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31.
Present study mainly focused on investigating the feasibility of waste loquat kernels as substrate in submerged culture of
Sclerotium rolfsii MT-6 for scleroglucan production. Loquat kernel contained high protein (22.5%) and total carbohydrate (71.2%) contents. Dried
and powdered kernels were subjected to acid hydrolysis with 2 N HCl. The obtained hydrolysate was used for the preparation
of loquat kernel extract (LKE) and detoxified loquat kernel extract (DLKE). S. rolfsii MT-6 was isolated from fermented squash (Cucurbita pepo). Optimal conditions for scleroglucan production were initial pH 5.0, shaking speed 150 rpm, 28°C, and cultivation time of
72 hr. Production media prepared with DLKE or LKE gave maximum biomass concentrations of 17.06 and 16.21 g/L, and maximum
scleroglucan concentrations of 12.08 and 10.53 g/L, respectively. DLKE was also favorable substrate for mycelial growth in
a uniform pellet form. This is a first report on the application of waste loquat kernels as scleroglucan production substrate
and on the use of a local S. rolfsii isolate for this purpose. 相似文献
32.
Speed, position and load characteristics of the ultrasonic motor is considerably influenced from the input characteristics
such as driving frequency, magnitude and phase difference of phase voltages. Input and output characteristics of a traveling-wave
ultrasonic motor have been investigated from the experimental point of view in the present study. For this aim, a half-bridge
serial-resonance inverter based drive system has been designed and then implemented. The inverter is featured with pulse width
modulation and pulse frequency modulation techniques. The frequency, amplitude and phase angle of two-phase sinusoidal output
of the driver has been designed to be changed for the control purpose. Then the measuring circuits and tools have been set
up to obtain required measurements. Input characteristics such as duty ratio of control signal-dc reference voltage, dc reference
voltage-driving frequency and output characteristics such as driving frequency-rotor speed, driving frequency-feedback voltage,
phase voltage-rotor speed are obtained from the experiments. Also load characteristics are studied with experiments. Afterwards
these characteristics are discussed in details. This study gives a systematical experimental approach in order to demonstrate
operating and control principles and characteristics of the travelling-wave ultrasonic motor. 相似文献
33.
Cagdas Baday Metin Yurddaskal Metin Ozgul Mehmet Zor Erdal Celik 《Journal of Materials Science: Materials in Electronics》2017,28(23):17468-17481
The objective of this study is to produce the thermoelectric (TE) module called as a Peltier module or element using new and promising materials that work at high temperature for generation of electricity with thermoelectric energy conversion from waste heat at high temperatures. Peltier modules used commercially nowadays can work at relatively low temperatures and their efficiency increase in proportion to the temperature difference between the surfaces of the modules. They consist of a pair of p- and n-type semiconductor. In this study, calcium cobalt oxide was chosen as a p-type semiconductor whilst zinc oxide was chosen as n-type semiconductor. Pure and aluminum-doped zinc oxide and silver-doped calcium cobalt oxide powders were synthesized via sol–gel processing successfully. The obtained powders were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), fourier transform infrared (FTIR), differential thermal analysis-thermogravimetry (DTA-TG), and scanning electron microscopy (SEM). In addition, the particle size distribution of the powders obtained via sol–gel processing was determined using a particle size analyzer. One and two leg oxide thermo-electric modules consisting of one pair of p-type 0.03 percent silver doped calcium cobalt oxide and n-type 0.02 percent aluminum doped zinc oxide bulks of 25 square millimeter cross-section and 3 millimeter heights were constructed. The thermoelectric module constructed was tested at high temperatures, and compared to other similar oxide modules reported in literature. Ultimately, the thermal stress and alteration of thermal stress depending on the leg length and side length of semiconductors were calculated using the finite element analysis (FEA) model in ANSYS 15.0 software. According to the results of the analysis, TE module was optimized in terms of mechanical behavior. 相似文献
34.
This paper presents a highly effective and precise neural network method for choosing the activation functions (AFs) and tuning the learning parameters (LPs) of a multilayer feedforward neural network by using a genetic algorithm (GA). The performance of the neural network mainly depends on the learning algorithms and the network structure. The backpropagation learning algorithm is used for tuning the network connection weights, and the LPs are obtained by the GA to provide both fast and reliable learning. Also, the AFs of each neuron in the network are automatically chosen by a GA. The present study consists of 10 different functions to accomplish a better convergence of the desired input–output mapping. Test studies are performed to solve a set of two-dimensional regression problems for the proposed genetic-based neural network (GNN) and conventional neural network having sigmoid AFs and constant learning parameters. The proposed GNN has also been tested by applying it to three real problems in the fields of environment, medicine, and economics. Obtained results prove that the proposed GNN is more effective and reliable when compared with the classical neural network structure. 相似文献
35.
Altabbaa Mhd. Tahssin Arsan Taner Panayirci Erdal 《Wireless Personal Communications》2019,108(3):1345-1361
Wireless Personal Communications - Femtocell technology is emerging as a key solution for mobile operators for its advantage in coverage and capacity enhancement along with its cost effectiveness.... 相似文献
36.
