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Gas bubble disease (GBD) is a condition that adversely affects aquatic animals exposed to supersaturated water. Fish mortality attributed to GBD has been observed in the tailrace of the Colider Dam on the Teles Pires River in Brazil during spillway releases. Gas supersaturation downstream of dams typically is caused by the dissolution of air bubbles entrained at depth in the stilling basin. The most common strategy to reduce total dissolved gas (TDG) concentration, and the risk of GBD, is to install spillway flow deflectors that redirect plunging flows horizontally and thus minimize the bubble transport to a depth at which dissolution is enhanced. This paper presents a numerical study, based on the open-source code OpenFOAM, assessing the design of spillway deflectors at Colider Dam and determining their effectiveness at reducing TDG. A two-fluid flow model was implemented in a free-surface solver to predict spillway jet regimes and TDG distribution for 900 m of the Colider tailrace. Residence time and TDG exposure in the tailrace were estimated using a particle tracking technique. A rigid-lid model was used to predict TDG distribution in the Teles Pires River 10 km downstream of the dam. Reasonable agreement was found between numerical model results and velocity data measured in a 1:120 reduced-scale hydraulic model. Predicted spillway jet regimes were consistent with the deflector performance curve obtained in a 1:60 reduced-scale sectional model. After calibration and validation against TDG field data, numerical simulations were performed to better understand the effect of the deflector curvature radius, length, and elevation on TDG production. Fish mortality or injury due to GBD was not observed in Colider during spill events after deflectors recommended in this study were installed in 2021. Field measurements indicate that TDG reduction by the deflectors is consistent with values predicted during the design of the deflectors. Fish mortality with gas bubble disease symptoms due to elevated total dissolved gas concentrations have been observed downstream of Colider Dam since the first spillway operation in 2018. The most common strategy to reduce TDG production downstream of hydropower dams is to install flow deflectors on the spillway face. This paper presents a numerical study to assess the performance of flow deflectors for Colider Dam. A computational fluid dynamic (CFD) model, comprising the air and water phases, and bubbles in the water phase, was developed to predict spillway jet regimes and TDG concentration. The model included the main features of the dam and a 10-km reach of the Teles Pires River. After calibration and validation, 28 simulations were performed to evaluate and improve the deflector design. A final deflector design was recommended based on TDG production and TDG exposure time. No fish mortality has been observed since the deflector construction was completed in 2021, even under operational conditions fatal to fish in the past. [ABSTRACT FROM AUTHOR]

Recent disasters involving upstream raised tailings dams in Brazil have caused regulatory agencies to prohibit the construction of new upstream dams and demand the decommissioning of existing ones. As such, new alternatives are being sought to safely dispose of iron ore exploitation byproducts. The dry stacking of filtered tailings is an option to diminish the risks associated with tailings storage facilities and cope with new legislation. Accordingly, this paper studies new solutions for enhancing the performance of tailings for dry stacking purposes. The behavior of reinforced and nonreinforced iron ore tailings-alkaline-activated cement (AAC) blends was studied through unconfined compressive strength tests and conventional triaxial testing. The AAC is produced from the residues of iron ore exploitation (waste and tailings). The addition of fibers has enhanced the performance of cemented iron ore tailings with increased strength regardless of the fiber content and ductility. Also, reinforcement effectiveness values were greater than those reported for other cement agents, due to the lower stiffness of the cemented matrix from AAC compared with others. A comparative analysis between using only AAC and ACC plus 0.5% of fibers within the η/Biv framework was proposed. The dosage curves for the same qu value yielded an AAC=20.80% for AAC only and AAC=3.80% when using 0.5% of fibers. Therefore, using fibers can collaborate with the feasibility of using a new waste-based AAC to construct dry stacking facilities. [ABSTRACT FROM AUTHOR]

Toll plazas are commonly described as a potential bottleneck due to the collection process at specific points on the highway. In a highway concession model, tolls are used to cover the majority of infrastructure costs. However, not all existing road concessions have toll plaza–related key performance indicators (KPIs), resulting in less efficient operations for transport managers and road users. To address this issue, this paper presents a discrete-event simulation (DES) model for policy analysis and the model for the planning, management, and evaluation of toll plazas using an extensible simulation package with animation capabilities, built by selecting modules that contain process features. The DES describes situations in which entities (vehicles) arrive, wait in the queue (if necessary), and then are attended to before leaving the system, either directly or indirectly. As a result, the simulation is based on discrete events (arrivals and departures) and statistical process data. This paper examines data from Brazil's first public–private partnership (PPP) project in the area of road infrastructure and analyzes the toll plaza in Itaúna/MG using a case study methodology. The DES model was used in this case study, and the results show that the toll plaza was in good operating condition during the peak hour analyzed because the vehicular flow was lower than the system capacity. The willingness to pay the toll rate through the concept of open road tolling or a free-flow system, on the other hand, would provide significant benefits to road users because it would significantly reduce the time it takes to cross the toll plaza. The developed DES model assists toll plaza managers in making decisions while keeping in mind the need to comply with the operational efficiency measures agreed upon in the concession contracts. [ABSTRACT FROM AUTHOR]

Low-impact development practices (LIDs) have been used to reduce the impacts of flash floods in Brazil. However, there is a lack of investigations on their construction costs concerning the effects on the mitigation of flash floods. This paper addresses the construction costs and the runoff reduction by using seven scenarios of LIDs for a 32-km2 basin in the Midwest Brazil region. The LIDs considered were permeable pavement (PP), rainwater harvesting (RWH), and infiltration trenches (IT). The first three LID scenarios considered PP, RWH, and IT techniques, respectively, and the other four used different combinations of the three LIDs. Scenario 3 showed a decrease of 15% in the runoff, achieved at a lower cost using only IT. This result corresponds to a 2.6% runoff reduction per $1 million spent. These analyses may help in the identification of the balance between benefit and cost by local stakeholders for the use of LIDs. [ABSTRACT FROM AUTHOR]

