bluuebunny/crossref_metadata_2025 huggingface dataset:
Marketing intelligence in SMEs: implications for the industry and policy makers
Authors: Cacciolatti L.A. , Fearne A.
Published: February 2013

Purpose

The aim of this paper is to demonstrate empirically the relationship between firm characteristics and information use within a small and medium sized enterprises (SME) context, proposing that firm characteristics are a catalyst of information use. With marketing information it is intended all data usable within for a marketing purpose.

Design/methodology/approach

First, firm characteristics and their impact on information use amongst SMEs were identified in the literature. After that, a quantitative study was performed analysing the data through multivariate data analysis techniques, specifically principal component analysis (PCA), canonical correlation analysis and regression. The results of the analysis are discussed and the paper ends with the conclusions, implications for practitioners and policy makers, limitations of the study and indications for future research.

Findings

The results of this study show the importance of the association between firm characteristics and information use amongst SMEs, demonstrating that strategic approach, firm size and resources allocation are catalysts of information use.

Originality/value

Different firm characteristics have an impact on information use. Understanding better what firm characteristics are potential catalysts of information use may empower practitioners’ with better marketing intelligence and policy makers with a measure to assess potential risk when subsidising small businesses.
An automated cross‐correlation based event detection technique and its application to a surface passive data set
Authors: Forghani‐Arani Farnoush , Behura Jyoti , Haines Seth S. , Batzle Mike
Published: February 2013

In studies on heavy oil, shale reservoirs, tight gas and enhanced geothermal systems, the use of surface passive seismic data to monitor induced microseismicity due to the fluid flow in the subsurface is becoming more common. However, in most studies passive seismic records contain days and months of data and manually analysing the data can be expensive and inaccurate. Moreover, in the presence of noise, detecting the arrival of weak microseismic events becomes challenging. Hence, the use of an automated, accurate and computationally fast technique for event detection in passive seismic data is essential. The conventional automatic event identification algorithm computes a running‐window energy ratio of the short‐term average to the long‐term average of the passive seismic data for each trace. We show that for the common case of a low signal‐to‐noise ratio in surface passive records, the conventional method is not sufficiently effective at event identification. Here, we extend the conventional algorithm by introducing a technique that is based on the cross‐correlation of the energy ratios computed by the conventional method. With our technique we can measure the similarities amongst the computed energy ratios at different traces. Our approach is successful at improving the detectability of events with a low signal‐to‐noise ratio that are not detectable with the conventional algorithm. Also, our algorithm has the advantage to identify if an event is common to all stations (a regional event) or to a limited number of stations (a local event). We provide examples of applying our technique to synthetic data and a field surface passive data set recorded at a geothermal site.
From Citizens' Deliberation to Popular will Formation? Generating Democratic Legitimacy in Transnational Deliberative Polling
Authors: Olsen Espen D. H. , Trenz Hans-Jörg
Published: February 2013

In this article, we critically discuss the democratic legitimacy of deliberative experiments taking place in a transnational setting. We argue that while deliberative polls through scientific design may enhance equal participation and informed opinion making of selected citizens, their representative status as part of a broader constituency and as a generator of democratic legitimacy is less clear-cut. To illustrate our argument, we analyse the results and organisation of Europolis, a transnational deliberative experiment. This is an ideal case for analysing the linkage between scientific validity of deliberative experiments and democratic legitimacy because it introduces variation in terms of constituency and group plurality. By critically scrutinising this deliberative event, we provide a first take on specifying scope conditions for deliberation, with direct reference to the lessons from the experiment, reflection on methodological problems and, finally, an attempt to discern ways to move from deliberation to will formation in the EU setting.
Characterizing the Public's Preferential Attitudes Toward End‐of‐Life Care Options: A Role for the Threshold Technique?
Authors: Trafford Crump R. , Llewellyn‐Thomas H.
Published: February 2013

Objectives

To assess the Threshold Technique's (TT) feasibility in community‐wide surveys of U.S. Medicare beneficiaries' preferences for end‐of‐life (EOL) care options.

Study Setting

Study participants were community‐dwelling Medicare beneficiaries in four different regions in the United States.

Study Design

During personal interviews, participants considered four EOL scenarios, each presenting a choice between a less intense and more intense care option.

Data Collection

Participants selected their initially favored option. Depending on that choice, in the subsequent TT the length of life offered by the more intense option was systematically increased or decreased until the participant “switched” to his or her initially rejected option.

Principal Findings

Participants were able to select an initially favored option (in 3 of the 4 scenarios; this was the less intense option). The majority of participants were able to engage with the subsequent TT. In all scenarios, regardless of the increase/decrease in the length of life offered by the more intense option, the majority of participants were unwilling to “switch” to their initially rejected option.

Conclusions

In surveys of populations' preferential attitudes toward EOL care options, the TT was a feasible elicitation method, engaging most participants and measuring the strength of their attitudes. Further methodological work is merited, involving (1) populations with various participant characteristics, and (2) different attributes in the TT task itself.
Psychosis‐inducing effects of cannabis are related to both childhood abuse and COMT genotypes
Authors: Alemany S. , Arias B. , Fatjó‐Vilas M. , Villa H. , Moya J. , Ibáñez M. I. , Ortet G. , Gastó C. , Fañanás L.
Published: February 2013

Objective

To test whether the association between childhood abuse, cannabis use and psychotic experiences (PEs) was moderated by the COMT (catechol‐O‐methyltransferase) gene.

