Abstract This paper presents an exact solution for the boundary-value problem which describes the linear buckling of axially-compressed cylindrical panels with frames attached to the circular edges. The boundary conditions differ from the classical simply supported ones, often assumed for design purposes, in the sense that the torsion resisted by the frames are also taken into account. The quality of the results reported herein may be valuable benchmark data.

Resumo Zeólitas LTA e FAU foram sintetizadas com brometo de cetiltrimetilamônio (CTAB) visando avaliar os efeitos das razões Si/Al, Na/Al e H2O/Al, do tempo e da temperatura no rendimento de cada estrutura. A significância de cada variável foi determinada através de planejamentos experimentais, cujas variáveis resposta foram as áreas de picos de difração de raios X específicos. O CTAB não agiu como direcionador estrutural, mas sim como modificador de crescimento, aumentando a taxa de crescimento dos cristais. Em temperatura baixa, LTA foi obtida em baixas razões Si/Al, enquanto FAU cristalizou-se em razões maiores, indicando uma competição entre as duas estruturas. O aumento da temperatura aumentou a cinética de recristalização das fases LTA e FAU, menos densas e metaestáveis, em fases mais densas e mais estáveis, como sodalita e cancrinita. A diminuição de concentração de Na+ e água reduziu a cristalinidade das estruturas, enquanto que o aumento de Na+ favoreceu a formação de FAU em detrimento de LTA.

Abstract LTA and FAU zeolites were synthesized with the addition of cetyltrimethylammonium bromide (CTAB) to assess the effects of Si/Al, Na/Al and H2O/Al ratios, time and temperature on the yield of each structure. The significance of each variable was determined by means of experimental designs, whose response variables were the areas of specific XRD peaks. CTAB did not act as a structure-directing agent, but rather as a growth modifier, increasing the growth rate of LTA and FAU crystals. At low temperature, LTA was afforded at low Si/Al ratio, while FAU crystallized at higher ratios, indicating a competition between the phases. Increasing temperature accelerated the kinetics of recrystallization of the less dense and metastable LTA and FAU phases in denser and more stable phases, such as sodalite and cancrinite. Decreasing the concentration of Na+ and water reduced the crystallinity of both structures, while increasing the concentration of Na+ favored LTA over FAU.

Emulsifying properties of sodium caseinate -locust bean gum Maillard conjugates produced at different temperatures (54 - 96 ºC), protein/polysaccharide ratios (0.3 - 1.0) and reaction times (1 - 24 hours) were evaluated. Conjugate formation was confirmed by formation of color and high molecular weight fractions and the decrease of the αs- and β-casein bands. The emulsions stabilized by Maillard conjugates showed good stability. The mean droplet diameter (d32) tended to decrease with the increase of incubation time and temperature, except at extreme conditions (24 hours and 90 ºC or 96 ºC) when the partial degradation of the conjugates was probably favored, resulting in phase separation of emulsions. The emulsion viscosity decreased with the increase in the protein/polysaccharide ratio and with the degradation of the conjugates. The conditions used in the experimental design made the optimization of the conjugate production viable, which showed greater emulsifier properties than the pure protein under acid conditions.

In previous work, it was observed that the covering of soybean seeds with bacteria and micronutrients enhances vigorous growth of the plant thereby avoiding use of ammoniacal fertilizers. In the spouted bed covering can be done by pulverization of the coater slurry on the soybean seeds using a pneumatic atomizer. The optimum thickness of the cover allows the fundamental gaseous interchanges for germination and provides the ideal conditions for bacterium activity. The objective of this work was to study the influence of the process variables on thickness of the cover. A simulation of the mass distribution of seeds was obtained using a population balance model. Through the results obtained the operational conditions under which the coating layer distribution were determined has the greatest uniformity.