Advanced concepts in electric vehicle design

In 1994, the Eco-Vehicle Project was begun to develop an electric vehicle (EV) using a ground-up design approach that incorporates unique designs specific to an EV. The Eco-Vehicle will be a high-performance, but ultrasmall, battery-powered vehicle. New designs for the Eco-Vehicle include an in-wheel motor drive system, a hollow load floor which will house the batteries, and a new battery management system. The Eco-Vehicle may also utilize other advanced concepts suitable especially for EVs, including solar panels for battery charging and intelligent crash avoidance and guidance systems     

Impact strength and melt viscosity of bisphenol-a polycarbonate and styrene-maleic-anhydride copolymer blends

Mixtures of 90, 80, and 70 percent by weight bisphenol-A-polycarbonate (PC) and 10, 20, and 30 percent by weight styrene maleic anhydride (SMA) copolymer were melt-blended in a single screw extruder. Differential scanning calorimetry (DCS) and scanning electron microscopy (SEM) were used to determine the miscibility of the blends. The viscosity, as a function of shear rate and temperature, was measured by an Instron capillary viscometer. The notched impact strength as a function of temperature was measured by an Izod impact tester. The results of DSC showed two glass transition temperatures which merged slightly towards each other, indicating marginal miscibility of these blends. There was a decrease in viscosity as the fraction of SMA copolymer was increased. The most significant decrease occurred with the initial addition of SMA copolymer. The viscosity also decreased with increases in temperature. The impact strength of the blends was also dependent on SMA copolymer content. The blends showed six to ten times lower impact strengths at room temperature than the 100 percent polycarbonate. SEM analysis helped to determine the reason why the impact strength was lower for the blends. High magnification showed the presence of SMA copolymer inclusions dispersed throughout the PC matrix. These inclusions, which increased in size as SMA copolymer content was increased, acted as defects in the system.     

Effect of pH on a gossypol complex with phospholipids: Gossypol-PE

PE, one of the major phospholipids in oilseed soapstock, may react with gossypol to form Schiff bases. PE amounts to 20–30% of the phosphorus compounds in soap-stock. In this report, the dependence on pH of the Schiff base products between PE and gossypol was investigated using a spectrophotometer, an HPLC equipped with an ELSD, and an LC-MS system. We observed that at pH 7 the Schiff reaction product and reactants were clearly detected by ELSD, absorption, and LC-MS spectra. The absorption spectra displayed the characteristic peak for the Schiff bases around 430–440 nm. The absorption spectra also indicated that the reaction was pH dependent. The reaction temperatures were 60 and 90°C. The LC-MS spectra supported the formation of Schiff bases as well as methyl ether derivatives of gossypol in alcohol at the elevated temperatures. The implications of these experimental findings are presented in this paper.     

Retrospective correction of intensity inhomogeneities in MRI

Medical imaging data sets are often corrupted by multiplicative inhomogeneities, often referred to as nonuniformities or intensity variations, that hamper the use of quantitative analyses. The authors describe an automatic technique that not only improves the worst situations, such as those encountered with magnetic resonance imaging (MRI) surface coils, but also corrects typical inhomogeneities encountered in routine volume data sets, such as MRI head scans, without generating additional artifact. Because the technique uses only the patient data set, the technique can be applied retrospectively to all data sets, and corrects both patient independent effects, such as rf coil design, and patient dependent effects, such as attenuation of overlying tissue experienced both in high field MRI and X-ray computed tomography (CT). The authors show results for several MRI imaging situations including thorax, head, and breast. Following such corrections, region of interest analyses, volume histograms, and thresholding techniques are more meaningful. The value of such correction algorithms may increase dramatically with increased use of high field strength magnets and associated patient-dependent rf attenuation in overlying tissues.     