Severe droughts, water-use conflicts, and minimum outflow requirements have caused infeasibilities in modeling large-scale complex hydrothermal systems. This paper presents and discusses a new formulation of objective function and constraints to better represent multiple water uses and deal with infeasibilities in the HIDROTERM model, a nonlinear programming (NLP) model developed to optimize the operation of the Brazilian interconnected hydrothermal system. The system is one of the largest in the world. In the last 10 years, approximately 72% of electricity consumed in Brazil has been supplied by hydropower plants, but with increasing shares from thermal, wind, and, more recently, solar power generation. Because of hydrological changes in recent years and the additional operational constraints imposed by environmental agencies, the use of models for decision making, such as HIDROTERM, frequently encounters the problem of infeasibility. To avoid this problem, a new objective function is proposed in HIDROTERM that incorporates economic penalties when the preset requirements are not met. Based on economic considerations, some hard constraints are removed from the constraint set and added to the objective function as penalty terms. These constraints are tightly linked with multiple water uses, including environmental protection, flood control, consumptive uses, and navigation purposes. The proposed change in the objective function and constraints avoids the problem of infeasibilities and makes it possible to apply the model to extreme conditions. Additionally, this formulation helps identify and minimize the risk, duration, and intensity of unavoidable non-compliance occurrences related to multiple water uses. The presented new version of the HIDROTERM model can be used to study and support decision making in the management and operation of large-scale hydrothermal systems. These systems can be formed by a set of hydraulically connected individual hydropower plants and reservoirs, located within a set of electrically connected subsystems. Each subsystem contains demands and other power plants, including thermal, wind, nuclear, and solar plants, and exchanges. The model has been developed with continued improvements since 2008 and applied to large systems such as the Brazilian Interconnected Power System (BIPS) with over 150 reservoirs. A graphical user interface is provided. The objective function is to minimize the total costs of additional thermal dispatch and exchanges, as well as avoid or minimize deficits in energy supply in subsystems, minimum releases, consumptive uses, and minimum storages in reservoirs. The decision variables are the power and nonpower releases for each hydropower plant and the thermal dispatches and exchanges for each subsystem. Some typical applications include (1) monthly planning operation of the system, considering a planning horizon from 3 to 5 years; (2) diagnostic studies about reliability and resilience of existing systems, processing the same system configuration to a set of different hydrological or energy demand scenarios; (3) impact analysis of changes in operational rules and constraints related to multiple uses of water; and (4) planning and evaluation of expansion alternatives. The model can be applied to a complete hydrothermal system or subsets of it, including subsystems, basins, cascades, or a single hydropower plant. [ABSTRACT FROM AUTHOR]

This paper proposes a new conceptual approach to address the gap in the understanding of benefits realization, which is an increasingly central element in the delivery of successful projects in architecture, engineering, and construction (AEC) design. The paper focuses on the link between uncertainty in front-end design (FED) and the delivery of project benefits as understood in the broader benefits realization theory. The paper builds on the nature of uncertainty and use of Dempster–Shafer theoretic and quality function deployment to model the various interdependences among design attributes. A social housing case study of Brazil's Mia Casa, Mia Vida Program demonstrated the application of the modeling approach. Optimal belief and plausibility structures in design decision-making were observed to increase with increasing consideration of more use models. These findings demonstrate that modeling uncertainty in FED can contribute to improved design decision-making. The paper's novel contribution is introducing uncertainty modeling to support design decision-making to overcome insufficiencies in the inherently rational design decision-making that often is unable to discern complexities in dynamic project contexts. [ABSTRACT FROM AUTHOR]

This research evaluates the geometric non-linear behavior of structures often used in transmission lines (TLs) and verifies the influence of different wire lengths, average wind speeds, and unevenness between adjacent towers, using the IEC 60826 standard. Different finite element numerical models were developed considering the isolated tower and also the complete system (tower, wires, and insulator chains). The analyses revealed that a simplified model can be employed for cases of adjacent, equal-length spans, but for cases with different lengths, the effect of geometric nonlinearities (GNLs) can become expressive and influence the type of analysis to be performed. Furthermore, it was found that increasing the average wind speed may imply an increase in the longitudinal unbalance. Finally, it was concluded that the unevenness between spans should be considered when calculating the loads to be applied to the structure, even if the simplified model is used. Based on the outcomes and considering wind speeds between 30 and 40 m/s and adjacent tower unevenness between 0 and 10%, this work establishes practical design criteria to be used by designers in the design of suspension structures of TLs located in the State of Minas Gerais, Brazil. The methodology presented in this paper can be extrapolated to other regions of the country, paying attention to the fact that the recommendations proposed here are valid only for self-supporting towers. [ABSTRACT FROM AUTHOR]

Adapting reservoir operation to a changing climate is important to improve water system performance toward benefits including water security, and energy production. However, managers still need to know if and how reoperation can also assist long-term mitigation of climate change impacts on aquatic ecosystems, creating, for example, opportunities to revert fish migration and recruitment losses. This paper investigates the operational adaptive capacity of water systems to mitigate climate change impacts on both hydropower and aquatic ecosystems, with a detailed representation of fish species recruitment response to flow regime changes. The methodology framework combines hydroclimatic modeling, explicit stochastic reservoir operation modeling, and predictive modeling of migratory fish recruitment abundance, illustrated using the large-scale hydropower system of the Paraná River Basin in Brazil. Results identified that operating policies can be adapted to improve hydropower production under a changing climate with drier conditions by 2% to 8% compared with current operating policies. Although insufficient to eliminate all energy losses that climate change may cause, the optimized operation provided flexibility to adjust flow releases and reduce the likelihood of future severe multiyear deficits, which are very harmful to fish populations. Adapting operation to climate change sacrificed fish recruitment performance over a few years of the time horizon to maintain an overall higher storage, but it also improved the chances of producing flow releases in magnitude, timing, and duration during long drier periods that prevented more severe impacts of climate change on fish recruitment and population. This indicates that it might be possible to have synergies in adapting reservoir operation to not only prevent energy losses, but also to improve fish recruitment under climate change. The ecosystem resiliency under adapted operation increased up to 2 times compared with the isolated climate change effect. [ABSTRACT FROM AUTHOR]

Asphalt pavement failure is directly related to the traffic and climate effects. Temperature and moisture severely impact pavement service life. It is known that moisture changes the stiffness and stress–strain distribution and all the mechanical behaviors of the mixture/structure. There is a huge interest in studying the impact of water on the behavior of flexible pavements, mainly on freeze–thaw regions under tropical climates with high rainfall levels. The scope of the present paper was to check the susceptibility to moisture-induced damage of dense asphalt mixes produced and applied on highways in Brazil's southernmost region using different laboratory tests: visual adhesion of coarse aggregate; tensile strength ratio (TSR), and dynamic modulus ratio (DMR). Thus, this study evaluated the morphological, chemical, and mineralogical properties of aggregates from 11 quarries, as well as the interaction between aggregates and the respective bituminous binders. Rocks with high Si contents performed worse in visual adhesiveness tests; chemical ratios such as Fe/Si above 1 and Ca/K above 5, as well as the rougher texture of aggregates, considerably improved the coating, reducing the failures in adhesion. Results of TSR and DMR, after applying the induced moisture damage cycle, indicated greater susceptibility to conventional binders than mixtures containing modified binders in their composition. The action of moisture damage for most mixtures caused a reduction in strength and stiffness, warning of a decrease in the binder's ability within the mixture, completely changing the distribution of efforts within the structure. Therefore, from this study, it is possible to suggest using DMR instead of TSR to assess susceptibility to moisture damage. [ABSTRACT FROM AUTHOR]

