bluuebunny/crossref_metadata_2025 huggingface dataset:
Research and Application of Connections of Structural Steel Casting
Authors: Chen Y.Y. , Zhao X.Z. , Tong L.W.
Published: August 2010

Despite the increasing usage of steel casting connections in building structures in recent years, no systematical research has been carried out on the structural design of the connections due to the complexity of the configurations and stress distribution. In this paper, important issues on structural design of cast steel connections, including material properties, design criteria, theoretical and experimental stress/deformation analysis techniques, are addressed based on engineering applications and research experience. Of the three potential design criteria for cast steel connections, fully plasticity criterion is basically not applicable, whereas the elasticity criterion and partial plasticity criterion are usually used and the corresponding design methods are recommended. Through case studies, stress distribution and empirical equation estimating the resistance of certain joints with relatively regular configuration are demonstrated. Experimental analysis techniques are also discussed in the aspects of loading systems and appropriate simulation of restraints. For a cast steel joint with complicated configuration, experiment is a reliable way to verify its actual quality and structural capacity; results thus obtained can be used to validate corresponding finite element analysis, so that more exact information on the joint behavior may become available.
Convex Model for Earthquake Damage and Loss Estimation of Individual Buildings
Authors: Jia Lizhe , Li Hui , Duan Zhongdong
Published: August 2010

Probabilistic results drawn upon inadequate information are suspicious. The convex set theory, which requires much less information, is employed to model the uncertainties of the spectral displacement and damage state medians. Furthermore, a convex model of fragility function is established based on the Envelope Bound Convex Models of the spectral displacement and damage state medians. A bound loss estimation method is derived by integrating HAZUS-AEBM module with the convex set theory. The loss bounds of a hotel in southern China are obtained and compared to the loss calculated by HAZUS-AEBM method, which locates in the lower half interval of convex analysis results. The uncertainty propagation is analyzed and damage state medians are found to be most critical factor to the loss. Finally, the PEER's probabilistic loss estimation methodology is also applied to this example to deduce the probability of loss exceeding the bound values of convex analysis results.
Hot Jets and Sources of Jet Noise
Authors: Khavaran Abbas , Kenzakowski Donald C. , Mielke-Fagan Amy F.
Published: August 2010

A prediction method based on the generalized acoustic analogy is presented and used to evaluate aerodynamic noise radiated from high-speed hot jets. The set of Euler equations are divided into two sets of equations that govern what may be considered as a non-radiating base flow plus its residual components. Under certain conditions, the residual equations are rearranged to form a wave equation. This equation consists of a third-order wave operator, plus a number of non-linear terms that are regarded as the equivalent sources of sound and their statistical characteristics are modeled. A specialized RANS solver provides the base flow as well as the variance in both velocity and thermal fluctuations that determine the source strength. The main objective here is to evaluate the relative contribution from various source components to the far-field spectra and to show the significance of temperature fluctuations as a potential source of aerodynamic noise in hot jets.
Wave-Packet Models for Large-Scale Mixing Noise
Authors: Reba Ramons , Narayanan Satish , Colonius Tim
Published: August 2010

A wave-packet Ansatz is used to model jet noise generation by large-scale turbulence. In this approach, an equivalent source is defined based on the two-point space-time correlation of hydrodynamic pressure on a conical surface surrounding the jet plume. The surface is sufficiently near the turbulent flow region to be dominated by non-propagating hydrodynamic signatures of large-scale turbulent structures, yet sufficiently far that linear behavior can be assumed in extending the near-field pressure to the acoustic field. In the present study, a 78-microphone array was used to measure hydrodynamic pressure on the conical surface in order to identify parameters for the model and to validate the approach. Six microphones were distributed in the azimuthal direction at each of 13 axial locations spanning the first 8 jet diameters, allowing decomposition of azimuthal modes m = 0 and m = 1. We show that a source model based on a Gaussian correlation function provides a consistently good representation of the noise source attributed to large-scale structures. The results provide evidence that large-scale wave-like structures, known to dominate aft radiation at supersonic phase speeds, are also relevant at subsonic speeds.
On the Scaling of Small, Heat Simulated Jet Noise Measurements to Moderate Size Exhaust Jets
Authors: McLaughlin Dennis K. , Bridges James , Kuo Ching-Wen
Published: August 2010

Modern military aircraft jet engines are designed with variable geometry nozzles to provide optimum thrust in different operating conditions, depending on the flight envelope. However, the acoustic measurements for such nozzles are scarce, due to the cost involved in making full scale measurements and the lack of details about the exact geometry of these nozzles. Thus the present effort at The Pennsylvania State University and the NASA Glenn Research Center in partnership with GE Aviation is aiming to study and characterize the acoustic field produced by supersonic jets issuing from converging-diverging military style nozzles. An equally important objective is to validate methodology for using data obtained from small and moderate scale experiments to reliably predict the most important components of full scale engine noise. The experimental results presented show reasonable agreement between small scale and moderate scale jet acoustic data, as well as between heated jets and heat-simulated ones. Unresolved issues however are identified that are currently receiving our attention, in particular the effect of the small bypass ratio airflow. Future activities will identify and test promising noise reduction techniques in an effort to predict how well such concepts will work with full scale engines in flight conditions.
Acoustic Characteristics of Jets Emanating from Curved Triangular Topologies
Authors: Jothi T. J. S. , Srinivasan K.
Published: August 2010

