bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the mast cell enigma: a personal reflection of what remains to be done
Authors: Henz Beate M.
Published: November 2008

Abstract:  Mast cells are traditionally viewed as effector cells of allergic reactions and parasitic diseases, but their importance in host defense against bacteria, in tissue remodelling, their bone marrow and stem cell origin and a central role of the stem cell factor (SCF) as mast cell growth and chemotactic factor has been worked out only in recent years. Despite this, major aspects about the nature of the cells and their role in disease remain unclear. This holds in particular for the identification of mast cell precursors and the role of growth factors that stimulate specific mast cell commitment from stem cells, such as nerve growth factor, neutrotrophin‐3 and certain interleukins, alone and during interaction with SCF. Early data suggesting also an involvement of specific transcription factors need to be expanded in this process. Furthermore, although mast cell proliferative disease (mastocytosis) has been shown to be often associated with SCF receptor c‐kit mutations, reasons for the development of this disease remain unclear. This holds also for mast cell release mechanisms in many types of mast cell‐dependent urticaria. Exciting new insights are emerging regarding the role of mast cells in bacterial infections, in defense against tumors, in wound healing and in the interplay with the nervous system, with hormones, and in the neurohormonal network. The aim of this reflection is to delineate the many known and unknown aspects of mast cells, with a special focus on their development, and to discuss in detail two mast cell‐related diseases, namely mastocytosis and urticaria.
Ultraviolet A induced modulation of gap junctional intercellular communication by P38 MAPK activation in human keratinocytes
Authors: Bellei Barbara , Mastrofrancesco Arianna , Briganti Stefania , Aspite Nicaela , Ale‐Agha Niloofar , Sies Helmut , Picardo Mauro
Published: November 2008

Abstract:  Aberrant gap junctional intercellular communication (GJIC) has been implicated in tumor development and progression. UltravioletA (UVA)‐induced oxidative stress has been associated with skin carcinogenesis. We report a potential link between GJIC and the cellular stress response induced by UVA in normal human keratinocytes (NHK). In this study, UVA irradiation (10 J/cm2) compromised GJIC integrity in absence of cytotoxic effects as demonstrated by the absence of cell death and by the reversibility of GJIC down‐regulation. Inhibition of communication by UVA was associated with hyperphosphorylation and decreased expression of connexin43 (Cx43), the most abundant gap junction protein expressed by keratinocytes. Cx43 hyperphosphorylation induced by UVA is, at least in part, mediated through mitogen‐activated protein kinase (MAPK) activation as Ser279 and Ser282 sites, two downstream direct targets of p38 MAPK were found to be phosphorylated after UVA treatment. However, inhibition of p38 MAPK activity did not significantly protect from cell–cell communication inhibition because of a strong cellular cytotoxicity observed with SB202190 and SB203580, two selective inhibitors of p38 MAPK, in combination with UVA that compromises the outcome of dye transfer assay. By contrast, in Hacat cell line, inhibition of p38 activity reduced both phosphorylation and degradation of Cx43, demonstrating that these events are correlated.
Implications of body mass and predation for ape social system and biogeographical distribution
Authors: Lehmann Julia , Dunbar Robin
Published: November 2008

Despite the fact that all African great apes have overlapping diets, they differ substantially in both biogeographical distribution and social organisation:Gorillalives in relatively small, cohesive groups within a small biogeographical area whilePanis much more widely distributed and lives in large, fluid groups in which the members are rarely all together. In this study we use a modelling approach to identify possible causes and consequences of these differences. We use a time budget model which is based on the relationship between time available for various activities, group size, body mass and climate. We demonstrate the importance of body mass as a critical determinant for maximum ecologically tolerable group size as well as ape distribution patterns. In addition, we show that predation pressure may play a strong role in limiting the distribution of smaller‐bodied apes (Pan). Predation pressure appears to be especially important if the apes opt for a fission–fusion strategy because it obliges them to maintain larger (sub‐) groups. In effect, the apes appear to face a tradeoff between solving the predation problem by increasing body size (at the expense of reduced ecological flexibility) and going for ecological flexibility (but at some cost in terms of how they handle predation).
CITIZENSHIP EDUCATION, POLICY, AND THE EDUCATIONALIZATION OF EDUCATIONAL RESEARCH
Authors: Hodgson Naomi
Published: November 2008

Abstract In this essay, Naomi Hodgson reconsiders the value of Michel Foucault’s normalization thesis to the study of educationalization in relation to contemporary educational policy and research. Hodgson begins by analyzing educational researchers’ response to the recent introduction of citizenship education in England, focusing specifically on a review of research, policy, and practice in this area commissioned by the British Educational Research Association (BERA). She argues that the BERA review exemplifies the field of education policy sociology in that it is conducted according to the concepts of its parent discipline of sociology but lacks critical theoretical engagement with them. Instead, such work operationalizes sociological concepts in service of educational policy solutions. Hodgson identifies three dominant discourses of citizenship education within the BERA review— the academic discourse of education policy sociology, contemporary political discourse, and the discourse of inclusive education — and draws attention to the relation of citizenship education to policy initiatives, and thus to educationalization. She then discusses Foucault’s concept of normalization in terms of the demand on the contemporary subject to orient the self in a certain relation toward learning informed by the need for competitiveness in the European and global context. Ultimately, Hodgson concludes that the language and rhetoric of education policy sociology implicate such research in the process of educationalization itself.
EDUCATION AND PLACE: A REVIEW ESSAY
Authors: Nespor Jan
Published: November 2008

