Evaluation of the lactose Tergitol-7, m-Endo LES, Colilert 18, Readycult Coliforms 100, Water-Check-100, 3M Petrifilm EC and DryCult Coliform test methods for detection of total coliforms and Escherichia coli in water samples

In this study we compared the reference membrane filtration (MF) lactose Tergitol-7 (LTTC) method ISO 9308-1:2000 with the MF m-Endo LES method SFS 3016:2001, the defined substrate chromogenic/fluorogenic Colilert 18, Readycult Coliforms and Water Check methods, and ready-made culture media, 3M Petrifilm EC and DryCult Coli methods for the detection of coliforms and Escherichia coli in various water samples. When the results of E. coli detection were compared between test methods, the highest agreement (both tests negative or positive) with the LTTC method was calculated for the m-Endo LES method (83.6%), followed by Colilert 18 (82.7%), Water-Check (81.8%) and Readycult (78.4%), whereas Petrifilm EC (70.6%) and DryCult Coli (68.9%) showed the weakest agreement. The m-Endo LES method was the only method showing no statistical difference in E. coli counts compared with the LTTC method, whereas the Colilert 18 and Readycult methods gave significantly higher counts for E. coli than the LTTC method. In general, those tests based on the analysis of a 1-ml sample (Petrifilm EC and DryCult Coli) showed weak sensitivity (39.5-52.5%) but high specificity (90.9-78.8%).     

Rice Bran and Vitamin B6 Suppress Pathological Neovascularization in a Murine Model of Age-Related Macular Degeneration as Novel HIF Inhibitors

Pathological neovascularization in the eye is a leading cause of blindness in all age groups from retinopathy of prematurity (ROP) in children to age-related macular degeneration (AMD) in the elderly. Inhibiting neovascularization via antivascular endothelial growth factor (VEGF) drugs has been used for the effective treatment. However, anti-VEGF therapies may cause development of chorioretinal atrophy as they affect a physiological amount of VEGF essential for retinal homeostasis. Furthermore, anti-VEGF therapies are still ineffective in some cases, especially in patients with AMD. Hypoxia-inducible factor (HIF) is a strong regulator of VEGF induction under hypoxic and other stress conditions. Our previous reports have indicated that HIF is associated with pathological retinal neovascularization in murine models of ROP and AMD, and HIF inhibition suppresses neovascularization by reducing an abnormal increase in VEGF expression. Along with this, we attempted to find novel effective HIF inhibitors from natural foods of our daily lives. Food ingredients were screened for prospective HIF inhibitors in ocular cell lines of 661W and ARPE-19, and a murine AMD model was utilized for examining suppressive effects of the ingredients on retinal neovascularization. As a result, rice bran and its component, vitamin B6 showed inhibitory effects on HIF activation and suppressed VEGF mRNA induction under a CoCl₂-induced pseudo-hypoxic condition. Dietary supplement of these significantly suppressed retinal neovascularization in the AMD model. These data suggest that rice bran could have promising therapeutic values in the management of pathological ocular neovascularization.     

Response of steel-concrete composite panels to in-plane loading

Steel-Concrete Composite (SCC) panels consist of steel faceplates with welded shear studs and concrete infill. The shear studs, which perform a similar function to bond of rebars in reinforced concrete, act as springs resisting the shear slip between the faceplates and concrete. In spite of extensive research in the 1980s and 1990s due to the interest in using SCC in offshore construction and in nuclear power plants, and recently related Codes, there is no analytical method to-date to predict the shear studs response to in-plane loading. Shear connectors are sized according to various criteria unrelated to their actual forces under in-plane loads, such as prevention of faceplate buckling or out-of-plane shear resistance. This paper presents a closed analytical solution of the equilibrium and compatibility differential equations for steel and concrete displacements of SCC panels, based on distributed shear springs idealization. Analytical results presented in this paper are validated by test results of SCC panels loaded by pure shear forces and can be used as practical design formulas for the in-plane portion of the design loads.     

