bluuebunny/crossref_metadata_2025 huggingface dataset:
Trace Element Data for Gold, Iridium and Silver in Seventy Geochemical Reference Materials
Authors: Constantin Marc
Published: November 2008

New concentrations for Au, Ir and Ag obtained by instrumental neutron activation analysis are presented for seventy geochemical reference materials. Results in agreement with literature values for Au and Ir down to concentrations of a few ng g−1 were obtained. For Au and Ir concentrations above 10 ng g−1, the repeatability of replicate analyses of reference materials was mostly better than 10%. For concentrations between 1 and 10 ng g−1 the RSD for Ir was 10–30%, whereas for Au it was higher and more variable (20–50%). In addition, concentrations for Cd and Hg are presented for some of the same reference materials. The high RSD at relatively high concentrations seen in gold for some RMs (e.g., WMG‐1, WMS‐1) did not exist for Ir and suggests homogeneity for this platinum‐group element at the sub‐sample size used in this study. For the following eight RMs, mostly ultramafic rocks (CHR‐Pt+, OREAS‐13P, OREAS‐14P, PCC‐1, UMT‐1, WMG‐1, WMS‐1, WPR‐1), Ir measurements agreed within ± 10% of mostly certified or recommended concentrations, which ranged from 2 ng g−1 to 6 μg g−1. For the reference material UB‐N, iridium concentration compared favourably to published results obtained by isotope dilution ICP‐MS methods and a previously unrecognised heterogeneity is inferred for Au, Hg and Sb, but not for the other measured elements.
Participation des seniors au marché du travail en Argentine: un modèle de valeur d’option
Authors: Alós Marcelo , Apella Ignacio , Grushka Carlos , Muiños Marcelo
Published: November 2008

Résumé  Le présent article a pour but de définir les facteurs qui déterminent les décisions des seniors de continuer à prendre part au marché du travail en Argentine. Un modèle de valeur d’option est élaboré. Ce modèle est utilisé pour produire des estimations fondées sur des microdonnées provenant d’enquêtes auprès des ménages. Celles‐ci indiquent l’importance relative de l’incidence des conditions qui régissent l’admissibilité aux prestations sur les décisions de rester professionnellement actif. La conclusion est que les antécédents professionnels constituent le principal facteur dans ces décisions. Le caractère insuffisant des prestations de sécurité sociale et le capital humain accumulé créent également des incitations à la participation économique au troisième âge. Au départ de ces conclusions, des ajustements de la politique compensatoire destinés à améliorer la couverture, à augmenter le montant des prestations et à améliorer les conditions d’emploi pour les seniors sont proposés.
Prestations d'invalidité et travailleurs atteints du VIH/SIDA: problèmes de couverture et défis en République‐Unie de Tanzanie
Authors: Ackson Tulia
Published: November 2008

Résumé  Cet article examine la non‐accessibilité effective des prestations d'incapacité/invalidité pour les salariés du secteur structuré atteints du VIH/SIDA en République‐Unie de Tanzanie. La difficulté juridique d'établir un lien direct entre le VIH/SIDA et les accidents du travail et les maladies professionnelles représente un défi pour les institutions et régimes de sécurité sociale. En outre, parallèlement, ils sont confrontés aux problèmes grandissants du rétrécissement du secteur structuré et du faible niveau de couverture. Des réponses de fond sont proposées pour y remédier. Elles identifient les aménagements réglementaires et légaux nécessaires pour assurer à la fois la convergence des conditions requises pour les demandes de prestations d'invalidité auprès des institutions concernées, et pour assurer que ces conditions requises sont à la fois homogènes et conformes aux approches contemporaines de l'invalidité. Les aménagements suggérés simplifieraient et clarifieraient les conditions requises dans les cas d'invalidité concernant les affiliés des régimes existants, en rendant aussi possible une extension future de la couverture des prestations pour mieux refléter les réalités du marché du travail.
Teilnahme älterer Arbeitnehmer am argentinischen Arbeitsmarkt: Ein Optionswertmodell
Authors: Alós Marcelo , Apella Ignacio , Grushka Carlos , Muiños Marcelo
Published: November 2008

Auszug

Der vorliegende Artikel will die Faktoren definieren, die die Entscheidung älterer Arbeitnehmer in Argentinien beeinflussen, weiter am Arbeitsmarkt teilzunehmen. Es wird ein Optionswertmodell entwickelt. Dieses Modell wird verwendet, um anhand von Mikrodaten aus Haushaltsbefragungen Schätzungen zu erstellen. Sie liefern Hinweise auf die relative Bedeutung davon, wie sich die Zugangsvoraussetzungen für Renten auf die Entscheidung auswirken, weiter erwerbstätig zu bleiben. Die Erwerbsbiografie stellt sich als Hauptfaktor bei solchen Entscheidungen heraus. Auch die Unangemessenheit von Renten der sozialen Sicherheit und angehäuftes Humankapital bilden Anreize zur Erwerbstätigkeit im Alter. Ausgehend von diesen Ergebnissen, schlagen wir ergänzende politische Anpassungen vor zur besseren Deckung, zur Erhöhung der Rentenleistungen und zur Verbesserung der Arbeitsbedingungen für ältere Arbeitnehmer.
(A‐)typisch und (un‐)sicher? Zur sozialen Sicherung von „nicht standardisierten“ Arbeitsverhältnissen in Europa
Authors: Buschoff Karin Schulze , Protsch Paula
Published: November 2008

