bluuebunny/crossref_metadata_2025 huggingface dataset:
Reflections on the Colombian case law on the protection of medical personnel against punishment
Authors: Ortiz Linares Ekaterina , Silva Chau Marisela
Published: June 2014

One of the fundamental rules for the protection of health-care personnel in any circumstance, including contexts of armed conflicts, provides for a prohibition on punishing medical professionals who merely act in accordance with medical ethics. However, although the reasons for this prohibition may seem obvious, in contexts of non-international armed conflicts the provision of medical care to wounded and sick members of non-state armed groups can expose medical personnel to accusations of participation in criminal activities. Based on the Colombian domestic legislation and jurisprudence on the matter, this article aims to propose elements of analysis on the apparent contradiction that exists between, on the one hand, the prohibition against punishing medical personnel for merely providing health care to the wounded and sick who need it, and on the other, the prerogative of the state authorities to restore order and security within their territory through the imposition of criminal sanctions on members of non-state armed groups or their aiders and abettors.
Diagnostic performance of the PTSD checklist and the Vietnam Era Twin Registry PTSD scale
Authors: Magruder K. , Yeager D. , Goldberg J. , Forsberg C. , Litz B. , Vaccarino V. , Friedman M. , Gleason T. , Huang G. , Smith N.
Published: June 2014

Aims.

Self-report questionnaires are frequently used in clinical and epidemiologic studies to assess post-traumatic stress disorder (PTSD). A number of studies have evaluated these scales relative to clinician administered structured interviews; however, there has been no formal evaluation of their performance relative to non-clinician administered epidemiologic assessments such as the Composite International Diagnostic Interview (CIDI). We examined the diagnostic performance of two self-report PTSD scales, the PTSD checklist (PCL) and the Vietnam Era Twin Registry (VET-R) PTSD scale, compared to the CIDI.

Methods.

Data were derived from a large epidemiologic follow-up study of PTSD in 5141 Vietnam Era Veterans. Measures included the PCL, VET-R PTSD scale and CIDI. For both the PCL and VET-R PTSD scale, ROC curves, areas under the curve (AUC), sensitivity, specificity, % correctly classified, likelihood ratios, predictive values and quality estimates were generated based on the CIDI PTSD diagnosis.

Results.

For the PCL and VET-R PTSD scale the AUCs were 89.0 and 87.7%, respectively. Optimal PCL cutpoints varied from the 31–33 range (when considering sensitivity and specificity) to the 36–56 range (when considering quality estimates). Similar variations were found for the VET-R PTSD, ranging from 31 (when considering sensitivity and specificity) to the 37–42 range (when considering quality estimates).

Conclusions.

The PCL and VET-R PTSD scale performed similarly using a CIDI PTSD diagnosis as the criterion. There was a range of acceptable cutpoints, depending on the metric used, but most metrics suggested a lower PCL cutpoint than in previous studies in Veteran populations.
Degree of cognitive impairment and mortality: a 17-year follow-up in a community study
Authors: Santabárbara J. , Lopez-Anton R. , Marcos G. , De-la-Cámara C. , Lobo E. , Saz P. , Gracia-García P. , Ventura T. , Campayo A. , Rodríguez-Mañas L. , Olaya B. , Haro J. M. , Salvador-Carulla L. , Sartorius N. , Lobo A.
Published: June 2014

Background.

To test the hypothesis that cognitive impairment in older adults is associated with all-cause mortality risk and the risk increases when the degree of cognitive impairment augments; and then, if this association is confirmed, to report the population-attributable fraction (PAF) of mortality due to cognitive impairment.

Method.

A representative random community sample of individuals aged over 55 was interviewed, and 4557 subjects remaining alive at the end of the first year of follow-up were included in the analysis. Instruments used in the assessment included the Mini-Mental Status Examination (MMSE), the History and Aetiology Schedule (HAS) and the Geriatric Mental State (GMS)-AGECAT. For the standardised degree of cognitive impairment Perneczky et al's MMSE criteria were applied. Mortality information was obtained from the official population registry. Multivariate Cox proportional hazard models were used to test the association between MMSE degrees of cognitive impairment and mortality risk. We also estimated the PAF of mortality due to specific MMSE stages.

Results.

Cognitive impairment was associated with mortality risk, the risk increasing in parallel with the degree of cognitive impairment (Hazard ratio, HR: 1.18 in the ‘mild’ degree of impairment; HR: 1.29 in the ‘moderate’ degree; and HR: 2.08 in the ‘severe’ degree). The PAF of mortality due to severe cognitive impairment was 3.49%.

Conclusions.

A gradient of increased mortality-risk associated with severity of cognitive impairment was observed. The results support the claim that routine assessment of cognitive function in older adults should be considered in clinical practice.
Polish Adaptation and Psychometric Validation of the Anxiety Sensitivity Index-III
Authors: Michałowski Jarosław M. , Holas Paweł , Zvolensky Michael J.
Published: June 2014

The present study sought to adapt and validate the psychometric properties of the Anxiety Sensitivity Index-III in Poland. The ASI-III consists of three subscales, each representing one of the three domains of fears of the negative consequences of anxiety-related physical, cognitive, or social sensations. The study included a total of 116 panic disorder patients and 411 controls who did not show the presence of mental disorders. The results indicated that the Polish-language version of the ASI-III is characterized by high content validity, internal consistency, and stability over a period of 28 days. Moreover, its factor structure was largely equivalent to that found on the original ASI-III.
Agreeableness, Social Self-Efficacy, and Conflict Resolution Strategies
Authors: Field Ryan D. , Tobin Renée M. , Reese-Weber Marla
Published: June 2014

