bluuebunny/crossref_metadata_2025 huggingface dataset:
Employing Noncognitive Variables to Improve Admissions, and Increase Student Diversity and Retention
Authors: Kalsbeek David , Sandlin Michele , Sedlacek William
Published: July 2013

Today, a growing number of North American postsecondary institutions are incorporating the use of noncognitive variables into their requirements for a holistic admissions process. Why is there more and more interest in utilizing these nonacademic variables for students who are applying to these institutions? It's all about student success and institutional improvement. The results from those colleges and universities that have embraced holistic admissions by adding noncognitive measures to their admissions requirements include students’ academic success and improved institutional persistence and graduation rates—particularly among students who may be disadvantaged by traditional admission practices.
Harnessing the Influence of Reactive Edges and Defects of Graphene Substrates for Achieving Complete Cycle of Room‐Temperature Molecular Sensing
Authors: Randeniya Lakshman K. , Shi Hongqing , Barnard Amanda S. , Fang Jinghua , Martin Philip J. , Ostrikov Kostya (Ken)
Published: July 2013

Molecular doping and detection are at the forefront of graphene research, a topic of great interest in physical and materials science. Molecules adsorb strongly on graphene, leading to a change in electrical conductivity at room temperature. However, a common impediment for practical applications reported by all studies to date is the excessively slow rate of desorption of important reactive gases such as ammonia and nitrogen dioxide. Annealing at high temperatures, or exposure to strong ultraviolet light under vacuum, is employed to facilitate desorption of these gases. In this article, the molecules adsorbed on graphene nanoflakes and on chemically derived graphene‐nanomesh flakes are displaced rapidly at room temperature in air by the use of gaseous polar molecules such as water and ethanol. The mechanism for desorption is proposed to arise from the electrostatic forces exerted by the polar molecules, which decouples the overlap between substrate defect states, molecule states, and graphene states near the Fermi level. Using chemiresistors prepared from water‐based dispersions of single‐layer graphene on mesoporous alumina membranes, the study further shows that the edges of the graphene flakes (showing p‐type responses to NO2 and NH3) and the edges of graphene nanomesh structures (showing n‐type responses to NO2 and NH3) have enhanced sensitivity. The measured responses towards gases are comparable to or better than those which have been obtained using devices that are more sophisticated. The higher sensitivity and rapid regeneration of the sensor at room temperature provides a clear advancement towards practical molecule detection using graphene‐based materials.
Addressing perceptual insensitivity to facial affect in violent offenders: first evidence for the efficacy of a novel implicit training approach
Authors: Schönenberg M. , Christian S. , Gaußer A.-K. , Mayer S. V. , Hautzinger M. , Jusyte A.
Published: July 2013

Background

Although impaired recognition of affective facial expressions has been conclusively linked to antisocial behavior, little is known about the modifiability of this deficit. This study investigated whether and under which circumstances the proposed perceptual insensitivity can be addressed with a brief implicit training approach.

Method

Facial affect recognition was assessed with an animated morph task, in which the participants (44 male incarcerated violent offenders and 43 matched controls) identified the onset of emotional expressions in animated morph clips that gradually changed from neutral to one of the six basic emotions. Half of the offenders were then implicitly trained to direct attention to salient face regions (attention training, AT) using a modified dot-probe task. The other half underwent the same protocol but the intensity level of the presented expressions was additionally manipulated over the course of training sessions (sensitivity to emotional expressions training, SEE training). Subsequently, participants were reassessed with the animated morph task.

Results

Facial affect recognition was significantly impaired in violent offenders as compared with controls. Further, our results indicate that only the SEE training group exhibited a pronounced improvement in emotion recognition.

Conclusions

We demonstrated for the first time that perceptual insensitivity to facial affect can be addressed by an implicit training that directs attention to salient regions of a face and gradually decreases the intensity of the emotional expression. Future studies should focus on the potential of this intervention to effectively increase empathy and inhibit violent behavior in antisocial individuals.
Modelling sandgrouse (Pterocles spp.) distributions and large-scale habitat requirements in Spain: implications for conservation
Authors: BENÍTEZ-LÓPEZ ANA , VIÑUELA JAVIER , HERVÁS ISRAEL , SUÁREZ FRANCISCO , GARCÍA JESÚS T.
Published: July 2013

Knowledge of the factors determining species distributions is essential for developing conservation strategies. Sandgrouse Pterocles alchata and P. orientalis are threatened in Spain, the stronghold of European populations. Spatial modelling was used to: (1) assess the relative importance of abiotic, anthropogenic and geographical factors in the distribution of both sandgrouse species, (2) determine the most important anthropogenic predictors for each species occurrence, and (3) identify areas where conservation efforts should be prioritized. Abiotic and anthropogenic factors explained most of the variation in sandgrouse distributions. Both species were associated with arid flatlands, arable land cover being the most important anthropogenic variable determining their distribution. The Common Agricultural Policy (CAP) is the main driver of agricultural management in Europe, and may thus have a direct effect on sandgrouse distributions. P. orientalis exhibited broader habitat tolerance than P. alchata; the latter species tolerates warmer climates. Consequently, the network of core and marginally suitable areas identified for each species differs, and connectivity between the populations of these areas seems unlikely. Potential future changes in sandgrouse distribution will probably be directed principally by the synergistic effects of climate change and expected land-use transformations resulting from the new CAP and ongoing population growth, urbanization and infrastructure development.
Transient global amnesia
Authors: Boovalingam P , Shah N
Published: July 2013

