830 research outputs found

    Pyrrolizine-5-carboxamides: Exploring the impact of various substituents on the anti-inflammatory and anticancer activities

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    Towards optimization of the pyrrolizine-5-carboxamide scaffold, a novel series of six derivatives (4a-c and 5a-c) was prepared and evaluated for their anti-inflammatory, analgesic and anticancer activities. The (EZ)-7-cyano-6-((4-hydroxybenzylidene)amino)-N-(p-tolyl)-2,3-dihydro-1H-pyrrolizine-5-carboxamide (4b) and (EZ)-6-((4-chlorobenzylidene)-amino)-7-cyano-N-(p-tolyl)-2,3-dihydro-1H-pyrrolizine-5-carboxamide (5b) bearing the electron donating methyl group showed the highest anti-inflammatory activity while (EZ)-6-((4-chlorobenzylidene)amino)-7-cyano-N-phenyl-2,3-dihydro-1H-pyrrolizine-5-carboxamide (5a) was the most active analgesic agent. Cytotoxicity of the new compounds was evaluated against the MCF-7, A2780 and HT29 cancer cell lines using the MTT assay. Compounds 4b and 5b displayed high anticancer activity with IC50 in the range of 0.30–0.92 µmol L–1 against the three cell lines, while compound (EZ)-N-(4-chlorophenyl)-7-cyano-6-((4-hydroxybenzylidene)-amino)-2,3-dihydro-1H-pyrrolizine-5-carboxamide (4c) was the most active against MCF-7 cells (IC50 = 0.08 µmol L–1). Both the anti-inflammatory and anticancer activities of the new compounds were dependent on the type of substituent on the phenyl rings. Substituents with opposite electronic effects on the two phenyl rings are preferable for high cytotoxicity against the MCF-7 and A2780 cells. COX inhibition was suggested as the molecular mechanism of the anti-inflammatory activity of the new compounds while no clear relationship could be observed between COX inhibition and anticancer activity. Compound 5b, the most active against the three cell lines, induced dose-dependent early apoptosis with 0.1–0.2 % necrosis in MCF-7 cells. New compounds showed promising drug-likeness scores while the docking study revealed high binding affinity to COX-2. Taken together, this study highlighted the significant impact of the substituents on the anti-inflammatory and anticancer activity of pyrrolizine-5-carboxamides, which could help in further optimization to discover good leads for the treatment of cancer and inflammation

    Defect Signal Analysis For Nondestructive Testing Assesment

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    For fast assessment of defects in conductive materials, Eddy current testing is a most widely non-destructive testing (NDT) evaluation methods utilized in industry, especially in oil and gas, aircraft, nuclear and coating industries. Experimental studies of eddy current testing have emerged as an important approach alongside numerical modelling. This paper focus on investigating the defect signal characteristics of carbon steel pipe weld coating inspection using different frequency eddy current testing. The optimum frequency of carbon steel pipe weld coating is verified. Tests have been conducted utilizing positive and negative scanning method with frequency between 10 kHz to 100 kHz. Artificial defect use of this test is the horizontal affected zone (HAZ), centre line and transverse crack. Experimental results showed the frequency can be impression to the amplitude and phase angle eddy current testing signal. The optimum frequency for carbon steel weld plate is 100 kHz

    Determination of Critical Overload Transmission Line Using Novel Maximum Power Line Stability Index

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    Recent years, a larger number of DG’s are being employed especially at the critical load ends to reduce the burden on the main feeder. One of the benefits of employing DG that it improves the system voltage stability even with load increment. The primary focus of this paper rests on creating a novel line voltage stability index. The line stability index approach is proposed based on Thevenin theory to gauge the DG level impact on transmission line. Transmission issues due to the overloading of lines in high DG penetration areas during the outage scenarios taking place earlier. The rationale for the proposed strategy will be experimented on a standard IEEE 30 bus test system compared with other line voltage stability indexes

    Hybrid of Eddy Current Probe Based on Permanent Magnet and GMR Sensor

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    The eddy current testing (ECT) is used to inspect a material to determine its properties without destroying its utility. The applications include detection of flaws in aircrafts, pipeline, etc. An ECT is a weak sensitivity to a subsurface defect. Applications of giant magnetic sensors (GMR) are increasingly applied to the measurement of weak magnetic fields related to the currents they cause. In this paper, GMR sensor with magnet bar (permanent) is utilized. The proposed probe system is utilized to study the impact of the width and depth defect on the signal of eddy current testing. The maximum depth of flaw in a mild steel can be revealed by using this probe. The graph of the difference between the peak amplitude and the penetration depth of each slot of a different width of the two bands of mild steel shows the increase of the signal for each slot and flat above 3mm. The experimental result proves the inability of a PMGMR probe to detect a defect at a depth of 3mm on a surface defect

    Gas Turbine Configuration for Improving the performance of Combined Cycle Power Plant

