bluuebunny/crossref_metadata_2025_split huggingface dataset:
Environmental variation as a key process of co‐existence in flood‐meadows
Authors: Mathar Wanja , Kleinebecker Till , Hölzel Norbert 
Published: December 2014

AbstractQuestionHow does the species composition and functional structure of flood‐meadows change over time during a period with strong variations in flooding frequency and height?LocationFlood‐meadows at the northern Upper Rhine, Germany.MethodsFrom 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.ResultsProductivity 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.ConclusionsFlood‐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

AbstractPorites 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

AbstractBackgroundConstipation 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.MethodsTwo 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 ResultsIn 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 & InferencesThe 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

ContentsSouth 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.
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.
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.
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.
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.
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.