Transient global amnesia (TGA) has been described since the 19th century. It is characterized by an episode of anterograde and retrograde amnesia lasting less than 24 hours. During this episode patients are conscious and able to interact normally, but are typically distressed and repeat questions without remembering explanations. Despite progress in medical imaging, no cause for the condition has been proven. Prognosis is excellent and management centres on recognition and reassurance. We describe the epidemiology, pathophysiology, clinical features and management.
Towards ‘Total’ Recycling: Women, Waste and Food Waste Recovery in Germany, 1914–1939
Authors: WEBER HEIKE
Published: July 2013

In two critical periods of German history, namely during wartime Imperial Germany and the National Socialist era, the German state resorted to salvaging waste to mobilise both people and resources at home for the war effort. Waste recycling efforts were part of preparing the national economy as well as home front morale for ‘total’ war. Since domestic waste – the generation of which was largely an urban phenomenon before the advent of mass consumer society – has traditionally been defined as a female responsibility, urban women were seen as the main pillars of waste work. Collecting, separating and storing reusable leftovers became a pervasive element of their everyday lives, as well as those of schoolchildren. Moreover, in the case of the First World War, under the umbrella of the so-called National Women's Service (Nationaler Frauendienst or NFD), women's associations set up grass-roots local waste collections before the state discovered the potential of waste for its war mobilisation efforts from 1916 onwards. The article highlights this self-mobilisation in the case of food recycling. Furthermore, it explores the continuities and differences between First World War waste salvage and later Nazi waste policies. Claiming to have learnt their lessons from the salvage drives of the First World War, the Nazis aimed at a ‘total’ waste recovery at the latest from 1936 onwards and took a top-down approach to reach it; in contrast, waste salvage drives of the First World War had been dominated by local and often female initiatives.
The Glass Recycling Container in the Netherlands: Symbol in Times of Scarcity and Abundance, 1939–1978
Authors: OLDENZIEL RUTH , VEENIS MILENA
Published: July 2013

The Netherlands is reputed to be the first Western European country with separate waste collection. The first Dutch recycling container was established in 1972 by a local action committee of women, who were involved in raising environmental awareness and in critiquing the waste of consumer society. Their initiative was a huge success. Action committees in dozens of cities followed their example in short order, supported by national politicians. Six years later, glass recycling containers dotted the country. Although novel, and a powerful icon of the politicized climate of the 1970s, Oldenziel and Veenis argue that the quick success of glass containers cannot be explained in the political context of rising environmentalism alone. The ready acceptance of glass containers and the practice of separating waste were rooted in national practices of a culture of thrift on the one hand and coercive wartime policies of reuse on the other. Based on archival material, the authors analyse the ways that recycling container activism was rooted in the tradition of the culture of thrift. More specifically, they trace how the culture of thrift had been reinforced in coercive wartime policies when authorities dealt with shortages during the German occupation and how the practice became a source of the 1970s history of glass container activism.
Green Citizenship at the Recycling Junction: Consumers and Infrastructures for the Recycling of Packaging in Twentieth-Century Norway
Authors: JØRGENSEN FINN ARNE
Published: July 2013

This article investigates the making of the Norwegian recycling consumer-citizen by discussing recycling as both a cultural activity – an expression of environmentalist sentiment, an everyday habit and a social expectation – and a technological infrastructure consisting of disposal stations, legal frameworks, transportation systems and the recycling technologies themselves. Using a concept of ‘recycling junctions’ as a means of understanding historical recycling processes, the article focuses on beverage packaging to argue that effective recycling in the modern green state depends on a combination of technologically mediated convenience and green consumer-citizenship, involving a wide range of actors.
THE LESS-INVASIVE PERINATAL AUTOPSY: CURRENT STATUS AND FUTURE DIRECTIONS
Authors: ARTHURS O J , TAYLOR A M , SEBIRE N J
Published: July 2013

Full autopsy. A combination of external examination, radiological investigations, evisceration, dissection and subsequent full organ examination with detailed histological evaluation. This is the current “gold standard” of care against which other approaches are compared.
Post‐synthetic Modification of MOFs
Authors: Burrows Andrew D.
Published: July 2013

