bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental studies of the material properties of the forewing of cicada(Homóptera, Cicàdidae)
Authors: Song F. , Lee K. L. , Soh A. K. , Zhu F. , Bai Y. L.
Published: July 2004

Detailed investigations on the structural and mechanical properties of the forewing of the cicada were carried out. Measurement of the structures of the wings showed that the thickness of the membrane of each cell and the diameter of each vein were non-uniform in both the longitudinal and transverse directions, and their means were approximately 12.2 and 133.3 μm,respectively. However, the aspect ratios of the wings and the bodies were quite uniform and were approximately equal to 2.98 and 2.13, respectively. Based on the measured thickness, mass and area of the membranes of the cells,the mean density and the mean area density of the wing were approximately 2.3 g cm-3 and 2.8×10-3 g cm-2,respectively. In addition, the diameters of the veins of the wings, including the diameters of the holes in the vein of the leading edge, were examined. The mechanical properties of the wing were investigated separately by nanoindentation and tensile testing. The results indicated that the mean Young's modulus, hardness and yield stress of the membranes of the wings were approximately 3.7 GPa, 0.2 GPa and 29 MPa, respectively, and the mean Young's modulus and strength of the veins along the direction of the venation of wings were approximately 1.9 GPa and 52 MPa, respectively. Finally, the relevant results were briefly analyzed and discussed, providing a guideline to the biomimetic design of the aerofoil materials of micro air vehicles.
To freeze or not to freeze: adaptations for overwintering by hatchlings of the North American painted turtle
Authors: Packard Gary C. , Packard Mary J.
Published: July 2004

Many physiologists believe that hatchling painted turtles (Chrysemys picta) provide a remarkable, and possibly unique, example of `natural freeze-tolerance' in an amniotic vertebrate. However, the concept of natural freeze-tolerance in neonatal painted turtles is based on results from laboratory studies that were not placed in an appropriate ecological context,so the concept is suspect. Indeed, the weight of current evidence indicates that hatchlings overwintering in the field typically withstand exposure to ice and cold by avoiding freezing altogether and that they do so without benefit of an antifreeze to depress the equilibrium freezing point for bodily fluids. As autumn turns to winter, turtles remove active nucleating agents from bodily fluids (including bladder and gut), and their integument becomes a highly efficient barrier to the penetration of ice into body compartments from frozen soil. In the absence of a nucleating agent or a crystal of ice to `catalyze'the transformation of water from liquid to solid, the bodily fluids remain in a supercooled, liquid state. The supercooled animals nonetheless face physiological challenges, most notably an increased reliance on anaerobic metabolism as the circulatory system first is inhibited and then caused to shut down by declining temperature. Alterations in acid/base status resulting from the accumulation of lactic acid may limit survival by supercooled turtles, and sublethal accumulations of lactate may affect behavior of turtles after the ground thaws in the spring. The interactions among temperature,circulatory function, metabolism (both aerobic and anaerobic), acid/base balance and behavior are fertile areas for future research on hatchlings of this model species.
The electric fish Brachyhypopomus pinnicaudatus produces jamming avoidance responses to signals that are harmonically related to its own discharges
Authors: Capurro Alberto , Pakdaman Khashayar
Published: July 2004

Jamming avoidance responses (JARs) are exhibited by pairs of pulse type electric fish that discharge with similar frequencies whenever their individual pulses are about to coincide: responses consist of the transient shortenings in inter-discharge intervals in the fish with the higher frequency. This study describes and models novel forms of JARs observed in sexually mature male or female Brachyhypopomus pinnicaudatus.

One novel JAR was observed in male-female pairs in their natural habitat. It happened when the baseline frequencies were not similar but, rather, when one was almost twice that of the other; moreover, the transient interval shortenings occurred not in the fish with the higher frequency but in the slower one.

Transient interval shortenings similar to those in all natural JARs were observed in individual fish in tanks and submitted to periodic electrical pulse trains. They happened not only when pulse frequencies were slightly lower than the unperturbed frequency emitted by the fish but also when slightly lower than the frequency's sub- or higher harmonics (e.g. one half or twice).

The proposed model satisfactorily reproduces all experimental observations. In it, forthcoming inter-pulse intervals reflect the differences between the cophases of pulses that arrive within the `sensitive windows' belonging to either consecutive (i.e. one and the next) or alternating (e.g. every other,every three) intervals.

Paired pulse fish embody interacting oscillators, and, in particular, JARs embody either quasiperiodic phase walk-throughs and intermittencies or periodic and locked forms. Hence, their study would profit by the powerful theories and approaches advanced by nonlinear dynamics.
Ontogenesis of the attachment ability in the bugCoreus marginatus(Heteroptera, Insecta)
Authors: Gorb Stanislav N. , Gorb Elena V.
Published: July 2004

