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Artykuły w czasopismach na temat "Dual fuel mode"
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Ramesha, D. K., Adhiviraj Singh Bangari, Chirag P. Rathod i Chaitanya R. Samartha. "Experimental Investigation Of Biogas-Biodiesel Dual Fuel Combustion In A Diesel Engine". Journal of Middle European Construction and Design of Cars 13, nr 1 (1.06.2015): 12–20. http://dx.doi.org/10.1515/mecdc-2015-0003.
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Abstract This study is an attempt at achieving diesel fuel equivalent performance from diesel engines with maximum substitution of diesel with renewable fuels. In this context the study has been designed to analyze the influence of B20 algae biodiesel as a pilot fuel in a biodiesel biogas dual fuel engine, and results are compared to those of biodiesel and diesel operation at identical engine settings. Experiments were performed at various loads from 0 to 100 % of maximum load at a constant speed of 1500 rpm. In general, B20 algae biodiesel is compatible with diesel in terms of performance and combustion characteristics. Dual fuel mode operation displays lower thermal efficiency and higher fuel consumption than for other fuel modes of the test run across the range of engine loads. Dual fuel mode displayed lower emissions of NOx and Smoke opacity while HC and CO concentrations were considerably higher as compared to other fuels. In dual fuel mode peak pressure and heat release rate were slightly higher compared to diesel and biodiesel mode of operation for all engine loads.
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Shu, Zepeng, Huibing Gan, Zhenguo Ji i Ben Liu. "Modeling and Optimization of Fuel-Mode Switching and Control Systems for Marine Dual-Fuel Engine". Journal of Marine Science and Engineering 10, nr 12 (15.12.2022): 2004. http://dx.doi.org/10.3390/jmse10122004.
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The marine dual-fuel engine can switch between diesel and gas modes according to the requirements of sailing conditions, fuel cost, and other working conditions to make sure the ship is in the best operating condition. In fuel-mode switching in engines, problems such as unstable combustion and large speed fluctuations are prone to occur. However, there are some disadvantages, such as poor safety, environmental pollution, and easy damage to the engine, when the large, marine dual-fuel engine is directly tested on the bench. Therefore, in this paper, a joint simulation model of a dual-fuel engine is built using GT Power and MATLAB/Simulink to investigate the engine’s transient process of fuel-mode switching, and the conventional fuel PID(Proportion Integral Differential) control system is optimized using the cuckoo search (CS) algorithm. The simulation results show that the dual-fuel engine model has good accuracy, and the response in transient conditions meets the manufacturer’s requirements. In the process of switching from gas mode to diesel mode, due to the rapid change in fuel, the engine parameters, such as speed, fluctuate significantly, which is prone to safety accidents. In the process of switching from diesel to gas mode, because the fuel switching is gentle, all parameters are relatively stable, and the possibility of safety accidents is slight. The fuel PID control system optimized based on the cuckoo search algorithm has a better engine control effect than the traditional fuel control system.
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Sahoo, Bibhuti B., Niranjan Sahoo i Ujjwal K. Saha. "Dual Fuel Performance Studies of a Small Diesel Engine Using Green Fuels". Applied Mechanics and Materials 110-116 (październik 2011): 2101–8. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.2101.
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The objective of this work is to review state of art practices and potential in diesel engines using greener fuels. Biogas with jatropha bio-diesel as ignition source was tested in a compression ignition diesel engine at six different loads under dual fuel mode. With a simple modification, the base engine was qualified to a dual fuel operation. For all the loads evaluated, dual fuel mode achieved a possible bio-diesel substitution of about 65%. In addition, it consumed lesser friction power as compared to the diesel mode during the operation. There were reductions in thermal efficiency, cylinder peak pressure and combustion noise under the dual fuel operation than the diesel mode due to lower burning velocity of biogas together with a longer pilot delay. However, this operation registered extremely lower NOx levels at all loads along-with reduced CO emissions at medium and higher loads. While significant increases in hydrocarbon emissions were observed.
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García, Antonio, Javier Monsalve-Serrano, David Villalta i Rafael Sari. "Fuel sensitivity effects on dual-mode dual-fuel combustion operation for different octane numbers". Energy Conversion and Management 201 (grudzień 2019): 112137. http://dx.doi.org/10.1016/j.enconman.2019.112137.
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Stepanenko, Denys, i Zbigniew Kneba. "ECU calibration for gaseous dual fuel supply system in compression ignition engines". Combustion Engines 182, nr 3 (30.09.2020): 33–37. http://dx.doi.org/10.19206/ce-2020-306.
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The dual fuel (DF) combustion mode is proven solution that allows to improve or get at the same level engine performance and reduce toxic compounds in exhaust gases which is confirmed by researchers and end-users. DF combustion mode uses two fuels gaseous fuel as a primary energy source and a pilot quantity of diesel fuel as ignition source. However, in order, to fully take advantage of the potential of the dual fuel mode, DF system must be proper calibrated. Despite the existence of commercial control systems for dual fuel engines on the market, the literature on the important parameters for the engine's operation introduced during calibration is scarce. This article briefly describes a concept of working algorithm and calibration strategy of a dual fuel electronic control unit (ECU) The purpose of calibration is to achieve the greatest possible use of an alternative gaseous fuel without causing accelerated engine wear.
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Zhang, Fan, Huiqiang Zhang i Bing Wang. "Conceptual study of a dual-rocket-based-combined-cycle powered two-stage-to-orbit launch vehicle". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 232, nr 5 (1.05.2017): 944–57. http://dx.doi.org/10.1177/0954410017703148.
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The liquid oxygen/methane staged cycle liquid-rocket engine is one of the most potential rocket engines in the future for its higher performance, higher fuel density and reusable capacity. Two working states of this liquid-rocket engine named as full-load state and half-load state are defined in this paper. Based on this liquid-rocket engine, a dual-rocket-based-combined-cycle propulsion system with liquid oxygen /air/methane as propellants is therefore proposed. The dual-rocket-based-combined-cycle system has then five working modes: the hybrid mode, pure ejector mode, ramjet mode, scramjet mode and pure rocket mode. In hybrid mode, the booster and ejector rockets driven by the full-load liquid-rocket engine work together with the purpose of reducing thrust demand on ejector rocket. In scramjet mode, the fuel-rich burned hot gas generated by the half-load liquid-rocket engine is used as fuel, which is helpful to reduce the technical difficulty of scramjet in hypersonic speed. The five working modes of dual-rocket-based-combined-cycle are highly integrated based on the full- or half-load state of the liquid oxygen/methane staged cycle liquid-rocket engine, and the unified single type fuel of liquid methane is adopted for the whole modes. Then a preliminary design of a horizontal takeoff two-stage-to-orbit launch vehicle is conducted based on the dual-rocket-based-combined-cycle propulsion system. Under an averaged baseline thrust and specific impulse, the launch trajectory to reach a low Earth orbit at 100 km is optimized via the pseudo-spectral method subject to maximizing the payload mass. It is shown that the two-stage-to-orbit vehicle based on the dual-rocket-based-combined-cycle can achieve the payload mass fraction of 0.0469 and 0.0576 for polar mission and equatorial mission, respectively. Conclusively, insights gained in this paper can be usefully applied to a more detailed design of the dual-rocket-based-combined-cycle powered two-stage-to-orbit launch vehicle.
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Chaichan, Miqdam, i Dina Muneam. "Operational Parameters Influence on Resulted Noise of Multi-Cylinders Engine Runs on Dual Fuels Mode". Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ), nr 1 (14.10.2021): 186–204. http://dx.doi.org/10.55562/jrucs.v35i1.269.
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Noise is a pollutant by the combustion process that may have direct effect upon surrounding environment. In this study, noise measurements were taken for multi cylinders, four stroke Fiat engine converted to run as dual fuel engine on diesel and gaseous fuels of liquefied petroleum gas (LPG) and natural gas (NG). The study focused on the influence of some operating parameters. These parameters included: engine load, pilot fuel injection timing, pilot fuel mass, and engine speed. It was found that using LPG as the main fuel in duel fuel mixture exhibits higher engine noise compared to NG or neat diesel. The results showed that advancing injection timing from optimum ones increased engine sound pressure levels.
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Tang, Yuanyuan, He Li, Yuchi Jiang, Wenwei Liang i Jundong Zhang. "The Control-Oriented Heat Release Rate Model for a Marine Dual-Fuel Engine under All the Operating Modes and Loads". Journal of Marine Science and Engineering 11, nr 1 (2.01.2023): 64. http://dx.doi.org/10.3390/jmse11010064.
