1,094 research outputs found
Nonequilibrium phase transitions and stationary state solutions of a three-dimensional random-field Ising model under a time dependent periodic external field
Nonequilibrium behavior and dynamic phase transition properties of a kinetic
Ising model under the influence of periodically oscillating random-fields have
been analyzed within the framework of effective field theory (EFT) based on a
decoupling approximation (DA). Dynamic equation of motion has been solved for a
simple cubic lattice () by utilizing a Glauber type stochastic process.
Amplitude of the sinusoidally oscillating magnetic field is randomly
distributed on the lattice sites according to bimodal and trimodal distribution
functions. For a bimodal type of amplitude distribution, it is found in the
high frequency regime that the dynamic phase diagrams of the system in
temperature versus field amplitude plane resemble the corresponding phase
diagrams of pure kinetic Ising model. Our numerical results indicate that for a
bimodal distribution, both in the low and high frequency regimes, the dynamic
phase diagrams always exhibit a coexistence region in which the stationary
state (ferro or para) of the system is completely dependent on the initial
conditions whereas for a trimodal distribution, coexistence region disappears
depending on the values of system parameters.Comment: 11 pages, 11 figure
Effective field theory analysis of 3D random field Ising model on isometric lattices
Ising model with quenched random magnetic fields is examined for single
Gaussian, bimodal and double Gaussian random field distributions by introducing
an effective field approximation that takes into account the correlations
between different spins that emerge when expanding the identities. Random field
distribution shape dependencies of the phase diagrams and magnetization curves
are investigated for simple cubic, body centered and face centered cubic
lattices. The conditions for the occurrence of reentrant behavior and
tricritical points on the system are also discussed in detail.Comment: 13 pages, 8 figure
Modeling and Experimental Investigation of Laminar Ceiling Air Distribution System for Operating Room in Merjan Teaching Hospital
Room air distribution in operating rooms is critical to successful surgical treatment. The present study investigated the effects of the location of the air supply and exhaust grills on the air movement and air parameters inside an operating room. This paper presents an experimental and numerical analysis of air distribution in the operating room. The experimental work was conducted in an operating room in Merjan Teaching Hospital in the city of Babylon. Air was supplied from one square plenum box located in the middle of the ceiling, while air was exhausted through eight grills: large exhaust grills in the four upper corners and small exhaust grills in the four lower corners. In the theoretical work, a model of the operating room was developed and two cases were analyzed using the FLUEN 6.3.26 software program. The first case included all eight exhaust grills, while the second case included only the four lower exhaust grills. The ceiling system gave good ventilation for air distribution inside the operating room. There was no clear effect of the small exhaust grills located in the upper corners of the operating room. The height of the ceiling room is an effective factor in air distribution
Variable structure based control strategy for treatment of HCV infection
Hepatitis C is such a harmful disease which can lead to serious health problems and it is caused by the Hepatitis C Virus (HCV) which causes liver inflammation and sometimes liver cancer. In this work, the control treatment strategy for HCV infection has been proposed. The advanced nonlinear dynamical mathematical model of HCV that has two control inputs and three state variables such as virions, infected hepatocytes and uninfected hepatocytes are considered for controller design in this research work. Moreover, four nonlinear controllers such as the Fractional Order Terminal Sliding Mode Controller (FOTSMC), Integral Terminal Sliding Mode Controller (ITSMC), Double Integral Sliding Mode Controller (DISMC) and Integral Sliding Mode Controller (ISMC) have been proposed in this work for HCV infection control inside the human body. In order to control the amount of uninfected hepatocytes to its required maximum safe limit, controllers are designed for antiviral therapy in which the amount of virions and infected hepatocytes are tracked to zero. One control input is ribavirin which blocks virions production and the other is pegylated interferon (peg-IFN-a) that acts as reducing infected hepatocytes. By doing so, uninfected hepatocytes increase and achieve the required maximum safe limit. To prove the stability of the whole system, Lyapunov stability analysis is used in this work. Simulation results and comparative analysis are carried out by using MATLAB/Simulink. It can be depicted from the given results that the virions and infected hepatocytes are reduced to their required levels completely using FOTSMC and the Sustained Virologic Response (SVR) rate is also enhanced in it. It reduces the treatment period as compared to previous strategies introduced in the literature and also system behaves very nicely even in the presence of un-modeled disturbances
Variable Structure-Based Control for Dynamic Temperature Setpoint Regulation in Hospital Extreme Healthcare Zones
In critical healthcare units, such as operation theaters and intensive care units, healthcare workers require specific temperature environments at different stages of an operation, which depends upon the condition of the patient and the requirements of the surgical procedures. Therefore, the need for a dynamically controlled temperature environment and the availability of the required heating/cooling electric power is relatively more necessary for the provision of a better healthcare environment as compared to other commercial and residential buildings, where only comfortable room temperature is required. In order to establish a dynamic temperature zone, a setpoint regulator is required that can control the zone temperature with a fast dynamic response, little overshoot, and a low settling time. Thus, two zone temperature regulators have been proposed in this article, including double integral sliding mode control (DISMC) and integral terminal sliding mode control (ITSMC). A realistic scenario of a hospital operation theater is considered for evaluating their responses and performance to desired temperature setpoints. The performance analysis and superiority of the proposed controllers have been established by comparison with an already installed Johnson temperature controller (JTC) for various time spans and specific environmental conditions that require setpoints based on doctors’ and patients’ desires. The proposed controllers showed minimal overshoot and a fast settling response, making them ideal controllers for operation theater (OT) zone temperature control
