Throughput and energy performance of TCP on a wideband CDMA air interface

In this paper, we present a study on the performance of TCP, in terms of both throughput and energy consumption, in the presence of a wideband CDMA radio interface typical of third generation wireless systems. The results show that the relationship between throughput and average error rate is largely independent of the network load, making it possible to introduce a universal throughput curve, empirically characterized, which gives throughput predictions for each value of the user error probability. Furthermore, the study of the energy efficiency shows the possibility to select an optimal power control threshold to maximize the trade‐off between throughput and energy, thereby potentially achieving very significant energy gains. Copyright © 2001 John Wiley & Sons, Ltd.     

Flame-retardant properties of phenol–formaldehyde-type resins and triphenyl phosphate in styrene–acrylonitrile copolymers

The thermal and flame-retardant properties of phenol–formaldehyde-type resins (crosslinked and noncrosslinked) in mixtures with triphenyl phosphate and styrene–acrylonitrile resins were evaluated. The mixtures show a synergistic effect between triphenyl phosphate and novolacs. Those containing phenol–formaldehyde novolac resins are found to be most flame retardant. There does not seem to be a relationship between the oxygen index (OI) and UL 94 tests. Scanning electron microscopy analysis show a surface structure with cavities and stratification, very similar to that of intumescent additives. Evidence was found indicating that this flame-retardant system works in both the gas and condensed phase. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1067–1076, 1998     

The effect of bleaching and physical refining on color and minor components of palm oil

An industrially degummed Indonesian palm oil was bleached and steam refined in a pilot plant to study the effect of processing on oil color and on the levels of carotenoids and tocopherols. Five concentrations of one natural and two activated clays mixed with a fixed amount of synthetic silica were used for bleaching. For color measurement, the Lovibond method was compared to the CIE (Commission Internationale de l’Eclairage) L^*,a^*,b^* method. The results showed that the L^*,a^*,b^* method is repeatable and that the values found are highly correlated with the carotenoid content of bleached oil samples. The various clays and synthetic silica mixes removed 20–50% of the carotenoids in the degummed oil, depending on clay concentration and activity. For the two activated clays, pigment adsorption increased with clay amount. Steam refining totally destroyed carotenoids in the claytreated oils by heat bleaching. Total tocopherols in the crude oil amounted to 1000 mg/kg, with γ-tocotrienol as the main tocopherolic component followed by α-tocopherol, α-tocotrienol, and δ-tocotrienol. Tocopherol concentrations increased after the bleaching treatment with the most acid clay, and the increase was proportional to the amount of clay used. Both bleaching and steam refining changed the ratios between the various to copherolic components, especially increasing the relative concentration of α-tocotrienol in the refined oil. An average 80% tocopherol retention was obtained after the treatment with acid clay + synthetic silica and steam refining of palm oil.     

Physicochemical,thermal, and pasting properties of flours and starches of eight Brazilian maize landraces (Zea mays L.)

Both genetic and environmental factors create significant variation in the amount and quality of maize landrace constituents. Details on the flours and starch characteristics have not been fully investigated. The physicochemical, pasting and thermal properties of 8 promising cultivars were assessed in this study and those properties were correlated. Higher values of swelling and solubility (RJ – 13.14%; 14.39%), lipid content (MG – 5.53%), WBC (PR – 18.89%), and amylose content (PR – 27.43%) were found for those genotypes. Lower onset temperatures of gelatinization (To) were observed for RX-F1 (66.1 °C) as RX-F1 (68.7 °C) genotype showed the lower pasting temperatures. A wide range of viscosity values was found among the maize landraces (MG-F0, 343 mPa s and RJ-F1, 175 mPa s) as well as for the retrogradation (R8C-F1, 796 mPa s and RX-F1, 22 mPa s). ATR-FTIR spectroscopy revealed amylose, amylopectin, lipids, and proteins as major flours constituents and their differences were discriminated by PCA analysis.     

Intake of isoflavone-supplemented soy yogurt fermented with <Emphasis Type="Italic">Enterococcus faecium</Emphasis> lowers serum total cholesterol and non-HDL cholesterol of hypercholesterolemic rats