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Atypische Beschäftigungsverhältnisse (Teilzeit, geringfügige Beschäftigung, Befristungen und Solo‐Selbstständigkeit) haben in den letzten Jahren insgesamt in vielen europäischen Ländern an Bedeutung gewonnen. Sie sind häufig Bestandteil unsteter Erwerbsverläufe und mit einem erhöhten Arbeitslosigkeitsrisiko verbunden. In einem Sechs‐Länder‐Vergleich (Deutschland, Vereinigtes Königreich, Niederlande, Italien, Dänemark und Polen) wird gefragt, ob und in welcher Weise die nationalen sozialrechtlichen Regelungen die einzelnen Formen atypischer Beschäftigungsverhältnisse umfassen und die mit ihnen verbundenen spezifischen Risiken berücksichtigen. Es wurden erhebliche Unterschiede zwischen den Ländern bezüglich der die Deckung bestimmenden Normen und Praxis festgestellt und die einzelnen Länder reagierten sehr unterschiedlich auf die verschiedenen Formen atypischer Beschäftigungsverhältnisse. Dabei wurde die Notwendigkeit einer weitergehenden verbesserten Koordination der Sozial‐ und Steuergesetzgebung deutlich.
Invalidenleistungen und Beschäftigte mit HIV/Aids: Fragen und Probleme bei der Deckung in der Vereinigten Republik Tansania
Authors: Ackson Tulia
Published: November 2008

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Dieser Artikel untersucht den Umstand, dass es in der Vereinigten Republik Tansania effektiv keine Invalidenleistungen gibt für Beschäftigte des formellen Sektors, die HIV/Aids‐infiziert sind, Die Schwierigkeit für die Institutionen und Systeme der sozialen Sicherheit besteht darin, einen direkten Bezug zwischen HIV/Aids und Arbeitsunfällen und Berufskrankheiten rechtlich zu fassen. Gleichzeitig versuchen sie, die wachsenden Probleme infolge eines schrumpfenden formellen Sektors und die geringe Deckung in den Griff zu bekommen. Es werden politische Abhilfemaßnahmen vorgeschlagen, die die gesetzlichen und rechtlichen Anpassungen ermitteln, die erforderlich sind, um sowohl die Angleichung der Anspruchsvoraussetzungen für Invalidenleistungsansprüche in den betreffenden Institutionen sicherzustellen als auch dafür zu sorgen, dass die Anspruchsvoraussetzungen dauerhaft sind und den heutigen Ansätzen bezüglich der Invalidität entsprechen. Die vorgeschlagenen Anpassungen würden die Anspruchsvoraussetzungen in Fällen, in denen Mitglieder der bestehenden Systeme von Invalidität betroffen sind, vereinfachen und klären und potenziell auch eine künftige Erweiterung der Leistungsdeckung zulassen, um die Arbeitsmarktrealitäten besser zu reflektieren.
Zwischen Arbeitsmarkt und Altersrente — flexible Übergänge als ein neues Paradigma für alternde Gesellschaften?
Authors: Bredt Stephan
Published: November 2008

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Die Anhebung des gesetzlichen Rentenalters aufgrund steigender Lebenserwartung stößt auf heftigen politischen Widerstand. Aus gesundheitlichen und Arbeitsmarktgründen wird es für manche Berufstätige stets unmöglich sein, den Zugang zur Vollrente unmittelbar aus der Beschäftigung zu erwerben. Selbst wenn die Möglichkeiten für den vorgezogenen Renteneintritt nicht beschränkt werden, sind die Zuverdienstgrenzen zur Finanzierung einer Frühverrentung sehr eng definiert. Folglich ist es für Vorruheständler unmöglich, die Rentenabschläge auszugleichen, von denen sie betroffen sind. Entgegen der allgemeinen Tendenz zur Anhebung des Rentenalters wird derzeit in sozialpolitischen Kreisen in Deutschland ein alternativer Reformvorschlag diskutiert. Dieser zeichnet sich durch folgende Elemente aus: freie Entscheidung über den Renteneintritt im Alter von 60 Jahren, unbegrenzte Akkumulation zusätzlicher Rentenansprüche während der (fortgesetzten) Berufstätigkeit, versicherungsmathematische Abschläge bei vorgezogenem Renteneintritt und Berücksichtigung der Lebenserwartung bei der Anpassung der Rentenhöhe. Diese Lösung führt zu einer finanziellen Entlastung des staatlichen Rentensystems, verbessert die Situation älterer Berufstätiger auf dem Arbeitsmarkt, bietet die Möglichkeit eines selbstbestimmten Übergangs von der Arbeit in den Ruhestand und verringert den Widerstand gegen Rentenreformen. Die Arbeitsmarktauswirkungen für Ältere müssen noch untersucht werden.
New records of chytridiaceous fungi (Chytridiomycota) from the Reserva Natural Selva Marginal Punta Lara (Argentina) with comments on some previously reported species
Authors: Marano Agostina V. , Steciow Mónica M. , Arellano María L.
Published: November 2008

