bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential interactions of bacterial lipopolysaccharides with lipid membranes: implications for TRPA1-mediated chemosensation
Authors: Startek Justyna B. , Talavera Karel , Voets Thomas , Alpizar Yeranddy A.
Published: August 2018

Bacterial lipopolysaccharides (LPS) activate the TRPA1 cation channels in sensory neurons, leading to acute pain and inflammation in mice and to aversive behaviors in fruit flies. However, the precise mechanisms underlying this effect remain elusive. Here we assessed the hypothesis that TRPA1 is activated by mechanical perturbations induced upon LPS insertion in the plasma membrane. We asked whether the effects of different LPS on TRPA1 relate to their ability to induce mechanical alterations in artificial and cellular membranes. We found that LPS from E. coli, but not from S. minnesota, activates TRPA1. We then assessed the effects of these LPS on lipid membranes using dyes whose fluorescence properties change upon alteration of the local lipid environment. E. coli LPS was more effective than S. minnesota LPS in shifting Laurdan’s emission spectrum towards lower wavelengths, increasing the fluorescence anisotropy of diphenylhexatriene and reducing the fluorescence intensity of merocyanine 540. These data indicate that E. coli LPS induces stronger changes in the local lipid environment than S. minnesota LPS, paralleling its distinct ability to activate TRPA1. Our findings indicate that LPS activate TRPA1 by producing mechanical perturbations in the plasma membrane and suggest that TRPA1-mediated chemosensation may result from primary mechanosensory mechanisms.
Plasma metabolomic analysis in mature female common bottlenose dolphins: profiling the characteristics of metabolites after overnight fasting by comparison with data in beagle dogs
Authors: Suzuki Miwa , Yoshioka Motoi , Ohno Yoshito , Akune Yuichiro
Published: August 2018

The present study was aimed at determining the characteristics of plasma metabolites in bottlenose dolphins to provide a greater understanding of their metabolism and to obtain information for the health management of cetaceans. Capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS) and liquid chromatograph-time-of-flight mass spectrometry (LC-TOFMS) were conducted on plasma samples after overnight fasting from three common bottlenose dolphins as well as three beagle dogs (representative terrestrial carnivores) for comparison. In total, 257 and 227 plasma metabolites were identified in the dolphins and the dogs, respectively. Although a small number of animals were used for each species, the heatmap patterns, a principal component analysis and a cluster analysis confirmed that the composition of metabolites could be segregated from each other. Of 257 compounds detected in dolphin plasma, 24 compounds including branched amino acids, creatinine, urea, and methylhistidine were more abundant than in dogs; 26 compounds including long-chained acyl-carnitines and fatty acids, astaxanthin, and pantothenic acid were detected only in dolphins. In contrast, 25 compounds containing lactic acid and glycerol 3-phosphate were lower in dolphins compared to dogs. These data imply active protein metabolism, differences in usage of lipids, a unique urea cycle, and a low activity of the glycolytic pathway in dolphins.
A Novel Frequency Selectivity Approach Based on Travelling Wave Propagation in Mechanoluminescence Basilar Membrane for Artificial Cochlea
Authors: Kim Yooil , Kim Ji-Sik , Kim Gi-Woo
Published: August 2018

This study presents the initial assessment for a new approach to frequency selectivity aimed at mimicking the function of the basilar membrane within the human cochlea. The term cochlea tonotopy refers to the passive frequency selectivity and a transformation from the acoustic wave into a frequency signal assisted by the hair cells in the organ of Corti. While high-frequency sound waves vibrate near the base of the cochlea (near the oval windows), low-frequency waves vibrate near the apex (at the maximum distance from the base), which suggests the existence of continuous frequency selectivity. Over the past few decades, frequency selectivity using artificial membranes has been utilized in acoustic transducers by mimicking cochlea tonotopy using cantilever-beam arrays with defined physical parameters such as length and thickness. Unlike the conventional cantilever-beam array type, the travelling wave propagation based-mechanoluminescence (ML) membrane made of ZnS:Cu- polydimethylsiloxane (ZnS:Cu-PDMS) composite that we describe here provides new frequency selectivity more similar to that demonstrated by the human membrane. Here, we explored the potential of the ML membrane to deliver new frequency selectivity by using a non-contact image sensor to measure visualized frequencies. We report that the ML basilar membrane can provide effective visualization of the distribution of strain rate associated with the position of maximal amplitude of the travelling wave.
Proliferative heterogeneity of murine epithelial cells in the adult mammary gland
Authors: Shehata Mona , Waterhouse Paul D. , Casey Alison E. , Fang Hui , Hazelwood Lee , Khokha Rama
Published: August 2018

Breast cancer is the most common cancer in females. The number of years menstruating and length of an individual menstrual cycle have been implicated in increased breast cancer risk. At present, the proliferative changes within an individual reproductive cycle or variations in the estrous cycle in the normal mammary gland are poorly understood. Here we use Fucci2 reporter mice to demonstrate actively proliferating mammary epithelial cells have shorter G1 lengths, whereas more differentiated/non-proliferating cells have extended G1 lengths. We find that cells enter into the cell cycle mainly during diestrus, yet the expansion is erratic and does not take place every reproductive cycle. Single cell expression analyses feature expected proliferation markers (Birc5, Top2a), while HR+ luminal cells exhibit fluctuations of key differentiation genes (ER, Gata3) during the cell cycle. We highlight the proliferative heterogeneity occurring within the normal mammary gland during a single-estrous cycle, indicating that the mammary gland undergoes continual dynamic proliferative changes.
Catalytic N-modification of α-amino acids and small peptides with phenol under bio-compatible conditions
Authors: Dominguez-Huerta Alejandra , Perepichka Inna , Li Chao-Jun
Published: August 2018