Method

Psychotic experiences (PEs), childhood abuse, cannabis use and COMT Val158Met genotypes were assessed in 533 individuals from the general population. Data were analysed hierarchically by means of multiple linear regression models.

Results

Childhood abuse showed a significant main effect on both positive (β = 0.09; SE = 0.04; P = 0.047) and negative PEs (β = 0.11; SE = 0.05; P = 0.038). A significant three‐way interaction effect was found among childhood abuse, cannabis use and the COMT gene on positive PEs (β = −0.30; SE = 0.11; P = 0.006). This result suggests that COMT genotypes and cannabis use only influenced PE scores among individuals exposed to childhood abuse. Furthermore, exposure to childhood abuse and cannabis use increased PE scores in Val carriers. However, in individuals exposed to childhood abuse but who did not use cannabis, PEs increased as a function of the Met allele copies of the COMT gene.

Conclusion

Cannabis use after exposure to childhood abuse may have opposite effects on the risk of PEs, depending on the COMT genotypes providing evidence for a qualitative interaction. Val carriers exposed to childhood abuse are vulnerable to the psychosis‐inducing effects of cannabis.
The Multiple Faces of the Decidual Natural Killer Cell
Authors: Winger Edward E. , Reed Jane L.
Published: February 2013

The decidual NK (dNK) cell is called on to support placental growth by providing an array of growth factors that directly transform the spiral artery and direct trophoblast invasion. Successful transformation is dependent upon adequate stimulation paradoxically stimulating the cell for placental support rather than cytotoxicity. With the identification of its supportive role, the presence of an intact cytotoxic mechanism has been confusing. Investigators have found that the cell remains fully capable of cytotoxic responses particularly in response to pathogen‐specific signals. We postulate a dual threshold model where moderate stimulation results in release of stimulatory factors supporting placentation while intense stimulation, particularly triggered through pathogen‐specific receptors, restores the cell to its protective, cytotoxic, role. Individual dNK cells mature attaining the capacity to respond to the delivery of cognate signals. The process, known as ‘licensing’ tunes responsiveness to the degree to which stochastically selected inhibitory receptors block cytotoxic response to self. A changing licensing milieu within the decidua may result in altered and unsuitable receptor expression. We postulate that a heterogeneous population of dNK cells where cells inappropriately licensed for the milieu contributes to pathology.
Dire Necessity and Transformation: Entry‐points for Modern Science in Islamic Bioethical Assessment of Porcine Products in Vaccines
Authors: Padela Aasim I. , Furber Steven W. , Kholwadia Mohammad A. , Moosa Ebrahim
Published: February 2013

The field of medicine provides an important window through which to examine the encounters between religion and science, and between modernity and tradition. While both religion and science consider health to be a ‘good’ that is to be preserved, and promoted, religious and science‐based teachings may differ in their conception of what constitutes good health, and how that health is to be achieved.

This paper analyzes the way the Islamic ethico‐legal tradition assesses the permissibility of using vaccines that contain porcine‐derived components by referencing opinions of several Islamic authorities. In the Islamic ethico‐legal tradition controversy surrounds the use of proteins from an animal (pig) that is considered to be impure by Islamic law. As we discuss the Islamic ethico‐legal constructs used to argue for or against the use of porcine‐based vaccines we will call attention to areas where modern medical data may make the arguments more precise. By highlighting areas where science can buttress and clarify the ethico‐legal arguments we hope to spur an enhanced applied Islamic bioethics discourse where religious scholars and medical experts use modern science in a way that remains faithful to the epistemology of Islamic ethics to clarify what Islam requires of Muslim patients and healthcare workers.
Binding and content updating in working memory tasks
Authors: Artuso Caterina , Palladino Paola
Published: February 2013

Working memory updating can involve processing of either a specific memory content or a binding. So far, research has focused mainly on single contents as objects of updating, via recall accuracy measures. Here, we have addressed more direct measurement of the updating process (i.e., response times), assessing individually the role of single contents, as well as bindings. To this end, we compared two updating tasks from separate research traditions: a RT‐based computer task and a classical accuracy‐based task. The former consisted of trials where measures of content and binding updating were obtained, allowing a dissociation between these two components. The latter measured recall accuracy and intrusion rate for lists of words under different conditions of maintenance/inhibition. These results enable a better understanding of the updating process for the dual components of binding and content updating, and their potential role in an accuracy‐based task. An overlap between the underlying components of updating tasks was demonstrated, specifically between binding updating RT and intrusion rate. Notably, binding updating appears to be a more sensitive measure in explaining results in the classical updating task.
Manchester iStent study: early results from a prospective UK case series
Authors: Patel Ilesh , de Klerk Timothy A , Au Leon
Published: February 2013

Background

To evaluate the 6‐month efficacy and safety of the iStent microtrabecular bypass stent in patients with open‐angle glaucoma.

Design

A prospective, uncontrolled, interventional case series.

Participants

Forty‐four eyes with open‐angle glaucoma were reported.

Methods

All subjects underwent ab interno implantation of a single iStent together with (n = 40) or without (n = 4) cataract surgery.

Main Outcome Measures

Patients were assessed at postoperative week 1, months 1 and 3, and quarterly, thereafter. Data collected included visual acuity, intraocular pressure measurement using Goldmann tonometry, number of glaucoma medications, and number and type of complications.

