bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradation of potential barriers in ZnO-based chip varistors due to electrostatic discharge
Authors: Hirose Sakyo , Niimi Hideaki , Kageyama Keisuke , Ieki Hideharu , Omata Takahisa , Otsuka-Yao-Matsuo Shinya
Published: August 2012

Degradation of potential barriers in ZnO-based varistors due to the electrostatic discharge (ESD) was investigated using scanning probe microanalysis and capacitance-time and isothermal capacitance transient spectroscopies. Pr6O11-ZnO (Pr-ZnO) varistors exhibit excellent ESD withstand capability compared with Bi2O3-ZnO (Bi-ZnO) varistors. After the application of ESD, asymmetrically degraded double Schottky barriers were observed in both Pr-ZnO and Bi-ZnO varistors, and the Schottky barrier in Bi-ZnO was found to be destroyed. The potential barriers of both types of varistors can respond to an ESD pulse, whose rise time is ∼1 ns, but after application of the ESD pulse, the Bi-ZnO varistor takes more time to recover its initial capacitance than does the Pr-ZnO varistor. Such difference in the transient behaviors of potential barriers is attributed to differences in the energy and distribution of interfacial states of Pr-ZnO and Bi-ZnO varistors. Experimental results clearly indicated a strong correlation between the transient behaviors of potential barriers and the ESD withstand capabilities of ZnO-based varistors.
Gain enhancement in graphene terahertz amplifiers with resonant structures
Authors: Takatsuka Yuya , Takahagi Kazuhiro , Sano Eiichi , Ryzhii Victor , Otsuji Taiichi
Published: August 2012

Terahertz (THz) devices have been investigated over the last decade to utilize THz waves for non-destructive sensing and high-speed wireless communications. Graphene with gapless and linear energy spectra is expected to exhibit population inversion and has negative dynamic conductivity in the THz range when it is illuminated by infrared light. We analyze a THz amplifier utilizing this negative dynamic conductivity combined with electric field enhancements due to surface plasmon polaritons induced on a metal mesh and with a resonant structure. We evaluate its characteristics through finite-difference time-domain electromagnetic simulations. The amplifier is expected to remarkably enhance THz emissions compared with amplifiers without the resonant structure.
Reconstructions and electronic structure of (112¯2) and (112¯2¯) semipolar AlN surfaces
Authors: Kalesaki E. , Lymperakis L. , Kioseoglou J. , Neugebauer J. , Karakostas Th. , Komninou Ph.
Published: August 2012

Τhe energetics, atomic geometry, and electronic structure of semipolar (112¯2) and (112¯2¯) AlN surfaces are investigated employing first principles calculations. For metal-rich growth conditions, metallic reconstructions are favoured on both polarity surfaces. For N rich to moderate Al rich conditions, the (112¯2) planes promote semiconducting reconstructions having 2 × 2 or c(2 × 2) periodicity. In contrast, under the particular range of the Al chemical potential the (112¯2¯) surfaces stabilize reconstructions with excess metal and it is only at the extreme N rich limit that the semiconducting c(2 × 2) N adatom structure prevails. The present study reveals that the reconstructed (112¯2) surfaces do not contain steps in contrast to (112¯2¯) where surface steps are inherent for N rich to moderate metal rich growth conditions and may result in intrinsic step-flow growth and/or growth of parasitic semipolar orientations.
Communication: Barium ions and helium nanodroplets: Solvation and desolvation
Authors: Zhang Xiaohang , Drabbels Marcel
Published: August 2012

The solvation of Ba+ ions created by the photoionization of barium atoms located on the surface of helium nanodroplets has been investigated. The excitation spectra corresponding to the 6p 2P1/2 ← 6s 2S1/2 and 6p 2P3/2 ← 6s 2S1/2 transitions of Ba+ are found to be identical to those recorded in bulk He II [H. J. Reyher, H. Bauer, C. Huber, R. Mayer, A. Schafer, and A. Winnacker, Phys. Lett. A 115, 238 (1986)], indicating that the ions formed at the surface of the helium droplets become fully solvated by the helium. Time-of-flight mass spectra suggest that following the excitation of the solvated Ba+ ions, these are being ejected from the helium droplets either as bare Ba+ ions or as small Ba+Hen (n < 20) complexes.
Effective dielectric constant of two phase systems: Application to mixed conducting systems
Authors: Petrovsky Vladimir , Jasinski Piotr , Dogan Fatih
Published: August 2012

Theoretical approaches to electrical characterization of two phase systems are mostly limited to the systems where the individual components exhibit the same type of conductivity (pure dielectric or pure conductive systems). In this article, the brick wall geometry is extended to the mixed conductive systems with percolation. Impedance spectroscopy techniques were used for experimental investigation of slurries. Various metal oxide powders and host liquids were analyzed using a wide range of solids loadings. Comparison of experimental results with theoretical predictions shows good fitting of the experimental data. Parameters (the values of permittivity for both phases and percolation threshold) calculated from this fitting match the corresponding values of components of two phase systems. Analysis of both low frequency (less than 10 kHz) as well as high frequency (10 kHz to 1 MHz) responses of impedance spectra allows determining of permittivity of dielectric powders suspended in various liquids. Low frequency response provides better accuracy for systems with high dielectric contrast between components, while high frequency response is more accurate for low contrast systems.
Assessing the distribution patterns of wildfire sizes in Mississippi, USA
Authors: Sun Changyou , Tolver Branden
Published: August 2012

