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21.
M. J. Manohar Rao 《控制论与系统》2013,44(1):29-41
The amplitude of a postsynaptic potential attenuates as it spreads from the synapse to the trigger zone, where spike generation is initiated. Thus, especially in neurons with a large dendritic structure, great variability in synaptically evoked changes of the membrane potential at the trigger zone can be expected. Therefore the randomly distributed magnitudes of jumps caused by input processes were assumed in Stein's neuronal model with reversal potentials. Two distributions, normal and exponential, were applied for this purpose. The normal distribution has no influence on statistical characteristics of the interspike interval (1SI). For the exponential distribution the mean ISI, as well as the coefficient of variation, increases nonlinearly with the parameter of the distribution. The coefficient of variation is limited by the value 1. The estimation of the mean ISI by the method of Smith and Smith (1984) is not applicable for the investigated model. 相似文献
22.
Thrupathihalli Pandurangapp Krishna Murthy Balaraman Manohar 《International Journal of Food Science & Technology》2012,47(6):1229-1236
Curcuma amada (Mango ginger) was dried at four different power levels ranging 315–800 W to determine the effect of microwave power on moisture content, moisture ratio, drying rate, drying time and effective diffusivity. Among the fifteen thin layer drying models considered for evaluating the drying behaviour, the semi‐empirical Midilli et al., model described the drying kinetics very well with R2 > 0.999. Drying rate and effective diffusivity increased as the microwave power output increased. Activation energy was estimated by a modified Arrhenius type equation and found to be 21.6 kW kg?1. A feed‐forward artificial neural network using back‐propagation algorithm was also employed to predict the moisture content during MW drying and found adequate to predict the drying kinetics with R2 of 0.985. 相似文献
23.
Optimization of tensile properties thermoplastic blends from soy and biodegradable polyesters: Taguchi design of experiments approach 总被引:1,自引:0,他引:1
Soy meal-based biodegradable blends were prepared by melt extrusion process. The effects of denaturants, i.e., urea and sodium
sulfite and plasticizer (glycerol) and polyester type (polybutylene succinate, polycaprolactone, polybutylene adipate terephthalate)
on tensile strength and elongation at break were investigated using a Taguchi experimental design approach. The results showed
that the sodium sulfite had little or no effect on final properties of the blends. Also, biodegradable polyester type had
significant effect on the tensile strength and elongation at break of the blends prepared. The predicted values and experimental
were found to be in tune with each other. The chemical structure and morphology of the optimum sample was probed by FT-IR
spectroscopy and scanning electron microscopy (SEM). Also, the results provided an insight into how important the plasticization
and destructurization of soy protein to obtain the blends with desired mechanical properties. 相似文献
24.
Gurdeep Rattu P. Murali Krishna 《International Journal of Food Science & Technology》2021,56(9):4328-4337
l -lactate is a conjugate base of α-hydroxy acid, a key organic chemical in food processing, fermentation, biology and chemical industries. We are reporting for the first time a facile and rapid non-enzymatic nanosensor for l -lactate detection in tomato-based products using 3-aminophenylboronic acid (3-APBA)-added zinc oxide nanoparticles (ZnO NPs). 3-APBA-functionalised ZnO NPs have a selective and stable SPR intensity change at pH 5.5 to 7.5 and forms a reversible ester with bound l -lactate revealing the wavelength shift from λ = 300 nm to 288 nm in UV-VIS absorption spectrometry. In the spiked (2.5–20 mm ) samples of tomato puree, absorption peak increased as per l -lactate addition with the lower detection limit of 3.98 mm . l -lactate binds with a trigonal form of 3-boronate, thereby generating the tetrahedral complex. ZnO NPs stabilise the tetragonal complex. Nanosensor validated with standard HPLC. This method is useful for l -lactate detection and alternates to conventional techniques. 相似文献
25.
A computationally efficient approach for hidden-Markov model-augmented fingerprint-based positioning
John Roth Murali Tummala John McEachen 《International journal of systems science》2016,47(12):2847-2858
This paper presents a computationally efficient approach for mobile subscriber position estimation in wireless networks. A method of data scaling assisted by timing adjust is introduced in fingerprint-based location estimation under a framework which allows for minimising computational cost. The proposed method maintains a comparable level of accuracy to the traditional case where no data scaling is used and is evaluated in a simulated environment under varying channel conditions. The proposed scheme is studied when it is augmented by a hidden-Markov model to match the internal parameters to the channel conditions that present, thus minimising computational cost while maximising accuracy. Furthermore, the timing adjust quantity, available in modern wireless signalling messages, is shown to be able to further reduce computational cost and increase accuracy when available. The results may be seen as a significant step towards integrating advanced position-based modelling with power-sensitive mobile devices. 相似文献
26.
