Hydrolytic Activity of Castor Bean Powder: Effect of Gum Arabic,Lipase and Oil Concentrations

Lipase activity from castor bean seed powders was evaluated in hydrolysis reactions at 37 °C. The effects of different concentrations of lipase powder (LP), substrate (high oleic sunflower oil, O) and surfactant (gum arabic, A) on lipase activity (R) were assessed using experimental designs. Considered variable bounds were: 0.05–0.15 g_LP, 0.07–0.20 oil:aqueous phase (w/w) and 0–0.025 g gum arabic/mL. All variables had significant effects on the transformed response, R ^1/2. The most important result was the negative effect of gum arabic in lipase activity, even when high oil concentrations were used. Experimental lipase activities involved in this work were within 0.32–16.90 mmol_FFA/g_oil·g_LP·h. Using 0.05 g_LP and 0.20 oil:aqueous phase (w/w) without gum arabic, the activity of 20.47 ± 7.19 mmol_FFA/g_oil·g_LP·h was reached.     

Electrical,mechanical, and piezoresistive properties of carbon nanotube–polyaniline hybrid filled polydimethylsiloxane composites

The electrical, mechanical, and piezoresistive properties of ternary composites based on elastomeric polydimethylsiloxane (PDMS), carbon nanotubes (CNTs), and polyaniline (PANI) were studied and compared with those of binary PDMS–CNT composites. The presence of PANI affected the percolating network of the CNTs. At lower PANI concentrations (2.5 and 5%), the conductive network of the CNTs was constructively modified; this led to an enhancement in the conductivity in the sample containing 2% CNTs. A higher PANI content (7.5%) hindered the flow of main charge carriers through the composite. The piezoresistive response of the binary and ternary composites was studied by cyclic experiments under compression loads. In all of the samples, the electrical resistance increased monotonically up to a 10% strain. The reproducibility of the piezoresistive behavior in the binary and ternary composites provided evidence that the fillers could reversibly recover their initial position together with the PDMS chains without a significant displacement with respect to their original positions. The reduction of the piezoresistive sensibility by PANI addition was attributed to the displacement restrictions of the CNTs within the composite under pressure because of the volume exclusion of PANI particles; this maintained the probability of CNT contact and increased the possibility of the formation of new CNT conductive channels. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44780.     

Determination of Fecal Sterols Following a Diet with and without Plant Sterols

The aim of this study was to develop a method for neutral fecal sterols determination in subjects receiving a normal diet with or without a plant sterols-enriched beverage using gas chromatography–mass spectrometry (GC/MS). Sample preparation conditions (homogenization of lyophilized feces with water) were evaluated. Sterol determination required direct hot saponification, unsaponifiable extraction with hexane, and the formation of trimethylsilyl (TMS) ether derivatives. The method allows the quantification of cholesterol, plant sterols and their metabolites (coprostanol, coprostanone, cholestanol, cholestanone, methylcoprostanol, methylcoprostanone, ethylcoprostenol, stigmastenol, ethylcoprostanol and ethylcoprostanone). Good linearity was obtained (r > 0.96) and interference was only observed for coprostanone, where the standard addition method proved necessary for quantification. The limits of detection (LOD) ranged from 0.10 to 3.88 µg/g dry feces and the limits of quantitation (LOQ) from 0.34 to 12.94 µg/g dry feces. Intra- and inter-assay precision (RSD %) were 0.9–9.2 and 2.1–11.3, respectively. Accuracy, expressed as percentage recovery (80–119%) was obtained for all determined sterols.     

Improved gas selectivity of polyetherimide membrane by the incorporation of PIM polyimide phase

The aim of this work was to prepare blend membranes of a polyetherimide (PEI) and different ratios of a microporous polyimide (PIM‐B) in order to obtain an improved material for gas selectivity. Miscibility of the membranes was studied through fourier transform infrared spectroscopy (FTIR), Fluorescence, ultraviolet‐visible spectroscopy (UV–vis), polarize light microscope images, X‐ray diffraction (XRD), and differential scanning calorimetry analysis. Gas permeability assays were also performed. Results showed blends were partially miscible along the different ratios due to the existence of: (i) absorption shoulders at lower wavenumbers on the carbonyl stretching band; (ii) red‐shifting of Fluorescence and UV–vis absorption bands; (iii) decreasing of d‐spacing as the amount of PIM‐B phase increased; and (iv) composition‐dependent glass transition temperatures (T_gs). The mobility selectivity (D_i/j) dominated H₂ and O₂ gas separations. High solubility coefficients (S) linked to PIM‐B microporosity improved the ideal gas selectivity of the blend membranes. PEI/PIM‐B membrane at the ratio of 80/20 showed impressive H₂/CO₂ (8.66) and O₂/N₂ (10.90) gas separation factors. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44682.     

A traditional aboriginal condiment as an antioxidant agent in the development of biodegradable active packaging

In this study, antioxidant food‐packaging materials were developed by the incorporation of merkén, an aboriginal Chilean spice, into a biodegradable polymer matrix, poly(lactic acid). Antioxidant activity assays and the phenolic content of merkén showed interesting results compared to other condiments, such as oregano and parsley. Active materials with merkén at 3 and 5 wt % were successfully obtained by extrusion. Chromatographic analysis revealed the chemical composition of merkén, and its active material was based on interesting flavonoids and organic acids, such as catechin, myricetin, and gallic and ellagic acids. Scanning electron micrographs showed that the merkén particles accumulated in aggregates; this resulted in an increase in the permeability values and a reduction in the crystallinity and mechanical properties of the polymer matrix. Nevertheless, these materials presented interesting antioxidant activities as radical scavengers on aqueous food simulants. The kinetics of release was dependent on the type of food and the nominal content of merkén in the films. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44692.     

