bluuebunny/crossref_metadata_2025 huggingface dataset:
Work culture within the hospital context in Canada: professional versus unit influences
Authors: Khokher Patricia , Lynn Bourgeault Ivy , Sainsaulieu Ivan
Published: June 2009

Purpose

This paper sets out to explore health professionals' views and experiences regarding the work culture that exists in their hospital units, and further how patients influence these experiences.

Design/methodology/approach

The paper employs a qualitative approach involving individual interviews with 60 health professionals in Canada employed in what is conceptualised as “open” (emergency room and maternity care) and “closed” (intensive care, head and neck surgery) units.

Findings

The paper finds that the influence of the hospital unit outweighs the influence of professional boundaries but for some groups more than for others. Health professionals in more open units tend to be less satisfied with their work, have more difficult relations with patients, and experience tensions with co‐workers and management. Those in closed units tend to be more satisfied with their work, have relatively better relations with patients and co‐workers, and tend to have more cooperative relations with management. The different structural conditions of work in open and closed units are also clearly important.

Research limitations/implications

The sample for the study was self‐selected from one hospital, which may limit the generalisability of some of the findings.

Practical implications

The insights garnered from the study may help professionals and managers to develop unit‐specific policies to create a more positive workplace culture.

Originality/value

There is a growing body of research on professional culture and oganisational culture that often does not clearly delineate how the two exist concurrently. The paper explicitly investigates this issue by examining work culture across various health professional groups and also across hospital units, and further how patients figure in these experiences.
Home care in transition: the complex dynamic of competing drivers of change in Norway
Authors: Vabø Mia
Published: June 2009

Purpose

This paper seeks to draw attention to the historical and institutional context of Norwegian home care and to the way in which care agencies have been pressed to reconcile competing demands caused by conflicting policy aims and administrative values. The paper also aims to explore how ideas of contractual management have been interpreted and put into practice in this field of tension.

Design/methodology/approach

The study draws on policy documents, historical and social research reports, and personal interviews with managers and home care staff from three different case studies representing different eras of management ideas. From this micro perspective the study examines professional work as the intersection between new public management and the health care state.

Findings

The findings demonstrate how contractual management is highly influenced by competing drivers of change. Reforms, stressing cost reduction, do not act as a unidirectional reform programme. Instead, they are infused with administrative arguments linked to previous reform ideas aiming to create legitimacy both from “above” and from “below”. The dynamic of change often has unintended consequences which in turn prompt further reform efforts.

Originality/value

The paper provides insights into the complexity of change following on from New Public Management (NPM). More specifically, change is characterised by tensions originating in competing normative drivers as well as the co‐existence of old and new forms of organising.
User involvement in Finland: the hybrid of control and emancipation
Authors: Leppo Anna , Perälä Riikka
Published: June 2009

Purpose

The new “agenda of choice” in public services emphasises service users' needs and agency. The ideals of consumerism and user involvement have set new challenges for professionals. This paper aims to explore the effects of consumerism and user involvement at the level of day‐to‐day service delivery, looking at the encounters between professionals and service users.

Design/methodology/approach

The paper applies an ethnographic approach. Observation data were collected at two Finnish drug treatment institutions: a needle exchange and health counselling service, and a specialised maternity clinic for pregnant women. Data from each institution consist of seven to 12 months of participant observation notes, which were subsequently systematically coded and analysed comparing the two institutions.

Findings

The promotion of new ideals does not automatically result in the empowerment of service users or the erosion of professional power. The two institutions differ greatly: institutional context and gender shape the everyday realisation of the new ideals. In both institutions, however, professionals have adopted new practices and rethought their role. The cultivation of service users' choice and agency can become valuable professional capital, a new kind of “know how” that can also be used by the professionals to justify the importance of their work.

Originality/value

The paper provides a nuanced and contextualised insight into “how” the ideals of consumerism and user involvement are translated into everyday encounters between service providers and users.
“Pseudo‐scientific hokus pokus”: motivational research's Australian application
Authors: McLeod Amanda
Published: June 2009

Purpose

The purpose of this paper is to examine motivational research (MR) – the most maligned and misunderstood branch of market research. It argues that MR has been too easily dismissed by researchers. In so doing, they have ignored a potentially significant insight into the post World War II consumer's motivations and domestic life.

Design/methodology/approach

This paper utilises previously unexamined primary source material to examine David T. Bottomley's construction of MR.

Findings

By looking at in‐depth market research studies, a greater, more rounded picture of the postwar consumer can be gained. Throughout the 1960s, some market researchers turned to consumer motivations to uncover the psychological dimensions of purchasing behaviour by determining the symbolic meanings goods had to their consumers. Rather than viewing consumer behaviour as predictable by factors such as economic class, motivational researchers held that consumers are multi‐faceted subjects and life‐stage and attitudes to colour are important factors influencing consumer behaviour.

Research limitations/implications

Research that considers consumer motivations should not be so easily dismissed as deceptive or corruptive research without genuine merit for historical research. Nor should Dichter's style of research be considered to be the only version of MR.

