432 research outputs found
ASM Journals Eliminate Impact Factor Information from Journal Websites
No full textFull author list omitted for brevity. For the full list of authors, see article.At the recent Journals Board meeting that took place during ASM Microbe 2016 in Boston, MA, the journal editors in chief and the American Society for Microbiology (ASM) leadership decided to no longer advertise the impact factors of ASM journals. This editorial was published simultaneously by the following ASM journals: Antimicrobial Agents and Chemotherapy, Applied and Environmental Microbiology, Clinical Microbiology Reviews, Infection and Immunity, Journal of Clinical Microbiology, mBio, Microbiology and Molecular Biology Reviews, mSphere, and mSystems
Nanostructured partially stabilized zirconia as an interlayer in a multi layered thermal barrier coating
No full textStresses developed within a thermal barrier coating (TBC) due to the mismatch in thermal expansion of different coating components causes coating failure. Nanostructured materials have an increased volume fraction of grain boundaries and this microstructural attribute may allow coatings to relieve the strain in the coating structure; thereby improving the effectiveness and the lifetime of the TBC. Multi – layered TBCs were prepared using two techniques; atmospheric pressure plasma spray using a commercial system, and reduced pressure plasma spray using the Triple Torch Plasma Reactor. The coatings were deposited on mullite and on NiCrAlY-coated steel substrates, and consisted of an inter layer of nano-phase partially stabilized zirconia (n-PSZ) and a layer of yttria stabilized zirconia coating (YSZ) as the top thermal barrier coat. The coatings were heat treated at various temperatures and the microstructural changes analyzed using scanning electron microscopy (SEM) images. It was observed that the changes in porosity, a critical microstructural feature that is necessary for the coatings to perform under operational conditions were not altered significantly - the data lay within the estimated deviations of the image analysis measurements. Mechanical properties of the coating were studied using micro-indentation and four point bend testing to better understand the effect of the n-PSZ inter-layer on the strain relief mechanisms that may be operative within the TBC
Early Biotechnology: The Delft Connection. Early Dutch microbiologists fostered their own golden age of microbiology
No full textInfluence of ultrasonic melt treatment on the formation of primary intermetallics and related grain refinement in aluminum alloys
No full textThis article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited - The article can also be accessed from the link below - Copyright @ 2011 SpringerUltrasonic melt treatment (UST) is known to induce grain refining in aluminum alloys. Previous studies have clearly shown that in Al-Zr-Ti alloys, the primary Al(3)Zr intermetallics were dramatically refined by cavitation-assisted fragmentation, and a good refinement effect was achieved. In this article, Al-Ti, Al-Ti-Zr alloys, and some commercial aluminum alloys are used to analyze the effect of UST on primary intermetallics and grain refinement. The addition of a small amount of Al-3Ti-B master alloy is also studied in order to compare with the addition of Ti and Zr in commercial aluminum alloys. Experimental results show that the ultrasonic grain refining effect is not only related to the size of particles which are refined and/or dispersed by UST, but also related to an undercooling available for activation of these particles in the solidification process. Athermal heterogeneous nucleation theory is considered to explain the effect of size and distribution of substrate particles on the grain structure with different undercoolings. The distribution of primary particle sizes results in the distribution of required undercoolings. Grain refining occurs when the undercooling is large enough to activate the refined primary intermetallics or dispersed inoculants.This study is supported by the Materials Innovation Institute and China Scholarship Counci
Proceedings of Cardiff Institute for Tissue Engineering & Repair Annual Scientific Meeting (CITER ASM 2021)
No full textCITER ASM 2021
The abstracts appearing in this book comprise the proceedings of the CITER ASM 2021, held between the 13th and 14th of September 2021. The posters presented reflect the authors’ opinions and are published as presented and without change (formatting and minor editing expected). Their inclusion in this publication does not necessarily constitute endorsement by the editors, CITER, or the Cardiff University.
