scholarly journals New Technology Demonstration Program - Results of an Attempted Field Test of Full-Spectrum Polarized Lighting in a Mail Processing/Office Space

2001 ◽  
Author(s):  
Eric E Richman
2019 ◽  
Vol 16 (5) ◽  
pp. 875-893 ◽  
Author(s):  
Jinzhu Hu ◽  
Xingyu Zhang ◽  
Yubing Gao ◽  
Zimin Ma ◽  
Xinzeng Xu ◽  
...  

Abstract Directional presplit blasting (DPB) technology for an innovative no-pillar mining approach is introduced. First, a mechanical model is established to analyze crack initiation and coalescence using the new technology. The explosion pressure formula containing tress concentration factor explains the relationship between the quantity of explosives and the crack initiation and coalescence. Subsequently, a dynamic finite element simulation method is used to study the stress and damage evolution process of the blasthole wall in ordinary explosion and DPB. The simulation results indicate that the stress concentration factor is approximately 4c10 for the same quantity of explosives. Finally, a field test was conducted in the Fucheng coal mine of China. Based on the field test, the concept of cracking ability is proposed, the relationship between the quantity of explosives and cracking ability is determined, and the quantity of explosives is divided into four stages that are compatible with the roof rock strength. The results can provide some clinical guidance for application of DPB in other projects of the gob-side entry retaining by roof cutting.


Author(s):  
Robert S. Mazzawy

This paper describes the installed performance potential for a recently patented new design concept for a variable pitch composite fan blade [1,2]. The unique characteristic of this design is the compactness and light weight of the assembly of fan plus variable pitch mechanism. This design enables turbofan engine cycles with higher propulsive efficiency that previously were not viable due to high installation weight and performance penalties. As part of its mandate to support new technology that improves fuel efficiency, the Connecticut Coalition for the Advancement of Technology (CCAT) sponsored a study to quantify the potential savings. A comparison is made between a current high bypass ratio engine and an advanced very high bypass ratio engine both configured to deliver approximately 30,000 lbs of thrust at the sea level static takeoff (SLTO) power setting. These engines are evaluated to determine the installed thrust and fuel consumption characteristics over the full spectrum of flight operation, enabling fuel burn to be evaluated for any aircraft mission. For a nominal mission profile considered in this paper, the advanced engine cycle enabled by the use of the variable pitch composite fan blade provided more than 12% reduction in fuel burn.


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