The functionalization of α-amino acids and peptides provides the opportunity to tailor the properties of these biomolecules for diverse applications in chemistry and biology. Previous methods for N-modification involve the use of aliphatic alcohols, aldehydes, or halides. Alternatively, phenolic compounds are more desirable alkylating reagents as they constitute the backbone of lignin, making them an attractive bio-renewable resource. Here we report a method to N-modify 17 out of the 20 amino acids with phenol or derivatives, with water as the sole by-product. N-arylation is achieved using 2-cyclohexen-1-one and cyclohexanone as the coupling partners. Notably, phenol is successfully used to N-cyclohexylate α-amino acids and small peptides in excellent yields under bio-compatible conditions without racemization.
A multi-omic atlas of the human frontal cortex for aging and Alzheimer’s disease research
Authors: De Jager Philip L. , Ma Yiyi , McCabe Cristin , Xu Jishu , Vardarajan Badri N. , Felsky Daniel , Klein Hans-Ulrich , White Charles C. , Peters Mette A. , Lodgson Ben , Nejad Parham , Tang Anna , Mangravite Lara M. , Yu Lei , Gaiteri Chris , Mostafavi Sara , Schneider Julie A. , Bennett David A.
Published: August 2018

We initiated the systematic profiling of the dorsolateral prefrontal cortex obtained from a subset of autopsied individuals enrolled in the Religious Orders Study (ROS) or the Rush Memory and Aging Project (MAP), which are jointly designed prospective studies of aging and dementia with detailed, longitudinal cognitive phenotyping during life and a quantitative, structured neuropathologic examination after death. They include over 3,322 subjects. Here, we outline the first generation of data including genome-wide genotypes (n=2,090), whole genome sequencing (n=1,179), DNA methylation (n=740), chromatin immunoprecipitation with sequencing using an anti-Histone 3 Lysine 9 acetylation (H3K9Ac) antibody (n=712), RNA sequencing (n=638), and miRNA profile (n=702). Generation of other omic data including ATACseq, proteomic and metabolomics profiles is ongoing. Thanks to its prospective design and recruitment of older, non-demented individuals, these data can be repurposed to investigate a large number of syndromic and quantitative neuroscience phenotypes. The many subjects that are cognitively non-impaired at death also offer insights into the biology of the human brain in older non-impaired individuals.
A multi-regional input-output table mapping China's economic outputs and interdependencies in 2012
Authors: Mi Zhifu , Meng Jing , Zheng Heran , Shan Yuli , Wei Yi-Ming , Guan Dabo
Published: August 2018

Multi-regional input-output (MRIO) models are one of the most widely used approaches to analyse the economic interdependence between different regions. We utilised the latest socioeconomic datasets to compile a Chinese MRIO table for 2012 based on the modified gravity model. The MRIO table provides inter-regional and inter-sectoral economic flows among 30 economic sectors in China’s 30 regions for 2012. This is the first MRIO table to reflect China’s economic development pattern after the 2008 global financial crisis. The Chinese MRIO table can be used to analyse the production and consumption structure of provincial economies and the inter-regional trade pattern within China, as well as function as a tool for both national and regional economic planning. The Chinese MRIO table also provides a foundation for extensive research on environmental impacts by linking industrial and regional output to energy use, carbon emissions, environmental pollutants, and satellite accounts.
A tissue-based draft map of the murine MHC class I immunopeptidome
Authors: Schuster Heiko , Shao Wenguang , Weiss Tobias , Pedrioli Patrick G.A. , Roth Patrick , Weller Michael , Campbell David S. , Deutsch Eric W. , Moritz Robert L. , Planz Oliver , Rammensee Hans-Georg , Aebersold Ruedi , Caron Etienne
Published: August 2018

The large array of peptides presented to CD8+ T cells by major histocompatibility complex (MHC) class I molecules is referred to as the MHC class I immunopeptidome. Although the MHC class I immunopeptidome is ubiquitous in mammals and represents a critical component of the immune system, very little is known, in any species, about its composition across most tissues and organs in vivo. We applied mass spectrometry (MS) technologies to draft the first tissue-based atlas of the murine MHC class I immunopeptidome in health. Peptides were extracted from 19 normal tissues from C57BL/6 mice and prepared for MS injections, resulting in a total number of 28,448 high-confidence H2Db/Kb-associated peptides identified and annotated in the atlas. This atlas provides initial qualitative data to explore the tissue-specificity of the immunopeptidome and serves as a guide to identify potential tumor-associated antigens from various cancer models. Our data were shared via PRIDE (PXD008733), SysteMHC Atlas (SYSMHC00018) and SWATH Atlas. We anticipate that this unique dataset will be expanded in the future and will find wide applications in basic and translational immunology.
Outerly functionalized and non-functionalized boron clusters intercalated into layered hydroxides with different modes of binding: materials for superacid storage
Authors: Melánová Klára , Holub Josef , Hynek Jan , Fanfrlík Jindřich , Beneš Ludvík , Kutálek Petr , Krejčová Anna , Hnyk Drahomír , Zima Vítězslav
Published: August 2018

It was found that the protic acids derived from the B10H10and B12H12clusters have an unusual intercalation bonding scheme,i.e., Hδ−⋯Hδ+bonds.
Structure and properties of a novel boride: ThNi12B6
Authors: Steiner Soner , Rogl Gerda , Michor Herwig , Rogl Peter , Giester Gerald , Gonçalves Antonio Pereira
Published: August 2018

