bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulations of surfactant effects on the dynamics of coalescing drops and bubbles
Authors: Martin David W. , Blanchette François
Published: January 2015

We present simulations of coalescence in the presence of surfactant. We consider a fluid-fluid interface where we track surfactant concentration. Our model is applicable to a soap bubble merging with a suspended soap film and to a surfactant covered liquid drop merging with a reservoir. In both cases, we determine the regime in which coalescence is only partial. Along with viscous effects, represented by the Ohnesorge number, the elasticity of the surface tension relative to the surfactant concentration is seen to play a key role and exhibits a surprising nonmonotonic influence, for which we present a physical mechanism. The effects of gravity are also simulated, along with effects of differing initial conditions, as well as those of uneven initial surfactant concentration, as are likely to arise in physical applications. We describe how the presence of surfactants can influence a coalescence cascade.
An investigation of Ar metastable state density in low pressure dual-frequency capacitively coupled argon and argon-diluted plasmas
Authors: Liu Wen-Yao , Xu Yong , Liu Yong-Xin , Peng Fei , Guo Qian , Li Xiao-Song , Zhu Ai-Min , Wang You-Nian
Published: January 2015

An tunable diode laser absorption spectroscopy has been used to determine the Ar*(3P2) and Ar*(3P0) metastable atoms densities in dual-frequency capacitively coupled plasmas. The effects of different control parameters, such as high-frequency power, gas pressure and content of Ar, on the densities of two metastable atoms and electron density were discussed in single-frequency and dual-frequency Ar discharges, respectively. Particularly, the effects of the pressure on the axial profile of the electron and Ar metastable state densities were also discussed. Furthermore, a simple rate model was employed and its results were compared with experiments to analyze the main production and loss processes of Ar metastable states. It is found that Ar metastable state is mainly produced by electron impact excitation from the ground state, and decayed by diffusion and collision quenching with electrons and neutral molecules. Besides, the addition of CF4 was found to significantly increase the metastable destruction rate by the CF4 quenching, especially for large CF4 content and high pressure, it becomes the dominant depopulation process.
Piezoresistive characterization of bottom-up, n-type silicon microwires undergoing bend deformation
Authors: McClarty Megan M. , Bruce Jared P. , Freund Michael S. , Oliver Derek R.
Published: January 2015

The piezoresistance of silicon has been studied over the past few decades in order to characterize the material's unique electromechanical properties and investigate their wider applicability. While bulk and top-down (etched) micro- and nano-wires have been studied extensively, less work exists regarding bottom-up grown microwires. A facile method is presented for characterizing the piezoresistance of released, phosphorus-doped silicon microwires that have been grown, bottom-up, via a chemical vapour deposition, vapour-liquid-solid process. The method uses conductive tungsten probes to simultaneously make electrical measurements via direct ohmic contact and apply mechanical strain via bend deformation. These microwires display piezoresistive coefficients within an order of magnitude of those expected for bulk n-type silicon; however, they show an anomalous response at degenerate doping concentrations (∼1020 cm−3) when compared to lower doping concentrations (∼1017 cm−3), with a stronger piezoresistive coefficient exhibited for the more highly doped wires. This response is postulated to be due to the different growth mechanism of bottom-up microwires as compared to top-down.
Research on synchronization of 15 parallel high gain photoconductive semiconductor switches triggered by high power pulse laser diodes
Authors: Wang Wei , Xia Liansheng , Chen Yi , Liu Yi , Yang Chao , Ye Mao , Deng Jianjun
Published: January 2015

The synchronization of 15 parallel high gain gallium arsenide photoconductive semiconductor switches (GaAs PCSS) has been researched aiming to get higher output voltage. Each PCSS is triggered independently by a high power pulse laser diode. The pulse width, energy, peak power, and central wavelength of the laser pulse are approximately 18 ns, 360 μJ, 20 kW, and 905 nm, respectively. In the stacked Blumlein transmission lines structure, the synchronous conduction of 15 parallel GaAs PCSSs has been achieved by offering optimized bias voltage and laser parameters. The method of synchronization calculation is given, and the synchronization of the 15 parallel GaAs PCSSs is measured as 775 ps. Furthermore, influences of the bias voltage, laser parameters on the synchronization are analyzed. In the output terminal, superimposed by the output voltages of 15 Blumlein transmission lines, the total output voltage reaches up to 328 kV, which is the highest output voltage of GaAs PCSSs that has been reported so far.
Terahertz photoluminescence from S.I.-GaAs by below gap excitation via EL2 level
Authors: Oyama Yutaka , Dezaki Hikari , Shimizu Yusaku , Maeda Kensaku
Published: January 2015

