ABSTRACT:The permeabilities of isoniazid and amitriptyline hydrochloride in chitosan membranes were investigated. Drug concentration was changed from 0.1 to 1.0% while membrane thickness was varied from 40 to 150 m. The release rate was measured in water at 30 Ϯ 0.1°C by spectrophotometric determination. The drugs presented quite different permeabilities, which were related to their molecular weights; the permeabilities did not change with thickness or drug concentration for the ranges investigated.

Chitosan membranes were manufactured and used in the study of diffusion of aqueous potassium chloride solution. Diffusion was found to be outside the Fickian regime, this deviation being correlated with possible changes in the membrane structure during the experiments as well as to the occurrence of osmosis. © 2001 Society of Chemical Industry

No abstract

Nowadays we are witnessing a significant increase in the amount of IoT devices and the volume of data generated by these devices. Associated with this, more IoT applications have ultra low latency and response time requirements, such that cloud-centric IoT platforms are unable to address these requirements and to adequately handle the increasing volume of data. To support these new applications and handle the increasing volume of IoT data, Fog Computing platforms have been proposed. The Fog Computing paradigm is characterized by a horizontal, system-level architecture where devices that are in the path of IoT data, from its origin in IoT devices to the cloud, are used for processing distribution, storage, and data control. Fog Computing platforms aim to abstract the highly dynamic and heterogeneous environment where they are inserted, in order to facilitate the development of applications by users. This chapter has the following objectives: (i) to present the Fog Computing paradigm; (ii) to survey and discuss the main requirements that guide the development of Fog Computing platforms; (iii) to discuss two proposals of reference architecture for Fog Computing; (iv) to describe the main Fog Computing platforms and contrast them with the requirements previously raised; (v) to demonstrate in a practical way the use of a Fog Computing platform for the context of smart cities. Resumo Atualmente presenciamos um aumento significativo na quantidade de dispositivos IoT e no volume de dados gerados por estes dispositivos. Associado a isto, cada vez mais aplicações IoT possuem requisitos de latência e tempo de resposta ultra baixo, de tal forma que as plataformas IoT centradas na nuvem não conseguem endereçar estes requisitos e tão pouco tratar de maneira adequada o volume crescente de dados. Para suportar estas novas aplicações e tratar o volume crescente de dados IoT, plataformas que empregam

Many technologies are needed to build computational systems in the context of Smart Cities. At present, the construction of scalable, intelligent and ubiquitous systems is a constant challenge for developers. The evolution of the Internet of Things is one of the several paths to be pursued with the aid of this development. In this way, new models and platforms have been proposed to support the development of its applications. Allied to this challenge this work presents a generic and a conceptual model of an IoT application for Smart Parking. This model is implemented as RFID and RaspberryPi. In addition, it evaluates the ThingSpeak cloud service for its use as an IoT platform.