In this research, crosslinked Polyvinyl Alcohol (PVA)/Chitosan blends loaded with 1, 3, and 5 %w/w of nanoclay were synthesized to investigate its potential as membranes for CO2 separation. Elaborated membranes were characterized by using FTIR, water uptake, contact angle, porosity, and mechanical measurements. The separation capacity was evaluated through pure gases CO2 and N2 permeability tests. The addition of nanoclay caused a higher porosity and water absorption capacity, and better mechanical properties in the membranes. Moreover, the contact angle decreased, which signs the hydrophilic character of this material. The CO2 permeability increased with nanoclay addition, and the maximum CO2 permeability was reached for 1 %w/w nanoclay PVA-Chitosan membranes; the selectivity CO2/N2 also presented highest value with this nanoclay concentration.

Full Text

These days, water pollution is very common, due to industrial progress thus the abundance of pollutants such as fertilizers, dyes, heavy metal, petroleum oils and many other pollutants. Chitosan is a very promising material to be used as an adsorbent due to the presence of hydroxyl and amino groups in its molecules which contribute to the adsorption of Chitosan to various pollutants including dyes, phenols, ions, metals, pesticides and herbicides. In this research Chitosan is used to adsorb two different types of dyes which are Methylene Blue which is an anionic dye and Methyl Red which is a cationic dye. Effects of factors; initial solution pH, adsorbent dose, contact time and initial dye concentration were studied for both dyes. To obtain the best contact time at which the maximum removal efficiency reached its maximum value, the experiments were performed at different times and under the following fixed conditions; adsorbent dose = 2 g/L, initial dye concentration = 0.5 mg/L and pH = 4. The removal percentage of Methylene Blue and Methyl Red increased from 86.8 to 90.84 % and from 85.5 to 94.8 %, respectively with increasing in the contact time from 5 to 90 minutes. To obtain the best pH at which the Methylene Blue removal efficiency reached its maximum value, the experiments were performed at different levels of pH and under the following fixed conditions; optimum time 90 min, adsorbent dose 2 g/L and initial dye concentration of 0.5 mg/L. The removal efficiency of Methylene Blue and Methyl Red increased from 86.16 to 94.89 % and from 89.88 % to 91.6 %, respectively with increasing in the pH from 2 to 4. With further increase in the pH from 6 to 12, the removal efficiency for Methylene Blue and Methyl Red decreased from 93.61 to 88.08 % and from 4.7 to 74.1 %. To obtain the best initial concentrations for both of dyes at which the removal efficiency reached its maximum value, the experiments were performed at different levels of initial dye concentrations and under the following conditions; optimum time 90 min, optimum pH = 4 and adsorbent dose 2 g/L. The removal efficiency of Methylene Blue increased from 89.35 to 93.25 % with increasing in the initial dye concentration in range from 0.1 to 0.3 mg/L and with further increase in the initial dye concentration from 0.3 to 0.5 mg/L resulted in decreasing in the removal efficiency from 93.25 to 92.76 %. The removal efficiency of Methyl Red increased from 91.39 to 84.93 % with increasing in the initial Methyl Red concentration from 0.1 to 0.5 mg/L. To obtain the best adsorbent dose at which the removal efficiency reached its maximum value, the experiments were performed at different levels of adsorbent dose and under the following conditions; optimum time 90 min, pH = 4 and initial dye concentration of 0.3 mg/L. The removal efficiency of Methylene Blue and Methyl Red increased from 79.77 to 93.61 % and from 69.86 to 91.6%, respectively with increasing in the adsorbent dose from 0.25 to 2 g/L. The Methylene Blue and Methyl Red adsorption were well described by pseudo second order kinetic model (R2 value for both = 0.999) as it fitted with the experimental results of both dyes. The rate limiting step was determined using intra-particle diffusion model and Byod plot. For two parameters isotherm model; Freundlich and Halsey isotherms for Methylene Blue and Methyl Red R2 = 0.964 and 0.995, respectively were fitted with the experimental results. For three parameters isotherm; Koble-Corrigan isotherm where the less value of Sum of Squared Error (SSE) = 0.0001 is fitted with the experimental results of Methylene Blue more than Langmuir –Freundlich and Redlich-Peterson isotherms. While for Methyl Red; the best fitted Three-Parameter model with the experimental results was Koble-Corrigan isotherm with SSE = 0.006 lower that Langmuir-Freundlich and Redlich-Peterson isotherm models.

