Low-temperature post-treatment of anaerobically treated-sewage in anaerobic filter with cationic-polymer addition.

The post-treatment of domestic sewage pretreated in a 6 m3 UASB was investigated in two high-rate anaerobic filter (AF) reactors operated in parallel. The difference between the two AF reactors was only the addition of cationic polymer to the second reactor (AF + P). The reactors were operated at low temperatures, ranged between 13 and 20 degrees C. The media in each AF reactor consisted of vertical sheets of reticulated-polyurethane foam (RPF) with knobs. The results demonstrated that the AF + P reactor (HRT = 3 h) with cationic polymer addition (2 mg/L) was an efficient system for post-treatment. The removal efficiencies for total, suspended, colloidal and dissolved COD were, respectively, 41, 86 and 76 and 12% in the AF + P reactor and they were, respectively, 80, 97, 77 and 66% in the UASB + (AF + P) system. The removal of total, suspended and colloidal COD in the UASB + (AF + P) system were significantly higher than those achieved in the UASB + AF system. As hardly any nutrient was removed in the UASB + (AF + P) system, the effluent after pathogen removal is a valuable product for irrigation and fertilisation to close the water and nutrients cycle.     

Extractive Properties of Synergistic Mixtures of Dipicolinic Acid Diamides and Chlorinated Cobalt Dicarbollide

Extraction of Cs, Sr, Eu, U, Np, and Am with mixtures of dipicolinic acid diamides with chlorinated cobalt dicarbollide was studied. A synergistic effect was revealed.     

An Acoustic Converter Used to Measure Ionizing Radiation Energy Loss

A monitor is proposed based on ultrasonic production when ionizing radiation passes through a medium. The recording element is a 0.2 mm aluminum plate mounted in a ceramic acoustic converter AC in the form of a wedge of thickness 2 mm. The low plate thickness minimizes the beam parameter distortion, while special technology used in the AC provides high sensitivity. The device has been calibrated in the proton beam from the ITEP accelerator at 200 MeV with 2·10⁹–6·10¹⁰ particles in a pulse and a pulse length of 70 nsec.     

Theoretical analysis of cladding-mode waveguide dispersion and its effects on the spectra of long-period fiber grating

A new method to control the free spectral range (FSR) of a long-period fiber grating (LPFG) is proposed and theoretically analyzed. As the refractive index decreases radially outward in the silica cladding by graded doping of fluorine, waveguide dispersion in the cladding modes was modified to result in the effective indexes change and subsequently the phase-matching conditions for coupling with the core mode in a LPFG. Enlargement of the FSR in a LPFG was theoretically confirmed.     

An investigation of sugar extraction methods and the use of microwave power for date syrup processing: efficiency and color related considerations.

This study investigates the effect of extraction methods on the color of date syrup and the potential use of microwave power for syrup processing. Sugar solutions were extracted from dates by boiling, soaking and blending. Color and sugar content of the extracted solutions were measured, and the percentage of sugar extracted form the total fruit sugar determined. Boiling was found to be the most efficient method of extraction whereby 74% of total samples sugar was extracted. In contrast, only 54.2% of fruit sugar was extracted by blending and 42% by soaking. In addition, solutions extracted by soaking and blending had a foaming problem in the subsequent concentration process. The extraction method had no effect on the product final color. The extracted solution was concentrated using two heating methods: conventional and microwave heating at a 600 W capacity and a frequency of 2450 MHz applied at three power levels: 10, 7, and 6. In the heating process, 180 minutes were needed to achieve a 77% degrees Brix using convective heating, while it took 81, 138, and 166 minutes of microwave heating at power level 10, 7, and 6, respectively to achieve the same concentration. Water activity of the syrup was measured within a sugar content range of 50 to 80% degrees Brix and the sugar concentration at which the product is shelf stable was determined at 76%.     

Reactions Between Ingredients in Binary Silicate Glasses

It is demonstrated that the density of binary glasses upon variation of the molar content of the modifier in their compositions obeys a parabolic dependence, whose parameters can be used to estimate the extent and type of reactions between the components. The reaction parameters in glasses that are prone to liquation are lower by an order of magnitude and have the negative sign.     

Hf-doped and NH/sub 3/-nitrided high-K gate dielectric thin film with least drain current degradation and flatband voltage shift

A novel technique to form high-K dielectric of HfSiON by doping base oxide with Hf and nitridation with NH/sub 3/, sequentially, is proposed. The HfSiON gate dielectric demonstrates excellent device performances such as only 10% degradation of saturation drain current and almost 45 times of magnitude reduction in gate leakage compared with conventional SiO/sub 2/ gate at the approximately same equivalent oxide thickness. Additionally, negligible flatband voltage shift is achieved with this technique. Time-dependent dielectric breakdown tests indicate that the lifetime of HfSiON is longer than 10 years at V/sub dd/=2 V.     

X-Ray Study of the Effect of Heat on the Structural Parameters of Armos Fibres

In studying a series of fibre samples spun in steady-state conditions, the following was found: as a function of the conditions of processing Armos fibre, two structural modifications of the polymer can form; intensive crystallization of the modification corresponding to the 28.7° reflection begins in heat treatment above 220°C; above 320°C, intensive crystallization of the modification corresponding to the 14.25° reflection is observed; at 360°C, symbatic enhancement of the intensities of both reflections with a weak change in the other structural parameters of the fibre is observed.     

Development of a Continuous Segmented Flow Tubular Reactor and the “Scale‐out” Concept – In Search of Perfect Powders

The synthesis of powders with controlled shape and narrow particle size distributions is still a major challenge for many industries. A continuous Segmented Flow Tubular Reactor (SFTR) has been developed to overcome homogeneity and scale‐up problems encountered when using batch reactors. Supersaturation is created by mixing the co‐reactants in a micromixer inducing precipitation; the suspension is then segmented into identical micro‐volumes by a non‐miscible fluid and sent through a tube. These micro‐volumes are more homogeneous when compared to large batch reactors leading to narrower size distributions, better particle morphology, polymorph selectivity and stoichiometry. All these features have been demonstrated on single tube SFTR for different chemical systems. To increase productivity for commercial application the SFTR is being “scaled‐out” by multiplying the number of tubes running in parallel instead of scaling‐up by increasing their size. The versatility of the multi‐tube unit will allow changes in type of precipitate with a minimum of new investment as new chemistry can be researched, developed and optimised in a single tube SFTR and then transferred to the multi‐tube unit for powder production.