Each tarsus of Coreus marginatus L. (Coreidae) bears a pair of smooth flexible pulvilli adapted for attachment to relatively smooth surfaces,such as their host plant Rumex crispus L. (Polygonaceae). This account quantifies insect attachment abilities on smooth surfaces at various stages of ontogenesis. Friction (shear) force (FF) of adults and juvenile insects was measured by the use of a computer controlled centrifugal force tester equipped with a fibre optical sensor. Pad area, body size and body mass were determined individually for each experimental insect. Light microscopy revealed no difference in pulvilli area between different leg pairs. Pulvilli area demonstrated a stronger increase with increasing linear dimensions, as predicted by scaling laws. Since friction coefficient (relationship between FF and body weight) (FC) was always higher than 1, it was concluded that adhesion has strongly contributed to the measured friction. The frictional properties of pulvilli do not change during ontogenesis. Thus, only the growth of pulvilli and, therefore, the increased contact area, contribute to the increasing attachment ability in insects at later larval stages. Due to different scaling of the body mass and area of attachment organs, smaller insects attach relatively more strongly. Both FF and FC were higher in experiments in which higher angular acceleration (AC) was applied. Lateral tenacity determined individually for experimental insects and pooled for all animals and accelerations is 0.097 N m-2. These data led us to suggest that viscosity of the pad secretion and/or visco-elastic properties of the foam-like material of pulvilli play an important role in the attachment ability of insects.
Structure and properties of the glandular surface in the digestive zone of the pitcher in the carnivorous plantNepenthes ventrataand its role in insect trapping and retention
Authors: Gorb Elena , Kastner Victoria , Peressadko Andrei , Arzt Eduard , Gaume Laurence , Rowe Nick , Gorb Stanislav
Published: July 2004

Carnivorous plants of the genus Nepenthes grow in nutrient-poor habitats and have evolved specialised trapping organs, known as pitchers. These are composed of different surface zones serving the functions of attraction, capture and digestion of insects, which represent a main source of nitrogen. To investigate the role of the glandular digestive zone in the trapping mechanism of the pitcher, structural, mechanical and physico-chemical studies were applied to N. ventrata and combined with insect behavioural experiments. It was found that the glandular surface is microscopically rough since it is regularly structured with multicellular glands situated in epidermal depressions. The presence of downward-directed`hoods' over the upper part of glands and sloped depressions in the proximal direction of the pitcher causes a marked anisotropy of the surface. The glandular zone surface is composed of relatively stiff material (Young's modulus, 637.19±213.44 kPa). It is not homogeneous, in terms of adhesive properties, and contains numerous areas without adhesion as well as adhesive areas differing greatly in tenacity values (range, 1.39-28.24 kPa). The surface is readily wettable with water (contact angle, 31.9-36.0°C)and has a high surface free energy (56.84-61.93 mN m-1) with a relatively high polar component (33.09-52.70 mN m-1). To examine the effect of the glandular secretion on attachment systems of insects having hairy and smooth adhesive pads, forces generated on different surfaces by Calliphora vicina flies and Pyrrhocoris apterus bugs,respectively, were measured. Flies attached equally well to both fresh and air-dried glandular surfaces whereas bugs generated a significantly lower force on the fresh glandular surface compared with the air-dried one. It is assumed that the contribution of the glandular surface to insect retention,due to its effect on insect attachment, differs depending on insect weight and the type of insect attachment system. Surface anisotropy does not facilitate effective claw interlocking so that insects possessing only claws are probably not able to cling to the glandular surface. However, stiffness of the pitcher wall material in the digestive zone can provide claw clinging viapunching of the pitcher wall by claws. Small insects lacking pads may use adhesive areas on the plant surface to attach themselves, but such solitary points with very strong adhesion possibly impede their overall locomotion and chance of escape. Pad-bearing insects are presumably able to attach to smooth parts of the glandular surface located between glands. High free surface energy of the plant substrate may promote adhesion. Gland secretion may decrease attachment ability in insects with smooth adhesive pads but not influence attachment of insects with hairy attachment systems.
The importance of the lateral line in nocturnal predation of piscivorous catfish
Authors: Pohlmann Kirsten , Atema Jelle , Breithaupt Thomas
Published: July 2004

In a previous study we showed that nocturnal piscivorous catfish track the wake left by a swimming prey fish to locate it, following past locations to detect the present location of the prey. In a wake there are hydrodynamic as well as chemical signatures that both contain information on location and suitability of the prey. In order to determine how these two wake stimuli are utilised in prey tracking, we conducted experiments in catfish in which either the lateral line or the external gustation was ablated. We found that a functional lateral line is indispensable for following the wake of swimming prey. The frequency of attack and capture was greatly diminished and the attacks that did occur were considerably delayed when the lateral line was ablated. In contrast, catfish with ablated external taste still followed the wakes of their prey prior to attacking, albeit their attacks were delayed. The external taste sense, which was reported earlier to be necessary for finding stationary (dead) food, seems to play a minor role in the localisation of moving prey. Our finding suggests that an important function of the lateral line is to mediate wake-tracking in predatory fish.
Magnetic sense in the Japanese eel, Anguilla japonica, as determined by conditioning and electrocardiography
Authors: Nishi Takaaki , Kawamura Gunzo , Matsumoto Keisuke
Published: July 2004