Please use the following format to cite material from these Proceedings:
Author, AB, Author, XY, and Author, DE (2021), Title of paper, Proc. Cardiff Institute for Tissue Engineering & Repair Annual Scientific Meeting (CITER ASM 2021), M Al-Amri, R Weiser (Eds), pp. a–b, Cardiff, UK, 13-14 Sept. 2021, ISSN 2634-100X
Proceedings reference number: ISSN 2634-100X
Published by Cardiff University
For information, contact: CITER, Cardiff University, Redwood Building, King Edward VII Avenue, CF10 3NB.
Email: [email protected]
Abstract State Machines 1988-1998: Commented ASM Bibliography
No full textHartmut Ehrig asked the first author to write for this column what are the distinguishing features of the ASM approach to specification and verification of complex computing systems. In [21] an attempt had already been made to answer that question by discussing, in general comparative terms, some specific features which are characteristic for the ASM approach with respect to other well known approaches in the literature. That explanation seems to have been understood, as shown by the many positive reactions, but even more the numerous critical reactions of colleagues in the field who felt—rightly—that ASMs put justified doubt on cherished denotational, declarative, logical, functional and similar widespread beliefs in pure, i.e. not operational methods. Nevertheless some dissatisfaction remained with that paper because the discussion, in a sense unavoidably, remained in general terms which have been used during the last two or three decades again and again for the justification of many other methods. The attempt to answer the question in a more concrete way led the two authors of this commented bibliography to systematically review again, revising and updating [20], what are the achievements and failures of ASM research since the discovery of the notion by Yuri Gurevich in 1988. What follows here is a way of answering Hartmut Ehrig’s question; namely, we try to let the research results speak for the method. If somebody really wants to know whether there is anything useful in the notion of ASM which has not been covered by competing methods in the literature, he or she should try out the method on a challenging (not a toy) specification or verification problem. We have no doubt that then it will become clear why so much successful research could be done in such a short period by a relatively small number of researchers, as documented in the commented bibliography below
Cold cracking in DC-cast high strength aluminum alloy ingots: An intrinsic problem intensified by casting process parameters
No full textFor almost half a century the catastrophic failure of direct chill (DC) cast high strength aluminum alloys has been challenging the production of sound ingots. To overcome this problem, a criterion is required that can assist the researchers in predicting the critical conditions which facilitate the catastrophic failure of the ingots. This could be achieved at first glance by application of computer simulations to assess the level and distribution of residual thermal stresses. However, the simulation results are only able to show the critical locations and conditions where and when high stresses may appear in the ingots. The prediction of critical void/crack size requires simultaneous application of fracture mechanics. In this paper, we present the thermo-mechanical simulation results that indicate the critical crack size distribution in several DC-cast billets cast at various casting conditions. The simulation results were validated upon experimental DC-casting trials and revealed that the existence of voids/cracks with a considerable size is required for cold cracking to occur.Materials Science & EngineeringMechanical, Maritime and Materials Engineerin
‘Mining women’ and livelihoods: Examining the dominant and emerging issues in the ASM gendered economic space
No full textCopyright © The Author(s) 2024. The intractable challenges faced by female mine workers have come to dominate the discourse and scholarship on artisanal and small-scale mining (ASM) operations. However, the extensive focus on the informal and labour-intensive segments has engendered a failure to capture the nuances in the duality of ASM operations and how it impacts female outcomes. Drawing on intersectionality as a lens, in this article the authors map the dynamics on how issues related to the gender, situatedness and positionality of female mine workers interact to shape their situated labour outcomes. Highlighting the differentiated outcomes for female mine workers within the contingencies of the broader socio-cultural context in which ASM work is organised, the article sheds light on how the social identity structures such as gender, sexuality and class interact to give form to the marginalisation, occupational roles, the ‘boom town’ narrative and occupational and health challenges that characterise the ASM gendered economic space.The authors received no financial support for the research, authorship, and/or publication of this article
An integrated optic and acoustic (IOA) approach for measuring suspended sediment concentration in highly turbid environments