Wildland fires can produce dramatic ecological and economic impacts. The objective of this study was to analyse the temporal and spatial distribution patterns of wildland fires using 64 474 fire records in Mississippi, collected between 1991 and 2007. The methodology employed was descriptive statistics and extreme value statistics. The analyses were conducted for all the fires combined, and also by year, period, ecoregion and cause separately. Wildland fires occurred most frequently between February and May, with more than half of all the fires occurring in that period. The ecoregion of outer coastal plain mixed-forest province had more fire occurrences and the ecoregion of south-eastern mixed-forestry province had more catastrophic fires. By fire cause, debris and incendiary fires combined were responsible for 89.6% of the area burned. The top 10% of the largest fires burned 58.8% of the total area. The extreme value statistics revealed that wildfires in Mississippi displayed a generalised Pareto distribution. Based on predictions from the peaks-over-threshold models, the largest wildland fire in Mississippi within the next 10 years could burn 2171 ha. These outcomes can help landowners and government agencies make better decisions related to forest investments, fire suppression and budget planning.
Structure of the yeast F
1
F
o
-ATP synthase dimer and its role in shaping the mitochondrial cristae
Authors: Davies Karen M. , Anselmi Claudio , Wittig Ilka , Faraldo-Gómez José D. , Kühlbrandt Werner
Published: August 2012

We used electron cryotomography of mitochondrial membranes from wild-type and mutant
Saccharomyces cerevisiae
to investigate the structure and organization of ATP synthase dimers in situ. Subtomogram averaging of the dimers to 3.7 nm resolution revealed a V-shaped structure of twofold symmetry, with an angle of 86° between monomers. The central and peripheral stalks are well resolved. The monomers interact within the membrane at the base of the peripheral stalks. In wild-type mitochondria ATP synthase dimers are found in rows along the highly curved cristae ridges, and appear to be crucial for membrane morphology. Strains deficient in the dimer-specific subunits
e
and
g
or the first transmembrane helix of subunit 4 lack both dimers and lamellar cristae. Instead, cristae are either absent or balloon-shaped, with ATP synthase monomers distributed randomly in the membrane. Computer simulations indicate that isolated dimers induce a plastic deformation in the lipid bilayer, which is partially relieved by their side-by-side association. We propose that the assembly of ATP synthase dimer rows is driven by the reduction in the membrane elastic energy, rather than by direct protein contacts, and that the dimer rows enable the formation of highly curved ridges in mitochondrial cristae.
Circadian changes in long noncoding RNAs in the pineal gland
Authors: Coon Steven L. , Munson Peter J. , Cherukuri Praveen F. , Sugden David , Rath Martin F. , Møller Morten , Clokie Samuel J. H. , Fu Cong , Olanich Mary E. , Rangel Zoila , Werner Thomas ,   NISC Comparative Sequencing Program, Mullikin James C. , Klein David C. ,   NISC Comparative Sequencing Program, Benjamin Betty , Blakesley Robert , Bouffard Gerry , Brooks Shelise , Chu Grace , Coleman Holly , Dekhtyar Mila , Gregory Michael , Guan Xiaobin , Gupta Jyoti , Han Joel , Hargrove April , Ho Shi-ling , Johnson Taccara , Legaspi Richelle , Lovett Sean , Maduro Quino , Masiello Cathy , Maskeri Baishali , McDowell Jenny , Montemayor Casandra , Novotny Betsy , Park Morgan , Riebow Nancy , Schandler Karen , Schmidt Brian , Sison Christina , Stantripop Mal , Thomas James , Vemulapalli Meg , Young Alice
Published: August 2012

Long noncoding RNAs (lncRNAs) play a broad range of biological roles, including regulation of expression of genes and chromosomes. Here, we present evidence that lncRNAs are involved in vertebrate circadian biology. Differential night/day expression of 112 lncRNAs (0.3 to >50 kb) occurs in the rat pineal gland, which is the source of melatonin, the hormone of the night. Approximately one-half of these changes reflect nocturnal increases. Studies of eight lncRNAs with 2- to >100-fold daily rhythms indicate that, in most cases, the change results from neural stimulation from the central circadian oscillator in the suprachiasmatic nucleus (doubling time = 0.5–1.3 h). Light exposure at night rapidly reverses (halving time = 9–32 min) levels of some of these lncRNAs. Organ culture studies indicate that expression of these lncRNAs is regulated by norepinephrine acting through cAMP. These findings point to a dynamic role of lncRNAs in the circadian system.
Identifying multi-layer gene regulatory modules from multi-dimensional genomic data
Authors: Li Wenyuan , Zhang Shihua , Liu Chun-Chi , Zhou Xianghong Jasmine
Published: August 2012

Motivation: Eukaryotic gene expression (GE) is subjected to precisely coordinated multi-layer controls, across the levels of epigenetic, transcriptional and post-transcriptional regulations. Recently, the emerging multi-dimensional genomic dataset has provided unprecedented opportunities to study the cross-layer regulatory interplay. In these datasets, the same set of samples is profiled on several layers of genomic activities, e.g. copy number variation (CNV), DNA methylation (DM), GE and microRNA expression (ME). However, suitable analysis methods for such data are currently sparse.

