Optimal design method of the load-level isolation system for industrial steel racking

This paper focuses on an innovative system for mitigating seismic actions on industrial steel racking, called Load-Level Isolation System (LLIS). It consists of placing isolators directly between the pallet masses and the load level, thus exploiting the pallet masses (much greater than the structural mass) as tuned mass dampers. Specifically, the paper aims to derive a general design procedure for the LLIS, based on the amount of mass isolated, the position of the LLIS within the rack, and the main dynamic characteristics of the structural system. To this end, an analytical optimization method is proposed, based on the minimization of the displacement variance of a reduced structural model, representative of the rack dynamics with the LLIS. This method is applied parametrically to derive the optimal damping and frequency values of the LLIS in various design situations, and a sensitivity analysis is subsequently conducted to propose cost-effective LLIS design solutions. Prediction models of the LLIS parameters are therefore provided, as well as a simple step-by-step procedure for designing the control system. Finally, a case study is presented, with the dual objectives of showing the application of the design procedure and the effectiveness of the LLIS in mitigating seismic effects in a standard pallet rack. The results of the Time-History analysis demonstrate the validity of the proposed design method and the possibility of achieving large reductions in the seismic response of the rack using this control system, and up to 60% for both maximum displacements and axial forces of the uprights

Effect of retrofit interventions on seismic fragility of Italian residential masonry buildings

In this paper, the vulnerability of ordinary unreinforced masonry (URM) buildings is analyzed, and the literature related to possible seismic retrofit interventions is reviewed in order to investigate their feasibility and effectiveness. These interventions are then simulated on a data-base of 445 buildings through Vulnus_4.0 software, that performs simplified mechanical analyses accounting for both global and local behavior of masonry buildings. The fragility of each building is assessed both in its as-built state and after the simulation of retrofit interventions. Fragility curves are then processed, and a fragility model for four building typologies is obtained for the as -built and the seismic retrofitted configurations. Lastly, mean damage maps are elaborated, and the performance of the proposed retrofit interventions is analyzed. The results of this work allow evaluating and comparing the improvement of seismic behavior brought by various retrofit in-terventions and could serve as a basis for further theoretical studies and for practical design in real cases

Application of a CFD validated model to plan fan heater position within flour mills during a heat treatment for insect pest control

The development of environmentally-friendly methods as alternatives to chemical fumigation for controlling insect pests has attracted public attention. Among these methods, heat treatment is based on the use of fan heaters that are positioned by operators who typically establish their number and position within buildings to be treated. The aim of this research was to improve heat treatment effectiveness by applying a validated computational fluid dynamics (CFD) model for planning fan heater positions within the building environment. Based on a CFD model, which was built and validated according to experimental data acquired during heat treatment of a flour mill, simulations were carried out by changing the position and/or rotation of fan heaters with the aim of enhancing temperature distribution inside the building. The results showed that in some simulations the percentage of internal wall surfaces having a temperature value lower than that required for heat treatment efficacy was considerably reduced, by up to 56.7%. Therefore, the CFD approach proposed in this study could be used as a decision support system for improving heat treatment efficacy

Avaliação técnico-econômica do controle de gramíneas em milho em área de várzea.

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Planejamento fatorial para extra\ue7\ue3o de enzima fibrinolitica de Mucor subtilissimus UCP1262 mediante sistema de duas fases aquosas (PEG/fosfato)

A factorial design was used to select the best conditions of fibrinolytic protease from Mucor subtilissimus by aqueous two-phase system (PEG/phosphate)

A new approach for the recovery of polyphenols from Arthrospira platensis: advancement of green process through high pressure/temperature extraction

The cyanobacterium Arthrospira (Spirulina) platensis was used as raw material for the recovery of polyphenols by the high temperature/high pressure extraction process, to be used as ingrediet for fuctional foods preparation

Desempenho de cultivares de milho em áreas de rotação com arroz irrigado no ano agrícola 2004/05.

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Plasma technology increases the efficacy of prothioconazole against fusarium graminearum and fusarium proliferatum contamination of maize (Zea mays) seedlings

The contamination of maize by Fusarium species able to produce mycotoxins raises great concern worldwide since they can accumulate these toxic metabolites in field crop products. Further-more, little information exists today on the ability of Fusarium proliferatum and Fusarium graminearum, two well know mycotoxigenic species, to translocate from the seeds to the plants up to the kernels. Marketing seeds coated with fungicide molecules is a common practice; however, since there is a growing need for reducing chemicals in agriculture, new eco-friendly strategies are increasingly tested. Technologies based on ionized gases, known as plasmas, have been used for decades, with newer material surfaces, products, and approaches developed continuously. In this research, we tested a plasma-generated bilayer coating for encapsulating prothioconazole at the surface of maize seeds, to protect them from F. graminearum and F. proliferatum infection. A minimum amount of chemical was used, in direct contact with the seeds, with no dispersion in the soil. The ability of F. graminearum and F. proliferatum species to translocate from seeds to seedlings of maize has been clearly proven in our in vitro experiments. As for the use of plasma technology, the combined use of the plasma-generated coating with embedded prothioconazole was the most efficient approach, with a higher reduction of the infection of the maize seminal root system and stems. The debated capability of the two Fusarium species to translocate from seeds to seedlings has been demonstrated. The plasma-generated coating with embedded prothioconazole resulted in a promising sustainable approach for the protection of maize seedlings