Noise generated from two geometrically contrasting jet flow topologies – concave and convex triangular jets are considered in the present work. Jets are generated from disk-nozzles made by cutting out the requisite concave/convex geometries on thin plates. The areas as well as the radii of curvature of concave and convex jets are maintained the same. Acoustic characteristics of the curved jets are measured and compared with those of a regular equilateral triangular jet. Experiments are conducted for underexpanded conditions for pressure ratios ranging from 2 to 7, corresponding to fully expanded jet Mach numbers of 1.04 ≤ Mj ≤ 1.92. Acoustic characterization has been carried out in terms of overall sound pressure levels, spectra, and directivity. The results show that mid-edge planes are noisier than vertex planes. The initial jet perimeter is found to be a key parameter influencing the noise emission of curved jets. Along the mid-edge planes, the concave jet is the noisiest, followed by regular equilateral triangular jet and then by the convex triangular jet. Curvature brings about a reduction in the shock-cell length – the equilateral triangular jet has the highest shock cell length followed by the convex and concave triangular jets.
Running between the Wickets in Cricket: What is the Fastest Technique?
Authors: Houghton Laurence A.
Published: August 2010

This study followed a repeated-measures design (n = 12, age range 18–22 years) and measured times to run a single: holding the bat in one hand (1H), or ‘paddling’ with the bat in two hands (2H); and times to turn when running a two and three run: holding the bat in the stronger hand and turning on the perceived strong side (1H+S); holding the bat in two hands and turning on the perceived strong side (2H+S); or holding the bat in two hands and turning on the perceived weak side (2H+W). For the singles, time was measured between 0 and 17.7 m. For the two and three runs, turn time was measured for the 5 m deceleration into and 5 m acceleration out of the 180° turn. Values are mean ± typical error. It was significantly quicker to run a single using the 1H compared to the 2H technique (1H vs. 2H: 3.110 ± 0.099 s vs. 3.165 ± 0.080 s, p = 0.032). There was a significant trial effect for turning in a two (1H+S vs. 2H+S vs. 2H+W: 2.318 ± 0.114 s vs. 2.363 ± 0.098 vs. 2.399 ± 0.097 s; p = 0.027). Similarly, 1H+S was the quickest turn technique when running a three (p = 0.018). The fastest running between the wicket technique is to hold the bat in one hand and turn on the perceived strongest side.
Personality Trait Differences of Traditional Sport Athletes, Bullriders, and other Alternative Sport Athletes
Authors: Rhea Deborah J. , Martin Scott
Published: August 2010

The purpose of this study was to examine the personality characteristics of traditional and alternative sport athletes. The participants were comprised of 70 male University Division I traditional sport athletes (e.g., tennis and volleyball), 63 male bullriders, and 50 male contemporary alternative sport athletes (moto-cross, wakeboarding, etc.). Athletes provided demographic information and responded to items related to Zuckerman's Sensation Seeking Scale and Cattell's 16 Personality Factor Inventory. Results indicated significant differences between the two alternative sport groups and the traditional sport group. Specifically, the alternative sport athletes were more reserved, self-sufficient, and sensation seeking than traditional athletes. Alternative sport athletes may need to be coached, conditioned, and rehabilitated differently than traditional sport athletes, because they seem to possess different personality characteristics than traditional sport athletes.
Use of Sport Science Evidence in a National Rugby League Judiciary Case
Authors: Gabbett Tim
Published: August 2010

In March 2008, Brisbane Broncos rugby league fullback, Karmichael Hunt was charged by the National Rugby League (NRL) judiciary with a Grade 3 careless high tackle. The charge resulted from an 18th minute collision between Hunt and Braith Anasta (Sydney Roosters five-eighth) during their Round 2 NRL match at the Sydney Football Stadium. Hunt would be suspended for a minimum of one week if found guilty by the judiciary. At the time, the Brisbane Broncos Rugby League Club had not won a single NRL judiciary case for 14 years. This case study documents the scientific arguments presented as expert evidence in this case. The scientific defence focused on 3 key elements: (1) the height that the ball-carrier (Anasta) had fallen at the moment of impact, (2) the time for Hunt to make a decision and respond to the movements of the ball-carrier, and (3) the body position of the defending player (Hunt). Karmichael Hunt was found not guilty by the NRL judiciary panel, and was free to play in the following week's fixture. The judiciary panel agreed that the collision between Hunt and Anasta was neither deliberate nor avoidable. This case study reports the evidence presented in a high profile NRL judiciary case and documents the practical utility of sport science in football judiciary cases.
Using ‘Coach Developers' to Facilitate Coach Learning and Development: Qualitative Evidence from the UK
Authors: North Julian
Published: August 2010

