bluuebunny/crossref_metadata_2025 huggingface dataset:
Compressive sensing of frequency-dependent seismic radiation from subduction zone megathrust ruptures
Authors: Yao Huajian , Shearer Peter M. , Gerstoft Peter
Published: March 2013

Megathrust earthquakes rupture a broad zone of the subducting plate interface in both along-strike and along-dip directions. The along-dip rupture characteristics of megathrust events, e.g., their slip and energy radiation distribution, reflect depth-varying frictional properties of the slab interface. Here, we report high-resolution frequency-dependent seismic radiation of the four largest megathrust earthquakes in the past 10 y using a compressive-sensing (sparse source recovery) technique, resolving generally low-frequency radiation closer to the trench at shallower depths and high-frequency radiation farther from the trench at greater depths. Together with coseismic slip models and early aftershock locations, our results suggest depth-varying frictional properties at the subducting plate interfaces. The shallower portion of the slab interface (above ∼15 km) is frictionally stable or conditionally stable and is the source region for tsunami earthquakes with large coseismic slip, deficient high-frequency radiation, and few early aftershocks. The slab interface at intermediate depths (∼15–35 km) is the main unstable seismogenic zone for the nucleation of megathrust quakes, typically with large coseismic slip, abundant early aftershocks, and intermediate- to high-frequency radiation. The deeper portion of the slab interface (∼35–45 km) is seismically unstable, however with small coseismic slip, dominant high-frequency radiation, and relatively fewer aftershocks.
Serotonin spillover onto the axon initial segment of motoneurons induces central fatigue by inhibiting action potential initiation
Authors: Cotel Florence , Exley Richard , Cragg Stephanie J. , Perrier Jean-François
Published: March 2013

Motor fatigue induced by physical activity is an everyday experience characterized by a decreased capacity to generate motor force. Factors in both muscles and the central nervous system are involved. The central component of fatigue modulates the ability of motoneurons to activate muscle adequately independently of the muscle physiology. Indirect evidence indicates that central fatigue is caused by serotonin (5-HT), but the cellular mechanisms are unknown. In a slice preparation from the spinal cord of the adult turtle, we found that prolonged stimulation of the raphe-spinal pathway—as during motor exercise—activated 5-HT
1A
receptors that decreased motoneuronal excitability. Electrophysiological tests combined with pharmacology showed that focal activation of 5-HT
1A
receptors at the axon initial segment (AIS), but not on other motoneuronal compartments, inhibited the action potential initiation by modulating a Na
+
current. Immunohistochemical staining against 5-HT revealed a high-density innervation of 5-HT terminals on the somatodendritic membrane and a complete absence on the AIS. This observation raised the hypothesis that a 5-HT spillover activates receptors at this latter compartment. We tested it by measuring the level of extracellular 5-HT with cyclic voltammetry and found that prolonged stimulations of the raphe-spinal pathway increased the level of 5-HT to a concentration sufficient to activate 5-HT
1A
receptors. Together our results demonstrate that prolonged release of 5-HT during motor activity spills over from its release sites to the AIS of motoneurons. Here, activated 5-HT
1A
receptors inhibit firing and, thereby, muscle contraction. Hence, this is a cellular mechanism for central fatigue.
A dual of MacMahon’s theorem on plane partitions
Authors: Ciucu Mihai , Krattenthaler Christian
Published: March 2013

A classical theorem of MacMahon states that the number of lozenge tilings of any centrally symmetric hexagon drawn on the triangular lattice is given by a beautifully simple product formula. In this paper, we present a counterpart of this formula, corresponding to the exterior of a concave hexagon obtained by turning 120° after drawing each side (MacMahon’s hexagon is obtained by turning 60° after each step).
Highly tunable propagating surface plasmons on supported silver nanowires
Authors: Wei Hong , Zhang Shunping , Tian Xiaorui , Xu Hongxing
Published: March 2013

Surface plasmons, the quanta of the collective oscillations of free electrons at metal surface, can be easily tuned by changing the surrounding dielectric materials, which is well known for metal nanoparticles and metal surfaces, but less is known for one-dimensional metal nanowires. Here, we find an extremely large tunability of surface plasmons on Ag nanowires with a beat period of the near-field distribution pattern increasing by 90 nm per nanometer of Al
2
O
3
coating, or by 16 µm per refractive index unit change in the surrounding medium. Such high sensitivity is crucial to directly control the optical signal distribution for various routing and demultiplexing functions in plasmonic circuits and may pave the way to the development of on-chip ultrasensitive biosensing.
NMR-based functional profiling of RASopathies and oncogenic RAS mutations
Authors: Smith Matthew J. , Neel Benjamin G. , Ikura Mitsuhiko
Published: March 2013

