti-Charbonney Anne , Poublanc Julien , Crawley Adrian P , Sam Kevin , Fierstra Jorn , Mandell Daniel M , Mikulis David J , Duffin James , Fisher Joseph A
Published: November 2014

Attribution of vascular pathophysiology to reductions in cerebrovascular reactivity (CVR) is confounded by subjective assessment and the normal variation between anatomic regions. This study aimed to develop an objective scoring assessment of abnormality. CVR was measured as the ratio of the blood-oxygen-level-dependent magnetic resonance signal response divided by an increase in CO2, standardized to eliminate variability. A reference normal atlas was generated by coregistering the CVR maps from 46 healthy subjects into a standard space and calculating the mean and standard deviation (s.d.) of CVR for each voxel. Example CVR studies from 10 patients with cerebral vasculopathy were assessed for abnormality, by normalizing each patient's CVR to the same standard space as the atlas, and assigning a z-score to each voxel relative to the mean and s.d. of the corresponding atlas voxel. Z-scores were color coded and superimposed on their anatomic scans to form CVR z-maps. We found the CVR z-maps provided an objective evaluation of abnormality, enhancing our appreciation of the extent and distribution of pathophysiology compared with CVR maps alone. We concluded that CVR z-maps provide an objective, improved form of evaluation for comparisons of voxel-specific CVR between subjects, and across tests sites.
Effect of Age and Vascular Anatomy on Blood Flow in Major Cerebral Vessels
Authors: Amin-Hanjani Sepideh , Du Xinjian , Pandey Dilip K , Thulborn Keith R , Charbel Fady T
Published: November 2014

Measurement of volume flow rates in major cerebral vessels can be used to evaluate the hemodynamic effects of cerebrovascular disease. However, both age and vascular anatomy can affect flow rates independent of disease. We prospectively evaluated 325 healthy adult volunteers using phase contrast quantitative magnetic resonance angiography to characterize these effects on cerebral vessel flow rates and establish clinically useful normative reference values. Flows were measured in the major intracranial and extracranial vessels. The cohort ranged from 18 to 84 years old, with 157 (48%) females. All individual vessel flows and total cerebral blood flow (TCBF) declined with age, at 2.6 mL/minute per year for TCBF. Basilar artery (BA) flow was significantly decreased in individuals with one or both fetal posterior cerebral arteries (PCAs). Internal carotid artery flows were significantly higher with a fetal PCA and decreased with a hypoplastic anterior cerebral artery. Indexing vessel flows to TCBF neutralized the age effect, but anatomic variations continued to impact indexed flow in the BA and internal carotid artery. Variability in normative flow ranges were reduced in distal vessels and by examining regional flows. Cerebral vessel flows are affected by age and cerebrovascular anatomy, which has important implications for interpretation of flows in the disease state.
Direct glucose sensing in the physiological range through plasmonic nanoparticle formation
Authors: Unser Sarah , Campbell Ian , Jana Debrina , Sagle Laura
Published: November 2014

An enzyme-free, non-invasive glucose assay is developed involving gold nanoparticle formation and shows glucose sensitivity in the range of 3–50 mM in urine.
Analytic gradients, geometry optimization and excited state potential energy surfaces from the particle-particle random phase approximation
Authors: Zhang Du , Peng Degao , Zhang Peng , Yang Weitao
Published: November 2014

The energy gradient for electronic excited states is of immense interest not only for spectroscopy but also for the theoretical study of photochemical reactions.
Length dependence of electron transport through molecular wires – a first principles perspective
Authors: Khoo Khoong Hong , Chen Yifeng , Li Suchun , Quek Su Ying
Published: November 2014

The length dependence of coherent electron transport through molecular wires is discussed in the context of a survey of state-of-the-art first principles calculation methods.
Dynamics of the chemical bond: inter- and intra-molecular hydrogen bond
Authors: Arunan Elangannan , Mani Devendra
Published: November 2014

In this discussion, we show that a static definition of a ‘bond’ is not viable by looking at a few examples for both inter- and intra-molecular hydrogen bonding. This follows from our earlier work (Goswami and Arunan,Phys. Chem. Chem. Phys.2009,11, 8974) which showed a practical way to differentiate ‘hydrogen bonding’ from ‘van der Waals interaction’. We report results fromab initioand atoms in molecules theoretical calculations for a series of Rg⋯HX complexes (Rg = He/Ne/Ar and X = F/Cl/Br) and ethane-1,2-diol. Results for the Rg⋯HX/DX complexes show that Rg⋯DX could have a ‘deuterium bond’ even when Rg⋯HX is not ‘hydrogen bonded’, according to the practical criterion given by Goswami and Arunan. Results for ethane-1,2-diol show that an ‘intra-molecular hydrogen bond’ can appear during a normal mode vibration which is dominated by the O⋯O stretching, though a ‘bond’ is not found in the equilibrium structure. This dynamical ‘bond’ formation may nevertheless be important in ensuring the continuity of electron density across a molecule. In the former case, a vibration ‘breaks’ an existing bond and in the later case, a vibration leads to ‘bond’ formation. In both cases, the molecule/complex stays bound irrespective of what happens to this ‘hydrogen bond’. Both these cases push the borders on the recent IUPAC recommendation on hydrogen bonding (Arunanet al. Pure. Appl. Chem.2011,831637) and justify the inclusive nature of the definition.
Overcoming biomass recalcitrance for enhancing sugar production from fast pyrolysis of biomass by microwave pretreatment in glycerol
Authors: Zheng Anqing , Zhao Zengli , Huang Zhen , Zhao Kun , Wei Guoqiang , Jiang Liqun , Wang Xiaobo , He Fang , Li Haibin
Published: November 2014

