bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the Performance of H3BO3-filled Polyamide Composite
Authors: Unal H. , Yetgin S.H. , Sen U. , Mimaroglu A.
Published: April 2009

In this study, the performance of boric acid (H3BO3)-filled polyamide composites were studied and evaluated at dry-sliding friction conditions. Wear tests were carried out using configuration of composite pin on a rotating AISI D2 steel disc. Test conditions were atmospheric conditions, 10, 30, 50 N applied load values, and 0.4, 0.80, 1.20 m/s sliding speeds. The results show a large drop in the coefficient of friction of PA6 with the addition of H3BO3 filler and a significant change in specific wear rate. Furthermore, the coefficient of friction decreases while the specific wear increases with the increase in sliding speed and applied load values, respectively. Moreover, for the range of load and sliding speed values in this study, the coefficient of friction also registered lower values with the increase in H3BO3 content percentage. The influence of boric acid on the coefficient of friction and wear is more pronounced at severe working conditions. Finally, the coefficient of friction of H 3BO3-filled composite is a round 0.1 value and its specific wear rate is in the order of 10—4 m3/N m.
Studies on Mechanical Performance and Water Absorption of Recycled Newspaper/Glass Fiber-reinforced Polypropylene Hybrid Composites
Authors: Shakeri A. , Raghimi M.
Published: April 2009

The present experimental work is aimed at studying the performance of recycled newspaper and recycled newspaper/glass fiber hybrid polypropylene composites. The effects of glass fiber loading and maleic anhydride (MA) as a coupling agent on the tensile behavior and impact strength of composites containing 30 wt% fiber were examined. The results suggest that the tensile strengths of the recycled newspaper/PP composites increase with increasing glass fiber content. A value of 55 MPa for tensile strength and 4.1 GPa for the tensile modulus is achieved from a hybrid composite containing 10 wt% of newspaper and 20 wt% of glass fiber. The impact strength of the newspaper/PP composites progressively decreased with increasing glass fiber content. Adding (MA) by 2 wt% in the composite formulation significantly improved both the dimensional stability and mechanical properties. Microstructure analysis of the fractured surfaces of modified composites confirmed improved interfacial bonding. Dimensional stability and strength properties of the composites can be improved by increasing the glass fiber content and or by addition of coupling agent. This project has shown that the composites treated with glass fiber and coupling agents will be desirable as building materials due to their improved stability and strength properties.
Master Curves of Residual Creep and Fatigue Strengths for Damaged CFRP Composites
Authors: Hongneng Cai  , Miyano Yasushi , Nakada Masayuki , Sihn Sangwook
Published: April 2009

This article proposes a new concept of residual strength master curves for damaged carbon fiber-reinforced plastic (CFRP) after various spectral creep and fatigue loadings by using master curves for pristine CFRP, based on an accelerated testing methodology (ATM) and a statistical linear cumulative damage (SLCD) rule. Three-point bending fatigue tests for plain-woven CFRP composites were carried out under various cyclic loadings with both constant and variable amplitudes and frequencies. It was shown from the viewpoint of statistics that the SLCD rule can be applicable to the prediction of the flexural fatigue life of these CFRP composites under variable amplitudes and frequencies of cyclic loading. A method to construct the master curve of residual strengths for damaged CFRP from the master curves of creep and fatigue strengths for pristine materials was introduced.
Bond and Short-term Prestress Losses of Prestressed Composites for Strengthening PC Beams with Integrated Anchorage
Authors: Kim Yail J. , Green Mark F. , Gordon Wight R.
Published: April 2009

This article presents modeling of bond performance and short-term prestress losses of prestressed carbon fiber-reinforced polymer (CFRP) composite sheets for strengthening prestressed concrete beams, using an integrated anchor system that consists of steel plates bonded with CFRP sheets. A simple fracture mechanics model, validated with the experiment, is developed to examine the bond performance of the CFRP sheets for the plate-type anchor system. To predict the short-term prestress losses of the prestressed CFRP sheets used in the integrated anchor system, a closed-form solution is developed. Seven prestressed concrete beams strengthened with prestressed CFRP sheets are used to validate the proposed model. Fracture energy and tensile modulus of the CFRP sheets are the most critical factors affecting debonding failure of the plate-type anchor system. For design purposes, it is recommended that the short-term prestress loss be 10% of the applied prestress using the proposed anchor system.
Influence of Tool Assembly Schemes and Integral Molding Technologies on Compaction of T-stiffened Skins in Autoclave Process
Authors: Xueming Wang  , Fuyuan Xie  , Min Li  , Zuoguang Zhang
Published: April 2009