Defects in the RAS small G protein or its associated network of regulatory proteins that disrupt GTPase cycling are a major cause of cancer and developmental RASopathy disorders. Lack of robust functional assays has been a major hurdle in RAS pathway-targeted drug development. We used NMR to obtain detailed mechanistic data on RAS cycling defects conferred by oncogenic mutations, or full-length RASopathy-derived regulatory proteins. By monitoring the conformation of wild-type and oncogenic RAS in real-time, we show that opposing properties integrate with regulators to hyperactivate oncogenic RAS mutants. Q61L and G13D exhibited rapid nucleotide exchange and an unexpected susceptibility to GAP-mediated hydrolysis, in direct contrast with G12V, indicating different approaches must be taken to inhibit these oncoproteins. An NMR methodology was established to directly monitor RAS cycling by intact, multidomain proteins encoded by RASopathy genes in mammalian cell extracts. By measuring GAP activity from tumor cells, we demonstrate how loss of neurofibromatosis type 1 (NF1) increases RAS-GTP levels in NF1-derived cells. We further applied this methodology to profile Noonan Syndrome (NS)-derived SOS1 mutants. Combining NMR with cell-based assays allowed us to differentiate defects in catalysis, allosteric regulation, and membrane targeting of individual mutants, while revealing a membrane-dependent compensatory effect that attenuates dramatic increases in RAS activation shown by Y337C, L550P, and I252T. Our NMR method presents a precise and robust measure of RAS activity, providing mechanistic insights that facilitate discovery of therapeutics targeted against the RAS signaling network.
Actin depolymerization under force is governed by lysine 113:glutamic acid 195-mediated catch-slip bonds
Authors: Lee Cho-yin , Lou Jizhong , Wen Kuo-kuang , McKane Melissa , Eskin Suzanne G. , Ono Shoichiro , Chien Shu , Rubenstein Peter A. , Zhu Cheng , McIntire Larry V.
Published: March 2013

As a key element in the cytoskeleton, actin filaments are highly dynamic structures that constantly sustain forces. However, the fundamental question of how force regulates actin dynamics is unclear. Using atomic force microscopy force-clamp experiments, we show that tensile force regulates G-actin/G-actin and G-actin/F-actin dissociation kinetics by prolonging bond lifetimes (catch bonds) at a low force range and by shortening bond lifetimes (slip bonds) beyond a threshold. Steered molecular dynamics simulations reveal force-induced formation of new interactions that include a lysine 113(K113):glutamic acid 195 (E195) salt bridge between actin subunits, thus suggesting a molecular basis for actin catch-slip bonds. This structural mechanism is supported by the suppression of the catch bonds by the single-residue replacements K113 to serine (K113S) and E195 to serine (E195S) on yeast actin. These results demonstrate and provide a structural explanation for actin catch-slip bonds, which may provide a mechanoregulatory mechanism to control cell functions by regulating the depolymerization kinetics of force-bearing actin filaments throughout the cytoskeleton.
Historical changes in northeastern US bee pollinators related to shared ecological traits
Authors: Bartomeus Ignasi , Ascher John S. , Gibbs Jason , Danforth Bryan N. , Wagner David L. , Hedtke Shannon M. , Winfree Rachael
Published: March 2013

Pollinators such as bees are essential to the functioning of terrestrial ecosystems. However, despite concerns about a global pollinator crisis, long-term data on the status of bee species are limited. We present a long-term study of relative rates of change for an entire regional bee fauna in the northeastern United States, based on >30,000 museum records representing 438 species. Over a 140-y period, aggregate native species richness weakly decreased, but richness declines were significant only for the genusBombus. Of 187 native species analyzed individually, only three declined steeply, all of these in the genusBombus. However, there were large shifts in community composition, as indicated by 56% of species showing significant changes in relative abundance over time. Traits associated with a declining relative abundance include small dietary and phenological breadth and large body size. In addition, species with lower latitudinal range boundaries are increasing in relative abundance, a finding that may represent a response to climate change. We show that despite marked increases in human population density and large changes in anthropogenic land use, aggregate native species richness declines were modest outside of the genusBombus. At the same time, we find that certain ecological traits are associated with declines in relative abundance. These results should help target conservation efforts focused on maintaining native bee abundance and diversity and therefore the important ecosystems services that they provide.
An RNA recognition motif-containing protein is required for plastid RNA editing in
Arabidopsis
and maize
Authors: Sun Tao , Germain Arnaud , Giloteaux Ludovic , Hammani Kamel , Barkan Alice , Hanson Maureen R. , Bentolila Stéphane
Published: March 2013

Significance

Transcripts in plant organelles are altered by conversion of cytidines to uridines in a process termed RNA editing. Members of two protein families have been identified in the plant editosome, but its complete composition is unknown. Now a unique protein that contains an RNA recognition motif has been found to be essential for editing of multiple plastid transcripts in both
Arabidopsis
and maize. Phylogenetic analysis indicates that this protein belongs to a sub-family of RNA recognition-motif proteins predominantly predicted to be targeted to organelles and that are thus likely to play roles in organelle RNA metabolism.
Unstructured to structured transition of an intrinsically disordered protein peptide in coupling Ca
2+
-sensing and SK channel activation
Authors: Zhang Miao , Pascal John M. , Zhang Ji-Fang
Published: March 2013

