Effect of handling material on mechanical and optical properties of feldspathic porcelain.

Objective: To evaluate the optical, chemical, and mechanical properties of feldspathic porcelain after handling with different instrument materials.

Material And Methods: Feldspathic porcelain was manipulated with different spatula compositions: metal spatula (MS), plastic spatula (PS), and glass spatula (GS) for the fabrication of 30 (n = 10) disks. Contrast ratio (CR), translucency parameter (TP), and surface Knoop microhardness (KHN) were measured.

Sodium hydroxide or urea pretreatment of acerola (Malpighia emarginata) fruit residue increases dry matter degradability and reduces methane production in in vitro rumen fermentation.

The aim of this study was to evaluate the effect of adding different concentrations of either urea or NaOH in dehydrated acerola (Malpighia emarginata) fruit residue (DAFR) on chemical composition, in vitro rumen degradability, and gas and methane production. A completely randomized design was used with the following seven treatments: control, without chemical treatment, or pretreatment of DAFR with urea or NaOH at 20, 40, or 60 g/kg dry matter (DM). DM degradability and gas and methane production of DAFR were evaluated by semi-automated in vitro gas production technique.

Diets containing cunhã (Clitoria ternatea L.) hay and forage cactus (Opuntia sp.) meal on production and meat quality of Boer crossbred goat.

The aim of this study was to evaluate the effect of association of forage cactus meal (CM) and cunhã hay (CH) on carcass traits, meat quality, and fatty acid (FA) profile of goats. Twenty-four goats were finished on diets composed with the association of CM and CH (83% CH + 17% CM, 67% CH + 33% CM, or 50% CH + 50% CM), corresponding to 60% of the total diet; the remainder was composed of 10% elephant grass and 30% concentrate. The control treatment consisted of 70% elephant grass and 30% concentrate.

Theoretical study of acid-catalyzed hydrolysis of epoxides.

A theoretical study of propylene oxide acid-catalyzed hydrolysis was performed by investigation of the S(N)1 and S(N)2-like mechanisms. By using chemometric tools, hierarchical cluster analysis (HCA), and principal component analysis (PCA), the MP2/6-311++G** level of theory was selected from HF, MP2, and DFT as the best method to describe the geometry of the basic skeleton (oxirane). At this level of theory, geometry optimizations, vibrational frequencies, intrinsic reaction coordinate (IRC), and other thermodynamic calculations have shown that the borderline S(N)2 mechanism is more favorable than pure S(N)2 and S(N)1 mechanisms in the gas phase.