bluuebunny/crossref_metadata_2025 huggingface dataset:
Interdisciplinary benefits of a theory of cultural evolution centered at the group-level: The emergence of macro-neuroeconomics and social evolutionary game theory
Authors: Mattei Tobias A.
Published: June 2014

The theoretical concepts developed in the target article, in which the author proposes a new paradigm of cultural evolution based not on the individuals' characteristics, but rather on more global collective properties described as “group-traits” (which emerge when a group of individuals exhibit both differentiation and organization), may have a broader scientific impact that transcend the boundaries of social and evolutionary psychology, paving the way for the emergence of macro-neuroeconomics and social evolutionary game theory.
Explaining group-level traits requires distinguishing process from product
Authors: Panchanathan Karthik , Mathew Sarah , Perreault Charles
Published: June 2014

Smaldino is right to argue that we need a richer theory of group-level traits. He is wrong, however, in limiting group-level traits to units of cultural selection, which require explanations based on group selection. Traits are best understood when explanations focus on both process (i.e., selection) and product (i.e., adaptation). This approach can distinguish group-level traits that arise through within-group processes from those that arise through between-group processes.
Group-level traits are not units of selection
Authors: Santana Carlos , Weisberg Michael
Published: June 2014

We argue that Smaldino has not established that group-level traits constitute a unit of selection distinct from selection on individuals, as group-level traits are neither replicators nor interactors. Moreover, we argue that Wimsatt's analysis of emergence and aggregativity supports an understanding of group-level and other emergent traits as explanatorily reducible to the individual level.
Language as an emergent group-level trait
Authors: Shuai Lan , Gong Tao
Published: June 2014

Following Smaldino's definition, we claim that language is also an emergent group-level trait, and propose two facets (human groups tend to organize in a way to efficiently trigger language and linguistic interactions can render formation of certain social organization) to verify this statement, both of which also provide a general framework to address the future work about group-level traits.
Groups as units of functional analysis, individuals as proximate mechanisms
Authors: Wilson David Sloan
Published: June 2014

Whenever selection operates at a given level of a multitier hierarchy, units at that level should become the object of functional analysis, and units at lower levels should be studied as proximate mechanisms. This intuition already exists for the study of genes in individuals, when individuals are the unit of selection. It is only beginning to be applied for the study of individuals in groups, when groups are the unit of selection. Smaldino's target article is an important step in this direction with an emphasis on human cultural evolution, but the same algorithm applies to all multilevel evolutionary processes.
Pneumatically powered robotic exercise device to induce a specific force profile in target lower extremity muscles
Authors: Henderson Gregory C. , Ueda Jun
Published: June 2014

The goal of this research is to establish a methodology to actively control a pneumatically driven robotic device that can induce specific muscle force patterns in target muscles during a subject's voluntary movement. In this paper, the generation of constant forces in the rectus femoris muscle throughout the knee extension, i.e., isotonic contractions, was studied. Due to a highly nonlinear nature of mapping the joint torque to muscle force, a simple application of constant torques to the knee joint would not realize isotonic contractions. The proposed robotic exercise accounted for nonlinear moment arms of muscles as functions of joint angles and nonlinear coordination of multiple muscles in the neuromuscular system to accomplish individual muscle control. A pneumatically powered one degree-of-freedom device that can impose active force feedback control has been designed and built. An exercise-planning algorithm has been developed that involved a musculoskeletal model of the lower body, and the dynamics of a pneumatic actuator. Five constant force profiles were tested for 20 healthy volunteers and electromyographic signals were collected while the device was applying calculated force profiles.
VAR INTERPRETATIONS OF HAAVELMO’S MARKET MODEL OF CAPITAL AND INVESTMENT
Authors: Biørn Erik
Published: June 2014

In the paper attempts are made to integrate two parts of Trygve Haavelmo’s work: investment theory and dynamic econometric models of interrelated markets. Specifically, the duality in the representation of the capital service price and the capital quantity in relation to the investment price and quantity are brought to the forefront and confronted with elements from simultaneous equation modeling of vector autoregressive systems containing exogenous variables (VARX), using linear four-equation models. The role of the interest rate and the modeling of the expectation element in the capital service price and the capital’s retirement pattern, and their joint effect on the model’s investment quantity and price dynamics are discussed. Stability conditions are illustrated by examples. Extensions relaxing geometric decay and ways of accounting for forward-looking behavior, including rational expectations, are outlined. Some remarks on the theory-data confrontation of this kind of model are given.
CONSOLIDATION OF THE HAAVELMO-COWLES COMMISSION RESEARCH PROGRAM
Authors: Qin Duo
Published: June 2014

Much of modern econometrics stems directly from the post-1940 works of Haavelmo and the Cowles Commission (CC) Monograph 10. This paper examines the consolidation process of the Haavelmo-CC research program mainly during the 1950–70 period from three aspects: (i) developments of econometrics textbooks, (ii) emerging themes and trends in econometric research, and (iii) the contribution of the program to empirical modeling of real-world issues. The examination reveals that the program has gained dominance primarily through its adherence to the scientific banner and style rather than its empirical relevance. The adoption of the hard science methodology is decisive in winning over the academic community; the taxonomy of econometrics into steps involving primarily specification, identification, and estimation has played a pivotal role in generating compartmentalized research topics with manageable technical challenge and also in facilitating the educational need for compiling self-contained subjects and definitely soluble questions.
Sensitive periods for the effect of peer victimization on self-cognition: Moderation by age and gender
Authors: Roeder Kathryn M. , Cole David A. , Sinclair Keneisha R. , Dukewich Tammy L. , Preacher Kristopher J. , Felton Julia W. , Jacky Amy , Tilghman-Osborne Carlos
Published: June 2014