In situations of fluctuating water availability, the optimal reservoir operation policy, resulting from classical models, fails to be implemented for political reasons. This paper proposes a collaborative modeling approach to define the hedging rules of a two-basin reservoir system, in which the acceptable risks, rationing ratio, and reasonable transfer values are defined by the water allocation agents for different phases/drought states. An optimization algorithm is then applied to determine a politically viable hedging operation policy. The methodology showed good results for the Jaguaribe–Metropolitan system in Brazil, and the resulting policy could be applied to the real operation, as the simulated rationing frequencies were close to those defined by the managers' consensus. The proposed methodology guarantees a politically viable alternative with conflict management possibilities. However, the performance of the resulting hedging rules depends on the negotiation capacity and tacit knowledge of the stakeholders. The proposed approach is a good alternative when the implementation of the mathematically optimum policy fails. [ABSTRACT FROM AUTHOR]

Visual management (VM) is a strategy for information management that aims to increase process transparency, one of the main principles of the lean production philosophy. It has been widely used in manufacturing, but the use of VM in construction is still very limited. As the development of VM is mostly based on trial and error efforts, it is useful to produce taxonomies of VM practices, which can lead to typologies to support the understanding of concepts and the development of theories. The main contribution of this paper is a typology of concepts related to VM that extends the contribution of taxonomies previously proposed in the literature, by emphasizing the role of collaboration and communication, as well as the need to integrate VM practices into managerial routines and to other practices. This typology has been used to assess the implementation of VM in 16 construction sites located in Brazil. Moreover, it has identified improvement opportunities, based on the comparisons of VM practices used in those sites to a sample of manufacturing plants. [ABSTRACT FROM AUTHOR]

We propose the usage of social media as the primary way to collect and consolidate disaster data to provide a less costly and faster economic evaluation process. Through a systematic literature review (SLR) of over 406 peer-reviewed papers, this study first offers a taxonomy to show how social media can be applied to economic disaster assessments. Then we deliver an economic assessment to a flooding disaster in Brazil based on text mining of Twitter messages. Finally, we compare our findings with the Brazilian local government's assessment and the literature. The results prove the feasibility of delivering a multisector disaster economic evaluation report based entirely on social media. The comparison analysis shows that social media is a valuable tool for the design and implementation of public policies, allowing the traceability of the collected information, the identification of unaccounted costs, and inquiries into the amounts and costs estimated by the local government. [ABSTRACT FROM AUTHOR]

Corruption has become an innate feature of Brazil's construction industry, particularly the procurement of infrastructure projects. Consequently, the Brazilian Federal Police are actively pursuing individuals and companies who are engaged with corruptive practices, particularly overpricing. To address the issue of overpricing in infrastructure projects, this paper describes the current method used by the Brazilian Federal Police and presents a probabilistic approach that is deemed to be a more reliable approach for determining its occurrence. This paper provides legal fraternities in other developing countries facing similar problems with additional support to ensure convictions for overpricing are pursued. Limitations of the current method and future research toward the development of a probabilistic method are identified. [ABSTRACT FROM AUTHOR]

The historic Imperial Dom Pedro II Bridge, located in Bahia, Brazil, underwent a major rehabilitation program that began in 2018. All tensioned diagonals, made of puddled iron, were replaced with new components, made of stronger steel. This paper presents a numerical model of the Dom Pedro II Bridge capable of reproducing structural performance before and during the replacement work. Numerical results were verified by the experimental data derived from monitoring systems installed in the bridge on several occasions. The differences observed from the numerical results could be justified by the bridge's age and maintenance condition. In general, the numerical results were fairly similar to the measured data, indicating the numerical solution could be used to assess other sequences of tensioned diagonal replacements. It was concluded that the replacement work improved the safety of the bridge, and the proposed modeling process may be suitable for other sequences of replacements, including other steel truss bridges. [ABSTRACT FROM AUTHOR]

This paper evaluates the impacts of multiple water uses on the operation of a system of existing reservoirs that originally were designed for hydropower generation. The research reported in this paper utilizes a nonlinear optimization model, developed to optimize hydropower production for a system of interconnected reservoirs. This model was modified to include water withdrawals for consumptive uses. The formulated multiobjective optimization problem is solved by employing the weighting method. The formulation considers water allocation policy for consumptive uses and individual hydropower plants. By parametrically varying the weighting coefficients, the tradeoff relationship (Pareto front) between hydropower generation and water demand for consumptive uses was traced out. The modified model is applied to the São Francisco River Basin in Brazil, where there are several hydropower plants in operation with a total installed capacity of 10.7 GW. The river basin is an important agricultural land that requires water supply for crop irrigation. The power generation loss as a result of increased water demand due to consumptive uses was evaluated. Water demand scenarios range from current estimated consumptive uses to the amount expected to be granted by the federal government in the future. It is concluded that these demands cannot fully be met in critical drought periods, and the proposed methodology can be helpful in leading to more equitable solutions among competing water users. [ABSTRACT FROM AUTHOR]

The design of an access channel is based on regulations and recommendations from each country after considering natural and vessel-related criteria and characteristics, always focusing on navigation safety. This paper presents a set of criteria and technical parameters necessary for the planimetric dimensioning, in straight and curved sections, of navigation channels for inland waterways and port access channels, using a computational tool developed and called DimChannel (Channel Dimensioning Navigation), based on the recommendations of the World Water Transport Infrastructure Association (PIANC). The DimChannel was supported by the technical criteria present in recommendations of the PIANC, in which the characteristics of the vessels and waterways adopted in the standard are like the characteristics of Brazilian inland navigation. The software was validated through a case study in the lower Tapajós River, Amazon, Brazil. The results obtained showed that DimChannel is a tool of great importance for the planimetric dimensioning of navigation channels. [ABSTRACT FROM AUTHOR]

In Brazil's public university sector, there is a lack of information regarding the building inspection activity; besides, there is a normative gap in this area. This paper's objective was to develop and validate an inspection management method focused on the management of building maintenance in universities. Design science research was adopted to develop the artifact called the inspection method for maintenance management, which was evaluated in a university in Brazil. This method consists of scope, planning, inspection, verification, prioritization, and recommendation steps. It was found that the application of the inspection method in the case study provided a maintenance inspection guided by scope and prioritization. However, it is necessary to align design information, especially for new buildings, with the maintenance strategies to meet the required performance criteria. The inspection method for maintenance management could be experimented in other commercial buildings, as long as the design needs were adjusted. [ABSTRACT FROM AUTHOR]

