Search results for: marine diesel engine (two and four stroke)
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2050

Search results for: marine diesel engine (two and four stroke)

1960 Waste Heat Recovery System

Authors: A. Ramkumar, Anvesh Sagar, Preetham P. Karkera

Abstract:

Globalization in the modern era is dependent on the International logistics, the economic and reliable means is provided by the ocean going merchant vessel. The propulsion system which drives this massive vessels has gone through leaps and bounds of evolution. Most reliable system of propulsion adopted by the majority of vessels is by marine diesel engine. Since the first oil crisis of 1973, there is demand in increment of efficiency of main engine. Due to increase in the oil prices ship-operators explores for reduction in the operational cost of ship. And newly adopted IMO’s EEDI & SEEMP rules calls for the effective measures taken in this regard. The main engine of a ship suffers a lot of thermal losses, they mainly occur due to exhaust gas waste heat, radiation and cooling. So to increase the overall efficiency of system, we have to look into the solution to harnessing this waste energy of main engine to increase the fuel economy. During the course of research, engine manufacturers have developed many waste heat recovery systems. In our paper we see about additional options to harness this waste heat. The exhaust gas of engine coming out from the turbocharger still holds enough heat to go to the exhaust gas economiser to produce steam. This heat of exhaust gas can be used to heat a liquid of less boiling point after coming out from the turbocharger. The vapour of this secondary liquid can be superheated by a bypass exhaust or exhaust of turbocharger. This vapour can be utilized to rotate the turbine which is coupled to a generator. And the electric power for ship service can be produced with proper configuration of system. This can be included in PMS of ship. In this paper we seek to concentrate on power generation with use of exhaust gas. Thereby taking out the load on the main generator and increasing the efficiency of the system. This will help us to comply with the new rules of IMO. Our method helps to develop clean energy.

Keywords: EEDI–energy efficiency design index, IMO–international maritime organization PMS-power management system, SEEMP–ship energy efficiency management plan

Procedia PDF Downloads 321
1959 Biodiesel Production from Palm Oil Using an Oscillatory Baffled Reactor

Authors: Malee Santikunaporn, Tattep Techopittayakul, Channarong Asavatesanupap

Abstract:

Biofuel production especially that of biodiesel has gained tremendous attention during the last decade due to environmental concerns and shortage in petroleum oil reservoir. This research aims to investigate the influences of operating parameters, such as the alcohol-to-oil molar ratio (4:1, 6:1, and 9:1) and the amount of catalyst (1, 1.5, and 2 wt.%) on the trans esterification of refined palm oil (RPO) in a medium-scale oscillatory baffle reactor.  It has been shown that an increase in the methanol-to-oil ratio resulted in an increase in fatty acid methyl esters (FAMEs) content. The amount of catalyst has an insignificant effect on the FAMEs content. Engine testing was performed on B0 (100 v/v% diesel) and blended fuel or B50 (50 v/v% diesel). Combustion of B50 was found to give lower torque compared to pure diesel. Exhaust gas from B50 was found to contain lower concentration of CO and CO2.

Keywords: biodiesel, palm oil, transesterification, oscillatory baffled reactor

Procedia PDF Downloads 136
1958 Predictive Semi-Empirical NOx Model for Diesel Engine

Authors: Saurabh Sharma, Yong Sun, Bruce Vernham

Abstract:

Accurate prediction of NOx emission is a continuous challenge in the field of diesel engine-out emission modeling. Performing experiments for each conditions and scenario cost significant amount of money and man hours, therefore model-based development strategy has been implemented in order to solve that issue. NOx formation is highly dependent on the burn gas temperature and the O2 concentration inside the cylinder. The current empirical models are developed by calibrating the parameters representing the engine operating conditions with respect to the measured NOx. This makes the prediction of purely empirical models limited to the region where it has been calibrated. An alternative solution to that is presented in this paper, which focus on the utilization of in-cylinder combustion parameters to form a predictive semi-empirical NOx model. The result of this work is shown by developing a fast and predictive NOx model by using the physical parameters and empirical correlation. The model is developed based on the steady state data collected at entire operating region of the engine and the predictive combustion model, which is developed in Gamma Technology (GT)-Power by using Direct Injected (DI)-Pulse combustion object. In this approach, temperature in both burned and unburnt zone is considered during the combustion period i.e. from Intake Valve Closing (IVC) to Exhaust Valve Opening (EVO). Also, the oxygen concentration consumed in burnt zone and trapped fuel mass is also considered while developing the reported model.  Several statistical methods are used to construct the model, including individual machine learning methods and ensemble machine learning methods. A detailed validation of the model on multiple diesel engines is reported in this work. Substantial numbers of cases are tested for different engine configurations over a large span of speed and load points. Different sweeps of operating conditions such as Exhaust Gas Recirculation (EGR), injection timing and Variable Valve Timing (VVT) are also considered for the validation. Model shows a very good predictability and robustness at both sea level and altitude condition with different ambient conditions. The various advantages such as high accuracy and robustness at different operating conditions, low computational time and lower number of data points requires for the calibration establishes the platform where the model-based approach can be used for the engine calibration and development process. Moreover, the focus of this work is towards establishing a framework for the future model development for other various targets such as soot, Combustion Noise Level (CNL), NO2/NOx ratio etc.

