bluuebunny/crossref_metadata_2025 huggingface dataset:
When the Pathologist is Giving the Answer: An Unusual Case of Pulmonary Hypertension
Authors: Priore Elia Lo , Fusi-Schmidhauser Tanja
Published: September 2014

Wir berichten über einen Fall eines 75-jährigen Patienten mit schwerem Lungenhochdruck, der mit einer rapid progredienten interstitiellen Lungenerkrankung assoziiert ist, die zum Exitus führt. Die Obduktion zeigt das Vorhandensein eines Siegelzellringkarzinoms des Magens, sowie eine Lungenembolie aus Karzinomzellen und eine sogenannte «pulmonary tumour thrombotic microangiopathy». Wir diskutieren die klinischen Befunde, die diagnostischen Massnahmen sowie möglichen Therapieoptionen und die Prognose.
Late Life Human Development
Authors: Kolling Thorsten , Knopf Monika
Published: September 2014

Human development in late life is characterized by a multitude of biological changes, some of which are presumed to occur universally as the result of biological aging factors in a narrow sense, whereas others may have their basis in individual lifestyle. The present paper first describes the various different views of the aging process from a biological perspective (evolutionary, probabilistic, deterministic views) and then outlines how these universal biological changes are boosted or buffered by negative or positive individual lifestyles focusing on recent research using telomere length as a biomarker of aging. We conclude that this perspective on lifestyle-dependent differential plasticity of universal biological aging can be used by clinicians to promote healthy aging.
MiR-181a Regulates Blood-Tumor Barrier Permeability by Targeting Krüppel-Like Factor 6
Authors: Ma Jun , Yao Yilong , Wang Ping , Liu Yunhui , Zhao Lini , Li Zhen , Li hiqing , Xue Yixue
Published: September 2014

Blood-tumor barrier (BTB) constitutes an efficient organization of tight junctions that impairs the delivery of therapeutic drugs. However, the methods and molecular mechanisms underlying the BTB opening remain elusive. MicroRNAs (miRNAs) have recently emerged as key regulators of various biologic processes and therapeutic targets. In this study, we have identified microRNA-181a (miR-181a) as a critical miRNA in opening BTB. MicroRNA-181a expression was upregulated in glioma endothelial cells (GECs), which were obtained by coculturing endothelial cells (ECs) with glioma cells. Overexpression of miR-181a resulted in an impaired and permeability increased BTB, and meanwhile reduced the expression of zonula occluden (ZO)-1, occludin, and claudin-5. Kruppel-like factor 6 (KLF6), a transcription factor of the zinc-finger family, was downregulated in GECs. Mechanistic investigations defined it as a direct and functional downstream target of miR-181a, which was involved in the regulation of BTB permeability and the expression of ZO-1, occludin, and claudin-5. Furthermore, luciferase assays and chromatin immunoprecipitation assays showed that KLF6 upregulated the promoter activities and interacted with the promoters of ZO-1, occludin, and claudin-5 in GECs. Collectively, we showed the possibility that overexpression of miR-181a contributes to the increased permeability of BTB by targeting KLF6, thereby revealing potential therapeutic targets for the treatment of brain gliomas.
Identification and characterization of novel serum microRNA candidates from deep sequencing in cervical cancer patients
Authors: Juan Li , Tong Hong-li , Zhang Pengjun , Guo Guanghong , Wang Zi , Wen Xinyu , Dong Zhennan , Tian Ya-ping
Published: September 2014

Small non-coding microRNAs (miRNAs) are involved in cancer development and progression and serum profiles of cervical cancer patients may be useful for identifying novel miRNAs. We performed deep sequencing on serum pools of cervical cancer patients and healthy controls with 3 replicates and constructed a small RNA library. We used MIREAP to predict novel miRNAs and identified 2 putative novel miRNAs between serum pools of cervical cancer patients and healthy controls after filtering out pseudo-pre-miRNAs using Triplet-SVM analysis. The 2 putative novel miRNAs were validated by real time PCR and were significantly decreased in cervical cancer patients compared with healthy controls. One novel miRNA had an area under curve (AUC) of 0.921 (95% CI: 0.883, 0.959) with a sensitivity of 85.7% and a specificity of 88.2% when discriminating between cervical cancer patients and healthy controls. Our results suggest that characterizing serum profiles of cervical cancers by Solexa sequencing may be a good method for identifying novel miRNAs and that the validated novel miRNAs described here may be cervical cancer-associated biomarkers.
The Therapeutic Potential of hERG1 K+ Channels for Treating Cancer and Cardiac Arrhythmias
Authors: Mitcheson John , Arcangeli Annarosa
Published: September 2014

hERG potassium channels present pharmacologists and medicinal chemists with a dilemma. On the one hand hERG is a major reason for drugs being withdrawn from the market because of drug induced long QT syndrome and the associated risk of inducing sudden cardiac death, and yet hERG blockers are still widely used in the clinic to treat cardiac arrhythmias. Moreover, in the last decade overwhelming evidence has been provided that hERG channels are aberrantly expressed in cancer cells and that they contribute to tumour cell proliferation, resistance to apoptosis, and neoangiogenesis. Here we provide an overview of the properties of hERG channels and their role in excitable cells of the heart and nervous system as well as in cancer. We consider the therapeutic potential of hERG, not only with regard to the negative impact due to drug induced long QT syndrome, but also its future potential as a treatment in the fight against cancer.
Antibodies as Ion Channel Modulators
Authors: Edwards Wilson , Wickenden Alan D.
Published: September 2014

