bluuebunny/crossref_metadata_2025 huggingface dataset:
Openness to Experience and Intellect Differentially Predict Creative Achievement in the Arts and Sciences
Authors: Kaufman Scott Barry , Quilty Lena C. , Grazioplene Rachael G. , Hirsh Jacob B. , Gray Jeremy R. , Peterson Jordan B. , DeYoung Colin G.
Published: December 2014

The Big Five personality dimension Openness/Intellect is the trait most closely associated with creativity and creative achievement. Little is known, however, regarding the discriminant validity of its two aspects—Openness to Experience (reflecting cognitive engagement with perception, fantasy, aesthetics, and emotions) and Intellect (reflecting cognitive engagement with abstract and semantic information, primarily through reasoning)—in relation to creativity. In four demographically diverse samples totaling 1,035 participants, we investigated the independent predictive validity of Openness and Intellect by assessing the relations among cognitive ability, divergent thinking, personality, and creative achievement across the arts and sciences. We confirmed the hypothesis that whereas Openness predicts creative achievement in the arts, Intellect predicts creative achievement in the sciences. Inclusion of performance measures of general cognitive ability and divergent thinking indicated that the relation of Intellect to scientific creativity may be due at least in part to these abilities. Lastly, we found that Extraversion additionally predicted creative achievement in the arts, independently of Openness. Results are discussed in the context of dual‐process theory.
First Report of Aster Yellows Phytoplasma (16SrI‐B) Associated with Witches' Broom Disease of Melia azedarach var. japonica in Korea
Authors: Han Sang‐Sub , Baek So‐Jin , Lee Sang‐Hyun , Seo Sang‐Tae , Seralathan Kamala‐Kannan
Published: December 2014

Melia azedarach var. japonica trees with leaf yellowing, small leaves and witches' broom were observed for the first time in Korea. A phytoplasma from the symptomatic leaves was identified based on the 16Sr DNA sequence as a member of aster yellows group, ribosomal subgroup 16SrI‐B. Sequence analyses of more variable regions such as 16S–23S intergenic spacer region, secY gene, ribosomal protein (rp) operon and tuf gene showed 99.5−100% nucleotide identity to several GenBank sequences of group 16SrI phytoplasmas. Phylogenetic analysis confirmed that the Melia azedarach witches' broom phytoplasma belongs to aster yellows group.
Flood disturbance effects on benthic diatom assemblage structure in a semiarid river network
Authors: Tornés Elisabet , Acuña Vicenç , Dahm Clifford N. , Sabater Sergi
Published: December 2014

Disturbances such as floods and droughts play a central role in determining the structure of riverine benthic biological assemblages. Extreme disturbances from flash floods are often restricted to part of the river network and the magnitude of the flood disturbance may lessen as floods propagate downstream. The present study aimed to characterize the impact of summer monsoonal floods on the resistance and resilience of the benthic diatom assemblage structure in nine river reaches of increasing drainage size within the Gila River in the southwestern United States. Monsoonal floods had a profound effect on the diatom assemblage in the Gila River, but the effects were not related to drainage size except for the response of algal biomass. During monsoons, algal biomass was effectively reduced in smaller and larger systems, but minor changes were observed in medium systems. Resistance and resilience of the diatom assemblage to floods were related to specific species traits, mainly to growth forms. Tightly adhered, adnate and prostrate species (Achnanthidium spp., Cocconeis spp.) exhibited high resistance to repeated scour disturbance. Loosely attached diatoms, such as Nitzschia spp. and Navicula spp., were most susceptible to drift and scour. However, recovery of the diatom assemblage was very quick indicating a high resilience, especially in terms of biomass and diversity. Regional hydroclimatic models predict greater precipitation variability, which will select for diatoms resilient to bed‐mobilizing disturbances. The results of this study may help anticipate future benthic diatom assemblage patterns in the southwestern United States resulting from a more variable climate.
Environmental variation as a key process of co‐existence in flood‐meadows
Authors: Mathar Wanja , Kleinebecker Till , Hölzel Norbert
Published: December 2014

Question

How does the species composition and functional structure of flood‐meadows change over time during a period with strong variations in flooding frequency and height?

Location

Flood‐meadows at the northern Upper Rhine, Germany.

Methods

From 1998 to 2004 annually, and again in 2008, species composition and above‐ground biomass were studied in 46 permanent plots located along a flooding gradient ranging from frequently flooded Magnocaricion to rarely flooded Arrhenaterion meadows. The plots were situated in the functional floodplain (natural) and in the fossil floodplain on the land side of high winter levees (anthropogenic altered). Temporal variation of the functional structure was analysed based on community‐weighted mean traits.

Results

Productivity and functional structure varied markedly over the study period and between the functional and fossil floodplain. During the study period two contrasting extreme events occurred: a summer flood in 1999 and a drought period after 2003. After the flood in 1999, species composition and functional structure of the studied flood‐meadows shifted towards the species composition of wetter sites. Flooding reduced species richness in the functional floodplain, but not in the fossil floodplain.