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    AbstractThe thermodynamic analysis of combined cycle gas turbine with effect different configuration for gas turbine are presented and discussed in this paper. The effects of ambient temperature and compression ratio have been proposed to select optimum configuration for gas turbine and its effect on CCGT performance. The analysis performance code has been performed used the MATLAB software. The simulating code for gas turbine configuration results show that the simple gas turbine configuration is more suitable with regards to power output, but the regenerative gas turbine configuration has higher efficiency with effect ambient temperature. The simple gas turbine configuration has higher power output with effect the compression ratio, while the regenerative gas turbine configuration has higher efficiency with effect lower compression ratio, therefore the variation of total power output is insignificance at lower compression ratio. The extensive modelling performed in this study reveals that, the ambient temperature and compression ratios are strongly influence on the performance of combined cycle, a higher overall efficiency can be achieved for combined cycle with add regenerative to topping cycle

    Hybrid particle swarm optimization for robust digital image watermarking

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    This paper presents an image watermarking algorithm for the optimization between robustness and transparency which is recently considered as one of the most challenging issues. The novelty is to associate the Hybrid Particle Swarm Optimization (HPSO), instead of a single optimization, as a model with singular value decomposition (SVD). To embed and extract the watermark, the singular values of the blocked host image are modified according to the watermark and scaling factors. A series of training patterns are constructed by employing between two images. Moreover, the work takes accomplishing maximum robustness and transparency into consideration. HPSO method is used to estimate the multiple parameters involved in the model. Simulation results demonstrated that the proposed scheme can effectively improve the quality of the watermarked image and resist common image manipulations such as adding noise, resizing compression, tempering, etc. and some geometric attacks

    Hybrid of Eddy Current Probe based on Permanent Magnet and GMR Sensor

    Get PDF
    The eddy current testing (ECT) is used to inspect a material to determine its properties without destroying its utility. The applications include detection of flaws in aircrafts, pipeline, etc. An ECT is a weak sensitivity to a subsurface defect. Applications of giant magnetic sensors (GMR) are increasingly applied to the measurement of weak magnetic fields related to the currents they cause. In this paper, GMR sensor with magnet bar (permanent) is utilized. The proposed probe system is utilized to study the impact of the width and depth defect on the signal of eddy current testing. The maximum depth of flaw in a mild steel can be revealed by using this probe. The graph of the difference between the peak amplitude and the penetration depth of each slot of a different width of the two bands of mild steel shows the increase of the signal for each slot and flat above 3mm. The experimental result proves the inability of a PMGMR probe to detect a defect at a depth of 3mm on a surface defect

    Optimized Load Balancing based Task Scheduling in Cloud Environment

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    The fundamental issue of Task scheduling is one important factor to load balance between the virtual machines in a Cloud Computing network. However, the optimal broadcast methods which have been proposed so far focus only on cluster or grid environment. In this paper, task scheduling strategy based on load balancing Quantum Particles Swarm algorithm (BLQPSO) was proposed. The fitness function based minimizing the makespan and data transmission cost. In addition, the salient feature of this algorithm is to optimize node available throughput dynamically using MatLab10A software. Furthermore, the performance of proposed algorithm had been compared with existing PSO and shows their effectiveness in balancing the load

    Differential evolution optimization algorithm based on generation systems reliability assessment integrated with wind energy

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    Generating systems are said to be adequately reliable when they can satisfy the load demand. Meanwhile, the reliability of electrical systems is currently being influenced by the increasing acceptance of "Wind Energy Conversion System" (WECS) in power systems compared to other conventional sources. This stuffy proposed a novel optimization method labeled the "Differential Evolution Optimization Algorithm" (DEOA) to assess the reliability of power generation systems (PGS). The DEOA technique is used to improve the assessment of the reliability and adequacy of the generation systems by incorporating wind energy from a WECS. The basis of DEOA is the meta- heuristic searching used to simulate the generation systems operation and considering the random failures of existing systems and the unstable character of WECS- sourced wind energy. The effectiveness of the suggested algorithm to assess the reliability and adequacy of power generation systems with WECS was demonstrated. Additionally, the efficiency of the planned algorithm in numerical simulation was compared to that of the "Monte Carlo simulation" (MCS)

    Adaptive Dynamic Inverse Controller for Advanced Coupled Tank Liquid Levels System

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    Inversion technique has been successfully applied in the tracking control of many Multi Input Multi Output (MIMO) process of engineering as well as science. The difficulty in controller design on account of variations in process dynamics as well as interactions between process variables. In this paper, the combination of neural network and dynamic inversion control is applied in Coupled Tank System (CTS) tracking water level problem. The liquids need to be pumped in total process and stored in the two tanks which are coupled together for certain desired level. Transfer function matrix of the system is gained experimentally from the tension loop response of the system. The PID neural network (PID-NN) controller used as a desired system control. Within MATLAB environment, conduction of simulate experiment is to testify the operation of the system according to Settling Time, Rise Time, Steady State Error and Overshoot. Numerical simulations and experiments have both been conducted to prove the validity of the proposed method. It has been attested that capabilities of CTS are ameliorated by suggested proposed method
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