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Railway Engineering Science - Electrified railways are becoming a popular transport medium and these consume a large amount of electrical energy. Environmental concerns demand reduction in energy...  相似文献   
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Gas exchange through the compacted final cover soil at landfill sites plays a vital role for emission, fate, and transport of toxic landfill gases. This study involved measuring the soil-gas diffusivity (Dp/Do, the ratio of gas diffusion coefficients in soil and free air) and air permeability (ka) for differently compacted soil samples (reddish-brown soil) from the final cover at the Maharagama landfill in Sri Lanka. The samples were prepared by either standard Proctor compaction or hand compaction to dry bulk densities of 1.60–1.94??g?cm-3. Existing and modified models for predicting Dp/Do and ka were tested against the measured data. The simple, single-parameter Buckingham model predicted measured Dp/Do values across compaction levels equally well or better than a dry bulk density (DBD) dependent model and a soil-water retention (SWR) dependent model. The measured ka values for differently compacted samples were highly affected by the compaction level and the sample moisture preparation method. Also, for air permeability, a single-parameter Buckingham-type ka model was most accurate in predicting ka in the differently compacted soil samples. Equivalent air-filled pore diameters (the effective diameter of the drained pores active in leading air through the sample) for gas flow, deq, were calculated from the measured Dp/D0 and ka values. The deq increased with compaction level, suggesting that a very high compaction level creates well-connected macropores in the reduced total pore space of the cover soil. This is an important consideration when designing cover soils for optimally low water and high oxygen exchange while minimizing climate and toxic gas emissions from the waste layer to the atmosphere.  相似文献   
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We demonstrate sensitive spatially resolved detection of physiological chromophores that emit in the ultraviolet (<330 nm). An atypical laser source (a visible wavelength femtosecond optical parametric oscillator), and an unconventional collection geometry (a lensless detector that detects the forward-emitted fluorescence) enable this detection. We report the excitation spectra of the catecholamines dopamine and norepinephrine, together with near-UV emitters serotonin and tryptophan, in the range of 550-595 nm. We estimate the molecular two-photon action cross section of dopamine, norepinephrine, and serotonin to be 1.2 mGM (1 GM, or Goppert Mayor, is equal to 10(-58) m4 s(-1) photon(-1)), 2 mGM, and 43 mGM, respectively, at 560 nm. The sensitivity achieved by this method holds promise for the microscopic imaging of vesicular catecholamines in live cells.  相似文献   
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This study provides insight into consumers’ perception of regionality when purchasing regional wine in terms of regional specialisation for style, volume of production of the wine style, quality of the wine, heritage of the wine region and the distinctiveness of the wine styles produced in the wine regions of Australia. Data were collected from 203 Australian wine consumers through an online survey. The study compares the results of this study with Easingwood et al. [2011. The drivers of wine regionality. Journal of Wine Research, 22(1), 19–33.] study on experts’ opinion of regionality drivers. This paper will expand knowledge on how consumer involvement levels impact decisions relating to purchasing regional wine. This study is of value to academics and wine practitioners alike. It contributes to the wine literature by providing a new perspective on consumers’ perception and draws attention to the risk of drawing conclusions about wine consumption based on experts’ opinions as being reflective of the average consumers’ purchase decision-making.  相似文献   
5.
Kaushalya SK  Balaji J  Garai K  Maiti S 《Applied optics》2005,44(16):3262-3265
In confocal fluorescence correlation microscopy (FCM) it is important to ensure that the correlation measurement is actually performed at the chosen location of the three-dimensional image of the specimen. We present a confocal FCM design that provides an automatic real-time readout of the location in the confocal microscopic image, which is aligned with the detector of the fluorescence correlation spectrometer. The design accomplishes this without using any special positioning device. The design is based on an apertured fluorescence detector placed close to the back aperture of the objective lens and can be easily incorporated into virtually any confocal microscope. We demonstrate the method by performing FCM measurements of a dye diffusing on a cell membrane.  相似文献   
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采用酿酒酵母Saccharomyces cerevisiae KD对苹果、猕猴桃、梨混合果汁进行发酵,研究了该混合果汁发酵过程中酿酒酵母对真菌毒素棒曲霉素的去除作用及其降解产物对大肠杆菌的毒性,并对其发酵过程中的抗氧化能力及对α-淀粉酶、脂肪酶的抑制效果进行分析。结果发现,混合果汁发酵过程中棒曲霉素的含量持续下降直至完全降解,且棒曲霉素的降解产物对大肠杆菌无毒害;对抗氧化能力指标进行检测,发现发酵果汁的DPPH·、ABTS+·清除率和还原力相比新鲜果汁分别提高了15.0%、45.9%和9.6%,抗氧化能力显著增强(P<0.05)。此外,混合发酵果汁可以有效地抑制与肥胖相关的α-淀粉酶、脂肪酶的活力,抑制率分别为52.4%和45.2%。本文的研究结果可为开发功能性发酵果汁提供科学依据和技术支持。  相似文献   
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Coriander (Coriandrum sativum L) is an important spice crop and is used in Indian diets. Physiological characters of plants and biochemical constituents like structural carbohydrate and phytate were studied in developing coriander (var Narnaul and Panth) seeds. Moisture decreased with advancement of seed development. Neutral detergent fibre, acid detergent fibre, hemicellulose, cellulose and lignin levels increased with maturation of seed in both coriander varieties. Significant variations were observed in biochemical constituents between varieties and during different stages of seed development. The presence of phytate did not vary at different stages of seed development. The height of plants varied from 134 to 139 cm with 10 branches. Umbels varied from 89 to 99 with an average of six umbellets. Narnaul seed weight was double that of the variety Panth.  相似文献   
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Fennel (Foeniculum vulgare) is the major spice/condimental crop of Haryana, generally used in India for preparing pickles and in vegetable cooking. Flowers were tagged at anthesis, fennel seeds (local variety) were collected at 1-week intervals after 40 days from anthesis for studying biochemical constituents. Moisture and protein contents decreased significantly with the advancement of seed development. Oil content ranged from 68 to 135·7 g kg?1 (dry weight basis), which increased with seed development. The oil content was greater in mature seeds. The presence of phytate (11·35–13·10 mg g?1) was also observed, which affects the availability of Zn and Fe. Fennel seeds were found to be a rich source of micro- and macroelements. Neutral detergent fibre, acid detergent fibre, cellulose and lignin contents increased significantly with the advancement of seed development. Oleic and linoleic fatty acids were found to be major fatty acids and variable proportions of different fatty acids were observed.  相似文献   
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