Off-state modulation of SOI floating-body

Off-state modulation of the floating-body potential in partially depleted silicon-on-insulator (PDSOI) transistors from the 90-nm technology generation is observed using pulsed current-voltage (I-V) measurements. Varying the off-value of the gate voltage is shown to either decrease the transient on-current (I/sub on,trans/) of PDSOI devices through gate-to-body leakage or increase I/sub on,trans/ due to gate-induced drain leakage. Dependence of I/sub on,trans/ on off-state gate bias is not observed in bulk devices, PDSOI devices with body contacts, or fully depleted SOI devices, confirming the role of floating-body in the observed effects. Thus, off-state conditions should be accounted for when considering floating-body effects and when using pulsed I-V measurements to study self-heating.     

SiGe pMODFETs on silicon-on-sapphire substrates with 116 GHzfmax

The dc and microwave results of Si_0.2Ge_0.8/Si_0.7Ge_0.3 pMODFETs grown on silicon-on-sapphire (SOS) substrates by ultrahigh vacuum chemical vapor deposition are reported. Devices with L_g=0.1 μm displayed high transconductance (377 mS/mm), low output conductance (25 mS/mm), and high gate-to-drain breakdown voltage (4 V). The dc current-voltage (I-V) characteristics were also nearly identical to those of control devices grown on bulk Si substrates. Microwave characterization of 0.1×50 μm² devices yielded unity current gain (f_T) and unilateral power gain (f _max) cutoff frequencies as high as 50 GHz and 116 GHz, respectively. Noise parameter characterization of 0.1×90 μm² devices revealed minimum noise figure (F_min) of 0.6 dB at 3 GHz and 2.5 dB at 20 GHz     

The effect of organic loading on process performance and membrane fouling in a submerged membrane bioreactor treating municipal wastewater

The results of experiments on municipal wastewater primary effluent are presented for a pilot-scale submerged membrane bioreactor (SMBR). The SMBR pilot plant employed an ultrafiltration membrane with a nominal pore size of 0.035 microm and was operated at a constant membrane flux of 30 L/m(2)h. The mixed liquor suspended solids (MLSS) concentration was maintained at 8+/-2 g/L and steady-state fouling rates were determined for 10, 5, 4, 3, and 2-d MCRTs, corresponding to food-to-microorganism (F/M) ratios of 0.34, 0.55, 0.73, 0.84, and 1.41 gCOD/gVSS d, respectively. Membrane fouling rates increased as the F/M was increased. Steady-state membrane fouling rates were correlated with total soluble microbial products (SMP) concentrations. The membrane fouling rates did not correlate well with soluble COD measured on a 0.45 microm membrane filtrate of mixed liquor or with soluble COD rejection (effluent COD/soluble COD).     

Instance-based automaticity and aging: Acquisition, reacquisition, and long-term retention.

This research examined age differences in the acquisition and reacquisition of instance-based automaticity. In 2 experiments, young and older adults were trained to enumerate targets presented in otherwise empty displays or in displays that contained distractors. Experiment 1 revealed that older adults required more practice to reach asymptote than young adults. For both age groups, modifications of the identities and locations of targets produced substantial disruptions in performance, whereas modifications of the identities or locations of distractors produced little interference. However, no age differences in the representations of instances in memory were obtained in participants who reached asymptote. Experiment 2 revealed age deficits in the long-term retention and rate of reacquisition of instance-based automaticity 18 months after initial training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enantioselective hydrogenation of pyruvate esters in the mesoporous environment of Pt-MCM-41

Pt-MCM-41 catalysts having loadings of up to 2% Pt have been synthesised using three strategies: (i) direct synthesis from a Pt²⁺-containing gel, (ii) exchange of Na⁺ in Al-MCM-41 (containing 8% aluminium) for Pt²⁺, (iii) exchange of H⁺ in H-MCM-41 (containing 1% aluminium) for Pt²⁺. HRTEM confirmed the retention of the mesoporous structure in the active catalysts and gave information on Pt particle size and location. ²⁷Al NMR provided information on the movement of aluminium within the structure during catalyst preparation. Enantioselective hydrogenation of methyl and ethyl pyruvate was catalysed by cinchonidine-modified Pt-MCM-41 at 293 K and elevated hydrogen pressures; performance was compared to that provided by the standard reference catalyst EUROPT-1. Catalysts prepared by strategies (i) and (ii) performed best, giving values of the enantiomeric excess comparable to those afforded by EUROPT-1 at rates moderated by an order of magnitude by mass transfer effects. Performance was impaired when Pt particle size in the mesopores was so small that conditions favoured racemic reaction. This revised version was published online in August 2006 with corrections to the Cover Date.     

Evidence-based strategies improve assessment of pediatric bipolar disorder by community practitioners.

The misdiagnosis of pediatric bipolar disorder (PBD) has become a major public health concern. Would available evidence-based assessment (EBA) strategies help improve diagnostic accuracy and are clinicians willing to consider these strategies in practice? The purpose of the present study was to document the extent to which using an EBA decision tool—a probability nomogram—improves the interpretation of family history and test data by clinicians and to examine the acceptability of the nomogram technique to clinicians. Over 600 clinicians across the U.S. and Canada attending continuing education seminars were trained to use the nomogram. Participants estimated the probability that a youth in a clinical vignette had bipolar disorder, first using clinical judgment and then using the nomogram. Brief training of clinicians (less than 30 minutes) in using the nomogram for assessing PBD improved diagnostic accuracy, consistency, and agreement. The majority of clinicians endorsed using the nomogram in practice. EBA decision aids, such as the nomogram, may lead to a significant decrease in overdiagnosis and help clinicians detect true cases of PBD. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

COMPARATIVE MALTING PERFORMANCE OF OLD AND NEW BARLEY VARIETIES

A comparison was made of the malting behaviour of eight barley varieties representing a range from ancient to modern types. Plants were grown under controlled conditions in a glasshouse with two different nitrogen treatments and the grain obtained was subjected to a factorial micro-malting analysis. Under the conditions of this experiment there was little evidence of an improvement in malting ability between Plumage Archer and Ark Royal and there is limited scope for further increases in potential hot water extract. It would therefore appear that emphasis should now be given to the production of varieties with good agronomic characteristics which maintain this potential and modify rapidly without the need for abrasion and exogenous GA₃.     

Nutrient digestion, ruminal fermentation and plasma lipids in steers fed combinations of hydrogenated fat and lecithin

Commercial soybean lecithin replaced hydrogenated fat in steer diets to determine if phospholipids enhance fatty acid digestion and microbial fermentation in ruminants. Four diets were fed in a 4 x 4 Latin square to four Angus steers with ruminal cannula. One diet contained no added fat (control) and three contained hydrogenated fat and lecithin in weight ratios of 100:0, 86:14, and 72:28. All diets with added fat had lower fatty acid digestibilities compared with the control diet with no difference due to level of lecithin. Ruminal acetate and acetate:propionate ratios were reduced by all fat supplements but reduced less for the supplements containing lecithin. Plasma triglyceride and cholesterol concentrations were increased from dietary fat but not increased as much if lecithin were present in the diet. Feeding lecithin to ruminants does not improve digestibility of hydrogenated fats that are highly saturated.