Originality/value

Previous scholars have largely ignored the significance of market research to the development of the consumer market and the construction of the postwar consumer. Given the dearth of scholarly examinations, the paper is based almost entirely on primary research data.
The Americanization of Italian advertising during the 1950s and the 1960s
Authors: De Iulio Simona , Vinti Carlo
Published: June 2009

Purpose

The purpose of this paper is to focus on the Americanization of European advertising in the post‐war years as a phenomenon of cultural transfer and it aims to explore the interaction between the USA and Italian advertising traditions during the 1950s and the 1960s.

Design/methodology/approach

The analysis is in two parts. First, the role of those cross‐cultural mediators who contributed to changing marketing communication strategies of many Italian companies during the 1950s and the 1960s is studied. Second, the ways in which US advertising rules and patterns are combined with the local tradition in order to fit the Italian context of the post‐war years are looked at. The research is based on a study of the main USA and Italian marketing and advertising literature of the post‐war years, and on an analysis of press campaigns and TV commercials.

Findings

This research shows that during the 1950s and the 1960s, the conflict between the American approach and the Italian approach to advertising did not prevent interaction and negotiation. In the post‐war years, the USA know‐how and practices, are re‐interpreted through the process of transfer to Italy, creating original, and unexpected solutions.

Originality/value

Although some research has been conducted on the Italian advertising scene during the post‐World War II years, the few existing contributions did not focus on the interaction between the imported American model and the local traditions. This paper provides a good overview of the ways in which notions, methodologies, and strategies coming from the USA are implemented.
Editing The History of Marketing Thought
Authors: Tadajewski Mark
Published: June 2009

Purpose

This paper aims to be a reflection on the production of The History of Marketing Thought.

Design/methodology/approach

Historical review.

Findings

Marketing has been largely ahistorical. Hopefully with the production of this collection, it will become less so as students and scholars alike engage with the history of marketing thought.

Research limitations/implications

Some possible limitations of the collection are outlined.

Practical implications

The major work articulates the value of historical research for marketing and management practice.

Originality/value

This paper reflects a personal perspective on the production of a collection of scholarly articles.
Reflections on The History of Marketing Thought
Authors: Shaw Eric H.
Published: June 2009

Purpose

The purpose of this paper is to stimulate historical thinking in dealing with problems of marketing thought, by explaining the advantages of studying the history of a discipline's ideas; examining what has been included in prior histories; and evaluating the completeness of coverage in Tadajewski and Jones' (2008) The History of Marketing Thought.

Design/methodology/approach

This paper presents a comparative analysis based upon prior histories of marketing thought.

Findings

For teaching, with modest supplementation, The History of Marketing Thought provides a full appreciation of the intellectual heritage of marketing. For research purposes, The History of Marketing Thought does reasonably well in organizing concepts and theories into schools of marketing thought but less well in showing how these ideas can be organized across the readings to produce new knowledge.

Practical implications

There were some important omissions in the collection. Marketing's leading thinker was largely neglected and many significant problems for marketing thought are overlooked. There was no discussion of methodological issues and minimal editorial commentary connected the parts and sections to provide a research thrust to the work. Consequently, it is recommended that another volume or two be added to this set.

Originality/value

The educational value of this work is in transmitting the knowledge base of the discipline from one generation of marketing scholars to the next. It is only after the ideas developed by earlier marketing thinkers are fully understood that innovative theories can be constructed and new knowledge created.
Subject trends in The History of Marketing Thought: from simplicity towards complexity
Authors: Svensson Göran
Published: June 2009

Purpose

The purpose of this paper is to describe and position the work by Tadajewski and Jones on The History of Marketing Thought as it relates to complexity sciences and the future of marketing thought.

Design/methodology/approach

A conceptual discussion is provided based upon a series of identified subject trends in the history of marketing thought.

Findings

There appears to be a common denominator across the addressed subject trends in The History of Marketing Thought, namely the movement from simplicity towards complexity. Marketing thought is mostly descriptive, and to some extent explanatory, but it has not yet reached the level of providing predictability.

Research limitations/implications

The future of marketing thought may benefit from the inclusion and inspiration of approaches derived from the complexity sciences.

Practical implications

The author poses some concerns regarding the future of marketing thought.

Originality/value

The author contends that there is a need for attention to be paid to the evident movement from simplicity towards complexity in marketing thought.
The case for megapolitan growth management in the twenty‐first century
Authors: Ziegler Edward H.
Published: June 2009

Purpose

The purpose of this paper is to demonstrate significant problems in the US' development pattern of regional automobile‐dependent sprawl and local growth management and to make suggestions about adopting a regional growth management model that might better provide for more sustainable development of the built environment.

Design/methodology/approach

This paper reviews trends in the USA and elsewhere to determine the negative effects of the current system of sprawl and the potential benefits of developing higher‐density urban centers. The paper also looks to models in some US cities and Europe to further analyze potential legal and political issues related to this type of regional sustainable development.

Findings

Unsustainable, automobile‐dependent regional sprawl is a result of local zoning, growth management, and parking programs and has negative effects both now and for the future. The result has been more time, money, and resources wasted in automobile transit instead of new planning models that would lead to a more sustainable and less automobile‐dependent future.

