Summing Pauli asymptotic series to solve the wedge problem

The use of the asymptotic treatment for the wedge diffraction problem established long ago by Pauli [Phys. Rev.54, 924 (1938)] is here revisited and proposed in the character of a powerful computational tool for accurately retrieving the total electromagnetic field even in the near zone. After proving its factorial divergent character, the Pauli series is summed through the Weniger transformation, a nonlinear resummation scheme particularly efficient in the case of factorial divergence. Numerical results are carried out to show the accuracy and effectiveness of the proposed approach.     

An integrated approach to the design and management of a supply chain system

In the modern competitive business environment, the design and management of supply chains is one of the most important and critical problems facing managers of multinational companies operating worldwide. There are three levels of decisions in a supply chain: strategic, tactical, and operational levels. The literature generally treats these decisions separately. This study defines a conceptual framework for the development of new modeling approaches for the Production Distribution Logistic System Design (PDSD) problem. In particular, the authors introduce the initial basis for the development of an innovative decision support systems platform capable of integrating the design, management, control, and optimization activities for a supply chain system.     

Testing of a VIS-NIR System for the Monitoring of Long-Term Apple Storage

The development of diseases during long-term storage of apples is a well-known issue causing loss of product for warehouses. Non-destructive characterization of fruit can be helpful in order to reduce waste and maximize apple quality. The aim of this study was to evaluate the applicability of visible and near-infrared (VIS-NIR) spectroscopy to monitor and manage lots of apples during long-term storage in a cold room. A bench-top VIS-NIR apparatus (600–1200 nm) was used to classify apples from two different cultivars, Golden Delicious and Red Delicious, based on their total soluble solids content (TSS). The evolution of the originally created classes was analyzed during 7 months of storage by monitoring TSS and firmness (peak force and penetration energy), and the estimation ability of the VIS-NIR device was evaluated. The results indicate that the spectroscopic technique allows for an accurate estimation of chemical-physical parameters for non-destructive classification of apples in homogeneous lots. Regarding the estimation ability of the compact VIS-NIR spectrophotometer, the results show good prediction ability both for total soluble solids content and firmness indices. The use of the instrument for on-line selection and classification of fruits is therefore desirable. This can lead to better management of postharvest storage and the destination of lots, with a consequent reduction in fruit wastage. This approach is important to plan the opening sequence of storage rooms during the winter season, providing the market with the best available products all year round.     

Reaction of Aryl Diazonium Salts and Diiron(I) Dithiolato Carbonyls: Evidence for Radical Intermediates

Treatment of Fe(2)(pdt)(CO)(4)(dppv) (1) with aryldiazonium salts affords the 34e(-) adducts [Fe(2)(pdt)(μ-N(2)Ar)(CO)(4)(dppv)](+) (pdt(2-) = 1,3-propanedithiolate, dppv = cis-C(2)H(2)(PPh(2))(2)). Under some conditions, the same reaction gave substantial amounts of [1](+), the product of electron-transfer. Consistent with the influence of electron transfer in the reactions of some electrophiles with Fe(I)Fe(I) dithiolates, the reaction of [Me(3)S(2)](+) and Fe(2)(pdt)(CO)(4)(dppbz) was found to give [Fe(2)(pdt)(CO)(4)(dppbz)](+) as well as Me(2)S and Me(2)S(2) (dppbz = 1,2-bis(diphenylphosphino)benzene).     

A unified multimedia and semantic perspective for data retrieval in the semantic web

In recent years, the emerging diffusion of peer-to-peer networks is going beyond the single-domain paradigm like, for instance, the mono-thematic file sharing one (e.g. Napster for music). Peers are more and more heterogeneous data sources which need to share data with commercial, educational, and/or collaboration purposes, just to mention a few. Moreover, in current information processing applications data cannot be meaningfully searched by precise database queries that would return exact matches (e.g. when dealing with multimedia, proteomic, statistical data).     

A Modular Framework for Fast Prototyping of Cooperative Unmanned Aerial Vehicle

Unmanned Aerial Vehicles (UAVs) are gaining increasing interest thanks to their flexibility and versatility. However, these systems are very complex and a good simulation platform is needed. In this paper, a new Framework for simulation and fast prototyping of UAV control laws is presented. The Framework exploits the high realism of the simulations carried out in a three-dimensional virtual environment with the easiness of use of development systems such as Matlab? for fast prototyping of control systems. Then a novel method that exploits the benefits of Model Predictive Control (MPC) for cooperative scenarios is introduced. The obtained results show good performances of MPC in solving the formation problem of unmanned aerial vehicles; finding an optimal solution and taking into account different constraints. The developed framework allows also to easily change from simulated agent to real?one.     

Evaluation and Remediation of an Abandoned Gypsum Mine

The remediation measures taken for an abandoned gypsum mine in the Italian Alps are presented. The mine consists of four levels, excavated by the room-and-pillar method in an evaporitic formation. The two lower levels were flooded by water coming from adjacent strata after mining ended about 30 years ago. The dissolution process affecting the submerged pillars can jeopardize the long term stability of the entire mine. An overview of the problem is given, and experimental results of dissolution tests are shown. An analytical model developed to simulate the laboratory data is applied to determine the time to failure of the mine. It is demonstrated that the expected collapse time is relatively short. Remedial measures consisting of chamber filling with an appropriate mixture of cement, water, and silty clay are proposed. A theoretical analysis of their effects in delaying time to failure and minimizing its consequences is presented. The analysis allowed the optimal mechanical characteristics of the filling mixture to be determined. The results of a full-scale field test to check the validity of the remedial action are highlighted.     

Doping of SiGe core-shell nanowires

Dopant deactivation in pure Si and pure Ge nanowires (NWs) can compromise the efficiency of the doping process at nanoscale. Quantum confinement, surface segregation and dielectric mismatch, in different ways, strongly reduce the carrier generation induced by intentional addition of dopants. This issue seems to be critical for the fabrication of high-quality electrical devices for various future applications, such as photovoltaics and nanoelectronics. By means of Density Functional Theory simulations, we show how this limit can be rode out in core-shell silicon-germanium NWs (SiGe NWs), playing on the particular energy band alignment that comes out at the Si/Ge interface. We demonstrate how, by choosing the appropriate doping configurations, it is possible to obtain a 1-D electron or hole gas, which has not to be thermally activated and which can furnish carriers also at very low temperatures. Our findings suggest core-shell NWs as possible building blocks for high-speed electronic device and new generation solar cells.