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In order to design an efficient micro-irrigation system, a monitoring approach allowing quantification of the main variables affecting the level of uniformity should be pursued. In the present work, we assess the performances of a commercial dripline, the product 'Neptune PC AS', furnished by TORO Company, employing an ad hoc built experimental benchmark, in doing so, defining the dripline's acceptable working conditions. Neptune PC AS has been tested at different operating pressure heads (range 1.5-3.5 bar), and its performances have been evaluated employing a series of metrics (the emitter technological variation coefficient, the emitter uniformity, and the application efficiency). The obtained results show that Neptune PC AS is characterised by a strong pressure-compensating effect on the emitters and by very good/excellent performances for all the investigated operating pressure heads. Moreover, Neptune PC AS is characterised by little differences between the maximum and the minimum of the emitter flow rate in the case of operating pressure heads equal to 1.5 bar and 2.0 bar, while such differences tend to increase for higher operating pressures. [ABSTRACT FROM AUTHOR]

In this study, an experimental benchmark with different welding conditions is developed. In-situ diagnostics tools (high-speed camera, thermocouple) and ex-situ diagnostics devices (high-resolution digital microscope, measuring arm, X-Ray diffraction device) are exploited to measure various physical quantities. These measurements set up a complete database of laser welding benchmarks, which can establish a relationship between welding parameters and thermo-mechanical consequences. Meanwhile, the finite element method is used to investigate such a process and understand the multi-physics coupling problems behind the process. Numerical and experimental comparisons are performed in two steps. Firstly, the molten pool morphology and temperature evolution are employed to calibrate the 3D volumetric heat source. Secondly, a thermo-mechanical coupling is carried out by imposing the thermal strain calculated from the calibrated thermal model. Thermo-elastoplastic models with isotropic and kinematic hardening are used to compute the distortion and residual stresses. Mechanical results (distortions and residual stresses) of numerical models are compared with those of the benchmark. Overall, a good correlation is found. Thus, this paper provides a full experimental case study and numerical solution for laser welding process, which allows researchers to validate their numerical models and also gives some insights for modeling welding processes.

Our study provides an experimental benchmark for state-of-the-art solution algorithms with hub location problems. Such problems are fundamental optimization problems in location science with widespread application areas, such as transportation, telecommunications, economics, and geography. Given they combine aspects of facility location and quadratic assignment problems, the majority of hub location problems are NP-hard and, accordingly, several solution techniques have been proposed for solving these problems. In this study, we report on the results of a large benchmark and reproduction effort to investigate 12 fundamental hub location problems that combine single or multiple allocation, a p-hub median objective or fixed hub set-up costs, capacitated or uncapacitated hubs, and complete or incomplete networks. We implemented four standard exact algorithms on these 12 problems as proposed in the literature. Algorithms are evaluated on subsets of three standard data sets in the field (CAB, TR, and AP); we computed more than 5,000 optimal solutions for these data sets. We report comparisons of solution techniques regarding wall clock time, convergence speed, memory use, and the impact of data features. In addition, we identify patterns in optimal solutions across these 12 problems, extracting insights regarding solution similarity, hub set candidates, and economies of scale. All results and programs are being made available to the public for free academic use. [ABSTRACT FROM AUTHOR]

Sprinkler systems are one of the most popular methods of irrigation worldwide. One of their key parameters is the so-called level of uniformity, i.e. every portion of the soil should be irrigated with the same amount of water. Assessing the level of uniformity is crucial for optimal design of sprinkler systems. In this manuscript, a novel experimental benchmark is presented in order to test irrigation sprinklers, assess their performance, and define their acceptable working conditions. Different sprinklers have been tested, their water application depth curves have been determined, and their performance has been evaluated using a combination of metrics. Results show that the majority of sprinklers are characterized by very good performance in terms of operating pressures in the range 2.0-3.0 bar and tend to decrease their efficiency for operating pressures outside of that range.

