19 research outputs found

    A Novel Intelligent Control System Design for Water BathTemperature Control

    Get PDF
    Abstract: In this paper a neuro-fuzzy controller (NFC) for temperaturecontrol of a water bath system is proposed.A five layer neural network is used to adjust input and output parameters of membership function in a fuzzy logic controller. The hybrid learning algorithm is used for training this network. The simulation results show that the proposedcontroller has good set point tracking and disturbance rejectionproperties. Also it is robust against changes in the systemparameters. It is also superior to the conventional PID controller

    Evaluation and Variability of Flood-Oriented Health of Shiraz Darwazeh Quran Watershed from Watershed Management Structures

    Get PDF
    IntroductionCurrently, many disasters threaten the health of ecosystems. The pressures caused by extensive human interventions and the unprincipled exploitation of natural resources have led to the degradation of natural resources and the structure and functioning of ecosystems. Hence, evaluating the consequences of human intervention in nature and meeting the growing need of humans to receive diverse services has made it necessary to evaluate the performance of watershed ecosystems in providing different services. Healthy watersheds play an important role in providing a wide variety of ecosystem services. Therefore, watershed health monitoring and evaluation is vital for the conservation of ecosystems and achieving the optimal level of services. In such a way a suitable collaborative and executive approach is established between research and watershed management. In this connection, watershed health analysis can provide valuable help in achieving the goals of integrated management of watersheds and, of course, the balance between the needs of human societies and ecosystems. However, the assessment of the health and sustainability of the watershed affected by human activities has not been sufficiently documented yet.Materials and MethodsThe current pilot research has evaluated the health of the Shiraz Darwazeh Quran Watershed in Fars Province, Iran, and the effect of existing watershed management structures in the region on the health of the watershed with a focus on floods. For this purpose, 36 key criteria from a set of climatic, anthropogenic, and hydrologic factors were identified based on the conditions of the region and the analysis of the flood occurrence process in the watershed. The selected criteria were then categorized into the three indices of pressure (P), state (S), and response (R). After screening the selected criteria in exploring the conceptual approach of pressure, state, and response (PSR), the health status was evaluated in two cases with and without watershed management structures.Results and DiscussionThe results showed that the health condition without considering the watershed management structures was at average conditions with health index of 0.55. In addition, the results of the watershed health assessment verified the non-significant effects of stone and mortar structures on improving watershed health. So that, the health conditions was remained at average status with health index of 0.53. Therefore, it can be acknowledged that the existing watershed management structures, due to the limited both number and spatial coverage, have not been able to noticeably affect the improvement of the general conditions of the watershed, despite the effect on the factors affecting the health of the sub-watersheds where the structures have been constructed. The spatial changes of the calculated variables showed that the abandoned lands, time of concentration, area under military activities, surface of sensitive formations to erosion, high density of the drainage network, density of the roads, areas of regions with high potential in producing runoff and sediment, and size of the residential areas were the most important factors affecting the health situation of the Darwazeh Quran Watershed.ConclusionAccording to the results of the analysis of the indicators and criteria considered in evaluation of the health of the Shiraz Darwazeh Quran Watershed based on the PSR approach, it was found that the watershed had an average health status. Therefore, it can be acknowledged that the existing watershed management structures have not been able to impose a noticeable effect on the prosperity and improvement of watershed health conditions. In general, it can be said that abandoned lands, short concentration time, military activities, the presence of formations sensitive to erosion, high density of drainage network and road, and the potential of high runoff and sediment production, and the size of residential areas are among the most important factors affecting the declining the health of Darwazeh Quran Watershed. Therefore, it is necessary to pay further attention to the aforesaid factors by conducting periodical monitoring with more comprehensive data, in time and also analyzing the trend of relative changes of the indicators in order to explain the adaptive and intelligent management of the watershed. The necessary measures should also be taken into account simultaneously. Therefore, it is suggested to turn the weak points of the region into strong points by applying bioengineering measures and use the opportunities in the region such as the potential of tourism and ecological features in order to improve the health status of the watershed

