Validation of SeaWiFS-derived chlorophyll for the Rio de la Plata Estuary and adjacent waters

The South Atlantic Ocean near the Río de la Plata Estuary is a highly dynamic region that encompasses four different water bodies: the Río de la Plata, the continental shelf and the Brazil and Malvinas currents. Bio-optical measurements obtained during 6–11 November 1999 provided the initial field data for validating Sea viewing Wide Field of view Sensor (SeaWiFS)-derived chlorophyll imagery for this region. The turbid waters of the Río de la Plata Estuary showed the highest variability and complexity in water optical properties, while the offshore waters of the Brazil Current had the lowest. In most cases, the estimates of chlorophyll using the SeaWiFS algorithm were higher than in situ measured values.     

Grading and color evolution of apples using RGB and hyperspectral imaging vision cameras

The potential of RGB digital imaging and hyperspectral imaging (900–1700 nm) was evaluated for discriminating maturity level in apples under different storage conditions along the shelf-life. Segmentation, preprocessing and partial least squares-discriminant analysis (PLS-DA) were used for hyperspectral data analysis, while illumination correction, dimensionality reduction and linear discriminant analysis (LDA) were used for RGB data analysis. The results showed that hyperspectral discrimination classified different storage regimes better than RGB, with an overall success rate of 95.83%. In addition, color evolution of apples during shelf-life under different storage regimes was modeled using RGB zero and first order regression models, fitting better to a first order kinetic model.     

Validation of a Method for Quantitation of Soybean Lectin in Commercial Varieties

Soybean agglutinin (SBA) protein, also known as soybean lectin, is regarded as an anti‐nutrient due to its negative effect on the ability of monogastric animals to gain weight following consumption of raw soybean seed. Historically, SBA has been measured using a time‐consuming and cumbersome hemagglutination procedure. The objective of our research was to obtain a validated methodology that is precise and accurate in the measurement of SBA while allowing minimally equipped laboratories to effectively conduct the analysis, thus our focus was on evaluating an existing commercially available ELISA, an enzyme‐linked‐lectin‐assay (ELLA), and a hybrid ELISA/ELLA. A new ELLA technique that can detect and quantify lectins was chosen and modified specifically for the quantitation of SBA in soybean seed. The proposed ELLA methodology is similar to a standard sandwich ELISA, and uses polyacrylamide‐linked N‐acetylgalactosamine (Gal–NAc–PAA) for a capture phase and the biotinylated version (Gal–NAc–PAA–Biotin) for detection. Based upon the validation data, the ELLA method can precisely and accurately determine soybean lectin levels in soybean seed. The validated ELLA method was used to quantify SBA in nine commercial soybean varieties introduced between 1972 and 2008 and demonstrated that the natural variability of SBA is subject to the effects of genotype and environment.     

Challenges for integrated design (ID) in sustainable buildings

It is often argued that integrated design (ID) is a powerful way to enhance collaboration in construction projects. This collaboration is seen as a way of improving innovation to create more sustainable buildings. Contrary to the traditional silo-type and linear design process, ID is based on upfront stakeholder involvement and a holistic approach to project decision-making. Although ID’s premises are theoretically-founded, a close empirical look at its practices shows that numerous challenges compromise its results and efficiency. This study examines the ID process through an iterative process that includes the construction of a conceptual framework and its empirical validation. We examine three green construction projects in Canada. Based on the analysis of 26 interviews with key project stakeholders and more than 198 construction documents, the study assembles – and ultimately applies – a multi-lens framework based on four themes: the fragmented nature of construction; risk perception; stakeholders’ commitment; and efficiency in the design process. Results show that three tensions arise in ID practices: between collaboration and process efficiency, between short-term and long-term goals, and between integrated methods and traditional ones. The study sheds light on ID limits and reveals how stakeholders can improve their interactions to design more sustainable buildings.     