Results

The mean age of the sample was 76.8 years. The mean duration since glaucoma diagnosis was 5.3 years (standard deviation 2.9 years). The mean visual acuity was 0.53 logMAR at baseline that improved to 0.23 at 6 months postoperatively. The mean baseline intraocular pressure was 21.1 mmHg, and this decreased significantly to 16.7 mmHg at 6 months (P < 0.01). The mean number of drops prescribed preoperatively was 2.3, which decreased to 0.6 at 6 months (P < 0.01). Sixty‐six per cent of patients were drop‐free at 6 months. One patient developed an hyphaema following surgery; no other adverse events were recorded.

Conclusions

The iStent proved to be a safe and effective treatment for patients with open‐angle glaucoma over our 6‐month follow up period. Insertion resulted in a significant decrease in intraocular pressure as well as the number of topical antiglaucoma medications required for adequate intraocular pressure control.
Early intervention and evaluation for adult‐onset psychosis: the JCEP study rationale and design
Authors: Hui Christy L.M. , Chang Wing C. , Chan Sherry K.W. , Lee Edwin H.M. , Tam Wendy W.Y. , Lai Dik C. , Wong Gloria H.Y. , Tang Jennifer Y.M. , Li Frendi W.S. , Leung Kwok F. , McGhee Sarah M. , Sham Pak C. , Chen Eric Y.H.
Published: February 2013

Aim

Psychotic disorders incur substantial long‐term burdens to patients and society. Early intervention (EI) during the initial years of psychotic disorders can improve long‐term outcome. In Hong Kong, a pilot EI programme (EASY, Early Assessment Service for Young people with psychosis) had been set up since 2001 to serve clients under 25 years of age. Although EASY has been effective in improving outcome, consolidation of early psychosis work requires further development.

Methods

The present paper describes a new EI development which targets adult patients with psychosis in Hong Kong. The Jockey Club Early Psychosis (JCEP) project was launched in 2009. Expanding the service to patients above 25 years old, JCEP aims to deliver a territory‐wide specialized EI service to adult‐onset psychosis patients, to promote public awareness on early psychosis, and to research on the optimal intervention model and duration for early psychosis in a 4‐year randomized controlled trial (RCT). Participants were randomly assigned to receive either 4 years of EI service, 2 years of EI service, or 4 years of standard care. Their symptoms, neurocognitive functions, psychosocial well‐being and health economics were regularly assessed.

Results

To date, 360 patients were recruited into the RCT, and 740 patients were recruited in a 2‐year naturalistic study. Prospective, longitudinal follow‐up assessments of these patients are still underway.

Conclusions

JCEP is the first EI project to provide adult early psychosis service in Chinese population. Future data would help to address the optimal duration of EI and its cost‐effectiveness. This would also assist regional and international mental health development.
Equine proliferative enteropathy – a review of recent developments
Authors: Pusterla N. , Gebhart C. J.
Published: February 2013

Equine proliferative enteropathy (EPE) is a disease of foals caused by the obligate intracellular organismLawsonia intracellularis. This emerging disease affects mainly weanling foals and causes fever, lethargy, peripheral oedema, diarrhoea, colic and weight loss. The diagnosis ofEPEmay be challenging and relies on the presence of hypoproteinaemia, thickening of segments of the small intestinal wall observed upon abdominal ultrasonography, positive serology and molecular detection ofL. intracellularisin faeces. Although the clinical entity, diagnostic approach and treatment ofEPEare well established and described, the epidemiology for this disease has remained largely unaddressed. This article focuses on new developments in the field ofEPE, including epidemiology, pathophysiology, clinical signs, diagnosis, treatment and prevention.

TheSummary is available inChinese – seeSupporting information.
Interannual variation in pelagic juvenile rockfish (Sebastes spp.) abundance – going with the flow
Authors: Ralston S. , Sakuma K.M. , Field J.C.
Published: February 2013

We report results from 28 yr of a midwater trawl survey of pelagic juvenile rockfish (Sebastes spp.) conducted off the central California coast. The fishery‐independent survey is designed to provide pre‐recruit indices of abundance for use in groundfish stock assessments. Standardized catch rate time series for 10 species were developed from delta‐generalized linear models that include main effects for year, station, and calendar date. Results show that interannual fluctuations of all 10 species are strongly coherent but highly variable, demonstrating both high‐ and low‐frequency components. A similarly coherent result is observed in the size composition of fish, with large fish associated with elevated catch rates. In contrast, spatial and seasonal patterns of abundance show greater species‐specific differences. A comparison of the shared common trend in pelagic juvenile rockfish abundance, derived from principal components analysis, with recruitments from five rockfish stock assessments shows that the time series are significantly correlated. An examination of oceanographic factors associated with year‐to‐year variability indicates that a signature of upwelled water at the time of the survey is only weakly related to abundance. Likewise, basin‐scale indices (the Multivariate El Niño‐Southern Oscillation Index, the Pacific Decadal Oscillation, the North Pacific Gyre Oscillation, and the Northern Oscillation Index) are poorly correlated with abundance. In contrast, sea level anomalies in the months preceding the survey are well correlated with reproductive success. In particular, equatorward anomalies in the alongshore flow field following the spawning season are associated with elevated survival and poleward anomalies with poor survival.
The use of long‐term monitoring data for studies of planktonic diversity: a cautionary tale from two Swiss lakes
Authors: Straile Dietmar , Jochimsen Marc C. , Kümmerlin Reiner
Published: February 2013

Long‐term data have been suggested as resources for investigating environmental influences on biodiversity and, in turn, the role of biodiversity for ecosystem dynamics. However, scientists analysing biodiversity patterns in long‐term data need to recognise that multidecadal time series are likely to suffer from inconsistencies in methodology, which might strongly complicate the interpretation of diversity patterns. Unfortunately, such inconsistencies are usually difficult to detect, and consequently, it is not known how strongly they affect the conclusions drawn.