This research examined Agreeableness and social self-efficacy as predictors of positive (compromise, negotiation) and negative (attacking, power assertion) conflict resolution strategies in emerging adults (N = 699). Participants completed self-report measures of Agreeableness and social self-efficacy. Conflict resolution strategies were assessed using a multi-method approach. As predicted, social self-efficacy significantly moderated the relation between Agreeableness and negative conflict resolution strategies, but it did not for positive resolution strategies. For individuals higher in Agreeableness, follow-up analyses revealed that those higher in social self-efficacy endorsed negative resolution strategies less frequently than those lower in social self-efficacy.
Microscopically-Tuned Band Structure of Epitaxial Graphene through Interface and Stacking Variations Using Si Substrate Microfabrication
Authors: Fukidome Hirokazu , Ide Takayuki , Kawai Yusuke , Shinohara Toshihiro , Nagamura Naoka , Horiba Koji , Kotsugi Masato , Ohkochi Takuo , Kinoshita Toyohiko , Kumighashira Hiroshi , Oshima Masaharu , Suemitsu Maki
Published: June 2014

Graphene exhibits unusual electronic properties, caused by a linear band structure near the Dirac point. This band structure is determined by the stacking sequence in graphene multilayers. Here we present a novel method of microscopically controlling the band structure. This is achieved by epitaxy of graphene on 3C-SiC(111) and 3C-SiC(100) thin films grown on a 3D microfabricated Si(100) substrate (3D-GOS (graphene on silicon)) by anisotropic etching, which produces Si(111) microfacets as well as major Si(100) microterraces. We show that tuning of the interface between the graphene and the 3C-SiC microfacets enables microscopic control of stacking and ultimately of the band structure of 3D-GOS, which is typified by the selective emergence of semiconducting and metallic behaviours on the (111) and (100) portions, respectively. The use of 3D-GOS is thus effective in microscopically unlocking various potentials of graphene depending on the application target, such as electronic or photonic devices.
Explosive synchronization as a process of explosive percolation in dynamical phase space
Authors: Zhang Xiyun , Zou Yong , Boccaletti S. , Liu Zonghua
Published: June 2014

Explosive synchronization and explosive percolation are currently two independent phenomena occurring in complex networks, where the former takes place in dynamical phase space while the latter in configuration space. It has been revealed that the mechanism of EP can be explained by the Achlioptas process, where the formation of a giant component is controlled by a suppressive rule. We here introduce an equivalent suppressive rule for ES. Before the critical point of ES, the suppressive rule induces the presence of multiple, small sized, synchronized clusters, while inducing the abrupt formation of a giant cluster of synchronized oscillators at the critical coupling strength. We also show how the explosive character of ES degrades into a second-order phase transition when the suppressive rule is broken. These results suggest that our suppressive rule can be considered as a dynamical counterpart of the Achlioptas process, indicating that ES and EP can be unified into a same framework.
High-sensitivity fluorescence imaging of iron in plant tissues
Authors: Park Mi-Jeong , Jung Hak-Sung , Kim Young-Jae , Kwon Young-Ju , Lee Jin-Kyu , Park Chung-Mo
Published: June 2014

Fluorescence imaging of Fe ions in (a) leaf epidermal cells, (b) the stem, and (c) the root stem of Arabidopsis plants by the rapid, simple, and inexpensive photoinduced electron transfer (PET) fluorescent probing method.
A novel anode material derived from organic-coated ZIF-8 nanocomposites with high performance in lithium ion batteries
Authors: Han Yuzhen , Qi Pengfei , Li Siwu , Feng Xiao , Zhou Junwen , Li Haiwei , Su Shuangyue , Li Xingguo , Wang Bo
Published: June 2014

A general method of preparing nanocomposites from carbon-coated ZIF-8 is introduced. Pyrolysis of these nanocomposites gives anode materials with high capacity (750 mA h g−1) and improved cyclability.
Nitrate anion templated synthesis of a [2]catenane for nitrate recognition in organic–aqueous solvent media
Authors: Langton Matthew J. , Beer Paul D.
Published: June 2014

The first example of a catenane synthesised using a nitrate anion template is demonstrated. The resulting interlocked host is capable of selectively recognising nitrate over a range of more basic oxoanions in a competitive organic–aqueous solvent mixture.
Fluorescent probes for hydrogen sulfide detection and bioimaging
Authors: Yu Fabiao , Han Xiaoyue , Chen Lingxin
Published: June 2014

In this feature article, we address the synthesis and design strategies for the development of fluorescent probes for H2S, based on the reaction type between H2S and the probes.
Semi-artificial and bioactive ferroxidase with nanoparticles as the active sites
Authors: Li L. , Zhang L. , Carmona U. , Knez M.
Published: June 2014

L-chain apoferritin can be turned into a more stable and cellular active ferroxidase with nanoparticles as the artificial active sites.
Thermotropic cubic and tetragonal phases made of rod-like molecules
Authors: Vogrin M. , Vaupotič N. , Wojcik M. M. , Mieczkowski J. , Madrak K. , Pociecha D. , Gorecka E.
Published: June 2014

For rod-like molecules with two chiral centers de-racemization results in formation of a tetragonal mesophase instead of a cubic one.
Tuning cellulose pyrolysis chemistry: selective decarbonylation via catalyst-impregnated pyrolysis
Authors: Mettler Matthew S. , Paulsen Alex D. , Vlachos Dionisios G. , Dauenhauer Paul J.
Published: June 2014

Improving bio-oil stability through aldehydic furan decarbonylation by impregnating cellulose with supported palladium catalysts.
Hydrometallation of amino-trialkynylsilanes – intramolecular M–N interactions (M = Al, Ga) and potential activation of Si–N bonds
Authors: Uhl Werner , Bohnemann Jörg , Kappelt Benedikt , Hepp Alexander , Layh Marcus
Published: June 2014