Abstract In this review essay, Jan Nespor uses three recent contributions to place‐based education, Paul Theobald’s Teaching the Commons, C.A. Bowers’s Revitalizing the Commons, and David Gruenewald and Gregory Smith‘s edited volume Place‐Based Education in the Global Age, to examine some fundamental conceptual and practical issues in the area. One is how “place” is defined in place‐based education theory, and in particular how moralizing idealizations of place woven into problematic distinctions (place/nonplace, urban/rural, local/global, and so on) may actually make it harder for us to understand education and place. A second is how class, ethnicity, gender, and other forms of difference are addressed — or not — in the field’s theoretical formulations. Finally, Nespor explores problems of articulating the visions of place‐based education in these texts with larger social or political movements to transform schooling and environmental practices.
The twin‐arginine translocation (Tat) systems from Bacillus subtilis display a conserved mode of complex organization and similar substrate recognition requirements
Authors: Barnett James P. , van der Ploeg René , Eijlander Robyn T. , Nenninger Anja , Mendel Sharon , Rozeboom Rense , Kuipers Oscar P. , van Dijl Jan Maarten , Robinson Colin
Published: November 2008

The twin arginine translocation (Tat) system transports folded proteins across the bacterial plasma membrane. In Gram‐negative bacteria, membrane‐bound TatABC subunits are all essential for activity, whereas Gram‐positive bacteria usually contain only TatAC subunits. In Bacillus subtilis, two TatAC‐type systems, TatAdCd and TatAyCy, operate in parallel with different substrate specificities. Here, we show that they recognize similar signal peptide determinants. Both systems translocate green fluorescent protein fused to three distinct Escherichia coli Tat signal peptides, namely DmsA, AmiA and MdoD, and mutagenesis of the DmsA signal peptide confirmed that both Tat pathways recognize similar targeting determinants within Tat signals. Although another E. coli Tat substrate, trimethylamine N‐oxide reductase, was translocated by TatAdCd but not by TatAyCy, we conclude that these systems are not predisposed to recognize only specific Tat signal peptides, as suggested by their narrow substrate specificities in B. subtilis. We also analysed complexes involved in the second Tat pathway in B. subtilis, TatAyCy. This revealed a discrete TatAyCy complex together with a separate, homogeneous, ∼ 200 kDa TatAy complex. The latter complex differs significantly from the corresponding E. coli TatA complexes, pointing to major structural differences between Tat complexes from Gram‐negative and Gram‐positive organisms. Like TatAd, TatAy is also detectable in the form of massive cytosolic complexes.
The evolution of a pre-heated intergalactic medium
Authors: Borgani S. , Viel M.
Published: November 2008

We analyse the evolution of the intergalactic medium by means of an extended set of large box size hydrodynamical simulations which include pre-heating. We focus on the properties of the z∼ 2 Lyman α forest and the population of clusters and groups of galaxies at z= 0. We investigate the distribution of voids in the Lyman α flux and the entropy–temperature relation of galaxy groups, comparing the simulation results to recent data from high-resolution quasar spectra and X-ray observations. Pre-heating is included through a simple phenomenological prescription, in which at z= 4 the entropy of all gas particles, whose overdensity exceeds a threshold value δh, is increased to a minimum value Kfl. While the entropy level observed in the central regions of galaxy groups requires a fairly strong pre-heating, with Kfl > 100 keV cm2, the void statistics of the Lyman α forest impose that this pre-heating should take place only in relatively high-density regions, δh≳ 30, in order not to destroy the cold filaments that give rise to the forest. We conclude that any injection of non-gravitational energy in the diffuse baryons should avoid low-density regions at high redshift and/or take place at relatively low redshift z≲ 1.
A Strategic Framework for Monitoring Coastal Change in Australia's Wet‐dry Tropics – Concepts and Progress
Authors: MAX FINLAYSON C. , ELIOT IAN , ELIOT MATTHEW
Published: November 2008

A strategic framework for monitoring natural and human‐induced change in the coastal plains of the Alligator Rivers Region in the wet‐dry tropics of northern Australia is presented. The framework also supports refinement of methods used to monitor the vulnerability of coastal areas to change, including human‐induced climate change and sea‐level rise. The information derived through the framework can be used to assess scenarios, highlight the potential significance and implications of changes, and assist land managers formulate management responses.

The framework incorporates several large‐scale studies for monitoring atmospheric and hydrodynamic processes as well as mapping and monitoring projects specific to environmental change in the freshwater wetlands and the floodplains of the Region. Monitoring is proposed to address processes influencing the stability and rate of change of the floodplain environments. These include large‐scale processes, such as inter‐annual variability in weather conditions affecting the morphology of the coastal plains, shoreline and riverbank stabilisation, headward expansion of tidal creeks, and salinisation of freshwater basins.

