bluuebunny/crossref_metadata_2025 huggingface dataset:
Classifying matters
Authors: Kirk John
Published: May 2007

Although the rhetoric of classlessness has never quite found the resonance that it has in North American mythology, there have been key moments in British culture when this proposition occupied a hegemonic role in sociological and cultural commentary. In recent years this position has strengthened so that a range of factors have displaced class and produced a more confident and strident rhetoric of classlessness in British society than heard hitherto. A focus in academic disciplines on identity politics and the rise of the consumer has meant a retreat from class analysis in a range of disciplines. This article aims to engage with ideas of classlessness through a reading of Beverley Skeggs recent Class, Self, Culture. It ends by making some suggestions on how class analysis might be resituated once more at the centre of cultural analysis.
Micro-independent record labels in the UK
Authors: Strachan Robert
Published: May 2007

This article examines the relationship between the practices of do-it-yourself (DIY) micro-independent record labels in the UK and wider mediated discourses surrounding the music industry. It is suggested that a heightened version of the art versus commerce dichotomy central to rock ideology provides the basis for a number of legitimizing theories through which the aesthetic and industrial conventions of these practitioners are justified and given importance. First, the article suggests that these legitimizing theories serve to narrow the scope of, and draw distinct boundaries around, small-scale cultural production. Second, through a self-conscious critique of globalized corporate media they serve as an engagement with the politics of cultural production and, ultimately, media power. Finally, using two prominent case studies relating to new technology (Arctic Monkeys and Clap Your Hands Say Yeah) the article examines the ways in which discourses relating to DIY cultural production impact upon mainstream music industry practice and discourse.
Marketization, participation, and communication within New Zealand retirement villages: a critical—rhetorical and discursive analysis
Authors: Simpson Mary , Cheney George
Published: May 2007

The retirement village sector1 is one part of the increasingly marketized `aged-care' services in New Zealand and in many other parts of the industrialized world. While critical researchers have examined organizational and residents' representations of aging, retirement, and retirement communities in the context of `the market', there is no research that examines communication related to residents' enactment of participation within these settings with respect to these processes of marketization. We aim to refine, complicate, and extend what we might call `the marketization thesis' through this study that examines resident participation within retirement communities. This essay is based on a comparative examination of two major New Zealand retirement community organizations. The rhetorical and critical discourse analysis reveals the complexity of what `participation' means for the residents within the context of an institution that is in transition from a medicalized to a marketized model of service delivery. Through a close examination of these meanings, we offer new insights into issues of individual action and freedom within the frame of a market-driven and avowedly `customer-centred' organization and consequently suggest a reconsideration of participation in organizations in which clients are also `insiders'.
False positive PCR detection of Tropheryma whipplei in the saliva of healthy people
Authors: Rolain Jean-Marc , Fenollar Florence , Raoult Didier
Published: May 2007

Background

Tropheryma whipplei, the agent of Whipple's disease (WD), has been recently isolated and the genomes of two isolates have been fully sequenced. Previous diagnosis tools for the diagnosis of the disease used sequence analysis of the 16S rRNA gene. Using this target gene, the high percentage of detection of the bacterium in saliva of healthy people was in contrast to the negative results obtained with specific target genes. The aim of our study was to compare previously published primers targeting the 16S rRNA gene to real-time PCR with Taqman* probes targeting specific repeat genes only found in the genome of T. whipplei in a series of 57 saliva from healthy people.

Results

Although the specific real-time PCR assays with both primers and probes were negative for all the samples, 13 out of 57 samples were positive with different primers previously reported targeting the 16S rRNA gene. Among the positive samples, 8 yielded a 231-bp sequence that was 99.1% identical to that of Actinomyces odontolyticus, 2 yielded a 226-bp that was 99.6% identical to that of A. turicensis, and 3 yielded a 160-bp sequence that was 98.5% identical to that of Capnocytophaga gingivalis. We found that the C. gingivalis and A. odontolyticus 16S rRNA sequences obtained in our study share more than 80% homology with the corresponding 16S rRNA sequences of the T. whipplei genomes especially at 5' and 3' end.

Conclusion

Asymptomatic carriers of T. whipplei in saliva may exist but their prevalence is much lower than those previously reported. Testing the specificity of designed primers is critical to avoid false positive detection of T. whipplei. In atypical case we recommend to test two different specific target genes before concluding.
Optimization and clinical validation of a pathogen detection microarray
Authors: Wong Christopher W , Heng Charlie Lee Wah , Wan Yee Leong , Soh Shirlena WL , Kartasasmita Cissy B , Simoes Eric AF , Hibberd Martin L , Sung Wing-Kin , Miller Lance D
Published: May 2007

