Reactivity of aluminum sulfate and silica in molten alkalimetal sulfates in order to prepare mullite

With the aim of preparing mullite, reactions between aluminum sulfate and silica in appropriate proportions and molten sulfate media M2SO4 (M=Na and/or K) were performed at different temperatures. The powders obtained were characterized by XRD, FT-IR, SEM and TEM. The reactivity was the same in Na2SO4 and (K,Na)2SO4 media. The best results in terms of yield (98.3%) and weight of mullite produced (95%) were obtained in Na2SO4 at 950 °C. The mullite phase exhibits an acicular morphology (75×0.75 μm) and a specific surface area close to 20 m2/g. In K2SO4 medium, a potassium alumino silicate is formed as well as mullite

Synthesis of CoAl2O4 by double decomposition reaction between LiAlO2 and molten KCoCl3

Submicronic CoAl2O4 powders were prepared by double decomposition reaction between solid LiAlO2 and molten KCoCl3 at 500 ◦C for 24 h. The reaction mechanism involves the dissolution of LiAlO2 shifted by the precipitation of CoAl2O4 until complete transformation and the reaction leads to powders with a very homogeneous chemical composition. The powders obtained were mainly characterized by XRD, FTIR, ICP, X.EDS, electron microscopy and diffraction and diffuse reflexion. The blue pigments obtained exhibit a high thermic stability allowing their use for the colouring of ceramic tiles

Blockchain & Multi-Agent System: A New Promising Approach for Cloud Data Integrity Auditing with Deduplication

Recently, data storage represents one of the most important services in Cloud Computing. The cloud provider should ensure two major requirements which are data integrity and storage efficiency. Blockchain data structure and the efficient data deduplication represent possible solutions to address these exigencies. Several approaches have been proposed, some of them implement deduplication in Cloud server side, which involves a lot of computation to eliminate the redundant data and it becomes more and more complex. Therefore, this paper proposed an efficient, reliable and secure approach, in which the authors propose a Multi-Agent System in order to manipulate deduplication technique that permits to reduce data volumes thereby reduce storage overhead. On the other side, the loss of physical control over data introduces security challenges such as data loss, data tampering and data modification. To solve similar problems, the authors also propose Blockchain as a database for storing metadata of client files. This database serves as logging database that ensures data integrity auditing function

Efficient Method Based on Blockchain Ensuring Data Integrity Auditing with Deduplication in Cloud

With the rapid development of cloud storage, more and more cloud clients can store and access their data anytime, from anywhere and using any device. Data deduplication may be considered an excellent choice to ensure data storage efficiency. Although cloud technology offers many advantages for storage service, it also introduces security challenges, especially with regards to data integrity, which is one of the most critical elements in any system. A data owner should thus enable data integrity auditing mechanisms. Much research has recently been undertaken to deal with these issues. In this paper, we propose a novel blockchain-based method, which can preserve cloud data integrity checking with data deduplication. In our method, a mediator performs data deduplication on the client side, which permits a reduction in the amount of outsourced data and a decrease in the computation time and the bandwidth used between the enterprise and the cloud service provider. This method supports private and public auditability. Our method also ensures the confidentiality of a client's data against auditors during the auditing process

A New Protection for Android Applications

Today, Smartphones are very powerful, and many of its applications use wireless multimedia communications. Prevention from the external dangers (threats) has become a big concern for the experts these days. Android security has become a very important issue because of the free application it provides and the feature which make it very easy for anyone to develop and published it on Play store. Some work has already been done on the android security model, including several analyses of the model and frameworks aimed at enforcing security standards. In this article, we introduce a tool called PermisSecure that is able to perform both static and dynamic analysis on Android programs to automatically detect suspicious applications that request unnecessary or dangerous permissions

A study of retrograde degeneration of median nerve forearm segment in carpal tunnel syndrome of variable severities

Introduction: Carpal tunnel syndrome (CTS) is a disorder of the hand which results from compression of the median nerve within its fibro-osseous tunnel at the wrist. The slowing in the forearm motor conduction velocity suggests the presence of retrograde degeneration. Existing studies conflict regarding a correlation between the severities of the entrapment neuropathy in CTS and slowing of median motor nerve conduction velocity in the forearm.Aims: The objective of this work was to study retrograde degeneration (RGD) of the median nerve forearm segment in patients with CTS and its relation to variable severity of CTS in Egyptian patients.Patients and methods: Twenty-four patients with CTS were included in this study. The Forearm mixed nerve conduction is presumed to be indicative of the conduction of the median nerve over the forearm and is used widely to assess the causes of slowing forearm conduction velocity in CTS. In addition to conventional nerve conduction studies of the upper limb, forearm median mixed conduction studies were performed. Median motor forearm amplitudes and nerve conduction velocities (NCVs) as well as forearm median mixed amplitudes and NCVs were considered as parameters of RGD. Results: There were statistically significant differences as regards forearm mixed nerve action potential (MNAP) amplitude and median motor amplitude in the forearm segment but there were no statistically significant differences as regards forearm median mixed peak latency and NCV. There was no statistically significant relation between grades of severities of CTS in the studied hands and both forearm median motor NCV and forearm MNAP amplitude using Monte Carlo test (MCp = 0.323 and 0.464).Conclusions: Retrograde degeneration exists in patients with CTS. Forearm median motor NCV and median mixed conduction study are valid electrophysiologic tools for the assessment of RGD in patients with CTS. Retrograde degeneration is not related to grade of severity of CTS.KEYWORDS Carpal tunnel syndrome; Electrodiagnosis; Forearm median mixed study; Retrograde degeneratio

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Fuzzy Logic based Intrusion Detection System against Black Hole Attack in Mobile Ad Hoc Networks

A Mobile Ad hoc NETwork (MANET) is a group of mobile nodes that rely on wireless network interfaces, without the use of fixed infrastructure or centralized administration. In this respect, these networks are very susceptible to numerous attacks. One of these attacks is the black hole attack and it is considered as one of the most affected kind on MANET. Consequently, the use of an Intrusion Detection System (IDS) has a major importance in the MANET protection. In this paper, a new scheme has been proposed by using an Adaptive Neuro Fuzzy Inference System (ANFIS) and Particle Swarm Optimization (PSO) for mobile ad hoc networks to detect the black hole attack of the current activities. Evaluations using extracted database from a simulated network using the Network Simulator NS2 demonstrate the effectiveness of our approach, in comparison to an optimized IDS based ANFIS-GA