Research examining underpricing in social infrastructure projects has been limited (e.g., schools), yet this is a reality that confronts many governments worldwide. The upshot of underpricing is often contractual claims and delays, which can harm the social and economic well-being of citizens. Cognizant of experiencing potential cost overruns, this paper demonstrates that agencies within the Brazilian public sector institutionalized the winner's curse to ensure their infrastructure projects did not exceed their budgets. This action resulted in contractors abandoning works before they were completed and, in doing so, being subjected to contractual sanctions. For the government agencies, this led to increased costs because an alternative contractor was required to complete works. The decision to accept a low bid, therefore, had the opposite of the desired effect because the final project costs exceeded their budgets. It is proposed that government agencies introduce an irresponsible bid threshold, which acts as a benchmark for determining a bid's disqualification to address the winner's curse phenomenon. [ABSTRACT FROM AUTHOR]

Natural resources in the current scenario of energy production and consumption demands appropriate management. Due to increasing urbanization worldwide, energy consumption optimization has become fundamental, including in the building sector. Many authors mention bioclimatic architecture as an intelligent way to achieve energy efficiency, reducing energy consumption while providing thermal comfort for the users. This paper aims to evaluate the energetic performance of a bioclimatic pilot plant in Bioclimatic zone 2. The methodology to evaluate the energetic performance of the bioclimatic building was developed from hygrothermal measurements and simulations in eQUEST version 3.65. The building was compared to its similar nonbioclimatic one by changing its envelope characteristics in the simulation. The results show the efficiency of bioclimatic strategies, which ensures the building's thermal and hygrometric stability, besides thermal comfort conditions most of the time. Consequently, these strategies allow one to reduce about 25% of the electric energy consumption compared to the nonbioclimatic building. [ABSTRACT FROM AUTHOR]

In Brazil, roadway intersections are designed based on the precepts contained in manuals prepared by official government agencies and documents such as the Highway Capacity Manual (HCM). However, some types of intersections, termed alternative intersections, are not included in these documents, such as elongated roundabouts (ERs). This study proposed a method to estimate the level of service of this type of intersection located on two-lane rural highways. For this purpose, traffic data were collected in the field to obtain diverse traffic patterns and to characterize the desired speeds at sites with ERs. The Aimsun Next traffic simulator was used to create several hypothetical scenarios, which allowed the development of models to estimate the chosen performance measures for ER analysis (the average delay, di, and extra distance travel time, EDTT) as a function of traffic and geometry parameters. The validation of the proposed method was performed, and it was observed that the traffic models produced values of di and EDTT close to those found in the field. [ABSTRACT FROM AUTHOR]

Flood mapping is a crucial tool for assisting urban planning and emergency response plans and, consequently, preventing or reducing the risks associated with flood disasters. However, in developing countries that often lack or have limited data, to produce such maps is a challenging task. When topographic data are lacking, digital elevation models (DEMs) derived from the Shuttle Radar Topography Mission (SRTM) are frequently used as a freely available surrogate, albeit with additional uncertainty. This work presents an integrated framework to investigate flood inundation areas using a Bayesian approach, while including steps for calibrating SRTM data and determining the river bathymetry below the WSE. A flood event in the Itaqui municipality, in the state of Rio Grande do Sul, southern Brazil is used to demonstrate the proposed framework. Findings suggest benefits in using calibrated SRTM DEMs for flood mapping regardless of whether flood inundation areas were derived directly from projections of WSEs on the terrain or based on hydraulic simulations. Results further highlight the potential of using a Bayesian approach to improve quality and reliability of flood hazards maps, especially in regions that lack topographic data. [ABSTRACT FROM AUTHOR]

Numerous recent failures of tailings storage facilities (TSFs) (e.g., the 2019 Brumadinho failure in Brazil, the 2018 Cadia failure in Australia) have occurred in the last decade, providing important case histories and lessons to improve the design of TSF facilities. This study is focused on the Cadia TSF failure; specifically, we reexamine and expand the triggering analyses conducted in the forensic study after the failure. In addition, this study also presents the first comprehensive posttriggering and runout assessment of the Cadia failure. The triggering mechanisms were evaluated through Lagrangian-based analyses with the finite-difference method (FDM), which is well suited for small to moderate deformations, whereas the posttriggering mechanisms and runout were evaluated using the material point method (MPM), which is well suited for the evaluation of large deformations. The FDM-based analyses show that the interaction between a relatively weak layer in the foundation [Forest Reef Volcanic Unit A (FRV-A)], the deposited tailings, and the construction of a buttress system is critical in explaining the failure triggering. The MPM-based assessments are useful in investigating posttriggering mechanisms, suggesting a retrogressive failure and stress redistribution occurring within the mine tailings. In addition, the MPM-based assessments also explore the influence of key factors on the posttriggering mechanisms and runout. These factors include the tailings liquefaction extent and strength, the failure propagation rate, the strength of the foundation materials, and the buttress construction. The analyses suggest that the foundation strength, mine tailings liquefaction extent, and buttressing affect the runout assessments significantly. In this context, MPM proves to be especially useful in investigating postfailure conditions. [ABSTRACT FROM AUTHOR]

An essential process in earthworks is projecting effective routes for material allocation. In highway construction, haul road planning is a challenge for practitioners once there are few consolidated methodologies to rationally select existing haul routes or construct new ones. Some authors indicated geographic information system (GIS)-based methods for routing through least-cost algorithms. However, most proposed methodologies overlook the logistics related to allocations, not considering supply–demand relations in their criteria. Consequently, through a case study in Brazil, we present an earthwork optimization system that integrated established mathematical programming techniques for allocation and a GIS-based algorithm for haul road construction. In summary, we formulated a model capable of selecting different routes based on their impact on earthworks logistics cost. Thus, we built several paths between source and demand points utilizing two methods. First, based on recent literature, we used a GIS-based least-cost algorithm using the measuring attractiveness by a categorical-based evaluation technique (MACBETH) as a multicriteria support system incorporating multiple economic and environmental parameters. Second, we built routes based on Euclidian distance between the same source and demand points, analyzing if the savings in operational costs would payoff additional expenses of choosing a shorter route. After applying our methodology to the case study, we observed that the proposed procedure presented a lower budget in a reasonable processing time compared with the original project. Therefore, we inferred that the strategy of proposing path alternatives can be significantly efficient when applied to highways. Based on the results, we also found opportunities for improvement of our GIS step once it generated long paths when the distance between source and demand was short. [ABSTRACT FROM AUTHOR]

A railway bridge over the Paraopeba River was built in Moeda, Minas Gerais, Brazil; however, the railway line for which it was intended was deactivated and, to reuse it as a road bridge, a concrete deck was installed. Upon closer inspection, anomalies were revealed and their causes were found to be related to the installation of the new deck. This work intends to contribute to the structural evaluation and rehabilitation of steel bridges through numerical analysis. For this purpose, a three-dimensional numerical finite-element model of the structure using the SAP2000 version 15 software was developed, in which the acting loads were applied according to the Brazilian standards. The outcomes obtained by the performed nonlinear analysis indicate the occurrence of buckling due to the axial compression load in some structural elements, a phenomenon also observed during the bridge's first inspection. Thus, to ensure that the bridge is safely reused, the locking of the truss diagonals is proposed as a structural reinforcement. Additionally, the posts' lateral locking of the three end spans is recommended. [ABSTRACT FROM AUTHOR]