Practical implications

A metropolitan sustainable development governing framework for growth management in the twenty‐first century is essential for a sustainable future. This includes higher‐density urban centers, transit‐oriented development centers, and a change in public attitude away from “not in my back yard” thinking.

Originality/value

This paper provides the potential benefits of creating a metropolitan governing framework to identify and regulate “growth areas” in a region. It further demonstrates how linking these areas to regional transit planning will help achieve the development of higher‐density, mixed use, and intensive urban core job/housing areas where people could live, work, shop, and play without the use of the automobile.
The New South Wales strata and Community Titles Acts
Authors: Sherry Cathy
Published: June 2009

Purpose

The purpose of this paper is to present a case study of the legislative creation of high rise and master planned communities to provide a common basis for future discussions, research and international comparison in the field.

Design/methodology/approach

The case study addresses relevant legislation in the Australian state of New South Wales. This has been a model for that in other jurisdictions, including Singapore, the UK and the Dubai International Financial Centre. The legal terms and their significance are discussed in a way that is comprehensible to both lawyers and non‐lawyers.

Findings

The legislation is shown to have achieved a range of outcomes that are not possible in ordinary Anglo‐Australian property law. For example, it has created governing “bodies corporate” which regulate communities with private by‐laws and facilitates the continued enforcement of detailed architectural guidelines imposing a master plan.

Research limitations/implications

The research describes the legal framework for the creation of communities in a single jurisdiction. More research is needed on the specific way that legal structures hinder or promote satisfactory community living in this and in other jurisdictions.

Originality/value

The paper will aid discussions between a range of academics and practitioners working on high rise and master planned communities. It will assist communication between lawyers and non‐lawyers, providing a clear description of the significance of legislation in the creation of communities. It will facilitate transnational discussion, as differences in legal systems and inconsistent terminology are a barrier to effective communication and common understanding.
An analysis of the key challenges to the widespread use of mediation in the Turkish construction industry
Authors: Ilter Deniz , Dikbas Attila
Published: June 2009

Purpose

The Turkish Ministry of Justice submitted the Draft Law on mediation in legal disputes, which was predicated on the European Council (EC) Directive on certain aspects of mediation in civil and commercial matters, to the Turkish Parliament in June 2008. Contentious arguments have followed on the provisions of the Draft Law as well as on the overall applicability of mediation in Turkey. The purpose of this paper is to examine the context surrounding the new mediation phenomenon in order to identify the key challenges awaiting its widespread use in the Turkish construction industry.

Design/methodology/approach

Two complementary approaches were adopted in this paper. First, an analysis of the most debated papers of the Draft Law is carried out to determine the potential problems associated with the legislation by making comparisons with the EC mediation directive and mediation laws in some of the member states. Second, a series of structured interviews are organized among the Turkish construction industry to gain better insight on prevalent perceptions of mediation, assess pertinent demand and determine the sector specific challenges.

Findings

The comparative analysis of the Draft Law and the empirical results obtained from the industry indicate a promising platform for the deployment of mediation. However, the adverse attitude of lawyers, inadequate financial incentives, the lack of an industry specific institutional framework and low level of knowledge on mediation in the industry hinder wide acceptance despite the growing interest, as evidenced in the results of the interviews.

Originality/value

This paper is aimed to be a timely contribution to the process of the establishment of mediation in the Turkish construction industry. The paper provides a comprehensive analysis of the Draft Law through comparison with other legislation and furnishes original data on the perceptions of mediation in the Turkish construction industry in the quest for making projections for its further development.
The Portuguese building regulation system: a critical review
Authors: Branco Pedro João , Meijer Frits , Visscher Henk
Published: June 2009

Purpose

The purpose of this paper is to provide a critical review of the building regulations and the building control system in Portugal. The organisation, content, and authorities responsible for building regulations are described and an overview is provided of the main stages of the building permit procedure.

Design/methodology/approach

The paper reviews the relevant legal and regulatory provisions and discusses these in the context of commentary published by the various professional associations.

Findings

The Portuguese building regulation system has undergone significant changes in the last 20 years. Almost all building regulations currently in force are approved during that period. Some of these are resulted from the implementation of European Directives. Others are changed due to advances in scientific knowledge. Changes in the building control system have mainly been driven by the changing demands of present‐day practice, in particular, the absence of sufficient municipal technicians, and the need to expedite building control procedures. The solution has been to move away from public building control and to make private parties responsible for compliance with building regulations. The paper concludes that, although there have been significant improvements in the building regulation system over recent years, two structural problems nevertheless persist. First, building regulations continue to be complex and fragmented, and second the qualifications of technicians are still not adequately defined.