Results: In this article, we introduced a sparse Multi-Block Partial Least Squares (sMBPLS) regression method to identify multi-dimensional regulatory modules from this new type of data. A multi-dimensional regulatory module contains sets of regulatory factors from different layers that are likely to jointly contribute to a local ‘gene expression factory’. We demonstrated the performance of our method on the simulated data as well as on The Cancer Genomic Atlas Ovarian Cancer datasets including the CNV, DM, ME and GE data measured on 230 samples. We showed that majority of identified modules have significant functional and transcriptional enrichment, higher than that observed in modules identified using only a single type of genomic data. Our network analysis of the modules revealed that the CNV, DM and microRNA can have coupled impact on expression of important oncogenes and tumor suppressor genes.

Availability and implementation: The source code implemented by MATLAB is freely available at: http://zhoulab.usc.edu/sMBPLS/.

Contact:  xjzhou@usc.edu

Supplementary information:  Supplementary material are available at Bioinformatics online.
An R package suite for microarray meta-analysis in quality control, differentially expressed gene analysis and pathway enrichment detection
Authors: Wang Xingbin , Kang Dongwan D. , Shen Kui , Song Chi , Lu Shuya , Chang Lun-Ching , Liao Serena G. , Huo Zhiguang , Tang Shaowu , Ding Ying , Kaminski Naftali , Sibille Etienne , Lin Yan , Li Jia , Tseng George C.
Published: August 2012

Summary: With the rapid advances and prevalence of high-throughput genomic technologies, integrating information of multiple relevant genomic studies has brought new challenges. Microarray meta-analysis has become a frequently used tool in biomedical research. Little effort, however, has been made to develop a systematic pipeline and user-friendly software. In this article, we present MetaOmics, a suite of three R packages MetaQC, MetaDE and MetaPath, for quality control, differentially expressed gene identification and enriched pathway detection for microarray meta-analysis. MetaQC provides a quantitative and objective tool to assist study inclusion/exclusion criteria for meta-analysis. MetaDE and MetaPath were developed for candidate marker and pathway detection, which provide choices of marker detection, meta-analysis and pathway analysis methods. The system allows flexible input of experimental data, clinical outcome (case–control, multi-class, continuous or survival) and pathway databases. It allows missing values in experimental data and utilizes multi-core parallel computing for fast implementation. It generates informative summary output and visualization plots, operates on different operation systems and can be expanded to include new algorithms or combine different types of genomic data. This software suite provides a comprehensive tool to conveniently implement and compare various genomic meta-analysis pipelines.

Availability:  http://www.biostat.pitt.edu/bioinfo/software.htm

Contact:  ctseng@pitt.edu

Supplementary Information:  Supplementary data are available at Bioinformatics online.
Metallibacterium scheffleri gen. nov., sp. nov., an alkalinizing gammaproteobacterium isolated from an acidic biofilm
Authors: Ziegler Sibylle , Waidner Barbara , Itoh Takashi , Schumann Peter , Spring Stefan , Gescher Johannes
Published: August 2012

A Gram-stain-negative, non-motile, facultatively anaerobic, acid-tolerant rod, designated strain DKE6T, was isolated from an acidic biofilm (pH 2.5) harvested in the pyrite mine Drei Kronen und Ehrt in Germany. The isolate grew optimally at pH 5.5, between 25 and 30 °C and only with casein as the carbon and energy source; although a variety of sugars were tested as growth substrates, none supported growth of the isolate. During casein consumption, strain DKE6Tproduced ammonium, which led to an alkalinization of the medium. This is a possible strategy to raise the pH in the direct vicinity of the cell and hence modulate the pH towards the growth optimum. The predominant fatty acids (>5 %) were iso-C11 : 03-OH, iso-C15 : 0, iso-C17 : 0and iso-C17 : 1ω9c. The DNA G+C content was 66.6 %. Strain DKE6Twas not able to oxidize iron or thiosulfate. Iron reduction was detected. The isolate showed 93.3 % 16S rRNA gene sequence similarity to the most closely related cultivable strain,Dokdonella koreensisDS-123T, but <93.2 % sequence similarity with other type strains of closely related type species of theGammaproteobacteria. On the basis of physiological and biochemical data, the isolate is considered to represent a novel species of a new genus in the classGammaproteobacteria, for which we propose the nameMetallibacterium schefflerigen. nov., sp. nov. The type strain of the type species is DKE6T( = DSM 24874T = JCM 17596T).
Moniliella carnis sp. nov. and Moniliella dehoogii sp. nov., two novel species of black yeasts isolated from meat processing environments
Authors: Thanh Vu Nguyen , Hai Dao Anh , Hien Dinh Duc , Takashima Masako , Lachance Marc-André
Published: August 2012

