943 resultados para Cymbopogon citratus (DC.) Stapf-Essential oil


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Intravenous immunoglobulin (IVIg) is widely used to treat autoimmune diseases. Several mutually nonexclusive mechanisms are proposed to explain the beneficial effects of IVIg in patients (1, 2). Lately, Ravetch and colleagues (3) demonstrate that anti-inflammatory activity of IVIg is mediated mainly by antibodies that contain terminal _2,6-sialic acid linkages at the Asn297-linked glycan of Fc region.

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This paper presents the programming an FPGA (Field Programmable Gate Array) to emulate the dynamics of DC machines. FPGA allows high speed real time simulation with high precision. The described design includes block diagram representation of DC machine, which contain all arithmetic and logical operations. The real time simulation of the machine in FPGA is controlled by user interfaces they are Keypad interface, LCD display on-line and digital to analog converter. This approach provides emulation of electrical machine by changing the parameters. Separately Exited DC machine implemented and experimental results are presented.

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In the education of physical sciences, the role of the laboratory cannot be overemphasised. It is the laboratory exercises which enable the student to assimilate the theoretical basis, verify the same through bench-top experiments, and internalize the subject discipline to acquire mastery of the same. However the resources essential to put together such an environment is substantial. As a result, the students go through a curriculum which is wanting in this respect. This paper presents a low cost alternative to impart such an experience to the student aimed at the subject of switched mode power conversion. The resources are based on an open source circuit simulator (Sequel) developed at IIT Mumbai, and inexpensive construction kits developed at IISc Bangalore. The Sequel programme developed by IIT Mumbai, is a circuit simulation program under linux operating system distributed free of charge. The construction kits developed at IISc Bangalore, is fully documented for anyone to assemble these circuit which minimal equipment such as soldering iron, multimeter, power supply etc. This paper puts together a simple forward dc to dc converter as a vehicle to introduce the programming under sequel to evaluate the transient performance and small signal dynamic model of the same. Bench tests on the assembled construction kit may be done by the student for study of operation, transient performance and closed loop stability margins etc.

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This thesis discusses the use of sub- and supercritical fluids as the medium in extraction and chromatography. Super- and subcritical extraction was used to separate essential oils from herbal plant Angelica archangelica. The effect of extraction parameters was studied and sensory analyses of the extracts were done by an expert panel. The results of the sensory analyses were compared to the analytically determined contents of the extracts. Sub- and supercritical fluid chromatography (SFC) was used to separate and purify high-value pharmaceuticals. Chiral SFC was used to separate the enantiomers of racemic mixtures of pharmaceutical compounds. Very low (cryogenic) temperatures were applied to substantially enhance the separation efficiency of chiral SFC. The thermodynamic aspects affecting the resolving ability of chiral stationary phases are briefly reviewed. The process production rate which is a key factor in industrial chromatography was optimized by empirical multivariate methods. General linear model was used to optimize the separation of omega-3 fatty acid ethyl esters from esterized fish oil by using reversed-phase SFC. Chiral separation of racemic mixtures of guaifenesin and ferulic acid dimer ethyl ester was optimized by using response surface method with three variables per time. It was found that by optimizing four variables (temperature, load, flowate and modifier content) the production rate of the chiral resolution of racemic guaifenesin by cryogenic SFC could be increased severalfold compared to published results of similar application. A novel pressure-compensated design of industrial high pressure chromatographic column was introduced, using the technology developed in building the deep-sea submersibles (Mir 1 and 2). A demonstration SFC plant was built and the immunosuppressant drug cyclosporine A was purified to meet the requirements of US Pharmacopoeia. A smaller semi-pilot size column with similar design was used for cryogenic chiral separation of aromatase inhibitor Finrozole for use in its development phase 2.

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The aim of this study was to look at the freedom of ordinary people as they construct it. The scope, however, was limited to contemporary Finnish sailors and their freedom discourses. The study belongs to the field of the anthropology of religions, which is part of comparative religion. Worldview, which is one of the key concepts in comparative religion, provided the broader theoretical basis of the study. The data consisted of 92 interviews with Finnish professional seafarers conducted in 1996, 1999, 2000 and 2005, field journals that were written during two periods of fieldwork in 1996 and 1999-2000, and correspondence with some of the seafarers during 1999-2005. The analysis process incorporated new rhetoric and metaphor theory. The thesis is in three parts. The first part discusses the methodological challenges of this type of ethnography, the second an ethnography of modern Finnish shipworld focuses on work, organization, hierarchy and gender, and the third part discusses the freedom concepts of seafarers. It was found that seafarers use two kinds of freedom discourse. The first is in line with the stereotypical Jack Tar, a free-roving sailor who is not bound to land and its mundane routines, and the second views shipworld as freedom from freedom, meaning one is not responsible for one s own actions because one is not free to make a choice. It was also found that seafarers are well aware of the stereotypical images that are attached to their profession: they not only deny them, but also utilize, reflect on and construct them.

