A testability metric for path delay faults and its application

Abstract — In this paper, we propose a new testability metric for path delay faults. The metric is computed efficiently using a non-enumerative algorithm. It has been validated through extensive experiments and the results indicate a strong correlation between the proposed metric and the path delay fault testability of the circuit. We further apply this metric to derive a path delay fault test application scheme for scan-based BIST. The selection of the test scheme is guided by the proposed metric. The experimental results illustrate that the derived test application scheme can achieve a higher path delay fault coverage in scan-based BIST. Because of the effectiveness and efficient computation of this metric, it can be used to derive other design-for-testability techniques for path delay faults. I

Impacts of Light Rail Transit Tram on the Voltage and Unbalance of the Distribution System

This paper presents the three-phase voltage and unbalance analysis for the distribution system with the loading of a light rail transit (LRT) tram. To investigate the dynamic responses of the system voltage and current, this paper adopts the Alternative Transients Program (ATP) software to model and simulate a multigrounded four-wire distribution system with an LRT loading. Two different definitions about unbalance are used to evaluate the problem. In this paper, the traction supply substation (TSS) with a single-phase transformer configuration is designed first for providing the electric power to the trams of LRT. However, it may result in the significant neutral line current and unbalance phenomenon to deteriorate the power quality of the distribution system. A Le-Blanc connection transformer in the TSS is therefore proposed to solve the problems

Spontaneous Arrangement of Two-way Flow in Water Bridge

By revisiting the century-old problem of water bridge, we demonstrate that it is in fact dynamic and comprises of two coaxial currents that carry different charges and flow in opposite directions. Initially, the inner flow is facilitated by the cone jet that is powered by H+ and flows out of the anode beaker. The negative cone jet from cathode is established later and forced to take the outer route. This spontaneous arrangement of two-way flow is revealed by the use of chemical dyes, e.g., fluorescein and FeCl3, carbon powder, and the Particle Image Velocimetry. These two opposing flows are found to carry non-equal flux that results in a net transport of water to the cathode beaker. By combining the above information and taking into account the counter flow to equate the water level from the connecting pipe, we can estimate the cross section and flow speed of these co-axial flows as a function of time and applied voltage.Comment: 5 pages, 5 figure

Genotoxicity Assessment of Multispecies Probiotics Using Reverse Mutation, Mammalian Chromosomal Aberration, and Rodent Micronucleus Tests

Genotoxicity assessment is carried out on freeze dried powder of cultured probiotics containing Lactobacillus rhamnosus LCR177, Bifidobacterium adolescentis BA286, and Pediococcus acidilactici PA318. Ames tests, in vitro mammalian chromosome aberration assay, and micronucleus tests in mouse peripheral blood are performed. For 5 strains of Salmonella Typhimurium, the Ames tests show no increased reverse mutation upon exposure to the test substance. In CHO cells, the frequency of chromosome aberration does not increase in responding to the treatment of probiotics. Likewise, the frequency of micronucleated reticulocytes in probiotics-fed mice is indistinguishable from that in the negative control group. Taken together, the toxicity assessment studies suggest that the multispecies probiotic mixture does not have mutagenic effects on various organisms

Paper-based tuberculosis diagnostic devices with colorimetric gold nanoparticles

A colorimetric sensing strategy employing gold nanoparticles and a paper assay platform has been developed for tuberculosis diagnosis. Unmodified gold nanoparticles and single-stranded detection oligonucleotides are used to achieve rapid diagnosis without complicated and time-consuming thiolated or other surface-modified probe preparation processes. To eliminate the use of sophisticated equipment for data analysis, the color variance for multiple detection results was simultaneously collected and concentrated on cellulose paper with the data readout transmitted for cloud computing via a smartphone. The results show that the 2.6 nM tuberculosis mycobacterium target sequences extracted from patients can easily be detected, and the turnaround time after the human DNA is extracted from clinical samples was approximately 1 h