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101.
Wendy Hollands Gary M. Brett Pauline Radreau Shikha Saha Birgit Teucher Richard N. Bennett Paul A. Kroon 《Food chemistry》2008
Blackcurrant (BC) fruits are a rich source of biologically active anthocyanins but little is known of the anthocyanin content of commonly consumed BC products or how processing affects the absorption. We report that whereas fresh and frozen whole BC were a rich source of anthocyanins, containing 897 and 642 mg (100 g FW)−1 of total anthocyanins the levels in all other products were substantially lower (0.05–10.3% of the levels in fresh fruit). Further, when the absorption and excretion of BC was assessed in volunteers consuming a portion (100 g) of frozen whole BC (642 mg total anthocyanins) and, 300 g of a BC drink made by diluting concentrated syrup (33.6 mg total anthocyanins), only small quantities of BC anthocyanins were excreted in urine (fruit, 0.053 ± 0.022%; drink, 0.036 ± 0.043%; mean percent urinary yield ± SD) and they were not detected in plasma. These data indicate that fresh and frozen BC, but not processed products, are rich sources of anthocyanins but, regardless of the food source, these anthocyanins are poorly bioavailable. 相似文献
102.
Riham M. Morcos Alexandra Navrotsky Tamas Varga Dongjoon Ahn Atanu Saha Fabrizia Poli Klaus Müller Rishi Raj 《Journal of the American Ceramic Society》2008,91(7):2391-2393
This communication reports new results on the enthalpy of formation of pseudo-amorphous ceramic compounds constituted from silicon, carbon, oxygen, and nitrogen (SiCNO), made from the polymer route. Again, like the SiCO materials, although with one exception, the enthalpy of formation from crystalline components (SiO2 cristobalite, β-Si3 N4 , SiC, and excess C) is negative. Some of the alloyed oxygen–nitrogen compositions yield enthalpies that are much more negative (∼100 kJ/g·atom) in comparison with compositions that contain mainly oxygen or nitrogen (∼20 kJ/g·atom). The exception, having a N/O ratio near 2, has a positive value for the enthalpy. This may reflect the presence of nanoclusters of stoichiometric Si2 N2 O instead of the pseudo-amorphous nanodomain structure seen for the other samples. 相似文献
103.
Suman Roy Janardan Misra Indranil Saha 《Software Testing, Verification and Reliability》2016,26(8):548-571
We revisit the problem of real‐time verification with dense‐time dynamics using timeout and calendar‐based models and simplify this to a finite state verification problem. We introduce a specification formalism for these models and capture their behaviour in terms of semantics of timed transition systems. We discuss a technique, which reduces the problem of verification of qualitative temporal properties on infinite state space of a large fragment of these timeout and calender‐based transition systems into that on clock‐less finite state models through a two‐step process comprising of digitization and finitary reduction. This technique enables us to verify safety invariants for real‐time systems using finite state model checking avoiding the complexity of infinite state (bounded) model checking and scale up models without applying techniques from induction‐based proof methodology. In the same manner, we verify timeliness properties. Moreover, we can verify liveness for real‐time systems, which are not possible by using induction with infinite state model checkers. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
104.
Investigation on jet stability,fiber diameter,and tensile properties of electrospun polyacrylonitrile nanofibrous yarns 下载免费PDF全文
Electrospinning is a flexible and efficient method for producing nanofibers by using relatively dilute polymer solution. However, there are many parameters related to material and processing that influence the morphology and property of the nanofibers. This study investigates the influence of electric field and flow rate on diameter and tensile properties of nanofibers produced using polyacrylonitrile (PAN)‐dimethylformamide (DMF) solution. Stability of the spinning jet is investigated via fiber current measurement and an image system at different electric fields and solution flow rates. It is observed that a set of electric field and flow rate conditions favor producing thinnest, strongest, and toughest nanofibers during electrospinning process. Other conditions may lead to instability of the Taylor cone, discontinuous jet, larger diameter fiber, and lower mechanical properties. Finally, a simple dynamic whipping model is adopted to correlate the nanofiber diameter with volumetric charge density and is found to be excellent validating our experimental results. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41918. 相似文献
105.
Jiang‐Ping Wu Anjan K. Saha Nizar Haddad Carl A. Busacca Jon C. Lorenz Heewon Lee Chris H. Senanayake 《Advanced Synthesis \u0026amp; Catalysis》2016,358(12):1924-1928
A simple N‐heterocyclic carbene (NHC) derived from 1‐methyl‐3‐ethylimidazolium tetrafluoroborate was found to be an efficient ligand for a range of copper‐catalyzed cross‐coupling reactions, leading to the formation of aromatic ethers and thioethers.
