496 research outputs found

    Low Temperature Selective Catalytic Reduction (SCR) of NOx Emissions by Mn-doped Cu/Al2O3 Catalysts

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    The 15 mol% Cu/Al2O3 catalysts with different Mn doping (0.5, 1.0, 1.5, mol%) were prepared using PEG-300 surfactant following evaporation-induced self-assembly (EISA) method. Calcination of precursors were performed in flowing air conditions at 500 ÂșC. The catalysts were characterized by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscope Energy Dispersive X-Ray (SEM-EDX), Fourier Transform Infra Red (FTIR), and N2 physisorption. The catalysts activities were evaluated for H2 assisted LPG-SCR of NO in a packed bed tubular flow reactor with 200 mg catalyst under the following conditions: 500 ppm NO, 8 % O2, 1000 ppm LPG, 1 % H2 in Ar with total flow rate of 100 mL/min. Characterization of the catalysts revealed that surface area of 45.6-50.3 m2/g, narrow pore size distribution (1-2 nm), nano-size crystallites, Cu2+ and Mn2+ phases were principal active components. Hydrogen enhanced significantly selective reduction of NO to N2 with LPG over 1.0 mol % Mn-Cu/Al2O3 giving 95.56 % NO reduction at 150 ÂșC. It was proposed that the synergistic interaction between H2 and LPG substantially widened the NO reduction temperature window and a considerable increase in both activity and selectivity. Negligible loss of catalyst activity was observed for the 50 h of stream on run experiment at 150 ÂșC. The narrow pore size distribution, thermal stability of the catalyst and optimum Mn doping ensures good dispersion of Cu and Mn over Al2O3 that improved NO reduction in H2-LPG SCR system.

    A non destructive method to detect the incipient fault in rolling element bearing

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    It is essential to have prior warning of incipient fault (s) in any critical equipment occurring due to vibration. Vibration monitoring is good nondestructive technique to detect the fault of machines at an early stage. Capturing vibration signature of machines at slow speed is a difficult task due to impact of low energy, mostly absorbed by the structural path and falls much below the cut off frequency of the normally available accelerometer. To resolve the issue, a systematic proce-dure has been developed. It has the facility to break the signal in different level, envelope capturing and finally convert to frequency spectrum. The system has been tested under various operating condition that suits to industry to diagnose the problem of bearing. The method can predict the problem very well at its inception

    A Comparative Study on Shape Reorganization

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    This paper proposes a new mechanism for identifying two-dimensional shapes called the SKS algorithm and compares it with three other state-of-art methods in detail. These include the Hu Moments, CSS matching and Shape context. The algorithm uses the philosophy of evidence accumulation equal to generalized Hough transform and is highly parallel in nature. The performance of each algorithm is evaluated under affine transforms - translation, rotation in the plane, scale (zoom) and also under partial occlusion

    Neutron Structural Studies on the Superconducting (Nd₁₋ₓCax)(Ba₁.₆La₀.₄)Cu₃Oz System

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    We have investigated the influence of Ca ion substitution on the structural and superconducting properties of (Nd1−xCax)(Ba1.6La0.4)Cu3Oz system. Magnetization, x-ray diffraction, and neutron diffraction studies have been carried out on a series of compounds with x=0.0-0.6. The superconducting transition temperature Tc, determined from magnetization measurements, increases with increasing Ca2+ substitution. Neutron diffraction studies reveal that these compounds crystallize in a tetragonal structure (space group P4/mmm). A detailed analysis of the neutron diffraction data reveals that Ca and La ions are intermixed at the nominal Ba and Nd sites. While a major fraction of Ca ions occupy the usual Nd site, a small fraction occupies the Ba site. Consequently, the corresponding amount of La substitutes at the nominal Nd site. The intermixing of Ca and La sites randomizes the chain site oxygens leading to a tetragonal structure despite an oxygen content close to 7.0 for all the Ca doped samples. Further increase in Ca content leads to change in its coordination from sixfold to eightfold at x\u3e=0.4

    Neutron structural studies on the superconducting (Nd1-xCax)(Ba1.6La0.4)Cu3Oz system

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    We have investigated the influence of Ca ions substitution on the structural and superconducting properties of (Nd1-xCax)(Ba1.6La0.4)Cu3Oz system. Magnetization, X-ray diffraction and neutron diffraction studies have been carried out on a series of compounds with x = 0.0 to 0.6. The superconducting transition temperature Tc, determined from magnetization measurements increases with increasing Ca2+ substitution. Neutron diffraction studies reveal that these compounds crystallize in a tetragonal structure (space group P4/mmm). A detailed analysis of the neutron diffraction data reveals that Ca and La ions are intermixed at the nominal Ba and Nd sites. While a major fraction of Ca ions occupy the usual Nd site, a small fraction occupies the Ba site. Consequently, the corresponding amount of La substitutes at the nominal Nd site. The intermixing of Ca and La sites randomizes the chain site oxygens leading to a tetragonal structure despite an oxygen content close to 7.0 for all the Ca doped samples. Further increase of Ca content lead to change in its co-ordination from six-fold to eight-fold at x >= 0.4.Comment: 13 Pages, 5 Figure

