scholarly journals Fuel-Lubricant Interactions: Critical Review of Recent Work

2021 ◽  
Author(s):  
Robert Ian Taylor
Keyword(s):  
Recent Work ◽  
Diesel Engines ◽  
Critical Review ◽  
Liquid Fuels ◽  
Gasoline Engines ◽  
Particulate Filters ◽  
Engine Design ◽  
Fuel Dilution ◽  
Active Regeneration ◽  
Near Future

A critical review of recent work on fuel lubricant interactions is undertaken. The work focusses on liquid fuels used in diesel and gasoline vehicles. The amount of fuel that contaminates the lubricant depends on driving conditions, engine design, fuel type and lubricant type. When fuel contaminates a lubricant, the viscosity of the lubricant will change (it will usually decrease), the sump oil level may increase, there may be a tendency for more sludge formation, there may be an impact on friction and wear, and low speed pre-ignition could occur. The increased use of biofuels (particularly biodiesel) may require a reduction in oil drain intervals, and fuel borne additives could contaminate the lubricant. The move to active regeneration of particulate filters by delayed fuel post-injection and the move to hybrid electric vehicles, and vehicles equipped with stop-start systems will lead to increased fuel dilution. This will be of more concern in diesel engines, since significant fuel dilution could still persist at sump oil temperatures in the range 100-150C (whereas in gasoline engines the more volatile gasoline fuel will have substantially evaporated at these temperatures). It is anticipated that more research into fuel lubricant interactions, particularly for diesel engines, will be needed in the near future.

scholarly journals Fuel-Lubricant Interactions: Critical Review of Recent Work

Lubricants ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 92
Author(s):  
Robert Ian Taylor
Keyword(s):  
Recent Work ◽  
Diesel Engines ◽  
Critical Review ◽  
Liquid Fuels ◽  
Gasoline Engines ◽  
Particulate Filters ◽  
Engine Design ◽  
Fuel Dilution ◽  
Active Regeneration ◽  
Near Future

A critical review of recent work on fuel lubricant interactions is undertaken. The work focusses on liquid fuels used in diesel and gasoline vehicles. The amount of fuel that contaminates the lubricant depends on driving conditions, engine design, fuel type, and lubricant type. When fuel contaminates a lubricant, the viscosity of the lubricant will change (it will usually decrease), the sump oil level may increase, there may be a tendency for more sludge formation, there may be an impact on friction and wear, and low speed pre-ignition could occur. The increased use of biofuels (particularly biodiesel) may require a reduction in oil drain intervals, and fuel borne additives could contaminate the lubricant. The move towards the active regeneration of particulate filters by delayed fuel post-injection and the move towards hybrid electric vehicles and vehicles equipped with stop-start systems will lead to increased fuel dilution. This will be of more concern in diesel engines, since significant fuel dilution could persist at sump oil temperatures in the range of 100–150 °C (whereas in gasoline engines the more volatile gasoline fuel will have substantially evaporated at these temperatures). It is anticipated that more research into fuel lubricant interactions, particularly for diesel engines, will be needed in the near future.

scholarly journals Peer Assessment in Writing: A Critical Review of Previous Studies

2019 ◽  
Vol 10 ◽  
pp. 1478-1487
Author(s):  
Sonia Dutta Gupta ◽  
Fatimah Abdullah ◽  
Gu Li ◽  
Yang Xueshuang
Keyword(s):  
Foreign Language ◽  
Critical Review ◽  
English Language ◽  
Assessment Tool ◽  
Peer Assessment ◽  
Student Centered ◽  
Efl Context ◽  
Effective Assessment ◽  
Near Future

Peer assessment has attracted more attention an effective assessment tool in recent years. Peer assessment refers to the arrangement for peers to consider the quality of learning outcomes of others of similar status, it received attention of various studies due to the growing interest in the student centered approach as learners need to be involved in the learning process even in the assessment. This paper is a critical review of previous studies on peer assessment in English as Second/Foreign Language (ESL/EFL) context. Fifteen peer assessment studies from 2004 to 2017 were extensively reviewed and systematically analyzed. Peer assessment of  the reviewed studies were on the quality of the writing outcomes of students in the EFL/ESL contexts, as writing skill occupies an important role in teaching English language.  As a critical review paper of these studies, this paper highlights practical use of peer assessment and the important challenges or issues that need to be considered when utilizing peer assessment in the classroom. This paper hopes that practical measures of peer assessment will be utilized effectively by educators in the ESL and EFL classrooms in the near future.

