Effect of heat treatment and milling on the seed, flour, rheology and baking quality of some amaranth ecotypes

Forty-five harvests corresponding to the two predominating domestic species of amaranth in Mexico were studied. The proximate analysis revealed some statistically significant differences throughout three years of observation. The Ca, P and Fe content did not vary greatly in 15 samples. No chemical differences were either manifested in the Mercado and Aztec types of A. hypochondriacus, nor in the Mexican type of A. cruentus. The latter exhibits a higher grain yield and a shorter life cycle; however, its baking quality is apparently inferior to that of the Mercado type of A. hypochondriacus. The heat treatment of the seeds (toasting, popping and cooking) affected protein and lysine contents as does in cereals and leguminous seeds although toasting in particular improves its sensory characteristics without altering digestibility and PER. Popping only improves PER. Heating at 90 or 170 degrees C for three to five minutes, at the usual seed's moisture rate of 6 to 15%, does not affect protein content and does so only slightly in the case of the fatty acids content. Amylographic and farinographic values of the starchy fractions indicate similarities to C. quinoa and differences with respect to wheat. In the case of "amaranth milk", viscosity and gelatinization temperature produced satisfactory values. The extension of amaranth cultivation in the country is hereby suggested in view of the seed's nutritional quality, and considering the behavior of whole amaranth flour and its fractions.     

Development of bakery products for greater adult consumption based on wheat and rice flour

The present investigation was developed as a contribution to Guatemalan's elderly food and nutrition. Its main objective was to evaluate the chemical, nutritional and sensory quality of bread prepared from the partial substitution of wheat flour with rice flour. Wheat flour substitutions with rice flour in the order of 15, 20, 30, 40, 50 and 60% were evaluated. Differences with the control (100% wheat bread) were found during the process of preparation, as well as texture, volume, height, weight and specific volume. Important effects in dough handling were noted specifically in the 40, 50 and 60% rice bread. Thus, a sandy texture was found in breads of higher rice levels. The bread protein quality increased with the level of substitution; however the protein quality difference between the wheat bread and the bread with 60% rice flour did not achieve statistical significance. Based on a statistical analysis of the physical properties the bread with 30 and 40% rice flour was selected, and through a preference test between these last two, the 30% rice flour bread was selected as the sample best suited to the present study's purposes. This bread was not different to wheat bread in many nutritional parameters, although in others it showed to be superior. Each serving size of bread has a weight of 80 grams (2 slices) that contributes adequate quantity of calories, protein and sodium, although a little less dietary fiber than 100% wheat bread.     

Discriminating power of the hydrocarbon content from virgin olive oil of extremadura cultivars

Samples of virgin olive oils (105) from seven Extremaduran olive varieties (Cacereña, Carrasqueña, Cornezuelo, Corniche, Morisca, Picual, and Verdial de Badajoz) in three stage of maturity (green, semi-ripe, and ripe) were collected and the alkane, alkene, and sesquiterpene contents determined. There were significant differences at the 0.01 probability level in most of the hydrocarbons, both by variety and by state of maturity. Discriminant analysis applied to 70 samples explained 72.3% of the variance between the different groups of varieties and allowed 90% of the samples to be classified according to their variety. The acceptability of the model was verified against the remaining 35 samples, giving a mean level of correct classification of 94%.     

Use of an environmental specimen bank for evaluating the impact of the Prestige oil spill on the levels of trace elements in two species of Fucus on the coast of Galicia (NW Spain)

In the present study we investigated possible contamination by trace elements due to the oil slick caused by the shipwreck of the Prestige oil tanker, in two species of brown macroalgae (Fucus vesiculosus and Fucus ceranoides) collected from the coastal area most severely affected by the spill (Galicia, NW Spain). The oil slick apparently did not cause significant increases in the concentrations of the trace elements studied, except vanadium. It appears that the magnitude of terrestrial inputs to coastal waters is sufficiently high to mask the inputs of trace elements from the fuel. The observed exception of V suggests that bioaccumulation of this element by the two species of Fucus may be used to indicate exposure to petrochemical products similar to the Prestige fuel. The findings of the study are another example of the importance of the existence of Environmental Specimen Banks for studies of this type.     

