bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrosion behaviour of electrodeposited Ni‐Mn alloys ‐ electrochemical impedance measurements
Authors: Stephen A. , Ananth M.V. , Ravichandran V.
Published: July 2002

Ni‐Mn alloys were electrodeposited on mild steel substrates from sulphate baths. Their corrosion behaviour was evaluated in 3 per cent NaCl with electrochemical impedance spectroscopy. The observed corrosion properties were found to be dependent on microstructure seen under an optical colour polarisation microscope. The corrosion resistance was maximum in the samples displaying a near homogeneous texture. Multi‐textured deposits suffered severe corrosion.
The creativity advantage ‐ is your organization the leader of the pack?
Authors: Cook Peter
Published: July 2002

Success in product and service innovation depends on creativity as a key input. Without a healthy and continuing supply of ideas, most organizations would cease to exist. A fundamental challenge facing leaders in the twenty‐first century is how to profit from individual potential and then leverage it so that it produces organizational innovation and excellence. This article takes a strategic view of creativity as a key element of competitive advantage. It outlines the conditions for creativity to flourish and is supported through the use of a number of case studies. Creativity is not predominantly something that can be “forced” through creativity “techniques”. It depends crucially on the setting of an appropriate context for ideas to emerge and their subsequent mobilisation into innovative products and services. When the context is right techniques can play their part in raising the level and type of creativity within organizations.
Good, bad or essential fats: what is the story with Omega‐3?
Authors: Sinclair Rosemary
Published: July 2002

Explains the value of Omega‐3 fatty acids in the human diet. Outlines the recommended daily amounts needed and possible sources. Explores their protective effects against heart disease and rheumatoid arthritis. Looks at recent research into the value of Omega‐3 fatty acids in infant nutrition, dermatological problems, lung disease and gastro‐intestinal disease.
The German dual system ‐ a model for Europe?
Authors: Deissinger Thomas
Published: July 2002

Examines the dual system of vocational education and training in Germany and points out that the system is more than just an alternative training arrangement. Draws on the five major features which underlie the principle of the dual system (dualism of learning venues, legalism and public responsibility for vocational training, the principle of self‐government, private commitment to training and the vocational principle) and assesses training which goes beyond the scope of individual companies as well as specific job requirements. Compares these specific features with training in Britain. Concludes that the German system of training provision may solve qualification problems, but is unlikely to provide a basis for emulation elsewhere in Europe.
TQM and BPR ‐ can you spot the difference?
Authors: Valentine Rob , Knights David
Published: July 2002

Business process re‐engineering (BPR) has been widely promoted as a technique for organisational survival in an increasingly competitive environment. The initial message and language of BPR was radical, calling for the obliteration of traditional methods of processing business. Organisations were encouraged to reinvent themselves. However, survey and case study evidence of the success rate of BPR projects has been disappointing. As a result, BPR is under revision, with new definitions and new remedies on offer. When examined, the similarities between the revised language of BPR and TQM are striking. This suggests that incremental process improvements are the more viable option for organisations seeking to improve quality and performance.
The study of news
Authors: Hannabuss Stuart
Published: July 2002

With intellectual convergence between the information and
communication professions, there is an increasing need to understand the
construction and dissemination of news, a product common to both
domains. Discusses major approaches to the study of news. Identifies
sources useful for the study of news in the context of higher education
library and information studies courses. Defines news as product and
process as socially constructed, sourced and created within complex
organizational frameworks. It is an ongoing professional responsibility
for information specialists to investigate news as information made up
of fact and opinion, objectivity and bias.
Theoretical approaches to the study of bullying at work
Authors: Rayner Charlotte , Sheehan Michael
Published: July 2002

This article provides a brief overview and commentary on theoretical approaches discussed in the articles by Einarsen, Liefooghe and Olafsson, and Rayner in the theoretical section of this special issue. In highlighting the difficulty in defining bullying, this article suggests that definitional boundaries ought to be all encompassing and open for discussion as a way of further developing the debate about workplace bullying. A discussion of methodological approaches, including those used by the authors in the theoretical section then follows. The article suggests that a collaborative approach between employers and researchers would help further address the problem of workplace bullying.
Tracminer: traction‐enhancing mining equipment accessory
Authors: Armada Manuel , Maza Mario , Fontaine Jean‐Guy , Gonzalez de Santos Pablo , Papantoniou Vasilios
Published: July 2002

Explains how the Tracminer project aimed to provide a robust, low cost device to be mounted as an accessory on the motorized wheels of traction machines, in order to increase grip on loose soils. The main goal was to provide a device increasing by 30‐40 per cent the traction capacity of the given machine in soft or marshy soil working conditions. The intended device was designed to be robust and simple to adapt to existing machines. A key element of the development strategy was to provide an accessory easy to mount on the machine, which can remain “idle” (in this case, retracted) while not needed. The machine may then be operated as usual, with the opportunity to engage the accessory in action when a better ground grip is required. Such a possibility offers significant advantages for the Tracminer accessory when compared with other permanent traction enhancement solutions such as metallic frames with grids attached to the wheels, accessory caterpillars, etc.
Designing a parts feeding system for maximum flexibility
Authors: Wolfson Wendy , Gordon Steven J.
Published: July 2002

