Developments in Two-Stroke Cycle Engine Exhaust Emissions

1992 ◽  
Vol 206 (2) ◽  
pp. 93-106 ◽  
Author(s):  
R G Kenny
Keyword(s):  
High Performance ◽  
Fuel Injection ◽  
Low Cost ◽  
Exhaust Emissions ◽  
Spark Ignition Engines ◽  
Engine Exhaust ◽  
Wide Range ◽  
Direct Fuel Injection ◽  
Stroke Engine ◽  
Stroke Cycle

This paper is concerned with the exhaust emissions from two-stroke cycle spark ignition engines and the means being investigated to reduce them. The simple two-stroke engine has inherently low levels of NOx emissions and high levels of hydrocarbon emissions. The reasons for these emissions characteristics are explained by reference to the open literature. The two-stroke engine is used in a wide range of applications including low-cost, low-output mopeds and high-performance motorcycles. More recently there has been a resurgence of interest in the two-stroke as an alternative to the four-stroke engine for automotive use. A number of the recently reported approaches to emissions control are reviewed, including the use of exhaust oxidation catalysts in simple low-cost engines and direct fuel injection on more costly, multi-cylinder engines.

scholarly journals Development of a Two-Stroke Cycle Engine for Use in the Agricultural Aviation Sector

2020 ◽  
pp. 52-61
Author(s):  
Samara Herrmann ◽  
Macklini Dalla Nora ◽  
Thompson Diordinis Metzka Lanzanova
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Low Cost ◽  
Short Circuit ◽  
Fuel Mixture ◽  
Large Power ◽  
Valve Overlap ◽  
Direct Fuel Injection ◽  
Stroke Engine ◽  
Stroke Cycle

Reciprocating internal combustion engines have wide application in agricultural, recreational and experimental aircraft, resulting from their low cost and less complex maintenance compared to other engines. Thus, this work analyzed the performance of a conventional four-stroke engine operating in the two-stroke cycle by means of direct fuel injection and mechanical air supercharging. The use of a supercharger was essential in this design to provide adequate gas exchange inside the cylinder during the long valve overlap required, while direct fuel injection made it possible to reduce the short circuit of air-fuel mixture to the exhaust. Due to the double ignition frequency compared to a four-stroke engine, it was possible to obtain a large power density (40 kW/L) at a speed of 2400 rpm, also a specific fuel consumption of 270 g/kWh with gasoline and 400 g/kWh with ethanol. The use of ethanol in replacement of gasoline made it possible to operate at full load (160 Nm/L) at 800 rpm without the occurrence of knocking combustion.

scholarly journals Applicability of Cork as Novel Modifiers to Develop Electrochemical Sensor for Caffeine Determination

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
Mayra K. S. Monteiro ◽  
Djalma R. Da Silva ◽  
Marco A. Quiroz ◽  
Vítor J. P. Vilar ◽  
Carlos A. Martínez-Huitle ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Linear Response ◽  
High Performance ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Caffeine Concentration ◽  
Real Samples ◽  
Wide Range ◽  
Potential Use

This study aims to investigate the applicability of a hybrid electrochemical sensor composed of cork and graphite (Gr) for detecting caffeine in aqueous solutions. Raw cork (RAC) and regranulated cork (RGC, obtained by thermal treatment of RAC with steam at 380 °C) were tested as modifiers. The results clearly showed that the cork-graphite sensors, GrRAC and GrRGC, exhibited a linear response over a wide range of caffeine concentration (5–1000 µM), with R2 of 0.99 and 0.98, respectively. The limits of detection (LOD), estimated at 2.9 and 6.1 µM for GrRAC and GrRGC, suggest greater sensitivity and reproducibility than the unmodified conventional graphite sensor. The low-cost cork-graphite sensors were successfully applied in the determination of caffeine in soft drinks and pharmaceutical formulations, presenting well-defined current signals when analyzing real samples. When comparing electrochemical determinations and high performance liquid chromatography measurements, no significant differences were observed (mean accuracy 3.0%), highlighting the potential use of these sensors to determine caffeine in different samples.

scholarly journals Towards a Glass New World: The Role of Ion-Exchange in Modern Technology

2021 ◽  
Vol 11 (10) ◽  
pp. 4610
Author(s):  
Simone Berneschi ◽  
Giancarlo C. Righini ◽  
Stefano Pelli
Keyword(s):  
Ion Exchange ◽  
Communication Networks ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Modern Technology ◽  
Historical Background ◽  
Wide Range ◽  
Happy Marriage

Glasses, in their different forms and compositions, have special properties that are not found in other materials. The combination of transparency and hardness at room temperature, combined with a suitable mechanical strength and excellent chemical durability, makes this material indispensable for many applications in different technological fields (as, for instance, the optical fibres which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors). For its part, ion-exchange from molten salts is a well-established, low-cost technology capable of modifying the chemical-physical properties of glass. The synergy between ion-exchange and glass has always been a happy marriage, from its ancient historical background for the realisation of wonderful artefacts, to the discovery of novel and fascinating solutions for modern technology (e.g., integrated optics). Getting inspiration from some hot topics related to the application context of this technique, the goal of this critical review is to show how ion-exchange in glass, far from being an obsolete process, can still have an important impact in everyday life, both at a merely commercial level as well as at that of frontier research.

