Effects of Nonionic, Cationic, and Mixed Nonionic-Cationic Surfactants on the Acid-Base Behavior of Phenyl Salicylate

The effects of Brij 35 micelles, CTABr micelles, and mixed Brij 35–CTABr micelles on the acid–base behavior of phenyl salicylate (PST) have been studied in aqueous solution containing 2% v/v acetonitrile. The apparent pK_b (pK^app_b) of PST is decreased by 1.5 pK units with the increase in [Brij 35] from 0 to 0.02 M which is attributed to micellar medium effect. The values of pK^app_b remain almost independent of [CTABr] within its range 0.01–0.03 M. The increase in [CTABr] from 0 to 0.03 M in aqueous solution containing 0.02 M Brij 35 has not resulted in a change in pK^app_b. This shows that the characeristic structural features of nonionic Brij 35 micelles remain essentially unchanged on addition of CTABr under the present experimental conditions.     

Reactor production of anhydrous18F ion

The direct production of anhydrous¹³F ion has been achieved through the incorporation of a new approach to hot atom reactions for reactor generated radiopharmaceuticals. Capitalizing on the traditional Li₂CO₃ method for hydrated¹⁸F production, a unique target design and geometry utilizing neutron generated energetic tritions emerging from the surface of a thin LiF embedded stainless steel matrix react with gaseous O₂ to produce¹⁸F as a free recoiling anhydrous species. Approximately 10–15 MBq of reactive anhydrous¹⁸F ion absorbed onto a metallic foil has been produced by this method. Verification of the production of¹⁸F was substantiated through decay measurements using Ge(Li) spectroscopic analysis, and by the synthesis of¹⁸F-fluoromethane gas. Cyclotron gas target chemistry which has been instrumental in the preparation of¹⁸F-2FDG and other metabolic tracers may be reproduced using this technique by the addition of 1% F₂ scavenger gas to a recirculating reactor gas handling system.     

Ultra Moisturizing Anti-Wrinkle Lotion Enriched with Tocotrienols

A stable palm-based anti-wrinkle lotion enriched with tocotrienols was successfully prepared. The stability of the product was due to the presence of liquid crystalline structure in the emulsion system. It helps in bringing the active to the dermis layer. Functionality active ingredients such as tocotrienols and anti-wrinkle were added in the formulation. A commercial plant extract was used to strengthen the collagen seated at the dermis layer. The product was formulated to pH 5.5 which is suitable for the skin. The mean droplet size is 10.2 µm with a monomodal distribution pattern which prevents agglomeration. This will decrease Brownian motion, thus prolonging its stability. Long-term acute moisturizing tests show a significant increase of between 24% and 17% hydration for five and six weeks respectively. The efficacy testing on 12 subjects confirmed a reduction in natural fine wrinkles on faces during aging or premature aging at ?7.6%.     

X-ray diffraction studies on crystallite size evolution of CoFe2O4 nanoparticles prepared using mechanical alloying and sintering

Nanosized cobalt ferrite spinel particles have been prepared by using mechanically alloyed nanoparticles. The effects of various preparation parameters on the crystallite size of cobalt ferrite which includes milling time; ball-to powder weight ratio (BPR) and sintering temperature, were studied using X-ray diffractometer (XRD). Scherrer's equation was used to study the crystallite size evolution of the as-prepared materials. The results of the as-milled sample revealed that both milling time and BPR plays a role in determining the crystallite size of the milled powder. However, where sintering is involved, the sintering temperature results in grain growth, and thus plays a dominant role in determining the final crystallite size of the samples sintered at higher temperature (above 900 °C). From the vibrating-sample magnetometer (VSM) measurement it was observed that the coercivity of the as-milled samples without sintering is almost negligible, which is a type characteristic of superparamagnetic material. However, for the sintered samples, the saturation increases while coercivity decreases with increases sintering temperature.     

Investigation of Brillouin effects in small-core holey optical fiber: lasing and scattering

We demonstrate for what is believed to be the first time a Brillouin laser based on a holey fiber (HF). Using a simple Fabry-Perot resonator scheme containing a 73.5-m-long highly nonlinear HF with an effective area of 2.85 microm(2) , we obtain a threshold of 125 mW and a slope efficiency of ~70% . Stimulated and spontaneous Brillouin scattering effects are investigated in the HF, and we show that the high lasing threshold is due mainly to reduction of the effective gain coefficient caused by structural nonuniformity along the fiber length.     

Remediation of <Superscript>137</Superscript>Cs radionuclide in nuclear waste effluents by polymer composite: adsorption kinetics,isotherms and gamma irradiation studies

Polypyrrole is incorporated with activated carbon in large size dopant solution and investigated for ¹³⁷Cs removal studies. Adsorption experiments showed optimum conditions within 240 min contact time, pH 6, 0.2 g adsorbent and?≤?100 mg/l adsorbate dose, respectively, while the kinetic data followed pseudo-first-order model. Isotherm data were reproducible by the Langmuir isotherm yielding 23 mg/g maximum sorption capacity. Regeneration of adsorbent was attempted and indicated promising results within three cycles. The surface behavior has also been examined and revealed a well-ordered structure under gamma irradiation. This is a cheap adsorbent to consider and has also proven to possess higher sorption capacity than most highly-cost inorganic materials in use.     

Gain and noise figure improvements in a shorter wavelength region of EDFA using a macrobending approach

Gain and noise figure improvements are demonstrated in a shorter wavelength region of a double-pass EDFA using a macrobending approach. The EDF is wound in a small radius to suppress the amplified spontaneous emission at the longer wavelength in order to achieve a high amplification in the shorter wavelength. Gain enhancements of about 12–14 dB are obtained with macrobending at the wavelength region between 1480 and 1530 nm. The macrobending also reduces the noise figure of the EDFA at wavelengths shorter than 1525 nm with a maximum improvement of 25 dB.     

Synthesis and X-ray analysis of (RS)-N-tert-butyl-2-anilino-

The crystal and molecular structure of (RS)-N-Tert-butyl-2-anilino-3,3-dimethylbutanamide, a derivative of an amino acid that was obtained by highly selective cleavage of 1,3-di-tert-butylaziridinone by aniline, is described. The racemic mixture of the amide crystallizes in the space groupP 2₁/n with four molecules per unit cell. Crystal Data:a=10.483(2) Å,b=6.206(1) Å,c=24.767(5) Å,β=90.39(3),V=1611.5(6) A³,R(F)[I>2σ(I)]=0.0679.wR(F ²) [I>2σ(I)]=0.1148.