Em sistemas de abastecimento de água (SAA), os grandes volumes de perda de água não apenas acarretam prejuízos financeiros, mas, também, representam desperdício de recursos naturais, sendo estes alguns dos principais desafios enfrentados pelo setor no Brasil. Neste estudo, realizou-se ranqueamento para avaliar os sistemas de abastecimento de água de 397 municípios em relação às perdas de água, por meio de indicadores de desempenho disponíveis no Sistema Nacional de Informações em Saneamento Básico (Sinisa). A análise foi conduzida em dois contextos: uma avaliação geral, abrangendo todos os municípios incluídos no estudo, e uma avaliação estratificada, considerando a divisão dos municípios em diferentes estratos populacionais. Os resultados indicaram os municípios com maiores oportunidades de melhoria em implementação de medidas de redução de perdas e os que podem ser utilizados como referência para coleta de informações sobre boas práticas de redução e controle de perdas de água.
Mohamed Mahmoud Sebbab, Abdelhadi El Ouahidi, Mehdi Ousbih
et al.
The purpose of this paper is to identify, quantify and delineate the areas with suitable aggregate resources in the Precambrian massif of Ifni and the limestone plateau of Lakhssas (southwest Morocco). To fulfill this objective, a study was undertaken on the geotechnical parameters of the various geological outcrops of the region based on the analysis of 42 rock samples (carbonate, magmatic, detritic and volcano-detritic). Initially, we subjected these samples to a series of laboratory tests (impact resistance (L.A), wear resistance (MDE), density, porosity, absorption), to classify them according to geotechnical standards. Then, a geospatial database was created, to exploit these geotechnical data, from a geographical information system (GIS) to produce various thematic maps. Based on the results of this study, all geotechnical classes according to the standards (A to E for the European standard and 1A to 6D for the Moroccan standard) are present with good to very good geomechanical properties (L.A between 12% and 35%, MDE between 5% and 30%). This classification allowed us to use GIS to identify and quantify potential areas for exploitation by assigning five categories of geotechnical suitability levels (high (4), medium (3), low (2), very low (1) and others (0)) and to show that approximately 72% of the study area belongs to the categories high, medium and low. The combination of laboratory results and GIS has allowed us to carry out geotechnical mapping that will be used by regional authorities and actors for good management of the field of quarrying to rationalize the national natural heritage.
Urban water bodies have a cooling effect and alter the local urban thermal environment. However, current research is unclear regarding the relationships between factors such as the spatial density, area proportion, and distribution pattern of water bodies and the cooling effect of water on the local thermal environment. To clarify these relationships, it is critical to quantify and evaluate the influence these factors have on the cooling effect of water in the urban landscape. Therefore, we analyzed the cooling effect of different water bodies on the local thermal environment at the microscale by comparing their area proportions and distribution patterns using numerical simulations. Furthermore, we analyzed the day–night variation in the cooling effect of urban water bodies with different areas and distribution patterns. We used the area proportion, separation index (SI), and landscape shape index (LSI) to indicate the layouts of water bodies. The results showed that the cooling effect of a water body was higher during the day than at night. These results also showed that area proportion and LSI were positively correlated with the water body’s cooling effect. However, the efficiency of the cooling effect gradually decreased with increasing area proportion. When the LSI increased, more areas within the region displayed larger cooling effect values, but the uniformity of the regional cooling diminished. Additional results showed that the cooling effect had no significant positive correlation with SI. A moderate SI could enhance the uniformity of the cooling effect in the region and link the cooling effect between water patches.
Identifying organic matter in laminae is fundamental to petroleum geology; however, many factors restrict manual quantification. Therefore, computer recognition is an appropriate method for accurately identifying microscopic components. In this study, we used support vector machine (SVM) to classify the preprocessed photomicrographs into seven categories: pyrite, amorphous organic matter, mineral matter, alginite, sporinite, vitrinite, and inertinite. Then, we performed a statistical analysis of the classification results and highlighted spatial aggregation of some categories using the kernel density estimation method. The results showed that the SVM can satisfactorily identify the macerals and minerals of the laminae, and its overall accuracy, kappa, precision, recall, and F1 are 82.86%, 0.80, 85.15%, 82.86%, and 82.75%, respectively. Statistical analyses revealed that pyrite was abundantly distributed in bright laminae; vitrinite and sporinite were abundantly distributed in dark laminae; and alginite and inertinite were equally distributed. Finally, the kernel density maps showed that all classification results, except inertinite, were characterized by aggregated distributions: pyrite with the distribution of multi-core centers, alginite, and sporinite with dotted distribution, and vitrinite with stripe distribution, respectively. This study may provide a new method to quantify the organic matter in laminae.