Characterization of the crystal structure and physico-chemical behaviour of ThNi12B6clearly documents the two-dimensional character of Fermi surfaces originating from 3342-Ni-nets.
Tracking mitochondrial dynamics during apoptosis with phosphorescent fluorinated iridium(iii) complexes
Authors: Zhang Chen , Qiu Kangqiang , Liu Chaofeng , Huang Huaiyi , Rees Thomas W. , Ji Liangnian , Zhang Qianling , Chao Hui
Published: August 2018

A series of phosphorescent fluorinated Ir(iii) complexes, which exhibit low cytotoxicity, excellent photostability and specificity of mitochondria-targeting, were used for tracking mitochondrial dynamics during apoptosis.
Design and preliminary implementation of onsite electrochemical wastewater treatment and recycling toilets for the developing world
Authors: Cid Clément A. , Qu Yan , Hoffmann Michael R.
Published: August 2018

Self-contained toilet wastewater treatment system prototypes based on electrochemical oxidation of feces and urine using bi-layered semiconductor anodes ([Bi2O3]z[TiO2]1−z/IrxTayO2/Ti) have been designed, constructed, and implemented in regions where access to proper and sufficient sanitation is limited.
Low voltage induced reversible magnetoelectric coupling in Fe3O4 thin films for voltage tunable spintronic devices
Authors: Zhang Le , Hou Weixiao , Dong Guohua , Zhou Ziyao , Zhao Shishun , Hu Zhongqiang , Ren Wei , Chen Mingfeng , Nan Ce-Wen , Ma Jing , Zhou Hua , Chen Wei , Ye Zuo-Guang , Jiang Zhuang-De , Liu Ming
Published: August 2018

A giant ME coefficient of 368 Oe V−1 at 1.5 V with good reversibility can be effectively controlled by IL gating in Fe3O4, which could be used to design tunable spintronic devices.
In situstudy of the precursor conversion reactions during solventless synthesis of Co9S8, Ni3S2, Co and Ni nanowires
Authors: Scott John A. , Angeloski Alexander , Aharonovich Igor , Lobo Charlene J. , McDonagh Andrew , Toth Milos
Published: August 2018

Synthesis of Co9S8, Ni3S2, Co and Ni nanowires by solventless thermolysis of a mixture of metal(ii) acetate and cysteine in vacuum is reported.
Penta-Pt2N4: an ideal two-dimensional material for nanoelectronics
Authors: Liu Zhao , Wang Haidi , Sun Jiuyu , Sun Rujie , Wang Z. F. , Yang Jinlong
Published: August 2018

Two-dimensional Penta-Pt2N4 with excellent electronic and mechanical properties.
Flexible transfer of plasmonic photonic structures onto fiber tips for sensor applications in liquids
Authors: Wang Yan , Liu Feifei , Zhang Xinping
Published: August 2018

A flexible transfer technique is reported for fabricating plasmonic photonic structures on fiber tips for direct sensor detection in liquids.
Enantioselective total synthesis of decytospolide A and decytospolide B using an Achmatowicz reaction
Authors: Ghosh Arun K. , Simpson Hannah M. , Veitschegger Anne M.
Published: August 2018

Enantioselective syntheses of decytospolides are described using an Achmatowicz rearrangement, transfer hydrogenation and Friedel–Crafts acylation as the key steps.
Analysis of text difficulty in lower-secondary chemistry textbooks
Authors: Rusek Martin , Vojíř Karel
Published: August 2018

This paper focuses on the procedure and results for analyzing text-difficulty in lower-secondary chemistry textbooks in the Czech Republic. The authors use established methodology for text-difficulty analysis by Nestler, adapted by Průcha and Pluskal by adding a second independent analyser to improve reliability. Some textbooks do not follow the expected trend of either text-difficulty coherence or increasing text-difficulty between books for the 8th and 9th grade. No trend in topic difficulty was found either. The results show that learning outcomes may differ significantly when different books are used, despite the fact that they are supposed to support the same curriculum. For this reason, the results serve to support not only teachers when selecting a textbook, but also researchers as a starting point for lesson observations.
A fluorescent methylation-switchable probe for highly sensitive analysis of FTON6-methyladenosine demethylase activity in cells
Authors: Cheong Adeline , Low Joanne J. A. , Lim Andrea , Yen Paul M. , Woon Esther C. Y.
Published: August 2018

A dynamic biosensor which switches conformation according to its methylation status enables highly sensitive detection of m6A-demethylase activity. This strategy may be adapted to a broad range of RNA-modifying enzymes.
Bending behavior of CNT fibers and their scaling laws
Authors: Adnan Mohammed , Pinnick Robert A , Tang Zhao , Taylor Lauren W , Pamulapati Sushma Sri , Carfagni Gianni Royer , Pasquali Matteo
Published: August 2018

Carbon nanotube (CNT) fibers are a promising material for wearable electronics and biomedical applications due to their combined flexibility and electrical conductivity.
Parameter-free predictions of the viscoelastic response of glassy polymers from non-affine lattice dynamics
Authors: Palyulin Vladimir V. , Ness Christopher , Milkus Rico , Elder Robert M. , Sirk Timothy W. , Zaccone Alessio
Published: August 2018

