bluuebunny/crossref_metadata_2025_split huggingface dataset:
The utility of reticulocyte indices in distinguishing iron deficiency anemia from anemia of inflammatory disease, portosystemic shunting, and breed‐associated microcytosis in dogs
Authors: Schaefer Deanna M. W. , Stokol Tracy 
Published: December 2014

BackgroundIndices of reticulocyte cell size and hemoglobin content show promise for diagnosing iron deficiency (FeDef), but have not been evaluated in other causes of canine anemia or microcytosis.ObjectivesThe aims of this study were to establish reference intervals (RI) for reticulocyte indices in dogs, and to compare results from dogs with FeDef anemia to dogs with 3 conditions that may mimic FeDef on hematologic and biochemical testing, including anemia of inflammatory disease (AID), portosystemic shunting (PSS), or breed‐associated microcytosis (BAM).MethodsReticulocyte indices were measured using theADVIA2120. Reference intervals were determined prospectively in 122 healthy dogs, and retrospectively compared between dogs with FeDef (n = 11),AID(n = 12),PSS(n = 12), andBAM(n = 7).ResultsAlmost all dogs had at least one reticulocyte index outside theRI. The most discriminating reticulocyte indices were reticulocyte hemoglobin concentration (CHCMr) (FeDef ≤ 26 g/dL,AID ≥ 26 g/dL,PSS ≥ 24.1 g/dL, andBAM ≥ 27.7 g/dL), reticulocyte hemoglobin content (CHr) (FeDef ≤ 20.1 pg,AID ≥ 21.8 pg,PSS ≥ 19.2 pg,BAM ≥ 21 pg), percentage of reticulocytes with low CHCMr (%Hypo‐r) (FeDef ≥ 74.2%, AID ≤ 80.1%,PSS ≤ 91.5%,BAM ≤ 61.6%,), and percentage of reticulocytes with low CHr (%LowCHr) (FeDef ≥ 50.7%,AID ≤ 31.3%,PSS ≤ 63.2%,BAM ≤ 34.1%).ConclusionsReticulocyte indices can be altered in dogs with various conditions, and are not specific for FeDef. Dogs with CHCMr, CHr, %Hypo‐r, and %LowCHr beyond the above cutoffs are suspicious for FeDef. Dogs withAID,PSS, orBAMwith reticulocyte indices altered beyond the ranges reported for those subgroups warrant evaluation for concurrent iron deficiency.
Light Weight Pistons for Friction Optimized Spark Ignition Engines
Authors: Gabriel Dieter , Adelmann Jochen , Hettich Thomas , Hammen Andreas 
Published: December 2014

This article describes the development of MAHLE piston technology with the goal of meeting increasing requirements of advanced, highly efficient gasoline engines. The new EVOLITE® lightweight piston from MAHLE is a continuation of the development of its predecessor, the EVOTEC® 2, and is based on the EVOTEC® design concept.
This concept differs from the design approach of previous decades in that the piston geometry has inverted asymmetry on the thrust and antithrust side. A narrow thrust side is combined with a wide, elastic antithrust side for skirt guidance.
The light, robust EVOTEC® 2 piston is available with ring carrier or cooling gallery - Figure 1.
The EVOLITE® concept represents further refinement of the EVOTEC® design concept by increasing asymmetry further. By geometrically optimizing the box wall connection between the skirt and crown, the lifetime has been increased by up to 8 times in comparison with the EVOTEC® 2, depending on stress location, while the weight has been reduced by up to 5%. Friction, which is critical for low CO2 emissions, is also reduced with this new piston type.
Application of Model Reduction Techniques Within Cummins Inc.
Authors: Tahilramani Dhaneesh R. , Hitchins Juliet 
Published: December 2014

For the past decade Cummins Inc. have increased the use of standard Finite Element Analysis (FEA) techniques to drive the design of its products. However, as FEA models are not scalable to the limits of hardware, running traditional FEA, especially on large High Horse Power (HHP) engine structures’ assemblies, both reliably and within a reasonable time frame was found to be not possible. This led to carrying out numerous analyses with fewer parts and assumed boundary conditions. This strategy ignores effects due to system vibration of the assembly. To reduce the risk of failures on complex assemblies, high speed engines required a more accurate analytical prediction of modal stresses on a system level. To increase the capacity of running system level analyses, a structured approach was followed and the Model Reduction Techniques Functional Excellence mini team was set up to develop methods and train analysts.
The team have been using Six Sigma tools [1] to carry out voice of the customer interviews in order to define the analytical requirements for running models for large complex structures (>20 million degree of freedom). This consists of brainstorming concepts to select solutions based on advanced analytical Substructuring techniques to best fit requirements. The benefits of the new process include a significant reduction in solve time, the ability to carry out system analysis, to follow an efficient working practice using a modular approach, to allow parallel processing globally and secure intellectual property rights when working with suppliers and customers of the Cummins Inc. products.
This paper shares experience on applying model reduction techniques following a structured approach and highlights computing and training resources for an analysis team.
Advanced Numerical Approach to Simulate GDI Sprays Under Engine-Like Conditions
Authors: Ishii Eiji , Abe Motoyuki , Ehara Hideharu , Yasukawa Yoshihito 
Published: December 2014