Urban green spaces play a key role in the improvement of environmental quality, livability, and sustainability of towns and cities. The aim of this paper is to elicit the willingness of the population of Passo Fundo, a town in southern Brazil, to pay for improvements, maintenance, and conservation of a park situated in the Cidade Universitária (University Campus) subdivision. After the preliminary description of the current situation of the park, a scenario was defined for environmental valuation offered by proposed improvements according to different experts in urban and environmental planning. A total of 338 households in the urban area of Passo Fundo were surveyed through the application of a questionnaire and by the contingent valuation method. An economic value between R$964,560.00 (US$550,547.94) and R$2,531,970.00 (US$1,445,188.35) was obtained for the improvement, maintenance, and conservation of the park. Also, a relationship was observed between the socioeconomic characteristics of the population and willingness to pay. The analysis of economic viability for the investments in this park showed a positive net present value. [ABSTRACT FROM AUTHOR]

Governments throughout the world have been actively engaging in public-private partnership (PPP) arrangements to upgrade and develop their road networks. The transportation sector and particularly the road sector has remarkably increased its use of PPP arrangements for building, upgrading, operating, and financing these investments due to a shortage of public spending, which is necessary to satisfy infrastructure needs of growing economies. Fast-growing economies, such as Brazil, are facing bottlenecks in their economic development due to a lack of proper transportation infrastructures. This paper discusses the use of PPP contracts in the road sector, focusing the analysis on the Brazilian case study MG-050. This road was the first PPP project in the road sector in Minas Gerais (Brazil) during the recent so-called PPP wave and can provide valuable lessons for future development of road projects, not only in Brazil but also in other fast-growing economies, such as sub-Saharan Africa, the Middle East, or Southeast Asia countries. [ABSTRACT FROM AUTHOR]

Visual management (VM) is the managerial strategy of consciously integrating visual tools in workspaces with the aim of increasing transparency on construction sites. Several VM tools and approaches that had been originally developed in the manufacturing context were implemented in construction. However, research on the application of VM in construction as a managerial strategy is scarce. This paper aims to investigate and classify the types of visual devices that can be used in construction sites through multiple case studies carried out in nine construction companies actively implementing VM. It also discusses strategies for the implementation of VM in construction. The main contributions of this investigation are: (1) a VMtools taxonomy that can be used to identify VM application opportunities, providing a basis for evaluating the level of VM implementation in construction; and (2) identification of critical factors for the implementation and various features of the VM strategy in construction. [ABSTRACT FROM AUTHOR]

Many reservoirs of hydroelectric power plants currently operate with outdated data due to the continuous sedimentation process. This fact demands management and operation policies for these reservoirs based on data different from those actually found. This paper presents a case study of Três Irmãos Reservoir (in São Paulo state, Brazil), where a bathymetric survey was conducted in 2008. From the comparison of the data obtained in the survey and data from 1975 (provided by the power supplier), it was possible to estimate the reservoir losses of total, active, and inactive capacities. From the observation of changes in the reservoir's operational data, a simulation of the power plant and the reservoir operation was conducted using MODSIM/AcquaNet software to analyze the interference of the reservoir sedimentation with the generation of electricity. [ABSTRACT FROM AUTHOR]

The United States and Brazil both deal with water-related problems associated with being large territorial areas having uneven distribution of water resources and population. Water transfer projects have been widely considered to be feasible solutions to the mitigation of local water shortages. This paper contrasts American and Brazilian water allocation systems and water transfer projects, located in the Colorado and Piracicaba River basins, seeking potential exchanges between these two water management systems and analyzing their adaptability to trends in water demand and climate. This evaluation indicates that the American system could potentially benefit from some of the principles present in Brazilian framework, including (1) participatory approach involving government, users, and citizens; (2) recognition of the economic value of water; and (3) prioritization of drinking water supply during shortage times. In turn, the Brazilian system could benefit from certain characteristics of American water management, including reduced bureaucracy and a more efficient decision and operation process. Interestingly, both countries have found it useful to employ soft-path solutions to ensure system adaptability to future water demand and supply. [ABSTRACT FROM AUTHOR]

Despite the widespread usage of the anchoring technique in geotechnical projects in Brazil, mainly in underground works and retaining walls, limited research has been carried out on the determination of load capacity in anchors. Ground anchored walls in Brazil are often dimensioned by methodologies that are not satisfactorily adapted to the reality of the national soil. In this context, this work proposes a simplified computational methodology for forecasting the load capacity of anchors in geotechnical projects. To this end, a fuzzy model is proposed using specific selected characteristics of the soils and geometry of tieback wall systems, whose measurements are easier to be obtained when compared with the load capacity measurement itself. For validation, calibration, and application of the model, the results of 40 performance tests (load tests) were used. Thirty-two samples were used to train the algorithm whereas eight were used to test the model. The results obtained using the proposed approach were close to the extrapolated values of the performance tests according to the existing empirical method, showing that the model is a viable alternative for the design of anchors. Finally, the methodology presented in this work seems to be a first step for the prediction of the anchor bearing capacity and therefore it will certainly benefit from the addition of new test databases of different locations around the world. [ABSTRACT FROM AUTHOR]

From distributed or semidistributed hydrological models, it is possible to identify where land use decisions can bring greater economic benefits in relation to water use. This study aimed to integrate simulations of a hydrological model varying the land use in four reforestation scenarios that influence the economic benefits of provision environmental services, including the user's alternatives as a key parameter and finally estimating the economic value of such benefits. The "avoided costs" method was used for economic valuation of flow regularization service and adequacy of water quality in the Piracicaba River basin, aiming to generate various economic instruments to support decision makers. The cost for water storage was estimated from the rising rain volume infiltrating the soil from the change in the dynamics of land use, whereas the cost of maintaining water quality was obtained from the variation between the effects of scenarios in nitrogen, phosphorus, and sediment loads. The valuation methodology allowed us to estimate the avoided costs, which will mainly contribute to application of economic instruments to manage water resources, directing land use decisions in hydrographic basins, guiding environmental impact assessment studies, and the definition of mitigation measures. [ABSTRACT FROM AUTHOR]