DNA microarrays used as 'genomic sensors' have great potential in clinical diagnostics. Biases inherent in random PCR-amplification, cross-hybridization effects, and inadequate microarray analysis, however, limit detection sensitivity and specificity. Here, we have studied the relationships between viral amplification efficiency, hybridization signal, and target-probe annealing specificity using a customized microarray platform. Novel features of this platform include the development of a robust algorithm that accurately predicts PCR bias during DNA amplification and can be used to improve PCR primer design, as well as a powerful statistical concept for inferring pathogen identity from probe recognition signatures. Compared to real-time PCR, the microarray platform identified pathogens with 94% accuracy (76% sensitivity and 100% specificity) in a panel of 36 patient specimens. Our findings show that microarrays can be used for the robust and accurate diagnosis of pathogens, and further substantiate the use of microarray technology in clinical diagnostics.
Unexpected Events during the Intrahospital Transport of Critically Ill Patients
Authors: Papson Jonathan P.N. , Russell Kassandra L. , Taylor David McD.
Published: May 2007

Objectives:To examine unexpected events (UEs) that occur during the intrahospital transport of critically ill emergency department patients.

Methods:This was a prospective observational study of consecutive intrahospital transports between March 2003 and June 2004. The escorting emergency physician completed the data collection document either during or immediately after the transport. This document detailed equipment‐related UEs, patient instability and invasive line‐related UEs, whether the UEs required intervention, and whether the UEs were potentially life threatening (serious UEs).

Results:Of 339 transports observed, 230 (67.9%; 95% confidence interval [CI] = 62.6% to 72.7%) were associated with 604 UEs. Overall, there was a median of 1.0 UE per transport (range, 0–16). There were 277 (45.9%; 95% CI = 41.8% to 49.9%) UEs related to equipment, 158 (26.2%; 95% CI = 22.7% to 29.9%) related to patient instability, 156 (25.8%; 95% CI = 22.4% to 29.6%) related to equipment lines, and 13 (2.2%, 95% CI = 1.2% to 3.8%) miscellaneous UEs. The most common UEs were oxygen saturation probe failures, lead and line tangles, hypotension, and the wearing off of sedation and/or paralysis. Most UEs (478 [79.1%]; 95% CI = 75.6% to 82.3%) required an intervention. Emergency physicians had a significantly lower UE rate than residents. Thirty serious UEs occurred; 5.0% (95% CI = 3.4% to 7.1%) of UEs and 8.9% (95% CI = 6.2% to 12.5%) of transports were associated with a serious UE. The most common were severe hypotension, decreasing consciousness requiring intubation, and increased intracranial pressure.

Conclusions:Unexpected events during the intrahospital transport of critically ill patients from the emergency department are common and can be potentially life threatening. Transporting physician experience is associated with UE rate. Strict adherence to and review of existing transport guidelines is recommended.
Dynamic programming algorithms for the cutting problem of equal circles
Authors: Cui Yaodong , Zhang Xianquan , Zhang Hongxia , Zhao Xinfang
Published: May 2007

The current paper presents an approach for generating cutting patterns of equal circular blanks processed with the shearing and punching process, which includes two stages. A guillotine machine divides the sheet into strips at the first stage. A stamping press punches out the blanks from the strips at the second stage. Normal patterns consisting of orthogonal strips are proposed and four dynamic programming algorithms for generating them are presented. The first two algorithms deal with the unconstrained problem in which there is no constraint on the number of blanks included in a pattern, and the last two deal with the constrained problem in which the blank demand must be met exactly. The computational results indicate that the algorithms are efficient in both computation time and material utilization.
A revised cost-benefit algorithm for solving the expediting completion time of end product problem with defective materials in the product structure diagram
Authors: Chiu Singa Wang , Shih Chih-Chang , Chiu Yuan-Shyi Peter
Published: May 2007

This paper proposes a revised cost-benefit algorithm for solving the expediting completion time of end product (ECTEP) problem with defective components/materials in the product structure diagram. The existing cost-benefit ECTEP algorithm assumes that all materials produced or purchased are of perfect quality. However, the procurement of defective materials in a real-life situation is inevitable. This study extends the algorithm to take imperfect-quality component parts into consideration. Adjusted unit procurement cost and adjusted required quantity are incorporated to address the issue of defective materials procured. Both random and stationary imperfect quality rates are examined. The critical path method and time-costing method are utilized in the proposed solution procedures for finding the optimal material procurement alternatives that minimize the end product unit manufacturing cost (including compensatory cost for defective materials) as well as expediting its total completion time. A numerical example is provided to demonstrate its practical usage.
Development of a flexure hinge-based stack-type five-degrees-of-freedom nanometre-scale stage for a heavy-loading machining process
Authors: Jywe Wenyuh , Liu Chien-Hung , Teng Yun-Feng
Published: May 2007