Most proteins, such as ion channels, form well-organized 3D structures to carry out their specific functions. A typical voltage-gated potassium channel subunit has six transmembrane segments (S1–S6) to form the voltage-sensing domain and the pore domain. Conformational changes of these domains result in opening of the channel pore. Intrinsically disordered (ID) proteins/peptides are considered equally important for the protein functions. However, it is difficult to explore the structural features underlying the functions of ID proteins/peptides by conventional methods, such as X-ray crystallography, because of the flexibility of their secondary structures. Unlike voltage-gated potassium channels, families of small- and intermediate-conductance Ca
2+
-activated potassium (SK/IK) channels with important roles in regulating membrane excitability are activated exclusively by Ca
2+
-bound calmodulin (CaM). Upon binding of Ca
2+
to CaM, a 2 × 2 structure forms between CaM and the CaM-binding domain. A channel fragment that connects S6 and the CaM-binding domain is not visible in the protein crystal structure, suggesting that this fragment is an ID fragment. Here we show that the conformation of the ID fragment in SK channels becomes readily identifiable in the presence of NS309, the most potent compound that potentiates the channel activities. This well-defined conformation of the ID fragment, stabilized by NS309, increases the channel open probability at a given Ca
2+
concentration. Our results demonstrate that the ID fragment, itself a target for drugs modulating SK channel activities, plays a unique role in coupling Ca
2+
sensing by CaM and mechanical opening of SK channels.
Chaperone activation by unfolding
Authors: Foit Linda , George Jenny S. , Zhang Bin W. , Brooks Charles L. , Bardwell James C. A.
Published: March 2013

Significance

For proteins, function is generally associated with order. Some proteins, however, are at least partially disordered. Because proteins tend to evolve into disorder in the absence of selection, it has been difficult to establish any significance of disorder for protein function. Here, we isolate a constitutively active variant of the normally acid-activated, conditionally disordered chaperone HdeA. We find this mutant to be largely destabilized, partially unstructured, and monomeric at a concentration at which it prevents the aggregation of a client protein. Our data therefore provide experimental evidence for the significance of partial disorder in protein function.
Dysregulation of synaptic plasticity precedes appearance of morphological defects in a Pten conditional knockout mouse model of autism
Authors: Takeuchi Koichi , Gertner Michael J. , Zhou Jing , Parada Luis F. , Bennett Michael V. L. , Zukin R. Suzanne
Published: March 2013

The phosphoinositide signaling system is a crucial regulator of neural development, cell survival, and plasticity. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) negatively regulates phosphatidylinositol 3-kinase signaling and downstream targets. Nse-
Cre
Pten conditional knockout mice, in which Pten is ablated in granule cells of the dentate gyrus and pyramidal neurons of the hippocampal CA3, but not CA1, recapitulate many of the symptoms of humans with inactivating PTEN mutations, including progressive hypertrophy of the dentate gyrus and deficits in hippocampus-based social and cognitive behaviors. However, the impact of Pten loss on activity-dependent synaptic plasticity in this clinically relevant mouse model of Pten inactivation remains unclear. Here, we show that two phosphatidylinositol 3-kinase- and protein synthesis-dependent forms of synaptic plasticity, theta burst-induced long-term potentiation and metabotropic glutamate receptor (mGluR)-dependent long-term depression, are dysregulated at medial perforant path-to-dentate gyrus synapses of young Nse-
Cre
Pten conditional knockout mice before the onset of visible morphological abnormalities. In contrast, long-term potentiation and mGluR-dependent long-term depression are normal at CA3–CA1 pyramidal cell synapses at this age. Our results reveal that deletion of Pten in dentate granule cells dysregulates synaptic plasticity, a defect that may underlie abnormal social and cognitive behaviors observed in humans with Pten inactivating mutations and potentially other autism spectrum disorders.
Tunable soft structure in charged fluids confined by dielectric interfaces
Authors: Zwanikken Jos W. , Olvera de la Cruz Monica
Published: March 2013

Fluids of charged particles act as the supporting medium for chemical reactions and physical, dynamical, and biological processes. The local structure in an electrolytic background is deformed by micro- and nanoscopic polarizable objects. Vice versa, the forces between the objects are regulated by the cohesive properties of the background. We study here the range and strength of these forces and the microscopic origin from which they emerge. We find the forces to be sensitively dependent on the material properties of the charged fluid and the immersed solutes. The induced interactions can be varied over decades, offering high tunability and aided by accurate theory, control in experiments and applications. To distinguish correlational effects from simple ionic screening, we describe electrolyte-induced forces between neutral objects. The interplay of thermal motion, short-range repulsions, and electrostatic forces is responsible for a soft structure in the fluid. This structure changes near polarizable interfaces and causes diverse attractions between confining walls that seem well-exploited by microbiological systems. For parameters that correspond to monovalent electrolytes in biologically and technologically relevant aqueous environments, we find induced forces between nanoscopic areas of the order of piconewtons over a few nanometers.
Cognitive load in simultaneous interpreting
Authors: Seeber Kilian G.
Published: March 2013

