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71.
In an advanced manufacturing system, accurate assessment of tool life estimation is very essential for optimising the cutting performance in turning operations. Estimation of tool life generally requires considerable time and material and hence it is a relatively expensive procedure. In this present work, back-propagation feed forward artificial neural network (ANN) has been used for tool life prediction. Speed, feed, depth of cut and flank wear were taken as input parameters and tool life as an output parameter. Twenty-five patterns were used for training the network. Recently there have been significant research efforts to apply evolutionary computational techniques for determining the network weights. Hence an evolutionary technique named particle swarm optimisation has been used instead of a back-propagation algorithm and it is proven that the experimental results matched well with the values predicted by both artificial neural network with back-propagation and the proposed method. It is found that the computational time is greatly reduced by this method .  相似文献   
72.
73.
A unique attempt to exploit silicate chemistry for a possible enhancement of the electrochemical properties of a lithium ion system via exploration of the novel category lithium intercalating LiNiSiO(4) cathode has been made through the present study. A novel citric acid assisted modified sol-gel method (CAM sol-gel) has been adopted to synthesize the title compound with a formation temperature positioned well below 500?°C, as derived from thermal studies. A powder x-ray diffraction (PXRD) pattern evidenced the absence of undesirable peaks and confirmed the formation of a hexagonal lattice structure with enhanced crystallinity and phase purity, and the presence of uniformly distributed particles of ~200?nm size with well defined grain boundaries is obvious from the scanning electron microscopy (SEM) image of LiNiSiO(4) material. Further, magic angle spinning (MAS) (7)Li nuclear magnetic resonance (NMR) results from LiNiSiO(4) confirmed the presence of a layered type of crystal arrangement. A cyclic voltammetry (CV) study performed on a LiNiSiO(4) cathode revealed an excellent reversibility without any change in the peak position upon extended cycling, thus substantiating the structural stability upon progressive cycling.  相似文献   
74.
Water conservation and water management practices have been adopted at Neyveli to ensure proper hydrologic balance. These practices are important because ground water pumping is a prerequisite for lignite mining in the Neyveli basin. This paper delineates some of these practices and the scientific studies undertaken by the Neyveli Lignite Corporation to develop and implement them. Optimal water utilization would be achieved by maintaining the ground water recharge (input) and the ground water extraction (output) ratio in the basin.  相似文献   
75.
Novel photoluminescent donor–acceptor poly(p-phenylenevinylene)-type conjugated polymers containing thiophene and 1,3,4-thiadiazole units in the main chain were synthesized from 2,5-bis(5-bromomethyl-2-thienyl)-1,3,4-thiadiazole and 1,3/1,4-benzenedialdehyde by Wittig–Horner reaction. The synthesized polymers were characterized by the use of thermal analysis and spectroscopic (infrared, UV-visible absorption, and photoluminescence) measurement. The resultant material exhibited bluish green, green, and orange fluorescence in their solution and thin film and solid forms, respectively. The redox property of the polymers has also been studied by cyclic voltammetry. The optical and electrochemical studies reveal that these novel polymers are new promising materials for the development of efficient polymer light-emitting diodes. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   
76.
The effect of the composition of artificial sea water (ASW) medium on the growth properties and docosahexaenoic acid (DHA) production from Thraustochytrium aureum ATCC 34304 was investigated. A maximum dry cell weight (DCW) of 3.71 g/l was obtained when the NaCl and MgSO4 concentration in the ASW media were 15 and 0 g/l, respectively. The maximum initial specific growth (ISG) rate of 0.16 was attained at 7.5 g/l NaCl and 18 g/l MgSO4, while the minimum ISG rate (0.02) was obtained at 5.0 g/l NaCl and 4.5 g/l MgSO4. The least doubling time required for biomass production was 4.3 h at 7.5 g/l NaCl and different MgSO4 concentrations. A maximum of 7.9 g/l DCW was obtained on the fourth day of cultivation at 30 g/l glucose and 2.5 g/l (each) yeast extract (YE) and peptone. The DHA content in the lipids was significantly affected by the concentration of glucose and nitrogen sources (YE and peptone) in the ASW medium. At the lowest glucose (10 g/l) and YE/peptone (0.5 g/l) concentration and highest glucose (30 g/l) and YE/peptone (2.5 g/l) concentration, the DHA content was 34.725 and 40.33%, respectively, relative to total lipid content. However, the DHA content in the lipid was not affected by the NaCl and MgSO4 concentration. At the lowest NaCl (2.5 g/l) and MgSO4 (4.5 g/l) concentration and highest NaCl (60 g/l) and MgSO4 (18 g/l) concentration the DHA content was 39.62 and 38.48%, respectively. The maximum DHA content in the lipid was 49.01% after four days of cultivation when 7.5 g/l NaCl and 4.5 g/l MgSO4 were in the ASW medium. The growth properties of T. aureum ATCC 34304 for biomass production and DHA yield in the lipid content were found to be affected by NaCl and glucose concentration.  相似文献   
77.