Thirteen strains of yeasts typical of the genus Moniliella were isolated from fermenting meat and meat processing tools in Vietnam. PCR fingerprints generated by primer (GAC)5 subdivided the strains into two distinctive genetic groups. In a phylogenetic tree based on D1/D2 large subunit rRNA gene sequences, the strains formed a well-supported clade with Moniliella spathulata and Moniliella suaveolens but represented two new lineages. The names Moniliella carnis sp. nov. and Moniliella dehoogii sp. nov. are proposed. The two novel species can be distinguished from each other and from known species of Moniliella based on phenotypic characteristics. It is assumed that the yeasts were associated with fatty substances that contaminated the meat processing tools. The type strain of Moniliella carnis is KFP 246T ( = CBS 126447T = NRRL Y-48681T) and the type strain of Moniliella dehoogii is KFP 211T ( = CBS 126564T = NRRL Y-48682T).
Naumovozyma baii sp. nov., an ascomycetous yeast species isolated from rotten wood in a tropical forest
Authors: Liu Wan-Qiu , Han Pei-Jie , Qiu Jun-Zhi , Wang Qi-Ming
Published: August 2012

Two strains isolated from rotten wood were included in the Saccharomyces group based on morphological characteristics. However, rRNA gene sequence analyses (including the 18S rRNA gene, 26S rRNA gene D1/D2 domain and internal transcribed spacer region) indicated that these two strains represent a novel species of Naumovozyma, for which the name Naumovozyma baii sp. nov. is proposed (type strain: BW 22T = CGMCC 2.04520T = CBS 12642T). The MycoBank number of the new species is MB800484.
A Land-Plant-Specific Glycerol-3-Phosphate Acyltransferase Family in Arabidopsis: Substrate Specificity, sn-2 Preference, and Evolution
Authors: Yang Weili , Simpson Jeffrey P. , Li-Beisson Yonghua , Beisson Fred , Pollard Mike , Ohlrogge John B.
Published: August 2012

Arabidopsis (Arabidopsis thaliana) has eight glycerol-3-phosphate acyltransferase (GPAT) genes that are members of a plant-specific family with three distinct clades. Several of these GPATs are required for the synthesis of cutin or suberin. Unlike GPATs with sn-1 regiospecificity involved in membrane or storage lipid synthesis, GPAT4 and -6 are unique bifunctional enzymes with both sn-2 acyltransferase and phosphatase activity resulting in 2-monoacylglycerol products. We present enzymology, pathway organization, and evolutionary analysis of this GPAT family. Within the cutin-associated clade, GPAT8 is demonstrated as a bifunctional sn-2 acyltransferase/phosphatase. GPAT4, -6, and -8 strongly prefer C16:0 and C18:1 ω-oxidized acyl-coenzyme As (CoAs) over unmodified or longer acyl chain substrates. In contrast, suberin-associated GPAT5 can accommodate a broad chain length range of ω-oxidized and unsubstituted acyl-CoAs. These substrate specificities (1) strongly support polyester biosynthetic pathways in which acyl transfer to glycerol occurs after oxidation of the acyl group, (2) implicate GPAT specificities as one major determinant of cutin and suberin composition, and (3) argue against a role of sn-2-GPATs (Enzyme Commission 2.3.1.198) in membrane/storage lipid synthesis. Evidence is presented that GPAT7 is induced by wounding, produces suberin-like monomers when overexpressed, and likely functions in suberin biosynthesis. Within the third clade, we demonstrate that GPAT1 possesses sn-2 acyltransferase but not phosphatase activity and can utilize dicarboxylic acyl-CoA substrates. Thus, sn-2 acyltransferase activity extends to all subbranches of the Arabidopsis GPAT family. Phylogenetic analyses of this family indicate that GPAT4/6/8 arose early in land-plant evolution (bryophytes), whereas the phosphatase-minus GPAT1 to -3 and GPAT5/7 clades diverged later with the appearance of tracheophytes.
Lotus japonicus ARPC1 Is Required for Rhizobial Infection
Authors: Hossain Md Shakhawat , Liao Jinqiu , James Euan K. , Sato Shusei , Tabata Satoshi , Jurkiewicz Anna , Madsen Lene H. , Stougaard Jens , Ross Loretta , Szczyglowski Krzysztof
Published: August 2012

Remodeling of the plant cell cytoskeleton precedes symbiotic entry of nitrogen-fixing bacteria within the host plant roots. Here we identify a Lotus japonicus gene encoding a predicted ACTIN-RELATED PROTEIN COMPONENT1 (ARPC1) as essential for rhizobial infection but not for arbuscular mycorrhiza symbiosis. In other organisms ARPC1 constitutes a subunit of the ARP2/3 complex, the major nucleator of Y-branched actin filaments. The L. japonicus arpc1 mutant showed a distorted trichome phenotype and was defective in epidermal infection thread formation, producing mostly empty nodules. A few partially colonized nodules that did form in arpc1 contained abnormal infections. Together with previously described L. japonicus Nck-associated protein1 and 121F-specific p53 inducible RNA mutants, which are also impaired in the accommodation of rhizobia, our data indicate that ARPC1 and, by inference a suppressor of cAMP receptor/WASP-family verpolin homologous protein-ARP2/3 pathway, must have been coopted during evolution of nitrogen-fixing symbiosis to specifically mediate bacterial entry.
New Insights into Roles of Cell Wall Invertase in Early Seed Development Revealed by Comprehensive Spatial and Temporal Expression Patterns of GhCWIN1 in Cotton
Authors: Wang Lu , Ruan Yong-Ling
Published: August 2012

