bluuebunny/crossref_metadata_2025 huggingface dataset:
Scaling body size fluctuations
Authors: Giometto Andrea , Altermatt Florian , Carrara Francesco , Maritan Amos , Rinaldo Andrea
Published: March 2013

The size of an organism matters for its metabolic, growth, mortality, and other vital rates. Scale-free community size spectra (i.e., size distributions regardless of species) are routinely observed in natural ecosystems and are the product of intra- and interspecies regulation of the relative abundance of organisms of different sizes. Intra- and interspecies distributions of body sizes are thus major determinants of ecosystems’ structure and function. We show experimentally that single-species mass distributions of unicellular eukaryotes covering different phyla exhibit both characteristic sizes and universal features over more than four orders of magnitude in mass. Remarkably, we find that the mean size of a species is sufficient to characterize its size distribution fully and that the latter has a universal form across all species. We show that an analytical physiological model accounts for the observed universality, which can be synthesized in a log-normal form for the intraspecies size distributions. We also propose how ecological and physiological processes should interact to produce scale-invariant community size spectra and discuss the implications of our results on allometric scaling laws involving body mass.
Role of caspase-1 in regulation of triglyceride metabolism
Authors: Kotas Maya E. , Jurczak Michael J. , Annicelli Charles , Gillum Matthew P. , Cline Gary W. , Shulman Gerald I. , Medzhitov Ruslan
Published: March 2013

Caspase-1 is a cysteine protease that can be activated by both endogenous and exogenous inflammatory stimuli and has been shown to have important functions in processes as diverse as proteolytic activation of cytokines, cell death, and membrane repair. Caspase-1–dependent production of the inflammatory cytokines IL-1 and IL-18 has also been implicated in the regulation of appetite, body weight, glucose homeostasis, and lipid metabolism. Consistent with the emerging views of caspase-1 in metabolic regulation, we find that caspase-1–deficient mice have dramatically accelerated triglyceride clearance, without alteration in lipid production or absorption, and resultant decrease in steady-state circulating triglyceride and fatty acid levels. Surprisingly, this effect is independent of IL-1-family signaling, supporting the concept that caspase-1 influences lipid metabolism through multiple mechanisms, not limited to cytokines.
Arabidopsis
AHP2, AHP3, and AHP5 histidine phosphotransfer proteins function as redundant negative regulators of drought stress response
Authors: Nishiyama Rie , Watanabe Yasuko , Leyva-Gonzalez Marco A. , Van Ha Chien , Fujita Yasunari , Tanaka Maho , Seki Motoaki , Yamaguchi-Shinozaki Kazuko , Shinozaki Kazuo , Herrera-Estrella Luis , Tran Lam-Son Phan
Published: March 2013

Cytokinin is an essential phytohormone controlling various biological processes, including environmental stress responses. In
Arabidopsis
, although the cytokinin (CK)-related phosphorelay—consisting of three histidine kinases, five histidine phosphotransfer proteins (AHPs), and a number of response regulators—has been known to be important for stress responses, the AHPs required for CK signaling during drought stress remain elusive. Here, we report that three
Arabidopsis
AHPs, namely AHP2, AHP3, and AHP5, control responses to drought stress in negative and redundant manner. Loss of function of these three
AHP
genes resulted in a strong drought-tolerant phenotype that was associated with the stimulation of protective mechanisms. Specifically, cell membrane integrity was improved as well as an increased sensitivity to abscisic acid (ABA) was observed rather than an alteration in ABA-mediated stomatal closure and density. Consistent with their negative regulatory functions, all three
AHP
genes’ expression was down-regulated by dehydration, which most likely resulted from a stress-induced reduction of endogenous CK levels. Furthermore, global transcriptional analysis of
ahp2,3,5
leaves revealed down-regulation of many well-known stress- and/or ABA-responsive genes, suggesting that these three AHPs may control drought response in both ABA-dependent and ABA-independent manners. The discovery of mechanisms of activation and the targets of the downstream components of CK signaling involved in stress responses is an important and challenging goal for the study of plant stress regulatory network responses and plant growth. The knowledge gained from this study also has broad potential for biotechnological applications to increase abiotic stress tolerance in plants.
Altered paralimbic interaction in behavioral addiction
Authors: Rømer Thomsen Kristine , Joensson Morten , Lou Hans C. , Møller Arne , Gross Joachim , Kringelbach Morten L. , Changeux Jean-Pierre
Published: March 2013