Model selection, identification and validation in anaerobic digestion: a review

Anaerobic digestion enables waste (water) treatment and energy production in the form of biogas. The successful implementation of this process has lead to an increasing interest worldwide. However, anaerobic digestion is a complex biological process, where hundreds of microbial populations are involved, and whose start-up and operation are delicate issues. In order to better understand the process dynamics and to optimize the operating conditions, the availability of dynamic models is of paramount importance. Such models have to be inferred from prior knowledge and experimental data collected from real plants. Modeling and parameter identification are vast subjects, offering a realm of approaches and methods, which can be difficult to fully understand by scientists and engineers dedicated to the plant operation and improvements. This review article discusses existing modeling frameworks and methodologies for parameter estimation and model validation in the field of anaerobic digestion processes. The point of view is pragmatic, intentionally focusing on simple but efficient methods.     

碳钢在人造小孔中阳极溶解的研究

<正> 孔蚀的发生与发展既受材料因素的制约,又受环境条件的影响。由于小孔在生长过程中其总表面积一直在变化,直接测定小孔生长速度十分困难,因此有人采用人工小孔模型以研究小孔的生长规律。本工作采用人造小孔模型系统研究了环境因素对碳钢单蚀孔阳极溶解的影响规律及蚀孔内表面膜的组成与作用。     

Integrated material flow and radioactivity distribution methodology within the calculation tool for evaluation of parameters for decommissioning of nuclear installations

Decommissioning of nuclear facilities becomes an important issue in all areas of nuclear technology, mainly in their energetic applications. Decommissioning process has to be planned in the safe, ecological and economic manner. It determines the requirements on appropriate evaluation of needed technologies, media, amount of solid materials released into the environment, radioactivity of effluents, amount of radioactive waste for disposal, number and exposure of personnel and finally the financial demands. A detailed evaluation of these parameters may be done by analytical calculation approach. This approach models a real process of decommissioning with its individual basic activities. The methodology of integrated material flow and radioactivity distribution within this calculation evaluation tool is applied and implemented to describe the real decommissioning activities and their mutual relations to obtain more accurate outputs.     

ICRP Publication 114. Environmental protection: transfer parameters for reference animals and plants

In Publication 103 (ICRP, 2007), the Commission included a section on the protection of the environment, and indicated that it would be further developing its approach to this difficult subject by way of a set of Reference Animals and Plants (RAPs) as the basis for relating exposure to dose, and dose to radiation effects, for different types of animals and plants. Subsequently, a set of 12 RAPs has been described in some detail (ICRP, 2008), particularly with regard to estimation of the doses received by them, at a whole-body level, in relation to internal and external radionuclide concentrations; and what is known about the effects of radiation on such types of animals and plants. A set of dose conversion factors for all of the RAPs has been derived, and the resultant dose rates can be compared with evaluations of the effects of dose rates using derived consideration reference levels (DCRLs). Each DCRL constitutes a band of dose rates for each RAP within which there is likely to be some chance of the occurrence of deleterious effects. Site-specific data on Representative Organisms (i.e. organisms of specific interest for an assessment) can then be compared with such values and used as a basis for decision making. It is intended that the Commission's approach to protection of the environment be applied to all exposure situations. In some situations, the relevant radionuclide concentrations can be measured directly, but this is not always possible or feasible. In such cases, modelling techniques are used to estimate the radionuclide concentrations. This report is an initial step in addressing the needs of such modelling techniques. After briefly reviewing the basic factors relating to the accumulation of radionuclides by different types of biota, in different habitats, and at different stages in the life cycle, this report focuses on the approaches used to model the transfer of radionuclides through the environment. It concludes that equilibrium concentration ratios (CRs) are most commonly used to model such transfers, and that they currently offer the most comprehensive data coverage. The report also reviews the methods used to derive CRs, and describes a means of summarising statistical information from empirical data sets. Emphasis has been placed on using data from field studies, although some data from laboratory experiments have been included for some RAPs. There are, inevitably, many data gaps for each RAP, and other data have been used to help fill these gaps. CRs specific to each RAP were extracted from a larger database, structured in terms of generic wildlife groups. In cases where data were lacking, values from taxonomically-related organisms were used to derive suitable surrogate values. The full set of rules which have been applied for filling gaps in RAP-specific CRs is described. Statistical summaries of the data sets are provided, and CR values for 39 elements and 12 RAP combinations are given. The data coverage, reliance on derived values, and applicability of the CR approach for each of the RAPs is discussed. Finally, some consideration is given to approaches where RAPs and their life stages could be measured for the elements of interest under more rigorously controlled conditions to help fill the current data gaps.     