Looks at short‐run production, frequent product modifications, and pressures to reduce product time to market make flexible manufacturing increasingly desirable. Despite advances in flexible systems, the problem of feeding parts to an assembly line is not fully addressed by conventional methods such as bowl feeders. New technologies such as Intelligent Automation Systems’ FPF2000 Flexible Feeder for Small Parts offer additional versatility for short production cycles with frequent changes, and multiple simultaneous assembly lines.
A comparison of defects in houses constructed by owners and registered builders in the Australian State of Victoria
Authors: Georgiou J. , Love P.E.D. , Smith J.
Published: July 2002

The lack of attention to quality control by house builders in the Australian State of Victoria has been a contentious issue for more than two decades. In an attempt to improve the quality of housing, various mechanisms have been adopted and discarded by industry‐based organisations and government legislation. While builders are encouraged to improve construction quality, little is known and published about the quality of housing produced by owner builders. This paper presents findings from an ongoing research project that compares the defects in houses built by owner builders with those of registered builders. The initial findings suggest that there is no significant difference between the quality of housing procured by owner builders and registered builders. The functional elements within a house where defects are likely to occur are identified and discussed. The paper concludes by suggesting that the use of a registered builder’s management expertise does not necessarily guarantee a better quality product.
Calculation of PCB track impedance
Authors: Burkhardt Andrew J. , Gregg Christopher S. , Staniforth J. Alan
Published: July 2002

The value of the controlled impedance of various track configurations is usually obtained using algebraic equations. Most of these equations, particularly those for non‐zero track thickness, have been obtained by either theoretical approximations or curve‐fitting the results of numerical solutions of the basic electromagnetic equations. With the advent of modern PCs it is now possible to calculate the impedances directly and quickly, using numerical techniques. This has the advantage of improving the accuracy of the impedance value and increasing the range of validity. Furthermore, a wider range of configurations is now possible. The paper discusses the algebraic equations and numerical solutions in more detail.
Kinanthropometry study of the physique of disciplined personnel
Authors: Tsang Brenda , Chan C.K. , Taylor G.
Published: July 2002

This paper applies the study of kinanthropometry to define the physique of 49 Hong Kong‐Chinese Fire Services recruits. Kinanthropometry has been widely used in predicting the secular trend in increased body size of and among different ethnic groups world‐wide. It has also been applied in the studies of the physiques of Olympic athletes. The criteria developed for this research can be used as standards for physical recruitment in the disciplined forces, as well as for streamlining and improving the basic measurement scale for the manufacture of uniforms. The results showed that the somatotypes of the studied disciplined personnel were distributed in the range of endomorphic mesomorph. Significant correlation was observed between somatotype components and body girths and length measurements.
Communications: quick response in clothing merchandising – a study of the buying office using network analyses
Authors: Leung Chun‐sun , Yeung Merinda
Published: July 2002

The merchandising process of a large buying office in Hong Kong was studied using a network analyses tool, programme evaluation and review technique (PERT). Quantitative and qualitative data were both obtained by in‐depth interviews with key people in the company. The delivery lead time, which was the cycle time from the receipt of an order by the buying office to the point where the garment lot was ready for shipment at the manufacturer’s factory, was determined quantitatively, and probabilities of late shipments analysed. For bulk orders of woven garments, the activity time of fabric manufacture and garment manufacture was found to account for about half and one‐third, respectively, of the total delivery lead time (about 69 days). Also the PERT was shown to help identify critical activities which were redundant and thereafter, through process re‐engineering, could shorten the delivery lead time and reduce the work load of the merchandiser.
Two‐component multilayered woven fabrics: weaves, properties and computer simulation
Authors: Lomov S.V. , Primachenko B.M. , Truevtzev N.N.
Published: July 2002

Presents general properties and examples of weaves for two‐component multilayered woven fabrics. Such fabrics have a combination of properties which it is difficult to achieve in traditional fabrics (bulk combined with good tenacity, high cover level with porosity), can be used in liningless garments and can cope with ergonomical restrictions when using fibres with special protective properties. Describes a CAD system which can be used as an aid for a technologist to choose yarns for warp and weft, fabric weave and picks/ends count to meet demands specified by a particular fabric usage. It employs a new method of coding of multilayered fabric structure; mathematical methods used are based on the mechanical model of yarns interaction in a fabric. This describes the spatial disposition of yarns which allows production of any desired images of fabric geometry, i.e. surface smoothness or shape of pores. Discusses the complex nature of porosity of multilayered fabrics.
The concept of virtual measurement
Authors: Stylios G.K. , Wan T.R.
Published: July 2002