scholarly journals Optimization of Plant Extract Purification Procedure for Rapid Screening Analysis of Sixteen Phenolics by Liquid Chromatography

Separations ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 13
Author(s):  
Petra Ranušová ◽  
Ildikó Matušíková ◽  
Peter Nemeček
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Solid Phase ◽  
Low Cost ◽  
Sinapic Acid ◽  
Rapid Screening ◽  
Coumaric Acid ◽  
Laboratory Equipment ◽  
Wide Range ◽  
Methoxycinnamic Acid

A solid-phase extraction (SPE) procedure was developed for simultaneous monitoring of sixteen different phenolics of various polarity, quantified by high-performance liquid chromatography (HPLC). The procedure allowed screening the accumulation of intermediates in different metabolic pathways that play a crucial role in plant physiology and/or are beneficial for human health. Metabolites mostly involved in phenylpropanoid, shikimate, and polyketide pathways comprise chlorogenic acid, gentisic acid, vanillic acid, caffeic acid, protocatechuic acid, ferulic acid, rutin, quercetin, epicatechin, gallic acid, sinapic acid, p-coumaric acid, o-coumaric acid, vanillin; two rarely quantified metabolites, 2,5-dimethoxybenzoic acid and 4-methoxycinnamic acid, were included as well. The procedure offered low cost, good overall efficiency, and applicability in laboratories with standard laboratory equipment. SPE recoveries were up to 99.8% at various concentration levels. The method allowed for routine analysis of compounds with a wide range of polarity within a single run, while its applicability was demonstrated for various model plant species (tobacco, wheat, and soybean), as well as different tissue types (shoots and roots).

scholarly journals Process Design Kit and Design Automation for Flexible Hybrid Electronics

2019 ◽  
Vol 16 (3) ◽  
pp. 117-123
Author(s):  
Tsung-Ching Huang ◽  
Ting Lei ◽  
Leilai Shao ◽  
Sridhar Sivapurapu ◽  
Madhavan Swaminathan ◽  
...  
Keyword(s):  
Process Design ◽  
Design Automation ◽  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Thin Film Transistor ◽  
Solution Process ◽  
Oxide Semiconductor ◽  
Wearable Electronics ◽  
Wide Range

Abstract High-performance low-cost flexible hybrid electronics (FHE) are desirable for applications such as internet of things and wearable electronics. Carbon nanotube (CNT) thin-film transistor (TFT) is a promising candidate for high-performance FHE because of its high carrier mobility, superior mechanical flexibility, and material compatibility with low-cost printing and solution processes. Flexible sensors and peripheral CNT-TFT circuits, such as decoders, drivers, and sense amplifiers, can be printed and hybrid-integrated with thinned (<50 μm) silicon chips on soft, thin, and flexible substrates for a wide range of applications, from flexible displays to wearable medical devices. Here, we report (1) a process design kit (PDK) to enable FHE design automation for large-scale FHE circuits and (2) solution process-proven intellectual property blocks for TFT circuits design, including Pseudo-Complementary Metal-Oxide-Semiconductor (Pseudo-CMOS) flexible digital logic and analog amplifiers. The FHE-PDK is fully compatible with popular silicon design tools for design and simulation of hybrid-integrated flexible circuits.

Application of SU-8 photoresist as a multi-functional structural dielectric layer in FOWLP

2017 ◽  
Vol 2017 (DPC) ◽  
pp. 1-19
Author(s):  
Raquel Pinto ◽  
André Cardoso ◽  
Sara Ribeiro ◽  
Carlos Brandão ◽  
João Gaspar ◽  
...  
Keyword(s):  
Structural Material ◽  
High Performance ◽  
Microelectromechanical Systems ◽  
Low Cost ◽  
Process Conditions ◽  
Processing Temperature ◽  
Wafer Level ◽  
Fast Growing ◽  
Wide Range ◽  
Different Types