Parameter-free predictions of viscoelastic moduli at finite temperature are obtained by accounting for internal stresses and instantaneous normal modes within athermal non-affine theory.
An ultrasensitive NO2 gas sensor based on a hierarchical Cu2O/CuO mesocrystal nanoflower
Authors: Hu Jing , Zou Cheng , Su Yanjie , Li Ming , Han Yutong , Kong Eric Siu-Wai , Yang Zhi , Zhang Yafei
Published: August 2018

A room temperature NO2 gas sensor with superior sensitivity and selectivity based on hierarchical Cu2O/CuO mesocrystals.
A thermal interface material based on foam-templated three-dimensional hierarchical porous boron nitride
Authors: Tian Zhilin , Sun Jiajia , Wang Shaogang , Zeng Xiaoliang , Zhou Shuang , Bai Shulin , Zhao Ni , Wong Ching-Ping
Published: August 2018

A high thermal conductivity boron nitride based thermal interface material was developed by a foam-templated method.
Complexes of magnetic nanospheres with amphiprotic polymer–Zn systems for the selective isolation of lactoferrin
Authors: Guo Zhiyong , Zhang Dandan , Song Shunfen , Shu Yang , Chen Xuwei , Wang Jianhua
Published: August 2018

The selective isolation of lactoferrin from complex matrices is achievedviaa strategy of “deferrization–coordination–restoration”.
Enhancing anti-thrombogenicity of biodegradable polyurethanes through drug molecule incorporation
Authors: Xu Cancan , Kuriakose Aneetta E. , Truong Danh , Punnakitikashem Primana , Nguyen Kytai T. , Hong Yi
Published: August 2018

An anti-thrombogenic, elastic, biodegradable polyurethane with covalently incorporated drug can reduce blood platelet deposition on the surface.
Lithium trapping as a degradation mechanism of the electrochromic properties of all-solid-state WO3//NiO devices
Authors: Dong Dongmei , Wang Wenwen , Rougier Aline , Barnabé Antoine , Dong Guobo , Zhang Fan , Diao Xungang
Published: August 2018

There has been keen interest for years in the research of all-solid-state transmittance-type electrochromic (EC) devices due to their various applications especially in “smart windows”. However, limited durability remains a severe issue.
Electrophoretic‐deposited HAP nano‐layer as a QCM‐D sensor coating: effects of suspension concentration and electric‐field strength
Authors: Zheng Liang , Gong Wei , Tang Yue , Ma Genlei , Zheng Jing , Chen Shi‐zhe , Li Wei‐hua
Published: August 2018

This study investigates the fabrication of hydroxyapatite (HAP) nano‐coating on a gold–quartz crystal sensor used for quartz crystal microbalance with dissipation (QCM‐D) measurement using an electrophoretic deposition technique. Surface morphology and thickness of the HAP coating are examined via scanning electron microscopy and nano‐indention testing. Its repeatability is verified via QCM‐D testing. Results show that electrophoretic deposition with ultrasonic treatment is feasible and cost‐effective for fabricating nano‐thick HAP coatings on a QCM‐D gold–quartz crystal sensor surface. Both suspension concentration and electric‐field strength influence the compactness of HAP coatings. There exists a non‐linear relationship between HAP coating compactness and the suspension concentration/electric‐field strength. When the HAP suspension concentration is 30 g/l and the applied electric‐field strength is 150 V/cm, the HAP coating on the QCM‐D gold–quartz crystal sensor surface is uniform and compact with a thickness of 35 nm and is tightly bonded to the sensor surface. The obtained HAP‐coated sensor is thus suitable for QCM‐D measurement.
Highly digital 1 GS/s 7‐bit PWM ADC in 65 nm CMOS using time‐domain quantisation
Authors: Saha A. , Harjani R.
Published: August 2018

A 2 × time‐interleaved 1 GS/s 7b ADC is presented, which uses pulse‐width modulation and time domain quantisation for digitisation and is designed for wide channel bandwidths available at mm‐wave frequencies. The area, resolution and power performance of the highly digital time‐domain architecture is likely to scale with technology. The prototype ADC achieves 5.24 ENOB at a Nyquist rate while consuming 5.22 mW of power, resulting in a fJ/conversion step in TSMC's 65 nm GP CMOS process.
Comprehensive computer‐aided diagnosis for breast T1‐weighted DCE‐MRI through quantitative dynamical features and spatio‐temporal local binary patterns
Authors: Piantadosi Gabriele , Marrone Stefano , Fusco Roberta , Sansone Mario , Sansone Carlo
Published: August 2018

Dynamic contrast enhanced‐magnetic resonance imaging (DCE‐MRI) is a valid complementary diagnostic method for early detection and diagnosis of breast cancer. However, due to the amount of data, the examination is difficult without the support of a computer‐aided detection and diagnosis (CAD) system. Since magnetic resonance imaging data includes different tissues and patient movements (i.e. breathing) may introduce artefacts during acquisition, CADs need some stages aimed to identify breast parenchyma and to reduce motion artefacts. Among the major issues in developing a fully automated CAD, there are the accurate segmentation of lesions in regions of interest and their consequent staging (classification). This work introduces breast lesion automatic detection and diagnosis system (BLADeS), a comprehensive fully automated breast CAD aimed to support the radiologist during the patient diagnosis. The authors propose a hierarchical architecture that implements modules for breast segmentation, attenuation of motion artefacts, localisation of lesions and, finally, classification according to their malignancy. Performance was evaluated on 42 patients with histopathologically proven lesions, performing cross‐validation to ensure a fair comparison. Results show that BLADeS can be successfully used to perform a fully automated breast lesion diagnosis starting from T1‐weighted DCE‐MRI, without requiring any operator interaction in any of the processing stages.
View synthesis method for 3D video coding based on temporal and inter view correlation
Authors: Tung Long Vuong , Le Dinh Minh , HoangVan Xiem , Dinh Trieu Duong , Vu Tien Huu , Le Ha Thanh
Published: August 2018

