Performance enhancement of an induction motor by secondaryimpedance control

The paper demonstrates the use of nonresistive secondary control of an induction motor to improve efficiency, power factor and torque. A mathematical algorithm is presented to predict the control requirements in terms of secondary capacitance. The required secondary capacitance is implemented by a novel electronic switching technique that effectively increases the value of the used capacitor. This overcomes the high-capacitance demand and provides a feasible solution. Experimental verification is presented in the results obtained from a small induction motor drive     

A Device to Provide Respiratory-Mechanical Unloading

A commercially available and widely used servo-controlled ventilator has been modified to provide controlled inspiratory resistive unloading of the human respiratory system. This is achieved by establishing a positive mouth pressure throughout inspiration in a constant proportion to instantaneous flow, i.e., the ratio of mouth pressure to flow, which defines the "assistance," remaining constant. The performance of this device has been evaluated in four healthy subjects during steady-state, constant-load cycling (20-120 W). It is demonstrated that i) the device can successfully implement controlled degrees of inspiratory assistance on a breath-to-breath basis; ii) the assistance can be sustained over a substantial range of ventilatory drive (i.e., for ventilations up to some 30 1/min) and to an extent which approaches a 100 percent reduction of the normal respiratory resistance. This device should prove useful in experimental and clinical investigations of the respiratory responses to resistive unloading of the respiratory system.     

There's more to touch than meets the eye: The salience of object attributes for haptics with and without vision.

The availability and salience of object attributes under haptic exploration, with and without vision, were assessed by 2 tasks in which Ss sorted objects that varied factorially in size, shape, texture, and hardness. In the directed-discrimination task, Ss were instructed to sort along a particular dimension. Although levels on all dimensions were easily discriminated, shape was relatively less so for haptic explorers without vision, as was hardness for those using vision and haptics. Size was least discriminable for both groups. In the free-sorting task, Ss were to sort objects by similarity. Three groups used haptic exploration only; these were differentiated by the experimenters' definition of object similarity: unbiased haptics, haptically biased haptics, haptics plus visual imagery. A 4th group used vision as well as haptics, with instructions like those of the unbiased haptics group. Results support the contention that the haptic and visual systems have distinct encoding pathways, with haptics oriented toward the encoding of substance rather the shape. This may reflect a direct influence of haptic exploratory procedures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Potential energy planning conflicts in the UK

During the latter half of the 19ar 1970s there was great concern about potential conflicts over energy development proposals in the UK, most of which were expected to emerge within the framework of land use planning procedures and the associated opportunities for public participation. While there has been widespread dissatisfaction with the way in which the planning system handles energy developments, there is little consensus about the nature of the problem or about possible solutions to it. Greatly reduced energy forecasts allow a pause for reflection, but it is argued that there is no room for complacency about conflict over energy developments in future.     

Toward a comprehensive assessment of fundamental motivation: Factor structure of the Reiss Profiles.

Two instruments were developed to provide a comprehensive assessment of the strength of a person's fundamental end goals and motivational sensitivities. One instrument was a self-report inventory for adolescents and adults in general, and the other was an informant-rating scale for adolescents and adults with mental retardation and development disabilities. Exploratory and confirmatory factor analyses and test-retest reliabilities are reported in 7 studies, with independent samples of participants from diverse geographical areas, occupations, and social groups, N?=?2,548. Each instrument was found to have a 15-factor solution, and the 2 solutions were similar to one another. Because the factors assess universal motives that are also seen in animals, a genetics-behavior-cognitive model of fundamental motivation is suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Articular cartilage volume in the knee: semiautomated determination from three-dimensional reformations of MR images