Terahertz emission by radiative transitions in semi-conductors via shallow impurity states is investigated. We report on the observation of terahertz photoluminescence from S.I.-GaAs by below gap excitation via EL2 level which is located at the center of band gap. In order to investigate the terahertz wave emission mechanisms, the emission spectra and temperature dependence of the emission intensity are evaluated. It is shown that intense terahertz emission from S.I.-GaAs over 120 K is observed due to the thermal recovery of photo-quenched EL2 meta-stable state, and that the emission peak frequency looks to be attributed to the shallow level energy in GaAs.
Influence of microstructure on the enhancement of soft magnetic character and the induced anisotropy of field annealed HITPERM-type alloys
Authors: Blázquez J. S. , Marcin J. , Varga M. , Franco V. , Conde A. , Skorvanek I.
Published: January 2015

Hitperm-type rapidly quenched ribbons were submitted to field annealing, both longitudinal field (LF) and transversal field (TF) to the axis of the ribbon. LF annealing yields a reduction of the magnetic anisotropy and results can be explained in the frame of random anisotropy model. A coercivity of 3 A/m is obtained for Fe39Co39Nb6B15Cu1 alloy. The addition of Cu to these Nb-containing Hitperm-type alloys is a key factor to refine the microstructure in order to reach this very low coercivity value. TF annealing produces samples with sheared hysteresis loops suitable for sensor and high frequency applications.
Child obesity service provision: a cross-sectional survey of physiotherapy practice trends and professional needs
Authors: Milne Nikki , Choy Nancy Low , Leong Gary M. , Hughes Roger , Hing Wayne
Published: January 2015

This study explored current physiotherapy practice trends for management of children who are overweight or obese. The professional needs of physiotherapists working with this population were also assessed, including the perceived need for physiotherapy clinical guidelines for prevention and management of children with obesity. A cross-sectional survey design was used, with questionnaires purposefully distributed through 13 key physiotherapy services throughout Australia. Snowball sampling resulted in completed questionnaires from 64 physiotherapists who provided services to children. Half (n = 33, 52%) of respondents provided services specifically to overweight or obese children. Of those providing services, one-quarter had prior training specific to working with this population. Most used multi-disciplinary models (n = 16, 76%) and provided under 5 h of obesity-related services each week (n = 29, 88%). Half (n = 16, 49%) used body mass index as an outcome measure but more (n = 25, 76%) used bodyweight. Only 14 (42%) assessed motor skills. The majority of respondents (n = 57, 89%) indicated a need for physiotherapy guidelines to best manage overweight and obese children. Professional development priorities included: ‘Educating children and families’, ‘Assessment methods’ and ‘Exercise prescription’ for overweight and obese children. This data provides workforce intelligence to guide future professional training and inform development of clinical guidelines for physiotherapists in prevention and management of children with obesity and related chronic disease.
Kant on the construction and composition of motion in the Phoronomy
Authors: Sutherland Daniel
Published: January 2015

This paper examines the role of Kant’s theory of mathematical cognition in his phoronomy, his pure doctrine of motion. I argue that Kant’s account of how we can construct the composition of motion rests on the construction of extended intervals of space and time, and the representation of the identity of the part–whole relations the construction of these intervals allow. Furthermore, the construction of instantaneous velocities and their composition also rests on the representation of extended intervals of space and time, reflecting the general approach to instantaneous velocity in the eighteenth century.
Counterion release from a discretely charged surface in an electrolyte: Monte Carlo simulation study
Authors: Hernández-Contreras M
Published: January 2015

Monte Carlo simulations allowed us to determine the amount of released electric charges from a discretely charged surface in 1:1 aqueous electrolyte solution as a function of surface charge density. Within the restricted primitive model and for a fixed concentration of 0.1 M bulk electrolyte in solution, there is an increase in the number of released counterions per unit surface area as the strength of the surface charge is enhanced. A similar behaviour of the number of released counterions was also found through the use of mean field and liquid theory methods.
Development of Al-killed/Ti stabilized steels
Authors: Ramirez-Ledesma A L , Aguilar-Mendez M A , Rodriguez-Diaz R A , Aramburo G , Juarez-Islas J A
Published: January 2015

Several Al-killed/Ti-stabilized low carbon steels were developed in a Mexican steel industry with the aim of obtaining an interstitial free steel for automotive applications. The steelmaking route involved the use of 100% sponge iron which was feed into an electric arc furnace, vacuum degassed, ladle treated and continuously casted. The resulting slabs were then hot rolled at 1100 °C and coiled at 650 °C. Then, the steel plates were cold rolled at room temperature and sheets annealed at 700 °C. As-cast micro structure showed the presence of α-ferrite with titanium nitrides in matrix and grain boundaries while in the ashot rolled condition, elongated grains showed the presence of titanium nitrides, titanium sulfides and titanium carbosulfides. The annealed sheets showed, additionally to the other precipitates, the presence of titanium carbides. Microstructure, texture, the Lankford ratio and mechanical properties of fully recrystallized coils fulfilled the target properties established by the automobile industry.
Modeling of the Inductance of a Blumlein Circuit Spark Gap
Authors: Aboites V , Rendón L , Hernández A I , Valdés E
Published: January 2015

