A knowledge-based system for sensor selection

This paper presents a Knowledge-based system (KBS) developed to allow users, who may not be knowledgeable about sensors, to select sensors suitable for their specific needs. The KBS runs on a micro-computer. The selection criteria are user specified and are based on the desired measurement parameters. The system output includes all of the operational and dimensional parameters of the recommended sensor, price, and vendor information.     

Terson''s syndrome in a patient with acute promyelocytic leukemia on all-trans retinoic acid treatment

Hypothermia induced by surface cooling has shown to protect vulnerable regions of the brain during an ischemic insult. This study evaluated the neuroprotective efficacy of neurotensin, a potent hypothermic agent, using a 5-min carotid occlusion procedure in the gerbil. In Experiment 1, the dose-response and time course of neurotensin-induced hypothermia were evaluated (n = 5/dose). Central infusion of 10, 20, and 30 micrograms neurotensin were found to significantly decrease core body temperature of conscious gerbils within 30 min of administration. In Experiment 2, gerbils pretreated with 30 micrograms neurotensin were permitted to become hypothermic or were maintained at 37 degrees-38 degrees C (rectal) during ischemic insult. Other gerbils were pretreated with peptide vehicle prior to ischemic insult (at 37 degrees -38 degrees C) or underwent a sham procedure (n = 6/condition). At 24 h after surgery, gerbils were tested for increased locomotor activity in an open-field apparatus. Gerbils pretreated with peptide vehicle or neurotensin and maintained at 37 degrees-38 degrees C during ischemia had significantly higher activity levels compared to the other treated groups. In contrast, gerbils made hypothermic with neurotensin exhibited activity levels similar to sham gerbils. Histological assessment revealed that neurotensin-induced hypothermia protected the CA1 region from ischemic damage.     

Influence of ferrite-martensite microstructural morphology on tensile properties of dual-phase steel

The influence of ferrite-martensite microstructural morphology, volume fraction of martensite, epitaxial ferrite on the tensile behaviour of dual-phase steels, was studied. It was observed that increasing the martensite content and its aspect ratio raised tensile strength and ductility. Epitaxial ferrite in rolled material strongly reduced the strength and improved the ductility, suggesting that substructure strengthening of material, as well as increased stress transfer to the hard phase, contribute to the strength of thermo-mechanically processed material. Mettallographic analysis of deformed samples revealed that void nucleation occurs predominantly along the ferrite-martensite interface. The void density in the necked region increased towards the fracture surface in all samples and was higher for samples which exhibited localized necking.     

Time jitter analysis of 1-bit sigma-delta synthesizer

This letter presents a general analysis of time jitter in sigma-delta synthesizer. One of the practical applications of 1-bit sigma-delta systems is a generation of high-resolution local oscillator (LO) signals. In order to generate LO signals, one may use a single-bit sigma-delta technique to encode sine waves. Today, direct generation of high-frequency sine wave using a clock with higher frequency, is possible. In this letter, we will analyze different LO signal generators and develop a practical way of computation to decide how to choose the best configuration under minimum degradation of signal-to-noise ratio (SNR) at the output.     

Influence of sources of dietary oils on the life span of stroke-prone spontaneously hypertensive rats

In recent studies, the life span of stroke-prone spontaneously hypertensive (SHRSP) rats was altered by a variety of dietary fats. It was relatively shorter in rats fed canola oil as the sole source of fat. The present study was performed to find out whether the fatty acid profile and the high content of sulfur compounds in canola oil could modulate the life span of SHRSP rats. SHRSP rats (47 d old, n=23/group) were matched by body weight and systolic blood pressure and fed semipurified diets containing 10% canola oil, high-palmitic canola oil, low-sulfur canola oil, soybean oil, high-oleic safflower oil, a fat blend that mimicked the fatty acid composition of canola oil, or a fat blend high in saturated fatty acids. A 1% sodium chloride solution was used as drinking water to induce hypertension. After consuming the diets for 37 d, five rats from each dietary group were killed for collection of blood and tissue samples for biochemical analysis. The 18 remaining animals from each group were used for determining their life span. The mean survival time of SHRSP rats fed canola oil (87.4±4.0 d) was not significantly different (P>0.05) from those fed low-sulfur canola oil (89.7±8.5 d), suggesting that content of sulfur in canola oil has no effect on the life span of SHRSP rats. The SHRSP rats fed the noncanola oil-based diets lived longer (mean survival time difference was 6–13 d, P<0.05) than those fed canola and low-sulfur canola oils. No marked differences in the survival times were observed among the noncanola oil-based groups. The fatty acid composition of the dietary oils and of red blood cells and liver of SHRSP rats killed after 37 d of treatment showed no relationship with the survival times. These results suggest that the fatty acid profile of vegetable oils plays no important role on the life span of SHRSP rat. However, phytosterols in the dietary oils and in liver and brain were inversely correlated with the mean survival times, indicating that the differential effects of vegetable oils might be ascribed, at least partly, to their different phytosterol contents.     

