979 research outputs found

    Diffraction Efficiency of Transient Grating and Relaxation Profiles of some Laser Dyes

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    Gas chromatography–mass spectrometry (GC-MS) analysis of antimicrobial compounds produced by mahua oil cake against the stem rot pathogen- Sclerotium rolfsii

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    The antifungal property containing oil cakes play a significant role in reducing plant disease in a wide range of soil-borne pathogens. A destructive soil-borne pathogen, Sclerotium rolfsii is infecting a vast range of crops worldwide. In-vitro efficacy of five different oil cakes viz. mahua cake, neem cake, pungam cake, coconut cake and castor cake extracts was tested against the stem rot pathogen of groundnut. Among the five different oil cakes, mahua oil cake extract produced the minimum mycelial growth of 1.57and1.29 cm at 5%, and 10% concentrations, respectively and showed maximum percent growth inhibition of 83.33and 86.66% respectively. Bioactive compounds in mahua oil cake were analyzed through GC-MS. From the result of GC-MS, the high retention time and peak area percentage were observed with major important bioactive compounds like n-Hexadecanoic acid (24.968) (12.22), Hexadecanoic acid, ethyl ester (23.655) (2.9), 9,12-Octadecadienoic acid (Z, Z)-(28.659)(35.61), 9-Octadecenoic acid, (E)-(28.786) (13.15), Octadecanoic acid (29.137) (33.59) and a1-Octyn-3-ol (3.023) (0.04).The bioactive compounds identified through GC-MS from mahua oil cake extract were found to be exhibiting antifungal activity against S. rolfsii

    Active LC Clamp dv/dt Filter for Voltage Reflection due to Long Cable in Induction Motor Drives

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    This paper presents an active LC clamped dv/dt filter to mitigate the over voltages appearing across the motor terminals. The over voltages at motor terminal is due to voltage reflection effect of long motor cable connected between high frequency PWM inverter having high dv/dt switching waveforms and ac motor drives. The voltage reflection due to fast switching transients can be reduced by increasing the rise time and fall time of inverter output voltage pulses. The most commonly available mitigating technique is a passive dv/dt filter between inverter and cable.  Since, size, cost and losses of passive LC dv/dt filter is more, an active dv/dt filtering technique is used to reduce over voltage at motor terminals. Active LC clamp filtering technique used here consists of a small LC filter designed for a single motor cable length which can be used for any lengths of cable up to 1000m only by changing the active control of the PWM pulses to achieve the desired voltage slope during voltage transition period. The basic principle of active dv/dt filer used here is to charge and discharge the capacitor in the filter with modified PWM pulses to increase the rise time and fall time of output voltage pulses without any extra devices to handle the transient response of the LC filter. Detailed investigation is carried out by simulation using MATLAB-Simulink software with active control of common LC clamp dv/dt filter suitable for various cable lengths ranging from 100 m to 1000 m. Comparative analysis is done with active dv/dt filter designed with a common LC clamp filter and active LC clamp dv/dt filter designed for various cable lengths and also with diode clamped passive dv/dt filter. The results proves the effectiveness of the active common LC dv/dt filter to mitigate the over voltages at motor terminal for cable lengths up to 1000m

    Phytochemicals characterization of nutraceutical enriched fruits and nuts spread

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    The present study aimed to formulate a nutraceutical enriched fruits and nuts spreads and analyze the presence of phytochemicals in the formulated spread. The pumpkin seeds and cucumber seeds were roasted at 150° C for 15 mins and made into powder. The seed powder was mixed to the pulp of ?-carotene rich fruits like mango, papaya and muskmelon in order to make fruits and nuts spread. Treatments like Mango with pumpkin seed powder (T1), Papaya with pumpkin seed powder (T2), Muskmelon with pumpkin seed powder (T3), Mango with cucumber seed powder (T4), Papaya with cucumber seed powder (T5) and Muskmelon with cucumber seed powder (T6). The fruits and nuts spreads were analyzed for the presence of phytochemicals ?-carotene, polyphenols, tannins, flavonoids and antioxidant activity. The formulated fruits and nuts spreads were packed in polypropylene boxes, glass bottles and stored under refrigerated condition at 4°C. ?-carotene content was found to be high (634.21?g/g) in Mango with Pumpkin seed powder spread (T1), tannin content was higher (52.61 mg/g) in Papaya with Pumpkin seed powder spread (T2), flavonoid components were higher (3.25 mg/g) in Mango with Pumpkin seed powder spread (T1), and polyphenols content were found to be high (59.33 mg/g) in Papaya with Cucumber seed powder spread (T5). The antioxidant property was high in the Mango with Pumpkin seed powder spread (T1) when compared to all other treatments. Pumpkin seeds comprised of excellent amount of bioactive compounds. The pumpkin seed incorporated spread showed a high level of phytochemicals when compared to other spreads. This was ready to eat spread which had 3 months of shelf life under refrigerated condition is preferred for people of all age groups