Full Text

An alternative approach to time delay estimation for the Bispectral Index (BIS) monitor is presented in this work. The practical implementation of the cross-correlation analysis (CCA) method is presented. The time delay estimation using windows and the robustness comparison between Peaks-Shift Correlation (PSC) and CCA methods are studied. Although both estimation methods are based on the correlation analysis, the time delay obtained with each one is different because the principle of the algorithms is different as well.

Full Text

In this work, two controllers, a Proportional Integral (PI) and a Model-based Predictive Controller (MPC), have been designed to regulate a DC/DC Buck converter. First, the modeling and linearization of the system was performed using a frequency response estimation method. Then the PI controller was designed around a certain setpoint. Next, an algorithm was designed according to the Extended Prediction Self-Adaptive Control (EPSAC). Finally, the performance of the controllers is evaluated for setpoint tracking and disturbance rejection.

Full Text

This paper presents the application of the Binary Firefly Algorithm (BFA) in tuning PID parameters for a coupled tank system. The agent position in the BFA represents the potential combination the PID parameters. This agent position is modeled using a string of 32 binary bits where the every eight bits represents the value of and respectively. represents the values of PID parameters. The first five bits represents the decimal value while the remaining are fraction value. The model of the coupled tank system is taken from well-established literature. The proposed approach is then implemented on the model that used a PID controller as the control mechanism. This study proposed a priority based fitness formulation where the agent will give priority to the following parameters in the given order: 1) Sum of Absolute Error (SAE); 2) Overshoot (OS); 3) Settling Time (ST), and Steady-State Error (SSE). The result discussed the effect of number of agent and number of iteration towards the performance of the proposed approach.

Full Text

In the last decade, the development of embedded on-chip SRAM memories has been radically increasing. The demand of on-chip processing and computations of data in wireless sensor networks (WSN) and Internet-of-Things (IoT) applications have been consistently increasing. This increased requirement influences the embedded on-chip Static Random Access (SRAM) memory to be vital and constantly improve the performance, stability and energy efficiency. The low power, high-performance and energy efficient SRAM has become a very important component in modern systems. In this research work, a Novel Low Power (NLP) FinFET based SRAM cell with 10T is proposed. The proposed cell is designed using 14 nm FinFET technology to reduce the power, read/write delay and improve the stability. The NLP cell has minimized 40% write power and 50% read power. In addition, 50% average delay has improved for write operations and 40% delay for read operations. The NLP cell is proved to be stable in worse conditions with temperature ranging from -50°C to 140°C and works for various VDD starting from 0.8V to 0.25V. Overall, the speed and stability have also improved in read operations due to three transistors. The read stability is improved 2.86x than the conventional cell because of the separate read circuit. The proposed NLP SRAM cell has also improved the read/write stability against the PVT (process, voltage, temperature) variations. It is also observed that the cell has 33.33% area overhead compared to 6T SRAM Cell.

Full Text

This work describes the development of a portable prototype of a CO2 level meter with set point applying IoT for hydrocarbon collection and treatment stations, developed to monitor the amount of CO2 that is present around its environment, through the use of any device that has internet connection. The following describes the development process at hardware and software level and the tests carried out to verify the correct equipment operation. Mention is also made of some technical details for the end user, which will facilitate the use of the equipment at the time of use.

Full Text

The major concerns of the policy and management of cities around the world is the reduction of emissions of air pollutants. The main challenges facing local decision-makers are climate change, population growth, pollution and rising energy costs. It should be noted that air pollution is one of the most complex environmental problems. Given the limited financial resources of most municipalities, the main objective of this paper is to provide a less costly decision support model for the assessment of air pollutant concentrations, particularly SO2. In our article "Using a statistic Approach: An Application for Assessing Concentration of Air Pollutants" published in 2019, we used the Six Sigma approach, in its "analysis" section, for the evaluation of the daily average of SO2 concentrations measured during the one-year period. The application of statistical tests made it possible to evaluate the compliance of this pollutant with the limit value set by the standards for the protection of the environment. In this article, we will propose as well a decision support approach based mainly on the statistical tools of the Six Sigma approach. The work is divided into two parts, in the first the SO2 indicator of the city of Casablanca is analyzed using superior capability, control charts, Bote à moustache. In the second part, we also used the six-sigma approach to compare the daily SO2 pollutant averages found in the city of Casablanca / Morocco and the city of Istanbul.