Foreign infrastructure investment (FII) is essential to the economic growth of developing countries. However, developing countries are prone to higher levels of political risk, which act as detractors to such investment. The nature of political risk has been well documented and includes such factors as corruption, inadequate legal protections, opaque regulatory processes, and unstable governments prone to volatile shifts in project support. Even so, the impact of political risk on FII does not arise from environmental factors alone, but also emanates from the internal attributes of the infrastructure delivery system; which is to say not all projects are impacted to the same extent by a given political climate. Although the external political risk environment has been extensively explored, the internal vulnerabilities are not well understood. This study identifies the impacts of foreign infrastructure vulnerability on FII and its mediating capacity in offsetting the adverse effects of political risk on FII in developing countries. It draws on a database of China and Brazil from 2006 to 2019, as exemplars of developing nations. A partial least-square structural equation model (PLS-SEM) method is employed in analyzing the database against existing system vulnerability factors as identified: political risk exposure of the system, system's capability of dealing with political risk, and the relationship between host and home countries. The findings confirm that, ceteris paribus, FII flows are hindered when infrastructure projects carry higher risk exposure. Moreover, where systems possess the capacity to mediate political risk, FII participation is facilitated, while also diluting the negative impacts of that risk on the delivery system. These findings add to the body of knowledge in the domain of vulnerability theory, while offering a practical political risk management pathway for multination investors. [ABSTRACT FROM AUTHOR]

While hydropower scheduling is a well-defined problem, there are institutional differences that need to be identified to promote constructive and synergistic research. We study how established toolchains of computer models are organized to assist operational hydropower scheduling in Brazil, Norway, and the United States' Colorado River System (CRS). These three systems have vast hydropower resources, with numerous, geographically widespread, and complex reservoir systems. Although the underlying objective of hydropower scheduling is essentially the same, the systems are operated in different market contexts and with different alternative uses of water, where the stakeholders' objectives clearly differ. This in turn leads to different approaches when it comes to the scope, organization, and use of models for operational hydropower scheduling and the information flow between the models. We describe these hydropower scheduling toolchains, identify the similarities and differences, and shed light on the original ideas that motivated their creation. We then discuss the need to improve and extend the current toolchains and the opportunities to synergistic research that embrace those contextual differences. [ABSTRACT FROM AUTHOR]

Catastrophic failures of tailings dams, primarily due to liquefaction, have occurred in Brazil in the last few years. Mine tailings deposited behind upstream dams are materials of low in situ densities and strengths. To avoid future disasters, chemical improvement methodologies such as deep mixing and mass stabilization technologies are being studied as alternatives to be used before decommissioning for in situ improvements of upstream tailings dams with a high risk of collapse. The present research aims to analyze the mechanical behavior of reconstituted state gold tailings specimens, in contrast to artificially cemented gold mine tailings specimens, considering the use of small and large amounts of Portland cement under a similar high void ratio. The influence of Portland cement content in the stabilization of gold tailings specimens molded with their in-situ void ratio was evaluated through saturated undrained triaxial compression tests carried out under small confining pressures. A reduced amount of Portland cement (about 12 kg/m3) was enough to avoid liquefaction (with the generation of negative pore-pressure), keeping the same unique critical state line (CSL) for reconstituted tailings and slightly cemented tailings specimens, with a gradient (Mtc) of 1.41. The use of high amounts of Portland cement insertion (75 and 150 kg/m3) caused an alteration in the ultimate condition of the studied tailings, and Mtc changed to 2.36. Finally, the in-situ addition of Portland cement to tailings deposited behind upstream dams is an important alternative for the safe decommissioning of such structures. [ABSTRACT FROM AUTHOR]

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2020 led to a significant change in human behaviors, mainly because of the quarantine to avoid the spread of the virus. Measures affected both economic activities and citizens' behaviors as they developed more intense hygiene habits to avoid contamination and switched to home offices. These exceptional behaviors also affected the way that water is consumed and need to be fully understood to manage supply systems. Therefore, this study aims to investigate changes in residential and commercial water consumption in 31 municipalities in the state of São Paulo, Brazil, during SARS-CoV-2. To do this, the expected consumption for the first half of 2020 was forecasted using the Holt-Winters multiplicative method and compared with the data observed for the same period. In addition, we compared monthly records of new contaminations and the social distancing index to establish a correlation with changes in water consumption. The results show an average difference between forecasted and observed consumption equal to +6.23% and −18.59% for residential and commercial activities, respectively. For the first one, the consumption per capita increased at the rate of 8.44 L.person−1.day−1. The observed changes in consumption seem to be a consequence of hygiene habits, social distancing and the closing of nonessential services in commerce. [ABSTRACT FROM AUTHOR]

Procurement practices are often characterized by competitive tendering. The overarching purpose of this is to ingrain transparency, probity, and value for money into the processes of acquiring goods and services. When tenderers collude and clients are unable to detect them, bids will become uncompetitive. Yet, there have been a limited number of effective practical tools and methods developed that can be used by procurement authorities, controllers, and public officials to detect collusive tendering. Using data obtained from the Brazilian Federal Police and their ongoing criminal investigation titled Operation Car Wash, a robust and practical probabilistic method is developed. The main findings were that the method was able to accurately identify (81%–96%) the occurrence of collusion during a sealed tendering process. Conclusions are drawn from the lessons learned from the forensic investigations, indicating that the approach presented for detecting collusive behavior during tendering is grounded in reality. This paper presents a new way to utilize statistics and probability to identify the presence of and control collusion in public- and private-sector tendering. [ABSTRACT FROM AUTHOR]

Heavy metals in industrial waste cause environmental damage because they metals are toxic, nonbiodegradable, and are bioaccumulated. As such, treatments are needed to reduce heavy metals to legally acceptable levels before disposal. As such, the aim of this study was to assess copper ion adsorption in aqueous solution using Ranufe bentonite (raw, sodium and pillared), which is abundant in Northeastern Brazil. Sodium bentonite was obtained using ionic exchange with sodium acetate and pillared bentonite was formulated with a pillarizing agent (aluminum hydroxide and sodium). Treatment efficiency was assessed using Brunauer–Emmett–Teller (BET), X-ray fluorescence (XRF), and X-ray diffraction (XRD) analyses. The surface area obtained by BET showed behavior characteristics of a mesoporous material. XRD exhibited basal spacing consistent with the pattern of clays. XRF analyses confirmed the changes on the raw bentonite surface, proving its transformation in the sodium and pillared forms. Adsorption capacity was assessed as a function of pH, contact time, adsorbent mass, initial metal concentration, ligand and co-ion effects on copper removal efficiency, reaching a maximum rate of 85.76%. Adsorption isotherms were fit to the Langmuir model, assuming adsorption on homogeneous surfaces in the form of monolayers, with maximum adsorption capacity of 12.92 mg/g−1 (raw bentonite) and 24.51 mg/g−1 (sodium bentonite). The kinetic study demonstrated that bentonite (raw and sodium) fit the pseudo-second-order kinetic model, indicating a process governed by ionic exchange between copper and the ions present in the bentonite layers. The thermodynamic adsorption parameters demonstrated that adsorption using raw and sodium bentonite is endothermic (favored by the rise in temperature) and nonspontaneous (energy is needed to promote adsorption). In a study on desorption, four adsorption and desorption cycles were sufficient to assess the regeneration capacity of the material, showing a decrease in adsorption capacity from the first to last cycle from 69.47% to 41.33% (raw bentonite) and from 48.36% to 22.46% (sodium bentonite). A decline in adsorption capacity is related to chemical degradation caused by acid solutions and mechanical agitation during the adsorption cycles. [ABSTRACT FROM AUTHOR]