The introduction of magnetoencephalography has made it possible to study electromagnetic signaling in deeper, paralimbic cortical structures such as the medial prefrontal/anterior cingulate (ACC) and medial parietal/posterior cingulate (PCC) cortices. Self-awareness and self-control have been attributed to these regions. To test the hypothesis that they are dysfunctional in pathological gambling with poor self-control, we studied gamblers with and without previous stimulant abuse and age- and sex-matched controls. We found that pathological gamblers were more impulsive than controls in a stop-signal task and attributed this to changes in the activity of the paralimbic network: Pathological gamblers had reduced synchronization at rest in the high gamma range (55–100 Hz) compared with controls and failed to show an increase in gamma synchronization during rest compared with the task, as observed in controls. Subgroup analysis revealed that pathological gamblers without a history of stimulant abuse had lower PCC power during the stop-signal task compared with controls and gamblers with previous stimulant abuse. Furthermore, gamblers with a history of stimulant abuse had up to four times higher power at the ACC site during rest and the task compared with controls. In conclusion, pathological gamblers had higher impulsivity and functional paralimbic abnormalities, which could not be explained by a history of stimulant abuse. In addition, previous stimulant abuse had a marked effect on the amplitude of oscillatory brain activity in the ACC and PCC, suggesting long-term deleterious effects of repeated dopaminergic drug exposure. These consequences should be investigated in more detail in longitudinal studies.
Calorimetric glass transition explained by hierarchical dynamic facilitation
Authors: Keys Aaron S. , Garrahan Juan P. , Chandler David
Published: March 2013

The glass transition refers to the nonequilibrium process by which an equilibrium liquid is transformed to a nonequilibrium disordered solid, or vice versa. Associated response functions, such as heat capacities, are markedly different on cooling than on heating, and the response to melting a glass depends markedly on the cooling protocol by which the glass was formed. This paper shows how this irreversible behavior can be interpreted quantitatively in terms of an East-model picture of localized excitations (or soft spots) in which molecules can move with a specific direction, and from which excitations with the same directionality of motion can appear or disappear in adjacent regions. As a result of these facilitated dynamics, excitations become correlated in a hierarchical fashion. These correlations are manifested in the dynamic heterogeneity of the supercooled liquid phase. Although equilibrium thermodynamics is virtually featureless, a nonequilibrium glass phase emerges when the model is driven out of equilibrium with a finite cooling rate. The correlation length of this emergent phase is large and increases with decreasing cooling rate. A spatially and temporally resolved fictive temperature encodes memory of its preparation. Parameters characterizing the model can be determined from reversible transport data, and with these parameters, predictions of the model agree well with irreversible differential scanning calorimetry.
The borrowers
Authors: O’Brien Sharon
Published: March 2013

The paper considers the interdisciplinary interaction of research on the cognitive aspects of translation. Examples of influence from linguistics, psychology, neuroscience, cognitive science, reading and writing research and language technology are given, with examples from specific sub-disciplines within each one. The breadth of borrowing by researchers in cognitive translatology is made apparent, but the minimal influence of cognitive translatology on the respective disciplines themselves is also highlighted. Suggestions for future developments are made, including ways in which the domain of cognitive translatology might exert greater influence on other disciplines.
Investigating the conceptual-procedural distinction in the translation process
Authors: Alves Fabio , Gonçalves José Luiz
Published: March 2013

This article draws on relevance theory (Sperber and Wilson 1986/1995) and its application to translation (Gutt 2000) to investigate processing effort in translation in relation to two different types of encodings, namely conceptual and procedural encodings (Blakemore 2002, Wilson 2011). Building on the experimental paradigm of data triangulation in translation process research (Alves 2003; Jakobsen 2005), it analyses the translation processes of eight professional translators when performing a direct and an inverse translation task. The analysis focuses on the number and types of encodings found in micro/macro translation units (Alves and Vale 2009; 2011). Results suggest that processing effort in translation is greater in instances of procedural than conceptual encodings.
Anesthesia of Juvenile Pacific Lampreys with MS-222, BENZOAK, AQUI-S 20E, and Aquacalm
Authors: Christiansen Helena E. , Gee Lisa P. , Mesa Matthew G.
Published: March 2013

Effective anesthetics are a critical component of safe and humane fish handling procedures. We tested three concentrations each of four anesthetics—Finquel (tricaine methanesulfonate, herein referred to as MS-222), BENZOAK (20% benzocaine), AQUI-S 20E (10% eugenol), and Aquacalm (metomidate hydrochloride)—for efficacy and safety in metamorphosed, outmigrating juvenile Pacific Lampreys Entosphenus tridentatus. The anesthetics MS-222 (100 mg/L) and BENZOAK (60 mg/L) were the most effective for anesthetizing juvenile Pacific Lampreys to a handleable state with minimal irritation to the fish. Fish anesthetized with BENZOAK also had lower rates of fungal infection than those exposed to MS-222, AQUI-S 20E, or no anesthetic. Exposure to AQUI-S 20E irritated juvenile Pacific Lampreys, causing them to leap or climb out of the anesthetic solution, and Aquacalm anesthetized fish to a handleable state too slowly and incompletely for effective use with routine handling procedures. Our results indicate that MS-222 and BENZOAK are effective anesthetics for juvenile Pacific Lampreys, but field studies are needed to determine whether exposure to MS-222 increases risk of fungal infection in juvenile Pacific Lampreys released to the wild.

