Nanostructured mesoporous carbon as electrodes for supercapacitors

Symmetrical carbon/carbon double layer capacitors (EDLCs) were fabricated employing nanostructured mesoporous nongraphitized carbon black (NMCB) powders and their EDLC behavior was studied using electrochemical techniques viz., cyclic voltammetry, a.c.-impedance, and constant current cycling. Rectangular shape cyclic characteristics were observed indicating the double layer behavior of the NMCB carbon electrodes. The mechanism of double layer formation and frequency dependent capacitance were deduced from the ac-impedance analysis. Specific capacitance, power density and energy density were derived from constant current charge/discharge measurements. NMCB powders demonstrated a specific capacitance of about ∼39 F g−1 and the power density of 782 W kg−1 at a current density of 32 mA cm−2. Nevertheless, at a low current density (3 mA cm−2), the specific capacitance of ∼44 F g−1 was achieved, which corroborates with the values obtained by means of ac-impedance (40 F g−1) and cyclic voltammetry (41.5 F g−1). The test cells demonstrated the stable cycle performance over several hundreds of cycles

Smart Irrigation Employing Direct Root Watering

This paper proposes implementation an automated irrigation system using which the watering is carried out bypassing the top soil and directly irrigating to the root zone of the plant. This system makes use of a soil moisture sensor that monitors the moisture content of the plant’s root zone continuously and compares it with the previously set values as threshold. Monitoring the soil moisture sensor readings, water is supplied only to the root area of the plant. Zigbee modules are used to facilitate the wireless communication of remote sensor with the controller and increase the flexibility of the system. The system design eliminates the loss of water before reaching the root zone that is absorbed by the top soil and makes a system well suitable for dry and drought prone areas

Recent development in spinel cobaltites for supercapacitor application

Precious metal oxides exhibit impressive characteristics that caught worldwide attention due to their promising capacitive performance, excellent electrochemical stability and low resistance, and these metal oxides have been extensively employed in supercapacitor application. This type of supercapacitors is known as redox supercapacitors or pseudocapacitors which applied faradaic process in storing energy in their systems. Thus, new materials with impressive electrochemical performance are highly demanded. In this aspect, cobaltite system with spinel structure has been the subject of intense research due to its established applications in electrochemistry. Besides, carbonaceous materials like activated carbons, carbon nanotubes, graphites, graphenes and fullerenes utilize electric double-layer capacitance whereby energy is stored by charge separation at an electrode/electrolyte interface. With greater development conducted on metal oxides and carbonaceous materials for supercapacitor application, introduction of hybrid and composite electrodes comprise of these two types of materials have been well received

Emulated Control System for a Nuclear Reactor

This paper discusses some of the instrumentation aspects of process control system developed for a nuclear power plant. Monitoring and controlling are the essential elements in the normal, abnormal and emergency operation of nuclear power plant. Through their sensors and transmitters, control systems measure process variables and inturn to control valves, motors and other electromechanical equipments of the nuclear plant. In this context, we have developed a Labview based such control system aimed at developing a real time system to deploy via IoT(Internet of Things). We represent here our conceptual design developed in Labview platform integrated with Arduino Uno microcontroller. The instrumentation and control system measures basic physical parameters like level, temperature and pressure using sensors. The monitoring and control of the temperature is done using virtual instrument software LabView, which acts as data acquisition module. It monitors performance and helps in controlling the nuclear plant operations to keep the process variables within the plant design limits and ensures the plant safety. The transmission of data from one end to another end is done through wireless technology ZigBee, to monitor and analyzeplant processes and equipment on the Labview platform

Non-Destructive Oil-Gas Pipeline Corrosion Monitoring

This paper proposes an in-line corrosion monitoring of oil-gas pipeline and evaluating the associated risks in minutes through real time data logging. The rapid changes in the resistive layer of the steel pipeline when it gets corroded are taken in account. When corrosion begins, thickness of the material of the pipeline decreases. The current passing through the layer varies and hence the potential. This change in the potential is measured and processed so that the control station is alerted about the progressive changes and necessary measures are taken to solve the issue. The proposed work saves the economic loss by preventing the digging of the whole area. It implies a kind of non-destructive approach. This is a long time process and whenever the system finds some rapid changes in the rate of corrosion, an alert is made so that it can facilitate in taking necessary measures to control the situation