The low thermal conductivity of phase change materials (PCMs) is a crucial challenge in utilizing latent heat thermal energy storage (LHTES) systems. Incorporating fins into LHTES system is an effective approach to overcoming the low thermal conductivity of PCM and enhancing its performance. In the present study, computational fluid dynamics is used to investigate the effects of fin configurations and operating conditions on the performance of a shell-and-tube system assisted by fins. The heat transfer rate and liquid fraction are investigated to evaluate the thermal behavior of the proposed system. The enthalpy–porosity technique is employed to simulate the phase change. The temperature variations over time at different PCM locations are calculated and compared with the measured temperatures. The predicted results show that the fin thickness and the inlet temperature of the heat transfer fluid play a key role in reducing the melting and solidification time. The obtained results indicated that by increasing the fin thickness from 0.5 to 1 mm, the heat transfer rate increased by approximately 17%. Also, increasing the inlet temperature from 60 °C to 65 °C improved the heat transfer rate by 36.2%.
Orthodontists correct dental malocclusion, but major facial skeleton deformations (skeletal malocclusion) are often subject to surgical correction. Several speech pathologies are associated with both of the occlusal anomalies mentioned above. The majority of articulation disorders and primary functions cannot be improved without skeletal correction. This study aimed to investigate the outcome of the multimodal and logopaedics treatment of Polish adults affected by skeletal malocclusion and speech-language pathology. A total of 37 adults affected by skeletal Class II and III malocclusion were included, along with the relationship between the malocclusion and speech deficiency (20 phonemes tested) in the subjects before and after surgical correction. The impact of surgery on pronunciation improvement and types of Polish phonemes most often misarticulated by Polish adults were also examined. Patients underwent combined treatment and received a full speech pathology examination. The treatment improved speech (<i>p</i> < 0.05), but the study did not prove that a specific surgery type was associated with pronunciation improvement. Some patients were provided with speech therapy during childhood, yet most had some minor difficulties with lip and tongue movements. Palatal, alveolar (<i>p</i> < 0.05), fricatives (<i>p</i> < 0.05), and labiodental consonant pronunciation (<i>p</i> < 0.05) improved. The surgical correction of malocclusion leads to better articulation of Polish consonants in adults and improves some primary functions.
Major public projects in Laos are faced with multiple challenges, including project identification and its decision-making. Generally, an identification is an important key identifying the potential needs and requirements for achieving the development goal. However, the process was developed without a formal framework and assurance tools that have been criticized for negative social and environmental consequences as “white elephant projects” over the past few years. Considering this context, the study aimed to develop a conceptual framework to navigate an alternative solution for the right project. Based on contextual analysis and systematic literature review, the proposed framework provided the process of concept development and its assurance that it could be systematically developed in a cause-effect chain of needs. The findings indicate areas that reflect new insights of both strategic performance and a governance system, and reforms the decision-making process in providing new knowledge, new rules, and procedures for effective governance.
Engineering (General). Civil engineering (General), City planning
This work concerns the concept and verification of the experimental possibility of using a wavelet transform to assess a steel structure’s condition. In the research, a developed measuring stand was used. Mechanical waves in the metal plate were excited by the impact. These waves were recorded with an electroacoustic transducer and registered in the form of electrical signals. Both the signals generated by the actuator of the plate and the signals reaching the transducer were recorded. The registered data were decomposed into wavelet coefficients. Laboratory tests have shown the possibility of applying this type of test to identify damage in steel structural elements—the relationship between the details of the wavelet transform and the type of damage was demonstrated.