Hydrometallation of amino-alkynylsilanes afforded highly functionalized alkenyl–alkynylsilanes with a fascinating diversity of intramolecular donor–acceptor interactions.
Citrate–hydrazine hydrogen-bonding driven single-step synthesis of tunable near-IR plasmonic, anisotropic silver nanocrystals: implications for SERS spectroscopy of inorganic oxoanions
Authors: Pattanayak Satarupa , Swarnkar Abhishek , Priyam Amiya , Bhalerao Gopal M.
Published: June 2014

Anisotropic silver nanocrystals (NCs) having Vis-to-NIR plasmon tunability have been synthesized by tailoring the hydrogen-bonding interactions between a mild stabilizer (citrate) and a mild reductant (hydrazine hydrate).
Assembly and photocatalysis of two novel 3D Anderson-type polyoxometalate-based metal–organic frameworks constructed from isomeric bis(pyridylformyl)piperazine ligands
Authors: Wang Xiuli , Chang Zhihan , Lin Hongyan , Tian Aixiang , Liu Guocheng , Zhang Juwen
Published: June 2014

Two 3D Anderson-based MOFs constructed from two isomeric bis(pyridylformyl)piperazine have been synthesized. The isomeric ligands and Anderson-type polyanions play key roles in the construction of the final frameworks.
Concluding remarks: astrochemistry of dust, ice and gas
Authors: Herbst Eric
Published: June 2014

In this closing article, we first introduce the topics of dust and ice chemistry and their role in astrochemistry. We then discuss the invited contributions and discussions concerning these topics, dividing the papers into groupings by subject: (i) astronomical sources, (ii) basic properties of dust, (iii) processes on bare grains, (iv) processes on and in ice mantles, and (v) complex organic molecules. A sample of poster contributions is included in the text, when they complement the discussion. The article ends with some suggestions for future research.
Towards the rational biosynthesis of substituted phenazines and phenoxazinones by laccases
Authors: Sousa Ana Catarina , Oliveira M. Conceição , Martins Lígia O. , Robalo M. Paula
Published: June 2014

The laccase-catalysed oxidative coupling of substituted aromatic amines is described, extending the scope of laccases towards the production of phenazine and phenoxazinone derivatives.
Comparison of analytical performance of benchtop and handheld energy dispersive X-ray fluorescence systems for the direct analysis of plant materials
Authors: Bueno Guerra Marcelo Braga , de Almeida Eduardo , Carvalho Gabriel G. A. , Souza Paulino F. , Nunes Lidiane Cristina , Júnior Dário Santos , Krug Francisco José
Published: June 2014

Handheld and benchtop EDXRF systems presented similar analytical performances with pellets of plant materials aiming at plant nutrition diagnosis.
Investigation of acoustic streaming patterns around oscillating sharp edges
Authors: Nama Nitesh , Huang Po-Hsun , Huang Tony Jun , Costanzo Francesco
Published: June 2014

Perturbation approach is utilized to study the acoustic streaming phenomenon induced by the oscillation of sidewall sharp-edges.
One-pot and highly regio-selective 1,3-dipole cycloaddition of azomethine ylide generated in situ to tetraethyl vinylidenebisphosphonate (VBP) catalyzed by cerium(iv) oxide
Authors: Li Guozhu , Wu Mingshu , Kong Dulin , Liu Rendie , Zhou Xueming , Liu Fengjiao
Published: June 2014

Higly regio-selective heterocyclic bisphosphonates are obtained in moderate yields (30–70%). The structures of the targeted molecules are characterized by NMR (such as COSY, HSQC, and HMBC), IR and MS.
Thermodynamic data for Pb2+and Zn2+sequestration by biologically important S-donor ligands, at different temperatures and ionic strengths
Authors: Crea Francesco , Falcone Gabriella , Foti Claudia , Giuffrè Ottavia , Materazzi Stefano
Published: June 2014

A thermodynamic picture is reported for cys–Pb2+, psh–Pb2+, gsh–Pb2+, and gsh–Zn2+systems, and equilibrium constants can be predicted for any experimental condition.
Solving the nanostructure problem: exemplified on metallic alloy nanoparticles
Authors: Petkov Valeri , Prasai Binay , Ren Yang , Shan Shiyao , Luo Jin , Joseph Pharrah , Zhong Chuan-Jian
Published: June 2014

An approach to solve the “nanostructure problem” is presented and illustrated on Pd–Ni nanoparticles explored for catalytic applications.
Nanosized LiFePO4-decorated emulsion-templated carbon foam for 3D micro batteries: a study of structure and electrochemical performance
Authors: Asfaw Habtom D. , Roberts Matthew R. , Tai Cheuk-Wai , Younesi Reza , Valvo Mario , Nyholm Leif , Edström Kristina
Published: June 2014

A highly porous and reticulated carbon foam electrode can be used to fabricate 3D micro-sized batteries with increased capacity and rate performance.
DNA-based detection of mercury(ii) ions through characteristic current signals in nanopores with high sensitivity and selectivity
Authors: Zeng Tao , Li Ting , Li Yuru , Liu Lei , Wang Xingyong , Liu Quansheng , Zhao Yuliang , Wu Hai-Chen
Published: June 2014

Translocation of a partial duplex containing T–Hg2+–T pairings through α-hemolysin generates characteristic three-level signature events, allowing unambiguous detection of Hg2+.
Synthesis of WO3·H2O nanoparticles by pulsed plasma in liquid
Authors: Chen Liliang , Mashimo Tsutomu , Okudera Hiroki , Iwamoto Chihiro , Omurzak Emil
Published: June 2014

