The circuit realization of Mexican Hat wavelet function

A wavelet network circuit implementation for Mexican Hat mother wavelet has been proposed for nonlinear function approximation which can also be used for the realization of the algebraic nonlinear components. The Mexican Hat mother wavelet function has been implemented with discrete circuit components and it has been observed that the experimental waveform obtained from the realized circuit is approximately same as the Spice simulation of the original function. The circuit simulations of exemplar functions implemented in Spice are also given.     

Effects of interesterified vegetable oils and sugar beet fibre on the quality of Turkish-type salami

Turkish‐type salami is an emulsion type product that is only shelf stable at chilling temperature. The use of three interesterified vegetable oils (IVOs) prepared from either palm, cottonseed or olive oil (IPO, ICO and IOO, respectively) together with 2% sugar beet fibre (SBF) (<425 μm) was studied in the production of Turkish‐type salami. These compounds were used to modify the fatty acid composition and increase the dietary fibre content of the traditional product. Beef fat (10%) was replaced by one of the IVOs at either 60 or 100%. The addition of SBF significantly increased (P < 0.05) the total dietary fibre content and water‐holding capacity of salamis. Incorporation of IVOs improved the nutritional content of the product because it altered the fatty acid composition. It was found that total or partial replacement of beef fat by IVOs, as well as the presence of 2% SBF, did not lead to significant changes in appearance, colour, texture, flavour or sensory score. The use of IVO and SBF as fat substitutes could be used to obtain a low fat product with high dietary fibre and a modified fatty acid composition.     

ION EXCHANGE PROPERTIES OF BiO(NO3) 0.5H2O TOWARDS FLUORIDE IONS

ABSTRACT

We studied the ion exchange behavior of the inorganic anion exchanger BiO(NO₃)0.5H₂O with regard to fluoride ions. The ion exchange reaction was rapid at pH 1, 6.6, and 12. The mechanisms of ion exchange reactions at pH 1 and pH 2-12 were studied in a solution with fluoride ions excess to BiO(NO₃)0.5H₂O. A mixture of the β-phase and an unknown phase was produced in the solution at pH 1. BiOF was produced at pH 2-12. Fluoride ions did not react at pH 13, due to the decomposition of BiO(NO₃) 0.5H₂O at pH 13 to yield Bi₂O₃ (major) and Bi₂O₂CO₃ (minor). The structure of the reaction products depended on the solution pH, mole ratios of BiO(NO₃)0.5H₂O to F’, and the reaction time. We observed that BiO(NO₃)0.5H₂O is capable of removing 99% of the fluoride ions from the solution at pH 1-12 under optimal conditions. The ion exchange reaction of BiO(NO₃)0.5H₂O with fluoride ions was studied under the co-existence of both Cl and Br^?at pH 1, 6.6, 12, and 13. The order of decreasing affinity was found to be (Br^?, Cl^?)> F^?. The reaction product was not a simple mixture of BiOCl, BiOBr, and bismuth oxide fluorides, but an unknown compound.     

The impact of Nd3+ ions on linear/nonlinear and the ionizing radiation attenuation parameters of TeO2-PbO-Y2O3 glasses

Journal of Materials Science: Materials in Electronics - The influence of Nd3+ ion-reinforced yttrium lead borotellurite glasses based on (49-x)B2O3-35TeO2-15PbO-1.0Y2O3-xNd2O3 (where...     

Catalytic epoxidation of methyl linoleate

The epoxidation of methyl linoleate was examined using transition metal complexes as catalysts. With a catalytic amount of methyltrioxorhenium (4 mol%) and pyridine, methyl linoleate was completely epoxidized by aqueous H₂O₂ within 4 h. Longer reaction times (6 h) were needed with 1 mol% catalyst loading. Manganese tetraphenylporphyrin chloride was found to catalyze the partial epoxidation of methyl linoleate. A monoepoxidized species was obtained as the major product (63%) after 20 h.     