To investigate mass transport and energy dissipation in space environments for solar system planet, a balloon-borne planetary atmospheric spectral telescope (PAST) is designed with 0.8-m aperture in spectral range from 280 nm to 680 nm will be floated at 35–40 km altitude to observe and investigate the global space environment of Mercury, Venus, Mars, and Jupiter. The telescope is designed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CIOMP, CAS), and supported by the Strategic Priority Research Program of Chinese Academy of Sciences, that is the Scientific Experimental system in Near-SpacE (SENSE). The telescope is mainly supported by a Ritchey-Chrétien optical system which can achieve 0.5" angular resolution observation, and the optical system has the function of focusing and stabilizing. The telescope is combined with a two-dimension rotate platform to achieve planetary atmospheric imaging in long exposure time. This paper mainly introduces the PAST scheme briefly.
Currently, buildings are on the rise, which causes significant environmental pollution due to the lack of controlled landfills to deposit solid construction wast; an alternative solution is to recycle this waste produced by the construction and or demolition of concrete elements structural, and use them as coarse aggregate in the manufacture of concrete. On the other hand, the metalworking industry uses iron and steel as primary inputs, which are the main components of industrial waste, with its generation sources being industrial plants and manufacturing workshops for small and medium enterprises; a solution to this problem is to use your waste as a fine aggregate in the production of concrete due to its good properties. These solution alternatives preserve natural resources and promote their sustainability. The research work developed focuses on the use of structural concrete and steel waste to reduce its amount of waste and it is proposed to add it to the concrete. The results show that the addition of steel chips in concrete compared to standard concrete results in reduced slump, increased unit weight and contributes to the improvement of compressive strength, tcylinder splitting tensile strength and flexural strength.
This paper proposes system architecture and protocols for the deployment of a toll-free electric vehicle charging service. The architecture enables the party initiating the electric vehicle (EV) charging to have their service request authorized by the system and paid for by a third party.
Josep-Andreu Vidal-Clos, Eduard Bullich-Massagué, Mònica Aragüés-Peñalba
et al.
Isolated microgrids must be able to perform autonomous operation without external grid support. This leads to a challenge when non-dispatchable generators are installed because power imbalances can produce frequency excursions compromising the system operation. This paper addresses the optimal operation of PV–battery–diesel-based microgrids taking into account the frequency constraints. Particularly, a new stochastic optimization method to maximize the PV generation while ensuring the grid frequency limits is proposed. The optimization problem was formulated including a minimum frequency constraint, which was obtained from a dynamic study considering maximum load and photovoltaic power variations. Once the optimization problem was formulated, three complete days were simulated to verify the proper behavior. Finally, the system was validated in a laboratory-scaled microgrid.
Mining machines are strongly nonlinear systems, and their transmission vibration signals are nonlinear mixtures of different kinds of vibration sources. In addition, vibration signals measured by the accelerometer are contaminated by noise. As a result, it is inefficient and ineffective for the blind source separation (BSS) algorithm to separate the critical independent sources associated with the transmission fault vibrations. For this reason, a new method based on wavelet de-noising and nonlinear independent component analysis (ICA) is presented in this paper to tackle the nonlinear BSS problem with additive noise. The wavelet de-noising approach was first employed to eliminate the influence of the additive noise in the BSS procedure. Then, the radial basis function (RBF) neural network combined with the linear ICA was applied to the de-noised vibration signals. Vibration sources involved with the machine faults were separated. Subsequently, wavelet package decomposition (WPD) was used to extract distinct fault features from the source signals. Lastly, an RBF classifier was used to recognize the fault patterns. Field data acquired from a mining machine was used to evaluate and validate the proposed diagnostic method. The experimental analysis results show that critical fault vibration source component can be separated by the proposed method, and the fault detection rate is superior to the linear ICA based approaches.
With the development of intelligent transportation system, there occurs further demand for high precision localization and route planning, and simultaneously the traditional road-level map fails to meet with this requirement, by which this paper is motivated. In this paper, t he three-layer lane-level map architecture for vehicle path guidance is established, and the mathematical models of road-level layer, intermediate layer and lane-level layer are designed considering efficiency and precision. The geometric model of the lane-level layer of the map is characterized by Cubic Hermite Spline for continuity. A method of generating the lane geometry with fixed and variable control points is proposed, which can effectively ensure the accuracy with limited num ber of control points. In experimental part, a multi-layer map of an intersection is built to validate the map model, and an example of a local map was generated with the lane-level geometry.