Originality/value

A structured overview of the system is provided and the main weaknesses are identified. The proposals for change are suggested by professional associations are summarised, and possible improvements are suggested.
Gahnite Devitrification in Ceramic Frits: Mechanism and Process Kinetics
Authors: Escardino A. , Amorós J. L. , Gozalbo A. , Orts M. J. , Moreno A.
Published: July 2009

Devitrification of a frit (glass) based on the oxide system SiO2–Al2O3–ZnO–CaO was studied. The following major crystalline phases were identified: gahnite (ZnAl2O4), willemite (Zn2SiO4), and a solid solution exhibiting an anorthite structure. A kinetic model was used to fit the experimental results. The model was derived by assuming that a precursor phase with an anorthite crystalline structure devitrified first and subsequently decomposed to form gahnite, while willemite crystallized independently. The proposed model satisfactorily reproduced the amount of gahnite, willemite, and anorthite‐type crystals that formed during firing. The equations developed allowed the prediction of the anorthite structure, gahnite, and willemite crystal volume fractions in the resulting glaze as a function of firing temperature and time.
In situ Growth of SiC Whisker in Pyrolyzed Monolithic Mixture of AHPCS and SiC
Authors: Zheng Jing , Kramer Matthew J. , Akinc Mufit
Published: July 2009

In situ whisker growth was observed during heat treatment of allylhydridopolycarbosilane (AHPCS) and SiC powder in the temperature range of 1250°–1350°C. TEM equipped with an electron energy loss spectrometer (EELS) verified that the banded whiskers are twinned single‐grained β‐SiC. Convergent beam electron diffraction patterns (CBED) of the whisker tips were consistent with formation by a vapor–solid (VS) mechanism. The effects of process variables on whisker growth were addressed. The mechanism of whisker growth was discussed and attributed to the reaction between the gaseous products of the polymers AHPCS and polycarbosilane (PCS). Thermal decomposition behavior of the polymers was followed to relate gas evolution to whisker formation.
High‐Temperature Mechanical Properties of Si‐B‐C‐N‐Precursor‐Derived Amorphous Ceramics and the Applicability of Deformation Models Developed for Metallic Glasses
Authors: Christ Martin , Thurn Günter , Weinmann Markus , Bill Joachim , Aldinger Fritz
Published: July 2009

The characterization of Si‐B‐C‐N amorphous ceramics using isothermal compression creep testing in the temperature range of 1200°–1500°C is reported. The deformation rate contains a stress‐dependent component that is proportional to the applied stress, which indicates that this portion of the deformation mechanism is based on viscous flow. An increase in the creep resistance is observed, following either preliminary annealing or hot isostatic pressing, which may be explained by a reduction of free volume in the amorphous material. The application of two deformation models that are used to predict similar deformation behavior in metallic glasses also is discussed. Although both models accurately predict the time dependence of the deformation rate of precursor‐derived amorphous ceramics, the free‐volume model fits the observed temperature dependence better than the “two‐step” rearrangement model.
Influence of Fe3+/Fe2+ Ratio on the Crystallization of Iron‐Rich Glasses Made with Industrial Wastes
Authors: Karamanov Alexander , Pisciella Paola , Cantalini Carlo , Pelino Mario
Published: July 2009

The influence of the Fe3+/Fe2+ ratio on the crystallization of iron‐rich glasses was investigated in this study. The glass batches were made from two hazardous industrial wastes: mud (goethite and jarosite) originating from the zinc hydrometallurgical process and electric arc furnace dust (EAFD). Glass compositions were prepared by adding different percentages of carbon powder. The crystallization process was investigated by a combined thermogravimetry/differential thermal analysis technique, in air or nitrogen atmospheres, using powder and bulk glass samples. The crystalline phases formed, i.e., pyroxene and spinels, and their relative ratio were determined by X‐ray diffractometry. The experimental results indicated that melting temperature and crystallization behavior were influenced by the initial Fe3+/Fe2+ ratio and by the amount of carbon added to the glass batch. For goethite and jarosite glass compositions, decreasing the Fe3+/Fe2+ ratio increased the crystallization rate by favoring magnetite formation. For EAFD glass compositions, the addition of carbon to the batch inhibited chromite–magnetite spinel formation and favored the attainment of an amorphous glassy phase.
Stress Rupture in Ceramic‐Matrix Composites: Theory and Experiment
Authors: Halverson Howard G. , Curtin William A.
Published: July 2009

A micromechanically based model for the deformation, strength, and stress‐rupture life of a ceramic‐matrix composite is developed for materials that do not degrade by oxidative attack. The rupture model for a unidirectional composite incorporates fiber‐strength statistics, fiber degradation with time at temperature and load, the state of matrix damage, and the effects of fiber pullout, within a global load sharing model. The constituent material parameters that are required to predict the deformation and lifetime can all be obtained independent of stress‐rupture testing through quasi‐static tension tests and tests on the individual composite constituents. The model predicts the tertiary creep, the remaining composite strength, and the rupture life, all of which are dependent critically on the underlying fiber‐strength degradation. Sensitivity of the rupture life to various micromechanical parameters is studied parametrically. To complement the model, an extensive experimental study of stress rupture in a Nextel 610/alumina–yttria composite at temperatures of 950° and 1050°C is reported. The Larson–Miller and Monkman–Grant life‐prediction methods are inadequate to explain the current data. Constituent parameters for this material system are derived from quasi‐static tests and literature data, and the micromechanical model predictions are compared with measured behavior. For a slow‐crack‐growth model of fiber‐strength degradation, the lifetime predictions are shorter by two orders of magnitude. When the rupture life is fitted with one parameter, however, the model prediction of the tertiary creep and residual strength at 1050°C agrees well with the experimental results. For a more complex degradation model, the rupture life and tertiary creep at 1050°C can be predicted quite well; however, the spread in residual strength is not, and the lifetimes at 950°C are greatly overpredicted. Thus, the micromechanical model can be successful quantitatively but clearly shows that the rupture life of the composite is extremely sensitive to the detailed mechanisms of fiber degradation. The model has practical applications for extrapolating laboratory lifetime data and predicting life in components with evolving spatial stresses.
Variations in a Boehmite Gel and Oleic Acid Emulsion under Calcination
Authors: Lin Chih‐Peng , Wen Shaw‐Bing
Published: July 2009