The Chytridiomycota (chytrids) of Argentina are not well known from freshwater and terrestrial ecosystems. We collected samples of water and floating organic matter (vegetable debris) from a lotic environment and wet soil from four terrestrial habitats at the Reserva Natural Selva Marginal Punta Lara (Bs. As.) and added cellulosic, chitinic and keratinic baits to these samples. We also placed Rosa spp. fruits and corn leaves for colonization in the stream. We recorded 21 taxa. Four of them (Chytriomyces hyalinus var. granulatus, Cylindrochytridium johnstonii, Cladochytriumreplicatum and Septochytrium variabile) are new records for Argentina and we describe and illustrate them here.
Critical notes on Saussurea pulvinata (Asteraceae) in China
Authors: Xu Bing‐Qiang , Xia Nian‐He
Published: November 2008

Saussurea ruoqiangensis K. M. Shen is reduced to a synonym of S. pulvinata Maxim., a distribution map and a key to S. pulvinata and related species is provided.
A new species of Taraxacum sect. Celtica (Asteraceae) from the Portuguese mountains
Authors: Galán de Mera A. , Vicente Orellana J. A.
Published: November 2008

Taraxacum
estrelense A. Galán & Vicente Orell. sp. nov. (sect. Celtica, Asteraceae) collected from Serra da Estrela and Gêres in Portugal is described and illustrated. Differences from allied species are discussed.
Musa yunnanensis (Musaceae) and its intraspecific taxa in China
Authors: Häkkinen Markku , Wang Hong
Published: November 2008

Musa yunnanensis Häkkinen & H. Wang (Musaceae) is distributed across the Mekong River watershed in Yunnan, China. In the present study its intraspecific taxa are thoroughly investigated. These wild Musa species and varieties are commonly planted for animal fodder in higher elevations due to their cold tolerance. Three varieties of M. yunnanensis described here as a new taxa, M.yunnanensis var. caii Häkkinen & H. Wang, M.yunnanensis var. yongpingensis Häkkinen & H. Wang and M.yunnanensis var. jingdongensis Häkkinen & H. Wang, are morphologically described and illustrated based on data from field studies in Yunnan, China in 2005, 2006 and 2007. A table with the diagnostic characters of the new varieties, as well as for M. yunnanensis var. yunnanensis, is provided.
Calsequestrin content and SERCA determine normal and maximal Ca2+ storage levels in sarcoplasmic reticulum of fast‐ and slow‐twitch fibres of rat
Authors: Murphy Robyn M. , Larkins Noni T. , Mollica Janelle P. , Beard Nicole A. , Lamb Graham D.
Published: November 2008

Whilst calsequestrin (CSQ) is widely recognized as the primary Ca2+ buffer in the sarcoplasmic reticulum (SR) in skeletal muscle fibres, its total buffering capacity and importance have come into question. This study quantified the absolute amount of CSQ isoform 1 (CSQ1, the primary isoform) present in rat extensor digitorum longus (EDL) and soleus fibres, and related this to their endogenous and maximal SR Ca2+ content. Using Western blotting, the entire constituents of minute samples of muscle homogenates or segments of individual muscle fibres were compared with known amounts of purified CSQ1. The fidelity of the analysis was proven by examining the relative signal intensity when mixing muscle samples and purified CSQ1. The CSQ1 contents of EDL fibres, almost exclusively type II fibres, and soleus type I fibres [SOL (I)] were, respectively, 36 ± 2 and 10 ± 1 μmol (l fibre volume)−1, quantitatively accounting for the maximal SR Ca2+ content of each. Soleus type II [SOL (II)] fibres (∼20% of soleus fibres) had an intermediate amount of CSQ1. Every SOL (I) fibre examined also contained some CSQ isoform 2 (CSQ2), which was absent in every EDL and other type II fibre except for trace amounts in one case. Every EDL and other type II fibre had a high density of SERCA1, the fast‐twitch muscle sarco(endo)plasmic reticulum Ca2+‐ATPase isoform, whereas there was virtually no SERCA1 in any SOL (I) fibre. Maximal SR Ca2+ content measured in skinned fibres increased with CSQ1 content, and the ratio of endogenous to maximal Ca2+ content was inversely correlated with CSQ1 content. The relative SR Ca2+ content that could be maintained in resting cytoplasmic conditions was found to be much lower in EDL fibres than in SOL (I) fibres (∼20 versus >60%). Leakage of Ca2+ from the SR in EDL fibres could be substantially reduced with a SR Ca2+ pump blocker and increased by adding creatine to buffer cytoplasmic [ADP] at a higher level, both results indicating that at least part of the Ca2+ leakage occurred through SERCA. It is concluded that CSQ1 plays an important role in EDL muscle fibres by providing a large total pool of releasable Ca2+ in the SR whilst maintaining free [Ca2+] in the SR at sufficiently low levels that Ca2+ leakage through the high density of SERCA1 pumps does not metabolically compromise muscle function.
A New Device for Measuring Knee Rotational Kinematics Using Magnetic Resonance Imaging
Authors: Carpenter R. Dana , Shefelbine Sandra J. , Lozano Jesus , Carballido-Gamio Julio , Majumdar Sharmila , Benjamin Ma C.
Published: November 2008

