Justification of the gasification channel length in underground gas generator

Double skin ventilated roof is one of the important passive cooling techniques to reduce solar heat gain through roofs. In this research, an experimental study was performed to investigate the thermal behaviour of a double skin roof model. The model was made of two parallel galvanized steel plates. Galvanized steel has been used in the roof construction of industrial buildings and storehouses in Iraq. The effect of inclination angle (ϴ) from the horizontal and the spacing (S) between the plates was investigated at different radiation intensities. It is found that using a double skin roof arrangement with a sufficient air gap (S) can reduce the heat gain significantly. The higher the inclination angle (ϴ) the higher the ventilation rate, the lower the heat gain through the roof. In this study, increasing the air gap from 2 cm to 4 cm reduced the heat gain significantly but when the gap was further increased to 6 cm, the reduction in the heat flux was insignificant. A dimensionless correlation was also reduced between Nusselt number () and the single parameter where L is the channel length. This correlation can be handily utilized for designing of engineering applications dealing with high temperature difference natural convection heat transfer.

Download Full-text

Circuit Voltage Probe Based on Time-Integrated Measurements of Optical Emission From Leakage Current

ISTFA 2002: Conference Proceedings from the 28th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2002p0667 ◽

2002 ◽

Author(s):

Franco Stellari ◽

Peilin Song ◽

James C. Tsang ◽

Moyra K. McManus ◽

Mark B. Ketchen

Keyword(s):

Leakage Current ◽

Voltage Drop ◽

Optical Emission ◽

Channel Length ◽

Operating Conditions ◽

Power Circuit ◽

Hot Carrier ◽

Optical Inspection ◽

Low Threshold ◽

Circuit Power

Abstract Hot-carrier luminescence emission is used to diagnose the cause of excess quiescence current, IDDQ, in a low power circuit implemented in CMOS 7SF technology. We found by optical inspection of the chip that the high IDDQ is related to the low threshold, Vt, device process and in particular to transistors with minimum channel length (0.18 μm). In this paper we will also show that it is possible to gain knowledge regarding the operating conditions of the IC from the analysis of optical emission due to leakage current, aside from simply locating defects and failures. In particular, we will show how it is possible to calculate the voltage drop across the circuit power grid from time-integrated acquisitions of leakage luminescence.

Download Full-text

Current-Signature-Based Analysis of Complex Test Fails

ISTFA 1999: Conference Proceedings from the 25th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa1999p0377 ◽

1999 ◽

Author(s):

Anne E. Gattiker ◽

Phil Nigh ◽

Wojciech Maly

Keyword(s):

Failure Analysis ◽

Physical Nature ◽

Channel Length ◽

Test Methods ◽

Multiple Test ◽

Physical Mechanisms ◽

Test Behavior ◽

Complex Test ◽

Current Signature ◽

Insight Into

Abstract This article provides an analysis of a class of failures observed during the SEMATECH-sponsored Test Methods Experiment. The analysis focuses on use of test-based failure analysis and IDDQ signature analysis to gain insight into the physical mechanisms underlying such subtle failures. In doing so, the analysis highlights techniques for understanding failure mechanisms using only tester data. In the experiment, multiple test methods were applied to a 0.45 micrometer effective channel length ASIC. Specifically, ICs that change test behavior from before to after burn-in are studied to understand the physical nature of the mechanism underlying their failure. Examples of the insights provided by the test-based analysis include identifying cases where there are multiple or complex defects and distinguishing cases where the defect type is likely to be a short versus an open and determining if the defect is marginal. These insights can be helpful for successful failure analysis.

Download Full-text