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In this letter, we report the synthesis of Au nanoparticles (NPs) and polyaniline (PANI) on the same cation-exchange resin beads and demonstrate their use in catalyzing the oxidation of glucose to gluconic acid by Au NPs and simultaneously in detecting the formation of the acid by the color change of PANI. The synthesis was carried out by exchanging the cations of the resins with HAuCl4 and anilinuium chloride and then reducing the metal ions by NaBH4 to produce Au NPs followed by polymerization of aniline using H2O2. The green emeraldine salt form of PANI thus obtained was treated with NaOH to be converted to blue emeraldine base before use. The deposition of Au NPs was confirmed by a change in color of the bead, visible spectroscopy, X-ray diffraction, and scanning electron microscopic measurements. On the other hand, the presence of PANI was confirmed by Fourier transform infrared (FTIR) and ultraviolet−visible (UV−vis) spectroscopy. The formation of gluconic acid from glucose was confirmed by FTIR spectroscopy. We could detect the presence of glucose of a minimum 1.0 mM concentration in water, using the present method. Our experimental observations demonstrate the possibility of the incorporation of multifunctional components on the surfaces of resins for carrying out a chemical reaction as well as detection of the product.

In this paper we report a new method of solubilization of polyaniline and polyaniline−Au-nanoparticle composite by encapsulating nanometer-size particles in starch. The solubilization was carried out in the presence of ultrasonic waves. We also report that the encapsulation was completely reversible and the dissolved polyaniline as well as the composite could be recovered by replacement with molecular iodine. In addition, the polymer particles could also replace molecular iodine from starch−iodine complex. UV−Visible and Fourier transform infrared (FTIR) spectroscopic measurements established the reversible nature of encapsulation. Transmission electron microscopic measurements showed that the sizes of the particles encapsulated in starch were on the order of 10−20 nm for both polyaniline and Au-nanoparticle−polyaniline composite particles. X-ray diffraction evidenced the presence of Au-nanoparticles in the starch−polyaniline−Au-nanoparticle composite. Finally, we also mention here that the dissolved polyaniline could also be recovered as a precipitate by enzyme (diastage) hydrolysis of the polyaniline encapsulating starch.

We report the synthesis of Au nanoparticles, with tunable longitudinal plasmon band and shape selectivity, mediated by starch in the presence of ultrasonic waves. The synthesis was carried out by reduction of HAuCl4, at various concentrations, using H2O2 as the reducing agent. When the reactions were carried out in the absence of ultrasonic waves, there was no occurrence of the longitudinal resonance band, while the transverse plasmon resonance band shifted toward a higher wavelength. Transmission electron microscopic measurements revealed an increase in particle sizes with increasing higher initial HAuCl4 concentration. On the other hand, in the presence of ultrasonic waves, as the initial concentration of HAuCl4 was increased, while the transverse plasmon resonance band remained the same, the longitudinal plasmon resonance band increasingly shifted toward a higher wavelength. Transmission electron microscopic measurements revealed the change in shape from spherical to triangular to hexagonal particles with increasing initial HAuCl4 concentration. We also report that the starch-stabilized nanoparticles could be precipitated from the solution by a starch digesting enzyme which also binds with the particles resulting in its precipitation.

In this paper we report the experimental observation of spreading and recoil of surfactant-containing water drops on various alcohol films supported on glass slides. The time evolution of spreading and recoil behavior was recorded by placing a web camera above the drop. We observed that the drop spread the fastest on CH3OH, followed by C2H5OH, and the slowest on i-PrOH. On the other hand, the recoil behavior was just the opposite. The drop recoiled the slowest on CH3OH and fastest on i-PrOH, while it recoiled in an intermediate time on C2H5OH. In addition, concentration of surfactant in the drop played a prominent role in the spreading and recoil time of the drop, with higher surfactant concentration making the drop spread and recoil faster. The time evolution of spreading velocity of the drop on different alcohol films at various surfactant concentrations occurred with a Gaussian distribution and the peak velocity was reached earliest on CH3OH followed by C2H5OH, while on i-PrOH it took the longest time. The recoil behavior was similar. The variation of velocity as a function of radius exhibited oscillatory behavior, indicating the existence of an interfacial phenomenon. We also report the observation that spreading of the drop occurred without observable fingering instability. Further, we observed by Fourier transform infrared (FTIR) spectroscopic measurements that the drop had mixed with the alcohol films as it spread. Miscibility of the alcohol in the film with the drop, alcohol evaporation cooling-induced temperature gradient, and Marangoni effect probably play important roles in the spreading and recoil behavior of the drop.