Keywords: diesel engine, machine learning, NOₓ emission, semi-empirical

Procedia PDF Downloads 78
1957 Mistuning in Radial Inflow Turbines

Authors: Valentina Futoryanova, Hugh Hunt

Abstract:

One of the common failure modes of the diesel engine turbochargers is high cycle fatigue of the turbine wheel blades. Mistuning of the blades due to the casting process is believed to contribute to the failure mode. Laser vibrometer is used to characterize mistuning for a population of turbine wheels through the analysis of the blade response to piezo speaker induced noise. The turbine wheel design under investigation is radial and is typically used in 6-12 L diesel engine applications. Amplitudes and resonance frequencies are reviewed and summarized. The study also includes test results for a paddle wheel that represents a perfectly tuned system and acts as a reference. Mass spring model is developed for the paddle wheel and the model suitability is tested against the actual data. Randomization is applied to the stiffness matrix to model the mistuning effect in the turbine wheels. Experimental data is shown to have good agreement with the model.

Keywords: vibration, radial turbines, mistuning, turbine blades, modal analysis, periodic structures, finite element

Procedia PDF Downloads 393
1956 Radial Fuel Injection Computational Fluid Dynamics Model for a Compression Ignition Two-Stroke Opposed Piston Engine

Authors: Tytus Tulwin, Rafal Sochaczewski, Ksenia Siadkowska

Abstract:

Designing a new engine requires a large number of different cases to be considered. Especially different injector parameters and combustion chamber geometries. This is essential when developing an engine with unconventional build – compression ignition, two-stroke operating with direct side injection. Computational Fluid Dynamics modelling allows to test those different conditions and seek for the best conditions with correct combustion. This research presents the combustion results for different injector and combustion chamber cases. The shape of combustion chamber is different than for conventional engines as it requires side injection. This completely changes the optimal shape for the given condition compared to standard automotive heart shaped combustion chamber. Because the injection is not symmetrical there is a strong influence of cylinder swirl and piston motion on the injected fuel stream. The results present the fuel injection phenomena allowing to predict the right injection parameters for a maximum combustion efficiency and minimum piston heat loads. Acknowledgement: This work has been realized in the cooperation with The Construction Office of WSK "PZL-KALISZ" S.A." and is part of Grant Agreement No. POIR.01.02.00-00-0002/15 financed by the Polish National Centre for Research and Development.

Keywords: CFD, combustion, injection, opposed piston

Procedia PDF Downloads 225
1955 Diesel Engine Performance Optimization to Reduce Fuel Consumption and Emissions Issues

Authors: hadi kargar, bahador shabani

Abstract:

In this article, 16 cylinder motor combustion CFD modeling with a diameter of 165 mm and 195 mm along the way to help the FIRE software to optimize its function to work. A three-dimensional model of the processes that formed inside the cylinder made that involves mixing the fuel and air, ignition and spraying. In this three-dimensional model, all chemical species, density of air fuel spraying and spray with full profile intended to detailed results from mixing the fuel and air, igniting the ignition advance, spray, and mixed media in different times and get fit by moving the piston. Optimal selection of the model for the shape of the piston and spraying fuel specifications (including the management of spraying, the number of azhneh hole, start time of spraying and spraying angle) to achieve the best fuel consumption and minimal pollution. The spray hole 6 and 7 in three different configurations with five spraying and gives the best geometry and various performances in the simulation. 6 hole spray angle, finally spraying 72.5 degrees and two forms of spraying a better performance in comparison with other items of their own.

Keywords: spray, FIRE, CFD, optimize, diesel engine

Procedia PDF Downloads 379
1954 Calculation and Comparison of a Turbofan Engine Performance Parameters with Various Definitions

Authors: O. Onal, O. Turan

Abstract:

In this paper, some performance parameters of a selected turbofan engine (JT9D) are analyzed. The engine is a high bypass turbofan engine which powers a wide-body aircraft and it produces 206 kN thrust force (thrust/weight ratio is 5.4). The objective parameters for the engine include calculation of power, specific fuel consumption, specific thrust, engine propulsive, thermal and overall efficiencies according to the various definitions given in the literature. Furthermore, in the case study, wasted energy from the exhaust is calculated at the maximum power setting (i.e. take off phase) for the engine.

Keywords: turbofan, power, efficiency, trust

Procedia PDF Downloads 258
1953 Effect of Injection Pressure and Fuel Injection Timing on Emission and Performance Characteristics of Karanja Biodiesel and its Blends in CI Engine

Authors: Mohan H., C. Elajchet Senni

Abstract:

In the present of high energy consumption in every sphere of life, renewable energy sources are emerging as alternative to conventional fuels for energy security, mitigating green house gas emission and climate change. There has been a world wide interest in searching for alternatives to petroleum derived fuels due to their depletion as well as due to the concern for the environment. Vegetable oils have capability to solve this problem because they are renewable and lead to reduction in environmental pollution. But high smoke emission and lower thermal efficiency are the main problems associated with the use of neat vegetable oils in diesel engines. In the present work, performance, combustion and emission characteristics of CI engine fuelled with 20% by vol. methyl esters mixed with Karanja seed Oil, and Fuel injection pressures of 200 bar and 240 bar, injection timings (21°,23° and 25° BTDC) and Proportion B20 diesel respectively. Vegetable oils have capability to solve this problem because they are renewable and lead to reduction in environmental pollution. But, high smoke emission and lower thermal efficiency are the main problems associated with the use of neat vegetable oils in diesel engines. In the present work, performance, combustion and emission characteristics of CI engine fuelled with 20% by vol. methyl esters mixed with Karanja seed Oil, and Fuel injection pressures of 200 bar and 240 bar ,Injection timings (21°,23° and 25° BTDC) and Proportion B20 diesel respectively. Various performance, combustion and emission characteristics such as thermal efficiency, and brake specific fuel consumption, maximum cylinder pressure, instantaneous heat release, cumulative heat release with respect to crank angle, ignition lag, combustion duration, HC, NOx, CO, exhaust temperature and smoke intensity were measured.