In this paper, we describe variations in a boehmite (AlOOH) and oleic acid emulsion during the process of forming superfine α‐Al2O3 crystallites from the mixture of oleic acid and a boehmite gel precursor. We also propose that the oleic acid decomposes under calcination, generating carbon, which can effectively prevent agglomeration of Al2O3 particles. Calcination for the present study was conducted under a reduced oxygen atmosphere, in the temperature range 25°–1100°C. Phase variations of the mixture under calcination were identified by Fourier transform infrared spectrometry (FTIR), X‐ray diffractometry (XRD), and transmission electron microscopy (TEM). The FTIR spectra were used when the mixed emulsion of oleic acid and boehmite gel was heated, to investigate the adsorption reaction of the aluminum oleate; the C—O—C cross‐linking structure of oxygenation, which aided in carbon formation; and the ability of the carbon generated with α‐Al2O3 during phase transformation to prevent agglomeration (vermicularity). The products were analyzed by XRD at different temperatures, and TEM was used to examine the individual diameters of the α‐Al2O3 crystallites.
Permeability of High‐Alumina Refractory Castables Based on Various Hydraulic Binders
Authors: Innocentini Murilo D. M. , Pardo Arturo R. F. , Pandolfelli Victor C. , Menegazzo Bruno A. , Bittencourt Luis R. M. , Rettore Roberto P.
Published: July 2009

This work investigated the changes in the permeability of high‐alumina self‐flowing refractory castables based on calcium aluminate cement (CAC) and hydratable alumina binder (HAB) pretreated between 110° and 1650°C. Permeability constants k1 and k2 were fitted from Forchheimer's equation based on airflow tests conducted at room temperature. The results indicated that dehydration was the main contributing factor for increased permeability in bodies pretreated up to 600°C and that sintering effects prevailed between 900° and 1650°C. Castables based on HAB were less permeable than those based on CAC, a behavior ascribed to the type of hydrates formed and to the particle‐packing features of the matrix and the matrix–aggregate interfaces.
Ab Initio Calculations of Pristine and Doped Zirconia Σ5 (310)/[001] Tilt Grain Boundaries
Authors: Mao Zugang , Sinnott Susan B. , Dickey Elizabeth C.
Published: July 2009

The structure of the cubic‐ZrO2 symmetrical tilt Σ5 (310)/[001] grain boundary is examined using density functional theory within the local density and pseudopotential approximations. Several pristine stoichiometric grain‐boundary structures are investigated and compared with Z‐contrast scanning transmission electron microscopy and electron energy loss spectroscopy results. The lowest‐energy grain‐boundary structure is found to agree well with the experimental data. When Y3+ is substituted for Zr4+ at various sites in the lowest‐energy grain‐boundary structure, the calculations indicate that Y3+ segregation to the grain boundary is energetically preferred to bulk doping, in agreement with experimental results.
Influence of Threshold Stress on the Estimation of the Weibull Statistics
Authors: Lu Chunsheng , Danzer Robert , Fischer Franz Dieter
Published: July 2009

The influence of threshold stress on the estimation of the Weibull statistics is discussed in terms of the Akaike information criterion. Numerical simulations show that, if sample data are limited in number and threshold stress is not too large, the two‐parameter Weibull distribution is still a preferred choice. For example, the fit of strength data of glass and ceramics to the two‐ and three‐parameter Weibull distributions is compared.
Spark Plasma Sintering of Alumina
Authors: Shen Zhijian , Johnsson Mats , Zhao Zhe , Nygren Mats
Published: July 2009

A systematic study of various spark plasma sintering (SPS) parameters, namely temperature, holding time, heating rate, pressure, and pulse sequence, was conducted to investigate their effect on the densification, grain‐growth kinetics, hardness, and fracture toughness of a commercially available submicrometer‐sized Al2O3 powder. The obtained experimental data clearly show that the SPS process enhances both densification and grain growth. Thus, Al2O3 could be fully densified at a much lower temperature (1150°C), within a much shorter time (minutes), than in more conventional sintering processes. It is suggested that the densification is enhanced in the initial part of the sintering cycle by a local spark‐discharge process in the vicinity of contacting particles, and that both grain‐boundary diffusion and grain‐boundary migration are enhanced by the electrical field originating from the pulsed direct current used for heating the sample. Both the diffusion and the migration that promote the grain growth were found to be strongly dependent on temperature, implying that it is possible to retain the original fine‐grained structure in fully densified bodies by avoiding a too high sintering temperature. Hardness values in the range 21–22 GPa and fracture toughness values of 3.5 ± 0.5 MPa·m1/2 were found for the compacts containing submicrometer‐sized Al2O3 grains.
Synthesis and Sintering of Large Batches of Barium Zirconate Nanopowders
Authors: Sin Agusti , El Montaser B. , Odier Philippe , Weiss F.
Published: July 2009