Microwave pretreatment can selectively remove AAEM, lignin and hemicellulose fractions for enhancing levoglucosan yield from fast pyrolysis of pretreated corncob.
Temperature-responsive nanobiocatalysts with an upper critical solution temperature for high performance biotransformation and easy catalyst recycling: efficient hydrolysis of cellulose to glucose
Authors: Limadinata Priscilia A. , Li Aitao , Li Zhi
Published: November 2014

A novel concept of engineering an UCST-type temperature-responsive nanobiocatalyst for efficient catalysis and easy catalyst separation upon temperature change was demonstrated and successfully applied in hydrolysing cellulose to glucose.
Consequences of stratospheric ozone depletion and climate change on the use of materials
Authors: Andrady A. L. , Torikai A. , Redhwi H. H. , Pandey K. K. , Gies P.
Published: November 2014

Materials used in the exterior of buildings and in construction are routinely exposed to solar UV radiation. Especially in the case of wood and plastic building materials, the service life is determined by their weather-induced deterioration. Any further increase in ground-level solar UV radiation, UV-B radiation in particular, will therefore reduce the outdoor service life of these products. Any increase in ambient temperature due to climate change will also have the same effect. However, the existing light-stabilizer technologies are likely to be able to mitigate the additional damaging effects due to increased solar UV radiation and maintain the outdoor lifetimes of these materials at the present levels. These mitigation choices invariably increase the lifetime cost of these products. A reliable estimate of what this additional cost might be for different products is not available at the present time. Personal exposure to UV radiation is reduced both by clothing fabrics and glass windows used in buildings and automobiles. This assessment describes how the recent technical advances in degradation and stabilization techniques impact the lifetimes of plastics and wood products routinely exposed to solar UV radiation and the protection to humans offered by materials against solar UV radiation.
A high-performance ethanol–hydrogen peroxide fuel cell
Authors: An L. , Zhao T. S. , Zhou X. L. , Wei L. , Yan X. H.
Published: November 2014

We propose to create the cathode potential by introducing a redox couple to the cathode while using hydrogen peroxide to chemically charge the redox ions, which eliminates the mixed potential associated with direct reduction of hydrogen peroxide.
Ultrasensitive and stable determination of lead ions by a glassy carbon electrode modified with a phenanthroline-based electropolymerized film
Authors: Ji C. Y. , Li P. , Ma H. W. , Yang G. C. , Zhang M.
Published: November 2014

A novel electro-active compound, 3,8-bis(9,9-bis(6-(9H-carbazol-9-yl)hexyl)-9H-fluoren-2-yl)-1,10-phenanthroline (TCFC), is used to modify a glassy carbon electrode (GCE) for the electrochemical detection of Pb2+.
Thiol–ene adhesives from clove oil derivatives
Authors: Donovan Brian R. , Cobb Jared S. , Hoff Ethan F. T. , Patton Derek L.
Published: November 2014

This paper reports the synthesis of catechol-functionalized thiol–ene networks as photocurable adhesives, where adhesive interactions are derived from 4-allylpyrocatechol – an alkene readily obtained from Syzygium aromaticum flower buds (clove oil).
Plasmonic heating with near infrared resonance nanodot arrays for multiplexing optofluidic applications
Authors: Steinbrück A. , Choi J.-W. , Fasold S. , Menzel C. , Sergeyev A. , Pertsch T. , Grange R.
Published: November 2014

In this work, we show local laser-induced heating in fluids with gold nanodot arrays prepared by electron-beam lithography that cover resonances in the near infrared spectral range from 750 nm to 880 nm.
Developing diazirine-based chemical probes to identify histone modification ‘readers’ and ‘erasers’
Authors: Yang Tangpo , Liu Zheng , Li Xiang David
Published: November 2014

New chemical tools to ‘trap’ post translational modification (PTM)-mediated protein–protein interactions.
Environmentally benign synthesis of branched Bi2O3–Bi2S3 photocatalysts by an etching and re-growth method
Authors: Chen Lang , He Jie , Yuan Qing , Liu Ying , Au Chak-Tong , Yin Shuang-Feng
Published: November 2014

Branched Bi2O3–Bi2S3 photocatalysts with heterostructures have been synthesized by an environment-benign process. The composites show enhanced photocatalytic activity and photocurrent responses under visible light illumination.
Respiratory sinus arrhythmia in young men and women at different chest wall configurations
Authors: Mortola Jacopo P. , Marghescu Domnica , Siegrist-Johnstone Rosmarie
Published: November 2014