Keywords: karanja oil, injection pressure, injection timing, karanja oil methyl ester

Procedia PDF Downloads 251
1952 Epidemiology, Knowledge, Attitude, and Practices among Patients of Stroke

Authors: Vijay nandmer, Ajay Nandmer

Abstract:

Stigmatized psycho-social perception poses a serious challenge and source of discrimination which impedes stroke patients from attaining a satisfactory quality of life. The present study was aimed to obtain information on knowledge, attitudes and practices (KAP) of stroke patients in the institute. We included 1000 people in our random sampling survey. Demographic details and responses to a questionnaire assessing the knowledge, attitude and practices were recorded. Although the majority of the patients belonged to low socioeconomic strata, the literacy rate was reasonably high (96.3%). A large majority (91.3%) of people had heard about stroke and (85.2%) knew that stroke can be treated with modern drugs. However, a negative attitude was reflected in the belief that stroke happens due to supernatural powers (hawa lagne se) (50.6%). Analysis of the data revealed regional differences in KAP which could be attributed to local Factors, such as literacy, awareness about stroke, and practice of different systems of medicine. Some of the differences can also be attributed to a category of study population whether it included patients or non-stroke individuals since the former are likely to have less negative attitudes than the public. There is a need to create awareness about stroke on a nation-wide basis to dispel the misconceptions and stigma through effective and robust programs with the aim to lessen the disease burden.

Keywords: epidemiology, sroke, literacy, stroke

Procedia PDF Downloads 347
1951 Ipsilateral Weakness Caused by Ipsilateral Stroke: A Case Series

Authors: Naim Izet Kajtazi

Abstract:

Introduction: There are few reported cases of ipsilateral weakness following ischemic or hemorrhagic stroke. In these rare cases, ipsilateral weakness is typically the result of damage to uncrossed components of the corticospinal tract (CST), which were recruited in response to previous CST injury. Patients and Methods: We report a series of six cases of acute ipsilateral weakness or numbness following a hemorrhagic or ischemic stroke from three medical institutions in Saudi Arabia. Results: Three of these patients presented with right-sided weakness caused by an ipsilateral right hemispheric stroke, while two exhibited left-sided symptoms and one had only left-sided numbness. In all six cases, the ipsilateral corona radiata, internal capsule, basal ganglia, insula, and thalamus were involved. No concomitant opposite hemisphere or brainstem lesion in none of the patients was evident. Two patients had previous strokes affecting the brainstem and left corona radiata, respectively. A complete stroke workup to reveal the cause of the stroke was carried out, however, no functional MRI was performed. Conclusion: Ischemic or hemorrhagic stroke may indeed result in ipsilateral weakness or numbness, though in very rare cases. We assume that the most likely mechanism of their ipsilateral weakness subsequent to the ipsilateral stroke was a functional reorganization favoring CST pathways within the ipsilateral hemisphere.

Keywords: stroke, weakness, MRI brain, stroke unit

Procedia PDF Downloads 46
1950 ANSYS Investigation on Stability and Performance of a Solar Driven Inline Alpha Stirling Engine

Authors: Joseph Soliman, Youssef Attia, Khairy Megalla

Abstract:

The stable operation of an inline Stirling engine will be achieved when both engine configurations and operating conditions are optimum. This paper presents stability and performance investigation of an inline Stirling engine using ANSYS. Dynamic motion of engine pistons such as the displacer and the power piston are both obtained. For engine design, the optimum parameters are given such as engine specifications, engine characteristics and working conditions to yield the maximum efficiency and reliability. The prototype was built and tested and it is used as a validation case. The comparison of both experimental and simulation results are provided and discussed. Results were found to be encouraging to initiate a Stirling engine project for 3 kW power output. The working fluids are air, hydrogen, nitrogen and helum.

Keywords: stirling engine, solar energy, new energy, dynamic motion

Procedia PDF Downloads 374
1949 Prevalence of Depression among Post Stroke Survivors in South Asian Region: A Systematic Review and Meta-Analysis

Authors: Roseminu Varghese, Laveena Anitha Barboza, Jyothi Chakrabarty, Ravishankar

Abstract:

Depression among post-stroke survivors is prevalent, but it is unidentified. The purpose of this review was to determine the pooled prevalence of depression among post-stroke survivors in the South Asian region from all published health sciences research articles. The review also aimed to analyze the disparities in the prevalence of depression among the post-stroke survivors from different study locations. Data search to identify the relevant research articles published from 2005 to 2016 was done by using mesh terms and keywords in Web of Science, PubMed Medline, CINAHL, Scopus, J gate, IndMED databases. The final analysis comprised of 9 studies, including a population of 1,520 men and women. Meta-analysis was performed in STATA version 13.0. The overall pooled post-stroke depression prevalence was 0.46, 95% (CI), (0.3- 0.62). The prevalence rate in this systematic review is evident of depression among post-stroke survivors in the South Asian Region. Identifying the prevalence of post-stroke depression at an early stage is important to improve outcomes of the rehabilitative process of stroke survivors and for its early intervention.