Temperature-dependent diffusion coefficient of soluble substances during ethanol extraction of clove

The temperature dependence of the diffusion coefficient of ethanol-soluble substances from ground cloves (particle size 250 μm) during extraction was estimated by fitting batch extraction data at several temperatures (27.8, 40, 50, and 60°C) to a previously developed mass transfer model. The model was based on spherical geometry of particles. Nonlinear regression analysis was used to develop an equation that describes the diffusivity as a function of temperature. The temperature dependence ofD _A was of the Arrhenius type.     

Fuzzy decision support system for fertilizer

Fuzzy geographic information systems is a newly emerging field of computational intelligence. It combines fuzzy logic with spatial context. Most of the natural phenomena are fuzzy in nature. They show a degree of uncertainty or vagueness in their extent and attribute, which cannot be expressed by a crisp value. Agriculture is one of the fields of the spatial domain that needs to be described in fuzzy terms. Fertilizer is a key input for the agriculture sector. In this article, the spatial surfaces of fertilizers are developed for the wheat crop using a fuzzy decision support system. The algorithm of our system takes soil nutrients and cropping time as input, applies fuzzy logic on the input values, defuzzifies the fuzzy output to crisp value, and generates a fertilizer surface. The resultant output surface of fertilizer describes the amount of fertilizer needed to cultivate a specific crop in a specified area. The complexity of our algorithm is \(O(mnr)\) , where \(m\) is the height of the raster, \(n\) is the width of the raster, and \(r\) is the number of expert rules.     

High aspect ratio gold nanopillars on microelectrodes for neural interfaces

Microelectrode arrays (MEA) have become an established tool in applied and fundamental research. Low impedance at the interface between tissue and conducting electrodes is of utmost importance for the electrical recording or stimulation of electrophysiological active cells such as cardiac myocytes and neurons. A common way to improve this interface is to increase the electrochemically active surface area of the electrode. In this paper the fabrication of microelectrodes covered with very high aspect ratio (AR > 100) gold nanopillars is presented and electrode biocompatibility is investigated using cell culture experiments. The nanopillar electrodes show decreased impedance over the entire scanned frequency range of 1 Hz–100 kHz and an impedance improvement of up to 89.5 at 1 kHz depending on nanopillar height. Neurons adhere well to the substrate and electrodes and signals with amplitudes up to ten times higher than with conventional gold electrodes were recorded in cell culture experiments.     

Effect of competitive interference on the biosorption of lead(II) by Chlorella vulgaris

Batch experiments were carried out to asses the effect of Cu(II) and Zn(II) on the biosorption of lead(II) ions by non-living Chlorella vulgaris. The uptake of Pb(II) was examined for single, binary and ternary solutions at different initial concentrations and different pH values. The experimental results showed that the uptake increased with increasing pH from 3.0 to an optimum value of 5.0. The biosorption of Pb(II) was found to be adversely affected by the presence of Cu(II) ions, while Zn(II) ions seemed to have negligible effect on the process. The equilibrium data were fitted to four isotherm models: Langmuir, Freundlich, Sips and Dubinin–Radushkevich; the Sips isotherm gave the best fit for the data. Modeling of the controlling mechanisms indicated that both intrinsic kinetics and mass transfer played major roles in controlling the process. A new dimensionless parameter, Ψ, was defined to asses the relative contributions of the two mechanisms to the biosorption of lead(II). Mass transfer seemed to be the dominant mechanism at low initial lead(II) concentrations, while intrinsic kinetics dominates at high concentrations.