Targeting ion channels with functional antibodies is a promising approach that offers several theoretical advantages over traditional small molecule approaches, including long half-life, high potency and the potential for true pharmacological selectivity. In this chapter, we will summarize the existing evidence supporting the feasibility of targeting ion channels with functional antibodies, describe the current status of antibody-based ion channel drug discovery and discuss some possible technical challenges that may need to be addressed before the promise of ion channel antibody therapeutics can be fully realized.
Applicability of the bismuth bulk rotating disk electrode for heavy metal monitoring in undisturbed environmental and biological samples: determination of Zn(ii) in rainwater, tap water and urine
Authors: Morales María de la Gala , Marín M. Rosario Palomo , Blázquez Lorenzo Calvo , Gil Eduardo Pinilla
Published: September 2014

Bismuth bulk rotating disk electrode applicability for SWASV of Zn(ii) and Cd(ii) in undisturbed environmental water and urine samples.
Bicontinuous mesoporous carbon thin films via an order–order transition
Authors: Deng Guodong , Zhang Yuanzhong , Ye Changhuai , Qiang Zhe , Stein Gila E. , Cavicchi Kevin A. , Vogt Bryan D.
Published: September 2014

Fabrication of mesoporous carbon films with gyroid morphology using soft templating with resol is sensitive to exact details of solvent processing, thermal annealing and the age of the resol.
Efficient approach to prepare multiple chemotherapeutic agent conjugated nanocarrier
Authors: N Vijayakameswara Rao , Dinda Himadri , Ganivada Mutyala Naidu , Das Sarma Jayasri , Shunmugam Raja
Published: September 2014

A pH-responsive, multiple chemotherapeutic agent derived nanocarrier has been synthesized by conjugating doxorubicin, indomethacin, and folate to the backbone of norbornene polymer.
Facile synthesis of hierarchical hollow MoS2 nanotubes as anode materials for high-performance lithium-ion batteries
Authors: Li Guangda , Zeng Xiaoying , Zhang Tiandong , Ma Wanyong , Li Wenpeng , Wang Meng
Published: September 2014

Novel hierarchical hollow MoS2 nanotubes have been fabricated, which exhibited excellent electrochemical performance as anode materials for lithium-ion batteries.
Evolution of oxidation dynamics of histidine: non-reactivity in the gas phase, peroxides in hydrated clusters, and pH dependence in solution
Authors: Liu Fangwei , Lu Wenchao , Fang Yigang , Liu Jianbo
Published: September 2014

Oxidation of histidine by 1O2 is an important process associated with oxidative damage to proteins during aging, diseases and photodynamic therapy of tumors and jaundice, and photochemical transformations of biological species in the troposphere.
Influence of water-soluble derivatives of [60]fullerene on therapeutically important targets related to neurodegenerative diseases
Authors: Kotelnikova R. A. , Smolina A. V. , Grigoryev V. V. , Faingold I. I. , Mischenko D. V. , Rybkin A. Yu. , Poletayeva D. A. , Vankin G. I. , Zamoyskiy V. L. , Voronov I. I. , Troshin P. A. , Kotelnikov A. I. , Bachurin S. O.
Published: September 2014

Water soluble fullerene derivativesIandIIwere shown to behave as promising neuroprotective agents that improve cognitive functioning in animals.
Synthesis of nitrogen-doped reduced graphene oxide directly from nitrogen-doped graphene oxide as a high-performance lithium ion battery anode
Authors: Du Meng , Sun Jing , Chang Jie , Yang Fan , Shi Liangjing , Gao Lian
Published: September 2014

A new route has been developed to synthesize nitrogen-doped reduced graphene oxide (N-RGO) with excellent lithium storage properties.
Preparation of hierarchically structured anodic aluminum oxide by a hexagonal embedded nanosphere array
Authors: Cong Ming , Wang Yuyang , Wang Xinnan , Wang Yi , Xu Shuping , Xu Weiqing
Published: September 2014

A hierarchically structured anodic aluminum oxide (AAO) with multilayered channels was achieved. A “defect anodization” mechanism based on a new voltage/interpore distance relation was proposed.
Magnetically separable ZnFe2O4, Fe2O3/ZnFe2O4 and ZnO/ZnFe2O4 hollow nanospheres with enhanced visible photocatalytic properties
Authors: Li Junqi , Liu Zhenxing , Zhu Zhenfeng
Published: September 2014

Magnetically separable ZnFe2O4-based composite hollow nanospheres with dimensions of 230 nm were successfully synthesized via an impregnating–calcination process using phenolic formaldehyde nanospheres (PFS) as a template.
Theory and simulation of diffusion–adsorption into a molecularly imprinted mesoporous film and its nanostructured counterparts. Experimental application for trace explosive detection
Authors: Zhu Wei , Wang Chen , Wang Hui , Li Guangtao
Published: September 2014