Conclusions

Flood‐meadows in the Upper Rhine fully recover from extreme disturbance events within a time frame of less than 10 yr. Environmental fluctuations and disturbances, enabling the co‐existence of species with contrasting ecological requirements are a key factor for the preservation of plant biodiversity in flood‐meadows.
Low calcification rates and calcium carbonate production in Porites panamensis at its northernmost geographic distribution
Authors: Norzagaray‐López Carlos Orión , Calderon‐Aguilera Luis Eduardo , Hernández‐Ayón José Martín , Reyes‐Bonilla Héctor , Carricart‐Ganivet Juan P. , Cabral‐Tena Rafael Andrés , Balart Eduardo Francisco
Published: December 2014

Porites panamensis is a hermatypic coral present in the eastern Pacific Ocean. Skeletal growth parameters have been reported, but studies of the relationship between annual calcification rates and environmental controls are scarce. In this study, we investigated three aspects of the annual calcification rates of P. panamensis: growth parameters among three P. panamensis populations; the sea surface temperature as a calcification rate control spanning a latitudinal gradient; and calcium carbonate production among three sites. Growth parameters varied among the sites due to the colony growth form. Massive colonies in the north showed a higher calcification rate than encrusting colonies in the south (mean: 1.22–0.49 g CaCO3 · cm−2 · yr−1), where variations in calcification rates were related to growth rate (0.91–0.38 cm · yr−1) rather than to skeletal density differences (overall mean ± SD, 1.31 ± 0.04 g CaCO3 · cm−3). Our results showed a positive linear relationship between annual calcification rates and sea surface temperatures within these P. panamensis populations. Differences were related to distinct oceanographic environments (within and at the entrance of the Gulf of California) with different sea surface temperature regimes and other chemical properties. Different populations calcified under different environmental conditions. Calcium carbonate production was dependent upon the calcification rate and coral cover and so carbonate production was higher in the north (coral cover 12%) than in the south (coral cover 3.5). Thus, the studied sites showed low calcium carbonate production (0.25–0.43 kg CaCO3 · m−2 · yr−1). Our results showed reduced calcification rates, regional temperature regime control over calcification rates, different growth forms, low coral cover and low calcium carbonate production rates in P. panamensis.
Safety and efficacy of the vibrating capsule, an innovative non‐pharmacological treatment modality for chronic constipation
Authors: Ron Y. , Halpern Z. , Safadi R. , Dickman R. , Dekel R. , Sperber A. D.
Published: December 2014

Background

Constipation is a common disorder. Because the prevalence is high and the satisfaction level with currently available treatment is low, there is an unmet need for innovative treatment. We assessed the safety and efficacy of the Vibrant Capsule, a non‐pharmacological device that is assumed to induce a normal peristaltic wave in the large intestine to alleviate constipation.

Methods

Two animal safety studies and a safety study on healthy volunteers were conducted, followed by a prospective, non‐randomized, open‐label, single group assignment, safety and efficacy study. The latter was conducted among 26 patients who ingested the capsule twice weekly for a study period of 7.5 weeks, after a run‐in period of 2 weeks without usual treatment for constipation.

Key Results

In the studies on animals and healthy volunteers, there were no adverse events. Twenty‐eight patients began the clinical trial and 26 completed it (25 women). The mean age was 47.0 ± 12.6 years (range: 19–65). The two dropouts, who completed the safety phase, and the 26 who completed the entire study expelled the capsule without difficulty. Twelve participants reported 27 adverse events, none serious, and all transient. There was a significant increase of 1.60 ± 1.09 in the mean number of bowel movements/week from 2.19 ± 0.67 to 3.79 ± 1.31 (p < 0.001). This increase was seen in 23 of the 26 patients (88.5%). The mean number of spontaneous bowel movements for the study group increased in each treatment week compared to baseline.

Conclusions & Inferences

The Vibrant Capsule is safe and potentially effective in the treatment of constipation, justifying randomized controlled studies.
Biochemical and Protein Profile of Alpaca (Vicugna pacos) Uterine Horn Fluid During Early Pregnancy
Authors: Argañaraz ME , Apichela SA , Zampini R , Vencato J , Stelletta C
Published: December 2014

Contents

South American camelids show high embryo loss rate, during the first 60 days of pregnancy. One of the factors which may be related to this situation is that over 98% of the embryos implant in the left uterine horn (LUH) even though both ovaries contribute similarly to ovulation. There is scarce information about the uterine environment of female camelids at any physiological state that could explain the capability of the LUH to attract the embryo and maintain pregnancy. We describe, for the first time, the biochemical and protein profile of uterine fluid (UF), addressing the right and LUH environment in non‐pregnant and pregnant alpacas. Different substrates, electrolytes and metabolites were assayed in both uterine horn fluids. Small changes were observed in glucose and total protein levels, which were more noticeable during pregnancy. In addition, 10 specific proteins were found in the left horn fluid in 5‐week‐pregnant alpacas, and two protein bands were identified in non‐pregnant alpaca right horn fluid. These results would provide basic information for identification of possible markers for pregnancy diagnosis, reproductive diseases and hormone‐treated animals evaluation and hence contributing to improve the pregnancy rate.
Utilization and quality of cryopreserved red blood cells in transfusion medicine
Authors: Henkelman S. , Noorman F. , Badloe J.F. , Lagerberg J. W. M.
Published: December 2014