The link between the experience of peer victimization (PV) and future psychological maladjustment has been consistently documented; however, little is known about intermediary cognitive processes that underlie this relation or how these processes vary across childhood. The present study examined the prospective relations between physical and relational PV and the development of negative and positive automatic thoughts and self-cognitions. Self-reports of cognitions and peer nomination measures of victimization were obtained from 1,242 children and young adolescents (Grades 3 through 6) in a two-wave longitudinal study. The results revealed that PV predicted significant increases in negative views of the self, world, and future and decreases in self-perceived competence for girls under 11 years of age, with the effect being stronger for younger girls. PV was not significantly associated with changes in positive or negative self-cognitions for older girls or for boys of any age. These findings support the hypothesis that PV may be linked to future psychopathology through its influence on self-cognitions, but only for girls.
COMMON-LAW JUDICIAL REASONING AND ANALOGY
Authors: Rigoni Adam
Published: June 2014

Proponents of strict rule-based theories of judicial reasoning in common-law systems have offered a number of criticisms of analogical alternatives. I explain these criticisms and show that at best they apply equally well to rule-based theories. Further, I show how the analogical theories explain a feature of judicial common-law reasoning—the practice of distinguishing cases—that rule-based theories ignore. Finally, I show that reason-based, analogical theories of common-law judicial reasoning, such as those offered by John Horty and Grant Lamond, offer especially strong rejoinders to the rule-theorist objections and persuasive accounts of distinguishing.
Understanding consumer choices for Ontario produce
Authors: Dukeshire Steven , Masakure Oliver , Mendoza Julio , Holmes Bev , Murray Nathan
Published: June 2014

Research has demonstrated growing public interest in local food and that this interest is driven by a number of factors including supporting local farmers, reducing the distance food travels, sustaining the environment, and food safety and quality. However, there has been very little research relating factors to actual purchase behavior. This study begins to fill that gap by relating consumer beliefs and values toward local foods with activities that support local foods as well as the actual purchase behavior for 22 fresh produce items. Data were collected through an Ontario-wide, web-based survey that is part of a longitudinal panel regarding food issues. Results from 1879 completed surveys indicated consumers had positive perceptions of local food and felt responsible for buying local, but also experienced barriers when trying to do so. Positive perceptions toward local food and a greater sense of personal responsibility to buy local were positively associated and higher barriers negatively associated with the likelihood of engaging in activities related to supporting local food as well as buying fresh produce items that were produced in Ontario. Implications of these findings are discussed in the context that consumers seem to have an overall orientation or schema to buying local in general, rather than a highly specific schema directed to one or a few particular products.
A multi-scale approach of the mechanisms underlying exopolysaccharide auto-organization in the Proteus mirabilis extracellular matrix
Authors: Lahaye Élodie , Qin Yun , Jamme Frédéric , Aubry Thierry , Sire Olivier
Published: June 2014

Supramolecular organization within the extracellular matrix triggers the swarming/consolidation alternation in response to a periodic variation of water activity.
Lab-on-a-drop: biocompatible fluorescent nanoprobes of gold nanoclusters for label-free evaluation of phosphorylation-induced inhibition of acetylcholinesterase activity towards the ultrasensitive detection of pesticide residues
Authors: Zhang Ning , Si Yanmei , Sun Zongzhao , Li Shuai , Li Shuying , Lin Yuehe , Wang Hua
Published: June 2014

The catalysis and phosphorylated inhibition of acetylcholinesterase were monitored using fluorescent AuNCs nanoprobes for detecting pesticide residues.
Angiopoietin-1 peptide QHREDGS promotes osteoblast differentiation, bone matrix deposition and mineralization on biomedical materials
Authors: Feric Nicole T. , Cheng Calvin C. H. , Goh M. Cynthia , Dudnyk Vyacheslav , Di Tizio Val , Radisic Milica
Published: June 2014

QHREDGS upregulates osteogenic genes and promotes osteogenesis more effectively than RGDS when immobilized onto titanium medical devices or biomaterials.
Efficient metal-free hydrosilylation of tertiary, secondary and primary amides to amines
Authors: Blondiaux Enguerrand , Cantat Thibault
Published: June 2014

Hydrosilylation of secondary and tertiary amides to amines is described using catalytic amounts of B(C6F5)3. The organic catalyst enables the reduction of amides with cost-efficient, non-toxic and air stable PMHS and TMDS hydrosilanes. The methodology was successfully extended to the more challenging reduction of primary amides.
A low bandgap asymmetrical squaraine for high-performance solution-processed small molecule organic solar cells
Authors: Yang Daobin , Yang Qianqian , Yang Lin , Luo Qian , Chen Yao , Zhu Youqin , Huang Yan , Lu Zhiyun , Zhao Suling
Published: June 2014

A low-bandgap asymmetrical squaraine ASQ-5 bearing an indoline substituent for solution-processed organic solar cells with high Jsc and PCE was synthesized.
Biomimetic oxidation of pyrene and related aromatic hydrocarbons. Unexpected electron accepting abilities of pyrenequinones
Authors: López-Moreno Alejandro , Clemente-Tejeda David , Calbo Joaquín , Naeimi Atena , Bermejo Francisco A. , Ortí Enrique , Pérez Emilio M.
Published: June 2014