In this paper we present an analysis of the time-varying inductance in the spark gap of a Blumlein circuit. We assume several mathematical expressions to describe the inductance and compare theoretical and computational calculations with experimental results. The time-varying inductance is approximated by a constant, a straight line and two parables which differ in their concavity. This is the first time to our knowledge, in which the time-varying ignition inductance of a nitrogen laser is modeled.
Photoluminescence Emission and Structure Diversity in ZnO:Ag Nanorods
Authors: Lozada E Velázquez , González G M Camacho , Torchynska T
Published: January 2015

The photoluminescence, its temperature dependences, as well as structural characteristics by methods of Scanning electronic microscopy (SEM) have been studied in ZnO:Ag nanorods prepared by the ultrasonic spray pyrolysis (USP). The PL spectra of the ZnO:Ag NRs over the temperature range from 10 K to 300 K are investigated. Three types of PL bands have been revealed: i) the near-band-edge (NBE) emissions, ii) defect related emission and iii) IR emissions. It is shown the IR emission corresponds to the second-order diffraction of the near-band-edge (NBE) emission bands. The study of NBE PL temperature dependences reveals that the acceptor bound exciton (ABE) and its second-order diffraction peak disappeared at the temperature higher than 200 K. The attenuation of the ABE peak intensity is ascribed to the thermal dissociation of ABE with appearing of a free exciton (FE). The PL bands, related to the LO phonon replica of FE and its second-order diffraction, dominate in the PL spectra at room temperature that testify on the high quality of the ZnO:Ag films prepared by the USP technology.
High precision speed measurement by using interferometric techniques
Authors: Ávila M A Rodríguez , Valiente R Ochoa , Trujillo L A García
Published: January 2015

In this work we present the experimental realization of speed measurement by the use of a two wave interferometer and digital signal processing techniques. We built an automated Michelson interferometer and using an He-Ne laser and with the use of the Fast Fourier Transform (FFT) and computer algorithms we derived a method for finding the speed of displacement. We report uncertainties in the order of 2-3 μm/s. with the use of this procedure. This brings the potential of another physical variable measurement like distance or pressure by this indirect measurement method. This approach is compared with an ultrasonic Logger Pro ® speed measurement system, and the results are compared between systems.
Effect of patterned coupled optical micro-cavities in twodimensional Si-ZnO hybrid photonic structure
Authors: Carrillo-Vázquez V M , Murillo J G
Published: January 2015

The optical characterization of the Si-ZnO hybrid photonic device fabricated and studied in this work revealed its ability to selectively enhance the reflectance on specific wavelengths in the border of VIS-NIR range. This ability was attributed to the coupling of the embedded micro-cavities in the photonic crystal. The results found suggest the presence of a photonic band gap around the border of VIS-NIR range in the hybrid photonic structure studied.
TRAPPED PROTON FLUXES AT LOW EARTH ORBITS MEASURED BY THE PAMELA EXPERIMENT
Authors: Adriani O. , Barbarino G. C. , Bazilevskaya G. A. , Bellotti R. , Boezio M. , Bogomolov E. A. , Bongi M. , Bonvicini V. , Bottai S. , Bruno A. , Cafagna F. , Campana D. , Carbone R. , Carlson P. , Casolino M. , Castellini G. , De Donato C. , De Santis C. , De Simone N. , Felice V. Di , Formato V. , Galper A. M. , Karelin A. V. , Koldashov S. V. , Koldobskiy S. , Krutkov S. Y. , Kvashnin A. N. , Leonov A. , Malakhov V. , Marcelli L. , Martucci M. , Mayorov A. G. , Menn W. , Mergé M. , Mikhailov V. V. , Mocchiutti E. , Monaco A. , Mori N. , Munini R. , Osteria G. , Palma F. , Panico B. , Papini P. , Pearce M. , Picozza P. , Ricci M. , Ricciarini S. B. , Sarkar R. , Scotti V. , Simon M. , Sparvoli R. , Spillantini P. , Stozhkov Y. I. , Vacchi A. , Vannuccini E. , Vasilyev G. I. , Voronov S. A. , Yurkin Y. T. , Zampa G. , Zampa N. , Zverev V. G.
Published: January 2015

We report an accurate measurement of the geomagnetically trapped proton fluxes for kinetic energy above ∼70 MeV performed by the PAMELA mission at low Earth orbits (350 ÷ 610 km). Data were analyzed in the frame of the adiabatic theory of charged particle motion in the geomagnetic field. Flux properties were investigated in detail, providing a full characterization of the particle radiation in the South Atlantic Anomaly region, including locations, energy spectra, and pitch angle distributions. PAMELA results significantly improve the description of the Earth's radiation environment at low altitudes, placing important constraints on the trapping and interaction processes, and can be used to validate current trapped particle radiation models.
China's Dairy United: A New Model for Milk Production
Authors: Wang Jingjing , Chen Mei , Klein Peter G.
Published: January 2015