Design of Phosphonated Imidazolium-Based Ionic Liquids Grafted on γ-Alumina: Potential Model for Hybrid Membranes

Imidazolium bromide-based ionic liquids bearing phosphonyl groups on the cationic part were synthesized and grafted on γ-alumina (γ-Al₂O₃) powders. These powders were prepared as companion samples of conventional mesoporous γ-alumina membranes, in order to favor a possible transfer of the results to supported membrane materials, which could be used for CO₂ separation applications. Effective grafting was demonstrated using energy dispersive X-ray spectrometry (EDX), N₂ adsorption measurements, fourier transform infrared spectroscopy (FTIR), and special attention was paid to ³¹P and ¹³C solid state nuclear magnetic resonance spectroscopy (NMR).     

Characterization of polyacrylamides used in enhanced oil recovery

Polyacrylamides can be readily characterized using techniques such as IR spectroscopy, ¹³C-NMR, elementary analysis, TGA, and x-ray diffraction. The first three techniques can also be used quantitatively to measure the degree of hydrolysis of the polymers, without the need to know accurately the weight of the sample. The presence of inorganic salts, such as Na₂SO₄, Na₄(CO₃)SO₄, and Na₂CO₃, is readily detected via IR or wide-angle x-ray diffraction. No evidence of crystallinity is found in the samples studied.     

Use of β-hydroxyacyl-CoA-dehydrogenase (HADH) activity to differentiate frozen from unfrozen fish and shellfish

 Further work on an enzymic method to differentiate frozen from unfrozen fish and shellfish is reported. The method is based on the release of the β-hydroxyacyl-CoA-dehydrogenase (HADH) from mitochondria during freezing. Enzymic activity was evaluated in fresh and frozen thawed samples from sole (Solea solea), sea bream (Pagellus centrodontus), hake (Merluccius merluccius), gilt headed bream (Sparus aurata), sea bass (Dicentrarchus labrax), salmon (Salmo salar), prawn (Penaeus japonicus) and Norwegian lobster (Nephrops norvegicus). Changes in the HADH activity of fresh and frozen thawed samples were compared after freezing at –196  °C for 15 min. Two values were obtained: U (by dividing: HADH activity of samples frozen at –196  °C, then thawed/HADH activity of unfrozen samples) and F (by dividing: HADH activity of samples frozen at –18  °C, thawed, then frozen at –196  °C /HADH activity of samples frozen at –18  °C, then thawed). Statistical analysis showed significant differences (P≤0.05) between both quotients for gilt headed bream, salmon, sea bream, sole and prawn, and an arbitrary limit was set at 2 to differentiate frozen thawed from unfrozen samples. The application of this limit made it possible to discriminate the unfrozen from the frozen thawed state of around 90% of the total samples analysed. Best results were obtained for prawn (100% of samples differentiated). In the present paper, a laboratory routine is proposed based on the comparison of the HADH activity of a sample analysed straight away and that of a sample frozen at –196  °C and then thawed. The reported method is simple and fast. The entire laboratory procedure can be performed in 45 min. Received: 20 July 1998 / Revised version: 2 November 1998     

Interfacial and emulsifying behaviour of crayfish protein isolate

The interfacial behaviour of adsorbed protein films constituted with a crayfish protein derivate that is typically produced as by-product from the food industry, has been studied at the air-water and oil-water interfaces. An analysis of the surface pressure under compression-expansion cycles of this protein was carried out as a function of time, concentration and pH (2 and 8). Besides, interfacial tension and adsorption kinetics also were determined as a function of time at different concentrations and pH values. Interfacial rheological properties were studied under dilatational deformations applied to a single droplet, either at the initial step of film formation or once the interfacial tension was at equilibrium and the film was completely formed. The contribution of the interfacial properties to the behaviour of oil-in-water emulsions stabilised with this protein derivative were also analysed. Finally, droplet size distributions obtained for concentrated emulsions stabilised by crayfish protein were analysed and related to the interfacial tension behaviour. We have demonstrated that crayfish proteins at pH 8 show higher solubility, smaller aggregates and better interfacial activity (higher surface pressure and lower interfacial tension) with higher interfacial viscoelasticity, than at pH 2. A two-dimensional model of the results showed that oil-water and air-water interfaces are clearly related to the improved stability of emulsion made with crayfish proteins at pH 8.