Canadian Field Soils I. Mineral Composition by XRD/XRF Measurements

Forty Canadian soils were laboratory tested for the presence of quartz and other minerals using X-ray diffraction/X-ray fluorescence techniques. On average, the highest quartz content was observed in soil samples from sites in Nova Scotia followed by Prince Edward Island sites, whereas soil sample from British Columbia sites had the lowest quartz content. The second most abundant mineral was albite that mainly occurred in soil samples from Ontario and Quebec sites. Illite was the third most abundant and prevailed in soils mainly from British Columbia and New Brunswick sites. Soil samples from British Columbia sites had the highest combined clay and silt content and were composed of illite, albite, kaolinite, and chlorite. The lowest clay content was found in the samples from the Quebec sites. The highest microcline (a potassium feldspar) content was observed in Quebec, Ontario, and Prince Edward Island sites. In contrast to other provinces, samples from Quebec and Ontario sites also included amphibole. Soil samples from Saskatchewan and Manitoba sites also comprised carbonates, i.e., calcite and dolomite. Iron oxides (e.g., goethite) were present in all soils, except the Quebec sites, but their occurrence was rather insignificant.     

Transient stability considering dynamic load in bulk power system with high DG penetration

Transient stability may be seriously affected when a large number of distributed generators (DG) stop simultaneously during voltage sag. It is necessary to analyze accurately the dynamics of bulk power systems with high DG penetration. In this paper, transient stability is studied by analyzing power‐angle curves of generators while considering load dynamics and model order reduction at lower voltages. Based on the analysis, a decrease in the load internal resistance after voltage sag causes transient instability of generators. The phenomenon is confirmed through simulation using a one‐machine and one‐load model. This paper also suggests that the simulation results might be misled by traditional bulk power system modeling such as using the static load model and ignoring impedance at lower voltages. As for the numerical simulation, a large level of DG stoppage leads to transient step out in a bulk power system, and the stability is greatly improved by DG voltage regulation. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(2): 20– 29, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20608     

Radiation grafting of α,β,β-trifluorostyrene onto poly(ethylene-tetrafluoroethylene) film by preirradiation method. II. Properties of cation-exchange membrane obtained by sulfonation and hydrolysis of the grafted film

A Study was made on certain properties of the cation-exchange membranes obtained by the preirradiation grafting of α,β,β-trifluorostyrene (TFS) noto poly(ethylene-tetrafluoroethylene) (ETFE), followed by sulfonation and hydrolysis of the grafted film. Swelling, water uptake, electric conductivity, and transport number of the membranes were measured as a function of ino-exchange capacity. Thermal and chemical stability were also investigated. These properties were found to be mainly dependent on ion-exchange capacity. The stable membrane properties were established due to a homogeneous ion-exchange group distribution in the membrane, as confirmed by x-ray imcroscopy analysis of the membrane cross sections. In addition, the membranes showed good electrochemical, thermal, and chemical properties, and were found to be scceptable for practical use as cation-exchange membranes.     

Antioxidant Effects of Herbal Tea Leaves from Yacon (Smallanthus sonchifolius) on Multiple Free Radical and Reducing Power Assays,Especially on Different Superoxide Anion Radical Generation Systems

Yacon (Smallanthus sonchifolius), a native Andean plant, has been cultivated as a crop and locally used as a traditional folk medicine for the people suffering from diabetes and digestive/renal disorders. However, the medicinal properties of this plant and its processed foods have not been completely established. This study investigates the potent antioxidative effects of herbal tea leaves from yacon in different free radical models and a ferric reducing model. A hot‐water extract exhibited the highest yield of total polyphenol and scavenging effect on 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH) radical among four extracts prepared with hot water, methanol, ethanol, and ethylacetate. In addition, a higher reducing power of the hot‐water extract was similarly demonstrated among these extracts. Varying concentrations of the hot‐water extract resulted in different scavenging activities in four synthetic free radical models: DPPH radical (EC₅₀ 28.1 μg/mL), 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) cation radical (EC₅₀ 23.7 μg/mL), galvinoxyl radical (EC₅₀ 3.06 μg/mL), and chlorpromazine cation radical (EC₅₀ 475 μg/mL). The yacon tea‐leaf extract further demonstrated superoxide anion (O₂^?) radical scavenging effects in the phenazine methosulfate‐NADH‐nitroblue tetrazolium (EC₅₀ 64.5 μg/mL) and xanthine oxidase assay systems (EC₅₀ 20.7 μg/mL). Subsequently, incubating human neutrophilic cells in the presence of the tea‐leaf extract could suppress the cellular O₂^? radical generation (IC₅₀ 65.7 μg/mL) in a phorbol 12‐myristate 13‐acetate‐activated cell model. These results support yacon tea leaves may be a good source of natural antioxidants for preventing O₂^? radical‐mediated disorders.     