A milk scandal erupted in China in 2008 when the industrial chemical melamine was found in dairy products nationwide. While many Chinese dairy companies faced huge losses or bankruptcy as a result, one small firm, Dairy United, accelerated its development. Dairy United is one of the fastest‐growing and most innovative Chinese dairy producers, one that features an unusual organizational structure and business model. Unlike most corporate and cooperative dairies that purchase cows on the market, Dairy United leases dairy cows from local farmers, giving it access to its primary asset without a large up‐front investment, and letting the firm grow its dairy herds with newborn heifers. In return, farmers receive fixed payments biannually, but relinquish control rights and residual claims to the firm. Thus, Dairy United's leasing is helping transform Chinese milk production from a backyard, labor‐intensive activity to a more industrialized mode of farming. The case is particularly interesting for understanding applications of agency theory in agribusiness.
Development of Black Soldier Fly (Diptera: Stratiomyidae) Larvae Fed Dairy Manure
Authors: Myers Heidi M. , Tomberlin Jeffery K. , Lambert Barry D. , Kattes David
Published: January 2015

Black soldier flies, Hermetia illucens L., are a common colonizer of animal wastes. However, all published development data for this species are from studies using artificial diets. This study represents the first examining black soldier fly development on animal wastes. Additionally, this study examined the ability of black soldier fly larvae to reduce dry matter and associated nutrients in manure. Black soldier fly larvae were fed four rates of dairy manure to determine their effects on larval and adult life history traits. Feed rate affected larval and adult development. Those fed less ration daily weighed less than those fed a greater ration. Additionally, larvae provided the least amount of dairy manure took longer to develop to the prepupal stage; however, they needed less time to reach the adult stage. Adults resulting from larvae provided 27 g dairy manure/d lived 3–4 d less than those fed 70 g dairy manure. Percentage survivorship to the prepupal or adult stages did not differ across treatments. Larvae fed 27 g dairy manure daily reduced manure dry matter mass by 58%, whereas those fed 70 g daily reduced dry matter 33%. Black soldier fly larvae were able to reduce available P by 61–70% and N by 30–50% across treatments. Based on results from this study, the black soldier fly could be used to reduce wastes and associated nutrients in confined bovine facilities.
Behavioral Diversity of Predatory Arboreal Ants in Coffee Agroecosystems
Authors: Philpott Stacy M. , Perfecto Ivette , Vandermeer John
Published: January 2015

Aspects of predator assemblages that alter predator effects on prey have received extensive recent attention. Among other mechanisms, differences in behavior or resource use within predator trophic levels may enhance predator effects on prey, especially if effects of each predator species differ with environmental conditions. We address whether three common ant species (Azteca instabilis F. Smith, Camponotus textor Forel, and Crematogaster spp.) are functionally unique in coffee agroecosystems, asking if each species differs in (1) cooperative foraging behavior, (2) responses to experimentally introduced herbivores, and (3) responses to pest outbreaks. Furthermore, we examined the behaviors and effects of each ant species under different conditions by varying herbivore species, herbivore size, and herbivore density and carrying out observations in different seasons. Ant species significantly differed in foraging behaviors, in effects on individual herbivores, and in responses to pest outbreaks in terms of both type and time of response to herbivores. The behaviors and effects of each ant species differed in the dry and wet seasons and for different herbivore species and sizes. Although A. instabilis generally removed more larvae and more quickly removed larvae, this was not the case under all conditions. The data presented thus support that common ant species in coffee agroecosystems are behaviorally diverse in their responses to herbivores under different conditions. We discuss the implications of these differences in ant behaviors for enhancement of predatory function in light of both multipredator effects and in terms of the potential importance of predator diversity.
Pulpit and Cross: Preaching the Crusade in Fourteenth-Century England
Authors: Guard Timothy
Published: January 2015

In contrast to earlier periods, the activity of crusade preachers and their propaganda in the fourteenth century has been little studied. Partly this is a result of the repeated failure to embark on grand crusades to the east after the 1270s and of the increasing fragmentation of crusading along alternative fronts, beyond easy control of the church. It has long been tempting to agree with one expert that, in the era of the later crusades, ‘preaching was much less important than it had been’: there was no Peter the Hermit or Fulk Neuilly of the fourteenth century. Yet, closer scrutiny of the English sources shows that preacherly transmission of the crusade idea remained a dynamic force, open to varied influences and pursuing various objectives. Besides core messages of support for ‘wars of the Cross’, it could involve basic instruction on Christian civility, good manners, orthodoxy and pious living. It was also a platform for comment on matters of national interest and papal policy. Drawing heavily upon little-known sources, including an unedited English crusade sermon, the primary aim of this article is to provide a case-study of crusade promotion in the 1300s—of what it meant to engage and mobilise public opinion in practice. Two key questions are addressed: how was crusade preaching organised in this period, and what can be reconstructed of the preacher’s voice?
James II and David Nairne: The Exiled King and his First Biographer
Authors: Corp Edward
Published: January 2015

