Due to its popularity and high crack sensitivity, 6061 aluminum alloy was selected as a test material for the newly developed double-sided arc welding (DSAW) process. The microstructure, crack sensitivity, and porosity of DSAW weldments were studied systematically. The percentage of fine equiaxed grains in the fully penetrated welds is greatly increased. Residual stresses are reduced. Porosity ...

Presented is a 0.9 V rail-to-rail constant gm CMOS amplifier input stage consisting of complementary differential pairs and a gm control circuit. The gm control circuit eliminates the gm dead zone, which occurs in the conventional rail-to-rail amplifier with ultra-low supply voltages. The proposed amplifier input stage has a constant gm that varies by +2.3% for rail-to-rail input common-mode le...

Preventing broken-rail-caused derailments is a high priority for the rail industry and government. The current practice is to periodically inspect rails using non-destructive technologies such as ultrasonic rail inspection. Determining the optimal inspection frequency is a critical decision in railway infrastructure management. The objective of this paper is to develop an analytical framework t...

Rail surface defects such as the abrasion, scratch and peeling often cause damages to the train wheels and rail bearings. An efficient and accurate detection of rail defects is of vital importance for the safety of railway transportation. In the past few decades, automatic rail defect detection has been studied; however, most developed methods use optic-imaging techniques to collect the rail su...

The type and magnitude of loads passing through the track superstructure have a great impact on both the design and the performance of concrete sleepers and fastening systems. To date, the majority of North American research focusing on quantifying rail infrastructure loading conditions has been conducted on heavy-haul freight railroads. However, the results and recommendations from these studi...

ion of Models of Stress Corrosion Cracking of Drip Shield and Waste Package Outer Barrier and Hydrogen Induced Corrosion of Drip Shield TABLE OF CONTENTS Page 1. PU R P O SE ............................................................................................................................... 8 2. QUALITY ASSURANCE .............................................. 8 3. COMPUTER SOFTWARE AN...

This chapter describes basic logic circuits. This can be seen as largely background material for applications in later chapters in the design of dividers and phase detectors in frequency synthesizers. The types of logic discussed will be CMOS rail-to-rail logic, CMOS current mode logic (CML), bipolar CML, and bipolar emitter coupled logic (ECL). Note that CML is a general term and applies to bo...

This study evaluates rail transit benefits based on a comprehensive analysis of transportation system performance in major U.S. cities. It finds that cities with large, wellestablished rail systems have significantly higher per capita transit ridership, lower average per capita vehicle ownership and annual mileage, less traffic congestion, lower traffic death rates, lower consumer expenditures ...

AbstractA BiCMOS rail-to-rail operational amplifier capable of operating from supply voltages as low as 1.W is presented. A new technique of achieving a rail-to-rail input common mode range us'ing a bipolar input stage is developed. The new technique avoids the use of complementary pairs at the input and thus avoids complicated schemes for monitoring the constant g,?, . The resulting variation ...

Rail is a framework for building web applications that can precisely identify inappropriately disclosed data after a vulnerability is discovered. To do so, Rail introduces retroactive disclosure auditing: re-running the application with previous inputs once the vulnerability is fixed, to determine what data should have been disclosed. A key challenge for Rail is to reconcile state divergence be...