Received August 28, 2012; accepted November 26, 2012
Complement to the appendix of: “On the Howe duality conjecture”
Authors: Rallis Steve
Published: March 2013

Let

F

{\mathbb F}

be a local field, nonarchimedean and of characteristic not 2. Let

(
V
,
Q
)

(V,Q)

be a nondegenerate quadratic space over

F

{\mathbb F}

, of dimension

n
n

. Let

M
r

M_r

be the direct sum of

r
r

copies of

V
V

. We prove that, for

r
>
n

r>n

there is no nonzero distribution on

M
r

M_r

which under the action of the orthogonal group transforms according to the character determinant.
Hydrophobic gold nanoparticles via silane conjugation: chemically and thermally robust nanoparticles as dopants for nematic liquid crystals
Authors: Mirzaei Javad , Urbanski Martin , Kitzerow Heinz-S. , Hegmann Torsten
Published: March 2013

We examine for the first time how chemically and thermally stable gold nanoparticles (NPs), prepared by a silane conjugation approach, affect both the thermal and the electro-optical properties of a nematic liquid crystal (LC), when doped at concentrations ranging from 0.25 to 7.5 wt%. We find that the octadecylsilane-conjugated gold NPs stabilize both the enantiotropic nematic and the monotropic smectic-A phases of the LC host with a maximum stabilization of 2
°
C for the nematic and 3.5
°
C for the smectic-A phases for the mixture containing 1 wt% of the silanized particles. The same mixture shows the lowest values for the Fréedericksz transition threshold voltage and the highest value for the dielectric anisotropy. Generally, all NP-containing mixtures, except mixtures with NP concentrations exceeding 5 wt%, reduce the threshold voltage, increase the dielectric anisotropy and reduce both rise and decay time; the latter particularly at temperatures at least 10
°
C below the isotropic–nematic phase transition on cooling.
Electro-induced orientational ordering of anisotropic pigment nanoparticles
Authors: Greasty Robert J. , Richardson Robert M. , Klein Susanne , Cherns David , Thomas Michael R. , Pizzey Claire , Terrill Nick , Rochas Cyrille
Published: March 2013

The response of anisotropic pigment particle suspensions to externally applied electric fields has been explored for possible application in reflective display technologies. Three different types of pigment particle were suspended in dodecane, using a polymeric stabilizer, and showed Schlieren textures between crossed polarizers at high concentrations (greater than 25–30 wt%), indicating the formation of colloidal nematic phases. Orientational order parameters were determined by X-ray scattering, and the influence of polydispersity on the values is discussed. X-ray scattering measurements also demonstrated a change in the structure factor consistent with the onset of a colloidal nematic phase. In addition, the pigment particles were dispersed into various liquid crystal hosts at low concentrations (less than 5 wt%) with and without the presence of mesogenic mimic stabilizers. However, the influence of these stabilizers on orientational ordering could not be confirmed. The electro-induced ordering determined via scattering was related to the electro-optical response of each suspension using a simple model. The particles in nematic hosts not only showed a high degree of orientational ordering at lower electric field strengths, but also showed a reduction in stability. Although these systems have shown strong orientational ordering, the optical response has been limited by the intrinsic shape of the pigment particles and the distribution of the transition dipoles moments within them. Nevertheless, the feasibility of developing materials for display applications has been demonstrated.
Liquid crystal phase transitions in suspensions of mineral colloids: new life from old roots
Authors: Lekkerkerker H. N. W. , Vroege G. J.
Published: March 2013

A review is given of the field ofmineral colloidal liquid crystals: liquid crystal phases formed by individual mineral particles within colloidal suspensions. Starting from their discovery in the 1920s, we discuss developments on the levels of both fundamentals and applications. We conclude by highlighting some promising results from recent years, which may point the way towards future developments.
Liquid crystals of carbon nanotubes and graphene
Authors: Zakri Cécile , Blanc Christophe , Grelet Eric , Zamora-Ledezma Camilo , Puech Nicolas , Anglaret Eric , Poulin Philippe
Published: March 2013

Liquid crystal ordering is an opportunity to develop novel materials and applications with spontaneously aligned nanotubes or graphene particles. Nevertheless, achieving high orientational order parameter and large monodomains remains a challenge. In addition, our restricted knowledge of the structure of the currently available materials is a limitation for fundamental studies and future applications. This paper presents recent methodologies that have been developed to achieve large monodomains of nematic liquid crystals. These allow quantification and increase of their order parameters. Nematic ordering provides an efficient way to prepare conductive films that exhibit anisotropic properties. In particular, it is shown how the electrical conductivity anisotropy increases with the order parameter of the nematic liquid crystal. The order parameter can be tuned by controlling the length and entanglement of the nanotubes. In the second part of the paper, recent results on graphene liquid crystals are reported. The possibility to obtain water-based liquid crystals stabilized by surfactant molecules is demonstrated. Structural and thermodynamic characterizations provide indirect but statistical information on the dimensions of the graphene flakes. From a general point of view, this work presents experimental approaches to optimize the use of nanocarbons as liquid crystals and provides new methodologies for the still challenging characterization of such materials.
Polymorphism ofmer-μ-oxalato-bis[chloridotripyridinecobalt(II)] pyridine disolvate
Authors: Modec Barbara
Published: March 2013