The mental effort required to perform a simultaneous interpreting task or the cognitive load generated by it has attracted the interest of many a researcher in the field. To date, however, there is little agreement on the most suitable method to measure this phenomenon. In this contribution, I set out to discuss four of the most common methods of measuring cognitive load and the way in which they have been applied in interpreting research, providing examples for each and highlighting their respective advantages and disadvantages. The main focus of the contribution will be on pupillometry, a psycho-physiological method I deem to be among the most promising approaches to objectively measure cognitive load during simultaneous interpreting in real time.
Towards a new linguistic-cognitive orientation in translation studies
Authors: House Juliane
Published: March 2013

A new linguistic-cognitive orientation in translation studies is important today because it can complement the current strong wave of socially and culturally oriented research into and around translation. For balance, it is also necessary and insightful to describe and explain how strategies of comprehending, decisionmaking and re-verbalisation come about in a translator’s bilingual mind. In this paper I sketch some ideas about such a new linguistic-cognitive approach. I first review introspective and retrospective studies and behavioural experiments. Secondly, I assess the value of neuro-linguistic studies for translation. Thirdly, I suggest a new combination of a translation theory and a neuro-functional theory of bilingualism.
Translation competence
Authors: Göpferich Susanne
Published: March 2013

This article introduces Dynamic Systems Theory (DST) as a framework for the investigation of translation competence development. After a presentation of the basic concepts and assumptions underlying this theory, results from the longitudinal study TransComp will be discussed against the background of DST. TransComp is a three-year product- and process-oriented longitudinal study of the development of translation competence in 12 students of translation, whose translation products and processes were compared with those of 10 professional translators. The article outlines both the difficulties involved in the application of DST to the investigation of translation competence development and the added value that it promises for our understanding of developmental processes in translators, including the ways they can be fostered in translation training.
The role of archival and manuscript research in the investigation of translator decision-making
Authors: Munday Jeremy
Published: March 2013

This paper discusses the application of research methodologies from history and literary studies to the analysis of the translation process. Specifically, this concerns the use of literary archive and manuscript material to investigate the various stages in the construction of the translation product. Such material has been drastically underexploited in translation studies to date. The paper describes the type of material available for researchers and how this has been used. This is followed by a case study involving the detailed textual analysis of a translator’s drafts and revisions. The paper considers the value of such research methods in investigating the translation process and how they might complement and interact with other methodologies.
Sound effects in translation
Authors: Mees Inger M. , Dragsted Barbara , Hansen Inge Gorm , Jakobsen Arnt Lykke
Published: March 2013

On the basis of a pilot study using speech recognition (SR) software, this paper attempts to illustrate the benefits of adopting an interdisciplinary approach in translator training. It shows how the collaboration between phoneticians, translators and interpreters can (1) advance research, (2) have implications for the curriculum, (3) be pedagogically motivating, and (4) prepare students for employing translation technology in their future practice as translators. In a twophase study in which 14 MA students translated texts in three modalities (sight, written, and oral translation using an SR program), Translog was employed to measure task times. The quality of the products was assessed by three experienced translators, and the number and types of misrecognitions were identified by a phonetician. Results indicate that SR translation provides a potentially useful supplement to written translation, or indeed an alternative to it.
Turkish nationalism at its beginning: Analysis ofTürk Yurdu, 1913–1918
Authors: Balkιlιç Özgür , Dölek Deniz
Published: March 2013

Turkish nationalism became an element of the Ottoman political scene in the late nineteenth century. Although its roots can be traced back to the Hamidian period (1876–1909), Turkish nationalism emerged as one of the most important political ideologies during the Constitutional Regime. Wars that the Ottoman State participated in from 1911 to the end of the empire in 1918 resulted in population and land losses. Especially, following the Balkan Wars, most of the lands that were populated by non-Muslim and non-Turkish subjects were lost. Within this context, Turkish nationalism came to be seen as the most dominant ideological tool intended to save the Empire. This article argues that Turkish nationalism emerged as a reactive ideology that addressed Ottomanism and Islamism, which were the two other dominant state ideologies during the late Ottoman State, due to the changing political context. In this article,Türk Yurdu, a well-known and influential periodical, is used as the primary source of reference to demonstrate the basic features of Turkish nationalism in its infancy.
Moduli of PT-semistable objects II
Authors: Lo Jason
Published: March 2013

We generalise the techniques of semistable reduction for flat families of sheaves to the setting of the derived category

D
b

(
X
)

D^b(X)

of coherent sheaves on a smooth projective three-fold

X
X

. Then we construct the moduli of PT-semistable objects in

D
b

(
X
)

D^b(X)

as an Artin stack of finite type that is universally closed. In the absence of strictly semistable objects, we construct the moduli as a proper algebraic space of finite type.
Liquid-crystal-enabled electrophoresis of spheres in a nematic medium with negative dielectric anisotropy
Authors: Lazo Israel , Lavrentovich Oleg D.
Published: March 2013