Here, we highlight two long‐term data sets sampled by one laboratory to analyse patterns in phytoplankton richness in two Swiss lakes, Lake Zurich and Lake Walen. Apparent patterns in the long‐term species richness in the two lakes arise from: (i) inconsistencies in species identification (changes in taxonomic literature and/or taxonomic expertise of the counting personnel) and (ii) changes in the detection limits of taxa. Hence, bias in these two case studies was strong enough to obscure any possible effects on species richness of environmental change (oligotrophication).

We show that in the case of these two data sets, inconsistency confounds estimates of phytoplankton richness not only at the species level but even at the generic and familial levels. This suggests that a solution often proposed for inconsistency, that is, reanalysis of the data after aggregation to genus or family, may be insufficient.

We suggest the use of two diagnostic plots, which may be used in other studies examining richness patterns in either long‐term time series or comparative studies in which several scientists/laboratories contributed to data acquisition. These plots illustrate temporal or spatial patterns in (i) the percentage of taxa identified only to genus and (ii) in the 5% percentile of the concentrations of individual algal taxa. They will help to identify inconsistency problems due to changes or differences in (i) taxonomic expertise and (ii) detection limits.
Can one blood draw replace transrectal ultrasonography‐estimated prostate volume to predict prostate cancer risk?
Authors: Carlsson Sigrid V. , Peltola Mari T. , Sjoberg Daniel , Schröder Fritz H. , Hugosson Jonas , Pettersson Kim , Scardino Peter T. , Vickers Andrew J. , Lilja Hans , Roobol Monique J.
Published: February 2013

What's known on the subject? and What does the study add?

Previous studies have shown that a statistical model based on a panel of kallikrein markers in blood (total, free and intact PSA and kallikrein‐related peptidase 2) can predict prostate cancer on biopsy.

The current study explores the relationship between the above‐mentioned panel and prostate volume, and whether this panel could be an alternative for clinical measures such as DRE and TRUS in predicting prostate cancer on biopsy.

Objective

To explore whether a panel of kallikrein markers in blood: total, free and intact prostate‐specific antigen (PSA) and kallikrein‐related peptidase 2, could be used as a non‐invasive alternative for predicting prostate cancer on biopsy in a screening setting.

Subjects and Methods

The study cohort comprised previously unscreened men who underwent sextant biopsy owing to elevated PSA (≥3 ng/mL) in two different centres of the European Randomized Study of Screening for Prostate Cancer, Rotterdam (n = 2914) and Göteborg (n = 740).

A statistical model, based on kallikrein markers, was compared with one based on established clinical factors for the prediction of biopsy outcome.

Results

The clinical tests were found to be no better than blood markers, with an area under the curve in favour of the blood measurements of 0.766 vs. 0.763 in Rotterdam and 0.809 vs. 0.774 in Göteborg.

Adding digital rectal examination (DRE) or DRE plus transrectal ultrasonography (TRUS) volume to the markers improved discrimination, although the increases were small. Results were similar for predicting high‐grade cancer.

There was a strong correlation between the blood measurements and TRUS‐estimated prostate volume (Spearman's correlation 0.60 in Rotterdam and 0.57 in Göteborg).

Conclusions

In previously unscreened men, each with indication for biopsy, a statistical model based on kallikrein levels was similar to a clinical model in predicting prostate cancer in a screening setting, outside the day‐to‐day clinical practice.

Whether a clinical approach can be replaced by laboratory analyses or used in combination with decision models (nomograms) is a clinical judgment that may vary from clinician to clinician depending on how they weigh the different advantages and disadvantages (harms, costs, time, invasiveness) of both approaches.
Legitimate Force in a Particularistic Democracy: Street Police and Outlaw Legislators in the Republic of China on Taiwan
Authors: Martin Jeffrey T.
Published: February 2013

This article explores a “particularistic” concept of legitimacy important to Taiwanese democracy. This form of legitimacy, I suggest, has been instrumental for Taiwan's successful democratic consolidation in the absence of the rule of law. As evidence, I combine ethnographic observation of neighborhood police work with historical consideration of a type of political figure emergent in the process of democratic reform, which I call the “outlaw legislator.” I focus my analysis on the institutional and ideological processes articulating local policing into the wider political field. The center of these processes is a mode of popular representation that positions the outlaw legislator as a crucial hinge articulating the particularistic local order with central state powers. By analyzing the cultural content of the dramaturgical work used to reconcile low policing with higher-level state operations, this article shows how a particularistic idiom of legitimacy helps hold Taiwanese democracy together.
High‐Pressure Behavior of Mullite: An X‐Ray Diffraction Investigation
Authors: Kalita Patricia E. , Schneider Hartmut , Lipinska Kristina , Sinogeikin Stanislav , Hemmers Oliver A. , Cornelius Andrew
Published: February 2013