Because the flying height between a magnetic head and magnetic disk surface in hard disk storages is to be decreased to less than 1 nm, the head wear reliability due to intermittent asperity contacts and slider instability become critical issues. Nevertheless, detailed asperity characteristics of perpendicular magnetic disk have never been reported in open literatures. This paper presents the detailed features of surface texture parameters intrinsic to the perpendicular magnetic grains of commercially available magnetic disk drives (500 GB/platter), i.e., mean asperity height, asperity density, distance between the nearest asperities, radius of curvature of the asperities, and their histograms in addition to typical roughness parameters. It was found that mean asperity height is ～0.5 nm, asperity density ～5000 μm-2, nearest asperity distance ～11 nm. The asperity radius of curvature has an anisotropic nature, probably due to lubricant molecular conformation, but its averaged value is ～20 nm. Various parameter values of mountain and valley are also presented. On the basis of the measured roughness parameter values, the previous analytical results for the head-disk interface characteristics are reviewed.
Mechanical engineering and machinery, Engineering machinery, tools, and implements
Laser absorption spectroscopy (LAS) has been used over the last several
decades for the measurement of trace gasses in the atmosphere. For over a
decade, LAS measurements from multiple sources and tens of retroreflectors
have been combined with sparse-sample tomography methods to estimate the 2-D
distribution of trace gas concentrations and underlying fluxes from point-like
sources. In this work, we consider the ability of such a system to detect and
estimate the position and rate of a single point leak which may arise as a
failure mode for carbon dioxide storage. The leak is assumed to be at a
constant rate giving rise to a plume with a concentration and distribution
that depend on the wind velocity. We demonstrate the ability of our approach
to detect a leak using numerical simulation and also present a preliminary
measurement.
A mathematical model of the thermal state of the metal in the run-out roller table continuous wide
hot strip mill. The mathematical model takes into account heat generation due to the polymorphic γ → α
transformation of supercooled austenite phase state and the influence of the chemical composition of the steel
on the physical properties of the metal. The model allows calculation of modes of accelerated cooling strips on
run-out roller table continuous wide hot strip mill. Winding temperature calculation error does not exceed 20°C
for 98.5 % of strips of low-carbon and low-alloy steels
Mechanical engineering and machinery, Structural engineering (General)
This paper demonstrates for the first time the potential of explicitly modelling the individual roof surfaces to reconstruct 3-D prismatic
building models using spaceborne tomographic synthetic aperture radar (TomoSAR) point clouds. The proposed approach is modular
and works as follows: it first extracts the buildings via DSM generation and cutting-off the ground terrain. The DSM is smoothed using
BM3D denoising method proposed in (Dabov et al., 2007) and a gradient map of the smoothed DSM is generated based on height
jumps. Watershed segmentation is then adopted to oversegment the DSM into different regions. Subsequently, height and polygon
complexity constrained merging is employed to refine (i.e., to reduce) the retrieved number of roof segments. Coarse outline of each
roof segment is then reconstructed and later refined using quadtree based regularization plus zig-zag line simplification scheme. Finally,
height is associated to each refined roof segment to obtain the 3-D prismatic model of the building. The proposed approach is illustrated
and validated over a large building (convention center) in the city of Las Vegas using TomoSAR point clouds generated from a stack of
25 images using Tomo-GENESIS software developed at DLR.
Omar D. Hernández-Arboleda, Paula A. Ortiz-Valencia, Jorge A. Herrera-Cuartas
<p>This paper presents the design of a robust controller for a rotary kiln. The designed controller is a combination of a fractional PID and linear quadratic regulator (LQR), these are not used to control the kiln until now, in addition robustness criteria are evaluated (gain margin, phase margin, strength gain, rejecting high frequency noise and sensitivity) applied to the entire model (controller-plant), obtaining good results with a frequency range of 0.020 to 90 rad/s, which contributes to the robustness of the system.</p>