Radio Frequency Energy Harvesting and Management for Wireless Sensor Networks

Radio Frequency (RF) Energy Harvesting holds a promising future for generating a small amount of electrical power to drive partial circuits in wirelessly communicating electronics devices. Reducing power consumption has become a major challenge in wireless sensor networks. As a vital factor affecting system cost and lifetime, energy consumption in wireless sensor networks is an emerging and active research area. This chapter presents a practical approach for RF Energy harvesting and management of the harvested and available energy for wireless sensor networks using the Improved Energy Efficient Ant Based Routing Algorithm (IEEABR) as our proposed algorithm. The chapter looks at measurement of the RF power density, calculation of the received power, storage of the harvested power, and management of the power in wireless sensor networks. The routing uses IEEABR technique for energy management. Practical and real-time implementations of the RF Energy using Powercast harvesters and simulations using the energy model of our Libelium Waspmote to verify the approach were performed. The chapter concludes with performance analysis of the harvested energy, comparison of IEEABR and other traditional energy management techniques, while also looking at open research areas of energy harvesting and management for wireless sensor networks.Comment: 40 pages, 9 figures, 5 tables, Book chapte

Transport of small anionic and neutral solutes through chitosan membranes: Dependence on cross-linking and chelation of divalent cations

Chitosan membranes were prepared by solvent casting and cross-linked with glutaraldehyde at several ratios under homogeneous conditions. The cross-linking degree, varying from 0 to 20%, is defined as the ratio between the total aldehyde groups and the amine groups of chitosan. Permeability experiments were conducted using a side-by-side diffusion cell to determine the flux of small molecules of similar size but with different chemical moieties, either ionized (benzoic acid, salicylic acid, and phthalic acid) or neutral (2-phenylethanol) at physiological pH. The permeability of the different model molecules revealed to be dependent on the affinity of those structurally similar molecules to chitosan. The permeability of the salicylate anion was significantly enhanced by the presence of metal cations commonly present in biological fluids, such as calcium and magnesium, but remained unchanged for the neutral 2-phenylethanol. This effect could be explained by the chelation of metal cations on the amine groups of chitosan, which increased the partition coefficient. The cross-linking degree was also correlated with the permeability and partition coefficient. The change in the permeation properties of chitosan to anionic solutes in the presence of these metallic cations is an important result and should be taken into consideration when trying to make in vitro predictions of the drug release from chitosan-based controlled release systems

Design of Regenerative Braking System and Energy Storage with Supercapacitors as Energy Buffers

Vehicles are part of urban area transport and are subjected to variable loads as they traverse the city with varying slopes and stop-and-go traffic. Electric Vehicles (EVs) can be a good option because of their high efficiency under stop-and-go conditions and ability to gain energy from braking. However, limited battery energy makes EVs less efficient and degrades their lifetime. In contrast to a Li-Ion battery, supercapacitors work well under high power charge and discharge cycles. However, their high cost and low energy density prevent them from being viable replacements for batteries. Due to the slow charging and discharging process of batteries, they have a low power density, but a high energy density compared to the supercapacitor. In this paper, we discussed our system design consisting of both a battery and a supercapacitor. The main aim is to design and develop a scheduling algorithm to optimize energy flow between the battery, supercapacitor, and motor. We further described an analogue-based control methodology and algorithm for the supercapacitor, augmented battery-powered motoring process. This is in addition to a charge controller designed to optimize the supercapacitor bank's current-based charge-discharge profile. The system design and tests are developed on PSPICE and a hardware platform

Advanced Technologies for Oral Controlled Release: Cyclodextrins for oral controlled release

Cyclodextrins (CDs) are used in oral pharmaceutical formulations, by means of inclusion complexes formation, with the following advantages for the drugs: (1) solubility, dissolution rate, stability and bioavailability enhancement; (2) to modify the drug release site and/or time profile; and (3) to reduce or prevent gastrointestinal side effects and unpleasant smell or taste, to prevent drug-drug or drug-additive interactions, or even to convert oil and liquid drugs into microcrystalline or amorphous powders. A more recent trend focuses on the use of CDs as nanocarriers, a strategy that aims to design versatile delivery systems that can encapsulate drugs with better physicochemical properties for oral delivery. Thus, the aim of this work was to review the applications of the CDs and their hydrophilic derivatives on the solubility enhancement of poorly water soluble drugs in order to increase their dissolution rate and get immediate release, as well as their ability to control (to prolong or to delay) the release of drugs from solid dosage forms, either as complexes with the hydrophilic (e.g. as osmotic pumps) and/ or hydrophobic CDs. New controlled delivery systems based on nanotechonology carriers (nanoparticles and conjugates) have also been reviewed