Pure orthorhombic-phase WO3·H2O nanoparticles with sizes of about 5 nm were synthesized by pulsed plasma in deionized water, in which tungsten electrodes provide the source of tungsten and the water is the source of oxygen and hydrogen.
Anion exchange membranes by bromination of benzylmethyl-containing poly(fluorene ether sulfone)s
Authors: Mei Wenhai , Lü Changli , Yan Jingling , Wang Zhen
Published: June 2014

Fluorene-containing anion exchange membranes were synthesized via the bromination reaction of poly(sulfone)s, which exhibited reasonably high conductivities.
Label-free cell phenotypic profiling identifies pharmacologically active compounds in two traditional Chinese medicinal plants
Authors: Zhang Xiuli , Deng Huayun , Xiao Yuansheng , Xue Xingya , Ferrie Ann M. , Tran Elizabeth , Liang Xinmiao , Fang Ye
Published: June 2014

Label-free cell phenotypic profiling with three cell lines identified multiple pharmacologically active compounds including niacin in two TCM plants.
Iron complexation of pharmaceutical catechins through selective separation
Authors: Manna Mriganka Sekhar , Saha Prabirkumar , Ghoshal Aloke Kumar
Published: June 2014

Enrichment of pharmaceutical catechins through iron complexation in their recovery process based on a liquid membrane technique.
Design, synthesis, and biological evaluation of a new class of MT2-selective agonists
Authors: Zhang Xuan , Wang Zhilong , Huang Qingqing , Luo Yu , Xie Xin , Lu Wei
Published: June 2014

In this study, we have designed and synthesized a novel class of chiral 2,3-dihydro-1H-indene derivatives as highly selective MT2 agonists.
Ionic liquid-doped and p-NIPAAm-based copolymer (p-NIBIm): extraordinary drug-entrapping and -releasing behaviors at 38–42 °C
Authors: Seo Jae-Won , Hwang Ji-Young , Shin Ueon Sang
Published: June 2014

Temperature-dependent size changes of p-NIBIm and extraordinary BSA-entrapping and releasing behaviors of p-NIBIm/BSA complexes at 38–42 °C.
Stochastic microsensors as screening tools for neuron specific enolase
Authors: Stefan-van Staden Raluca-Ioana , Comnea Ionela Raluca , van Staden Jacobus Frederick , Stanciu Gavan Camelia
Published: June 2014

Stochastic microsensors based on nanostructured materials from the classes of porphyrins and cyclodextrins, and carbon onions were used for new screening tools of whole blood samples for neuron specific enolase, a lung cancer biomarker.
Formation of superconducting yttrium barium copper oxide using sulphur-containing templates
Authors: Boston R. , Awaya K. , Nakayama T. , Ogasawara W. , Hall S. R.
Published: June 2014

Protein from the acorn barnacle used to template high temperature superconductors.
Chemical insights into dodecylamine spore lethal germination
Authors: Mi Luo , White Andrew D. , Shao Qing , Setlow Peter , Li Yongqing , Jiang Shaoyi
Published: June 2014

Investigations into dodecylamine spore lethal germination mechanism shed light on the design of future antispore molecules.
Aqueous rechargeable lithium batteries using NaV6O15 nanoflakes as high performance anodes
Authors: Sun Dan , Jin Guanhua , Wang Haiyan , Liu Ping , Ren Yu , Jiang Yifan , Tang Yougen , Huang Xiaobing
Published: June 2014

NaV6O15 nanoflakes with a 3-D tunneled structure were synthesized by a two-step approach and the NaV6O15//LiMn2O4 ARLB system with superior cycling performance (ca. 80% at 1 C after 400 cycles) was constructed. The origins of such superior electrochemical properties were explained well.
Exploiting stable radical states for multifunctional properties in triarylamine-based porous organic polymers
Authors: Hua Carol , Rawal Aditya , Faust Thomas B. , Southon Peter D. , Babarao Ravichandar , Hook James M. , D'Alessandro Deanna M.
Published: June 2014

Redox-active porous organic polymers (POPs) have enormous potential in applications ranging from electrocatalysis to solar energy conversion.
Conversion of polystyrene foam to a high-performance doped carbon catalyst with ultrahigh surface area and hierarchical porous structures for oxygen reduction
Authors: You Chenghang , Liao Shijun , Qiao Xiaochang , Zeng Xiaoyuan , Liu Fangfang , Zheng Ruiping , Song Huiyu , Zeng Jianhuang , Li Yingwei
Published: June 2014

A high performance carbon-based ORR catalyst with ultra-high surface area and hierarchical porous structures was derived from polystyrene foam waste.
Spacer effects in metal-free organic dyes for visible-light-driven dye-sensitized photocatalytic hydrogen production
Authors: Watanabe Motonori , Hagiwara Hidehisa , Iribe Aoi , Ogata Yudai , Shiomi Kenta , Staykov Aleksandar , Ida Shintaro , Tanaka Keiji , Ishihara Tatsumi
Published: June 2014

Metal-free organic dyes containing benzo[b]phenothiazine were synthesized and effectively used for dye-sensitized visible-light-driven photocatalytic hydrogen production.
Polycyanoacrylate porous material for bone tissue substitution
Authors: Rustamov I. R. , Dyatlov V. A. , Grebeneva T. A. , Dyatlov A. V. , Zaitsev V. V. , Maleev V. I.
Published: June 2014