We present a mild catalytic method to oxidize PAHs and, in particular, pyrene, and we characterize the electron accepting abilities of pyrenequinones both in gas phase and in solution.
Crystallization of poly(butylene-2,6-naphthalate-co-butylene adipate) copolymers: regulating crystal modification of the polymorphic parent homopolymers and biodegradation
Authors: Papageorgiou George Z. , Tsanaktsis Vasilios , Bikiaris Dimitrios N.
Published: June 2014

Random PBNAd copolymers were synthesized. They showed isodimorphic cocrystallization. β PBN crystals were formed in copolymers with high BN content.
The calculation of 29Si NMR chemical shifts of tetracoordinated silicon compounds in the gas phase and in solution
Authors: Zhang Cong , Patschinski Pascal , Stephenson David S. , Panisch Robin , Wender Josef Heinrich , Holthausen Max C. , Zipse Hendrik
Published: June 2014

29Si NMR chemical shifts have been calculated for a variety of silicon-based species relevant in organic synthesis.
Use of heteroaromatic spacers in isoindigo-benzothiadiazole polymers for ambipolar charge transport
Authors: Kim Gyoungsik , Han A-Reum , Lee Hae Rang , Oh Joon Hak , Yang Changduk
Published: June 2014

Not only do we report two new polymers (PIIG-DTBT and PIIG-DSeBT) involving isoindigo and benzothiadiazole blocks constructed with thiophene and selenophene spacers, but also explore the optical, electrochemical, and charge-transport properties.
Non-uniform sampling in EPR – optimizing data acquisition for HYSCORE spectroscopy
Authors: Nakka K. K. , Tesiram Y. A. , Brereton I. M. , Mobli M. , Harmer J. R.
Published: June 2014

Non-uniformly sampled HYSCORE data combined with maximum entropy reconstruction can shorten experimental times by approximately an order of magnitude.
Single-crystal X-ray diffraction studies on structural transformations of porous coordination polymers
Authors: Zhang Jie-Peng , Liao Pei-Qin , Zhou Hao-Long , Lin Rui-Biao , Chen Xiao-Ming
Published: June 2014

This review gives a brief overview of single-crystal X-ray diffraction studies and single-crystal to single-crystal transformations of porous coordination polymers.
Hydrodeoxygenation of fatty acids and triglycerides by Pt-loaded Nb2O5 catalysts
Authors: Kon Kenichi , Onodera Wataru , Takakusagi Satoru , Shimizu Ken-ichi
Published: June 2014

Pt/Nb2O5 shows more than 60 times higher TON than non-SMSI Pt catalysts and previous catalysts for the hydrodeoxygenation of stearic acid to n-octadecane at 180 °C in 8 bar H2. Nb2O5 can act as an activation site of carbonyl groups.
Characterization of a meso-chiral isomer of a hexanuclear Cu(ii) cage from racemization of thel-alanine Schiff base
Authors: Rajesh Chinnaiyan Mahalingam , Ray Manabendra
Published: June 2014

Revising well studied Schiff base racemization led to isolation of a new chiral architecture exhibiting relatively rare ferromagnetic properties.
Multifunctional structural energy storage composite supercapacitors
Authors: Shirshova Natasha , Qian Hui , Houllé Matthieu , Steinke Joachim H. G. , Kucernak Anthony R. J. , Fontana Quentin P. V. , Greenhalgh Emile S. , Bismarck Alexander , Shaffer Milo S. P.
Published: June 2014

This paper addresses the challenge of producing multifunctional composites that can simultaneously carry mechanical loads whilst storing (and delivering) electrical energy. The embodiment is a structural supercapacitor built around laminated structural carbon fibre (CF) fabrics. Each cell consists of two modified structural CF fabric electrodes, separated by a structural glass fibre fabric or polymer membrane, infused with a multifunctional polymeric electrolyte. Rather than using conventional activated carbon fibres, structural carbon fibres were treated to produce a mechanically robust, high surface area material, using a variety of methods, including direct etching, carbon nanotube sizing, and carbon nanotubein situgrowth. One of the most promising approaches is to integrate a porous bicontinuous monolithic carbon aerogel (CAG) throughout the matrix. This nanostructured matrix both provides a dramatic increase in active surface area of the electrodes, and has the potential to address mechanical issues associated with matrix-dominated failures. The effect of the initial reaction mixture composition is assessed for both the CAG modified carbon fibre electrodes and resulting devices. A low temperature CAG modification of carbon fibres was evaluated using poly(3,4-ethylenedioxythiophene) (PEDOT) to enhance the electrochemical performance. For the multifunctional structural electrolyte, simple crosslinked gels have been replaced with bicontinuous structural epoxy–ionic liquid hybrids that offer a much better balance between the conflicting demands of rigidity and molecular motion. The formation of both aerogel precursors and the multifunctional electrolyte are described, including the influence of key components, and the defining characteristics of the products. Working structural supercapacitor composite prototypes have been produced and characterised electrochemically. The effect of introducing the necessary multifunctional resin on the mechanical properties has also been assessed. Larger scale demonstrators have been produced including a full size car boot/trunk lid.
Structural diversity and bioactivities of natural benzophenones
Authors: Wu Shi-Biao , Long Chunlin , Kennelly Edward J.
Published: June 2014