Single crystals of a triclinic polymorphic form ofmer-μ-oxalato-bis[chloridotripyridinecobalt(II)] pyridine disolvate, [Co2(C2O4)Cl2(C5H5N)6]·2C5H5N, have been prepared by solvothermal methods. The structure and geometric parameters strongly resemble those of the previously reported monoclinic polymorph [Bolte (2006).Acta Cryst.E62, m597–m598]. In both polymorphic forms, the dinuclear complex molecules are located on a crystallographic centre of inversion, with the CoIIcations in a distorted octahedral environment consisting of a chloride ligand, three pyridine ligands and a chelating bis-bidentate oxalate ligand. This last serves as a bridging ligand between two CoIIcations. The polymorphs differ in the mutual orientation of their pyridine ligands in the dinuclear molecules and in their intermolecular connectivity. In the triclinic polymorph, C—H...O, C—H...Cl, C—H...π and π–π interactions link the dinuclear molecules into a three-dimensional structure. Pyridine solvent molecules are attached to this structureviaweak interactions.
Bis[μ-2-({2-[2-(2-chlorophenoxy)-1-oxidoethylidene]hydrazinylidene}methyl)phenolato]bis[pyridinecopper(II)] methanol disolvate
Authors: Zhao Ning
Published: March 2013

In the title compound, [Cu2(C15H11ClN2O3)2(C5H5N)2]·2CH3OH, the coordination geometry of the metal centre can be described as square pyramidal. Pairs of pentacoordinated metal centres are bridged by symmetry-related phenolate O atoms about the inversion centre at (1 \over 2, 0, 1 \over 2), resulting in a binuclear metal clusterviaedge-sharing.
The characterisation by liquid chromatography of lake pigments prepared from European buckthorn (Rhamnus cathartica L.)
Authors: Deveoglu Ozan , Torgan Emine , Karadag Recep
Published: March 2013

Purpose

The purpose of this paper is to prepare, analyse and measure the colour values of the lake pigments obtained from the reaction of Al3+, Fe2+ and Sn2+ metal salts with the natural dyes present in European buckthorn (Rhamnus cathartica L.).

Design/methodology/approach

A reversed‐phase high performance liquid chromatography (HPLC) with diode‐array detection method was utilised for the identification of buckthorn lake pigments. The extraction of dyes from the lake pigments was carried out with 37% hydrochloric acid/methanol/water (2:1:1; v/v/v) solution.

Findings

According to the results of the HPLC analysis of the lake pigments, it was determined that rhamnetin, kaempferol, and emodin were present in the acid hydrolysed plant extract and in the lake pigment that was precipitated by Sn(II), quercetin‐3‐arabinosid, rhamnetin, and emodin were present in the non‐hydrolysed plant extract, and kaempferol, rhamnetin, isorhamnetin, and emodin were found in the lake pigment that was precipitated by Al(III). Rhamnetin and emodin were present in the lake pigment that was precipitated by Fe(II).

Research limitations/implications

In the present context for the preparation of buckthorn lake pigments, a simple and practical method is presented. In addition, the analysis of the lake pigments was performed by reversed phase HPLC (RP‐HPLC) with diode array detector (DAD).

Practical implications

The paper describes the preparation of lake pigments and their qualitative analysis. This method can be used to determine the origins of the dyestuffs used in historical art pieces.

Originality/value

The paper describes the development of methods for the analysis and the preparation of European buckthorn lake pigments.
Effectiveness of amine functional aniline furfuraldehyde condensate as toughening agent for epoxy resin
Authors: Samanta B.C. , Maity T.
Published: March 2013

Purpose

The purpose of this paper is to find a new toughening agent for diglycidyl ether of bisphenol A (DGEBA) resin and to check effectiveness of this new toughening agent to obtain toughness and chemical resistance of cured epoxy.

Design/methodology/approach

For this purpose, an investigation was carried out to synthesise, characterise and to study the toughening reaction of amine functional aniline furfuraldehyde condensate (AFAFFC) with DGEBA resin. AFAFFC was first synthesised from the reaction of aniline and furfuraldehyde in the acid medium (pH‐4) and characterised by FT‐IR spectroscopy, elemental analysis and concentration of primary and secondary amine analysis. Then various formulations were made by mixing DGEBA, AFAFFC and ambient temperature curing agent triethylene tetramine (TETA) in different compositions and the modified networks were evaluated to their mechanical and thermal properties. The dynamic mechanical analysis (DMA), scanning electron microscopy (SEM) studies and thermogravimetric analysis (TGA) of toughened epoxy were also reported.