Recently, in three‐dimensional (3D) television, the temporal correlation between consecutive frames of the intermediate view is used together with the inter‐view correlation to improve the quality of the synthesised view. However, most temporal methods are based on the motion vector fields (MVFs) calculated by the optical flow or block‐based motion estimation which has very high computational complexity. To alleviate this issue, the authors propose a temporal‐disparity‐based view synthesis (TDVS) method, which uses the MVFs extracted from the bitstreams of side views and motion warping technique to create the temporal correlation between views in the intermediate position. Then a motion compensation technique is used to create a temporal‐based view. Finally, the temporal‐based view is fused with a disparity‐based view which is generated by a traditional depth image‐based rendering technique to create the final synthesised view. The fusion of these views is performed based on the side information which is determined and encoded at the sender‐side of the 3D video system using a dynamic programming algorithm and rate‐distortion optimisation scheme. Experimental results show that the proposed method can achieve the synthesised view with appreciable improvements in comparison with the view synthesis reference software 1D fast (VSRS‐1D Fast) for several test sequences.
Efficient interpolated compressed sensing reconstruction scheme for 3D MRI
Authors: Datta Sumit , Deka Bhabesh
Published: August 2018

3D magnetic resonance imaging (3D MRI) is one of the most preferred medical imaging modalities for the analysis of anatomical structures where acquisition of multiple slices along the slice select gradient direction is very common. In 2D multi‐slice acquisition, adjacent slices are highly correlated because of very narrow inter‐slice gaps. Application of compressed sensing (CS) in MRI significantly reduces traditional MRI scan time due to random undersampling. The authors first propose a fast interpolation technique to estimate missing samples in the k‐space of a highly undersampled slice (H‐slice) from k‐space (s) of neighbouring lightly undersampled slice/s (L‐slice). Subsequently, an efficient multislice CS‐MRI reconstruction technique based on weighted wavelet forest sparsity, and joint total variation regularisation norms is applied simultaneously on both interpolated H and non‐interpolated L‐slices. Simulation results show that the proposed CS reconstruction for 3D MRI is not only computationally faster but significant improvements in terms of visual quality and quantitative performance metrics are also achieved compared to the existing methods.
Equilateral triangular dielectric resonator based co‐radiator MIMO antennas with dual‐polarisation
Authors: Sharma Abhishek , Sarkar Anirban , Biswas Animesh , Jaleel Akhtar Mohammad
Published: August 2018

In this study, two types of dielectric resonator antennas (DRAs) with dual‐polarisation are proposed and investigated for multiple‐input multiple‐output (MIMO) applications. The first design is a dual‐slant polarised DRA and exhibits the measured impedance bandwidth of 8.2% (5.27–5.72 GHz) and 11.2% (5.05–5.65 GHz) for Port1 and Port2, respectively. Across the operating frequency band, the isolation between the input ports is better than 22 dB and the measured gain of the antenna varies in the range of 5.99–6.38 dBi. The second design developed here is a dual‐linearly polarised DRA which is able to provide horizontal and vertical polarisations and is realised by integrating a two‐stage rat‐race coupler with the DRA for excitation purpose. In this case, the measured impedance bandwidths are 11.81% (5.18–5.83 GHz) and 15.18% (4.93–5.74 GHz) for Port1 and Port2, respectively, and the inter‐port isolation is better than 20 dB throughout the operating frequency band. The antenna exhibits the measured gain variation of 5.94–6.48 dBi for Port1 and 5.54–5.86 dBi for Port2. Furthermore, for both the antennas, the envelope correlation coefficient is below 0.0004 throughout the bandwidth and the total active reflection coefficient is better than −10 dB, confirming the good diversity and radiation performance.
Enhanced gain saturation model of non‐linear semiconductor optical amplifiers
Authors: Kharraz O.M. , Supa'at A.S.M. , Atieh A. , Zamzuri A.K. , Mahdi M.A.
Published: August 2018

This study proposes an enhanced gain saturation model of non‐linear semiconductor optical amplifiers (SOAs) by incorporating material‐dependent gain compression factor. The rate equations are utilised with the extra gain compression term for Indium–Gallium–Arsenide material‐based SOA to account for the steep relaxation oscillations behaviour of non‐linear SOAs. The proposed gain saturation model is verified with experimental results that showed very good agreements with a mean square error of 0.094.
MIMO–monopulse target localisation for automotive radar
Authors: Feng Ruoyu , Uysal Faruk , Aubry Pascal , Yarovoy Alexandar
Published: August 2018

In this study, the authors propose a novel direction of arrival (DoA) estimation algorithm called ‘multiple‐input–multiple‐output (MIMO)–monopulse’ by combining the monopulse approach with MIMO radar. Monopulse is fast and accurate angle estimation algorithm, which has been well developed for tracking radar. The application of the monopulse technique on MIMO radar is not much considered before, especially for automotive‐radar application, and will be discussed in this study. Conventional methods of monopulse DoA estimation include amplitude and phase comparison monopulse. In this study, to improve the performance of monopulse, they utilise Chebyshev and Zolotarev weighting to synthesise sum and difference patterns. A new visualisation method for monopulse ratio is discussed. Finally, they demonstrate the success of the proposed algorithm by processing real data from a 79 GHz frequency‐modulated continuous‐wave automotive radar.
Periodic clutter suppression in iron road structures for automotive radar systems
Authors: Lee Seongwook , Yoon Young‐Jun , Yoon Jungmin , Sim Heonkyo , Kim Seong‐Cheol
Published: August 2018