The current paper concentrates on the design and manufacturing process of a stack-type nanometre positioning stage with high accuracy and multiple degrees of freedom for a heavy-loading machine. The stack-type stage described in this paper comprises a flexible structure as the primary component and can be easily adjusted from single-axis movement to a five-degrees-of-freedom motion to cope with different needs. Piezoelectric actuators are known for their unique features, such as quick response, high resolution, electrical mechanical coupling efficiency, and low heat generation. Therefore, six piezoelectric actuators are provided to trigger the five-degrees-of-freedom motion for the positioning stage. The stage sensor is provided with five capacitive sensors inside the five-degrees-of-freedom stage to measure the stage displacement. As indicated by the experimental results, the linear displacement reaches 52. 76 μm along the x axis, 51. 79 μm along the y axis, and 12. 08 μm along the z axis. The rotation displacement around the x axis is θ x = 184 μrad and the rotation displacement around the y axis is θ y = 277 μrad. The heavy-loading test indicates that the stage is capable of taking a load of 12 kgs.
Internet-based framework to support integration of the customer in the design of customizable products
Authors: Ninan J A , Siddique Z
Published: May 2007

Integration of customers is a necessary element to design and produce customer centric products. Design tools and methodologies need to be altered to accommodate customers into the process of designing customized products. In the current paper a mass customization framework is presented, that uses computer-aided design (CAD) and finiteelement-based optimization tools to integrate the customer into the design process via the internet. A mass customization template for generating optimized user-customized products is also presented. The capability of the system is demonstrated by a case study on customization of bicycle frames.
Modelling the effects of constraints and single axis welding process parameters on angular distortions in one-sided fillet welds
Authors: Mahapatra M M , Datta G L , Pradhan B , Mandal N R
Published: May 2007

Welding process parameters and joint fit-ups significantly affect angular distortion patterns. By using constraints at proper positions the angular distortion can be minimized. In the present work the effect of constraints in the form of tack welds to minimize angular distortion in one-sided fillet welds has been analysed. It has been observed that proper positioning of tacks plays an important role in controlling angular distortion. The process was modelled using the three-dimensional finite element technique. Three-dimensional transient thermal analyses were done for predicting temperature distributions by considering a moving heat source. The element birth and death technique was used for simulating filler material deposition. The fillet welds were sectioned and microstructure zones were measured. The thermal model was verified by comparing the temperatures obtained from the thermal analysis with experimental results. Transient thermal and non-linear structural analyses were carried out in order to predict angular distortions.
A new overhead estimation methodology: A case study in an electrical engineering company
Authors: Niazi A , Dai J S , Balabani S , Seneviratne L
Published: May 2007

Manufacturing cost is the largest element of overall product cost. This element is made up of several subelements: material costs, direct labour, and overheads. A good cost control system requires a better understanding of these individual subelements and their contribution to the total manufacturing cost. The aim of the current study is to analyse the existing manufacturing cost estimation methodology and to ascertain the contribution of the three cost subelements to the overall manufacturing cost in an electrical engineering company. The study identified a need to implement an improved overhead estimation methodology based on dividing manufacturing overheads into time- and material-related costs. A new mathematical model for estimating overhead for an individual product is, therefore, suggested that allows the apportionment of total overheads based on both the product lead times and material quantities. The new model's effects on the overall expected manufacturing costs are followed up retrospectively for a four-year period. The expected manufacturing costs obtained using the existing methodology and the proposed one are compared against the actual manufacturing costs. The proposed methodology is found to be superior to the existing one, as overheads are more accurately estimated. The study also reveals breakdown statistics for the three major elements of manufacturing cost.
Developing an automated design modification system for aluminium disc wheels
Authors: Hsu Yeh-Liang , Yu Chia-Chieh , Wu Shang-Chieh , Hsu Ming-Hsiu
Published: May 2007

Disc wheels intended for normal use on passenger cars have to pass three tests before going into production: the dynamic cornering fatigue test, the dynamic radial fatigue test, and the impact test. Fatigue prediction has been an important issue in the design of aluminium disc wheels. This paper presents an automated design modification system that integrates engineering analysis results and common redesign strategies by engineers with a fuzzy logic algorithm in order to provide effective strategies to reduce the failure probability in the fatigue test. A probability model, which uses simulation results to provide quantitative information regarding ‘how likely the wheel is going to fail in the fatigue test’, is described first, then engineers' common strategies for redesigning the wheels are provided. Sensitivities of the strategies with respect to the probability of fatigue failures have been calculated to evaluate these strategies. A set of fuzzy rules on how to reduce the failure probability using these strategies is established and an automated design modification system is constructed. Finally, this system is validated using three real wheel design examples. Using this system, designers' previous experience can be properly transformed and utilized by all designers.
Benchmarking of three processes for producing castings incorporating micro/mesoscale features with a high aspect ratio
Authors: Charmeux J-F , Minev R , Dimov S , Brousseau E , Minev E , Harrysson U
Published: May 2007

