Modification of Parylene film-coated glass with TiO2 nanoparticles and its photocatalytic properties

A titania film was deposited on Parylene-coated glass by a one-step, ultrasound-assisted procedure. The TiO₂ nanoparticles formed during the sonochemical hydrolysis of Ti(i-OPr)₄ were thrown to the surface and strongly attached to the Parylene substrate. By using different solvents (water, ethanol or their mixture) and reagent concentrations, the thickness, uniformity and crystallinity of the deposited layer were regulated. PVP was used to stabilize the highly homogeneous distribution of TiO₂ nanocrystals on the Parylene surface. The morphology and structure of the coated films were characterized by physical and chemical methods such as: X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), Rutherford backscattering spectrometry (RBS), and optical spectroscopy. The photocatalytic activity of the titania-modified Parylene film in the photo discoloration of methylene blue was demonstrated. The experimental results revealed a correlation between the uniformity of the nanostructured anatase titania film and its photocatalytic properties.     

SULFURIC ACID RECOVERY THROUGH SOLVENT AIDED DECOMPOSITION OF AMMONIUM SULFATE.

A process for the recovery of sulfuric acid through anmonium sulfate (I) is described. This process is based on extraction-aided disproportionation of anmonium hydrogen sulfate to ammonium sulfate and sulfuric acid. Acid-base couple solvents were found to be more suitable for this process than oxygenated solvents as they can operate at higher temperatures and concentrations. A solvent composed of 0.50M methyl tricaprylyl ammonium salt of dinonyl naphthalene sulfonic acid in aromatics-free white spirits, was chosen. Sulfuric acid, at a concentration of about 35%, can be obtained from the H₂SO₄-(NH₄)₂SO₄-H₂O system. This disproportionation may be applied to recover sulfuric acid from gypsum. CaSO₄ is converted in reaction with carbon dioxide, anmonia and water to CaCO₃ and ammonium sulfate, which is thermally decomposed to ammonia and ammonium hydrogen sulfate. The overall process is equivalent to the displacement of H₂SO₄ from CaSO₄. by means of CO₂ and thermal energy.     

Effects of crew composition on crew performance: Does the whole equal the sum of its parts?

Varied the composition of Israeli 3-person military crews (mean age 19 yrs) by assigning the male members according to all possible combinations of levels of ability and motivation. Crews performed real military tasks in a military field setting, and unit commanders ranked the effectiveness of their performance at the end of 2 mo of military activity. There were 208 crews, or 624 Ss, in all. Findings show that both ability and motivation had an additive effect on crew performance. Crew composition effects were found for ability but not for motivation. The performance of uniformly high-ability crew members far exceeded the levels expected on the basis of individual crew members' ability, whereas the performance of uniformly low-ability crews fell considerably below the expected level. It is concluded that when crews perform highly interdependent tasks, performance is likely to be affected in a nonadditive manner by crew composition. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tel-Aviv

Tel-Aviv is Israel's largest metropolitan area. The 1983 Census of Population found in greater Tel-Aviv some 1.565 million people who comprised 38.5% of the total population of Israel. The conurbation of Tel-Aviv now consists of 41 localities, compared to 27 in 1972.¹ These data reflect the enormous growth of a very young city, just 75 years old, competing with two ancient ones; Jerusalem and Jaffa. Jerusalem has always been the religious centre of the country, and since the beginning of the British Mandate after the first world war, it has served as the political centre as well. Jaffa, now a section of the city of Tel-Aviv, has been considered the maritime gate of mountainous Jerusalem.     

Validity of an assessment center for identifying future female officers in the military.

Focused on a comparative evaluation of traditional selection procedures (e.g., selection interviews) with static and dynamic assessment techniques of an assessment center. The latter were designed to identify officer potential of 193 18–19 yr old women applicants for commissioned service in the military. All were admitted to officer's school, regardless of the assessment achievements obtained prior to arrival at the assessment center. The final score attained in officer training served to evaluate the predictive validity of all selection procedures compared. A high multiple correlation was found between assessment center predicting measures and final score in officer training. This validity was substantially higher than that attained in relation to the same Ss using traditional predictors (e.g., selection interviews). (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A synthesis theory for self-oscillating adaptive systems (SOAS)

A quantitative synthesis theory is presented for the Self-Oscillating-Adaptive-System (SOAS), whose nonlinear element has a static, odd character with hard saturation. The synthesis theory is based upon the quasilinear properties of the SOAS to forced inputs, which permits the extension of quantitative linear feedback theory to the SOAS. A reasonable definition of optimum design is shown to be the minimization of the limit cycle frequency ω₀. The great advantages of the SOAS is its zero sensitivity to pure gain changes. However, quasilinearity and control of the limit cycle amplitude at the system output, impose additional constraints which partially or completely cancel this advantage, depending on the numerical values of the design parameters. By means of narrow-band filtering, an additional factor is introduced which permits trade-off between filter complexity and ω₀ minimization. It is shown that any SOAS design is inherently sensitive to external disturbances, and it is shown how to find the extreme disturbance for which quasilinearity holds. The theory permits optimum design to achieve specified bounds on system response to command inputs, despite given ranges of plant parameter uncertainty.     

Effect of relative magnitude of reward and type of need on satisfaction.

Tested the hypothesis of an interaction between type of need and magnitude of relative reward in their effect on level of satisfaction. It was predicted that there would be gradually increasing differences between satisfaction scores of large vs small magnitude of relative reward as the need was located in a higher position on A. Maslow's (1954) need hierarchy (excluding the self-actualization need). The analysis of the reactions of 40 female married 18-40 yr old undergraduates to a questionnaire designed for this purpose confirmed the hypothesis. Findings are discussed in terms of the social comparison and Maslow's hierarchy theories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sonochemical deposition of Au nanoparticles on titania and the significant decrease in the melting point of gold

In this article, sub-micron size particles of titania were coated by a nanosized gold particles with the aid of power ultrasound. We could achieve a uniform coating of gold nanoparticles on a titania surface with a maximum gold loading of 10 wt%. In addition, we report on the experimental evidence for a significant decrease in the melting point of gold nanoparticles (<2 nm) by approximately 850 degrees C from that of the bulk material.     

High-sensitivity Q-band electron spin resonance imaging system with submicron resolution

A pulsed electron spin resonance (ESR) microimaging system operating at the Q-band frequency range is presented. The system includes a pulsed ESR spectrometer, gradient drivers, and a unique high-sensitivity imaging probe. The pulsed gradient drivers are capable of producing peak currents ranging from ～9 A for short 150 ns pulses up to more than 94 A for long 1400 ns gradient pulses. Under optimal conditions, the imaging probe provides spin sensitivity of ～1.6 × 10(8) spins∕√Hz or ～2.7 × 10(6) spins for 1 h of acquisition. This combination of high gradients and high spin sensitivity enables the acquisition of ESR images with a resolution down to ～440 nm for a high spin concentration solid sample (～10(8) spins∕μm(3)) and ～6.7 μm for a low spin concentration liquid sample (～6 × 10(5) spins/μm(3)). Potential applications of this system range from the imaging of point defects in crystals and semiconductors to measurements of oxygen concentration in biological samples.