Heat transfer analysis of peristaltic flow in a curved channel

We investigate the effects of heat transfer on peristaltic flow of a viscous fluid in a curved channel. Governing equations for flow and heat transfer are derived using long wavelength and small Reynolds number assumptions. Exact solution is obtained for stream function. The temperature field is obtained numerically by a shooting method using Runge–Kutta algorithm. Effects of curvature parameter and Brinkman number are analyzed on various features of peristaltic motion and temperature field. It is found that peristaltic pumping rate increases in going from straight to curved channel. It is further noted that the symmetry of trapped bolus is destroyed in the curved channel and upper bolus pushes the lower bolus toward the lower wall. Moreover, the rate of heat transfer decreases in a curved channel in comparison with the case of straight channel.     

Shelf Life Enhancement of Butter,Ice-Cream,and Mayonnaise by Addition of Lycopene

Lycopene crystals were incorporated in butter (20 ppm), ice-cream (70 ppm), and mayonnaise (50 ppm) and were analyzed for their sensory characteristics during storage for 4 months. The peroxide value generally increased with the storage time. Higher peroxides and free fatty acids were observed in control samples as compared to that of lycopene-treated products. Lycopene as an antioxidant slowed the development of off-flavor, off-odors, and color changes in lycopene-added butter, ice cream, and mayonnaise during storage as it interrupts the chain of free radicals involved in autoxidation. Results showed that there were insignificant changes in hunter L*, a*, and b* values of butter, ice cream, and mayonnaise during the 4 months of storage. Thus, it could be concluded that lycopene-treated products are in comparison with control market samples. The sensory scores of ice cream, butter, and mayonnaise revealed that the sensory attributes were similar to those of control samples. With increased storage, the sensory scores decreased but a significant decrease was observed in the 4th month of storage for all samples.     

小甘菊花有效成分的初步研究

采用水提取法、醇提取法和石油醚提取法对小甘菊花的化学成分进行了比较全面的定性实验。水提取物中检测出有蛋白质、氨基酸、糖类、生物碱、有机酸等物质，醇提取物中检测到了酚类、有机酸、挥发油、黄酮类和生物碱等化学物质，酸水液中检测到了生物碱，石油醚提取物主要作为挥发油、甾体、油脂、皂甙、内酯及香豆素等亲脂性成分的检测。     

Incompressible SPH simulation of solitary wave propagation on permeable beaches

Wave propagation on uniformly sloped beaches is a canonical coastal engineering topic that has been studied extensively in the past few decades.However,most of ...     

Preparation of nanospinels NiMnxFe2−xO4 using sol–gel method and their applications on removal of azo dye from aqueous solutions

In this paper, nanospinels NiMn_xFe_2−xO₄ (x = 0.05, 0.1, 0.3, 0.5, 0.7, and 1) were prepared by sol–gel method in the presence of nitrate–metal–ethylene glycol (EG) polymerized complex. The nanospinels were characterized using thermogravimetry analysis (TGA), X-ray powder diffraction (XRD), Fourier infrared spectroscopy (FTIR), and transmission electron microscope (TEM). The adsorption of an azo dye, reactive blue 5 (RB5), from water was determined using the prepared nanospinels. The effect of operational parameters such as the initial dye concentration, the concentration of nanospinels, temperature, and pH on the degradation of dye was investigated. The adsorption process follows second-order kinetics and Arrhenius behavior. Two common models, the Langmuir and Freundlich isotherms were used to investigate the interaction of dye and nanospinels. The isotherm evaluations revealed that the Freundlich model provides better fit to the experimental data than that of the Langmuir model. The photocatalytic degradation of RB5 at pH 1 under UV irradiation was examined. The results showed that the degradation of RB5 dye follows merely an adsorption process.     

C 1-stably ℒ p shadowable homoclinic classes

Let p be a hyperbolic saddle of diffeomorphism f on closed manifold M and H(p, f) be the homoclinic class associated with it. In this article, we introduce the notion of C ¹-stably ? _p shadowing and prove that if f is C ¹-stably ? _p shadowable on a homoclinic class H(p, f) then, H(p, f) has a dominated splitting. Moreover, we prove that if f is C ¹-stably Lipschitz ? _p shadowable on H(p, f) and H(p, f)-germ of f is expansive then the homoclinic class is hyperbolic.     