Respiratory sinus arrhythmia (RSA) is an acceleration of heart rate during inspiration and deceleration with expiration. We asked whether or not in humans some of the volume-related information necessary for RSA originated from the chest wall. Men and women, 19–20 years old, were breathing supine. Rib cage and abdomen displacement provided an index of tidal volume (VT) and RSA was computed breath-by-breath from the peak and trough of instantaneous heart rate. First, measurements were taken during breathing at rest (protocol a, 129 male and 164 female). Then, in subgroups of the original subject population, measurements were collected for the first five breaths immediately following a brief breath-hold period (protocol b), predominantly with the rib cage or predominantly with the abdomen (protocol c), above functional residual capacity or below it (protocol d). As long as VT was constant, severe chest wall distortion (protocol c) did not modify RSA. A drop in absolute lung volume (protocol d) or an increase in VT (protocol b) respectively decreased and increased RSA. The results, globally taken, are compatible with the notion that in humans changes in lung volume are detected by lung mechanoreceptors, whereas chest wall reflexes play no role in RSA. No difference in RSA emerged between genders during resting breathing or modest breath-hold hyperventilation.
Enhanced MIL tracker with distribution field‐based features and temporal fusion framework
Authors: Dong Qiang , Liu Aidong
Published: November 2014

A new tracker based on multiple instance learning (MIL) with distribution field (DF)‐based features and a novel temporal fusion framework is presented. DF‐based features make the representations less sensitive to the object's appearance variation. In addition, the tracker introduces a new temporal fusion framework based on the randomised policy, aiming at adding robustness against outliers during the tracking. Experimental results on challenging video sequences show the effectiveness of the proposed method.
Performance analysis and characterisation of micro‐nanopositioning systems
Authors: Tan Ning , Clévy Cédric , Chaillet Nicolas
Published: November 2014

Separation and quantification of error components in micro‐nanopositioning systems are presented with theoretical analysis and experimental characterisation, which are illustrated with a single‐axis nanopositioning stage. The concepts of intrinsic and extrinsic repeatabilities are proposed.
Green‐light‐enhanced super‐continuum generation in tapered photonic crystal fibre for efficient fceo detection of Yb:fibre laser frequency combs
Authors: Niu Fuzeng , Jiang Tongxiao , Lai Shunnan , Zhang Wei , Wang Aimin , Zhang Zhigang
Published: November 2014

Green‐light‐enhanced super‐continuum generation which covers the range from 500 to 1600 nm with a strong peak at 530 nm in a tapered photonic crystal fibre with pump pulse energy as low as 280 pJ from a mode‐locked Yb:fibre laser is reported. By the f‐to‐2f self‐reference technique, a 27 dB fceo signal was detected using the frequency pair at the Yb:laser wavelength (∼1060 nm) and this green light peak. It demonstrates the feasibility and high efficiency of fceo beat detection for simplified Yb:fibre laser frequency combs.
Low read‐only memory distributed arithmetic implementation of quaternion multiplier using split matrix approach
Authors: Petrovsky N. , Stankevich A. , Petrovsky A.
Published: November 2014

In most algorithms that use quaternion numbers, the key operation is a quaternion multiplication, of which the efficiency and accuracy obviously determine the same properties of the whole computational scheme of a filter or transform. A digit (L‐bit)‐serial quaternion multiplier based on the distributed arithmetic (DA) using the splitting of the multiplication matrix is presented. The circuit provides the facility to compute several products of quaternion components concurrently as well as to reduce the memory capacity by half in comparison with the known DA‐based multiplier, and it is well suited for field programmable gate array (FPGA)‐based fixed‐point implementations of the algorithms. Apart from a theoretical development, the experimental design results which are obtained using a Xilinx Virtex 6 FPGA are reported.
High power factor LED power supply based on SEPIC converter
Authors: Tian Gao , Qi Wang , Yan Yang , Jiang Yan Zhong
Published: November 2014

A single‐ended primary inductor converter (SEPIC)‐based light‐emitting diode (LED) power supply, which can achieve power factor correction (PFC) and constant‐current drive for LED in the critical conduction mode (CRM), is presented. The circuit principle is described in detail. Meanwhile the formulas for metal–oxide semiconductor field‐effect transistor switch‐on time, switching frequency and the main influences of power factor are given. Experimental results show that the power can drive the LED with high efficiency by virtue of its high power factor, low power loss and stable output. Furthermore, it can be applied to low‐power lighting occasions with simple structure and high reliability.
Enhanced isolation with defected ground structure in MIMO antenna
Authors: Anitha R. , Sarin V.P. , Mohanan P. , Vasudevan K.
Published: November 2014

A defected ground structure (DGS) for improving isolation between four ports in a collocated multiple‐input–multiple‐output (MIMO) antenna is proposed. Isolation improvement by 7 dB is achieved by reducing surface waves within the dielectric substrate. Mutual coupling values as low as −25 dB are obtained along both the E‐ and H‐planes. The MIMO antenna includes a square patch antenna surrounded by a square ring patch antenna with the DGS etched in the form of a square ring. The DGS effectively suppresses the cross‐polarisation levels for all radiating modes. The design and effectiveness of the DGS in improving isolation for a fabricated 4‐port antenna are discussed.
Robust low‐rank image representations by deep matrix decompositions
Authors: Yang Chenxue , Ye Mao , Li Xudong , Liu Zijian , Tang Song , Li Tao
Published: November 2014

