bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the effect of cataractous vision on the general characteristics of handwriting: its forensic implications
Authors: PERTSINAKIS M , PLAINIS S , LIMNOPOULOU A , GIANNAKOPOULOU T , ILIAKI O , TSILIMBARIS MK , PALLIKARIS IG , JACKSON AWR , PLATT AWG
Published: November 2010

Purpose To evaluate any effect of cataractous vision on handwriting performance.

Methods Nine patients were enrolled for Phase I with an average age of 75 yrs (range: 69 to 84 yrs). Visual acuity (VA) was evaluated using the European‐wide logMAR charts for far, intermediate and near vision. Measurements were performed pre‐operatively and three‐ months post‐operatively, with habitual correction, under both monocular and binocular viewing conditions. Patients were asked to give signature and handwriting samples at each visit. The signatures were compared, focusing on the general characteristics of line quality, general design, size, arrangement, spacing, slant and their sub‐elements.

Results Average monocular and binocular VA was found to improve at all measured distances post‐operatively. E.g., average binocular intermediate acuity increased from 0.52 (±0.29) to 0.20 (±0.24) logMAR, while near acuity increased from 0.70 (±0.33) to 0.52 (±0.17) logMAR. The forensic analysis showed that cataractous vision tends to influence some general characteristics, eg decreasing the line quality of the allographs and creating significant dissimilarity on the size sub‐elements. On average, the general characteristics of general design, intra‐allograph ratio and slant were not influenced by the compromised vision. A number of "non liquet" results were manifested, caused by the complete differentiation of the structure of certain allographs before and after the cataract surgery.

Conclusion Cataractous vision compromises some handwriting characteristics. Future research will focus on quantifying and exporting the results to the general population.
Relation of walking behavior and visual function during the Graz Mobility Test
Authors: GEORGI T , IVASTINOVIC D , HORNIG R , BRANDNER M , VELIKAY‐PAREL M
Published: November 2010

Purpose Epiretinal prostheses are developed to enhance the orientation of low vision patients and consequently their mobility. However to document visual progress repeated testing is necessary to eliminate learning effects. For this purpose we developed the Graz Mobility Test (GMT) and evaluated its suitability in low vision patients with retinitis pigmentosa. Aim of this study was to investigate the relation of visual function parameters and walking behavior of patients.

Methods Low vision patients (n=16) with visual acuity (VA) ranging from light perception to 1.0 logMAR passed through a mobility test consisting of four different, structurally similar mazes with black obstacles. Each test was completed four to six times. A people tracking system and a specially designed computer program recorded head movements and the patient´s walking path. In addition passage time and number of contacts were recorded. VA was tested with the Modified Grating Test (MGT) and visual field (VF) was examined with the Goldmann perimeter.

Results The subjects were divided into groups according to their VA. Patients with eccentric fields in general proved to have fewer contacts (mean: 3,4 contacts) due to their early detection of peripheral obstacles than those with less peripheral perception (mean: 9,7 contacs). Patients with better VA required less time and less head movements to pass the maze.

Conclusion Recordings and measurement of visual function and formation into groups allowed us evaluation of individual coping strategies. Hence potential benefits of epiretinal prostheses could be evaluated by comparing pre‐ and postoperative values.
Normal values for the Rarebit Fovea Test in children
Authors: BRAUTASET RL , SCHALIN S , SVANBERG M , NILSSON M
Published: November 2010

Purpose Visual acuity (VA) testing using optotypes is insensitive for detecting subtle defects in the visual function. The Rarebit Fovea Test (RFT) was therefore developed for detection of small defects of the foveal function (Frisén, 2002) at a stage before these defects affect VA. The RFT has been found to be well tolerated by children between 7 and 9 years of age. However, for determination of reference values the number of subjects in previous studies has been to small. The aim of the present study was to establish normal values for children between 6 and 10 years of age, and to evaluate the learning effect after repeated tests.

Methods RFT was conducted in a group of 181 subjects between 6‐10 years as part of a screening programme at a compulsory school, in Stockholm, Sweden

Results Normal values ranged from median MHR (Mean Hit Rate) 94.0 to 97.5% between pre‐school children and 3rd year children. For the entire group of children the median MHR was 96% (range 57‐100). The 3rd year children performed significantly better than pre‐school children (p<0.01) and 1st year children (p<0.05). An improvement from first to second test was noticed in all groups. There was a very weak but significant correlation between MHR and age (p<0.0001; R2=0.17) and between MHR and VA (p= 0.0093; R2=0.063).

Conclusion The RFT proved to be well tolerated among children in an age group between 6‐10 years and more than 90% of the children were considered to give reliable results close to what is normal for adults. Therefore the Rarebit Fovea Test proved to be useful for evaluation of the foveal function in children.
Influence of coloured stimulus on the mesopic pupillary diameter
Authors: LOBATO RINCON LL , CABANILLAS MC , AGUIRRE VILA‐CORO V , LLORENS B , NINO‐RUEDA A , SANCHEZ RAMOS C
Published: November 2010

Purpose To know and quantify the effects of the coloured stimulus in the mesopic pupilar diameter.