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An accurate model plays an important role in control strategy development of smart ships. For the control-oriented engine models, calibration by experienced personnel is key to outputting high accuracy. However, the dual-fuel engine runs in liquid fuel mode, gas fuel mode, and fuel sharing mode. It is impossible to tune a single model or a set of parameters for the dual-fuel engine under all operating modes and loads. On the basis of our experience and practice, a Wiebe-based heat release rate model is used. To make the Wiebe model available for the dual-fuel engine, the Wiebe parameters are assumed to be linear functions. The combustion beginning angle is modeled as a function of fuel quantity in liquid fuel mode and as a look-up table in gas fuel mode for all loads. The combustion duration and the combustion distribution factor are modeled as a function of fuel quantity and engine revolution both in liquid fuel mode and in gas fuel mode. In fuel sharing mode, the heat release rate is modeled as a combination of the heat release rate models in liquid fuel mode and gas fuel mode. This model is called the SL model. For a further discussion, four types of combinations in fuel sharing mode are investigated. In addition, in liquid fuel mode and gas fuel mode, the combustion duration model and the combustion distribution factor model are replaced by the Woschni/Anisits model, which was specifically used in the diesel engine. This variation of model is called the WA model. To validate our hypothesis and models, the Wiebe parameters in liquid fuel mode and gas fuel mode are given, four types of combinations and two cases of comparisons in fuel sharing model are discussed, and the engine performance is checked and analysed. Results show that for the SL model, the average RMSE is 1.45% in the liquid fuel mode, 2.22% in the gas fuel mode, and 2.53% in the fuel sharing mode. For the WA model, the RMSE of the NOx is 9.79% in liquid fuel mode and 45.20% in gas fuel mode. Its maximum error reaches −65.54%. The proposed SL model is accurate and can generate Wiebe parameters that are better than the carefully tuned parameters. The WA model is not suitable for engine models that require NOx-emission-related parameters.
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Arbi Trihatmojo, Ahmad, Bambang Sudarmanta i Oki Muraza. "Performance and Combustion Process of a Dual Fuel Diesel Engine Operating with CNG-Palm Oil Biodiesel". Journal of Railway Transportation and Technology 2, nr 1 (31.03.2023): 10–20. http://dx.doi.org/10.37367/jrtt.v2i1.22.
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Efforts to build and develop a low-emission transportation system have been carried out, one of which is by applying biodiesel and gas to dual-fuel diesel engines. Biodiesel is an oxygenated, low-sulfur, and high flash point alternative diesel fuel. In the dual fuel mode, CNG is used as a substitute fuel and palm biodiesel as a combustion pilot which is injected directly into the combustion chamber at 13 °CA BTDC. CNG injection timing was 110 °CA ATDC and the CNG injection duration was gradually increased. Performance and combustion processes in single-fuel mode and dual-fuel mode are compared. The engine was kept at a constant speed of 2000 rpm at all load conditions. The results show that the dual fuel mode at low and medium loads produces in-cylinder pressure and the heat release rate is lower than the single fuel mode, but at high loads, it produces in-cylinder pressure and the heat release rate is 5.14% greater. CO and HC emissions produced by the dual fuel mode are higher than the single fuel mode at all loads. conversely, the dual-fuel mode produces 95.58% lower smoke emissions than the single-fuel mode at all loads.
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Vaught, C., M. Witt, D. Netzer i A. Gany. "Investigation of solid-fuel, dual-mode combustion ramjets". Journal of Propulsion and Power 8, nr 5 (wrzesień 1992): 1004–11. http://dx.doi.org/10.2514/3.23585.
Pełny tekst źródłaRozprawy doktorskie na temat "Dual fuel mode"
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Singh, Sunmeet. "Utilization of methane in a compression ignition engine under dual fuel mode". Thesis, IIT Delhi, 2017. http://localhost:8080/xmlui/handle/12345678/7243.
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Lago, Sari Rafael. "Dual Mode Dual Fuel Combustion: Implementation on a Real Medium Duty Engine Platform". Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/165366.
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[ES] Históricamente, el sector del transporte de servicio mediano y pesado ha sido desafiado por las regulaciones de emisiones que se han impuesto a lo largo de los años, lo que requirió intensificar el esfuerzo de investigación con el objetivo de avanzar en el desarrollo tecnológico para ofrecer una opción que cumpla con las normas a un precio similar para el propietario. No obstante, la reciente introducción de la normativa EUVI ha requerido la adición de un complejo sistema de postratamiento, agregando nuevos costes fijos al producto, así como costes operativos con el consumo de urea. Este avance fue necesario debido a la limitación de la combustión diésel convencional que no puede desacoplar las altas emisiones de NOx y la eficiencia.
Esta limitación tecnológica ha impulsado la investigación sobre diferentes conceptos de combustión que podrían mantener niveles de eficiencia similares a los de la combustión diésel controlando la formación de emisiones durante el proceso de combustión. Entre las diferentes soluciones que han ido apareciendo a lo largo de los años, se demostró que la Ignición por Compresión Controlada por Reactividad (RCCI por sus siglas en inglés) tiene una ventaja competitiva debido a su mejor controlabilidad, alta eficiencia y bajas emisiones de hollín y NOx. A pesar de sus beneficios, la extensión de RCCI a la operación de mapa completo ha indicado limitaciones importantes como gradientes de presión excesivos a alta carga, o alta inestabilidad de combustión y productos no quemados a baja carga del motor. Recientemente, se introdujo el concepto de combustión Dual-Mode Dual-Fuel (DMDF) como un intento de resolver los inconvenientes de la combustión RCCI manteniendo sus ventajas. Los resultados preliminares obtenidos en un motor mono cilíndrico (SCE por sus siglas en inglés) han demostrado que el DMDF puede alcanzar niveles de eficiencia similares a los de la combustión diésel convencional al mismo tiempo que favorece niveles ultra bajos de hollín y NOx. Si bien, los requisitos de la condición límite son difíciles de encajar en el rango operativo de sistema de gestión de aire, así como inconvenientes como el exceso de HC y CO que aún persiste en la zona de baja y media carga, lo que puede ser un desafío para el sistema de postratamiento. Además, las futuras regulaciones a corto plazo exigirán una reducción del 15 % de las emisiones de CO2 en 2025, reto que la literatura sugiere que no se logrará fácilmente solo mediante la optimización del proceso de combustión.
En este sentido, esta tesis tiene como objetivo general la implementación del concepto de combustión DMDF en un motor multicilindro (MCE por sus siglas en inglés) bajo las restricciones de las aplicaciones reales para realizar una combustión limpia y eficiente en el mapa completo a la vez que brinda alternativas para reducir la concentración de HC y CO y lograr un ahorro de CO2.
Este objetivo se logra mediante un primer extenso procedimiento de calibración experimental que tiene como objetivo trasladar las pautas de la combustión DMDF del SCE al MCE respetando los límites operativos del hardware original, evaluando su impacto en los resultados de combustión, rendimiento y emisiones en condiciones estacionarias y condiciones de ciclo de conducción. A continuación, se realizan estudios específicos para abordar el problema relacionado con la concentración excesiva de productos no quemados mediante investigaciones experimentales y simulaciones numéricas para comprender las consecuencias del uso de combustibles con diferente reactividad en la eficiencia de conversión del catalizador de oxidación original y su capacidad para lograr emisiones en el escape menores que el límite EUVI. Finalmente, se busca la reducción de CO2 a través de la modificación del combustible, investigando tanto la mejora del proceso de combustión como el equilibrio entre el ciclo de vida del combustible.[CA] Històricament, el sector del transport de servei mitjà i pesat ha sigut desafiat per les regulacions d'emissions que s'han imposat al llarg dels anys, la qual cosa va requerir intensificar l'esforç d'investigació amb l'objectiu d'avançar en el desenvolupament tecnològic per a oferir una opció que complisca amb les normes a un preu similar per al propietari. No obstant això, la recent introducció de la normativa EUVI ha requerit l'addició d'un complex sistema de postractament, agregant nous costos fixos al producte, així com costos operatius amb el consum d'urea. Aquest avanç va ser necessari a causa de la limitació de la combustió dièsel convencional que no pot desacoblar les altes emissions de NOx i l'eficiència. Aquesta limitació tecnològica ha impulsat la investigació sobre diferents conceptes de combustió que podrien mantindre nivells d'eficiència similars als de la combustió dièsel controlant la formació d'emissions durant el procés de combustió. Entre les diferents solucions que han anat apareixent al llarg dels anys, es va demostrar que la Ignició per Compressió Controlada per Reactivitat (RCCI per les seues sigles en anglés) té un avantatge competitiu a causa de la seua millor controlabilitat, alta eficiència i baixes emissions de sutge i NOx. Malgrat els seus beneficis, l'extensió del RCCI a l'operació de mapa complet ha indicat limitacions importants com a gradients de pressió excessius a alta càrrega, o alta inestabilitat de combustió i productes no cremats a baixa càrrega del motor. Recentment, es va introduir el concepte de combustió Dual-Mode Dual-Fuel (DMDF) com un intent de resoldre els inconvenients de la combustió RCCI mantenint els seus avantatges. Els resultats preliminars obtinguts en un motor mono-cilíndric (SCE per les seues sigles en anglés) han demostrat que el DMDF pot aconseguir nivells d'eficiència similars als de la combustió dièsel convencional al mateix temps que afavoreix nivells ultra baixos de sutge i NOx. Si bé, els requisits de la condició límit són difícils d'encaixar en el rang operatiu de sistema de gestió d'aire, així com inconvenients com l'excés de HC i CO que encara persisteix en la zona de baixa i mitja càrrega, la qual cosa pot ser un desafiament per al sistema de postractament. A més, les futures regulacions a curt termini exigiran una reducció del 15% de les emissions de CO¿ en 2025, repte que la literatura suggereix que no s'aconseguirà fàcilment només mitjançant l'optimització del procés de combustió. En aquest sentit, aquesta tesi té com a objectiu general la implementació del concepte de combustió DMDF en un motor multi-cilindre (MCE per les seues sigles en anglés) sota les restriccions de les aplicacions reals per a realitzar una combustió neta i eficient en el mapa complet alhora que brinda alternatives per a reduir la concentració de HC i CO i aconseguir un estalvi de CO¿. Aquest objectiu s'aconsegueix mitjançant un primer extens procediment de calibratge experimental que té com a objectiu traslladar les pautes de la combustió DMDF del SCE al MCE respectant els límits operatius del motor original, avaluant el seu impacte en els resultats de combustió, rendiment i emissions en condicions estacionàries i condicions de cicle de conducció. A continuació, es realitzen estudis específics per a abordar el problema relacionat amb la concentració excessiva de productes no cremats mitjançant investigacions experimentals i simulacions numèriques per a comprendre les conseqüències de l'ús de combustibles amb diferent reactivitat en l'eficiència de conversió del catalitzador d'oxidació original i la seua capacitat per a aconseguir emissions al tub d'escapament menors que el límit EUVI. Finalment, es busca la reducció de CO2 a través de la modificació del combustible, investigant tant la millora del procés de combustió com l'equilibri entre el cicle de vida del combustible.