Cryopreserved (frozen) red blood cells have been used in transfusion medicine since the Vietnam war. The main method to freeze the red blood cells is by usage of glycerol. Although the usage of cryopreserved red blood cells was promising due to the prolonged storage time and the limited cellular deterioration at subzero temperatures, its usage have been hampered due to the more complex and labour intensive procedure and the limited shelf life of thawed products. Since the FDA approval of a closed (de) glycerolization procedure in 2002, allowing a prolonged postthaw storage of red blood cells up to 21 days at 2–6°C, cryopreserved red blood cells have become a more utilized blood product. Currently, cryopreserved red blood cells are mainly used in military operations and to stock red blood cells with rare phenotypes. Yet, cryopreserved red blood cells could also be useful to replenish temporary blood shortages, to prolong storage time before autologous transfusion and for IgA‐deficient patients. This review describes the main methods to cryopreserve red blood cells, explores the quality of this blood product and highlights clinical settings in which cryopreserved red blood cells are or could be utilized.
A Parameter Uniform Almost First Order Convergent Numerical Method for a Semi-Linear System of Singularly Perturbed Delay Differential Equations
Authors: Shivaranjan Nagaranjan , Miller John J H , Valarmathi Sigmani
Published: December 2014

In this paper an initial value problem for asemi-linear system of two singularly perturbed first order delay differential equations is considered on the interval(0,2]. The components of the solution of this system exhibit initial layers at 0 and interior layers at 1. A numerical method composed of a classical finite difference scheme on a piecewise uniform Shishkin mesh is suggested. This method is proved to be first order convergent in the maximum norm uniformly in the perturbation parameters.
Regular and Discontinuous Solutions in a Reaction-Diffusion Model for Hair Follicle Spacing
Authors: Rashkov Peter
Published: December 2014

Solutions of a model reaction-diffusion system inspired by a model for hair follicle initiation in mice are constructed and analysed for the case of a one-dimensional domain. It is shown that all regular spatially heterogeneous solutions of the problem are unstable. Numerical tests show that the only asymptotically stable weak solutions are those with large jump discontinuities.
Multifragmentation Markov Modeling of a Reactor Trip System
Authors: Kharchenko Vyacheslav , Butenko Valentina , Odarushchenko Oleg , Sklyar Vladimir
Published: December 2014

Markov models (MM) are widely used in dependability assessment of complex safety-critical systems. The main computational difficulties in using MMs are model size and stiffness. Selection of the solution approach (SA) and tools based on analysis of MM stiffness and complexity increases the assessment accuracy. This paper presents the safety assessment of nuclear power plan instrumentation and control system (NPP I&Cs): a two-channel FPGA-based reactor trip system with three parallel tracks on “2-out-of-3” logic. The MM was built using a multifragmentation approach and solved with several SAs and tools. The analysis of results shows few application problems: the importance of usability-oriented tool selection, achieving an accurate result, and supporting the results verification.
Implementation Challenges and Solutions for Homogenous Charge Compression Ignition Combustion in Diesel Engines
Authors: Asad Usman , Zheng Ming , Ting David , Tjong Jimi
Published: December 2014

Homogenous charge compression ignition (HCCI) combustion in diesel engines can provide for cleaner operation with ultra-low NOx and soot emissions. While HCCI combustion has generated significant attention in the last decade, however, to date, it has seen very limited application in production diesel engines. HCCI combustion is typically characterized by earlier than top-dead-center (pre-TDC) phasing, very high pressure rise rates, short combustion durations and minimal control over the timing of the combustion event. To offset the high reactivity of the diesel fuel, large amounts of EGR (30 to 60%) are usually applied to postpone the initiation of combustion, shift the combustion towards TDC and alleviate to some extent, the high pressure rise rates and the reduced energy efficiency.

In this work, a detailed analysis of HCCI combustion has been carried out on a high-compression ratio, single-cylinder diesel engine. The effects of intake boost, EGR quantity/temperature, engine speed, injection scheduling and injection pressure on the operability limits have been empirically determined and correlated with the combustion stability, emissions and performance metrics. The empirical investigation is extended to assess the suitability of common alternate fuels (n-butanol, gasoline and ethanol) for HCCI combustion. On the basis of the analysis, the significant challenges affecting the real-world application of HCCI are identified, their effects on the engine performance quantified and possible solutions to overcome these challenges explored through both theoretical and empirical investigations. This paper intends to provide a comprehensive summary of the implementation issues affecting HCCI combustion in diesel engines.
A First Application of Thermographic Phosphors in a Marine Two-Stroke Diesel Engine for Surface Temperature Measurement
Authors: Abou Nada Fahd , Hult Johan , Knappe Christoph , Richter Mattias , Mayer Stefan , Aldén Marcus
Published: December 2014

