Flow-Induced Vibration in a Single Row of Cylinders With p/D = 1.26

Crossflow over a row of cylinders with a close space ratio presents an asymmetric configuration with large and narrow wakes behind the cylinders. The wake interaction can impact the vibration response of the cylinders. In tube banks, the impact results in damages to the equipment. The present experimental study aims to analyze the influence of close space observed in a single row of cylinders on the flow-induced vibration. The study compares a single row with fixed cylinders and a single row with one cylinder free to vibrate. The cylinder free to vibrate is tested in four configurations. The study was conducted with an aerodynamic channel with a cross-section of 0.193 × 0.146 m and smooth cylinders with a diameter of 25.1 mm, space ratio is 1.26. The measurements are executed with hot-wire anemometry and accelerometers, for the cases with one cylinder free to vibrate and with hot-wire anemometry and microphones for the case with all fixed cylinders. The Reynolds number ranges between 1.0 × 104 and 4.5 × 104, obtained with the reference flow velocity, measured with a Pitot tube, and the cylinder diameter. The comparison between the wake response for single row fixed and single row and free to vibrate are executed using Fourier transform and Wavelet Transform. The comparison of the results with the models presented in the literature to predict the elastic instability of the fluid in a single row of cylinders is performed.

Post Necking Behaviour and Hardening Characterization of Mild Steel

This paper investigates the post necking phenomenon in mild steel using six different hardening laws (Hollomon, Swift, Ludwik, Ghosh, Voce and Hockett-Sherby) by extrapolation method. This is carried out through the finite element simulation on tensile deformation of a mild steel specimen under quasi-static condition. Reference flow curves are obtained analytically and found helpful for the numerical simulation. The material parameters of the above hardening laws are evaluated by curve fitting method based on the pre necking experimental data and their suitability is examined before and after necking.

DIFFERENT METHODS FOR MEASURING EVAPORATION IN A TROPICAL RESERVOIR: THE CASE OF THE GAVIÃO RESERVOIR IN THE STATE OF CEARÁ

ABSTRACT Studies that allow the estimation of evaporation in reservoirs represent an important action for the adequate management of water resources. Thus, this study aimed at estimating evaporation in the tropical reservoir Gavião, located in the municipality of Pacatuba, Ceará, Brazil, and to verify the effect of these estimates on the water availability of the reservoir using the VYELAS model. The results of Penman's methods and the Water Balance were compared with the values obtained from the hydrostatic pressure sensor, the most accurate. It was possible to verify that, in relation to the pressure difference method, all the conventional methods overestimate the evaporation in the reservoir. The method that presented estimates closer to those obtained by the pressure difference sensor was that of Penman, based on data from an onboard station in the lake, with a deviation of only 12%. The method of water balance also presented reliable results for monthly average. The two methods usually accepted in the evaporation calculation (water balance ignoring the infiltration; and Penman's method for meteorological station data on land distant from the lake) presented the most disturbing evaporation values significantly altering the water availability. The results of the VYELAS model showed that evaporated flows, estimated by several methods, exceeded the reference flow by up to 83%. The results demonstrate the great sensitivity of the estimate of water availability in relation to the evaporation rate in the lake.

Reference flow: reducing reference bias using multiple population genomes

Most sequencing data analyses start by aligning sequencing reads to a linear reference genome, but failure to account for genetic variation leads to reference bias and confounding of results downstream. Other approaches replace the linear reference with structures like graphs that can include genetic variation, incurring major computational overhead. We propose the reference flow alignment method that uses multiple population reference genomes to improve alignment accuracy and reduce reference bias. Compared to the graph aligner vg, reference flow achieves a similar level of accuracy and bias avoidance but with 14% of the memory footprint and 5.5 times the speed.

Implementation of Life Cycle Based Tools in the Circular Economy Context—Case Study of Plastic Waste

This article describes research done within the CIRCE2020 project, implemented under the Interreg CENTRAL EUROPE 2014–2020 Programme. The main aim is to present the results of a life cycle assessment (LCA) and life cycle costing (LCC) carried out for a recycling plant in Wielkopolska. From the LCA perspective, the analyzed recycling plant performs two functions; therefore, two research approaches were adopted: from the final waste management perspective (Approach 1) and from the production of secondary products (Approach 2). From the first perspective, the total environmental impact for the reference flow (215.140 kg of multi-material waste) was 552.32 Pt. When focused on the second perspective, the environmental impact for the production of plastic boards (3.073 boards) reached 659.58 Pt. The difference in the obtained values results from the fact that the second analysis, besides waste processing, included additionally the generation of raw materials corrected by the quality factor. The total production cost of boards made of multi-material waste was PLN 165,957.23. Energy consumption is the main cost-generating element of production and also the most important environmental hot spot. To increase environmental efficiency and reduce costs, the use of technology allowing for the reduction of energy demand should be considered first.

Seasonality and criteria for concession of water in the Ivinhema basin

Global demand for water has been increasing per year due to population growth, economic development, and changes in consumption patterns, among other factors. This increase in water demand is expected to continue in the next decades. The objective of this work was to evaluate the use of different criteria to grant the use of water from the Ivinhema river basin, Brazil. Monthly periods were compared to annual periods to calculate the reference flows Q7,10 and Q95. The relative differences in water availability using different reference flow rates for water concession were quantified. The replacement of the annual criteria (standard in Brazil) for water concession by 50% of monthly Q7,10 and 70% of monthly Q95 can potentially increase the use and improve the management of water resources. The best criteria to award grants is the monthly Q7,10, which despite being more restrictive, it allows higher flow rates when there is excess water, and lower rates in the months of low water availability.

