The Effects of Aqueous Extracts of Echium Amoenum and Citrus Aurantiflia on Blood Pressure and Heart Rate before and after phynelephrine Injection in Rat

Abstract: Background & Aims: Echium amoenum and Citrus aurantifolia are used in traditional medicine for the treatment of cardiac arrhythmia and regulation of blood pressure. In this study the effects of co-administration of these herbs on heart rate and blood pressure of rats before and after phynelephrine injection were investigated. Methods: Ten groups of rats respectively received 100, 200, 400 and 600 mg/kg Echium Amoenum, 250 mg/kg Citrus Aurantiflia and combination of 250 mg/kg Citrus Aurantiflia with 100, 200, 400 and 600 mg/kg Echium Amoenum for 6 days. Control group received water. Blood pressure and heart rate before and after phynelephrine injection were measured and compared among groups. Results: Echium amotnum at 400 and 600 mg/kg dozes significantly increased blood pressure of rats in comparison to the control group (P<0.05) and this effect was more significant after phynelephrine injection (P<0.05). Echium amoenum in combination whit citrus aurantiflia decreased heart rate after phynelephrine injection and also in comparison to the control group. This decreasing effect was more than the effect of 6.688 mg/kg phynelephrine (P<0.05). Conclusion: Since Echium amoentum has an increasing effect on blood pressure especially in higher blood pressures, it is not suggested for those with hypertension. Co-administration of Echium amoentum and Citrus aurantiflia is recommended for decreasing heart rate. Keywords: Blood pressure, Heart rate, Echium, Citrus aurantifoli

Load Frequency Control for Hydropower Plants using PID Controller

Many development republics began to get rid of conventional energy and towards to use renewable energy like hydropower system, solar cells and wind turbines as soon as possible. Load Frequency Control (LFC) problem is coming to be the main topics for mentioning schemes due to not corresponding between main power system inputs such as change load demand and change in speed turbine settings. This paper illustrates a selftuning control of hydropower system that suggested and confirmed under Automatic Generation Control (AGC) in power scheme. The suggested power system involves one single area. The suggested self-tuning control system is employed in performing the automatic generation control for load frequency control request and compared it with conventional control structure. The power system dynamic modeling has regularly built in several essential parameters which have a significant influence According to frequency limitation. The main problem with all controllers is an exaggerated reaction to minor errors, producing the system to oscillate. The output response results for hydropower system obviously proved the benefit of using maximum load demand by tuning PID controller. Whereas, tuning PID controller has got properly more rapid output response and minimal overshoot

Nanocrystalline Nickel Oxide (NiO) Thin Films Grown on Quartz Substrates: Influence Of Annealing Temperatures

In the present investigation, nanocrystalline NiO thin films were prepared by thermal oxidation annealing of DC magnetron sputtered Ni thin films on quartz substrates. The effect of annealing temperature on the films structural, morphological and optical properties was investigated. The XRD analysis shows that all prepared films were of NiO with cubic structure and (200) orientation. The thickness of NiO films was in range of 40-100 nm. The average crystallite size is found to increase from 16 to 36 nm and the optical band gap energy decreases from 3.62 to 3.38 eV by increasing the annealing temperature from 400 • C to 600 • C. The AFM and SEM results show that the annealing temperature effectively influences the surface morphology of the films

In vitro activities of tetracyclines against different clones of multidrug-resistant Acinetobacter baumannii isolates from two Iranian hospitals.

Acinetobacter baumannii has emerged as one of the most challenging healthcare-related pathogens and its occurrence has increased worldwide, especially in patients admitted to intensive care units. A. baumannii isolates are frequently resistant to multiple antimicrobial agents and there are recent reports of isolates resistant to virtually all clinically relevant drugs. In the present study, the in vitro activities of tigecycline, minocycline and doxycycline against 67 MDR-AB isolates recovered from 29 burn and 38 non-burn Iranian patients hospitalised in Tehran and Tabriz, respectively, were studied. Tigecycline and minocycline may be still considered effective therapeutic options for MDR-AB infections. However, ongoing monitoring of A. baumannii susceptibility to these antibiotics is required

CFD analysis of wind blocking vs. venturi effect: a case study in tropical climate