This paper investigates the capabilities of three different process chains for vacuum investment casting of parts incorporating micro/mesoscale features. The first two process chains employ the classical Lost Wax Process and make use of layer-based manufacturing technologies, ThermoJet and PatternMaster respectively, to create patterns out of a thermoplastic material, while the third one, Fcubic, produces directly a casting tree in zirconia ceramics. The study involves the manufacture of test parts in aluminium/zinc alloys and stainless steel with microfeatures in the range of 250 to 700 μm and aspect ratios up to 50. The dimensional accuracy, surface quality, and production costs of the investigated manufacturing routes are compared. A metallographic analysis is performed on castings in aluminium to investigate the evolution of the dendrite structure and eutectic clusters of microfeatures as a function of their aspect ratios together with their influence on the parts' mechanical properties. Conclusions are drawn about the applicability of the studied three processes for casting parts with micro/mesoscale features.
Position tolerancing in reverse engineering: The fixed fastener case
Authors: Kaisarlis G J , Diplaris S C , Sfantsikopoulos M M
Published: May 2007

The present paper addresses the assignment of geometrical position tolerances in reverse engineering. Specification of manufacturing position tolerances for a reconstructed component of an existing mechanical assembly constitutes a complicated task that requires a well-grounded approach. Among features of size, cylindrical features such as holes in conjunction with pegs, pins, or screws are the most frequently used for critical functions, as are the alignment of mating surfaces or the fastening of mating parts. The relationship between mating features is classified either as a fixed or as a floating fastener type. The presented method focuses on the fixed fastener case. It is based on the systematic formulation of dimensional and geometrical relationships and constrains that allow for rational computer-aided processing and evaluation of the measured data from the reference parts, for which appropriately developed algorithmic tools are used. It is shown that the method is reliable, provides for realistic results, and is also time and cost competent as compared with the conventional trial-and-error methods. A case study demonstrates the concept and method.
Some considerations on tool wear and workpiece surface quality of holes finished by reaming or milling in a nickel base superalloy
Authors: Axinte D A , Andrews P
Published: May 2007

Higher-strength heat-resistant superalloys are continually being developed to meet the engineering requirements for increased efficiency of gas turbine engines. In addition, work on machinability assessment is needed to fill the gap between the material development and manufacturing capabilities before considering the implementation of such materials in production lines. The present paper presents selected results on optimization of cutting conditions for hole-making processes of a new aerospace nickel (RR1000)-based superalloy manufactured via a powder route. The mechanical properties and the chemistry of RR1000 alloy indicate lower machinability when compared with the current disc alloys (e.g. Inconel, Waspaloy, Udimet). The hole-making processes, involving a succession of roughing (drilling) and finishing (normal/special reaming or plunge milling) operations, were evaluated through a multicriteria procedure consisting of the following output measures: tool life, hole accuracy, surface roughness, workpiece surface integrity, and level of cutting torque. It was found that simultaneous fulfilment of multicriteria quality measures is more dependent on the selection of tooling/cutting edge preparation involved in the finishing step rather than the relatively narrow intervals of operating parameters. While drilling and normal reaming lead to surface overheating (white layers) and material dragging, the change of edge preparation (e.g. double-relief angle) on the special reamers or the use of alternative cutting strategies (e.g. plunge milling) can generate finished holes within the required surface integrity standards. An original relationship between a derived measure from output sensory signals (i.e. specific cutting energy per tooth per revolution) and workpiece surface integrity (i.e. depth of strained material) has been investigated to assist further the selection of the ‘best’ finish machining operation. Additionally, this approach opens the avenue towards online surface integrity inspection via ‘key sensory measures’.
A procedure for benchmarking in multi-product manufacturing
Authors: Sharma S
Published: May 2007

Almost all the progressive industries run their manufacturing facilities at a certain optimum level. However, continuous efforts are still necessary to reduce the costs further. An approach is presented in the current paper for benchmarking in engineering manufacture. The manufacturing rate of a product is swapped with that of another appropriate product in the group and this paper provides a theoretical analysis of the effects on the relevant cost. The backorders and their effects on the total cost are included. The non-productive time in a cycle is also emphasized. The procedures are useful for improving the industrial operations further in the different manufacturing situations that they face.
An approach for condition monitoring of a turning tool
Authors: Sharma V S , Sharma S K , Sharma A K
Published: May 2007

Manufacturing has changed markedly in recent years. The trend is for saving on the cost of production because of market pressure. In order to achieve this goal, greater consideration has been given to automation in manufacturing. In this regard, a fundamental step is to know the condition of the cutting tool, which requires a reliable system to monitor the condition of the tool. Experimental investigation of cutting tool wear and a model for tool wear estimation is reported in the current paper. The changes in the values of cutting forces, vibrations, and acoustic emissions with cutting tool wear are recorded and analysed. On the basis of experimental results a model is developed for tool wear estimation in turning operations using an adaptive neuro fuzzy inference system (ANFIS). Acoustic emission (ring down count), vibrations (acceleration), and cutting forces, along with time, have been used to formulate the model. This model is capable of estimating the wear rate of the cutting tool. The wear estimation results obtained by the model are compared with the practical results and are presented. The model performed quite satisfactorily and gave good results with the actual and predicted tool wear values.
Evaluation of delamination in drilling medium density fibreboard
Authors: Davim J P , Clemente V , Silva S
Published: May 2007