Nickel removal characteristics of an immobilized macro fungus: equilibrium,kinetic and mechanism analysis of the biosorption

BACKGROUND: An immobilized new biosorbent was prepared from macro fungi Lactarius salmonicolor for the effective removal of nickel ions from aqueous media. Operating conditions were optimized as functions of initial pH, agitation time, sorbent amount and dynamic flow rate. Immobilization and biosorption mechanism were examined and the developed biosorbent was tested for the removal of nickel ions from real wastewater. RESULTS: Biosorption performance of the biomass continuously increased in the pH range 2.0–8.0. The coverage of the biosorbent surface by silica gel resulted in a significant increase in biosorption yield of nickel ions. The highest nickel loading capacity was obtained as 114.44 mg g^?1 using a relatively small amount of immobilized biosorbent. Biosorption equilibrium time was recorded as 5 min. Experimental data were analyzed by different isotherm and kinetic models. Infrared spectroscopy, scanning electron microscopy and X‐ray energy dispersive analysis confirmed the process. The sorbent exhibited relatively good recovery potential in dynamic flow mode studies. Biosorption capacity of immobilized biosorbent was noted as 14.90 mg g^?1 in real wastewater. CONCLUSION: Silica gel immobilized biomass of L. salmonicolor is to be a low cost and potential biosorbent with high biosorption capacity for the removal of contaminating nickel from aqueous media. © 2012 Society of Chemical Industry     

Influence of manganese oxide on the liquid-perovskite equilibrium in the CaO–SiO2–TiO2 system at 1400 °C in air

In the Selective Crystallization and Phase Separation (SCPS) process, manganese oxide is used as an additive to promote the precipitation of perovskite. However, the influence of manganese oxide on the liquid domain of the perovskite primary phase field is still unclear. In the present work, the liquid-perovskite equilibrium with the addition of 0–15 wt% Mn₃O₄ was experimentally determined using a high-temperature isothermal equilibration-quenching technique, combined with X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS). It was confirmed that manganese was mainly existed as Mn²⁺ and Mn³⁺ in the molten phase, whereas titanium existed as Ti⁴⁺. Within the composition range of the present study, the 1400 °C liquid compositions varying from 0 wt% to 15 wt% Mn₃O₄ overlapped significantly, mainly located at w (CaO)/w (SiO₂) ratios between 0.9 and 1.1. The isotherms simulated by FactSage, as well as the data from the literature, generally agreed well with the present experimental results. The calculated 1400 °C isotherms at different Mn₃O₄ levels indicated that perovskite precipitation by manganese oxide was mainly promoted by increasing the Mn₃O₄ concentration to expand the primary phase field of perovskite toward both higher and lower TiO₂ content areas.     

Experimental investigation and three-dimensional computational fluid-dynamics modeling of the flash-converting furnace shaft: Part I. Experimental observation of copper converting reactions in terms of converting rate, converting quality, changes in particle size, morphology, and mineralogy

An experimental investigation was conducted to elucidate the main features of the processes taking place in the shaft of a continuous flash-converting furnace for solid copper mattes. The experiments were conducted in a large laboratory furnace. The test variables included the matte grade, oxygen content in the process gas, particle size of the feed material, and oxygen-to-matte ratio. The observed variables included the fractional completion of the oxidation reactions, fraction of sulfur remaining in the particles, copper-to-iron atomic ratio, particle-size distribution, morphology, and mineralogy of the reacted particles. The experiments showed substantial differences in the oxidation behavior of high-grade (72 pct Cu) and low-grade (58 pct Cu) matte particles. Low-grade matte particles reacted evenly throughout the furnace, increased in size, and experienced no substantial fragmentation during oxidation. High-grade matte particles tended to be oxidized unevenly and experienced severe fragmentation leading to generation of dust. The order of the effects of the test variables on the observed variables was found to be (1) the oxygen-to-matte ratio, (2) the particle size of the feed material, and (3) the oxygen content in the process gas. Microscopic examination revealed that the oxides of copper and iron were the main oxidation products, with little elemental copper present in the reacted particles. Potential implications of the experimental findings on the operation of an industrial flash-converting furnace are discussed.     