A novel approach based on low‐rank representations (LRRs) for image representations is proposed. LRR seeks the lowest‐rank representations among all the coefficient matrices that represent the images as linear combinations of the basis in the given dictionary. Unlike LRR methods of enforcing additional constraints on the representation and dictionary, an iterative process in which the low‐rank decomposition is performed on the coefficient matrices has been developed. The rank of the representation matrices will be lower and lower with the iterations, termed as the deep low‐rank (DLR) method. Extensive experiments were conducted to verify the state‐of‐the‐art performance for classification tasks of the DRL method.
Physical origin of gate voltage‐dependent drain–source capacitance in short‐channel MOSFETs
Authors: Hong Seoyoung , Lee Seonghearn
Published: November 2014

For the first time, it is revealed that the physical origin of the gate–source voltage (Vgs)‐dependent drain–source capacitance in short‐channel metal–oxide semiconductor field‐effect transistors (MOSFETs) comes from the depletion capacitance components between the drain and channel end in the saturation region. On the basis of this origin, it is newly found that the Vgs‐dependent channel resistance should be connected in series with the drain–source capacitance to model the high‐frequency (HF) response of the intrinsic output capacitance. The accuracy of an improved MOSFET model, including the channel resistance, is validated by observing the excellent agreement with the measured S‐parameters in the wide range of Vgs up to 40 GHz.
Synthesis design of UWB bandpass filter using multiple resonance resonator (MRR)
Authors: Khalid Sohail , Peng Wen Wong , Cheong Lee Yen
Published: November 2014

An ultra‐wideband (UWB) bandpass filter synthesis and design, using a multiple resonance resonator (MRR), is presented. Mixed‐mode coupling is used to introduce a finite transmission zero to increase the filter selectivity. The equivalent circuit of the design is used to find the filtering function using even–odd mode analysis. The synthesis procedure is done on an extracted filtering function in order to realise the quasi‐Chebyshev filtering response. Finally, a compact filter prototype has been fabricated to validate the synthesis theory and simulated design. The measured and simulated results show good agreement.
Izhikevich neuron circuit using stochastic logic
Authors: Sato S. , Akima H. , Nakajima K. , Sakuraba M.
Published: November 2014

A digital circuit of the Izhikevich neuron model using stochastic logic is proposed. Stochastic logic is employed in order to save the number of transistors required for multiplication operations. Successful operation of the proposed circuit has been confirmed.
Optimal convergecast scheduling for hierarchical wireless industrial systems: performance bounds and two‐stage algorithms
Authors: Zhang Xiaoling , Liang Wei , Yu Haibin , Feng Xisheng
Published: November 2014

Increased mobility coupled with a possible reduction of cabling costs and deployment time makes wireless communication an attractive alternative for the industrial process monitoring and control. The major obstacles towards the utilisation of wireless industrial systems are predominantly the timing and reliability requirements. In this study, the authors take jointly the timing and reliability requirements, limited wireless resources and the cyclic data feature into consideration, and study the performance bounds and two‐stage time‐ and channel‐optimal convergecast scheduling algorithms for wireless industrial systems with hierarchical star and mesh architecture. Specifically, they consider the convergecast communication for wireless industrial systems operating according to the recent wireless network for industrial automation–process automation standard; and they will provide bounds on the minimum convergecast schedule length and bounds on the minimum number of channels for cluster‐line and cluster‐tree routing structures. In both cases, they propose time‐ and channel‐optimal two‐stage scheduling algorithms. They evaluate the author's two‐stage scheduling algorithms by both simulation and real hardwares. Numerical results demonstrate that their algorithms are efficient compared with traditional time division multiple access‐based convergecast scheduling algorithms.
Partial phase weighting selected mapping scheme for peak‐to‐average power ratio reduction in orthogonal frequency division multiplexing system
Authors: Wang Lingyin , Liu Ju
Published: November 2014

As one of the most attractive schemes, selected mapping (SLM) provides an effective solution for peak‐to‐average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) system. However, in conventional SLM (CSLM), the large number of inverse fast Fourier transform (IFFT) operations are required for achieving the satisfactory PAPR reduction performance, which results in the large computational complexity. In this study, a partial phase weighting SLM (PPW‐SLM) for PAPR reduction in OFDM system is proposed. In the proposed PPW‐SLM, partial phase weighting method and the properties of IFFT are employed for simplifying the calculations of IFFTs and obtaining good PAPR reduction performance. Theoretical analysis and simulation results show that, compared with CSLM, the proposed PPW‐SLM can obtain a significant computational complexity reduction in similar PAPR reduction performance.
Analysis of asynchronous frequency hopping multiple‐access network performance based on the frequency hopping sequences
Authors: Guan Lei , Li Zan , Si Jiangbo , Hao Benjian
Published: November 2014