    A Security Platform Using Software Defined Infrastructure

    No full text
    In this work, we designed an architecture for cloud network security, leveraging Software Defined Infrastructure, which enables centralized management of compute and networking resources. We show that utilizing SDIâ s service chaining and its Software Defined Networking approach, network security functions such as intrusion detection and prevention, as well as distributed firewalls can be realized as services in the cloud, as modeled in Network Function Virtualization. In our platform, protective resources are located as close as possible to the entity being protected. Furthermore, the design of the user-friendly interfaces for these services to be used is discussed, where the user traffic flows are associated with Enhanced Security Profiles, together forming Enhanced Security Groups. We also discuss our implemented proof-of-concept on SAVI testbed.M.A.S

    Corrosion Behavior of Amorphous-Nanocrystalline Ni50Ti50 Shape Memory Alloy

    No full text
    In the present study, the corrosion behaviors of amorphous-nanocrystalline Ni50Ti50 shape memory alloy with different crystallite sizes were investigated. The Ni50Ti50 homogenized specimens were hot rolled and annealed at 950°C. Thereafter, the nanocrystalline Ni50Ti50 specimens with different crystalline sizes in the range of 40-350 nm were prepared by cold rolling and annealing at temperature range of 400 to 900°C. The corrosion resistance of Ni50Ti50 specimen with coarse grain size has significantly increased after cold rolling as a result of the formation of amorphous-nanocrystalline structure. The amorphous and nanocrystalline (with the crystallite size of about 40 nm) Ni50Ti50 samples exhibited the best corrosion resistance in the 5% HCl electrolyte with the corrosion potential and corrosion current density of about –197 mV and 2.34×10-6 A/cm2, respectively. This effect can be attributed to the higher density of crystalline defects in amorphous and nanocrystalline structures to quickly form protective films on the surface

    Calculation of Mitral Valve Area in Mitral Stenosis: Comparison of Continuity Equation and Pressure Half Time With Two-Dimensional Planimetry in Patients With and Without Associated Aortic or Mitral Regurgitation or Atrial Fibrillation

    No full text
    Accurate measurement of Mitral Valve Area (MVA) is essential to determining the Mitral Stenosis (MS) severity and to achieving the best management strategies for this disease. The goal of the present study is to compare mitral valve area (MVA) measurement by Continuity Equation (CE) and Pressure Half-Time (PHT) methods with that of 2D-Planimetry (PL) in patients with moderate to severe mitral stenosis (MS). This comparison also was performed in subgroups of patients with significant Aortic Insufficiency (AI), Mitral Regurgitation (MR) and Atrial Fibrillation (AF). We studied 70 patients with moderate to severe MS who were referred to echocardiography clinic. MVA was determined by PL, CE and PHT methods. The agreement and correlations between MVA’s obtained from various methods were determined by kappa index, Bland-Altman analysis, and linear regression analysis. The mean values for MVA calculated by CE was 0.81 cm (±0.27) and showed good correlation with those calculated by PL (0.95 cm, ±0.26 ) in whole population (r=0.771, P<0.001) and MR subgroup (r=0.763, P<0.001) and normal sinus rhythm and normal valve subgroups (r=0.858, P<0.001 and r=0.867, P<0.001, respectively). But CE methods didn’t show any correlation in AF and AI subgroups. MVA measured by PHT had a good correlation with that measured by PL in whole population (r=0.770, P<0.001) and also in NSR (r=0.814, P<0.001) and normal valve subgroup (r=0.781, P<0.001). Subgroup with significant AI and those with significant MR showed moderate correlation (r=0.625, P=0.017 and r=0.595, P=0.041, respectively). Bland Altman Analysis showed that CE would estimate MVA smaller in comparison with PL in the whole population and all subgroups and PHT would estimate MVA larger in comparison with PL in the whole population and all subgroups. The mean bias for CE and PHT are 0.14 cm and -0.06 cm respectively. In patients with moderate to severe mitral stenosis, in the absence of concomitant AF, AI or MR, the accuracy of CE or PHT method in measuring MVA is nearly equal. But in the presence of significant AI or MR, PHT method is obviously superior to CE and in the presence of AF neither have sufficient accuracy

    Robust and General Model to Forecast the Heat Transfer Coefficient for Flow Condensation in Multi Port Mini/Micro-Channels