Information management is also addressed, and a Geographic Information System structure proposed for effective data collation, analysis and management. The information management system will facilitate data sharing and participation of multiple agencies and organisations interested in coastal change, especially where a landscape perspective or whole ecosystem approach is advocated.
Planning to Reduce Risk: The Wildfire Management Overlay in Victoria, Australia
Authors: HUGHES RACHEL , MERCER DAVID
Published: November 2008

In a world where climate change is a ‘given’, the concepts of vulnerability, resilience and risk are now pivotal in public policy debates in many countries. Within this context, planning controls are designed to facilitate safe, sustainable and prosperous communities. In line withMarch's (2007, 11) observation that ‘one important “reason to plan” is the reduction of risk’, Victoria's Wildfire Management Overlay (WMO) was developed with the aim of mitigating wildfire risk through the identification of high risk areas and ensuring that minimum fire protection measures are implemented. The need for such an Overlay is becoming increasingly apparent as climate change contributes to the growing frequency and intensity of bushfires in Australia. Empirical research has found that, by following WMO prescriptions, the risk of a dwelling igniting from direct flame or radiant heat generated in a one in 50‐year fire event can be greatly minimised. Yet not all local Councils in Victoria have built the WMO into their land use planning processes and schemes. Barriers to adoption include: lack of political will, a distrust of ‘over‐regulation’, lack of training and mentoring of planning staff, and potential conflicts with vegetation conservation objectives.
Cerebral oxygenation decreases during exercise in humans with beta‐adrenergic blockade
Authors: Seifert T. , Rasmussen P. , Secher N. H. , Nielsen H. B.
Published: November 2008

Aim:  Beta‐blockers reduce exercise capacity by attenuated increase in cardiac output, but it remains unknown whether performance also relates to attenuated cerebral oxygenation.

Methods:  Acting as their own controls, eight healthy subjects performed a continuous incremental cycle test to exhaustion with or without administration of the non‐selective beta‐blocker propranolol. Changes in cerebral blood flow velocity were measured with transcranial Doppler ultrasound and those in cerebral oxygenation were evaluated using near‐infrared spectroscopy and the calculated cerebral mitochondrial oxygen tension derived from arterial to internal jugular venous concentration differences.

Results:  Arterial lactate and cardiac output increased to 15.3 ± 4.2 mm and 20.8 ± 1.5 L min−1 respectively (mean ± SD). Frontal lobe oxygenation remained unaffected but the calculated cerebral mitochondrial oxygen tension decreased by 29 ± 7 mmHg (P < 0.05). Propranolol reduced resting heart rate (58 ± 6 vs. 69 ± 8 beats min−1) and at exercise exhaustion, cardiac output (16.6 ± 3.6 L min−1) and arterial lactate (9.4 ± 3.7 mm) were attenuated with a reduction in exercise capacity from 239 ± 42 to 209 ± 31 W (all P < 0.05). Propranolol also attenuated the increase in cerebral blood flow velocity and frontal lobe oxygenation (P < 0.05) whereas the cerebral mitochondrial oxygen tension decreased to a similar degree as during control exercise (delta 28 ± 10 mmHg; P < 0.05).

Conclusion:  Propranolol attenuated the increase in cardiac output of consequence for cerebral perfusion and oxygenation. We suggest that a decrease in cerebral oxygenation limits exercise capacity.
(A)typique et (in)certaine? De la protection sociale des formes d'emploi «non standardisées» en Europe
Authors: Buschoff Karin Schulze , Protsch Paula
Published: November 2008

Résumé  Au cours de ces dernières années, les formes d'emploi atypiques que sont le travail à temps partiel, les emplois faiblement rémunérés, les contrats à durée déterminée (CDD) et le travail indépendant exercé en solitaire ont pris une place de plus en plus importante dans de nombreux pays européens. Elles font souvent partie intégrante de parcours professionnels irréguliers et sont liées à un risque de chômage accru. En comparant six pays, à savoir l'Allemagne, le Royaume‐Uni, les Pays‐Bas, l'Italie, le Danemark et la Pologne, nous nous demandons si et dans quelle mesure les législations sociales nationales incluent ces formes d'emploi atypiques et tiennent compte de leurs risques spécifiques. En matière de normes et de pratiques de couverture, des différences considérables entre les pays, ainsi que des variations importantes à l'intérieur de ces mêmes pays, ont été constatées dans leurs réponses aux différents types d'emplois atypiques. Un besoin d'approfondir et d'améliorer la coordination des législations, tant sociale que fiscale, a été identifié.
Strategic supporting role of a regional state‐level hospital during medical rescue after Wenchuan earthquake
Authors: Shi Ying Kang , Zheng Shang Wei
Published: November 2008

