The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Marco Pierini - One of the best experts on this subject based on the ideXlab platform.
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the effect of lightweighting in automotive lca perspective estimation of Mass induced fuel consumption Reduction for gasoline turbocharged vehicles
Journal of Cleaner Production, 2017Co-Authors: Francesco Del Pero, Massimo Delogu, Marco PieriniAbstract:Abstract The paper proposes a method aimed to support Life Cycle Assessment (LCA) in the evaluation of environmental benefits achievable by lightweight design solutions in the automotive field. The study is based on an in-depth calculation of car weight-induced Fuel Consumption (FC) resulting in the Fuel Reduction Value (FRV) coefficient; this is functional in modelling the use stage in a LCA perspective. The research is focused on Gasoline Turbocharged (GT) cars, since to date there is no systematic analysis of weight-induced FC Reduction regarding this propulsion technology. The FRV is evaluated for a wide range of vehicle case studies representative of different classes within the 2015 European market. The assessment is performed concentrating on four standardized driving cycles in order to evaluate various driving styles both in the case of primary Mass Reduction only and in the case of secondary effect (powertrain adaptation in order to maintain vehicle's performance). For the vehicle case studies under consideration, FRV is within the range 0.159–0.237 and 0.252–0.477 l/100 km*100 kg respectively for Mass Reduction only and secondary effect. Starting from the data obtained, a criterion is refined for estimating the FRV coefficient based on car technical features. Such a method allows to estimate FC Reduction precisely by means of the value of FRV closest to the specific application, and it is proposed as a valuable tool for LCA practitioners within the automotive lightweight context.
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Lightweight design solutions in the automotive field: Environmental modelling based on fuel Reduction value applied to diesel turbocharged vehicles
Sustainability (Switzerland), 2016Co-Authors: Massimo Delogu, Francesco Del Pero, Marco PieriniAbstract:A tailored model for the assessment of environmental benefits achievable by “light-weighting” in the automotive field is presented. The model is based on the Fuel Reduction Value (FRV) coefficient, which expresses the Fuel Consumption (FC) saving involved by a 100 kg Mass Reduction. The work is composed of two main sections: simulation and environmental modelling. Simulation modelling performs an in-depth calculation of weight-induced FC whose outcome is the FRV evaluated for a wide range of Diesel Turbocharged (DT) vehicle case studies. Environmental modelling converts fuel saving to impact Reduction basing on the FRVs obtained by simulations. Results show that for the considered case studies, FRV is within the range 0.115–0.143 and 0.142–0.388 L/100 km × 100 kg, respectively, for Mass Reduction only and powertrain adaptation (secondary effects). The implementation of FRVs within the environmental modelling represents the added value of the research and makes the model a valuable tool for application to real case studies of automotive lightweight LCA.
Michael F Orourke - One of the best experts on this subject based on the ideXlab platform.
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different role of wave reflection magnitude and timing on left ventricular Mass Reduction during antihypertensive treatment
Journal of Hypertension, 2008Co-Authors: Junichiro Hashimoto, Berend E Westerhof, Nico Westerhof, Yutaka Imai, Michael F OrourkeAbstract:OBJECTIVE Regression of left ventricular (LV) Mass during antihypertensive treatment has been associated with Reduction in aortic augmentation index, a composite measure of peripheral wave reflection. The aim of this study was to clarify which of the two reflection factors, that is magnitude or timing, plays the dominant role in this regression. METHODS We evaluated the reflection magnitude (RM; the reflected-to-forward pressure wave amplitude ratio), the round-trip travel time of the pressure wave (a parameter for reflection timing), and the aortic pulse wave velocity (PWV) with echocardiographic LV Mass in 61 hypertensive patients before and after 1-year standard medical treatment. RESULTS Antihypertensive therapy significantly (P < 0.01) decreased brachial and aortic blood pressures and aortic PWV, reduced LV Mass, and increased travel time. Neither increase in travel time nor decrease in PWV, however, was related to the Reduction in LV Mass. By contrast, treatment-induced change in RM was significantly correlated with change in LV Mass; the correlation was particularly close in patients with LV hypertrophy (r = 0.61, P < 0.001). Only a marginal correlation was observed between the changes in RM and travel time. The association between RM decrease and LV Mass Reduction was independent of age, sex, changes in travel time and blood pressure, and use of renin-angiotensin system inhibitors (beta = 0.41, P = 0.001). CONCLUSION Decreased wave RM contributes to LV Mass regression more strongly than, and independently of, delayed reflection timing. Peripheral muscular arteries (from which reflection arises) appear to be more important therapeutic targets in regressing LV Mass than central elastic arteries.