To understand the diffusion–adsorption of small gas molecules in molecularly imprinted porous (MIP) systems, two general and suitable physicomathematical models have been developed for the molecularly imprinted mesoporous film and its nanostructured counterparts.
Enhancement of LTE RACH through extended random access process
Authors: Kim J.S. , Munir D. , Hasan S.F. , Chung M.Y.
Published: September 2014

Accommodating an increasing number of machine‐to‐machine (M2M) devices is one of the main issues faced by the cellular networks. In a typical M2M setup, several devices may try to connect to the network simultaneously. Long‐term evolution advanced (LTE‐A) networks use a random access procedure for this purpose, which is not sufficient to cater for a large number of devices. The conventional procedure is extended by allowing several devices to access the network with reduced collisions. Mathematical analysis and simulation results show that the proposed scheme increases the access probability as well as the number of successful transmissions.
Deep hash: semantic similarity preserved hash scheme
Authors: Feng Weiguo , Jia Baozhi , Zhu Ming
Published: September 2014

A novel hashing scheme based on a deep network architecture is proposed to tackle semantic similarity problems. The proposed methodology utilises the ability of deep networks to learn nonlinear representations of the input features. The equivalence of the neuron layer and the sigmoid smoothed hash functions is introduced, and by incorporating the saturation and orthogonality regulariser, the final compact binary embeddings can be achieved. The experiments illustrate that the proposed scheme exhibits superior improvement compared with conventional hashing methods.
Substation planning method based on the weighted Voronoi diagram using an intelligent optimisation algorithm
Authors: Lu Zhiying , Wang Shiju , Ge Shaoyun , Wang Chengshan
Published: September 2014

Distribution network planning is a very complicated, non‐linear, large scale multi‐objective and multi‐constraint combinatorial optimisation problem. The capacity, location and power supply range of the substation and the distribution network are optimised based on the load forecasting. In previous studies, this problem usually decomposes into two sub‐problems, one is substation planning and the other is distribution network planning. The authors propose a method based on the self‐adjustment weighted Voronoi diagram (WVD) using genetic algorithms and particle swarm optimisation for planning substations, which can optimise the location and power range of the substations when both the number and capacity of the substations are known. The weight is calculated according to the substation capacity and load distribution, and then the authors form the self‐adjusted WVD whose weight can be adaptively adjusted. This method ensures the convergence of the algorithm and also makes the location and power supply range of the substations more reasonable. On this basis, the self‐adjusted WVD based on the elitist selection genetic algorithm (ESGA‐WVD) or the particle swarm optimisation algorithm (PSO‐WVD) is achieved using the global search feature of the ESGA or the PSO. Numerical results show that ESGA‐WVD and PSO‐WVD are more reliable and reasonable than single ESGA, PSO or WVD; both in the determination of substation location and in the division of the substation power supply range. Compared with ESGA‐WVD, PSO‐WVD is better in terms of running time, convergence rate and investment costs.
Loss‐of‐mains protection system by application of phasor measurement unit technology with experimentally assessed threshold settings
Authors: Laverty David M. , Best Robert J. , Morrow D. John
Published: September 2014

Loss‐of‐mains protection is an important component of the protection systems of embedded generation. The role of loss‐of‐mains is to disconnect the embedded generator from the utility grid in the event that connection to utility dispatched generation is lost. This is necessary for a number of reasons, including the safety of personnel during fault restoration and the protection of plant against out‐of‐synchronism reclosure to the mains supply. The incumbent methods of loss‐of‐mains protection were designed when the installed capacity of embedded generation was low, and known problems with nuisance tripping of the devices were considered acceptable because of the insignificant consequence to system operation. With the dramatic increase in the installed capacity of embedded generation over the last decade, the limitations of current islanding detection methods are no longer acceptable. This study describes a new method of loss‐of‐mains protection based on phasor measurement unit (PMU) technology, specifically using a low cost PMU device of the authors’ design which has been developed for distribution network applications. The proposed method addresses the limitations of the incumbent methods, providing a solution that is free of nuisance tripping and has a zero non‐detection zone. This system has been tested experimentally and is shown to be practical, feasible and effective. Threshold settings for the new method are recommended based on data acquired from both the Great Britain and Ireland power systems.
Constrained spectral clustering‐based methodology for intentional controlled islanding of large‐scale power systems
Authors: Quirós‐Tortós Jairo , Sánchez‐García Rubén , Brodzki Jacek , Bialek Janusz , Terzija Vladimir
Published: September 2014

Intentional controlled islanding is an effective corrective approach to minimise the impact of cascading outages leading to large‐area blackouts. This study proposes a novel methodology, based on ‘constrained spectral clustering’, that is computationally very efficient and determines an islanding solution with minimal power flow disruption, while ensuring that each island contains only coherent generators. The proposed methodology also enables operators to constrain any branch, which must not be disconnected, to be excluded from the islanding solution. The methodology is tested using the dynamic models of the IEEE 39‐ and IEEE 118‐bus test systems. Time‐domain simulation results for different contingencies are used to demonstrate the effectiveness of the proposed methodology to minimise the impact of cascading outages leading to large‐area blackouts. In addition, a realistically sized system (a reduced model of the Great Britain network with 815 buses) is used to evaluate the efficiency and accuracy of the methodology in large‐scale networks. These simulations demonstrate that the author's methodology is more efficient, in a factor of approximately 10, and more accurate than another existing approach for minimal power flow disruption.
Analytical approach for optimal siting and sizing of distributed generation in radial distribution networks
Authors: Gopiya Naik Sevya Naik , Khatod Dheeraj Kumar , Sharma Mahendra Pal
Published: September 2014