Gasoline direct-injection (GDI) engines provide both higher engine power and better fuel efficiency than port-injection gasoline engines. However, they emit more particulate matter (PM) than the latter engines. Fuel stuck on walls of pistons and combustion chambers forms a high-density region of fuel in the air/fuel mixture, which becomes a source of PM. To decrease the amount of PM, fuel injectors with short length of spray-penetration are required. A fuel-spray simulation was previously developed; that is, the air/fuel-mixture simulation was integrated with the liquid-column-breakup simulation. The developed fuel-spray simulation was used to optimize the nozzle shapes of fuel injectors for gasoline direct-injection engines.
In the present study, the factors that influence spray-penetration length were identified by the numerical simulation. The simulation results were validated by comparing the simulated spray-penetration length with the measured ones and revealing good agreement between them. Angle α was defined as that formed between the direction of flow entering the nozzle inlet and the direction of flow leaving the nozzle outlet; in other words, a indicates a change of flow direction. It was found that α and spray-penetration length was closely related. Velocity that are accelerated with a were studied, and it was found that the velocity within a plane perpendicular to the center axis of the nozzle increases with increasing α.
Sensitivity Analysis of Cylinder Head Fatigue Life Prediction Using Statistical Models
Authors: Szasz Christoph , Lauer Sven 
Published: December 2014

For the efficient virtual development of combustion engine cylinder heads in terms of high cycle fatigue (HCF) it is highly important to have a reliable development process that represents reality in the best possible way. Most of today’s standard HCF procedures are capable of delivering high quality results for a specific load combination. However, loads are usually subject to variation. This is also valid for loads the cylinder head is subjected to. Assembly loads and operating loads considered during the virtual development process are widely determined by the production process which again is subject to variation due to certain tolerances, wear of the tooling equipment etc. As it is highly important to ensure the fatigue design of a cylinder head, there is the need for new analysis models capable of capturing every possible load variation.
Within the framework of this paper the influence of different variable loading parameters on the cylinder head HCF margin of a heavy duty diesel engine will be discussed. A design of experiments (DoE) analysis is used together with the 3-d finite element method (FEM) for the investigations. Furthermore a methodology for the probabilistic assessment of the cylinder head HCF margin based on stochastic loading data is introduced. At the same time an effective methodology for the identification of the worst case boundary conditions for HCF analysis will be presented.
With the presented probabilistic method it is possible to achieve a highly accurate prediction of the HCF design margin. Due to the probabilistic approach a better understanding of the entire system is possible, as the interaction between input and output parameters can be illustrated. Therefore HCF optimization problems can be encountered more effectively. Furthermore the presented methodology can be used for error estimation of analysis results and assessment of the result sensitivity. Thus, a borderline layout of the cylinder head can be achieved. Also the minimum input information quality, which is required for a profound HCF analysis, can be assessed by using the sensitivity analysis presented. Therefore the proposed methods enable a fast and reliable development of cylinder heads and other combustion engine components.
Nano Napier Steel Second Ring for SI Applications
Authors: Sytsma Steve , Rabassa Erich 
Published: December 2014

Piston top compression rings utilized in North American Spark Ignition (SI) passenger car and light truck engines have undergone a significant migration driven by desire to reduce axial height, mass, radial thickness, wear, incidence of risk of foundry defects and to enable utilization of a consistent, global material independent of manufacturing location.
Second rings utilized in similar applications are now in the earlier stages of a similar migration.
This paper will present product development of an innovative steel second ring including engine testing (blowby, and lube oil consumption via radiometric tracer method), supplemented by simulation modeling utilizing MIT code, including several more conventional ring cross sectional alternatives.
Estimation Methodology for Automotive Turbochargers Speed Fluctuations due to Pulsating Flows
Authors: Ponti F. , Ravaglioli V. , De Cesare M. 
Published: December 2014