Microelectromechanical Systems (MEMS) are a fast growing technology for sensor and actuator miniaturization finding more and more commercial opportunities by having an important role in the field of Internet of Things (IoT). On the same note, Fan-out Wafer Level Packaging (FOWLP), namely WLFO technology of NANIUM, which is based on Infineon/ Intel eWLB technology, is also finding further applications, not only due to its high performance, low cost, high flexibility, but also due to its versatility to allow the integration of different types of components in the same small form-factor package. Despite its great potential it is still off limits to the more sensitive components as micro-mechanical devices and some type of sensors, which are vulnerable to temperature and pressure. In the interest of increasing FOWLP versatility and enabling the integration of MEMS, new methods of assembling and processing are continuously searched for. Dielectrics currently used for redistribution layer construction need to be cured at temperatures above 200°C, making it one of the major boundary for low temperature processing. In addition, in order to accomplish a wide range of dielectric thicknesses in the same package it is often necessary to stack very different types of dielectrics with impact on bill of materials complexity and cost. In this work, done in cooperation with the International Iberian Nanotechnology Laboratory (INL), we describe the implementation of commercially available SU-8 photoresist as a structural material in FOWLP, allowing lower processing temperature and reduced internal package stress, thus enabling the integration of components such as MEMS/MOEMS, magneto-resistive devices and micro-batteries. While SU-8 photoresist was first designed for the microelectronics industry, it is currently highly used in the fabrication of microfluidics as well as microelectromechanical systems (MEMS) and BIO-MEMS due to its high biocompatibility and wide range of available thicknesses in the same product family. Its good thermal and chemical resistance and also mechanical and rheological properties, make it suitable to be used as a structural material, and moreover it cures at 150°C, which is key for the applications targeted. Unprecedentedly, SU-8 photoresist is tested in this work as a structural dielectric for the redistribution layers on 300mm fan-out wafers. Main concerns during the evaluation of the new WLFO dielectric focused on processability quality; adhesion to multi-material substrate and metals (copper, aluminium, gold, ¦); between layers of very different thicknesses; and overall reliability. During preliminary runs, processability on 300 mm fan-out wafers was evaluated by testing different coating and soft bake conditions, exposure settings, post-exposure parameters, up to developing setup. The outputs are not only on process conditions and results but also on WLFO design rules. For the first time, a set of conditions has been defined that allows processing SU-8 on WLFO, with thickness values ranging from 1 um to 150 um. The introduction of SU-8 in WLFO is a breakthrough in this fast-growing advanced packaging technology platform as it opens vast opportunities for sensor integration in WLP technology.

PUSHING STANDARD CMOS TECHNOLOGIES INTO SMART POWER CONVERSION AND AMPLIFICATION

1995 ◽  
Vol 05 (03) ◽  
pp. 455-463 ◽  
Author(s):  
S. FINCO ◽  
F. H. BEHRENS ◽  
J. GUILHERME ◽  
M. I. CASTRO SIMAS ◽  
M. LANÇA
Keyword(s):  
Integrated Circuit ◽  
High Performance ◽  
Low Cost ◽  
Smart Power ◽  
Medium Voltage ◽  
Wide Range ◽  
Power Integrated Circuit ◽  
Lateral Structures ◽  
Lightly Doped Drain ◽  
Specific Control

A smart power integrated circuit to be fabricated with standard CMOS technologies was developed in view to obtain a versatile, high performance and low cost basic building block, suitable for a wide range of low power applications. This circuit merges together two transistors, connected in a low-side/high-side switch configuration, with specific control and protection circuitries. These transistors are NMOS medium-voltage lateral structures, which use the lightly doped drain concept and are targeted to handle currents up to 2 A and to support 25 V at OFF state. Experimental results on different applications and topologies show the applicability of the smart switching cell on portable systems power supplies and amplifiers (up to 20 W). Its performance also proves the ability of standard CMOS technologies to implement smart power circuits.

scholarly journals A Study of Direct Fuel-Injection Two-Stroke Cycle Methanol Engine.

1991 ◽  
Vol 57 (539) ◽  
pp. 2442-2448
Author(s):  
Shuicci KAJITANI ◽  
Norihiro SAWA ◽  
Shigenobu HAYASHI ◽  
Yuzuru KUBOTA
Keyword(s):  
Fuel Injection ◽  
Direct Fuel Injection ◽  
Stroke Cycle

The historical development of the magnetic method in exploration

Geophysics ◽  
2005 ◽  
Vol 70 (6) ◽  
pp. 33ND-61ND ◽  
Author(s):  
M. N. Nabighian ◽  
V. J. S. Grauch ◽  
R. O. Hansen ◽  
T. R. LaFehr ◽  
Y. Li ◽  
...  
Keyword(s):  
World War Ii ◽  
High Performance ◽  
Oil And Gas ◽  
Low Cost ◽  
Regional Scale ◽  
Magnetic Method ◽  
Geothermal Resources ◽  
Wide Range ◽  
Weakly Magnetic ◽  
New Applications

The magnetic method, perhaps the oldest of geophysical exploration techniques, blossomed after the advent of airborne surveys in World War II. With improvements in instrumentation, navigation, and platform compensation, it is now possible to map the entire crustal section at a variety of scales, from strongly magnetic basement at regional scale to weakly magnetic sedimentary contacts at local scale. Methods of data filtering, display, and interpretation have also advanced, especially with the availability of low-cost, high-performance personal computers and color raster graphics. The magnetic method is the primary exploration tool in the search for minerals. In other arenas, the magnetic method has evolved from its sole use for mapping basement structure to include a wide range of new applications, such as locating intrasedimentary faults, defining subtle lithologic contacts, mapping salt domes in weakly magnetic sediments, and better defining targets through 3D inversion. These new applications have increased the method's utility in all realms of exploration — in the search for minerals, oil and gas, geothermal resources, and groundwater, and for a variety of other purposes such as natural hazards assessment, mapping impact structures, and engineering and environmental studies.

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