This paper discusses the concept of virtual measurement in textiles and describes the development of a virtual 3D fabric drape measurement system. In this system, a physical based model is used to predict the draping performance, static and dynamic drape of a given fabric sample. Fabric mechanical properties are used for simulating the virtual 3D shape of the fabric samples, which produce a time‐variable deformation of the virtual fabric drape. The 3D fabric drape can be observed under any view angle. An algorithm is developed, applied and integrated into the system for carrying out virtual fabric drape measurements in order to evaluate the drapeability of a given fabric. Important fabric aesthetic attributes such as number of fabric folds, fold variation and depth of fold are presented and implemented together with the drape co‐efficient.
School values and teachers’ feelings: a LISREL model
Authors: Pang Nicholas S.K.
Published: July 2002

Based on a sample of 101 teachers from 14 aided secondary schools in Hong Kong, a survey was conducted in March‐April 1994 to collect data about organizational values in schools and teachers’ feelings. Two new instruments, the “School values inventory” and the “Teachers’ feelings questionnaire”, were developed for this study. Using LISREL computer program to analyse the data, builds a linear structural equation model of school values and teachers’ feelings. The result is a LISREL model of school values and teachers’ feelings which indicates that cultural linkage in schools promotes teachers’ feelings of commitment, job satisfaction, sense of community and order and discipline, whereas bureaucratic linkage undermines such feelings. Implies that school principals should resort more to cultural linkages as the strategies to bind people together and to give people meaning in their work.
Standards: the varying perceptions of senior staff in higher education institutions
Authors: Lomas Laurie , Tomlinson Kevin
Published: July 2002

Reports on and analyses the attitudes towards standards in higher education of a random sample of senior managers, senior administrators and senior academics in a range of different types of higher education institutions. In order to construct an analytical framework for the empirical research, there is a synthesis of the current debate on standards. The research data were collected in two phases; first, by means of 21 in‐depth interviews in seven higher education institutions and, second, through the questionnaire responses of a larger number of senior staff in a greater number of institutions. Generally, the research results indicate that senior academics are more concerned about falling standards than their senior manager and senior administrator colleagues. This concern over standards appears to be more pronounced in older universities.
Readin’, writin’, arithmetic, and information competency: adding a basic skills component to a university’s curriculum
Authors: Goetsch Lori A. , Kaufman Paula T.
Published: July 2002

Describes work at the University of Tennessee, Knoxville, USA, in developing information across the curriculum. Similar to writing competency programs, this approach will require students to take a number of information‐intensive courses and necessitate a close partnership between librarians and teaching faculty in establishing requirements, integrating information skills into the curriculum, and evaluating outcomes.
The importance of trust in electronic commerce
Authors: Ratnasingham Pauline
Published: July 2002

In this paper a new concept “trust”, and how it influences the process of managing the security of an organization operating in an electronic commerce environment has been introduced. Pragmatically, the study suggests awareness for organizations entering into electronic commerce and theoretically the study aims to develop a framework of trust and security for electronic commerce thus providing a set of guidelines for secure electronic commerce.
The modelling of housing submarkets
Authors: Fletcher Mike , Gallimore Paul , Mangan Jean
Published: July 2002

This paper is concerned as to whether it is more appropriate to use aggregate or disaggregate models in forecasting house prices using hedonic modelling. It is accepted that the implicit pricing of some of the attributes is not stable between locations, property types and ages but it is argued that this can be effectively modelled with an aggregate method. The models are developed using a dataset of nearly 18,000 transactions in the UK Midlands region in 1994. The comparative performance of these models is then considered using two approaches. Chow tests of the error differences between actual price and the price predicted by the models suggest that the submarket models lead to statistically significant, though small, improvements. A second approach, using comparison of the root mean square errors, is conducted on the models’ forecasts for a 10 per cent sample of nearly 2,000 transactions excluded from the modelling process. This shows little practical difference in the forecasting ability between the two approaches. Great care needs to be taken over sample size if a disaggregate model is used.
Solution structure of a yeast ubiquitin‐like protein Smt3: The role of structurally less defined sequences in protein–protein recognitions
Authors: Sheng Wanyun , Liao Xiubei
Published: July 2002

Smt3 belongs to a growing family of ubiquitin‐related proteins involved in posttranslational protein modification. Independent studies demonstrate an essential function of Smt3 in the regulation of nucleocytoplasmic transport, and suggest a role in cell‐cycle regulation. Here we report the high‐resolution NMR structure of yeast Smt3 in the complex free form. Our comparison of the Smt3 NMR structure with the Smt3 crystal structure in complex with the C‐Terminal Ulp1 protease domain revealed large structural differences in the binding surface, which is also involved in the Smt3‐Ubc‐9 interaction detected by NMR. The structural differences in the region indicate the important functions of conserved residues in less structurally defined sequences.
Threading of a glycosylated protein loop through a protein hole: Implications for combination of human chorionic gonadotropin subunits
Authors: Xing Yongna , Williams Christopher , Campbell Robert K. , Cook Stephanie , Knoppers Maria , Addona Theresa , Altarocca Valter , Moyle William R.
Published: July 2002