In this study, the authors propose a periodic clutter suppression method in iron road structures for automotive radar systems. Specific road structures made of iron such as tunnels, soundproof walls, and guardrails have periodic steel frames that generate unwanted reflected signals called radar clutter. This clutter degrades the detection performance of an automotive radar and leads to misdetection of targets. Therefore, efficient signal processing is required to mitigate the adverse effect of clutter within those iron structures. Since the spacings between steel frames are uniform, beat frequencies corresponding to them also appear at regular intervals. This phenomenon is maintained in each radar scan when a vehicle travels in the iron structures. Thus, they suggest an effective periodic clutter suppression method using the relationship between adjacent radar scans. Their proposed clutter suppression scheme was applied to radar signals obtained from the iron road structures and successfully suppressed the periodic clutter.
Spectroscopic identification of INTEGRAL high-energy sources with VLT/ISAAC
Authors: Fortin F. , Chaty S. , Coleiro A. , Tomsick J. A. , Nitschelm C. H. R.
Published: August 2018

Context. The INTEGRAL satellite has been observing the γ-ray sky for 15 years and has detected over 900 X-ray sources of various nature. However, more than 200 of these sources still lack precise identification.

Aims. Our goal is to reveal the nature of the high-energy sources detected by INTEGRAL. In particular, we want to improve the census of X-ray binaries.

Methods. Photometry and spectroscopy were performed in July 2012 on 14 INTEGRAL sources in near-infrared at the Very Large Telescope on the European Southern Observatory-UT3 telescope equipped with the ISAAC spectrograph. We used Ks images reaching to a depth of magnitude 18.5 to look for unique counterparts to high-energy detections to check for both extended sources and photometric variability. The analysis of near-infrared spectral features allows us to constrain the nature of these X-ray sources by comparing them to stellar spectra atlases.

Results. We present photometric and/or spectroscopic data for 14 sources (IGR J00465–4005, IGR J10447–6027, IGR J12489–6243, IGR J13020–6359, IGR J13186–6257, IGR J15293–5609, IGR J17200–3116, IGR J17404–3655, IGR J17586–2129, IGR J17597–2201, IGR J18457+0244, IGR J18532+0416, IGR J19308+0530, and IGR J19378–0617). We conclude that 5 of these are active galactic nuclei, 5 are cataclysmic variables, 2 are low- or intermediate-mass X-ray binaries, and 2 are Be high-mass X-ray binaries.
S–PASS view of polarized Galactic synchrotron at 2.3 GHz as a contaminant to CMB observations
Authors: Krachmalnicoff N. , Carretti E. , Baccigalupi C. , Bernardi G. , Brown S. , Gaensler B. M. , Haverkorn M. , Kesteven M. , Perrotta F. , Poppi S. , Staveley-Smith L.
Published: August 2018

We have analyzed the southern sky emission in linear polarization at 2.3 GHz as observed by the S -band Polarization All Sky Survey (S-PASS). Our purpose is to study the properties of the diffuse Galactic polarized synchrotron as a contaminant to B-mode observations of the cosmic microwave background (CMB) polarization. We studied the angular distribution of the S-PASS signal at intermediate and high Galactic latitudes by means of the polarization angular power spectra. The power spectra, computed in the multipole interval 20 ≤ ℓ ≤ 1000, show a decay of the spectral amplitude as a function of multipole for ℓ ≲ 200, typical of the diffuse emission. At smaller angular scales, power spectra are dominated by the radio point source radiation. We find that, at low multipoles, spectra can be approximated by a power law CℓEE,BB ∝ ℓα, with α ≃ −3, and characterized by a B-to-E ratio of about 0.5. We measured the polarized synchrotron spectral energy distribution (SED) in harmonic space, by combining S-PASS power spectra with low frequency WMAP and Planck ones, and by fitting their frequency dependence in six multipole bins, in the range 20 ≤ ℓ ≤ 140. Results show that the recovered SED, in the frequency range 2.3–33 GHz, is compatible with a power law with βs = −3.22 ± 0.08, which appears to be constant over the considered multipole range and in the different Galactic cuts. Combining the S-PASS total polarized intensity maps with those coming from WMAP and Planck we derived a map of the synchrotron spectral index βs at angular resolution of 2° on about 30% of the sky. The recovered βs distribution peaks at the value around −3.2. It exibits an angular power spectrum which can be approximated with a power law Cℓ ∝ ℓγ with γ ≃ −2.6. We also measured a significant spatial correlation between synchrotron and thermal dust signals, as traced by the Planck 353 GHz channel. This correlation reaches about 40% on the larger angular scales, decaying considerably at the degree scales. Finally, we used the S-PASS maps to assess the polarized synchrotron contamination to CMB observations of the B-modes at higher frequencies. We divided the sky in small patches (with fsky ≃ 1%) and find that, at 90 GHz, the minimal contamination, in the cleanest regions of the sky, is at the level of an equivalent tensor-to-scalar ratio rsynch ≃ 10−3. Moreover, by combining S-PASS data with Planck 353 GHz observations, we recover a map of the minimum level of total polarized foreground contamination to B-modes, finding that there is no region of the sky, at any frequency, where this contamination lies below equivalent tenor-to-scalar ratio rFG ≃ 10−3. This result confirms the importance of observing both high and low frequency foregrounds in CMB B-mode measurements.
Horizontal photospheric flows trigger a filament eruption
Authors: Roudier T. , Schmieder B. , Filippov B. , Chandra R. , Malherbe J. M.
Published: August 2018

Context. A large filament composed principally of two sections erupted sequentially in the southern hemisphere on January 26, 2016. The central, thick part of the northern section was first lifted up and lead to the eruption of the full filament. This event was observed in Hα with the Global Oscillation Network Group (GONG) and Christian Latouche IMageur Solaire (CLIMSO), and in ultraviolet (UV) with the Atmospheric Imaging Assembly (AIA) imager on board the Solar Dynamic Observatory (SDO).