Keywords: depression, post stroke survivors, prevalence, systematic review

Procedia PDF Downloads 121
1948 Assessment of the Neuroprotective Effect of Oral Hypoglycemic Agents in Patients with Acute Ischemic Stroke

Authors: A. Alhusban, M. Alqawasmeh, F. Alfawares

Abstract:

Introduction: Diabetes is a chronic health problem and a major risk factor of stroke. A number of therapeutic modalities exist for diabetes management. It’s still unknown whether the different oral hypoglycemic agents would ameliorate the detrimental effect of diabetes on stroke severity. The objective of this work is to assess the effect of pretreatment with oral hypoglycemic agents, insulin and their combination on stroke severity at presentation. Patients and Methods: Patients admitted to the King Abdullah University Hospital (KAUH)-Jordan with ischemic stroke between January 2015 and December 2016 were evaluated and their comorbid diseases, treatment on admission and their neurologic severity was assessed using the National Institute of Health Stroke Scale (NIHSS) were documented. Stroke severity was compared for non-diabetic patients and diabetic patients treated with different antidiabetic agents. Results: Data from 324 patients with acute stroke was documented. The median age of participants was 69 years. Diabetes was documented in about 50% of the patients. Multinomial regression analysis identified diabetes treatment status as an independent predictor of neurological severity of stroke (p=0.032). Patients treated with oral hypoglycemic agents had a significantly lower NIHSS as compared to nondiabetic patients and insulin treated patients (p < 0.02). The positive effect of oral hypoglycemic agents was blunted by insulin co-treatment. Insulin did not alter the severity of stroke as compared to non-diabetics. Conclusion: Oral hypoglycemic agents may reduce the severity of neurologic deficit of ischemic stroke and may have neuroprotective effect.

Keywords: diabetes, stroke, neuroprotection, oral hypoglycemic agents

Procedia PDF Downloads 123
1947 Isolation and Characterization of Bio-surfactant Producing Alcaligenes sp YLA1 and Its Diesel Degradation Potentials

Authors: Abdulrahman Abdulhamid Arabo, Raji Arabi Bamanga, Mujiburrahman Fadilu, Musa Abubakar, Fatima Abdullahi Shehu, Hafeez Muhammad Yakasai, Nasiru Abdullahi

Abstract:

The aim of this study was to isolate and identify biosurfactant-producing and diesel alkanes degrading bacteria. For this reason, bacteria isolated from the diesel-contaminated site were screened for their potential to produce biosurfactants and degrade diesel alkanes. Primary selection of diesel degraders was carried out by using the conventional enrichment culture technique, where 12 bacterial strains were isolated based on their ability to grow on minimal media supplemented with diesel as the sole carbon source, which was followed by qualitative screening methods for potential biosurfactant production. Isolate B11 was the only candidate that showed positive signs for drop collapse, foaming, hemolytic test, oil displacement of more than 22 ± 0.05 mm, and emulsification (E24) of 14 ± 0.30%. The effect of various culture parameters (incubation time, diesel concentration, nitrogen source, pH and temperature) on the biodegradation of diesel was evaluated. The optimum incubation time was confirmed to be 120 days for isolate B11, and the optimum PH was confirmed as 8.0 for the isolate; similarly, the optimum temperature was confirmed as 35oC. In addition, diesel oil was used as the sole carbon source for the isolates. The favorable diesel concentration was 12.5 % (v/v) for the isolate. The isolate has shown degradative ability towards Tridecane (C13), dodecane, 2, 6, 10-trimethyl- (C15), Tetradecane (C14), 2,6,10-Trimethyltridecane (C16), Pentadecane (C15). It degraded between 0.27% - 9.65% of individual diesel oil alkanes. The strain has exhibited the potential of degrading diesel oil n-alkanes and was identified as Alcaligenes species strain B11 (MZ027604) using the 16S rRNA. Sequencing.

Keywords: diesel oil, biosurfactant, Alcaligenes sp, biodegradation

Procedia PDF Downloads 56
1946 More Precise: Patient-Reported Outcomes after Stroke

Authors: Amber Elyse Corrigan, Alexander Smith, Anna Pennington, Ben Carter, Jonathan Hewitt

Abstract:

Background and Purpose: Morbidity secondary to stroke is highly heterogeneous, but it is important to both patients and clinicians in post-stroke management and adjustment to life after stroke. The consideration of post-stroke morbidity clinically and from the patient perspective has been poorly measured. The patient-reported outcome measures (PROs) in morbidity assessment help improve this knowledge gap. The primary aim of this study was to consider the association between PRO outcomes and stroke predictors. Methods: A multicenter prospective cohort study assessed 549 stroke patients at 19 hospital sites across England and Wales during 2019. Following a stroke event, demographic, clinical, and PRO measures were collected. Prevalence of morbidity within PRO measures was calculated with associated 95% confidence intervals. Predictors of domain outcome were calculated using a multilevel generalized linear model. Associated P -values and 95% confidence intervals are reported. Results: Data were collected from 549 participants, 317 men (57.7%) and 232 women (42.3%) with ages ranging from 25 to 97 (mean 72.7). PRO morbidity was high post-stroke; 93.2% of the cohort report post-stroke PRO morbidity. Previous stroke, diabetes, and gender are associated with worse patient-reported outcomes across both the physical and cognitive domains. Conclusions: This large-scale multicenter cohort study illustrates the high proportion of morbidity in PRO measures. Further, we demonstrate key predictors of adverse outcomes (Diabetes, previous stroke, and gender) congruence with clinical predictors. The PRO has been demonstrated to be an informative and useful stroke when considering patient-reported outcomes and has wider implications for considerations of PROs in clinical management. Future longitudinal follow-up with PROs is needed to consider association of long-term morbidity.