The structure of T-stiffened skins molded integrally by co-curing or co-bonding is widely used in aircraft industry nowadays. Ongoing research focuses on the study of the compaction of simple structure composite components and the analysis of mechanical properties of T-stiffened skins. In this article, using carbon fiber/bismaleimide prepregs, T-stiffened skins were integrally fabricated by different tool assembly schemes in autoclave. The influence of tool assembly schemes and integral molding technologies on the compaction of T-stiffened skins was discussed in detail. A method of self-designing solid pressure testing was introduced to measure the pressure distribution upon T-stiffeners during cure process. The compaction of T-stiffeners was studied quantitatively by thickness distribution and analyzed qualitatively by pressure transferring. The experimental results showed that the pressure distribution in T-stiffeners was significantly influenced by tool assembly schemes and tool radii, which directly affected the compaction of T-stiffeners. The optimum assembly of rigid tool and triangle flexible tool with appropriate stiffness was adopted. In comparisons of co-curing and co-bonding, little difference of compaction in web and flange of T-stiffeners were found except higher thickness in corner section for co-curing.
Knowledge Economy and Knowledge Society—Role of University	Outreach Programmes in India
Authors: Narasimharao B. Panduranga
Published: April 2009

India has the necessary potential to become a global leader in the knowledge economy. However, this cannot be achieved without the universities playing a prominent and leading role. Globally, higher education is poised to become more responsive to societal needs. Although many developments have taken place in the Indian higher education system, it still has to come to terms with modern society. The university outreach programme concept is fast picking up globally, and many universities use it for community development and building relationships with industries. In offering outreach programmes for community or for industries, we should go beyond merely providing some relevant courses. Some examples of universities where the relationship with society or industries has moved on from just offering distance education courses are given in this article. We need to find ways to use the ‘whole’ university, incorporating the various recent developments and meeting the requirements of various stakeholders of higher education. It is shown that university outreach is one of the best strategies where we can include various concepts like open distance learning, online learning, virtual universities, corporate universities, and so on, which have taken place in recent years. Universities, both traditional and distance education institutes, should move beyond their traditional boundaries to become more flexible and incorporate the new innovations that help in creating a knowledge society.
Centres of Excellence and Relevance
Authors: Beerkens Eric
Published: April 2009

This article analyses how the global model of centres of excellence and relevance (CERs) is adopted and adapted in three countries, Indonesia, Malaysia and the Netherlands. Each of these three countries have to some extent embraced the discourse of the knowledge society and knowledge economy in their higher education and science policies, and have—in their own ways—promoted the development of strategic research and the establishment of centres of excellence and relevance. It is the objective of this article to explore how these global models become embedded in the national institutional context, and factors that explain the different paths in which the three centres of excellence and relevance have evolved.
Learning and Innovation
Authors: Lorentzen Jo
Published: April 2009

Much innovation research views catch-up as a process that at low levels of development starts with imitation, and whose end point is innovation; and it posits that different stages require different frameworks to explain what is going on. In its more extreme versions it adds a horizontal to the over-time differentiation and demands that individual or groups of countries be appreciated for their contextual dissimilarities, requiring in each case yet another tailor-made model. The purpose of this review essay is to argue that to derive and justify different sui-generis frameworks from differential catch-up experiences is a non-sequitur, theoretically unsatisfactory, empirically unhelpful and not constructive for policy.

Conceptually, all the pieces for a more unified approach are in place. We know how firms gain competitiveness through dynamic capabilities and complementary assets. We also know that firm-level technological capabilities are related to national (and perhaps regional) technological capabilities. Finally, we know that governing and supporting institutions matter in addressing the uncertainty resulting from problems of information, coordination, and so forth. This provides an opportunity to apply insights from theories of firm behaviour and new evolutionary thinking on technologies and institutions to historically informed, comparative studies of firm-based catch-up over the last decade or so.
Negotiating Different Assumptions
Authors: Akazaki Misa
Published: April 2009

Growing diversity among international students requires analysis of the experience of particular groups of international students, which would provide implications to understand other groups of students. Changes in the society encouraged the Japanese to seek professional training on postgraduate courses in Japan as well as overseas. Employing a qualitative approach, semistructured interviews were conducted with mature Japanese students and staff to illustrate how these students negotiate their experiences. Among several findings identified in the research are the gaps in assumptions among stakeholders of international higher education. The stakeholders appear not to appreciate fully that these students learn from their experience and improve in four competencies: knowledge, communication, academic expectation, and learning from experience. The research reveals the potential of training courses on the awareness of these assumptions, and the crucial role of institutional leadership of universities to implement these training courses for staff and students.
Life Impairments in Adults With Medication-Treated ADHD
Authors: Safren Steven A. , Sprich Susan E. , Cooper-Vince Christine , Knouse Laura E. , Lerner Jonathan A.
Published: April 2009