Methods 132 binoculars measures were analyzed in 5 people of ages ranging between 24 and 31 years old, within mesopic conditions and a time of adaptation to the darkness of 15 minutes. The pupilometer utilized was the Power Refractor II from PlusOptix. The interfered filters of 450, 510 and 600 nm were from EDMUND Optics trademark, were placed in front of a photographic flash Metz (60CT‐1) with a circular opening of 7 mm of diameter. The patients maintained the fixation on the infrared sensor of pupilometer placed to 1 meter of distance whereas the flash was placed to 2 meters of distance, both instruments in line with the midpoint of the eyes of the patient.

Results There have not been significant differences between both eyes. The average of the maximum values of the mesopic pupilar diameter was of 5,93± 0,13mm in a without filter condition; 6,10±0,03mm for the filter of 450nm; 6,03±0,08mm for the filter 510nm; and 5,84±0,03mm for the filter of 600nm. The average of the change to mesopic pupilar stimulation without filter was of 2,61±0,53mm; with 600 filter, it was of 2,06±0,51mm; with 510 filter, it was of 2,21±0,41mm and with 450 filter it was of 2,12±0,32mm. These results point out a greater reaction to mesopic pupilar with the filter of 510nm and minor reaction with filter of 600nm. The stimulus of wavelength of 510nm in mesopic condition is the one that provides major pupilar contraction, whereas, in contrast, the stimulus of 600nm is the one that provides less reaction to pupilar.

Conclusion The mesopic pupilar diameter varies in regarding with wavelength of the stimulus.
Poor Responsiveness to Antiplatelet Drugs in Acute Coronary Syndromes: Clinical Relevance and Management
Authors: Reny Jean‐Luc , Bonvini Robert F. , Bonvini John M. , Roffi Marco , Fontana Pierre
Published: November 2010

Cardiovascular diseases are the most common cause of mortality and morbidity in Western countries, accounting for more than 40% of total mortality. An optimal pharmacological management in these patients is of major importance and antiplatelet agents remain the cornerstone of acute coronary syndrome (ACS) therapy at hospital admission and during percutaneous coronary interventions (PCI). The recently described poor biological responses to aspirin and clopidogrel have been source of major concern, especially in era of drug eluting stent implantation. Indeed, insufficient platelet inhibition at the time of PCI has been consistently associated with an increased risk of complications and recurrence of ischemic events. Despite the lack of uniformly accepted definitions of aspirin and clopidogrel poor response, we sought to describe the current evidence and gaps in knowledge. While trials on the potential benefit of an increased antiplatelet maintenance dose after PCI have shown only marginal benefits, the strengthening of the initial antiplatelet regimens by additional loading doses of clopidogrel, by the administration of glycoprotein IIb/IIIa receptor inhibitors or phosphodiesterase inhibitors might further improve outcomes during ACS and PCI in patients with poor responsiveness to conventional dual antiplatelet therapy. Overall, tailoring the antiplatelet treatment on the basis of the individual biological response improves the short‐term outcome after PCI. New and more potent antiplatelet drugs may overcome the clinical consequences of the poor response to antiplatelet agents.
“Rastrierte Blätter, aber mit keiner Note beschrieben”: The Musical Sublime and Aporias of Inscription in Hoffmann'sRitter Gluck
Authors: Stanyon Miranda
Published: November 2010

Hoffmann'sRitter Gluckportrays music as sublime. Overwhelming and violent, music both engulfs and empowers the subject. Hoffmann's musical sublime works through a dialectical relationship with script: music exists at the opposite end of a spectrum to a finite, material, textual world, yet paradoxically also has form in the physical world. This paradox illuminates the artist's dilemma and the curious status of written music inRitter Gluck.In its unstable, slippery, self‐reflexive dramatizations of the musical sublime, the tale becomes an account of the aporias of relating the ideal to the real. This points towards an understanding of Hoffmann's engagement with Idealism, and suggests an interpretation of the story's climax, Gluck's sublime performance from an empty score. Inscribing music becomes a figure for representing and embodying the sublime in the finite world and in signs—a task impossible, yet imperative.
“Fräulein Bürstners weißte Bluse”: Making Sense Stick in Kafka's The Trial
Authors: Kalinowski Gregor
Published: November 2010

Where many readings of Kafka's The Trial would have us choose between high‐powered symbolical ascriptions and biographical interpretations, both of these tendencies are complicit in the generation of Joseph K.'s plot. Careful attention to the earliest written chapters of The Trial uncovers evidence of an obscured, if rather mundane, transgression which has always already been swept under the more alluring ascription of a trial. Although the figures required to advance this plot constantly seek to draw K.'s attention to the exaggeration that occasioned them, K. demonstrates an effortlessly virtuoso ability to interpret their appeals as further corroborations of his own version of events. The current reading seeks to highlight just some of the sleight‐of‐hand negotiations and lexical manipulations whereby K. becomes the seemingly unconscious vehicle of his own plot. This involves reading The Trial against the powerful narratological force invested in the figure of K.
Zur Autobiographik von Germanisten im Exil: Selbstbestimmung und Selbstreflexivität bei Bernhard Blume und Egon Schwarz
Authors: Maeding Linda
Published: November 2010