Shortly after the Wenchuan earthquake, the administrative leaders of West China Hospital accurately defined the role of the hospital during the medical rescue work as the treatment center for seriously wounded people, the support center for local hospitals and clinics in the disaster areas in Sichuan Province, and the logistics support center for medical teams from other provinces. Integrated leadership of management and efficient multidepartment co‐ordination and co‐operation were emphasized. The hospital was immediately transformed from regular mode into a double‐track emergency mode. Scientific allocation and dispatch of resources were ensured to meet the changing demand from all levels of rescue work. Three stages were defined based on the conditions of wounded people delivered to the hospital, with different main focuses for each stage. Because of the multidisciplinary co‐operation and concerted efforts of a large number of experts from other provinces and countries, an effective and efficient medical rescue service was offered to all wounded people. Until 2 June 2008, 2618 injured people from the disaster area have been treated, of whom 1751 were admitted to the inpatient department, 1135 were seriously wounded, 127 were admitted into the intensive care unit, 1239 underwent surgery, and 77 were treated with haemodialysis. There was an inpatient mortality less than 0.7%. Moreover, even during such a period, routine medical service was offered to patients other than people wounded in the disaster.
Emergency response and medical rescue in the worst hit Mianyang areas after the Wenchuan earthquake
Authors: Lei Bai Ling , Zhou Yun , Zhu Ying , Huang Xuan Yin , Han Si Run , Ma Qiang , He Jing , Li Yong Qing
Published: November 2008

The 12 May 2008 earthquake caused damage to 88% of the health systems in the worst hit areas of Mianyang with 326 casualties and the direct economic loss of RMB 3124 billion. Within 30 minutes of the earthquake, the Mianyang headquarters for earthquake disaster relief and the Mianyang public health headquarters for medical rescue and treatment were organized. Five medical teams were sent to Beichuang County, the worst hit Mianyang area, four hours after the earthquake. A total of 22,947 wounded and sick people were delivered to local hospitals after simple triage and rapid treatment through three stations. By 30 June, the Mianyang medical organization had received 379,600 people and admitted 21,628 inpatients. These 2772 severely wounded (including 146 with limbs amputated and 846 who died in hospital). Since 17 May, 3381 wounded had been transferred to 14 provincial and city‐level hospitals across China. On 20 June, the Mianyang Rehabilitation Center for wounded and sick people was established and received 156 rehabilitation inpatients. Together with the medical team for psychological intervention, they provided psychological support for over 70,000 people. Within two hours of the earthquake, the Mianyang Organization for Health and Epidemic Control and Prevention launched the emergency response plan for major natural disasters. The organization sent emergency teams for disease prevention and control and completed disinfection and burial of corpses and disposal of carcasses, monitoring of water quality and epidemics, disinfection of environmental ruins, epidemic control in resettled areas, precautions against secondary disasters caused by the earthquake, and large‐scale health education. The emergency command system for medical rescue and disease control and prevention in the Mianyang areas integrated resources, carried out unified command, and responded rapidly. Furthermore, the headquarters of medical relief co‐ordinated and united the governmental and nongovernmental organizations, achieving good performance for both medical relief and epidemic control. This experience of earthquake medical relief will benefit post‐disaster reconstruction, as well as the establishment of national and regional emergency response systems.
Clinical features of antinuclear antibodies‐negative type 1 autoimmune hepatitis
Authors: Miyake Yasuhiro , Iwasaki Yoshiaki , Kobashi Haruhiko , Yasunaka Tetsuya , Ikeda Fusao , Takaki Akinobu , Okamoto Ryoichi , Takaguchi Kouichi , Ikeda Hiroshi , Makino Yasuhiro , Ando Masaharu , Sakaguchi Kohsaku , Yamamoto Kazuhide
Published: November 2008

Aim:  Antinuclear antibodies (ANA) are the main serologic markers of type 1 autoimmune hepatitis (AIH); however 20–30% of patients are negative for ANA. We assessed the clinical features of ANA‐negative patients.

Methods:  A retrospective analysis was performed of 176 patients with type 1 AIH (153 females, median age 55 years). A diagnosis of AIH was made based on the revised scoring system proposed by the International Autoimmune Hepatitis Group. ANA titers were measured using a standard indirect immunofluorescence technique.

Results:  Thirty‐eight patients (22%) had low titers of ANA (1:40 or 1:80), and 114 (65%) had high titers (≥ 1:160). Of 24 ANA‐negative patients, 15 were positive for smooth muscle antibodies (SMA). Three of nine both ANA‐ and SMA‐negative patients developed ANA during follow‐up. The other six were diagnosed based on histological characteristics. Thirteen ANA‐negative patients relapsed after the normalization of serum alanine aminotransferase (ALT) levels. ANA‐negative patients more frequently showed acute presentation and, at presentation, had lower serum immunoglobulin G levels, higher serum levels of bilirubin and transaminase, and higher frequencies of histological acute hepatitis and zone 3 necrosis than those with high titers. However, the frequency of advanced stage of fibrosis was similar. The response to corticosteroids was not different among the three groups.