In the United Kingdom (UK), a significant Government investment was made into recruiting, developing and deploying 45 ‘Coach Development Officers' (CDOs). One of the CDOs' roles was to provide 1:1 development support to coaches – therefore establishing relations with, and facilitating and directly providing development opportunities for, practicing coaches. This article provides evidence of impact of the CDO's ‘coach developer’ role using qualitative interviews with 46 coaches who had received CDO support. The evidence suggests that the CDOs provided a range of services including access to information and signposting (for example, to workshops and mentoring opportunities), and direct support. It was these direct services – support through Training Needs Analysis (TNAs), Personal Development Plans (PDPs), observing sessions and providing feedback, and being an informal mentor or critical friend – which were the most valued.
Coping with Academy-to-First-Team Transitions in Elite English Male Team Sports: The Coaches' Perspective
Authors: Finn Jon , McKenna Jim
Published: August 2010

Perceptions of seven elite development coaches (M age = 45.47 years) were examined in relation to the academy-to-first-team career transitions: 1) The nature of these transitions; 2) Sources of strain for the athletes; 3) Coping strategies athletes used and were influenced to use; and 4) Uniquely, athletes' use of meaning-focused coping (MFC) strategies. This transition, which was specifically studied within football, rugby union, rugby league and cricket, is comparable to Bloom's development-to-perfection/mastery transitions, and similar transitional models described by Wylleman and Lavallee, and Stambulova. Coaches reported that this transition was potentially extremely demanding, with athletic and social sources of strain being problematic. Evidence suggested that meaning-focused coping was an important technique for successful transitions. Further, coaches also believed coping strategies closely resembling planful problem solving, acceptance of responsibility, self-control and positive-reappraisal strategies, to be beneficial to transition success, whilst strategies similar to distancing and escape avoidance coping could be detrimental.
What Could an Executive Coach Do for an Association Football Manager?
Authors: Jenkins Simon
Published: August 2010

The question of whether an Association football (soccer) manager might benefit from working with an executive coach can be broached with regard to the work of Marshall Goldsmith, who is author of the best-selling What Got You Here Won't Get You There. The title of this book is apt in the context of discussing the career of Roy Keane, who has made a difficult transition into football management from being one of the game's leading players. With journalists having pointed to apparent weaknesses in Keane's interpersonal skills, Goldsmith's eight-stage behavioural coaching process could be of value and utility to Keane. In order to facilitate commentaries on this target article, issues related to leadership, trust and caring are presented.
A Fast Digital Image Transmission Approach in the Distributed Maritime Training System
Authors: Liu Dan
Published: August 2010

In the Distributed Maritime Training system, the real-time transmission of large-scale 3D scene is one of the main problems. In recent years, fractal image compression techniques have gained more interests because of their capability to achieve high compressive ratios while maintaining very good quality of the reconstructed image. Since fractal image compression is computationally very expensive, some researchers tried to parallelize the encoding algorithm. Spiral Architecture is a relatively new and powerful approach to general-purpose machine vision system. On this novel architecture, Spiral Addition and Multiplication achieve image processing. In this paper, a novel implement based on Spiral Architecture will be presented, keeping the compressive ratio of fractal image compression at maximal to fast the speed of image transmission in the Distributed Maritime Training System.
A Multi-Level Approach for Modelling Distributed Agent Network
Authors: Makoond Bippin , Khaddaj Souheil , Oudrhiri Radouane
Published: August 2010

The task of building distributed application network is plagued by cost, ambiguous requirements and schedule overrun. A fundamental problem in building distributed applications is the presence of unreliable estimation to formulate the list of requirements in the initial stage of project life cycle. Subsequently, this often leads to reactive response from decision-makers against error occurrences, leaving a very small space for developers to establish forward planning. Unless estimations are enhanced to include more sophisticated verification and validation methodologies, the problem will remain. This paper looks at Petri Nets as a modelling and simulation instrument to verify and validate models of distributed application networks.
SGS Analysis of the Evolution Equations of the Mixture Fraction and the Progress Variable Variances in the Presence of Spray Combustion
Authors: Meftah H. , Reveillon J. , Mir A. , Demoulin F. X.
Published: August 2010

In this paper, direct numerical simulation databases have been generated to analyze the impact of the propagation of a spray flame on several subgrid scales (SGS) models dedicated to the closure of the transport equations of the subgrid fluctuations of the mixture fraction Z and the progress variable c. Computations have been carried out starting from a previous inert database [22] where a cold flame has been ignited in the center of the mixture when the droplet segregation and evaporation rate were at their highest levels. First, a RANS analysis has shown a brutal increase of the mixture fraction fluctuations due to the fuel consumption by the flame. Indeed, local vapour mass fraction reaches then a minimum value, far from the saturation level. It leads to a strong increase of the evaporation rate, which is also accompanied by a diminution of the oxidiser level. In a second part of this paper, a detailed evaluation of the subgrid models allowing to close the variance and the dissipation rates of the mixture fraction and the progress variable has been carried out. Models that have been selected for their efficiency in inert flows have shown a very good behaviour in the framework of reactive flows.
Trends in Atomization Theory
Authors: Le Moyne Luis
Published: August 2010

