Search

Lead oxide (PbO) is a candidate direct conversion material for medical X-ray applications. We produced various samples and detectors with thick PbO layers. X-ray performance data such as dark current, charge generation yield and temporal behavior were evaluated on small samples. The influence of the metal contacts was studied in detail. We also covered large a-Si thin-film transistor (TFT)-plates with PbO. Imaging results from a large detector with an active area of 18 cm x 20 cm are presented. The detector has 960 x 1080 pixels with a pixel pitch of 184 [micro]m. The modulation transfer function at the Nyquist frequency of 2.72 line-pairs/mm is 50%. Finally, a full size X-ray image is presented. Index Terms--Contacts, detective quantum efficiency, direct detection, lead oxide, PbO, X-ray detector.

Results show a a linear relationship between silicon-silicon bond strength whereas no correlation between silicon-hydrogen bond strength. Data suggest that highly stable and mobile thin film transistors required a dense amorphous silicon:hydrogen layer with compressive stress characteristics.

A study was conducted to analyze a technique for generating a truly seamless tilled image sensor from four similar subarrays supporting a tilled image sensor with no missing pixels. Four conventional amorphous silicon photodiode-thin film transistor arrays were cut parallel to the busbars. The seam between each tile supported no adjacent bus-bar. Experimental results indicated the feasibility of the technique.

A new computer program aids in modelling the properties of amorphous silicon thin film transistors and includes a defect pool model for the defect states. This program is used to model amorphous silicon thin film transistors, both prior to and after alternating the density of states by bias annealing method. The computer program is useful for measuring field-effect conductance.

The forward characteristics of amorphous hydrogenated Si nip and pin diodes were described using a model. The results showed that the quality factor of the diodes decreased as the temperature became higher. The occurence of different ideality factors were due to varying energy dependencies in the density of deep states in the i layer.

The relation of the defect pool model applied to the defects near the interface of hydrogenated amorphous silicon thin film transistors to the different traansistor characteristics in material systems is discussed. Plasma deposited silicon nitrides, plasma deposited silicon oxides and thermally grown silicon oxides were used as gate dielectrics. An improved method for the determination of interface quality measurements was established.

The combined inductively coupled plasma mass spectrometry and direct injection nebulization (DIN) methods provided precise and reliable analysis of mercury content in drinking water. The tandem analytical system could function using only a small sample size and could provide results with minimal memory effects. Moreover, the efficiency of the analysis could be increased with the application of a flow injection valve or an automated sampling system. The results further revealed that DIN gave detection limits comparable to a pneumatic nebulizer.

The demonstration of dark-current induced degradation of material in Si:H n-i-n devices show that direct current stressing under aggravated stress conditions gives rise to an assymetrical density of states distribution. The density of states is increasednear the electron extracting contact similar to reverse-bias anneal experiment on p-i-n diodes. Equilibration to the assymetric distribution of the valence band-tail trapped hole concentration leads to assymetric density.

Background: The global prevalence of extended-spectrum beta-lactamase-producing Escherichia coli is rising and is dominated by blaCTX-M spread by plasmids. Travellers to South Asia from Western Europe have high rates of acquisition of faecal CTX-M-producing E. coli (CTX-M-EC).Aims: To determine the conjugative ability of CTX-M-EC acquired by healthy volunteers after travel to South Asia, the proportion of travel-acquired CTX-M-EC where blaCTX-M is encoded on a plasmid vs on the bacterial chromosome, and the relatedness of travel-acquired CTX-M-EC plasmids to previously sequenced plasmids.Methods: Faecal samples were collected pre- and post-travel from 23 volunteers who visited South Asia, and CTX-M-EC were cultured. After short- and long-read sequencing, 10 plasmid sequences were identified and compared with previously sequenced plasmids in GenBank. Conjugation to E. coli K-12 was undertaken using filter mating.Findings: Thirty-five percent of CTX-M-EC isolates tested transferred the blaCTX-M plasmid by conjugation. Travel-acquired CTX-M-EC carried blaCTX-M on a plasmid in 62% of isolates, whereas 38% of isolates had blaCTX-M on the chromosome. CTX-M-EC plasmids acquired after travel to South Asia had close homology to previously described epidemic plasmids which are widely disseminated in humans, animals and the natural environment.Conclusion: Globally successful epidemic plasmids are involved in the spread of CTX-M-EC. Targeted strategies may be used to displace such plasmids from the host strain as part of efforts in infection prevention and control in healthcare settings. Bacteria with blaCTX-M plasmids were readily acquired by healthy volunteers, and were carried on return to the UK, providing opportunities for onward dissemination. [ABSTRACT FROM AUTHOR]

A theoretical model to account for Kinetics of defect creation in amorphous silicon thin film transistors, subjected to gate bias stress has been developed. The two parameter stretched hyperbola approximation, which was proposed by them to describe defect creation kinetics, is a reasonable approximation of the numerical results provided that the initial band-tail carrier density is the same in all devices being compared.

Examines the prevalence of diabetes mellitus in Asian people in Coventry, England. Percentage of the population infected with diabetes mellitus; Characteristic of the excess of diabetes in the subjects; Absence of body mass differences.