The conflicting demands for water used for irrigating crops, generating power, and supplying humans and livestock have placed many river basins around the world under stress. The competition for scarce water resources will be exacerbated by the impact of climate change. This article uses a residual imputation and net rents approach to obtain economic values and water demand curves of irrigators in Brazil's Sao Marcos River Basin (SMRB). We estimate that current water prices must increase by over 230 times in the dry season to reduce the water consumption in the basin to the level that is required to accommodate its use to generate electricity as required by the water regulator. These estimated water prices are constrained efficient in the sense that they promote the efficient reduction in water consumption from the agricultural sector to satisfy the existing water permit granted for electricity generation. [ABSTRACT FROM AUTHOR]

The abundance of wood in Brazil combined with the advantages of its use has lead to many studies focusing on optimizing the application of this raw material. In particular, stress-laminated-timber decks are an alternative to conventional building materials for short- to medium-span bridges, and its advantages include low weight and excellent flexibility that enable a high prefabrication rate and quick assembly on site. In order to make the best use of wood, this work studies the behavior of a stress-laminated-timber bridge deck using hardwoods. In brief, three different species were used as laminates, which with the prestress effect made it really difficult to have optimal precision in the numerical analysis, then resulting in higher displacements than those from the tests in almost all comparisons. However, the results of the experimental and numerical displacements followed the same pattern and linearity with reasonable values and low deflections, which demonstrates that the system worked as an orthotropic plate equivalent to the same deck system constructed out of conifers, as widely used in North America for such structures. Further research should be performed with one species only, so that even better results could be found. [ABSTRACT FROM AUTHOR]

In recent years, industries have been demanded for better disposal methods of byproducts. In addition, civil construction in Brazil has been steadily growing, necessitating the development of new resources and the use of new materials. Thus, to reduce the environmental impact and costs, the use of byproducts in civil construction plays an important role. This study presents experimental results on the development of cementitious material-based plates for the construction system of panel slabs using powder technology to reduce the amount of concrete in the slab. In this study, sand was partially (58.1% by weight, C3) and totally (C1) replaced by basalt powder, a byproduct of the basaltic rock beneficiation process. Cementitious plates were obtained by uniaxial pressing at different compaction pressures. The moulded plates (M) using sand and cement were obtained as references. The bending strength at 28 days of curing was 2.50±0.10 MPa , which is higher than that of the moulded plates (1.94±0.11 MPa). It was concluded that pressing and sand substitution by basalt reduced the linear expansion from 0.059%±0.003% (M) to 0.042%±0.007% (C3), reducing the risk of cracking. The evaluation of the environmental impact showed the potential of replacing sand with basalt, thus reducing the cost of the material. Therefore, pressed plates with the total substitution of sand by basalt achieved better results related to the moulded plates and demonstrated considerable potential for application in the civil construction industry. [ABSTRACT FROM AUTHOR]

The Santo Antônio is the fifth largest hydro plant in Brazil. Due to the environmental constraints, the plant follows a run-of-river operation and, to handle inflow variability, possesses the 50 most oversized bulb generating units (GUs) in the world. These issues render a challenging short-term hydro scheduling problem (STHS), where the critical aspect is modeling the hydropower function (HPF). In this context, this article proposes a two-step strategy based on mixed-integer linear programming (MILP) to solve the STHS, that: (1) explores the symmetry related to the identical GUs by applying a binary expansion to find which units will be active, and (2) obtain the optimal load distribution by linearizing a series of nonlinear problems. In both steps, the HPF is linearized using the logarithmic aggregated convex combination (LACC) model. The symmetry exploration based on the binary expansion is new in the context of the STHS. The experiments show that the proposed strategy yields equal solutions to those obtained by an individual-LACC approach while providing, on average, a 74% reduction in computational time. [ABSTRACT FROM AUTHOR]

In Brazil, large quantities of iron ore tailings (IOT) are produced as a result of iron mining, which may affect the environment negatively. This work evaluated the use of IOT in hot mix asphalt type C (HMA-C). For this purpose, IOT was incorporated as a filler (at 1% in relation to the total mass of HMA-C). The hot asphalt mix with IOT (called HMA-IOT) was designed and compared with a control HMA-C. The behavior of the mixtures under monotonic (indirect tensile strength, ITS, and the Marshall stability test), under dynamic (fatigue and resilient modulus tests), and static (static creep test) loading conditions was evaluated. Also, the resistance to induced moisture damage (tensile strength ratio, TSR) was calculated. As a general conclusion, it was shown that the use of IOT in HMA improves its mechanical response without increasing mixing and compaction temperatures and using less effective asphalt binder content. This could provide a new form of environmentally safe disposal of IOTs. [ABSTRACT FROM AUTHOR]

Low impact development (LID) practices contribute to the reduction of flooding and improvement of water quality. Water crises may be a result of water scarcity and flooding due to climatic changes and the increase of impervious areas, and thus, stormwater harvesting becomes a sustainable alternative solution for relative water problems. The performance of a bioretention system with the submerged zone (SZ) and unsaturated zone (USZ) was evaluated as an alternative for stormwater harvesting. The study was carried out on a laboratory scale, using a bioretention box to simulate the processes that occur in a real system and in the field. The system was efficient in removing TP (68.5% and 76.5%), COD (71.6% and 56.9%), and NO2 (28% and 16.6%) in USZ and SZ events, respectively. NH3 removal (31%) occurred only at SZ events. NO3 was exported at all events tested but at values below the Brazilian CONAMA Resolution 357/2005 on the quality of water bodies for supply. The bioretention effluent showed relatively high values of turbidity; however, the pH parameter presented good values in all experiments (>6.5 and <7.5), and E. coli only in some cases presented satisfactory values to meet the Brazilian Standard for Rainwater Usage for nonpotable purposes (<200 MPN/100 mL). In general, both configurations provide different improvements for stormwater to support sustainable water resources management. This study presents a comparison between bioretention systems with and without SZ as an initial proposal for the improvement in bioretention systems in Brazil; however, more experiments must be monitored, and new improvements should be tested for reaching restrictive water reuse purposes. [ABSTRACT FROM AUTHOR]