Phosphor thermometry is applied for the first time in a large-bore two-stroke diesel engine. The work proves the practicality of phosphor thermometry in large-bore engines. The experiments were conducted on the MAN 4T50ME-X marine research engine equipped with an optical cylinder head. By employing a thin surface coating of CdWO4 phosphor, cycle resolved temperature measurements of the cylinder wall were obtained. Motored and fired engine operations were tested at engine loads covering the low and medium engine load range. Phosphor thermometry proved to be successful in retrieving the temperature with standard deviations ranging around 1–8 K. Experimental considerations like detector linearity, coating thickness and an automated phosphor calibration routine will be addressed.
Effect of Particle Size Distribution on the Deep-Bed Capture Efficiency of an Exhaust Particulate Filter
Authors: Viswanathan Sandeep , Sakai Stephen S. , Hageman Mitchell , Foster David E. , Fansler Todd , Andrie Michael , Rothamer David A.
Published: December 2014

The exhaust filtration analysis system (EFA) developed at the University of Wisconsin – Madison was used to perform micro-scale filtration experiments on cordierite filter samples using particulate matter (PM) generated by a spark-ignition direct injection (SIDI) engine fueled with gasoline. A scanning mobility particle sizer (SMPS) was used to characterize running conditions with four distinct particle size distributions (PSDs). The distributions selected differed in the relative number of accumulation versus nucleation mode particles. The SMPS and an engine exhaust particle sizer (EEPS) were used to simultaneously measure the PSD downstream of the EFA and the real-time particulate emissions from the SIDI engine to determine the evolution of filtration efficiency during filter loading. Cordierite filter samples with properties representative of diesel particulate filters (DPFs) were loaded with PM from the different engine operating conditions. The results were compared to understand the impact of particle size distribution on filtration performance as well as the role of accumulation mode particles on the diffusion capture of PM. The most penetrating particle size (MPPS) was observed to decrease as a result of particle deposition within the filter substrate. In the absence of a soot cake, the penetration of particles smaller than 70 nm was seen to gradually increase with time, potentially due to increased velocities in the filter as flow area reduces during filter loading, or due to decreasing wall area for capture of particles by diffusion. Particle re-entrainment was not observed for any of the operating conditions.
The Effect of Ash Accumulation on Gasoline Particulate Filters: A Comparison Between Laboratory and Field Aged Samples
Authors: Jorgensen James , Murray Timothy , Sappok Alexander , Wong Victor , Börensen Christoph , Lambert Christine , Pakko James , Warner James
Published: December 2014

Stringent regulations worldwide will limit the level of particulate matter (PM) and particle number (PN) emitted from gasoline engines. Gasoline particulate filters (GPFs) present one strategy for meeting PM and PN limits over the full operating range of the engine. Over time these filters accumulate incombustible ash, increasing system pressure drop and adversely effecting engine performance. The effect of aging as a result of ash accumulation is examined over the full lifetime of gasoline particulate filters, using a novel accelerated aging system. This system utilizes a gasoline combustion chamber into which lubricating oil is injected simulating combustion in the cylinder — the primary source of ash. This report details the construction and validation of this system.
Computational Analysis in Test Cell Design With Application in Emissions Control
Authors: Lee Paul , Yang Ligong , Demirdogen Caner
Published: December 2014

Computer-Aided Engineering (CAE) tools have been widely used in the design of automotive components and systems. Methods, procedures and measurables for analyses involving Internal Combustion Engine (ICE) components are well-defined and well developed. Comparatively, significantly less attention has been paid to the design and analysis of test cells. Better designed test cells will lead to increased test cell availability and thus also increases engine performance test opportunities.

This trend was observed in Cummins Inc. where CAE-guided test cell designs improved test-cell availability and rate of engine development. Here, improved conversion efficiencies in test cell Selective Catalyst Reduction (SCR) modules were predicted using Computational Fluid Dynamics (CFD) tools, and validated against data collected from the test cells. The resultant improvements resulted in dramatic increases in test cell up-time.

This paper documents how CAE tools commonly used in engine design were successfully expanded to aid the design of Cummins Inc. test cells. It presents the CFD methods that were used in this analysis, compares CFD predictions to actual conversion efficiencies in the SCR module, and also proposes a set of analysis tasks and methods that can be applied to improve test cell design and performance in the future.
Development Strategies for Gas Engines in High- and Medium-Speed Applications
Authors: Franke Michael , Lierz Klaus , Heuser Peter , Geiger Jose , Jagodzinski Bartosch , Schlemmer-Kelling Udo
Published: December 2014