Objective: In developing psychosocial approaches to augment outcomes for medication-treated adults with ADHD, it is important to understand what types of life-impairments are most affected by continued ADHD symptoms that occur despite medication treatment. This may assist in delineating targets for interventions, as well as assessments of functional outcomes that are sensitive to change in this population. Method: The sample consists of 105 adults with ADHD presenting for entry into clinical trials of CBT for residual ADHD. Life impairments are rated by a clinician using the LIFE-RIFT, which has subscales for work impairment, interpersonal impairment, life-satisfaction, and recreation, ADHD symptoms using the ADHD Rating Scale, overall ADHD severity using the clinical global impression, and associated distress using the Hamilton Depression and Anxiety Rating Scales. Results: The most problematic impairments are in the domain of work, followed by interpersonal. Generally, the subscales of the LIFE-RIFT are associated, at the bivariate level, with all 4 symptom indices. Work and interpersonal impairments are uniquely associated with overall severity of ADHD symptoms using both the CGI and the ADHD Rating Scale. However interpersonal and life-satisfaction impairments are uniquely associated with depression, and life-satisfaction is uniquely associated with anxiety. Conclusion: In medication-treated adults with ADHD, work and interpersonal impairments appear to be the most problematic areas of life-impairment, which are uniquely associated with ADHD severity. Life-satisfaction appears to be uniquely associated with distress as defined by anxiety and depression symptoms, with interpersonal impairments also playing a role. Psychosocial treatments for medication treated adults should target work and interpersonal domains and should include skills for managing associated distress.
Effects of Extended-Release Guanfacine on ADHD Symptoms and Sedation-Related Adverse Events in Children With ADHD
Authors: Faraone Stephen V. , Glatt Stephen J.
Published: April 2009

Objective: Guanfacine extended release (GXR) is a selective α2A-adrenoceptor agonist that is shown to be an effective nonstimulant treatment for the symptoms of attention-deficit/hyperactivity disorder. This report documents the time course and predictors of symptom efficacy and sedation-related adverse events (AEs) that emerge during GXR treatment throughout 3 randomized, placebo-controlled, double-blind trials of the drug. Method: Analysis of data from 3 GXR clinical trials. Results: Few variables related to the study participants or their treatment regimen affects the emergence or magnitude of sedation-related AEs. The best predictor of sedation is treatment duration, with the likelihood of sedation-related AEs decreasing with increasing time on medication. Sedation-related AEs are not predicted by the actual dose a participant receives, the magnitude of any dose changes, or the relationship between dose received and the magnitude of dose changes. Rates of discontinuation because of sedation-related side effects average 6.3% for GXR-treated participants and 0.5% for placebo-treated participants across the three trials. Conclusion: These results suggest that acclimation to GXR may minimize the risk for, and magnitude of, sedation-related AEs. (J. of Att. Dis. 2010; 13(5) 532-538)
Use of Wolfe Graft for the Treatment of Mucous Cysts
Authors: JAMNADAS-KHODA B. , AGARWAL R. , HARPER R. , PAGE R. E.
Published: April 2009

Many surgical procedures have been described for the treatment of mucous cysts. We report a case series of a surgical technique that excises the cyst along with overlying skin and reconstructs the defect using a Wolfe graft harvested from the wrist crease. This technique can be applied to cysts in all locations, even those adjacent to the nail. The procedure has been performed on 51 mucous cysts with satisfactory results, a very low recurrence rate (4%) and negligible complications.
Histological Staging and Dupuytren’s Disease Recurrence or Extension after Surgical Treatment: A Retrospective Study of 124 Patients
Authors: BALAGUER T. , DAVID S. , IHRAI T. , CARDOT N. , DAIDERI G. , LEBRETON E.
Published: April 2009

Dupuytren’s disease has a high rate of recurrence after treatment. In this study we have assessed the usefulness of histological staging in the prediction of recurrence. We have also verified whether there is a correlation between histological staging and features of Dupuytren’s diathesis. We studied 139 hands in 124 Caucasian patients treated between 1997 and 2004. There was a significant difference in the recurrence rate between the three histological types ( P = 0.04). Histological staging was independent of features of Dupuytren’s diathesis. This study confirms that histological staging is a reliable method for predicting recurrence. However, it should be used in association with clinical data to determine precisely the prognosis of patients suffering from Dupuytren’s contracture.
Evaluation of microstructures and wear properties of duplex boride coatings
Authors: Samadi V. , Habibolahzade A.
Published: April 2009

To improve wear behaviour of AISI 316L austenitic stainless steel, duplex surface treatments, including borochromising, borotitanising or borovanadising, were carried out using the pack cementation method. Chromising, titanising and vanadising treatments were performed at 1050°C for 4 h and then boriding was carried out on all pretreated specimens at 1000°C for 6 h. Optimum properties have been evaluated in borochromised samples, especially in respect to their surface hardness and wear resistance. Examination of the worn surfaces shows that the oxidation fatigue wear mechanism is predominant on wear failure of coated samples.
Surface characterisation of Pb1−xMnxTe alloy by atomic force microscopy and magnetic force mode
Authors: Kojić D , Matija L , Petrov L , Mitrović R , Koruga D
Published: April 2009

