Characterisation of grain quality in diverse sorghum germplasm using a Rapid Visco-Analyzer and near infrared reflectance spectroscopy

BACKGROUND: Twenty‐two diverse sorghum landraces, classified as normal and opaque types obtained from Ethiopia, were characterised for grain quality parameters using near infra‐red spectroscopy (NIRS), chemical and Rapid Visco‐Analyzer (RVA) characteristics. RESULTS: Protein content ranged from 77 to 182 g kg^?1, and starch content from 514 to 745 g kg^?1. The NIRS analysis indicated the pig faecal digestible energy range from 14.6 to 15.7 MJ kg^?1 as fed, and the ileal digestible energy range from 11.3 to 13.9 MJ kg^?1 as fed. The normal sorghums had higher digestible energy than the opaque sorghums, which exhibited lower RVA viscosities, and higher pasting temperatures and setback ratios. The RVA parameters were positively correlated with the starch content and negatively correlated with the protein content. The normal and opaque types formed two distinct groups based on principal component and cluster analyses. CONCLUSION: The landraces were different for the various grain quality parameters with some landraces displaying unique RVA and NIRS profiles. This study will guide utilisation of the sorghum landraces in plant improvement programs, and provides a basis for further studies into how starch and other constituents behave in and affect the properties of these landraces. Copyright © 2011 Society of Chemical Industry     

Catchment management groups in England and Wales: extent,roles and influences

Both nonstatutory community‐based catchment management groups and existing statutory groups seek effective environmental management characterised by public participation, collaborative working and decentralised modes of assessment, planning and decision making. The characteristics and challenges of catchment management for water resources and protection of water quality require such approaches, and an expansion of both community‐based and state‐led initiatives has been evident in the United Kingdom. Available information about these developments is, however, limited and this paper reports survey findings of such initiatives, providing a mid‐to‐late 2009 ‘snapshot’ of the situation in England and Wales. Catchment management groups are profiled in terms of size, organisational structure, membership, financing, technology transfer, policy influence and other outcomes. The results are interpreted with reference to a growing international literature, the potential sustainability, effectiveness and impact of groups and environmental governance challenges, including those posed by the European Union Water Framework Directive.     

Electroaddressing Functionalized Polysaccharides as Model Biofilms for Interrogating Cell Signaling

Bacteria often reside at surfaces as complex biofilms in which an exopolysaccharide matrix entraps the population while allowing access to its chemical environment. There is a growing awareness that the biofilm structure and activity are integral to a wide array of properties important to health (the microbiome), disease (drug resistance) and technology (fouling). Despite the importance of bacterial biofilms, few experimental platforms and systems are available to assemble complex populations and monitor their activities. Here, a functionalized alginate composite material for creating in vitro model biofilms suitable for cell‐cell signaling studies by entrapping bacterial cells in situ is reported. Biofilm assembly is achieved using device‐imposed electrical signals to electrodeposit the stimuli‐responsive polysaccharide alginate. This electrodeposition mechanism is versatile in that it allows control of the bacterial population density and distribution. For instance, it is demonstrated that a mixed population can be homogeneously distributed throughout the biofilm or can be assembled as spatially segregated populations within a stratified biofilm. The “electroaddressable” biofilms are visualized using both a planar 2D chip with patterned electrodes and a microfluidic bioMEMS device with sidewall electrodes. Specifically, it is observed that bacteria entrapped within the model biofilm recognize and respond to chemical stimuli imposed from the fluidic environment. Finally, reporter cells are used to demonstrate that bacteria entrapped within this model biofilm engage in intercellular quorum sensing. This work demonstrates the functionality of the stimuli‐responsive polysaccharide by biofabricating pseudo‐3D cell‐gel biocomposites, mimicking the formation of biofilms, for interrogating phenotypes of E. coli bacterial populations. In addition to controlling assembly, the microfluidic device allows the biofilm to be monitored through the fluorescence methods commonly used in biological research. This platform technology should be able to be exploited for monitoring biofilm development, as well as for extending the understanding of the interactions between various bacterial species arranged in controlled patterns.     

Strain rate-dependant mechanical properties of OFHC copper

The mechanical properties of high purity copper have been extensively studied in the literature, with yield and flow stresses measured as a function of strain rate, grain size, and temperature. This paper presents a comprehensive study of the strain rate and grain size dependence of the mechanical properties of OFHC copper, including an investigation of the previously observed upturn in rate dependence of flow stress at high rates of strain (≥500 s^?1). As well as a comprehensive review of the literature, an experimental study is presented investigating the mechanical properties of OFHC copper across a range of strain rates from 10^?3 to 10⁵ s^?1, in which the copper samples were designed to minimize the effects of inertia in the testing. The experimental data from this study are compared with multiple sources from the literature varying strain rate and grain size to understand the differences between experimental results on nominally the same material. It is observed that the OFHC copper in this study showed a similar increase in flow stress with strain rate seen by other researchers at high strain rates. The major contribution to the variation between experimental results from different studies is most likely the starting internal structure for the materials, which is dependent on cold working, annealing temperature, and annealing time. In addition, the experimental variation within a particular study at a given strain rate may be due to small variations in the internal structure and the strain rate history.     

