Container NATs and Session-Oriented Standards: Friends or Foe?

This article highlights issues that arise when deploying network address translation middle-boxes through containers. We focus on Docker as the container technology of choice and present a thorough analysis of its networking model, with special attention to the default bridge network driver that is used to implement network address translation functionality. We discuss some unexpected shortcomings we identified and elaborate on the suitability of containers for deploying services based on the Interactive Connectivity Establishment standard protocol. To support our findings, we present experiments we conducted in a real-world operational environment, namely a WebRTC service based on the Janus media server

Acoustic cavitation by means ultrasounds in the extra virgin olive oil extraction process

Abstract The virgin olive oil extraction process has changed very little over the past 20 years when the mechanical crushers, malaxers, horizontal and vertical centrifuges, took place in the olive mills. However, malaxation process remains the main critical step due to the discontinuity of this process. In previous activities, the same authors demonstrated how application of new emerging technologies could offer an interesting number of advantages to remove this bottleneck and, among the others, the ultrasound (US) technology is the most promising one, due to its mechanical and thermal effects due to the acoustic cavitation phenomenon. Acoustic cavitation, provided by means of low frequency high power ultrasounds, increases the quality, the work capacity and efficiency of the extraction plant, guaranteeing the sustainability. The paper shows how the authors have designed, realized and tested the first in the world continuous ultrasonic full-scale device for the extra virgin olive oil industry, with the aim to obtain the best product quality at the highest efficiency. Considering the heterogeneity of the olive paste, which is composed of different tissues, and considering the large number of parameters able to influence the process, a 3D multiphase CFD analysis was used as auxiliary tool in the design a so-called Sono-Heat-Exchanger (SHE). This innovative device, to be placed between the crusher and the decanter, is a combination of a heat-exchanger with plate-shape ultrasonic transducers. Finally, experimental results about yields and phenols contents demonstrated the relevance of this innovation

Gate Leakage Reduction by Clocked Power Supply of Adiabatic Logic Circuits

Losses due to gate-leakage-currents become more dominant in new technologies as gate leakage currents increase exponentially with decreasing gate oxide thickness. The most promising Adiabatic Logic (AL) families use a clocked power supply with four states. Hence, the full <i>V</i>_<i>DD</i> voltage drops over an AL gate only for a quarter of the clock cycle, causing a full gate leakage only for a quarter of the clock period. The rising and falling ramps of the clocked power supply lead to an additional energy consumption by gate leakage. This energy is smaller than the fraction caused by the constant <i>V</i>_<i>DD</i> drop, because the gate leakage exponentially depends on the voltage across the oxide. To obtain smaller energy consumption, Improved Adiabatic Logic (IAL) has been introduced. IAL swaps all n- and p-channel transistors. The logic blocks are built of p-channel devices which show gate tunneling currents significantly smaller than in n-channel devices. Using IAL instead of conventional AL allows an additional reduction of the energy consumption caused by gate leakage. Simulations based on a 90nm CMOS process show a lowering in gate leakage energy consumption for AL by a factor of 1.5 compared to static CMOS. For IAL the factor is up to 4. The achievable reduction varies depending on the considered AL family and the complexity of the gate

Effects of Ultrasound and Green Synthesis ZnO Nanoparticles on Biogas Production from Olive Pomace

Abstract Agro-biomass residues can play a crucial role in promoting the fossil-fuel replacement in agro-food farms. Apulia, a region in Southern Italy, concentrates 22% of farms and 57% of total national olive and olive oil production, resulting the leader producer of the Country. So that, a high quantity of biomass (olive pomace) can be recovered from the milling process. This study investigates the biogas production that occurs during the anaerobic digestion of olive pomace by means of an ultrasound pre-treatment or by means of green synthesis of ZnO Nanoparticles mixed with olive pomace, in order to facilitate its digestion or co-digestion. Measurement of dry matter and biogas produced volume during the anaerobic process were investigated starting from 3-phase and 2-phase olive pomace by means of high specific energy and low frequency ultrasound values. The results highlight a promising influence of ultrasound pre-treatment useful at increasing the biogas yield of olive pomace

Influencia del batido y de los parámetros de extracción en la calidad del aceite de oliva virgen

The mixing time, the temperature and the degree of dilution of olive paste are the main parameters liable to change during mixing and oil ext raction. They can greatly differ from a processing run to another, with variations being observed in Tuscan oil mills, between 26ºC and 36ºC, 40’ and 90’, and 10% and 50% respectively, for the temperature, the mixing time and the water added during the centrifugal extraction. This note reports on the results of some experimental trials run during the 1998 olive oil year in Tuscany. The mixing time and temperature as well as the olive paste dilution were changed one at a time and were assessed for their influence on extraction yield and oil quality. The best conditions to optimise the product yield and quality were identified.El tiempo de batido, la temperatura y el grado de dilución de la pasta de aceituna, son los principales parámetros que pueden sufrir cambios durante el batido y la extracción del aceite. Estos pueden diferir mucho de un proceso a otro, habiendo sido observadas variaciones en los aceites de molino de Toscana, entre 26ºC y 36ºC, 40’ y 90’, y 10% y 50% respectivamente, para la temperatura, el tiempo de batido y el agua añadida durante la extracción por centrifugación. Este artículo presenta los resultados de algunos ensayos experimentales realizados durante el año 1998 con aceite de oliva de Toscana. El tiempo de batido y la temperatura, así como la dilución de la pasta de aceitunas, se variaron uno a uno y se evaluaron por su influencia en el rendimiento de la extracción y la calidad del aceite. Las mejores condiciones para optimizar el rendimiento y la calidad del producto fueron identificadas

Jattack: A WebRTC load testing tool

We present Jattack, an automated stressing tool for the analysis of the performance of WebRTC-enabled server-side components. Jattack has been initially conceived with the primary objective of performing a thorough scalability analysis of the well-known Janus WebRTC gateway. As such, it re-uses most of the Janus core stack components in order to reliably emulate the behavior of a dynamically adjustable number of WebRTC clients. The specific testing .scenario can indeed be programmatically reproduced by writing a small "controller" component, which takes on the responsibility of properly orchestrating the scenario itself. The general-purpose nature of the tool, together with its flexibility deriving from the controller-based programmable approach, makes Jattack also suitable for stress-testing other WebRTC-enabled servers

Centralized Conferencing in the IP Multimedia Subsystem: from theory to practice

In this paper we present a conferencing architecture compliant with the IP Multimedia Subsystem (IMS) specification. To the purpose, we embrace a practical approach, by describing an actual implementation of an open source centralized video-conferencing system, called CONFIANCE, capable to offer advanced communication experience to end-users through the effective exploitation of mechanisms like session management and floor control. CONFIANCE has been designed to be fully compliant with the latest standard proposals coming from both the IETF and the 3GPP and can be considered as an outstandingexample of a real-time application built on top of the grounds paved by the SIP protocol. We will discuss in the paper both the design of the overall conferencing framework and the most important issues we had to face during the implementation phase