[EN] The medium and heavy-duty transport sector was historically challenged by the emissions regulations that were imposed along the years, requiring to step up the research effort aiming at advancing the product development to deliver a normative compliant option at similar price to the owner. Nonetheless, the recent introduction of EUVI normative have required the addition of a complex aftertreatment system, adding new fixed costs to the product as well as operational costs with the urea consumption. This breakthrough was required due to the limitation of the conventional diesel combustion which cannot decouple high NOx emissions and efficiency. This technological limitation has boosted the investigation on different combustion concepts that could maintain similar efficiency levels than the diesel combustion while controlling the emission formation during the combustion process. Among the different solutions that have appeared along the years, Reactivity Controlled Compression Ignition (RCCI) was demonstrated to have a competitive edge due to its better controllability, high efficiency and low soot and NOx emissions. Despite the benefits, the extension of RCCI to full map operation has presented significant limitations, as excessive pressure gradients at high load and high combustion instability and unburned products at low engine load. Recently, Dual-Mode Dual-Fuel (DMDF) combustion concept was introduced as an attempt of solving the drawbacks of the RCCI combustion while maintaining its advantages. The preliminary results obtained in single cylinder engine (SCE) have evidenced that DMDF can achieves similar efficiency levels than those from conventional diesel combustion while promoting ultra-low levels of soot and NOx. Albeit, the boundary condition requirements are hard to fit in the operating range of commercial air management system as well as drawbacks like excessive HC and CO that still persists from low to medium load, which can be a challenge for the aftertreatment system. Moreover, short-term future regulations will demand a 15 % reduction of CO2 emissions in 2025 which was proven in the literature to not be easily achieved only by combustion process optimization. In this sense, this thesis has as general objective the implementation of the DMDF combustion concept in a multi-cylinder engine (MCE) under the restrictions of real applications to realize clean and efficient combustion in the complete map while providing alternatives to reduce the HC and CO concentration and accomplish CO2 savings. This objective is accomplished by means of a first extensive experimental calibration procedure aiming to translate the guidelines of the DMDF combustion from the SCE to the MCE while respecting the operating limits of the stock hardware, assessing its impacts on combustion, performance, and emission results under steady and driving cycle conditions. Next, dedicated studies are performed to address the issue related with the excessive concentration of unburned products by means of experimental investigations and numerical simulations, to understand the consequences of using fuels with different reactivity in the stock oxidation catalyst conversion efficiency and its ability in achieving EUVI tailpipe emissions. Finally, CO2 reduction is explored through fuel modification, investigating both combustion process improvement and well-to-wheel balance as paths to realize CO2 abatement.
This doctoral thesis has been partially supported by the Spanish Ministry of Science Innovation and Universities under the grant:"Ayudas para contratos predoctorales para la formación de doctores" (PRE2018-085043)
Lago Sari, R. (2021). Dual Mode Dual Fuel Combustion: Implementation on a Real Medium Duty Engine Platform [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/165366
TESIS
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FILHO, FERNANDO FERRARI. "EVALUATION OF DIESEL CYCLE ENGINE OPERATING IN THE DUAL FUEL MODE: DIESEL / ETHANOL". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=19636@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROEste trabalho avaliou o comportamento de um motor do ciclo Diesel, operando no modo original (Diesel puro) e no modo bicombustível (Diesel / etanol), em dois modos de hidratação do álcool (70 e 93 graus INPM). A rotação foi mantida fixa em 1800 rpm. A finalidade foi estudar os parâmetros de desempenho do motor e analisar a liberação de calor pela combustão, como também, o calor trocado com as paredes. Avaliou-se como parâmetros de desempenho, o rendimento térmico, consumo específico de combustível e emissão de poluentes. A fase inicial do trabalho constou de ensaios experimentais realizados no conjunto motor / dinamômetro nos modos mencionados acima. O objetivo foi coletar a variação de pressão no interior do cilindro, consumo de combustível, emissão de gases, temperaturas em pontos estratégicos, entre outros. Em uma segunda etapa foi realizada uma análise dos parâmetros de desempenho e da liberação de calor. Para emissões de poluentes, observou-se uma diminuição de MP em altas taxas de substituição. No entanto, notou-se um aumento elevado de HC. Em baixas cargas e taxas de substituição elevadas houve redução de emissão de NOx. O rendimento térmico apresentou comportamentos similares em 70 e 93 graus INPM. Em altas cargas e altas taxas de substituição houve um sensível aumento do rendimento quando comparado ao modo original. O rendimento foi menor para baixas cargas com altas taxas de substituição, em relação ao modo original. O início da combustão no modo bicombustível foi antecipado em relação ao modo original, nas condições de altas cargas e máximas taxas de substituição. Isto foi devido à liberação de calor que ocorreu mais cedo no modo bicombustível. Ressalta-se que, nas mesmas condições, houve a ocorrência de um maior calor trocado com as paredes do cilindro, em ambos os modos de hidratação (70 – 93 graus INPM), quando comparado ao modo original.
This work aimed to evaluate a Diesel cycle engine operating in the original (only Diesel) and dual-fuel modes (Diesel / ethanol) in two levels of hydration of alcohol (70 and 93 degrees INPM). Speed was kept fixed at 1800 rpm. The purpose was to study the parameters of engine performance and analyze the heat release by combustion and heat exchanged to the cylinder’s walls. For parameters of performance, evaluation of thermal efficiency, specific fuel consumption and emissions were conducted. Initial activities consisted in trial tests on the engine / dynamometer in the two modes as mentioned above. The goal was to collect the variation of indicated cylinder pressure data, as well as fuel consumption, emissions and temperatures at strategic points. Secondly, performance parameters and heat release analysis was performed. For emissions, a decrease in PM was found at higher replacement rates; however, in the same condition a large increase in HC was obtained. At low loads and at higher replacement rates, NOx emissions were reduced. Thermal efficiency showed similar behavior at 70 and 93 degrees INPM. At high loads and at higher replacement rates a significant increase in thermal efficiency compared to the original mode and for low loads with higher replacement rates thermal efficiency was decreased. In high loads and at higher replacement rates conditions, the process of combustion occurred before in the dual fuel mode, due to earlier heat release compared to original mode (only Diesel). In the same conditions an increase of heat exchanged to the cylinder’s wall in both modes of hydration of alcohol (70 and 93 degrees INPM) compared to the original mode was obtained.
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Júnior, Roberto Freitas Britto. "Experimental analysis of a diesel engine operating in diesel-ethanol dual-fuel mode". Instituto Tecnológico de Aeronáutica, 2014. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=3043.
