Treatment of municipal wastewater UASB reactor effluent by unconventional flotation and UV disinfection.

Post-treatment of an UASB reactor effluent, fed with domestic sewage, was conducted using two-stage flotation and UV disinfection. Results were compared to those obtained in a parallel stabilisation pond. The first flotation stage employed 5 - 7.5 mg L(-1) cationic flocculant to separate off more than 99% of the suspended solids. Then, phosphate ions were completely recovered using carrier flotation with 5-25 mg L(-1) of Fe (FeCl3) at pH 6.3-7.0. This staged flotation led to high recoveries of water and allowed us to separate organic matter and phosphate bearing sludge. The water still contained about 1 x 10(2) NMP/100 mL total coliforms, which were removed using UV radiation to below detection levels. Final water turbidity was < 1.0 NTU, COD < 20 mg L(-1) O2 and 71 mNm(-1), the liquid/air interfacial tension. This flotation-UV flowsheet was found to be more efficient than the treatment in the stabilisation pond and appears to have some potential for water reuse. Results were discussed in terms of the biological, chemical and physicochemical mechanisms involved.     

Changing the hydrogen content of alloy steel in relation to the technology used to cool cast slabs

Results are reported from the production of two trial heats of alloy steel in which the cast slabs were cooled in a thermostatted chamber and in a dense stack. It is shown that cooling slabs in such a chamber makes it possible to reduce the hydrogen content of the steel 30% compared to slabs that are cooled while stacked.     

Reconfigurable arrays by phase-only control

Due to space or cost reasons, a single array antenna can be required to radiate more than one pattern, each pattern being selected by an electronic control, in which only the phase can be modified. A synthesis method for such a problem that is able to determine both the common amplitude and the various phases in an integrated way is presented. Moreover, the approach is flexible enough to take into account additional constraints and allows an efficient implementation. Some test cases showing the effectiveness of the method are presented     

Catalyst for desulfurization of high-end-point diesel fuel

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 34–35, March, 1992.     

Catalytic cracking in presence of an aromatic addition

Fluidized bed catalytic cracking of vacuum gas oil fractions in the presence of extract from phenol purification of heavy lubricating oil fraction as an aromatic addition was investigated. Results show that, at the optimum concentration of the addition, coke formation on the catalyst decreases by 50 to 70% while the content of olefinic hydrocarbons in gasoline decreases, with a corresponding increase in the content of paraffin/naphthene hydrocarbons. The yield of gasoline increases, while its octane number increases by about two units.     

A computer program for generating power-system load-point minimalpaths

In reliability evaluation that uses minimal cut-set theory, the deduction of minimal cut-set orders is crucial and depends on all the identified minimal paths associated with the load point whose reliability indices are desired. An input-reduction programming technique that automates this deduction is presented. The technique can be applied to a network of any configuration and finds its greatest application in complex networks with multiple inputs. The power-system structure in the form of power-arms (termination busbars, branch and protective device) is the only initial input data needed. The results obtained, in terms of minimal paths and minimal cut-set orders for all the load points, using the program on a sample power system compare well with the existing results. The program is compact, modular, and easy to use and can be applied to any complex system to generate minimal cut-sets of the desired orders     

Vitamin E constituents of Weaning Foods from Germinated Cereals and Legumes

Four weaning food formulations prepared from 70% 72-hr germinated rice/corn and 30% 48-hr germinated mungbean/cowpea were studied for tocopherol constituents and compared to ungerminated controls. γ-TocopheroIs were the major constituents of the mungbean-supplemented samples. The cowpea-supplemented foods contained a predominance of δ-tocopherols followed closely by γ-tocopherols, α-Tocopherols were comparatively higher in corn- than in rice-formulations. Tocopherols in the weaning foods decreased due to germination especially the γ-tocopherols of germinated corn-mungbean.     

Combination surface hardening of steel (laser alloying + nitriding)

In recent years, combination methods for surface hardening of alloys have been actively developed and incorporated into industrial practice. The widespread interest in such technologies is explained by the possibility of obtaining extremely high-quality surface properties for the pieces. In this paper, we consider the technology for combination surface hardening of low-carbon steel, involving laser alloying of the surface with nitride forming elements followed by nitrïding of the entire alloyed layer. We have investigated the properties of the hardened surface layer.Moscow Highway Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 3, pp. 2–5, March, 1994.