The acrylamide gelification process is a fast, inexpensive, reproducible, and easily scaled up chemical method for obtaining nanopowders of BaZrO3 that can be used for sintering crucibles and many electronic applications. This method enables the production of 100 g of high‐purity powders in one run, using simple laboratory equipment and low‐cost raw materials. The gelification process, synthesis temperature, and gas conditions required for obtaining high‐quality powders were the subjects of the present study. Fine powders were sintered to full density at 1450°C, making the fabrication of BaZrO3 crucibles possible for many laboratories.
Microstructures and Pyroelectric Properties of Multicomposition 0.9PbZrO3·xPbTiO3·(0.1−x)Pb(Zn1/3Nb2/3)O3Ceramics
Authors: Wu Yong Jun , Uekawa Naofumi , Sasaki Yoshinori , Kakegawa Kazuyuki
Published: July 2009

The microstructures and pyroelectric properties of multicomposition 0.9PbZrO3·xPbTiO3·(0.1−x)Pb(Zn1/3Nb2/3)O3(PZ–PT–PZN) ceramics were investigated. The PZ–PT–PZN ceramics with nearly theoretical density were prepared by spark plasma sintering at low temperature (800°C) for a very short time (10 min) from two original compositions withx= 0.025 andx= 0.050. The heat treatment was successfully used to control the diffusion between the different compositions in such ceramics. For ceramics heat‐treated at 900°C, two pyroelectric peaks corresponding to the original compositions were observed. When the heat‐treatment temperature was increased to 1200°C, these two pyroelectric peaks combined into one sharp pyroelectric peak, which corresponds to average composition. When the spark‐plasma‐sintered ceramics were heat‐treated at 950°C, a high and stable pyroelectric coefficient (>100 nC·cm−2·K−1) over a wide temperature range (23°–47°C) was obtained. It was found that the pyroelectric properties strongly depended on the microstructures.
Effect of Weave Architecture on Tensile Properties and Local Strain Heterogeneity in Thin‐Sheet C–SiC Composites
Authors: Berbon Min Z. , Rugg Kevin L. , Dadkhah Mahyar S. , Marshall David B.
Published: July 2009

Room‐temperature tensile properties were measured for two thin C–SiC composites fabricated from single sheets of carbon fiber fabric with nominally the same weave architecture, but different fiber packing densities. The SiC matrixes were formed by infiltration and pyrolysis of a polymer precursor (allylhydridopolycarbosilane). The tensile properties are related to microstructural characteristics, observed damage mechanisms, and measurements of local strain concentrations by speckle interferometry. Differences are observed between the responses of these thin‐sheet composites and conventional CVI‐matrix composites of larger thickness. Debonding between transverse and longitudinal fiber tows allows significant strains due to straightening of initial wavy fiber tows and leads to local stress concentrations. The strength and elastic modulus are affected by the waviness of the longitudinal tows.
Stepwise‐Graded Si3N4–SiC Ceramics with Improved Wear Properties
Authors: Thompson Scott C. , Pandit Anjali , Padture Nitin P. , Suresh Subra
Published: July 2009

The processing of stepwise graded Si3N4/SiC ceramics by pressureless co‐sintering is described. Here, SiC (high elastic modulus, high thermal expansion coefficient) forms the substrate and Si3N4 (low elastic modulus, low thermal expansion coefficient) forms the top contact surface, with a stepwise gradient in composition existing between the two over a depth of ∼1.7 mm. The resulting Si3N4 contact surface is fine‐grained and dense, and it contains only 2 vol% yttrium aluminum garnet (YAG) additive. This graded ceramic shows resistance to cone‐crack formation under Hertzian indentation, which is attributed to a combined effect of the elastic‐modulus gradient and the compressive thermal‐expansion‐mismatch residual stress present at the contact surface. The presence of the residual stress is corroborated and quantified using Vickers indentation tests. The graded ceramic also possesses wear properties that are significantly improved compared with dense, monolithic Si3N4 containing 2 vol% YAG additive. The improved wear resistance is attributed solely to the large compressive stress present at the contact surface. A modification of the simple wear model by Lawn and co‐workers is used to rationalize the wear results. Results from this work clearly show that the introduction of surface compressive residual stresses can significantly improve the wear resistance of polycrystalline ceramics, which may have important implications for the design of contact‐damage‐resistant ceramics.
Direct Ink‐Jet Printing of Vertical Walls
Authors: Zhao Xinglong , Evans Julian R. G. , Edirisinghe Mohan J. , Song Jin‐Hua
Published: July 2009