    Prediction of Tail-Off Pressure Peak Anomaly on Small-Scale Rocket Motors

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    Numerical studies intended to predict solid rocket motors anomalies are the major contributors when developing strategies to both limit expensive fire tests and to investigate and understand the physical phenomena from which anomalies can arise. This paper aims to present a mathematical–physical method to evaluate the pressure peak, namely Friedman Curl, occurring at the tail-off phase of small-scale rocket motors. Such phenomenon is linked to the grain solid particles arrangement (i.e., packing effect); indeed, those particles show a tendency to accumulate at a certain distance from the metallic case, implying a local burn rate increment and a combustion chamber pressure rise close to the tail-off phase. Comparisons between experimental and simulated combustion chamber pressure profiles are outlined to prove the effectiveness of the mathematical–physical approach. Simulations were carried out with an internal ballistic simulation tool developed by the authors of this work

    Domestic Dishwasher Simulated Energy Efficiency Evaluation Using Thermoelectric Heat Pump for Water Heating and Dish Drying

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    A quasi-steady state, coupled thermoelectric and heat transfer model heat and mass transfer lumped model was developed to predict the energy consumption and drying performance of domestic dishwashers. A numerical finite element solution was applied, assuming that the following components could each be treated as a lumped thermal capacitance: dish load, tub, wash water, and air in tub. The model was used to predict the energy consumption savings of heating water using a thermoelectric heat pump that extracts heat from the surrounding air, and the drying performance of circulating tub air through the cold and then hot side of TE modules

    Low Speed Estimation of Sensorless DTC Induction Motor Drive Using MRAS with Neuro Fuzzy Adaptive Controller

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    This paper presents a closed loop Model Reference Adaptive system (MRAS) observer with artificial intelligent Nuero fuzzy controller (NFC) as the adaptation technique to mitigate the low speed estimation issues and to improvise the performance of the Sensorless Direct Torque Controlled (DTC) Induction Motor Drives (IMD). Rotor flux MRAS and reactive power MRAS with NFC is explored and detailed analysis is carried out for low speed estimation. Comparative analysis between rotor flux MRAS and reactive power MRAS with PI as well as NFC as adaptive controller is performed and results are presented in this paper. The comparative analysis among these four speed estimation methods shows that reactive power MRAS with NFC as adaptation mechanism shows reduced speed estimation error and actual speed error at steady state operating conditions when the drive is subjected to low speed operation. Simulation carried out using MATLAB-Simulink software to validate the performance of the drive especially at low speeds with rated and variable load conditions

    Pathogenicity locus, core genome, and accessory gene contributions to Clostridium difficile virulence

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    Clostridium difficile is a spore-forming anaerobic bacterium that causes colitis in patients with disrupted colonic microbiota. While some individuals are asymptomatic C. difficile carriers, symptomatic disease ranges from mild diarrhea to potentially lethal toxic megacolon. The wide disease spectrum has been attributed to the infected host’s age, underlying diseases, immune status, and microbiome composition. However, strain-specific differences in C. difficile virulence have also been implicated in determining colitis severity. Because patients infected with C. difficile are unique in terms of medical history, microbiome composition, and immune competence, determining the relative contribution of C. difficile virulence to disease severity has been challenging, and conclusions regarding the virulence of specific strains have been inconsistent. To address this, we used a mouse model to test 33 clinical C. difficile strains isolated from patients with disease severities ranging from asymptomatic carriage to severe colitis, and we determined their relative in vivo virulence in genetically identical, antibiotic-pretreated mice. We found that murine infections with C. difficile clade 2 strains (including multilocus sequence type 1/ribotype 027) were associated with higher lethality and that C. difficile strains associated with greater human disease severity caused more severe disease in mice. While toxin production was not strongly correlated with in vivo colonic pathology, the ability of C. difficile strains to grow in the presence of secondary bile acids was associated with greater disease severity. Whole-genome sequencing and identification of core and accessory genes identified a subset of accessory genes that distinguish high-virulence from lower-virulence C. difficile strains

    Bio synthesis, Characterization of ZnO Nanoparticles from Scoparia dulcis L. plant extract and its in-vitro Antioxidant, Acetylcholinesterase Activity

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    The current investigation is focused on the use of green synthesis methods for zinc oxide nanoparticles (ZnO NPs) from Scoparia dulcis L. extract (SDE). SDE-mediated ZnO NPs (SDE-ZnO-NPs) were made using a simple and eco-friendly method that required little reaction time and calcinations temperature. UV-Vis, FTIR, X-ray powder diffraction, SEM, TEM & EDAX were used into characterizes the skeletal and synthetic properties concerning biosynthesized ZnO nonmaterial. The UV–Visible spectroscopy absorption peak for SDE-ZnO-NPs was found to be at 380 nm, confirming the production of ZnO NPs. The FTIR spectrum also revealed bioactive functional groups as well as metal-oxygen groups. Synthesized ZnO NPs had a rod shape in 200 nm, according to TEM examination. The Zn and O in the produced ZnO NPs were approved by the EDAX analysis. The XRD results revealed that it had a crystal structure that was similar to SDE-ZnO-NPs. The dose-related Acetylcholinesterase inhibitory action of SDE-ZnO NPs was determined utilizing the Ellman’s test. AChE activity of the synthesized nanoparticles showed potential inhibitory activity with IC50 values of 75.34 µg/mL. The antioxidant activity was investigated the biosynthesized ZnO-NPs using DPPH, ABTS assay
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