Sprays are widely used in industry for combustion, coating, painting, and a number of other applications. They have in common the principle of dividing a continuous liquid phase into a dispersed phase made of numerous droplets. Among all the techniques employed to atomize liquids, very few are fully described by a model or a convenient theory. We summarize in this work the main trends and principles of spray and atomization models. The mechanisms identified as being at the origin of atomization, such as aerodynamic drag, cavitation, turbulence, electrostatic forcing, etc., are listed and the appropriate models are described. Linear instability theory, cavitation models, electrostatic equations, along with Eulerian models, and statistical descriptions of sprays are presented. The need for intense work and improvement of knowledge is brought out in the conclusion.
Evaluation of StereoPIV Measurement of Droplet Velocity in an Effervescent Spray
Authors: Ghaemi Sina , Rahimi Payam , Nobes David S.
Published: August 2010

Particle image velocimetry (PIV) is a well known technique for measuring the instantaneous velocity field of flows. However, error may be introduced when measuring the velocity field of sprays using this technique when the spray droplets are used as the seed particles. In this study, the effect of droplet number density, droplet velocity profile, and droplet size distribution of a spray produced by an effervescent atomizer on velocity measurement using a StereoPIV has been investigated. A shadowgraph-particle tracking velocimetry (S-PTV) system provided measurement of droplet size and velocity for comparison. This investigation demonstrated that the StereoPIV under-estimates velocity at near-field dense spray region where measurement accuracy is limited by multi-scattering of the laser sheet. In the dilute far-field region of the spray, StereoPIV measurement is mostly in agreement with velocity of the droplet size-class which is close to the mean diameter based on droplet number frequency times droplet cross sectional area.
Design of Test Benches for the Hovering Performance of Nano-Rotors
Authors: Liu Zhen , Moschetta Jean-Marc , Chapman Nathan , Barènes Roger , Xu Min
Published: August 2010

With the reduction of rotor diameter and motor size, the hovering performance measurement becomes a challenge for rotary wing Nano Air Vehicles (NAVs). Conventional test benches for Micro Aerial Vehicles fail to measure some characteristics of Nano Air Vehicles. In this paper, five test benches with highly sensitive mechanisms were successively designed in order to measure the thrust and torque of nano-rotors simultaneously and respond to the change of variables rapidly with sufficient accuracy. A commercial micro brushless motor and a micro rotor were studied experimentally and computationally at a low Reynolds range from 4,000 to 19,000. Computational and experimental comparisons were carried out and the performance of the test benches was discussed. The analysis suggests that the thrust coefficients measured by each test bench vary little from each other, while the power coefficients present significant differences. Then the hovering performance of the micro rotor and power efficiency of the motor were studied. Degradation of motor efficiency and rotor figure of merit are observed with size reduction associated with NAV applications.
Applying Science to Medicine
Authors: French Joel , Weathersby Robert
Published: August 2010

Only 55% of patients receive recommended care, with little difference found between care recommended for prevention, to address acute episodes, or to treat chronic conditions (McGlynn et al, 2003). The lag time between the discovery of more effective forms of medical treatment and their incorporation into routine patient care averages seventeen (17) years (IOM). Computerized provider order entry (CPOE) has been widely documented as a necessary tool to reduce preventable medication and other related errors but only 7.4% of acute care hospitals in the United States utilize CPOE with appropriate rules and evidence (HIMSS Analytics). The most fundamental building block for CPOE is the evidence based order set, but complexities associated with creating, managing and updating order sets have introduced major obstacles to CPOE implementation efforts. Chronic conditions such as heart disease, diabetes or arthritis affect more than 130 million Americans directly, and account for 7 in 10 deaths. Further, these chronic conditions consume 75% of all healthcare spending, and account for nearly two-thirds of the growth in health spending over the past 20 years -costing the U. S. economy $1 trillion annually (Almanac of Chronic Conditions, 2008 Edition). Estimates suggest the average patient upon hospitalization has 2.75 diagnoses - meaning "appropriate care" must span and synthesize multiple morbidity-specific best practices to effectively administer care to that "average" patient. The traditional approach to treating patients with evidence based protocols requires a physician to perform an ad hoc exercise of "mental merging" - reconciling duplicate candidate orders across multiple order sets to treat a patient with co-morbidities (today's norm). A more clinically effective, productive, and patient safety-centric alternative is to employ a proprietary software merging algorithm. These advanced algorithms remove duplicate orders, resolve conflicts, completes validation of the appropriate medical evidence and organizes the resulting merged order set so the physician can succinctly address the patients' often complicated treatment by focusing on the unique combination of labs, medications, etc. appropriate for the specific presenting conditions. This article describes a patent-pending propriety method of algorithmically merging multiple independent order sets for patients with co-morbid and chronic conditions into a single, maintenance free and evidence-based order set that can be immediately implemented into physician workflow to satisfy "Meaningful Use" guidelines for incremental provider reimbursement based on the American Recovery and Reinvestment Act (ARRA) legislation.
Innovation in Health Care
Authors: Harrington H. , Voehl Frank
Published: August 2010