In this paper the authors present the results of surface characterisation of a lead telluride alloy conducted by atomic force microscopy and magnetic force microscopy. Relationship between surface morphology, in the range of several nanometres, and the magnetic properties allows precise determination of nanomagnetic particles size with their distribution within a scanned area. This method allows the characterisation of nanoparticles in dimensional and magnetic sense since the paramagnetic and diamagnetic range can be examined.
Study on properties of electroless (Ni–P)–Fe3O4 (nanometre) composite plated PET fabrics
Authors: Zhang H , Liu R L
Published: April 2009

Electroless composite plating of (Ni–P)–Fe3O4 nanoparticles on PET fabric was performed in the laboratory. The (Ni–P)–Fe3O4 coated fabric was investigated by means of scanning electron microscopy, energy dispersive spectroscopy, thermal gravimetric and X‐ray diffraction analysis. The electromagnetic shielding performance and abrasion resistance were also measured. The results showed that the onset decomposition temperature of electroless composite plated fabric was lower than that of the original one. The shielding effectiveness of (Ni–P)–Fe3O4 plated fabric increased with increasing the add‐ons of Fe3O4 nanoparticles. As compared with the Ni–P plated fabric, the abrasion resistance of (Ni–P)–Fe3O4 plated fabric became worse.
Erosion properties of Fe based amorphous/nanocrystalline coatings prepared by wire arc spraying process
Authors: Liang X. B. , Cheng J. B. , Bai J. Y. , Xu B. S.
Published: April 2009

Fe–Cr–B–Si–Mn–Nb–Y and Fe–B–Si–Nb–Cr amorphous/nanocrystalline coatings were fabricated by wire arc spray process. The microstructure and phase compositions of the coatings were characterised by means of SEM, EDAX and XRD. The formation mechanism of amorphous phase and nanocrystalline phase was discussed. The elevated temperature erosion behaviour of the coatings was also investigated using an air solid particle erosion rig. The microstructures of the coatings consist of amorphous phase and α-(Fe,Cr) nanocrystalline phase. Both coatings are fully dense with low porosity. The coatings exhibit better erosion resistance at lower impact angles. With increasing erosion temperature, the erosion rates of the coatings decrease. The Fe–B–Si–Nb–Cr coating has better elevated temperature erosion resistance than that of the Fe–Cr–B–Si–Mn–Nb–Y coating.
The ITP syndrome: pathogenic and clinical diversity
Authors: Cines Douglas B. , Bussel James B. , Liebman Howard A. , Luning Prak Eline T.
Published: April 2009

Immune thrombocytopenia (ITP) is mediated by platelet autoantibodies that accelerate platelet destruction and inhibit their production. Most cases are considered idiopathic, whereas others are secondary to coexisting conditions. Insights from secondary forms suggest that the proclivity to develop platelet-reactive antibodies arises through diverse mechanisms. Variability in natural history and response to therapy suggests that primary ITP is also heterogeneous. Certain cases may be secondary to persistent, sometimes inapparent, infections, accompanied by coexisting antibodies that influence outcome. Alternatively, underlying immune deficiencies may emerge. In addition, environmental and genetic factors may impact platelet turnover, propensity to bleed, and response to ITP-directed therapy. We review the pathophysiology of several common secondary forms of ITP. We suggest that primary ITP is also best thought of as an autoimmune syndrome. Better understanding of pathogenesis and tolerance checkpoint defects leading to autoantibody formation may facilitate patient-specific approaches to diagnosis and management.
FlyPhy: a phylogenomic analysis platform for Drosophila genes and gene families
Authors: Wu Jinyu , Xu Xiang , Xiao Jian , Xu Long , Yi Huiguang , Gao Shengjie , Liu Jing , Bao Qiyu , Zhao Fangqing , Li Xiaokun
Published: April 2009

Background

The availability of 12 fully sequenced Drosophila species genomes provides an excellent opportunity to explore the evolutionary mechanism, structure and function of gene families in Drosophila. Currently, several important resources, such as FlyBase, FlyMine and DroSpeGe, have been devoted to integrating genetic, genomic, and functional data of Drosophila into a well-organized form. However, all of these resources are gene-centric and lack the information of the gene families in Drosophila.

Description

FlyPhy is a comprehensive phylogenomic analysis platform devoted to analyzing the genes and gene families in Drosophila. Genes were classified into families using a graph-based Markov Clustering algorithm and extensively annotated by a number of bioinformatic tools, such as basic sequence features, functional category, gene ontology terms, domain organization and sequence homolog to other databases. FlyPhy provides a simple and user-friendly web interface to allow users to browse and retrieve the information at multiple levels. An outstanding feature of the FlyPhy is that all the retrieved results can be added to a workset for further data manipulation. For the data stored in the workset, multiple sequence alignment, phylogenetic tree construction and visualization can be easily performed to investigate the sequence variation of each given family and to explore its evolutionary mechanism.

