90 research outputs found
A dynamic fake source algorithm for source location privacy in wireless sensor networks
Wireless sensor networks (WSNs) are commonly used in asset monitoring applications, where it is often desirable for the location of the asset being monitored to be kept private. The source location privacy (SLP) problem involves protecting the location of a WSN source node from an attacker who is attempting to locate it. Among the most promising approaches to the SLP problem is the use of fake sources, with much existing research demonstrating their efficacy. Despite the effectiveness of the approach, the most effective algorithms providing SLP require network and situational knowledge that makes their deployment impractical in many contexts. In this paper, we develop a novel dynamic fake sources-based algorithm for SLP. We show that the algorithm provides state-of-the-art levels of location privacy under practical operational assumptions
Towards understanding source location privacy in wireless sensor networks through fake sources
Source location privacy is becoming an increasingly important property in wireless sensor network applications, such as asset monitoring. The original source location problem is to protect the location of a source in a wireless sensor network from a single distributed eavesdropper attack. Several techniques have been proposed to address the source location problem, where most of these apply some form of traffic analysis and engineering to provide enhanced privacy. One such technique, namely fake sources, has proved to be promising for providing source location privacy. Recent research has concentrated on investigating the efficiency of fake source approaches under various attacker models. In this paper, we (i) provide a novel formalisation of the source location privacy problem, (ii) prove the source location privacy problem to be NP-complete, and (iii) provide a heuristic that yields an optimal level of privacy under appropriate parameterisation. Crucially, the results presented show that fake sources can provide a high, sometimes optimal, level of privacy
Assessing the performance of phantom routing on source location privacy in wireless sensor networks
As wireless sensor networks (WSNs) have been applied across a spectrum of application domains, the problem of source location privacy (SLP) has emerged as a significant issue, particularly in safety-critical situations. In seminal work on SLP, phantom routing was proposed as an approach to addressing the issue. However, results presented in support of phantom routing have not included considerations for practical network configurations, omitting simulations and analyses with larger network sizes. This paper addresses this shortcoming by conducting an in-depth investigation of phantom routing under various network configurations. The results presented demonstrate that previous work in phantom routing does not generalise well to different network configurations. Specifically, under certain configurations, it is shown that the afforded SLP is reduced by a factor of up to 75
A review of the valorization and management of industrial spent catalyst waste in the context of sustainable practice: The case of the State of Kuwait in parallel to European industry
Industrial solid waste management encompasses a vital part of developed and developing countries strategies alike. It manages waste generated from vital industries and governs the hazardous waste generated as a major component of integrated waste management strategies. This article reviews the practices that govern the management approaches utilized in the developed world for industrial spent catalysts. It critically assesses the current situation of waste management within the developing world region focusing on the industrial waste component, in a novel attempt to crucially develop a strategy for a way forward based on best practices and future directions with major European industries. The review also draws parallels with European countries to compare their practices with those of the State of Kuwait, which rely solely on landfilling for the management of its industrial waste. Spent catalysts recovery methods are discussed at length covering conventional methods of valuable metals and chemicals recovery (e.g., hydrometallurgical, solid–liquid and liquid–liquid extraction) as well as biological recovery methods. A major gap exists within regulations that govern the practice of managing industrial waste in Kuwait, where it is essential to start regulating industries that generate spent catalysts in-view of encouraging the establishment of valorization industries for metal and chemical recovery. This will also create a sustainable practice within state borders, and can reduce the environmental impact of landfilling such waste in Kuwait
CO2 assisted blending of poly(lactic acid) and poly(ε-caprolactone)