Die lebensgeschichtliche Erfahrung von Vertreibung und Exil kollidiert im Versuch ihrer Darstellung nur allzu leicht mit zentralen Gattungskonventionen der Autobiographie: Die Souveränität des autobiographischen Subjekts sowie sein Selbstverständnis als Agens werden durch die im Exil erfahrene Ohnmacht grundlegend in Frage gestellt. Bernhard Blume (1901–1978) und Egon Schwarz (geboren 1922) verarbeiten die Desintegrationserfahrungen in ihren Autobiographien auf je unterschiedliche Weise, wobei die Fragmentierung des Lebenslaufs beide zu grundlegenden Reflexionen über Darstellungsverfahren führte. Während Blume im unvollendet gebliebenen Narziß mit Brille (1985) die Autobiographie “gegen den Strich” bürsten will und im Versuch ihrer Erneuerung das Scheitern seines ehrgeizigen Projekts bewusst in Kauf nimmt, vollzieht Schwarz mit Keine Zeit für Eichendorff (1979) einen narrativen Akt der Selbstbestimmung, der durchaus als Erfolgsgeschichte zu lesen ist. Gemeinsam ist beiden Autoren, dass sie ihre Texte nicht nur aus der Perspektive betroffener Exilanten schreiben, sondern auch als Literaturwissenschaftler: Nur so erklärt sich die ausgeprägte Selbstreflexivität dieser Autobiographien, die zu einer weitreichenden Auseinandersetzung mit traditionellen Gattungspostulaten und Subjektvorstellungen führt.
Effects of martial arts on health status: A systematic review
Authors: Bu Bin , Haijun Han , Yong Liu , Chaohui Zhang , Xiaoyuan Yang , Singh Maria Fiatarone
Published: November 2010

Objective To systematically summarize the evidence for the effects of martial arts on health and fitness, to show the strengths of different types of martial arts, and to get a more complete picture of the impacts of martial arts on health, and also to provide a basis for future research on martial arts as an exercise prescription in exercise therapy.

Method We searched for “martial arts”“health” and “random” in eight databases (n= 5432). Randomized controlled trials and controlled clinical trials on the health effects of martial arts were included in the study.

Results The final analysis included 28 papers (one general martial arts, one kung fu, sixteen tai chi, six judo, three karate, and one taekwondo). Among the disciplines of martial arts, tai chi was the most well‐studied, followed by judo, karate, and taekwondo. Research topics varied widely, and included health, injuries, competition, morals and psychology, and herbal medicine. Most found positive effects on health. Tai chi is no‐contact, low‐impact, soft body and mindfulness exercise, which has been widely adopted by elderly people and proven to be a beneficial health promotion exercise. Research on judo, karate, and taekwondo mainly focused on improvements to athletes’ competitive abilities, rather than on health effects. We did not find any published randomized controlled trials or controlled clinical trials on aikido, kendo, sumo, kyudo, qi gong, or other disciplines.

Discussion and Conclusion Since martial arts are widely practiced, their effects on physiology, morphology, immunology, and neurology should be further studied in order to help people to select the best discipline or style to accomplish their purposes. This necessitates categorizing and classifying the disciplines and styles according to their effects on different body systems and levels of contact, as well as standardizing evaluation criteria for martial arts. Martial arts as an exercise prescription can then move from an experience‐based to an evidence‐based treatment.
Epidermal growth factor receptor mutation‐guided treatment for lung cancers: Where are we now?
Authors: Su Zengliu
Published: November 2010

Epidermal growth factor receptor (EGFR) kinase domain mutations (from exon 18 to 21) alter the efficacy of the EGFR tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva). Lung cancer patients with drug‐sensitive EGFR mutations initially respond, but acquire resistance after approximately one year of tyrosine kinase inhibitor treatment. This review summarizes EGFR gene mutation profiles for East Asian non‐small‐cell lung cancer patients according to recent publications. Strategies for the treatment of acquired resistance mediated by EGFR T790M are also reviewed.
Facility Location: A Robust Optimization Approach
Authors: Baron Opher , Milner Joseph , Naseraldin Hussein
Published: November 2010

In this research, we apply robust optimization (RO) to the problem of locating facilities in a network facing uncertain demand over multiple periods. We consider a multi‐period fixed‐charge network location problem for which we find (1) the number of facilities, their location and capacities, (2) the production in each period, and (3) allocation of demand to facilities. Using the RO approach we formulate the problem to include alternate levels of uncertainty over the periods. We consider two models of demand uncertainty: demand within a bounded and symmetric multi‐dimensional box, and demand within a multi‐dimensional ellipsoid. We evaluate the potential benefits of applying the RO approach in our setting using an extensive numerical study. We show that the alternate models of uncertainty lead to very different solution network topologies, with the model with box uncertainty set opening fewer, larger facilities. Through sample path testing, we show that both the box and ellipsoidal uncertainty cases can provide small but significant improvements over the solution to the problem when demand is deterministic and set at its nominal value. For changes in several environmental parameters, we explore the effects on the solution performance.
Competitive Pricing in a Multi‐Product Multi‐Attribute Environment
Authors: Kachani Soulaymane , Shmatov Kyrylo
Published: November 2010