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A significant part of the world economy depends on stationary or vehicular Diesel engines. Such engines are fed mainly by fossil fuels, among these, the standard diesel. The growing interest in renewable energy sources makes the use of ethanol in these engines a real technological demand. From the existing concepts to meet this goal the Diesel-Ethanol in the Dual-Fuel mode has demand for published experimental data. Such concept brings a greater degree of freedom, but implications in technological challenges. It works through a PFI (Port Fuel Injection) system to prepare a pre-mixture of air and ethanol in the intake port which is compressed in the combustion chamber and ignited by pilot injection of diesel. In this work a single cylinder research engine with 100% electronically controlled calibration was used. The engine control parameters were set to maximize diesel substitution rate by ethanol with a limited indicated efficiency loss. Comparisons were made among different working conditions. Initially, the flow structure in the combustion chamber was tested in both quiescent and high swirl modes. Compression ratios were adjusted at 3 different levels: 14:1, 16:1 and 17:1. Two injectors were tested, the first one with mass flow of 35 g/s and another of 45 g/s. Regarding pressure diesel injection, 4 levels were investigated namely 800, 1000, 1200 and 1400 bar. The experiments discussed in this work were able to achieve up to 65% of diesel energy substituted by hydrated ethanol energy with an indicated efficiency of 49%. In comparison with the diesel only running condition, the NOx emissions was improved by up to 60%. But the HC, CO and aldehydes emissions had a penalty, showing a trade-off that shall be further investigated with a final design engine in the beginning of product development process.
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Riley, Logan Patrick. "Unstart Phenomenology of a Dual-Mode Scramjet Subject to Time-Varying Fuel Input". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1554740828968894.
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Boronat, Colomer Vicente. "Dual-Fuel Dual-Mode combustion strategy to achieve high thermal efficiency, low NOx and smoke emissions in compression ignition engines". Doctoral thesis, Universitat Politècnica de València, 2018. http://hdl.handle.net/10251/113413.
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Elevada eficiencia térmica y mínimas emisiones contaminantes impuestas por las restrictivas normativas anticontaminación en motores alternativos representan el principal objetivos de los fabricantes de motores.
La estrategia de combustión diésel convencional es ampliamente utilizada en el mundo gracias a su excelente economía en el consumo de carburante. Esta estrategia permite operar con mezclas pobres de combustible y aire proporcionando elevada eficiencia térmica. Además, este tipo de combustión puede ser aplicada desde motores tanto para vehículos ligeros como en motores marinos. Sin embargo, este proceso de combustión conlleva a la generación de elevadas emisiones de NOx y emisiones de partículas (comúnmente llamado hollín en los diésel), siendo imposible reducir ambos contaminantes de forma simultánea. Por tanto, los fabricantes han incorporado sistemas de post-tratamiento con el objetivo de cumplir con las normativas de emisiones, cuya intención es la de proveer emisiones más limpias y elevada eficiencia. Por el contrario, este tipo de sistemas para mitigar las emisiones contaminantes incrementan la complejidad del motor dado el complejo proceso llevado a cabo durante el post-tratamiento y una aumento en los costes tanto de producción como operativos a lo largo del ciclo de vida del motor. La comunidad científica continua desarrollando soluciones alternativas a la combustión diésel convencional manteniendo los beneficios de este proceso de combustión mientras que las emisiones son reducidas (principalmente NOx y hollín).
La comunidad científica ha encontrado en las estrategias de combustión de baja temperatura un proceso de combustión capaz de proporcionar elevada eficiencia térmica y emisiones ultra bajas de NOx y humo. En este sentido, la revisión bibliográfica dice que estos tipos de combustión permiten la reducción simultánea de ambas emisiones, rompiendo así el tradicional "trade-off" existente en la combustión diésel convencional. Sobre todas las estrategias, la que muestra un potencial superior es la estrategia conocida como combustión dominada por la reactividad del combustible. Este proceso de combustión se caracteriza por emplear dos combustibles, siendo capaz de solucionar los principales problemas de las estrategias de baja temperatura tales como el fasado de la combustión. Sin embargo, esta estrategia de combustión también presenta algunos inconvenientes como el elevado nivel de monóxido de carbono e hidrocarburos inquemados a baja carga y elevado gradiente de presión y presión en cámara a elevada carga que limitan el rango de operación.
El objetivo general de la presente investigación es proveer de una estrategia de combustión "dual-fuel" capaz de operar sobre todo el rango de operación de un motor proporcionando igual o mejores eficiencia térmica que el diésel convencional y emisiones ultra bajas de NOx y humos. Adicionalmente, esta investigación implica una exploración delas emisiones de las partículas del concepto de combustión ya que el número de partículas se encuentra actualmente regulado por la normativa anticontaminante.
El proceso de combustión que responde a este objetivo es "Dual-Mode Dual-Fuel". Este concepto de combustión emplea dos combustibles y cambia de combustión premezclada a baja carga a combustión de naturaleza difusiva a plena carga. Con el deseo de explorar las capacidades de la estrategia de combustión, se han empleado dos configuraciones de "hardware" y se ha realizado un estudio de la distribución por tamaños de las partículas.
Finalmente, considerando los principales resultados de la investigación, el último capítulo pretende resumir las principales bondades del concepto de combustión así como sus limitaciones y trabajos futuros.Elevada eficiència tèrmica i mínimes emissions contaminants impostes per les normatives anticontaminants en motores alternatius representen el principal objectiu dels fabricants de motors. La estratègia de combustió diésel convencional es àmpliament utilitzada per tot el mon gracies al excel·lent consum de carburant. Esta estratègia permet operar el motor amb dosatges pobres que resulten en elevada eficiència tèrmica. A més, aquest tipus de combustió pot ser aplicada tant a els motor mes lleugers con als motor per aplicacions marines. No obstant això, aquest procés de combustió implica la generació de elevats nivells de emissió de NOx i sutja, que no es poden reduir simultàniament. Per tant, els fabricants han incorporat sistemes de post-tractament amb el objectiu de acomplir les normatives anticontaminació, que pretenen obtindre motors en emissions mes netes i mes eficients. Per el contrari, aquest tipus de sistemes per a reduir les emissions incrementen la complexitat del motor i els costos tant de producció com operatius al llarg del cicle de vida del motor. La comunitat científica continua desenvolupant solucions alternatives a la combustió dièsel mantenint els beneficis d¿aquest tipus de combustió però reduint les emissions (principalment NOx i sutja). La comunitat científica ha trobat a les estratègies de combustió de baixa temperatura un procés de combustió que te elevada eficiència tèrmica i extremadament baixes emissions de NOx y partícules. En aquest sentit, la revisió bibliogràfica constata que aquests tipus de combustions permeten la reducció simultània dels contaminants NOx i sutja, trencant el tradicional "trade-off" existent a la combustió dièsel. De entre totes les estratègies proposades de baixa temperatura, la estratègia combustió dominada per la reactivitat del combustible presenta mes potencial que les altres. Aquest procés de combustió es caracteritza per utilitzar dos combustibles, lo que li permet solventar els principals problemes que han aparegut al llarg de la investigació de les estratègies de baixa temperatura com el control de la combustió. No obstant, aquest concepte de combustió també presenta algunes limitacions com el excessiu nivell de monòxid de carbó e inquemats a baixa càrrega i el elevat gradient de pressió i elevada pressió en càmera a elevada càrrega que limiten el rang de operació del motor. El objectiu de la investigació es proposar un concepte de combustió "dual-fuel" que puga operar en tot el rang de operació de un motor proporcionant el mateix o millorant la eficiència tèrmica que el dièsel amb emissions ultra baixes de NOx y partícules. A més, aquesta investigació també implica realitzar una exploració de les partícules emitides per el concepte ja que actualment està regulat per les normatives anticontaminants. El procés de combustió que compleix el objectiu es diu "Dual-Mode Dual-Fuel". Aquest concepte de combustió utilitza dos combustibles de diferent reactivitat y modifica la combustió de totalment premesclada a baixa càrrega a combustió de natura difusiva a plena càrrega. Amb el desig de explorar les capacitats del concepte, s¿han arribat a provar dos configuracions de pistons diferent per a adequar la relació de compressió i també un anàlisi per tamanys de les partícules. Finalment, considerant els principals resultats obtinguts, el últim capítol pretén resumir les principals avantatges del concepte ací com les principals limitacions y , per tant, els treballs futurs.
High thermal efficiency coupled to minimum pollutants emissions imposed by the stringent standard emissions limitations in reciprocating engines represent the main target of the engine manufacturers industry. Conventional diesel combustion strategy is widely used worldwide due to its excellent fuel economy. This combustion strategy allows operating under lean mixtures of fuel and air that provide high thermal efficiency. In addition, this type of combustion can be applied from light-duty engines to large bore marine engines. However, the combustion process leads to high NOx and particle matter emissions, being impossible to reduce both pollutants simultaneously. Hence, manufactures have incorporated aftertreatment systems in order to meet the imposed standard emissions limitations, which are aimed to provide cleaner emissions and high efficiency. By contrast, these systems required for the emissions mitigation result in a very complex processes and an increase in the engine production and operational costs. The research community continues developing alternative solutions to the conventional diesel combustion concept keeping the benefits of this combustion process while the emissions are reduced (mainly focused on NOx and soot). Research community have found in the low temperature combustion strategies the combustion process able to provide excellent high thermal efficiency and ultra-low NOx and smoke emissions. In this sense, the literature review states that this types of combustion processes allow the simultaneous reduction of NOx and smoke, breaking the traditional trade-off found in diesel engines. Amongst others, the most promising strategy is the reactivity controlled compression ignition. This combustion process is characterized by using two fuels and is able to solve the main challenges of the low temperature combustion processes such as combustion phasing control. Nonetheless, the reactivity controlled strategy also presents some challenges such as excessive carbon monoxide and unburned hydrocarbons during low load operation and high pressure rise rate and in-cylinder pressure that limit the engine range operation. The general objective of this investigation is to provide a dual-fuel strategy able to operate over the whole range providing similar or better thermal efficiency that the conventional diesel combustion and ultra-low values of NOx and smoke. In addition, the investigation also explores the particle emissions of the concept since it is regulated by the standard emissions. The combustion process that responds to the target provided at the general objective is the Dual-Fuel Dual-Mode concept. This concept uses two fuels and switches from a dual-fuel fully premixed strategy (based on the RCCI concept) during low load operation to a diffusive nature during high load operation. In order to explore the capabilities of the concept, two hardware configurations are used and a particle size distribution exploration is performed. Finally, considering the main findings of the investigation, the last chapter is aimed to provide the benefits of the combustion process developed as well as the main limitations or future works of the concept.