Chorionic gonadotropin (hCG) is a heterodimeric placental glycoprotein hormone essential for human reproduction. Twenty hCG β‐subunit residues, termed the seatbelt, are wrapped around α‐subunit loop 2 (α2) and their positions “latched” by a disulfide formed by cysteines at the end of the seatbelt (Cys 110) and in the β‐subunit core (Cys 26). This unique arrangement explains the stability of the heterodimer but raises questions as to how the two subunits combine. The seatbelt is latched in the free β‐subunit. If the seatbelt remained latched during the process of subunit combination, formation of the heterodimer would require α2 and its attached oligosaccharide to be threaded through a small β‐subunit hole. The subunits are known to combine during oxidizing conditions in vitro, and studies described here tested the idea that this requires transient disruption of the latch disulfide, possibly as a consequence of the thioredoxin activity reported in hCG. We observed that alkylating agents did not modify either cysteine in the latch disulfide (Cys 26 or Cys 110) during heterodimer formation in several oxidizing conditions and had minimal influence on these cysteines during combination in the presence of mild reductants (1–3 mM β‐mercaptoethanol). Reducing agents appeared to accelerate subunit combination by disrupting a disulfide (Cys 93–Cys 100) that forms a loop within the seatbelt, thereby increasing the size of the β‐subunit hole. We propose a mechanism for hCG assembly in vitro that depends on movements of α2 and the seatbelt and suggest that the process of glycoprotein hormone subunit combination may be useful for studying the movements of loops during protein folding.
An extended hudrophobic core induces EF‐hand swapping
Authors: Håkansson Maria , Svensson Anders , Fast Jonas , Linse Sara
Published: July 2002

The structure of calbindin D9k with two substitutions was determined by X‐ray crystallography at 1.8‐Å resolution. Unlike wild‐type calbindin D9k, which is a monomeric protein with two EF‐hands, the structure of the mutated calbindin D9k reveals an intertwined dimer. In the dimer, two EF‐hands of the monomers have exchanged places, and thus a 3D domain‐swapped dimer has been formed. EF‐hand I of molecule A is packed toward EF‐hand II of molecule B and vice versa. The formation of a hydrophobic cluster, in a region linking the EF‐hands, promotes the conversion of monomers to 3D domain‐swapped dimers. We propose a mechanism by which domain swapping takes place via the apo form of calbindin D9k. Once formed, the calbindin D9k dimers are remarkably stable, as with even larger misfolded aggregates like amyloids. Thus calbindin D9k dimers cannot be converted to monomers by dilution. However, heating can be used for conversion, indicating high energy barriers separating monomers from dimers.
NMR and SAXS characterization of the denatured state of the chemotactic protein Che Y: Implications for protein folding initiation
Authors: Garcia Pascal , Serrano Luis , Durand Dominique , Rico Manuel , Bruix Marta
Published: July 2002

The denatured state of a double mutant of the chemotactic protein CheY (F14N/V83T) has been analyzed in the presence of 5 M urea, using small angle X‐ray scattering (SAXS) and heteronuclear magnetic resonance. SAXS studies show that the denatured protein follows a wormlike chain model. Its backbone can be described as a chain composed of rigid elements connected by flexible links. A comparison of the contour length obtained for the chain at 5 M urea with the one expected for a fully expanded chain suggests that ∼25% of the residues are involved in residual structures. Conformational shifts of the α‐protons, heteronuclear 15N‐{1H} NOEs and 15N relaxation properties have been used to identify some regions in the protein that deviate from a random coil behavior. According to these NMR data, the protein can be divided into two subdomains, which largely coincide with the two folding subunits identified in a previous kinetic study of the folding of the protein. The first of these subdomains, spanning residues 1–70, is shown here to exhibit a restricted mobility as compared to the rest of the protein. Two regions, one in each subdomain, were identified as deviating from the random coil chemical shifts. Peptides corresponding to these sequences were characterized by NMR and their backbone 1H chemical shifts were compared to those in the intact protein under identical denaturing conditions. For the region located in the first subdomain, this comparison shows that the observed deviation from random coil parameters is caused by interactions with the rest of the molecule. The restricted flexibility of the first subdomain and the transient collapse detected in that subunit are consistent with the conclusions obtained by applying the protein engineering method to the characterization of the folding reaction transition state.
Mass spectrometric study of the Escherichia coli repressor proteins, IcIR and GcIR, and their complexes with DNA
Authors: Donald Lynda J. , Hosfield David J. , Cuvelier Susan L. , Ens Werner , Standing Kenneth G. , Duckworth Harry W.
Published: July 2002

In Escherichia coli, the IclR protein regulates both the aceBAK operon and its own synthesis. Database homology searches have identified many IclR‐like proteins, now known as the IclR family, which can be identified by a conserved C‐terminal region. We have cloned and purified one of these proteins, which we have named GclR (glyoxylate carboligase repressor). Although purification is straightforward, both the IclR and GclR proteins are difficult to manipulate, requiring high salt (up to 0.6 M KCl) for solubility. With the advent of nanospray ionization, we could transfer the proteins into much higher concentrations of volatile buffer than had been practical with ordinary electrospray. In 0.5 M ammonium bicarbonate buffer, both proteins were stable as tetramers, with a small amount of dimer. In a separate experiment, we found that IclR protein selected from a random pool a sequence which matched exactly that of the presumed binding region of the GclR protein, although IclR does not regulate the gcl gene. We designed a 29 bp synthetic DNA to which IclR and GclR bind, and with which we were able to form noncovalent DNA‐protein complexes for further mass spectrometry analysis. These complexes were far more stable than the proteins alone, and we have evidence of a stoichiometry which has not been described previously with (protein monomer : dsDNA) = (4 : 1).
A Ca2+‐permeable non‐selective cation channel activated by depletion of internal Ca2+ stores in single rabbit portal vein myocytes
Authors: Albert A. P. , Large W. A.
Published: July 2002