In this study, the authors investigate the impact of the frequency‐hopping (FH) sequence on the packet transmission performance of the asynchronous frequency‐hopping multiple‐access (FHMA) network. According to the model of the asynchronous FHMA network given in this study, the authors analyse the impact of the two important FH sequence factors – uniformity and frequency slot number – on the correct transmission probability and the packet transmission frequency efficiency. According to the non‐collision probability analysed in this study, the uniformity of the FH sequence is an important issue to determine the correct packet transmission probability. Moreover, based on the definition of the packet transmission frequency efficiency given in this study, the optimal frequency slot number employed to obtain the maximum frequency efficiency is obtained. By employing three typical FH sequences, the simulation results are also included, which validates the theoretical analysis about the packet transmission performance of the asynchronous FHMA network.
Probabilistic multi‐objective generation and transmission expansion planning problem using normal boundary intersection
Authors: Mavalizadeh Hani , Ahmadi Abdollah , Heidari Alireza
Published: November 2014

This study presents a model of coordinated generation and transmission expansion planning (TEP). The proposed model simultaneously minimises total cost, including planning and total fuel cost, environmental impact in terms of SO2 and NOx emission and fuel price risk while maximising the system reliability. Owing to intermittent behaviour of loads and fuel prices, the expansion planning problem should be analysed using probabilistic approaches instead of deterministic ones. Therefore, a new approach is proposed to solve the multi‐objective probabilistic coordinated generation and TEP problem. The point estimate method is used to take into account the effect of uncertainty in fuel prices and system demand. The normal boundary intersection (NBI) method is used to obtain the Pareto‐optimal solutions. Moreover, fuzzy decision‐making process is employed to select one of the Pareto‐optimal solutions as the most preferred solution. The proposed model is implemented on the modified Garver6‐bus system to evaluate its efficiency. Finally, the results of the NBI method are compared with the classical weighted sum method. Additionally, the model is implemented on the IEEE 24‐bus reliability test system, and the results are compared with the virtual database‐supported non‐dominated sorting genetic algorithm II (VDS‐NSGA II) and NSGA II methods.
Evaluation of the effectiveness of auditory speeding warnings for commercial passenger vehicles –a field study in Wuhan, China
Authors: He Yi , Yan Xinping , Wu Chaozhong , Zhong Ming , Chu Duanfeng , Huang Zhen , Wang Xu
Published: November 2014

Auditory warning of speeding behaviour is considered to be one of the most effective methods developed to reduce the accidents involving commercial passenger vehicles. Facing a complex, mixed traffic condition and a lot of risky driving behaviours in China, commercial passenger vehicles need an effective speeding warning system to reduce the high accident rate. Although many automobile manufacturers have installed the speeding warning systems on their vehicles, the styles of these auditory speeding warning systems are different, and few studies has been found to investigate the effectiveness of the auditory speeding warning systems for commercial passenger vehicles. Therefore this study is intent to fill such a gap to evaluate the effectiveness of three different sound‐based speeding warning styles. In this study, thirty drivers qualified for driving the commercial passenger vehicles are recruited and then asked to drive for four 80‐km field trips on an expressway in Wuhan, China. Driving behaviour is logged by a monitoring system and is monitored by two observers during these trips. Study results showed that ‘beep warning’ is most effective and ‘break‐sound warning’ is the least. Basically, the results of this study could provide a good reference for development of future voice‐based speed warning systems in China.
Analytical solution of scattering by a DB/D′B′ cylinder coated with multilayer anisotropic media for cloaking applications
Authors: Montaseri Nasser , Dadashzadeh Gholamreza
Published: November 2014

In this study, analytical solution of plane wave scattering is presented by a circular DB/D′B′ cylinder coated with multilayer anisotropic media. The relative permittivity and permeability tensors of each layer, when referring to principle axes (ρ, φ, z), are biaxial and diagonal; so, the radial eigenfunctions are complex ordered Bessel's functions. In order to compare different boundary conditions and cloaks, scattering width is calculated in some examples. Theory and simulation results show that scattering width of the circular DB (or D′B′) cylinder coated with Cloak I (or Cloak II) has the same value in both TMz and TEz polarisations. Furthermore, it is demonstrated that the DB boundary condition and Cloak I have good performance in the invisibility of cylindrical structures, which may provide a potential way to design a dual polarised cloak.
Rapid design of microstrip antenna arrays by means of surrogate‐based optimisation
Authors: Koziel Slawomir , Ogurtsov Stanislav
Published: November 2014

A technique for rapid simulation driven design of planar microstrip antenna arrays is introduced. It exploits the surrogate‐based optimisation paradigm and variable‐fidelity electromagnetic (EM) simulations. The design process includes radiation pattern optimisation and matching. Two low‐fidelity models are utilised: a coarse‐mesh EM model of the entire array and a model of the array based on the simulated single element radiation response combined with the array factor. Both models, after suitable correction, guide the optimisation process towards the optimum of the antenna array high‐fidelity model. Design optimisation of a 5 × 5 and 7 × 7 microstrip antenna arrays is conducted and described to demonstrate operation as well as efficiency of the proposed technique. The computational cost of optimised designs is equivalent to a few high‐fidelity simulations of the entire array despite a large number of design variables.
Two feeding methods based on substrate integrated waveguide for microstrip patch antennas
Authors: Mikulasek Tomas , Lacik Jaroslav
Published: November 2014