Critical Review. Jaundice: A Review of Recent Work

QJM ◽  
1923 ◽  
Vol os-16 (64) ◽  
pp. 390-420 ◽  
Author(s):  
J. W. McNee
Keyword(s):  
Recent Work ◽  
Critical Review

scholarly journals Design and Optimization of an Integrated Turbo-Generator and Thermoelectric Generator for Vehicle Exhaust Electrical Energy Recovery

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3134 ◽  
Author(s):  
Prasert Nonthakarn ◽  
Mongkol Ekpanyapong ◽  
Udomkiat Nontakaew ◽  
Erik Bohez
Keyword(s):  
Diesel Engines ◽  
High Performance ◽  
Thermoelectric Generator ◽  
Waste Heat ◽  
Electrical Energy ◽  
Vehicle Exhaust ◽  
Gasoline Engines ◽  
Design And Optimization ◽  
Charging Station ◽  
Turbo Generator

The performance of turbo-generators significantly depends on the design of the power turbine. In addition, the thermoelectric generator can convert waste heat into another source of energy. This research aims to design and optimize an integrated turbo-generator and thermoelectric generator for diesel engines. The goal is to generate electricity from the vehicle exhaust gas. Electrical energy is derived from generators using the flow, pressure, and temperature of exhaust gases from combustion engines and heat-waste. In the case of turbo-generators and thermoelectric generators, the system automatically adjusts the power provided by an inverter. Typically, vehicle exhausts are discarded to the environment. Hence, the proposed conversion to electrical energy will reduce the alternator charging system. This work focuses on design optimization of a turbo-generator and thermoelectric generator for 2500 cc. diesel engines, due to their widespread usage. The concept, however, can also be applied to gasoline engines. Moreover, this model is designed for a hybrid vehicle. Charging during running will save time at the charging station. The optimization by variable van angles of 40°, 50°, 62°, 70°, and 80° shows that the best output power is 62°, which is identical to that calculated. The maximum power outputted from the designed prototype was 1262 watts when operating with an exhaust mass flow rate of 0.1024 kg/s at 3400 rpm (high performance of the engine). This research aims to reduce fuel consumption and reduce pollution from the exhaust, especially for hybrid vehicles.

Experimental study of lubricant-derived ash effects on diesel particulate filter performance

2019 ◽  
pp. 146808741987457 ◽  
Author(s):  
Jun Zhang ◽  
Yanfei Li ◽  
Victor W Wong ◽  
Shijin Shuai ◽  
Jinzhu Qi ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Diesel Particulate Filter ◽  
Particulate Filter ◽  
Maximum Temperature ◽  
Particle Emissions ◽  
Diesel Particulate ◽  
Particulate Filters ◽  
Filter Performance ◽  
Soot Loading ◽  
Active Regeneration

Diesel particulate filters are indispensable for diesel engines to meet the increasingly stringent emission regulations. A large amount of ash would accumulate in the diesel particulate filter over time, which would significantly affect the diesel particulate filter performance. In this work, the lubricant-derived ash effects on diesel particulate filter pressure drop, diesel particulate filter filtration performance, diesel particulate filter temperature field during active regeneration, and diesel particulate filter downstream emissions during active regeneration were studied on an engine test bench. The test results show that the ash accumulated in the diesel particulate filter would decrease the diesel particulate filter pressure drop due to the “membrane effect” when the diesel particulate filter ash loading is lower than about 10 g/L, beyond which the diesel particulate filter pressure drop would be increased due to the reduction of diesel particulate filter effective volume. The ash loaded in the diesel particulate filter could significantly improve the diesel particulate filter filtration efficiency because it would fill the pores of diesel particulate filter wall. The diesel particulate filter peak temperature during active regeneration is consistent with the diesel particulate filter initial actual soot loading density prior to regeneration at various diesel particulate filter ash loading levels, while the diesel particulate filter maximum temperature gradient would increase with the diesel particulate filter ash loading increase, whether the diesel particulate filter is regenerated at the same soot loading level or the same diesel particulate filter pressure drop level. The ash accumulation in the diesel particulate filter shows little effects on diesel particulate filter downstream CO, total hydrocarbons, N2O emissions, and NO2/NO x ratio during active regeneration. However, a small amount of SO2 emissions was observed when the diesel particulate filter ash loading is higher than 10 g/L. The ash accumulated in the diesel particulate filter would increase the diesel particulate filter downstream sub-23 nm particle emissions but decrease larger particle emissions during active regeneration.

