Condition monitoring is implementation of the advanced diagnostic
techniques to reduce downtime and to increase the efficiency and reliability.
The research is for determining the usage of advanced techniques like Vibration
analysis, Oil analysis and Thermography to diagnose ensuing problems of the
Plant and Machinery at an early stage and plan to take corrective and preventive
actions to eliminate the forthcoming breakdown and enhancing the reliability of
the system. Nowadays, the most of the industries have adopted the condition
monitoring techniques as a part of support system to the basic maintenance strategies.
Major condition monitoring technique they follow is Vibration Spectrum
Analysis, which can detect faults at a very early stage. However implementation
of other techniques like Oil analysis or Ferrography, Thermography etc. can
further enhance the data interpretation as they would detect the source of abnormality
at much early stage thus providing us with a longer lead time to plan and take
the corrective actions. In Large Captive Power Plants and Aluminium Smelters,
Integrated Condition Monitoring techniques play an important role as stoppage
of primary system and its auxiliaries (boiler, steam turbine, generator, coal and
ash handling plants etc.) results into the stoppage of the entire plant, which in turn
leads to loss of productivity. From economical and operational point of view, it is
desirable to ensure optimum level of system availability. 相似文献
Bearing the merits of rapid, minimally destructive, and simultaneous multi-element analyses, laser-induced breakdown spectroscopy (LIBS) shows its unique advantages in quantitative analyses of lead, cadmium, and hexavalent chromium in plant materials. However, the greatest challenge LIBS must confront is calibration. Various methods for calibration are proposed and put into effect; nevertheless, limits of detection acquired by LIBS are not acceptable when they are compared with the maximum residue limits drawn up by governments, and LIBS's performances in quantitative analyses are to be improved. This review summarizes recent studies of analyzing lead, cadmium, and hexavalent chromium in plant materials quantitatively by LIBS; weighs the strengths and weaknesses of their calibration methods; and recommends the combination of matrix-matched standards based on spiked sample materials and internal standard as well as chemometrics in complicated situations for calibration in LIBS. Selecting the emission line of the analyte, sample enrichment and signal enhancement are measures that this review puts forward to improve the performances of LIBS in calibration. These quantitative analyses of lead, cadmium, and hexavalent chromium in plant materials by LIBS provide an opportunity to be utilized in mapping distributions and remediation for soil and water, as well as supervision for agricultural products safety and pollution treatments. 相似文献
Some natural plant extract formulations (NPEFs, also referred to as essential oils) used in organic farming have been shown to contain synthetic pesticides. We obtained samples of four NPEFs (Muso, Hekiro, Kensogen-Ten, and Nurse Green) that were contaminated with the synthetic pyrethroid cypermethrin, and we used gas chromatography coupled with combustion, cryofocusing, and isotope ratio mass spectrometry to determine the stable carbon isotope ratios (δ13C) for the cypermethrin in the four NPEF samples, as well as in ten cypermethrin reagents and two commercial pesticide formulations (Agrothrin emulsion and Agrothrin water-dispersible powder). Our goal was to identify the source of the cypermethrin in the NPEFs. Cryofocusing markedly sharpened the cypermethrin peak and thus improved the accuracy and precision of the determined δ13C values. The δ13C values (±?SD) of the 16 cypermethrin samples ranged from ?28.3?±?0.2 to ?24.5?±?0.2?‰. Surprisingly, the four NPEFs showed similar δ13C values (?26.8 to ?27.3?‰), suggesting that the cypermethrin in all the samples came from the same source (either the same chemical reaction or the same primary material). This possibility was supported by previously published results. In addition, the δ13C values of the two commercial pesticides were similar to the values for the NPEFs, suggesting that the commercial pesticides had been diluted and sold as NPEFs. 相似文献
The surface of the taro plant leaf was replicated using a nanoimprinting technique (NIT) supplemented with an electric field. This field‐aided nanoimprinting method (FA‐NIT) consists of two steps: applying an electric field to a liquid polymer under the plant leaves and the curing process of the polymer with the applied electric field. An appropriate electric field was needed to induce the electrokinetic phenomena of a liquid polymer to obtain a good replicated surface. The roughness fabricated by the FA‐NIT was about 45% higher than the one prepared by NIT. The FA‐NIT method is a good supplementary technique to improve the quality of NIT.