Aims. The aim of the paper is to relate the photospheric motions below the filament and its environment to the eruption of the filament.

Methods. An analysis of the photospheric motions using Solar Dynamic Observatory Helioseismic and Magnetic Imager (SDO/HMI) continuum images with the new version of the coherent structure tracking (CST) algorithm developed to track granules, as well as large-scale photospheric flows, has been performed. Following velocity vectors, corks migrate towards converging areas.

Results. The supergranule pattern is clearly visible outside the filament channel but difficult to detect inside because the modulus of the vector velocity is reduced in the filament channel, mainly in the magnetized areas. The horizontal photospheric flows are strong on the west side of the filament channel and oriented towards the filament. The ends of the filament sections are found in areas of concentration of corks. Whirled flows are found locally around the feet.

Conclusions. The strong horizontal flows with an opposite direction to the differential rotation create strong shear and convergence along the magnetic polarity inversion line (PIL) in the filament channel. The filament has been destabilized by the converging flows, which initiate an ascent of the middle section of the filament until the filament reaches the critical height of the torus instability inducing, consequently, the eruption. The n decay index indicated an altitude of 60 Mm for the critical height. It is conjectured that the convergence along the PIL is due to the large-scale size cells of convection that transport the magnetic field to their borders.
Theγ-ray emitting region in low synchrotron peak blazars
Authors: Arsioli B. , Chang Y-L.
Published: August 2018

Aims.From the early days inγ-ray astronomy, locating the origin of GeV emission within the core of an active galactic nucleus (AGN) persisted as an open question; the problem is to discern between near- and far-site scenarios with respect to the distance from the super massive central engine. We investigate this question under the light of a complete sample of low synchrotron peak (LSP) blazars which is fully characterized along many decades in the electromagnetic spectrum, from radio up to tens of GeV. We consider the high-energy emission from bright radio blazars and test for synchrotron self-Compton (SSC) and external Compton (EC) scenarios in the framework of localizing theγ-ray emission sites. Given that the inverse Compton (IC) process under the EC regime is driven by the abundance of external seed photons, these photons could be mainly ultraviolet (UV) to X-rays coming from the accretion disk region and the broad-line region (BLR), therefore close to the jet launch base; or infrared (IR) seed photons from the dust torus and molecular cloud spine-sheath, therefore far from jet launch base. We investigate both scenarios, and try to reveal the physics behind the production ofγ-ray radiation in AGNs which is crucial in order to locate the production site.

Methods.Based on a complete sample of 104 radio-selected LSP blazars, with 37 GHz flux density higher than 1 Jy, we study broadband population properties associated with the nonthermal jet emission process, and test the capability of SSC and EC scenarios to explain the overall spectral energy distribution (SED) features. We use SEDs well characterized from radio toγrays, considering all currently available data. The enhanced available information from recent works allows us to refine the study of Syn to IC peak correlations, which points to a particularγ-ray emission site.

Results.We show that SSC alone is not enough to account for the observed SEDs. Our analysis favors an EC scenario under the Thomson scattering regime, with a dominant IR external photon field. Therefore, the far-site (i.e., far from the jet launch) is probably the most reasonable scenario to account for the population properties of bright LSP blazars in cases modeled with a pure leptonic component. We calculate the photon energy density associated with the external field at the jet comoving frame to beU′ext= 1.69 × 10−2erg cm−3, finding good agreement to other correlated works.
Contribution of the Galactic centre to the local cosmic-ray flux
Authors: Jaupart Étienne , Parizot Étienne , Allard Denis
Published: August 2018

Context. Recent observations of unexpected structures in the Galactic cosmic ray (GCR) spectrum and composition, as well as growing evidence for episodes of intense dynamical activity in the inner regions of the Galaxy, call for an evaluation of the high-energy particle acceleration associated with such activity and its potential impact on the global GCR phenomenology.

Aims. We investigate whether particles accelerated during high-power episodes around the Galactic centre can account for a significant fraction of the observed GCRs, or, conversely, what constraints can be derived regarding their Galactic transport if their contributions are negligible.

Methods. Particle transport in the Galaxy is described with a two-zone analytical model. We solved for the contribution of a Galactic centre cosmic-Ray (GCCR) source using Green functions and Bessel expansion, and discussed the required injection power for these GCCRs to influence the global GCR phenomenology at Earth.

Results. We find that, with standard parameters for particle propagation in the galactic disk and halo, the GCCRs can make a significant or even dominant contribution to the total CR flux observed at Earth. Depending on the parameters, such a source can account for both the observed proton flux and boron-to-carbon ratio (in the case of a Kraichnan-like scaling of the diffusion coefficient), or potentially produce spectral and composition features.

