Thermal and mechanical properties of La–Al–Sb alloys

We fabricated La–Al–Sb alloy by arc melter system and the fabrication conditions were described in detail. Microstructural analyses were performed and it was found that LaSb, Al₁₁La₃ Al₄La, AlLa₃ and Sb phases formed for different heat treatment conditions. The resistivity results showed the metallic and semiconducting type behavior depending on heat treatment temperatures. The thermal-conductivity measurement was performed in the range of 2–300 K and the data were analyzed by the sum of lattice and carrier components. The linear temperature dependence of thermo power indicates metallic type characteristic of the samples. The micro-hardness values of the phases in the samples were analyzed and it was found that there are two different hardness regions in the samples.     

Effect of High-Temperature Microwave Irradiation on Municipal Thickened Waste Activated Sludge Solubilization

Sludge digestion and stabilization governs almost half of the operating cost of wastewater treatment plants, and hydrolysis is the limiting step in sludge digestion. Increasing hydrolysis by implementing pretreatment prior to digestion can increase the digestion efficiency. Among pretreatment methods, thermal pretreatment at temperatures around 160–175°C tends to produce better solubilization. Microwave (MW) pretreatment was recently studied as an alternative method to conventional thermal pretreatment. Until now, MW pretreatment above boiling point had not been studied for sludge solubilization and digestion. This paper provides preliminary results on the effect of MW pretreatment operating conditions such as high temperature (T) (110–175°C), MW intensity (I) (1.25 and 3.75°C/min), and sludge concentration (C) (6 and 11.85%) on solubilization. From experimental results and three-factor fixed-effect analysis of variance (ANOVA) determination it was found that T, I, and C main effects and T:I and T:C interactions as well as T:I:C interaction are significant at a 94% confidence interval.     

Management of vasodilatory shock after cardiac surgery: identification of predisposing factors and use of a novel pressor agent

BACKGROUND:Cardiopulmonary bypass can be associated with vasodilatory hypotension requiring pressor support. We have previously found arginine vasopressin to be a remarkably effective pressor in a variety of vasodilatory shock states. We investigated the incidence and clinical predictors of vasodilatory shock in a general population of cardiac surgical patients and the effects of low-dose arginine vasopressin as treatment of this syndrome in patients with heart failure. METHODS: Patients undergoing cardiopulmonary bypass (n = 145) were studied prospectively. Preoperative ejection fraction, medications, and perioperative hemodynamics were recorded, and postbypass serum arginine vasopressin levels were measured. Vasodilatory shock was defined as a mean arterial pressure lower than 70 mm Hg, a cardiac index greater than 2.5 L/min/m2, and norepinephrine dependence. Predictors of vasodilatory shock were investigated by logistic regression analysis. The hemodynamic responses of patients who received arginine vasopressin infusions for vasodilatory shock after cardiopulmonary bypass for left ventricular assist device placement or heart transplantation were analyzed retrospectively. RESULTS: Eleven of 145 general cardiac surgery patients (8%) met criteria for postbypass vasodilatory shock. By multivariate analysis, an ejection fraction lower than 0.35 and angiotensin-converting enzyme inhibitor use were independent predictors of postbypass vasodilatory shock (relative risks of 9.1 and 11.9, respectively). Vasodilatory shock was associated with inappropriately low serum arginine vasopressin concentrations (12.0 +/- 6.6 pg/mL). Retrospective analysis found 40 patients with postbypass vasodilatory shock who received low-dose arginine vasopressin infusions, resulting in increased mean arterial pressure and decreased norepinephrine requirements. CONCLUSIONS: Low ejection fraction and angiotensin-converting enzyme inhibitor use are risk factors for postbypass vasodilatory shock, and this syndrome is associated with vasopressin deficiency. In patients exhibiting this syndrome after high-risk cardiac operations, replacement of arginine vasopressin increases blood pressure and reduces catecholamine pressor requirements.     

Estimates of the atmospheric deposition of sulfur and nitrogen species: Clean Air Status and Trends Network 1990-2000