An alternate method, which we call as the R dot approach, to obtain the quasi steady state (QSS) rate expression for linear kinetics mechanisms (both sequential reaction mechanism and mechanisms with parallel pathways) had been recently proposed. This method requires the use of intermediate reaction routes (IRR's) to solve for the unknown intermediate species concentrations. In mechanisms where there are many choices of IRR's, it was not clear which one must be chosen so as to obtain the correct rate expression matching with the QSS rate expression. In this work, it is shown that the correct choice is the one which will make the rate limiting step (RLS) reversibility equal to the overall reversibility. This also provides a condition to check the applicability of the R dot method to a particular linear kinetics mechanism. For a mechanism with non linear kinetics, the R dot method may sometimes provide unsatisfactory approximations even if the applicability conditions are satisfied. These are illustrated through four mechanism examples.  相似文献   
78.
Healthy Body Healthy Spirit was a multicomponent intervention to increase fruit and vegetable (F & V) consumption and physical activity (PA) delivered through Black churches. Sixteen churches were randomly assigned to 3 intervention conditions. At baseline, 1,056 individuals were recruited across the 16 churches, of which 906 (86%) were assessed at 1-year follow-up. Group 1 received standard educational materials, Group 2 received culturally targeted self-help nutrition and PA materials, and Group 3 received the same intervention as did Group 2 as well as 4 telephone counseling calls based on motivational interviewing (MI) delivered over the course of 1 year. At 1-year follow-up, Groups 2 and 3 showed significant changes in both F & V intake and PA. Changes were somewhat larger for F & V. For F & V, but not PA, there was a clear additive effect for the MI intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
79.
Laser speckle interferometry has been used to determine the displacement pattern on the chest wall produced by the heart action during the systolic phase of the cardiac cycle. The time averaged specklegram, recorded in the image plane, is scanned by the pointwise method. From the values of the spacings of Young's fringes, measured at various points, the corresponding displacement pattern in the form of a 40 x 30 matrix, equal to that of the cardiac region, is reconstructed and color-coded by a PDP 11/23 image processor. This pattern shows significant variations in displacements at various locations. Depending on the clinical status of the subjects, further changes in the pattern are observed. The reconstructed cardiac displacement patterns, obtained by this new noncontact and noninvasive technique, provide information on the functioning of various parts of the heart in cardiac disorders which are in qualitative agreement with that of two-dimensional echocardiography.  相似文献   
80.
Spinel lithium manganese oxide, LiMn2O4, is beset with problems of capacity fade upon repeated cycling. The loss in capacity upon cycling is attributable to Jahn-Teller distortion and manganese dissolution in the electrolyte in the charged state. One way to circumvent this capacity fade is to introduce other 3d bdtransition metal ions in the LiMn2O4 lattice. In this paper, we report on the effect of partial substitution of manganese in the LiMn2O4 phase with copper (II) and chromium (III) ions. It has been shown that the higher octahedral stabilization energy of trivalent chromium imparts greater structural stability to chromium-doped LiMn2O4 spinels. Both copper and chromium reduce the capacity of the spinel in the 4 V region. In terms of its good reversible capacity and ability to sustain cycling with minimal capacity fade, LiCr0.1Mn1.9O4 may be considered as a potential cathode material for lithium rechargeable cells.  相似文献   
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