Magnetosensitivity of the Japanese eel, Anguilla japonica, was examined by conditioning and electrocardiography. Marine eels, river eels and farmed eels were conditioned to an imposed magnetic field ranging from 12 663 nT to 192 473 nT parallel to the fish body, which was placed along the earth's west-east axis. Electrocardiograms were recorded with electrodes placed close to the fish body inside a PVC pipe shelter. After 10-40 conditioning runs, all the eels exhibited a significant conditioned response (i.e. slowing of the heart beat) to a 192 473 nT magnetic field and even to a 12 663 nT magnetic field, respectively equivalent to 5.92× and 0.38× the horizontal geomagnetic field (32 524 nT) at our laboratory. The west-east vector of the imposed magnetic field (12 663 nT) combined with that of the geomagnetic field and produced a horizontal resultant magnetic field of 21° easterly. Therefore, Japanese eel are magnetosensitive whether they are at sea, in the river or in the farm. Results of the present study were compared with those of past studies that showed no magnetic sense in the American eel, Anguilla rostrata, and the European eel, Anguilla anguilla.
The biomechanical and neural control of hydrostatic limb movements in Manduca sexta
Authors: Mezoff Sheri , Papastathis Nicole , Takesian Anne , Trimmer Barry A.
Published: July 2004

Caterpillars are ecologically successful soft-bodied climbers. They are able to grip tightly to foliage using cuticular hooks at the tips of specialized abdominal limbs called prolegs. The neural control of proleg retraction has been examined in some detail but little is known about how prolegs extend and adduct. This is of particular interest because there are no extensor muscles or any obvious mechanisms for directing hydraulic flow into the proleg. In restrained tobacco hornworms (Manduca sexta),adduction can be evoked by stimulating mechanosensory hairs on the medial surface of the proleg. 3-D kinematics show that extension and adduction occur simultaneously through an unfolding of membrane between the pseudo segments. Hemolymph pressure pulses are not necessary to extend the proleg; instead, the pressure at the base of the proleg decreases before adduction and increases before retraction. It is proposed that these pressure changes are caused by muscles that stiffen and relax the body wall during cycles of retraction and adduction. Electromyographic recordings show that relaxation of the principal planta retractor muscle is essential for normal adduction. Extracellular nerve and muscle recordings in reduced preparations show that medial hair stimulation of one proleg can strongly and bilaterally excite motoneurons controlling the ventral internal lateral muscles of all the proleg-bearing segments. Ablation, nerve section and electromyographic experiments show that this muscle is not essential for adduction in restrained larvae but that it is coactive with the retractors and may be responsible for stiffening the body wall during proleg movements.
Postprandial increases in nitrogenous excretion and urea synthesis in the giant mudskipperPeriophthalmodon schlosseri
Authors: Ip Yuen K. , Lim Chiat K. , Lee Serene L. M. , Wong Wai P. , Chew Shit F.
Published: July 2004

The objective of this study was to determine the effects of feeding on the excretory nitrogen (N) metabolism of the giant mudskipper, Periophthalmodon schlosseri, with special emphasis on the role of urea synthesis in ammonia detoxification. The ammonia and urea excretion rates of P. schlosseri increased 1.70- and 1.92-fold, respectively, within the first 3 h after feeding on guppies. Simultaneously, there were significant decreases in ammonia levels in the plasma and the brain, and in urea contents in the muscle and liver, of P. schlosseri at 3 h post-feeding. Thus,it can be concluded that P. schlosseri was capable of unloading ammonia originally present in some of its tissues in anticipation of ammonia released from the catabolism of excess amino acids after feeding. Subsequently, there were significant increases in urea content in the muscle,liver and plasma (1.39-, 2.17- and 1.62-fold, respectively) at 6 h post-feeding, and the rate of urea synthesis apparently increased 5.8-fold between 3 h and 6 h. Increased urea synthesis might have occurred in the liver of P. schlosseri because the greatest increase in urea content was observed therein. The excess urea accumulated in the body at 6 h was completely excreted between 6 and 12 h, and the percentage of waste-N excreted as urea-N increased significantly to 26% during this period, but never exceeded 50%, the criterion for ureotely, meaning that P. schlosseriremained ammonotelic after feeding. By 24 h, 62.7% of the N ingested by P. schlosseri was excreted, out of which 22.6% was excreted as urea-N. This is the first report on the involvement of increased urea synthesis and excretion in defense against ammonia toxicity in the giant mudskipper, and our results suggest that an ample supply of energy resources, e.g. after feeding,is a prerequisite for the induction of urea synthesis. Together, increases in nitrogenous excretion and urea synthesis after feeding effectively prevented a postprandial surge of ammonia in the plasma of P. schlosseri as reported previously for other fish species. Consequently, contrary to previous reports, there were significant decreases in the ammonia content of the brain of P. schlosseri throughout the 24 h period post-feeding, accompanied by a significant decrease in brain glutamine content between 12 h and 24 h.
When vortices stick: an aerodynamic transition in tiny insect flight
Authors: Miller Laura A. , Peskin Charles S.
Published: July 2004

We have used computational fluid dynamics to study changes in lift generation and vortex dynamics for Reynolds numbers (Re) between 8 and 128. The immersed boundary method was used to model a two-dimensional wing through one stroke cycle. We calculated lift and drag coefficients as a function of time and related changes in lift to the shedding or attachment of the leading and trailing edge vortices.

