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Continuous screening of ferrous sinter mixtures was studied in a laboratory screen (310 × 600) incorporating continuous weighing of the underflow and overlfow streams with the aim of checking the applicability of recent batch sieving results [1] to continuous screening.The results of the study show that the two operations are comparable in all respects if deck length in continuous screening and time in batch sieving are interchanged.The effect of oversize particles is again found to be beneficial in speeding up the screening of near-mesh material.Calculated screening rate constants with and without the presence of oversize, unfortunately, also parallel the results of batch sieving and this problem of theory is, therefore, still unresolved. 相似文献
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Meta A. Mittermayer J. Prats P. Scheiber R. Steinbrecher U. 《Geoscience and Remote Sensing, IEEE Transactions on》2010,48(2):759-769
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Meta Kokalj Metka Rihtari?Samo Kreft 《Chemometrics and Intelligent Laboratory Systems》2011,108(2):154-161
The use of infrared spectroscopy has spread from single compound research to the investigation of complex biological samples. In infrared spectroscopy, spectral pre-treatment techniques have been assumed to be equally applicable and effective in the analysis of biological samples with complex chemical composition and structure. In this research, the most commonly used pre-treatment techniques were investigated based on the identification of species from whole leaf samples of pharmaceutically important Epilobium and Hypericum genera. Two spectral collection modes were used; whole leaf transmission and KBr-tablet transmission mode. The results of this study do not support the current standard in pre-treatment methods. After the frequency decomposition of a spectral signal by Fourier transform and wavelet decomposition, it was revealed that the important information of whole plant leaf as an example of biological samples was contained in the spectral details. Therefore, smoothing techniques were not appropriate because high frequency information is lost. A vast majority of published work used a Savitzky-Golay smoothing method on infrared spectra of complex biological samples. This method was shown to be less effective. In contrast, taking the derivative of the spectra showed significantly better results; with this pre-treatment method, the overlapping bands become more evident. 相似文献
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Improvement of ammonia removal in activated sludge process with feedforward-feedback aeration controllers. 总被引:1,自引:0,他引:1
Darko Vrecko Nadja Hvala Aljaz Stare Olga Burica Marjeta Strazar Meta Levstek Peter Cerar Sebastjan Podbevsek 《Water science and technology》2006,53(4-5):125-132
In the paper three linear aeration controllers that can be easily implemented are presented and evaluated on the activated sludge process pilot plant. Controllers differ according to the information that is used about the process, which can be oxygen in the last aerobic reactor, ammonia in the last aerobic reactor and ammonia in the influent. The aeration controllers that are addressed are: oxygen cascade PI controller, ammonia cascade PI controller and ammonia feedforward-cascade PI controller. Experiments show that, in comparison with the oxygen cascade PI controller, the ammonia cascade PI controller allows better control of effluent ammonia and airflow savings of around 23%, while the ammonia feedforward-cascade PI controller gives the best reduction of ammonia peaks and can save up to 45% of the airflow. 相似文献
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Polyurethane oligomers from 1,4-butanediol (BD) and toluene diisocyanate (TDI) with a various excess of BD were synthesized. Their molar masses were measured by gel permeation chromatography and the molar mass distribution correlated with the statistic theory. 1H-, 13C-, 1H–1H-COSY–, ATP–, and 15N-NMR spectra of reaction products were recorded, and from the ratio of proton integrals of characteristic terminal and inner urethane groups, the reactivity ratio of the para and ortho NCO groups in 2,4-TDI was calculated to be approximately 1.8 at a lower excess of BD. 15N-NMR spectroscopy was found not to be selective enough to detect small amounts of side reactions. © 1993 John Wiley & Sons, Inc. 相似文献
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A pilot-plant study was conducted to evaluate the performance of a moving-bed biofilm reactor process using PVA-gel beads as a biocarrier. Real primary-settled wastewater was fed to the pre-denitrification system and removals of nitrogenous and organic contaminants were evaluated over a 1-year period. The results demonstrated that at a total nitrogen (TN) loading of 18 mg/L.h, a TN removal efficiency in keeping with and even exceeding the theoretical maximum efficiency based on the level of internal recycle, was possible and a nitrification rate of 15 mg/L.h was sustained with a HRT of only 2.5 h at 15 degrees C. Furthermore, soluble COD and BOD5 in the effluent of the pilot plant were reduced to levels well below most regulatory discharge limits. In addition, the possibility of using this biocarrier in a system, including the elimination of waste organic sludge, was discussed. 相似文献
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Lopez Neil Stephen Mouy Meta Africa Aaron Don 《Clean Technologies and Environmental Policy》2022,24(2):595-605
Clean Technologies and Environmental Policy - Drivers to global carbon emissions have been widely investigated in the scientific literature. However, most previous studies have been limited to... 相似文献
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ABSTRACT: The objectives of this study were to determine the frying stability of soybean oil (SBO) treated with a natural citric acid-based antioxidant, EPT-OILShield™ able to withstand high temperatures and to establish the oxidative stability of food fried in the treated oil. Soybean oil with 0.05% and 0.5% EPT-OILShield and an untreated control SBO were used for intermittent batch frying of tortilla chips at 180 °C for up to 65 h. Oil frying stability was measured by free fatty acids (FFA) and total polar compounds (TPC). Chips were aged for up to 4 mo at 25 °C and evaluated for rancid flavor by a 15-member, trained, experienced analytical sensory panel and for hexanal content as an indicator of oxidation. Oil with 0.05% EPT-OILShield had significantly less FFA and TPC than the control. The effect of EPT-OILShield was apparently retained in aged chips because hexanal levels were significantly lower in chips fried in oil with 0.05% EPT-OILShield than in chips fried in the control. Tortilla chips fried in the control were rancid after 2 mo at 25 °C at sampling times evaluated from 25 to 65 h; however, chips fried in oil with 0.05% EPT-OILShield and used for 65 h were described as only slightly rancid after 4 mo. Gamma tocopherol levels were significantly higher in the chips fried in the oil with 0.05% EPT-OILShield than in the control, helping to inhibit oxidation in the tortilla chips during storage. 相似文献
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