During the last years of his life in exile, King James II became increasingly dependent on, and even friendly with, one of his servants at Saint-Germain-en-Laye named David Nairne. Yet none of the many biographies of the king shows any awareness of this. In fact there is no mention of Nairne in any of the books devoted to the life of the king. The present article therefore has a double purpose. The first is to draw attention to an interesting master–servant relationship which has been overlooked for too long. The second is to use that relationship to shed new light on the final years of the king. One reason why those years have posed such a problem for his biographers is that almost all of the king’s papers were destroyed during the French Revolution. By studying the close relationship between James II and David Nairne, we are able to demonstrate that Nairne was both the king’s archivist and his first biographer. James II entrusted his papers to Nairne and asked him to use them to write his Life. Immediately after the king’s death, Nairne continued to assemble and arrange all of these papers, and it is his detailed diary entries which enable us to have a good general idea as to what was lost when they were destroyed. It is to a great extent the involvement of James II with Nairne, who was Scottish, which has misled so many people into wrongly identifying the Stuart court at Saint-Germain with Scotland.
Hypoxic Pulmonary Vasoconstriction
Authors: Lumb Andrew B. , Slinger Peter
Published: January 2015

AbstractAbstract

Hypoxic pulmonary vasoconstriction (HPV) represents a fundamental difference between the pulmonary and systemic circulations. HPV is active in utero, reducing pulmonary blood flow, and in adults helps to match regional ventilation and perfusion although it has little effect in healthy lungs. Many factors affect HPV including pH or Pco
2, cardiac output, and several drugs, including antihypertensives. In patients with lung pathology and any patient having one-lung ventilation, HPV contributes to maintaining oxygenation, so anesthesiologists should be aware of the effects of anesthesia on this protective reflex. Intravenous anesthetic drugs have little effect on HPV, but it is attenuated by inhaled anesthetics, although less so with newer agents. The reflex is biphasic, and once the second phase becomes active after about an hour of hypoxia, this pulmonary vasoconstriction takes hours to reverse when normoxia returns. This has significant clinical implications for repeated periods of one-lung ventilation.

Hypoxic pulmonary vasoconstriction matches lung perfusion to ventilation in patients with lung disease and during one-lung ventilation. This review describes its physiology, factors affecting its activity, and how the reflex impacts on clinical anesthesiology.
Asymmetric Sternotomy and Sternal Wound Complications: Assessment Using 3-Dimensional Computed Tomography Reconstruction
Authors: Jacobson Joshua Y. , Doscher Matthew E. , Rahal William J. , Friedmann Patricia , Nikfarjam Jeremy S. , D'Alessandro David A. , Michler Robert E. , Garfein Evan S.
Published: January 2015

Objective

Wound complications after midline sternotomy result in significant morbidity and mortality. Despite many known risk factors, the influence of sternal asymmetry has largely been ignored. The purpose of this study was to assess the utility of 3-dimensional computed tomographic scan reconstructions to assess sternal asymmetry and determine its relationship with sternal wound infection.

Methods

A retrospective chart review was conducted for patients who underwent midline sternotomy and received a postoperative computed tomographic scan between 2009 and 2010. Cases were composed of all patients who had a sternal wound infection after undergoing sternotomy. Controls were randomly selected from patients without poststernotomy wound complications. Sternal asymmetry was defined as the difference between the left and the right sternal halves and was expressed as a percentage of the total sternal volume.

Results

Twenty-six cases were identified and 32 controls were selected as described earlier. The patients were similar in baseline characteristics and risk factors including age, sex, smoking status, diabetes, chronic obstructive pulmonary disease, preoperative creatinine, and operative time. Univariate factors associated with sternal wound infection include an asymmetry of 10% or greater, body mass index, and internal mammary artery harvest. In a multivariate logistic regression, independent predictors of sternal wound infection included an asymmetry of 10% or greater (odds ratio, 3.6; P = 0.03) and diabetes (odds ratio, 3.3; P = 0.0442).