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indices of pulse wave analysis are better predictors of left ventricular Mass Reduction than cuff pressure
American Journal of Hypertension, 2007Co-Authors: Junichiro Hashimoto, Yutaka Imai, Michael F OrourkeAbstract:Background Studies have required large numbers of patients to associate regression of left ventricular (LV) Mass with a decrease in brachial cuff blood pressure (BP) in the treatment of hypertension. Hence, we prospectively examined potential superiority of pulse wave analysis over conventional BP measurement in predicting treatment-induced LV Mass Reduction. Methods Forty-six untreated patients (mean age, 56 ± 7 years) with hypertension received standard medical treatment based on international guidelines. Echocardiography and measurements of various LV load indices were made before and after 1 year of treatment. Results Antihypertensive treatment significantly (P < .05) reduced LV load, manifest by a decrease in measured brachial BP, estimated aortic BP, carotid–femoral pulse wave velocity (PWVcf), aortic augmentation index (AIa), aortic augmented pressure (AugP), and radial augmentation index (AIr). These changes were accompanied by significant Reduction in LV Mass index (LVMI) and improvements in systolic ejection fraction and diastolic early-to-atrial ratio of transmitral flow velocities. The treatment-induced LVMI change was not correlated with changes in brachial BP or PWVcf, but was closely correlated with factors influenced by wave reflection—changes in AIa, AIr, AugP, and aorta-to-arm pulse pressure amplification. On multivariate analysis, AIa change was the strongest determinant of LVMI change, independent of brachial BP and PWVcf changes (β = 0.51, P < .001). Estimated subject numbers required for predicting a significant LVMI Reduction were far less when wave reflection-related factors were used rather than conventional bracial BP. Conclusions These results suggest that Reduction in wave reflection is an important therapeutic strategy for reducing LV Mass, which can be predicted with modest subject numbers.
Junichiro Hashimoto - One of the best experts on this subject based on the ideXlab platform.
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different role of wave reflection magnitude and timing on left ventricular Mass Reduction during antihypertensive treatment
Journal of Hypertension, 2008Co-Authors: Junichiro Hashimoto, Berend E Westerhof, Nico Westerhof, Yutaka Imai, Michael F OrourkeAbstract:OBJECTIVE Regression of left ventricular (LV) Mass during antihypertensive treatment has been associated with Reduction in aortic augmentation index, a composite measure of peripheral wave reflection. The aim of this study was to clarify which of the two reflection factors, that is magnitude or timing, plays the dominant role in this regression. METHODS We evaluated the reflection magnitude (RM; the reflected-to-forward pressure wave amplitude ratio), the round-trip travel time of the pressure wave (a parameter for reflection timing), and the aortic pulse wave velocity (PWV) with echocardiographic LV Mass in 61 hypertensive patients before and after 1-year standard medical treatment. RESULTS Antihypertensive therapy significantly (P < 0.01) decreased brachial and aortic blood pressures and aortic PWV, reduced LV Mass, and increased travel time. Neither increase in travel time nor decrease in PWV, however, was related to the Reduction in LV Mass. By contrast, treatment-induced change in RM was significantly correlated with change in LV Mass; the correlation was particularly close in patients with LV hypertrophy (r = 0.61, P < 0.001). Only a marginal correlation was observed between the changes in RM and travel time. The association between RM decrease and LV Mass Reduction was independent of age, sex, changes in travel time and blood pressure, and use of renin-angiotensin system inhibitors (beta = 0.41, P = 0.001). CONCLUSION Decreased wave RM contributes to LV Mass regression more strongly than, and independently of, delayed reflection timing. Peripheral muscular arteries (from which reflection arises) appear to be more important therapeutic targets in regressing LV Mass than central elastic arteries.
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indices of pulse wave analysis are better predictors of left ventricular Mass Reduction than cuff pressure
American Journal of Hypertension, 2007Co-Authors: Junichiro Hashimoto, Yutaka Imai, Michael F OrourkeAbstract:Background Studies have required large numbers of patients to associate regression of left ventricular (LV) Mass with a decrease in brachial cuff blood pressure (BP) in the treatment of hypertension. Hence, we prospectively examined potential superiority of pulse wave analysis over conventional BP measurement in predicting treatment-induced LV Mass Reduction. Methods Forty-six untreated patients (mean age, 56 ± 7 years) with hypertension received standard medical treatment based on international guidelines. Echocardiography and measurements of various LV load indices were made before and after 1 year of treatment. Results Antihypertensive treatment significantly (P < .05) reduced LV load, manifest by a decrease in measured brachial BP, estimated aortic BP, carotid–femoral pulse wave velocity (PWVcf), aortic augmentation index (AIa), aortic augmented pressure (AugP), and radial augmentation index (AIr). These changes were accompanied by significant Reduction in LV Mass index (LVMI) and improvements in systolic ejection fraction and diastolic early-to-atrial ratio of transmitral flow velocities. The treatment-induced LVMI change was not correlated with changes in brachial BP or PWVcf, but was closely correlated with factors influenced by wave reflection—changes in AIa, AIr, AugP, and aorta-to-arm pulse pressure amplification. On multivariate analysis, AIa change was the strongest determinant of LVMI change, independent of brachial BP and PWVcf changes (β = 0.51, P < .001). Estimated subject numbers required for predicting a significant LVMI Reduction were far less when wave reflection-related factors were used rather than conventional bracial BP. Conclusions These results suggest that Reduction in wave reflection is an important therapeutic strategy for reducing LV Mass, which can be predicted with modest subject numbers.