Factors affecting soluble selenium removal by a selenate-reducing bacterium Bacillus sp. SF-1

High concentrations of soluble selenium, selenate and selenite, have acute and chronic toxicity toward living things. With the aim of developing a biological process for selenium removal, the effects of a variety of parameters on the reduction of soluble selenium by a Bacillus sp. strain SF-1, which is capable of reductively transforming selenate into selenite and, subsequently, into nontoxic insoluble elemental selenium, were studied. The bacterial strain could effectively reduce 20 mM of selenate to selenite and 2 mM of selenite to elemental selenium in the presence of an appropriate carbon source and in the absence of oxygen. The reduction rate of selenate to selenite was much higher than that of selenite to elemental selenium, resulting in the transient accumulation of selenite during selenate reduction. The selenate reduction rate increased with increases in the selenate concentration up to 20 mM, while the rate of selenite reduction decreased sharply at selenite concentrations of more than 2 mM. The elemental selenium transformed from selenate via selenite was found both inside and outside the cells. Bacillus sp. SF-1 was able to utilize a variety of organic acids or sugars as a carbon source in selenate reduction. Although the copresence of sulfate did not inhibit selenate reduction, it was completely inhibited by some other oxyanions, including nitrate. A model sequencing batch system using the bacterial strain was developed and exhibited good performance in the treatment of wastewater containing high concentrations of selenate.     

An improved synthesis of taurine- and glycine-conjugated bile acids

A simple and efficient method for the synthesis of taurine- and glycine-conjugated bile acids is described. The condensation reaction was achieved by the simple mixing of unconjugated bile acid (1.0 eq.), taurine (2.0 eq.) (or glycinate ester), diethyl phosphorocyanidate (1.2 eq.) in the presence of triethylamine at room temperature for 30-60 min. Sample clean-up was effected by the use of a prepacked Sep-Pak C18 cartridge for reversed-phase solid extraction or by direct recrystallization, yielding the desired taurine and glycine conjugates in 89-93 and 92-96% isolated yields, respectively.     

Radiation grafting of α,β,β-trifluorostyrene onto poly(ethylene–tetrafluoroethylene) film by preirradiation method. I. Effects of preirradiation dose,monomer concentration,reaction temperature,and film thickness

Preirradiation grafting of α,β,β-trifluorostyrene onto poly(ethylene–tetrafluoroethylene) film was studied. The trapped radicals formed upon irradiation were able to induce graft polymerization under appropriate conditions. The influences of the grafting conditions were analyzed kinetically. The grafting rate dependency on the preirradiation dose was found to be of order 0.3, and the monomer concentrations, 1.0. The overall activation energies for this grafting were calculated to be 6.2 × 10⁴ and 9.3 × 10³ J/mol below and above 50°C. The grafting rate was found to be independent of the film thickness, which ranged from 25 to 100 μm.     

Desiccation survival of Listeria monocytogenes and other potential foodborne pathogens on stainless steel surfaces is affected by different food soils

Food processing environments are suspected to be the primary source of Listeria monocytogenes contamination of foods. We investigated the survival of L. monocytogenes on stainless steel that was soiled with food components (minced tuna, ground pork, and cabbage) followed by dehydration. Stainless steel coupons were inoculated with 10⁷ CFU/coupon and stored up to 30 days. In comparison with Staphylococcus aureus and Salmonella Typhimurium, L. monocytogenes demonstrated the highest survivability where about 3 log CFU/coupon remained at the end of the experimental period. While survival during the early storage period was markedly affected by both food-component attachment and food type, a long dehydration period diminished the effect of those.     

Evaluation of myocardial perfusion and fatty acid uptake using a single injection of iodine-123-BMIPP in patients with acute coronary syndromes

The purpose of this study was to clarify the possibility of simultaneous evaluation of myocardial perfusion and fatty acid metabolism using a single injection of 123I-beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) in patients with acute coronary syndromes. METHODS: Thirty patients with unstable angina pectoris (UAP group) and 15 patients with acute myocardial infarction (MI group) were studied. BMIPP dynamic SPECT was performed 2 min after the injection of BMIPP (185 MBq), and images were obtained every 3 min for 15 min with a three-head gamma camera. Conventional BMIPP SPECT was also performed 30 min after the injection. Serial BMIPP and resting 201TI images were compared. RESULTS: A 201TI-BMIPP mismatch between 30-min BMIPP and resting 201TI images was observed in 27 of 30 patients in the UAP group and 8 of 15 patients in the MI group, respectively. However, a 201TI-BMIPP mismatch between early (2-5-min) BMIPP and resting 201TI images was observed in only 2 of 30 patients in the UAP group and in only 2 of 15 patients in the MI group, respectively. The kappa statistics of tracer uptake between early BMIPP and resting 201TI images showed good concordance in UAP (kappa = 0.823) and MI (kappa = 0.765) groups, respectively. These results indicated that initial distribution of BMIPP reflects myocardial perfusion in patients with acute coronary syndromes. CONCLUSION: Myocardial perfusion and fatty acid metabolism can be evaluated simultaneously using a single injection of BMIPP, when images are taken soon (2-5 min) and long after the injection in patients with acute coronary syndromes.