We describe electrophoresis of spherical dielectric particles in a uniformly aligned nematic medium with a negative dielectric anisotropy. A spherical particle that orients the liquid crystal (LC) perpendicularly to its surface moves under the application of a uniform direct current or alternating current electric field. The electric field causes no distortions of the LC director far away from the sphere. Electrophoresis in the nematic LC shows two types of nonlinearity in the velocity versus field dependence. The velocity component parallel to the applied electric field grows linearly with the field, but when the field is high enough, it also shows a cubic dependence. The most interesting is the second type of nonlinear electrophoresis that causes the sphere to move perpendicularly to the applied field. This perpendicular component of velocity is proportional to the square of the field. The effect exists only in an LC and disappears when the material is melted into an isotropic fluid. The quadratic effect is caused by the dipolar symmetry of director distortions around the sphere and is classified as an LC-enabled electrophoresis (LCEEP). The nonlinear electrophoretic mobility of particles in LCEEP offers a rich variety of control parameters to design three-dimensional trajectories of particles for microfluidic and optofluidic applications.
Isomorphous methyl- and chloro-substituted small heterocyclic analogues obeying the chlorine–methyl (Cl–Me) exchange rule
Authors: Rajni Swamy V. , Müller P. , Srinivasan N. , Perumal S. , Krishnakumar R. V.
Published: March 2013

The two new isomorphous structures [3-methyl-4-(4-methylphenyl)-1-phenyl-6-trifluoromethyl-1H-pyrazolo[3,4-b]pyridin-5-yl](thiophen-2-yl)methanone, C26H18F3N3OS, (I), and [4-(4-chlorophenyl)-3-methyl-1-phenyl-6-trifluoromethyl-1H-pyrazolo[3,4-b]pyridin-5-yl](thiophen-2-yl)methanone, C25H15ClF3N3OS, (II), are shown to obey the chlorine–methyl exchange rule. Both structures show extensive disorder, treatment of which greatly improves the quality of the description of the structures. In addition, it is worth noting that the presence of extensive disorder may make it difficult to detect the isomorphism automatically during data-mining procedures (such as searches of the Cambridge Structural Database).
The structure of the 1H-imidazol-3-ium lawsonate salt aided byab initiogas-phase calculations
Authors: Ribeiro Marcos Antônio , Oliveira Willian Xerxes Coelho , Stumpf Humberto Osório , Pinheiro Carlos Basílio
Published: March 2013

For the new organic salt 1H-imidazol-3-ium 1,4-dioxo-1,4-dihydronaphthalen-2-olate, C3H5N2+·C10H5O3−,ab initiocalculations of the gas-phase structures of the lawsonate and imidazolium ions were performed to help in the interpretation of the structural features observed. Three different types of hydrogen bond are responsible for the three-dimensional packing of the salt.
A one-dimensional coordination polymer of 5-[(imidazol-1-yl)methyl]benzene-1,3-dicarboxylic acid with CuIIcations
Authors: Patra Ranjan , Goldberg Israel
Published: March 2013

5-[(Imidazol-1-yl)methyl]benzene-1,3-dicarboxylic acid (H2L) was synthesized and the dimethylformamide- and dimethylacetamide-solvated structures of its adducts with CuII, namelycatena-poly[[copper(II)-bis[μ-3-carboxy-5-[(imidazol-1-yl)methyl]benzoato]] dimethylformamide disolvate], {[Cu(C12H9N2O4)2]·2C3H7NO}n, (I), andcatena-poly[[copper(II)-bis[μ-3-carboxy-5-[(imidazol-1-yl)methyl]benzoato]] dimethylacetamide disolvate], {[Cu(C12H9N2O4)2]·2C4H9NO}n, (II), the formation of which are associated with mono-deprotonation of H2L. The two structures are isomorphous and isometric. They consist of one-dimensional coordination polymers of the organic ligand with CuIIin a 2:1 ratio, [Cu(μ-HL)2]n, crystallizing as the dimethylformamide (DMF) or dimethylacetamide (DMA) disolvates. The CuIIcations are characterized by a coordination number of six, being located on centres of crystallographic inversion. In the polymeric chains, each CuIIcation is linked to four neighbouring HL−ligands, and the organic ligand is coordinatedviaCu—O and Cu—N bonds to two CuIIcations. In the corresponding crystal structures of (I) and (II), the coordination chains, aligned parallel to thecaxis, are further interlinked by strong hydrogen bonds between the noncoordinated carboxy groups in one array and the coordinated carboxylate groups of neighbouring chains. Molecules of DMF and DMA (disordered) are accommodated at the interface between adjacent polymeric assemblies. This report provides the first structural evidence for the formation of coordination polymers with H2Lviamultiple metal–ligand bonds through both carboxylate and imidazole groups.
Effects of coating of nano‐ and microemulsion silicones on thermal properties and flammability of polyethylene terephthalate textile
Authors: Parvinzadeh Gashti Mazeyar , Yousefpour Navid Mohammad , Hossein Rahimi Mohammad
Published: March 2013

Purpose

Silicone softeners are widely used in the textile industry to improve the performance of textile products. The thermal characteristics and flammability of polyester fabrics can be influenced by these compounds, which need to be considered, as important issues of human safety. The purpose of this paper is to investigate the changes induced on the polyester fibre by silicone softener treatment using a pad/dry/cure method.