We find that the fluid dynamics around the wing fall into two distinct patterns. For Re≥64, leading and trailing edge vortices are alternately shed behind the wing, forming the von Karman vortex street. For Re≤32, the leading and trailing edge vortices remain attached to the wing during each `half stroke'. In three-dimensional studies, large lift forces are produced by `vortical asymmetry' when the leading edge vortex remains attached to the wing for the duration of each half stroke and the trailing edge vortex is shed. Our two-dimensional study suggests that this asymmetry is lost for Re below some critical value (between 32 and 64), resulting in lower lift forces. We suggest that this transition in fluid dynamics is significant for lift generation in tiny insects.
Functional roles of the transverse and longitudinal flagella in the swimming motility ofProrocentrum minimum(Dinophyceae)
Authors: Miyasaka Iku , Nanba Kenji , Furuya Ken , Nimura Yoshihachiro , Azuma Akira
Published: July 2004

Equations describing the motion of the dinoflagellate Prorocentrum minimum, which has both a longitudinal and a transverse flagellum, were formulated and examined using numerical calculations based on hydrodynamic resistive force theory. The calculations revealed that each flagellum has its own function in cell locomotion. The transverse flagellum works as a propelling device that provides the main driving force or thrust to move the cell along the longitudinal axis of its helical swimming path. The longitudinal flagellum works as a rudder, giving a lateral force to the cell in a direction perpendicular to the longitudinal axis of the helix. Combining these functions results a helical swimming motion similar to the observed motion. Flagellar hairs present on the transverse flagellum are necessary to make the calculated cell motion agree with the observed cell motion.
Does condition of Atlantic cod (Gadus morhua) have a greater impact upon swimming performance atUcrit or sprint speeds?
Authors: Martínez M. , Bédard M. , Dutil J.-D. , Guderley H.
Published: July 2004

To compare the sensitivity of sprint and critical(Ucrit) swimming speeds to the condition of Atlantic cod(Gadus morhua) and to identify the best anatomic, behavioural and biochemical correlates of these types of swimming, we established two groups of cod that were fed or starved for 12 weeks. We evaluated sprint swimming and Ucrit performance as well as the speed at which repeated burst-coast movements began in the Ucrit test before measuring the metabolic capacities of red and white muscle sampled caudally,centrally and rostrally and the anatomic characteristics of the cod. White muscle lactate was measured directly after the Ucrit test. As expected, the twofold difference in Fulton's condition factor(0.5±0.04 for starved and 1.0±0.1 for fed cod) was accompanied by large differences in the anatomic and biochemical parameters measured. Despite the relative sparing of muscle aerobic capacity during starvation and despite the greater use of oxidative fibres during Ucritcompared with sprint swimming, these types of swimming differed by much the same extent between starved and fed cod. In the Ucrittests, white muscle lactate levels and lactate accumulation per burst-coast movement were considerably higher in fed than starved cod, suggesting more intensive use of fast muscle fibres in cod in good condition. Multiple regression analysis indicated strong correlations between Ucrit, the speed at which regular burst-coasting began and the activity of pyruvate dehydrogenase (PDH) in red muscle (both caudal and central positions). PDH activity may limit the rate of oxidative ATP production by red muscle. The activity of cytochrome c oxidase in rostral white muscle was the strongest correlate of sprint swimming,suggesting that aerobic preparation of white muscle facilitates rapid contraction. The correlation between Ucrit and sprint swimming was weak, perhaps due to inter-individual differences in sensitivity during sprint tests.
Peripheral innervation patterns and central distribution of fin chromatophore motoneurons in the cuttlefishSepia officinalis
Authors: Gaston Michelle R. , Tublitz Nathan J.
Published: July 2004

Body patterning behavior in unshelled cephalopod molluscs such as squid,octopuses, and cuttlefish is the ability of these animals to create complex patterns on their skin. This behavior is generated primarily by chromatophores, pigment-containing organs that are directly innervated by central motoneurons. The present study focuses on innervation patterns and location of chromatophore motoneurons in the European cuttlefish Sepia officinalis, specifically those motoneurons that control chromatophores of the fin. The fin is known to be innervated by the large, branching fin nerve. This study further characterizes the innervation of fin chromatophores by the fin nerve, generates a reference system for the location of fin nerve branches across individuals, and localizes the neurons whose axons innervate fin chromatophores through the fin nerve. Data from extracellular stimulation of fin nerve branches in intact animals demonstrate topographic innervation of fin chromatophores, while retrograde labeling data reveal the posterior subesophageal mass of the brain as the primary location of fin chromatophore motoneurons.
Prey snapping and visual distance estimation in Texas horned lizards, Phrynosoma cornutum
Authors: Ott Matthias , Ostheim Joachim , Sherbrooke Wade C.
Published: July 2004

Captive Texas horned lizards were high-speed videotaped while feeding on ants in order to study the role of vision in facilitating tongue-protrusion capture of prey. Analysis of tongue movements revealed that prey snapping in these lizards is not a typical fixed-action pattern. By contrast, it is variable in performance and duration. Lizards adjusted head and tongue direction during the strike, within a few milliseconds, in response to movements of the prey. The duration of a typical tongue strike was 100-150 ms. The strike duration was prolonged after ophthalmic lenses were placed in front of one or both eyes. These lenses were used to investigate whether horned lizards use accommodation to judge prey distance. Focal changes of negatively powered ophthalmic lenses (employed monocularly) induced a clear underestimation of prey distance by the lizards, confirming the hypothesized expectation that accommodation is used for depth perception. The effect of the lenses was different in the two animals tested with monocular restriction. This, together with the lack of difference in responses by the lizards when untreated and when both eyes were lens covered (binocular treatment of equal power, -9 D), illustrates that horned lizards also use other visual parameters for depth perception.
How the house sparrowPasser domesticusabsorbs glucose
Authors: Chang Min-Hwang , Karasov William H.
Published: July 2004