This paper presents a faster RRT-based path planning approach for regular 2-dimensional (2D) building environments. To minimize the planning time, we adopt the idea of biasing the RRT tree-growth in more focused ways. We propose to calculate the skeleton of the 2D environment first, then connect a geometrical path on the skeleton, and grow the RRT tree via the seeds generated locally along this path. We conduct batched simulations to find the universal parameters in manipulating the seeds generation. We show that the proposed skeleton-biased locally-seeded RRT (skilled-RRT) is faster than the other baseline planners (RRT, RRT*, A*-RRT, Theta*-RRT, and MARRT) through experimental tests using different vehicles in different 2D building environments. Given mild assumptions of the 2D environments, we prove that the proposed approach is probabilistically complete. We also present an application of the skilled-RRT for unmanned ground vehicle. Compared to the other baseline algorithms (Theta*-RRT and MARRT), we show the applicability and fast planning of the skilled-RRT in real environment. 相似文献
37.
Erdal Kusvuran Ali Samil Osman Malik Atanur Oktay Erbatur 《Applied catalysis. B, Environmental》2005,58(3-4):211-216
In this study, photocatalytic degradation of 2,4,6-trimethylphenol (TMP), 2,4,6-trichlorophenol (TCP), 2,4,6-tribromophenol (TBP), 2,4-dimethylphenol (DMP), 2,4-dichlorophenol (DCP) and 2,4-dibromophenol (DBP) has been studied by TiO2/UV. Although degraded phenolic compound concentration increased by increasing initial concentration photocatalytic decomposition rates of di- and tri-substituted phenols at 0.1–0.5 mM initial concentrations decreased when the initial concentration increased. The fastest degradation observed for TCP and the slowest for TMP. Photodegradation kinetics of the compounds has been explained in terms of Langmuir–Hinshelwood kinetics model. Degradation rate constants have been observed to be extremely depended on electronegativity of the substituents on phenolic ring. Degradation rate constant and adsorption equilibrium constant of TCP were calculated as k 0.0083 mM min−1 and K 9.03 mM−1. For TBP and TMP the values of k and K were obtained as 0.0040 mM min−1, 19.20 mM−1, and 0.0017 mM min−1, 51.68 mM−1, respectively. Degradation rate constant of DBP was similar as DCP (0.0029 mM min−1 for DBP and 0.0031 mM min−1 for DCP) whereas adsorption equilibrium constants differed (48.40 mM−1 for DBP and 30.52 mM−1 for DCP). K and k of DMP found as 83.68 mM−1 and 0.0019 mM min−1, respectively. The adsorption equilibrium constants in the dark were ranged between 1.11 and 3.28 mM−1 which are lower than those obtained in kinetics. Adsorption constants have inversely proportion with degradation rate constants for all phenolic compounds studied. 相似文献
38.
In this work, a dynamic model was developed to simulate the transient behaviour of a pilot scale, continuous, siagewise, 15 plate distillation column separating a mixture of ethanol, iso-propanol and isobutanol. The accuracy of the predictions was assessed by transient response data collected during experiments under step changes in reflux ratio, feed flow rate and feed composition.
Results demonstrated the feasibility of simulating multicomponent distillation under unsteady state conditions with fairly good success. Further improvements were suggested for a better accuracy 相似文献
Results demonstrated the feasibility of simulating multicomponent distillation under unsteady state conditions with fairly good success. Further improvements were suggested for a better accuracy 相似文献
39.
Aylin Şakar-Deliormanlı Erdal Çelik Mehmet Polat 《Journal of Materials Science: Materials in Electronics》2008,19(6):577-583
The aim of this study was to investigate the effects of the rare earth element neodymium on the phase formation and microstructural
development of relaxor ferroelectric lead magnesium niobate, Pb(Mg1/3Nb2/3)O3 (PMN) system. Perovskite phase PMN powders were prepared using the sol–gel method and the effect of neodymium doping was
investigated at different doping levels ranging from 0.1 mol% to 30 mol%. The precursors employed in the sol–gel process were
lead (II) acetate, magnesium ethoxide, and niobium (V) ethoxide. All the experiments were performed at room temperature while
the calcination temperatures ranged between 800 °C and 1,100 °C. Results showed that it was possible to obtain the pure perovskite
phase at 950 °C using the sol–gel method. Nd+3 addition influenced the phase formation and microstructure of the multicomponent system. Pyrochlore was detected along with
the perovskite phase above 10 mol% Nd. Results also demonstrated that grain size of the synthesized powders depended on the
Nd+3 concentration. 相似文献
40.
Khang DY Xiao J Kocabas C MacLaren S Banks T Jiang H Huang YY Rogers JA 《Nano letters》2008,8(1):124-130
We have studied the scaling of controlled nonlinear buckling processes in materials with dimensions in the molecular range (i.e., approximately 1 nm) through experimental and theoretical studies of buckling in individual single-wall carbon nanotubes on substrates of poly(dimethylsiloxane). The results show not only the ability to create and manipulate patterns of buckling at these molecular scales, but also, that analytical continuum mechanics theory can explain, quantitatively, all measurable aspects of this system. Inverse calculation applied to measurements of diameter-dependent buckling wavelengths yields accurate values of the Young's moduli of individual SWNTs. As an example of the value of this system beyond its use in this type of molecular scale metrology, we implement parallel arrays of buckled SWNTs as a class of mechanically stretchable conductor. 相似文献