The Clean Air Status and Trends Network (CASTNet) was established by the U.S. EPA in response to the requirements of the 1990 Clean Air Act Amendments. To satisfy these requirements CASTNet was designed to assess and report on geographic patterns and long-term, temporal trends in ambient air pollution and acid deposition in order to gauge the effectiveness of current and future mandated emission reductions. This paper presents an analysis of the spatial patterns of deposition of sulfur and nitrogen pollutants for the period 1990-2000. Estimates of deposition are provided for two 4-yr periods: 1990-1993 and 1997-2000. These two periods were selected to contrast deposition before and after the large decrease in SO2 emissions that occurred in 1995. Estimates of dry deposition were obtained from measurements at CASTNet sites combined with deposition velocities that were modeled using the multilayer model, a 20-layer model that simulates the various atmospheric processes that contribute to dry deposition. Estimates of wet deposition were obtained from measurements at sites operated bythe National Atmospheric Deposition Program. The estimates of dry and wet deposition were combined to calculate total deposition of atmospheric sulfur (dry SO2, dry and wet SO4(2-)) and nitrogen (dry HNO3, dry and wet NO3-, dry and wet NH4+). An analysis of the deposition estimates showed a significant decline in sulfur deposition and no change in nitrogen deposition. The highest rates of sulfur deposition were observed in the Ohio River Valley and downwind states. This region also observed the largest decline in sulfur deposition. The highest rates of nitrogen deposition were observed in the Midwest from Illinois to southern New York State. Sulfur and nitrogen deposition fluxes were significantly higher in the eastern United States as compared to the western sites. Dry deposition contributed approximately 38% of total sulfur deposition and 30% of total nitrogen deposition in the eastern United States. Percentages are similar for the two 4-yr periods. Wet sulfate and dry SO2 depositions were the largest contributors to sulfur deposition. Wet nitrate, wet ammonium, and dry HNO3 depositions were the largest contributors to nitrogen deposition.     

Effect of nitrogen source in the fertilizing solution on nutritional quality of three members of the Portulaca oleracea aggregate

BACKGROUND: Portulaca oleracea (purslane) is nutritious but, in addition to the essential α‐linolenic acid, vitamin C and tocopherols, it contains undesirable oxalic acid. Knowing the effects of nitrate and ammonium on oxalate accumulation, we tested the agronomic potential of three members of the P. oleracea aggregate under various nitrogen fertilization conditions, by measuring biomass production and accumulation of fatty acids, organic acids and tocopherol in the commercial P. sativa (Pos) and two natural members: P. nitida (Pon) and P. papillato‐stellulata (Pop). RESULTS: With nitrate as the sole N source, we measured differences between Pon and Pos in concentrations of the essential ω‐3 fatty acid α‐linolenic acid. Pos also gained less dry biomass under these conditions, implying a higher agronomical and nutritional value for Pon. Increasing the fertilizer ammonium concentration and reducing that of nitrate significantly decreased oxalic acid by factors of up to 1.7, 2.6 and 3.4 in Pos, Pop and Pon, respectively, significantly increased concentrations of tocopherol and malic acid, had no effect on fatty acids or ascorbic acid, but reduced biomass. CONCLUSION: In spite of the recumbent growth habit of Pon, the present findings indicate its agronomic potential. Because early flowering and seed production may be the limiting factors in purslane agriculture, growing Pon in nitrate‐poor conditions might be agriculturally favorable. Copyright © 2010 Society of Chemical Industry     

Effects of microwave frying and different flour types addition on the microstructure of batter coatings

In this study, the influences of microwave frying and various flour types on microstructure of batter coatings were investigated. Control batter formulation contained only wheat and corn flour. To determine the effects of different flour types, 30% of the corn and wheat flour mix was replaced with chickpea, rice or soy flours. Frying was performed in microwave oven at 365 W (70%) power level for 1.5 min after bringing the oil temperature to 180 ± 1 °C. Samples were also fried in a conventional fryer at 180 °C for 1.5 and 5.0 min for comparison. Microwave fried samples had higher specific bulk volume and porosity values and also smoother inner surface as compared to conventionally fried samples. Porosity values of different batter formulations were in the range of 0.425–0.484 in 1.5 min microwave fried chicken samples and 0.348–0.392 in 5.0 min conventionally fried ones. Microwave fried samples had comparable or lower hardness values than the conventionally fried ones depending on the flour type used in batter formulation. Microstructure of fried batter was different for different batter formulations. Microwave fried control and chickpea flour containing batter provided formation of larger gas cells on the outer surface. Soy flour containing batter resulted in smallest size gas cells for both frying methods.     

Effects of cooking methods on the formation of heterocyclic aromatic amines of two different species trout

Heterocyclic aromatic amines (HAAs) are sometimes formed in meats and fish cooked at high temperatures. In the present study, the effects of cooking methods by deep-fat frying, pan-frying, grilling and barbecuing on the formation of HAAs of fillets of rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta fario) were investigated. Barbecued brown trout (1 g) was estimated to contain 0.12 ng of IQ (2-amino-3-methylimidazo[4,5-f]quinoline), 0.02 ng 4,8-DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline). Grilled rainbow trout (1 g) was estimated to contain 0.02 ng 4,8-DiMeIQx. MeIQ (2-amino-3,4-dimethylimidazo[4,5-f]quinoline), MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) were not detectable in all cooked fish.