Despite substantial evidence on the essential roles of cell wall invertase (CWIN) in seed filling, it remains largely unknown how CWIN exerts its regulation early in seed development, a critical stage that sets yield potential. To fill this knowledge gap, we systematically examined the spatial and temporal expression patterns of a major CWIN gene, GhCWIN1, in cotton (Gossypium hirsutum) seeds from prefertilization to prestorage phase. GhCWIN1 messenger RNA was abundant at the innermost seed coat cell layer at 5 d after anthesis but became undetectable at 10 d after anthesis, at the onset of its differentiation into transfer cells characterized by wall ingrowths, suggesting that CWIN may negatively regulate transfer cell differentiation. Within the filial tissues, GhCWIN1 transcript was detected in endosperm cells undergoing nuclear division but not in those cells at the cellularization stage, with similar results observed in Arabidopsis (Arabidopsis thaliana) endosperm for CWIN, AtCWIN4. These findings indicate a function of CWIN in nuclear division but not cell wall biosynthesis in endosperm, contrasting to the role proposed for sucrose synthase (Sus). Further analyses revealed a preferential expression pattern of GhCWIN1 and AtCWIN4 in the provascular region of the torpedo embryos in cotton and Arabidopsis seed, respectively, indicating a role of CWIN in vascular initiation. Together, these novel findings provide insights into the roles of CWIN in regulating early seed development spatially and temporally. By comparing with previous studies on Sus expression and in conjunction with the expression of other related genes, we propose models of CWIN- and Sus-mediated regulation of early seed development.
Investigations into the improvement of the metal grinding process: application of a sub‐zero temperature cutting fluid
Authors: Daisley Richard P. , Chowdary Boppana V.
Published: August 2012

Purpose

The purpose of this paper is to investigate the effects of liquid carbon dioxide (LCO2) on grinding of stainless steel.

Design/methodology/approach

A factorial experimental approach was used to compare the LCO2's performance against grinding under dry air and emulsion coolants.

Findings

The experimental results have a great use to practitioners. It was found that under special conditions, LCO2 proves to be an alternative coolant for grinding of temperature sensitive materials. Furthermore, grinding under LCO2 conditions produced the lowest tangential force, while the normal forces were close to the values found under emulsion fluid environment. When compared to grinding under dry conditions, LCO2 coolant was successful in reducing the work piece temperatures. LCO2 and emulsion conditions inhibit work hardening by reducing material deformation at the grinding zone.

Originality/value

The paper shows that sub‐zero temperature coolants have the ability to bring about lower grinding temperatures than what is typically achieved under conventional fluids.
The artiﬁcial neural network based prediction of friction properties of Al2O3‐TiO2 coatings
Authors: Cetinel Hakan
Published: August 2012

Purpose

The purpose of this paper is to predict friction/wear properties of Al2O3‐TiO2 coatings using artificial neural networks (ANN).

Design/methodology/approach

Wear experiments were conducted in dry and acidic conditions. Wear loss values were determined and an ANN model was fixed in order to predict wear loss and friction coefficient values.

Findings

Experimental and theoretical study results were well matched for wear loss and friction coefficient values.

Research limitations/implications

The paper covers comparison of experimental and theoretical friction/wear results.

Practical implications

A practical implication is that wear loss values can be predicted without further wear experiments.

Originality/value

In this paper, the wear behavior of Al2O3‐TiO2 coatings has been investigated, both experimentally and theoretically, for the first time.
Inverse approach for the pressure, temperature, and pressure‐viscosity index determination in TEHL of line contacts
Authors: Chu Li‐Ming , Hsu Hsiang‐Chen , Lin Jaw‐Ren , Chang Yuh‐Ping
Published: August 2012

Purpose

The purpose of this paper is to describe an inverse approach to estimate the pressure distribution, temperature distribution, and pressure‐viscosity index (z) in a thermal elastohydrodynamic lubrication (TEHL) line contact.

Design/methodology/approach

Once the film thickness is given, the pressure distribution can be calculated using the inverse approach. Subsequently, thermal expansivity and temperature‐viscosity coefficient of lubricant are given, and then the z is guessed initially. The Gauss‐Seidel iteration is employed to calculate the temperature distribution from the rheology, energy, and surface temperature equations. In order to increase the algorithm stability, the least‐squares method must be employed to calculate the optimum value of the z in the computational domain. Furthermore, the pressure‐viscosity index must be updated by the iteration method to calculate accurate temperature distribution and apparent viscosity until convergence.

Findings

This approach presents a smooth curve of the pressure and temperature distributions with the measurement error from the resolution in the film thickness measurement and z value. Furthermore, this approach still provides a superior solution in apparent viscosity, whereas the direct method provides a much larger error in apparent viscosity.