Effect of precooking and polyphosphate treatment on the quality of catfish fillets cooked in pouch in boiling water

Cooking or reheating food in a vacuum‐sealed bag has been a common method of preparing vegetables, meats and poultry products. However, there are very few examples of vacuum‐sealed bags designed for cooking catfish fillets. The objective was to examine properties of raw frozen and precooked frozen catfish fillets that were cooked in a vacuum‐sealed pouch in boiling water. The effect of a commercial polyphosphate blend (IQF) on product properties was also evaluated. Sample analyses included weight loss, proximate content, colour (CIE L*a*b*), pH, mechanical texture and lipid peroxidation (TBARS) measurements. Both raw frozen and precooked frozen IQF fillets showed a significantly lower per cent moisture loss after cooking, of less than 2.7% relative to the fillets without polyphosphate (6.2–7.4%). Colour analysis showed a significantly higher b*(C) (yellowness) value for fillets without polyphosphate. Similar texture properties were observed between cooking treatments, with a harder texture (~1.3–1.7 times) determined for fillets without polyphosphate.     

Boiling from metal surfaces immersed in liquid nitrogen and liquid hydrogen

A study of bubble nucleation in liquid nitrogen and liquid hydrogen has been made in a 120 mm bubble chamber using a high speed cine camera.The initiation and growth of bubbles from artificially prepared cavities was studied. These cavities, produced in both copper and brass surfaces, had mouth radii ranging from 50 μm to 190 μm with depths varying from 110 μm to 500 μm. The liquids were superheated by either heating the surface containing the cavities or by reducing the pressure of the liquid, or by combining both of these methods.The heat fluxes required for initiation of boiling were greater than those required to sustain nucleation from a given site. The growth rate of the bubbles at constant liquid pressure was dependent on a number of factors. It changes as a bubble grew out of the thermal or superheated layer above the metal surface. After an initial period of more rapid growth the vapour volume increased linearly with time. The growth rate was dependent on the liquid used; being slower in liquid hydrogen than in liquid nitrogen. Formulae were obtained which predicted the observed variations in growth rate and departure volume.No nucleation was observed from the test surfaces for a pressure drop alone; the surfaces had to be heated before nucleation would occur. It is thought that this was due to the existence of a zero contact angle for cryogenic liquids on solid surfaces.     

Method for quantifying volumetric lesion change in interval liver CT examinations

We propose a method of using a relatively low degree of freedom (DOF) warping to accurately measure the interval change of lesions having homogeneous contrast. The setting presented here presupposes the use of interval computed tomography (CT) liver exams. After a 3 x 24 DOF warping of the later examination to match the liver's pose in the earlier exam of the interval pair is performed, the lesion's volume change is estimated using the computed difference volume of the two data sets via a novel method that counts partial volume contributions and is insensitive to slight misregistration. A mathematically generated phantom is used to quantify accuracy in the presence of noise. We also quantify the accuracy of our CT liver registrations using microcoils implanted for chemotherapy. A probabilistic liver atlas is used to support automatic masking and liver-focused registration.     

Construction of an abdominal probabilistic atlas and its application in segmentation

There have been significant efforts to build a probabilistic atlas of the brain and to use it for many common applications, such as segmentation and registration. Though the work related to brain atlases can be applied to nonbrain organs, less attention has been paid to actually building an atlas for organs other than the brain. Motivated by the automatic identification of normal organs for applications in radiation therapy treatment planning, we present a method to construct a probabilistic atlas of an abdomen consisting of four organs (i.e., liver, kidneys, and spinal cord). Using 32 noncontrast abdominal computed tomography (CT) scans, 31 were mapped onto one individual scan using thin plate spline as the warping transform and mutual information (MI) as the similarity measure. Except for an initial coarse placement of four control points by the operators, the MI-based registration was automatic. Additionally, the four organs in each of the 32 CT data sets were manually segmented. The manual segmentations were warped onto the "standard" patient space using the same transform computed from their gray scale CT data set and a probabilistic atlas was calculated. Then, the atlas was used to aid the segmentation of low-contrast organs in an additional 20 CT data sets not included in the atlas. By incorporating the atlas information into the Bayesian framework, segmentation results clearly showed improvements over a standard unsupervised segmentation method.