Local and regional factors influencing zooplankton communities in the connected Kasseb Reservoir, Tunisia
Associations between zooplankton community structure and abiotic (temperature, dissolved oxygen, turbidity, nutriments) and biotic factors (chlorophyll a and phytoplankton community) were examined, in Kasseb Reservoir, northern Tunisia. Samples were taken bimonthly from July to December 2002 at 3 sampling stations (deepest station: Station 1, Brik River: Station 2 and M’Zaz Stama River: Station 3). From our results it is evident that zooplankton exhibit seasonally and spatially heterogeneous distribution. The highest density of zooplankton was recorded in September at a depth of 5 m (10.8 × 103 ind·l-1). At Station 1 cyclopoid copepods (65% of total abundance) were the most abundant group followed by Cladocera (21% of total abundance). At Station 2 (93% of total abundance) and Station 3 (98% of total abundance) cyclopoid copepodswere numerically dominant throughout the study period. Canonical correspondence analysis (CCA) was used to estimate the influence of abiotic and biotic factors in structuring the zooplankton assemblage. Zooplankton abundance was negatively correlated with turbidity (r= -0.381,
Isolation and identification of phenolic compounds from Eugenia caryophyllus and study on its biological effect against Macrophomina phaseolina
Clove is one of the oldest and most famous spices. Its seeds resemble nails. It is used in medicinal fields, but its fungicidal activity is unknown. The aim of the study was to test the inhibitory activity of phenolic extracts of cloves against the pathogenic fungus Macrophomina phaseolina. The research was conducted under laboratory conditions to test the inhibitory ability of Eugenia caryophyllus phenolic extracts on the fungus M. phaseolina, which was partially diagnosed on strawberry plants based on Polymerase chain reaction (PCR) technique, in addition to its morphological and microscopic characteristics. The active compounds present The active compounds (Chlorogenic acid, Qurcetine, Gallic acid, Apigenin, Caffeic acid, Ferulic acid, Kaempferol, Rutin, Catechine) present in the extract of Industrial Methylated Spirit (IMS) separated from cloves were determined using High-performance liquid chromatography (HPLC). and active compounds of IMS phenols) Qurcetine, Apigenin, Ferulic acid, Kaempferol. (The inhibitory effect of phenols extracted from E. caryophyllus against M. phaseolina was tested. The results showed that the acetone extract and acetone phenols, which were used at concentrations of 10 and 15 mg/ml in PDA medium, had a significant effect on the growth of the fungus by 100%, as these fungi failed to grow. Formation of spores on Peptone dextrose medium (PDA) medium. While the percentage of inhibition of acetone phenols was 25% at a concentration of 5 mg/ml. As for the IMS extract and IMS phenols, it had a significant effect on the growth of the fungus at all concentrations used, but with different inhibition ratios, which increased directly with increasing concentration of the extract.
Design and implement WSN/IoT smart parking management system using microcontroller
With the dramatic expansion of new networks such as Wireless Sensor Network (WSN) and Internet-of-Things (IoT), tremendous opportunities have been emerged to incorporate such technologies for valuable tasks. One of these tasks is the smart car parking where there is an imperative demand to manage the parkings in various facilities which may help drivers to save their time. Several research studies have addressed this task using wide range of approaches. However, the energy consumption is still a serious concern. This paper proposes a smart car parking based on cloud-based approach along with variety of sensors. Passive Infrared Sensors (PIRs) have been used to sense the object motion. While Light Dependent Resistor (LDR) sensors have been utilized to sense the light of the parking alarm and display inmformation regarding the occupied and non-occupied parking lots. Finally, multi-micro controller of Arduino have been exploited in order to transmit the information collected to the server. Finally, a prototype Android application has been developed in order to recieve the infromation from the server. Results of simulation showed the efficacy of the proposed method
Copolymerazaion of N-vinyl-2-pyrrolidon with Acrylic Acid and Methylmethacrylate
Low conversion copolymerization of N-vinyl-2-pyrrolidon M.W = (111.14) VP (monomer-1) has been conducted with acrylic acid AA and methymethacrylate MMA in ethanol at 70ºC , using Benzoyl peroxide BPO as initiator . The copolymer composition has been determined by elemental analysis. The monomer reactivity ratios have been calculated by the Kelen-Tudos and Finman-Ross graphical procedures . The derived reactivity ratios (r1 , r2 ) are : (0.51 , 4.85) for (VP / AA ) systems and (0.34 , 7.58) for (VP , MMA) systems , and found the reactivity ratios of the monomer AA , MMA is mor than the monomer VP in the copolymerization of (VP / AA) and (VP /MMA) systems respectly . The reactivity ratios values were used for microstructures calculation
Design and implementation home security system and monitoring by using wireless sensor networks WSN/internet of things IOT
The dramatic advancments on communication and networking technologies have led to the emergence of Internet-of-Things (IoT). IoT technology has opened the door for various applications. In particular, the home automation was one of the common applications that took the advantage of IoT. Several research efforts have addressed the home automation system using IoT covering wide range of functionalities. One of the concerning tasks is providing a secure system that can give alarms for suspicious activities within the house. This paper presents a secure house system based on IoT where several activities are being sensed and detected. Specifically, gas, humidity, body temperature and motion have been considered within the sensing based on two main types of micro-controller including Arduino and Raspberry Pi. Consequentially, an Android prototype has bene developed in order to give an interactive interface for warning the house owner regarding any suscpicious activities. Results of simulation demonstrated the efficancy of the proposed syste
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