    No full text
    A general correlation for predicting the two-phase heat transfer coefficient (HTC) during condensation inside multi-port mini/micro-channels was presented. The model was obtained by correlating the two-phase multiplier, &phi;tp with affecting parameters using the genetic programming (GP) method. An extensive database containing 3503 experimental data samples was gathered from 21 different sources, including a broad range of operating parameters. The newly obtained correlation fits the broad range of measured data analyzed with an average absolute relative deviation (AARD) of 16.87% and estimates 84.73% of analyzed data points with a relative error of less than 30%. Evaluation of previous correlations was also conducted using the same database. They showed the AARD values ranging from 36.94% to 191.19%. However, the GP model provides more accurate results, AARD lower than 17%, by considering the surface tension effects. Finally, the effect of various operating parameters on the HTC was studied using the proposed correlation

    Robust and General Model to Forecast the Heat Transfer Coefficient for Flow Condensation in Multi Port Mini/Micro‐Channels

    Get PDF
    A general correlation for predicting the two‐phase heat transfer coefficient (HTC) during condensation inside multi‐port mini/micro‐channels was presented. The model was obtained by correlating the two‐phase multiplier, φtp with affecting parameters using the genetic programming (GP) method. An extensive database containing 3503 experimental data samples was gathered from 21 different sources, including a broad range of operating parameters. The newly obtained correlation fits the broad range of measured data analyzed with an average absolute relative deviation (AARD) of 16.87% and estimates 84.73% of analyzed data points with a relative error of less than 30%. Evaluation of previous correlations was also conducted using the same database. They showed the AARD values ranging from 36.94% to 191.19%. However, the GP model provides more accurate results, AARD lower than 17%, by considering the surface tension effects. Finally, the effect of various operating parameters on the HTC was studied using the proposed correlation

    Synthesis, microstructure, magnetic and electromagnetic behavior of graphene oxide/hexagonal barium ferrite aerogel nanocomposites within the frequency range of 1–18 GHz

    No full text
    The fabrication of lightweight graphene oxide aerogel (GOA) composites with barium ferrite (BF) nanoparticles is investigated in this study as a method of shielding electronic and telecommunication equipment from electromagnetic radiation. The effects of various weight percentages of barium ferrite nanoparticles on the microstructure, phase, magnetic characteristics, and wave absorption were investigated. The XRD, FTIR, Raman spectroscopy, X-ray Photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC), FESEM, and vibrational magnetometry (VSM) and the vector network analyzer (VNA) were used to characterize the sample.Results show that barium ferrite nanoparticles had a saturation magnetization of 42.94 emu/g, whereas graphene oxide aerogel composite containing 67 wt% of barium ferrite nanoparticles had a saturation magnetization of 29 emu/g. The Coercivity of the composite rose when the amount of barium ferrite nanoparticles was reduced. Within the matched frequency of 12.1 GHz and an effective absorption bandwidth (RL < −10 dB) of 2.6 GHz, the graphene aerogel nanocomposite sample with a thickness of 4 mm and 40 wt% of barium ferrite nanoparticles had the highest level of reflection loss (−43 dB)

    Cholesterol Transporters ABCA1 and ABCG1 Gene Expression in Peripheral Blood Mononuclear Cells in Patients with Metabolic Syndrome

    No full text
    ABCA1 and ABCG1 genes encode the cholesterol transporter proteins that play a key role in cholesterol and phospholipids homeostasis. This study was aimed at evaluating and comparing ABCA1 and ABCG1 genes expression in metabolic syndrome patients and healthy individuals. This case-control study was performed on 36 patients with metabolic syndrome and the same number of healthy individuals in Hamadan (west of Iran) during 2013-2014. Total RNA was extracted from mononuclear cells and purified using RNeasy Mini Kit column. The expression of ABCA1 and ABCG1 genes was performed by qRT-PCR. Lipid profile and fasting blood glucose were measured using colorimetric procedures. ABCG1 expression in metabolic syndrome patients was significantly lower (about 75%) compared to that of control group, while for ABCA1 expression, there was no significant difference between the two studied groups. Comparison of other parameters such as HDL-C, FBS, BMI, waist circumference, and systolic and diastolic blood pressure between metabolic syndrome patients and healthy individuals showed significant differences (P<0.05). Decrease in ABCG1 expression in metabolic syndrome patients compared to healthy individuals suggests that hyperglycemia, related metabolites, and hyperlipidemia over the transporter capacity resulted in decreased expression of ABCG1. Absence of a significant change in ABCA1 gene expression between two groups can indicate a different regulation mechanism for ABCA1 expression
    corecore