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Summary: Structural health monitoring (SHM) has been increasingly exploited in recent years as a valuable tool for assessing performance throughout the life cycle of structural systems, as well as for supporting decision‐making and maintenance planning. Although a great assortment of SHM methods has been developed, only a limited number of studies exist serving as reference basis for the comparison of different techniques. In this paper, the vibration‐based assessment of a small‐scale wind turbine (WT) blade is experimentally investigated, with the aim of establishing a benchmark case study for the SHM community. The structure under consideration, provided by Sonkyo Energy as part of the Windspot 3.5 kW WT model, is tested in both healthy and damaged states under varying environmental, that is, temperature, conditions as imposed by means of a climatic chamber. This study offers a thorough documentation of the configuration of this experimental benchmark, including the types of deployed sensors, the nature of excitation and available measurements, and the investigated damage scenarios and environmental variations enforced. Lastly, an overview of the raw and processed measurement data, made available to researchers via an open access Zenodo repository, is herein provided. [ABSTRACT FROM AUTHOR]

In view of the frequent ventilation network changes during production in underground mining, decreasing sensors and actuators without altering production control and safety is one of the chief engineering challenges. This work is focused on modeling identification and control strategies for underground ventilation networks in small‐scale mines using an experimental benchmark. Guidelines to obtain a discrete state space model are provided, considering the conservation laws in the network to define the structure of the linear model. The main purpose of the paper is to analyze the use of classic controllers in the mine ventilation system when there are limitations on the number of sensors and actuators available to design a feedback control system. A comparison of three classic control strategies is presented considering the a constraint on the available number of sensors. Experimental and simulation results are presented. [ABSTRACT FROM AUTHOR]

Numerous power generation technologies rely on plate geometry for the purpose of transporting heat through and across mediums. In the case of nuclear technology, this is relevant to that of plate-type-fuel and compact heat-exchangers; these components have high surface area to volume ratio provide ideal capacity for heat transfer to and through their respective parts. However, under highly advective conditions these plate-type geometries are susceptible to buckling and vibration which have possible safety-related implications associated with them. These complex phenomena occurring through fluid-structure-interactions have traditionally been quite difficult to predict using computational tools given their stiffly coupled nature. While recent efforts have demonstrated well aligned agreement with the use of advanced computational tools to predict flutter and buckling of unique mechanical geometries these tools have been found to consume significant computational resources not available to many within the community. This study investigates an industry tool's ability to compute the natural frequency of plates under various boundary conditions for the purpose of demonstrating relevance and limitations of its computing capacity when compared against experimental data to develop an objective basis for the use of such a tool in design and safety related predictions of components which comprise plate-type geometries. The goal of this study is to demonstrate a new method using an off-the-shelf software tool which is capable of operating on a standard desktop workstation and can readily predict the dynamic response of a mechanical structure in a fluid environment – a capability not previously demonstrated or otherwise shown to be successful in literature.A set of experimental plates were characterized to understand their dynamic response in both air and water. In an attempt to gain further insight into the vibration of the experimental test plates, a numeric benchmark study was performed to calculate their fundamental frequencies in both air and water, employing a novel modeling method to simulate submersion; one which allowed both the plate and the fluid domain to be modeled exclusively in a computational structural mechanics software package. Results show that the air simulation compares well with the analytic solutions; however comparison against experimental data is challenging, with no obvious trends present. Given the available experimental data, select air simulations are quite accurate, and careful selection of numeric boundary conditions yields representative results for alternative experimental boundary conditions. For simulations of plates submerged underwater, larger data sets for both experimental and numeric will be required to establish trends with a high degree of confidence; however preliminary results suggest the method can be accurate to a first order of magnitude approximation, requiring minimal computational resources.

Connecting vehicles securely and reliably is pivotal to the implementation of next generation ITS applications of smart cities. With continuously growing security threats, vehicles could be exposed to a number of service attacks that could put their safety at stake. To address this concern, both US and European ITS standards have selected Elliptic Curve Cryptography (ECC) algorithms to secure vehicular communications. However, there is still a lack of benchmarking studies on existing security standards in real-world settings. In this paper, we first analyze the security architecture of the ETSI ITS standard. We then implement the ECC based digital signature and encryption procedures using an experimental test-bed and conduct an extensive benchmark study to assess their performance which depends on factors such as payload size, processor speed and security levels. Using network simulation models, we further evaluate the impact of standard compliant security procedures in dense and realistic smart cities scenarios. Obtained results suggest that existing security solutions directly impact the achieved quality of service (QoS) and safety awareness of vehicular applications, in terms of increased packet inter-arrival delays, packet and cryptographic losses, and reduced safety awareness in safety applications. Finally, we summarize the insights gained from the simulation results and discuss open research challenges for efficient working of security in ITS applications of smart cities. [ABSTRACT FROM AUTHOR]