Turbocharging technique, together with engine downsizing, will play a fundamental role in the near future as a way to reach the required maximum performance while reducing engine displacement and, consequently, CO2 emissions.
However, performing an optimal control of the turbocharging system is very difficult, especially for small engines fitted with a low number of cylinders. This is mainly due to the high turbocharger operating range and to the fact that the flow through compressor and turbine is highly unsteady, while only steady flow maps are usually provided by the manufacturer. In addition, in passenger cars applications, it is usually difficult to optimize turbocharger operating conditions because of the lack of information about pressure/temperature in turbine upstream/downstream circuits and turbocharger rotational speed.
This work presents a methodology suitable for instantaneous turbocharger rotational speed determination through a proper processing of the signal coming from an accelerometer mounted on the compressor diffuser or a microphone faced to the compressor. The presented approach can be used to evaluate turbocharger speed mean value and turbocharger speed fluctuation (due to unsteady flow in turbine upstream and downstream circuits), that can be correlated to the power delivered by the turbine.
The whole estimation algorithm has been developed and validated for a light duty turbocharged Common-Rail Diesel engine mounted in a test cell. Nevertheless, the developed methodology is general and can be applied to different turbochargers, both for Spark Ignited and Diesel applications.
Filtration Characteristics of Fuel Neutral Particulates Using a Heterogeneous Multi-Scale Filtration Model
Authors: Gong Jian , Rutland Christopher J. 
Published: December 2014

Filtration characteristics of fuel neutral soot particulate were studied using a recently developed heterogeneous multi-scale filtration (HMF) model. In the HMF model, a PDF based pore size distribution and a porosity distribution across the filter wall are introduced to represent the heterogeneous multi-scale porous structure. The HMF model was validated by an exhaust filtration analysis (EFA) system, which was designed for fundamental experimental filtration studies.
Various sources of particulates from combustion engines were used in the filtration studies. Some particulates were sampled from a spark ignited direct injection (SIDI) engine fueled with gasoline and ethanol blends. Particulates from a compression ignition engine fueled with diesel for conventional and advanced combustion regimes were investigated as well. The micro-structure of the porous wall was found to be more critical and necessary to simulate filtration of particulates from gasoline and advanced diesel combustion engines than those from conventional diesel combustion engines. The interactions between the porous wall and trapped particulates were investigated. The dynamic filtration characteristics including filtration efficiency, pressure drop and particulate distribution inside the wall are strongly dependent on total particulate volume rather than total particulate number concentration. The change of the filter structure as well as the shape of the particulate size distribution play important roles on particulate penetration.
CFD Simulation of Gasoline Compression Ignition
Authors: Kodavasal Janardhan , Kolodziej Christopher , Ciatti Stephen , Som Sibendu 
Published: December 2014

Gasoline compression ignition (GCI) is a low temperature combustion (LTC) concept that has been gaining increasing interest over the recent years owing to its potential to achieve diesel-like thermal efficiencies with significantly reduced engine-out nitrogen oxides (NOx) and soot emissions compared to diesel engines. In this work, closed-cycle computational fluid dynamics (CFD) simulations are performed of this combustion mode using a sector mesh in an effort to understand effects of model settings on simulation results. One goal of this work is to provide recommendations for grid resolution, combustion model, chemical kinetic mechanism, and turbulence model to accurately capture experimental combustion characteristics. Grid resolutions ranging from 0.7 mm to 0.1 mm minimum cell sizes were evaluated in conjunction with both Reynolds averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) based turbulence models. Solution of chemical kinetics using the multi-zone approach is evaluated against the detailed approach of solving chemistry in every cell. The relatively small primary reference fuel (PRF) mechanism (48 species) used in this study is also evaluated against a larger 312-species gasoline mechanism.
Based on these studies the following model settings are chosen keeping in mind both accuracy and computation costs — 0.175 mm minimum cell size grid, RANS turbulence model, 48-species PRF mechanism, and multi-zone chemistry solution with bin limits of 5 K in temperature and 0.05 in equivalence ratio. With these settings, the performance of the CFD model is evaluated against experimental results corresponding to a low load start of injection (SOI) timing sweep. The model is then exercised to investigate the effect of SOI on combustion phasing with constant intake valve closing (IVC) conditions and fueling over a range of SOI timings to isolate the impact of SOI on charge preparation and ignition. Simulation results indicate that there is an optimum SOI timing, in this case −30°aTDC (after top dead center), which results in the most stable combustion. Advancing injection with respect to this point leads to significant fuel mass burning in the colder squish region, leading to retarded phasing and ultimately misfire for SOI timings earlier than −42°aTDC. On the other hand, retarding injection beyond this optimum timing results in reduced residence time available for gasoline ignition kinetics, and also leads to retarded phasing, with misfire at SOI timings later than −15°aTDC.
Onboard Hydrogen Generation for IC Engine Emissions Reduction
Authors: Mastanduno Richard , Roychoudhury Subir , Etemad Shahrokh 
Published: December 2014