Keywords: morbidity, patient-reported outcome, PRO, stroke

Procedia PDF Downloads 94
1945 Implementation of Video Education to Improve Patient’s Knowledge of Activating Emergency Medical System for Stroke Symptoms: Evidence- Based Practice Project on Inpatient Neurology Unit in the United States

Authors: V. Miller, T. Jariel, C. Cooper-Chadwick

Abstract:

Early treatment of stroke leads to higher survival and lower disability rates. Increasing knowledge to activate the emergency medical system for signs of stroke can improve outcomes for patients with stroke and decrease morbidity and mortality. Even though patients who get discharged from the hospital receive standard verbal and printed education, nearly 20% of them answer the question incorrectly when asked, “What will you do if you or someone you know have signs of stroke?” The main goal of this evidence-based project was to improve patients’ knowledge of what to do if they have signs of stroke. Evidence suggests that using video education in conjunction with verbal and printed education improves patient comprehension and retention. The percentage of patients who noted that they needed to call 911 for stroke symptoms increased from 80% to 87% in six months after project implementation. The results of this project demonstrate significant improvement in patients’ knowledge about the necessity of activation of emergency medical systems for stroke symptoms.

Keywords: emergency medical systems activation, evidence-based practice nursing, stroke education, video education

Procedia PDF Downloads 34
1944 Research on Straightening Process Model Based on Iteration and Self-Learning

Authors: Hong Lu, Xiong Xiao

Abstract:

Shaft parts are widely used in machinery industry, however, bending deformation often occurred when this kind of parts is being heat treated. This parts needs to be straightened to meet the requirement of straightness. As for the pressure straightening process, a good straightening stroke algorithm is related to the precision and efficiency of straightening process. In this paper, the relationship between straightening load and deflection during the straightening process is analyzed, and the mathematical model of the straightening process has been established. By the mathematical model, the iterative method is used to solve the straightening stroke. Compared to the traditional straightening stroke algorithm, straightening stroke calculated by this method is much more precise; because it can adapt to the change of material performance parameters. Considering that the straightening method is widely used in the mass production of the shaft parts, knowledge base is used to store the data of the straightening process, and a straightening stroke algorithm based on empirical data is set up. In this paper, the straightening process control model which combine the straightening stroke method based on iteration and straightening stroke algorithm based on empirical data has been set up. Finally, an experiment has been designed to verify the straightening process control model.

Keywords: straightness, straightening stroke, deflection, shaft parts

Procedia PDF Downloads 287
1943 A Hybrid Combustion Chamber Design for Diesel Engines

Authors: R. Gopakumar, G. Nagarajan

Abstract:

Both DI and IDI systems possess inherent advantages as well as disadvantages. The objective of the present work is to obtain maximum advantages of both systems by implementing a hybrid design. A hybrid combustion chamber design consists of two combustion chambers viz., the main combustion chamber and an auxiliary combustion chamber. A fuel injector supplies major quantity of fuel to the auxiliary chamber. Due to the increased swirl motion in auxiliary chamber, mixing becomes more efficient which contributes to reduction in soot/particulate emissions. Also, by increasing the fuel injection pressure, NOx emissions can be reduced. The main objective of the hybrid combustion chamber design is to merge the positive features of both DI and IDI combustion chamber designs, which provides increased swirl motion and improved thermal efficiency. Due to the efficient utilization of fuel, low specific fuel consumption can be ensured. This system also aids in increasing the power output for same compression ratio and injection timing as compared with the conventional combustion chamber designs. The present system also reduces heat transfer and fluid dynamic losses which are encountered in IDI diesel engines. Since the losses are reduced, overall efficiency of the engine increases. It also minimizes the combustion noise and NOx emissions in conventional DI diesel engines.

Keywords: DI, IDI, hybrid combustion, diesel engines

Procedia PDF Downloads 479
1942 The Optimum Biodiesel Blend in Low Sulfur Diesel and Its Physico-Chemical Properties and Economic Aspect

Authors: Ketsada Sutthiumporn, Sittichot Thongkaw, Malee Santikunaporn

Abstract:

In Thailand, biodiesel has been utilized as an attractive substitute of petroleum diesel and the government imposes a mandatory biodiesel blending requirement in transport sector to improve energy security, support agricultural sector and reduce emissions. Though biodiesel blend has many advantages over diesel fuel such as improved lubricity, low sulfur content and higher flash point, there are still some technical problems such as oxidative stability, poor cold- flow properties and impurity. Such problems were related to the fatty acid composition in feedstock. Moreover, Thailand has announced the use of low sulfur diesel as a base diesel and will be continually upgrading to EURO 5 in 2023. With ultra low sulfur content, it may affect the diesel fuel properties especially lubricity as well. Therefore, in this study, the physical and chemical properties of palm oil-based biodiesel in low sulfur diesel blends from different producers will be investigated by standard methods per ASTM and EN. Also, its economic benefits based on diesel price structure in Thailand will be highlighted. The appropriate biodiesel blend ratio can affect the physico-chemical properties and reasonable price in the country. Properties of biodiesel, including specific gravity, kinematic viscosity, FAME composition, flash point, sulfur, water, oxidation stability and lubricity were measured by standard methods of ASTM and EN. The results show that the FAME composition of biodiesel has the fatty acid of C12:0 to C20:1, mostly in C16:0, C18:0, C18:1, and C18:2, which were main characteristic compositions of palm biodiesel. The physical and chemical properties of biodiesel blended diesel was found to be increases with an increasing amount of biodiesel such as specific gravity, flash point and kinematic viscosity while sulfur value was decreased. Moreover, in this study, the various properties of each biodiesel blends were plotted to determine the appropriate proportional range of biodiesel-blended diesel with an optimum fuel price.It can be seen that the amount of B100 can be filled from 1% up to 7% in which the quality was in accordance with Notification of the department of Energy business.The understanding of relation between physico-chemical properties of palm oil-based biodiesel and pricing is beneficial to guide the better development of desired feedstock in Thailand and to implement biodiesel blends with comparative price and diesel engine performance.