Post‐synthetic modification is increasingly recognised as an important and versatile tool in the preparation of functionalised metal organic frameworks (MOFs). The process involves one or more reactions on a pre‐formed MOF, and it can be used to prepare MOFs that are not accessible by direct combination of metal and linker. This review explores the methods and strategies that have been developed for post‐synthetically modifying MOFs, concentrating on four classes of reaction: covalent transformations of the linker, coordination of a metal centre to a linker, modification of the inorganic part of the MOF and exchange of counter‐ions. Examples of the use of the modified MOFs are given, with a focus on their utility in catalysis.
Strategies for Creating Active Sites in MOFs
Authors: Llabrés i Xamena Francesc X. , Luz Ignacio , Cirujano Francisco G.
Published: July 2013

This chapter presents a general overview of the main properties of MOFs that make them very appealing for applications in heterogeneous catalysis. Great efforts have been directed in the last decade to study the potential of MOFs in catalysis. We will now see what is behind this “MOF rush”. Next, we will present some general considerations that should be taken into account when planning the use of MOFs as heterogeneous catalysts, such as stability, recovery and reusability. And finally, we will review the different strategies that can be used to introduce the desired catalytic centers into the MOFs. We will show how it is possible by using these strategies to engineer the material for catalysis, and to fine tune the properties of the MOF to influence the catalytic performance.
Catalysis at the Metallic Nodes of MOFs
Authors: Vermoortele Frederik , Valvekens Pieterjan , De Vos Dirk
Published: July 2013

The intrinsically high metal content of MOFs makes them appealing for use in catalysis. Over the past few years, a wide variety of MOFs has been intensively studied as catalysts in various liquid phase organic reactions. The most intriguing class of MOF catalysts is that in which the structural nodes themselves act as the catalytic centres. This chapter will give an overview of some research on MOF catalysts in which the metal ions are the active sites. The examples given show that this class of materials offers a unique opportunity to finely tune the active site with tools previously only available in homogeneous complexes. This aspect, combined with their facile recycling, raises high expectations that MOFs can be applied by industry in the near future.
MOFs as Nano‐reactors
Authors: Juan‐Alcañiz Jana , Ramos‐Fernandez Enrique V. , Kapteijn Freek , Gascon Jorge
Published: July 2013

The use of metal organic frameworks (MOFs) as catalytic nanoreactors is thoroughly reviewed. Two approaches can be followed for the encapsulation of catalytically active species into the scaffold of a MOF: (i) ship in a bottle and (ii) bottle around a ship. In the first case, formation of metallic nanoparticles or metal oxides are among the most studied systems, and metal precursor impregnation followed by reduction/oxidation is the widely used synthetic strategy. Also worth mentioning are the few examples of enzyme encapsulation. On the other hand, bottle around a ship has been used when the active phase is added to the MOF synthesis and in situ encapsulated. The most studied example has been described for heteropolyacids, where templating effects have been discovered. The encapsulation of other macromolecules, such as porphyrins, illustrate the great opportunities that MOFs offer for direct encapsulation. The confinement of the active sites affects their catalytic behaviour when compared with their homogeneous counterparts, in most cases enhancing both conversion and selectivity to the desired products. In addition, confined active sites are protected from deactivation by leaching or aggregation, thus facilitating catalyst reusability.
Recycling Policy: The Sound Material Cycle Society and 3R Concepts from Japan to Developing Asia
Authors: Hotta Yasuhiko
Published: July 2013

The key challenges in waste management facing rapidly developing economies are the consideration of increasing resource consumption and waste generation, as well as the establishment of a “sound material cycle society”. The latter refers to the concept of promoting a social change in which the consumption of natural resources is minimised and the environmental load is reduced as much as possible by preventing products from becoming wastes, promoting appropriate recycling of products, and securing appropriate disposals of wastes that are not recycled.

This chapter proposes that recycling is not only about technical solutions or engineering of resource‐recovery from waste. Rather, it is an issue of how to systematically organise institutional infrastructure and physical infrastructure to sustain recycling mechanisms. Lessons from the ‘sound material cycle society’ policy of Japan are discussed. By reviewing policy‐related issues for recycling in developing Asia, the challenges and opportunities for the institutionalisation of recycling and the establishment of a ‘sound material cycle society’ in the context of developing economies are summarised.
Transmission‐constrained intrahour coordination of wind and pumped‐storage hydro units
Authors: Khodayar Mohammad E. , Abreu Lisias , Shahidehpour Mohammad
Published: July 2013

This study proposes a coordination methodology for wind and pumped‐storage hydro (PS) units in the day‐ahead operation planning of power systems. PS units that can store the extra wind energy will improve the dispatchability of variable wind energy for delivering hourly firmed energy to a power grid. With coordination, the PS unit can offset intrahour wind energy imbalances (i.e. deviations from hourly schedules) and minimise wind energy curtailments. The proposed coordination, which is incorporated into the transmission‐constrained unit commitment, can be used by a vertically integrated utility or an independent system operator. The concept of intrahour wind energy imbalances and the wind‐PS coordination is illustrated using two case studies. The numerical results for the 6‐bus and the IEEE 118‐bus system include case studies with and without the coordination of PS and wind generation units. The results that include the intrahour variability of real‐time wind speed show the applicability of the proposed wind‐PS coordination approach to the short‐term power system operation.
Bilevel approach for optimal location and contract pricing of distributed generation in radial distribution systems using mixed‐integer linear programming
Authors: Rider Marcos J. , López‐Lezama Jesús María , Contreras Javier , Padilha‐Feltrin Antonio
Published: July 2013

