Alternatives for the recovery and renewal of degraded pastures

This review aimed to approach the dynamics of pasture degradation, relating its causes and forms of recovery and/or renewal. Despite being based on extensive systems, Brazilian agriculture faces serious problems related to pasture degradation. The reduction in forage productivity directly affects the production system, having negative impacts on the economy and the ecosystem. Factors such as the choice of forage species, grazing management and the use of fire are the main factors responsible for the degradation of pastures in Brazil, causing an environmental and productive imbalance. However, it is possible to stop the progress of degradation and resume system productivity using pre-defined techniques in accordance with the objective of the production system. Furthermore, pasture recovery techniques are efficient for the resumption of productivity, and environmental protection, by helping to reduce greenhouse gases. Nevertheless, more research is needed to prove and consolidate pasture recovery techniques in the environmental, economic, and social scope.

Evaluation of recycled asphalt pavement in Colombia

Reclaimed asphalt pavements are obtained from existing pavements through recovery techniques and are used for new asphalt mixtures production with the inclusion of virgin aggregates and asphalt cement, constituting environmentally friendly mixtures at a lower total cost, by requiring fewer quantities of new materials. This research, unlike the studies found on the subject, focuses on the study of reclaimed asphalt pavement by analyzing its granulometric distribution and asphalt cement content. For this purpose, representative reclaimed asphalt pavement samples were taken from four Colombia cities, to verify their heterogeneity. The obtained reclaimed asphalt pavement was analyzed in the laboratory, to obtain the material granulometric distribution, through extraction and asphalt content tests, following Colombian regulations from the “Instituto Nacional de Vías”. The results show that the granulometry of all cities has a central tendency (average) that moves towards an upper limit in the 2 mm particles. When analyzing the granulometry separately of the four cities, it is observed that they present a different trend in their granulometry, which shows their heterogeneity. The asphalt cement content presented values between 4.0% and 5.0%.

Avaliação de eficiência da implantação de técnica de bioengenharia de solos

O Baixo São Francisco está em constante dinâmica hidroambiental resultante das alterações promovidas na calha do rio, representadas pelos processos geomorfológicos ou por ações antrópicas como a construção das barragens que por sua vez provocou mudanças geomorfológicas resultando na aceleração de processos erosivos nas suas margens. O objetivo deste trabalho foi avaliar a implantação de técnicas de recuperação hidroambiental com uso de bioengenharia de solos na margem do rio São Francisco. A área estudada compreende um trecho do baixo curso do rio São Francisco, localizado no município de Amparo do São Francisco, no estado de Sergipe, nordeste do Brasil, onde técnica de bioengenharia de solos, como enrocamento vegetado, foi implementada no ano de 2011. Três grupos de indicadores individuais foram selecionados que juntos contribuíram para a avaliação da Recuperação da Área Degradada relacionados à qualidade do solo, como resistência do solo à penetração e Velocidade de Infiltração Básica, à recuperação da biodiversidade como banco de sementes e a regeneração natural da área por meio de indicadores como composição e cobertura linear de espécies. A metodologia empregada contempla uma avaliação dos resultados originados do uso da biotécnica a partir da identificação da contribuição da vegetação que auxilia na contenção de taludes, uma vez que a cobertura vegetal protege a superfície do solo contra ações erosivas como o vento e a água da chuva. O reforço mecânico trazido pelo sistema radicular das plantas contra cisalhamento do solo se mostrou pela menor resistência à penetração do solo e maior Taxa de infiltração. Evaluation of efficiency of the implementation of soil bioengineering techniqueA B S T R A C TThe Lower São Francisco is in constant hydro-environmental dynamics resulting from the changes promoted in the river channel, represented by geomorphological processes or by anthropic actions such as the construction of dams that in turn caused geomorphological changes resulting in the acceleration of erosive processes on its banks. The objective of this work was to evaluate the implementation of hydroenvironmental recovery techniques using soil bioengineering on the bank of the São Francisco River. The studied area comprises a stretch of the low course of the São Francisco River, located in the municipality of Amparo do São Francisco, in the state of Sergipe, northeastearn Brazil, where soil bioengineering technique, such as vegetated rockfill, was implemented in 2011. Three groups of individual indicators were selected that together contributed to the assessment of Degraded Area Recovery related to soil quality, such as soil resistance to penetration and Basic Infiltration Speed, to the recovery of biodiversity as a seed bank and the natural area regeneration through indicators such as composition and linear species coverage. The employed methodology includes an evaluation of the results from the use of biotechnology based on the identification of the vegetation contribution that helps to contain slopes, since the vegetation cover protects the soil surface against erosive actions such as wind and rainwater. The mechanical reinforcement brought by the root system against soil shear was shown by the lower resistance to soil penetration and a higher infiltration rate.Keywords: Degraded Areas Recovery, erosion, São Francisco River