This study presents an analytical approach for optimal siting and sizing of distributed generation (DG) in radial power distribution networks to minimise real and reactive power losses. For this purpose, suitable analytical expressions have been derived which are based on change in active and reactive components of branch currents cause by the DG placement. This method first determines the DG capacity causing maximum benefit at different buses, and then selects the bus as the best location for DG placement which corresponds to highest benefit. The proposed method is applicable for sizing and siting of single as well as multiple DG units. Moreover, the proposed method requires only the results of base case load flow to determine the optimal size of DG unit(s). The proposed method is tested on 33‐bus and 69‐bus radial distribution test systems. The results obtained by this proposed method validate the suitability and importance of proposed analytical method to determine the size and site of DG unit(s).
Emitter selection criteria for passive multistatic synthetic aperture radar imaging
Authors: Stevens Sean R. , Jackson Julie Ann
Published: September 2014

Passive radar provides a means of spectrum sharing in a congested environment. In passive radar, the radar design problem is one of emitter selection, rather than waveform optimisation. This study combines relevant criteria (signal‐to‐noise ratio, ambiguity function integrated sidelobes, effective multistatic resolution area and contrast ratio) in a multiobjective optimisation to select subsets of available emitters for passive multistatic synthetic aperture radar (SAR). Extensions to well‐known monostatic and bistatic performance criteria are defined for the multistatic SAR case. Assumed limitations in the number of available receiver channels constrain the emitter selection. The proposed emitter selection framework is demonstrated for a simulated scenario of 24 analogue and digital emitters, with a constraint of four receiver channels. Results indicate that the proposed ranking successfully differentiates between emitter sets resulting in good images and those sets resulting in poor images, providing a first step towards formulating a general image quality equation for multistatic SAR.
Wind turbine signal modelling approach for pulse Doppler radars and applications
Authors: Karabayir Osman , Yucedag Senem Makal , Coskun Ahmet Faruk , Yucedag Okan Mert , Serim Huseyin Avni , Kent Sedef
Published: September 2014

Recently, there have been great demands on wind farm installations all over the world. However, it has been well recognised that wind turbines (WTs) may cause severe interferences on radar systems because of their scattering and motional behaviour. In this study, a novel signal model for pulse‐Doppler radars (PDRs) which considers time‐varying scattering and complicated motional characteristics of WTs is introduced. Using the proposed model, some applications including WT detection, construction of WT detection probability distribution and assessment of the detection performance of a target in the vicinity of a WT are demonstrated. In addition, an analytical and probabilistic model for WT clutter (WTC) is developed with the help of the proposed signal model. The signal model, applications and WTC model put forth within this study would be helpful in determining the deteriorating WT effects on PDRs before mitigation or other advanced processes to overcome WT effects.
Comparative study of miscellaneous methods applied to a benchmark, inlet scattering problem
Authors: Fromentin‐Denozière Beatrice , Simon Jérôme , Tzoulis Andreas , Weinmann Frank , Anastassiu Hristos T. , Escot Bocanegra David , Poyatos Martínez David , Fernández Recio Raúl , Zdunek Adam
Published: September 2014

Several well‐known computational methods, based on various mathematical concepts, are applied to the electromagnetic scattering analysis of a benchmark cavity structure. Specifically, a simplified jet engine inlet configuration is defined, constructed and used as reference, whereas predicted numerical results for the radar cross‐section are compared with measurements. The merits and drawbacks of each method are highlighted and quantified, with respect to accuracy, efficiency, resource requirements, reliability and robustness. Conclusions may be exploited in the near future in the construction of reliable classifiers, used in non‐cooperative target identification.
Intelligent electrocardiogram pattern classification and recognition using low‐cost cardio‐care system
Authors: Sutar Rajendra G. , Kothari Ashwin G.
Published: September 2014

Electrocardiogram (ECG) contains detailed information regarding incidental abnormality of a subject. Manual analysis of a long time ECG record is a lengthy process. Computerised ECG analysis supports clinicians in decision making. While designing a low‐cost diagnostic support system, constraints on the system resources limit the processing speed, eventually affecting the reliability. To resolve these issues, three key factors have been addressed in this study: the feature extraction method, total number of features and the database used. For feature extraction, ‘polar Teager energy’ algorithm has been developed, yielding nearly 70% saving in processing time as compared to other well‐known methods. Using features with linear relationship leads to reduction in feature vector dimension, without compromising its classification performance. Therefore the linear relationship between two ECG features, namely ‘informational entropy’(S) and ‘mean Teager energy’ has been revealed. These features are utilised for ECG beat classification using ‘fuzzy C‐means clustering’ algorithm. The algorithm is evaluated using the MIT‐BIH database and then tested by ECG measured with the cardio‐care unit. The QRS detection performance of the proposed method is very good, with 0.27% detection error rate. For classification of ECG beats, average sensitivity and positive prediction rate achieved are 98.93% each.
Convergence analysis of non‐linear filtering based on cubature Kalman filter
Authors: Zarei Jafar , Shokri Ehsan
Published: September 2014