Keywords: fatty acid methyl ester, biodiesel, fuel price structure, palm oil in Thailand

Procedia PDF Downloads 71
1941 Incidence of Post-Stroke Depression in a Tertiary Hospital in Cebu City, Philippines

Authors: Ivory A. Rulona, Jarungchai Anton S. Vatanagul

Abstract:

Background: Depression is common after stroke with quoted rates ranging from 18% to 61%. 8 Mood disturbance is common after stroke and may present as depression or anxiety. Psychological mood disturbance is associated with higher rates of mortality, long term disability, and hospital readmission. Objectives: To investigate the incidence of post-stroke depression in a tertiary hospital in Cebu City, Philippines and to determine its associated factors. The study is designed to be prospective, descriptive, cross-sectional survey. Participants: Adult patients seen and diagnosed to have stroke either infarct or hemorrhage within the period of January 1 to July 31, 2014. Results: A total of 100 patients with stroke were interviewed using the 17-item Hamilton Depression Rating Scale (HDRS) questionnaire. The average age of the respondents was 60.50 years old ±1.18, majority were males (55%), 83% were married, and 81% were employed. The most common co-morbidity was hypertension 78% followed by diabetes mellitus at 50%. Moreover, 39% of these patients had stroke in months, 26% in years, and 18% in weeks. The average functional capacity based on Modified Rankin Scale was 2.14+/-0.14. Among 100 patients, a total of 30 patients (30%) had depression: 2 (2%) very severe, 5 (5%) moderate and 23 (23%) had mild depression while 70 patients (70%) had no depression. Stroke located at the dominant hemisphere was not associated with severe depression (p=0.102). A similar trend was also noted among those with stroke at the right side (p=0.183), pons (p=0.634), bilateral (p=0.776), and midbrain (p=0.336). Conclusion: This study showed that majority of stroke patients were males with average age of 60.50 years. Hypertension was the most common co-morbidity. There was no association between stroke location and depression. The incidence of PSD was 30%.

Keywords: post-stroke depression, co-morbidity, disturbance, bilateral

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1940 Biomarkers in a Post-Stroke Population: Allied to Health Care in Brazil

Authors: Michael Ricardo Lang, AdriéLle Costa, Ivana Iesbik, Karine Haag, Leonardo Trindade Buffara, Oscar Reimann Junior, Chelin Auswaldt Steclan

Abstract:

Stroke affects not only the individual, but has significant impacts on the social and family context. Therefore, it is necessary to know the peculiarities of each region, in order to contribute to regional public health policies effectively. Thus, the present study discusses biomarkers in a post-stroke population, admitted to a stroke unit (U-stroke) of reference in the southern region of Brazil. Biomarkers were analyzed, such as age, length of stay, mortality rate, survival time, risk factors and family history of stroke in patients after ischemic stroke. In this studied population, comparing men and women, it was identified that men were more affected than women, and the average age of women affected was higher, as they also had the highest mortality rate and the shortest hospital stay. The risk factors identified here were according to the global scenario; with SAH being the most frequent and those associated with sedentary lifestyle in women the most frequent (dyspilipidemia, heart disease and obesity). In view of this, the importance of studies that characterize populations regionally is evident, strengthening the strategic planning of policies in favor of health care.

Keywords: biomarkers, sex, stroke, stroke unit, population

Procedia PDF Downloads 221
1939 Design Manufacture and Testing of a Combined Alpha-Beta Double Piston Stirling Engine

Authors: A. Calvin Antony, Sakthi Kumar Arul Prakash, V. R. Sanal Kumar

Abstract:

In this paper a unique alpha-beta double piston 'stirling engine' is designed, manufactured and conducted laboratory test to ameliorate the efficiency of the stirling engine. The paper focuses on alpha and beta type engines, capturing their benefits and eradicating their short comings; along with the output observed from the flywheel. In this model alpha engine is kinematically with a piston cylinder arrangement which works quite like a beta engine. The piston of the new cylinder is so designed that it replicates a glued displacer and power piston as similar to that of beta engine. The bigger part of the piston is the power piston, which has a gap around it, while the smaller part of the piston is tightly fit in the cylinder and acts like the displacer piston. We observed that the alpha-beta double piston stirling engine produces 25% increase in power compare to a conventional alpha stirling engine. This working model is a pointer towards for the design and development of an alpha-beta double piston Stirling engine for industrial applications for producing electricity from the heat producing exhaust gases.

Keywords: alpha-beta double piston stirling engine , alpha stirling engine , beta double piston stirling engine , electricity from stirling engine

Procedia PDF Downloads 500
1938 Lubrication Performance of Multi-Level Gear Oil in a Gasoline Engine

Authors: Feng-Tsai Weng, Dong- Syuan Cai, Tsochu-Lin

Abstract:

A vehicle gasoline engine converts gasoline into power so that the car can move, and lubricants are important for engines and also gear boxes. Manufacturers have produced numbers of engine oils, and gear oils for engines and gear boxes to SAE International Standards. Some products not only can improve the lubrication of both the engine and gear box but also can raise power of vehicle this can be easily seen in the advertisement declared by the manufacturers. To observe the lubrication performance, a multi-leveled (heavy duty) gear oil was added to a gasoline engine as the oil in the vehicle. The oil was checked at about every 10,000 kilometers. The engine was detailed disassembled, cleaned, and parts were measured. The wear of components of the engine parts were checked and recorded finally. Based on the experiment results, some gear oil seems possible to be used as engine oil in particular vehicles. Vehicle owners should change oil periodically in about every 6,000 miles (or 10,000 kilometers). Used car owners may change engine oil in even longer distance.