A novel polycyanoacrylate-based bone-substituting foam material has been developed, which provides independent release of two polypeptide actives followed by biodegradation and bone substitution.
Joint power control and component carrier assignment scheme in heterogeneous network with carrier aggregation
Authors: Qinjuan Zhang , Lin Guo , Can Sun , Xudong An , Xiaochen Chen
Published: June 2014

A distributed interference coordination scheme is proposed to alleviate cross‐tier and inner‐tier interference in heterogeneous network (HetNet), consisting of a power control strategy based on game theory to acquire both Nash equilibrium among femtocells and Stackelberg equilibrium between femtocells and macrocells. Component carrier assignment is the other interference coordination dimension for HetNet with carrier aggregation. The proposed method is a two‐dimensional interference coordination scheme combining power control and component carrier assignment. The simulation results demonstrate the effectiveness and improvement of the proposed scheme.
Quasi‐cyclic low‐density parity‐check codes based on finite set systems
Authors: Gholami Mohammad , Esmaeili Morteza , Samadieh Mehdi
Published: June 2014

A finite set system (FSS) is a pair (V, ℬ) where V is a finite set whose members are called points, equipped with a finite collection of its subsets ℬ whose members are called blocks. In this paper, FSSs are used to define a class of quasi‐cyclic low‐density parity‐check (LDPC) codes, called FSS codes, such that the constructed codes possess large girth and arbitrary column‐weight distributions. Especially, the constructed column weight‐2 FSS codes have higher rates than the column weight‐2 geometric and cylinder‐type codes with the same girths. To find the maximum girth of FSS codes based on (V, ℬ), inevitable walks are defined in ℬ such that the maximum girth is determined by the smallest length of the inevitable walks in ℬ. Simulation results show that the constructed FSS codes have very good performance over the additive white Gaussian noise channel with iterative decoding and achieve significantly large coding gains compared with the random‐like LDPC codes of the same lengths and rates.
Performance analysis comparison of transmit antenna selection with maximal ratio combining and orthogonal space time block codes in equicorrelated Rayleigh fading multiple input multiple output channels
Authors: Kulkarni Mandar , Choudhary Lovish , Kumbhani Brijesh , Kshetrimayum Rakhesh Singh
Published: June 2014

In this study, bit error rate (BER) performance of multiple input multiple output (MIMO) systems employing transmit antenna selection with maximal ratio combining (TAS/MRC) and orthogonal space time block codes (OSTBC) is analysed and compared. Analysis has been done for several modulation schemes in equicorrelated Rayleigh fading channels. Novel infinite series expressions for BER of TAS/MRC are proposed in this work. The authors observe that the existing literature on performance analysis of TAS/MRC in correlated channels implicitly or explicitly assume no correlation on the transmitter side. In this work the authors overcome this shortcoming. An alternate closed‐form expression for BER performance of OSTBC MIMO systems is derived. This closed‐form expression is computationally efficient than existing expressions. Monte Carlo simulations were performed to validate the analytical results. It has been observed that TAS/MRC outperforms OSTBC in terms of BER performance in equicorrelated Rayleigh fading channel. As a case study, performance comparison of cognitive radio (CR) links employing OSTBC and TAS/MRC MIMO systems is investigated in order to show the usefulness of the present analytical study. Even though TAS is the optimum transmit antenna technique in terms of BER performance, OSTBC seems to be a promising alternative for more realistic scenarios in CR systems.
Polarisation oblique projection for radar seeker tracking in chaff centroid jamming environment without prior knowledge
Authors: Yang Yong , Xiao Shun‐ping , Feng De‐jun , Wang Xue‐song
Published: June 2014

Chaff centroid jamming makes the indicated angle of a target by a radar seeker bias off the target, which is catastrophic to the radar seeker target tracking. In this study, the authors propose to suppress the chaff centroid jamming by polarisation oblique projection without prior knowledge of the target and the jamming polarisation parameters. At first, they prove that interference‐to‐signal ratio and in‐phase monopulse ratio error after polarisation oblique projection are both independent of the estimation errors of the target polarisation parameters by theoretical derivation and geometrical interpretation. Then they estimate the polarisation parameters of chaff centroid jamming directly by the radar seeker received signal, and construct the polarisation oblique projection operator using the estimated jamming polarisation parameters and randomly set target polarisation parameters. They suppress the chaff centroid jamming with the estimated polarisation oblique projection operator, and demonstrate the validity of the proposed method by Monte Carlo simulations.
Detection of a distributed target with direction uncertainty
Authors: Liu Weijian , Xie Wenchong , Liu Jun , Zou Dujian , Wang Honglin , Wang Yongliang
Published: June 2014

In this study, the authors deal with the problem of detecting a distributed target in coloured noise with unknown covariance matrix. The target echoes are all assumed to come from the same direction. However, the exact direction is unknown a priori. Precisely, the signal steering vector lies in a certain known subspace, but with unknown coordinate. They derive the Wald test and two‐step Wald test and also show that there is no meaningful Rao test or its two‐step variation. Moreover, it is found that the two‐step Wald test is equivalent to an existing direction detector. Additionally, it is shown that the Wald test possesses the constant false alarm rate property. Some numerical examples are given to compare the detection performance of the novel direction detector with its counterparts, both in the cases of matched and mismatched signals.
Measurement of harmonic distortion and Skewness of stator current of induction motor at crawling in Clarke plane
Authors: Chattopadhyay Surajit , Chattopadhyaya Aveek , Sengupta Samarjit
Published: June 2014