Drilling is a frequently practised machining process in furniture manufacture owing to the need for component assembly. The drilling of medium density fibreboard (MDF) is significantly affected by the delamination tendency of these materials under the action of cutting parameters. The aim of this article is to study the cutting parameters (cutting speed and feed rate) on delamination in MDF drilling. A plan of experiments was performed drilling with cutting parameters prefixed in two MDF panels. The objective was to establish the correlation between cutting velocity and feed rate with the delamination around the MDF blind hole. The delamination factor decreases with the increase of cutting velocity and increases with the feed rate for both materials. The drill tests showed the important role of the cutting speed on the evolution of the delamination factor as a function of the material removal rate (MRR). The advantage of using a high cutting speed in drilling these materials is clear.
Numerical investigations of the flow mechanisms in a subsonic compressor rotor with axial-skewed slot
Authors: Lu X , Chu W , Zhu J
Published: May 2007

By applying a concept similar to ‘domain scaling’ treatment often used in multi-stage turbomachinery flow field to the interface between the rotor blade passage and end-wall treatments, a series of computational studies were carried out to understand the physical mechanism responsible for improvement in stall margin of a modern subsonic axial-flow compressor rotor due to the axial-skewed slot casing treatment. Particular attention was given to examining the interaction between the rotor tip flow and the axial-skewed slot. In order to validate the multi-block model applied in the rotor blade end-wall region, the computational results for the modern subsonic compressor rotor both with and without axial-skewed slot casing treatment were correlated with available experimental test data. The computed results agree fairly well with the experimental data, and the computations are then used to describe the interaction between the rotor tip flow and axial-skewed slot. Detailed analyses of the flow visualization at the tip have exposed the different tip flow topologies between the cases with axial-skewed slot and with untreated smooth wall. It was found that the primary stall margin enhancement afforded by the axial-skewed slot casing treatment is a result of the tip flow manipulation. The repositioning of the tip vortex trajectory further towards the trailing edge of the blade passage and delaying the movement of incoming/tip clearance flow interface to the leading edge plane are the physical mechanisms responsible for extending the compressor stall margin.
NOx formation pathways in lean-premixed-prevapourized combustion of fuels with carbon-to-hydrogen ratio between 0.25 and 0.88
Authors: Rutar T , Lee J. C Y. , Dagaut P , Malte P. C. , Byrne A. A.
Published: May 2007

NO x measurements in jet-stirred reactor (JSR) combustion of seven fuels are modelled using three complete chemical kinetic mechanisms. The two JSRs are operated at 1790 K, 1 atm, 2–4 ms, and the fuel-air equivalence ratio of 0.61. The modelled fuels are methanol, methane, ethane, ethene, propane, n-butane, and toluene. The experimental database also includes C1-C4 alkane mixtures, two light naphtas, four number two diesel oils, and benzene. The fuels and air are premixed, prevapourized, and preheated with a temperature-staged prevapourizer-premixer and an air-heater. Experiments show NO x and CO increase when burning fuels with increasing carbon-to-hydrogen ratio (from 0.25 to 0.88). The data are analysed using three complete chemical kinetic mechanisms: GRI 3.0 Mech., CNRS' C1-C4 hydrocarbon oxidation mechanism, and CNRS' toluene oxidation mechanism. The modelling shows that the increase in NO x with the fuel carbon-to-hydrogen ratio is because of the increase in the NO formation via NNH, Zeldovich, and nitrous oxide pathways. The NNH pathway produces between 25 and 45 per cent of the NO formed. GRI 3.0 Mech. tends to favour this pathway since it forms more O, H, and NNH reactive species than the CNRS' C1-C4 hydrocarbon mechanism. Several rate constants for NNH + O → NH + NO are considered and best agreement using two and three perfectly stirred reactor schemes is found with the rate constant k = 7 × 1013 cm3/mol/s.
Transient theoretical analysis of a multi-layered type of heat exchanger using porous media
Authors: Maramisaran M , Nassab S. A Gandjalikhan.
Published: May 2007

On the basis of an effective energy conversion phenomenon between gas enthalpy and thermal radiation, the thermal characteristics of a new type of multi-layered porous heat exchanger (PHE) are obtained in this study. This system has a five-layered structure consisting of two high temperature section, two heat recovery sections, and one low-temperature section. In each section, a transient theoretical analysis is conducted for a one-dimensional system in which convection, conduction, and radiation take place simultaneously in porous layers. The coupled energy equations for the gas flows and porous layers based on the two-flux radiation model are solved numerically to investigate the transient heat transfer characteristics of the system. It is clarified that this type of PHE operates efficiently, especially when the porous layers have high optical thickness.
Computational fluid dynamics technique as a tool for description of the phenomena occurring in pulverized coal combustion systems
Authors: Filkoski R. V. , Belosevic S. V. , Petrovski I. J. , Oka S. N. , Sijercic M. A.
Published: May 2007