Using synchrotron X‐ray diffraction and diamond anvil cells we performed in situ high‐pressure studies of mullite‐type phases of general formula Al4+2xSi2−2xO10−x and differing in the amount of oxygen vacancies: 2:1‐mullite (x = 0.4), 3:2‐mullite (x = 0.25), and sillimanite (x = 0). The structural stability of 2:1‐mullite, 3:2‐mullite, and sillimanite was investigated up to 40.8, 27.3, and 44.6 GPa, respectively, in quasi‐hydrostatic conditions, at ambient temperature. This is the first report of a static high‐pressure investigation of Al2O3–SiO2 mullites. It was found that oxygen vacancies play a significant role in the compression mechanisms of the mullites by decreasing the mechanical stability of the phases with the number of vacancies. Elevated pressure leads to an irreversible amorphization above ~20 GPa for 2:1‐mullite and above 22 GPa for 3:2‐mullite. In sillimanite, only a partial amorphization is observed above 30 GPa. Based on Rietveld structural refinements of high‐pressure X‐ray diffraction patterns, the pressure‐driven evolution of unit cell parameters is presented. The experimental bulk moduli obtained are as follows: K0 = 162(7) GPa with K0′ = 2.2(6) for 2:1‐mullite, K0 = 173(7) GPa with K0′ = 2.3(2) for 3:2‐mullite, K0 = 167(7) GPa with K0′ = 2.1(4) for sillimanite.
Eu3+‐Activated Borogermanate Scintillating Glass with a High Gd2O3 Content
Authors: Sun Xin‐Yuan , Jiang Da‐Guo , Chen Shi‐Wei , Zheng Guo‐Tai , Huang Shi‐Ming , Gu Mu , Zhang Zhi‐Jun , Zhao Jing‐Tai
Published: February 2013

Eu3+‐activated borogermanate scintillating glasses with compositions of 25B2O3–40GeO2–25Gd2O3–(10−x)La2O3–xEu2O3 were prepared by melt‐quenching method. Their optical properties were studied by transmittance, photoluminescence, Fourier transform infrared (FTIR), Raman and X‐ray excited luminescence (XEL) spectra in detail. The results suggest that the role of Gd2O3 is of significance for designing dense glass. Furthermore, energy‐transfer efficiency from Gd3+ to Eu3+ ions can be near 100% when the content of Eu2O3 exceeds x = 4, the corresponding critical distance for Gd3+–Eu3+ ion pairs is estimated to be 4.57 Å. The strongest emission intensities of Eu3+ ions under both 276 and 394 nm excitation are simultaneously at the content of 8 mol% Eu2O3. The degree of Eu–O covalency and the local environment of Eu3+ ions are evaluated by the value of Ωt parameters from Judd–Ofelt analysis. The calculated results imply that the covalency of Eu–O bond increases with the increasing concentration of Eu3+ ions in the investigated borogermanate glass. As a potential scintillating application, the strongest XEL intensity under X‐ray excitation is found to be in the case of 6 mol% Eu2O3, which is slightly different from the photoluminescence results. The possible reason may be attributed to the discrepancy of the excitation mechanism between the ultraviolet and X‐ray energy.
Microwave‐Assisted Hydrothermal Synthesis of Fe2O3‐Sensitized SrTiO3 and its Luminescent Photocatalytic deNOx Activity with CaAl2O4:(Eu,Nd) Assistance
Authors: Li Huihui , Yin Shu , Wang Yuhua , Sato Tsugio
Published: February 2013

This work focused on the synthesis of high‐activity strontium titanate (SrTiO3) photocatalysts through an environmentally friendly process. A high energy‐efficient microwave‐assisted hydrothermal method was employed to prepare Fe‐loaded SrTiO3 that consisted of small particles around 50 nm in diameter. To achieve the effective assistance of long‐lasting fluorescence, the obtained Fe‐loaded SrTiO3 samples were coupled with CaAl2O4:(Eu, Nd). The photocatalytic activities were evaluated by the photo‐decomposition of NO. Fe loaded SrTiO3 showed high photocatalytic activities not only under visible light irradiation but also in the dark with fluorescence assistance.
Semiconductivity in Acceptor‐Doped BaTi1−xHoxO3−x/2−δ/2
Authors: Liu Yang , West Anthony R
Published: February 2013

Acceptor‐doped BaTiO3 powders of formula: BaTi1−xHoxO3−x/2−δ/2: x = 0.0001, 0.001, 0.01, 0.03, and 0.07, were prepared by sol‐gel synthesis, fired at 800°C–1500°C and either quenched or slow‐cooled to room temperature. Electrical properties of ceramics depended on firing conditions, Ho content, and cooling rate. Pellets of all x values fired at 800°C–1000°C were insulating and, from the presence of OH bands in the IR spectra, charge balance appeared to involve co‐doping of Ho3+ and H+ ions without necessity for oxygen vacancy creation. At higher firing temperatures, OH bands were absent. Pellets fired at 1400°C in air and slow cooled were insulating for both low x (0.0001) and high x (0.07) but at intermediate x (0.001 and 0.01) passed through a resistivity minimum of 20–30 Ω cm at room temperature, attributed to the presence of Ti3+ ions; it is suggested that, for these dilute Ho contents, each oxygen vacancy is charge compensated by one Ho3+ and one Ti3+ ion. At higher x, charge compensation is by Ho3+ ions and samples are insulating. A second, more general mechanism to generate Ti3+ ions, and a modest level of semiconductivity, involves reversible oxygen loss at high temperatures.
Ion‐Beam‐Induced Chemical Mixing at a Nanocrystalline CeO2–Si Interface
Authors: Edmondson Philip D. , Young Neil P. , Parish Chad M. , Moll Sandra , Namavar Fereydoon , Weber William J. , Zhang Yanwen
Published: February 2013