In this study, a novel approach for the optimal location and contract pricing of distributed generation (DG) is presented. Such an approach is designed for a market environment in which the distribution company (DisCo) can buy energy either from the wholesale energy market or from the DG units within its network. The location and contract pricing of DG is determined by the interaction between the DisCo and the owner of the distributed generators. The DisCo intends to minimise the payments incurred in meeting the expected demand, whereas the owner of the DG intends to maximise the profits obtained from the energy sold to the DisCo. This two‐agent relationship is modelled in a bilevel scheme. The upper‐level optimisation is for determining the allocation and contract prices of the DG units, whereas the lower‐level optimisation is for modelling the reaction of the DisCo. The bilevel programming problem is turned into an equivalent single‐level mixed‐integer linear optimisation problem using duality properties, which is then solved using commercially available software. Results show the robustness and efficiency of the proposed model compared with other existing models. As regards to contract pricing, the proposed approach allowed to find better solutions than those reported in previous works.
Study on the field effects under reduced‐scale DC/AC hybrid transmission lines
Authors: Zhang Bo , Li Wei , He Jinliang , Zeng Rong
Published: July 2013

The possibility for DC and AC power lines running parallel to each other, sharing the same right‐of‐way or even the same tower has been increased in China. In this work, the coupled DC and AC electric field effects are analysed with a reduced‐scale model. Improved measuring methods are proposed to obtain both the DC and AC components of the ground level electric field and ion current density. Depressing effects of the AC field on the ground level DC field and of the DC field on the ground level AC field are observed when the applied DC voltage exceeds the onset value. The mechanism of the influences of AC power lines on the nearby DC power lines is analysed with experiments and simulations. Both the influence of the AC field on the corona onset on the surfaces of DC conductors and the influence of the AC field on the motion of the space charges are proved to be important in the field effects under the hybrid lines.
Turn‐to‐earth fault modelling of power transformer based on symmetrical components
Authors: Gouda Osama E. , Dein Adel Zein El , Moukhtar Ibrahem
Published: July 2013

In this paper, a new approach to simulate transformer turn to earth fault, by using symmetrical components approach, has been presented. In the suggested novel modeling technique, the transformer turn to earth fault is simulated as a new healthy transformer with new short circuit (SC) impedance. This SC impedance is considered as the SC impedance of the transformer with the fraction part of the transformer winding through which the turn to earth fault occurs. The SC impedance of the reminder part of the transformer winding is added to the transmission line impedance or load impedance as external impedance. Hence, by using this suggested modelling technique, the system of turn to earth fault transformer is represented with a new system of a new healthy transformer, and the turn to earth fault is represented as an external line to ground fault. The values of the turn to earth fault current from this novel modelling technique (using the symmetrical components approach) were compared with those obtained by Electromagnetic Transient Program/Alternative Transient Program (EMTP/ATP). Finally, a suggestion method to estimate general information about the SC impedance of a three‐phase three‐winding transformer at different percentages of turn to earth fault is discussed.
Ultra wideband loop antenna on contact with human body tissues
Authors: Tuovinen Tommi , Berg Markus , Yekeh Yazdandoost Kamya , Iinatti Jari
Published: July 2013

Human body tissues have a strong effect on the antenna operation in wireless body area networks (WBANs). In this study, the authors present the deep investigations of the effect of body tissue thicknesses on the performance of an ultra wideband (UWB) loop antenna by simulations when the antenna is operated on contact with tissues. The planar UWB loop antenna is designed for the examinations, which is targeted to be used in UWB WBAN applications. The effect of tissue thicknesses on the antenna performance is analysed and characterised in the terms of reflection coefficient S11, gain and total antenna efficiency, group delay, radiation patterns and specific absorption rate by simulations. A parametric layered human body tissue model with the frequency‐dependent behaviour is exploited in the investigations. Further, the reflection coefficient of the presented antenna is measured in the different locations of the author's body. The main aim of these investigations is to demonstrate how the thickness of outermost body tissues affects the antenna performance.
Applications of electrically tunable composite right/left handed transmission lines based on barium–strontium–titanate thick films and open resonators
Authors: Durán‐Sindreu Miguel , Damm Christian , Sazegar Mohsen , Bonache Jordi , Jakoby Rolf , Martín Ferran
Published: July 2013

This paper is focused on the study and applications of tunable composite right/left handed transmission lines (CRLH TL) based on open resonators. Specifically, it will be demonstrated that CRLH TL based on open split ring resonators (OSRRs) and open complementary split ring resonators (OCSRRs) can be tuned by means of barium–strontium–titanate thick‐films. These artificial lines are applied to the design of tunable band‐pass filters, phase shifters, dual‐band impedance inverters and dual‐band power dividers, where independent or simultaneous tuning of different resonators can be considered, depending on the application. The design methodology and different proof‐of‐concept demonstrators are reported.
Reconfigurable‐bandwidth bandpass filter within 10–50%
Authors: Sánchez‐Soriano Miguel Á. , Gómez‐García Roberto , Torregrosa‐Penalva Germán , Bronchalo Enrique
Published: July 2013