Design/methodology/approach

The fibres were first treated with nano‐ and microemulsion silicone softeners. The influence of the silicone emulsion type on thermal properties and flammability of the resultant samples were investigated by various analytical techniques, namely, the differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), dynamical mechanical thermal analysis (DMTA) and horizontal flammability test (HFT).

Findings

Results showed that the silicone softeners increase the thermal degradation and flammability of the polyethylene terephthalate (PET) substrate.

Originality/value

The paper's study of thermal and flammability of the silicone‐treated sample is novel and can be used to optimize the properties of silicone polymers during production and consumption.
UV cure acrylate monomers: synthesis, analysis and storage
Authors: Kulkarni R.D. , Chaudhari M.E. , Mishra S.
Published: March 2013

Purpose

The purpose of this paper is to provide a critical and in‐depth review of the present status and recent developments in synthetic methodologies, reaction engineering, process design and quality control aspects associated with the manufacture of mono and multifunctional acrylate monomers.

Design/methodology/approach

This paper reviews commercially important UV cure mono and multifunctional acrylate monomers. It covers their synthesis, catalyst, and appropriate solvents for azeotropic removal of byproducts. The detail discussion on catalysis, basis of design of reactors and commercial plant and the process engineering associated with the manufacture has been supported through citation of synthesis of various acrylate monomers. The methodologies adopted for determination of physical, chemical and compositional characterisation of acrylate monomers have been presented. In addition, the guidelines regarding the bulk storage and commercial handling of acrylates have been reviewed.

Findings

The reaction engineering of esterification reaction between acrylic acid and polyol has been worked out to provide the basis for selection of reactors. The reaction has been modeled as a series – parallel complex reaction for providing explanation for generation of various byproducts/adducts and multiple esters.

Practical implications

The detailed discussion on formation, characterisation and treatment of Michael adducts and purification of acrylate monomers will be relevant for new researchers for further development. A review of guidelines on selection of homogenous and heterogeneous catalysts for synthesis of acrylate monomers has been presented.

Originality/value

Since the related literature on acrylate monomers is scarce, scattered and proprietary, the consolidated coverage in one paper will be useful.
Solder joint degradation and detection using RF impedance analysis
Authors: Bin Yao , Yudong Lu , Ming Wan
Published: March 2013

Purpose

The purpose of this paper is to clarify the method of using RF impedance changes as an early indicator of degradation of solder joint. It proposes the mode of crack propagation in solder joint and outlines why RF impedance analysis can be capable of detecting small cracks. The study aims to show the potential of RF impedance analysis as a prognostic tool that can provide advanced warning of impending failures of solder joint.

Design/methodology/approach

In this paper, the mode of crack propagation in solder joint was studied to show why RF impedance analysis could be capable of detecting small cracks. A real simple impedance‐controlled test vehicle was developed to allow RF impedance and DC resistance measurements to monitor solder joint degradation. The influence of crack length on RF impedance was evaluated by high frequency structure simulator (HFSS) simulation for the first time.

Findings

The paper demonstrates that RF resistance can respond to an open state of a solder joint as well as DC resistance. Furthermore, RF impedance can monitor partial degradation of solder joints, while the DC resistance cannot do it. In addition, time‐domain reflection coefficient is found to be more useful than RF impedance in detecting solder joint degradation. The HFSS simulation results show that even very slight physical degradation of solder joints can be detected using RF impedance analysis.

Originality/value

In this paper, HFSS simulation is used for the first time to evaluate the influence of crack length on RF impedance.
Immersed volume method for solving natural convection, conduction and radiation of a hat‐shaped disk inside a 3D enclosure
Authors: Hachem E. , Digonnet H. , Massoni E. , Coupez T.
Published: March 2013

Purpose

The purpose of this paper is to present an immersed volume method that accounts for solid conductive bodies (hat‐shaped disk) in calculation of time‐dependent, three‐dimensional, conjugate heat transfer and fluid flow.

Design/methodology/approach

The incompressible Navier‐Stokes equations and the heat transfer equations are discretized using a stabilized finite element method. The interface of the immersed disk is defined and rendered by the zero isovalues of a level set function. This signed distance function allows turning different thermal properties of each component into homogeneous parameters and it is coupled to a direct anisotropic mesh adaptation process enhancing the interface representation. A monolithic approach is used to solve a single set of equations for both fluid and solid with different thermal properties.

Findings

In the proposed immersion technique, only a single grid for both air and solid is considered, thus, only one equation with different thermal properties is solved. The sharp discontinuity of the material properties was captured by an anisotropic refined solid‐fluid interface. The robustness of the method to compute the flow and heat transfer with large materials properties differences is demonstrated using stabilized finite element formulations. Results are assessed by comparing the predictions with the experimental data.