Thin films of nanocrystalline ceria deposited onto a silicon substrate have been irradiated with 3 MeV Au+ ions to a total dose of 34 displacements per atom to examine the film/substrate interfacial response upon displacement damage. Under irradiation, a band of contrast is observed to form that grows under further irradiation. Scanning and high‐resolution transmission electron microscopy imaging and analysis suggest that this band of contrast is a cerium silicate phase with an approximate Ce:Si:O composition ratio of 1:1:3 in an amorphous nature. The slightly nonstoichiometric composition arises due to the loss of mobile oxygen within the cerium silicate phase under the current irradiation condition. This nonequilibrium phase is formed as a direct result of ion‐beam‐induced chemical mixing caused by ballistic collisions between the incoming ion and the lattice atoms. This may hold promise in ion beam engineering of cerium silicates for microelectronic applications e.g., the fabrication of blue LEDs.
Highly Efficient Room Temperature Synthesis of Silver‐Doped Zinc Oxide (ZnO:Ag) Nanoparticles: Structural, Optical, and Photocatalytic Properties
Authors: Yıldırım Özlem Altıntaş , Unalan Husnu Emrah , Durucan Caner
Published: February 2013

Synthesis of silver‐doped zinc oxide (ZnO:Ag) nanoparticles through precipitation method has been reported. The synthesis was conducted at room temperature and no subsequent thermal treatment was applied. ZnO nanoparticles were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), fourier transmission infrared spectroscopy (FTIR), and ultraviolet‐visible (UV–Vis) spectroscopy. Detailed crystallographic investigation was accomplished through Rietveld refinement. The effect of silver content on structural and optical properties of resultant ZnO nanoparticles has been reported. It was found that silver doping results in positional shifts for the XRD peaks and the absorption band edge of ZnO. These were attributed to the substitutional incorporation of Ag+ ions into Zn2+ sites within the ZnO crystal. In addition, higher silver incorporation resulted in smaller size for ZnO nanoparticles. The photocatalytic activity of the ZnO:Ag nanoparticles was also determined by methylene orange (MO) degradation studies and compared to that of undoped ZnO. Improved photocatalytic activity was obtained for ZnO:Ag nanoparticles. It has been shown that an optimum amount of silver dopant is required to obtain maximum photocatalytic activity.
Enhanced Electrocaloric Effects in Spark Plasma‐Sintered Ba0.65Sr0.35TiO3‐Based Ceramics at Room Temperature
Authors: Liu Xiao Qiang , Chen Ting Ting , Wu Yong Jun , Chen Xiang Ming
Published: February 2013

Improvement of electrocaloric effect was investigated in the lead‐free undoped and Mn‐doped Ba0.65Sr0.35TiO3 ceramics prepared by spark plasma sintering process. Owing to the merit of spark plasma sintering process, a fully dense undoped and Mn‐doped Ba0.65Sr0.35TiO3 ceramics with fine grain sizes could be obtained. The electrocaloric (EC) effect can be significantly enhanced from 0.83 K for conventional sintered Ba0.65Sr0.35TiO3 to 3.08 K for spark plasma‐sintered Mn‐doped Ba0.65Sr0.35TiO3 ceramics since the dielectric strength was dramatically increased. This work indicated an effective way to achieve the significantly enhanced EC effect in a lead‐free system at room temperature.
Synthesis of Y3Al5O12:Eu2+ Phosphor by a Facile Hydrogen Iodide‐AssistedSol–Gel Method
Authors: Zhu Qiang Qiang , Hu Wei Wei , Ju Li Chen , Hao Lu Yuan , Xu Xin , Agathopoulos Simeon
Published: February 2013

Pure yttrium aluminum garnet (YAG) phosphor doped with Eu2+ has been successfully synthesized by a facile sol–gel method. The use of hydrogen iodide aimed to get Eu2+ ions, confirmed by X‐ray absorption near‐edge structure (XANES) analysis. Nearly spherical and well dispersed particles were synthesized. The produced YAG:Eu2+ phosphor powder had a broad emission band in the range of 400–600 nm with a peak at 480 nm, attributed to the allowed 4f7–4f65d1 transition of electrons in Eu2+ ions. The proposed method could also be expanded to prepare many other Eu2+‐doped phosphors with a solution method.
Evaluating Pore Space in Macroporous Ceramics with Water‐Based Porosimetry
Authors: Andersson Linnéa , Larsson Per Tomas , Wågberg Lars , Bergström Lennart
Published: February 2013

We show that water‐based porosimetry (WBP), a facile, simple, and nondestructive porosimetry technique, accurately evaluates both the pore size distribution and throat size distribution of sacrificially templated macroporous alumina. The pore size distribution and throat size distribution derived from the WBP evaluation in uptake (imbibition) and release (drainage) mode, respectively, were corroborated by mercury porosimetry and X‐ray micro‐computed tomography (μ‐CT). In contrast with mercury porosimetry, the WBP also provided information on the presence of “dead‐end pores” in the macroporous alumina.
Enhanced Hydrothermal Resistance of Y‐TZP Ceramics Through Colloidal Processing
Authors: Rayón E. , Moreno R. , Alcázar C. , Salvador M. D. , Manjón F.J. , Jiménez‐Piqué E. , LLanes L.
Published: February 2013