An original and simple approach to design electronically reconfigurable‐bandwidth microwave planar bandpass filters is reported. It exploits the use of transversal signal‐interference filtering sections shaped by a branch‐line directional coupler arranged in reflection mode with switchable stubs. Thus, by switching on/off these stubs through p–i–n diodes, sharp‐rejection filtering functions with different bandwidths and multiple out‐of‐band transmission zeros are produced. Analytical equations and guidelines for the synthesis of the basic switchable filter building block are detailed. Moreover, a 2 GHz two‐stage proof‐of‐concept microstrip prototype, with five distinct bandwidth states ranging from ∼10 to 50%, is built and characterised for experimental verification.
Design of electronically switchable single‐to‐balanced bandpass low‐noise amplifier
Authors: Lin Yo‐Shen , Wu Jian‐Fong , Hsia Wei‐Fan , Wang Ping‐Chieh , Chung Yu‐Hsuan
Published: July 2013

In this work, the design of novel electronically switchable single‐to‐balanced bandpass low‐noise amplifier (LNA) is proposed so as to improve the level of integration for radio frequency (RF) front‐end design. By realising the input matching circuit with an electronically switchable bandpass filter and the output matching circuit as a bandpass balun, the LNA can also exhibit the functions of RF switch, bandpass filter and balun simultaneously. In this way, more compact circuit size and less mismatch loss can then be obtained in RF front‐end design. To demonstrate the performance and effectiveness of the proposed design method, a 2‐GHz electronically switchable single‐to‐balanced bandpass LNA is implemented on printed circuit board using packaged E‐pHEMT transistor.
Stable and compact multiband frequency selective surfaces with Peano pre‐fractal configurations
Authors: da Silva Marcelo Ribeiro , Nóbrega Clarissa de Lucena , da Fonseca Silva Paulo Henrique , D'Assunção Adaildo Gomes
Published: July 2013

This work presents a fractal design methodology for frequency selective surfaces (FSSs) with Peano pre‐fractal patch elements. The proposed FSS structures are composed of periodic arrays of metallic patches printed on a single‐layer fibreglass dielectric. The shapes presented by pre‐fractal patches allow one to design compact FSSs that behave like dual‐polarised band‐stop spatial filters. On the other side, the space‐filling and self‐similarity properties of Peano fractals became possible various configurations for patch elements. An FSS parametric analysis is performed in terms of the fractal iteration‐number and cell‐size of pre‐fractal patches. To validate the used methodology four FSS prototypes are built and tested in the range from 1.0 to 13.5 GHz. Experimental characterisation of the FSS prototypes is accomplished through three different measurement setups with commercial horns and circular monopole microstrip antennas. Results show that the proposed FSS presents most of the desired features for spatial filters: compact design, multiband responses, dual‐polarisation, excellent angular stability and facility for reconfiguration.
Robust compressive multi‐input–multi‐output imaging
Authors: Zhao Guanghui , Wang Qi , Shen Fangfang , Li Xiaoming , Shi Guangming
Published: July 2013

Canonical multi‐input–multi‐output (MIMO) imaging methods suffer from limited resolution, poor robustness against noise and high computational complexity, especially when the array aperture is limited (affecting angular resolution) and the number of snapshots is limited (affecting Doppler resolution). In this study, the authors discuss a new range‐angle‐Doppler monostatic MIMO imaging method through adaptive estimation of the generalised Cauchy prior distribution (GCD). The superiority of GCD‐based model over existing ℓp‐norm‐based model (which actually assumes the prior as general Gaussian distribution) is theoretically verified through the issue of signal compressibility. The authors adapt a reweighted ℓ2‐norm iterative algorithm to solve the model. In our model the authors do not pre‐define the scaling factor of the prior distribution and, during the iteration, the authors use a novel ‘quantile‐of‐OS’ method to adaptively estimate the scaling parameter of the prior distribution, enhancing the robustness of the method. Simulation results verify the image quality and speed advantages of the proposed method.
Exponential filter‐based delay estimation algorithm for active systems in the presence of multi‐targets
Authors: Zhang Lu , Deng Ke , Wang Hui‐Qi , Luo Mao‐Kang
Published: July 2013