Conclusions:  ANA‐negative type 1 AIH shows acute‐onset more frequently but may include not only acute autoimmune hepatitis, but also acute exacerbation of inactive chronic disease. Regarding the diagnosis of ANA‐negative AIH, the determination of ANA during follow‐up and the response to immunosuppressive treatment may be helpful.
Object Identification and Tracking via Noise Updated Iterative Extended Kalman Filter
Authors: Bondarenko A. , Halevi Y. , Shpitalni M.
Published: November 2008

The paper considers the problem of simultaneous identification and trajectory tracking of moving objects (either 2D or 3D) from moving sensors. The identification is parametric and is based on knowing the family that the object belongs to, e.g. ball, ellipsoid, box, etc. The mathematical formulation results in implicit measurements, i.e. an algebraic equation that includes both state variables and actual measurements. The method of solution is via Extended Kalman Filter where the unknown parameters are regarded as additional state variables. Standard Extended Kalman Filter and Iterative Extended Kalman Filter yielded unsatisfactory results, mainly due to the nonlinearity of the measurements in both the state vector and the noise. A new algorithm, called Noise Updated Iterative Extended Kalman Filter is suggested. Its deviation from the standard iterative Kalman filter is in estimating the measurement noise at each iteration. The estimated noise is then used in the linearization stage to obtain a more accurate linear approximation. The method has been applied to the online identification and tracking problem, with substantial improvement in performance.
Advances in the Production of Seamless Rolled Rings With an Outer Profile
Authors: Pentleit A. , Golz J. , Meier H.
Published: November 2008

The aim of this research project is the extension of the shaping boundaries for the radial axial rolling of rings with an outer profile. Basis for this extension is the displacement of the ring from the longitudinal machine axis during the rolling process. This displacement causes a change of the deformation ratios for the benefit of the main roll, resulting in an improved material flow behaviour and thereby improving the profile filling of the ring. To enable the usage of this displacement approach the ring rolling machine located at the Chair of Production Systems had to be equipped with a displacement controller. To use the displacement without damaging the ring, the additional forces inflicted by the displacement have to be limited. Therefore a force controller is developed that calculates and sets the forces of the centering arms according to the current geometric and mechanical properties of the ring. Concluding to the theoretical development of the displacement and force controllers experimental rollings are presented that prove the capabilities of the controllers, the positive effects of the displacing and guidelines on how to set strategies for the displacement.
Energetic, Exergetic and Exergetic Cost Analysis for a Cogeneration System Integrated by an Internal Combustion Engine, HRSG and an Absorption Refrigeration System
Authors: Gonzalez Palomina Raul , Nebra Silvia A.
Published: November 2008

The objective of this work is to do an energetic, exergetic and thermoeconomic analysis of a cogeneration system. This system is composed of an internal combustion engine, a heat recovery steam generator (HRSG), an absorption refrigeration system (ARS) and a cooling tower (CT). With the use of the mass and energy balances, several parameters of efficiency based in the First Law of Thermodynamics were calculated for the cogeneration system. With the use of the exergy balance, the exergetic efficiencies for the engine, HRSG, ARS, CT and the total system were calculated. Also, the irreversibility contribution of each system component was shown. An optimization was done, having as functional objective the maximization of the difference of the operational incomes and expenses. An exergetic cost analysis was made using the Theory of the Cost Exergetic (TCE). The system in study gets to save up to 28,5% of fuel in comparison with the divided production of heat and electric energy. The largest irreversibility that happened in the cycle is due to the engine, which participates in the average with 78% of the total. The analysis with the TCE showed that the product of the ARS is more expensive in comparison with the process heat and electricity.
An Optimum Bending Groove Design of Panel to Minimize Noise Power
Authors: Jeon Jin-Young , Okuma Masaaki , Nakura Yusuke
Published: November 2008

In this paper, the authors propose a new method for optimum design of bending grooves on vibrating panel-like structures to reduce noise. It is proposed in the method to use the mapping of sound pressure level on the vibrating panel’s surface for best positioning of a bending groove and to apply the particle swarm optimization algorithm (PSOA) for determining the best dimensions of the bending groove. The optimum design method is applied to a rectangular aluminum panel whose size is 0.45×0.4m with thickness 0.001m under the boundary condition of clamping four edge lines. Then, a panel with a bending groove is actually made according to the optimum design, and an experiment is carried out to the panel for verification. The application study is carried out for two cases of different position of a point force excitation on the panel. The two applications demonstrate that the bending grooves designed by the optimization method can realize good reduction of sound power.
Energy Analysis of CO2 Removal in a CHP Plant Fired With Corex Export Gas
Authors: Lampert Krzysztof , Ziebik Andrzej , Manfrida Giampaolo
Published: November 2008

The Corex process is a more environmental-friendly method of pig iron production than the blast-furnace process. Additionally, this technology is accompanied by production of a fuel gas with a LHV twice as high as blast-furnace gas. Corex gas may be a useful fuel in a metallurgical CHP plant including a combined gas-and-steam cycle. The utilization of Corex gas contributes also to a decrease of CO2 emissions, which is an advantage from the viewpoint of the greenhouse effect. Moreover removing CO2 from the gas before its consumption can allow a further reduction of greenhouse issues. The paper considers the application of two methods of CO2 removal, namely “physical absorption (Selexol solvent)” and “cryogenic gas separation”. The effect of CO2 removal on the operation of CHP plants has been investigated. The removal of CO2 affects first of all the quality of fuel gas in comparison with the raw Corex gas. However, the CO2-removal installation is characterized by a considerable power consumption. Thus the net power and the efficiency of the CHP plant are reduced. Comparing the two considered methods of CO2 removal the cryogenic separation method requires more input energy, but in some cases liquefied CO2 may be an attractive agent. The paper contains the results of a quantitative analysis of the application of these two CO2-removal methods in the Corex technology and their effect on the exploitation characteristics of CHP plants fired with Corex gas.
Experimental and Analytical Study of the Hysteretic Behaviour of Bolted Joints
Authors: Oldfield Matthew J. , Ouyang Huajiang , Mottershead John E.
Published: November 2008