There are few commonly used clinical techniques to quantify the rotational stability and joint contact kinematics in knees in vivo. A magnetic-resonance-imaging-compatible device capable of applying axial and torsional loads to the foot was developed and used to measure in vivo knee kinematics in 14 healthy volunteers. The device was used to apply an internal torque and an axial compressive load at the foot, with the thigh held in place. Sagittal scans were made of the knee with and without an applied internal torque, and three-dimensional geometric representations of the knee joint were constructed from the images. Repeat scans of four volunteers were performed to assess precision, and phantom scans were performed to assess accuracy. Rotational measurements had a root mean square error of 0.1 deg, and precision errors for repeat measurements were 1.6 deg for internal tibial rotation, 0.3–1.1 mm for contact centroid translations, and 24.5 mm2 for a contact area. Results indicated that the device induced significant internal tibial rotation with respect to the femur and significant translation of the medial and lateral contact centroids. A preliminary study on five anterior cruciate ligament (ACL)-deficient patients did not detect any rotational difference between ACL-deficient and contralateral knees under an isolated internal torque. This method is able to calculate rotations and centroid translations out of the scan plane and has potential applications in investigating the effects of knee injury and recovery of function.
A Newly Developed Infant Remote Monitoring System
Authors: Hsu Cheung-Hwa
Published: November 2008

The present invention relates to an infant remote monitoring system, in particular, to one that monitors the heat from the breath of a baby to aid in the prevention of sudden infant death syndrome caused by asphyxia. This innovative device monitors the airflow frequency and temperature of the infant’s breathing using thermosensors. These airflow frequencies, linked with respiratory rates, are indicated on the monitor. The key advantage of this innovation is that it requires absolutely no contact with the baby’s skin, thereby preventing skin irritations and reducing infant discomfort normally found with traditional monitors. The system detects temperature changes induced by breathing and analyzes the breathing frequency changes, displaying the data on both a computer monitor and a light emitting diode array. Data are collected and analyzed simultaneously via personal computer, which can be linked to the central nursery room’s monitoring system. This device provides a convenient way for pediatricians or nurses to detect abnormalities in respiratory frequency in real time, so they can identify and respond to any emergency as it happens and give appropriate treatment immediately. Ten clinical cases were analyzed, and function validation of the device was performed as well.
Stress-Strain Behavior of a Smart Magnetostrictive Actuator for a Bone Transport Device
Authors: Luo Yuehao , Hutapea Parsaoran
Published: November 2008

The ultimate goal of our research is to develop a bone transport device using a magnetostrictive alloy actuation system. The device is designed to be subcutaneously mounted on the periosteal surface of the tibia. The magnetomechanical behavior of Terfenol-D smart magnetostrictive material has been well investigated in the literature when a magnetic field is applied along the longitudinal direction of the Terfenol-D material (perpendicular to the material’s magnetic moment). However, the requirement of our device is to have the magnetic field transversely applied on the Terfenol-D material (along the material’s magnetic moment). Therefore, the objective of this work was to study the magnetomechanical behavior of Terfenol-D under a transversely applied magnetic field. Experimental work was performed and a Terfenol-D material constitutive behavior was investigated.
Vision Aid for Power Wheelchair Users
Authors: Smith Kyle C. , Kemeny Carlos A. C. , Cipra Raymond , Duerstock Bradley S.
Published: November 2008

The sitting posture of power wheelchair (WC) users greatly limits their overall visibility. Without the ability to stand or lean forward, WC users are prevented from peering over most obstacles and into deep containers. A vision aid to raise or extend forward the line of sight of power WC users would be useful in many daily living, educational, and occupational activities. The design of the WC camera was based on the human factor requirements of a quadriplegic WC user and the results of a detailed House of Quality. The development of a pulley and belt-driven linkage system with a digital camera satisfied the top-ranked client and engineering requirements. Comprehensive engineering analyses were also performed to study the strength, safety, and failure modes of the WC camera mechanism. The WC camera provided a range of viewing positions from the front of the WC at eye level to more than 2 ft in front of the WC user’s knees at waist level. The solutions to expand visibility of WC users have not been adequately addressed in previous investigations in wheeled mobility.
Energy Generators Driven by Nonlinear Transport Phenomena
Authors: Sieniutycz Stanislaw
Published: November 2008

We describe quantitatively effects of nonlinear transfer phenomena that drive energy generators (thermal engines) and heat pumps. It is shown that these transports can be treated either in a standard way or as peculiar rate processes (chemical reactions governed by appropriate affinities). An approach to nonlinear transports links heat fluxes with differences of temperature in certain power Ta. A more recent approach distinguishes in each elementary transfer step two competitive (unidirectional) fluxes and the resulting flux as their difference. We show how the kinetics of this sort can be implemented into the contemporary theory of thermal energy generators.
Thermal Design Analysis of a Space Solar Power System Module
Authors: Furukawa Masao
Published: November 2008