The paper presents the overall frame, principal steps, and some results of a numerical model of a power boiler furnace that uses pulverized coal, with tangential disposition of the burners. This model demonstrates the application potential of the computational fluid dynamics (CFD) technique and of the computational thermal analysis. Complex three-dimensional furnace geometry, two-phase turbulent flow, coal combustion, and heat transfer have been examined. Two numerical modelling approaches were employed in the investigation, both based on the Euler-Lagrangean two-phase flow concept and on the gas-phase semiempirical k-ɛ turbulence model. The first approach is based on a specially developed comprehensive model of processes in a pulverized coal furnace. In the second case, a commercial CFD code is used to create a three-dimensional furnace model. Some distinctive results concerning the performance of the boiler that was examined are presented graphically. On the basis of a comparison between the simulation predictions and available site measurements, a conclusion can be drawn that these two numerical codes provide realistic insight into furnace processes. Qualitative agreement indicates that the calculations are reasonable and validates the submodels employed.
Liner dome shape effect on the annulus flow characteristics with and without swirl for a can-combustor model
Authors: Rahim A , Singh S. N. , Veeravalli S. V.
Published: May 2007

The annulus flow characteristics of a can-combustor model for different liner dome shapes have been experimentally established under isothermal flow conditions for both nonswirling and swirling flows. Pressure taps were used to measure the wall pressure along the air casing and liner, whereas, velocity and pressure profiles were measured with the help of a threehole pressure probe in null mode. Turbulence intensity has also been measured with a constant temperature hot-wire anemometer. The effects of dome shapes on the recirculation zone, as well as on flow uniformity in the annulus region, for fixed dump gap, have been specially looked into. It was observed that the liner dome shape affects the size of recirculation zone and flow uniformity in the annulus region. The performance of the system was also assessed in terms of total pressure loss and static pressure recovery between the first and last measurement stations. It was found that swirling flow with a hemispherical dome liner gives better flow characteristics in the annulus region when compared with the other two dome shapes (namely, ellipsoidal, and vertical ellipsoidal).
Investigation of liquid fuel combustion in a cross-flow burner
Authors: Kamal M. M. , Amohamad A
Published: May 2007

A rotary swirl burner was employed for liquid fuel spray combustion in a cross-flow stream of air. The effect of fuel spray orientation on mixing dynamics with the swirled air was investigated for different nozzle angles, including -45°, 0°, and 45°, respectively, with a variable portion of the air (from 0 to 100 per cent) allowed to flow aligned with the spray without swirl. The effect of swirl on CO and NO x emissions was found to be dominated by the competitive influences of improved mixing and increased kinetic rates. For cross injector alignment with air, NO x emissions were reduced by increasing the co-current air flowdue to the improved premixing effect, while for inclined alignment its emissions exhibited a reduction by supplying enough air to the spray lee side. High swirl intensity (swirl number up to 12) and co-current/cross-flow combination produce a reduction in the unburned hydrocarbons. The enhancement in flame radiation output with swirl was pronounced by an increase to 1.9 times the output without swirl. Inserting a porous medium at the burner exit, increased the enhancement to 4.18 times and promoted droplet evaporation. Enlarging the re-circulation zone beneath the fuel injector to a certain extent improved mixing and combustion efficiency.
Experimental verification of cross-angle for noise reduction in hydraulic piston pumps
Authors: Johansson A , Övander J , Palmberg J-O
Published: May 2007

One of the most important drawbacks with hydraulic systems is noise and vibration, which mainly originate from the hydrostatic pump. A great number of noise-reducing design features have been developed, but they are all, to a greater or lesser extent, sensitive to variations in operational conditions. The present paper is concerned with optimal design and experimental verification of the cross-angle in an axial piston pump. The cross-angle is a small fixed incline of the swash plate in the direction that is perpendicular to the traditional displacement direction. It enables effective noise reduction throughout the whole range of displacement angles.

Simulation-based optimization is used to design a pump with optimal cross-angle and a matching valve plate. The design is manufactured and experimentally evaluated. Source flow measurements using the two-microphone method show good agreement between simulation and experiments, which verifies the applicability of the simulation model used. The benefits from using the cross-angle are then verified by comparing it with a pump with a traditional swash plate design, i.e. without the cross-angle. Both source flow measurements and sound level measurements in an anechoic chamber show good improvements from using the cross-angle.
The feedforward minimal control synthesis algorithm and its application to the control of shaking-tables
Authors: Stoten D P , Shimizu N
Published: May 2007

Since the early 1990s, research in Europe, the Far East, and America on the control of shaking-tables for seismic investigations has been made all the more urgent, following a series of catastrophic earthquakes across the globe. The fidelity of the results from shaking-table tests, on which many designs of earthquake-proof systems depend, is largely governed by the accuracy of the controlled motion of the table and the test structure.