This paper presents the experimental results of a single joint rig subjected to torsional excitation and the analytical models for representing the experimental results. A bolted joint connecting two beams is shaken at the resonant frequency and the time-domain data and the resultant hysteresis loops of the torque versus the relative angular displacement of the joint are obtained. Damping behaviour evolving from linear viscous type to nonlinear friction type is clearly seen. Both the Jenkins element model and the Bouc-Wen model are used to fit with the hysteresis loops of the experimental results. The capability of the two models in representing experimental hysteresis loops is discussed.
Design and Analysis of Thermal-Bubble-Based Micromachined Accelerometer
Authors: Liao Ke-Min , Chen Rongshun , Chou Bruce C. S.
Published: November 2008

In this study, a novel thermal-bubble-based micromachined accelerometer with advantages of no proof mass, preferable frequency response, and high sensitivity is presented. Unlike the other techniques, the only moving element in the proposed device is a small thermal-bubble created by using a high flux heater to vaporize the liquid contained in the micro chamber. In order to improve the performance of the accelerometer, the basic physical characteristics of this sensor have been analyzed. Numerical simulations are conducted to study the heat transfer and fluid flow behavior of the device and to demonstrate the feasibility of our design. The temperature profile and the velocity field distribution under different applied acceleration have been acquired. Moreover, a method for manufacturing the accelerometer by using the techniques of micromachining is provided and the performance of the presented design has been examined. The results concluded that the proposed design has better response and sensitivity comparing to its counterparts.
Robust QFT Control of a Piezo-Based Vibration Isolation System With Consideration of Hysteresis Effect
Authors: Tsai Meng-Shiun , Chiang Feng-Ching , Sun Yan-Shuo , Wu Jen-Hua
Published: November 2008

In this paper, we investigate a three-degree-of-freedom (X-Y-Z) piezo-based vibration isolation platform. The hysteresis effect together with system uncertainties are represented by an approximate model. The approximate model consists of a variable gain and variable time-delay which are the functions of the input magnitude and frequency. Experiments are performed to identify the parameters of the proposed approximate model. To achieve robust performance of the isolation system with consideration of the hysteresis effect, quantitative feedback theory (QFT) controller is proposed. The hysteresis model is naturally built into the template of plant. It is shown from closed loop experiments that the designed controller can achieve high disturbance rejection within the bandwidth of 10–60Hz for the MIMO vibration isolation system.
Identification Technique of Aircraft Gas Turbine Engine’s Health
Authors: Pashayev A. M. , Askerov D. D. , Sadiqov R. A. , Abdullayev P. S.
Published: November 2008

Groundlessness of probability-statistic methods application is shown, especially at an early stage of the aviation gas turbine engine (GTE) technical condition diagnosing, when the volume of the information has property of the fuzzy, limitation and uncertainty. Hence efficiency of application of new technology Soft Computing at these diagnosing stages with the using of the fuzzy logic and neural networks methods is considered. Training with high accuracy of multiple linear and nonlinear models (the regression equations) received on the statistical fuzzy data basis is made. For models choice is offered the application of the fuzzy correlation analysis results. Dynamics of correlation coefficients changes is considered. At the information sufficiency it is offered to use recurrent algorithm of aviation GTE technical condition identification (Hard Computing technology is used) on measurements of input and output parameters of the multiple linear and nonlinear generalised models at presence of noise measured (the new recursive least squares method). As application of the given technique the estimation of the new operating aviation engine D-30KU-154 (aircraft Tu-154M) technical condition was made.
A Robotic Approach to Stereotactic Radio-Surgery
Authors: Rossi Aldo , Trevisani Alberto , Gasparetto Alessandro , Zanotto Vanni
Published: November 2008

The aim of this paper is to present a new robotic system for minimally invasive radio surgery. The system is called DAANS and is used to move a new miniaturized x-ray source called PRS with great precision and repeatability. By means of the DAANS the PRS dose delivery center can be moved linearly along the emission axis and rotated about the same axis. Moreover the DAANS is provided with a load cell which measures the force, along the emission axis, exerted by the PRS on a patient’s tissues, and which allows generating an appropriate force feedback on a specifically developed haptic console. The system is now being manufactured and will soon be employed in clinical tests.
Flow Pattern Evolution With Time Mixing of Non-Newtonian Fluid in a Stirred Tank Using Particle Image Velocimetry
Authors: Fransolet E. , Marchot P. , Toye D. , Crine M.
Published: November 2008