A theoretical analysis has been made to examine feasibilities of a proposed Space Solar Power System module in thermal aspects. Analyzed first is the system thermal balance. Obtained analysis results are normalized by the electromagnetic transmitting power to express the specific cold plate area, the specific radiator area, and the specific heat rejection. Equations for the cold plate design are derived from relations describing the boiling heat transfer and the two-phase heat transport in a modeled evaporator. Solutions are arranged to determine the equivalent hydraulic diameter and the heat transfer surface are density. Equations governing the radial heat transfer, the axial heat transport, and the heat rejection are solved to give the total condenser length and the dimensionless active surface area of a condensing radiator. A fluid loop pressure loss model and a system mass breakdown model are also presented. All the expressions and models are coded to form a computer program available to parametric design studies. Computations have been done with the solar concentration ratio and the cell base plate temperature as main parameters of interest. Numerical results are graphically shown in the figures to contribute to design practices of a 100 kW power module composed of equally sized seven submodules.
Design and Development of Integrated Thick-Film Sensors for Prosthetic Hands
Authors: Cotton Darryl , Cranny Andy , White Neil , Beeby Steve , Chappell Paul
Published: November 2008

The majority of prosthetic hands lack an intelligent feedback control system requiring the user to rely on either visual feedback to detect whether an object is slipping out of the hand or if an unnecessarily large force is being applied. Screen printed thick film piezoresistive resistors and piezoelectric dynamic sensors offer a cheap and compact solution for detecting grip force and slip of an object from a prosthesis. This paper investigates the surface strain produced on two different fingertip designs with different attachment and loading methods in an attempt to optimise sensor position for maximum measurement sensitivity.
Estimating the Sampling Strategy for Circular Features in Coordinate Metrology
Authors: Cebulla Frank M. , Midha Sagar , Smith Gordon
Published: November 2008

To set up a measuring strategy for coordinate measuring machines (CMM) is a highly complex task. It includes the selection of a sampling strategy, which is the number and distribution of touch points. In this paper a method is proposed for estimating the number of touch points for circular features required to meet a certain test objective. Thus the number of touch-points are optimized, in order not to take either too few or too many. Supported by simulations the proposed method proved to be effective in determining an equidistant sampling strategy. To explore factors that affect the sampling strategy, different CMM performances, environmental conditions and workpiece deviations are investigated.
A Knowledge-Based Tool for the Selection of Design Options During the Competitive Tendering of Vehicle Systems
Authors: Kerr Clive I. , Roy Rajkumar , Sackett Peter J.
Published: November 2008

In the automotive industry the activities of documenting the design options and generating the necessary request for quotations, for Tier 1 system suppliers to be awarded contracts for design and development, is complex and time-consuming since these activities are predominately manual and paper-based. Thus, a knowledge-based tool is being developed to aid the selection of the design options for vehicle systems during competitive tendering. The tool is based on ontologies in order to provide a common and shared definition for the options available for a given vehicle system. An overview of this approach is provided and, as a ‘proof of concept’, a case study involving seating systems is presented. This paper shows, through the seating system case study, how the functionalities and features of a vehicle system can be selected and documented in order to streamline the business process of contracting out product development through the supply chain.
Modelling of Optimum Return From Disassembly of Products
Authors: Motevallian Behzad , Abhary Kazem , Luong Lee H. S.
Published: November 2008

To design products simultaneously for disassembly and commercial viability, a cost-benefit model need to be developed for assessing the design for ease of disassembly as well as materials recyclability. This paper presents a mathematical formulation to maximize the profits from disassembly of products. Disassembly process involves several activities each with its associated costs and benefits. The model in this paper looks at the balance between the costs of disassembly operations and the benefits it generates through reutilization of retrieved components, and reprocessing of retrieved materials. A cost-benefit analysis include factors such as: the disassembly cost, sorting and recovery cost, dumping cost for remaining fractions, and the revenues from retrieved parts, subassemblies, components, and materials as well as the environmental benefits such as benefits of emission reduction from energy savings by savings from extraction of raw materials and their processing.
Requirements for Remote Maintenance for Medical Wearable Devices
Authors: Du¨ltgen P. , Meier H.
Published: November 2008

Telematics applications in the healthcare service are usually, abstractly equated with the telemedicine. In both cases, what this means is deploying the current information and communication technologies to arrive at a significant improvement of information flow between all facilities and persons engaged in the health maintenance, delivery and regeneration. By means of telemedicine, an effective, less expensive and more pleasant treatment in favour of the patient can be achieved.
State of the Art in Laser Surface Texturing
Authors: Etsion Izhak
Published: November 2008

Surface texturing has emerged in the last decade as a viable option of surface engineering resulting in significant improvement in load capacity, wear resistance, friction coefficient etc. of tribological mechanical components. Various techniques can be employed for surface texturing but Laser Surface Texturing (LST) is probably the most advanced so far. LST produces a very large number of micro-dimples on the surface and each of these micro-dimples can serve either as a micro- hydrodynamic bearing in cases of full or mixed lubrication, a micro-reservoir for lubricant in cases of starved lubrication conditions, or a micro-trap for wear debris in either lubricated or dry sliding. The present paper reviews the current effort being made world wide on surface texturing in general and on laser surface texturing in particular. It presents the state of the art of LST and the potential of this technology in various lubricated applications like mechanical seals, piston rings and thrust bearings. The paper also describes some fundamental on going research around the world with LST.
Numerical Prediction of Erosion of Mild Steel Surfaces by Boiler Fly Ash Particles
Authors: Mbabazi John G. , Sheer Thomas J.
Published: November 2008