In vitro cultures of scarlet flax (Linum grandiflorum L.), an important ornamental flax, have been established as a new possible valuable resource of lignans and neolignans for antioxidant and anti-inflammatory applications. The callogenic potential at different concentrations of α-naphthalene acetic acid (NAA) and thidiazuron (TDZ), alone or in combinations, was evaluated using both L. grandiflorum hypocotyl and cotyledon explants. A higher callus induction frequency was observed on NAA than TDZ, especially for hypocotyl explants, with a maximum frequency (i.e., 95.2%) on 1.0 mg/L of NAA. The presence of NAA (1.0 mg/L) in conjunction with TDZ tended to increase the frequency of callogenesis relative to TDZ alone, but never reached the values observed with NAA alone, thereby indicating the lack of synergy between these two plant growth regulators (PGRs). Similarly, in terms of biomass, NAA was more effective than TDZ, with a maximum accumulation of biomass registered for medium supplemented with 1.0 mg/L of NAA using hypocotyls as initial explants (DW: 13.1 g). However, for biomass, a synergy between the two PGRs was observed, particularly for cotyledon-derived explants and for the lowest concentrations of TDZ. The influence of these two PGRs on callogenesis and biomass is discussed. The HPLC analysis confirmed the presence of lignans (secoisolariciresinol (SECO) and lariciresinol (LARI) and neolignan (dehydrodiconiferyl alcohol [DCA]) naturally accumulated in their glycoside forms. Furthermore, the antioxidant activities performed for both hypocotyl- and cotyledon-derived cultures were also found maximal (DPPH: 89.5%, FRAP 866: µM TEAC, ABTS: 456 µM TEAC) in hypocotyl-derived callus cultures as compared with callus obtained from cotyledon explants. Moreover, the anti-inflammatory activities revealed high inhibition (COX-1: 47.4% and COX-2: 51.1%) for extract of hypocotyl-derived callus cultures at 2.5 mg/L TDZ. The anti-inflammatory action against COX-1 and COX-2 was supported by the IC50 values. This report provides a viable approach for enhanced biomass accumulation and efficient production of (neo)lignans in L. grandiflorum callus cultures. 相似文献
In the, at present, unstable fuel market, much attention is devoted to alternative technologies for fuel production and development
of alternative products of the petrochemical industry. One of the prospective sources of fuel and alternative petrochemical
products is biomass, and the use of oil plants is one of the possibilities. This paper reports on a possible conversion of
rapeseed oil produced in Poland into intermediate hydrocarbon fractions by pyrolysis combined with parallel catalytic conversion.
The products were analysed by gas chromatography coupled with a mass detector. The process was performed in a fixed-bed reactor
and was monitored by FTIR and 1H NMR. Depending on the catalysts applied, the products contained: water, carbon oxides, hydrogen, aliphatic or aromatic hydrocarbons
accompanied by some amount of C2-C5 hydrocarbons formed during the cracking process.
Presented at the 35th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 26–30 May
2008. 相似文献
Complex mixtures of polychlorostyrenes are produced and released into the environment by reaction of chlorine with graphite at high temperatures, e.g. in electrodes. The occurrence of these compounds in the environment or human tissues is often indicative of pollution from electrolytic processes. Combined gas chromatography coupled to electron impact and negative ion chemical ionization mass spectrometry is described here for the analysis of these compounds in sediments, human venous sera and cord sera. This method has allowed a specific congener identification and quantification of the chlorostyrene mixtures present in fluvial sediments polluted by effluents from a chlorine-alkali plant. Besides octachlorostyrene, the mixture of compounds identified involved the six possible heptachlorostyrenes, fifteen hexachlorostyrenes and seven pentachlorostyrenes, having concentrations in the range of 76–16 000 ng g−1 dry weight. In human sera from the population exposed to airborne emissions from this plant these compounds ranged between 17 and 63 ng L−1 and the distributions were dominated by octachlorostyrene, three heptachlorostyrenes, including β,β-2,3,4,5,6-heptachlorostyrene, and α-2,3,4,5,6-hexachlorostyrene. Both distribution patterns showed major differences in composition despite the common pollution source that was influencing both types of samples. The method also revealed qualitative differences between maternal and cord sera from the exposed population. 相似文献
In this study, we have developed a sensitive, rapid and simple procedure for the energy dispersive X-ray fluorescence (EDXRF) spectrometry measurement of tungsten in tobacco plant parts. Only 0.1 g of dried plant material is needed instead of the usual 1 g. EDXRF spectrometry is used for quantitative measurement, after the foliar application of solutions of tungstophosphoric acid (WPA), its magnesium salt and compounds with glycine (Gly) and alanine (Ala), in exact quantities. After that, the leaves, trunks and summits were collected and prepared separately. Tungsten is determined directly in raw dried material, and the overlap of the tungsten peak with zinc's that is present is avoided by the spectral deconvolution to obtain quantitative results. The prepared dry tablets weighed 100 mg, and measurement time was 2000 s. The radioisotope excitation source used was 109Cd and tungsten was identified and quantified at the Lα1 and Lα2 lines at the energies of 8397.6 eV and 8335.2 eV, respectively. EDXRF spectrometry was applied in a wide range of concentrations (up to 2000 mg/kg), with an estimated detection concentration limit of 15 mg/kg, calculated on dried material. Quantitative analysis of different parts of the treated plant plus the washings gave 94.47% recovery of the applied tungsten in different compound forms. After the foliar application of investigated WPA compounds, there were noticed both vertical and horizontal distributions of tungsten through out the tobacco plants, according to the EDXRF spectrometry results. This conclusion is also in agreement with the positive effects of WPA on Tobacco mosaic tobamovirus (TMV) infection of Nicotiana tabacum (Solanaceae). 相似文献