This study analyses the stability of cubature Kalman filter (CKF) for non‐linear systems with linear measurement. The certain conditions to ensure that the estimation error of the CKF remains bounded are proved. Then, the effect of process noise covariance is investigated and an adaptive process noise covariance is proposed to deal with large estimation error. Since adaptation law has a very important role in convergence, fuzzy logic is proposed to improve the versatility of the proposed adaptive noise covariance. Accordingly, a modified CKF (MCKF) is developed to enhance the stability and accuracy of state estimation. The performance of the modified CKF is compared to the CKF in two case studies. Simulation results demonstrate that the large estimation error may lead to instability of CKF, while the MCKF is successfully able to estimate the states. In addition, the superiority of MCKF that uses fuzzy adaptation rules is shown.
How well-connected is the surface of the global ocean?
Authors: Froyland Gary , Stuart Robyn M. , van Sebille Erik
Published: September 2014

The Ekman dynamics of the ocean surface circulation is known to contain attracting regions such as the great oceanic gyres and the associated garbage patches. Less well-known are the extents of the basins of attractions of these regions and how strongly attracting they are. Understanding the shape and extent of the basins of attraction sheds light on the question of the strength of connectivity of different regions of the ocean, which helps in understanding the flow of buoyant material like plastic litter. Using short flow time trajectory data from a global ocean model, we create a Markov chain model of the surface ocean dynamics. The surface ocean is not a conservative dynamical system as water in the ocean follows three-dimensional pathways, with upwelling and downwelling in certain regions. Using our Markov chain model, we easily compute net surface upwelling and downwelling, and verify that it matches observed patterns of upwelling and downwelling in the real ocean. We analyze the Markov chain to determine multiple attracting regions. Finally, using an eigenvector approach, we (i) identify the five major ocean garbage patches, (ii) partition the ocean into basins of attraction for each of the garbage patches, and (iii) partition the ocean into regions that demonstrate transient dynamics modulo the attracting garbage patches.
Characterization of few-layer 1T-MoSe2 and its superior performance in the visible-light induced hydrogen evolution reaction
Authors: Gupta Uttam , Naidu B. S. , Maitra Urmimala , Singh Anjali , Shirodkar Sharmila N. , Waghmare Umesh V. , Rao C. N. R.
Published: September 2014

Based on earlier results on the photocatalytic properties of MoS2, the 1T form of MoSe2, prepared by lithium intercalation and exfoliation of bulk MoSe2, has been employed for the visible-light induced generation of hydrogen. 1T-MoSe2 is found to be superior to both 2H and 1T MoS2 as well as 2H-MoSe2 in producing hydrogen from water, the yield being in the 60–75 mmol h−1 g−1 range with a turn over frequency of 15–19 h−1. First principles calculations reveal that 1T-MoSe2 has a lower work function than 2H-MoSe2 as well as 1T and 2H-MoS2, making it easier to transfer an electron from 1T-MoSe2 for the production of H2.
On the Laplace transform of the Fréchet distribution
Authors: Penson K. A. , Górska K.
Published: September 2014

We calculate exactly the Laplace transform of the Fréchet distribution in the form γx−(1 + γ)exp (−x−γ), γ > 0, 0 ≤ x < ∞, for arbitrary rational values of the shape parameter γ, i.e. for γ = l/k with l, k = 1, 2, …. The method employs the inverse Mellin transform. The closed form expressions are obtained in terms of Meijer G functions and their graphical illustrations are provided. A rescaled Fréchet distribution serves as a kernel of Fréchet integral transform. It turns out that the Fréchet transform of one-sided Lévy law reproduces the Fréchet distribution.
Local versus global electronic properties of chalcopyrite alloys: X-ray absorption spectroscopy and ab initio calculations
Authors: Sarmiento-Pérez Rafael , Botti Silvana , Schnohr Claudia S. , Lauermann Iver , Rubio Angel , Johnson Benjamin
Published: September 2014

Element-specific unoccupied electronic states of Cu(In, Ga)S2 were studied as a function of the In/Ga ratio by combining X-ray absorption spectroscopy with density functional theory calculations. The S absorption edge shifts with changing In/Ga ratio as expected from the variation of the band gap. In contrast, the cation edge positions are largely independent of composition despite the changing band gap. This unexpected behavior is well reproduced by our calculations and originates from the dependence of the electronic states on the local atomic environment. The changing band gap arises from a changing spatial average of these localized states with changing alloy composition.
High quantum efficiency photocathode simulation for the investigation of novel structured designs
Authors: Opachich Y. P. , Ross P. W. , MacPhee A. G. , Hilsabeck T. J. , Nagel S. R. , Huffman E. , Bell P. M. , Bradley D. K. , Koch J. A. , Landen O. L.
Published: September 2014

A computer model in CST Studio Suite has been developed to evaluate several novel geometrically enhanced photocathode designs. This work was aimed at identifying a structure that would increase the total electron yield by a factor of two or greater in the 1–30 keV range. The modeling software was used to simulate the electric field and generate particle tracking for several potential structures. The final photocathode structure has been tailored to meet a set of detector performance requirements, namely, a spatial resolution of <40 μm and a temporal spread of 1–10 ps. We present the details of the geometrically enhanced photocathode model and resulting static field and electron emission characteristics.
Critical interpretation of CH– and OH– stretching regions for infrared spectra of methanol clusters (CH3OH)n (n = 2–5) using self-consistent-charge density functional tight-binding molecular dynamics simulations
Authors: Nishimura Yoshifumi , Lee Yuan-Pern , Irle Stephan , Witek Henryk A.
Published: September 2014