106.
Indranil Saha Lokesh Kumar Sambasivan Subhas Kumar Ghosh Ranjeet Kumar Patro 《Wireless Networks》2010,16(6):1511-1524
In wireless multi-hop and ad-hoc networks, minimizing power consumption and at the same time maintaining desired properties
of the network topology is of prime importance. In this work, we present a distributed algorithm for assigning minimum possible
power to all the nodes in a static wireless network such that the resultant network topology is k-connected. In this algorithm, a node collects the location and maximum power information from all nodes in its vicinity,
and then adjusts the power of these nodes in such a way that it can reach all of them through k optimal vertex-disjoint paths. The algorithm ensures k-connectivity in the final topology provided the topology induced when all nodes transmit with their maximum power is k-connected. We extend our topology control algorithm from static networks to networks having mobile nodes. We present proof
of correctness for our algorithm for both static and mobile scenarios, and through extensive simulation we present its behavior. 相似文献
107.
There has been growing concern about man-made and naturally occurring chemicals in the environment in recent years. These chemicals interfere with the hormone (or endocrine) system, suggesting far-reaching effects on reproduction and development in current and future man and wildlife generations. Recent research has highlighted the existence of these substances in sewage and industrial effluents and their potential for recycling back into the environment, including drinking water, through point and non-point sources. 17β-Oestradiol (E2) and 17α-ethinyl oestradiol (EE2) are amongst the compounds of concern since they were found to cause adverse effects to fish even at low concentration levels.In this work, the adsorption of E2 and EE2 onto several granular activated carbons and Macronet polymers was investigated by batch experiments after a low level detection system was developed using Gas Chromatography Mass Spectrometry (GC/MS). Equilibrium experiments were carried out for all adsorbents to quantify the sorption capacity for E2 and EE2 and the data were correlated using conventional theoretical treatments. For better assessment of the sorbents, their physical properties including surface area, average pore diameter and micropore volume and chemical structure were characterised by N2 adsorption experiments. Further characterisation was performed with scanning electron microscopy (SEM), FTIR spectroscopy, sodium capacity determination, pH titration, development of proton-binding curves and zeta potential measurements. Kinetic experiments were performed at different size ranges of adsorbents and the results were analysed by applying a particle diffusion model. This study demonstrates the potential of these adsorbents for the removal of endocrine-disrupting compounds from aqueous solution. 相似文献
108.
109.
Diurnal variation in faecal excretion of dietary chromium (Cr) was studied in this experiment in mature swine. Five gestating sows weighing between 225 and 250 kg were fed a corn/soya bean meal diet containing 14% crude protein, NRC recommended amounts of vitamins and minerals with a Ca: P ratio of 1.3:1. Chromic oxide was added (0.1% w/w) to the test diet, and ferric oxide was added (0.5% w/w) to the pre-test and post-test diets as dietary markers. Sows received 0.9 kg of the diet twice daily for 8 days. Total faeces from the test diet were collected and a sample of approximately 150 g of morning samples for days 6 to 9 of the experiment was separated. Faecal recovery of dietary Cr was calculated from the total collection and the samples of the 4-day period. It was found that faecal concentration of the Cr varied between days (P < 0.05) and between times of the day (P < 0.05); true equilibrium of Cr excretion was never reached. Diurnal variation in faecal excretion of dietary Cr was shown to exist; Cr concentration was higher in the late morning samples than in the morning samples (P < 0.05). Total faecal recovery of dietary Cr was 93.27%, whereas a greater (P < 0.05) value was obtained by morning sampling (118.76%). A portion of the dietary Cr (6.73%) was retained in the gastrointestinal tract even after 2 days of Cr withdrawal from the diet. 相似文献
110.
Elimination, or reduction, of burrs formed during machining is drawing focus of manufacturers and researchers since long or suppressing a burr regarding its formation or removal of it through a suitable deburring process. Deburring is an extra process often required to undertake, and it involves additional time and cost. Presence of burr may cause several problems, such as difficulty in assembly, dimensional inaccuracy, injury to the operator, etc. Like other industries, avoidance of burr on milled component surfaces in railways is of concern. In the present investigation, formation of burr in face milling is tried to reduce by beveling the exit edge of blocks of medium carbon steel (45C8) which is widely used in railways for manufacture of different components. Cutting conditions are also varied to observe the effect on burr formation. It is observed that at an exit edge bevel angle of 15°, negligible burr is formed at most of the cutting conditions undertaken, and hence, recommended. 相似文献