Experimental design for extraction of bio-oils from flax seeds under supercritical ethanol conditions

A central composite design was applied to the extraction of bio-oils from flax seeds under supercritical ethanol (Sc-EtOH) conditions. The effects of three factors (temperature, time, and biomass concentration) on bio-oil and biomass conversion yields were examined. Extraction temperature was statistically found to be the most significant factor which affected both bio-oil yield and biomass conversion. The predicted results matched the experimental results with the following coefficient of determination: (R ²) 0.95 for bio-oil yield and 0.92 for biomass conversion yield. The composition of bio-oils consisted mainly of fatty acid ester derivatives, and other oxygenated hydrocarbons. Based on the relative concentrations of the compounds, the major compound was ethyl oleate.     

Realization of a VCO for WLAN applications using 0.35 μm‐siGe BICMOS technology

In this article, a 4.5–5.8 GHz, ?G_m LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is designed with Austria MicroSystems 0.35 μm SiGe BiCMOS process that includes high‐speed SiGe heterojunction bipolar transistors (HBTs). According to measurement results, phase noise is ?102.3 dBc/Hz at 1 MHz offset from 5 GHz carrier frequency. A linear, 1300 MHz tuning range is obtained utilizing accumulation‐mode varactors. Phase noise is relatively low because of the advantage of differential tuning concept. Output power of the fundamental frequency changes between ?1.6 and 0.9 dBm depending on the tuning voltage. Average second and third harmonic levels are ?25 and ?41 dBm, respectively. The circuit draws 14 mA DC current from 3.3 V supply including buffer circuits leading to a total power dissipation of 46.2 mW. The prototype VCO occupies an area of 0.6 mm² on Si substrate, including DC and RF pads. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

Factors affecting the electrical resistivity of soybean oil

The electrical resistivity of soybean oil that had been purified to remove polar constituents was determined, and the effect of measuring conditions and the addition of polar constituents (free fatty acids, phospholipids, monoglyceride, α-to-copherol, β-sitosterol, β-carotene, peroxides, and water) on resistivity was investigated. For reproducible resistivity measurements, voltages in excess of 50 volts and charging times greater than 120 s were necessary. As temperature was increased linearly, the resistivity of the oil decreased logarithmically. For making comparisons, a temperature of 24°C, a potential of 50 volts, and 120 s charging times were chosen. All polar constituents decreased the resistivity of the purified soybean oil, but water, phospholipids, and monoglycerides had the greatest effects. Water increased the resistivity-lowering effects of all other constituents except for free fatty acids, which were affected by water only slightly. The synergistic effect of water was much greater for phospholipids and monoglyceride than for other constituents.     

Human serum albumin (HSA) adsorption with chitosan microspheres

In this study, chitosan microspheres were prepared and characterized for adsorption of human serum albumin (HSA) as affinity sorbent. The chitosan microspheres were obtained with a “suspension crosslinking technique” in the size range of 30–700 μm by using a crosslinker, i.e., glutaraldehyde. The chitosan microspheres used in HSA adsorption studies were having the average size of 170 ± 81 μm. Adsorption medium pH and the initial HSA concentration in the adsorption medium were changed as 4.0–7.0 and 0.5–2.0 mg HSA/mL, respectively, to investigate the HSA adsorption capacity of chitosan microspheres. Maximum HSA adsorption (i.e., 11.35 mg HSA/g chitosan microspheres) was obtained at pH 5.0 and 1.5 mg HSA/mL of the initial HSA concentration in the adsorption medium was obtained as the saturation value for HSA adsorption. A very common dye ligand, i.e., Cibacron Blue F3GA was attached to the chitosan microspheres to increase the HSA adsorption capacity. Actually, the HSA adsorption capacity was increased up to 15.35 mg HSA/g chitosan microspheres in the case of Cibacron Blue F3GA attached to chitosan microspheres used. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3035–3039, 2002     

Cross‐Coupled Ratio Control Structure

Abstract

In this paper, a cross‐coupled ratio control structure with two blend stations has been proposed. The main feature of the proposed structure is to give a good ratio performance for both set‐point changes and load disturbances that might occur in any one of the two loops. A simple tuning procedure for the inner controllers of the two loops and an easy design methodology for the blend stations have been proposed in order to avoid any significant tuning and design effort for the implementer. The proposed structure is realized on a microcontroller based system. This cross‐coupled ratio control structure that has been embedded into the microcontroller is then used to maintain the prescribed ratio “a” of the two processes, namely heat transfer process trainer (PT 326‐Feedback) and process control simulator (PCS 327‐Feedback). The same two processes are run under another alternative ratio control structure and the results are compared with each other.