According to the hypothesis that most glucose absorption occurs passively across intestinal tight junctions (paracellular absorption), one would predict fairly similar rates of in vivo absorption of l-glucose,the stereoisomer of d-glucose that is absorbed only passively and is not catabolized, and of 3-O-methyl-d-glucose(3OMd-glucose), the d-glucose analogue that is actively and passively transported and not catabolized. In house sparrows Passer domesticus, we applied a pharmacokinetic method to measure simultaneous in vivo absorption of [14C]l-glucose and[3H]3OMd-glucose in a situation in which intestinal glucose transporters were relatively saturated (gavage solution contained 200 mmol l-1 3OMd-glucose). Fractional absorptions(F) were not significantly different between[3H]3OMd- and [14C]l-glucose (0.80 vs 0.79), and the apparent rates of absorption did not differ significantly. When we performed the same experiment on other sparrows in a situation in which intestinal glucose transporters were relatively unsaturated(200 mmol l-1 mannitol replaced 3OMd-glucose in the gavage solution), the apparent rate of absorption was significantly reduced for [14C]l-glucose by 39% and for[3H]3OMd-glucose by 26%. A simulation model showed that a reduction is not predicted if most of the[3H]3OMd-glucose is actively absorbed, because the absorption rate of the tracer should increase when competitive inhibitor(unlabeled 3OMd-glucose) is removed. The similar extent and rates of absorption of [3H]3OMd- and[14C]l-glucose, and the acceleration of their rates of absorption in the presence of luminal 3OMd-glucose, are most consistent with Pappenheimer's hypothesis that the majority of dietary d-glucose is absorbed passively.
Development and validation of a dynamic model for a gaseous-fuel engine
Authors: Sim H , Sunwoo M
Published: August 2004

A dynamic model of a gaseous-fuel engine is developed in order to design an engine control system. This model includes estimation methods of dynamic characteristics to be affected by components in mixture. An effective air mass ratio is defined as air mass flow divided by mixture mass flow, and is proposed to predict variations of the air flow, manifold pressure and the air-fuel ratio according to the water vapour and the gaseous fuel in the mixture. The dynamic engine model is validated with a liquefied petroleum gas (LPG) engine-dynamometer under steady and transient operating conditions. Experimental results from an LPG gaseous-fuel engine show that estimation of the airflow and the air-fuel ratio based upon the effective air mass ratio is more accurate than that of a normal engine model.
Influence of liquid slosh on ride quality of liquid cargo tank vehicles
Authors: Xu L , Dai L , Dong M , Setiawan B
Published: August 2004

Ride comfort helps to improve driving safety and vehicle control by increasing the stability of the vehicle and reducing driver fatigue. This paper investigates the ride quality of liquid cargo vehicles subjected to sloshing forces generated by the liquid carried in a partially filled tank. A multi- degree-of-freedom model of the dynamic response of the tank vehicle is established for the analysis of ride quality in a low-frequency domain. The dynamic liquid motion within the tank is modelled with a spring-mass sloshing system. Vibration data numerically simulated with the models are prepared as power spectral density (PSD) plots for the vertical and horizontal accelerations of the seat. Influences of various road conditions, liquid fill levels, vehicle speeds and types of seat suspension system on the ride quality of the vehicles are analysed and compared.
A study of a pressure regulator for an anti-lock braking system for low-powered vehicles
Authors: Mao Y J , Tseng C H
Published: August 2004

This study proposes an innovative design of a hydraulic pressure regulator for an anti-lock braking system, called EconABS, for extremely low-powered vehicles. This system utilizes the braking force generated at the caliper as the energizing force to reduce the pressure in the caliper and to prevent over-braking. This approach limits power consumption and means that only minimal electric power is manipulated to supply the electric circuit and logic valve. The mathematical model is derived and the operating performance is simulated. Experimental results for the static situation are retrieved using a test rig. The experimental results represent consistency with the simulations as the design parameters are modified. The regulator design is shown to be a feasible solution for extremely low-powered vehicles.
Quality assurance of exhaust emissions test data
Authors: Konstantas G , Stamatelos A
Published: August 2004

Tight requirements posed by the increasingly stringent legislation complicate the design procedure for exhaust aftertreatment devices and systems. Since design optimization relies heavily on experiments and tests, emissions test data acquisition should comply with strict quality standards. Time-varying exhaust emission measurements incorporate a wealth of information stemming from the engine type, its fuel injection and ignition management and valve timing and the exhaust gas treatment devices present. The objective of this paper is to present the preliminary development process of a test data quality assurance methodology that may be coded in the form of computer software. This paper is a first attempt in this direction and is based on 15 years of experimental and computational experience of the authors' laboratory in exhaust gas treatment testing and modelling. The methodology comprises three steps. The first step involves modal analysis of the driving cycles. This allows comparison between different types of engine and test procedure regarding engine management philosophy and exhaust aftertreatment characteristics. The second step involves a systematic data synchronization and preprocessing procedure, which significantly improves data quality. The third and most important part of the methodology involves systematic checking by means of molecular and elemental balance calculations.
Advanced hybrid neural network automotive friction component model for powertrain system dynamic analysis. Part 2: System simulation
Authors: Cao M , Wang K W , Fujii Y , Tobler W E
Published: August 2004