This paper presents an experimental analysis of the evolution with time of the flow pattern in a stirred tank equipped with a rotor-stator mixer, when mixing a time dependent non-Newtonian fluid. Particle image velocimetry (PIV) is used to determine 2D velocity maps. Polyacrylamide (PAAm) aqueous solution is used as model of time dependent shear thinning fluids. Creep compliance and recovery tests are performed to follow the evolution of the fluid rheology, from a viscoelastic behaviour to a purely viscous one. This indicates mixing has almost completely destroyed the initial network structure of the non-Newtonian fluid. The evolution of the flow pattern with the mixing time is compared with the flow patterns obtained in presence of Newtonian fluids as water and glycerol aqueous solution.
Influence of Non Uniform Boundary Conditions on Laminar Free Convection in Wavy Square Cavity With Partial Partitions
Authors: Sabeur-Bendehina A. , Aounallah M. , Adjlout L. , Imine O. , Imine B.
Published: November 2008

In the present work, a numerical study of the effect of non uniform boundary conditions on the heat transfer by natural convection in cavities with partial partitions is investigated for the laminar regime. This problem is solved by using the partial differential equations which are the equation of mass, momentum and energy. The tests were performed for different boundary conditions and different Rayleigh numbers while the Prandtl number was kept constant. Four geometrical configurations were considered namely three and five undulations with increasing and decreasing partition length. The results obtained show that the non uniform temperature in the vertical walls affects the flow and the heat transfer. The mean Nusselt number decreases comparing with the heat transfer in the undulated square cavity without partitions for all non uniform boundary conditions tested.
Vibration Measurement and Analysis Using Image Processing Method
Authors: Narimani Roya , Hoviattalab Maryam , Abadpour Arash , Yadolahi Azadeh
Published: November 2008

A large number of people are exposed to whole body vibration in their occupational life. Measuring vibration is an important tool in rehabilitation and biomechanical fields of research. We have proposed image processing as a new method to record and determine the frequency response of human body. The arranged set up for forced vibration consisted of an AC motor, a variable speed drive unit and a shaking table for producing one directional sinusoidal vibration. Volunteers were asked to stand on the shaking table at a relaxed posture. Two digital camcorders were used to capture the motion of colored pencil-dot markers on the skin of human body (forehead) and on the edge of the shaking table. After color spotting each frame, the binary image results were processed using new circle factor criteria proposed in this work, for fast finding circles based on second order statistics. The extracted points were calibrated using our own extended version of the direct linear transformation (DLT) method. Subsequently Vibration measuring software has been completely developed in Borland Delphi 5.0. Finally obtained displacement function of the body and the shaking table has been used in conjunction with Matlab 6.5 to prepare a proper algorithm for analyzing human body vibration. We discussed mechanical characteristics of the body by obtaining mechanical impedance and transmissibility from the shaking table to the head as example applications of the conducted software. The important point is the fact that all devices used in our developed measurement system are usually available in a biomechanics laboratory where a Gait system is functioning. This gives the opportunity for such laboratory to add vibration measurement to its capabilities without much excessive costs. The system has the advantage of lower noise sensitivity in comparison to accelerometer. The main advantage of this method is working with a simple user-familiar hardware with no external device attached to the subject and also a user-friendly-software.
Cavitation Detection of a Centrifugal Pump Using Instantanous Angular Speed
Authors: Al-Hashmi S. , Gu F. , Li Y. , Ball A. D. , Fen Tao , Lui Ke
Published: November 2008

Cavitation is a common fault in centrifugal pumps. The detection and diagnosis of the onset and severity of the cavitation provide the means of preventing the cavitation from causing harmful effects such as deterioration of the hydraulic performance, damage to pump components and the pollution by vibration and noise. This paper presents a new approach to monitoring cavitation based on the measurement of instantaneous angular speed (IAS) of the pump. IAS is measured using a cheap shaft encoder and processed using order spectrum analysis. It has been found that the normalised amplitude at the third order of the rotational speed can be used as a primary monitoring feature to detect the onset of the cavitation and to quantify the severity of the cavitation. A secondary detection feature is also defined in the high frequency range. This makes the detection results more reliable.
Evaluating the Implementation of the Component-Based System in the Automotive Sector
Authors: Ong Min Huey , Monfared Radmehr P. , Lee Szer Ming , West Andrew A. , Harrison Robert
Published: November 2008

Current evaluations of manufacturing automation and systems technology are often focused on cost savings and the impact on resources such as information and human resources are often not given sufficient attention. Furthermore, evaluations are still largely ad-hoc. A structured method for evaluating the implementation of Component-Based manufacturing systems in the automotive sector is outlined in this paper. Although the Component-Based Approach (CBA) has been applied in the software industry for quite some time [1–4], it is still relatively new in the automotive sector in terms of the manufacturing control for machinery. The CBA has been adopted for developing a component based control system, which is targeted for replacing the centralized programmable logic control (PLC) based systems in transfer-line and assembly machine applications [5, 6]. The implementation of such an approach will inevitably brings with it many challenges and changes to the operation of an enterprise. Research conducted to understand the impact of these changes is outlined in this paper. The paper first looks into the CBA in the software industry and draws lessons from its development in that domain. This is followed by a description of the approaches used in this research, namely, knowledge elicitation, process representation, modeling, scenario testing and analysis of results. The information from the knowledge elicitation phase is being documented in the form of process representation and modeling, based on the CIMOSA process modeling approach. This is further supplemented with scenario based testing. A set of matrices, including business and human factors, is established for evaluation, and finally, observations and results from the research will be outlined.
Finite Element Formulation of Pre-Stressed Ball Screw Drives
Authors: Zaeh Michael F. , Oertli Thomas
Published: November 2008

