Search results for "FFL"
showing 6 items of 546 documents
Influence of Viscosity on Mass Transfer Performance of Unbaffled Stirred Vessels
2013
Unbaffled stirred tanks are seldom employed in the process industry as they are considered poorer mixers than baffled vessels. However they may be expected to provide significant advantages in a wide range of applications (e.g. crystallization, food and pharmaceutical processes, etc) where the presence of baffles is often undesirable. Moreover, in plants or animal cell cultivation bioreactors, where cell damage is often caused by bursting bubbles at the air –medium interface (Barret et al., 2010), they can provide sufficient mass transfer through the free surface vortex, so bubble formation and subsequent bursting inside the reactor can be conveniently avoided (Scargiali et al., 2012). In t…
SOLID-LIQUID SUSPENSIONS IN UNBAFFLED TANKS
2009
Unbaffled stirred tanks are seldom employed in the process industry as they are considered poorer mixers than baffled tanks. However, they might provide significant advantages in a wide range of applications like crystallization processes as well as for food and pharmaceutical industries, where the presence of baffles is often undesirable. In the present work solid-liquid suspension in an unbaffled stirred tank was investigated. A novel experimental method (steady cone radius method) was devised to ease the evaluation of the minimum impeller speed for complete particle suspension (Njs). Experiments encompassed a quite wide range of particle sizes, densities and solids concentration. The Njs…
A Computationally Efficient Online/Offline Signature Scheme for Underwater Wireless Sensor Networks
2022
Underwater wireless sensor networks (UWSNs) have emerged as the most widely used wireless network infrastructure in many applications. Sensing nodes are frequently deployed in hostile aquatic environments in order to collect data on resources that are severely limited in terms of transmission time and bandwidth. Since underwater information is very sensitive and unique, the authentication of users is very important to access the data and information. UWSNs have unique communication and computation needs that are not met by the existing digital signature techniques. As a result, a lightweight signature scheme is required to meet the communication and computation requirements. In this researc…
Effect of temperature on anaerobic treatment of black water in UASB-septic tank systems
2007
The effect of northern European seasonal temperature changes and low temperature on the performance of upflow anaerobic sludge blanket (UASB)-septic tanks treating black water was studied. Three UASB-septic tanks were monitored with different operational parameters and at different temperatures. The results indicated the feasibility of the UASB-septic tank for (pre)treatment of black water at low temperatures with respect to removal of suspended solids and dissolved organic material. Inoculum sludge had little effect on COD(ss) removal, though in the start-up phase some poorly adapted inoculum disintegrated and washed out, thus requiring consideration when designing the process. Removal of …
Particle balance and return loops for microplastics in a tertiary-level wastewater treatment plant.
2021
Highlights: Dewatering by centrifugation was a step that removed a high number of MPs from the sludge. Sludge retained especially the fibrous microplactics. Reject water transported microplastics inside a wastewater treatment plant. Disc filter-based tertiary treatment ensured removal of 99% of microplastics in wastewater. Microplastics (MPs) from households, stormwater, and various industries are transported to wastewater treatment plants (WWTPs), where a high proportion of them are captured before discharging their residuals to watersheds. Although recent studies have indicated that the removed MPs are mainly retained in wastewater sludge, sludge treatment processes have gained less atten…
Resource Allocation and Computation Offloading for Wireless Powered Mobile Edge Computing
2022
In this paper, we investigate a resource allocation and computation offloading problem in a heterogeneous mobile edge computing (MEC) system. In the considered system, a wireless power transfer (WPT) base station (BS) with an MEC sever is able to deliver wireless energy to the mobile devices (MDs), and the MDs can utilize the harvested energy for local computing or task offloading to the WPT BS or a Macro BS (MBS) with a stronger computing server. In particular, we consider that the WPT BS can utilize full- or half-duplex wireless energy transmission mode to empower the MDs. The aim of this work focuses on optimizing the offloading decision, full/half-duplex energy harvesting mode and energ…