Two feeding methods for microstrip patch antennas (MPAs), namely aperture coupling (AC) and probe feeding (PF), based on a substrate integrated waveguide (SIW) are presented in this study. Exploiting an SIW structure for MPA feeding combines the benefits of both structures. It results in a compact antenna structure retaining advantageous properties of MPAs and having a radiation characteristic non‐effected by spurious radiation that is usually produced by a conventional feeding line. The proposed antenna structures are studied using parametric analyses and their design procedures are presented. The antenna structures are fabricated and verified by measurement at 10 GHz. At the operation frequency, the fabricated AC‐MPA and PF‐MPA with a coax‐to‐SIW transition achieved an impedance bandwidth of 9 and 13.1% and a gain of 8.6 and 9.2 dBi, respectively.
Planar antennas for compact multiband transceivers using a microstrip feedline and multiple open‐ended ground slots
Authors: Antoniades Marco A. , Dadgarpour Abdolmehdi , Razali Ahmad Rashidy , Abbosh Amin , Denidni Tayeb A.
Published: November 2014

Two planar antennas for compact multiband transceivers are presented, that employ an open‐ended microstrip feedline that couples to multiple open‐ended ground slots. The effect of separately introducing each of the slots on the antenna performance is outlined, and it is shown that the resonant frequencies of the antennas can be independently controlled by adjusting the dimensions of the ground slots. Antenna 1, consisting of an open‐ended microstrip feedline that couples to three open‐ended ground slots, exhibits a measured |S11| < −6 dB in the frequency ranges of 1.64–3.50 GHz, and 5.22–6.81 GHz, covering the standards of DCS, PCS, UMTS, Wibro, Bluetooth, WiMAX, HiperLAN 2 and WLAN with a measured gain that varies between 1.85 and 3.98 dBi, and with radiation efficiencies in excess of 80%. Antenna 2, consisting of an open‐ended microstrip feedline that couples to four open‐ended ground slots, exhibits a measured |S11| < −6 dB in the entire frequency range of 2.74–6.71 GHz, covering the standards of WiMAX, HiperLAN 2 and WLAN with a measured gain that varies between 4.98 and 5.28 dBi, and with radiation efficiencies in excess of 80%. Both antennas occupy a total size of only 40 × 30 × 1.6 mm3.
Loading metamaterial perfect absorber method for in‐band radar cross section reduction based on the surface current distribution of array antennas
Authors: Li Si‐Jia , Gao Jun , Cao Xiang‐Yu , Zhao Yi , Zhang Zhao , Liu Hong‐Xi
Published: November 2014

A loading metamaterial perfect absorber (MPA) method is proposed to reduce the in‐band radar cross section (RCS) and preserve the radiation characters for the guidewave slot array antennas in this study. The surface current distributions of the array antennas are divided into the strong current area and the weak current area. The metal surface with the strong current is retained to avoid the radiation deterioration, and the MPA is only loaded on the weak current area by the three layers MPA for RCS reduction. The RCS of a 1 × 10 guidewave slot array antennas is reduced using the method. Simulated S11, radiation patterns, gain and RCS reduction of the array antennas are compared with measured results. Experimental results indicated that the in‐band RCS of the array antennas loading the MPA has dramatically reduced with only about 0.73 dB gain reduction and the RCS reduction are not significant in out‐of‐band while the radiation characters is unchanged. The experimental results are in good agreement with the numerical simulations.
Space‐vector pulse‐width modulation algorithm for multilevel voltage source inverters based on matrix transformation and including operation in the over‐modulation region
Authors: Jiang Weidong , Li Wangmin , Wu Zhiqing , She Yangyang , Tao Ziran
Published: November 2014

Multilevel voltage source inverters are most promising when employed in high‐power and high‐voltage applications. As the number of inverter levels increases, the algorithm of space‐vector pulse‐width modulation (SVPWM) becomes increasingly complex. Based on the intrinsic relationship between SVPWM algorithms for 2‐level inverters and those for arbitrary‐level inverters, here a novel SVPWM algorithm is proposed for an arbitrary‐level inverter. Considering that the nearest three vectors are used to synthesise the reference vector, the on‐time of the voltage vector for an arbitrary‐level inverter can be acquired from that for a 2‐level inverter via the use of a linear transformation. This algorithm is verified through simulation and experiments, with the latter proving that the proposed algorithm can meet the real‐time requirements of multilevel inverters.
Discovery and characterization of magnetism in sigma-phase intermetallic Fe-Re compounds
Authors: Cieślak J. , Dubiel S. M. , Reissner M. , Tobola J.
Published: November 2014

Systematic experimental studies (vibrating sample magnetometry) supported by theoretical calculations (electronic structure by spin self-consistent Korringa-Kohn-Rostoker Green's function method) were performed on a series of intermetallic sigma-phase Fe100−xRex (x = 43–53) compounds. All investigated samples exhibit magnetism with an ordering temperature ranging between ∼65 K for x = 43 and ∼23 K for x = 53. The magnetism was revealed to be itinerant and identified as a spin-glass (SG) possibly having a re-entrant character. The SG was found to be heterogeneous, viz., two regimes could be distinguished as far as irreversibility in temperature dependence of magnetization is concerned: (1) of a weak irreversibility and (2) of a strong one. According to the theoretical calculations, the main contribution to the magnetism comes from Fe atoms occupying all five sub lattices, while Re atoms have rather small magnetic moments. However, the calculated average magnetic moments highly (ferromagnetic ordering model) or moderately (antiparallel ordering model) overestimate the experimental data.
Quantum skew divergence
Authors: Audenaert Koenraad M. R.
Published: November 2014