Conclusion

With the above functionalities, FlyPhy will be a useful resource and convenient platform for the Drosophila research community. The FlyPhy is available at http://bioinformatics.zj.cn/fly/.
Prestack seismic data enhancement with partial common-reflection-surface (CRS) stack
Authors: Baykulov Mikhail , Gajewski Dirk
Published: April 2009

We developed a new partial common-reflection-surface (CRS) stacking method to enhance the quality of sparse low-fold seismic data. For this purpose, we use kinematic wavefield attributes computed during the automatic CRS stack. We apply a multiparameter CRS traveltime formula to compute partial stacked CRS supergathers. Our algorithm allows us to generate NMO-uncorrected gathers without the application of inverse NMO/DMO. Gathers obtained by this approach are regularized and have better signal-to-noise ratio compared with original common-midpoint gathers. Instead of the original data, these improved prestack data can be used in many conventional processing steps, e.g., velocity analysis or prestack depth migration, providing enhanced images and better quality control. We verified the method on 2D synthetic data and applied it to low-fold land data from northern Germany. The synthetic examples show the robustness of the partial CRS stack in the presence of noise. Sparse land data became regularized, and the signal-to-noise ratio of the seismograms increased as a result of the partial CRS stack. Prestack depth migration of the generated partially stacked CRS supergathers produced significantly improved common-image gathers as well as depth-migrated sections.
Interferometric interpolation of missing seismic data
Authors: Wang Yibo , Luo Yi , Schuster Gerard T.
Published: April 2009

We have developed an interferometric interpolation method for filling in trace gaps in common-shot gathers. There are two steps for implementation. First, virtual traces are created in the trace gaps by crosscorrelating recorded traces in a shot gather followed by summing correlated trace pairs over all shot positions. Second, a 1D matching filter is applied to the predicted events to correct for wavelet and amplitude distortions. By using a 1D assumption (assuming a layered medium around the midpoint in a common-midpoint (CMP) gather), the interferometric interpolation method can be applied to CMP gathers. It is a fully data-driven method that requires only the original data. Results with synthetic and field data empirically show that the near-offset traces can be interpolated; but because of the approximations introduced by a limited recording aperture, there are still some artifacts. For comparison, a 2D nonstationary prediction-error filter (PEF) was also used instead of a 1D matching filter in the second step of the interferometric interpolation method. The comparison between the 1D matching filter results and 2D PEF results does not show significant differences.
Estimating primaries by sparse inversion and application to near-offset data reconstruction
Authors: van Groenestijn G. J. , Verschuur D. J.
Published: April 2009

Accurate removal of surface-related multiples remains a challenge in many cases. To overcome typical inaccuracies in current multiple-removal techniques, we have developed a new primary-estimation method: estimation of primaries by sparse inversion (EPSI). EPSI is based on the same primary-multiple model as surface-related multiple elimination (SRME) and also requires no subsurface model. Unlike SRME, EPSI estimates the primaries as unknowns in a multidimensional inversion process rather than in a subtraction process. Furthermore, it does not depend on interpolated missing near-offset data because it can reconstruct missing data simultaneously. Sparseness plays a key role in the new primary-estimation procedure. The method was tested on 2D synthetic data.
Waveform inversion using a back-propagation algorithm and a Huber function norm
Authors: Ha Taeyoung , Chung Wookeen , Shin Changsoo
Published: April 2009

Waveform inversion faces difficulties when applied to real seismic data, including the existence of many kinds of noise. The [Formula: see text]-norm is more robust to noise with outliers than the least-squares method. Nevertheless, the least-squares method is preferred as an objective function in many algorithms because the gradient of the [Formula: see text]-norm has a singularity when the residual becomes zero. We propose a complex-valued Huber function for frequency-domain waveform inversion that combines the [Formula: see text]-norm (for small residuals) with the [Formula: see text]-norm (for large residuals). We also derive a discretized formula for the gradient of the Huber function. Through numerical tests on simple synthetic models and Marmousi data, we find the Huber function is more robust to outliers and coherent noise. We apply our waveform-inversion algorithm to field data taken from the continental shelf under the East Sea in Korea. In this setting, we obtain a velocity model whose synthetic shot profiles are similar to the real seismic data.
Just What Word Did Mandel'shtam Forget? A Mnemopoetic Solution to the Problem of Saussure's Anagrams
Authors: Gronas Mikhail
Published: April 2009

To the extent that memorability is one of the poet's chief (even if unconscious) concerns, poetic composition may be seen as a kind of mnemonic “reverse engineering” that utilizes the very operating procedures of verbal memory. In this article, I focus on the similarities between the cognitive operations involved in the tip-of-the-tongue phenomenon (a frustrating failure to retrieve a known but temporarily unavailable word) and those involved in creating the anagram, a poetic device discovered by Ferdinand de Saussure, in which the phonemes of the important theme word of a poem are dispersed throughout the body of the poem, while the word itself remains unsaid. Both the retrieval of a word on the tip of one's tongue and the (re)construction of an anagram involve sorting through the phonetic and semantic cues that hint at the absent target word. I suggest that these similarities may be due to the fact that both phenomena are subserved by a common cognitive mechanism: semantic and perceptual priming. On the basis of this analogy, I argue that in both ancient and modern literary traditions the anagram, whose origin puzzled Saussure, may have served a mnemonic function. The case study is provided by Osip Mandel'shtam's poem “I have forgotten the word that I wanted to say”—which both contains an anagram and presents an introspective analysis of the tip-of-the-tongue phenomenon.
Tête-À-Tête, Face-À-Face: Brodsky, Levinas, and the Ethics of Poetry
Authors: Williams David-Antoine
Published: April 2009

