Polyphenolic extracts from the olive mill wastewater as a source of biopesticides and their effects on the life cycle of the Mediterranean fruit fly Ceratitis capitata (Diptera, Tephriditae)

AbstractThe Mediterranean Fruit Fly Ceratitis capitata (Wiedemann) (Diptera, Tephriditae) is an important pest in the Mediterranean region causing severe economic losses. Currently, pyrethroids are the most common insecticides used in the control of the Medfly. However, the demand for biopesticides is growing due to the necessity to limit the use of hazardous chemical pesticides in the context of the integrated pest management. In this context, a valid alternative is the use of plant derived pesticides with a selective action against target pests and a shorter persistence in ecosystems.Among plant products, olive tree phenolic and polyphenolic compounds show potent bioactive properties as insecticides and growth regulators. The olive mill wastewater is an important source of these compounds.We are reporting here that the polyphenolic fractions of the olive mill wastewater, show ovicidal effects in terms of reduction of the hatching rate, whereas the larval development is not affected by the treatments.On the adults, we show that selected fractions induce a complete block of the fecundity of the females probably due to an induced disruption of the oogenesis.These results suggest that the polyphenolic fractions derived from the olive mill wastewater can be used as a strong natural chemosterilant against the Mediterranean Fruit fly and can be considered as a putative ovicidal agent

Numerical and experimental analysis of the thermoforming process parameters of semi-spherical glass fibre thermoplastic parts

Abstract The thermoforming process is considered among the most promising manufacturing processes for delivering both high quality and volume of thermoplastic composite parts as it exploits all the principal advantages these materials provide. Nevertheless, a series of critical defects may be introduced during the process such as wrinkles, shear deformation of the textile, variation on the thickness as well as geometric distortions and residual stresses which are highly dependent on the material characteristics and the parameters of the process itself. In the present work presented is an analysis of these parameters and their influence on a simple semi-spherical geometry using finite element modelling. The results are also compared with actual experimental results

On the Predictive Tools for Assessing the Effect of Manufacturing Defects on the Mechanical Properties of Composite Materials

Abstract Despite the recent advances in the field of manufacturing of composite materials, with both thermosetting and thermoplastic matrix, the presence of irregularities that influence their mechanical properties and behavior remains a critical issue to the industry. The defects with the form of porosity, fiber misalignment, delamination and poor consolidation are considered an unavoidable form of initial damage to composite materials. The reduction of the defects by optimizing the manufacturing process and the creation effective tools for predicting the residual properties of these materials during the design and/or the manufacturing phase are of great interest. In the present work, presented are these numerical tools and methodologies based either on the idea of optimizing the manufacturing process or by using data derived from non-destructive tests. Finally, the possibility of combining the two approaches is being proposed

Optimization of Friction Stir Welding of Thermoplastics

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Monitoring of MMCs grinding process by means of IR thermography

Abstract The objective of this investigation is to assess the IR thermography as a monitoring system able to detect the grinding conditions in order to test its use as an industrial tool for optimizing and control the process. To this aim an experimental investigation has been carried out in the grinding of Metal Matrix Composites (MMCs). These materials exhibit additional drawbacks with respect to conventional materials due to the abrasive nature of the reinforcement together with the softness of the matrix. The results show how the IR thermography can give a significant contribution in the definition of a strategy to control the grinding process as well as for the maintenance of the grinding machine

advances in mechanical clinching employment of a rotating tool

Abstract In the recent years, high efforts have been spent concerning the development of fast mechanical joining processes. This is due to the growing employment of materials that are difficult to weld and hybrid structures involving different materials. Mechanical clinching enables to solving the major concerns in this field. However, the formability of the materials represent a limitation to the successful employment of the process. The present research illustrates a new concept of clinching, namely friction clinching that differs from the conventional process by the employment of a rotating tool, which heats up the sheet (by friction) during the process leading to an increase in the material formability. Preliminary tests were performed to verify the feasibility of the process and determine a sound processing window. The process was applied to join thin aluminium sheets and Carbon Fibre Reinforced Plastic (CFRP) laminate. Morphological analysis and mechanical characterization of the joints was performed in order to evaluate the suitability of such the rotating tool to increase the material formability and thus the aluminium sheet integrity. According to the achieved results, the employment of the rotating tool enables to avoid crack formation in the metal sheet, improves the material flow and reduces the joining forces

Adult and Egg Mortality of Rhynchophorus Ferrugineus Oliver (Coleoptera: Curculionidae) Induced by Thiamethoxam and Clothianidin.