In vascular smooth muscle cells many agonists cause the release of Ca2+ ions from internal stores. An important problem concerns the mechanism by which the intracellular stores are refilled subsequent to depletion. In the present study, we describe the properties of a Ca2+‐permeable non‐selective cation channel current that is activated in rabbit portal vein myocytes by depletion of internal Ca2+ stores. Application of cyclopiazonic acid (CPA), which depletes internal Ca2+ stores, activated whole‐cell currents that had a reversal potential (Er) of about +50 mV in 1.5 mm external Ca2+ (Ca2o+). In 0 mm Ca2o+, the currents were larger and Er was ∼0 mV. Application of CPA and caffeine during cell‐attached recording activated single inward channel currents at negative potentials, which had a slope conductance of 2–3 pS and an Er of +20 mV. The slope conductance in 0 and 110 mm Ca2o+ was 7 and 1.5 pS, respectively, and Er values indicated that these non‐selective cation channels are highly permeable to Ca2+ ions. Bath application of the cell‐permeant Ca2+ chelator, BAPTA‐AM, also activated similar currents, indicating that these channels are not activated by Ca2+. Spontaneous channel currents with similar properties to store‐operated channels were observed in some patches. Application of W‐7, an inhibitor of the Ca2+‐binding protein calmodulin, also activated similar Ca2+‐permeable channel currents. In conclusion, it is demonstrated that agents that deplete Ca2+ stores and inhibit calmodulin binding activate Ca2+‐permeable non‐selective cation channel currents in rabbit portal vein myocytes. These channels may have an important role in vascular smooth muscle in providing an influx of Ca2+ to refill depleted internal Ca2+ stores and appear to possess different characteristics to store‐operated channels described in other vascular smooth muscle preparations.
Limb neurovascular control during altered otolithic input in humans
Authors: Monahan Kevin D. , Ray Chester A.
Published: July 2002

Head‐down rotation (HDR), which activates the vestibulosympathetic reflex, increases leg muscle sympathetic nerve activity (MSNA) and produces calf vasoconstriction with no change in either cardiac output or arterial blood pressure. Based on animal studies, it was hypothesized that differential control of arm and leg MSNA explains why HDR does not alter arterial blood pressure. Fifteen healthy subjects were studied. Heart rate, arterial blood pressure, forearm and calf blood flow, and leg MSNA responses were measured during HDR in these subjects. Simultaneous recordings of arm and leg MSNA were obtained from five of the subjects. Forearm and calf blood flow, vascular conductances, and vascular resistances were similar before HDR, as were arm and leg MSNA. HDR elicited similar significant increases in leg (Δ6 ± 1 bursts min−1; 59 ± 16 % from baseline) and arm MSNA (Δ5 ± 1 bursts min−1; 80 ± 28 % from baseline). HDR significantly decreased calf (−19 ± 2 %) and forearm vascular conductance (−12 ± 2 %) and significantly increased calf (25 ± 4 %) and forearm vascular resistance (15 ± 2 %), with ∼60 % greater vasoconstriction in the calf than in the forearm. Arterial blood pressure and heart rate were not altered by HDR. These results indicate that there is no differential control of MSNA in the arm and leg during altered feedback from the otolith organs in humans, but that greater vasoconstriction occurs in the calf than in the forearm. These findings indicate that vasodilatation occurs in other vascular bed(s) to account for the lack of increase in arterial blood pressure during HDR.
Subplasmalemmal endoplasmic reticulum controls KCa channel activity upon stimulation with a moderate histamine concentration in a human umbilical vein endothelial cell line
Authors: Frieden Maud , Malli Roland , Samardzija Mariana , Demaurex Nicolas , Graier Wolfgang F.
Published: July 2002