In this paper, we study the quantum generalisation of the skew divergence, which is a dissimilarity measure between distributions introduced by Lee in the context of natural language processing. We provide an in-depth study of the quantum skew divergence, including its relation to other state distinguishability measures. Finally, we present a number of important applications: new continuity inequalities for the quantum Jensen-Shannon divergence and the Holevo information, and a new and short proof of Bravyi's Small Incremental Mixing conjecture.
Line mixing effects in isotropic Raman spectra of pure N2: A classical trajectory study
Authors: Ivanov Sergey V. , Boulet Christian , Buzykin Oleg G. , Thibault Franck
Published: November 2014

Line mixing effects in the Q branch of pure N2 isotropic Raman scattering are studied at room temperature using a classical trajectory method. It is the first study using an extended modified version of Gordon's classical theory of impact broadening and shift of rovibrational lines. The whole relaxation matrix is calculated using an exact 3D classical trajectory method for binary collisions of rigid N2 molecules employing the most up-to-date intermolecular potential energy surface (PES). A simple symmetrizing procedure is employed to improve off-diagonal cross-sections to make them obeying exactly the principle of detailed balance. The adequacy of the results is confirmed by the sum rule. The comparison is made with available experimental data as well as with benchmark fully quantum close coupling [F. Thibault, C. Boulet, and Q. Ma, J. Chem. Phys. 140, 044303 (2014)] and refined semi-classical Robert-Bonamy [C. Boulet, Q. Ma, and F. Thibault, J. Chem. Phys. 140, 084310 (2014)] results. All calculations (classical, quantum, and semi-classical) were made using the same PES. The agreement between classical and quantum relaxation matrices is excellent, opening the way to the analysis of more complex molecular systems.
Diffusion and surface excess of a confined nanoswimmer dispersion
Authors: Xiao Song , Wang Zhengjia , Chen Hsuan-Yi , Sheng Yu-Jane , Tsao Heng-Kwong
Published: November 2014

The diffusivity and surface excess of nanoswimmers which are confined in two plates with the separation H are explored by dissipative particle dynamics. Both mean squared displacement and velocity autocorrelation function methods are used to study the diffusive behavior of nanoswimmers with the Brownian diffusivity D0 and the results obtained from both methods are consistent. The active diffusivity of confined nanoswimmers (D − D0) depends on the wall separation, swimming speed va, and run time τ. Our simulation results show that \documentclass[12pt]{minimal}\begin{document}$(D-D_{0})/v_{a}^{2}\tau$\end{document}(D−D0)/va2τ is a function of vaτ/H. The reduction in the diffusivity of active colloids is more significant than that of passive particles. The distribution of nanoswimmers between two parallel walls is acquired and two regions can be identified. The accumulation of nanoswimmers near walls is quantitatively described by the surface excess Γ. It is found that Γ grows as the nanoswimmer concentration cb, swimming speed va, and run time τ are increased. The coupling between the ballistic trajectory of nanoswimmers and the walls results in nanoswimmer accumulation. The simulation outcomes indicate that Γ/Hcb is a function of H/vaτ.
The effect of cesium carbonate on 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C61 aggregation in films
Authors: Lindemann William R. , Wang Wenjie , Fungura Fadzai , Shinar Joseph , Shinar Ruth , Vaknin David
Published: November 2014

Surface-pressure versus molecular area isotherms, X-ray reflectivity, and X-ray near-total reflection fluorescence were used to study the properties of 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C61 (PCBM) that was pre-mixed with cesium carbonate and spread as a film at the air-water interface. The pre-mixed PCBM with cesium carbonate demonstrated a strikingly strong effect on the organization of the film. Whereas films formed from pure PCBM solution were rough due to strong inter-molecular interactions, the films formed from the mixture were much smoother. This indicates that the cesium carbonate moderates the inter-molecular interactions among PCBM molecules, hinting that the cesium diffusion observed in inverted organic photovoltaic structures and the likely ensuing ionic Cs-PCBM interaction decrease aggregation tendency of PCBM. This implies that the use of cesium salts affects the morphology of the organic layer and consequently improves the efficiency of these devices.
Downscaling of global solar irradiation in complex areas in R
Authors: Antonanzas-Torres F. , Martínez-de-Pisón F. J. , Antonanzas J. , Perpinan O.
Published: November 2014

A methodology for downscaling solar irradiation from satellite-derived databases is described using R software. Different packages such as raster, parallel, solaR, gstat, sp, and rasterVis are considered in this study for improving solar resource estimation in areas with complex topography, in which downscaling is a very useful tool for reducing inherent deviations in satellite-derived irradiation databases, which lack of high global spatial resolution. A topographical analysis of horizon blocking and sky-view is developed with a digital elevation model to determine what fraction of hourly solar irradiation reaches the Earth's surface. Eventually, kriging with external drift is applied for a better estimation of solar irradiation throughout the region analyzed including the use of local measurements. This methodology has been implemented as an example within the region of La Rioja in northern Spain. The mean absolute error found using the methodology proposed is 91.92 kW h/m2 vs. 172.62 kW h/m2 using the original satellite-derived database (a striking 46.75% lower). The code is freely available without restrictions for future replications or variations of the study at https://github.com/EDMANSolar/downscaling.
Optical chromatographic sample separation of hydrodynamically focused mixtures
Authors: Terray A. , Hebert C. G. , Hart S. J.
Published: November 2014