Two decades have passed since Joseph Brodsky used his Nobel address to advance the idea that “aesthetics is the mother of ethics.” Yet despite the increasing prominence of ethics in literary studies during this time, very little has been written to elucidate his claim. One thing the “turn to ethics” in literary studies has produced is a rise in popularity of Emmanuel Levinas among critics. The invocation of Levinasian responsibility, with its refusal to entertain a practical or normative ethics, demonstrates, among other things, how far some streams of ethical criticism have traveled from the politically inflected theory of earlier decades. In this article I place Levinas's writings alongside the critical prose of Brodsky, whose radical commitment to poetry—what Seamus Heaney called his “peremptory trust in words”—is set at a similar theoretical distance from the idea that the didactic, the deontological, or the political may be constitutive of ethics. To admit from the outset that Brodsky's maxim is inimical to Levinas's project—which is to establish ethics as the mother of philosophy, as it were—is to acknowledge that the rapprochement intended here cannot be in any sense final. Instead, in collocating Levinasian reflection on encounter, the originary, and the face-à-face with Brodsky's writings on poetry, I want to give philosophical substance to Brodsky's musings on the ethics of aesthetic encounter while simultaneously demonstrating one way Levinas can inform literary criticism.
Inverse finite element analysis of indentation tests to determine hyperelastic parameters of soft-tissue layers
Authors: Namani R , Simha N
Published: April 2009

Indentation is being used increasingly to probe the mechanical behaviour of cells, the extra-cellular matrix, and organs. Multiple hyperelastic parameters have been extracted from indentation data, but their accuracy has not been evaluated. Consequently, this paper examines whether two non-linear hyperelastic parameters or even a single generalized elastic modulus E can be extracted accurately from atomic force microscopy and nanoindentation force–depth data. Tissue was modelled as incompressible isotropic Mooney–Rivlin (MR), polynomial (POLY), or exponential (EXP) layers. For each model, n = 9 sets of the two hyperelastic parameters (all with R2 > 0.99) were extracted from an artificial ‘benchmark’ by running our inverse finite-element-based extraction algorithm multiple times. Error between the mean extracted E and the known ‘benchmark’ value was 5.5 per cent for an MR layer, 3.6 per cent for a POLY layer, and 20.6 per cent for an EXP layer. Errors in at least one of the two hyperelastic parameters reached 75 per cent for the MR layer, 33 per cent for the POLY layer, and 400 per cent for the EXP layer, indicating that indentation has limited potential to extract two or more hyperelastic parameters accurately. However, the generalized elastic modulus extracted from indentation could be used as a quantitative measure to evaluate the influence of altered processing conditions, pathology, etc.
Parametrical optimization of laser surface alloyed NiTi shape memory alloy with Co and Nb by the Taguchi method
Authors: Ng K W , Man H C , Lawrence J , Yue T M
Published: April 2009

Different high-purity metal powders were successfully alloyed on to a nickel titanium (NiTi) shape memory alloy (SMA) with a 3 kW carbon dioxide (CO2) laser system. In order to produce an alloyed layer with complete penetration and acceptable composition profile, the Taguchi approach was used as a statistical technique for optimizing selected laser processing parameters. A systematic study of laser power, scanning velocity, and pre-paste powder thickness was conducted. The signal-to-noise ratios (S/N) for each control factor were calculated in order to assess the deviation from the average response. Analysis of variance (ANOVA) was carried out to understand the significance of process variables affecting the process effects. The Taguchi method was able to determine the laser process parameters for the laser surface alloying technique with high statistical accuracy and yield a laser surface alloying technique capable of achieving a desirable dilution ratio. Energy dispersive spectrometry consistently showed that the per cent by weight of Ni was reduced by 45 per cent as compared with untreated NiTi SMA when the Taguchi-determined laser processing parameters were employed, thus verifying the laser's processing parameters as optimum.
Neural-network-based model for build-time estimation in selective laser sintering
Authors: Munguía J , Ciurana J , Riba C
Published: April 2009

Cost assessment for rapid manufacturing (RM) is highly dependent on time estimation. Total build time dictates most indirect costs for a given part, such as labour, machine costs, and overheads. A number of parametric and empirical time estimators exist; however, they normally account for error rates between 20 and 35 per cent which are then translated to inaccurate final cost estimations. The estimator presented herein is based on the ability of artificial neural networks (ANNs) to learn and adapt to different cases, so that the developed model is capable of providing accurate estimates regardless of machine type or model. A simulation is performed with MATLAB to compare existing approaches for cost/time estimation for selective laser sintering (SLS). Error rates observed from the model range from 2 to 15 per cent, which shows the validity and robustness of the proposed method.
Job remaining cycle time estimation with a post-classifying fuzzy-neural approach in a wafer fabrication plant: A simulation study
Authors: Chen T
Published: April 2009