Neurobiology of parasitic platyhelminths: possible solutions to the problems of correlating structure with function

Parasitology ◽  
1991 ◽  
Vol 102 (S1) ◽  
pp. S31-S39 ◽  
Author(s):  
R. A. Pax ◽  
J. L. Bennett
Keyword(s):  
Nervous System ◽  
Patch Clamp ◽  
Recent Work ◽  
Small Molecule ◽  
Critical Review ◽  
Patch Clamp Recording ◽  
Quantitative Fluorescence ◽  
Recording Techniques

This paper provides an overview of research on the nervous system of parasitic platyhelminths. We have emphasized studies concerned with the physiological, pharmacological and biochemical nature of the major small molecule neurotransmitters of these parasites. We have attempted to provide a critical review of the work by focusing on important unresolved issues. Finally, we have focused on some recent work in our laboratory, using patch-clamp recording techniques and quantitative fluorescence cytometry, as an example of newer methods that will hopefully resolve some of the unanswered questions concerning the nervous system of these parasites.

Use of Ethanol Based Oxygenates for Smoke Reduction in C.I. Engines

2005 ◽  
Author(s):  
Dhananjay B. Zodpe ◽  
Nishikant V. Deshpande
Keyword(s):  
Experimental Investigation ◽  
Fuel Economy ◽  
Diesel Engines ◽  
Thermal Efficiency ◽  
Substantial Reduction ◽  
Brake Thermal Efficiency ◽  
Gasoline Engines ◽  
Brake Power ◽  
Smoke Density ◽  
Harmful Effects

Diesel Engines have better fuel economy compared to gasoline engines. Society is now aware of various harmful effects of pollution and various researchers are trying to use fuel reformulation method to meet the forthcoming stringent air pollution norms for the diesel engines. This paper presents an experimental investigation on use of three different low price ethanol based oxygenate-diesel blends (oxygenate 4, 8 and 12% in blend) as an oxygen enriched fuel in diesel engine and its effect on brake thermal efficiency, smoke density and emissions of CO, HC, NOx etc is studied. It was observed that there is substantial reduction in the smoke density of exhaust gases and the observed reduction was found proportional to the mass of oxygen present in the blend. Marginal increase in NOx and brake thermal efficiency was observed and there was no significant change in the brake power of the engine.

scholarly journals The Gasoline Diesel

2012 ◽  
Vol 134 (09) ◽  
pp. 38-41 ◽  
Author(s):  
Steve Ciatti
Keyword(s):  
Fuel Economy ◽  
Diesel Engines ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Spark Ignition ◽  
Reliable Operation ◽  
Excellent Performance ◽  
Research Teams ◽  
Gasoline Engines ◽  
Engine Efficiency

This article evaluates engine efficiency as a step towards improving fuel economy and emissions performance. Diesel engines tend to be very efficient; however, they have an emissions problem. They require complex and expensive equipment to meet pollution mandates. Spark ignition gasoline engines, on the other hand, do a much better job with emissions, but they are inherently less efficient. Thus, the research team at Argonne National Laboratory has decided to look for ways to combine the best characteristics of both. This new system is more like traditional diesel combustion than spark ignition, but uses a gasoline-like fuel and an innovative approach to combustion to minimize emissions. Diesel engines tend to run lean, meaning there is more oxygen in the mix than fuel, which reduces in-cylinder average temperatures. Research shows that gasoline spark engines have fatal efficiency flaws but comply easily and relatively inexpensively with emission requirements. Diesels are more efficient, but carry a heavy penalty for emission compliance. Different research teams’ challenge is to ensure robust, reliable operation during transient operation. The new system’s torque profile is essentially the same as that of a conventional diesel, and it provides excellent performance in the powerband where most people drive.

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