Fly ash particles entrained in the flue gas from boiler furnaces in coal-fired power stations can cause serious erosive wear on steel surfaces along the downstream flow path. This paper describes research into fly ash impingement erosion on such surfaces, with particular reference to the heat transfer plates in rotary regenerative air heaters. The effect of the ash particle impact velocity and impact angle on the erosive wear of mild steel surfaces was determined through experimental investigations, using three different power station ash types. The experimental data were used to calibrate a fundamentally-derived model for the prediction of erosion rates. This erosion model was incorporated into a particle-tracking CFD flow simulation of the ash-laden flue gas flow through the complex channels between corrugated air heater plates. The predicted erosion rates were compared with measured erosion rates obtained using a large accelerated-erosion test facility located at a power station. Good agreement was obtained, the predictions generally being within 20 percent of the measured values.
Lubrication Modelling of Artificial Hip Joints: From Fluid Film to Boundary Lubrication Regimes
Authors: Wang Fengcai , Jin Zhongmin
Published: November 2008

A full numerical methodology was developed for the mixed lubrication analysis of hip implants, covering a continuous spectrum from full fluid film to boundary (dry contact) lubrication regimes. The methodology was applied to a typical hip implant employing an ultra high molecular weight polyethylene (UHMWPE) acetabular cup in articulation with a metallic femoral head. It was shown that as the viscosity decreased, direct contact was initiated at the exit regions both in the entraining and side-leakage directions where the minimum film thickness occurred. As the viscosity decreased further, the direct contact area increased and until eventually became similar to the dry contact area.
A One-Dimensional Numerical Model for Calculating the Efficiency of Pumps as Turbines for Implementation in Micro-Hydro Power Plants
Authors: Amelio Mario , Barbarelli Silvio
Published: November 2008

Increasing interest in renewable energy sources makes attractive the exploitation of many small power hydraulic resources (micro-hydro – less than 100 kW). However, the high cost of hydraulic turbines hinders the actual realization of micro-hydro plants. An alternative cheaper solution could be to replace the turbine with a reverse-mode centrifugal pump, developing therefore a pump as turbine (PAT) system. Unfortunately, although a wide number of centrifugal pumps are commercially available for micro-hydro engineering plant, manufacturers do not provide information regarding the performance of centrifugal pumps in turbine mode. In this paper, a simple method based on a one-dimensional numerical code is presented for deriving the turbine efficiency of commercially available centrifugal pumps. The code estimates a sizing of the component using information such as impeller diameter, specific speed, head and flow rate at pump BEP, machine overall dimension which are provided in manufacturer catalogues, to deduce geometrical parameters of the machine, calculating the losses and thus determining PAT performances. The method was validated by a comparison of the predicted characteristic curves with some experimental measurements available on PATs working in a range of specific speed (Head in meters and flow rate in m3/s) from 9 to 65. The numerical code calculations effectively predicted the measured efficiency of PATs. At BEP, the efficiency was estimated with a relative error of ±10% which is a value much lower than one obtained by using the available in literature correlations. A prediction within this error range is generally accepted for this kind of application.
Artificial Intelligence in Thesaurus for Design Engineering Information Query System
Authors: Takechi Hideo , Takahashi Yasuo
Published: November 2008

The aim of this project is to demonstrate competence of a query system built by an artificial intelligence for two dimensional weld objects stored in a online database. The structure of this system consists of a knowledge base for data store and LISP coded AI (Artificial Intelligence) objects designated for search engine at online query. The data structure to define two-dimensional object such as a figure in database, dominates the systematic way of identifying or recognizing objects among pursuing the query. It is also very crucial whether or not the inference engine can directly assess the derivatives of the figure difinitions such as the area of an object, when manipulating inference for the network of meshed objects like FEM (Finite Element Method) model used for weld joint.
Numerical Analysis of Performance of DF Chemical Laser With a Radial-Expansion Nozzle Array According to D2 Injection Angles
Authors: Park Jun Sung , Baek Seung Wook
Published: November 2008

It is chemical laser system that can be used for not only new strategic weapon system for the military purpose, but also a manufacturing tool in industrial areas due to the characteristic of high power laser beam in megawatt range. In order to increase laser beam power in the chemical laser system, mixing efficiency of fuel and oxidant should be higher and more excited molecules be produced by mean of chemical reaction. Basically, the production of a lot of excited molecules in the laser cavity results from the high mass flow rates of fuel and oxidant as well as high mixing and reaction efficiencies, however, it is difficult for the planar nozzle array which has been widely used until now to supply high mass flow to the chemical laser cavity. A radial expansion nozzle array as an innovated alternative of the planar nozzle system is designed. The laser beam generation in this system is achieved by mixing F atom from supersonic nozzle and D2 molecule from the holes of round-bended supply line which are distributed with zigzag configuration, hence the reaction surface will be stretched. Consequently, it is expected that more excited molecules will be produced and population inversion also be higher. Based on that the fuel injection angle with mainstream has a big influence of performance of supersonic combustor, the effects of D2 injection angles with the main F flow on mixing enhancement and laser beam power are numerically investigated. The results are discussed by comparison with three cases of D2 injection angles; 10°, 20° and 40° with the main flow direction. Major results reveal that the area where the DF(1) excited molecules as a representative product in the DF chemical laser system are produced becomes larger when the D2 injection angle increases. The reason is that the surface of chemical reaction is larger and the field temperature is higher with increase of the D2 injection angle. And in all the vibrational transitions, the distributions of the highest maximum small signal gains are observed near the inlet when the D2 injection angle is 40°. As the D2 injection angle increases, the values of the maximum SSG are higher and the area including the high gains is also wider for the most part of domain. Based on these maximum SSG distributions, the highest power of laser beam is expected to be generated when the D2 injection angle is 40°, namely higher. However, the range of population inversion becomes narrower as the D2 injection angle increases, because the collision of molecules or atoms happens more often so that the relaxation time will be reduced as the cavity pressure caused by the high D2 injection angle with the main flow direction increases.
Gas Turbine Power Augmentation Using Fog Inlet Air-Cooling System
Authors: Ameri Mohammad , Nabati Hamid , Keshtgar Alireza
Published: November 2008