This study was designed to elucidate the role of the subplasmalemmal endoplasmic reticulum (sER) in autacoid‐induced stimulation of Ca2+‐dependent K+ channels in the umbilical vein endothelial cell‐derived cell line EA.hy926. Cells were transfected with the Ca2+ probe cameleon targeted to the ER for visualization of the ER network. A patch pipette was then placed close to or far (> 5 μm away) from the sER, single channel recordings (patch clamp technique) were monitored simultaneously with measurements of either ER Ca2+ concentration (using the Ca2+ probe Cam4‐ER) or cytosolic free Ca2+ concentration ([Ca2+]i; using fura‐2) using a deconvolution imaging device. A voltage‐dependent, large conductance Ca2+‐dependent K+ channel (BKCa; single channel conductance (γ), 250 pS) was found. At membrane potentials of +40 and −40 mV, the EC50 for Ca2+ was 2.7 and 49.7 μm, respectively. In the vicinity of the sER, the BKCa channel activity induced by 10 μm histamine was 32 times higher (open probability (Po) = 0.083 ± 0.026) than in areas away from the sER (Po= 0.0026 ± 0.002). However, at supramaximal histamine stimulation (100 μm), BKCa channel activation was similar in patches in the vicinity of or away from the sER (Po= 0.18 ± 0.09 and 0.25 ± 0.07, respectively). In contrast to BKCa channel activity, ER Ca2+ depletion (Cam4‐ER) and elevation of [Ca2+]i in response to 10 and 100 μm histamine were not influenced by the pipette position. We conclude that in endothelial cells, the activation of BKCa channels in response to moderate histamine concentration essentially depends on the proximity of the sER domains to the mouth of this K+ channel. These findings further support our concept of the subplasmalemmal Ca2+ control unit (SCCU) and add the local activation of Ca2+‐activated K+‐channels to the function of the SCCU.
Dimensional Fault Diagnosis for Compliant Beam Structure Assemblies
Authors: Rong Q. , Ceglarek D. , Shi J.
Published: July 2002

A model-based diagnostic methodology is proposed for the dimensional fault diagnosis of compliant beam structures in automotive or aerospace assembly processes. In the diagnosis procedure, the product measurement data are used to detect and isolate dimensional faults caused by part fabrication error in compliant beam assemblies. The proposed method includes a predetermined fault patterns model and a fault mapping procedure. The fault patterns are modeled by the diagnostic vectors derived from the inversed stiffness matrix of the beam structure. The fault mapping procedure combines principal component analysis (PCA) of measurement data and fault pattern recognition using statistical hypothesis tests. Verification of the proposed method is presented through simulations and one case study. [S1087-1357(00)02502-8]
Experimental Comparison of Delayed Resonator and PD Controlled Vibration Absorbers Using Electromagnetic Actuators
Authors: Elmali Hakan , Renzulli Mark , Olgac Nejat
Published: July 2002

The Delayed Resonator (DR) is a recent active vibration absorption technique which uses time delayed position feedback generating ideal resonance feature in a passive vibration absorber. This objective can also be achieved using proportional and derivative (PD) control as well as other more sophisticated routines such as LQR, sliding mode control. In this paper, DR technique is compared with PD, a widely adopted control strategy. Actuator dynamics is taken into account in analyzing the system. An analytical comparison is presented which is followed by an experimental validation of the findings using a single-degree-of-freedom primary structure and an absorber with electromagnetic actuator. Both analytical and experimental results show that the DR and PD implementations can be equally effective in suppressing undesired oscillations. The latter, however, requires a velocity observer, which is an additional complexity beyond the DR feedback structure. [S0022-0434(00)02203-6]
Estimating Number of Shells in Shell and Tube Heat Exchangers: A New Approach Based on Temperature Cross
Authors: Gulyani B. B.
Published: July 2002

Multipass heat exchangers are often designed by using the rule of thumb FT⩾0.75, which is rather arbitrary. FT falls sharply with the increase in temperature cross. Hence, only a limited temperature cross can be allowed. The ability to accommodate temperature cross increases rapidly as the number of shell passes is increased. Though many investigators have emphasized the importance of temperature cross in exchanger design, it has as yet not been explicitly accounted for in the design. This paper introduces a new approach for estimating the number shells in a shell and tube exchanger which directly accounts for temperature cross, rather than routing this effect through FT or XP (Ahmad et al.’s parameter, which is again a correction factor not directly related to temperature cross). The approach is compatible with the established design procedures and bypasses the FT. It generates better designs by defining maximum permissible temperature cross, than the traditional designs based on specifying minimum permissible FT. Expressions have also been provided which correlate the present formulation with that of Ahmad et al. [S0022-1481(00)00803-3]
Advantages of the LV100 as a Power Producer in a Hybrid Propulsion System for Future Fighting Vehicles
Authors: Koschier Angelo V. , Mauch Hagen R.
Published: July 2002

The core of any hybrid propulsion system is a high power density, low weight, and fuel efficient electric energy producer. The LV100 recuperated turbine engine is such a system. This engine is well suited to provide electric power efficiently at a volume and weight significantly lower than current systems. Originally designed for vehicular use and environment to drive a Hydrokinetic transmission, the turbine’s high output speed lends itself to incorporate into the engine design an advanced generating device. This LV100 engine-based electric energy producer will provide in excess of 1MW of electric power in a volume of under one cubic meter at a weight of about 2500 pounds at fuel efficiencies comparable to advanced vehicular diesel engines. Recent state-of-the-art improvements in materials and component technology will permit further reductions in volume/weight and increase the system fuel efficiency. The technologies required to reach a volume of under one cubic meter, the system performance projections obtainable by technology upgrades and the program achievements to date are discussed. [S0742-4795(00)03103-3]
Enhancements in the Accuracy of the Center of Pressure (COP) Determined With Piezoelectric Force Plates Are Dependent on the Load Distribution
Authors: Schmiedmayer Heinz-Bodo , Kastner Josef
Published: July 2002