Coincident with these events has been the development of more advanced, adaptive, control systems that provide an opportunity for high-precision motion control in the face of dynamic interaction, non-linearity, and parameter variation within the test system. This paper discusses a new adaptive control algorithm, called the feedforward minimal control synthesis (FFMCS) algorithm, which offers improved shaking-table control, when used in conjunction with a more conventional fixed-gain controller. FFMCS has been developed as part of a joint Japan-UK initiative, motivated by prior testing of shaking-tables located in both Japan and Europe.

This paper describes the dynamic modelling of a typical shaking-table, in order to emphasize the key features required of its controller. Also detailed are the three-variable control (TVC) strategy, a conventional algorithm that is widely used within shaking-table test facilities, together with the development and stability proof of the FFMCS algorithm. A motivating and comparative implementation study of FFMCS on the control of a simple single-axis servohydraulic rig is also included, as well as comparative simulation studies on the previously modelled shaking-table.
Data reconciliation and gross error detection applied to wind power
Authors: Bennouna O , Heraud N , Rodriguez M , Camblong H
Published: May 2007

The current paper presents a method to identify and estimate gross errors for linear dynamic systems using polynomial approximation. The method presented in a previous paper which uses linear dynamic reconciliation, is extended to allow the dynamic estimation of errors. This method is applied to the doubly fed induction generator (DFIG) of a wind turbine. The technique is validated on an experimental system used to emulate the working of the wind turbine.
Predictive control of networked non-linear control systems
Authors: Ouyang H , Liu G. P. , Rees D , Hu W
Published: May 2007

Networked non-linear control systems (NNCS) are studied in this paper. A control scheme based on predictive control is proposed to address the problems introduced by the network. Based on the theory of the linearization of the non-linear process, a predictive control algorithm is constructed to generate a sequence of control predictions, some of which can suitably be selected to control the non-linear process and further compensate for the time delay. Methods are proposed to deal with the selection of control predictions, the control prediction sequence updating, and data disorders processing. The proposed control scheme is able to avoid the synchronization issue by modelling the predictive controller as an event-driven element. The stability of this NNCS has been studied by discussing the stability of an augmented system, the stability conditions of which can be transformed into a series of inequalities. In addition, the control method is validated by both simulations and experiments.
Constraint-based haptic rendering of a parametric surface
Authors: Zafer N
Published: May 2007

This paper presents a direct method for haptic rendering of a virtual object in which the object is represented as a virtual kinematic chain (virtual manipulator). The joint angles of the virtual manipulator (VM) are considered as parameters for the object's surface. The present algorithm is based on a closest-point approach that determines the joint angles (surface parameters) uniquely. The joint angles parameterize a point closest to the haptic device end-effector, and an impedance-type controller is designed for the haptic device that accounts for the haptic rendering algorithm. Within the control law, only the forces orthogonal to the object surface are rendered using the Jacobian of the VM, and the user feels a smooth surface whose stability (considering the coupled haptic device dynamics and closest-point algorithm kinematics) is guaranteed. Additional motion constraints on the virtual surface are also created by penalizing the joint angles of the VM, showing how this approach provides an efficient tool in designing a CAD (computer aided design) model.
Finite-element failure analysis of carbon fibre-reinforced plastic cylinders under transverse impact loading
Authors: Kaneko T , Sato K , Ujihashi S , Yomoda H
Published: May 2007

A finite-element (FE) model that can predict deformation and impact loading of carbon fibre-reinforced plastic cylinders under transverse impact loading is proposed. Thick-shell elements are used, and failure is evaluated at the integration points. A different failure criterion is defined for every failure mode. The fibre direction failure condition is defined by using failure strength obtained from three-point bending tests. Fibre transverse direction failure and out-of-plane failure conditions are determined by comparing impact test and FE analysis results for one test condition. These failure conditions are defined by calculating the principal shear stresses caused by impact, in a simulation with no other applied failure criteria, at the point of initial failure as determined by the experiment. The stiffness reduction coefficient after failure is determined by parameter study to minimize the errors between test and analysis. Using these failure criteria, the analysis results for the scale-size specimens and actual-size cylindrical structures, with different stacking sequence, matched.
Experimental characterization of the bond performance of a new type of glass fibre-reinforced polymer rebar for application in concrete structures
Authors: Moon D Y , Sim J , Oh H
Published: May 2007

This paper presents experimental results obtained from direct pull-out tests of commonly used and a new type of glass fibre-reinforced polymer (GFRP) rebar. The new GFRP rebar, developed by the authors, has a surface structure composed of milled glass fibres and epoxy resin, and its appearance resembles that of ordinary steel rebar. The effects of surface type and increased amounts of milled glass fibres in each rib on bonding with concrete were investigated to characterize the bond performance of the new type of GFRP rebar. The results indicated that the new type of GFRP rebar performed better with a higher bond strength to concrete compared with other tested types of GFRP rebar. Moreover, the rib bearing resistance and energy absorption appeared to increase with increased milled glass fibre in the ribs, which dominated the overall bond behaviour.
A wave-to-wire model of the SEAREV wave energy converter
Authors: Josset C , Babarit A , Clément A H
Published: May 2007

This paper describes a numerical wave-to-wire model of the second-generation wave energy converter called SEAREV. Governing equations are given in the time domain for the motion of the masses involved in the device and for the hydraulic power take-off (PTO) used to convert the motion into electricity. The hydrodynamic forces are derived using the standard linear potential theory. The memory term in the radiation force is replaced by additional states using the Prony method in order to change the equation of motion into the ordinary differential equation form. The PTO is composed of hydraulic rams, an accumulator, and a hydraulic generator, which delivers electricity when there is enough energy stored in the accumulator.