Vibrational infrared (IR) spectra of gas-phase O–H⋅⋅⋅O methanol clusters up to pentamer are simulated using self-consistent-charge density functional tight-binding method using two distinct methodologies: standard normal mode analysis and Fourier transform of the dipole time-correlation function. The twofold simulations aim at the direct critical assignment of the C–H stretching region of the recently recorded experimental spectra [H.-L. Han, C. Camacho, H. A. Witek, and Y.-P. Lee, J. Chem. Phys. 134, 144309 (2011)]. Both approaches confirm the previous assignment (ibid.) of the C–H stretching bands based on the B3LYP/ANO1 harmonic frequencies, showing that ν3, ν9, and ν2 C–H stretching modes of the proton-accepting (PA) and proton-donating (PD) methanol monomers experience only small splittings upon the cluster formation. This finding is in sharp discord with the assignment based on anharmonic B3LYP/VPT2/ANO1 vibrational frequencies (ibid.), suggesting that some procedural faults, likely related to the breakdown of the perturbational vibrational treatment, led the anharmonic calculations astray. The IR spectra based on the Fourier transform of the dipole time-correlation function include new, previously unaccounted for physical factors such as non-zero temperature of the system and large amplitude motions of the clusters. The elevation of temperature results in a considerable non-homogeneous broadening of the observed IR signals, while the presence of large-amplitude motions (methyl group rotations and PA-PD flipping), somewhat surprisingly, does not introduce any new features in the spectrum.
Beam-wave interaction behavior of a 35 GHz metal PBG cavity gyrotron
Authors: Singh Ashutosh , Jain P. K.
Published: September 2014

The RF behavior of a 35 GHz photonic band gap (PBG) cavity gyrotron operating in TE041-like mode has been presented to demonstrate its single mode operation capability. In this PBG cavity gyrotron, the conventional tapered cylindrical cavity is replaced by a metal PBG cavity as its RF interaction structure. The beam-wave interaction behavior has been explored using time dependent multimode nonlinear analysis as well as through 3D PIC simulation. Metal PBG cavity is treated here similar to that of a conventional cylindrical cavity for the desired mode confinement. The applied DC magnetic field profile has been considered uniform along the PBG cavity length both in analysis as well as in simulation. Electrons energy and phase along the interaction length of the PBG cavity facilitates bunching mechanism as well as energy transfer phenomena from the electron beam to the RF field. The RF output power for the TE041-like design mode as well as nearby competing modes have been estimated and found above to 100 kW in TE041-like mode with ∼15% efficiency. Results obtained from the analysis and the PIC simulation are found in agreement within 8% variation, and also it supports the single mode operation, as the PBG cavity does not switch into other parasitic modes in considerably large range of varying DC magnetic field, contrary to the conventional cylindrical cavity interaction structure.
Note: Reliable low-vibration piezo-mechanical shutter
Authors: Bauer Michael , Franzreb Philipp Pierre , Spethmann Nicolas , Widera Artur
Published: September 2014

We present a mechanical shutter based on a bending piezo-actuator. The shutter features an active aperture of about 2 mm, allowing for full extinction and lossless transmission of a beam. Acoustic noise and mechanical vibrations produced are very low and the shutter is outstandingly long-lived; a test device has undergone 20 × 106 cycles without breaking. A reflector makes the shutter capable of reliably interrupting a beam with at least 2 W of cw power at 780 nm. The shutter is well suited to create pulses as short as 16 ms, while pulse lengths down to 1 ms are possible. The rise and fall times are approximately 120 µs, with a delay of 2 ms. Jitter stays below 10 µs, while long-term drifts stay well below 500 µs.
Infrared laser induced plasma diagnostics of silver target
Authors: Ahmat L. , Ahmed I. , Nadeem Ali
Published: September 2014

In the present work, the optical emission spectra of silver (Ag) plasma have been recorded and analyzed using the laser induced breakdown spectroscopy technique. The emission line intensities and plasma parameters were investigated as a function of lens to sample distance, laser irradiance, and distance from the target surface. The electron number density (ne) and electron temperature (Te) were determined using the Stark broadened line profile and Boltzmann plot method, respectively. A gradual increase in the spectral line intensities and the plasma parameters, ne from 2.89 × 1017 to 3.92 × 1017 cm−3 and Te from 4662 to 8967 K, was observed as the laser irradiance was increased 2.29 × 1010–1.06 × 1011 W cm−2. The spatial variations in ne and Te were investigated from 0 to 5.25 mm from the target surface, yielding the electron number density from 4.78 × 1017 to 1.72 × 1017 cm−3 and electron temperature as 9869–3789 K. In addition, the emission intensities and the plasma parameters of silver were investigated by varying the ambient pressure from 0.36 to 1000 mbars.
The suppression effect of a periodic surface with semicircular grooves on the high power microwave long pill-box window multipactor phenomenon
Authors: Zhang Xue , Wang Yong , Fan Junjie , Zhong Yong , Zhang Rui
Published: September 2014