Proposta de enquadramento de corpos hídricos em classes de uso na bacia hidrográfica do rio Piranga utilizando geoprocessamento

O enquadramento dos corpos d’água em classes de uso consiste em uma importante ferramenta para a gestão dos recursos hídricos, pois permite a conexão entre os seus aspectos qualitativos e quantitativos. Sendo assim, o presente trabalho teve como objetivo elaborar uma proposta de enquadramento dos corpos hídricos em classes de uso na bacia do rio Piranga, estado de Minas Gerais. A metodologia foi aplicada em função de critérios considerados relevantes ao enquadramento e da meta de qualidade da água a ser alcançada na bacia, sendo executada com o auxílio do geoprocessamento. Os critérios utilizados para a elaboração do enquadramento foram: finalidade das outorgas, volume outorgado, uso e a ocupação do solo, vazão mínima de referência e densidade populacional. Para cada critério foi atribuído um peso e o mapa de enquadramento foi gerado a partir da sobreposição dos mapas dos critérios adotados. Para definição das áreas prioritárias de intervenção, o Índice de Conformidade ao Enquadramento (ICE) foi calculado com base no enquadramento obtido para os trechos de rio. Como resultado, os rios Piranga, Xopotó, Turvo Limpo e Ribeirão dos Oratórios foram enquadrados nas classes 1 e 2, sendo as zonas de cabeceira enquadradas prioritariamente como classe 1 com exceção para o rio Turvo Limpo, que foi classificado como classe 2 em toda sua extensão. Os resultados mostraram que a metodologia se mostrou adequada, entretanto alguns ajustes foram fundamentais para a obtenção do mapa final de enquadramento dos corpos hídricos na bacia. Proposed framing of water bodies in use classes in the Piranga river watershed using geoprocessingA B S T R A C TThe framing of water bodies in classes of use is an important tool for the management of water resources, as it allows the connection between their qualitative and quantitative aspects. Thus, the present work had as objective to elaborate a proposal of framing the water bodies in classes of use in the Piranga river basin, state of Minas Gerais. The methodology was applied according to criteria considered relevant to the framework and the water quality target to be obtained in the basin, being carried out with the aid of geoprocessing. The criteria used to elaborate the proposal were the purposes of the grants, volumes granted, usage and occupation of the soil, minimum reference flow and population density. For each criterion, a weight was attributed, and the framing map was generated from the overlay of the adopted criteria maps. Framing Conformity Index (FCI) was also calculated in order to define priority areas for intervention purposes. As a result, Piranga, Xopotó, Turvo Limpo e Oratórios rivers were classified in classes 1 and 2, and the headwaters classified as class 1, except for the Turvo Limpo river, which was classified as class 2 throughout extension. The results showed that the methodology proved to be adequate, however some adjustments were essential to obtain the final map of the water bodies in the basin.Keywords: geoprocessing, hydrology, Minas Gerais, water quality.

A regional flow type classification for South African perennial rivers

Flow classification provides a statistically robust method of defining an expected range of variability for flow metrics describing frequency, magnitude, duration and timing of events. Here, we characterised reference mean daily flows for 1950–1999 for all 5 838 quinary catchments of South Africa based on 150 metrics. Using a two-tiered approach, where sub-catchments were classified into similar flow types using principal components and cluster analyses, we defined 6 to 12 flow types for each of 8 hydrological regions reflecting rainfall seasonality. Redundancy between variables was 87% on average, so that site variability could be accounted for using 8–28 metrics. In general, flow volume metrics accounted for Axis 1 variability, while coefficients of dispersion had 1.8 times less leverage in Axis 2. With the incorporation into a spatial product and an associated database, this study provides a basis for defining statistically robust reference flow conditions for multiple flow metrics, against which current observed flows at specific sites may be compared.

Comparison of two methods for determining Q95 reference flow in the mouth of the surface catchment basin of the Meia Ponte river, state of Goiás, Brazil

The preferred data for analyzing water availability are those of historical flow series of the sources of interest; however, most Brazilian watersheds do not have sufficient fluviometric monitoring. Such cases require techniques for transposing data from one region to another, otherwise known as ‘flow regionalization’. The present work aimed to compare the method proposed by Secretaria de Meio Ambiente e Desenvolvimento Sustentável (SEMAD) of the state of Goiás with the traditional method of regionalization for determining reference flow at the mouth of the surface catchment basin of the Meia Ponte river. Data from eight fluviometric stations were used for regionalization, with the regression equations being adjusted using four different models. The result revealed that the potential and linear models performed the best, both with R2 and R2a values of 0.996 and 0.995, respectively. The relative error in the application of the potential model and of the method adopted by SEMAD were below 30%. The reference flows obtained by the two best performing methods differed, with flow determined by the traditional method being 5.93% lower than that of the SEMAD equation. Therefore, a more detailed study is recommended to determine which equation models better fit the region.