PRELIMINARY PERFORMANCE TESTS OF A PULSED JET PLEATED PAPER CARTRIDGE FILTER SYSTEM

ABSTRACT

A pulsed jet pleated paper cartridge filter system was tested for particle removal efficiency and operating stability using agricultural limestone as the test dust. The test system consisted of 6 pleated paper filter units arranged in parallel, each unit having an effective filtration area of 18.1 square meters. The system was operated at constant pressure drops of 6.25, 7.50 and 8.75 kPa (2.5, 3.0 and 3.5 inches of water), with face velocities of 0.78 to 1.04 m/ min (2.5 to 3.4 feet per minute) and dust loadings ranging from 0.5 g/ m to 2.5 g/ m³. Penetration through the media appeared to be relatively independent of dust loading, and efficiencies were in the 99.95 + % range. Slightly lower efficiencies were found for particles having diameters of 0.3 to 1.0 micrometers. A measure of the redeposition of dust pulsed from the filter was required to describe the effects on the pulse rate caused by changes in system flow and pulsing set point. Increased redeposition was found to occur with increasing flow rate, causing an increase in the pulse rate required to maintain operation of the system at a pulsing set point. Overall, the reverse pulse jet pleated paper cartridge filter system displayed extremely high particle removal efficiency in a compact unit that operated with low differential pressure.     

Application of coding theory to the construction of the Singer difference sets†

In this paper we give a new and simple construction for the cyclic [(q ^m ? 1)/(q ? 1), q ^m?1, q ^m?2(q? 1)]—difference sets (q = p ^γ is a prime power) using the methods of coding theory. The construction is such that, in the case q = 2, the 2-ranks of both the incidence matrix and its complementary matrix are easily determined.     

Changes in Selected Chemical and Antinutritional Components during Tempeh Preparation Using Fresh and Hardened Common Beans

A tempeh-type fermented product was prepared from fresh and hard-to-cook (HTC) common beans. Fermentation decreased fat and fiber content and increased soluble solids, total and soluble proteins, soluble carbohydrates and pH of both bean samples. About 12% of solids were reduced during 72 hr fermentations. Results suggested that Rhyzopus oligosporus was capable of hydrolyzing the trypsin inhibitor and phytic acid of the substrate. Lectin and tannin contents decreased as a result of treatments applied during substrate preparation. Fresh and HTC beans may be converted by this fermentation technique into products of higher quality.     

ExperTAXsm: an expert system for corporate tax planing

Abstract: This paper describes the development of ExperTAX^sm, an expert system designed as a part of the service rendered by the audit and tax practices of the accounting firm of Coopers & Lybrand in the corporate tax accrual and planning function. The current operating environment is described and the expert system based solution is presented. The knowledge engineering process is described in detail and novel techniques for knowledge extraction are presented. The resulting system and its knowledge base is also presented together with a discussion on detailed knowledge acquisition and ongoing knowledge base maintenance facilities.     

Defect Structure and Electrical Properties of Single-Crystal Ba0.03Sr0.97TiO3

The electrical conductivity and thermoelectric power of single-crystalline Ba_0.03Sr_0.97TiO₃ were measured over a wide temperature (800° to 1100°C) and oxygen partial pressure (10⁵ to 10^-15 Pa) range. Our experimental data, like those of previous workers on nominally undoped BaTiO₃ or SrTiO₃, support a defect model based on doubly ionized oxygen vacancies, electrons, holes, and accidental acceptor impurities. The simultaneous measurement of electrical conductivity and thermoelectric power, together with precise experimental data obtained with an advanced thermoectric power measurement technique, enabled us to determine for the first time reliable values for the preexponential factors and the activation energies which characterize the defect equilibrium constants. These calculated values, together with the defect model, were found to give an excellent fit to the experimental data, and were used to generate the boundaries, in P _o2-1/ T space, of the various defect regimes.     

NMR Study of Adsorbate Self-Diffusion in Porous Glasses

The NMR pulsed field gradient technique was used to study molecular transport in porous glasses. The adsorbent materials were produced by leaching phase-separated sodium-boron-silica glasses of different composition, then heat-treating. The pore diameters of the glass samples produced were within the interval 0.8 to 50 nm. Water, methanol, dodecane, and do-decene were used as adsorbates. The coefficients of adsorbate self-diffusion were found to decrease with decreasing pore diameter. In comparison with the neat liquids, a reduction in the adsorbate mobility (up to two orders of magnitude) was observed. For the larger pores, that decrease may be attributed to the tortuosity of the adsorbent, whereas the low diffusivities in the porous glasses with small pores are a consequence of the stabilizing effect of the rigid adsorbent framework.     

Effect of Metal Additions on the Microstructure of Zirconia

The diffusion of titanium into zirconia was studied to determine the mechanism by which increased sintering occurred in the metal-modified zirconias. Results revealed that the increased sintering occurred only when compositions above the solubility limit were fired considerably above the melting point of the titanium. Examination of the system Ti-Zr-0 revealed that considerable liquid was present at these firing temperatures. This liquid phase promoted the sintering of the zirconia. The increased sintering did not occur for compositions above the solubility limit fired below the temperature of liquid phase formation, or for compositions below the solubility limit fired considerably above or below the melting point of titanium.     

Caffeine Inhibition of Sterigmatocystin, Citrinin, and Patulin Production

Microbiological medium was used to study the effect of caffeine on sterigmatocystin, citrinin, and patulin production by Aspergillus versicolor, Penicillium citrinum, and Penicillium urticae, respectively. Caffeine inhibited the growth of the three fungal species and decreased sterigmatocystin and patulin production. The effect on citrinin production appeared to be limited to a delay in toxin synthesis. A preliminary examination of P. urticae suggested that caffeine's anti-mycotoxigenic activity does not involve a generalized inhibition of lipid synthesis.