The increasing level of integration in PCB technology demands from the designer a new level of
sensitivity to high electrical field problems and to the degradation processes that may be involved. ...High
electrical fields interacting with thermal and mechanical stresses could lead to the growth of
'latent defects', not easily identifiable during final stage acceptance tests, that could lead
the PCB's failure during service. The paper discusses degradation mechanisms which can lead to
dielectric failure, together with first results relevant to a wider research project regarding identification of
latent defects in PCBs and the development of new test procedures.
We report on the electrical and functional characterization of 3D Double-side, Double-Type-Column (3D-DDTC) detectors fabricated on p-type substrates. Results relevant to detectors in the diode, ...strip and pixel configurations are presented, and demonstrate a clear improvement in the charge collection performance compared to the first prototypes of these detectors.
Adenomas containing invasive carcinoma of the large bowel form the majority of early colorectal cancers. Conclusive histological diagnosis of early colorectal cancer depends on two conditions; first, ...the whole lesion must be examined and second the resection margin must border on healthy tissue. The presence of certain histopathological features makes it possible to distinguish between cases with high and low risk of having lymph node metastases. Sixty-six adenomas containing invasive carcinoma are reported. They comprised 3.15% of 2,095 adenomas removed by colonoscopic polypectomy during the same period. Five cases were lost to follow-up. Forty-nine patients considered to be at low risk of having lymph node metastases have been treated by endoscopic polypectomy only with a rigorous follow-up regime including CEA estimation, ultrasonography and total colonoscopy at regular intervals. In none have distant metastases been found on follow-up examinations at a mean duration of 3 years. Two of these cases have developed a metachronous colorectal carcinoma and 15 (30.5%) have metachronous adenomas. Two low risk patients with no tumour found in the operative specimen have undergone major surgical resection. Ten high risk cases have been referred for major surgery and lymph node metastases have been found in four (40%). The need for careful histological examination for lymphatic and veinous invasion is stressed by the presence of this finding in all four high risk patients with involved lymph nodes.
A small set of final prototypes of the ATLAS Inner Detector silicon tracker (Pixel and SCT) were used to take data during the 2004 Combined Test Beam. Data were collected from runs with beams of ...different flavour (electrons, pions, muons and photons) with a momentum range of 2 to 180 GeV/c. Four independent methods were used to align the silicon modules. The corrections obtained were validated using the known momenta of the beam particles and were shown to yield consistent results among the different alignment approaches. From the residual distributions, it is concluded that the precision attained in the alignment of the silicon modules is of the order of 5 mm in their most precise coordinate
Needle biopsy of submucosal lesions is an important addition to the diagnostic capabilities of gastrointestinal endoscopy. A series of 22 cases is described employing a guillotine needle to diagnose ...submucosal lesions, 4 of which were infiltrating adjacent carcinomas. The specimens obtained were sufficient for firm histological diagnosis in 20 cases. There were no complications apart from minor bleeding in 1 case.
Forty patients with irritable bowel syndrome were randomly allocated to treatment with octylonium bromide (20 mg TID) or cimetropium bromide (50 mg BID) in a double-blind trial lasting for six weeks. ...Drugs were taken before meals, according to a double-blind schedule. Clinical evaluations were made of digestive and other symptoms, objective findings (pain at palpation, contracted colon, tympanites), and overall effectiveness of treatment. Statistically significant decreases in severity of abdominal pain and subjective scores for bowel habits were obtained in both groups. The only statistically significant differences between treatments were in nondigestive symptoms (asthenia, palpitations, tremor, headache, etc.), which improved more in the cimetropium bromide group. No severe side effects were observed in either treatment group.
The increasing performance of simulation platforms coupled to the development of sophisticated numerical analysis tools makes more and more possible an approach to modelling complex electromagnetic ...devices in an innovative way, alternative to the well consolidated trial and error procedure, based mainly on analytical approaches, experience and prototyping. The design of electromagnetic actuators can be considered an interesting example of how a effective utilization of numerical methods can lead to optimized systems and components. The aim of the present paper is to show how from a simplified simulation model a high accuracy of the final behaviour of a device can be predicted.
Collagenous colitis is a newly identified condition, with clinical features of chronic watery diarrhea and abdominal pain. Histologically the main characteristic is the presence of a thick collagen ...band below the surface epithelium. Collagenous colitis occurs in adults, especially women. Endoscopy reveals no particular changes in the intestinal mucosa. Symptoms may persist for years with periods of remission and recurring acute attacks. The cause of this condition is still unknown, and because of no real knowledge only symptoms can be treated, usually with little success.
Effects of Single Event Upsets (SEU) and Single Event Transients (SET) are studied in the FE-I4B chip of the innermost layer of the ATLAS pixel system. SEU/SET affect the FE-I4B Global Registers as ...well as the settings for the individual pixels, causing, among other things, occupancy losses, drops in the low voltage currents, noisy pixels, and silent pixels. Quantitative data analysis and simulations indicate that SET dominate over SEU on the load line of the memory. Operational issues and mitigation techniques are presented.
In the last decade, multistage digital measuring systems of partial discharges (PDs) have been introduced, allowing one to support the diagnostic of defects (sites of PDs) in power electric ...components. They transfer information about defects from full data sets of PD patterns, obtained from a Phase Resolved Partial Discharge Analyser (PRPDA) to reduced data set by implementing pattern recognition techniques. The latter data sets are then classified versus similar reference data sets. The validity of the above diagnostic requires that the measuring process, which is influenced by several factors, is optimised. The three main settings of the PRPDA are among such factors of influence, but so far, as a simple mathematical model of this measuring process is not available, it has not been possible to quantitatively assess their "weight" on the validity of above diagnostic. This work presents a successful "Design Of Experiment" (DOE) approach to solve the latter problem. The DOE analysis of the results of 81 PD tests performed on a simple physical model of an insulation system quantified the weight and the interaction of the three factors and allowed one to derive criteria for selecting the "optimal" values of such factors and the "optimal" composition of the reduced data sets.
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