Epoxidized Soybean Oil: Evaluation of Oxidative Stabilization and Metal Quenching/Heat Transfer Performance

Vegetable and animal oils as a class of fluids have been used for hundreds of years, if not longer, as quenchants for hardening steel. However, when petroleum oils became available in the late 1800s and early 1900s, the use of these fluids as quenchants, in addition to their use in other industrial oil applications, quickly diminished. This was primarily, but not exclusively, due to their generally very poor thermal-oxidative instability and the difficulty for formulating fluid analogs with varying viscosity properties. Interest in the use of renewable fluids, such as vegetable oils, has increased dramatically in recent years as alternatives to the use of relatively non-biodegradable and toxic petroleum oils. However, the relatively poor thermal-oxidative stability has continued to be a significant reason for their general non-acceptance in the marketplace. Soybean oil (SO) is one of the most highly produced vegetable oils in Brazil. Currently, there are commercially produced epoxidized versions of SO which are available. The objective of this paper is to discuss the potential use of epoxidized SO and its heat transfer properties as a viable alternative to petroleum oils for hardening steel.     

Maternal anemia in Concepción province, Chile: association with maternal nutritional status and fetal growth

Previous studies in Santiago, Chile have established that anemia in the earliest stages of pregnancy is a public health issue. The situation in other parts of the country is unknown. The purpose of this study is to establish the prevalence of anemia in pregnant women in the province of Concepcion and evaluate its association with maternal nutricional status and fetal growth. The study included 1782 women with singleton pregnancies who began prenatal check-ups in 2004 at the public primary health care centers. Anemia was established using the following criteria: from WHO (Hb < 11 g / dl) and from the USA Center for Disease Control (CDC) (Hb < percentile 5 for each gestational week). Anemia prevalence was compared in relation to independent study variables: maternal age, parity, morbidity and smoking habit, and mother and child anthropometry. A multivariable logistic regression model studied the possible effect of anemia on fetal growth. The prevalence of anemia was 10.9% and 14.5% using the WHO and CDC criteria, respectively. The mother's nutritional status was significantly associated with anemia. However, anemia according to WHO and CDC criteria at the beginning of pregnancy was not significantly associated to fetal growth in the univariate and multivariate analyses. The prevalence of anemia in the province of Concepcion constitutes a public health problem that needs to be addressed and it is slightly higher to that recently observed in the county of Puente Alto, Santiago.     

Biohydrogenation intermediates are differentially deposited between polar and neutral intramuscular lipids of lambs

The deposition of C₁₈ fatty acids (FA), especially in rumen biohydrogenation intermediates, was studied using 36 lambs fed four diets with graded proportions of sunflower oil (SO) and linseed oil (LO). Lambs were fed one of four diets consisting on dehydrated lucerne with either: 6% SO, 4% SO plus 2% LO, 2% SO plus 4% LO and 6% LO. The profile of C₁₈ FA was greatly affected by replacement of SO with LO in both lipid fractions. In PL, oil replacement led to an extensive substitution of 18:2n‐6 with 18:3n‐3 and cis‐9 18:1, resulting in a fairly constant degree of unsaturation of C₁₈ FA in membrane PL. C₁₈ FA were differentially incorporated in NL and PL. Cis‐isomers like cis‐11; cis‐12; cis‐15 18:1 and cis‐12, cis‐15 18:2 were preferentially incorporated in PL with the exception of cis‐9, cis‐15 18:2. Trans C₁₈ FA, including CLA isomers, were preferentially incorporated in NL with the exception of cis‐11, trans‐13 18:2. The preferential deposition of biohydrogenation derived trans C₁₈ FA, including CLA isomers in NL, suggests that their potential to change membrane FA composition and structure is low.     

Physico‐chemical composition,fractionated glycerides and fatty acid profile of chicken skin fat

Skin is one of the several co‐products of chicken meat industries, considered as waste, being rarely utilized or underutilized. Brazil is the world leader in chicken exports (3.6 million tons) and the third largest producer with 10.9 million tons, from which 440 000 ton/year are residues. This work aimes at characterizing chicken skin fat (CSF), comparing it with soybean oil, a well‐known and abundant compound, evaluating the physico‐chemical composition, fractionated glycerides and fatty acid profile, searching for CSF use in interesterification reactions. For that, determination of peroxide and p‐anisidine values, as well as thiobarbituric acid, iodine, saponification, acidity, unsaponified matter and refraction indexes were accomplished, besides the glycerides fractionation, followed by FAME derivatization and identification by GC. The nutritional quality indexes were calculated from the lipid profile. CSF showed satisfactory quality due to low acidity (0.65 g oleic acid/100 g), peroxide (2.14 meq/kg), p‐anisidine (0.70 absorbance units/g) values, besides presenting high proportion of MUFA (40%). However, due to CSF low hypocholesterolemic/hypercholesterolemic value (HH = 2.72), it may be difficult to use it for nutritional purposes the way it is found, once it tends to increase cholesterol. CSF it is a promising residue for different purposes including interesterification reactions and biodiesel production.     

Improving the relaxivity by dimerizing Gd-AAZTA: Insights for enhancing the sensitivity of MRI contrast agents

The synthesis of a dimeric derivative of Gd-AAZTA is reported. It retains the basic properties of the parent complex (q = 2, high stability) and displays a relaxivity of 14.0 mM^?1 s^?1 at 20 MHz and 298 K. The outstanding relaxivity is the result of the increased molecular reorientational time and of the contribution arising from 4 to 5 water molecules in the second coordination sphere of the Gd(III) ions.     

Predictive accuracy of body mass index in estimating body fatness measured by bioelectrical impedance

The aim of this study was to determinate the performance of body mass index (BMI) for the diagnosis of obesity and as a predictor of body fatness in adult Chilean subjects. We conducted a study in 433 women (18-73 years old; BMI: 19.7 to 69.7 kg/m2) and 264 men (18-83 y.; BMI: 19.1 to 54.8 kg/m2). Bioelectrical resistance was measured by impedance method and fat mass percent (FM%) was calculated by fatness-specific equations developed by Segal et al. Obesity was defined as a BMI of at least 30 kg/m2. Increased fatness was defined by the FM% cut-off points of at least 25% for men and at least 30% for women. Sixty-four percent of women and 23.6% of men with BMI below 30 kg/m2 had FM% higher than 30% and 25%, respectively. A value of BMI of 26 kg/m2 in women and 30 kg/m2 in men had the best agreement to the cut-off points of fatness according to sensitivity vs. specificity analysis The following equations were developed to predict individual fatness: women FM% = 0.96 x BMI + 0.154 x age + 1.44 (r2 = 0.75; standard error 3.8%); men FM% = 0.99 x BMI + 0.141 x age - 9.914 (r2 = 0.66; standard error 4.4%). Differences between measured and predicted FM% presented a wide variation, with a range of +/- 2 sd of 7.5% in women and 8.8% in men. The commonly used value of BMI 330 kg/m2 as a cut-off point for obesity does not have adequate sensitivity and specificity for the screening of increased fatness subjects, specially in women. In this study BMI shows a low reliability as a predictor of individual body fatness, particularly in men and in subjects with a BMI below 30 kg/m2.     

A virtual sensor for backlash in robotic manipulators

Journal of Intelligent Manufacturing - Gear backlash is a quite serious problem in industrial robots, it causes vibrations and impairs the robot positioning accuracy. Backlash estimation allows...