Direct jet printing can assemble ceramic powder into a three dimensional shape by firing droplets of ink through a nozzle to build a multiple layered structure. As with stereolithography and selective laser sintering, the surface texture is expected to witness the layered assembly. The ability to create vertical walls by direct ink‐jet printing was explored using a test piece based on a maze. The structure and topography are discussed in terms of droplet spreading and drying.
Prediction of Rare‐Earth A2Hf2O7 Pyrochlore Phases
Authors: Stanek Christopher R. , Grimes Robin W.
Published: July 2009

Within the series of A2O3‐HfO2 phase diagrams (A ranges in cationic radius from Lu3+ to La3+), only those from Gd2Hf2O7 to La2Hf2O7 are known to exhibit a pyrochlore phase field. For A cations smaller than Gd3+, only a disordered fluorite phase field exists. Disorder energies for the entire series of pyrochlore oxides have been determined via atomistic simulation. These energies can be correlated to the order‐disorder temperatures from the phase diagrams. Consequently, we predict the existence of hitherto unobserved pyrochlores: Dy2Hf2O7, Ho2Hf2O7, and Er2Hf2O7.
Reactive Synthesis of a Porous Calcium Zirconate/Spinel Composite with Idiomorphic Spinel Grains
Authors: Suzuki Yoshikazu , Kondo Naoki , Ohji Tatsuki
Published: July 2009

Porous CaZrO3/MgAl2O4 composites were synthesized in air by pressureless reactive sintering of an equimolar mixture of dolomite (CaMg(CO3)2), monoclinic zirconia (m‐ZrO2), and α‐alumina powders, with a 0.5 wt% lithium fluoride additive. The reaction behavior of the mixed powders (with/without LiF additive) was studied using high‐temperature X‐ray diffraction. A bulk porous composite resulted from sintering at 1300°C for 2 h (in a nearly closed container, so as to increase the LiF‐doping effect), which consisted of fine grains (CaZrO3 and MgAl2O4, ∼0.5–1 μm) and well‐grown idiomorphic ones (MgAl2O4 octahedra ∼ 2–4 μm). The idiomorphic spinel grains were located around the inner walls of relatively large pores. The composite showed appreciably high bending strength (σf= 110 ± 8 MPa for a porosity of 31%). The porous CaZrO3/MgAl2O4 composites can be applied as high‐temperature filters and lightweight structural components.
Photocatalytic Activity of Monodispersed Spherical TiO2 Particles with Different Crystallization Routes
Authors: Cho Churl Hee , Kim Do Kyung , Kim Do Hyeong
Published: July 2009

Monodispersed spherical TiO2 particles were prepared by hydrothermal crystallization and/or calcination of spherical amorphous particles, synthesized by thermal hydrolysis of TiCl4. The crystallized spherical particles were secondary agglomerates of primary nanocrystallites. Different crystallization routes and conditions provided the spherical TiO2 particles with wide particle characteristics, such as the fraction of crystallization, the size and shape of the primary nanocrystallites, and the specific surface area. The photocatalytic activity showed complex dependence on the crystallization routes and conditions. The complex dependence behavior could be explained by combining the effects of the fraction of crystallization, the specific surface area, and the adsorption ability for hydroxyl ions. Especially, in the present study, the hydrothermally crystallized TiO2 particles with large primary nanocrystallites showed the highest photocatalytic activity. The high photocatalytic activity mainly resulted from the high surface adsorption ability for hydroxyl ions, which was closely related to the well‐developed (flat and faceted) morphology of primary nanocrystallite.
Dispersing Behavior of Hydroxyapatite Powders Produced by Wet‐Chemical Synthesis
Authors: Pretto Michele , Costa Anna Luisa , Landi Elena , Tampieri Anna , Galassi Carmen
Published: July 2009

Three hydroxyapatite powders with different surface properties were produced by wet‐chemical synthesis and characterized. The electrokinetic properties of powders dispersed in water were investigated by electroacoustic spectroscopy measurements. The different surface reactivity (pHiep and ζ potential versus pH curves) was related to the interplay of dissolution and adsorption of Ca2+ ions. With a view toward the preparation of porous bodies by sponge impregnation, the behavior of powder suspensions was studied. Four deflocculants were tested, and the optimum dispersing conditions for each powder were found. Anionic polyelectrolytes resulted in the best effective dispersing agent, with different optimum amounts added to the suspensions.
Formation of β‐Silicon Nitride Crystals from (Si,Al,Mg,Y)(O,N) Liquid: II, Population Dynamics and Coarsening Kinetics
Authors: Wang Lingling , Tien Tseng‐Ying , Chen I‐Wei
Published: July 2009

Precipitation, growth, and coarsening of Si3N4 crystals in (Si,Al,Mg,Y)(O,N) liquids at 1680°C has been studied. Contrary to the common observation in kinetics, coarsening rates of crystals in length and width are found to accelerate when the total volume of crystals remains little changed. This is attributed to the concomitant β‐Si3N4 to β′‐SiAlON transformation, which introduces an additional driving force for crystal dissolution and reprecipitation. As a result of the additional driving force, which has a nonmonotonic size dependence, the normalized size distribution is expected to evolve with time, initially broadening, then shifting skewing as the transformation passes the midpoint, and finally converging to a sharp distribution as the transformation completes. These evolutions have been observed in all the compositions studied.
Long‐term survival and late relapse in 2‐year survivors of autologous haematopoietic cell transplantation for Hodgkin and non‐Hodgkin lymphoma
Authors: Majhail Navneet S. , Bajorunaite Ruta , Lazarus Hillard M. , Wang Zhiwei , Klein John P. , Zhang Mei‐Jie , Rizzo J. Douglas
Published: July 2009