Keywords: multi-level gear oil, engine oil, viscosity, abrasion

Procedia PDF Downloads 286
1937 Numerical Approach to Boost an Internal Combustion Engine

Authors: Mohamed Amine El Hameur, Lyes Tarabet, Mahfoudh Cerdoun, Boubkr Zebiri, Giovanni Ferrara

Abstract:

Due to the drastic environmental and energy regulations regarding the reduction of exhaust emissions and fuel consumption, added to the increasing demand for powerful performance, several automotive manufacturers are constantly obliged to redesign their existing products and/or develop novel powertrain techniques to respond to the aforementioned restrictions. In this aspect, an implemented approach is proposed in the present work to boost a 1.5 L, three-cylinder Diesel engine with a new turbocharger, based on 1D preliminary design codes, 3D design, and numerical assessment of a suitable radial turbine followed by an accurate selection procedure of an adequate centrifugal compressor. Furthermore, to investigate the effect of the turbine’s rotor position on the simulation convergence, stability, and calculation time; two combinations (rotor blade- volute) have been assessed. Consequently, significant results are obtained when comparing the original turbocharged engine and the new one at the engine’s full load and rated speed (@4500rpm) conditions. A maximum improvement in terms of brake-specific fuel consumption, thermal efficiency, total-to-static turbine efficiency, and total-to-total compressor efficiency equal 6.5% (corresponding to a decrease of 2.3 litre/hr in fuel consumption), 7%, 10.9%, and 19.9%, respectively.

Keywords: CFD investigation, engine boosting, turbine design, turbocharger, rotor blade positioning

Procedia PDF Downloads 69
1936 A Novel Combustion Engine, Design and Modeling

Authors: M. A. Effati, M. R. Hojjati, M. Razmdideh

Abstract:

Nowadays, engine developments have focused on internal combustion engine design call for increased engine power, reduced engine size and improved fuel economy, simultaneously. In this paper, a novel design for combustion engine is proposed. Two combustion chambers were designed in two sides of cylinder. Piston was designed in a way that two sides of piston would transfer heat energy due to combustion to linear motion. This motion would convert to rotary motion through the designed mechanism connected to connecting rod. Connecting rod operation was analyzed to evaluate applied stress in 3000, 4500 and 6000 rpm. Boundary conditions including generated pressure in each side of cylinder in these 3 situations was calculated.

Keywords: combustion engine, design, finite element method, modeling

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1935 Effect of Variation of Injection Timing on Performance and Emission Characteristics of Compression Ignition Engine: A CFD Approach

Authors: N. Balamurugan, N. V. Mahalakshmi

Abstract:

Compression ignition (CI) engines are known for their high thermal efficiency in comparison with spark-ignited (SI) engines. This makes CI engines a potential candidate for the future prime source of power for transportation sector to reduce greenhouse gas emissions and to shrink carbon footprint. However, CI engines produce high levels of NOx and soot emissions. Conventional methods to reduce NOx and soot emissions often result in the infamous NOx-soot trade-off. The injection parameters are one of the most important factors in the working of CI engines. The engine performance, power output, economy etc., is greatly dependent on the effectiveness of the injection parameters. The injection parameter has their direct impact on combustion process and pollutant formation. The injection parameter’s values are required to be optimised according to the application of the engine. Control of fuel injection mode is one method for reduction of NOx and soot emissions that is achievable. This study aims to assess, compare and analyse the influence of the effect of injection characteristics that is SOI timing studied on combustion and emissions in in-cylinder combustion processes with that of conventional DI Diesel Engine system using the commercial Computational Fluid Dynamic (CFD) package STAR- CD ES-ICE.

Keywords: variation of injection timing, compression ignition engine, spark-ignited, Computational Fluid Dynamic

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1934 Investigation of the Flow Characteristics in a Catalytic Muffler with Perforated Inlet Cone

Authors: Gyo Woo Lee, Man Young Kim

Abstract:

Emission regulations for diesel engines are being strengthened and it is impossible to meet the standards without exhaust after-treatment systems. Lack of the space in many diesel vehicles, however, make it difficult to design and install stand-alone catalytic converters such as DOC, DPF, and SCR in the vehicle exhaust systems. Accordingly, those have been installed inside the muffler to save the space, and referred to the catalytic muffler. However, that has complex internal structure with perforated plate and pipe for noise and monolithic catalyst for emission reduction. For this reason, flow uniformity and pressure drop, which affect efficiency of catalyst and engine performance, respectively, should be examined when the catalytic muffler is designed. In this work, therefore, the flow uniformity and pressure drop to improve the performance of the catalytic converter and the engine have been numerically investigated by changing various design parameters such as inlet shape, porosity, and outlet shape of the muffler using the three-dimensional turbulent flow of the incompressible, non-reacting, and steady state inside the catalytic muffler. Finally, it can be found that the shape, in which the muffler has perforated pipe inside the inlet part, has higher uniformity index and lower pressure drop than others considered in this work.