We address the problem of simultaneous pricing of a line of several products, both complementary products and substitutes, with a number of distinct price differentiation classes for each product (e.g., volume discounts, different distribution channels, and customer segments) in both monopolistic and oligopolistic settings. We provide a generic framework to tackle this problem, consider several families of demand models, and focus on a real‐world case‐study example. We propose an iterative relaxation algorithm, and state sufficient conditions for convergence of the algorithm. Using historical sales and price data from a retailer, we apply our solution algorithm to suggest optimal pricing, and report on numerical results.
Comparison Between Steady and Unsteady Double-Entry Turbine Performance Using the Quasi-Steady Assumption
Authors: Copeland Colin D. , Martinez-Botas Ricardo , Seiler Martin
Published: November 2010

The experimental performance evaluation of a circumferentially divided, double-entry turbocharger turbine is presented in this paper with the aim of understanding the influence of pulsating flow. By maintaining a constant speed but varying the frequency of the pulses, the influence of frequency was shown to play an important role in the performance of the turbine. A trend of decreasing cycle-averaged efficiency at lower frequencies was measured. One of the principal objectives was to assess the degree to which the unsteady performance differs from the quasi-steady assumption. In order to make the steady-unsteady comparison for a multiple entry turbine, a wide set of steady equal and unequal admission flow conditions were tested. The steady-state data was then interpolated as a function of three, nondimensional parameters in order to allow a point-by-point comparison with the instantaneous unsteady operation. As an average, the quasi-steady assumption generally underpredicted the mass flow and efficiency loss through the turbine, albeit the differences were reduced as the frequency increased. Out-of-phase pulsations produced unsteady operating orbits that corresponded to a significant steady-state, partial admission loss, and this was reflected as a drop in the quasi-steady efficiency. However, these differences between quasi-steady in-phase and out-of-phase predictions were not replicated in the measured results, suggesting that the unequal admission loss is not as significant in pulsating flow as it is in steady flow.
Prediction of Ingestion Through Turbine Rim Seals—Part II: Externally Induced and Combined Ingress
Authors: Owen J. Michael
Published: November 2010

Ingress of hot gas through the rim seals of gas turbines can be modeled theoretically using the so-called orifice equations. In Part I of this two-part paper, the orifice equations were derived for compressible and incompressible swirling flows, and the incompressible equations were solved for axisymmetric rotationally induced (RI) ingress. In Part II, the incompressible equations are solved for nonaxisymmetric externally induced (EI) ingress and for combined EI and RI ingress. The solutions show how the nondimensional ingress and egress flow rates vary with Θ0, the ratio of the flow rate of sealing air to the flow rate necessary to prevent ingress. For EI ingress, a “saw-tooth model” is used for the circumferential variation of pressure in the external annulus, and it is shown that ε, the sealing effectiveness, depends principally on Θ0; the theoretical variation of ε with Θ0 is similar to that found in Part I for RI ingress. For combined ingress, the solution of the orifice equations shows the transition from RI to EI ingress as the amplitude of the circumferential variation of pressure increases. The predicted values of ε for EI ingress are in good agreement with the available experimental data, but there are insufficient published data to validate the theory for combined ingress.
The Design of Highly Loaded Axial Compressors
Authors: Dickens Tony , Day Ivor
Published: November 2010

Increasing compressor pressure ratios (thereby gaining a benefit in cycle efficiency), or reducing the number of stages (to reduce weight, cost, etc.), will require an increase in pressure rise per stage. One method of increasing the pressure rise per stage is by increasing the stage loading coefficient, and it is this topic, which forms the focus of the present paper. In the past, a great deal of effort has been expended in trying to design highly loaded blade rows. Most of this work has focused on optimizing a particular design, rather than looking at the fundamental problems associated with high loading. This paper looks at the flow physics behind the problem, makes proposals for a new design strategy, and explains sources of additional loss specific to highly loaded designs. Detailed experimental measurements of three highly loaded stages (Δh0/U2≈0.65) have been used to validate a computational fluid dynamics (CFD) code. The calibrated CFD has then been used to show that, as the stage loading is increased, the flow in the stator passages breaks down first. This happens via a large corner separation, which significantly impairs the stage efficiency. The stator can be relieved by increasing stage reaction, thus shifting the burden to the rotor. Fortunately, the CFD calculations show that the rotor is generally more tolerant of high loading than the stator. Thus, when stage loading is increased, it is necessary to increase the reaction to achieve the optimum efficiency. However, the design exercise using the calibrated CFD also shows that the stage efficiency is inevitably reduced as the stage loading is increased (in agreement with the experimental results). In the second part of the paper, the role that the profile loss plays in the reduction in efficiency at high stage loading is considered. A simple generic velocity distribution is developed from first principles to demonstrate the hitherto neglected importance of the pressure surface losses in highly loaded compressors.
Determination of a Local Bulk Temperature Based Heat Transfer Coefficient for the Wetted Surfaces in a Single Inline Row Impingement Channel
Authors: Ricklick Mark , Kapat J. S.
Published: November 2010