PURPOSE: To determine the accuracy of semiautomated quantification of articular cartilage volume from three-dimensional (3D) reformations of magnetic resonance (MR) images. MATERIALS AND METHODS: Sagittal, fat-suppressed, 3D, spoiled gradient-recalled-echo MR imaging of two bovine and two human cadaver knees was performed. Articular cartilage volume was calculated from 3D reformations of the MR images by using a semiautomated program written at the authors' institution. Calculated volumes were compared with directly measured volumes of the surgically removed articular cartilage. RESULTS: The percentage of error of the MR imaging-determined volumes was 6.53% +/- 4.75 (mean +/- standard deviation). A strong correlation between the two sets of observations was shown (r=.997). Linear regression showed the calculated volumes to be highly accurate (slope=1.002, P>.25). Repeated reformations yielded volumes that were reproducible (mean absolute error, 0.013 mL +/- 0.019) and not significantly different from the measured volume (P>.10). CONCLUSION: Semiautomated quantification of knee articular cartilage from MR images yields highly accurate cartilage volumes.     

Comparative evaluation of FUNGITEST and broth microdilution methods for antifungal drug susceptibility testing of Candida species and Cryptococcus neoformans

The FUNGITEST method (Sanofi Diagnostics Pasteur, Paris, France) is a microplate-based procedure for the breakpoint testing of six antifungal agents (amphotericin B, flucytosine, fluconazole, itraconazole, ketoconazole, and miconazole). We compared the FUNGITEST method with a broth microdilution test, performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines, for determining the in vitro susceptibilities of 180 isolates of Candida spp. (50 C. albicans, 50 C. glabrata, 10 C. kefyr, 20 C. krusei, 10 C. lusitaniae, 20 C. parapsilosis, and 20 C. tropicalis isolates) and 20 isolates of Cryptococcus neoformans. Overall, there was 100% agreement between the methods for amphotericin B, 95% agreement for flucytosine, 84% agreement for miconazole, 83% agreement for itraconazole, 77% agreement for ketoconazole, and 76% agreement for fluconazole. The overall agreement between the methods exceeded 80% for all species tested with the exception of C. glabrata (71% agreement). The poorest agreement between the results for individual agents was seen with C. glabrata (38% for fluconazole, 44% for ketoconazole, and 56% for itraconazole) and C. tropicalis (50% for miconazole). The FUNGITEST method misclassified as susceptible 2 of 12 (16.6%) fluconazole-resistant isolates, 2 of 10 (20%) itraconazole-resistant isolates, and 4 of 8 (50%) ketoconazole-resistant isolates of several Candida spp. Further development of the FUNGITEST procedure will be required before it can be recommended as an alternative method for the susceptibility testing of Candida spp. or C. neoformans.     

Attenuation of second sound in bulk flowing He II

New measurements of second sound attenuation in bulk flowing He II are reported which extend to a region of higher Reynolds number. An expression for the attenuation explicitly containing the quantum vortex line density is developed which allows comparison with vortex line density data taken by other means. A bellows driven experimental apparatus is used to produce bulk flow velocities of 0 to 1 m/sec in a channel of 4.064 mm square internal cross section. Second sound pulses are produced by applying a square voltage pulse 200 s width and variable height to a strain gauge heater. The second sound pulses are detected with thin film sensors mounted 56 and 119 mm downstream. The velocity-dependent attenuation, measured as a function of bulk flow velocity at 1.5, 1.8, and 2.0 K, is compared with data from other researchers. The attenuation, and thus the vortex line density, appears to follow a gradual transition from laminar to turbulent behavior. Current theories do not account for the presence of quantized vortices in bulk flowing He II, where (v _n–v _s), and thus do not explain the observed second sound attentuation in this regime.     

Isolation of two nitrogen-free toxins from tung kernels

Summary A procedure is described for isolating two nitrogen-free toxins from tung kernels and from press cake. Chick-feeding tests were used to determine which fraction was toxic at every separation. Both substances were highly toxic as 10-mg. doses killed 4-day old chicks. These substances were shown by chromatography on glass paper to be different and chromatography homogeneous, but also unstable. The elementary composition, hydroxyl content, saponification value, and specific rotation for the two toxins are given. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U, S. Department of Agriculture.