A multi‐targets delay estimation algorithm is presented for band‐limited and active systems to estimate delays from noisy received signal that consists of attenuated and delayed replicas of a known reference signal and an additive white Gaussian noise. The normal parameters (delays, amplitudes and number of targets, noise variance) of the received signal are assumed to be unknown. In the particular problem under study, range resolution and output signal‐to‐noise ratio (SNR) are the most important parameters. However, with the use of the conventional matched filter or inverse filter, one parameter is optimised while the other cannot be guaranteed at a desired level and the receiving system is always fixed by the initial design that is unsuitable for every actual condition. The authors proposed a novel delay estimation filter – exponential filter (EF), with a sensitivity exponent α that controls its output SNR and range resolution. Based on the proposed EF, delay estimation algorithm that is optimal for actual requirements is proposed for multi‐targets problem. Moreover, the range resolution can be significantly improved by a technique called CLEAN. Therefore, a CLEAN algorithm‐based target separation technique is also applied to the proposed algorithm, which can effectively suppress the interferences on weak targets brought by the stronger targets. Simulation results show the effectiveness of the proposed algorithm.
Information‐based algorithm for moving object detection
Authors: Andrić Milenko S. , Todorović Branislav M.
Published: July 2013

An algorithm for moving object detection using the information entropy is proposed and analysed. The proposed algorithm is applied on Doppler radar signal and it represents an alternative approach to Doppler radar signal analysis using the Fourier transform. The algorithm is tested using data obtained in real measurements by ground surveillance Doppler radar. The numerical results are compared with those obtained by the method using the Fourier transform. It is shown that the ground clutter due to windblown vegetation, which is the main challenge for radar to detect moving object, does not affect the information entropy. The impact of two main parameters of the algorithm on information entropy is analysed. The authors discuss on choice of the detector structure, threshold setting and decision rule. The computational complexity of the proposed algorithm is calculated and compared with the complexity of the method using Fourier transform. It is shown that the computational complexity of the proposed algorithm is one order of magnitude lower than the computational complexity of the method using Fourier transform.
Two helicopter classification methods with a high pulse repetition frequency radar
Authors: Zuo Lei , Li Ming , Zhang Xiao‐wei , Wu Yan
Published: July 2013

In this study, two helicopter classification methods with a high pulse repetition frequency radar are proposed. By analysing the returned signal from a main rotor, the authors find that the essential difference between rotors appears when none of blades is orthogonal to the incident waves. Based on this difference, the authors propose two methods to classify the helicopter. The first one is based on the matched filters (MFs), including the time MF and the time‐frequency MF. The second one derives from time‐frequency masks. Experimental results demonstrate that both methods have the ability to classify helicopters with the same micro‐Doppler parameters at a low signal‐to‐noise ratio. And they are robust against errors of the estimated parameters and the gesture of the helicopter.
Role of coherent structures in supersonic impinging jets
Authors: Kumar Rajan , Wiley Alex , Venkatakrishnan L. , Alvi Farrukh
Published: July 2013

This paper describes the results of a study examining the flow field and acoustic characteristics of a Mach 1.5 ideally expanded supersonic jet impinging on a flat surface and its control using steady microjets. Emphasis is placed on two conditions of nozzle to plate distances (h/d), of which one corresponds to where the microjet based active flow control is very effective in reducing flow unsteadiness and near-field acoustics and the other has minimal effectiveness. Measurements include unsteady pressures, nearfield acoustics using microphone and particle image velocimetry. The nearfield noise and unsteady pressure spectra at both h/d show discrete high amplitude impinging tones, which in one case (h/d = 4) are significantly reduced with control but in the other case (h/d = 4.5) remain unaffected. The particle image velocimetry measurements, both time-averaged and phase-averaged, were used to better understand the basic characteristics of the impinging jet flow field especially the role of coherent vortical structures in the noise generation and control. The results show that the flow field corresponding to the case of least control effectiveness comprise well defined, coherent, and symmetrical vortical structures and may require higher levels of microjet pressure supply for noise suppression when compared to the flow field more responsive to control (h/d = 4) which shows less organized, competing (symmetrical and helical) instabilities.
Simulated photodetachment spectra of AlH2−
Authors: Mok Daniel K. W. , Lee Edmond P. F. , Chau Foo-tim , Dyke John M.
Published: July 2013

We have carried out high-level ab initio calculations on AlH2 and its anion, as well as Franck-Condon factor calculations, which include anharmonicity and Duschinsky rotation, to simulate the photodetachment spectrum of AlH2−, with the aim of assigning the very recently reported photodetachment spectrum of AlH2− [X. Zhang, H. Wang, E. Collins, A. Lim, G. Ganteför, B. Kiran, H. Schnöckel, B. Eichhorn, and K. Bowen, J. Chem. Phys. 138, 124303 (2013)]10.1063/1.4796200. However, our simulated spectra do not support the assignment of the reported experimental spectrum to AlH2−.
The nature of the superoxide radical anion in water
Authors: Janik Ireneusz , Tripathi G. N. R.
Published: July 2013

Vibrational properties of the superoxide radical anion (O2−•) in liquid water have been experimentally investigated for the first time. The stretching frequency, its shift from the gas-phase to aqueous solution, anharmonicity constant, and the Raman bandwidths provide an insight into the radical-water interactions and the hydration cage. In view of the spectroscopic information obtained in this work, the structural models based on molecular dynamics simulation in solution and gas-phase infrared studies of the water molecules bound to O2−• are critically examined.
Fluid transport in thin liquid films using traveling thermal waves
Authors: Mao Wenbin , Oron Alexander , Alexeev Alexander
Published: July 2013