Conclusions

Our data suggest an association between asymmetric sternotomy and sternal wound infections. We recommend an assessment of sternal asymmetry to be performed in patients with sternal wound infection and if it is found to be 10% or greater, the surgeon should implement measures that stabilize the sternum.
Evidence for the buffer effect operating in multiple species at a national scale
Authors: Sullivan Martin J. P. , Newson Stuart E. , Pearce-Higgins James W.
Published: January 2015

A long-standing aim of ecologists is to understand the processes involved in regulating populations. One such mechanism is the buffer effect, where lower quality habitats are increasingly used as a species reaches higher population densities, with a resultant average reduction in fecundity and survival limiting population growth. Although the buffer effect has been demonstrated in populations of a number of species, a test of its importance in influencing population growth rates of multiple species across large spatial scales is lacking. Here, we use habitat-specific population trends for 85 bird species from long-term national monitoring data (the UK Breeding Bird Survey) to examine its generality. We find that both patterns of population change and changes in habitat preference are consistent with the predictions of the buffer effect, providing support for its widespread operation.
Thermal shock fracture mechanics analysis of a semi-infinite medium based on the dual-phase-lag heat conduction model
Authors: Wang B. , Li J. E. , Yang C.
Published: January 2015

The generalized lagging behaviour in solids is very important in understanding heat conduction in small-scale and high-rate heating. In this paper, an edge crack in a semi-infinite medium subjected to a heat shock on its surface is studied under the framework of the dual-phase-lag (DPL) heat conduction model. The transient thermal stress in the medium without crack is obtained first. This stress is used as the crack surface traction with an opposite sign to formulate the crack problem. Numerical results of thermal stress intensity factor are obtained as the functions of crack length and thermal shock time. Crack propagation predictions are conducted and results based on the DPL model and those based on the classical Fourier heat conduction model are compared. The thermal shock strength that the medium can sustain without catastrophic failure is established according to the maximum local stress criterion and the stress intensity factor criterion.
Evans function and Fredholm determinants
Authors: Karambal Issa , Malham Simon J. A.
Published: January 2015

We explore the relationship between the Evans function, transmission coefficient and Fredholm determinant for systems of first-order linear differential operators on the real line. The applications we have in mind include linear stability problems associated with travelling wave solutions to nonlinear partial differential equations, for example reaction–diffusion or solitary wave equations. The Evans function and transmission coefficient, which are both finite determinants, are natural tools for both analytic and numerical determination of eigenvalues of such linear operators. However, inverting the eigenvalue problem by the free-state operator generates a natural linear integral eigenvalue problem whose solvability is determined through the corresponding infinite Fredholm determinant. The relationship between all three determinants has received a lot of recent attention. We focus on the case when the underlying Fredholm operator is a trace class perturbation of the identity. Our new results include (i) clarification of the sense in which the Evans function and transmission coefficient are equivalent and (ii) proof of the equivalence of the transmission coefficient and Fredholm determinant, in particular in the case of distinct far fields.
A phylogenetic backbone for Bivalvia: an RNA-seq approach
Authors: González Vanessa L. , Andrade Sónia C. S. , Bieler Rüdiger , Collins Timothy M. , Dunn Casey W. , Mikkelsen Paula M. , Taylor John D. , Giribet Gonzalo
Published: January 2015

Bivalves are an ancient and ubiquitous group of aquatic invertebrates with an estimated 10 000–20 000 living species. They are economically significant as a human food source, and ecologically important given their biomass and effects on communities. Their phylogenetic relationships have been studied for decades, and their unparalleled fossil record extends from the Cambrian to the Recent. Nevertheless, a robustly supported phylogeny of the deepest nodes, needed to fully exploit the bivalves as a model for testing macroevolutionary theories, is lacking. Here, we present the first phylogenomic approach for this important group of molluscs, including novel transcriptomic data for 31 bivalves obtained through an RNA-seq approach, and analyse these data with published genomes and transcriptomes of other bivalves plus outgroups. Our results provide a well-resolved, robust phylogenetic backbone for Bivalvia with all major lineages delineated, addressing long-standing questions about the monophyly of Protobranchia and Heterodonta, and resolving the position of particular groups such as Palaeoheterodonta, Archiheterodonta and Anomalodesmata. This now fully resolved backbone demonstrates that genomic approaches using hundreds of genes are feasible for resolving phylogenetic questions in bivalves and other animals.
Payoff-based learning explains the decline in cooperation in public goods games
Authors: Burton-Chellew Maxwell N. , Nax Heinrich H. , West Stuart A.
Published: January 2015

Economic games such as the public goods game are increasingly being used to measure social behaviours in humans and non-human primates. The results of such games have been used to argue that people are pro-social, and that humans are uniquely altruistic, willingly sacrificing their own welfare in order to benefit others. However, an alternative explanation for the empirical observations is that individuals are mistaken, but learn, during the game, how to improve their personal payoff. We test between these competing hypotheses, by comparing the explanatory power of different behavioural rules, in public goods games, where individuals are given different amounts of information. We find: (i) that individual behaviour is best explained by a learning rule that is trying to maximize personal income; (ii) that conditional cooperation disappears when the consequences of cooperation are made clearer; and (iii) that social preferences, if they exist, are more anti-social than pro-social.
Competitive strategies for small manufacturers in high labor cost countries
Authors: Caskey Kevin R.
Published: January 2015

Purpose

– The paper aims to examine competitive strategies used by several small ski brands manufacturing in the USA. The motivation is to explain, while there are no major manufacturers in the USA, why many smaller manufacturers produce locally despite higher labor costs.