Originality/value

The proposed method demonstrates the capability of the model to simulate an unsteady three‐dimensional heat transfer flow of natural convection, conduction and radiation in a cubic enclosure with the presence of a conduction body. A previous knowledge of the heat transfer coefficients between the disk and the fluid is no longer required. The heat exchange at the interface is solved and dealt with naturally.
A differential quadrature method for numerical solutions of Burgers'‐type equations
Authors: Mittal R.C. , Jiwari Ram
Published: March 2013

Purpose

The purpose of this paper is to use the polynomial differential quadrature method (PDQM) to find the numerical solutions of some Burgers'‐type nonlinear partial differential equations.

Design/methodology/approach

The PDQM changed the nonlinear partial differential equations into a system of nonlinear ordinary differential equations (ODEs). The obtained system of ODEs is solved by Runge‐Kutta fourth order method.

Findings

Numerical results for the nonlinear evolution equations such as 1D Burgers', coupled Burgers', 2D Burgers' and system of 2D Burgers' equations are obtained by applying PDQM. The numerical results are found to be in good agreement with the exact solutions.

Originality/value

A comparison is made with those which are already available in the literature and the present numerical schemes are found give better solutions. The strong point of these schemes is that they are easy to apply, even in two‐dimensional nonlinear problems.
Natural convection from a vertical permeable cone in a nanofluid saturated porous media for uniform heat and nanoparticles volume fraction fluxes
Authors: Chamkha A.J. , Rashad A.M.
Published: March 2013

Purpose

The purpose of this paper is to study steady, laminar, natural convection boundary‐layer flow over a permeable vertical cone embedded in a porous medium saturated with a nanofluid in the presence of uniform lateral mass flux.

Design/methodology/approach

The paper studies steady, laminar, natural convection boundary‐layer flow over a permeable vertical cone embedded in a porous medium saturated with a nanofluid in the presence of uniform lateral mass flux.

Findings

The presence of nanoparticles has significant effects of heat transfer.

Originality/value

The area of nanofluids is very original.
Forced convection heat transfer within a moderately‐stenosed, patient‐specific carotid bifurcation
Authors: Bevan Rhodri L.T. , Lewis Roland W. , Nithiarasu Perumal
Published: March 2013

Purpose

The purpose of this paper is to numerically model forced convection heat transfer within a patient‐specific carotid bifurcation and to examine the relationship between the temperature and wall shear stress.

Design/methodology/approach

The procedure employs a parallel, fully explicit (matrix free) characteristic based split scheme for the solution of incompressible Navier‐Stokes equations.

Findings

The arterial wall temperature, rather than the blood temperature dominates the regions of low wall shear stress and high oscillating shear stress. Additionally, negligible temperature gradient was detected proximal to the arterial wall in this locality.

Originality/value

The presented results demonstrate a possible mechanism for cold air temperature to influence the atherosclerotic plaque region proximal to the stenosis. The proposed patient‐specific heat transfer analysis also provides a starting point for the investigation of the influence of induced hypothermia on carotid plaque and its stability.
Solution of a low Prandtl number natural convection benchmark by a local meshless method
Authors: Kosec Gregor , Šarler Božidar
Published: March 2013

Purpose

The purpose of this paper is to present the solution of a highly nonlinear fluid dynamics in a low Prandtl number regime, typical for metal‐like materials, as defined in the call for contributions to a numerical benchmark problem for 2D columnar solidification of binary alloys. The solution of such a numerical situation represents the first step towards understanding the instabilities in a more complex case of macrosegregation.

Design/methodology/approach

The involved temperature, velocity and pressure fields are represented through the local approximation functions which are used to evaluate the partial differential operators. The temporal discretization is performed through explicit time stepping.

Findings

The performance of the method is assessed on the natural convection in a closed rectangular cavity filled with a low Prandtl fluid. Two cases are considered, one with steady state and another with oscillatory solution. It is shown that the proposed solution procedure, despite its simplicity, provides stable and convergent results with excellent computational performance. The results show good agreement with the results of the classical finite volume method and spectral finite element method.

Originality/value

The solution procedure is formulated completely through local computational operations. Besides local numerical method, the pressure velocity is performed locally also, retaining the correct temporal transient.
Gary Hamel: managing while under the influence of innovation
Authors: Denning Stephen
Published: March 2013

Purpose

This paper aims to present an interview with Gary Hamel asking an existential question that all long‐established firms need to face: “Is there an effective competitive response to counter innovation by startups, and if so, what is it?”.

Design/methodology/approach

The paper presents Hamel's evaluation of current alternatives to dealing with the issue.

Findings

The paper concludes that the most reliable survival strategy is continuous innovation, which requires radical management innovation.

Practical implications

Hamel concludes that most large organizations must make fundamental changes in the way they are managed, if they wish to survive. One key step: enable first‐level and second‐level employees to obtain small amounts of experimental capital or time to work on something that's new.

