Failure analysis of a large span longwall drift under water-rich roofs and its control techniques

2016 ◽  
Vol 67 ◽  
pp. 15-32 ◽  
Author(s):  
Qing-Sheng Bai ◽  
Shi-Hao Tu
Author(s):  
John R. Devaney

Occasionally in history, an event may occur which has a profound influence on a technology. Such an event occurred when the scanning electron microscope became commercially available to industry in the mid 60's. Semiconductors were being increasingly used in high-reliability space and military applications both because of their small volume but, also, because of their inherent reliability. However, they did fail, both early in life and sometimes in middle or old age. Why they failed and how to prevent failure or prolong “useful life” was a worry which resulted in a blossoming of sophisticated failure analysis laboratories across the country. By 1966, the ability to build small structure integrated circuits was forging well ahead of techniques available to dissect and analyze these same failures. The arrival of the scanning electron microscope gave these analysts a new insight into failure mechanisms.


Author(s):  
Evelyn R. Ackerman ◽  
Gary D. Burnett

Advancements in state of the art high density Head/Disk retrieval systems has increased the demand for sophisticated failure analysis methods. From 1968 to 1974 the emphasis was on the number of tracks per inch. (TPI) ranging from 100 to 400 as summarized in Table 1. This emphasis shifted with the increase in densities to include the number of bits per inch (BPI). A bit is formed by magnetizing the Fe203 particles of the media in one direction and allowing magnetic heads to recognize specific data patterns. From 1977 to 1986 the tracks per inch increased from 470 to 1400 corresponding to an increase from 6300 to 10,800 bits per inch respectively. Due to the reduction in the bit and track sizes, build and operating environments of systems have become critical factors in media reliability.Using the Ferrofluid pattern developing technique, the scanning electron microscope can be a valuable diagnostic tool in the examination of failure sites on disks.


1987 ◽  
Vol 66 (2) ◽  
pp. 7
Author(s):  
C.W, Painter
Keyword(s):  

EDIS ◽  
2017 ◽  
Vol 2017 (5) ◽  
Author(s):  
Mary C. Bammer ◽  
Josh Campbell ◽  
Chase B. Kimmel ◽  
James D.. Ellis ◽  
Jaret C. Daniels

The establishment of native wildflower plantings in Florida can benefit agricultural producers as well as native pollinators and other beneficial insects (predators and parasitoids). The plantings do this by:  providing forage and nesting sites for bees, butterflies, and other pollinators, increasing wild bee numbers possibly across the farm, and increasing natural enemies of insect pests (that also depend on forage and nesting sites). This document discusses choosing the right mix of native plant species to benefit many pollinator species, as well as proper site selection, planting practices, and weed control techniques. Wildflower plots should be practical to manage, maximize benefits to wildlife, and fit into the overall management practices of the property. 


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