Natural gas as a fuel for high and medium speed engines in industrial, power generation and marine propulsion applications is used for various reasons. Apart from the operating costs which are essentially determined by the fuel price, legislation is an important factor governing the use and the conception of the engines. The engine requirements are influenced by regulatory standards. Engine exhaust emission limits will continue to be stringent, including greenhouse relevant emissions such as CO2 and CH4. Additionally, a corresponding infrastructure is needed to guarantee the availability of the gas for the extensive implementation and use of gas engines. In the past, gas engine products were typically developed from production diesel engines. Today, gas engine development strategies are tailored to the intended use of these engines. Requirements concerning performance and emissions, fuel quality and fuel availability, transient response, etc. define the general technical specifications of the gas engine. These requirements provide the basis for the selection of the appropriate combustion concepts. Open chamber, prechamber with and without gas scavenging, and dual fuel concepts represent a broad variety of combustion concepts. Each of the mentioned systems entails individual characteristics and limitations and requires specific layouts of the engine design and fuel supply. This paper provides an overview of various gas engine concepts and development tools for high- and medium-speed gas engines.
Vibration-Induced Ash Removal From Diesel Particulate Filters
Authors: Sappok Alexander , Costanzo Vincent , Bromberg Leslie , Waldo Cole , Salsgiver Rob
Published: December 2014

Ceramic, honeycomb-type diesel particulate filters (DPF) are commonly used in a wide range of on- and off-road diesel-powered vehicles and equipment to reduce particulate matter (PM) emissions to mandated levels. While the majority of the trapped PM can be removed from the filter through regeneration, incombustible ash builds up in the filter over time. The ash deposits are generally found accumulated in a porous layer along the channel walls, or packed as end-plugs towards the back of the filter channels. Ash accumulation in the filter restricts exhaust flow, reduces the filter’s soot storage capacity, and negatively impacts fuel consumption.

In order to mitigate these deleterious impacts on filter operation, the particulate filter is periodically removed for ash cleaning. This study examines the effects of vibrations to remove and dislodge ash deposits from diesel particulate filters, particularly the ash accumulated toward the back of the channels and packed in plugs. Fundamental measurements of ash properties, combined with experiments utilizing full-size, field-aged particulate filters were conducted to ascertain the effects of specific vibration frequencies and acceleration levels on ash plug break-up and transport out of the DPF channels. The results show considerable potential for the application of controlled vibrations in an offline cleaning system to aid in the removal of ash deposits plugging filter channels, thereby reducing the ash-related impact on vehicle fuel consumption and extending the useful life of the particulate filter.
Development of a Euro VI Diesel Engine System Optimised to Deliver Fuel Economy and Emissions Improvements on a Series Hybrid City Bus Application for One of the World’s Busiest Bus Networks
Authors: Ghadge Jeevan , Krishnan Alok , Gupta Samarth , Balasundaram Dhilip , Best Tim
Published: December 2014

Ongoing efforts to reduce CO2 and other pollutant tail pipe emissions have led to escalated demand for diesel-electric hybrid bus powertrains in Europe, similar to the trend in passenger car markets. This is fuelled by public expectations and initiatives by various European governments to reward bus fleet operators for reduced in-city emissions and noise thus improving air quality and wellbeing of the general population.

This paper describes the engineering efforts that developed a Euro VI certified diesel engine system, catering for series hybrids operating under ‘charge-depleting’ as well as ‘load following’ battery management strategies.

The development team delivered improved fuel economy whilst dealing with requirements around legislation, unique customer duty cycles and engine mechanical robustness. Focus was placed on capturing requirements from a diverse range of sources and harmonising them to develop a technical solution fit for purpose in day to day operation that differs from validation cycles and standard drivetrain operation.

In order to deliver a field-ready solution, application specific tuning and validation processes had to be defined and developed. This was achieved through close coordination with the European bus OEMs and their chosen hybrid system suppliers. Six-sigma tools were used to highlight key expectations and drive technical solutions. At a system level the focus was on OBD reliability, exhaust after-treatment management, controls functionality, hardware durability and tail pipe emissions. Performance targets including the number of start-stops per hour, idle management and engine speed-torque ramp rates were defined.

Drive cycle simulations helped define optimal engine and hybrid system operating strategies followed by physical testing to further optimise these running points. Vehicle-level validation was completed through field testing, specific European bus test cycles, as well as under exceptional scenarios encountered in real world use. This exercise was designed to find and solve interface and OBD issues. Integration challenges in the areas of engine speed-torque control, diesel particulate filter management and HVAC control were addressed.

The outcome is the release of a bespoke Euro VI diesel engine package, which enabled the hybrid bus system to exceed customer expectations. This integrated system operates on a set of optimised parameters delivering efficient sub system behaviour including aftertreatment management, engine protection and operating state control. It handles the full range of real-world vehicle operation with improved fuel economy, frequent start/stop operation and enhanced driveability.
Parametric Study of Injection Rates With Solenoid Injectors in an Injection Quantity and Rate Measuring Device
Authors: Busch Stephen , Miles Paul C.
Published: December 2014