Originality/value

The paper describes an inverse approach to estimate the pressure distribution, temperature distribution, and pressure‐viscosity index in a TEHL line contact. This approach overcomes the problems of pressure and temperature rise fluctuations and generates accurate results of pressure and temperature distribution from a small number of measured points of film thickness, which also saves computing time. Furthermore, this approach still provides a superior solution in apparent viscosity.
The effects of welding parameters on wear performance of clad layer with TiC ceramic
Authors: Peng De‐Xing
Published: August 2012

Purpose

The purpose of this paper is to test whether TiC clad layer deposited on carbon steel by gas tungsten arc welding (GTAW) improves carbon steel substrate wear resistance.

Design/methodology/approach

Cladding microstructure and cladded surface hardness were tested in samples prepared under varying welding parameters. The chemical composition, microstructure and surface morphology of the cladded layer were analyzed by optical microscope, scanning electron microscopy and energy dispersive X‐ray spectroscopy. The wear behavior of the cladded layer was studied with a block‐on‐ring tribometer. Wear mechanisms in the specimens are discussed based on microscopic study of wear surface characteristics.

Findings

The experimental results revealed an excellent metallurgical bond between the composite coating and substrate. Hardness was increased from HRb 6.6 in the substrate to HRb 65 in the modified layer due to the presence of the hard TiC phase. Experimental comparison of varying welding parameters revealed that welding speed and current had the largest effect on the hardness and wear resistance of the cladded layer.

Originality/value

The paper shows that by using cladding techniques to improve surface properties such as resistances to wear, corrosion, and oxidation, service life can be increased, and machinery costs can be reduced.
The interplay of structure and agency dynamics in strike activity
Authors: Darlington Ralph
Published: August 2012

Purpose

The purpose of this paper is to build on the insights of mobilisation theory to examine the interplay of structure and agency dynamics in strike activity. It proposes to do so by investigating the 2007 36‐hour strike undertaken by 2,300 engineering and infrastructure workers employed by the private consortium Metronet on the London Underground, focusing attention on the relationship between workers’ militancy, trade union leadership and left‐wing politics within a highly distinctive and union favourable “opportunity structure” context.

Design/methodology/approach

Semi‐structured in‐depth interviews were conducted with 24 RMT union informants within Metronet and the London Underground (including union members, reps, branch and regional officers); analysis was made of documentary industrial relations and trade union material; and personal fieldwork observation.

Findings

Although favourable specific contextual and contingent factors served as both provocations and resources for strike action, notably in enhancing workers’ bargaining position and lending feasibility to a strike mobilisation approach, the role of trade union leadership and left‐wing politics at every level of the union in collectivising workers’ experiences and aspirations in forms which directly encouraged combativity was also crucial.

Research limitations/implications

The specificity of the case study limits the degree of generalisation that can be made to other industries. Researchers are encouraged to test the proposed analytical approach further.

Originality/value

The paper provides case‐study empirical evidence into an important arena of employment in the UK, contributes to our understanding of the multi‐dimensional causes of strike activity; and adds an important political dimension to the analysis of collective mobilisation often neglected in both industrial relations and social movement literature.
Role typology for health and safety representatives
Authors: Harris Leigh‐Ann , Bendix Olsen Kirsten , Walker Robyn Jane
Published: August 2012

Purpose

The purpose of this paper is to focus on the development of a health and safety (HS) representative role typology that demonstrates how representatives enact their roles and improve occupational health and safety (OHS) under New Zealand law. It aims to consider the factors that influence the roles that HS representatives’ assume.

Design/methodology/approach

This qualitative, cross‐perceptual study centres on the role enactments of eight HS representatives at two metal manufacturers. Semi‐structured interviews were conducted with HS representatives, managers, workers, senior managers, OHS managers and a union convenor. “Types” were differentiated by the HS representatives’ purpose, activities and OHS impacts.

Findings

In total, four HS representative role “types” were identified: administrators, workshop inspectors, problem solvers and craft experts. Administrators implemented and operated OHS management systems and improved OHS management. Workshop inspectors undertook compliance and monitoring roles and improved workers’ attitudes towards OHS. Problem solvers found solutions to control hazards and improved production from an OHS perspective. Craft experts applied technical knowledge to influence strategic OHS decisions. Role enactment appeared to be influenced by representatives’ expert power, job roles and the organisational role definition. Representatives operating under both managerial and worker defined HS representative systems, increased worker “voice” by providing an avenue to redress OHS concerns.

Practical implications

Implications arise for OHS policy, HS representative training courses and organisational/managerial support.

Originality/value

The paper presents a HS representative role typology distinctively based on cross‐perceptual data that also provides a more holistic perspective of the HS representative role by considering representatives’ purpose, role enactment and OHS impact.
Engineering compliance and worker resistance in UK further education
Authors: Mather Kim , Worrall Les , Mather Graeme
Published: August 2012

Purpose

The purpose of this paper is to explore control and resistance in the UK further education (FE) sector by examining senior college managers’ attempts to engineer culture change and analysing lecturers’ resistance to such measures.