Keywords: catalytic muffler, perforated inlet cone, catalysts, perforated pipe, flow uniformity, pressure drop

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1933 Fuel Quality of Biodiesel from Chlorella protothecoides Microalgae Species

Authors: Mukesh Kumar, Mahendra Pal Sharma

Abstract:

Depleting fossil fuel resources coupled with serious environmental degradation has led to the search for alternative resources for biodiesel production as a substitute of Petro-diesel. Currently, edible, non-edible oils and microalgal plant species are cultivated for biodiesel production. Looking at the demerits of edible and non-edible oil resources, the focus is being given to grow microalgal species having high oil productivities, less maturity time and less land requirement. Out of various microalgal species, Chlorella protothecoides is considered as the most promising species for biodiesel production owing to high oil content (58 %), faster growth rate (24–48 h) and high biomass productivity (1214 mg/l/day). The present paper reports the results of optimization of reaction parameters of transesterification process as well as the kinetics of transesterification with 97% yield of biodiesel. The measurement of fuel quality of microalgal biodiesel shows that the biodiesel exhibit very good oxidation stability (O.S) of 7 hrs, more than ASTM D6751 (3 hrs) and EN 14112 (6 hrs) specifications. The CP and PP of 0 and -3 °C are finding as per ASTM D 2500-11 and ASTM D 97-12 standards. These results show that the microalgal biodiesel does not need any enhancement in O.S & CFP and hence can be recommended to be directly used as MB100 or its blends into diesel engine operation. Further, scope is available for the production of binary blends using poor quality biodiesel for engine operation.

Keywords: fuel quality, methyl ester yield, microalgae, transesterification

Procedia PDF Downloads 183
1932 Assessment of the Association between Serum Thrombospondin-1 Levels at the Time of Admission and the Severity of Neurological Deficit in Patients with Ischemic Stroke

Authors: A. Alhusban, M. Alqawasmeh, F. Alfawares

Abstract:

Introduction: Despite improvements in stroke management, it remains the leading cause of disability worldwide. It has been suggested that enhancing brain angiogenesis after stroke will improve stroke outcome. Promoting post stroke angiogenesis requires the upregulation of angiogenic factors with a simultaneous reduction of anti-angiogenic factors. Thrombospondin-1 is the main anti-angiogenic protein in the living cells. Counterintuitively, it has been shown that animals with Thrombospondin-1 knockdown will have better stroke outcome. Data about the clinical significance of Thrombspondin-1 levels at the time of admission is still lacking. The objective of this work is to assess the association between serum Thrombospondin-1 levels measured at the time of admission and baseline neurologic severity after stroke. Patients and Methods: Blood samples were collected from patients admitted to the King Abdullah University Hospital (KAUH) with ischemic stroke at the time of admission and serum Thrombopsondin-1 levels were measured using ELISA. Patients neurologic severity was evaluated using the National Institute of Health Stroke Scale (NIHSS). Results: Samples from 50 patients admitted between January 2016 and December 2016 were collected. The median age of participants was 68 years and the median NIHSS was 3. Multinomial regression identified serum Thrombospondin-1 as an independent predictor of stroke outcome (p=0.003). Baseline serum Thrombsopondin-1 was negatively associated with NIHSS at the time of admission (spearman rho correlation coefficient=0.272, p=0.032). Conclusion: Serum Thrombospondin-1 at the time of admission may be a useful marker of stroke severity that predicts more severe neurologic severity.

Keywords: thrombospondin, stroke, neuroprotection, biomarkers

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1931 The Risk of Post-stroke Pneumonia and Its One-Year Disability in Taiwan

Authors: Hui-Chi Huang, Su-Ju Yang, Ching-Wei Lin, Jui-Yao Tsai, Liang-Yiang

Abstract:

Background: Evidence exists that pneumonia is a frequently encountered complication after stroke which is associated with a higher rate of mortality and increased long-term disability Purpose: To determine the predictors associated with the risk of one-year disability in acute stroke. Methods: Data for this longitudinal follow-up study were extracted from a tertiary referral medical center’s stroke registry database in Northern Taipei. Eligible patients with acute stroke admitted to the hospital and completed a one-year follow up were recruited for analysis. Favorable outcome was defined as a modified Rankin Scale score ≤ 2. SAS version 9.2 was used for the multivariable regression analyses to examine the factors correlated with the one-year disability in stroke patients. Results: From January 2012 to December 2013, a total of 1373 (mean age: 70.49±15.4 years, 913(66.5%) males) consecutively administered acute stroke patients were recruited. Overall, the rate of one-year disability was 37.20%(404/1086) in those without post-stroke pneumonia. It increased to 82.93 %(238/287) in patients developed post-stroke pneumonia. Factors associated with increased risk of disability were age ≧ 75(OR= 4.845, p<.0001), female /gender (OR=1.568, p =.0062), previous stroke (OR= 1.868, p = <. 0001) ,dementia (OR= 2.872, p =.0047), ventilator use (OR= 4.653, p <. 0001),age ≧ 75 /pneumonia (OR=1.236, p <. 0001) , ICU admission (OR=3.314, p <.0001) , nasogastric tube insertion (OR= 4.28, p <.0001), speech therapy (OR= 1.79, p =.0142), urinary tract infection (OR= 1.865, p =.0018), estimated glomerular filtration rate (eGFR > 60 )(OR= 0.525, p= .0029), Admission NIHSS >11 (OR= 2.101, p = .0099), Length of hospitalization > 30(d) (OR= 5.182, p <.0001). Conclusion: Older age, severe neurological deficit, complications, rehabilitation intervention, length of hospitalization >30(d), and cognitive impairment were significantly associated with Post-stroke functional impairment, especially those with post-stroke pneumonia. These findings could open new avenues in the management of stroke patients.

Keywords: stroke, risk, pneumonia, disability

Procedia PDF Downloads 199