A post-classifying fuzzy-neural approach is proposed in this study for estimating the remaining cycle time of each job in a wafer fabrication plant, which has seldom been investigated in past studies but is a critical task for the wafer fabrication plant. In the methodology proposed, the fuzzy back-propagation network (FBPN) approach for job cycle time estimation is modified with the proportional adjustment approach to estimate the remaining cycle time instead. Besides, unlike existing cycle time estimation approaches, in the methodology proposed a job is not preclassified but rather post-classified after the estimation error has been generated. For this purpose, a back-propagation network is used as the post-classification algorithm. To evaluate the effectiveness of the methodology proposed, production simulation is used in this study to generate some test data. According to experimental results, the accuracy of estimating the remaining cycle time could be improved by up to 64 per cent with the proposed methodology.
Optimal production lot sizing with backlogging, random defective rate, and rework derived without derivatives
Authors: Leung K N F
Published: April 2009

Several researchers have recently derived formulae for economic production quantities (EPQs) with some variants without reference to the use of derivatives, neither for first-order necessary conditions nor for second-order sufficient conditions. In addition, this algebraic derivation immediately produces an individual formula for evaluating the minimum expected annual cost. The purpose of this note is twofold. First, this study extends earlier results to the EPQ formula, taking the imperfect rework process into account. Second, the algebraic complete-squares and perfect-squares methods can readily derive optimal expressions from an objective function in a more simple, direct, and natural manner than the algebraic method of unity decomposition adopted earlier. A numerical example has been solved to illustrate the solution procedure, and some remarks are made to conclude the note.
Three-dimensional static analysis of rectangular thick plates by using the meshless local Petrov—Galerkin method
Authors: Vaghefi R , Baradaran G H , Koohkan H
Published: April 2009

In this article, a meshless local Petrov—Galerkin (MLPG) approach is developed for three-dimensional (3D) analysis of thick plates. Two different MLPG methods including MLPG1 and MLPG5 are employed to solve the elasto-static problems of thick plates. In MLPG1, a namely fourth-order spline function is considered as test function, while the Heaviside step function is employed as test function in MLPG5. Considering 3D equilibrium equations, the local symmetric weak forms are derived. The moving least-squares approximation is used to interpolate the solution variables and the penalty method is applied to impose the essential boundary conditions. In the present study, brick-shaped domains are chosen as local subdomains and support domains. The integrals appearing in the weak formulation are easily evaluated over brick-shaped subdomains and their boundaries. Considering the present approach, elasto-static deformations and stresses are analysed for thick rectangular plates with various boundary conditions and different aspect ratios. Excellent agreement is seen comparing the present results with the known analytical and numerical solutions in the literature.
Geometrical design of skew conical involute gear drives in approximate line contact
Authors: Wu S H , Tsai S J
Published: April 2009

A novel design for skew conical involute gear drives in approximate line contact is proposed. Such a drive has a contact ellipse with a large major-to-minor-axis ratio, which allows it to overcome the weakness of conical gear drives for application in power transmission. This gearing design approach is characterized by reduced edge contact sensitivity and increased surface durability. The edge contact sensitivity that can arise with this kind of gear drive due to assembly or manufacturing errors is evaluated by analysing the value of the shift of the line of action caused by such errors. The surface durability is evaluated by calculating the Hertz stress. Some guidelines are developed based on the analysis of the influence of the gearing parameters on the edge contact sensitivity and the surface durability made possible using this design approach for conical gear drives in the approximate line contact. The guidelines are summarized and, finally, a practical example is given to demonstrate the feasibility of the approximate line contact design.
An experimental study of a multi-particle impact damper
Authors: Trigui M , Foltete E , Abbes M S , Fakhfakh T , Bouhaddi N , Haddar M
Published: April 2009

In this article, an experimental study of a vertical particle impact damper under free excitation is investigated. Specific impact damping is determined for a primary structure (clamped-free beam) with an enclosure attached to its free end and containing a lead particle. The influence of some system parameters such as clearance and intensity of excitation are investigated. An analytical model based on the concept of an equivalent system with impacting mass is presented and used to compute the specific impact damping. Driven by the experimental observation, it has been shown that a high value of specific damping capacity was reached with a particle impact damper. The obtained results prove the efficiency of this process for achieving high structural damping.
Observation of cavitation inception in separating water flows through constricted channels
Authors: Washio S , Fujiyoshi S , Takahashi S
Published: April 2009