At the center of its core, Health Care is the application of a general body of knowledge to the needs of a specific patient. For centuries, this knowledge was generally regarded as the property of the healing professions and the individual clinician, not necessarily of the health care delivery organization. Managerial practice also had a tendency to treat this knowledge as an attribute of the provider, thus focusing on the resources clinicians used as they provided care and on the hotel-type functions associated with inpatient institutions. That is, there was a deliberate differentiation between management practice, focused on business processes, and clinical practice, focused on the activities and decisions of diagnosis and treatment. Though often described as bureaucratic and incrementally changing, health care is also a very dynamic and innovative field. Around the globe, research scientists, private industries, academics, and governmental and nongovernmental agencies continue to work in innovating new ways to provide better care, find cures, and improve health. At the same time, health care delivery has been undergoing a gradual but important change. Patient care, once the domain of the individual practitioner, is becoming the domain of the care delivery organization. Additionally, the mission of these organizations is shifting. As science, technology, care processes, and care teams have become more complex and diverse, the way in which the activities of care are organized and the institutional context in which they occur have become an increasingly important determinant of the effectiveness and efficiency of that care. As a result, the object of management has changed. In response to these changes, health care managers have started focusing on the management of the care as well as the management of the institutions in which the care takes place, thereby creating a set of ‘Best Practices’ which are briefly described in this paper along with how the process of innovation is developing in the health care system.
Combining Ontologies and Cognitive Engineering to Innovate Electronic Health Records
Authors: Little Eric
Published: August 2010

Several challenges exist for implementing electronic health records (EHRs). Tantamount to these challenges are issues surrounding the most effective ways to model medical information and subsequently deliver that information to necessary stakeholders. Therefore, it is important to design and implement EHR systems that are robust in terms of their content and intuitive in terms of their use value. Ontologies can provide robust and intuitive EHR capabilities, since ontological approaches more closely mirror the ordinary ways in which people interact (and problem solve) with the world. In a like manner, cognitive systems engineering - particularly the area of cognitive work analysis (CWA) — offers empirically-based methodologies for better understanding the ways in which people interact with data. By combining ontologies and CWA methodologies in healthcare settings, it is possible to build systems that both model information in correct ways and present it to those that need to utilize it in their day-to-day work environments.
Numerical Modelling of Wind-Waves -Problems and Results
Authors: Polnikov V. G.
Published: August 2010

Stochastic wind sea is an intermediate small-scale physical process responsible for the state of the atmospheric boundary layer and the water upper layer, having dynamics of all scales. To describe behavior of this system, one could use the mathematical formalization based on a spectral evolution model for wind-waves. To this end, it needs a well-designed numerical model derived from the principal physical equations. On this way certain theoretical problems take place. At present some of these problems are solved, that gives possibility to construct a lot of numerical wind-wave models, the latest version of which was proposed in Polnikov (2005). With the aim of assessing real merits of the new source function proposed in the mentioned paper, the latter was tested and validated by means of modification of the well known model WAVEWATCH-III. Assessment was done on the basis of comparing the wave simulation results obtained by both models for a given wind field against the buoy data gotten in the three oceanic regions.

Estimation of simulation accuracy was obtained for three wind-wave parameters: significant wave height, Hs, peak wave period, Tp, and mean wave period, Tm. Comparison of these estimations between the original and modified model WAVEWATCH was fulfilled and analyzed. Advantage of the modified model was revealed, consisting in an increase of simulation accuracy for Hs in 1.2–1.5 times for more than 70% of buoys considered. Additionally, it was found that the speed of calculation was increased by 15%.
Breaking Wave Impact Pressure on a Vertical Wall
Authors: Rajasekaran C. , Sannasiraj S.A. , Sundar V.
Published: August 2010

Offshore and coastal structures experience wave impact loads particularly due to breaking waves throughout its design period. In the present paper, an experimental program has been devised to improve our perceptive of the physics and the characteristics of impact pressures due to breaking waves on a vertical wall. The salient features of the study such as model details, breaking wave simulation, the impact and dynamic pressure variation along the depth of the wall are presented. The maximum impact pressure magnitude is found to be of the order of ten times that of the non-breaking dynamic pressure and it always occurred above the still water level for different intensities of breaking waves considered. The minimum pressure rise time is observed to be 0.235 ms.
Healthcare Team Performance in Time Critical Environments: Coordinating Events, Foraging, and System Processes
Authors: Caldwell Barrett S. , Garrett Sandra K. , Boustany Karim C.
Published: August 2010