Natural benzophenones are a class of compounds with more than 300 members, mainly in the Clusiaceae family. We review key benzophenones, and provide an in-depth discussion of their great structural diversity and biological activity.
Facile synthesis of 5H-benzo[b]carbazol-6-yl ketones via sequential reaction of Cu-catalyzed Friedel–Crafts alkylation, iodine-promoted cyclization, nucleophilic substitution and aromatization
Authors: Wu Jing , Wang Dongping , Wang Haolong , Wu Fan , Li Xincheng , Wan Boshun
Published: June 2014

A convenient method to access 5H-benzo[b]carbazol-6-yl ketones from indoles and 2-(2-(alkynyl)benzylidene)malonates has been developed.
Convenient access to readily soluble symmetrical dialkyl-substituted α-oligofurans
Authors: Korshin Edward E. , Leitus Gregory M. , Bendikov Michael
Published: June 2014

A combination of heteroatom directed lithiation/CuCl2-induced homocoupling, Wittig olefination/Pd-catalyzed transfer hydrogenation followed by Suzuki–Miyaura or Stille cross-coupling enables convenient access to dialkyl-substituted α-oligofurans of potential interest for organic electronics.
Enantioselective synthesis of α,α-difluoro-β-lactams using amino alcohol ligands
Authors: Tarui Atsushi , Ikebata Takeshi , Sato Kazuyuki , Omote Masaaki , Ando Akira
Published: June 2014

A practical and highly enantioselective Reformatsky reaction of ethyl bromodifluoroacetate with imines using a cheap and commercially available amino alcohol ligand is described.
Direct synthesis of PEG-encapsulated gold nanoparticles using branched copolymer nanoreactors
Authors: Dunlop Iain E. , Ryan Mary P. , Goode Angela E. , Schuster Carlos , Terrill Nicholas J. , Weaver Jonathan V. M.
Published: June 2014

A highly scalable approach to generating PEG-stabilized gold nanoparticles for biomedical applications using micelle-like branched copolymers as nanoreactors.
Hydrothermal–thermal conversion synthesis of hierarchical porous MgO microrods as efficient adsorbents for lead(ii) and chromium(vi) removal
Authors: Zhang Linlin , Zhu Wancheng , Zhang Heng , Bi Siwei , Zhang Qiang
Published: June 2014

High crystallinity porous MgO microrods were synthesized via a NaCl and NP-9 assisted calcination of the hydrothermally synthesized MgC2O4·2H2O microrods, which exhibited satisfactory removal efficiency for Pb(ii) and Cr(vi) ions from aqueous solutions.
Multifunctional, robust, light-weight, free-standing MWCNT/phenolic composite paper as anodes for lithium ion batteries and EMI shielding material
Authors: Teotia Satish , Singh Bhanu Pratap , Elizabeth Indu , Singh Vidya Nand , Ravikumar Raman , Singh Avanish Pratap , Gopukumar S. , Dhawan S. K. , Srivastava Anchal , Mathur R. B.
Published: June 2014

Multifunctional, MWCNT/polymer composite of 140 μm thickness is demonstrated as an anode material for Li-ion battery and efficient EMI shielding material.
Dispersion-controlled PtCu clusters synthesized with citric acid using galvanic displacement with high electrocatalytic activity toward methanol oxidation
Authors: Lv Qing , Chang Jinfa , Xing Wei , Liu Changpeng
Published: June 2014

Dispersion-controlled carbon supported PtCu clusters were firstly synthesized using galvanic displacement of Cu/C, in which citric acid worked as the dispersion agent and its concentration was adjusted to form the as-synthesized clusters. It was found that dispersion played a significant role in tuning the activity for methanol electrooxidation.
Buckling of an elastic rod embedded on an elastomeric matrix: planar vs. non-planar configurations
Authors: Su Tianxiang , Liu Jia , Terwagne Denis , Reis Pedro M. , Bertoldi Katia
Published: June 2014

We investigate the buckling of a slender rod embedded in a soft elastomeric matrix through a combination of experiments, numerics and theory.
Understanding the variability of properties in Antheraea pernyi silk fibres
Authors: Wang Yu , Guan Juan , Hawkins Nick , Porter David , Shao Zhengzhong
Published: June 2014

We investigate the origin of variability in as-reeled natural silk fibres from different individuals using dynamic mechanical thermal analysis combined with polar solvent penetration.
Heteropoly acid and ZrO2 bifunctionalized organosilica hollow nanospheres for esterification and transesterification
Authors: Su Fang , An Sai , Song Daiyu , Zhang Xianghuan , Lu Bo , Guo Yihang
Published: June 2014

H3PW12O40/ZrO2-Et-HNS materials with strong Brönsted and Lewis acidity, unique hollow nanospherical morphology and enhanced surface hydrophobicity exihibit excellent catalytic activity.
A graphene oxide/conducting polymer nanocomposite for electrochemical dopamine detection: origin of improved sensitivity and specificity
Authors: Weaver C. L. , Li H. , Luo X. , Cui X. T.
Published: June 2014