Optical chromatography relies on the balance between the opposing optical and fluid drag forces acting on a particle. A typical configuration involves a loosely focused laser directly counter to the flow of particle-laden fluid passing through a microfluidic device. This equilibrium depends on the intrinsic properties of the particle, including size, shape, and refractive index. As such, uniquely fine separations are possible using this technique. Here, we demonstrate how matching the diameter of a microfluidic flow channel to that of the focusing laser in concert with a unique microfluidic platform can be used as a method to fractionate closely related particles in a mixed sample. This microfluidic network allows for a monodisperse sample of both polystyrene and poly(methyl methacrylate) spheres to be injected, hydrodynamically focused, and completely separated. To test the limit of separation, a mixed polystyrene sample containing two particles varying in diameter by less than 0.5 μm was run in the system. The analysis of the resulting separation sets the framework for continued work to perform ultra-fine separations.
Electric-field control of magnetic anisotropy in Fe81Ga19/BaTiO3 heterostructure films
Authors: Xie Yali , Zhan Qingfeng , Liu Yiwei , Dai Guohong , Yang Huali , Zuo Zhenghu , Chen Bin , Wang Baomin , Zhang Yao , Rong Xin , Li Run-Wei
Published: November 2014

We investigate the control of magnetism with an electric field in Fe81Ga19(FeGa)/BaTiO3(BTO) heterostructure films. The as-prepared FeGa/BTO samples present a uniaxial magnetic anisotropy, which is ascribed to be induced by the spontaneous ferroelectric polarization of the BTO substrates. With the electric field applied on the BTO substrates increasing from 0 to 6 kV/cm, the coercivity of FeGa films measured along the BTO[110] direction increases from 28 to 41 Oe, while the squareness of the hysteresis loop decreases from 0.99 to 0.31, which indicates that the easy and hard axes of FeGa films are swapped. The ferroelectric domains of BTO substrates and the magnetic domains of FeGa films exhibit the same dependence on the applied electric fields, manifesting the strong magnetoelectric coupling between the ferroelectricity of BTO substrates and the magnetism of FeGa films.
Influence of pulse poling on the piezoelectric property of Pb(Zr0.52,Ti0.48)O3 thin films
Authors: Kobayashi Takeshi , Suzuki Yasuhiro , Makimoto Natsumi , Funakubo Hiroshi , Maeda Ryutaro
Published: November 2014

We have investigated the influence of pulse poling on the piezoelectric property of Pb(Zr0.52,Ti0.48)O3 (PZT) thin films. 1.9-μm-thick PZT thin films were deposited by sol-gel method and fabricated into microelectromechanical systems (MEMS) based piezoelectric microcantilevers. 1 kHz of unipolar or bipolar triangle pulse wave between 30-100 V was applied to the PZT thin films. The effective piezoelectric constant d31, under small signal actuation at 1-3 Vpp, was estimated from the tip displacement of the piezoelectric microcantilevers. The highest piezoelectric constant |d31| as high as 105 pm/V has been obtained by downward unipolar pulse poling at 100 V.
Genetic data confirm the species status of Sepsis nigripes Meigen (Diptera : Sepsidae) and adds one species to the Alpine fauna while questioning the synonymy of Sepsis helvetica Munari
Authors: Rohner Patrick T. , Ang Yuchen , Lei Zhao , Puniamoorthy Nalini , Blanckenhorn Wolf U. , Meier Rudolf
Published: November 2014

Due to their interesting biology, conspicuous sexual dimorphism and the ability to conduct experiments on species that breed under laboratory condition, sepsid flies (Diptera : Sepsidae) are becoming increasingly important model organisms in evolutionary biology. Accurate species boundaries and well supported phylogenetic hypotheses are thus of interest to many biologists. Here we resolve the conflict surrounding the taxonomic status of the European Sepsis nigripes Meigen, 1826, which is shown to be a valid species using morphological and molecular data applied to multiple species concepts. The species is also placed onto a phylogenetic tree for the genus Sepsis that includes most European and North American species. In addition, we assess the genetic variability between two populations of the Holarctic Sepsis luteipes Melander & Spuler, 1917 from Europe and North America and find conflicting evidence between morphology and DNA sequences. Different species concepts here yield different inferences, and if two species were to be accepted based on molecular data, Sepsis helvetica Munari, 1985 from Europe would have to be resurrected from synonymy. We provide high-resolution images for all species in order to aid in accurate identification. Both species are also added to Sepsidnet, the digital reference collection for Sepsidae (http://sepsidnet-rmbr.nus.edu.sg). Lastly, we discuss a field site in the Swiss Alps where 12 species of Sepsis occur sympatrically on the same pasture.