High performance turbine airfoils are typically cooled with a combination of internal cooling channels and impingement. In such applications, the jets impinge against a target surface, and then exit along the channel formed by the jet plate, target plate, and side walls. Local convection coefficients are the result of both the jet impact, as well as the channel flow produced from the exiting jets. Numerous studies have explored the effects of jet array and channel configurations on both target and jet plate heat transfer coefficients. However, most current studies use the plenum temperature as the reference temperature in heat transfer calculations. This presents some difficulty to designers who need to determine heat transfer rates based on the local bulk temperatures. This paper examines three different methods to determining the local bulk temperature in a steady state impingement channel heat transfer experiment. The various methods will be compared based on their ease of application as well as their accuracy in describing the results. One method proves to be the most accurate, while another proves to be more easily implemented. The methods are compared for a single case previously studied, on a 15 hole, single row impingement channel, with dimensions of X/D=5, Y/D=4, Z/D=1 and 3, and an average jet based Reynolds number of 17,000 and 45,000. Effects due to the choice of the reference temperature in heat transfer calculations are shown to cause significant variations in the calculated heat transfer coefficients. These results point to a transition between different flow regimes in the post-impingement flow.
Stability Enhancement of a Multistage Compressor by Air Injection
Authors: Hiller Sven-Jürgen , Matzgeller Roland , Horn Wolfgang
Published: November 2010

Cold and hot air injection upstream of the first rotor tip of a multistage compressor was tested experimentally. The compressor operating range was extended toward lower mass flow by more than 60% indicating a better throttling capability when air injection was activated. A strong dependency of the stability enhancement on the injected mass flow and injection velocity was found. Both increasing injection mass flow rate and increasing injection velocity led to a considerable extension of the throttling line. Comparable enhancements were achieved when reducing the number of nozzles and hence the injection mass flow. It was also found that injection of hot air, at temperatures comparable to air that bled off at a following stage, had no penalty on the stability enhancement. Investigation of the influence of air injection on radial work distribution showed that only small amounts of injected air were sufficient to lead to a significant radial work redistribution. This in turn changed the operating point of the first stage, leading to axial rematching and thus changed the whole operational behavior of the compressor.
Predicting Separation and Transitional Flow in Turbine Blades at Low Reynolds Numbers—Part I: Development of Prediction Methodology
Authors: Sanders Darius D. , O’Brien Walter F. , Sondergaard Rolf , Polanka Marc D. , Rabe Douglas C.
Published: November 2010

There is an increasing interest in design methods and performance prediction for aircraft engine turbines operating at low Reynolds numbers. In this regime, boundary layer separation may be more likely to occur in the turbine flow passages. For accurate computational fluid dynamics (CFD) predictions of the flow, correct modeling of laminar-turbulent boundary layer transition is essential to capture the details of the flow. To investigate possible improvements in model fidelity, CFD models were created for the flow over two low pressure turbine blade designs. A new three-equation eddy-viscosity type turbulent transitional flow model, originally developed by Walters and Leylek (2004, “A New Model for Boundary Layer Transition Using a Single Point RANS Approach,” ASME J. Turbomach., 126(1), pp. 193–202), was employed for the current Reynolds averaged Navier–Stokes (RANS) CFD calculations. Previous studies demonstrated the ability of this model to accurately predict separation and boundary layer transition characteristics of low Reynolds number flows. The present research tested the capability of CFD with the Walters and Leylek turbulent transitional flow model to predict the boundary layer behavior and performance of two different turbine cascade configurations. Flows over low pressure turbine (LPT) blade airfoils with different blade loading characteristics were simulated over a Reynolds number range of 15,000–100,000 and predictions were compared with experimental cascade results. Part I of this paper discusses the prediction methodology that was developed and its validation using a lightly loaded LPT blade airfoil design. The turbulent transitional flow model sensitivity to turbulent flow parameters was investigated and showed a strong dependence on freestream turbulence intensity with a second-order effect of turbulent length scale. Focusing on the calculation of the total pressure loss coefficients to judge performance, the CFD simulation incorporating Walters and Leylek’s turbulent transitional flow model produced adequate prediction of the Reynolds number performance for the lightly loaded LPT blade cascade geometry. Significant improvements in performance were shown over predictions of conventional RANS turbulence models. Historically, these models cannot adequately predict boundary layer transition.
Effect of Mass Transfer on the Performance of Selective Catalytic Reduction (SCR) Systems
Authors: Kapas Nimrod , Shamim Tariq , Laing Paul
Published: November 2010