Findings

The resulting networks developed a two‐phase microstructure upon network formation and displayed significantly improved fracture toughness. The dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM) studies showed two‐phase morphology in the cured networks where AFAFFC particles were dispersed. TGA showed that the AFAFFC modified epoxy network was thermally stable up to around 311°C.

Research limitations/implications

The toughening agent AFAFFC has been synthesised by using aniline and furfuraldehyde. By changing amine and aldehyde other toughening agents could be synthesised and efficiency of these toughening agent for epoxy resin could also be studied.

Originality/value

The method for toughening of epoxy resin (DGEBA) is novel and relevant, as the toughened products have high performance applications in protective coatings, adhesives for most substrates and matrix resins for composites.
Effects of composite ferrotitanium on epoxy coating
Authors: Hua Dong Yu , Nan Liu Ya , Zhou Qiong
Published: March 2013

Purpose

The purpose of this paper is to evaluate effects of different contents of composite ferrotitanium pigment on corrosion protection performance of epoxy resin coatings.

Design/methodology/approach

Different contents of composite ferrotitanium pigment were added to the epoxy resin coatings and the corrosion performance of the coatings were investigated by electrochemical test (in 5 wt.% KCl solutions at 60°C), salt spray test and simulated test. The morphology of the coating before and after corrosion was characterised by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).

Findings

The composite ferrotitanium improved anti‐corrosion properties of the coating due to complex reaction of ferrous ions and phosphates as well as introduction of nano powder to the composite ferrotitanium. The coating with 10 wt.% composite ferrotitanium pigment had better anti‐corrosion properties than that of 5 wt.%. Simulated experiment in an autoclave indicated that the composite ferrotitanium pigment had the best protective performance among the three green pigments such as zinc phosphate, aluminium tri‐phosphate, and composite ferrotitanium.

Research limitations/implications

The pigments were added into the coating by high energy ball milling. Some of them dispersed in the coating heterogeneously and affected property of the coatings.

Practical implications

Composite ferrotitanium can be used to replace red lead and chromate pigments to meet environmental requirements.

Originality/value

The paper shows how the anti‐corrosion mechanism of the composite ferrotitanium pigment was investigated and several green pigments were selected to compare their protective performance in the autoclave.
Interfacial IMC layer growth and tensile properties of low‐silver Cu/SACBE/Cu solder joints
Authors: Bi Wenzhen , Ju Guokui , Lin Fei , Xie Shifang , Wei Xicheng
Published: March 2013

Purpose

In a previous study, the authors proposed a new low‐silver solder alloy Sn‐ x(1.0, 1.5, 2.0)Ag‐0.3Cu‐3.0Bi‐0.05Er (wt.%) (SACBE) and the purpose of this paper is to provide additional useful information for new solder alloy development. The growth behaviour of the interfacial IMC layers for Cu/SACBE/Cu and Cu/SAC/Cu joints and their bonding strengths after thermal aging at 150°C for 0, 24, 168 and 500 hours are investigated and the effects of adding elemental Bi and Er on the growth of interfacial IMC layers in the joints, and their tensile properties, are characterized and discussed.

Design/methodology/approach

The tensile properties of the Cu/Sn‐3.0Ag‐0.5Cu/Cu (Cu/SAC/Cu) and Cu/SACBE/Cu joints during thermal aging at 150°C for 0, 24, 168 and 500 hours were investigated, respectively. The thickness of interfacial IMC layer and the fracture surface of solder joint after isothermal aging were observed and analyzed by means of scanning electron micrograph (SEM) equipped with an energy dispersive spectroscopy X‐ray (EDX) analysis system.

Findings

It was found that the thickness of the IMC layer at the interface of a Cu/SACBE/Cu joint was remarkably thinner than that of a Cu/SAC/Cu joint. The addition of Bi and Er could significantly improve the tensile properties of the solder joint and enhance its resistance to high temperature aging. A mixture of ductile and brittle fracture mode was observed after tensile testing in the Cu/SACBE/Cu joints.

Originality/value

The paper implies that the addition of Bi and Er could complement effectively the effects of Ag, thereby reducing the cost of solder. The low‐silver SACBE solder is a potential alloy for electronic packaging production.
Experimental and numerical investigation of the flap application in an airfoil in combination with a cross flow fan
Authors: Hasan Shojaeefard Mohammad , Askari Salar
Published: March 2013

Purpose

The purpose of this paper is to study flap application in the airfoil comprising a cross flow fan by experiment and numerical simulation.