Full Text

The level of dissolved oxygen in water strongly affects the growth of organisms in aquaculture and profoundly affects economic in fishing industries. Continuing measure and monitor this level is very important. However, commercial sensors are expensive and not easy to apply to the aquaculture industries. Methods to measure the level of oxygen in the water have been developed long time ago using chemical, mechanical, and electrical principles. The optical principle has been recently utilized in this type of sensor in which Stern-Volmer law is used to estimate the quencher concentration. This work uses a very simple, low-cost, off-the-shelf MEMS visible spectrometer to measure the ratio of the intensity lights generated from the reaction when oxygen reacts to the fluorescent agents under excitation of the blue light. The sensor was built and tested against the commercial devices made by Extech (Model 407510). The heart of the sensor is the AS7262, a 6-Channel Visible Spectral ID Device made by AMS, and the fluorescent dye. Experimental results show a promising device which is very low cost, simple, low maintenance, and easy to use in the field to support aquaculture industries and environmental agencies.

Full Text

The evolution of the Internet of Things (IoT) over the last few years has a growing outcome, where LoRaWAN™ based solutions have a remarkable increase in its quality and innovation. This evolvement is pushing the integration of new capabilities, such as real-time responsiveness, resilient systems, massive management of devices, geolocation, tracking, and smarter notification systems. The current work presents a design and an implementation proposal of a LoRaWAN™ solution to monitor the probability of existing fire in a given location. This application is capable of integrating the above-mentioned features by exploiting the benefits of LoRaWAN™ protocol and its capability to interact with cloud services. The system makes use of The Thing Network (TTN) as LoRa™ Network Server (LNS), LoRa™ cloud Geolocation Services for tracking, Amazon Web Service Elastic Cloud Computing (AWS EC2) as a container of the application, and advanced features of Go programming language for the rest of features such as notifications, dashboards and data operations as extraction, transformation and load (ETL).

Full Text

The objective of this study is to analyze the feasibility of low-cost materials, which are adapted to commercial phantoms, used in quality and control in lung cancer treatments for radiotherapy. The studied materials are acrylic, three types of wood and ethylvinylacetate, obtaining computed tomography (CT) images with a Toshiba Asteion on two phantoms. One anthropomorphic thorax CIRS®, and another homogeneous acrylic cavity-plug type of the ArcCHECK® system under reference conditions clinic. Measurements of the Hounsfield units (HU), relative electron density (DE) and physical density (DF) were made. The radiation-matter interaction was also calculated with the MonteCarlo Monaco® (TPS) calculation algorithm, and finally the experimental measurement was carried out with the System PinPoint 3D 31016 dosimetric ionization chamber and PTW UNIDOS E T10010 electrometer, irradiating with an ELEKTA® Synergy linear accelerator under the calculation conditions, in order to compare the experimental and simulated conditions. As a result, the materials are discriminated according to their relevance to be used as a thorax simulator, finding that the wood of Ochroma pyramidale presents a value of HU, DE and DF approximated to the lung tissue. So it is dosimetrically viable as compatible material for the construction of phantoms of the thoracic region.

Full Text

Abstract:

The article discusses the problem that arises during the creation and processing of data containing spatial information, and describes the spatial-logical and topological relations between data elements when solving tasks of general planning. The use of topological rules makes it possible to improve the quality of the information available in the database and control it throughout the life cycle of the territory for construction, which largely ensures a reduction in the number of errors, the relevance and consistency of spatial information. It is proposed to use a multidimensional data model for storing spatial information about inter-object topological relations to solve the problem under consideration. Each matrix multidimensional data model (MDM) is the tuple of the set of objectives for which a specific spatial relation is determined. The study of this approach was carried out on test and real master plans of residential buildings. The advantages of using the method are obvious when solving problems of horizontal and vertical planning of a building area. Once formed and saved topological matrices between the elements of the general plan are saved in the database of the construction project, can be used to develop options for the layout of the situational plan of the construction site and are used at the operation stage. The complexity of the method at the initial stage and the high need for RAM indicate the need to use OLAP technology.

Full Text

Abstract:

The apparition of the novel SARS 2 or Covid-19 pandemic and its level of infectiousness as well as its status as a global pandemic have upset the human’s life. The difficulty of this disease is its rapid evolution through people contact. All means of development, transportation, communication, industrial, economic and social revolutions and the emergence of advanced urbanization have been affected by covid-19 pandemic. Moreover, in the absence of a vaccine, countries are forced to revolutionize their response and preparedness policies to health emergencies and compel themselves to the new global dynamic. Wireless sensor networks (WSNs), with a context-awareness sensing ability, can greatly improve the way such devices work, both in terms of its accuracy and efficiency. As it is known, WSNs are highly distributed self-organized systems which comprise a large number of resource constrained sensor nodes. This paper proposes a covid-19 context-aware WSN approach to detect affected persons of Covid-19, described by its architecture and different emerging cases.

Full Text