This study proposed to explore real estate trends in the high-rise housing market in Belém, Northern Brazil. We based the theoretical approach on the macroeconomic, territorial, and social elements of the high-rise segment both in national and international contexts. The sample comprised 137 high-rise projects launched throughout the 2005–2017 period. A quadratic regression model confirmed real estate susceptibility to macroeconomic oscillation. A geographically weighted regression model revealed that larger dwellings were launched more in upper-income, lower formal employment rate, and lower infrastructure coverage regions of Belém. A multinomial logit regression model established differences in the launching likelihood between different categories of housing size projects. The outcomes were compared with worldwide tendencies, seeking both common and unique patterns of real estate exploitation. The methodological forms of exploring real estate trends in developing countries—which are scarcer—add significant scientific value for the urban planning community, as they assist public policy by identifying the susceptibility of urban areas to land exploitation, in addition to enabling replication of such real estate diagnostics in other cities of emerging countries. [ABSTRACT FROM AUTHOR]

A great challenge for water managers and stakeholders is the maintenance and improvement of basin sustainability, tackling the ever-increasing threats and impacts. Some catchments, such as the Paranoá River basin (Central Brazil), are facing rapid urbanization, with increasing water demand and water quality impacts that threaten their sustainability. To assess this, two basin indices, the Watershed Sustainability Index (WSI) and the Water Resources System Dynamics (WRSD), were applied to the Paranoá basin in the period between 2015 and 2018. Off-the-shelf data and tailored surveys were used as information sources. The basin WRSD and WSI scores were 0.33 and 0.60, respectively, corresponding to a medium level of hydrologic and integrated sustainability. The WSI bottlenecks were the high unit water demand in the basin, and the incipient management responses with respect to the basin's environment, livelihood, and policy indicators. For the WRSD index, high water demand was the limiting sustainability factor. Adaptation measures to improve basin sustainability include effective water demand management and the establishment of new protected areas in the catchment. [ABSTRACT FROM AUTHOR]

This work develops a mathematical model for designing bikeway networks that integrate into public bus transport services in urban areas using concepts from network multiobjective optimization and mixed-integer linear programming (MILP). The proposed model maximizes 14 objectives and 14 constraints by referring in a generalized way to lane comfort, safety, path objectivity, network connectivity, intermodality with bus service, and monetary budgets. In the context of a developing country, we believe that this model can address the transit network design problem (TNDP) as an innovative proposal for integration between alternative modes of transport and buses. A case study in Sao Jose dos Campos city, Sao Paulo state, Brazil, is conducted, and exact solutions are obtained with partially connected networks (first approach) and fully connected networks (second approach). A scenario analysis enables verification of the integrated transportation system performance and, for the case study, prioritizes the least expensive bikeway type. Therefore, the results from the proposed model can contribute to urban planning in testing alternative scenarios for bike–bus networks. [ABSTRACT FROM AUTHOR]

Population growth and increasing food demand require cropping systems that produce higher yields with less water. Microirrigation can fulfill this demand but has a high investment cost, which can be reduced with adequate irrigation design and management. The design is based on pre-established emission uniformity (EU) by combining equipment characteristics and hydraulic configurations. This study evaluated the influence of EU and irrigation depth on the emission uniformity obtained after the design (EUad), yield uniformity, and the expected profit for a microsprinkler-irrigated citrus orchard on sloping terrain for the growing conditions of Leme, Sao Paolo, Brazil. The research was developed under different scenarios of EU values, negative slope gradients in the irrigation subunit, and critical period irrigation depths, resulting in practical guidelines for irrigation practitioners and farmers. To design a system under level conditions, an EU value of 85% is recommended, because the resulting EUad was always higher than the EU value considered at the design stage. For sloping conditions, the EU should be at least 90% in microirrigation subunits, and the higher the slope gradient, the greater the EU must be. Although the microirrigation system design was based on high values of the pre-established EU, the evaluated variation in the EU did not significantly modify the net crop profit. With a water supply, a 50% reduced irrigation depth generated a net profit 16.2% lower than that of the best option but had the highest irrigation water-use efficiency (IWUE) among the studied treatments. To obtain production uniformity and higher profit, not only the irrigation system uniformity but also the irrigation adequacy must be considered when selecting the appropriate water depth to be applied. [ABSTRACT FROM AUTHOR]

The Fletcher-Ponnambalam (FP) reservoir optimization method has been successfully applied to several case studies in the literature. As an explicit stochastic optimization problem, it requires the assumption of a probability distribution for the reservoir inflows in order to solve several integrals regarding the statistical moment equations for storage as well as probabilities of containment (storage within minimum and maximum levels), deficit (below minimum), and spill (above maximum). This technical note proposes an alternative way to approximate the solution of such integrals using the sample of historical inflow records. This does not involve the consideration of any distribution and leads to far shorter expressions as well as to less coding effort. The new formulation is applied to solve a water reservoir operation optimization problem for a major dam in Brazil. The results compare well with those from the current FP formulation and with those obtained by a Monte Carlo simulation of the monthly reservoir operation. [ABSTRACT FROM AUTHOR]

The abundance of wood in Brazil combined with the advantages of its use has lead to many studies focusing on optimizing the application of this raw material. In particular, stress-laminated-timber decks are an alternative to conventional building materials for short- to medium-span bridges, and its advantages include low weight and excellent flexibility that enable a high prefabrication rate and quick assembly on site. In order to make the best use of wood, this work studies the behavior of a stress-laminated-timber bridge deck using hardwoods. In brief, three different species were used as laminates, which with the prestress effect made it really difficult to have optimal precision in the numerical analysis, then resulting in higher displacements than those from the tests in almost all comparisons. However, the results of the experimental and numerical displacements followed the same pattern and linearity with reasonable values and low deflections, which demonstrates that the system worked as an orthotropic plate equivalent to the same deck system constructed out of conifers, as widely used in North America for such structures. Further research should be performed with one species only, so that even better results could be found. [ABSTRACT FROM AUTHOR]

Land leveling is used to correct soil surface irregularities to improve surface drainage and irrigation. It also makes the area more manageable for an array of agricultural activities such as planting and harvesting. The objective of this work was to evaluate two designs of land forming, one aimed at optimizing drainage and the other at optimizing surface irrigation, using fields with reliefs typical of the lowlands of southern Brazil. Seven commercial rice fields, ranging in size from 7 to 26 ha, were randomly selected and digital elevation designs generated for each. Land-leveling projects were developed using three designs: uniform slope (US) (control), land forming–drainage (LFD), and land forming–irrigation (LFI). Performance comparisons between the designs were evaluated through impacts on soil movement (SM), maximum cut in 99% of the area (MC), cumulative length of levees (LL), and total number of levees (NL). Results indicate that both LFD and LFI designs would reduce costs and require less soil disturbance compared to leveling to uniform slopes. LFD would require less soil movement and lower maximum cuts than LFI. However, LFI would reduce the lengths and numbers of rice levees that could have long-term economic and agronomic benefits not captured in these analyses. These results demonstrate that all land-leveling and land-forming alternatives should be thoroughly examined before undertaking field operations. Study outcomes will be useful to engineers and producers in evaluating options to improve the agricultural productivity of lowlands in southern Brazil, a region of national and international significance. [ABSTRACT FROM AUTHOR]