Gas turbines are almost constant volume machines at a specific rotating speed, i.e., air intake is limited to a nearly fixed volume of air regardless of ambient air conditions. As air temperature rises, its density falls. Thus, although the volumetric flow rate remains constant, the mass flow rate is reduced as air temperature rises. Power output is also reduced as air temperature rises because power output is proportional to mass flow rate. This power output reduction is from 0.5% to 0.9% of the ISO output power for every 1°C rise in the ambient temperature. The solution of this problem is very important because the peak demand season also happens in the summer. One of the useful methods to overcome this problem is to apply the fog inlet air cooling system for the gas turbines. In this paper the Rey Power Plant site climate conditions in the summer have been studied. The design conditions regarding the dry bulb temperature and relative humidity have been selected. The different inlet air cooling systems have been studied and the Fog system has been chosen. The economical study has shown that this system is very cheap in comparison with the installation of the new gas turbines. The capital cost is estimated to be 40 $/KW. The pay back period is around 1.5 year. The testing of this system has shown that the average power capacity of the power plant is increased by 19 MW and prevented the installation of a new gas turbine.
Requirements Capture for Inclusive Design Resources and Tools
Authors: Dong Hua , Clarkson P. John , Keates Simeon
Published: November 2008

In the past twenty years, a number of resources and tools to support inclusive design have been developed. However, the impact of these resources and tools on industry is not evident — few industrialists have been using them in practice. Investigations into industry have identified unmet needs, for example, the lack of appropriate user data relating to inclusive design. The fundamental problem is that few resources and tools have been developed based on rigorous requirements capture. In fact, many of them were developed only because the developers think the information could be useful. It is essential to prepare a detailed requirements list when clarifying the task at the product planning stage. This is also true for developing resources and tools for inclusive design. Requirements capture plays an important role in identifying real needs from users and developing appropriate methods of support for them. This paper starts with a survey of available resources and tools for inclusive design, and a discussion on their merits and deficiencies in respect to industry application. A number of methods are employed for the requirements capture for an inclusive design toolkit, which leads to a consistent result. An outline of the toolkit is also presented.
Comparison of Fine and Conventional Blanking Based on Ductile Fracture Criteria
Authors: Biglari Farid R. , Tavakoli Kermani Amir , Habibi Parsa Mohammad , Nikbin Kamran M. , O’Dowd Noel P.
Published: November 2008

A comparison between fine and conventional blanking is carried out in this paper. In the fine blanking process, V-ring indentation is applied to create hydrostatic pressure and prevent premature fracture in an undesired direction. Furthermore, a small clearance between the punch and die is employed along with a counterforce punch that causes concentrated strain in the sheared band region. A fracture mechanics oriented finite element procedure has been employed in this research work in order to obtain the fracture path. The fracture path is found according to the stress and strain histories which are calculated in each element. The numerical results have shown that the sheared edge quality in the blanking process is strongly influenced by the fracture path. In fine blanking, there are various parameters affecting the sheared edge quality and dimensional accuracy. The finite element calculation is carried out for an axisymmetric model. The commercial finite element code ABAQUS V6.2 is employed along with a controlling program that is written in Visual BASIC.
Discontinuous Mobility of a Folding Square-Block Toy: A Class of Single Loop Spatial 8-Bar Mechanism
Authors: Lee Chung-Ching
Published: November 2008

Based on the group theory and group algebraic structure of the displacement set, an interesting playing toy of the magic folding square block belonging to one class of single-loop spatial eight-revolute mechanism is offered to illustrate the discontinuous mobility of mechanism. This folding toy’s mobility generally has two finite global dofs as a whole kinematic chain. Nevertheless, during the movement, the permanent finite mobility of mechanism depends on the various positions of joints. When the block profile-shape constraints are taken into account, one bifurcation between one 2-dimensional manifold and one 1-dimensional manifold occurs at an initial transition position and the other bifurcation between two 1-dimensional manifolds exists in another specified configuration. In addition, any motion of one working mode destroys the geometrical condition that is required for the other modes but a bifurcation toward a spatial mode with two finite dofs remains possible by ingoring the profile shape constraints. In fact, there is a discontinuous mobility with a trifurcation among three subsets. It is composed of a general spatial mode with 2-dimensional manifold, one part mobility chain of 2-dimensional manifold and another part mobility chain of 1-dimensional manifold.
Anthropometric Modelling of the Pregnant Occupant
Authors: Acar B. Serpil , Weekes Alix M. , van Lopik David
Published: November 2008