This review paper addresses issues in how healthcare providers search, obtain, and share resources in provider teams. Based in part on a System of Systems (SoS) analysis of provider coordination and resource flows, this paper expands the concepts of resource foraging theory and event dynamics to develop systematic methods for studying healthcare provider coordination. Process flow and human factors emphases from industrial engineering are used to address critical concerns of single‐scale and multi‐scale performance in healthcare delivery settings. Provider strategies for acquiring the information and resources needed for successful healthcare delivery are dependent on interactions between task requirements, time constraints, and provider coordination processes, as well as limitations of information and resource flow capabilities. These improved definitions and measures will enhance engineers′ ability to contribute to improved patient care timeliness, effectiveness, quality, and safety.
Effect of Fire Induced Restraint on Fire Resistance of Reinforced Concrete Beams
Authors: Kodur Venkatesh , Dwaikat Monther
Published: August 2010

The effect of fire induced restraint on the fire response of reinforced concrete (RC) beams is addressed in this paper. A macroscopic finite element model, capable of tracing the behavior of restrained RC beams from pre-fire stage to collapse in fire is used in the analysis. The model is applied to investigate the effect of five parameters; namely, degree of axial restraint, span-to-depth ratio, fire scenario, load level, and failure criteria on the fire response of restrained RC beams. Through the results of the parametric study, it is shown that the five parameters have significant influence on fire resistance of RC beams. It is also shown that, fire induced restraint has negative effect on fire resistance of slender RC beams having high span-to-depth ratio.
The Deep Penetration of Concrete Targets by Rigid Rods - Revisited
Authors: Rosenberg Z. , Dekel E.
Published: August 2010

The penetration of rigid long rods into semi-infinite concrete targets is revisited. In particular, we focus on the deceleration of these rods during their penetration, as inferred from the experimental data for penetration depths vs. impact velocities. We find that for a given concrete these decelerations are independent on impact velocity, which enables us to construct a simple relation between the penetration depth and impact velocity. Our model is different from the model which is based on the dynamic cavity expansion analysis to account for the resisting forces on the rod. The cavity expansion model has two terms for the resisting force, a strength term and an inertia term which depends on the velocity of the rod. In the present work we show that there is no physical basis for the inclusion of an inertia term and that the concrete's resisting force depends only on its strength, as with metallic targets. We demonstrate the validity of our approach by comparing its predictions with penetration depths from published data for different concrete and grout targets. We also find an empirical relation between the concrete's resisting stress and its unconfined compressive strength. Several important issues concerning target dimensions and the strength of the rod are discussed. These issues should be carefully considered as they influence the rigid nature of the rod and the semi-infinite condition of the target.
Blast Walls for Structural Protection against High Explosive Threats: A Review
Authors: Smith PD
Published: August 2010

This paper presents a review of research into the performance of blast walls in providing protection against the damaging effects of a blast wave generated by the detonation of a quantity of high explosive. Explosive sources might be military weapons such as aerially-delivered bombs or, more likely in the context of the current world situation, improvised explosive devices such as might be deployed by terrorist organisations. The paper reviews studies concerned with how blast walls achieve structural protection with particular reference to the importance of the blast wall's location relative to the threat and the asset that is to be protected. The question of what damage a blast wall might sustain, while still retaining its protective capabilities, is also discussed. The paper presents examples of both ‘permanent’ and ‘temporary’ blast wall designs and constructions used by both military and civilian organisations.
Finite Element Model of Functionally-Graded Cementitious Panel under Small Projectile Impact
Authors: Lin V. W. J. , Quek S. T. , Maalej M. , Lee S. C.
Published: August 2010

This paper presents a three-dimensional finite element model for functionally-graded (FG) cementitious panel subjected to high-velocity small projectile impact using the commercial package, LS-DYNA. The FG-panel consists of PE-fibrous ferrocement as the top and bottom layers, sandwiching a thin layer of concrete with calcined bauxite aggregates and an infill of conventional mortar layer to form the remaining thickness. The impact responses of different panel configurations (by varying the thickness of individual layers) were simulated and the results compared well with experimental data for projectiles with striking velocities ranging from 300 m/s to 600 m/s. After model verification, an optimization study of the FG-panel configurations (thickness of composite layers) was performed with the aim of preventing perforation of the panel by a projectile with 600 m/s striking velocity. The impact response of a proposed FG-panel design was numerically simulated to evaluate its performance.
Directional Derivatives of Oblique Reflection Maps
Authors: Mandelbaum Avi , Ramanan Kavita
Published: August 2010

Given an oblique reflection map Γ and functions [Formula: see text] (the space of ℝK-valued functions that have finite left and right limits at every point), the directional derivative [Formula: see text] of Γ along χ, evaluated at ψ, is defined to be the pointwise limit, as [Formula: see text], of the family of functions [Formula: see text]. Directional derivatives are shown to exist and lie in [Formula: see text] for oblique reflection maps associated with reflection matrices of the so-called Harrison-Reiman class. When ψ and χ are continuous, the convergence of [Formula: see text] to [Formula: see text] is shown to be uniform on compact subsets of continuity points of the limit [Formula: see text], and the derivative [Formula: see text] is shown to have an autonomous characterization as the unique fixed point of an associated map. Directional derivatives arise as functional central limit approximations to time-inhomogeneous queueing networks. In this case ψ and χ correspond, respectively, to the functional strong law of large numbers and functional central limits of the so-called netput process. In this work it is also shown how the various types of discontinuities of the derivative [Formula: see text] are related to the reflection matrix and properties of the function Γ(ψ). In the queueing network context, this describes the influence of the topology of the network and the states (of underloading, overloading, or criticality) of the various queues in the network on the discontinuities of the directional derivative. Directional derivatives have also been found useful for identifying optimal controls for fluid approximations of time-inhomogoeneous queueing networks and are also of relevance to the study of differentiability of stochastic flows of obliquely reflected Brownian motions.
Excitation energy transfer in conjugated polymer/silicon nanocrystal-based bulk heterojunctions
Authors: Švrček Vladimir
Published: August 2010