Conclusions. Our results show that the contribution of GCCRs cannot be neglected a priori, and that they can influence the global GCR phenomenology significantly, thereby calling for a reassessement of the standard inferences from a scenario where GCRs are entirely dominated by a single type of sources distributed throughout the Galactic disk.
Characterization of the high temperature oxidation behavior of iron based alloys used as exhaust manifolds
Authors: Çelik G. Aktaş , Kahrıman Fulya , Atapek Ş. Hakan , Polat Şeyda
Published: August 2018

Nowadays engine capacities of vehicles spread in a wide range due to different vehicle power demands. Power density of engines affects exhaust gas and therefore exhaust gas temperature varies from 650 °C to 1000 °C in exhaust manifolds. Depending on the exhaust gas temperature, different types of iron based alloys are used as manifold materials such as ferritic ductile cast irons (GGG40, SiMo), austenitic ductile cast irons (Ni-resist D5S), ferritic cast stainless steels (ACIHK30, AISI 409) and austenitic cast stainless steels (CF8C). In this study high temperature oxidation behavior of different cast alloys used as exhaust manifold materials like, (i) GGG40 ferritic ductile cast iron, (ii) SiMo ferritic ductile cast iron (iii) AISI 409 ferritic cast stainless steel and (iv) CF8C austenitic cast stainless steel, were investigated.
Characterization of laser-borided Nimonic 80A-alloy
Authors: Kieruj Piotr , Makuch Natalia , Kukliński Mateusz
Published: August 2018

Nimonic 80A-alloy belongs to Nickel-based superalloys. Many of them are used in variety branches of industry due to high strength and resistance in aggressive conditions. Moreover, its mechanical properties are kept in high temperature. However, these materials should be coated by appropriate wear protection, under conditions of considerable mechanical wear. Unfortunately, the production of thick borided layer in diffusion boriding required high temperature and long duration of this processes. Therefore, in this study instead conventional diffusion process laser boriding was applied in order to produce boride layer on Nimonic 80A-alloy substrate. Laser alloying is the high-tech process which allows to modify the chemical composition of the surface. Laser boriding was arranged as a single tracks, therefore it was possible to evaluate the influence of laser treatment parameters on thickness and hardness of produced layers. The laser beam power P, laser scanning speed vl and laser beam diameter dl were the variable parameters used during laser alloying.
Shear failure of AA2024 and AA7175 under high strain rate loading
Authors: Manar Gunasilan , Longère Patrice
Published: August 2018

In the context of the design of aeronautical structures regarding accidental events, we are here investigating and comparing the shear failure of two aluminum alloys, namely AA2024 and AA7175, under high strain rate loading. With this aim in view, two experiments were carried out: (i) high strain rate shear compression of hat shaped structures, and (ii) impact test on the edge of double notched plates. The fractured surfaces of post-mortem specimens were observed using optical and scanning electron microscopes (SEM) in order to identify the failure mechanisms.
Τhe strategic role of Life Cycle Assessment in the problem of material criticality and in development of Chromium-free substitute for stainless steel
Authors: Stergiou Vasiliki I. , Morozinis Athanasios K. , Charitidis Constantinos A.
Published: August 2018

Sustainable and on-going technological developments in the field of materials require the establishment of methods and tools for assessing, comparing environmental impacts and providing solutions to the problem of “resource criticality” by identifying a policy of an economic and ecological plan. Therefore, there is a clear need for prevention and provision of additional knowledge beyond the defined protocols to achieve the reduction of impacts. For this reason, Life Cycle Assessment (LCA) has been developed as a scientific technique that systematically assesses and evaluates the environmental impacts associated with all stages of a product's life. In this work, LCA was applied in a part of a highly innovative process of production of advanced Iron-Aluminum (Fe-Al) based intermetallics. LCA role is particularly crucial, since the produced intermetallics are bound to substitute stainless steel, in specific applications, providing solution in the problem of Cr and Ni; as a result, the environmental burdens and impacts, as well as application of alternative solutions to minimize them, will decide if such an innovative, from the technical point of view, approach is also applicable/sustainable in large scale.
Local strain energy based fatigue assessment of cruciform welded joints: experimental data analysis and influence of hot-dip galvanization
Authors: Viespoli Luigi Mario , Mutignani Francesco , Gulyas Gabor , Remes Heikki , Berto Filippo
Published: August 2018

Performing the fatigue assessment of a welded joint using the Notch Stress Intensity Factors [1] presents two major challenges. The first is the necessity of a precise reconstruction of the stress field around the notch tip, thus needing an extremely refined discretization with an evident computational cost. The other, is that the dimensions of the N-SIFs and so their critical values, vary accordingly to the William’s solution [2] depending on the notch-opening angle. Consequence of this is that the mechanical properties necessary for the assessment vary as a function of the geometry treated. The research to overcome this issue has led to the use of the local Strain Energy Density [3]. The power of this parameter, used as a tool to perform fatigue assessment, consists of having a very low mesh refinement sensitivity [4], being the energy computed directly from nodal displacements and stiffness matrix [5], and having constant dimensions, so constant critical value for a given class of materials. In this paper, the local energetic method is applied to the analysis of the results of a series of tests performed on cruciform load carrying and non-load carrying specimens realized by S235 JRG2 structural steel plates. If load carrying, the fillet welded joints are made of S355 J2+N structural steel. The fatigue testing has been performed in atmosphere at room temperature in as welded condition both with and without the corrosion protective zinc layer. Particularly, the interest is focused on the influence of the zinc layer of the fatigue properties of the joint and on the capability of the local energetic approach, confronted with the classic nominal stress approach, to accurately predict the fatigue failure. To conclude, the investigation of the tests executed reveals no significant difference in the fatigue life for the coated samples, compared with the uncoated specimens and the predictions according to the IIW recommendations [6].