In this paper we report the demonstration of controlled fluid movement up along a soap bubble film from a solution on which the bubble floats. The control is achieved by controlling the gradient in surfactant concentration present in the bubble film and the solution below. We monitored the fluid flow by following the time-dependent visible absorption spectrum of a Rhodamine dye in the film that moved from the solution to the film due to fluid flow. Our observations suggest that an initial surfactant concentration gradient between the film and the solution (the solution having higher concentration) induces upward flow of fluid. Increase in the concentration gradient increases the rate of flow. No fluid flow was observed when the concentration gradient was zero or lower. In addition, our observation indicates that the upward movement of fluid occurs in concurrence with drainage of the film.

In this Letter we report a method for observing Marangoni convection driven fluid flow, in various soap bubble systems, using a UV−visible spectrophotometer. We also report time-dependent simultaneous measurement of the thickness of the fluid layer and thickness of the bubble film. The measurement is based on earlier reports^1,2 of time-dependent monitoring of film thickness in a soap bubble by observing the interference maxima and minima occurring in the UV−visible region of wavelength. In the present case the interference maxima and minima due to the upward fluid flow appeared superimposed on those due to film thickness. Our observations suggest that the fluid layer thickness remains nearly constant for both vertical and horizontal bubbles even though the film thickness changes with time. The observed values of the fluid layer thickness are about 6.94 ± 0.15 μm for the vertical bubble and about 4.75 ± 0.09 μm for the horizontal bubble. Also, the intensity of the interference peaks due to Marangoni convection goes down as the film thickness reduces which indicates a possible decrease in refractive index of the fluid with time.

The infrared and Raman spectra of 2,3-, 2,4-, and 2,5-dimethylbenzonitriles are recorded in the regions 400 to 4000 cm−1and 100 to 4000 cm−1, respectively. Depolarization measurements are also undertaken. Assuming a C, point group for all the molecules, vibrational analysis is carried out. The frequencies of the umbrella vibration (mode 11) are calculated, and the calculated values agree very well with the observed values.

One hundred and sixty four right and 187 left, dry, fully ossified human ulnae have been studied to derive regression formulae for the establishment of the total length of the ulna from the upper and lower segments, the line of division between the segments being the lowest level of insertion of the brachialis muscle.Also, 175 right and 179 left, dry, fully ossified tibiae have been studied to derive regression formulae for establishment of the total length of the tibia from the upper and lower segments, the line of division being the lower limit of the soleal line.All the formulae derived are statistically highly significant and have a high degree of prediction, and are valuable in establishing the stature of an individual.

Summary Optimal conditions for the induction of host-range mutants of cyanophage N-1 by acridine orange were established. Induced host-range mutants were isolated with a frequency of 0.1 to 4.0×10-5 over a spontaneous mutation frequency of 0.2–3.6×10-11.

1.The precipitation of yttrium oxinate commences at pH 3.84 and is complete at pH 4.78. It is not possible to separate thorium and yttrium in this way.2.Yttrium oxinate dissolves in dilute acids with decomposition.3.Yttrium oxinate has composition Y(Ox)3 as shown by the ignition of the oxinate to yttria and the bromination of the oxinate precipitate.4.By dissolving the precipitate in acetone or carbon tetrachloride and measuring the absorption of the solution at 330 mµ. and 340 mµ, respectively small quantities of yttria about 3 mg. per litre may be estimated.