    Detection of Defects on Cold Rolling Mill (CRM) Rolls with Ultrasonic and Eddy Current Flaw Dectors

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    The service induced defects in CRM rolls, due to them being subjected to complex mechanical & thermal stresses in cold rolling of steel strips or coils, if not removed completely during roll grinding, become primarily respo-nsible for roll spalling. The high instances of roll spalling lead to increased specific roll consumption and production delays. The inspection of some 15-20% of CRM work rolls with portable Ultrasonic and Eddy Current flaw detectors was undertaken to detect and remove the service induced defects on surface & sub-surface regions of rolls which would otherwise have remained undetected leading to roll spalling and other associated failures. The incid-ences of spalling has reduced by up to 38% during the period of roll inspection compared to the spalling incid-ences in the prior periods of time leading to prolonged uses of rolls. Although no reduction in Specific Roll Consumption (SRC) has been observed, the loss of useful roll materials due to reduced incidences of spalling has reduced. The reduced occurences of roll spalling have also resulted in savings of premature roll changing time lead-ing to increased mill availibility

    Therapeutic approaches to drug targets in atherosclerosis

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    AbstractNon-communicable diseases such as cancer, atherosclerosis and diabetes are responsible for major social and health burden as millions of people are dying every year. Out of which, atherosclerosis is the leading cause of deaths worldwide. The lipid abnormality is one of the major modifiable risk factors for atherosclerosis. Both genetic and environmental components are associated with the development of atherosclerotic plaques. Immune and inflammatory mediators have a complex role in the initiation and progression of atherosclerosis. Understanding of all these processes will help to invent a range of new biomarkers and novel treatment modalities targeting various cellular events in acute and chronic inflammation that are accountable for atherosclerosis. Several biochemical pathways, receptors and enzymes are involved in the development of atherosclerosis that would be possible targets for improving strategies for disease diagnosis and management. Earlier anti-inflammatory or lipid-lowering treatments could be useful for alleviating morbidity and mortality of atherosclerotic cardiovascular diseases. However, novel drug targets like endoglin receptor, PPARα, squalene synthase, thyroid hormone analogues, scavenger receptor and thyroid hormone analogues are more powerful to control the process of atherosclerosis. Therefore, the review briefly focuses on different novel targets that act at the starting stage of the plaque form to the thrombus formation in the atherosclerosis

    Approximate Multiplier based on Low power and reduced latency with Modified LSB design

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    The devised approximation multiplier can adapt the precision and processing power needed formul triplication sat run-time based on the needs of the user. To decrease error distance, we also suggest a straight forward error compensation circuit. There are two types of approximate multi pliers. Dynamic voltages caling can be used for the first kind, which controls the timing route of the multiplier. If the voltage is lower, the critical path will take longer to complete. As a result, when the time path is violated, errors occurs and approximated results are produced. These cond types involves redesigning precise multiplier circuits like the Wallace Tree Multiplier and Dadda Tree Multiplier in order to change the functional behaviors of multipliers. Most of the earlier research on rebuilding multipliers suggested erroneous m-n compressors, which have m inputs and producen outputs. It dynamically reduces the area covered under the multiplier LSB which enables the MSB in accurate manner and LSB in approximate manner. This convolution al system approach is regarded to sequential cover up more than 32 bit multiplier. Since the accompanied circuit reduce then tire area by10times lesser than original multiplier, this conventional unit is regarded as abled circuit in the segment. Since the process of compressing partial products absorbed the majority of the multiplier energy and resulted in a consider able route delay, these incorrect compressors were utilized to compress the partial products within multiplication. These functionality are over come through our experimental setup

    PE11, a PE/PPE family protein of Mycobacterium tuberculosis is involved in cell wall remodeling and virulence

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    The role of the unique proline-glutamic acid (PE)/proline-proline-glutamic acid (PPE) family of proteins in the pathophysiology and virulence of Mycobacterium tuberculosis is not clearly understood. One of the PE family proteins, PE11 (LipX or Rv1169c), specific to pathogenic mycobacteria is found to be over-expressed during infection of macrophages and in active TB patients. In this study, we report that M. smegmatis expressing PE11 (Msmeg-PE11) exhibited altered colony morphology and cell wall lipid composition leading to a marked increase in resistance against various environmental stressors and antibiotics. The cell envelope of Msmeg-PE11 also had greater amount of glycolipids and polar lipids. Msmeg-PE11 was found to have better survival rate in infected macrophages. Mice infected with Msmeg-PE11 had higher bacterial load, showed exacerbated organ pathology and mortality. The liver and lung of Msmeg-PE11-infected mice also had higher levels of IL-10, IL-4 and TNF-α cytokines, indicating a potential role of this protein in mycobacterial virulence
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