Sellamuthu N. Jaisankar Neelamegan Haridharan Adhigan Murali Ponyrko Sergii Milena Špírková Asit Baran Mandal Libor Matějka 《Polymer》2014
The sidewall functionalization of single-walled carbon nanotubes (SWCNTs) was established by poly (methyl methacrylate) (PMMA) using controlled radical polymerization (CRP) method. A bromide functionalized SWCNT (SWCNT-Br) has been used as an initiator for the synthesis of SWCNT-graft-PMMA (SWCNT-g-PMMA). The efficiency of the sacrificial initiator (S) was monitored during the polymerization process. The obtained polymers possess a uniform distribution of molecular weight with a lower polydispersity index of 1.36. The SWCNTs-based initiator acts as an efficient medium for the controlled growth of polymer on the SWCNTs surfaces. The presence of bimodal gel permeation chromatographic (GPC) curve for the SWCNT-g-PMMA(S) obtained through sacrificial initiator (S) confirms uncontrolled behavior. However, the clear sharp peak for SWCNT-g-PMMA obtained without sacrificial initiator shows its well-controlled process of polymerization, which acts as a mimic to bone cement. The efficiency of the functionalization of SWCNT and the controlled formation of SWCNT-g-PMMA composites were characterized by TGA, Raman, TEM, NMR, XPS and dispersion measurements. 相似文献
27.
Ram Manohar Yadav Pramod Singh Dobal T. Shripathi R. S. Katiyar O. N. Srivastava 《Nanoscale research letters》2009,4(3):197-203
This investigation deals with the effect of growth temperature on the microstructure, nitrogen content, and crystallinity
of C–N nanotubes. The X-ray photoelectron spectroscopic (XPS) study reveals that the atomic percentage of nitrogen content
in nanotubes decreases with an increase in growth temperature. Transmission electron microscopic investigations indicate that
the bamboo compartment distance increases with an increase in growth temperature. The diameter of the nanotubes also increases
with increasing growth temperature. Raman modes sharpen while the normalized intensity of the defect mode decreases almost
linearly with increasing growth temperature. These changes are attributed to the reduction of defect concentration due to
an increase in crystal planar domain sizes in graphite sheets with increasing temperature. Both XPS and Raman spectral observations
indicate that the C–N nanotubes grown at lower temperatures possess higher degree of disorder and higher N incorporation. 相似文献
28.
CdSxSe1−x films of different composition (0 < x < 1) were deposited by pulse plating technique at different duty cycles in the range of 10-50%. The films were polycrystalline and exhibited hexagonal structure. The band gap of the films varies from 1.68 to 2.39 eV as the concentration of CdS increases. Energy Dispersive analysis of X-rays (EDAX) measurements indicate that the composition of the films are nearly the same as that of the precursors considered for the deposition. Atomic force microscopy studies indicated that the grain size increased from 20 to 200 nm as the concentration of CdSe increased. Photoelectrochemical (PEC) cell studies indicated that the films of composition CdS0.9Se0.1 exhibited maximum photoactivity. Mott-Schottky studies indicated that the films exhibit n-type behaviour. Spectral response measurements indicated that the photocurrent maxima occurred at the wavelength value corresponding to the band gap of the films. 相似文献
29.
The controlled assembly of nanoparticles in thin film form on solid supports, both as monolayers and as superlattice structures, is a problem of considerable topical interest. Among the many interactions used to program the assembly of nanoparticles, electrostatic forces are particularly interesting for many reasons. This Account deals with assembling surface-modified nanoparticles in thin film form using electrostatic interactions at the air-water interface and in thermally evaporated lipid films. The generality of the electrostatic assembly protocol is demonstrated in the immobilization of DNA and proteins in lipid films. 相似文献
30.
J. Murali Krishnan K. R. Rajagopal Eyad Masad Dallas N. Little 《Canadian Metallurgical Quarterly》2006,6(1):36-45
This study is concerned with the constitutive modeling of asphalt concrete. Unlike most constitutive models for asphalt concrete that do not take into account the evolution of the microstructure of the material, this study incorporates the evolution of the microstructure by using a framework that recognizes that a body’s natural configurations can evolve as the microstructure changes. The general framework, on which this study is based, is cast within a full thermomechanical setting. In this paper, we develop models within the context of a mechanical framework that stems from the general framework for models based on the full thermodynamic framework and the resulting equations represent a nonlinear rate type viscoelastic model. The creep and stress relaxation experiments of Monismith and Secor are used for validating the efficacy of the model, and it is found that the predictions of the theory agree very well with the available experimental results. The advantages of using such a framework are many, especially when one wants to model the diverse mechanical and thermodynamic response characteristics of asphalt and asphalt concrete. 相似文献