Two commercial zirconia powders with 3 mol% of yttria (TZ3YE and TZ3YS, labeled as ZE and ZS, respectively) supplied by Tosoh (Japan) were used for this study. Maximum colloidal stability for ZE was achieved by dispersing the powders in a mixture of water/ethanol of 90:10 (wt/wt) using a sonication probe. The rheological behavior of the suspensions was optimized in terms of solids content ranging from 20 to 33 vol% and sonication time (0–6 min), the best results being obtained after 2 min. ZS samples were prepared to a solids loading of 30 vol% in water dispersing with 2 min‐sonication. Samples obtained by slip casting in plaster molds were used for dynamic sintering studies, and fully dense and nanostructured specimens were obtained at temperatures of 1300°C–1350°C (ZE samples) and 1400°C per 2 h (ZS samples). The Hardness (H) and Young's Modulus (E) properties of the specimens were studied by nanoindentation technique giving 17 and 250 GPa mean values for H and E, respectively. The specimens were then forced to a low‐temperature degradation (LTD) treatment at 130°C for 240 h in steps of 60 h. Raman spectroscopy and nanoindentation results of hydrothermally treated samples showed the absence of transformation from tetragonal to monoclinic phase until 180 h whereas the mechanical properties maintained constant even at the sample surface. After 240 h of LTD, the monoclinic phase was detected on all specimens by Raman peaks centered at 180, 191, and 383 cm−1. The nanoindentation study revealed an important loss of mechanical features reaching 10 and 175 GPa for H and E, respectively. In the case of the ZS specimens, no monoclinic phase is detected after 240 h of LTD treatment and no decay of E or H is detected. The free defect microstructure reached for the ZS specimen revealed a higher hydrothermal resistance so that it is concluded that the excellent behavior against thermal degradation is possible due to the large uniformity obtained by colloidal processing rather than the particle size of the starting powders.
Comparison of the Elastic–Plastic Indentation Response of MgAl2O4, AlON, and AlN
Authors: Muller Andrea M. , Green David J.
Published: February 2013

Contact damage in the form of localized cracking and inelastic deformation is of concern in the utilization of ceramics and is often studied using hard indenters; an approach that has spawned the field of indentation mechanics. This approach was taken in the current work to study the penetration resistance at low strain rates of four candidate ceramic armor materials: MgAl2O4 with two grain sizes, AlON and AlN. Spherical indentation was chosen as this allows the elastic–plastic behavior to be studied and the indentation stress–strain curves to be determined. To further quantify these data, the elastic and plastic indentation work contributions were measured. On empirical grounds, it was postulated that the area under the indentation stress–strain curves, termed the indentation strain energy density, was related to the total indentation work could be used to quantify the penetration resistance. As a test of this hypothesis, it was shown that the total indentation work correlated with the strain energy density and acted over a volume similar to that of the stress field. A simple figure of merit, derived from the indentation strain energy density, was suggested as a means to quantify the penetration resistance of materials at low strain rates and to identify the material parameters that control this process.
Uniform Coating of BaTiO3–Dy2O3–SiO2 Compound Nano Layer on Ni Particles for MLCC Electrode
Authors: Zhang Yichi , Wang Xiaohui , Kim Jin‐yong , Kim Jeong‐Ryeol , Hur Kang‐Heon , Li Longtu
Published: February 2013

Uniform coating of nanometer‐scale BaTiO3–Dy2O3–SiO2 layers on spherical Ni particles are achieved by controlled hydrolysis of tetrabutyl titanate (TBT), hydrothermal reaction with Ba(OH)2, and co‐precipitation of tetraethylorthosilicate (TEOS) and Dy(NO3)3. The composition of the coating layer is similar to rare earth oxide‐silica–doped BaTiO3, which is the main component of dielectric layer for base metal electrode (BME) multilayer ceramic capacitors (MLCCs). After coating, the shrinkage onset temperature of Ni particles is significantly increased. After sintered to pellets, the electrode has good electrical conductivity. This electrode material has good compatibility with rare earth oxide and silica‐doped BaTiO3 dielectric materials, and could serve as promising candidate for application in the next generation BME‐MLCCs.
Fabrication, Microstructure, and Luminescent Properties of Ce3+ ‐Doped Lu3Al5O12 (Ce:LuAG) Transparent Ceramics by Low‐Temperature Vacuum Sintering
Authors: Xu Jian , Shi Ying , Xie Jianjun , Lei Fang
Published: February 2013

The fabrication of 0.5 mol% Ce:LuAG transparent ceramics starting from synthetic nanosized Ce:LuAG powders was investigated by low temperature vacuum sintering. It was found that high quality optical Ce:LuAG ceramics could be densified successfully by vacuum sintering (<10–3 pa) at 1750°C for 10 h. The in‐line optical transmittance of as‐sintered Ce:LuAG ceramics with thickness of 0.7 mm could reach 73.48% at the wavelength of 550 nm. The microstructure observations revealed that transparent Ce:LuAG ceramics were composed of uniform LuAG grains with average size of 9 μm and HRTEM morphology indicated that no impurity segregation existed at grain boundaries or within Ce:LuAG grains. It was also demonstrated that the annealing treatment (at 1450°C for 20 h in air) could greatly enhance the luminescent intensity of as‐sintered Ce:LuAG ceramics under excitation of X‐ray radiation (75 kV, 25 mA), which makes it a potential candidate to be applied in radiation detector.
Large Piezoelectric Response and Polarization in Relaxor Ferroelectric PbTiO3–Bi(Ni1/2Zr1/2)O3
Authors: Rong Yangchun , Chen Jun , Kang Huajun , Liu Laijun , Fang Liang , Fan Longlong , Pan Zhao , Xing Xianran
Published: February 2013

