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

Experimental verification of trinary DC source cascaded H-bridge multilevel inverter using unipolar pulse width modulation

Multilevel inverters (MLIs) are an imperative solution for high power and high voltage applications. The MLIs can be classified into two categories such as symmetric and asymmetric. The asymmetric type MLIs has large number of output voltage steps with less number of input DC voltage sources and switching devices. In this paper, a single phase asymmetric (trinary sequence DC source) Cascaded H-Bridge MLI has been developed using unipolar PWM control schemes. The topology can produce 27-level output voltage with the help of 12 switches and 3 DC sources. It has been examined with a diverse combination of multicarrier unipolar PWM control. The PWM control includes Phase Disposition (PDPWM), Alternative Opposition Disposition (APODPWM), Carrier overlapping (COPWM), and Variable Frequency (VFPWM). The harmonic content of output voltage for each technique has been observed with different modulation indices. The demonstration of proposed topology for generating 27-level output voltage has been tested through simulation in MATLAB-SIMULINK and verified with laboratory-based experimental setup. From the results, it is evident that the APODPWM offers quality output voltage with relatively low harmonic distortion. Also, it has been observed that COPWM performance is superior since it delivers relatively higher fundamental RMS output voltage

Positioning and Surveying Requirements for Exploration and Exploitation of Ocean Wealth

Deep sea mining, such as is now being planned to be carried out in the Indian Ocean, requires an accurate positioning system for navigation and for the control of the equipment. Short range systems using electromagnetic principles cover only a limited area while the longer range systems which can be used for offshore, deep ocean work although covering large areas, have limited accuracy. This paper reviews the requirements for position fixing systems for deep ocean mining and the ways to reach the best solution at the most reasonable cost

Reconfiguration of Multilevel Inverter with Trapezoidal Pulse Width Modulation

This paper presents different multi-carrier unipolar trapezoidal pulse width modulation strategies for a reduced switch asymmetrical multilevel inverter. The different strategies are phase disposition, alternative phase opposition and disposition, and carrier overlapping and variable frequency that involve triangular waves as carriers with a unipolar trapezoidal wave as a reference. The reduced switch, asymmetrical multilevel inverter operation was examined for generating the seven-level output voltage using Matlab/Simulink 2009b and the results were verified with a real-time laboratory-based experimental setup using a field-programmable gate array. Different parameter analyses, such as total harmonic distortion, fundamental root mean square voltage, and distortion factor, were analyzed with different modulation indices to investigate the performance of the selected topology. Unipolar trapezoidal pulse width modulation provides a higher root mean square voltage value.publishedVersio

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

Processing and characterization of chitosan microspheres to be used as templates for layer-by-layer assembly

Chitosan (Ch) microspheres have been developed by precipitation method, cross-linked with glutaraldehyde and used as a template for layer-by-layer (LBL) deposition of two natural polyelectrolytes. Using a LBL methodology, Ch microspheres were alternately coated with hyaluronic acid (HA) and Ch under mild conditions. The roughness of the Ch-based crosslinked microspheres was characterized by atomic force microscopy (AFM). Morphological characterization was performed by environmental scanning electron microscopy (ESEM), scanning electron microscopy (SEM) and stereolight microscopy. The swelling behaviour of the microspheres demonstrated that the ones with more bilayers presented the highest water uptake and the uncoated cross-linked Ch microspheres showed the lowest uptake capability. Microspheres presented spherical shape with sizes ranging from 510 to 840 lm. ESEM demonstrated that a rougher surface with voids is formed in multilayered microspheres caused by the irregular stacking of the layers. A short term mechanical stability assay was also performed, showing that the LBL procedure with more than five bilayers of HA/Ch over Ch cross-linked microspheres provide higher mechanical stability

Biomaterials Approaches to Combating Oral Biofilms and Dental Disease

Background: Possibilities for biomaterials to impact the dental caries epidemic are reviewed with emphasis placed on novel delivery biomaterials and new therapeutic targets

Pine cone scale-inspired motile origami

Stimuli-sensitive hydrogels have received attention because of their potential applications in various fields. Stimuli-directed motion offers many practical applications, such as in drug delivery systems and actuators. Directed motion of asymmetric hydrogels has long been designed; however, few studies have investigated the motion control of symmetric hydrogels. We designed a pine cone scale-inspired movable temperature-sensitive symmetric hydrogel that contains Fe3O4. Alignment of Fe3O4 along the magnetic force is key in motion control in which Fe3O4 acts like fibers in a pine cone scale. Although a homogeneous temperature-sensitive hydrogel cannot respond to a temperature gradient, the Fe3O4-containing hydrogel demonstrates considerable bending motion. Varying degrees and directions of motion are easily facilitated by controlling the amount and alignment angle of the Fe3O4. The shape of the hydrogel layer also influences the morphological structure. This study introduced facile and low-cost methods to control various bending motions. These results can be applied to many fields of engineering, including industrial engineering.111Ysciescopu