Using the MATLAB Simulink tool, the equation of motion is solved to simulate the full device (including the power take-off) from the incident wave to the electricity delivered to the grid. Simulation results are presented in the paper and comparisons are made with a simpler PTO: a linear damper. They show that the torque applied to the hydraulic PTO must exceed a threshold to start absorbing energy, unlike the linear damping model. They also show that the power production can be very discontinuous, depending on the level of the incident wave power. This is due to the fact that the generator considered can transform the energy stored in the accumulator faster than the energy transmitted by the rams into the accumulator. It could therefore be interesting to use several generators to adapt the electrical energy production to the level of incident wave power, or a generator that could work efficiently at part load in order to achieve continuous energy production.
Novel DNA Staining Method and Processing Technique for the Quantification of Undamaged Double-stranded DNA in Epidermal Tissue Sections by PicoGreen Probe Staining and Microspectrophotometry
Authors: Gagna Claude E. , Kuo Hon-Reen , Chan Norman J. , Mitacek Eugene J. , Spivak Alla , Pasquariello Tiffany D. , Balgobin Chandrika , Mukhi Ruhayna , Lambert W. Clark
Published: May 2007

Histotechnological processing of DNA can cause damage to and loss of DNA and can change its structure. DNA probes have severe tissue-staining limitations. New DNA probes and improved histotechnology are needed to enhance the characterization of fixed tissue-bound DNA. Our team developed a novel DNA staining technique and histotechnological processing procedure that improves tissue-bound DNA retention and the qualification and quantification of intact double-stranded (ds)-B-DNA. We used the ultrasensitive PicoGreen ds-DNA probe for the histochemical characterization of ds-DNA. Fifteen fixatives were examined to determine which were best for preventing DNA denaturation and retaining original DNA content and structures. Our use of a microwave–vacuum oven reduced heating temperatures, shortened heating and processing times, and enhanced fixation. We achieved better qualitative and quantitative results by using superior tissue-acquisition techniques (e.g., reduced prefixation times) and improved histotechnology. We also compared our novel approach with archival tissues, delayed fixation, less sophisticated and conventional histological processing techniques, and by experimenting with preservation of tissue-bound ds-Z-DNA. Results demonstrate that our histotechnological procedure and nucleic acid staining method significantly improve the retention of intact, undamaged ds-DNA which, in turn, allows the investigator to more precisely quantify the content and structures of unaltered and undamaged tissue-bound ds-B-DNA. (J Histochem Cytochem 55: 999–1014, 2007)
β-Catenin (CTNNB1) in the Mouse Uterus During Decidualization and the Potential Role of Two Pathways in Regulating Its Degradation
Authors: Herington Jennifer L. , Bi JiaJia , Martin John D. , Bany Brent M.
Published: May 2007

β-catenin plays a role in cell adhesion and as a transcriptional coactivator. Its levels are regulated in cells by controlling its degradation through ubiquitination by two different E3 ligase complexes. One complex contains β-transducing repeat containing (BTRC) protein, which binds to β-catenin when phosphorylated on specific (S33 and S37) residues, whereas the other involves calcyclin-binding protein (CACYBP). The aim of this study was to determine the localization and levels of total and active (S33/S37-dephosphorylated) β-catenin in the pregnant mouse uteri and those undergoing artificially stimulated decidualization. These two forms of β-catenin were localized almost exclusively to the endometrial epithelia just prior to the onset of implantation. Although this localization continued after the onset of implantation, there were less epithelial cells present in areas of the uterus undergoing decidualization. Rather, there was a progressive increase in β-catenin localization in endometrial stromal cells undergoing decidualization in the anti-mesometrial and, to a lesser extent, in the mesometrial regions. The presence of a conceptus was not required for the changes in localization seen in the pregnant uterus because similar findings were also seen in uteri undergoing artificially stimulated decidualization. Finally, overall levels of total, active (S33 and S37 dephosphorylated), and phosphorylated (S33/S37/T42) β-catenin protein and the steady-state levels of calcyclin-binding protein mRNA changed in the uterus during decidualization. The result of this study shows the changing localization and levels of β-catenin in the mouse uterus during decidualization. Further, the results suggest potential roles for both the BTRC and CACYBP E3 ligase mechanisms of β-catenin ubiquitination in the uterus during decidualization.