Wind catchers are structures used for natural ventilation using the two basic principles of stack effect and wind induced natural ventilation and has recently attracted a lot of attention due to relying only on the free sustainable energy of wind and hence being able to reduce energy expenditure and greenhouse gas emission to a considerable amount. Even though this structures have been used for thousands of years in Iran and other regions of the Middle East but due to the low temperature difference between the indoor and outdoor in hot and humid climates these structures have not been used. However by the finding that stack ventilation has negligible effect on the ventilation compared to wind induced ventilation, hopes have arisen to provide comfort and high ventilation rates by high air exchange rates. Venturi shaped roof as one of the most effective way of producing driving force for ventilation is studied in this paper. A specific venturi shaped roof in University of Putra Malaysia was considered and a case study and CFD simulations were performed. The results showed that the venturi effect could be seen in the specific roof and hence a correct choice of ventilation technique and design has been applied for this case. Even though the results are optimistically stated and further studies and validation is required but could be a good initiation towards more efficient use of sustainable energy sources

Photovoltaic Grid-Connected Modeling and Characterization Based on Experimental Results

A grid-connected photovoltaic (PV) system operates under fluctuated weather condition has been modeled and characterized based on specific test bed. A mathematical model of a small-scale PV system has been developed mainly for residential usage, and the potential results have been simulated. The proposed PV model based on three PV parameters, which are the photocurrent, IL, the reverse diode saturation current, Io, the ideality factor of diode, n. Accuracy of the proposed model and its parameters evaluated based on different benchmarks. The results showed that the proposed model fitting the experimental results with high accuracy compare to the other models, as well as the I-V characteristic curve. The results of this study can be considered valuable in terms of the installation of a grid-connected PV system in fluctuated climatic conditions

Five Parameter PV Model Extraction and Improvement Based on Experimental Data

This paper presents a new approach of the single diode five parameters model extraction and performance evaluation. The proposed model is capable of analytically describing the I–V and P–V characteristics of a PV module in different conditions. The PV parameters identify, mainly, the accuracy of any PV model. The proposed model constructed in a method to be in a sounds level of accuracy and far from complication. In term of accuracy, different evaluation criteria have being used in this study, and results of all criteria showed merit level of accuracy comparison to those in the compared models. In addition, the performance of the five parameters has been improved and this improvement showed in the I–V and P–V characteristics. Effect of these five parameters on all of the maximum power point (MPP), short circuit current (Isc), and open circuit voltage (Voc) also showed in the results. The outcomes of this study could help in improving the total PV system performance and could be a guide for method of extraction the five parameters model, since it dependent mainly on real results

Solar Cell Parameters Extraction Based on Single and Double-Diode Models: A Review

This paper comprehensively describes and discusses the extraction of the DC parameters of solar cells by mathematical techniques based on single-diode and double-diode models. The main parameters of interest are the photocurrent, Iph, the reverse diode saturation current, Io, the ideality factor of diode, n, the series resistance, RS, and the shunt resistance, RSh. This paper reviews the foremost issues of the condition of the methodologies of the extraction of PV solar cell parameters. This paper classifies the reviewed models on the basis of the number of extracted parameters and provides specific comments for each model. Five parameters from different models that have identical attributes are characterized with respect to irradiance and temperature to demonstrate the behavior and characteristics of these parameters. In addition, this article implements two real models, single-diode and double-diode models, and examines the performance of the PV parameters for each model and its effect on the current–voltage (I–V) and power–voltage (P–V) characteristics. Furthermore, to assess the accuracy of each model with respect to the data provided by the manufacturer, this paper compares the I–V and P–V curves at standard test condition (STC) and for different parameters for a generic PV panel

Harmonic Distortion in an Off-Grid Renewable Energy System with Different Loads

This paper is started by discussed and compare the structures of three linear controller namely PI, PID, PR and RC controllers in order to reach the control of renewable energy systems. And continue by implementation of a PID controller with PWM inverter for controlling a single phase off-grid renewable energy system. The analysis includes dynamic response, voltage harmonic distortion and current harmonic distortion for different resistive and inductive loads. The system is simulated using Matlab Simulink and simulation results demonstrate the different effects of renewable energy systems on voltage and current waveform with different loads

Synthesis of Nickel-Doped TiO₂ Thin Films and Their Structural and Optical Properties at Different Annealing Temperatures

Titanium oxide (TiO₂) and nickel-doped TiO₂ thin films were deposited onto glass substrates by reactive DC magnetron sputtering technique at different oxygen contents. Then, prepared films were annealed at temperatures of 300 and 500°C. Influence of O₂/Ar ratio, nickel doping and annealing temperature on structural, morphological and optical properties of TiO₂ thin films were studied and discussed. The XRD analysis results have confirmed the amorphous nature of the films. The results show that increase of annealing temperature and oxygen content in argon-oxygen gas mixture have lead to an increase of films transparency. By doping the TiO₂ with nickel the optical band gap energy has slightly decreased. AFM analysis results have shown that the surface morphology of films is effectively influenced by annealing temperature