This paper presents a computational investigation of the effect of mass transfer on the performance of selective catalytic reduction (SCR) catalysts, which are employed to reduce NOx emissions from diesel engines. The paper employs a single-channel based, one-dimensional, isothermal model. The heterogeneous surface chemistry is modeled by considering standard and fast SCR mechanisms, and the mass transfer rate is described by using a one-dimensional film model and dimensionless Sherwood (Sh) number. The paper investigates the effect of Sh numbers on the catalyst conversion performance at various temperatures and space velocities. The results show that the effect of the Sh number on the SCR catalyst performance is temperature dependent and is more pronounced at high space velocities. In general, higher Sh numbers lead to increased conversion efficiencies.
Gas-to-Liquid Sprays at Different Injection and Ambient Conditions
Authors: Nguyen Dung Ngoc , Ishida Hiroaki , Shioji Masahiro
Published: November 2010

Alternative fuels exhibit potential as a clean fuel and suitable to address problems of energy security and environmental pollution. The main objective of this research was to provide the fundamental data of ignition delay and combustion characteristics for gas-to-liquid (GTL) fuels. Experiments were carried out in a constant-volume vessel under diesel-engine conditions to study the effects of various injection and ambient conditions on ignition and combustion characteristics. The results showed that all tested fuels exhibited similar ignition-delay trends: Ignition delay increased as ambient temperature, ambient pressure, and oxygen concentration decreased. The result of changing injection pressures and nozzle-hole diameters did not significantly affect ignition-delay values for all tested fuels. The variation in ignition-delay values was small at temperatures higher than 700 K but large at temperatures less than 700 K. In addition, the result showed that GTL fuels with high cetane number corresponded to shorter ignition delay and smoother heat-release rate than those for gas-oil (conventional diesel fuel) at the same temperature, pressure, and oxygen concentration. The blend GTL fuel improved ignition quality and combustion than that of gas-oil. Shadowgraph images showed that GTL fuels exhibited shorter spray penetration and mixed with the hot air quicker than gas-oil. In addition, GTL fuels showed suitability for premixed charge compression-ignition operations owing to ignitability at low temperature. The obtained results provide useful information for finding the optimal conditions for the design and control of diesel engines fuelled by synthetic GTL fuels.
Comparison of Steady and Unsteady RANS Heat Transfer Simulations of Hub and Endwall of a Turbine Blade Passage
Authors: El-Gabry Lamyaa A. , Ameri Ali A.
Published: November 2010

The necessity of performing an unsteady simulation for the purpose of predicting the heat transfer on the endwall surfaces of a turbine passage is addressed. This is measured by the difference between the two solutions obtained from a steady simulation and the time average of an unsteady simulation. The heat transfer coefficient (Nusselt number) based on the adiabatic wall temperature is used as the basis of the comparison. As there is no film cooling in the proposed case, a computed heat transfer coefficient should be a better measure of such difference than, say, a wall heat flux. Results show that the effect of unsteadiness due to wake passage on the pressures and recovery temperatures on both hub and casing is negligible. Heat transfer on the endwalls, however, is affected by the unsteady wake; the time-averaged results yield higher heat transfer; in some regions, up to 15% higher. The results for the endwall heat transfer were compared with results in open literature and were found to be comparable.
A Study on Modified Mechanical and Wear Characteristics of Epoxy-Particulate Filled Homogenous Composites and Their Functionally Graded Materials
Authors: Siddhartha  , Patnaik Amar , Satapathy Alok , Bhatt Amba D.
Published: November 2010

This article presents the investigations on modified mechanical and wear characteristics of cement kiln dust (CKD) reinforced homogeneous epoxy composites and its functionally graded materials developed for tribological applications. CKD reinforced homogeneous and functionally graded epoxy composites are developed by simple mechanical stirring and vertical centrifugal casting technique, respectively. Mechanical properties of these graded composites are evaluated and compared with those of homogenously filled epoxy composites. Sliding wear tests are conducted over a range of sliding velocities (105–314 cm/s), normal loads (20–40 N), filler contents (0–20 wt %), and sliding distances (0.5–2 km). For this, a pin-on-disk machine and the design of experiments approach using Taguchi’s orthogonal arrays are used. A theoretical model is proposed for estimating the sliding wear rates for homogeneous, as well as graded composites. The results found from the theoretical model so proposed are found to be in good agreement with the experimental values under similar test conditions. This study reveals that the presence of cement kiln dust particles enhances the sliding wear resistance of epoxy resin and the homogeneous composites suffer greater wear loss than the graded composites. scanning electron microscopy micrograph confirms the graded dispersion of CKD particles in the matrix.
Adult Male Circumcision Tool for Use in Traditional Ceremonies
Authors: Lemmermen Kyle A. , Van Wingen Tom F. , Spencer Craig M. , Scott Phil J. , Sienko Kathleen H.
Published: November 2010

Public health officials are currently supporting adult male circumcision to minimize the transmission of HIV during intercourse. Estimates indicate that more than 3 million lives could be saved in sub-Saharan Africa alone if the procedure were widely adopted. Complications including infection and accidental cutting/amputation of the glans during traditional circumcision ceremonies can lead to permanent injury or death. A low cost, adjustable (one-size-fits-most), culturally appropriate adult male circumcision tool was designed for use in traditional circumcision ceremonies to increase the likelihood of safe outcomes.
Modeling of Spatially Controlled Biomolecules in Three-Dimensional Porous Alginate Structures
Authors: Ozbolat Ibrahim T. , Koc Bahattin
Published: November 2010