Errors up to ±30 mm in determining the COP with piezoelectric force plates have been reported in the literature. To compensate for these errors, correction formulas were proposed, based on measurements with single point loads. In this paper, it will be shown that the errors in the COP depend on the load distribution. Two examples are presented: (1) simulated balance study, and (2) different pressure patterns during walking. Accurate corrections can only be made for forces distributed over a small area. Errors are expected to be overcompensated if there are only a few pressure peaks separated by large distances. These errors can be as large as the statistical errors 5.8±3.7 mm after compensation. For certain situations, it is probably better not to use correction formulas. [S0148-0731(00)01005-0]
Fracture Mechanics Analysis of Low Cost Solder Bumped Flip Chip Assemblies With Imperfect Underfills
Authors: Lau John H. , Lee S.-W. Ricky
Published: July 2002

Solder joint reliability of flip chip on various thickness of printed circuit board with imperfect underfill is presented in this study. Emphasis is placed on the determination of the temperature-dependent stress and plastic strain at the corner solder joint with different crack (delamination) lengths. Also, the strain energy release rate and phase angle at the crack tip of the interface between the underfill and solder mask are obtained by fracture mechanics. [S1043-7398(00)01104-X]
Behavior of a Rubber Spring Pendulum
Authors: Bhattacharyya R.
Published: July 2002

The stability of motion of a nonlinear neo-Hookean rubber spring pendulum under a special type of support oscillation is studied. The small swing motion is described by a Mathieu-Hill equation, corresponding stability curves for which are generated in a relevant parametric plane with a stability criterion obtained earlier. Autoparametric resonance in the special case of linearized motions is found to occur, as usual. [S0021-8936(00)00801-1]
Local Buckling of a Circular Interface Delamination Between a Layer and a Substrate With Finite Thickness
Authors: Sburlati R. , Madenci E. , Guven I.
Published: July 2002

An analytical study investigating the local buckling response of a circular delamination along the interface of an elastic layer and a dissimilar substrate with finite thickness is presented. The solution method utilizes the stability equations of linear theory of elasticity under axisymmetry conditions. In-plane loading and the presence of mixed boundary conditions on the bond-plane result in a homogeneous system of coupled singular integral equations of the second kind with Cauchy-type kernels. Numerical solution of these integral equations leads to the determination of local buckling stress and its sensitivity to geometric parameters and material properties. [S0021-8936(00)01503-8]
Flow Factors for Lubrication With Emulsions in Ironing
Authors: Schmid Steven R. , Zhou Jin
Published: July 2002

Oil-in-water emulsions are widely used as lubricants/coolants in the ironing of beverage and food containers. This paper investigates this system, where the two phased flow problem presented by the emulsion is modeled using the Dynamic Concentration Theory of Wilson et al. (1994) developed for rolling. An important part of such a model is the development of flow correction factors needed to model the interactions of oil and water. Flow factors suitable for ironing emulsions are developed computationally and take two forms, namely that for large oil droplets that are entrained as cylinders and that for small droplets entrained as hemispheres. The Dynamic Concentration Theory framework is developed for ironing emulsions using these new flow factors.
Turbulent Transient Gas Injections
Authors: Ouellette P. , Hill P. G.
Published: July 2002

Compressible transient turbulent gaseous jets are formed when natural gas is injected directly into a diesel engine. Multi-dimensional simulations are used to analyze the penetration, mixing, and combustion of such gaseous fuel jets. The capability of multi-dimensional numerical simulations, based on the k-ε turbulence model, to reproduce the experimentally verified penetration rate of free transient jets is evaluated. The model is found to reproduce the penetration rate dependencies on momentum, time, and density, but is more accurate when one of the k-ε coefficients is modified. The paper discusses other factors affecting the accuracy of the calculations, in particular, the mesh density and underexpanded injection conditions. Simulations are then used to determine the impact of chamber turbulence, injection duration, and wall contact on transient jet penetration. The model also shows that gaseous jets and evaporating diesel sprays with small droplet size mix at much the same rate when injected with equivalent momentum injection rate. [S0098-2202(00)02304-X]
An Experimental Investigation of Surface Pit Evolution During Cold-Rolling or Drawing of Stainless Steel Strip
Authors: Ahmed R. , Sutcliffe M. P. F.
Published: July 2002