This study deals with measurement of harmonic distortion and Skewness of stator current in Clarke plane at crawling of induction motor. Three‐phase current signals have been transformed into Clarke plane. Dominancy of seventh harmonic is observed by assessing maxima and minima of stator current Concordia in Clarke plane. Specific reference signals having sinusoidal nature and different frequencies are defined and then areas covered by the real system data with the reference signal have been determined, wherefrom individual contributions of fundamental waveform and harmonic components are measured separately and total harmonic distortion factors are determined. Then wavelet decomposition of stator current is done in Clarke plane, wherefrom, signals are assessed with the help of Skewness of approximate coefficient in Clarke plane. Significant differences are noted between those parameters found during crawling and that of normal condition which may be useful in detection of such fault.
Reference Correlation of the Viscosity of n-Heptane from the Triple Point to 600 K and up to 248 MPa
Authors: Michailidou E. K. , Assael M. J. , Huber M. L. , Abdulagatov I. M. , Perkins R. A.
Published: June 2014

This paper contains a new wide-ranging correlation for the viscosity of n-heptane based on critically evaluated experimental data. The correlation is valid from the triple point (182.55 K) to 600 K, and at pressures up to 248 MPa. The estimated uncertainty at a 95% confidence level is 3.5% over the whole range (with the exception of the near-critical region). Along the saturated liquid curve, the estimated uncertainty is 1% below 292 K, 0.6% in the region from 292 to 346 K, rising to 2% between 346 and 363 K, and 0.3% for the low-density gas at temperatures from 317 to 600 K and pressures to 0.3 MPa.
Investigation of the thermal stability of Cu nanowires using atomistic simulations
Authors: Granberg F. , Parviainen S. , Djurabekova F. , Nordlund K.
Published: June 2014

We present a method for determining the melting point of copper nanowires based on classical molecular dynamics simulations and use it to investigate the dependence of the melting point on wire diameter. The melting point is determined as the temperature at which there is a significant change in the fraction of liquid atoms in the wire, according to atomic bond angle analysis. The results for the wires with diameters in the range 1.5 nm to 20 nm show that the melting point is inversely proportional to the diameter while the cross-sectional shape of the wire does not have a significant impact. Comparison of results obtained using different potentials show that while the absolute values of the melting points may differ substantially, the melting point depression is similar for all potentials. The obtained results are consistent with predictions based on the semi-empirical liquid drop model.
Variable-delay polarization modulators for cryogenic millimeter-wave applications
Authors: Chuss D. T. , Eimer J. R. , Fixsen D. J. , Hinderks J. , Kogut A. J. , Lazear J. , Mirel P. , Switzer E. , Voellmer G. M. , Wollack E. J.
Published: June 2014

We describe the design, construction, and initial validation of the variable-delay polarization modulator (VPM) designed for the PIPER cosmic microwave background polarimeter. The VPM modulates between linear and circular polarization by introducing a variable phase delay between orthogonal linear polarizations. Each VPM has a diameter of 39 cm and is engineered to operate in a cryogenic environment (1.5 K). We describe the mechanical design and performance of the kinematic double-blade flexure and drive mechanism along with the construction of the high precision wire grid polarizers.
Analysis of capillary drainage from a flat solid strip
Authors: Ramé Enrique , Zimmerli Gregory A.
Published: June 2014

A long and narrow solid strip coated with a thin liquid layer is used as a model of a generic fluid mass probe in a spacecraft propellant tank just after a small thruster firing. The drainage dynamics of the initial coating layer into the settled bulk fluid affects the interpretation of probe measurements as the sensors' signal depends strongly on whether a sensor is in contact with vapor or with liquid. We analyze the drainage under various conditions of zero-gravity (i.e., capillary drainage) and with gravity aligned with the strip length, corresponding to the thruster acceleration. Long-time analytical solutions are found for zero and non-zero gravity. In the case with gravity, an approximate solution is found using matched asymptotics. Estimates show that a thrust of 10−3g0 significantly reduces drainage times.
A novel in situ device based on a bionic piezoelectric actuator to study tensile and fatigue properties of bulk materials
Authors: Wang Shupeng , Zhang Zhihui , Ren Luquan , Zhao Hongwei , Liang Yunhong , Zhu Bing
Published: June 2014

In this work, a miniaturized device based on a bionic piezoelectric actuator was developed to investigate the static tensile and dynamic fatigue properties of bulk materials. The device mainly consists of a bionic stepping piezoelectric actuator based on wedge block clamping, a pair of grippers, and a set of precise signal test system. Tensile and fatigue examinations share a set of driving system and a set of signal test system. In situ tensile and fatigue examinations under scanning electron microscope or metallographic microscope could be carried out due to the miniaturized dimensions of the device. The structure and working principle of the device were discussed and the effects of output difference between two piezoelectric stacks on the device were theoretically analyzed. The tensile and fatigue examinations on ordinary copper were carried out using this device and its feasibility was verified through the comparison tests with a commercial tensile examination instrument.
Scattering assisted injection based injectorless mid infrared quantum cascade laser
Authors: Singh Siddharth , Kamoua Ridha
Published: June 2014

An injectorless five-well mid infrared quantum cascade laser is analyzed which relies on phonon scattering injection in contrast to resonant tunneling injection, which has been previously used for injectorless designs. A Monte Carlo based self-consistent electron and photon transport simulator is used to analyze the performance of the analyzed design and compare it to existing injectorless designs. The simulation results show that the analyzed design could greatly enhance the optical gain and the characteristic temperatures of injectorless quantum cascade lasers (QCLs) which have typically been hindered by low characteristic temperatures and significant temperature related performance degradation. Simulations of the analyzed device predict threshold current densities of 0.85 kA/cm2 and 1.95 kA/cm2 at 77 K and 300 K, respectively, which are comparable to the threshold current densities of conventional injector based QCLs.
Model for triplet state engineering in organic light emitting diodes
Authors: Prodhan Suryoday , Soos Zoltán G. , Ramasesha S.
Published: June 2014