Using long wave theory and direct numerical solutions of the Navier–Stokes equations, we investigate thermocapillary flows arising in a thin liquid film covering a heated solid substrate with non-uniform temperature in the form of traveling thermal waves. Our results indicate that unidirectionally propagating interfacial waves are formed in the liquid film. The interfacial waves transport liquid, thereby creating a net pumping effect. We show that the frequency of thermal waves leading to the most efficient pumping is defined by their wave length and weakly depends on other system parameters. The results are useful for designing new methods for transporting liquids in open microfluidic devices.
Simulations of the breakup of liquid filaments on a partially wetting solid substrate
Authors: Ghigliotti Giovanni , Zhou Chunfeng , Feng James J.
Published: July 2013

We report direct numerical simulations of liquid filaments breaking up into droplets on partially wetting substrates. It is motivated by recent experiments, linear stability analyses, and lubrication-based calculations. The fluid flow is governed by the Stokes equations and the contact line motion is handled by a phase-field model, which also serves to capture the interfacial motion. The coupled Stokes and Cahn-Hilliard equations are solved using a finite-element algorithm in three dimensions. This avoids additional approximations of the fluid flow or contact line motion, and allows us to compute arbitrary contact angles on the substrate. We simulate both the breakup of infinite liquid filaments via growing capillary waves and that of finite liquid filaments with drops pinching off from the ends, with a focus on the effect of the wetting angle. In both cases, substrate hydrophobicity promotes breakup of the thread, and decreases the spacing of the daughter drops. The results show the differences in the two processes and in the final drop size and spacing. The development of capillary waves agrees well with prior linear analysis and the end-pinching results offer new insights into this poorly understood phenomenon.
Significant disorder-induced enhancement of the magnetization of Fe2CrGa by ball milling
Authors: Zhang H. G. , Zhang C. Z. , Zhu W. , Liu E. K. , Wang W. H. , Zhang H. W. , Cheng J. L. , Luo H. Z. , Wu G. H.
Published: July 2013

It is reported that ball milling gives rise to a different atomic configuration in Fe2CrGa than the order obtained upon preparation by arc melting. After ball milling, the magnetic moment has values of 3.2 to 3.9 μB/f.u., which is significantly higher than in arc-melted samples, and the Curie temperature increases by about 200 K. Combination of first-principles calculations and experimental results indicates that Fe2CrGa crystallizes in the Hg2CuTi-based structures with either Fe-Ga or Cr-Ga disorder, depending on the preparation method. It is shown that magnetic interactions play a crucial role in adopting atomic configurations which disobey the empirical rule.
Electrical transport through a scanning tunnelling microscope tip and a heavily doped Si contact
Authors: Zhang Xieqiu , Wang Kedong , Chen Wenjin , Loy M. M. T. , Wang J. N. , Xiao Xudong
Published: July 2013

By allowing the metallic tip of a scanning tunnelling microscope to penetrate a Si(111) sample at 5 K, we found that the electrical transport through the tip and the heavily doped Si(111) contact undergoes a transition from rectifying to ohmic behavior. This transition does not occur when the tip penetrates a moderately doped Si(111). This observed ohmic behavior when the Si(111) is heavily doped is semi-quantitatively simulated only by a vanishingly small Schottky barrier height, suggesting that the Schottky barrier height can be affected by the doping concentration in the semiconductor.
Spin wave propagation through an antidot lattice and a concept of a tunable magnonic filter
Authors: Semenova E. K. , Berkov D. V.
Published: July 2013

In this paper, we present a detailed numerical micromagnetic study of the spin wave propagation in a thin magnetic film where several columns of circular antidots (holes) are cut out. We determine the transmission coefficient of such a system as the function of the spin wave frequency (transmission spectrum), and study the absorption and transmission frequency regions in dependence on the interdot distances and on the number of antidot columns. It turns out that already several antidot columns are sufficient to obtain nearly perfect gaps in the transmission spectrum of spin waves, so that already a system of a few such columns can be used as a very effective magnonic filter. Next, we establish a close relation between the transmission spectrum of our system and the spectrum of eigenmodes of the corresponding infinite antidot lattice. Finally, we demonstrate that transmission and absorption bands can be easily tuned (for the given antidot arrangement) by changing the external magnetic field. Importantly, the transmission spectrum exhibits a universal scaling when the external field is changed, when this spectrum is plotted as the function of the magnon wave vector.
Polymorphic phase boundaries and enhanced piezoelectric response in extended composition range in the lead free ferroelectric BaTi1−xZrxO3
Authors: Kalyani Ajay Kumar , Senyshyn Anatoliy , Ranjan Rajeev
Published: July 2013