1. The hypertrophy of the thymus resulting from ovariectomy is shown to be true active tissue growth, as such tissue contains the same percentage of water, deoxyribose-nucleic acid, protein and ascorbic acid as the normal thymus.2. The hypertrophy of the thymus as a result of adrenalectomy is not considered to be a true tissue growth, as it is significantly low in total solids and ascorbic acid level. It is suggested that this response may be due to an unequal stimulation, by adrenalectomy, of the thymic components, the cortex and the medulla. It is thus shown that the adrenals and ovaries differ with regard to their relation to the thymus gland.3. The acceleration in body growth, after removal of the ovaries in young rats, is shown to be a true overall increase in body growth, as ovariectomy induces a significant increase in serum inorganic phosphate.4. Ovariectomy of previously thymectomized animals has shown that the thymus is not involved in the accelerated body growth resulting from ovariectomy alone.

A mathematical expression is given by Isaacs et al. for calculating the specific activity in fish using an assumed exponential growth equation. In the present work, experimentally verified limited growth cubic equation proposed by Von Bertalanffy is used in place of the exponential growth equation of Isaacs'. Further, assuming an age distribution function of the type n = alpha t e−atwhich is found to be applicable for the actual fish catches along the Indian coast, an expression is derived for the weighted average specific activity in fishes in an actual catch. There is a good agreement between the values calculated from the model proposed here and Isaacs' expression for nuclides having short physical and/or biological half lives. However, for nuclides having long physical and biological half lives (e.g. 45Ca, 55Fe and 90Sr), the values from the present model are significantly higher than Isaacs' limiting values and approach Isaacs' limiting values only at infinite age of the fish.

The precipitation of yttrium oxinate commences at pH3.84 and is complete at pH4.78. It is not possible to separate thorium and yttrium in this way.Yttrium oxinate dissolves in dilute acids with decomposition.Yttrium oxinate has composition Y(Ox)3as shown by the ignition of the oxinate to yttria and the bromination of the oxinate precipitate.By dissolving the precipitate in acetone or carbon tetrachloride and measuring the absorption of the solution at 330 mμ. and 340 mμ, respectively small quantities of yttria about 3 mg. per litre may be estimated.

A light-guiding, flexible fused-silica (FFS) capillary has been used in designing an optical fiber Cr VI sensor for monitoring Cr VI ions in water samples. The FFS capillary is similar to a conventional silica optical fiber in that it can guide light in the wavelength region from the UV to the near IR but different from a conventional optical fiber in that it is a tubular waveguide. The inner surface of the FFS capillary is fused silica, which one can modify to design an optical fiber chemical sensor. The FFS capillary has a cladding layer plus a protective polymer coating on its outside surface. The cladding layer ensures the ability of the FFS capillary to guide light. The protective coating increases the FFS capillary's mechanical strength and makes it robust for practical applications. Compared with conventional silica optical fibers, it is much easier and more feasible to use this FFS capillary to fabricate long-path (tens of meters to thousands of meters) evanescent-wave based chemical sensors. We describe a Cr VI sensor based on the intrinsic evanescent-wave absorption by Cr VI ions in a water sample filled inside the capillary as an example of use of a FFS capillary in chemical sensor design. This simple sensor, using a 30m light-guiding FFS capillary as a transducer, has the capability of detecting as little as 31 parts in 10^9 of Cr VI in a water sample, which is close to the detection limit of some sophisticated, expensive analytical instruments.

The study took 193 right and 189 left, dry, fully ossified human humeri to derive regression formulae for the establishment of the total length of the humerus from the upper and lower segments, the line of division between the segments being the lowest level of insertion of the deltoid muscle.Also studied have been 151 right and 126 left, dry, fully ossified radii to derive regression formulae for establishment of the total length of the radius from the upper and lower segments, the line of division between the segments being the lowest level of insertion of the pronator teres muscle.All the regression formulae have a high degree of prediction, and are valuable in establishing the stature of an individual.