Engineering the position of the lowest triplet state (T1) relative to the first excited singlet state (S1) is of great importance in improving the efficiencies of organic light emitting diodes and organic photovoltaic cells. We have carried out model exact calculations of substituted polyene chains to understand the factors that affect the energy gap between S1 and T1. The factors studied are backbone dimerisation, different donor-acceptor substitutions, and twisted geometry. The largest system studied is an 18 carbon polyene which spans a Hilbert space of about 991 × 106. We show that for reverse intersystem crossing process, the best system involves substituting all carbon sites on one half of the polyene with donors and the other half with acceptors.
A deformation of quantum affine algebra in squashed Wess-Zumino-Novikov-Witten models
Authors: Kawaguchi Io , Yoshida Kentaroh
Published: June 2014

We proceed to study infinite-dimensional symmetries in two-dimensional squashed Wess-Zumino-Novikov-Witten models at the classical level. The target space is given by squashed S3 and the isometry is SU(2)L × U(1)R. It is known that SU(2)L is enhanced to a couple of Yangians. We reveal here that an infinite-dimensional extension of U(1)R is a deformation of quantum affine algebra, where a new deformation parameter is provided with the coefficient of the Wess-Zumino term. Then we consider the relation between the deformed quantum affine algebra and the pair of Yangians from the viewpoint of the left-right duality of monodromy matrices. The integrable structure is also discussed by computing the r/s-matrices that satisfy the extended classical Yang-Baxter equation. Finally, two degenerate limits are discussed.
Detection of melting by X-ray imaging at high pressure
Authors: Li Li , Weidner Donald J.
Published: June 2014

The occurrence of partial melting at elevated pressure and temperature is documented in real time through measurement of volume strain induced by a fixed temperature change. Here we present the methodology for measuring volume strains to one part in 10−4 for mm3 sized samples in situ as a function of time during a step in temperature. By calibrating the system for sample thermal expansion at temperatures lower than the solidus, the onset of melting can be detected when the melting volume increase is of comparable size to the thermal expansion induced volume change. We illustrate this technique with a peridotite sample at 1.5 GPa during partial melting. The Re capsule is imaged with a CCD camera at 20 frames/s. Temperature steps of 100 K induce volume strains that triple with melting. The analysis relies on image comparison for strain determination and the thermal inertia of the sample is clearly seen in the time history of the volume strain. Coupled with a thermodynamic model of the melting, we infer that we identify melting with 2 vol.% melting.
Defects and strain enhancements of second-harmonic generation in Si/Ge superlattices
Authors: Bertocchi Matteo , Luppi Eleonora , Degoli Elena , Véniard Valérie , Ossicini Stefano
Published: June 2014

Starting from experimental findings and interface growth problems in Si/Ge superlattices, we have investigated through ab initiomethods the concurrent and competitive behavior of strain and defects in the second-harmonic generation process. Interpreting the second-harmonic intensities as a function of the different nature and percentage of defects together with the strain induced at the interface between Si and Ge, we found a way to tune and enhance the second-harmonic generation response of these systems.
Annealing temperature dependence of the efficiency and vertical phase segregation of polymer/polymer bulk heterojunction photovoltaic cells
Authors: Murari Nishit M. , Crane Matthew J. , Earmme Taeshik , Hwang Ye-Jin , Jenekhe Samson A.
Published: June 2014

We report observation of annealing temperature-induced simultaneous vertical phase segregation and large enhancement of power conversion efficiency (PCE) of all-polymer bulk heterojunction (BHJ) solar cells composed of a poly(3-hexylthiophene) (P3HT) donor and a naphthalene diimide-selenolo[3,2-b]selenophene copolymer (PNDISS) acceptor. The PCE of P3HT:PNDISS BHJ devices increased over 50-fold from 0.04% to 2.03% when the annealing temperature was increased from 50 to 150 °C. Absorption spectroscopy and photoluminescence quenching experiments provide evidence of increasing phase segregation of the polymer/polymer blend films with increasing annealing temperature. Field-effect charge transport, contact angle, surface energy, and variable angle ellipsometry measurements on the P3HT:PNDISS blend films showed that thermal annealing induced vertical phase segregation, whereby the low surface energy polymer (P3HT) migrated to the bulk, while the high surface energy polymer (PNDISS) enriches at the substrate/blend interface.
Diamagnetic drift effects on the low-n magnetohydrodynamic modes at the high mode pedestal with plasma rotation
Authors: Zheng L. J. , Kotschenreuther M. T. , Valanju P.
Published: June 2014

The diamagnetic drift effects on the low-n magnetohydrodynamic instabilities at the high-mode (H-mode) pedestal are investigated in this paper with the inclusion of bootstrap current for equilibrium and rotation effects for stability, where n is the toroidal mode number. The AEGIS (Adaptive EiGenfunction Independent Solutions) code [L. J. Zheng and M. T. Kotschenreuther, J. Comp. Phys. 211 (2006)] is extended to include the diamagnetic drift effects. This can be viewed as the lowest order approximation of the finite Larmor radius effects in consideration of the pressure gradient steepness at the pedestal. The H-mode discharges at Jointed European Torus is reconstructed numerically using the VMEC code [P. Hirshman and J. C. Whitson, Phys. Fluids 26, 3553 (1983)], with bootstrap current taken into account. Generally speaking, the diamagnetic drift effects are stabilizing. Our results show that the effectiveness of diamagnetic stabilization depends sensitively on the safe factor value (qs) at the safety-factor reversal or plateau region. The diamagnetic stabilization are weaker, when qs is larger than an integer; while stronger, when qs is smaller or less larger than an integer. We also find that the diamagnetic drift effects also depend sensitively on the rotation direction. The diamagnetic stabilization in the co-rotation case is stronger than in the counter rotation case with respect to the ion diamagnetic drift direction.
Note: Fast imaging of DNA in atomic force microscopy enabled by a local raster scan algorithm
Authors: Huang Peng , Andersson Sean B.
Published: June 2014