This paper proposes a non-contact original method to estimate local thermophysical properties (heat capacity and thermal conductivity) and heats of transition from plane thin specimens. This method is based on measurement of temperature fields with an infrared camera during a drop calorimetric experiment. A studied specimen and a reference specimen, with similar geometries, are simultaneously tested. Firstly, the method is validated by estimating heat capacity and thermal conductivity of Vanadium specimens and by comparing the determined values with those obtained by Differential Scanning Calorimetry and by a laser flash method, respectively. Secondly, the method is used to determine latent heats of martensitic transformations. These heats of transition are determined during homogeneous and heterogeneous drop calorimetric experiments of NiTi shape memory alloys specimens. Measured transformation temperatures and latent heats are in good accordance with results obtained by Differential Scanning Calorimetry. [ABSTRACT FROM AUTHOR]

Experiments and computational fluid dynamics/ radiation heat transfer simulations of an 8 X 8 array of heated rods within an air-filled aluminum enclosure are performed. This configuration represents a region inside the channel of a boiling water reactor fuel assembly between two consecutive spacer plates. The rods are oriented horizontally or vertically to represent transport or storage conditions. The measured and simulated rod temperatures are compared for three different rod heat generation rates to assess the accuracy of the simulation technique. Simulations show that temperature gradients in the air are much steeper near the enclosure walls than they are near the center of the rod array. The measured temperatures of rods at symmetric locations are not identical and the difference is larger for rods close to the wall than for those far from it. Small but uncontrolled deviations of the rod positions away from the design locations may cause these differences. The simulations reproduce the measured temperature profiles. For a total rod heat generation rate of 300 W, the maximum rod-to-enclosure temperature difference is 150°C. Linear regression shows that the simulations slightly but systematically overpredict the hotter rod temperatures but underpredict the cooler ones. For all rod locations, heat generation rates, and rod orientations, 95% of the simulated temperatures are within 11°C of the correlation values. For the hottest rods, which reside in the center of the domain where the air temperature gradients are small, 95% of the simulated temperatures are within 4.3°C of the correlation values. These results can be used to assess the accuracy of using simulations to design spent nuclear fuel transport and storage systems. [ABSTRACT FROM AUTHOR]

• A well-defined 3D methodology to model soil-structure interaction. • Proposed methodology is independent of the computer program used. • Tensile uplift load behavior is captured. • A comprehensive experimental verification study is presented. • Experimental calibration data for 24 specimens is provided. • Discrete modeling methods significantly underestimate the system capacity in weaker soils. In tall and light structures, such as transmission towers, wind turbines, and light-gauge steel structures, there is an increasing application of pile cap with helical pile foundation systems to resist the uplift loads due to the effects of windstorms and earthquakes. There is a lack of knowledge, published literature, or analysis methods to account for the effects of the pile cap, helical pile group, and soil interactions on the holistic response of the foundations, particularly, for the load conditions creating net uplift loads. In the lack of such, discrete modeling approaches are frequently employed in practice. These approaches isolate each system component and analyze them individually, neglecting the interactions between them. In an attempt to bridge this knowledge gap, this study proposes a system-level modeling methodology for the holistic analysis of pile cap systems in dry soil and static load conditions, while accounting for the effects of interactions between system components and the inherent material nonlinearities. The methodology employs a three-stage process in which the material and interaction properties are calibrated with the experimental benchmark specimens. The failure mechanisms are also experimentally verified based on the relative displacement of the piles. Important modeling considerations are discussed, and experimental benchmark specimens are provided to assist practitioners in accurately performing system-level analyses. The effectiveness of the proposed methodology is discussed, and the responses obtained, including the load–displacement responses, load capacities, and failure modes, are compared with those obtained from the discrete modeling approaches. The results demonstrate that discrete modeling approaches significantly underestimate the load capacity while not accurately predicting the governing behavior and the failure modes. [ABSTRACT FROM AUTHOR]