Design/methodology/approach

Data were derived from interviews with managers and lecturers in two English FE colleges and the analysis of college documents. Interview data were analysed thematically using NVIVO software.

Findings

It was found that college managers sought to build consent to change among lecturers based on values derived from “business‐like” views. Culture change initiatives were framed within the language of empowerment but lecturers’ experiences of change led them to feel disempowered and cynical as managers imposed their view of what lecturers should be doing and how they should behave. This attempt to gain control of the lecturers’ labour process invoked the “Stepford” lecturer metaphor used in the paper. Paradoxically, as managers sought to create lecturers who were less resistant to change, individualised resistance intensified as managers’ attempts to win hearts and minds conspicuously failed.

Research limitations/implications

The paper draws on data from two case study colleges and this limits the generalisability of its findings.

Practical implications

The paper provides a critical perspective on the received wisdom of investing in stylised change programmes that promise to win staff over to change but which may alienate those they purport to empower and ultimately lead to degenerative workplace relations.

Originality/value

The paper offers new insights into culture change from the juxtaposed, polarised views of senior managers and lecturers, while highlighting the negative consequences of imposing change initiatives from above.
Satyagraha and employee relations
Authors: Mathew Saji K. , Jones Robert
Published: August 2012

Purpose

The purpose of this paper is to analyse the role of non‐violent protest (satyagraha) in a multinational automobile plant in India that has suffered from considerable employee relations problems.

Design/methodology/approach

The paper employs a case study of a Japanese‐owned company using data obtained from 30 personal interviews and from internet media sources.

Findings

It is found that workers initially pursued their protests through satyagraha‐style methods before taking on a more violent posture when company management refused to accept any notion of jointly seeking a new harmony. The reasons for these developments are explored.

Practical implications

The paper has implications for the manner in which scholars and practitioners view the respective roles, significance, and management of satyagraha and non‐satyagraha protest in Indian companies.

Originality/value

The importance of satyagraha in Indian employee relations is under‐researched in comparison with other factors, and is especially significant for culturally‐unaware multinational companies in successfully understanding and managing protest in the workplace context.
Hearing voice and silence during stressful economic times
Authors: Schlosser Francine , Zolin Roxanne
Published: August 2012

Purpose

It is ironic that in stressful economic times, when new ideas and positive behaviors could be most valuable, employees may not speak up, leading to reduced employee participation, less organizational learning, less innovation and less receptiveness to change. The supervisor is the organization's first line of defense against a culture of silence and towards a culture of openness. The purpose of this paper is to ask what helps supervisors to hear prosocial voice and notice defensive silence.

Design/methodology/approach

The authors conducted a cross‐sectional field study of 142 supervisors.

Findings

The results indicate that prosocial voice is increased by supervisor tension and trust in employees, while defensive silence is increased by supervisor tension but reduced by unionization of employees and trust in employees. This indicates that, as hypothesized by others, voice and silence are orthogonal and not opposites of the same construct.

Research limitations/implications

The data are measured at one point in time, and further longitudinal study would be helpful to further understand the phenomena.

Practical implications

This research highlights the potential for supervisors in stressful situations to selectively hear voice and silence from employees.

Social implications

This research also has implications for supervisors who work in a unionized environment. Although seemingly counter‐intuitive, there is a value to employee unionization in terms of either reducing the level of actual defensive silence, or at least reducing supervisors’ perceptions of defensive silence.

Originality/value

The paper adds to our knowledge of prosocial voice and defensive silence by testing supervisors’ perceptions of these constructs during difficult times. It provides valuable empirical insights to a literature dominated by conceptual non‐empirical papers. Limited research on silence might reflect how difficult it is to study such an ambiguous and passive construct as silence (often simply viewed as a lack of speech). The paper contributes also to trust literature by identifying its role in increasing supervisor's perceptions of prosocial voice and reducing perceptions of defensive silence.
Office building conversion and sustainable adaptation: a comparative study
Authors: Remøy Hilde T. , Wilkinson Sara J.
Published: August 2012

Purpose

The City of Melbourne seeks to retrofit 1,200 CBD properties by 2020 as part of the strategy to become carbon neutral, whilst Amsterdam aims to cut CO2 emissions 40 per cent by 2025. Oversupply in the Amsterdam office market makes conversion to residential use viable. In examining converted buildings in Amsterdam and the Melbourne CBD typical attributes of converted stock can be identified to target retrofit measures. This paper seeks to focus on these initiatives.

Design/methodology/approach

In Amsterdam five case studies were undertaken to reveal and define building attributes that explain the viability of these conversions. On the other hand, the Melbourne study was based on a database assembled containing all Melbourne CBD office building adaptations carried out between 1998 and 2008. The research analysed the conversion of office buildings and the scope for sustainable retrofit evaluating a limited number of attributes known to be important in adaptation.

Findings

The outcomes of this research showed similarities and differences in scope, which are relevant to all urban areas where adaptation of office buildings can mitigate the impacts of climate change and enhance a city for another generation of citizens and users.

Practical implications

The outcomes highlight the property attributes that explain conversion viability and that are most strongly associated with conversions. In addition the research identifies some sustainability measures that are possible with this type of stock.