New binary system (1−x) PbTiO3−xBi(Ni1/2Zr1/2)O3 (PT–100x BNZ) with x ≤ 0.45 were synthesized via solid‐state reaction route. A morphotropic phase boundary (MPB) was identified around x = 0.40 by X‐ray diffraction (XRD) method. The ceramics with MPB composition exhibit enhanced ferroelectric properties. A large piezoelectric coefficient (d33) up to 400 pC/N was obtained for the PT–40BNZ, which is comparable with the PbTiO3–BiScO3 (PT–BS, 450 pC/N).The frequency dependence of dielectric permittivity of PT–40BNZ shows characteristic of a strong relaxor feature and a transition temperature around 290°C (1 MHz). Temperature effect on the unipolar strain was also investigated. The present system with high d33 is a competitive piezoelectric material, as no expensive oxide is used here compared with the PT–BS.
Suppressed Reactivity of AlN Powder in Water at 5°C
Authors: Kocjan Andraž , Dakskobler Aleš , Budič Bojan , Kosmač Tomaž
Published: February 2013

The hydrolysis behavior of AlN powder suspensions (5–25 wt%) at 5°C has been investigated to explore the impact of low temperatures on the hydrolysis behavior. Throughout the 312‐h long experiment, the pH value of the suspensions was below 9, where the hydrolysis remained in the induction period and was eventually suppressed due to the formation of a few‐nanometers‐thick film of amorphous aluminum hydroxide gel around the AlN particles, acting as a passivation layer. Moreover, the aqueous part of the suspension possessed a remarkably high value of dissolved [Al(III)]aq, being an order of magnitude higher at a given pH value than the aqueous AlCl3 solution.
Two‐Dimensional Orientation in Bi4Ti3O12 Prepared Using Platelet Particles and a Magnetic Field
Authors: Suzuki Tohru S. , Miwa Yasunari , Kawada Shinichiro , Kimura Masahiko , Uchikoshi Tetsuo , Sakka Yoshio
Published: February 2013

Tailoring the crystallographic orientation in piezoelectric ceramics is very useful for improving their properties. Orientation in ceramics can be controlled by templated grain growth, hot forging, etc. We have focused on using a strong magnetic field for the crystallographic orientation even in diamagnetic ceramics. In a previous study, although only a one‐directional orientation could be controlled by these methods, it was difficult to control the multi‐axis orientation in the ceramics. In this study, we demonstrated that alignments of the c‐axis and the <100> axis in Bi4Ti3O12 piezoelectric ceramics were controlled by using a strong magnetic field as well as platelet particles. We also estimated the degree of orientation by an electron back scattering diffraction analysis. When the magnetic field was applied to the platelet particles, appropriately 80% of the grains were aligned with the tilt angle made by the c‐axis and the vertical direction less than 10° and 73% of grains were oriented with the angle between the <100> axis and the magnetic field less than 10°.
Effect of Indigenous Processing Methods on Phenolics and Antioxidant Potential of Underutilized Legumes Acacia auriculiformis and Parkia roxburghii
Authors: Sathya Arumugam , Siddhuraju Perumal
Published: February 2013

The effect of soaking followed by autoclaving in various solutions such as ash, sodium bicarbonate, palm sugar and water; dry heating; and fermentation on antioxidant power of two underutilized legumes Acacia auriculiformis and Parkia roxburghii has been investigated. In comparison with the unprocessed ones, processed seed extracts of Acacia and Parkia have been registered with 1–29% loss and 4–29% gain of phenolics, respectively. The processing methods enhanced the reducing power (13–92%) and free radical‐scavenging activity on synthetic radicals (2,2′‐diphenyl‐1‐picryl‐hydrazyl [DPPH]: 5–31%; and 2,2‐azinobis [3‐ethyl benzothiazoline‐6‐sulfonic acid] diammonium salt [ABTS]: 1–80%). However, significant reductions were noticed on scavenging activity of biologically relevant radicals (hydroxyl: 8–87%; superoxide anion: 4–85%; and nitric oxide: 14–80%) and peroxidation inhibition (10–48%). Invariably, all the processing methods enhanced the protection capacity on erythrocytes and DNA against oxidative insults. Among the processing methods, dry heating and fermentation retained the antioxidant potential in A. auriculiformis and P. roxburghii, respectively, than other methods.

Practical Applications

Legume seeds, the protein‐rich plant sources, have to be cooked/processed before consumption so as to eliminate their native antiphysiological factors and to enrich their nutritional values. Daily consumption of legumes in preventing lifestyle diseases due to its phytoceuticals is best valued in the present scenario. Hence, this study demonstrated the effect of various processing methods on phenolics and the antioxidant capacity of two underutilized legumes Acacia auriculiformis and Parkia roxburghii by an array of in vitro tests. Knowledge on these types of locally available plants could provide useful data for the development of potential future crop resources for various food and feed applications and further reduces the pressure on conventional/cash crops.