A parametric anthropometric model of a pregnant woman has been produced for use in crash protection research. The model is based on anthropometric measurements of pregnant women, with the initial model representing a 5th percentile woman in her 30th week of gestation. The model has been developed to be easily scaleable so women of different sizes can be modeled and adapted to simulate any stage of pregnancy. Previous research has simply added an enlarged abdomen to existing females models. However the model presented describes a comprehensive depiction of the altered pregnant form by incoporating the anthropometry of the entire body. This paper presents the pregnant occupant model for use in evaluation of safety systems and vehicle interiors. This work is the first step toward a computational pregnant occupant for crash protection research, capable of simulating dynamic impact response and predicting injury risk in automobile crashes.
Active Predictive Control Applied to Suppress Dynamic Vibration Responses of Elastic Linkage Mechanisms With Piezoelectric Actuators and Sensors
Authors: Li Pengfei , Liu Hongzhao
Published: November 2008

An approach for suppressing elastic vibration responses of high-speed elastic linkage mechanisms with piezoelectric actuators and sensors was proposed using the active predictive control strategy. Based on the time-varying dynamic differential equation of a linkage mechanism, the discrete time state space equation was established, and the prediction model was formulated explicitly to express the dynamic responses of the mechanism. The weighted difference between predictive outputs and desired outputs was as the objective function, and the minimization of control energy was as the constraint condition. The model predictive control algorithm with real-time error prediction estimation was employed to suppress the dynamic vibration of the mechanism. The simulation results of the proposed method indicated that applying the simple predictive model of the controlled mechanism, the active prediction controller could be designed to suppress elastic vibration responses of linkage mechanisms efficiently, and meet the real-time demand of the system control.
Resolving the Complexity of Functional Representation in Design: A Transition From Computational Relationships to Performance Hierarchical Trees
Authors: Saridakis K. M. , Dentsoras A. J.
Published: November 2008

In the present paper, a method is presented based on the exploitation of the computational relationships among design entities in order to obtain valuable design knowledge concerning the performance and the function of the designed object (artifact, product, machine, etc.). The approach is applicable for most of the design problems and may be used in the design cases where the design problem under consideration can be formally decomposed and expressed in terms of design entities and associative relationships among them. The design knowledge is represented through different hierarchical tree types corresponding to the physical, computational and performance domains. The representation of the design knowledge in terms of computational relationships instead of terms of functional relationships is more convenient and flexible. Design modeling becomes simpler and more direct by assigning values to generic performance variables instead of defining and quantifying functional requirements, the design analysis resolution is adjustable and both the establishment and the categorization of computational operators into classes of sensitivity provide the ability of efficiently surveying and manipulating the relationships in case of value variations. The proposed method is applied to an example case of a conveyor’s design. Some remarks and a reference to future work conclude the paper.
Design Optimisation of Novel Pharmaceutical Actuator Using Optical Diagnostics
Authors: Versteeg Henk K. , Hargrave Graham K. , Genova Perry A. , Williams Robert C. , Deaton Dan , Kakade Prashant
Published: November 2008

Pharmaceutical metered dose inhalers (MDIs) are drug delivery devices that are designed to produce self-propelled aerosols for inhalation therapies. Conventional MDI actuators use configurations based on a “two-orifice-and-sump” design. This promotes partial expansion of the propellant as a pre-atomisation stage. The final aerosol contains large numbers of respirable particles (1–5μm), but the aerosol plume velocity tends to be very high (50–100m/s). The KOS Vortex Nozzle Assembly (VNA) is an innovative actuator concept, which enables a measure of control of plume velocity. The device utilises a combination of a vortex chamber and a Bernoulli horn to reduce the plume velocity whilst increasing the respirable fraction of drug particles. The aerosol generation process in all MDIs, including the KOS VNA, inevitably leads to a certain amount of internal and external drug deposition, which represents an inefficiency of the drug delivery technology that can threaten dose uniformity. This paper reports the findings of an experimental study using optical diagnostics to investigate the primary atomization mechanism and external drug deposition in the VNA. High-speed video imaging is used to document the developing aerosol plume in the near-orifice and mouthpiece regions as well as the flow regime inside the vortex chamber using transparent versions of the VNA manufactured by means of rapid prototyping. We consider how the improved understanding of the flow processes resulting from this study supports measurements of fine-particle fractions and mouthpiece deposition. We also discuss how this type of fundamental investigation using optical diagnostics can be used to drive design improvements to identify VNA geometries with improved aerosol properties and reduced external drug deposition.
Mathematical Model and Surface Deviation of Cylindrical Gears With Curvilinear Shaped Teeth Cut by a Hob Cutter
Authors: Tseng Jui-Tang , Tsay Chung-Biau
Published: November 2008

The generating motion of a cylindrical gear with curvilinear shaped teeth cut by a CNC hobbing machine is proposed. Based on the cutting mechanism and the gear theory, the surface equation of this kind of gear is developed as a function of hob cutter design parameters. Computer graphs of the curvilinear-tooth gear are presented based on the developed gear mathematical model, and the tooth surface deviations due to machine-tool setting with nominal radius of circular tooth trace are also investigated.