The research group including two of the present authors previously discovered a surprising phenomenon in oil flows through constricted channels; at a certain flowrate when there is no cavitation occurring, an infinitesimal cavity suddenly emerges on the wall where the flow separates. The newborn cavity grows and splits releasing many minute bubbles to downstream, as the flowrate increases. To see if this phenomenon occurs in water too, water flows through rectangular and cylindrical constrictions have been meticulously observed with very high resolution in terms of both time and space. As a result it has been confirmed that the same phenomenon does occur in separating water flows as well, although the developing process of a newborn cavity in water flows is different from that in oil flows probably depending on a large difference in Reynolds numbers between both flows. When the flowrate is substantially increased from that for the cavity inception, a large attached cavity is formed on the wall just downstream of the separation point, as it occurred in corresponding oil flows. The pressure inside the cavity has proved to be almost equal to the saturation vapour pressure of water.
Load-path-based modelling strategies for synovial joints
Authors: Yoxall A , Luxmoore J , Rodriguez-Falcon E
Published: April 2009

For designers there is a desire to understand the nature of strength and dexterity with regards to ageing, since by 2020 it is estimated that the majority of the UK population will be over 50 and the ageing processes lead to changes in a person's ability to grasp and manipulate objects. To that end work has been ongoing by the authors to model the human hand using the technique of finite-element (FE) analysis. Initially simple FE models were produced until better knowledge of the necessary issues could be obtained. This incremental approach led to the understanding of the nature of gripping and manipulation of objects before moving on to detailed modelling of skin, joints, and tendons. As part of this work, the authors undertook a detailed study on the most appropriate methods for modelling the synovial joint. The methods chosen were the Lagrangian formulation, arbitrary Lagrangian formulation, smoothed particle hydrodynamics, along with a constrained joint model. Little previous work has been undertaken in this area and is of interest not only for biomechanics modellers, but also for simulation engineers looking to model fluid—structural interaction problems. It was found that the arbitrary Lagrangian Eulerian (ALE) model was probably the most successful when compared against the small amount of data available in the literature.
Research on the port valve of a water hydraulic axial pump
Authors: Liu Y S , Wu D F , Long L , Cao S P
Published: April 2009

Water hydraulics using water as the working media is paid more attention because of its many advantages compared with oil ones. Water hydraulic pump is the key component in the applications of water hydraulics. Compared with the water hydraulic pump with port plate, the one with port valve has stronger anti-pollution ability and is more suitable for the open system where the working media cannot be filtered finely. For this kind of pump, the characteristics of port valve have direct and significant influences on the flow and pressure characteristics of the pump. In this article, the flow and pressure characteristics of different valves were compared experimentally and a disc valve was selected as the port valve. Then the mathematical model of a single-piston pump with port valve was built and the influences of different factors including spring rigidity, working pressure, etc. on the port valve were analysed. At last, a single-piston pump was developed to test the characteristics of the port valve. Based on these researches, some principles that should be abided in the design of the port valve were suggested.
Computational redesign of the test section for the Boeing/AFOSR Mach 6 Quiet Tunnel
Authors: Naiman H , Knight D D , Schneider S P
Published: April 2009

A proposed modification of the test section in the Boeing/AFOSR Mach 6 Quiet Tunnel is evaluated using CFD. The new design incorporates a section of increased diameter with the intention of enabling the tunnel to start in the presence of larger blunt models. Cone models with fixed base diameter (and hence fixed blockage ratio) are selected for this study. Cone half-angles from 15° to 75° are examined to ascertain the effect of the strength of the test model shock wave on the tunnel startup. The unsteady, laminar, compressible Navier—Stokes equations are solved. The resulting flowfields are examined to see what affect the shocks and shear layers would have on the quiet test section flow. This study indicates that cone angles ≤20° allow the tunnel to start.
Reductions in the effects of damping on stress concentration in premolars by post-endodontic restorations: A non-linear finite element study
Authors: Lo Y-J , Chang W-J , Lee S-Y , Chang K-J , Lin C-T , Huang H-M
Published: April 2009

The aim of this study was to measure the structural damping constants of premolars after treatment with a cast Co—Cr post—core system or permanent root filling, and to evaluate the stress damping effects of these restored premolars. Both the damping ratio and the natural frequency (NF) of the cast Co—Cr post—core restored premolars and the permanent root-filled premolars were detected by in-vitro NF testing experiments. Unprepared premolars served as the control. The damping constants β of the samples were calculated from the measured damping ratios and natural frequencies. The measured damping constants β of the test premolars were then used for dynamic finite element (FE) analyses. Stress contours and damping effects of stresses in each treated type of premolar were computed and compared using ANSYS. The measured damping constants β were 0.75×10−5 for the unprepared premolars, 0.69×10−5 for the root-filled premolars with coronal restoration, and 0.72×10−5 for the cast Co—Cr post—core restored premolars. The unprepared intact premolars demonstrated the highest stress dissipation effects with a ratio of 29.3 per cent at the middle root opposite to the loading side. However, no stress dissipation effects were found in the premolars that had been restored with the cast Co—Cr post—core system. The FE analysis showed that metallic post treatment attenuated the damping properties of the premolar. The effects of damping on stress concentration were significantly lower in restored premolars than in untreated vital premolars. These findings suggest that future research on post material should take the damping property into consideration.