The rate at which fuel is injected into the cylinder of a direct injection Diesel engine has significant implications for the ensuing mixture formation and combustion processes. Advances in fuel injector technology enable a variety of advanced injection strategies, particularly very closely coupled injection events. In this work, a Moehwald HDA injection quantity and rate measuring unit is used to investigate the injection rates obtained with a pre-production solenoid injector with a fast acting, pressure-balanced control valve using a blend of n-hexadecane and heptamethylnonane (DPRF58). The effects of digital signal filtering on the rate shape and injected mass are investigated for a single injection. Additionally, the effects of physical parameters such as fuel and measurement chamber temperature, axial clamping force on the injector, high pressure line length, and solenoid current pull up time on the rate shape are investigated. The primary purpose of these simple parameter variations is to establish whether or not they have an impact on the measured injection rate traces and/or total measured injected masses. At each dwell time, the rates of injection are compared between the three injectors tested. These results show that these pre-production injectors can operate with very short dwell times while the injection rate curves indicate distinct pilot and main injection events and an influence of dwell on the rate shape of the main injection. Testing with PRF, a blend of n-heptane and isooctane, shows that while rates of injection are comparable to those obtained with the DPRF for a single injection, they are dramatically different for multiple injections. This has significant implications for the optical diagnostic techniques that may be employed to study the effects of multiple injections on the mixture formation process.
Aftertreatment System Integration on a Tier 2 Evolution Locomotive: Analysis and Field Test Results
Authors: Balu Giri , Sethuraman Sharan , Lavertu Thomas M. , Akinyemi Wole , Primus Roy J. , Kiran Shashi
Published: December 2014

Results of an effort to integrate an aftertreatment system for the simultaneous reduction of NOx and PM emissions on a Tier 2 Evolution Locomotive are presented. The paper provides detail on the solution that was realized to meet packaging constraints and also highlights aftertreatment performance limitations that resulted from these design decisions. Analysis results showing the predicted impact on engine performance are presented and compared to results obtained from field testing of the integrated system.
An Historical Overview of the Development of the Chevrolet Small-Block V-8 Engine
Authors: Cole David E.
Published: December 2014

The Chevrolet Small-Block engine was officially introduced to the public as one of the two engines in the 1955 Chevrolet passenger car. Its companion engine powering Chevrolet products was the very dated “Blue-Flame” 6. This six-cylinder driven powertrain was a key contributor to the reputation at that time that Chevrolet cars were dull and, at best, average.

The team: In late 1952, my father, Ed Cole, assumed the role as Chevrolet Chief Engineer. A few years earlier he was the Chief Engineer at Cadillac and led the development of a new, advanced design overhead valve V-8. The expectation at Chevy was that he would lead the development of a Chevrolet version but he had other ideas. At this time each GM division had their own powertrain operations. Key people were recruited from across the company based on their unique skills. The entire effort of developing, tooling and launch of the engine, as well as the total vehicle, took less than 2 years.

The engine: The Small-Block engine was considered revolutionary at that time. Features included a new casting technology that reduced the casting cores by about half, a valve train that featured simple stamped rocker arms that pivoted on individual studs and elimination of all external oil lines. Its weight was over 40 pounds less than the Blue-Flame 6 and it was very compact.

The Chevrolet Small-Block V-8 was a revolutionary engine when it was developed in the 50’s, and even today the basic architecture of the current GM Small-Block is similar.
Damage Sensitivity and Multiple Damage Detection in Glass Fiber/Epoxy Laminates With Carbon Black Filler via Electrical Impedance Tomography
Authors: Tallman T. N. , Wang K. W.
Published: December 2014

Utilizing conductivity changes to locate matrix damage in glass fiber reinforced polymers (GFRPs) manufactured with nanocomposite matrices is a promising avenue of composite structural health monitoring (SHM) with the potential to ensure unprecedented levels of safety. Nanocomposites depend on the formation of well-connected nanofiller networks for electrical conductivity. Therefore, matrix damage that severs the connection between nanofillers will manifest as a local change in conductivity. This research advances state of the art conductivity-based SHM by employing electrical impedance tomography (EIT) to locate damage-induced conductivity changes in a glass fiber/epoxy laminate manufactured with carbon black (CB) filler. EIT for damage detection is characterized by identifying the lower threshold of through-hole detection and demonstrating the capability of EIT to accurately resolve multiple through holes. It is found that through holes as small as 3.18 mm in diameter can be detected, and EIT can detect multiple through holes. However, sensitivity to new through holes is diminished in the presence of existing through holes unless a damaged baseline is used. These research findings demonstrate the considerable potential of conductivity-based health monitoring for GFRP laminates with conductive networks of nanoparticles in the matrix.
A Belleville-Spring Based Piezoelectric or Electromagnetic Energy Harvester
Authors: Castagnetti Davide
Published: December 2014

Energy harvesting from kinetic ambient energy requires converters able to efficiently operate in the low frequency range. A limit of the solutions proposed in the literature, both electromagnetic and piezoelectric, is their operating frequency, which generally ranges from about 50 to 300 Hz. To overcome these limitations, this work proposes an innovative energy harvester exploiting two counteracting Belleville springs. Thanks to the peculiar height to thickness ratio of the springs a highly compliant elastic system is obtained, which can be used either for electromagnetic or piezoelectric harvesting. The harvester is modelled analytically and numerically both with regard to the force-displacement and to the modal response. The experimental validation of the harvester, highlights a noticeable power output but at a higher eigenfrequency than expected.
Design of Rectified Piezoelectric Power Generators by Finite Element Methods
Authors: Wu P. H. , Shu Y. C.
Published: December 2014