Boronat Colomer, V. (2018). Dual-Fuel Dual-Mode combustion strategy to achieve high thermal efficiency, low NOx and smoke emissions in compression ignition engines [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/113413
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Chintala, Venkateswarlu. "Experimental investigation on utilization of hydrogen in a compression ignition engine under dual-fuel mode". Thesis, IIT Delhi, 2016. http://localhost:8080/xmlui/handle/12345678/7021.
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EGUSQUIZA, JULIO CESAR CUISANO. "EXPERIMENTAL INVESTIGATION OF A DIESEL CYCLE ENGINE OPERATING ON DUAL-FUEL MODE: DIESEL / ETHANOL AND DIESEL / GAS". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=17103@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRONo presente trabalho, ensaios experimentais de um motor do ciclo Diesel consumindo etanol hidratado ou gás natural em substituição parcial ao óleo diesel, foram realizados. Os objetivos principais foram verificar as influências dos combustíveis alternativos e avaliar as técnicas do avanço da injeção do diesel e da restrição parcial do ar de admissão, em relação aos parâmetros característicos da combustão, desempenho e emissões. Com base nos dados do diagrama pressão-ângulo de virabrequim, foi possível analisar alguns parâmetros característicos da combustão, tais como o início da combustão, a máxima taxa de elevação de pressão e o pico de pressão. Os parâmetros do desempenho e emissões do motor foram analisados através do rendimento térmico e as concentrações de monóxido de carbono, hidrocarbonetos, material particulado e óxidos de nitrogênio. Os resultados obtidos mostraram que as técnicas avaliadas no modo bicombustível junto com as elevadas taxas de substituição do óleo diesel favoreceram a melhor queima dos combustíveis alternativos, refletindo-se favoravelmente em menores emissões de CO e MP, além de um pequeno aumento no rendimento térmico do motor. No entanto, houve também um acréscimo nas emissões de NOX e, no caso específico do avanço da injeção, foi notado um maior ruído gerado pelo motor.
In this report, experimental tests of a Diesel cycle engine running with hydrous ethanol or natural gas with partial substitution for diesel fuel were performed. The main objectives were to verify the influence of alternative fuels and evaluate the advancing of diesel injection timing and the air partial restriction, regarding the characteristic parameters of combustion, performance and emissions. Based on data from the pressure-crank angle diagram, it was possible to analyze some characteristic parameters of combustion, such as the start of combustion, the maximum rate of pressure rise and peak pressure. The parameters of the engine performance and emissions were analyzed through the thermal efficiency and the concentrations of carbon monoxide, hydrocarbons, particulate matter and nitrogen oxides. The results showed that the techniques evaluated in dual fuel mode with higher rates of substitution of diesel fuel favored a better burning of the alternative fuels, reflecting favorably in lower emissions of CO and PM, and also in a small increase in the engine thermal efficiency. However, there was also an increase in NOX emissions and, in the specific case of the advanced injection timing, it was noted a louder noise generated by the engine.
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Aklouche, Fatma Zohra. "Etude caractéristique et développement de la combustion des moteurs Diesel en mode Dual-Fuel : optimisation de l'injection du combustible pilote". Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2018. http://www.theses.fr/2018IMTA0072/document.
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La dégradation de l’environnement ainsi que l’épuisement progressif des énergies fossiles devient très inquiétant et incite les états à définir des limites d’émission polluantes plus strictes. Ceci a conduit les constructeurs automobiles à poursuivre leurs recherches dans le développement de conception propre et efficace des moteurs en utilisant des combustibles alternatifs dans les moteurs à combustion interne.Dans le présent travail, on s’intéresse à l’étude des moteurs fonctionnant en mode DF afin d’améliorer ses performances tout en minimisant les émissions polluantes, en particulier les HC et les CO. Pour ce faire des études expérimentales ont été menées. Une réduction de 77% des émissions de HC a été observée en passant d’une richesse de 0,35 à 0,7. Par ailleurs, Il a été noté aussi qu’une diminution de 20% à 50% des émissions de CO avec une amélioration de 30% du rendement peut être visualisée en variant l’avance à l’injection de 4,5 °V à 6 °V. Concernant la mise en place de la pré-injection, une baisse de 30% des émissions de NOx a été observée avec un gain de 12% à 30% de rendement par rapport à une seule injection. En dernier terme, un modèle thermodynamique à une zone a été développé afin de prédire la température et la pression dans le cylindre. Une bonne concordance a été notée entre les deux résultats avec une erreur moyenne relative inférieure à 5%Currently, the environmental degradation due to pollutant emissions and the gradual depletion of fossil fuels, becoming very worrying, are prompting European directives to set pollutant emission limits. These have led manufacturers to continue research in the development of clean and efficient engine designs using alternative fuels in internal combustion engines.In this work, we focus on the study of engines operating in dual-fuel mode to improve its performance while minimizing pollutant emissions, particularly HC and CO. For this, experimental studies were conducted. A reduction of about 77% in the HC emissions was observed as the equivalence ratio was varied from 0.35 to 0.7. Regarding the effect of injection timing, it was noted that the CO emissions decreased about 20% to 50% with an improvement in the brake thermal efficiency by 30% upon varying the injection advance from 4,5 °CA to 6 °CA. On the other hand, the introduction of pre-injection strategy led to a decrease by 30% in NOx emissions with an amelioration of brake thermal efficiency of 12% to 30% compared to a single injection. Lastly, a single zone thermodynamic model was developed to predict the in-cylinder temperature and pressure. A good agreement was noted between the predicted and experimental results. The average relative error was less than 5%
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ACCURSO, FRANCESCO. "Development of a Phenomenological Combustion Model for Large Bore Dual Fuel Engines". Doctoral thesis, Politecnico di Torino, 2022. http://hdl.handle.net/11583/2972101.
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Jeffrey, Waincymer. Part IX Costs, Funding, and Ideas for Optimization, 28 Optimizing the use of Mediation in International Arbitration: A Cost–Benefit Analysis of ‘Two Hat’ Versus ‘Two People’ Models. Oxford University Press, 2016. http://dx.doi.org/10.1093/law/9780198783206.003.0029.
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This chapter considers the question of whether an arbitrator may also adopt a mediation function or whether the dual roles are antithetical. It tests that hypothesis by engaging in a cost-benefit analysis of differing scenarios when mediation is utilized in an arbitral context. The prime comparison is between parallel mediation with a separate neutral and the alternative of a dual-role neutral. The three key points are: there should be much more mediation occurring at the international level, regarding both potential and actual arbitral disputes; a commercially minded arbitrator concerned for the parties’ good faith should encourage mediation where appropriate, in particular, when an adjudicated outcome will not be in the interests of either, usually because the dispute is a small part of a long-term relationship that can risk that relationship no matter who wins; and, while informed party autonomy should always support a dual-role neutral, in most factual permutations, informed parties could be expected to prefer parallel mediation provided there is full cooperation between mediator and arbitrator. The chapter argues that the relative benefits of the use of dual-role neutrals would be greatly outweighed by the costs in fairness and efficiency, and the inevitable need for a sub-optimal design of either or both dispute processes. The benefits would also be separately outweighed by the risks of significant disruption to any ensuing arbitration if a dual-role neutral fails to achieve a settlement.
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Lopes, Brian, i Lee Mccormack. Mastering Mountain Bike Skills. Wyd. 3. Human Kinetics, 2017. http://dx.doi.org/10.5040/9781718219526.