Neutron powder diffraction study of Ba(Ti1−xZrx)O3 at close composition intervals has revealed coexistence of ferroelectric phases: orthorhombic (Amm2) + tetragonal (P4mm) for 0.02 ≤ x ≤0.05 and rhombohedral (R3m) + orthorhombic (Amm2) for 0.07 ≤ x < 0.09. These compositions exhibit relatively enhanced piezoelectric properties as compared to their single phase counterparts outside this composition region, confirming the polymorphic phase boundary nature of the phase coexistence regions.
Combining the satellite imagery with bright sunshine hours: A review
Authors: Akinoglu B. G. , Ener Rusen S.
Published: July 2013

Present article is a review of recent researches on linking the satellite image data to surface measured bright sunshine hours. It first gives some basics on estimation procedures of the daily global solar irradiation on horizontal surface with the daily bright sunshine hours. Second, a satellite based model is presented briefly. Then, two recent combined models are reviewed and compared with the conventional models. The results on using one of the presented methods are discussed and recommended, for a couple of various cases which are classified by available data of the site of interest. It is concluded that the use of one of the combined model gives one of the best estimation performance for the daily global solar irradiation at the Earth's surface, whenever both of the data of bright sunshine and cloud index are available. However, satellite based model HELIOSAT also performs with high accuracy except for a number of days of one of the data sets. Hence, another conclusion is that, for the daily estimations, the use of HELIOSAT type satellite based models should be preferred, instead of using an Angström-Prescott type correlation of a location at a far point and/or having a different climate. Finally, a quadratic correlation which was tested for too many locations all over the world also performs quite accurately. Therefore, if only the bright sunshine hour data is available for a site, use of this quadratic correlation should be preferred.
Tailoring exchange bias through chemical order in epitaxial FePt3 films
Authors: Saerbeck T. , Zhu H. , Lott D. , Lee H. , LeClair P. R. , Mankey G. J. , Stampfl A. P. J. , Klose F.
Published: July 2013

Intentional introduction of chemical disorder into mono-stoichiometric epitaxial FePt3 films allows to create a ferro-/antiferromagnetic two-phase system, which shows a pronounced and controllable exchange bias effect. In contrast to conventional exchange bias systems, granular magnetic interfaces are created within the same crystallographic structure by local variation of chemical order. The amount of the exchange bias can be controlled by the relative amount and size of ferromagnetic and antiferromagnetic volume fractions and the interface between them. The tailoring of the magnetic composition alone, without affecting the chemical and structural compositions, opens the way to study granular magnetic exchange bias concepts separated from structural artifacts.
Compact bilinear operators and commutators
Authors: Bényi Árpád , Torres Rodolfo
Published: July 2013

A notion of compactness in the bilinear setting is explored. Moreover, commutators of bilinear Calderón-Zygmund operators and multiplication by functions in a certain subspace of the space of functions of bounded mean oscillations are shown to be compact.
Imaging and Manipulating Calcium Transients in Developing Xenopus Spinal Neurons
Authors: Spitzer Nicholas C. , Borodinsky Laura N. , Root Cory M.
Published: July 2013

Many forms of electrical excitability expressed in the embryonic nervous system depend on Ca2+ influx. This discovery has stimulated investigation of the functions of spontaneous elevations of intracellular Ca2+ and their roles in neuronal development. We present a protocol for imaging different classes of intracellular Ca2+ transients in embryonic Xenopus (amphibian) spinal neurons grown in dissociated cell culture and in the intact neural tube (the developing spinal cord), focusing on early stages of neuronal differentiation around the time of neural tube closure. The protocol describes methods for gain-of-function and loss-of-function experiments to reveal the functions of these Ca2+ transients. The methods can also be applied to explant and organotypic cultures. The procedures are sufficiently simple that they can be further adapted for dissociated neuronal cell cultures from other developing embryos, embryonic spinal cords of vertebrates such as zebrafish, and ganglia in the developing nervous systems of invertebrates.
Measuring Interstitial Diffusion, Convection, and Binding Parameters in Mouse Tumors
Authors: Jain Rakesh K. , Munn Lance L. , Fukumura Dai
Published: July 2013

Noninvasive techniques have been developed for the assessment of various parameters in normal and diseased tissues of mice. This protocol describes the measurement of extravascular parameters, including interstitial diffusion, convection, and binding parameters, in mouse tumors. A fluorescently labeled molecule of interest is infused into the tumor interstitium, followed by imaging using single-photon microscopy or multiphoton laser-scanning microscopy (MPLSM). Fluorescence recovery after photobleaching (FRAP) with spatial Fourier analysis is performed. To measure interstitial diffusion coefficients, multiphoton FRAP is performed.
The Fundamentals of RNA Purification
Authors: Nilsen Timothy W.
Published: July 2013

The ability to purify, analyze, and manipulate RNA is now essential for many laboratories working in the life sciences; however, the skills and practices required to work with RNA are not present in every laboratory, and initiating RNA research can be intimidating. In this article, we provide an overview of RNA purification procedures and discuss strategies to prevent RNA degradation, so that any competent researcher can confidently purify RNA and use it to perform meaningful experiments from the most basic to the highly sophisticated.