Determination of ultratrace levels of lead (II) in water samples using a modified carbon paste electrode based on a new podand

A new podand of 1,1′-thiobis(naphthalene-2,1-diyl)bis(2-aminobenzoate) (TNBA) was synthesized and used as a suitable carrier for construction of Pb²⁺ modified carbon paste electrode (CPE). The effects of various plasticizers; 2-nitrophenyloctylether (o-NPOE), dioctyl pththalate (DOP), dibutyl phthalate (DBP) and paraffin oil were studied. The best performance was obtained with a matrix composition of CPE with a DOP/graphite powder/TNBA weight percent ratio of 35/60.5/4.5. The sensor exhibits significantly enhanced selectivity toward Pb²⁺ ion over the concentration range 8.0 × 10^? 8 to 1.0 × 10^? 2 mol L^? 1 with a lower detection limit of 5.0 × 10^? 8 mol L^? 1 and a Nernstian slope of 29.0 ± 0.2 mV decade^? 1 of lead activity. It has a fast response time of 8 s with a working pH range from 3.5 to 7. The interaction between TNBA and Pb²⁺ was studied spectrophotometrically and it exhibits that the stoichiometry of the complex is 1:1 in acetonitrile solution. Finally, the electrode was satisfactorily used as an indicator electrode in complexometric titration of Pb²⁺ with EDTA and in direct determination of lead in various water samples.     

RESONANT PHOTOEMISSION OF BULK CeO2 AND NANO-CeO2 FILMS

1. IntroductionOne of the rare-earth oxides, CeO2, has been attracting much attention as it has alarge variety of applications such as optical filters, glass--polishing materials, and three waycata1ysts fOr the automotive industry. Its core level and valance band spectra have beenextensively studied both experimentally and theoretically. The detailed analyses of the3d phOto absorption and photo emission spectra of CeO2 based on an Anderson impuritymodel have pointed out that it is strongly …     

Phase time delay and Hartman effect in a one-dimensional photonic crystal with four-level atomic defect layer

The Hartman effect is revisited using a Gaussian beam incident on a one-dimensional photonic crystal (1DPC) having a defect layer doped with four-level atoms. It is considered that each atom of the defect layer interacts with three driving fields, whereas a Gaussian beam of width w is used as a probe light to study Hartman effect. The atom–field interaction inside the defect layer exhibits electromagnetically induced transparency (EIT). The 1DPC acts as positive index material (PIM) and negative index material (NIM) corresponding to the normal and anomalous dispersion of the defect layer, respectively, via control of the phase associated with the driving fields and probe detuning. The positive and negative Hartman effects are noticed for PIM and NIM, respectively, via control of the relative phase corresponding to the driving fields and probe detuning. The advantage of using four-level EIT system is that a much smaller absorption of the transmitted beam occurs as compared to three-level EIT system corresponding to the anomalous dispersion, leading to negative Hartman effect.     

Neutron transmission measurements of zinc and lead single crystals

Neutron transmission measurements of zinc and lead single crystals have been carried out in a neutron wavelength band from 0.03 to 0.55 nm at different orientations of the crystal with regard to the beam direction. The measurements were performed using both time-of-flight and fixed-angle scattering spectrometers installed in front of the ET-RR-1 reactor horizontal channels. It was found that the position of the observed dips in the neutron transmission measurements corresponded to the reflections from the (hkl) planes of the hexagonal zinc single crystal which was cut along the (002) plane, while in the case of lead, the single crystal was cut perpendicular to the (311) plane. The reflectivity from the (002) plane of zinc was determined using both transmission and reflection methods. The maximum reflectivity was found to be 55% when the zinc crystal was orientated at 45° to the beam direction. The wavelength spread of the observed reflectivity curve was found to be in agreement with the calculated one, taking into consideration the spectrometer's resolution and the crystal mosaic spread.