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If you want to ride like a pro, you should learn from a pro! In Mastering Mountain Bike Skills, Third Edition, world-champion racer Brian Lopes and renowned riding coach Lee McCormack share their elite perspectives, real-life race stories, and their own successful techniques to help riders of all styles and levels build confidence and experience the full exhiliration of the sport. Mastering Mountain Bike Skills is the best-selling guide for all mountain biking disciplines, including enduro, pump track racing, dual slalom, downhill, cross-country, fatbiking, and 24-hour races. It absolutely captures the sport and offers everything you need to maximize performance and excitement on the trail. Learn how to select the proper bike and customize it for your unique riding style. Develop a solid skills base so you can execute techniques with more power and precision. Master the essential techniques to help you carve every corner, nail every jump, and conquer every obstacle in your path. Last, but not least, prepare yourself to handle every type of weather and trail condition that the mountain biking world throws at you. Whether you're a recreational rider looking to rock the trails with friends, are a seasoned enthusiast, or are aspiring to be a top pro, Mastering Mountain Bike Skills will improve your ride and dust the competition. Don't just survive the trail–own the trail, and enjoy the thrill of doing it.
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Heunen, Chris, i Jamie Vicary. Categories for Quantum Theory. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198739623.001.0001.
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Monoidal category theory serves as a powerful framework for describing logical aspects of quantum theory, giving an abstract language for parallel and sequential composition and a conceptual way to understand many high-level quantum phenomena. Here, we lay the foundations for this categorical quantum mechanics, with an emphasis on the graphical calculus that makes computation intuitive. We describe superposition and entanglement using biproducts and dual objects, and show how quantum teleportation can be studied abstractly using these structures. We investigate monoids, Frobenius structures and Hopf algebras, showing how they can be used to model classical information and complementary observables. We describe the CP construction, a categorical tool to describe probabilistic quantum systems. The last chapter introduces higher categories, surface diagrams and 2-Hilbert spaces, and shows how the language of duality in monoidal 2-categories can be used to reason about quantum protocols, including quantum teleportation and dense coding. Previous knowledge of linear algebra, quantum information or category theory would give an ideal background for studying this text, but it is not assumed, with essential background material given in a self-contained introductory chapter. Throughout the text, we point out links with many other areas, such as representation theory, topology, quantum algebra, knot theory and probability theory, and present nonstandard models including sets and relations. All results are stated rigorously and full proofs are given as far as possible, making this book an invaluable reference for modern techniques in quantum logic, with much of the material not available in any other textbook.
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Stephens, Darryl, red. Bivocational and Beyond: Educating for Thriving Multivocational Ministry. Atla Open Press, 2022. http://dx.doi.org/10.31046/atlaopenpress.82.
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Bivocational and Beyond provides a wide range of perspectives on faith, leadership, and learning to equip pastors and theological educators for a future in which multivocational ministry may become the norm. Bivocational ministry— also called multivocational, covocational, dual career, partially funded, non-stipendiary, or tentmaking ministry—is a topic of increasing relevance to congregational vitality and the future of the church in North America. The rise of the “gig economy,” a blurring of traditional notions of sacred and secular, and missional innovation at the end of modern Christendom present challenges to received models of church and theological education. Bivocational pastors are being challenged to integrate diverse expressions of their calling, balance personal and professional obligations, overcome stigma, and achieve financial stability. Bivocational congregations are being challenged to adapt to new leadership styles and expectations of clergy and laity alike. Theological educators, including theological librarians, are also being challenged to adapt. Degree programs designed for full-time students preparing for fully funded pastoral ministry must be reassessed in light of multivocational realities. This book addresses these challenges as an opportunity for theological education and the church. Theological librarians and educators can guide congregational leaders to imagine the church in ways that transcend the “standard” model of a fully funded, professionally trained pastor of a single congregation. Contributors include researchers, reflective practitioners, denominational leaders, and theological educators. Appropriate to its subject matter, this book is written for multiple audiences: students and pastors as well as those who educate them, theological educators and librarians.
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Xie, Chuntao, red. China's Urbanization: Migration by the Millions. Tłumacz Chiying Wang. Global Century Press, 2016. http://dx.doi.org/10.24103/cus1.en.2016.
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Joseph Eugene Stiglitz, laureate of the Nobel Prize in Economic Sciences, once named urbanization in China and the new technical revolution led by the United States as the two great events shaping the world of the 21st century. British specialist Tom Miller refers to China’s urbanization as “the greatest migration in human history.” China's Urbanization: Migration by the Millions is a full-range description of how millions of farmers in China became urban citizens in different periods of history. It further explores the deep-rooted issues of the country’s land system and household registration system, issues that will be confronted by urbanization for a long time to come. China is the world’s largest single-country population transfer and urbanization country. Its urbanization is faced with ever more stringent constraints on resources and environment. This means China has to take a brand new path of urbanization with Chinese characteristics. Through this book, readers can get both the ropes of official and mainstream views on the new urbanization initiative and get familiar with multi-directional probes on this issue in academic circles so they may gain a comprehensive and balanced understanding of the whole picture. This book was first published by New World Press in 2014, and republished jointly by New World Press and Global Century Press in 2016. This joint publication is the first volume in the ‘China Urbanization Studies’ series. We have retained the original typesetting, but we have added DOI numbers for the book, Series Editors’ Prefaces and all chapters, as well as a section of dual language additions from Global Century Press in English and Chinese.
Części książek na temat "Dual fuel mode"
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Janakiram, Sushmitha, i T. M. Muruganandam. "Analytically Modeling a Dual-Mode Scramjet with Fuel Flow Rate as the Controlling Parameter". W Proceedings of the National Aerospace Propulsion Conference, 449–64. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5039-3_27.
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von Mitzlaff, Klaus, i Moses H. Mkumbwa. "Performance of A Small Diesel Engine Operating in a Dual Fuel Mode with Biogas". W Biogas Technology, Transfer and Diffusion, 343–54. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4313-1_43.
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Jamuwa, D. K., D. Sharma i S. L. Soni. "Influence of Intake Air Pre-Heat on a Diesel Engine Operating on Ethanol in Dual Fuel Mode". W Springer Proceedings in Energy, 271–78. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-47257-7_24.
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Shere, Anilkumar, i K. A. Subramanian. "Performance Enhancement and Emissions Reduction in a DME Fueled Compression Ignition Engine Using Hydrogen Under Dual-Fuel Mode". W Lecture Notes in Mechanical Engineering, 505–23. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-8517-1_40.
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Subani, Shaik, i Domakonda Vinay Kumar. "Artificial Neural Network (ANN) Approach in Evaluation of Diesel Engine Operated with Diesel and Hydrogen Under Dual Fuel Mode". W Lecture Notes in Mechanical Engineering, 535–43. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-1665-8_46.
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Liu, H. B., J. Razvi, R. Rucker, R. Cerbone, M. Merrill, W. Whittemore, D. Newell, S. Autry, W. Richards i J. Boggan. "TRIGA® Fuel Based Converter Assembly Design for a Dual-Mode Neutron Beam System at the McClellan Nuclear Radiation Center". W Frontiers in Neutron Capture Therapy, 295–300. Boston, MA: Springer US, 2001. http://dx.doi.org/10.1007/978-1-4615-1285-1_40.
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Sirajuddin, S., i R. Manimaran. "CFD Simulation on the Effect of Hydrogen Mass Fraction and Initial Temperature in a CI Engine Under Hydrogen-Diesel Dual Fuel Mode". W Advances in Energy Research, Vol. 2, 679–88. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-2662-6_61.
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Srinadh, Reddy, Velmurugan Ramanathan, Mayakrishnan Jaikumar, Raja Selvakumar, V. A. Shridhar, E. Sangeethkumar i N. Sasikumar. "Effect of Ethanol Fumigation on Performance and Combustion Characteristics of Compression Ignition Engine Fuelled with Used Cooking Oil Methyl Ester in Dual-Fuel Mode". W Intelligent Manufacturing and Energy Sustainability, 339–52. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-1616-0_33.
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Yaliwal, V. S., S. R. Daboji, K. N. Patil, M. K. Marikatti i N. R. Banapurmath. "Multiple Optimizations of Engine Parameters of Single-Cylinder Four-Stroke Direct Injection Diesel Engine Operated on Dual Fuel Mode Using Biodiesel-Treated and Untreated Biogas Combination". W Lecture Notes in Mechanical Engineering, 765–93. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5996-9_60.
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Barnstedt, Klaus Dieter, Peter Grabner i Helmut Eichlseder. "Experimental studies of dual-fuel combustion modes for heavy-duty application". W Proceedings, 577–88. Wiesbaden: Springer Fachmedien Wiesbaden, 2016. http://dx.doi.org/10.1007/978-3-658-12918-7_44.
Pełny tekst źródłaStreszczenia konferencji na temat "Dual fuel mode"
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Benajes, Jesus, Antonio Garcia, Javier Monsalve-Serrano i Rafael Sari. "Surrogate Fuel Formulation to Improve the Dual-Mode Dual-Fuel Combustion Operation at Different Operating Conditions". W SAE Powertrains, Fuels & Lubricants Meeting. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2020. http://dx.doi.org/10.4271/2020-01-2073.
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Miaomiao, Han, i Zhou Baozhong. "Dual-Mode Predictive Control of Solid Oxide Fuel Cell". W 2016 3rd International Conference on Information Science and Control Engineering (ICISCE). IEEE, 2016. http://dx.doi.org/10.1109/icisce.2016.207.
