高压辊磨预处理强化巴西镜铁矿球团

采用高压辊磨技术预处理镜铁矿,对强化其球团工艺及机理进行了研究.扫描电镜观测证实,通过优化高压辊磨闭路流程的循环负荷,巴西镜铁矿的表面形状及比表面积得到改善,成球性得到明显提高.以70%镜铁矿配加30%磁铁矿为原料,采用71%高压辊磨产品返回方式处理后,在添加2.4%的膨润土、造球时间15 min及造球水分8%的条件下,生球各指标与同配比未经高压辊磨处理的相比均有大幅度提高,其0.5 m落下强度达到4.5次,单球抗压强度10.25 N,爆裂温度455℃;生球在预热温度1 050℃、预热时间10 min,焙烧温度1 280℃、焙烧时间12 min的条件下焙烧,成品球单球抗压强度达到2 690.88 N,满足球团生产的要求.     

Application of chemometric tools in the development of food bars based on cocoa shell,soy flour and green banana flour

In this study, exploratory methods and the simplex-centroid design were applied in the development of food bars with cocoa shell, soy and green banana flours that were evaluated sensorially. The results of the chemical composition and texture were submitted to the Scott-Knott test and the Principal Component Analysis, and was observed a significant difference between the treatments (P < 0.05), as well as a tendency to form five groups, according to its nutritional characteristics. The design used to optimise the sensorial acceptance of the food bars was effective, whose contour surface indicated an optimal region with greater acceptance, with all formulations having good acceptance (scores above 5.52). Check-All-That-Apply, Contingency Analysis and Hierarchical Cluster Analysis allowed describing the products, demonstrating the sensory differences between treatments with the presence/absence of cocoa shell. It is concluded that the studied ingredients can be used in food bars, providing nutritional and sensory characteristics acceptable to the consumer.     

Tentative zinc biofortification of banana fruit via bunch spray and bunch stalk feeding

Due to the importance of banana consumption in developing countries and producing zinc-rich foods, the objective of this study was to evaluate the feasibility of banana bunch sprays and bunch stalk feeding with Zn aiming to biofortify this fruit. Zn sprays were carried out with a dose of 80 g ha⁻¹ using ZnCl₂ and ZnCl₂ combined with a chelating agent in two banana cultivars (‘Maravilha’ and ‘FHIA 18’). Bunch stalk feeding with Zn was carried out by fixing plastic bags on the stem end containing solutions of ZnSO₄ (0, 0.5, 1.0 and 2.0 g L⁻¹) in two banana cultivars (‘Williams’ and ‘Prata Anã’). Both strategies resulted in a maximum fruit Zn content of 0.14 mg 100 g⁻¹. Although it was possible to increase the Zn content in banana fruit from ‘FHIA 18’ and ‘Prata Anã’ cultivars, both strategies did not result in biofortified banana fruit with a Zn level which would fulfil the Zn dietary reference intake (DRI) of 2 mg dia⁻¹ for children. Banana bunch sprays with Zn did not affect the fruit quality, but bunch stalk feeding with Zn resulted in fruits with lower ratio, pH and ascorbic acid content.     

Shiga toxin–producing Escherichia coli isolated from pasteurized dairy products from Bahia,Brazil

The presence of pathogenic Shiga toxin–producing Escherichia coli (STEC) in dairy products represents a public health concern because of its ability to produce the toxins Stx1 and Stx2, which cause intestinal diseases. Monitoring the stages of milk production and checking dairy products for contamination are crucial steps to ensure dairy safety. This study aimed to report the occurrence of thermotolerant coliforms, E. coli, and STEC strains in pasteurized dairy products and to evaluate the antibiotic resistance profiles, serotypes, and characterizations of the STEC isolates by pulsed-field gel electrophoresis. We obtained a total of 138 pasteurized dairy products from 15 processing plants in Bahia, Brazil, to examine coliforms, E. coli, and STEC strains. We found that 43% of samples (59/138) contained thermotolerant coliforms, and 30% (42/138) did not comply with Brazilian regulations. Overall, 6% (9/138) were positive for E. coli and 4% (5/138) were positive for STEC. We recovered 9 STEC isolates from pasteurized cream (2/9), Minas Padrão cheese (2/9), Minas Frescal cheese (4/9), and ricotta (1/9). All isolates were stx2-positive, and 2 were eae-positive. All isolates were negative for the “big 6” STEC serogroups, belonging instead to serotypes ONT:HNT, ONT:H12, O148:H?, OR:H40, OR:HNT, and O148:HNT. Pulsed-field gel electrophoresis revealed 100% genetic similarity among 3 isolates from 2 different samples produced in the same production facility, which may suggest cross-contamination. As well, we found isolates that were 98% similar but in samples produced in different production facilities, suggesting a mutual source of contamination or a circulating strain. Two STEC strains exhibited resistance to streptomycin. Although the isolates presented a low resistance profile and no strain belonged to the “big 6” pathogenic group, the circulation of stx2-positive STEC strains in ready-to-eat products highlights the importance of epidemiological surveillance inside the Brazilian dairy chain.     

Horizontal projections of area 17 in Cebus monkeys: metric features, and modular and laminar distribution

Metric features and modular and laminar distributions of intrinsic projections of area 17 were studied in Cebus apella. Anterogradely and retrogradely labeled cell appendages were obtained using both saturated pellets and iontophoretic injections of biocytin into the operculum. Laminar and modular distributions of the labeled processes were analyzed using Nissl counterstaining, and/or cytochrome oxidase and/or NADPH-diaphorase histochemistry. We distinguished three labeled cell types: pyramidal, star pyramidal and stellate cells located in supragranular cortical layers (principally in layers IIIa, IIIb alpha, IIIb beta and IIIc). Three distinct axon terminal morphologies were found, i.e., Ia, Ib and II located in granular and supragranular layers. Both complete and partial segregation of group I axon terminals relative to the limits of the blobs of V1 were found. The results are compatible with recent evidence of incomplete segregation of visual information flow in V1 of Old and New World primates.     

Metallization thickness in bilateral and unilateral Finlines

The theory and numerical results are presented to the effective dielectric constant and characteristic impedance of bilateral and unilateral finlines with metallization thickness. The full wave analysis of the transverse transmission line — TTL method is used to determine the electromagnetic fields of the structure in Fourier transform domain — FTD. Applying the suitable boundary conditions and the moment method, a homogeneous matrix system is obtained and the effective dielectric constant is extracted. The characteristic impedance is obtained using the relation between the voltage in slot and the transmitted power. Computational programs are developed to obtain numerical results to the effective dielectric constant and characteristic impedance.     

Attesting compliance of biodiesel quality using composition data and classification methods

Neural Computing and Applications - Four methods for direct classification (decision tree classifier, K-nearest neighbors, support vector machine and artificial neural networks) have been optimized...