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101.
The commenters point out that the algorithm of S.A. Kumar and S.H. Lee for the enumeration of all minimal s -t cutsets is defective (see ibid., vol.R-26, p.51-5, April 1979). It is illustrated through an example that their algorithm misses several minimal cutsets. The commenters cite two reasons for this: the adjacency problem and the back-vertex problem 相似文献
102.
M. Lakshmi Kantam V. Swarna Jaya M. Jaya Lakshmi B. Ramachandra Reddy B.M. Choudary S.K. Bhargava 《Catalysis communications》2007,8(12):1963-1968
Alumina supported copper (Cu–Al2O3) nanoparticles were prepared and applied for the aziridination of olefins employing [N-(p-tolylsulfonyl)imino]phenyliodinane (PhI = NTs) as nitrene source to afford the corresponding 3-membered cyclic compounds in moderate to excellent yields. Cyclopropanation of several olefins was also carried out by using Cu–Al2O3 nanoparticles and ethyl diazoacetate as a carbene source. The catalyst was recovered by simple centrifugation and reused for four cycles. 相似文献
103.
Sayanti Bhattacharya Jaya P. Kamat Sandip K. Bandyopadhyay Subrata Chattopadhyay 《Food chemistry》2009
The protective activities of Emblica officinalis, Terminalia bellerica and Terminalia chebula ethanol extracts against photosensitization-induced oxidation of rat liver mitochondrial lipid were assessed. All the extracts could effectively prevent lipid peroxidation, as assessed by measuring thiobarbituric acid-reactive substrates, lipid hydroperoxide, conjugated diene and 4-hydroxynonenal. The E. officinalis extract was the most potent, revealing its superior ability to scavenge 1O2. The extracts also afforded excellent protection against iron-mediated lipid peroxidation that might also be useful in reducing photo-induced iron toxicity. The activities of the extracts were primarily due to their constituent phenolics. 相似文献
104.
Kumar Sankar Majumder 《Thin solid films》1977,45(3):527-535
Mott has suggested that the ideal creep-resistant material will be one with a fine grain size in which the grain boundaries are filled with some substance, say a refractory oxide, to inhibit the motion of grain boundaries. Such a system, alumina-dispersed copper, was prepared by high rate physical vapour deposition. The process parameters and their effect on structure and texture have been studied. The room temperature mechanical properties have also been reported. This paper deals with a high temperature mechanical property, i.e. tensile creep. Tests were made on a constant-stress vacuum creep rig with a Ferrometic feedthrough to ensure a zero leakage rotary seal. A vacuum of 1.33 X 10?3 Pa was maintained. The test temperatures were 500°C (0.57Tm) and 700°C (0.72Tm). The stresses applied were 2.07, 3.45, 4.14 and 6.89 X 107 Nm?2. Tests were made on as-deposited films and on cold-rolled condensates.Minimum creep rate curves showed the effect of the alumina content in raising the creep resistance of copper. Cold rolling also reduced the minimum creep rate markedly. Varying the temperature and stress affected the shape of these curves. Stress-rupture plots were used to summarize the data.Grain refinement together with a fine stable dispersion seem to give improved creep strength. The critical barrier of the Orowan stress was noted. The stress exponent for a low alumina deposit (0.21 vol.%) was about 8, and the apparent activation energy for creep was about 202 kJ mol?1 (0.13 vol.%). There was an inverse relationship between the rupture life and the minimum creep rate, their product being constant (about 0.2). 相似文献
105.
Single crystals of Lithium Ammonium Sulphate doped with Cu2+ ions were grown by slow evaporation technique. Electronic absorption spectra have been recorded at room and liquid nitrogen temperatures on Cary-2390 spectrophotometer. The spectrum is characteristic of a Cu2+ ion in octahedral symmetry. From the magnitude and and relative position of the bands a successful interpretation of all the observed bands has been made. The crystal field and tetragonal field parameters are derived. The observed and calculated energies are in good agreement. 相似文献
106.
A computer program to generate automatically the stiffness and mass matrices in finite element analysis is introduced. By using programs like this, researchers only need to derive the expressions for the energies (strain or kinetic) and the expressions for the displacements or stresses and their derivatives in terms of nodal variables. Tedious calculations to obtain the matrices are avoided. Such programs would facilitate checking of existing matrices and would encourage researchers to try out new finite element models. 相似文献
107.
Nathaporn Areerachakul Saravanamuthu Vigneswaran Huu Hao Ngo Jaya Kandasamy 《Korean Journal of Chemical Engineering》2008,25(4):663-669
The performance of both batch and continuous photo-catalytic reactors was studied to evaluate their capabilities in removing
the sulfonyl urea herbicide of metsulfuron methyl (MM). It was found in a batch reactor that the addition of a small amount
of powder activated carbon (PAC) significantly increased the rate of degradation of MM. The continuous photo-catalytic system
resulted in 57% of MM removal. When a small dose of activated carbon was added in the photo-catalytic system, MM removal increased
to 78–86% MM removal for retention times between of 5.25–21 min (corresponding to withdrawal rates of 10–40 mLmin−1). In this study, the pseudo first order rate constants of a continuous photo-catalytic system revealed that shorter retention
times were associated with lower rate constants. Solid phase micro extraction/gas chromatography (SPME/GC) results showed
that high concentrations of MM were broken down to small volatile organic compounds (VOCs) by photo-catalytic oxidation. PAC
adsorbed the photo-products and increased the degradation of MM. 相似文献
108.
In this paper, the problem of evaluation of reliability (probability of success) of a network consisting of several inputs and outputs is studied. Edges are assumed to be perfect and vertices are assigned the probabilities of success. A new concept called “vertex connected subgraph” is introduced for this purpose. This concept is useful even for dense graphs because they are of the order of 2(v-k-1) which is independent of e, where ν(e) is the number of vertices (edges) and k is the number of outputs of a graph. 相似文献
109.
Muthuvelu Kirupa Sankar Ethiraj Baranitharan Pramnik Shreyasi Raj N. Keerthish Venkataraman Swethaa Rajendran Devi Sri Bharathi Priyadharshini Palanisamy Elakiya Narayanan Anusri Sathiya Vaidyanathan Vinoth Kumar Muthusamy Shanmugaprakash 《Food science and biotechnology》2023,32(10):1337-1350
Food Science and Biotechnology - Despite centuries of developing strategies to prevent food-associated illnesses, food safety remains a significant concern, even with multiple technological... 相似文献
110.
The present study focuses on fabricating of polymer–clay nanocomposites by in situ polymerization method and investigating their permeability behavior toward vapor and liquid molecules, thus, to evaluating barrier properties of the nanocomposites. For this purpose, acrylonitrile (AN) monomer was grafted on to poly(vinyl alcohol) (PVA) chains after the addition of very low amount of fuller's earth (clay) into polymer matrix using a suitable initiator, such as potassium persulphate (KPS), and crosslinker N‐N′ methylene bisacrylamide (MBA). The prepared nanomaterials were characterized by Fourier‐Transformation infrared (FTIR) spectroscopy and wide‐angle X‐ray diffraction (WXRD) techniques. The morphological features of designed materials were studied by scanning electron microscopy. The graft materials impregnated with fuller's earth were examined for their permeability behavior by observing the permeation of solute and vapor molecules from aqueous dye solution and volatile organic solvent, respectively. The composition of the nanocomposites and the amount of fuller's earth content were found to affect the passage of solute and vapor molecules across the nanocomposite membrane. The permeation capacity was quantified by evaluating permeability parameters. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers 相似文献