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Patnaik, Nishant, Anup Kumar Panda i Richa Pandey. "Fuel Cell Based Sapf System with Dual Mode Operation". W 2020 5th International Conference on Devices, Circuits and Systems (ICDCS). IEEE, 2020. http://dx.doi.org/10.1109/icdcs48716.2020.243564.
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Grochowina, Marcus, Daniel Hertel, Simon Tartsch i Thomas Sattelmayer. "Ignition of Diesel Pilot Fuel in Dual-Fuel Engines". W ASME 2018 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/icef2018-9671.
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Dual-Fuel (DF) engines offer great fuel flexibility combined with low emissions in gas mode. The main source of energy in this mode is provided by gaseous fuel, while the Diesel fuel acts only as an ignition source. For this reason, the reliable autoignition of the pilot fuel is of utmost importance for combustion in DF-engines. However, the autoignition of the pilot fuel suffers from low compression temperatures caused by Miller valve timings. These valve timings are applied to increase efficiency and reduce nitrogen oxide emissions. Previous studies have investigated the influence of injection parameters and operating conditions on ignition and combustion in DF-engines using a unique periodically chargeable combustion cell. Direct light high-speed images and pressure traces clearly revealed the effects of injection parameters and operating conditions on ignition and combustion. However, these measurement techniques are only capable of observing processes after ignition. In order to overcome this drawback, a high-speed shadowgraph technique was applied in this study to examine the processes prior to ignition. Measurements were conducted to investigate the influence of compression temperature and injection pressure on spray formation and ignition. Results showed that the autoignition of Diesel pilot fuel strongly depends on the fuel concentration within the spray. The high-speed shadowgraph images revealed that in the case of very low fuel concentration within the pilot spray only the first-stage of the two-stage ignition occurs. This leads to large cycle-to-cycle variations and misfiring. However, it was found that a reduced number of injection holes counteracts these effects. The comparison of a Diesel injector with 10-holes and a modified injector with 5-holes showed shorter ignition delays, more stable ignition and a higher number of ignited sprays on a percentage basis for the 5-hole nozzle.
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Kapilan, N., R. P. Reddy i P. Mohanan. "Studies on Esters of Coconut Oil as Fuel for LPG-Biodiesel Dual Fuel Engine". W ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-42772.
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The rapid depletion in world petroleum reserves and uncertainty in petroleum supply due to political and economical reasons, as well as, the sharp escalation in the petroleum prices, have stimulated the search for alternatives to petroleum based fuels specially diesel and gasoline. Biodiesel is one of the renewable fuels, which will be the good replacement to diesel. But as a sole fuel, it gives poor performance and higher emissions. From the literature survey, it is observed that not much work has been done to use Methyl Ester (ME) of coconut oil as liquid fuel in sole and dual fuel mode of operation. Hence, in the present work, ME of coconut oil is chosen as a sole fuel to run the diesel engine and an alternative pilot fuel to run LPG-Biodiesel dual fuel engine. In dual fuel mode operation, LPG is used as the inducted gaseous fuel. LPG has been chosen as the inducted fuel on account of its easy availability in abundance in the present time. The existing compression ignition diesel engine was modified to work on dual fuel mode. Tests were carried out on a single cylinder, four strokes, water-cooled, direct injection, compression ignition engine using ME of coconut oil as fuel. To study the effect of injection timing, its is advanced and retarded from the standard injection timing recommended for diesel operation. From the results, it is observed that the advanced injection timing results in better performance and lower emissions of the diesel engine. In dual fuel mode operation, first the engine was started with ME of coconut oil as fuel and then the LPG flow rate was increased. With appropriate proportions of the injected (0.45, 0.65 and 0.75 kg/hr) and inducted fuels it is possible to improve the engine performance and reduce its emissions. From the experimental results, it is found that the pilot fuel rate of 0.65 kg/hr is preferred from the point view of brake thermal efficiency, fuel consumption and smooth running. ME of coconut oil were successfully used as sole fuel and pilot fuel. The performance and emission of the engine in sole fuel mode with better injection timing and dual fuel mode with better pilot quantity were compared. From the comparison, it is observed that the ME of coconut oil can be used as pilot fuel in dual fuel engine compared to sole fuel with regard to performance and emissions.
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Nojima, Kiyoshi, Mitsuhiro Soejima, Takuya Arakawa, Sadatake Tomioka i Noboru Sakuranaka. "Combustion Performance of Hydrocarbon Fuel in a Dual-Mode Combustor". W 52nd AIAA/SAE/ASEE Joint Propulsion Conference. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2016. http://dx.doi.org/10.2514/6.2016-4756.
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Nojima, Kiyoshi, Yu Suzuki, Sadatake Tomioka i Noboru Sakuranaka. "Investigation of Ethylene Fuel Combustion in a Dual-Mode Combustor". W 50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2014. http://dx.doi.org/10.2514/6.2014-3943.
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Krishnamoorthi, M., S. Sreedhara i Pavan Prakash Duvvuri. "Modelling of Soot Formation and Experimental Study for Different Octane Number Fuels in Dual Fuel Combustion Engine With Diesel". W ASME 2020 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/icef2020-2914.
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Abstract This work investigates the effects of low reactivity fuel (LRF) on reactivity controlled compression ignition (RCCI) engine with fossil diesel. RCCI mode of combustion is a low temperature combustion (LTC) strategy which reduces both oxides of nitrogen (NOx) and soot emissions simultaneously. Syngas and methanol can be obtained from renewable biological resources and conventional coal. LRF (methanol, syngas and gasoline) has been supplied to the engine along with intake air and diesel is injected to initiate the combustion process. Test engine has been operated for different dual fuel modes at constant engine speed (1500 rpm) and load (80%). Closed cycle combustion simulations have been performed to complement the experimental results and in-cylinder dynamics. Particle size mimic (PSM) model has been used to investigate the soot particle number and mass-size distributions and mean particle size. Results confirmed that maximum gross indicated thermal efficiency (38%) has been observed in gasoline/diesel dual fuel mode. Compared to gasoline/diesel dual fuel mode, about 74% and 86%, lower soot and NOx emissions have been observed for methanol/diesel dual fuel mode, while about 46% and 52% lower soot and NOx emissions have been found in syngas/diesel mode. About 53% higher carbon monoxide emission has been observed for syngas/diesel case as compared to gasoline/diesel case. Predictions from soot modelling reveal that condensation mode, surface growth mode and nucleation mode particles are dominant in methanol, syngas and gasoline/diesel dual fuel modes respectively. Bigger primary soot particles (diameter > 35 nm, nanometre) have been observed for methanol/diesel mode and the gasoline/diesel mode shows a smaller size of primary particles.
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Bilcan, A., M. Tazerout, O. Le Corre i A. Ramesh. "Ignition Delay in Dual Fuel Engines: An Extended Correlation for Gaseous Fuels". W ASME 2001 Internal Combustion Engine Division Spring Technical Conference. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/ices2001-105.
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Abstract Agricultural & municipal waste and wood residues can be easily converted to biogas or producer gas and used for producing heat and power. The main problem with these fuels is their low energy content. This is due to the presence of certain non-combustible gases like CO2 and N2 in these fuels. The use of these gases in SI engines is associated with problems like unstable operation and high levels of HC and CO emissions. Gaseous fuel can be easily used with good efficiencies and low emissions in diesel engines running in the dual-fuel mode. In dual-fuel engines, these gaseous fuels are inducted along with air and ignited after compression by a small spray of diesel called the pilot. The presence of these gases alters the thermodynamic properties of the intake charge and significantly influence the ignition delay of the pilot diesel fuel and hence the performance of the engine. The aim of this paper is to modify an existing correlation for ignition delay in a dual-fuel engine to incorporate the effects of the gaseous fuel concentration and composition on the polytropic index. An ignition delay correlation of a biogas dual-fuel engine was modified so that it can be used with any primary fuel. The polytropic index was assumed to be a function of the ratio of specific heats. Further, the effect of injection timing on ignition delay was included. The adapted model was introduced in a simulation program and the results of ignition delay were compared with those given in the literature for a dual-fuel engine. In addition, the correlation was used to predict the ignition delay of the pilot fuel when biogas, LPG, natural gas and producer gas were treated as primary fuels. The results obtained with the new correlation have been compared with experimental values from a LPG-diesel dual fuel engine. The comparison was also made for a biogas dual fuel engine. Errors less than 10% were obtained for both of the fuels between the experimental measurements and simulation results.
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De Simio, Luigi, Sabato Iannaccone, Vincenzo Pennino i Luca Marchitto. "Experimental Analysis of a Single-Cylinder Large Bore Engine with External Supercharging in Diesel/CNG Dual-Fuel Mode". W 16th International Conference on Engines & Vehicles. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-24-0058.