This study described long‐term outcomes of autologous haematopoietic‐cell transplantation (HCT) for advanced Hodgkin (HL) and non‐Hodgkin lymphoma (NHL). The study included recipients of autologous HCT for HL (N = 407) and NHL (N = 960) from 1990–98 who were in continuous complete remission for at least 2 years post‐HCT. Median follow‐up was 104 months for HL and 107 months for NHL. Overall survival at 10‐years was 77% (72–82%) for HL, 78% (73–82%) for diffuse large‐cell NHL, 77% (71–83%) for follicular NHL, 85% (75–93%) for lymphoblastic/Burkitt NHL, 52% (37–67%) for mantle‐cell NHL and 77% (67–85%) for other NHL. On multivariate analysis, mantle‐cell NHL had the highest relative‐risk for late mortality [2·87 (1·70–4·87)], while the risks of death for other histologies were comparable. Relapse was the most common cause of death. Relative mortality compared to age, race and gender adjusted normal population remained significantly elevated and was 14·8 (6·3–23·3) for HL and 5·9 (3·6–8·2) for NHL at 10‐years post‐HCT. Recipients of autologous HCT for HL and NHL who remain in remission for at least 2‐years have favourable subsequent long‐term survival but remain at risk for late relapse. Compared to the general population, mortality rates continue to remain elevated at 10‐years post‐transplantation.
Mechanisms underlying acquired von Willebrand syndrome associated with an IgM paraprotein
Authors: Mayerhofer M. , Haushofer A. , Kyrle P. A. , Chott A. , Müllner C. , Quehenberger P. , Worel N. , Traby L. , Eichinger S.
Published: July 2009

Acquired von Willebrand (vW) syndrome is a rare bleeding disorder which is frequently associated with immunological, malignant or cardiovascular disorders. The underlying pathomechanisms, particularly in patients with IgM monoclonal gammopathies, often remain unknown. We report a patient with indolent small B‐cell lymphoma (immunocytoma) and plasmacytic differentiation with an IgM κ paraprotein who was admitted with retroperitoneal haematoma. Medical history and coagulation testing were consistent with acquired vW syndrome. vW immunohistochemistry showed normal cytoplasmic labelling of endothelial cells and megakaryocytes, whereas the lymphomatous infiltrate was negative. Acquired vW syndrome due to adsorption of vW factor on malignant cells was thus excluded. In the multimeric analysis, all multimers were present similar to that in type 1 vW syndrome, but the triplet structures were blurred. The bands on serum immunofixation electrophoresis were also atypically broadened, which suggested complex formation between the IgM and vW factor. Immunoprecipitation studies showed that the 176‐kDa proteolytic fragment of vW factor co‐precipitated with the IgM paraprotein in the patient but not in the controls, suggesting a specific interaction between vW factor and the paraprotein in the patient. The patient required surgery and was successfully managed by chemotherapy consisting of rituximab and fludarabin as well as plasma exchange.
Increased temperature and precipitation interact to affect root production, mortality, and turnover in a temperate steppe: implications for ecosystem C cycling
Authors: BAI WENMING , WAN SHIQIANG , NIU SHULI , LIU WEIXING , CHEN QUANSHENG , WANG QIBING , ZHANG WENHAO , HAN XINGGUO , LI LINGHAO
Published: July 2009

Fine root production and turnover play important roles in regulating carbon (C) cycling in terrestrial ecosystems. In order to examine effects of climate change on root production and turnover, a field experiment with increased temperature and precipitation had been conducted in a semiarid temperate steppe in northern China since April 2005. Experimental warming decreased annual root production, mortality, and mean standing crop by 10.3%, 12.1%, 7.0%, respectively, while root turnover was not affected in 2006 and 2007 by the warming. Annual root production and turnover was 5.9% and 10.3% greater in the elevated than ambient precipitation plots. Changes in root production and mortality in response to increased temperature and precipitation could be largely attributed to the changes in gross ecosystem productivity (GEP) and belowground/aboveground C allocation. There were significant interactive effects of warming and increased precipitation on root productivity, mortality, and standing crop. Experimental warming had positive and negative effects on the three root variables (root production, mortality, standing crop) under ambient and increased precipitation, respectively. Increased precipitation stimulated and suppressed the three root variables in the unwarmed and warmed subplots, respectively. The positive dependence of soil respiration and ecosystem respiration upon root productivity and mortality highlights the important role of root dynamics in ecosystem C cycling. The nonadditive effects of increased temperature and precipitation on root productivity, mortality, and standing crop observed in this study are critical for model projections of climate–ecosystem feedbacks. These findings indicate that carbon allocation is a focal point for future research and that results from single factor experiments should be treated with caution because of factor interactions.