This work describes the performance of a graphene oxide/poly(3,4-ethylenedioxythiophene) nanocomposite material as a sensitive and selective electrochemical dopamine sensor.
Two-photon absorption in butadiyne-linked porphyrin dimers: torsional and substituent effects
Authors: Wilkinson James D. , Wicks Geoffrey , Nowak-Król Agnieszka , Łukasiewicz Łukasz G. , Wilson Craig J. , Drobizhev Mikhail , Rebane Aleksander , Gryko Daniel T. , Anderson Harry L.
Published: June 2014

Dyes exhibiting efficient two-photon absorption (2PA) are in demand for a wide range of applications, and meso–meso butadiyne-linked porphyrin dimers (bis-porphyrins) are promising chromophores in this area.
Disturbance observer control method in DGMSCMG
Authors: Sun Jin‐ji , Peng Cong
Published: June 2014

To restrain disturbances produced by parameter variations and external disturbances in the axial magnetic bearing in the application of a double‐gimbal control moment gyro (DGMSCMG), a disturbance observer control method is proposed, which integrated the H∞ controller and the disturbance observer. This method considers parameter variations of the magnetic bearing and the effect of gimbals on the axial magnetic bearing. Consequently, the state space equation is changed to the form which can eliminate the disturbances. Then the robust controller is designed, which includes the disturbance observer design and robust H∞ controller design. The stability analysis is given for the proposed controller. Experiments on the DGMSCMG verified the correctness of the proposed method.
Minimum separation distance of adjacent channel TV band devices from DTV protected contour in TV white space
Authors: Kang Kyu‐Min
Published: June 2014

The minimum separation distance of a TV band device (TVBD), operating on channels immediately adjacent to an active digital TV (DTV) channel, from the DTV protected contour is presented. The required keep‐out distances for personal/portable and fixed TVBDs are investigated by considering the expected overall propagation attenuation of adjacent channel TVBD signals from the TVBD transmitter to the DTV receiver. The adjacent channel keep‐out distances of TVBDs recently announced by the Federal Communications Commission (FCC) are set too long when compared with the case where the keep‐out distances are estimated with the free‐space path loss model with an additional margin. Adequate adjacent channel keep‐out distances are proposed for both personal/portable TVBDs and fixed TVBDs.
Out‐of‐phase power divider based on two‐layer SIW
Authors: Chen Qi , Xu J.
Published: June 2014

A novel out‐of‐phase power divider based on a two‐layer substrate integrated waveguide (SIW) is presented. The input of the proposed power divider in one substrate is coupled to four outputs in another substrate through a slot located in the broad wall of the waveguide. By employing a step SIW in the input structure, the power divider exhibits a wide passband and good output imbalance. The advantages of this structure are its good performance, low profile and ease of fabrication. The SIW structure could be integrated easily with other planar circuits.
InAs‐based heterostructure field‐effect transistor using AlAs0.16Sb0.84 double barriers
Authors: Lin Yue‐Min , Lin Kun‐Ping , Lee Ting‐Chi , Li Meng‐Ying , Lee Chien‐Ping
Published: June 2014

An InAs‐channel heterostructure field‐effect transistor on GaAs substrates is presented. The conduction channel was formed by the InAs/AlAs0.16Sb0.84/AlSb quantum well. With the addition of the AlAs0.16Sb0.84 layer, holes that are generated by impact ionisation at high voltages are effectively confined in the InAs channel because of the large ΔEv in this type‐I heterostructure. By suppressing the hole injection into and accumulation in the buffer layer, the feedback through the back gate is eliminated and excellent output characteristics were obtained. The fabricated devices had a threshold voltage of about −0.6 V with a channel mobility of 18 100 cm2/V‐s and a sheet carrier density of 1.2 × 1012 cm−2.
Compact bionic handling arm control using neural networks
Authors: Melingui A. , Merzouki R. , Mbede J.B.
Published: June 2014

The tip position control of a class of continuum manipulators namely the compact bionic handling arm (CBHA) is proposed. The control scheme includes two sub‐controllers. The first sub‐controller, based on the distal supervised learning scheme, deals with the stationary CBHA's behaviours; whereas the second based on adaptive control handles non‐stationary behaviours. The experimental results obtained using the CBHA robot demonstrate the efficiency of the proposed approach.
Improved multi‐stage clustering‐based blind equalisation in interference‐limited CDMA environments
Authors: Mitra R. , Bhatia V.
Published: June 2014

The improved multi‐stage clustering (IMSC)‐based blind equalisation algorithm proposed by Mitra and colleagues in 2011 gave rise to significant improvements in terms of performance metrics as compared with its state‐of‐the‐art counterparts. However, the present authors' research studies show that IMSC performance degrades significantly for multiple access interference (MAI) in code‐division multiplexing access (CDMA) systems. To mitigate MAI, code filtering by orthogonal Hadamard codes is a popular practice to minimise the interference. Code‐filtering techniques have been used in the past in which a de‐correlating transform (inverse of an orthonormal Hadamard matrix) has been incorporated into the cost function of the parent algorithm (which can be any traditional equalisation algorithm). A hybrid equalisation scheme is suggested which combines IMSC and code‐filtering, so as to mitigate interference in CDMA environments. The code‐filtered IMSC shows better performance than any of the previously proposed algorithms.
Comment on ‘Sparse block circulant matrices for compressed sensing’
Authors: Quan Lei , Xiao Song , Wang Mengsi
Published: June 2014