A Theoretical and Experimental Study of Heat Line Formation in a Roll Caster

The authors show that a steady state two-dimensional finite difference model has been developed to describe the roll casting process, incorporating a variable heat transfer coefficient through the roll bite. The model explains the formation of the speed limiting defects called ‘heat lines’ in terms of this variable strip/roll heat transfer coefficient. The results of subsequent casting speed trials are compared with the predictions made by the numerical model. Approximate values of the heat-transfer coefficients through the roll bite in the various regions proposed for the roll caster model have been determined by matching predicted strip exit temperatures to experimental measurements for various casting speeds. Further evidence for the values of the alloy/mould heat transfer coefficients were obtained from cooling curves. The model has been used to investigate the effect of varying various casting parameters on the strip exit temperature and the critical casting speed above which heat lines form.     

Modeling and experimental calibration of the corrosion of RHA steel in immersion and salt-fog environments

ABSTRACT

An investigation into the general and pitting corrosion rates of rolled homogeneous armour (RHA) steel in immersion and salt-fog environments is presented. Although the mechanical properties of RHA steel have been studied, the corrosion effects on RHA steel have not been quantified. An immersion environment of 3.5% NaCl was used to induce corrosion for four immersion samples. A Q-fog corrosion tester was used to simulate a salt-fog/humidity/drying environment for four salt-fog samples. The different mechanisms of corrosion and their rates were quantified through mass loss, laser profilometry and scanning electron microscopy. The immersion samples show a linear rate of corrosion of 1.47?g/year (R²?=?0.994) throughout the entire testing period. The salt-fog samples had a significant mass gain for the first 500?h of corrosion, as the corrosion products are retained. Immersion samples showed no signs of pitting, while the salt-fog samples had sustained pit nucleation, growth, and coalescence.     

Numerical and Experimental Study of Alternative Reductant Injection into the Raceway of the Blast Furnace

Aiming for the reduction of coke rates in blast furnace processes, auxiliary reducing agents are utilized as fuel and carbon carrier. CFD models have been developed, implemented, and validated to study the injection of plastics and fuel oil into the blast furnace raceway. Separate sets of conservation equations are solved for the appearing phases, accounting for heterogeneous transport phenomena. To provide for sound boundary conditions, experiments characterizing the involved materials were performed. The model predictions are used for the optimization of operating conditions, supporting further improvement of plant efficiency and economics.     

Multi‐pronged analysis of degradation rates of photovoltaic modules and arrays deployed in Florida

The long‐term performance and reliability of photovoltaic (PV) modules and systems are critical metrics for the economic viability of PV as a power source. In this study, the power degradation rates of two identical PV systems deployed in Florida are quantified using the Performance Ratio analytical technique and the translation of power output to an alternative reporting condition of 1000 W m⁻² irradiance and cell temperature of 50 °C. We introduce a multi‐pronged strategy for quantifying the degradation rates of PV modules and arrays using archived data. This multi‐pronged approach utilizes nearby weather stations to validate and, if needed, correct suspect environmental data that can be a problem when sensor calibrations may have drifted. Recent field measurements, including I‐V curve measurements of the arrays, visual inspection, and infrared imaging, are then used to further investigate the performance of these systems. Finally, the degradation rates and calculated uncertainties are reported for both systems using the methods described previously. Copyright © 2012 John Wiley & Sons, Ltd.     

Environmental Regulation: Recent Experience With Greenhouse Gas BACT Gives Valuable Guidance

January 1, 2011, marked the beginning of one of the most significant changes to the scope of New Source Review (NSR) rules since their enactment. As a result of greenhouse gases (GHGs) becoming a regulated pollutant under the Clean Air Act (CAA), the Environmental Protection Agency (EPA) determined that such pollutants must now be addressed as a part of Prevention of Significant Deterioration (PSD) reviews. Although no air quality analysis is required for such pollutants, sources must address best available control technology (BACT) for GHG emissions as a part of a complete PSD application.     

Discrete Fourier transform of correlation functions

The Van Vleck equation relating the polarity correlation function to the direct correlation function is used to derive a new algorithm for the evaluation of the discrete Fourier transform of the direct correlation function. Application of an implementation of the algorithm to correlation-based measurement is discussed.