Originality/value

The paper compares and contrasts qualitative data from a small sample of buildings in Amsterdam with quantitative data from a census of all change of use adaptations in Melbourne from 1998 to 2008. The contrasting approaches make it possible both to explain the driving forces of adaptations and to deliver statistical evidence of what is described in the case studies. Despite the differing approaches it is possible to compare and contrast the attributes of properties from both cities.
An empirical analysis of simplified valuation approaches for residential property tax purposes
Authors: Davis Peadar , McCluskey William , Grissom Terry V. , McCord Michael
Published: August 2012

Purpose

This paper seeks to examine the potential for simplified market value and non market value based banded approaches to be utilised for residential property tax purposes. The broad aim is to ascertain whether relatively low complexity approaches to establishing a property tax base can perform adequately in comparison to established best practice – in essence whether there is evidence of equifinality (equivalent performance from approaches of substantially different complexity) between simpler and more complex approaches.

Design/methodology/approach

The research comprises empirical analysis of a database of property sales and property attribute data drawn from a UK District Council area. Several simplified methods are used to create different tax base scenarios and the outflowing tax incidence is compared with that of using a complex, industry standard market value approach. The methods of comparison are regression and spline regression based models testing for tax inequity, drawn from the literature. The approach here differs from previous work in that it occurs at the actual tax bill level allowing the comparison of value, non‐value and banded approaches.

Findings

The findings of the research indicate that simplified approaches to establishing a property tax base can perform in a broadly similar fashion to more complex systems currently practiced in developed economies and therefore evidence of equifinality exists.

Practical implications

The research provides useful tools to property tax policy makers and practitioners in developing and transitional economies in furthering their aspirations of embedding robust property taxes for the furtherance of socio‐economic and political development and the general wellbeing of society and they are of value to property tax policy makers and to academics in the field.

Originality/value

The paper provides evidence of the efficacy of simplified and banded approaches as an option for jurisdictions in developing and transitional economic circumstances or elsewhere in circumstances which mitigate against full scale appraisal of the property tax base to discrete market values. The approaches and techniques pioneered open up opportunities to carry out a range of new comparative analysis of tax base options.
Wealth effect, credit price effect, and the inter‐relationships between Hong Kong's property market and stock market
Authors: Hui Eddie C.M. , Ng Ivan M.H.
Published: August 2012

Purpose

This paper aims to test the short‐ and long‐run interrelationships between Hong Kong's residential property market and stock market, as well as market fundamentals and China‐related factors, between 1990 and 2006.

Design/methodology/approach

The authors observed changes in the relationship between property prices and stock indexes by using Granger causality test, variance decomposition and CUSUM test. In contrast to some other studies, they have, at the same time, identified the break point(s) and variation of relation.

Findings

The findings reveal that the correlation between residential property price and stock index had become weaker over time, even though the trend of residential property price is similar to that of stock index during the sample period. Under such circumstances, it is more likely for investors to reap more benefits through portfolio diversifications.

Research limitations/implications

The credit price effect from the property market to the stock market, as observed between 1990 and 1994, has been replaced by a snowball effect within each of these two markets. In addition, stocks have become a hedge against inflation in the short‐run, while both stocks and real estate investments are utilized as such in the long‐run after 1995. Lastly, it appears that there are signs of interdependence between Hong Kong's stock market and the Chinese economy, whereas contagion might occur between China's economy and Hong Kong's property market.

Originality/value

The paper proffers some insights with regard to both real estate and stocks as investment options, and how closer integration between two regions (or nations) shape the interactions between various markets between them.
Measuring the impact of higher density housing development
Authors: Kupke Valerie , Rossini Peter , McGreal Stanley
Published: August 2012

Purpose

The introduction of higher density housing development within suburban areas has been favoured by state governments in Australia as a means of improving the efficiency of land use, reducing the costs associated with the delivery of government services and promoting home ownership. However it has been hypothesised that such development may have a negative impact on neighbourhood social structure, for example reducing diversity as measured by economic status and family makeup or in local housing market performance as measured by price. This paper aims to test this hypothesis.

Design/methodology/approach

The methodology employs a quantitative approach with principal components analysis used to capture the main social structure of the Adelaide Statistical Division. Social constructs, the product of principal components analysis, are used to measure outcomes of higher density development as measured by community or household change.

Findings

The results in this paper show that densification has had significant impact on certain neighbourhoods in the Adelaide Statistical Division notably in relation to their built form but not necessarily in neighbourhood structure or housing market performance.

Research limitations/implications

The findings are significant in highlighting that increasing medium densities and improving tenure mix may not necessarily improve the opportunities for socio‐economic mix or for cultural diversity with implications for policy makers seeking to follow strategies based on the promotion of mixed communities.

Originality/value

This paper seeks to add new research on the outcomes of higher density development in Australia in three ways. First, social constructs, the product of principal components analysis, are used to measure outcomes of higher density development as measured by community or household change. Second, the paper investigates the development at the local level where impacts are likely to be most important. Third, the analysis identifies a before and after scenario for those suburbs where higher density development has been most significant.