Design/methodology/approach

An airfoil was made and tested in a blowing wind tunnel. Because of complicated shape of the airfoil, distributed quantities in the flow field cannot be measured. They were computed by establishing a CFD code validated by the experimental data. The k‐ε model was used for the Reynolds stress modeling. Flow was considered incompressible, two dimensional and steady‐state. The pressure‐velocity coupling was performed by the SIMPLEC algorithm and convection terms were discretized by using the second‐order upwind discretization scheme.

Findings

Computed aerodynamic coefficients were in good agreement with the experimental results. Flap augmented lift and pitching moment coefficients of the airfoil considerably. It was perceived that the airfoil aerodynamic coefficients decrease with the Reynolds number, its lift and pitching moment coefficients increase and its drag coefficient decreases with the fan speed. Static pressure difference between the airfoil surfaces increased with the flap angle and consequently at higher flap angles it must have larger aerodynamic coefficients as proved by the experiments. This pressure difference increases with the Reynolds number that is equivalent to higher aerodynamic forces. It was shown by the numerical solution that surface pressure on the airfoil upper wall decreases with the fan speed while it is not sensitive to the fan speed on the airfoil bottom wall.

Originality/value

This is the first instance in which flap application in the airfoil with forced airflow provided by an integrated cross flow fan is studied.
Application of modified discrete ordinates method to combined conduction‐radiation heat transfer problems in irregular geometries
Authors: Amiri H. , Mansouri S.H. , Coelho P.J.
Published: March 2013

Purpose

The solution of radiative heat transfer problems in participating media is often obtained using the standard discrete ordinates method (SDOM). This method produces anomalies caused by ray effects if radiative boundary conditions have discontinuities or abrupt changes. Ray effects may be mitigated using the modified discrete ordinates method (MDOM), which is based on superposition of the solutions obtained by considering separately radiation from the walls and radiation from the medium. The purpose of this paper is to study the role of ray effects in combined conduction‐radiation problems and investigate the superiority of the MDOM over SDOM.

Design/methodology/approach

The MDOM has been used to calculate radiative heat transfer in irregular geometries using body‐fitted coordinates. Here, the blocked‐off region concept, originally developed in computational fluid dynamics, is used along with the finite volume method and SDOM or MDOM to solve combined conduction‐radiation heat transport problems in irregular geometries. Enclosures with an absorbing, emitting and isotropically or anisotropically scattering medium are analyzed.

Findings

The results confirm the capability of the MDOM to minimize the anomalies due to ray effects in combined heat transfer problems, and demonstrate that MDOM is more computationally efficient than SDOM.

Originality/value

The paper demonstrates the application of MDOM to combined conduction‐radiation heat transfer problems in irregular geometries using blocked‐off method.
Computational modeling of pyrolysis and combustion in a fixed‐bed waste gasifier
Authors: Chung‐Yin Tsai Johnny , Im Hong G. , Kim Taig‐Young , Kim Jaeho
Published: March 2013

Purpose

The purpose of this paper is to present a three‐dimensional CFD model that simulates the pyrolysis, combustion and heat transfer phenomena in a refuse‐derived fuel (RDF) gasifier. Correlations between different operation conditions and the waste stack morphology are also investigated. Parametric studies are conducted to optimize operating conditions to achieve an even stack surface minimal the local oxidation in the waste stack.

Design/methodology/approach

This paper proposes a Lagrangian pyrolysis submodel which can be applied to determine the local pyrolysis rate and porosity field by introducing the local characteristic diameter of the waste solid sphere. The flow field is described by a single‐phase porous flow model using the SIMPLE algorithm with momentum extrapolation. A one‐step global reaction was adapted for the chemical reactions inside the gasifier.

Findings

Computational results produced three‐dimensional distribution of the flow field, temperature, species concentration, porosity and the morphology of the waste stack under different operation conditions. Some parametric studies were conducted to assess the effects of the inlet temperature and the feeding rate on the waste stack shape. The results demonstrated that the model can properly capture the essential physical and chemical processes in the gasifier and thus can be used as a predictive simulation tool.

Research limitations/implications

Due to the lack of accurate reaction rate information, the computational results have not been directly compared against experimental data. Additional refinement and subsequent validation against prototype gasifier experiment will be reported in future work.

Originality/value

A full three‐dimensional computational model is developed for the complex two‐phase flow based on porous medium representation of the solid stack. A Lagrangian pyrolysis model based on the characteristic diameter of the solid waste material was proposed to describe the pyrolysis rate history. The developed model reproduces correct physical and chemical behavior inside gasifier with adequate computational efficiency and accuracy.
Cubic B‐spline differential quadrature methods for the advection‐diffusion equation
Authors: Korkmaz Alper , Dağ İdris
Published: March 2013

Purpose

Cubic B‐spline differential quadrature methods have been introduced. As test problems, two different solutions of advection‐diffusion equation are chosen. The first test problem, the transportion of an initial concentration, and the second one, the distribution of an initial pulse, are simulated. The purpose of this paper is to simulate the test problems.