This paper presents an experimental investigation of the mechanisms of pit elimination in strip drawing and rolling of stainless steel strips. Strip drawing tests with artificial indents confirm the role of micro-plasto-hydrodynamic lubrication (MPHL) in allowing pits to be reduced in size and depth. The similarity of results for two oils, which differ in viscosity by a factor of 10, is attributed to the fact that oil is drawn out of the pits rather easily, so that the behavior tends to the unlubricated case. Similar behavior is observed for strip drawing of shot blast white hot band. For much smoother bright anneal strip, it is suggested that the presence of an oil film in the unpitted region prevents generation of pressure differences between the pits and the unpitted regions. A comparison of strip-drawn and cold-rolled stainless steel samples show that the change in pit area and Rq roughness varies with overall reduction in a remarkably similar way. The reason for such similar behavior is attributed to the absence of hydrodynamic action in preventing pit elimination, albeit for opposite reasons. The similar rate of pit evolution in both cases confirms the usefulness of the strip drawing rig as a tool to model the change of surface topography during rolling, as long as care is taken in matching the regimes of lubrication.
Performance Benefit Assessment of Ceramic Components in an MS9001FA Gas Turbine
Authors: Grondahl C. M. , Tsuchiya T.
Published: July 2002

The introduction of a ceramic gas turbine component in commercial power generation service will require significant effort. A careful assessment of the power plant performance benefit achievable from the use of ceramic components is necessary to rationalize the priority of this development compared to other alternatives. This paper overviews a study in which the performance benefit from ceramic components was evaluated for an MS9001FA gas turbine in a combined cycle power plant configuration. The study was performed with guidelines of maintaining constant compressor inlet airflow and turbine exit NOx emissions, effectively setting the combustion reaction zone temperature. Cooling flow estimates were calculated to maintain standard design life expectancy of all components. Monolithic silicon nitride ceramic was considered for application to the transition piece, stage one and two buckets, nozzles and shrouds. Performance benefit was calculated both for ceramic properties at 1093°C (2200°F) and for the more optimistic 1315°C (2400°F) oxidation limit of the ceramic. Hybrid ceramic-metal components were evaluated in the less optimistic case.
A New Polynomial Solution to the Geometric Design Problem of Spatial R-R Robot Manipulators Using the Denavit and Hartenberg Parameters
Authors: Mavroidis Constantinos , Lee Eric , Alam Munshi
Published: July 2002

This paper presents a new method to solve the geometric design problem of spatial two degrees of freedom, open loop robot manipulators with revolute joints that perform tasks, which require the positioning of the end-effector in three spatial locations. Tsai and Roth [3] solved this problem first using screw parameters to describe the kinematic topology of the R-R manipulator and screw displacements to obtain the design equations. The new method, which is developed in this paper, uses Denavit and Hartenberg parameters and 4×4 homogeneous matrices to formulate and obtain the kinematic equations. The loop-closure geometric equations provide eighteen design equations in eighteen unknowns. Polynomial Elimination techniques are used to solve these equations and obtain the manipulator Denavit and Hartenberg parameters and the manipulator base and end-effector geometric parameters. A sixth order polynomial is obtained in one of the design parameters. Only two of the six roots of the polynomial are real and they correspond to two different robot manipulators that can reach the desired end-effector poses.
Hydrodynamic Modeling of Cerebrospinal Fluid Motion Within the Spinal Cavity
Authors: Loth Francis , Yardimci M. Atif , Alperin Noam
Published: July 2002

The fluid that resides within cranial and spinal cavities, cerebrospinal fluid (CSF), moves in a pulsatile fashion to and from the cranial cavity. This motion can be measured by magnetic resonance imaging (MRI) and may be of clinical importance in the diagnosis of several brain and spinal cord disorders such as hydrocephalus, Chiari malformation, and syringomyelia. In the present work, a geometric and hydrodynamic characterization of an anatomically relevant spinal canal model is presented. We found that inertial effects dominate the flow field under normal physiological flow rates. Along the length of the spinal canal, hydraulic diameter was found to vary significantly from 5 to 15 mm. The instantaneous Reynolds number at peak flow rate ranged from 150 to 450, and the Womersley number ranged from 5 to 17. Pulsatile flow calculations are presented for an idealized geometric representation of the spinal cavity. A linearized Navier–Stokes model of the pulsatile CSF flow was constructed based on MRI flow rate measurements taken on a healthy volunteer. The numerical model was employed to investigate effects of cross-sectional geometry and spinal cord motion on unsteady velocity, shear stress, and pressure gradient fields. The velocity field was shown to be blunt, due to the inertial character of the flow, with velocity peaks located near the boundaries of the spinal canal rather than at the midpoint between boundaries. The pressure gradient waveform was found to be almost exclusively dependent on the flow waveform and cross-sectional area. Characterization of the CSF dynamics in normal and diseased states may be important in understanding the pathophysiology of CSF related disorders. Flow models coupled with MRI flow measurements may become a noninvasive tool to explain the abnormal dynamics of CSF in related brain disorders as well as to determine concentration and local distribution of drugs delivered into the CSF space.
Forward Kinematics in Polynomial Form of the General Stewart Platform1
Authors: Innocenti Carlo
Published: July 2002

The paper presents a new algorithm to solve, in polynomial form, the forward kinematics of the general-geometry 6-6 fully-parallel manipulator. The forty solutions that the problem at hand admits in the complex domain are found by determining the roots of a 40th-order univariate polynomial equation. Unlike the existing algorithm, the proposed one is suitable for implementation in a standard floating-point computation environment. A numerical example shows application of the new algorithm to a case study.