Voltage-mode universal filter with one input and five outputs using DDCCTAs and all-grounded passive components

This paper presents a versatile voltage-mode universal active filter with one input and five output terminals. The proposed circuit is based on using the recently reported active building block, namely differential difference current conveyor transconductance amplifier (DDCCTA). It employs two DDCCTAs as active elements together with two resistors and two capacitors as passive elements, which are all grounded. The circuit simultaneously realizes all the five standard biquadratic filter functions; i.e., lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP), without changing circuit topology. The proposed circuit also has the advantage of high-input impedance terminal, and exhibits electronic tunability of its important parameters through the bias current of the DDCCTA as well as low sensitivity performance. PSPICE simulations using 0.5 μm MIETEC CMOS process are used to validate the theoretical predictions.     

Dietary assessment of refugees living in camps: a case study of Mae La Camp, Thailand

This study presents data on consumption patterns, methods of food procurement, and adequacy of dietary intake among Burmese refugee camp households living along Thailand's border with Burma. Households established for one or more years and with children under 15 years of age were sampled. A questionnaire was used to determine economic, food-consumption, and dietary intake patterns; foods consumed were weighed and measured using a 24-hour recall for the household unit; and nutritional status was determined by a Microtoise tape and digital standing scales. In total, 182 households containing 1,159 people were surveyed. The average household energy and protein intakes were 96.6% and 111.4%, respectively, of the recommended daily allowance (RDA) for healthy Thais. Twelve percent of protein was derived from animal sources. Carbohydrate, protein, and fat accounted for 84%, 9%, and 7% of total energy, respectively. The intake of vitamins A, B1, B2, and C and of calcium ranged from 24.2% to 53.1% of the RDA. Iron intake was 85.3% of the RDA, derived mainly from rice, fermented fish, mung beans, green leafy vegetables, and eggs. Ration foods supplied 60.5% to 98.18% of all nutrients consumed in the households, with the exception of vitamins A and C. Among children under five years of age, 33.7% were underweight, 36.4% were studied, and 8.7% were wasted. Although the refugees were able to procure some nonration foods by foraging, planting trees and vegetables, raising animals, and purchasing and exchanging ration foods for other items, the quantity and quality were not sufficient to compensate for the nutrients that were low or lacking in the ration. The overwhelming majority of dietary nutrients were provided by ration foods, and although the ration and the overall diet may be adequate for short-term subsistence, they do not suffice for long-term survival and optimal growth, especially for younger children.     

Single-input four-output voltage-mode universal filter using single DDCCTA

An electronically tunable universal voltage-mode biquadratic filter with single input and four outputs using one differential difference current conveyor transconductance amplifier (DDCCTA), two resistors and two grounded capacitors is proposed. All the five standard biquadratic filter functions; lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP), can be obtained from the circuit configuration. The LP, BP and HP are simultaneously available without component matching condition. By imposing component choice, the BS and AP responses can also be realized from the same circuit configuration. In addition, the proposed circuit provides an electronic control of its natural angular frequency (ω₀) and quality factor (Q) by adjusting the bias current of the DDCCTA. The simulation results together with the ideal values are also given to demonstrate the performance of the proposed circuit.     

Effect of chitin and chitosan on gelling properties of surimi from barred garfish (Hemiramphus far)

The addition of chitin/chitosan significantly increased the breaking force and deformation of gels prepared from barred garfish surimi (P < 0.05). Addition of 7B chitosan with 65.6% degree of deacetylation (% DD) at the level of 15 mg g⁻¹ resulted in the maximum increases in both breaking force and deformation of suwari and kamaboko gels compared to the control and gels containing chitin or chitosan with other % DD (P < 0.05). A chitosan concentration of 10 mg g⁻¹ was found to render the highest breaking force of kamaboko gel compared to other concentrations tested (P < 0.05). Kamaboko gel containing chitosan had an increased breaking force as the calcium chloride concentration increased (P < 0.05), indicating the role of endogenous transglutaminase in cross‐linking of protein–protein and protein–chitosan conjugates. Therefore the incorporation of chitosan and calcium chloride greatly improved the gelling properties of surimi from barred garfish without changes in colour. © 2000 Society of Chemical Industry     

Vasorelaxant and Antioxidant Activities of Spilanthes acmella Murr.

This study reports the effect of Spilanthes acmella Murr. extracts on phenylephrine-induced contraction of rat thoracic aorta as well as their antioxidant activity. Results show that the extracts exert maximal vasorelaxations in a dose-dependent manner, but their effects are less than acetylcholine-induced nitric oxide (NO) vasorelaxation. Significant reduction of vasorelaxations is observed in both N^G-nitro-l-arginine methyl ester (l-NAME) and indomethacin (INDO). In the presence of l-NAME plus INDO, synergistic effects are observed, leading to loss of vasorelaxation of both acetylcholine and the extracts. Similarly, the vasorelaxations of the extracts are completely abolished upon the removal of endothelial cells. This demonstrates that the extracts exhibit vasorelaxation via partially endothelium-induced NO and prostacyclin in a dose-dependent manner. Significantly, the ethyl acetate extract exerts immediate vasorelaxation (ED₅₀ 76.1 ng/mL) and is the most potent antioxidant (DPPH assay). The chloroform extract shows the highest vasorelaxation and antioxidation (SOD assay). These reveal a potential source of vasodilators and antioxidants.     

Natural rubber and butadiene rubber blend using diblock copolymer of isoprene–butadiene as compatibilizer

Blends of natural rubber (NR) and butadiene rubber (BR) have been studied with or without diblock copolymers of isoprene–butadiene (BIR). It was found that NR/BR blends displayed the optimal properties at about 4 wt % of BIR from the tensile measurements of NR/BR blends. Increase of molecular weight of BIR resulted in the decrease of tensile properties, but had no significant effect on their hardness. Abrasion resistance of rubber blends containing BIR was about 30% higher than that without BIR. The molecular weight of BIR did not show a remarkable effect on the abrasion index. Differential scanning calorimetry and dynamic mechanical analyses of rubber blends suggested a two-phase structure even in the presence of BIR. © 1993 John Wiley & Sons, Inc.     

Aroma enrichment and the change during storage of non-aromatic milled rice coated with extracted natural flavor

Three non-aromatic rice varieties (RD23, SPR1 and SPR90) were coated in a modified spouted bed with 30% sorbitol-plasticized rice-starch film containing 25% pandan (Pandanus amaryllifolius Roxb.) leaf extract produced by the supercritical fluid with carbon dioxide extraction method. The coated and uncoated samples and uncoated aromatic rice (KDML and PTT1 varieties) were packed in plastic bags (nylon15/PE20/LLDPE75) and stored at 25 °C for 6 months. Gas chromatography–mass spectrometry analysis revealed that the coating treatment resulted to similar flavor volatile profile as that of aromatic varieties, particularly the presence of 2-acetyl-1-pyrroline (ACPY) which is the main volatile compound responsible for the jasmine aroma. ACPY was absent in uncoated non-aromatic rice and ACPY content of non-aromatic rice coated with natural pandan extract was lower than that of uncoated aromatic rice. During storage, ACPY levels decreased. Coated non-aromatic rice retained higher ACPY levels than the aromatic PTT1 variety. The coating treatment also reduced the n-hexanal content of stored grains. Thus, the coating technique is a promising approach for rice aroma improvement and at the same time, for reducing the potential for oxidative rancidity during grain storage.