Poly(lactic acid) (PLA) is gaining increasing interest from the packaging industry as a biodegradable alternative to oil based polymers such as polypropylene (PP) and polyethylene terephthalate (PET). However, its’ inherent brittle nature prevents widescale commercial use. Blending in order to improve the Young’s modulus, yield stress and elongation to break, provides a possible alternative although many polymers have been found to be immiscible with PLA. In this study, high pressure carbon dioxide (CO2) was utilised during blending to encourage miscibility between two normally immiscible polymers: poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA). Blends were prepared by melt blending in the presence of carbon dioxide (CO2) and compared to solvent casting and melt blending with a single-screw extruder. CO2 assisted blends demonstrated a significant reduction in the size and number of PCL domains in a PLA matrix, and consequently improved the adhesion between phases at the microscale. The optimum melt blend composition for Young’s modulus, yield stress and elongation to break was found to be 75% PLA and 25% PCL. Mechanical properties of PLA 2002D blends were further improved when prepared by CO2 assisted melt blending
Reduction of aerobic and lactic acid bacteria in dairy desludge using an integrated compressed CO2 and ultrasonic process
International audienceAbstractCurrent treatment routes are not suitable to reduce and stabilise bacterial content in some dairy process streams such as separator and bactofuge desludges which currently present a major emission problem faced by dairy producers. In this study, a novel method for the processing of desludge was developed. The new method, elevated pressure sonication (EPS), uses a combination of low frequency ultrasound (20 kHz) and elevated CO2 pressure (50 to 100 bar). Process conditions (pressure, sonicator power, processing time) were optimised for batch and continuous EPS processes to reduce viable numbers of aerobic and lactic acid bacteria in bactofuge desludge by ≥3-log fold. Coagulation of proteins present in the desludge also occurred, causing separation of solid (curd) and liquid (whey) fractions. The proposed process offers a 10-fold reduction in energy compared to high temperature short time (HTST) treatment of milk
A Review of The Valorisation and Management of Industrial Spent Catalyst Waste in The Context of Sustainable Practice: The Case of The State of Kuwait in Parallel to European Industry
Industrial solid waste management encompasses a vital part of developed and developing countries strategies alike. It manages waste generated from vital industries and governs the hazardous waste generated as a major component of integrated waste management strategies. This communication reviews the practices that govern the management approaches utilised in the developed world for industrial spent catalysts. It critically assess the current situation of waste management within the developing world region focusing on the industrial waste component, in a novel attempt to crucially develop a way forward strategy based on best practices and future directions with major European industries. The review also draws parallels with European countries to compare their practices with those of the State of Kuwait, which rely solely on landfilling for the management of its industrial waste. Spent catalysts recovery methods are discussed in length covering conventional methods of valuable metals and chemicals recovery (e.g. hydrometallurgical, solid/liquid and liquid-liquid extraction) as well as biological recovery methods. A major gap exists within regulations that govern the practice of managing industrial waste in Kuwait, where it is essential to start regulating industries that generate spent catalysts in-view of encouraging the establishment of valorisation industries for metal and chemical recovery. This will also create a sustainable practice within state borders, and can reduce the environmental impact of landfilling such waste in Kuwait
An Examination of Celtic Craft and the Creative Consciousness as a Contribution to Marketing Creativity
Examination of the Celtic craft sector identifies a creative form of marketing which has its foundations in imagination, intuition and innovation, rather than the linear prescriptions of formal marketing frameworks and language which still dominate contemporary marketing management texts. The creative marketing competencies identified in the sector are also grounded within a wider creative marketing paradigm where experimental forms of marketing are encouraged, postmodern ideals are embraced and artistic philosophy and practice encouraged. The controlled Saxon influenced Marketing Establishment is challenged by the freer, more creative fringe of Celtic marketing as the avant garde
High-pressure rheological analysis of CO2-induced melting point depression and viscosity reduction of poly(ε-caprolactone)
High-pressure rheology has been used to assess the effects of supercritical carbon dioxide (scCO2) on the melting point (Tm) and viscosity of poly (ε-caprolactone) (PCL) over a range of temperatures and pressures up to 300 bar over a wide range of shear rates. Plots of the storage and loss moduli against temperature show a significant shift of Tm to lower temperatures in the presence of CO2, indicating that the polymer crystals melt at temperatures much lower than the ambient pressure Tm. Furthermore, a significant decrease in the viscosity of two PCL grades with different molecular weight (Mn ~ 10 kDa and 80 kDa) was also detected upon increasing the CO2 pressure to 300 bar. Experimental viscosity data were fitted to the Carreau model to quantify the extent of the plasticising effects on the zero-shear viscosity and relaxation time under different conditions. Similar analyses were conducted under high-pressure nitrogen, to compare the effects obtained in the presence of a non-plasticising gas
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