Originality/value

Hamel warns that fewer than one company out of 100 has made innovation part of every employee's job or trained every employee to be an innovator, but doing so is a matter of survival.
Connecting with the digital customer of the future
Authors: Berman Saul J. , Kesterson‐Townes Lynn
Published: March 2013

Purpose

The authors expect that media and entertainment (M&E) providers will increasingly be challenged to offer consumers entertainment experiences that are more relevant, and therefore perceived as more valuable. This paper aims to investigate this issue.

Design/methodology/approach

The paper looks at the authors' 2011 survey, which revealed four prominent types of “digital personalities” that are not age‐based, but instead are based on the combination of degree of access to content and intensity of content interaction.”

Findings

The paper finds that to move beyond merely distributing digital content, M&E providers should: think and act like business‐to‐consumer (B2C) companies, no matter where they sit in the industry value chain; target consumers' specific digital personalities; deliver holistic, relevant content experiences – not just content alone; and create new flexibly integrated, cross‐channel digital revenue models that can deliver value comparable to traditional models.

Research limitations/implications

The fourth annual IBM Institute for Business Value digital consumer survey questioned over 3,800 consumers in six countries – China, France, Germany, Japan, the UK and the USA – to evaluate current and future digital content consumption behaviors.

Practical implications

Making digital content more social includes finding smarter ways to connect to customers, connect the ecosystem and refine content.

Originality/value

The paper provides useful information on making digital content more social and smarter ways to connect to customers, the ecosystem and to refine content.
Three new business models for “the open firm”
Authors: Purdy Mark , Robinson Matthew C. , Wei Kuangyi
Published: March 2013

Purpose

The authors found that as more firms participate in open business ecosystems, the borders between an individual firm and its stakeholders – customers, suppliers, workers, partners and innovators – have become much more permeable and reconfigurable. This paper aims to address this issue.

Design/methodology/approach

The paper shows how new open business models enable firms to maximize the benefits of openness while limiting the risks.

Findings

The authors propose three “open firm” models based on their research, experience and observation: the harbor and fleet; the demand forum; and multivalent sourcing.

Research limitations/implications

Case studies are provided. For example, the supply chain tracing firm Historic Futures has developed an online application called String that enables participating companies to monitor products hour by hour and mile by mile along the supply chain.

Practical implications

The ability to establish and maintain appropriate networks is central to the success of open‐firm strategies.

Originality/value

As technological advances spur firms toward an era of greater openness, companies will increasingly need to examine the potential economic benefits of digitally linked clusters of businesses. The authors' framework can help executives decide which type of open‐firm model can work best.
Savoring surprise: the leadership learning opportunity
Authors: Kaplan Soren
Published: March 2013

Purpose

This paper aims to show that some astute leaders have learned to look for opportunity in surprises, sometimes discovering important strategic variables that contribute to long‐term success.

Design/methodology/approach

The paper proposes that market analysis surprises be routinely mined and sifted for bigger and better ideas, strategies and solutions.

Findings

Leaders need to learn how to harness the latent opportunities that reside within the inevitable surprises they will experience. Shaping how customers encounter surprise can actually make the difference between a trivial product or service experience and a memorable one that builds excitement and loyalty.

Practical implications

In the case of both Intuit's Quickbooks and Canon's Mark II camera, customer segments outside of the intended target revealed surprising market opportunities.

Originality/value

The author offers a matrix for identifying four tactical responses managers have for harnessing surprise: Seek & Shape, Prepare & Pivot, Catch & Capitalize, and React & Respond.
Exploring public sector managers' preferences for attracting consultants or academics as external experts
Authors: van Helden Jan , Grönlund Anders , Mussari Riccardo , Ruggiero Pasquale
Published: March 2013

Purpose

The purpose of this paper is to examine the reasons why public sector managers approach either consultants or academics for their help in solving problems related to public sector accounting and management reforms.

Design/methodology/approach

A field study based on reactions to real‐life constructs and answers to questions about the experiences of public sector managers in Italian, Dutch and Swedish central government agencies.

Findings

Public sector managers approach consultants, due to their experience‐based knowledge, for solving well‐defined practical and technical problems. In the case of tacit knowledge, a strong interaction between the public sector manager and the consultant, denoted as socialization, is the typical way of knowledge transfer. In accordance with expectations, public sector managers approach academics for advice regarding value‐laden problems in their organization. However, academics also give advice about practical and technical issues, usually being the primary domain of consultants, but often when impartial advice is required. Although the authors expected academics to transfer knowledge rather detached from their clients (interiorization), this was not corroborated, because often academics work closely with their counterparts in the client organization.

Research limitations/implications

The theoretical framework was helpful in explaining the role of consultants, but it required refinement in explaining the role of academics as external experts.

Practical implications

The paper contributes to a better articulated set of preferences of public sector managers in asking advice from either a consultant or an academic.

Originality/value

The paper offers a simultaneous and systematic empirical examination of the roles that consultants and academics play in public sector management and accounting reforms.