To improve the transmitting power in an S-band klystron, a long pill-box window that has a disk with grooves with a semicircular cross section is theoretically investigated and simulated. A Monte-Carlo algorithm is used to track the secondary electron trajectories and analyze the multipactor scenario in the long pill-box window and on the grooved surface. Extending the height of the long-box window can decrease the normal electric field on the surface of the window disk, but the single surface multipactor still exists. It is confirmed that the window disk with periodic semicircular grooves can explicitly suppress the multipactor and predominantly depresses the local field enhancement and the bottom continuous multipactor. The difference between semicircular and sharp boundary grooves is clarified numerically and analytically.
Anomalous anisotropic magnetoresistance effects in graphene
Authors: Liu Yiwei , Yang Rong , Yang Huali , Wang Duoming , Zhan Qingfeng , Zhang Guangyu , Xie Yali , Chen Bin , Li Run-Wei
Published: September 2014

We investigate the effect of external stimulus (temperature, magnetic field, and gases adsorptions) on anisotropic magnetoresistance (AMR) in multilayer graphene. The graphene sample shows superlinear magnetoresistance when magnetic field is perpendicular to the plane of graphene. A non-saturated AMR with a value of −33% is found at 10 K under a magnetic field of 7 T. It is surprisingly to observe that a two-fold symmetric AMR at high temperature is changed into a one-fold one at low temperature for a sample with an irregular shape. The anomalous AMR behaviors may be understood by considering the anisotropic scattering of carriers from two asymmetric edges and the boundaries of V+(V-) electrodes which serve as active adsorption sites for gas molecules at low temperature. Our results indicate that AMR in graphene can be optimized by tuning the adsorptions, sample shape and electrode distribution in the future application.
Homogeneity testing and quantitative analysis of manganese (Mn) in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS)
Authors: Unnikrishnan V. K. , Nayak Rajesh , Kartha V. B. , Santhosh C. , Sonavane M. S. , Yeotikar R. G. , Shah M. L. , Gupta G. P. , Suri B. M.
Published: September 2014

Laser-induced breakdown spectroscopy (LIBS), an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn) in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.7×109 W/cm2. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX) surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.
Is He Playing Solo or within an Ensemble? How the Context, Visual Information, and Expertise May Impact upon the Perception of Musical Expressivity
Authors: Glowinski Donald , Riolfo Arianna , Shirole Kanika , Torres-Eliard Kim , Chiorri Carlo , Grandjean Didier
Published: September 2014

Visual information is imperative when developing a concrete and context-sensitive understanding of how music performance is perceived. Recent studies highlight natural, automatic, and nonconscious dependence on visual cues that ultimately refer to body expressions observed in the musician. The current study investigated how the social context of a performing musician (eg playing alone or within an ensemble) and the musical expertise of the perceivers influence the strategies used to understand and decode the visual features of music performance. Results revealed that both perceiver groups, nonmusicians and musicians, have a higher sensitivity towards gaze information; therefore, an impoverished stimulus such as a point-light display is insufficient to understand the social context in which the musician is performing. Implications for these findings are discussed.
Superadditivity of the Ebbinghaus and Müller-Lyer Illusions Depends on the Method of Comparison Used
Authors: Foster Rachel M , Franz Volker H
Published: September 2014

Illusions are useful tools for understanding fundamental visual processing. The method used to measure illusion strength is important but often neglected. We identified two methods of comparing bipart illusion elements (eg of the Müller-Lyer or Ebbinghaus illusions). For simultaneous adjustment an increase in size of one figure causes a decrease in the other. For independent adjustment one figure remains fixed while the other is adjusted to match it. These direct comparison illusion effects are contrasted to separate comparison illusion effects, where a neutral stimulus is matched to each illusory figure. If the illusion is stronger for direct comparisons, it is superadditive. The superadditivity of the Ebbinghaus illusion has been investigated using only simultaneous adjustment (Franz, Gegenfurtner, Bülthoff, & Fahle, 2000, Psychological Science11 20–25), and the Müller-Lyer illusion using only independent adjustment (Gilster & Kuhtz-Buschbeck, 2010, Journal of Vision10(1):11, 1–13). Superadditivity was found for the Ebbinghaus but not the Müller-Lyer illusion, but this may have been due to the comparison method or differences between the illusions. Here we test both illusions with both methods of adjustment. Our results suggest that both illusions are superadditive for simultaneous adjustment, but for independent adjustment only under limited circumstances. Implications for research on illusions and perception and action are discussed.
Predicting feed intake and liveweight gain of Ongole (Bos indicus) cattle in Indonesia
Authors: Mayberry D. E. , Syahniar T. M. , Antari R. , Ningrum G. P. , Marsetyo  , Pamungkas D. , Poppi D. P.
Published: September 2014