A broad chemical and structural characterization of the damaged region of carbon implanted alumina

As candidate materials for future thermonuclear fusion reactors, isolating ceramics will be submitted to high energy gamma and neutron radiation fluxes together with an intense particle flux. Amorphization cannot be tolerated in ceramics for fusion applications, due to the associated volume change and the deterioration of mechanical properties. Therefore, a comprehensive study was carried out to examine the effects of carbon beam irradiation on polycrystalline aluminium oxide (Al₂O₃), a ceramic component of some diagnostic and plasma heating systems. Complementary techniques have allowed a complete chemical and structural surface analysis of the implanted alumina. Implantation with 75 keV, mono-energetic carbon ions at doses of 1 × 10¹⁷ and 5 × 10¹⁷ ions/cm² was performed on polished and thermally treated ceramic discs. The alumina targets were kept below 120 °C. The structural modifications induced during ion irradiation were studied by the GXRD and TEM techniques. Under these conditions, alumina is readily amorphized by carbon ions, the thickness of the ion-beam induced disordered area increasing with the ion dose. Matrix elements and ion implanted profiles were followed as a function of depth by using ToF-SIMS, indicating the maximum concentration of implanted ions to be in the deeper half of the amorphous region. Ion distribution and chemical modifications caused in the Al₂O₃ substrate by carbon irradiation were corroborated with XPS. The amount of oxygen in the vicinity of the implanted alumina surface was reduced, suggesting that this element was selectively sputtered during carbon irradiation. The intensity of those peaks referring to Al–O bonds diminishes, while contributions of reduced aluminium and metal carbides are found at the maximum of the carbon distribution. TEM observations on low temperature thermally annealed specimens indicate partial recovery of the initial crystalline structure.     

New Evaluated Semi-Empirical Formula Using Optical Model for 14–15 MeV (<Emphasis Type="Italic">n</Emphasis>, <Emphasis Type="Italic">t</Emphasis>) Reaction Cross Sections

In the next century the world will face the need for new energy sources. Nuclear fusion can be one of the most attractive sources of energy from the viewpoint of safety and minimal environmental impact. Fusion will not produce CO₂ or SO₂ and thus will not contribute to global warming or acid rain. Achieving acceptable performance for a fusion power system in the areas of economics, safety and environmental acceptability, is critically dependent on performance of the blanket and diverter systems which are the primary heat recovery, plasma purification, and tritium breeding systems. Tritium self-sufficiency must be maintained for a commercial power plant. The hybrid reactor is a combination of the fusion and fission processes. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. So working out the systematics of (n, t) reaction cross-sections are of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at energies up to 20 MeV. In this study, we have calculated non-elastic cross-sections by using optical model for (n, t) reactions at 14–15 MeV energy. We have investigated the excitation function character and reaction Q-values depending on the asymmetry term effect for the (n, t) reaction cross-sections. We have obtained new coefficients for the (n, t) reaction cross-sections. We have suggested semi-empirical formulas including optical model nonelastic effects by fitting two parameters for the (n, t) reaction cross-sections at 14–15 MeV. We have discussed the odd–even effect and the pairing effect considering binding energy systematic of the nuclear shell model for the new experimental data and new cross-sections formulas (n, t) reactions developed by Tel et al. We have determined a different parameter groups by the classification of nuclei into even–even, even–odd and odd–even for (n, t) reactions cross-sections. The obtained cross-section formulas with new coefficients have been discussed and compared with the available experimental data.