In this research, the advanced hybrid neural network (AHNN) friction-component model, presented in Part 1 of this two-part paper, is integrated with an automotive drivetrain model for system simulations. The AHNN model accurately predicts the dynamic behaviours of transmission friction components over a broad operating range. It also allows variable sampling time steps in a numerical integration process. In this investigation, the AHNN model is trained using experimental data obtained from a powertrain dynamometer test stand. Since typical dynamometer measurements are acquired at locations away from friction components, a backtracking algorithm is developed to evaluate friction component torque during engagement. The trained AHNN model, together with a comprehensive drivetrain model, is implemented to simulate the shifting process of an automatic transmission system under various operating conditions, including different oil-temperature and engine-throttle levels. Simulation results demonstrate that the AHNN friction component model can be effectively utilized as a part of the drivetrain model to accurately predict transmission shift dynamics.
Identification of steering system parameters by experimental measurements processing
Authors: Data S , Pesce M , Reccia L
Published: August 2004

The object of this investigation is to propose a procedure for the parameter identification of a steering system, processing experimental measurements obtained on a test bench by means of a developed software. This allows the isolation of a set of parameters and the performance ratings of a steering system with an objective approach. The adopted approach overcomes problems of repeatability of the test, influence of driver style, and feelings associated with the subjective drivers evaluation method.

In this paper a two degrees of freedom (dof) model dependent by synthesis parameters is used. The model has been developed in Simulink environment, both for hydraulic and electrical power steering systems. The experimental data, obtained by an ad hoc collected set of measurements, are used to identify the parameters in two steps. A set of parameters is first computed by means of a simple signal processing procedure. Then, the model is controlled by an optimization tool, which varies the parameters values in order to reach the best fitting between experimental data and model output. Identification leads to a complete characterization of the steering system. In particular, the following parameters are identified: steering ratio, torsional stiffness, power-steering characteristic curve, friction forces, and damping.
Computational study of the effects of the geometry of the piston bowl pip for a high-speed direct injection diesel engine
Authors: Zhu Y , Zhao H , Melas D A , Ladommatos N
Published: August 2004

The piston bowl design is one of the most important factors that affect the air/fuel mixing and the subsequent combustion and pollutant formation processes in a direct injection diesel engine. The bowl geometry and dimensions, such as the pip region, the bowl lip area and the torus radius, are all known to have an effect on the in-cylinder mixing and combustion process. In order to understand better the effect of the pip region, three piston bowls with different pip designs but with the same lip area and torus radius were designed and investigated using computational fluid dynamics (CFD) engine modelling. A commercial CFD KIVA3V with improved submodels was used to model the in-cylinder flows and combustion process, and it was validated on a high-speed direct injection (HSDI) engine with a second-generation common rail fuel injection system. The engine performance, in-cylinder flow and combustion and emission characteristics were analysed at maximum power and maximum torque conditions and at part-load operating conditions. Three injector protrusions and injection timings were investigated at full load conditions. The effect of injection timing and exhaust gas recirculation (EGR) at the part-load condition was considered.
CTAB-controlled Synthesis of One-dimensional Selenium Nanostructures
Authors: Zhang Juan , Zhang Sheng-Yi , Chen Hong-Yuan
Published: July 2004

Selenium nanowires, nanorods, and nanotubes have been successfully synthesized in aqueous solution by using cetyltrimethyl ammonium bromide (CTAB) as the soft template. The synthesis is performed by controlling CTAB concentration and temperature.
Synthesis and Structure Determination of Ytterbium Nanoparticles
Authors: Ascencio Jorge A , Rodríguez-Monroy Ana C , Liu Hong Bo , Canizal Gerardo
Published: July 2004

For the first time the synthesis of of Yb metal nanoparticles is reported. The synthesis was made using the bioreduction methods. By the change in the pH the nanoparticles of 2 up to 10 nm were obtained. Size and structure determination was made using low magnification and high resolution transmission electron microscopy, which demonstrated that the particles are mainly of fcc-like structures. Theoretical calculations for by of molecular dynamics simulation for configurations with 4000 atoms of the Yb nanoparticle demonstrated that the fcc-like structure is the lowest energy configuration.
A Three-component Reaction of Phenol, Aldehyde, and Active Methylene Substrate under Lewis acid Catalysis: Successful Trapping of o-Quinone Methide to Afford Benzopyran Systems
Authors: Mashraqui Sabir H , Patil Mamta B , Mistry Hitesh D , Ghadigaonkar Shailesh , Meetsma Auke
Published: July 2004

A three-component condensation involving reactive phenols, aldehydes, and active methylene substrates is described under BF3.Et2O catalysis to afford benzopyranyl products in satisfactory yields.
A New Blue Photoluminescent Salen-like Zinc Complex with Excellent Emission Quantum Yield
Authors: Deda Massimo La , Ghedini Mauro , Aiello Iolinda , Grisolia Annarita
Published: July 2004