No full textAccurate measurement of suspended sediment concentration (SSC) in highly turbid environments has been a problem due to optical or acoustic signal saturation and attenuation. The saturation returns a limited measurement range, and the attenuation raises an ambiguity problem that a low optical or acoustic output could mean a low or a high SSC. In this study, an integrated optic and acoustic (IOA) approach is proposed to (i) overcome the ambiguity problem; (ii) increase the measurement range to high SSC values; and (iii) obtain high-resolution SSC profiles. The IOA approach is a combination of Argus Suspension Meter (ASM), Optical Backscatter Sensor (OBS) and Acoustic Doppler Velocimeter (ADV). In this approach, the ASM-derived SSC is preferred because of its lowest relative error, followed by OBS and ADV. The ASM can produce high-resolution (1 cm interval) SSC profiles when it is not saturated (usually SSC < 9 g/L). When ASM is saturated, the SSC is recovered by OBS. Since the ambiguity problem is solved, the measurement range of OBS and ADV can be extended up to 300 g/L. The best way to use an ADV, however, is to have a rough estimation first and assist in the OBS conversion, because its estimates contain large uncertainty. To further mitigate the impact of sediment particle size on SSC retrieval, we suggest the usage of in-situ sediment samples for sensor calibration. The IOA approach was verified in the Yangtze Estuary which is a highly turbid system. Comparison of the IOA approach outputs against water sampling results demonstrates the reliability of the IOA approach with a relative error of 17–34%. The observed high SSCs were up to 63 g/L. The field data show that high SSCs were confined in the benthic layer (within 2 m above the bed) in the wet season under a high river discharge, whereas the suspension was better mixed throughout the water column in the dry season.Accepted Author ManuscriptCoastal EngineeringEnvironmental Fluid Mechanic
The behaviour of stock returns in Amman stock market : a thin emerging market
No full textIn this thesis the behaviour of stock returns of firms listed on the Amman Stock Market
is examined. The thin trading characteristic of the market is emphasised and its possible
effects on empirical investigations are analysed.
The first four chapters contain a review of the literature on the importance of stock
markets, the Efficient Market Theory and the Capital Asset Pricing Model. The
literature suggests that the allocative efficiency of funds via stock markets is related to
the operational and pricing efficiency of these markets. In such an efficient market, the
expected return on an investment is related only to its risk.
Chapter 5 tests the weak form efficiency of the ASM with particular emphasis on the
problem of thin trading. To achieve this, three alternatives for filling missing data gaps
are examined. In particular, it was found that extrapolation, based on market
movements, induces more dependence patterns. Yet, Examining the other two
alternatives, using daily price changes, statistical inefficiencies were detected, on the
one day level. Fewer dependence pa%erns were repored br \onger rnerva'1s. The
reported first order positive serial correlation can coriseqnence. o'i 'p'icrng uirrxs
imposed on trading in the market.
Chapter 6 provides a database of individual stock and market returns. Compiling this
database was a major contribution of this research.
Chapter 7 investigates the effects of different return measurement and beta estimation
approaches on tests of the CAPM. Specifically, the evidence indicates that the use of
different return measurement approaches can affect the results of tests of this
equilibrium model. Also, the adjustment of the trade-to-trade method, used for beta
estimation, reduces heteroscedasticity resulting from using non equal time intervals
when applying the market model.
The first part of chapter 8 provides an investigation of the sensitivity of the results, of
CAPM tests, to the length of the period used to estimate beta. The results suggest that
the longer the period, used to estimate beta, the more are the reported deviations from
the implied relationships of the model. The second part of Chapter 8 provides a test of
the CAPM using pooled data, and employing four lengths of periods to estimate beta.
The evidence was not consistent with the model. But, when specific attention was given
to the problem of thin trading, by constructing sub samples of the most traded stocks,
the validity of the model was established. However, this was only the case when beta is
estimated using 24 months of past returns, suggesting that market risk in Jordan changes
fairly rapidly.
Chapter 9 investigates the power of some firm-specific variables in explaining the cross
section of stock returns on the ASM. The evidence suggests that the book value,
earnings, leverage and the firm size, do not help in explaining the cross section variation
of firms listed on the ASM. This evidence is in accord with the CAPM
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