An excitation energy transfer in a bulk heterojunction based on freestanding silicon nanocrystals (Si-NCs) and conjugated polymers {poly(3-hexylthiophene) (P3HT), poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV)} is demonstrated. The electrochemical etching process is employed for fabrication of freestanding and polymer soluble Si-NCs. Formation of a bulk heterojunction is confirmed by a difference in a work function of both polymers and an ionization potential of the NCs. An annealing step significantly influences the polymer chain conformation and electronic interaction between the polymer and the NC, which improves the exciton energy migration. The presence of the Si-NCs in polymers suppresses the relative intensity of vibronic peaks, resulting in a red-shift of the blend photoluminescence (PL) spectra. This phenomenon is attributed to a temperature-dependent migration process of singlet exciton and Dexter excitation energy transfer from the polymer to the NC. Compared to MEH-PPV polymer, a lamella-type stacking structure of the P3HT and an abridged PL spectra overlap with NCs decreases an excitation energy transfer rate. At the same time, an improvement in photocurrent generation is recorded when Si-NCs are embedded in P3HT polymer. After Dexter-like excitonic energy transfer, the PL emission of both blends is controlled through a quantum confinement effect and electron-hole recombination in Si-NCs.
Discrepancies in International Normalized Ratio Results between Instruments: A Model to Split the Variation into Subcomponents
Authors: Sølvik Una Ø , Petersen Per H , Monsen Grete , Stavelin Anne V , Sandberg Sverre
Published: August 2010

BACKGROUND

Observed differences between results obtained from comparison of instruments used to measure international normalized ratio (INR) have been higher than expected from the imprecision of the instruments. In this study the variation of these differences was divided into subcomponents, and each of the subcomponents was estimated.

METHODS

Blood samples were collected at 4 different patient visits from each of 36 outpatients who were receiving warfarin treatment and were included in the study. INR was determined on 1 laboratory instrument (STA Compact®) and 3 point-of-care instruments (Simple Simon®PT, CoaguChek®XS, and INRatio™). All 4 INR instruments were compared in pairs. Linear regression was used to correct for systematic deviations. The remaining variation of the differences was subdivided into between-subject, within-subject, and analytical variation in an ANOVA nested design.

RESULTS

The mean difference between instruments varied between 1.0% and 14.3%. Between-subject variation of the differences (expressed as CV) varied between 3.3% and 7.4%, whereas within-subject variation of the differences was approximately 5% for all 6 comparisons. The analytical imprecision of the differences varied between 3.8% and 8.6%.

CONCLUSIONS

The differences in INR between instruments were subdivided into calibration differences, between- and within-subject variation, and analytical imprecision. The magnitude of each subcomponent was estimated. Within results for individual patients the difference in INR between 2 instruments varied over time. The reasons for the between- and within-subject variations of the differences can probably be ascribed to different patient-specific effects in the patient plasma. To minimize this variation in a monitoring situation, each site and patient should use results from only 1 type of instrument.
Detection of Exaggerated Blood Pressure Response Using Laboratory of Physical Science Protocol and Risk of Future Hypertension
Authors: Odahara Tsutomu , Irokawa Masataka , Karasawa Hiroshi , Matsuda Shinya
Published: August 2010

Detection of Exaggerated Blood Pressure Response Using Laboratory of Physical Science Protocol and Risk of Future Hypertension: Tsutomu Odahara, et al. Kagoshima Occupational Environmental Health Center

Objective

To assess the usefulness of the Laboratory of Physical Science (LOPS) protocol for detecting exaggerated blood pressure (BP) response as a risk factor for future hypertension when controlling for work and personal factors.

Methods

Subjects were 815 healthy normotensive men (mean age, 43.1 ± 6.76 yr; range, 29–64 yr) who participated in the LOPS protocol, a graded 4‐stage exercise test undertaken for the measurement of 40–70% of maximum oxygen consumption. A hypertensive response was defined as systolic blood pressure (SBP) of 250 mmHg or diastolic blood pressure (DBP) of 120 mmHg during the exercise test.

Results

New‐onset hypertension or the initiation of antihypertensive drug treatment had occurred in 108 men (13.3%) after 7 yr of follow‐up. Cox proportional survival analysis revealed significantly increased risks of developing hypertension were associated with exaggerated BP response to exercise (hazard ratio, 2.3; 95% confidence interval, 1.4–3.7) and higher frequency of business trips (hazard ratio, 1.7; 95% confidence interval, 1.2–2.5) after multivariable adjustments for work and personal‐related risk factors.