Methodological approaches to increasing the flooding system efficiency at the later stage of reservoir development

Based on the analysis of the efficiency of CVI.1 and CVI.2 oil reservoirs development, which partially coincide in structural terms, and the terrigenous strata of the Lower Carboniferous of one of Volga-Ural oil and gas province oil fields, an algorithm for assessing the efficiency of waterflooding was proposed, which takes into account the geological structure of the facility, the results of core and geophysical well surveys, as well as the historical performance of wells. The presented algorithm makes it possible to identify ineffective injection directions for making decisions on waterflooding system optimizing. The effect is the identified potential to cut costs by reducing inefficient injection, as well as identifying areas for the introduction of enhanced oil recovery techniques. Keywords: field development; reservoir pressure maintenance system; waterflooding efficiency; cost reduction.

Screening and assessing the conditions for effective oil recovery enhancing techniques application for hard to recover high-water cut reserves

For the conditions of deposits in Jurassic and Paleozoic terrigenous reservoirs of the Sherkalinsky trough and Shaimsky swell of Western Siberia, a criterion analysis and screening of enhanced oil recovery techniques used in the fields of the West Siberian oil and gas province were carried out. For various groups of oil fields, a set of the most effective technologies for the development of residual hard-to-recover reserves of flooded fields has been proposed. The areas for effective application of the selected techniques for deposits introduced into development within the considered tectonic-stratigraphic elements are determined. The areas determination was carried out on the basis of 19 parameters characterizing the geological-physical and physical-chemical properties of formations and fluids, as well as the maximum and minimum values of the canonical discriminant functions determined by the situational map. Based on the numerical modeling of oil recovery processes, a forecast of an increase in the final oil recovery factor was made for five facilities-field test sites of the selected groups of facilities. Keywords: hard-to-recover reserves; terrigenous reservoirs; factor analysis; enhanced oil recovery techniques; numerical modeling; criterion analysis.

Seismic resilience for recovery investments of bridges methodology

Bridges are fundamental links for the movement of goods and people and bridge damage can thus have significant impacts on society and the economy. Earthquakes can be extremely destructive and can compromise bridge functionality, which is essential for communities. Evaluation of bridge functionality is thus fundamental in the planning of emergency responses and socioeconomic recovery procedures. It is especially useful to define parameters to assess investments in bridge infrastructure. Resilience is a key parameter that can identify decision making procedures necessary for recovery investments. In this regard, resilience can be defined as the rapidity of a system to return to pre-disaster levels of functionality. This aim of this work was to assess the lack of robust analytical procedures for quantifying systematic restoration for earthquake-damaged bridges, to provide a link between the assessment of resilience and its application in decision making approaches. The proposed methodology (called seismic resilience for recovery investments of bridges) uses functionality–time curves that allow quantification of resilience along with readable findings for a wider range of stakeholders. The results presented in this paper should be of interest to multi-sectorial actors (i.e. bridge owners, transportation authorities and public administrators) and could drive interdisciplinary applications such as the assessment of recovery techniques and solutions.

Uses of Nanoclays and Adsorbents for Dye Recovery: A Textile Industry Review

Wastewater recovery is one of the most pressing contaminant-related subjects in the textile industry. Many cleaning and recovery techniques have been applied in recent decades, from physical separation to chemical separation. This work reviews textile wastewater recovery by focusing on natural or synthetic nanoclays in order to compare their capabilities. Presently, a wide variety of nanoclays are available that can adsorb substances dissolved in water. This review summarizes and describes nanoclay modifications for different structures (laminar, tubular, etc.) to compare adsorption performance under the best conditions. This adsorbent capacity can be used in contaminant industries to recover water that can be used and be recontaminated during a second use to close the production circle. It explores and proposes future perspectives for the nanoclay hybrid compounds generated after certain cleaning steps. This is a critical review of works that have studied adsorption or desorption procedures for different nanoclay structures. Finally, it makes a future application proposal by taking into account the summarized pros and cons of each nanoclay. This work addresses contaminant reuse, where part of the employed dyes can be reused in printing or even dyeing processes, depending on the fixing capacity of the dye in the nanoclay, which is herein discussed.