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In view of its non-toxicity, and good dielectric properties, castor oil, a polar liquid dielectric of vegetable origin is suggested as a possible alternative to PCB's for capacitor applications. In this paper the dielectric properties (including partial discharge behavior), of all-polypropylene and paper-polypropylene capacitors with castor oil as impregnant, are reported. The paper also contains results of life studies conducted under accelerated electrical and thermal stresses when they are occurring both individually and combined. The data obtained have been statistically analyzed and approximate life of the system calculated bylinear extrapolation.

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Thyristor forced commutated AC/DC convertors are useful for improving the power factor and waveform of AC-side line current. These are controlled through pulse-width modulation schemes for best performance. However, the 3-phase versions impose restrictions on the PWM strategies that can be implemented for excellent harmonic rejection. This paper presents new PWM control strategies for the 3-phase converters and compares them along with the conventional 4-pulse PWM strategy for harmonic elimination. Finally, two new PWM strategies are shown to be the best, for which oscillograms are presented from actual implementation.

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The electric field in certain electrostatic devices can be modeled by a grounded plate electrode affected by a corona discharge generated by a series of parallel wires connected to a DC high-voltage supply. The system of differential equations that describe the behaviour (i.e., charging and motion) of the conductive particle in such an electric field has been numerically solved, using several simplifying assumptions. Thus, it was possible to investigate the effect of various electrical and mechanical factors on the trajectories of conductive particles. This model has been employed to study the behaviour of coalparticles in fly-ash corona separators.

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Several new liquids impregnants for capacitors have been suggested as possible alternatives to PCB'S which are being replaced in view of their harmful effects.The application of castor oil, a vegetable product, has been studied in the authors laboratary with the same obejective.

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The fatty acid composition of ground nuts (Arachis hypogaea L.) commonly known as peanuts, is an important consideration when a new variety is being released. The composition impacts on nutrition and, importantly, self-life of peanut products. To select for suitable breeding material, it was necessary to develop a rapid, non-derstructive and cost-efficient method. Near infrared spectroscopy was chosen as that methodology. Calibrations were developed for two major fatty-acid components, oleic and linoleic acids and two minor components, palmitic and stearic acids, as well as total oil content. Partial least squares models indicated a high level of precision with a squared multiple correlation coefficient of greater than 0.90 for each constitutent. Standard errors for prediction for oleic, linoleic, palmitic, stearic acids and total oil content were 6.4%, 4.5%, 0.8%, 0.9% and 1.3% respectively. The results demonstrated that reasonable calibrations could be developed to predict oil composition and content of peanuts for a breeding programme.

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Common mode voltage (CMV) variations in PWM inverter-fed drives generate unwanted shaft and bearing current resulting in early motor failure. Multilevel inverters reduce this problem to some extent, with higher number of levels. But the complexity of the power circuit increases with an increase in the number of inverter voltage levels. In this paper a five-level inverter structure is proposed for open-end winding induction motor (IM) drives, by cascading only two conventional two-level and three-level inverters, with the elimination of the common mode voltage over the entire modulation range. The DC link power supply requirement is also optimized by means of DC link capacitor voltage balancing, with PWM control., using only inverter switching state redundancies. The proposed power circuit gives a simple power bits structure.

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Bovine herpesvirus 1 (BoHV-1) is an economically important pathogen of cattle associated with respiratory and reproductive disease. To further develop BoHV-1 as a vaccine vector, a study was conducted to identify the essential and non-essential genes required for in vitro viability. Randominsertion mutagenesis utilizing a Tn5 transposition system and targeted gene deletion were employed to construct gene disruption and gene deletion libraries, respectively, of an infectious clone of BoHV-1. Transposon insertion position and confirmation of gene deletion were determined by direct sequencing. The essential or non-essential requirement of either transposed or deleted open reading frames (ORFs) was assessed by transfection of respective BoHV-1 DNA into host cells. Of the 73 recognized ORFs encoded by the BoHV-1 genome, 33 were determined to be essential and 36 to be non-essential for virus viability in cell culture; determining the requirement of the two dual copy ORFs was inconclusive. The majority of ORFs were shown to conform to the in vitro requirements of BoHV-1 homologues encoded by human herpesvirus 1 (HHV-1). However, ORFs encoding glycoprotein K (UL53), regulatory, membrane, tegument and capsid proteins (UL54, UL49.5, UL49, UL35, UL20, UL16 and UL7) were shown to differ in requirement when compared to HHV-1-encoded homologues.

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Copper aluminum oxide films were prepared by direct current (dc) reactive magnetron sputtering under various substrate temperatures in the range of 303–648 K and systematically studied their physical properties. The physical properties of the films were strongly affected by the substrate temperature. The films formed at substrate temperatures <373 K were amorphous while those deposited at higher substrate temperatures (≥373 K) were polycrystalline in nature. The electrical properties of the films enhanced with substrate temperature due to the improved crystallinity. The Hall mobility of 9.4 cm2/V s and carrier concentration of 3.5 × 1017 cm−3 were obtained at the substrate temperature of 573 K. The optical band gap of the films decreased from 3.87 to 3.46 eV with the increase of substrate temperature from 373 to 573 K.