In this paper a stiffness matrix of the ball screw drive element is formulated as an approach for substitute modeling of the stiffness conditions at the ball-groove contacts in the engagement region of the ball screw and the nut. A scalar spring model is proposed, for the coupling between the ball screw and the nut with respect to both the stiffness properties and the screw degree of freedom of the ball screw drive. This permits combined modelling and vibration analysis of entire frame structures including ball screw feed drive systems by means of integral finite element models. The feed axis of a feed drives test station serves here as an example for demonstration and for verification of the modelling approach. A reduced order representation of the finite element model is used for simulation of the feed axis in control, the results of which match corresponding measurement results obtained from the test station.
Finite Element Modeling for Energy Release Rate in Human Cortical Bone
Authors: Charoenphan Saiphon , Polchai Apiwon
Published: November 2008

The energy release rates in human cortical bone are investigated using a hybrid method of experimental and finite element modeling techniques. An explicit finite element analysis was implemented with an energy release rate calculation for evaluating this important fracture property of bones. Comparison of the critical value of the energy release rate, Gc, shows good agreement between the finite element models and analytical solutions. The Gc was found to be approximately 820–1150 J/m2 depending upon the samples. Specimen thickness appears to have little effect on the plane strain condition and pure mode I assumption. Therefore the energy release rate can be regarded as a material constant and geometry independent and can be determined with thinner specimens. In addition, the R curve resulting from the finite element models during slow crack growth shows slight ductility of the bone specimen that indicates an ability to resist crack propagation. Oscillations were found at the onset of the crack growth due to the nodal releasing application in the models. In this study light mass-proportional damping was used to suppress the noises. Although this techniques was found to be efficient for this slow crack growth simulation, other methods to continuously release nodes during the crack growth would be recommended for rapid crack propagation.
Fatigue Failure Modes in Self-Piercing Riveted Aluminium Alloy Joints
Authors: Han L. , Young K. , Hewitt R. , Chrysanthou A. , O’Sullivan J. M.
Published: November 2008

Self-piercing riveting, as an alternative joining method to spot-welding, has attracted considerable interest from the automotive industry and has been widely used in aluminium intensive vehicles. One of the important factors that need to be considered is the effect of cyclic loading in service, leading to possible fatigue failure. The previous work reported in the public domain on the behaviour of self-piercing rivets has mainly focused on static tests. The work which is reported in this paper is concerned with the fatigue behaviour of single-rivet joints, joining two 2mm 5754 aluminium alloy sheets. The investigation also examined the effect of interfacial conditions on the fatigue behaviour. A number of fatigue failure mechanisms were observed based on rivet fracture, sheet fracture and combinations of these. The investigation has shown that they were dependent on the applied load and the sheet surface condition. Three-parameter Weibull analysis, using Reliasoft Weibull ++5.0 software, was conducted to analyse the experimental results. The analysis enabled the prediction of early-type failure (infant mortality failure) and wear-out failure patterns depending on the condition of the self-piercing riveted joints and the alloy sheet surface.
Development of a Calorimeter for Evaluating Thermal Performance of Evaporators
Authors: Piske Alexsander Cristo , Moura Lui´s Mauro , Mendes Nathan
Published: November 2008

It is presented in this work a prototype of calorimeter developed to evaluate the thermal performance of fin-and-tube evaporators under steady-state conditions. The calorimeter determines the heat rate absorbed by the evaporator, providing qualitative analysis of performance for a given geometry. The calorimeter domain represents the cooling compartment of household refrigerators because it is closed and does not change neither energy nor mass air (humidity). Like consequence, there is a tendency in dehumidifying the ambient. Parameters such as refrigerant mass flow and evaporation temperature can also be adjusted. Therefore, it is possible to establish favorable conditions in order to test evaporating heat exchangers. Results of evaporator performance in terms of heat fluxes and overall heat transfer coefficient (UA) are presented and discussed as well.
Piezoelectric Paint: Thick-Film Sensors for Structural Monitoring of Shock and Vibration
Authors: Hale J. M.
Published: November 2008

This paper describes dynamic strain sensors made using piezoelectric paint, a novel piezoelectric thick-film material which can be deposited using conventional paint spray equipment. The morphology of piezoelectric paint is described briefly, followed by a fuller description of the characteristics of thick-film vibration sensors made using it. It is shown that they have adequate properties (dynamic range and bandwidth) for use in structural monitoring applications, and that they are robust against environmental damage. Finally, a field trial is described in which a sensor has survived for three years without significant deterioration in a typical location on a bridge.