In ‘Sparse block circulant matrices for compressed sensing’, in order to apply Lemma 4, every off‐diagonal element of Gram matrix for the sparse block circulant matrix was separated into two component sums to make sure the terms in each sum are independent. In this comment, however, the authors show that separating every element into two sums is not sufficient to guarantee the independency of the terms in each sum. The authors also prove that the entries should be split into three parts instead of two to satisfy the requirements of Lemma 4. Finally, the authors modify the deduction and the result.
Time‐domain finite‐element technique for quantifying the effect of sustained ferroresonance on power transformer core bolts
Authors: Charalambous Charalambos A. , Wang Zhongdong , Jarman Paul , Sturgess Jonathan Peter
Published: June 2014

Detailed investigation of the effects of ferroresonance on power transformers requires a method that is able to quantitatively and topologically assess the core saturation and the stray fields attributed to flux redistribution. This study describes a time‐domain finite‐element approach to model a ferroresonance condition and quantify its effect. More specifically the model generates sustained ferroresonance waveforms and, crucially, also allows examination of the effect of the resulting high core fluxes on the transformer core clamping bolts. Two benchmarking concepts are used to aid this: (i) the space‐averaged permeability variation and (ii) a topological calculation of flux variation within the core.
Feminism and Futurity: Revisiting Marge Piercy's Woman on the Edge of Time
Authors: McBean Sam
Published: June 2014

This article considers the question of feminist futurity through Marge Piercy's Woman on the Edge of Time (1976). While dominant readings of this novel have focused on its relationship to the feminist Utopian genre and feminist theory from the 1970s, this essay aims to critically reframe the novel through contemporary feminist theorising on time and futurity. Drawing on recent feminist and queer theory that suggests that the future might most productively be figured through more nuanced and renewed engagements with the past, I argue that readings of Piercy's novel that frame it only through its contemporary moment obscure the novel's critique of singular, linear models of time. The novel represents the future through the themes of loss, mourning and haunting, which I argue resist a model of time that moves linearly from past to future and instead bring the past and future into complex relation with each other. In this regard, Piercy's novel is read as representing a form of feminist futurity that engages with progress in time as necessarily uneven, discontinuous and fractured, speaking to contemporary demands for a feminist futurity that might require more nuanced accounts of the past.
Quantum diffusion with drift and the Einstein relation. II
Authors: De Roeck Wojciech , Fröhlich Jürg , Schnelli Kevin
Published: June 2014

This paper is a companion to Paper I [W. De Roeck, J. Fröhlich, and K. Schnelli, “Quantum diffusion with drift and the Einstein relation. I,” J. Math. Phys. 55, 075206 (2014)]. The purpose of this paper is to describe and prove a certain number of technical results used in Paper I, but not proven there. Both papers concern long-time properties (diffusion, drift) of the motion of a driven quantum particle coupled to an array of thermal reservoirs. The main technical results derived in the present paper are: (1) an asymptotic perturbation theory applicable for small driving force, and (2) the construction of time-dependent correlation functions of particle observables.
Three-dimensional instability in flow past a rectangular cylinder ranging from a normal flat plate to a square cylinder
Authors: Choi Choon-Bum , Yang Kyung-Soo
Published: June 2014

Floquet stability analysis has been carried out to detect the onset of the three-dimensional (3D) instability in flow past a rectangular cylinder ranging from a normal flat plate to a square cylinder with various aspect ratios (AR). The conventional modes A, B, and QP vanish as AR decreases towards a thin normal flat plate, whereas new modes A2 and QP2 emerge. For “thin” rectangular cylinders, mode QP2 becomes unstable first with increasing Reynolds number (Re). In a certain range of AR, mode A becomes unstable and then stable again as Re increases, resulting in a closed curve on the neutral stability diagram. For validation, 3D simulations were also performed.
The dynamic bulk modulus of three glass-forming liquids
Authors: Gundermann Ditte , Niss Kristine , Christensen Tage , Dyre Jeppe C. , Hecksher Tina
Published: June 2014

We present dynamic adiabatic bulk modulus data for three organic glass-forming liquids: two van der Waal's liquids, trimethyl-pentaphenyl-trisiloxane (DC705) and dibuthyl phtalate (DBP), and one hydrogen-bonded liquid, 1,2-propanediol (PD). All three liquids are found to obey time-temperature superposition within the uncertainty of the measurement in the adiabatic bulk modulus. The bulk modulus spectra are compared to the shear modulus spectra. The time scales of the two responses were found to be similar. The shapes of the shear and bulk modulus alpha loss peak are nearly identical for DBP and DC705, while the bulk modulus spectrum for PD is significantly broader than that of the shear modulus. The data further suggest that a “bulk modulus version of the shoving model” for the temperature dependence of the activation energy using the bulk modulus relaxation strength, ΔK(T), works well for DC705 and DBP, but not PD, while a formulation of the model using the high-frequency plateau value, K∞(T), gave a poor result for all three liquids.
An 8-GW long-pulse generator based on Tesla transformer and pulse forming network
Authors: Su Jiancang , Zhang Xibo , Li Rui , Zhao Liang , Sun Xu , Wang Limin , Zeng Bo , Cheng Jie , Wang Ying , Peng Jianchang , Song Xiaoxin
Published: June 2014