A linear‐discrete scheduling model for the resource‐constrained project scheduling problem

For some specific types of construction projects, the classical CPM or PDM scheduling techniques are not the most suitable. Few specific scheduling approaches have been developed to cope with construction projects that are made of either repetitive activities or activities with linear developments. But real‐world construction projects do not consist only of such activities. They are generally made of a mixture of linear and/or repetitive activities and of more conventional activities. To allow this, the linear scheduling problem is reformulated, so classical schedule calculation approaches can be used. The implementation of some Allen's algebra features to avoid adverse discontinuities and to allow crew/work continuity, together with a resource‐driven and space‐constrained scheduling are among the key features of the proposed approach. It is also a spin‐off of off‐the‐field practices used for scheduling real projects in the particle accelerator construction domain; an excerpt from such a construction project is provided for illustrating the methodology.     

Characterization of surface functional groups present on laboratory-generated and ambient aerosol particles by means of heterogeneous titration reactions

A Knudsen flow reactor has been used to quantify surface functional groups on aerosols collected in the field. This technique is based on a heterogeneous titration reaction between a probe gas and a specific functional group on the particle surface. In the first part of this work, the reactivity of different probe gases on laboratory-generated aerosols (limonene SOA, Pb(NO₃)₂, Cd(NO₃)₂) and diesel reference soot (SRM 2975) has been studied. Five probe gases have been selected for the quantitative determination of important functional groups: N(CH₃)₃ (for the titration of acidic sites), NH₂OH (for carbonyl functions), CF₃COOH and HCl (for basic sites of different strength), and O₃ (for oxidizable groups). The second part describes a field campaign that has been undertaken in several bus depots in Switzerland, where ambient fine and ultrafine particles were collected on suitable filters and quantitatively investigated using the Knudsen flow reactor. Results point to important differences in the surface reactivity of ambient particles, depending on the sampling site and season. The particle surface appears to be multi-functional, with the simultaneous presence of antagonistic functional groups which do not undergo internal chemical reactions, such as acid–base neutralization. Results also indicate that the surface of ambient particles was characterized by a high density of carbonyl functions (reactivity towards NH₂OH probe in the range 0.26–6 formal molecular monolayers) and a low density of acidic sites (reactivity towards N(CH₃)₃ probe in the range 0.01–0.20 formal molecular monolayer). Kinetic parameters point to fast redox reactions (uptake coefficient γ₀>10^?3 for O₃ probe) and slow acid–base reactions (γ₀<10^?4 for N(CH₃)₃ probe) on the particle surface.     

The Effect of Biofuel Originated Potassium and Sodium on the NH3-SCR Activity of Fe–ZSM-5 and W–ZSM-5 Catalysts

The effect of potassium, sodium and water on Fe–ZSM-5, W–ZSM-5 and ZSM-5 catalysts was investigated. Catalysts were characterized by several techniques and tested in the NH₃-SCR reaction. The impact of water-, K- and Na-treatments on the activity of catalysts was negligible. Thus, the catalysts can be concluded to be resistant to K- and Na-treatments.     

Processing and mechanical properties of thermoplastic composites based on cellulose fibers and ethylene—acrylic acid copolymer

The melt processing and the tensile mechanical properties of composites consisting of 30 wt% softwood kraft pulp cellulose fibers and ethylene‐acrylic acid copolymer (EAA) with 7% acrylic acid content were studied. The compounding techniques used were extrusion mixing performed with a single screw extruder and elongation dispersive mixing performed with the injection‐molding machine. All blends were injection‐molded in a final step. Fiber length, fiber content, and mechanical properties were measured and the number and the size of the fiber aggregates were determined by microscopy analysis. It was concluded that two passes of elongation dispersive mixing had a beneficial effect on the mechanical properties, which could be related to the fewer and smaller amounts of aggregates. The different types of processing performed had a small or insignificant effect on the fiber length since the fiber lengths measured were within the same range as that of the starting material. POLYM. ENG. SCI., 52:1951–1957, 2012. © 2012 Society of Plastics Engineers