Gholam Hossien Liaghat - One of the best experts on this subject based on the ideXlab platform.
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explosive welding of stainless steel carbon steel coaxial pipes
Journal of Materials Science, 2012Co-Authors: Ehsan Zamani, Gholam Hossien LiaghatAbstract:Bi-metallic corrosion resistant steel pipes were produced through explosive welding process. The weldability window of the stainless steel pipe (inner pipe) and the carbon steel pipe (outer pipe) was determined by the use of available semi-empirical relations. The impact velocity of the pipes as the most important collision parameter was calculated by the finite element simulation. Direct effect of the explosive Mass Reduction on the bonding interface of the pipes was studied. Optical microscopy study showed that a transition from a wavy interface to a smooth one occurs with decrease in explosive load.
Gregory A Keoleian - One of the best experts on this subject based on the ideXlab platform.
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effect of Mass on multimodal fuel consumption in moving people and freight in the u s
Transportation Research Part D-transport and Environment, 2018Co-Authors: John Sullivan, Geoffrey M Lewis, Gregory A KeoleianAbstract:Abstract The United States transportation sector consumes 5 billion barrels of petroleum annually to move people and freight around the country by car, truck, train, ship and aircraft, emitting significant greenhouse gases in the process. Making the transportation system more sustainable by reducing these emissions and increasing the efficiency of this multimodal system can be achieved through several vehicle-centric strategies. We focus here on one of these strategies – reducing vehicle Mass – and on collecting and developing a set of physics-based expressions to describe the effect of vehicle Mass Reduction on fuel consumption across transportation modes in the U.S. These expressions allow analysts to estimate fuel savings resulting from vehicle Mass Reductions (termed fuel Reduction value, FRV), across modes, without resorting to specialized software or extensive modeling efforts, and to evaluate greenhouse gas emission and cost implications of these fuel savings. We describe how FRV differs from fuel intensity (FI) and how to properly use both of these metrics, and we provide a method to adjust FI based on Mass changes and FRV. Based on this work, we estimate that a 10% vehicle Mass Reduction (assuming constant payload Mass) results in a 2% improvement in fuel consumption for trains and light, medium, and heavy trucks, 4% for buses, and 7% for aircraft. When a 10% vehicle Mass Reduction is offset by an increase in an equivalent Mass of payload, fuel intensity (fuel used per unit Mass of payload) increases from 6% to 23%, with the largest increase being for aircraft.
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vehicle lightweighting vs electrification life cycle energy and ghg emissions results for diverse powertrain vehicles
Applied Energy, 2014Co-Authors: Anne Marie Lewis, Jarod C Kelly, Gregory A KeoleianAbstract:Abstract This work assesses the potential of electrified vehicles and Mass Reduction to reduce life cycle energy and greenhouse gas (GHG) emissions. Life cycle assessment (LCA) is used to account for processes upstream and downstream of the vehicle operation, thereby incorporating regional variation of energy and GHG emissions due to electricity production and distinct energy and GHG emissions due to conventional and lightweight materials. Design harmonization methods developed in previous work are applied to create baseline and lightweight vehicle models of an internal combustion vehicle (ICV), hybrid electric vehicle (HEV) and plug-in hybrid electric vehicle (PHEV). Thus, each vehicle is designed to be functionally equivalent and incorporate the structural support required for heavier powertrains. Lightweight vehicles are designed using body-in-white (BIW) Mass Reduction scenarios with aluminum and advanced/high strength steel (A/HSS). For the Mass Reduction scenarios considered in this work, results indicate that the greatest life cycle energy and GHG emissions Reductions occur when steel is replaced by aluminum. However, since A/HSS requires less energy to produce as compared to aluminum, the energy and GHG Reductions per unit Mass removed is greatest for A/HSS. Results of the design harmonization modeling method show that 0.2–0.3 kg of structural support is required per unit increase in powertrain Mass, thus extending previous methods.