Compact low-voltage class-AB analogue buffer

A new, simple, low-voltage class-AB unity-gain buffer is presented. The proposed approach combines use of floating-gate transistors with the flipped voltage follower to create a compact topology. Experimental results are provided that prove the proposed approach.     

Invariancia de las reglas admisibles y Bayes respecto de transformaciones monotonas

From an optimality point of view the solution of a decision problem is related to classes of optimal strategies: admissible, Bayes, etc. which are closely related to boundaries of the risk set S such as lower-boundary, Bayes boundary, positive Bayes boundary. In this paper we present some results concerning invariance properties of such boundaries when the set is transformed by means of a continuous monotonic increasing functionW.

     

Present trends in lead alloys for the manufacture of battery grids - a review

Probable trends in the future requirements for lead acid batteries are briefly reviewed and it is pointed out that the development of maintenance free batteries could have an important place in that future. Such batteries make special requirements on grid materials. Lead-calcium alloys and lead alloys with a low antimony content are favoured for this application. The physical, electrochemical and mechanical properties of these two types of alloy are reviewed together with their respective advantages and disadvantages and the problems that may arise from their use.     

What are the shapes of response time distributions in visual search?

Many visual search experiments measure response time (RT) as their primary dependent variable. Analyses typically focus on mean (or median) RT. However, given enough data, the RT distribution can be a rich source of information. For this paper, we collected about 500 trials per cell per observer for both target-present and target-absent displays in each of three classic search tasks: feature search, with the target defined by color; conjunction search, with the target defined by both color and orientation; and spatial configuration search for a 2 among distractor 5s. This large data set allows us to characterize the RT distributions in detail. We present the raw RT distributions and fit several psychologically motivated functions (ex-Gaussian, ex-Wald, Gamma, and Weibull) to the data. We analyze and interpret parameter trends from these four functions within the context of theories of visual search. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low-voltage transconductor with high linearity and large bandwidth

A linear tunable CMOS transconductor is proposed which uses a new low-voltage supercascode transistor to provide a high output resistance. Using a standard 0.8 /spl mu/m CMOS technology, simulation results are provided that show the operation of the proposed transconductor with a 1.2 V peak-to-peak differential input signal and 1.5 V supply voltage. The proposed transconductor features a high linearity and more than 100 MHz bandwidth.     

Multicentre evaluation of the Boehringer Mannheim/Hitachi 911 Analysis System

The analytical performance and practicability of the Boehringer Mannheim (BM)/Hitachi 911 analysis system have been assessed in a multicentre evaluation, which involved six laboratories from European countries. Analytes commonly used in classical clinical chemistry were tested in a core programme, which mainly followed the ECCLS guidelines. In addition, a satellite programme covered other analytes, such as proteins, drugs and urine analytes. In total, the study comprised more than 100 000 data items collected over a three-month period. The evaluation was supported with ‘Computer Aided Evaluation’ (CAEv) and telecommunications.Acceptance criteria for the results were established at the beginning of the study. Nearly all of the analytes met the imprecision limits: within-run imprecision (as CVs) was 2% for enzyme and substrate assays, 1% for ISE methods and 5% for immunoassays; between-day imprecision was 3l% for enzyme and substrate assays, 2% for ISE methods and 10% for immunoassays.No relevant drift effects (systematic deviation ≥ 3%) were observed over eight hours. The methods were linear over a wide range. Sample-related and reagent-dependent carry-over can be reduced to a negligible amount by integration of a softwarecontrolled wash-step.Endogenous interferences were found for creatinine (Jaffé method) and uric acid assays (caused by bilirubin), for creatine kinase, creatine kinase MB isoform and γ-glutamyltransferase (caused by haemoglobin), and for immunoglobulin A (caused by lipaemia)Accuracy was checked by an interlaboratory survey, recovery studies in control materials and method comparison studies. The survey showed that, with the exception of cholesterol and iron in two laboratories, the recovery of analytes did not deviate by more than 5%. Sixty-six of the 77 method comparisons performed met the acceptance criteria. The deviations of the remaining 11 results could be explained by differences in either calibration, application or by the use of different methods.Practicability was assessed using a questionnaire which covered all of the important aspects of an analysis system in the clinical laboratory. Twelve groups of attributes out of 14 were rater higher for the BM/Hitachi 911 than for the present situation in the laboratories concerned. Especially high scores were given for the versatility group.The acceptance criteria for the analytical performance of the BM/Hitachi 911 analysis system were fulfilled in all laboratory segments with few exceptions. The practicability exceeded the requirements in most of the attributes. The results of the study confirmed the usefulness of the system as a consolidated workstation in small- to medium-sized clinical laboratories and in STAT laboratories, or as an instrument for special analytes like proteins and drugs, or for urinalysis in large laboratories.     

Ultrasonography and intravenous urography in the diagnosis of blunt renal trauma

OBJECTIVE: To analyze the sensitivity of renal ultrasonography and intravenous urography in renal trauma. METHODS: An extensive analysis on the sensitivity of IVP and US in the assessment of renal trauma was conducted using CT, renal selective arteriography or surgical exploration as the gold standard tests of reference to validate the initial diagnosis. RESULTS: IVP and US are useful techniques because of their high sensitivity in the diagnosis of renal trauma. The sensitivity of US decreases as the severity of the trauma increases (75% for grade I, 88.9% for grade II, 73.3% for grade III and 0% for grade IV), while that of IVP remains high for all degrees of severity (100% for grade I, 92% for grade II, 100% for grade III and 100% for grade IV). CONCLUSIONS: IVP and US were found to be useful techniques because of their high sensitivity in the diagnosis of blunt renal trauma. The sensitivity of US decreases as the severity of the trauma increases, while that of IVP remains high for all degrees of severity.     

Biomolecule Arrays Using Functional Combinatorial Particle Patterning on Microchips

Biofunctionalization of surfaces in a microarray format has revolutionized biological assay applications. Here, a microarray system based on a microelectronic chip is presented that allows for a versatile combinatorial in situ molecule synthesis with very high density. Successfully demonstrating an application for peptide array synthesis, the method offers a compact approach, high combinatorial freedom, and, due to the intrinsic alignment, high and reproducible precision. Patterning the chip surface with different microparticle types which imbed different monomers, several thousand different molecule types can be simultaneously elongated layer‐by‐layer by coupling the particle imbedded monomers to the molecules growing on the chip surface. This technique has the potential for a wide application in combinatorial chemistry, as long as the desired monomeric building blocks are compatible with the chemical process.