A long-pulse generator TPG700L based on a Tesla transformer and a series pulse forming network (PFN) is constructed to generate intense electron beams for the purpose of high power microwave (HPM) generation. The TPG700L mainly consists of a 12-stage PFN, a built-in Tesla transformer in a pulse forming line, a three-electrode gas switch, a transmission line with a trigger, and a load. The Tesla transformer and the compact PFN are the key technologies for the development of the TPG700L. This generator can output electrical pulses with a width as long as 200 ns at a level of 8 GW and a repetition rate of 50 Hz. When used to drive a relative backward wave oscillator for HPM generation, the electrical pulse width is about 100 ns on a voltage level of 520 kV. Factors affecting the pulse waveform of the TPG700L are also discussed. At present, the TPG700L performs well for long-pulse HPM generation in our laboratory.
Thermoreflectance temperature measurement with millimeter wave
Authors: Pradere C. , Caumes J.-P. , BenKhemis S. , Pernot G. , Palomo E. , Dilhaire S. , Batsale J.-C.
Published: June 2014

GigaHertz (GHz) thermoreflectance technique is developed to measure the transient temperature of metal and semiconductor materials located behind an opaque surface. The principle is based on the synchronous detection, using a commercial THz pyrometer, of a modulated millimeter wave (at 110 GHz) reflected by the sample hidden behind a shield layer. Measurements were performed on aluminum, copper, and silicon bulks hidden by a 5 cm thick Teflon plate. We report the first measurement of the thermoreflectance coefficient which exhibits a value 100 times higher at 2.8 mm radiation than those measured at visible wavelengths for both metallic and semiconductor materials. This giant thermoreflectance coefficient κ, close to 10−3 K−1 versus 10−5 K−1 for the visible domain, is very promising for future thermoreflectance applications.
Capacitive energy storage and recovery for synchrotron magnets
Authors: Koseki K.
Published: June 2014

Feasibility studies on capacitive energy storage and recovery in the main-ring synchrotron of the Japan Proton Accelerator Research Complex were conducted by circuit simulation. The estimated load fluctuation was 96 MVA in total for dipole magnets, which is likely to induce a serious disturbance in the main grid. It was found that the energy stored in the magnets after the excitation period can be recovered to the storage capacitor by controlling the voltage across the energy-storage capacitor using a pulse-width-modulation converter and reused in the next operational cycle. It was also found that the power fluctuation in the main grid can be reduced to 12 MVA. An experimental evaluation of an aluminum metalized film capacitor revealed that capacitance loss was induced by a fluctuating voltage applied to the storage capacitor when applying the proposed method. The capacitance loss was induced by corona discharge around the edges of segmented electrodes of a self-healing capacitor. The use of aluminum-zinc alloy was evaluated as a countermeasure to mitigate the effect induced by the corona discharge. For a zinc content of 8%, which was optimized experimentally, a capacitor with a sufficient life time expectancy of 20 years and a working potential gradient of 250 V/μm was developed.
Understanding chemical reactions of CO2 and its isoelectronic molecules with 1-butyl-3-methylimidazolium acetate by changing the nature of the cation: The case of CS2 in 1-butyl-1-methylpyrrolidinium acetate studied by NMR spectroscopy and density functional theory calculations
Authors: Cabaço M. Isabel , Besnard Marcel , Chávez Fabián Vaca , Pinaud Noël , Sebastião Pedro J. , Coutinho João A. P. , Danten Yann
Published: June 2014

NMR spectroscopy (1H, 13C, 15N) shows that carbon disulfide reacts spontaneously with 1-butyl-1-methylpyrrolidinium acetate ([BmPyrro][Ac]) in the liquid phase. It is found that the acetate anions play an important role in conditioning chemical reactions with CS2 leading, via coupled complex reactions, to the degradation of this molecule to form thioacetate anion (CH3COS−), CO2, OCS, and trithiocarbonate (CS32−). In marked contrast, the cation does not lead to the formation of any adducts allowing to conclude that, at most, its role consists in assisting indirectly these reactions. The choice of the [BmPyrro]+ cation in the present study allows disentangling the role of the anion and the cation in the reactions. As a consequence, the ensemble of results already reported on CS2-[Bmim][Ac] (1), OCS-[Bmim][Ac] (2), and CO2-[Bmim][Ac] (3) systems can be consistently rationalized. It is argued that in system (1) both anion and cation play a role. The CS2 reacts with the acetate anion leading to the formation of CH3COS−, CO2, and OCS. After these reactions have proceeded the nascent CO2 and OCS interact with the cation to form imidazolium-carboxylate ([Bmim] CO2) and imidazolium-thiocarboxylate ([Bmim] COS). The same scenario also applies to system (2). In contrast, in the CO2-[Bmim] [Ac] system a concerted cooperative process between the cation, the anion, and the CO2 molecule takes place. A carbene issued from the cation reacts to form the [Bmim] CO2, whereas the proton released by the ring interacts with the anion to produce acetic acid. In all these systems, the formation of adduct resulting from the reaction between the solute molecule and the carbene species originating from the cation is expected. However, this species was only observed in systems (2) and (3). The absence of such an adduct in system (1) has been theoretically investigated using DFT calculations. The values of the energetic barrier of the reactions show that the formation of [Bmim] CS2 is unfavoured and that the anion offers a competitive reactive channel via an oxygen-sulphur exchange mechanism with the solute in systems (1) and (2).
Long-time self-diffusion of charged spherical colloidal particles in parallel planar layers
Authors: Contreras-Aburto Claudio , Báez César A. , Méndez-Alcaraz José M. , Castañeda-Priego Ramón
Published: June 2014