A new salen-like compound, H2L, bearing a 12-carbon atom length aliphatic chain bridging iminic nitrogen atoms, was successfully synthesized and characterized. Interestingly, its zinc complex, ZnL, showed an extraordinary high fluorescent quantum yield value of 75%, originating from a metal-perturbed ligand-centered state.
Dual Fluorescence of 1,2,4,5-Tetramethoxybenzene in 77 K Matrices Studied by Fluorescence Polarization
Authors: Ichinose Nobuyuki , Kishimoto Kazutoyo , Kinugasa Jun-ichiro , Hagiri Masahide , Nakayama Toshihiro
Published: July 2004

Anisotropy of the fluorescence spectrum of 1,2,4,5-tetrametoxybenzene (TEMB) in EPA matrix at 77 K showed a wavelength dependence indicating that the fluorescence was consisted of two components. This dual fluorescence can be explained by a modification of the S1(B2u) → S0(Ag) transition moment of TEMB through the coupling with a synchronous in-plane or out-of-plane bending motion of the methoxyl groups.
Preparation of La2O3-doped CeO2–ZrO2 Solid Solution with High Thermal Stability by Water-in-Oil Microemulsion
Authors: Jiang Pingping , Lu Guanzhong , Li Yangyang , Guo Yanglong , Guo Yun , Wang Xingyi
Published: July 2004

Nanoparticles of the CeO2–ZrO2–La2O3 solid solution were prepared by the W/O microemulsion method. Ceria–zirconia–lanthana (Ce/Zr/La = 1/1/0.06, mol) sample calcined at 1000 °C for 4 h has higher surface area (126 m2/g) and excellent thermal stability. Its particle size is 5–10 nm. The presence of lanthana in the sample can improve obviously the thermal stability of the CeO2–ZrO2 solid solution.
Facile Synthesis of Dendralenes Based on the Cross-coupling Reaction of 2,3-Bis(pinacolato)boryl-1,3-butadiene
Authors: Shimizu Masaki , Tanaka Kei , Kurahashi Takuya , Shimono Katsuhiro , Hiyama Tamejiro
Published: July 2004

Palladium-catalyzed cross-coupling reaction of 2,3-diboryl-1,3-butadiene with an alkenyl halide or a dienyl halide allowed us to straightforwardly prepare various kinds of acyclic cross-conjugated polyenes that are referred to as dendralenes. The present method is applicable to the synthesis of not only symmetrical [4]- and [6]dendralenes but also unsymmetrical [3]- to [5]dendralenes.
A Nonaqueous Route to Prepare Novel CuS Macroporous Material
Authors: Wan Songming , Guo Fan , Peng Yiya , Shi Liang , Qian Yitai
Published: July 2004

A novel nonaqueous route was applied to synthesize CuS macroporous material by the reaction between CuCl2·2H2O and S via the reducing action of ethylene glycol solvent. The CuS macroporous material was formed by the irregular intergrowth of CuS thin layer crystals.
Synthesis of Mesoporous Silica Thin Film with Three-dimensional Accessible Pore Structure
Authors: Naik Sajo P , Yamakita Shigehiro , Sasaki Yukichi , Ogura Masaru , Okubo Tatsuya
Published: July 2004

Continuous mesoporous silica thin films with three-dimensional (3-D) accessible pore structures have been prepared by a dip-coating technique using F127 triblock copolymer as the structure-directing agent under acidic conditions.
CO2 Sensing Properties of La-loaded SnO2 Thin Films Prepared by Sputtering
Authors: Sakama Hiroshi , Saeki Shinji , Ono Atsushi , Ichikawa Noriya , Tanokura Atsushi , Uetsuka Hiroshi , Onishi Hiroshi
Published: July 2004

The detection sensitivities of La-loaded SnO2 films prepared using reactive RF magnetron sputtering to CO2 were measured at various temperatures. The maximum sensitivity was attained at 200 °C for a film loaded with 5 atom % La. Pure SnO2 films revealed good crystallinity of the rutile phase. The crystallization of SnO2 films was suppressed by La loading.
Unprecedented Sequential Deprotonation of Ruthenium–Aqua Framework Affording Ruthenium–Oxo–Dithiolene Complex
Authors: Sugimoto Hideki , Sato Kazunobu , Takui Takeji , Tanaka Koji
Published: July 2004

A new type of aqua ruthenium–terpyridine complexes with dithiolenes (S2C2Ph2, S2C6H8) were synthesized. The pKa values were 3.8 and 7.0 for S2C2Ph2 complex and 6.5 for S2C6H8 one. The S2C2Ph2 complex gives the corresponding oxo one by the sequential deprotonation, whereas the S2C6H8 complex is just converted to the hydroxo one.
Conversion of 3-O-Substituted 1,2-Dibromoalkanes into 2-Bromo-1-alkenes by the Selective Elimination: Its Application to Total Synthesis of 12-Oxygenated Tremetones
Authors: Ohgiya Tadaaki , Nishiyama Shigeru
Published: July 2004

2-Bromo-1-alkenes were efficiently synthesized in good yields by the regioselective HBr-elimination reaction of 3-aryloxy- or 3-acyloxy-1,2-dibromoalkanes. Total synthesis of several oxygenated tremetones has been accomplished by using the 2-bromo-1-alkene derivative produced by this elimination reaction.
Heptakis(2,3-di-O-carboxymethyl)-β-cyclodextrin as a pH-sensitive Host
Authors: Kano Koji , Horiki Yasuhiro , Mabuchi Takahiro , Kitagishi Hiroaki
Published: July 2004