We evaluated the precision and accuracy of equations from the Australian Ruminant Feeding Standards (ARFS) and the Large Ruminant Nutrition System (LRNS) in predicting the performance of Ongole (Bos indicus) cattle under Indonesian conditions. A database was constructed using information from 121 cattle in five different pen-feeding experiments. Cattle included mature cows and growing bulls, and they were fed a range of diets commonly used by Indonesian farmers. We compared observed and predicted dry matter intake and daily liveweight gain. Model predictions were evaluated for precision and accuracy using mean bias, mean square prediction error and regression of observed against predicted values. Across all experiments, the LRNS provided the better estimates of intake and growth. While both models included animal age, sex, weight and body condition score, the LRNS provided better estimates of metabolisable energy requirements for maintenance of liveweight, feed quality and efficiency of energy utilisation. The LRNS model also better accounted for environmental conditions by including correction factors for minimum night temperature and relative humidity, in addition to average daily temperatures. Based on our results, the LRNS model appears suitable for use in Indonesian beef-production systems.
BeefSpecs fat calculator to assist decision making to increase compliance rates with beef carcass specifications: evaluation of inputs and outputs
Authors: McPhee M. J. , Walmsley B. J. , Mayer D. G. , Oddy V. H.
Published: September 2014

This study evaluated the BeefSpecs fat calculator, a decision-support system developed to assist the beef industry to increase compliance rates with carcass specifications (weight and fat specifications). A challenge to the BeefSpecs calculator and a sensitivity analysis were used to evaluate the inputs and outputs of BeefSpecs. Five industry datasets (n = 80, 97, 68, 25, and 13 for Datasets 1–5, respectively) of Bos taurus, Bos indicus, and Bos taurus × Bos indicus breeds for steers and heifers were collated to challenge BeefSpecs, and a nine-way factorial matrix (n = 57 600) of input variables was created for the sensitivity analysis. There were no significant (P > 0.05) differences in the mean bias between observed and predicted values in any of the datasets but there were significant (P < 0.01) differences in the unity of slope for Datasets 2, 3, and 5. The root-mean-square error was 1.72, 2.61, 2.87, 2.68, and 2.00 mm for Datasets 1–5. The decomposition of the mean-square error of prediction indicated that most of the error contained in the predictions of all models was of a random nature (94%, 85%, 85%, 95% for Datasets 1–4), except in Dataset 5, which had a 47% proportion of error in the slope component. All datasets indicated little bias (0.13%, 12.19%, 12.69%, 0.60%, and 0.12% for Datasets 1–5) in the model predictions. An analysis of variance with the nine-way factorial matrix on the predicted output of final P8 fat was conducted for the sensitivity analysis. A significant (P < 0.01) four-way interaction of days on feed × frame score × initial liveweight × sex was detected. Final P8 fat was sensitive to measurement error in the inputs of frame score when animals had longer feeding periods (e.g. 180 days) and to initial P8 fat when animals had lower initial liveweights (e.g. 200 kg) and higher frame scores (e.g. 7). For each unit of error in estimating frame score, BeefSpecs predicts final P8 with an error of up to 2.3 mm in heifers and up to 1.7 mm in steers. Error in the estimation of initial P8 fat of 2 mm will result in an error of up to 3 mm in the prediction of final P8 fat. The sensitivity analysis of BeefSpecs input variables (frame score and initial P8 fat) on the prediction of final P8 fat indicates that increasing the accuracy of estimating frame score and P8 fat is an issue that needs addressing.
Solvent Dependent Spin-State Behaviour via Hydrogen Bonding in Neutral FeII Diimine Complexes
Authors: Schulte Kelsey A. , Fiedler Stephanie R. , Shores Matthew P.
Published: August 2014

We report the syntheses, structures, and magnetic properties of cis-[Fe(pizR)2(NCS)2] complexes based on the pyridyl imidazoline ligands 2-(2′-pyridinyl)-4,5-dihydroimidazole (pizH, 1) and 2-(2′-pyridinyl)-4,5-dihydro-1-methylimidazole (pizMe, 2). The ligands, complexes, and magnetic measurements are chosen to separate hydrogen-bonding and intrinsic ligand field properties, so as to improve our understanding of the effect of hydrogen-bonding interactions on spin-state switching. In the solid state, both complexes are high spin between 5 and 300 K. In deuterated methanol and acetonitrile solutions, both complexes show gradual thermal spin crossover. Complex 1, capable of hydrogen bonding, shows solvent-sensitive spin crossover, whereas spin crossover in the methylated analogue 2 is insensitive to solvent identity.
Two-Dimensional Coordination Polymers with Spin Crossover Functionality
Authors: Sciortino Natasha F. , Neville Suzanne M.
Published: August 2014

In the solid state, the propagation of spin crossover (SCO) information is governed by a complex interplay between inner and outer coordination sphere effects. In this way, lattice cooperativity can be enhanced through solid state packing interactions (i.e. hydrogen-bonding and π-stacking) and via coordinatively linking spin switching sites (i.e. coordination polymers). SCO framework materials have successfully provided an avenue for enhanced cooperativity and additional function as host–guest sensors via their potential porosity. In this review, we explore two-dimensional SCO coordination polymers: (1) spin crossover frameworks (SCOFs) consisting of (4,4) grids and (2) Hofmann-type materials where layers are separated by organic ligands. These families have each allowed the elucidation of important structure–function properties and provided a novel platform for molecular sensing applications. Towards advancing the field of infinite polymeric SCO materials, two-dimensional materials can offer flexible porosity, potentially leading to novel spin state-switching functionality.