This paper presents a computer-aided design (CAD) of 3D porous tissue scaffolds with spatial control of encapsulated biomolecule distributions. A localized control of encapsulated biomolecule distribution over 3D structures is proposed to control release kinetics spatially for tissue engineering and drug release. Imaging techniques are applied to explore distribution of microspheres over porous structures. Using microspheres in this study represents a framework for modeling the distribution characteristics of encapsulated proteins, growth factors, cells, and drugs. A quantification study is then performed to assure microsphere variation over various structures under imaging analysis. The obtained distribution characteristics are mimicked by the developed stochastic modeling study of microsphere distribution over 3D engineered freeform structures. Based on the stochastic approach, 3D porous structures are modeled and designed in CAD. Modeling of microsphere and encapsulating biomaterial distribution in this work helps develop comprehensive modeling of biomolecule release kinetics for further research. A novel multichamber single nozzle solid freeform fabrication technique is utilized to fabricate sample structures. The presented methods are implemented and illustrative examples are presented in this paper.
Development of a Multifunction Isolator System for the Care of Medium-Sized Laboratory Animals Harboring Infectious Diseases
Authors: Pan Xin , Long Ming , Liang Hao , Chen Xiao , Li Han , Li Guang-bo , Zhao Zi-ye
Published: November 2010

The close phylogenetic relationship between humans and nonhuman primates makes nonhuman primates an irreplaceable model for the study of human infectious diseases. In this study, we describe the development of an automatic multifunctional isolation chamber for use with medium-sized laboratory animals carrying an infectious disease. The isolator system, including the transfer chain, disinfection chain, negative air pressure isolation system, animal welfare system, and the automated system, was designed to meet all biological safety standards. To create an internal chamber environment that was completely isolated from the exterior, variable frequency drive blowers were used in the air-intake and air-exhaust system, precisely controlling the filtered airflow and providing an air-barrier protection. To transfer the material between the interior of the isolation chamber and the outside, a double door transfer port was used. A peracetic acid sterilizer and its affiliated pipeline allowed for a complete disinfection of the isolation chamber. All of the isolator system parameters can be automatically controlled by a programmable computerized menu allowing for work with different animals in different sized cages depending on the research project. The multifunctional isolator system should be a useful safety device for working with medium-sized laboratory infectious animals in high-level biosafety laboratories.
Reflective electron beam lithography: A maskless ebeam direct write lithography approach using the reflective electron beam lithography concept
Authors: Petric Paul , Bevis Chris , McCord Mark , Carroll Allen , Brodie Alan , Ummethala Upendra , Grella Luca , Cheung Anthony , Freed Regina
Published: November 2010

Reflective electron beam litography (REBL) utilizes several novel technologies to generate and expose lithographic patterns at throughputs that could make ebeam maskless lithography feasible for high volume manufacturing. The REBL program was described in a previous article [P. Petric et al., J. Vac. Sci. Technol. B 27, 161 (2009)] 2 years ago. This article will review the system architecture and the progress of REBL in the past 2 years. The main technologies making REBL unique are the reflective electron optics, the rotary stage, and the dynamic pattern generator (DPG). Changes in how these concepts have been implemented in a new design will be discussed. The main disadvantage of today’s electron beam direct write is low throughput; it takes many tens of hours to expose a 300 mm wafer today using ebeam lithography. The projected system throughput performance with the integrated technology of the reflective optics, DPG, and a multiple wafer rotary stage will be shown incorporating the performance data for the new column design.
Atomic resolution force microscopy imaging on a strongly ionic surface with differently functionalized tips
Authors: Arai T. , Gritschneder S. , Tröger L. , Reichling M.
Published: November 2010

Three types of tips for noncontact atomic force microscopy imaging, namely, a silicon nanopillar tip, a carbon nanopillar tip, and a fluoride cluster tip, are prepared for atomic resolution imaging on the CaF2(111) surface. The most enhanced atomic corrugation is obtained with the fluoride cluster tip prepared by gently touching the fluorite surface. Atom resolved images are much harder to obtain with the other tips. This demonstrates the importance of having a polar tip for atomic resolution imaging of an ionic surface and supports the general notion that a surface is best imaged with a tip of the same material.
Variation in branch length inFagopyrum esculentumin response to density and emergence date: No evidence for true plasticity
Authors: Japhet Wisdom , Zhou Daowei , Wang Ping
Published: November 2010

Plasticity is an important attribute that enables plants to maintain fitness in heterogeneous environments. The objective of this study was to investigate plasticity in branch length in Fagopyrum esculentum Moench. Seeds of the species were sown under two contrasting conditions through the manipulation of planting density (inter-planting distances at 20, 15, 10, and 5 cm) and sowing date (25 July, 1 August, 5 August, and 15 August). Allometric analysis of the relationships between branch length and total biomass showed a significant (p < 0.05) departure from isometry. This indicates that branch length increased linearly as a function of size. However, branch length was smaller in the group of plants sown at higher densities and at late sowing dates. True plasticity, which would have been indicated by significant differences in allometric exponents within treatments, was not observed in this study. Our results suggest that the differences observed in branch length were due to the direct effect of size rather than as a result of true plastic investment in branches.
A quantitative analysis of leaf growth parameters inMyriophyllum aquaticum(Haloragaceae)
Authors: Jeune Bernard , Lacroix Christian R.
Published: November 2010