Design/methodology/approach

The cubic B‐spline functions are chosen as test functions in order to construct the differential quadrature method. The error between the numerical solutions and analytical solutions are measured using various error norms.

Findings

The cubic B‐spline differential quadrature methods have produced acceptable solution for advection‐diffusion equation.

Originality/value

The advection‐diffusion equation has never been solved by any differential quadrature method based on cubic B‐splines.
Towards a framework for non‐linear thermal models in shell domains
Authors: Chinesta Francisco , Leygue Adrien , Beringhier Marianne , Tuan Nguyen Linh , Grandidier Jean‐Claude , Schrefler Bernhard , Pesavento Francisco
Published: March 2013

Purpose

The purpose of this paper is to solve non‐linear parametric thermal models defined in degenerated geometries, such as plate and shell geometries.

Design/methodology/approach

The work presented in this paper is based in a combination of the proper generalized decomposition (PGD) that proceeds to a separated representation of the involved fields and advanced non‐linear solvers. A particular emphasis is put on the asymptotic numerical method.

Findings

The authors demonstrate that this approach is valid for computing the solution of challenging thermal models and parametric models.

Originality/value

This is the first time that PGD is combined with advanced non‐linear solvers in the context of non‐linear transient parametric thermal models.
Novel immersed boundary methods for thermal flow problems
Authors: Shu C. , Ren W.W. , Yang W.M.
Published: March 2013

Purpose

The purpose of this paper is to present two efficient immersed boundary methods (IBM) for simulation of thermal flow problems. One method is for given temperature condition (Dirichlet type), while the other is for given heat flux condition (Neumann type). The methods are applied to simulate natural and mixed convection problems to check their performance. The comparison of present results with available data in the literature shows that the present methods can obtain accurate numerical results efficiently.

Design/methodology/approach

The paper presents two efficient IBM solvers, in which the effect of thermal boundary to its surrounding fluid is considered through the introduction of a heat source/sink term into the energy equation. One is the temperature correction‐based IBM developed for problems with given temperature on the wall. The other is heat flux correction‐based IBM for problems with given heat flux on the wall. Note that in this solver, the offset of derivative condition is directly used to correct the temperature field.

Findings

As compared with existing solvers, the temperature correction‐based IBM determines the heat source/sink implicitly instead of pre‐calculated explicitly, so that the boundary condition for temperature is accurately satisfied. To the best of the authors' knowledge, the work of heat flux correction‐based IBM is the first endeavour for application of IBM to solve thermal flow problems with Neumann (heat flux) boundary condition. It was found that both methods presented in this work can efficiently obtain accurate numerical results for thermal flow problems.

Originality/value

The two methods presented in this paper are novel. They can effectively solve thermal flow problems with Dirichlet and Neumann boundary conditions.
Transformative scenario planning: changing the future by exploring alternatives
Authors: Kahane Adam
Published: March 2013

Purpose

This paper aims to describe “transformative scenario planning,” a methodology that enables people trying to change the future collaboratively to transform, rather than adapt to, a situation.

Design/methodology/approach

The process centers on constructing scenarios of possible futures for a situation, but takes the well‐established adaptive scenario planning methodology and turns it on its head – to construct scenarios not only to understand the future, but also to influence it.

Findings

Transformative scenario planning teams have tackled some of the most important and difficult challenges of our time: health care, economic development, and climate change across the Americas, Europe, the Middle East, Africa, Asia, and Australia. Some of these teams succeeded in changing their situation and others have failed.

Practical implications

The five steps of transformative scenario planning are: convening a team from across the whole system; observing what is happening; constructing stories about what could happen; discovering what can and must be done; and acting to transform the system.

Originality/value

The process centers on constructing scenarios of possible futures for a situation, not only to understand the future, but also to learn how to influence it.
A model for strategy implementation and conflict resolution in the franchise business
Authors: Davis Paul J.
Published: March 2013

Purpose

This paper aims to explore the inherent tensions of the franchisor‐franchisee relationship from the viewpoint of business strategy. It also aims to highlight seven areas of the partnership that can be developed to promote cooperation on a shared strategic direction that delivers improved business outcomes

Design/methodology/approach

The literature is reviewed and the author's extensive experience in franchising is drawn on. The Seven C Approach is discussed as a guide.

Findings

The paper finds that by adopting an approach based on communication, cooperation, consultation, collaboration, coordination, concession and competence franchisors and franchisees can work through their differences on strategy formulation and implementation.

Practical implications

The paper has real and immediate practical benefits for franchisors and franchisees in that it provides a seven‐step guide for improving the working relationship between the two. This will result in greater trust and better business outcomes.