The long-time self-diffusion coefficient, DL, of charged spherical colloidal particles in parallel planar layers is studied by means of Brownian dynamics computer simulations and mode-coupling theory. All particles (regardless which layer they are located on) interact with each other via the screened Coulomb potential and there is no particle transfer between layers. As a result of the geometrical constraint on particle positions, the simulation results show that DL is strongly controlled by the separation between layers. On the basis of the so-called contraction of the description formalism [C. Contreras-Aburto, J. M. Méndez-Alcaraz, and R. Castañeda-Priego, J. Chem. Phys. 132, 174111 (2010)], the effective potential between particles in a layer (the so-called observed layer) is obtained from integrating out the degrees of freedom of particles in the remaining layers. We have shown in a previous work that the effective potential performs well in describing the static structure of the observed layer (loc. cit.). In this work, we find that the DL values determined from the simulations of the observed layer, where the particles interact via the effective potential, do not agree with the exact values of DL. Our findings confirm that even when an effective potential can perform well in describing the static properties, there is no guarantee that it will correctly describe the dynamic properties of colloidal systems.
Holographic and time-resolving ability of pulse-pair two-dimensional velocity interferometry
Authors: Erskine David J. , Smith R. F. , Bolme C. A. , Ali S. J. , Celliers P. M. , Collins G. W.
Published: June 2014

Previous velocity interferometers used at research laboratories for shock physics experiments measured target motion at a point or many points on a line on the target. Recently, a two-dimensional (2d) version (2d-velocity interferometer system for any reflector) has been demonstrated using a pair of ultrashort (3 ps) pulses for illumination, separated by 268 ps. We have discovered new abilities for this instrument, by treating the complex output image as a hologram. For data taken in an out of focus configuration, we can Fourier process to bring narrow features such as cracks into sharp focus, which are otherwise completely blurred. This solves a practical problem when using high numerical aperture optics having narrow depth of field to observe moving surface features such as cracks. Furthermore, theory predicts that the target appearance (position and reflectivity) at two separate moments in time are recorded by the main and conjugate images of the same hologram, and are partially separable during analysis for narrow features. Hence, for the cracks we bring into refocus, we can make a two-frame movie with a subnanosecond frame period. Longer and shorter frame periods are possible with different interferometer delays. Since the megapixel optical detectors we use have superior spatial resolution over electronic beam based framing cameras, this technology could be of great use in studying microscopic three-dimensional-behavior of targets at ultrafast times scales. Demonstrations on shocked silicon are shown.
Zero kinetic energy photoelectron spectroscopy of triphenylene
Authors: Harthcock Colin , Zhang Jie , Kong Wei
Published: June 2014

We report vibrational information of both the first electronically excited state and the ground cationic state of jet-cooled triphenylene via the techniques of resonantly enhanced multiphoton ionization (REMPI) and zero kinetic energy (ZEKE) photoelectron spectroscopy. The first excited electronic state S1 of the neutral molecule is of A1′ symmetry and is therefore electric dipole forbidden in the D3h group. Consequently, there are no observable Franck-Condon allowed totally symmetric a1′ vibrational bands in the REMPI spectrum. All observed vibrational transitions are due to Herzberg-Teller vibronic coupling to the E′ third electronically excited state S3. The assignment of all vibrational bands as e′ symmetry is based on comparisons with calculations using the time dependent density functional theory and spectroscopic simulations. When an electron is eliminated, the molecular frame undergoes Jahn-Teller distortion, lowering the point group to C2v and resulting in two nearly degenerate electronic states of A2 and B1 symmetry. Here we follow a crude treatment by assuming that all e′ vibrational modes resolve into b2 and a1 modes in the C2v molecular frame. Some observed ZEKE transitions are tentatively assigned, and the adiabatic ionization threshold is determined to be 63 365 ± 7 cm−1. The observed ZEKE spectra contain a consistent pattern, with a cluster of transitions centered near the same vibrational level of the cation as that of the intermediate state, roughly consistent with the propensity rule. However, complete assignment of the detailed vibrational structure due to Jahn-Teller coupling requires much more extensive calculations, which will be performed in the future.
Two-stream instability with time-dependent drift velocity
Authors: Qin Hong , Davidson Ronald C.
Published: June 2014

The classical two-stream instability driven by a constant relative drift velocity between two plasma components is extended to the case with time-dependent drift velocity. A solution method is developed to rigorously define and calculate the instability growth rate for linear perturbations relative to the time-dependent unperturbed two-stream motions. Stability diagrams for the oscillating two-stream instability are presented over a large region of parameter space. It is shown that the growth rate for the classical two-stream instability can be significantly reduced by adding an oscillatory component to the relative drift velocity.
Wall current closure effects on plasma and sheath fluctuations in Hall thrusters
Authors: Frias Winston , Smolyakov Andrei I. , Kaganovich Igor D. , Raitses Yevgeny
Published: June 2014

The excitation of negative energy, ion sound type modes driven by the E × B drift and the reactive/dissipative response of the wall sheath interface is analyzed for conditions typical in a Hall thruster. Such sheath impedance modes are sensitive to the dielectric properties of the thruster wall material, which therefore may have direct influence (other than via the secondary electron emission) on fluctuations and transport. Our results predict mode frequencies consistent with the frequencies of fluctuations observed experimentally.