The article proposes designing rectified piezoelectric power generators based on the direct finite element method. It accounts for the consideration of common interface circuits such as the standard and parallel-/series-SSHI (synchronized switch harvesting on inductor) circuits, and complicated structural configurations such as arrays of piezoelectric oscillators. The proposed model suggests replacing the energy harvesting circuit by an equivalent load impedance in series with negative piezoelectric capacitance. As the expression of the equivalent load impedance can be explicitly derived, the proposed finite element approach is capable of handling common interface circuits without resorting to circuit solvers. Finally, the model is extended to the consideration of SECE (synchronized electric charge extraction) circuit which offers an advantage of independence of harvested power on external loads.
Uncertainty Analysis of a Finite Deformation Viscoelastic Model
Authors: Miles Paul , Hays Michael , Smith Ralph , Oates William S.
Published: December 2014

The viscoelasticity of the dielectric elastomer, VHB 4910, is experimentally characterized, modeled, and analyzed using uncertainty quantification. These materials are known for their large field induced deformation and applications in smart structures, although the rate dependent viscoelastic effects are not well understood. To address this issue, we first quantify hyperelastic and viscoelastic model uncertainty by comparing a finite deformation viscoelastic model to uni-axial rate dependent experiments. The utilization of Bayesian statistics is shown to provide additional insight into different viscoelastic processes within elastomers. This is demonstrated by coupling two hyperelastic models, an Ogden model and a nonaffine model, to different types of viscoelastic models.
Flow Energy Harvesters With a Nonlinear Restoring Force
Authors: Alhadidi Ali H. , Bibo Amin , Daqaq Mohammed F.
Published: December 2014

This ppppaper examines the performance of a galloping energy harvester possessing a nonlinear restoring force. To achieve this goal, a flow energy harvester consisting of a piezoelectric cantilever beam augmented with a square-sectioned bluff body at the free end is considered. Two magnets located near the tip of the bluff body are used to introduce the nonlinearity which strength and nature can be altered by changing the distance between the magnets. A lumped-parameter aero-electromechanical model adopting the quasi-steady assumption for aerodynamic loading is presented and utilized to numerically simulate the harvester’s response. Wind tunnel tests are also performed to validate the numerical simulations by conducting upward and downward wind velocity sweeps. Results comparing the relative performance of several harvesters with potential functions of different shapes demonstrate that a mono-stable potential function with a hardening restoring force can outperform all other configurations.
Vibration Damping Enhancement in Hybrid Carbon Fiber Composites With Zinc Oxide Nanowire Interphase
Authors: Malakooti Mohammad H. , Hwang Hyun-Sik , Sodano Henry A.
Published: December 2014

Traditional composite materials invented to be used in structures with the purpose of high load-bearing with excellent in-plane properties. Continuous fiber reinforced composites are one of the mostly used categories of advanced composites. This class of composites has gained a lot of attention due to their light-weight and decent mechanical properties. However, additional material design is required to tune both mechanical and structural properties of these composites. Since the load transfer between reinforcement phase and polymer matrix happens at the interfacial region, a better interphase might result in a composite with higher vibration damping. In this study, a gradient interphase between carbon fiber and polymer matrix has been created by using ZnO nanowires to engineer the damping loss factor of the carbon fiber composites. For the growth of ZnO nanowires on the carbon fabric, low temperature hydrothermal reaction has been used. Then the carbon fabrics with ZnO nanowires were infiltrated with a low viscosity epoxy using vacuum assisted resin transfer molding technique. The stiffness and structural damping of the composite were examined using dynamic mechanical analysis. The results show that the damping properties of hybrid composites using ZnO nanowires are enhanced compare to the bare carbon fabric composites. Since the growth of ZnO nanowires is a tunable process, the length, diameter and aspect ratio of the nanowires and consequently the architecture of the interphase can be tailored for the desired vibration damping in the system. Thus, the hybrid composites with ZnO nanowire interphase can be used to enhance the energy dissipation in a structural system.
Design and Evaluation of a Haptic Keypad System for Realistic Touch Interaction
Authors: Ryu Semin , Koo Jeong-Hoi , Yang Tae-Heon , Pyo Dongbum , Kyung Ki-Uk , Kwon Dong-Soo
Published: December 2014

This paper presents design and testing of a haptic keypad system using an array of haptic actuators. The research goals are to construct a prototype haptic keypad system using haptic actuators and to evaluate the performance of the prototype keypad for haptic rendering. To this end, an MR haptic actuator was designed and fabricated such that it can convey realistic force feedback to users. To demonstrate haptic applications of the MR actuator, a haptic keypad system was constructed, which consists of following components: (1) 3 × 3 array of haptic actuators, (2) 3 × 3 array of force sensing resistors (FSR), (3) a controller including a micro-processor, a current amplifier and a wireless communication module, (4) a graphic display unit with PC. After constructing a prototype keypad system, a haptic rendering technology was employed to interface the hardware keypad system with test software (virtual environment). The prototype system enabled human operators to interact with the target contents in a virtual environment more intuitively. The evaluation results show a feasibility of applications of MR fluids-based haptic actuators in real-world mobile applications.
Optimizing the Recycling Process of a Roof Edge Profile by Using Shape Memory Alloy Connecting Elements
Authors: Rathmann Christian , Fleczok Benjamin , Lygin Konstantin , Meier Horst
Published: December 2014

Shape memory alloys (SMAs) belong to the group of functional materials that can be thermally activated. After plastic deformation, they can remember any previously imprinted shape and reveal large actuating forces. This is attractive for actuator applications as well as for connecting elements.