Design/methodology/approach

– The paper first describes mid-volume, mid-complexity manufacturing. It then describes customization and innovation. Descriptions of the ski industry, ski manufacturing and customization and innovation, especially among smaller ski manufacturers, then follow. Publicly available information is the examined to understand the competitive strategy of firms in this sector. This is followed by interviews with principals at several smaller manufacturers.

Findings

– The findings show that small firms do use innovation and customization strategies and are able to compete while producing their product within the USA.

Research limitations/implications

– The interview method limits the ability to perform rigorous statistical analysis. Results in this sector may not carry over to other sectors of similar size and complexity.

Practical implications

– The findings give an example of the ability of manufacturing to remain in higher labor cost countries if customization and innovation are significant market drivers.

Social implications

– The health of manufacturing in Western Europe and North America is currently of significant political interest. Companies and government entities may consider what actions they can take to encourage innovation-driven markets.

Originality/value

– The paper provides an explanation for the success of small firms manufacturing mid-volume and complexity products in higher labor cost countries. As innovation and customization are found to be major drivers, this can inform manufacturers in other segments where the products and market share characteristics with those found in higher-end downhill skis.
Customer satisfaction and loyalty in Malaysian Islamic banks:a PAKSERV investigation
Authors: Kashif Muahmmad , Wan Shukran Sharifah Suzana , Rehman Mohsin Abdul , Sarifuddin Syamsulang
Published: January 2015

Purpose

– The purpose of this paper is to examine the impact of PAKSERV measures on customer satisfaction and loyalty in the Malaysian Islamic banking context.

Design/methodology/approach

– The dimensionality of the PAKSERV scale is examined with confirmatory factor analysis. A survey approach is adopted to collect data from 300 Islamic banking customers in Kuching, Malaysia.

Findings

– Results reveal an excellent model fit for the PAKSERV scale in collectivist cultural context of Malaysia. All dimensions of PAKSERV are validated except reliability. The issue of non-validity of the reliability dimension in an Islamic banking context is explained by extant literature.

Practical implications

– Islamic banks are recommended to focus on all the PAKSERV scale dimensions to impart service quality. Given a collectivist cultural setting, a “network marketing” approach is recommended to maintain a desirable level of customer satisfaction and loyalty.

Originality/value

– The PAKSERV scale has been employed for the first time to investigate the service quality-loyalty path in a collectivist cultural context. The validity of the PAKSERV scale has been operationalized for the first time in a collectivist cultural context.
How the personality of retail bank customers interferes with the relationship between service quality and loyalty
Authors: Al-hawari Mohammad Ahmad
Published: January 2015

Purpose

– The purpose of this study was to test how customers’ personality traits affect the importance of service quality in triggering customer loyalty.

Design/methodology/approach

– A survey was used to collect information from respondents about their attitude toward and experiences with their primary bank. The same survey was also used to explore respondents’ personality traits. AMOS 18 was used to test the hypothesized relationships.

Findings

– The findings, consistent with the literature, show that the overall quality of service affects customer loyalty. Services quality plays significant and more important role in triggering customer loyalty for customers that tend to be low on most of the five personality traits. For customers high on most of the personality traits, quality plays less of a role in triggering customer loyalty.

Practical implications

– This study demonstrates how bank managers could use their customers’ personality traits to offer the best services and, ultimately, foster stronger relationships.

Originality/value

– Very few papers speculated and non-tried to investigate the effect of customers’ personality traits on the quality-loyalty relationship within the context of retail banking. Thus, this paper fills this gap.
Design of prototype simulation system for driving performance of electromagnetic unmanned robot applied to automotive test
Authors: Chen Gang , Zhang Wei-gong
Published: January 2015

Purpose

– The purpose of this paper is to present a prototype simulation system for driving performance of an electromagnetic unmanned robot applied to automotive test (URAT) to solve that it is difficult and dangerous to online debug control program and to quickly obtain test vehicle dynamic performance.

Design/methodology/approach

– The driving performance of the electromagnetic URAT can be evaluated by the prototype simulation system. The system can simulate various driving conditions of test vehicles. An improved vehicle longitudinal dynamics model matching to the electromagnetic URAT is established. The proposed model has good real-time, and it is easy to implement. The displacement of throttle mechanical leg, brake mechanical leg, clutch mechanical leg and shift mechanical arm is used for the system input. Test vehicle speed and engine speed are used for the system output, and they are obtained by the computation of the established vehicle longitudinal dynamics model.

Findings

– Driving conditions simulation test and vehicle emission test are performed using a Ford Focus car. Simulation and experiment results show that the proposed prototype simulation system in the paper can simulate the driving conditions of actual vehicles, and the performance that electromagnetic URAT drives an actual vehicle is evaluated by the simulation system.

Research limitations/implications

– Future research will focus on improving the real time of the proposed simulation system.