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<div class="section abstract"><div class="htmlview paragraph">The need for a quick reduction in greenhouse gasses and noxious emissions is pushing maritime transportation to increase the use of alternative fuels. Natural Gas (NG) is well recognized as an effective solution to limit the use of marine diesel oil in the short/mid-term. In this scenario, dual-fuel technology is used to enable a conventional diesel engine to operate with a share of gaseous fuel while retaining the capability to run in full diesel mode. Dual-fuel (DF) engines allow the use of natural gas, or biomethane from renewable sources, as the main fuel, with advantages over CO<sub>2</sub>, SO<sub>x</sub> and PM emissions with the same levels of NOx.</div><div class="htmlview paragraph">This paper presents an experimental study investigating the effects of the diesel injection strategy on performance and emissions of a dual-fuel, single-cylinder, large bore, 4-stroke engine for marine applications. The engine is equipped with an external supercharging system; NG is injected in the port, while a Common Rail system injects the diesel pilot. Measurements were performed at 1500 rpm speed and Brake Mean Effective Pressure (BMEP) of 8.4 bar: the full diesel engine point representative of commercial Electronic Control Unit (ECU) map is chosen as reference. Further investigations will be performed to estimate the influence of dual-fuel combustion on the loss linked to the external supercharging. The performance of an externally supercharged and a turbocharged engine may differ: when working with turbocharged engines, boost and exhaust backpressure simultaneously increase. In contrast, when reproducing external supercharging behavior, an increase in the exhaust backpressure could alter the internal exhaust gas recycling and energy balances.</div></div>
Raporty organizacyjne na temat "Dual fuel mode"
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Cantor, Amy, Heidi D. Nelson, Miranda Pappas, Chandler Atchison, Brigit Hatch, Nathalie Huguet, Brittny Flynn i Marian McDonagh. Effectiveness of Telehealth for Women’s Preventive Services. Agency for Healthcare Research and Quality (AHRQ), czerwiec 2022. http://dx.doi.org/10.23970/ahrqepccer256.
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Objectives. To evaluate the effectiveness, use, and implementation of telehealth for women’s preventive services for reproductive healthcare and interpersonal violence (IPV), and to evaluate patient preferences and engagement for telehealth, particularly in the context of the coronavirus (COVID-19) pandemic. Data sources. Ovid MEDLINE®, CINAHL®, Embase®, and Cochrane CENTRAL databases (July 1, 2016, to March 4, 2022); manual review of reference lists; suggestions from stakeholders; and responses to a Federal Register Notice. Review methods. Eligible abstracts and full-text articles of telehealth interventions were independently dual reviewed for inclusion using predefined criteria. Dual review was used for data abstraction, study-level risk of bias assessment, and strength of evidence (SOE) rating using established methods. Meta-analysis was not conducted due to heterogeneity of studies and limited available data. Results. Searches identified 5,704 unique records. Eight randomized controlled trials, one nonrandomized trial, and seven observational studies, involving 10,731 participants, met inclusion criteria. Of these, nine evaluated IPV services and seven evaluated contraceptive care, the only reproductive health service studied. Risk of bias was low in one study, moderate in nine trials and five observational studies, and high in one study. Telehealth interventions were intended to replace usual care in 14 studies and supplement care in 2 studies. Delivery modes included telephone (5 studies), online modules (5 studies), and mobile applications (1 study), and was unclear or undefined in five studies. There were no differences between telehealth interventions to supplement contraceptive care and comparators for rates of contraceptive use, sexually transmitted infection, and pregnancy (low SOE); evidence was insufficient for abortion rates. There were no differences between telehealth IPV services versus comparators for outcomes measuring repeat IPV, depression, post-traumatic stress disorder, fear of partner, coercive control, self-efficacy, and safety behaviors (low SOE). The COVID-19 pandemic increased telehealth utilization. Barriers to telehealth interventions included limited internet access and digital literacy among English-speaking IPV survivors, and technical challenges and confidentiality concerns for contraceptive care. Telehealth use was facilitated by strategies to ensure safety of individuals who receive IPV services. Evidence was insufficient to evaluate access, health equity, or harms outcomes. Conclusions. Limited evidence suggests that telehealth interventions for contraceptive care and IPV services result in equivalent clinical and patient-reported outcomes as in-person care. Uncertainty remains regarding the most effective approaches for delivering these services, and how to best mobilize telehealth, particularly for women facing barriers to healthcare.
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Totten, Annette, Dana M. Womack, Marian S. McDonagh, Cynthia Davis-O’Reilly, Jessica C. Griffin, Ian Blazina, Sara Grusing i Nancy Elder. Improving Rural Health Through Telehealth-Guided Provider-to-Provider Communication. Agency for Healthcare Research and Quality, grudzień 2022. http://dx.doi.org/10.23970/ahrqepccer254.
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Objectives. To assess the use, effectiveness, and implementation of telehealth-supported provider-to-provider communication and collaboration for the provision of healthcare services to rural populations and to inform a scientific workshop convened by the National Institutes of Health Office of Disease Prevention on October 12–14, 2021. Data sources. We conducted a comprehensive literature search of Ovid MEDLINE®, CINAHL®, Embase®, and Cochrane CENTRAL. We searched for articles published from January 1, 2015, to October 12, 2021, to identify data on use of rural provider-to-provider telehealth (Key Question 1) and the same databases for articles published January 1, 2010, to October 12, 2021, for studies of effectiveness and implementation (Key Questions 2 and 3) and to identify methodological weaknesses in the research (Key Question 4). Additional sources were identified through reference lists, stakeholder suggestions, and responses to a Federal Register notice. Review methods. Our methods followed the Agency for Healthcare Research and Quality Methods Guide (available at https://effectivehealthcare.ahrq.gov/topics/cer-methods-guide/overview) and the PRISMA reporting guidelines. We used predefined criteria and dual review of abstracts and full-text articles to identify research results on (1) regional or national use, (2) effectiveness, (3) barriers and facilitators to implementation, and (4) methodological weakness in studies of provider-to-provider telehealth for rural populations. We assessed the risk of bias of the effectiveness studies using criteria specific to the different study designs and evaluated strength of evidence (SOE) for studies of similar telehealth interventions with similar outcomes. We categorized barriers and facilitators to implementation using the Consolidated Framework for Implementation Research (CFIR) and summarized methodological weaknesses of studies. Results. We included 166 studies reported in 179 publications. Studies on the degree of uptake of provider-to-provider telehealth were limited to specific clinical uses (pharmacy, psychiatry, emergency care, and stroke management) in seven studies using national or regional surveys and claims data. They reported variability across States and regions, but increasing uptake over time. Ninety-seven studies (20 trials and 77 observational studies) evaluated the effectiveness of provider-to-provider telehealth in rural settings, finding that there may be similar rates of transfers and lengths of stay with telehealth for inpatient consultations; similar mortality rates for remote intensive care unit care; similar clinical outcomes and transfer rates for neonates; improvements in medication adherence and treatment response in outpatient care for depression; improvements in some clinical monitoring measures for diabetes with endocrinology or pharmacy outpatient consultations; similar mortality or time to treatment when used to support emergency assessment and management of stroke, heart attack, or chest pain at rural hospitals; and similar rates of appropriate versus inappropriate transfers of critical care and trauma patients with specialist telehealth consultations for rural emergency departments (SOE: low). Studies of telehealth for education and mentoring of rural healthcare providers may result in intended changes in provider behavior and increases in provider knowledge, confidence, and self-efficacy (SOE: low). Patient outcomes were not frequently reported for telehealth provider education, but two studies reported improvement (SOE: low). Evidence for telehealth interventions for other clinical uses and outcomes was insufficient. We identified 67 program evaluations and qualitative studies that identified barriers and facilitators to rural provider-to-provider telehealth. Success was linked to well-functioning technology; sufficient resources, including time, staff, leadership, and equipment; and adequate payment or reimbursement. Some considerations may be unique to implementation of provider-to-provider telehealth in rural areas. These include the need for consultants to better understand the rural context; regional initiatives that pool resources among rural organizations that may not be able to support telehealth individually; and programs that can support care for infrequent as well as frequent clinical situations in rural practices. An assessment of methodological weaknesses found that studies were limited by less rigorous study designs, small sample sizes, and lack of analyses that address risks for bias. A key weakness was that studies did not assess or attempt to adjust for the risk that temporal changes may impact the results in studies that compared outcomes before and after telehealth implementation. Conclusions. While the evidence base is limited, what is available suggests that telehealth supporting provider-to-provider communications and collaboration may be beneficial. Telehealth studies report better patient outcomes in some clinical scenarios (e.g., outpatient care for depression or diabetes, education/mentoring) where telehealth interventions increase access to expertise and high-quality care. In other applications (e.g., inpatient care, emergency care), telehealth results in patient outcomes that are similar to usual care, which may be interpreted as a benefit when the purpose of telehealth is to make equivalent services available locally to rural residents. Most barriers to implementation are common to practice change efforts. Methodological weaknesses stem from weaker study designs, such as before-after studies, and small numbers of participants. The rapid increase in the use of telehealth in response to the Coronavirus disease 2019 (COVID-19) pandemic is likely to produce more data and offer opportunities for more rigorous studies.