Modeling the Effectiveness of Rain Barrels,Cisterns, and Downspout Disconnections for Reducing Combined Sewer Overflows in a City-Scale Watershed

Green Infrastructure / Low Impact Development (GI/LID) is an increasingly popular strategy to manage urban stormwater for individual properties, but the aggregate effect on runoff reduction at the city scale has not been thoroughly investigated. This study examined the potential combined effects of rain barrels, cisterns, and downspout disconnections on combined sewer overflows (CSOs) for a medium-sized urban center. To support a city-wide analysis, a novel simulation strategy was implemented using the Storm Water Management Model (SWMM). In this new approach, a modeling at the source technique for subcatchment delineation was combined with a set of R-language utilities to automatically configure GI/LID management scenarios. The reconfigured SWMM model was used to examine 99 distinct management scenarios based on different sizes, numbers, and locations of the targeted GI/LID features for the city of Buffalo, New York. For a typical hydrologic year, the deployment of large residential rain barrels (1000-gallon) resulted in up to a 12% reduction in predicted CSO volume, while the inclusion of large commercial-roof cisterns (5000-gallon) contributed up to an additional 12% reduction. Large variations in the predicted CSO reductions were observed across the various management scenarios, and the simulation tools were able to identify locations where the GI/LID features were most effective. In general, the modeling at the source approach and the R-language tools substantially enhanced the utility of SWMM for evaluating the effectiveness of GI/LID deployment as a CSO management strategy at the city scale, and the methodology can readily be adapted to cities with similar CSO issues.

     

Androgen regulation of lung lipids in the male rat

The aim of this study was to determine whether or not testosterone regulates the lipid concentration in rat lung tissue. Rats were either sham-operated controls, castrated, or castrated and injected with testosterone. Twenty-one days after castration, we observed in relation to the control: (i) Total lipids, phospholipids, and total cholesterol increased, while triglycerides decreased in whole lung. (ii) Phospholipid concentration increased in microsomes, lamellar bodies, and alveolar macrophages, but it decreased in extracellular surfactant. (iii) On a percentage basis, the concentration of phosphatidylcholine increased in microsomes, lamellar bodies, and alveolar macrophages, and it decreased in extracellular surfactant. (iv) Protein concentration decreased in extracellular surfactant and increased in microsomes, lamellar bodies, and alveolar macrophages. (v) The incorporation of [¹⁴C]glycerol into phospholipids of lung slices increased. (vi) The activity of CTP:phosphocholine cytidylyltransferase bound to the microsomal fraction increased without any change in the activity of the soluble form of the enzyme in the lung. The results obtained when testosterone was administered to castrated rats were similar to those obtained in the control in all cases. These results suggest that the lipid concentration in the lung is regulated at least partly directly or indirectly by androgens.     

Ebony (Phitecellobium flexicaule Benth) and proteins fractionation,solubilization, characterization and production of an isolate

Different combinations of pHs (2 to 12) and temperatures (25, 30 and 35 degrees C) were tested to obtain a protein isolate from ebony (Pithecellobium flexicaule, Benth) seeds. Seed proteins contained 54.6% albumins, 32% globulins, 5.7% glutelins and 1.3% prolamins. The isoelectric points for albumins, globulins and glutelins were in the pH range of 2.3-2.7. The average molecular weight of albumins ranged from 92 to 100 kDa and for the four globulin subunits in the range of 28.4 to 57.3 kDa. For isolate production, proteins were sequentially extracted with distilled water and a 5% NaCl solution. The resulting supernatants were mixed. The best extraction was achieved at pH 11 and 25 degrees C. 45.6% of the total seed protein was precipitated at pH 2.6 yielding an isolate with 90% protein (N x 6.25). The isolate contained high quantities of lysine, leucine, threonine and phenylalanine but were low in sulfur containing amino acids methionine and cysteine. The extraction process reduced tannins, phytates and trypsin inhibitor in 53, 70 and 70%, respectively. In vivo protein digestibility of the protein isolate was 85.4% and the corrected digestibility essential amino acid score was of 44% due to the lack of sulfur containing amino acids. In order to upgrade the protein quality of ebony isolate it is recommend to supplement with methionine or sulfur containing rich foods.     

Low cost coatings for flat plate solar collectors

Low cost, optically efficient, selective coatings are required for the flat plate collectors envisioned for solar heating and cooling applications. Plated coatings and paint coatings are two attractive types of coatings for this application. Black nickel (NiSZnS), black chrome (CrO_x) and black iron (FeO_x) were found to be attractive plated coatings from the standpoint of optical efficiency, durability and cost. Black nickel with α = 0.95 and ε = 0.07 had the best optical properties. Black chrome, which showed only minor degradation after 192 h exposure to the MIL-STD-810B humidity test, had the best durability. Black iron, with an estimated materials cost of 5

ft^?2, had the lowest cost. Paint coatings are potentially the lowest cost selective coating. The materials cost for a selective paint coating would be about 0.5

ft^?2. However, paints lack the optical efficiency of the plated coatings. The best optical performance achieved with a paint coating was α = 0.90 and ε = 0.30.