Improvement of internal combustion engine emissions and performance by the introduction of a reducing gas such as hydrogen has been the subject of research in recent years. The approach reduces engine exhaust emissions and improves fuel consumption. The gas may be introduced into the engine intake or upstream of the exhaust catalyst for different effects. To date, the technique has not been implemented due to the need for onboard storage or generation of hydrogen that complies with suitability for automotive applications.
In industrial processes and stationary applications, reforming reactors are well known, highly efficient, and durable means to convert liquid fuels such as diesel into hydrogen or other reducing gas mixtures (synthesis gas). Efficiency and durability for thousands of hours is required for these applications for economic viability. For an automotive application, however, in addition to the above features, fast transient response (e.g. during start up and turndown), compactness, and low cost are also required — while maintaining sufficient durability for the application. Also, the need for liquid water common to reactions such as steam reforming or auto-thermal reforming are impractical for automotive applications. A waterless catalytic partial oxidation approach avoids this shortcoming but is not without its own set of problems. Material durability, fuel/air mixing, coke avoidance and reliable ignition means are among the challenges for a practical automotive hydrogen production solution. The catalyst for reacting the fuel must be tolerant to sulfur content common to fuels in use today, and must have resistance to fouling by carbon formation.
To overcome these challenges, Precision Combustion, Inc. (PCI) has developed a diesel-fueled waterless catalytic partial oxidation reformer with efficiency and size suitable for onboard synthesis gas production at low cost. The goal of the development effort was to produce a novel mechanical design with the high efficiency of stationary reformers in a small package which could be operated with low parasitic loss from balance of plant components to maintain high engine efficiency. The reactor design (size, form factor) is discussed, along with performance data showing transient and steady state response of the prototype reactor. Catalytic partial oxidation (CPOX) of heavy fuels such as diesel poses unique challenges, relating to coking and fuel conversion efficiency, which have been addressed and presented in this paper.
The Dynamics of Second Ring Flutter and Collapse in Modern Diesel Engines
Authors: Cheng Chao , Schock Harold , Richardson Dan 
Published: December 2014

Second ring fluttering and radial ring collapse are recognized as having significant influences on engine blowby and oil consumption. As the gas flow is coupled with the piston ring motion, understanding the ring dynamics is important for understanding not only the engine blowby mechanism, but also oil consumption mechanisms and how to control them. Only second ring flutter and collapse that occurs around the top dead center firing conditions is examined in this paper based on a modern heavy-duty diesel engine. However, the principles described are equally applicable to all engines.
First, the authors describe the fundamental mechanisms of how second ring fluttering and radial ring collapse occurs. This is described by examining the forces that are acting on the second ring. Then, two cases are shown. One case shows second ring flutter and the other case shows stable second ring motion. The reasons for these two different cases are explained, including the effect of static twist and the end gaps of the rings.
A sensitivity study was performed to evaluate the effect of changing the top and second ring end gaps on ring lift. It was shown how the gaps could affect the second ring flutter and ring collapse.
It is concluded that the second ring will be more likely to flutter or collapse if it has a negative static twist, if the second ring end gap is large, and/or if the top ring end gap is small. If the second ring does not flutter, it may still be possible to design the ring pack such that there is not any reverse blowby. However, this must be carefully studied and controlled or the second land pressures will be too high, resulting in reverse blowby and/or top ring lifting.
Full Load Performance Optimization Based on Turbocharger Speed Evaluation via Acoustic Sensing
Authors: Cavina Nicolò , De Cesare Matteo , Ravaglioli Vittorio , Ponti Fabrizio , Covassin Federico 
Published: December 2014

Turbocharger performance optimization on passenger car engines is particularly challenging, especially in case of severe engine downsizing and downspeeding.
On high performance engines (e.g., heavy duty truck applications) turbocharger speed measurement is usually performed with the aim of maximizing engine power and torque, limiting turbocharger over-speed, which is harmful for its durability and reliability. This solution is too expensive for passenger cars, and the turbocharger speed sensor is typically not available.
In this work, an innovative and low cost sensing chain for the rotational speed evaluation of the turbocharger is applied. With this information, obtained via an acoustic sensor, a new turbocharger control architecture has been developed to optimize turbocharger performance, in order to improve engine output torque under full load conditions.
After a brief description of the new sensing chain and of the electronic components developed to manage this kind of information, the paper shows the new control architecture that takes advantage of the turbocharger speed information.
Moreover, experimental results on a small turbocharged Diesel engine for passenger car applications are presented, demonstrating the achieved benefits.