The aim of this study was to obtain an isoflavone-supplemented soy yogurt, fermented with Enterococcus faecium CRL 183 and Lactobacillus helveticus ssp jugurti, with suitable sensory properties and to assess the effects of the final product on blood lipids in hypercholesterolemic rats. Four isoflavone supplementation procedures were tested, in which the isoflavone was added at these stages: (1) before heat-treatment; (2) after heating and before fermentation; (3) after fermentation and (4) in the okara (by-product of soy milk) flour stirred into the fermented product when consumed. The products were subjected to a test of sensory acceptability. To assess their potential hypocholesterolemic properties in vivo, four groups of rats were used: control (C), hypercholesterolemic (H), hypercholesterolemic plus fermented product (HF) and hypercholesterolemic plus isoflavone-supplemented fermented product (HFI). Hypercholesterolemia was induced in rats of groups H, HF and HFI by feeding them on a commercial rat chow to which cholesterol and cholic acid had been added. Total, HDL and non-HDL cholesterol and triglycerides were measured in the blood of the rats. No significant sensorial differences were detected among the samples of soy yogurt supplemented with isoflavones at various processing stages. Rats fed a fermented soy product enriched with isoflavones (HFI group) had significantly (P < 0.05) less serum total cholesterol (15.5%) compared with rats fed a hypercholesterolemic diet (H group). Non-HDL cholesterol was less (P < 0.05) in rats fed a fermented soy product enriched or not with isoflavones (27.4 and 23.2%) compared to H group. The HDL-C and triglyceride concentrations did not differ significantly among the groups. It was possible to obtain an isoflavone-supplemented soy yogurt with satisfactory sensory characteristics. The resulting supplemented soy yogurt was capable of producing a lipid-lowering effect in hypercholesterolemic rats, relative to the animals that did not consume this product.     

High‐pressure homogenization: a non‐thermal process applied for inactivation of spoilage microorganisms in beer

The inactivation of spoilage microorganisms in beer using high‐pressure homogenization (HPH) was studied with the aim of evaluating the possibility of changing the conventional pasteurization process using this particular process. The homogenization pressure required for the inactivation of lactic acid bacteria, acetic bacteria and yeasts was investigated. For the most resistant microorganisms, the pressure inactivation kinetics and the effects of multiple process passes, initial temperature of the beer and the CO₂ concentration were studied. The results indicated that Lactobacillus delbrueckii was the most resistant microorganism tested, requiring 250 MPa to reach a six decimal reduction. Additionally, results showed that L. delbrueckii inactivation followed a second‐order kinetic process. A multi‐pass process and the use of a high initial beer temperature increased inactivation by HPH with L. delbrueckii, allowing the use of 150 MPa to achieve a five log cycle of inactivation. In contrast, a high CO₂ concentration reduced the efficacy of the HPH process. The results that were obtained are useful for high‐pressure homogenization applications in breweries and help to elucidate the effect of this new technology in a beverage that is both alcoholic and carbonated. Copyright © 2013 The Institute of Brewing & Distilling     

Effect of reconditioning and reuse of sucrose syrup in quality properties and retention of nutrients in osmotic dehydration of guava

The aim of this study was to assess the effect of reconditioning and reuse (RR) of sucrose syrup in quality properties and retention of nutrients in guava during osmotic dehydration (OD). Two trials of 15 OD cycles were conducted with RR of osmotic solution. The parameters of water loss (WL) and solid incorporation (SI), as well as microbial load and physical–chemical properties of syrup and fruit were evaluated. The results showed that the RR did not modify the parameters WL and SI, and the microbial load remained low. The RR did not influence the color of osmodehydrated fruit, as well as the nutrient retentions, but probably it influenced the citric acid and reduced sugar retentions. At the end, the syrup was enriched of vitamin C, polyphenols, potassium, with traces of lycopene, β-carotene, and other minerals (Fe, Mg, Mn, and Zn) and could be used to formulate new products.     

Isomerization of n-Butane over Ultrastable H-Y Zeolites with Different Si/Al Atomic Ratio

Ultrastable H-Y zeolites with different Si/Al atomic ratios (3n-butane isomerization. The initial activity of these catalysts is lower than that measured on tungsta supported on zirconia catalysts (WO _x /ZrO₂) and acidic mordenite catalysts; however, the Brønsted acid sites of the ultrastable H-Y zeolites are stable and selective towards isobutane. No deactivation of the catalysts was observed after 5 h of time on stream. In contrast, WO _x /ZrO₂ and acidic mordenite catalysts under the same experimental conditions are largely deactivated in less than 1 h of time on stream. The stability of the ultrastable H-Y zeolite in comparison to H-mordenite catalysts may be due to the three-dimensional structure of H-Y made of large supercages interconnected by apertures of 12 oxygen atoms. This structure may favour the diffusion of reactant and product decreasing the residence time and the ensuing degradation to coke. Acidic molecular sieves with monodimensional structure may favour the formation of the precursors of the coke responsible of the catalyst deactivation.     

Flight Initiation by Male <Emphasis Type="Italic">Rhodnius prolixus</Emphasis> is Promoted by Female Odors

Several triatomine bug species utilize chemical cues for sexual communication. We tested whether female or male Rhodnius prolixus, a vector of Chagas disease, produce volatile chemicals that elicit flight responses from conspecifics, and then isolated the source of the chemical. Males confronted with an airstream containing female odors showed a significantly greater take-off frequency compared to a blank airstream or an airstream with male odors. In contrast, females exhibited similar take-off frequencies to male or female odor as to a clean airstream. Occlusion of female metasternal glands with paraffin wax resulted in a significant decrease in male take-off frequency compared to that of intact females. Additionally, excised female metasternal glands elicited a similar take-off frequency from males as did intact females, both significantly greater than the take-off frequency to clean air. These results show that R. prolixus females release a pheromone from their metasternal glands that causes upwind flight in conspecific males.