Conclusions

These results suggest that the LOPS protocol is effective for detecting exaggerated BP response as a risk factor for future hypertension when controlling for work and personal‐related risk factors. Exaggerated BP response to exercise and higher frequency of business trips are risk factors for developing future hypertension.
Preditores clínicos do ganho estatural do primeiro ano de tratamento com dose fixa de hormônio de crescimento em crianças nascidas pequenas para idade gestacional
Authors: Furtado Adriana Claudia Lopes Carvalho , Castro Luiz Claudio Gonçalves de , Rodrigues Marcelo Palmeira , Naves Luciana Ansaneli
Published: August 2010

OBJETIVO: Identificar preditores clínicos associados à recuperação do crescimento no primeiro ano de tratamento com somatropina (rhGH) em um grupo de crianças nascidas pequenas para a idade gestacional (PIG). SUJEITOS E MÉTODOS: Foram avaliadas 39 crianças que estavam em terapia com rhGH por pelo menos um ano (0,33 mg/kg/semana). As variáveis analisadas foram idade cronológica (IC), idade óssea (IO), altura-alvo e escores de desvios-padrão (Z-escore) do peso e comprimento ao nascer, altura, peso e velocidade de crescimento pré e pós-rhGH. RESULTADOS: A terapia com rhGH foi associada a incremento significativo de 0,67 Z-escore (p < 0,01) na estatura nesse primeiro ano. IO e Z-escore de peso ao nascimento foram reconhecidos como preditores dessa resposta, com diferença significativa na variação do Z-escore de estatura entre pré-púberes e púberes (p = 0,016). CONCLUSÃO: Esses dados mostram ganho estatural significativo com dose fixa de rhGH, observando-se melhores resultados quando a terapia foi iniciada na fase pré-puberal.
Variabilidade genética em tambaquis (Teleostei: Characidae) de diferentes regiões do Brasil
Authors: Jacometo Carolina Bespalhok , Barrero Nelson Maurício Lopera , Rodriguez-Rodriguez Maria Del Pilar , Gomes Patrícia Cristina , Povh Jayme Aparecido , Streit Junior Danilo Pedro , Vargas Lauro , Resende Emiko Kawakami de , Ribeiro Ricardo Pereira
Published: August 2010

O objetivo deste trabalho foi avaliar a diversidade genética em quatro estoques de tambaquis (Colossoma macropomum) de diferentes regiões do Brasil, por meio de marcador RAPD. Foram utilizados 10 iniciadores para analisar 116 indivíduos, coletados de pisciculturas nos municípios de Urupá, RO, Teixeirópolis, RO, Neópolis, SE e Sorriso, MT. Foram encontradas diferenças nas frequências de 67 fragmentos, com um fragmento exclusivo em Sorriso e dois em Neópolis. Observaram-se altos valores de polimorfismo (72,92 a 83,33%), diversidade genética de Nei (0,27 a 0,30) e índice de Shannon (0,39 a 0,45). A análise da variância molecular, demonstrou que a maior parte da variação está dentro de cada estoque e não entre os estoques. A identidade e a distância genética entre os agrupamentos variou de 0,93 a 0,98 e 0,02 a 0,07, respectivamente, com menos distância entre os agrupamentos Urupá x Sorriso e entre Teixerópolis x Neópolis. A diferenciação genética variou de baixa a moderada (Fst = 0,03 a 0,15) e o número de migrantes por geração foi alto (Nm = 5,96 a 24,3), entre os agrupamentos. Os estoques apresentam alta variabilidade e baixa diferenciação e distância genética entre si.
Fatores clínicos e histológicos preditivos de metástase cervical em carcinomas epidermóides de língua e soalho de boca no estadio clínico II
Authors: Soares João Marcos Arantes , Rapoport Abrão , Rosas Marilene Paladino , Carvalho Marcos Brasilino de , Fava Antônio Sérgio
Published: August 2010

O encontro de fatores preditivos de metástase cervical seria de grande valia para o tratamento de pacientes com tumores de alto potencial metastatizante e com pescoço clinicamente negativo. Procuramos encontrar fatores clínicos e histológicos em tumores iniciais de língua e soalho de boca que pudessem indicar a realização de um esvaziamento cervical eletivo.Foram estudados os seguintes fatores: sexo, idade, tabagismo, etilismo, raça, tamanho da lesão, sítio primário, dor, tempo de queixa, primeira queixa, aspecto macroscópico da lesão, infiltrado inflamatório peritumoral, grau de diferenciação da biópsia, desmoplasia, invasão vascular, invasão perineural e número de mitoses por 10 campos de maior aumento. Nenhum dos fatores estudados foi capaz de predizer a ocorrência de metástase cervical no período pré-operatório. Acreditamos que outros fatores devam ser estudados e explorados para que se consiga indicar o esvaziamento cervical eletivo de modo criterioso para o tratamento destas lesões.