Originality/value

This paper distills the theory into a compact, practical and easily implementable seven‐step process for improving the franchising relationship. The result is a useful guide for franchising businesses based on research and experience. A new strategy model is developed for practitioners and is presented here for the first time.
Conference report – Dynamic discourse drives effective strategy implementation: Association for Strategic Planning's annual conference recap
Authors: Sterling John , Rader Dave
Published: March 2013

Purpose

The purpose of this paper is to report on the Association for Strategic Planning Conference.

Design/methodology/approach

The paper provides a conference report for the 2012 Association for Strategic Planning Conference, held in Lincolnshire, Illinois, USA from May 30‐June 2, 2012.

Findings

The paper reveals presentations of practitioners and veteran consultants who share what is working in their practice of strategic management.

Originality/value

The paper provides reviews of papers presented at the 2012 Association for Strategic Planning Conference provided by practitioners and veteran consultants who share what is working in their practice of strategic management.
Leadership communications: planning for the desired reaction
Authors: Fred Garcia Helio
Published: March 2013

Purpose

The author warns that when corporate leaders misunderstand and mishandle communication in a crisis, there can be existential consequences: customer loyalty can be jeopardized, market share lost to rivals, the ability to achieve key goals compromised, and perhaps a legal position undercut. The article aims to demonstrate how such pitfalls can be avoided.

Design/methodology/approach

The paper explains that effective communication requires mastering a discipline with two key skills – gaining a current and thorough knowledge of the expectations and needs of audience and understanding how to craft a message to achieve a desired reaction.

Findings

The author proposes and parses a working definition of communication is: “an act of will directed toward a living entity that reacts.”

Research limitations/implications

Case studies of communications failures are reported.

Practical implications

Organizations need defenses against their charismatic leaders.

Originality/value

The paper provides a guide to how effective leaders communicate with stakeholders by speaking and acting only after thoroughly studying their needs and interests.
The practical relevance of management accounting research and the role of qualitative methods therein
Authors: ter Bogt Henk , van Helden Jan
Published: March 2013

Purpose

The purpose of this paper is to present and analyze the opinions of a number of editors of accounting journals on the value they attach to the practical relevance of management accounting research and the potential role of qualitative methods in conducting this type of research.

Design/methodology/approach

This paper collects together commentaries from these journal editors about the theme indicated above, together with an overview and reflections by the editors of this special issue.

Findings

The journal editors do not regard a lack of practical relevance in management accounting research as a key concern. Most of them see practice‐relevance and theoretical advancement as complementary, while the latter is given by far the most weight as the core of academic work. Furthermore, most journal editors have no clear preference for either qualitative or quantitative research in relation to the practical relevance issue. Neither do they seem to have strong opinions about the specific benefits of qualitative methods in practice‐relevant studies. In their commentaries, the editors of this special issue advocate a stronger connection between the needs of practitioners and the content of the research, more interventionist research in which practitioners and researchers work together, and a greater focus on communication between academics and practitioners about the practical implications of management accounting research. The special issue editors specifically emphasize the importance of this communication in relation to safeguarding the “support” of various groups in society for academic research.

Practical implications

The paper contributes to the ongoing debate about the practical relevance of management accounting research, and particularly to the role of qualitative methods in practice‐relevant studies.

Originality/value

By collecting and analyzing the opinions of editors of several prominent accounting journals on the practice‐relevance of the research in this field, a contribution is made to the ongoing debate about this issue.
ERP systems and management accounting: a multiple case study
Authors: Sánchez‐Rodríguez Cristóbal , Spraakman Gary
Published: March 2013

Purpose

The present study seeks to refine the findings and theory on the impact that enterprise resource planning (ERP) implementations have had on management accounting. Specifically, the purposes of this paper are to analyze the changes that ERP implementations have had on performance measures, management accounting techniques, activities of management accountants, and the use of non‐financial information.

Design/methodology/approach

The controllers of 13 major Canadian firms were interviewed as part of a multiple case study. Open‐ended questions were used.

Findings

The research assesses how ERP implementations through more computational power, relational databases, standardized state‐of‐the‐art transaction processing, and extended chart of accounts change management accounting. The enhanced computing power and overall standardization lead to more accurate and timely information. The standardized transaction processing and the charts of accounts have increased the availability of information from units and products previously deficient of information, and ensured a consistency of information across all units and products. The standardization and automation of transaction processing has reduced the amount of data entry done by management accountants. Performance measures have been standardized, expanded to more units and products, increased in accuracy, and produced more quickly. Management accounting techniques have become more efficient and effective. Management accountants are less involved with data entry, thus allowing them to undertake more analyses. Non‐financial information is more extensive.

Originality/value

This research provides new insights or contributions to understanding how ERP systems impact management accounting and management accountants. First, ERP system implementations affect management accounting. Second, the three part lens or conceptual framework – physical, transactional, and information – explicates the impact of ERP systems on management accounting and management accountants. Third, understanding the impact is further guided by recognizing the expanded chart of accounts inherent with ERP systems.