Approaches to high-speed atomic force microscopy typically involve some combination of novel mechanical design to increase the physical bandwidth and advanced controllers to take maximum advantage of the physical capabilities. For certain classes of samples, however, imaging time can be reduced on standard instruments by reducing the amount of measurement that is performed to image the sample. One such technique is the local raster scan algorithm, developed for imaging of string-like samples. Here we provide experimental results on the use of this technique to image DNA samples, demonstrating the efficacy of the scheme and illustrating the order-of-magnitude improvement in imaging time that it provides.
Strong spin-orbit coupling and Zeeman spin splitting in angle dependent magnetoresistance of Bi2Te3
Authors: Dey Rik , Pramanik Tanmoy , Roy Anupam , Rai Amritesh , Guchhait Samaresh , Sonde Sushant , Movva Hema C. P. , Colombo Luigi , Register Leonard F. , Banerjee Sanjay K.
Published: June 2014

We have studied angle dependent magnetoresistance of Bi2Te3 thin film with field up to 9 T over 2–20 K temperatures. The perpendicular field magnetoresistance has been explained by the Hikami-Larkin-Nagaoka theory alone in a system with strong spin-orbit coupling, from which we have estimated the mean free path, the phase coherence length, and the spin-orbit relaxation time. We have obtained the out-of-plane spin-orbit relaxation time to be small and the in-plane spin-orbit relaxation time to be comparable to the momentum relaxation time. The estimation of these charge and spin transport parameters are useful for spintronics applications. For parallel field magnetoresistance, we have confirmed the presence of Zeeman effect which is otherwise suppressed in perpendicular field magnetoresistance due to strong spin-orbit coupling. The parallel field data have been explained using both the contributions from the Maekawa-Fukuyama localization theory for non-interacting electrons and Lee-Ramakrishnan theory of electron-electron interactions. The estimated Zeeman g-factor and the strength of Coulomb screening parameter agree well with the theory. Finally, the anisotropy in magnetoresistance with respect to angle has been described by the Hikami-Larkin-Nagaoka theory. This anisotropy can be used in anisotropic magnetic sensor applications.
Phase transitions in [001]-oriented morphotropic PbZr0.52Ti0.48O3 thin film deposited onto SrTiO3-buffered Si substrate
Authors: Shi Yin , Cueff M. , Niu Gang , Le Rhun G. , Vilquin B. , Saint Girons G. , Bachelet R. , Gautier B. , Robach Y. , Gemeiner P. , Guiblin N. , Defay E. , Dkhil B.
Published: June 2014

An 85 nm-thick morphotropic PbZr0.52Ti0.48O3 (PZT) film grown epitaxially and [001]-oriented onto a SrTiO3-buffered Si-wafer is investigated using temperature dependent X-ray diffraction. Two phase transitions, at Trt ∼ 500 K and Tc ∼ 685 K, are evidenced and are attributed to structural phase transitions from monoclinic-like to tetragonal-like phase and from tetragonal to paraelectric phase, respectively. The stronger upper shift of Trt value with respect to the bulk one and the weakly affected Tc (Tc bulk ∼ 665 K) are explained assuming misfit strain changes when crossing Trt. This finding opens new perspectives for piezoelectric PZT films in harsh applications.
Enhancing controllability and stability of bottom-gated graphene thin-film transistors by passivation with methylamine
Authors: Drapeko Maksim
Published: June 2014

This paper is intended to aid to bridge the gap between chemistry and electronic engineering. In this work, the fabrication of chemical vapour deposited graphene field-effect transistors employing silicon-nitride (Si3N4) gate dielectric is presented, showing originally p-type channel conduction due to ambient impurities yielding uncontrollable behaviour. Vacuum annealing has been performed to balance off hole and electron conduction in the channel, leading to the observation of the Dirac point and therefore improving controllability. Non-covalent functionalisation by methylamine has been performed for passivation and stability reasons yielding electron mobility of 4800 cm2/V s and hole mobility of 3800 cm2/V s as well as stabilised controllable behaviour of a bottom-gated transistor. The introduction of interface charge following the non-covalent functionalisation as well as the charge balance have been discussed and analysed.
Phonon renormalization and Raman spectral evolution through amorphous to crystalline transitions in Sb2Te3 thin films
Authors: Secor Jeff , Harris Matt A. , Zhao Lukas , Deng Haiming , Raoux Simone , Krusin-Elbaum Lia
Published: June 2014

A symmetry specific phonon mode renormalization is observed across an amorphous to crystalline phase transformation in thin films of the topological material Sb2Te3 using Raman spectroscopy. We present evidence for local crystalline symmetry in the amorphous state, eventhough, the q = 0 Raman selection rule is broken due to strong structural disorder. At crystallization, the in-plane polarized (Eg2) mode abruptly sharpens while the out-of-plane polarized (A1g) modes are only weakly effected. This effect unique to the Eg symmetry is exceptional considering that polarized spectra and comparison of the single phonon density of states between the amorphous and crystalline phases suggest that short range order of the amorphous phase is, on the average, similar to that of the crystalline material while electrical transport measurements reveal a sharp insulator-to-metal transition. Our findings point to the important role of anisotropic disorder affecting potential applications of topological and phase-change based electronics.