The increasing complexity of products makes their disassembly and recycling more difficult. Due to limited resources and legal requirements regarding environmental protection and the disposal of material, it is increasingly important for companies to recycle their products efficiently. SMA-based connecting elements are an innovative approach that can help companies to make their recycling processes more efficient by automating it.

As a starting point, traditional connection elements are evaluated regarding economical and technical performance indicators. To prove the advantages of SMA-based connecting elements, they are discussed using the example of a roof edge profile. The existing solution is analyzed with special emphasis on recyclability and disassembly. An alternative connection element made of shape memory alloys is designed, manufactured and tested. The results are compared with existing solutions with respect to time, costs and recyclability.

Finally, an overview of possible applications for the SMA-based connecting elements is given. Further studies should also investigate the applicability for maintenance processes and the substitutability of shape memory alloys connection elements to other traditional solutions, for example welded connections.
Improvement of the Attainable Working Frequency of SMA Wires by Means of Active Cooling and Working Strain-Ratios
Authors: Lara-Quintanilla Adrian , Bersee Harald E. N.
Published: December 2014

Shape Memory Alloys (SMAs) are one of the most widely used smart materials. Their attractive characteristics make them interesting for the development of novel devices. Most of these devices make use of their shape memory effect or superelasticity; these effects are based on diffusionless phase transitions. SMAs can be used in different forms. In particular, wires are often used for actuation purposes because they exert linear forces and large strokes, up to the 8% of their original (memorized) length. However, they work at very low frequencies. SMAs are thermally activated. The limitation on their actuation bandwidth is a consequence of their capability to increase and decrease their temperature. The most common way of heating SMA wires is by Joule heating. Afterwards, they normally cool down by releasing thermal energy to their surroundings by conduction or convection. The heating and the cooling come from different physic’s principles and the cooling is a slower process than the heating one. Therefore, the cooling of SMAs is the main concern regarding to the SMA wire’s maximum attainable working frequency. In this paper, the effect of different applied heating and cooling rates on the resulting SMA wire’s working frequency is studied. Different heating rates have been applied to an SMA wire by applying different levels of electrical power. In a similar manner, different cooling rates have been applied to the wire by applying different forced airflows around the SMA wire. The use of a forced airflow has shown to increase the convective heat transfer coefficient between the wire and the surrounding air up to eight-fold.

SMA wires’ working frequency depends on the amplitude of strains at which it performs. The higher the amplitude, the lower the maximum attainable frequency. Moreover, the relationship between the temperature and the strain is highly non-linear. For that reason, the range of strains in which the wire works has also an effect on the resulting attainable frequency for a given working amplitude. This is of great interest for SMA actuators since a similar working amplitude can result in very different attainable frequencies, depending on the range of temperatures within which the wire performs. Experimental results show that the SMA wire’s working frequency can be increased up to threefold by making it work within the appropriate temperature range. Afterwards, this improvement is reflected on the overall performance of the actuator in which the SMA wire is embedded.
Rapid Prototyping and Characterization of Circular Dielectric Electro-Active Polymers (DEAP) With Different Geometries
Authors: Hau Steffen , York Alexander , Seelecke Stefan
Published: December 2014

Dielectric electro-active polymer (DEAP) technology holds promise enabling lightweight, energy efficient and scalable sensors and actuators [1]. The circular DEAP configuration (also known as cone or diaphragm actuator) in particular shows potential in applications such as pressure or weight sensors [2, 3], pumps [4, 5], valves, micro-positioners and loudspeakers [6]. The geometric parameters of the circular DEAP dictate the stroke and work output performance of actuators and the sensitivity as well as the resolution of sensors.

The scalable geometric design allows DEAP actuators and sensors to be adapted to a variety of different applications. This paper presents a rapid prototyping technique and experimental characterization of DEAP actuators with various geometries. The DEAP’s consist of a silicone based elastomer and a carbon ink based electrode held together with a rigid frame. The rapid prototyping utilizes high resolution 3D printing technology to manufacture various shaped framing structures designed with computer aided design (CAD) software. The framing structure defines the DEAP geometry resulting in quick prototyping of various DEAP shapes and sizes.

After prototyping, these DEAP’s are tested for mechanical and electrical properties while loaded mechanically and electrically (constant voltage and constant force test). The measurement results for the different size actuators are then documented and compared. The measurements reveal that for increased size of the manufactured actuators, there is a linear increase in force and stroke output. This information allows us to predict the actuation performance and will be used for future modeling efforts.