This quantitative developmental study examines various parameters associated with the growth of leaves of Myriophyllum aquaticum (Vell.) Verdc. on different shoot systems from a single clonal plant to determine the dynamics of growth processes during the development of a normal, typical leaf. Early stages of development, representing the morphogenetic phase of leaf formation, were used to document the growth rate of leaves, the dynamics of leaf lobe formation, the location of initiation of leaf lobes, and allometric relationship between leaves and leaf lobes. Even though there were variations in maximum leaf length between shoot systems, similar growth patterns were observed. In addition, during the exponential phase of growth, the location of initiation of those lobes was constant in each shoot system. There was a positive correlation between the rate of growth of leaves and the rhythm of initiation of lobes resulting in the formation of strikingly similar leaf morphologies regardless of whether the leaf is long with more lobes or short with fewer lobes. An allometric relationship between leaf length and the length of its lobes was observed. To our knowledge, this has never been noted in a system like this. The existence of constant parameters of growth is essential to maintain some degree of consistency but variations in the modalities of those parameters allow for flexibility within the system. For example, the interplay between rates of leaf growth and duration of growth can explain the range of maximum leaf length observed or can be viewed as a way of using different means to achieve similar end products (fast rate of growth and short duration versus slower rate of growth and longer duration).
Structure of corystospermaceous ovules from the Upper Triassic of Zimbabwe
Authors: Barale Georges , Guignard Gaëtan , Bamford Marion K.
Published: November 2010

Isolated ovules from the Upper Triassic of Zimbabwe were observed using three complementary approaches: light microscopy and, for the first time, scanning electron microscopy and transmission electron microscopy. Complete ovules showed a curved bifid micropylar tube. Three envelopes were present: integument, nucellus, and megaspore. The integument appeared resiniferous. The nucellus was made up of bulging cells around the pollen chamber, which contained bisaccate pollen grains. The ultrastructure of the nucellus revealed a lamellar organization in their microsinuosities. The megaspore membrane was made up of agglomerate rounded bodies more or less closely arranged and surrounded by two layers. The material may be attributed to Umkomasiaceae. A comparison with ovules of different related groups (seed ferns, Caytoniales, Ginkgoales, Nilssoniales, and Coniferales) was made. The Umkomasiales are considered to be a more primitive group than the Pteridospermales with regard to integument and nucellus.
How do shoot clipping and tuber harvesting combine to affectBolboschoenus maritimusrecovery capacities?
Authors: Durant Daphné , Desnouhes Laurent , Guillemain Matthieu , Fritz Hervé , Mesléard François
Published: November 2010

In French Mediterranean wetlands, the combined effects of predation of tubers by wildlife and grazing of aboveground tissue by livestock on the recovery capacities of Bolboschoenus maritimus (L.) Palla are not well known. A container study was conducted that applied tuber harvests at varying levels (20%–90%) and shoot clipping (with or without). Response to harvesting and clipping was recorded as changes in total biomass, number, and mean mass of tubers (calculation of variation indexes). Bolboschoenus maritimus failed to recover from even the lowest tuber harvesting level of 20% and the total number of tubers and biomass decreased. A significant decrease in mean tuber mass over time and approximately no production of new tubers accounted for this absence of compensatory response. The harvesting level had a linear effect on the variation indices of total number of tubers and mean tuber mass. By separating the relative effect of shoot clipping from that of tuber harvesting alone, the results showed that clipping had an additive effect on mean tuber mass, reducing it by about 20%, without any effect on tuber number. The absence of compensatory response under our experimental conditions suggests that clonal plant regrowth partially depends on post-disturbance environmental conditions in the growing season, in our case, dry conditions.
Thermodynamics in the viscous early universe
Authors: Tawfik A.
Published: November 2010

Assuming that the matter in the background geometry is a free gas and that no phase transitions were occurring in the early Universe, we discuss the thermodynamics of this closed system using classical approaches. We find that essential cosmological quantities, such as the Hubble parameter H, the scaling factor a, and the curvature parameter k, can be derived from this simple model, which on one hand fulfills and entirely obeys the laws of thermodynamics, and on the other hand, its results are compatible with the Friedmann–Robertson–Walker model and the Einstein field equations. Including a finite bulk viscosity coefficient leads to important changes in all these cosmological quantities. Accordingly, our picture about the evolution of the Universe and its astrophysical consequences seems to undergoing a radical revision. We find that k strongly depends on the thermodynamics of background matter. The time scale at which negative curvature might take place depends on the relation between the matter content and the total energy. Using quantum and statistical approaches, we introduce expressions for H and the bulk viscosity coefficient ξ.