Practical implications

– The autonomous driving performance of electromagnetic URAT can be evaluated by the proposed prototype simulation system.

Originality/value

– A prototype simulation system for driving performance of an electromagnetic URAT based on an improved vehicle longitudinal dynamics model is proposed in this paper, so that it can solve the difficulty and danger of online debugging control program, quickly obtaining the test vehicle performance.
Welding robot system applied in sub-sea pipeline-installation
Authors: Yu Luo , Xiangdong Jiao , Canfeng Zhou , Jiaqing Chen , Suxin Han
Published: January 2015

Purpose

– The aim of this study was to develop a new generation of automatic systems based on cutting-edge design and practical welding physics to minimize downtime caused by defects and machine faults on the barges. Automatic welding has been used frequently on offshore pipeline projects.

Design/methodology/approach

– An automated welding robot system for sub-sea pipeline installation was constructed. The system utilized the double-car double-torch welding, which is light-weight and compact, suited for offshore applications. Several state-of-the-art technologies were integrated into the control system design, including a heterogeneous network based on EtherCAT technology, network communications based on CANopen, motor synchronization, all-position welding, etc. In addition, the utilization of the CAN bus reduced the number of cable lines and increased the extensibility of the proposed welding robot system. An internal clamp with copper shoes assured a nice root weld and narrow bevel design and the welding efficiency was improved accordingly.

Findings

– The trial was carried out to verify the rationality and effectiveness of the proposed automated system. The deposition rate of the backing welding could reach 17.78 kg/h; the average time for each welding was 340 s. This system was unique in that it features a dual-torch welding head that allowed for the deposition of one run with twice as much material as a single torch head. The experiment showed that the double-vehicle double-torch mode can greatly improve the welding efficiency of pipeline installation during the welding process.

Research limitations/implications

– The automated welding robot system will be applied to offshore pipeline projects.

Originality/value

– This robot is the first submarine pipeline installation welding robot to use a heterogeneous network based on EtherCAT technology. Various aspects of the submarine pipeline installation welding robot’s design and performance were discussed, including mechanical body design, control system design and welding process specification.
Absolute accuracy analysis and improvement of a hybrid 6-DOF medical robot
Authors: Joubair Ahmed , Zhao Long Fei , Bigras Pascal , Bonev Ilian
Published: January 2015

Purpose

– The purpose of this paper is to describe a calibration method developed to improve the accuracy of a six degrees-of-freedom medical robot. The proposed calibration approach aims to enhance the robot’s accuracy in a specific target workspace. A comparison of five observability indices is also done to choose the most appropriate calibration robot configurations.

Design/methodology/approach

– The calibration method is based on the forward kinematic approach, which uses a nonlinear optimization model. The used experimental data are 84 end-effector positions, which are measured using a laser tracker. The calibration configurations are chosen through an observability analysis, while the validation after calibration is carried out in 336 positions within the target workspace.

Findings

– Simulations allowed finding the most appropriate observability index for choosing the optimal calibration configurations. They also showed the ability of our calibration model to identify most of the considered robot’s parameters, despite measurement errors. Experimental tests confirmed the simulation findings and showed that the robot’s mean position error is reduced from 3.992 mm before calibration to 0.387 mm after, and the maximum error is reduced from 5.957 to 0.851 mm.

Originality/value

– This paper presents a calibration method which makes it possible to accurately identify the kinematic errors for a novel medical robot. In addition, this paper presents a comparison between the five observability indices proposed in the literature. The proposed method might be applied to any industrial or medical robot similar to the robot studied in this paper.
Facilities management practices in the Nigerian public universities
Authors: Odediran Sunday Julius , Gbadegesin Job Taiwo , Babalola Mujidat Olubola
Published: January 2015

Purpose

– The purpose of this paper is to contribute to the diffusion of facilities management (FM) as a sustainable tool to facility performance within the perspective of public universities in Nigeria.

Design/methodology/approach

– A review of the literature reveals the practices of FM in both the educational and institutional buildings. Factors influencing the practices and strategies for sustaining facilities condition were evaluated. Data were collected through a well-structured questionnaire administered on both the technical and managerial officers in charge of FM in Nigeria public universities. Data collected were subjected to both the descriptive and inferential statistical tools.

Findings

– The FM practice in the Nigeria public universities is found to be lagging behind private sector experience, despite the significant benefits of FM to learning process. In particular, passive actions are being taken to manage facilities, even when most are obsolete and deteriorated. Critical challenges to FM practice are low level of technology, poor funding and poor policy implementation. Outsourcing of technical personnel is essential to ameliorate the conditions of public universities’ facilities in Nigeria.

Practical implications

– This paper helps policymakers and administrators to know the condition of facilities and understand the FM practice in the Nigerian public universities.

Originality/value

– Reactive/passive practice is the norm in FM of public universities in Nigeria. However, outsourcing of technical personnel in FM has a great potential for functional facilities in public universities.