The red palm weevil (RPW) is the major pest of palms in the Mediterranean region. One of the most interesting control solutions for this pest is endotherapy, comprising injections of biologically active substances directly into the stem of the palm. The objective of the present work was to study the ovicidal and adulticidal properties of two neonicotinoid insecticides (clothianidin and thiamethoxam) under laboratory conditions, to obtain evidence for application of endotherapy in the control of RPW infestations. Our results show that both commercial compounds display a dose-dependent action and exhibit different modes of action: clothianidin is more rapid in its action, but in general is less effective for control of the adult stages, while thiamethoxam is more effective, but its action requires longer to show efficacy. The eggs are much less sensitive to treatments, especially for clothianidin

notes on the hybrid urans les turbulence modeling for internal combustion engines simulation

Abstract In the past 20 years, Large Eddy Simulation methods have continuously increased their popularity among the Internal Combustion Engines modeling community, due to their intrinsic potential in the description of the unsteady and randomly generated in-cylinder flow structures. Such capability has gained further relevance in the simulation of modern turbocharged GDI engines, where the high-fidelity resolution of cycle-to-cycle variability phenomena is crucial for the evaluation of the engine performance and emission trends. Nonetheless, even after many years of development the application of standard LES methods to full-scale engine geometries is still not straightforward, due to: the need for specific, turbulence-generating boundary conditions at open ends; more severe grid resolution/quality and time step requirements compared to unsteady RANS; the need for high-order (at least second-order accurate) numerical schemes. Therefore, a viable alternative might be found in hybrid URANS/LES turbulence modeling, which has the potential to achieve adequate scale-resolving levels wherever actually needed, but mitigating at the same time some of the aforementioned concerns. In the present work we discuss the current status and perspectives of URANS/LES hybrids in the ICE field, based on the scientific literature state-of-the art and on a series of previous computational studies made by the authors. Outcomes from this study essentially confirm that this class of methods deserve further attention and will likely support URANS and standard LES in the near future as an effective computational tool for the ICE development and optimization

Preliminary design of a fuel cell/battery hybrid powertrain for a heavy-duty yard truck for port logistics

Abstract The maritime transport and the port-logistic industry are key drivers of economic growth, although, they represent major contributors to climate change. In particular, maritime port facilities are typically located near cities or residential areas, thus having a significant direct environmental impact, in terms of air and water quality, as well as noise. The majority of the pollutant emissions in ports comes from cargo ships, and from all the related ports activities carried out by road vehicles. Therefore, a progressive reduction of the use of fossil fuels as a primary energy source for these vehicles and the promotion of cleaner powertrain alternatives is in order. The present study deals with the design of a new propulsion system for a heavy-duty vehicle for port applications. Specifically, this work aims at laying the foundations for the development of a benchmark industrial cargo–handling hydrogen-fueled vehicle to be used in real port operations. To this purpose, an on-field measurement campaign has been conducted to analyze the duty cycle of a commercial Diesel-engine yard truck currently used for terminal ports operations. The vehicle dynamics has been numerically modeled and validated against the acquired data, and the energy and power requirements for a plug-in fuel cell/battery hybrid powertrain replacing the Diesel powertrain on the same vehicle have been evaluated. Finally, a preliminary design of the new powertrain and a rule-based energy management strategy have been proposed, and the electric energy and hydrogen consumptions required to achieve the target driving range for roll-on and roll-off operations have been estimated. The results are promising, showing that the hybrid electric vehicle is capable of achieving excellent energy performances, by means of an efficient use of the fuel cell. An overall amount of roughly 12 kg of hydrogen is estimated to be required to accomplish the most demanding port operation, and meet the target of 6 h of continuous operation. Also, the vehicle powertrain ensures an adequate all-electric range, which is between approximately 1 and 2 h depending on the specific port operation. Potentially, the hydrogen-fueled yard truck is expected to lead to several benefits, such as local zero emissions, powertrain noise elimination, reduction of the vehicle maintenance costs, improving of the energy management, and increasing of operational efficiency

Assessment of a Hydrogen-Fueled Heavy-Duty Yard Truck for Roll-On and Roll-Off Port Operations

The port-logistic industry has a significant impact on the urban environment nearby ports and on the surrounding coastal areas. This is due to the use of large auxiliary power systems on ships operating during port stays, as well as to the employment of a number of fossil fuel powered road vehicles required for port operations. The environmental impact related to the use of these vehicles is twofold: on one hand, they contribute directly to port emissions by fuel consumption; on the other hand, they require some of the ship auxiliary systems to operate intensively, such as the ventilation system, which must operate to remove the pollutants produced by the vehicle engines inside the ship. The pathway to achieve decarbonization and mitigation of energy use in ports involves therefore the adoption of alternative and cleaner technology solutions for the propulsion systems of such port vehicles. This paper presents the performance analysis of a hydrogen powered cargo-handling vehicle for roll-on and roll-off port operations in a real case scenario. The fuel cell/battery hybrid powertrain of the vehicle has been previously designed by the authors. On the base of real data acquired during an on-field measurement campaign, and by means of a validated numerical model of the vehicle dynamics, different mission profiles are defined, in terms of driving and duty cycles, in order to represent typical port operations. A rule-based energy management strategy is then used to estimate the energy and hydrogen consumptions required by the vehicle and to assess its suitability to accomplish the defined target port operations. Outputs from this study show the potential of the proposed solution to take the place, in a foreseeable future, of conventional Diesel-engine vehicles, today commonly used in port logistics, towards a zero-emission scenario