Acid-dissociation of heptakis(2,3-di-O-carboxymethyl)-β-cyclodextrin occurred between pD 2 and 6. At pD 2.0, 1-pyrenesulfonate was included into the host cavity with a binding constant of 2300 ± 100 M−1, while no complexation occurred at pD > 6.0. Much sharper pH-dependency in complexation proceeded with 1-anilino-8-naphthalenesulfonate and 2-(p-methylanilino)-6-naphthalenesulfonate.
Template-free Growth of Vertically Aligned CdS Nanowire Array Exhibiting Good Field Emission Property
Authors: Tang Qun , Chen Xihong , Li Ting , Zhao Aiwu , Qian Yitai , Yu Dapeng , Yu Weichao
Published: July 2004

A novel template-free solvothermal route was successfully designed to fabricate single-crystal vertically aligned CdS nanowire array, and its field emission property for the first time, was studied. The relatively high emission current density and low turn-on field make the CdS nanowire array one of the promising candidates for field-emission display.
Healthcare and the information revolution: re-configuring the healthcare service encounter
Authors: Laing A. , Hogg G , Winkelman D
Published: July 2004

Utilisation of internet-derived information by patients within the healthcare service encounter is increasing. Encompassing both the use of unidirectional information sites as well as bidirectional computer-mediated communities, this is manifest in the growth of consumerist expectations on the part of patients. Based on interviews with patients, professionals and internet site managers, this paper examines the role of the internet as a source of patient information and support, and in particular the effect on the relationship between 'informed' consumers and professionals involved in the delivery of healthcare services. The core challenge for informed consumers is to develop frameworks that facilitate robust dialogue, exchange of information and emotional support to complement their rising authority. The parallel challenge is for the established medical profession to recognize the consequences of this evolving dialogue and develop approaches to service delivery that effectively engage with consumers on the basis of this increasing authority.
Change management of mergers: the impact on NHS staff and their psychological contracts
Authors: Cortvriend Penny
Published: July 2004

The NHS has experienced a significant amount of organisational change and restructuring, which has included numerous mergers and de-mergers, since the Labour party came to power in the UK in 1997. However, to date there has been little in the way of evaluation of such changes, particularly the impact of organisational restructuring on the staff involved. This paper examines the human aspect of a merger, and subsequent de-merger, within a primary care trust (PCT) in the North of England, using a focus group methodology. The findings demonstrate that leadership and management styles have a significant impact on staff experiencing such changes. In addition, the psychological contract can be damaged due to the impact of several factors, inducing exit or intention to leave. Employees experienced a constant cycle of change with little time for stabilisation or adjustment, leading to negativity and lowered motivation at times.
Using routinely recorded ethnicity: analysis of waiting times for elective admissions by ethnic group
Authors: Morgan O.W.C. , Hamm J.
Published: July 2004

Objective: To assess whether patients from non-white ethnic groups wait longer than white patients for elective in-patient admissions at St Mary's Hospital in London.

Methods: Patients who came off the waiting list for an elective inpatient admission between 1 April 2000 and 31 March 2001 were selected. A multivariable log linear model was developed to assess geometric mean waiting times for Black, Asian, Other and Missing ethnic groups compared to the White group, adjusted for age, sex, urgency and distance.

Results: Caution is needed in interpreting results, as a large number of patients had no usable ethnic code. There was no strong evidence that waiting times for ethnic groups were systematically different than for the White group. However, there was some evidence that white patients waited longer for a coronary arteriography than patients in other ethnic groups. This was partially explained by age, sex, clinical urgency and residential distance from St Mary's.

Conclusions: The large proportion of patients with no usable ethnic code, lack of robust methods for case-mix adjustment and multiple ethnic categories makes analysis methodologically difficult. Regular and informative analysis of ethnic coded data is a necessary step in improving the accuracy and completeness of coding.
A survey of staff attitudes and comparative managerial and non-managerial views in a clinical directorate
Authors: Braithwaite Jeffrey , Westbrook Mary T.
Published: July 2004

Widespread implementation of clinical directorates (CDs) has displaced traditional structures of hospitals over the past 20 years. Responses range from support for involving clinicians in organizational processes along with the associated managerial benefits, to criticism that foreshadows potential negative effects and warns that CDs will not of themselves resolve embedded health sector problems. There is limited empirical evidence about the transition and the views of staff toward CDs. To investigate staff attitudes, a questionnaire was developed and administered in a survey of 107 staff in a large hospital that had introduced CDs three years previously. Attitudes were assessed in terms of their intensity, polarity, uncertainty and positivism toward CDs. Managers and other staff held similar attitudes on 66% of questionnaire items. Significant differences were found in the remaining one-third of items. Managers were positive about CDs, whereas non-managers' approval was limited and muted. Managers' attitudes were more intense, less uncertain and less polarized than were non-managers'. They differed primarily in the areas of working relations and power. Over recent years, CDs seem to have become institutionalized and investigations into their operation have declined. Our results suggest that taking the benefits of CDs for granted is premature.