Mass transfer during the osmotic dehydration of West Indian cherry

The main purpose of this work was to study water loss, solids gain, and weight and moisture reduction during the osmotic dehydration process of the West Indian cherry (Malpighia punicifolia). The diffusion coefficient of West Indian cherry was estimated by the inverse method using average moisture contents. Osmotic dehydration was examined for 12 h in a 65°Brix solution at temperature of 27 °C, without agitation, using a fruit:solution mass ratio of 1:4, 1:10, and 1:15. The kinetics and internal changes occurring during the osmotic dehydration of West Indian cherry are reported. The product’s drying kinetics was simulated using the diffusion model, and two optimization methods, Levenberg–Marquardt and Differential Evolution algorithm, were used to predict the diffusion coefficient. The results indicated that the two optimization methods performed similarly in estimating the diffusion coefficient adequately. The average calculated diffusion coefficient was 1.663 × 10^?10 m²s^?1, which is consistent with values reported in the literature.     

The Combined Role of Soot Aggregation and Surface Effect on the Friction of a Lubricated Contact

One of the considered research paths to reduce friction loss consists in optimizing the interactions between surfaces and lubricants. The latter may significantly change with the lubricant ageing. In this framework, the tribological behaviour of aged formulated lubricant is analysed for various low-speed reciprocating motions and with different nature of surfaces. This paper focuses on soot aggregate formation processes in a lubricated contact and on their correlation to friction. Although no aggregates have been observed in pure rolling conditions, pure sliding conditions may lead to the appearance of aggregates moving through the contact as a function of the nature of the surfaces. The analysis of their displacement within the contact is used to discuss their interactions with the surfaces. Moreover, we show that the velocity and the dwell time of the aggregate depend on the sliding speed. The morphology of these aggregates evolves over time, affecting friction behaviour. An additive law combining a contribution from the shear of the aggregates with another one due to the shear of a thin lubricant film surrounding the aggregate is then proposed to interpret friction origin and friction evolution with time of shear. The aggregate motion also varies with the nature of the surfaces: in particular, DLC–DLC couple reduces aggregation phenomena and maintains a low friction without apparent wear.     

Effect of Aloe vera application on the content and molecular arrangement of glycosaminoglycans during calcaneal tendon healing

Although several treatments for tendon lesions have been proposed, successful tendon repair remains a great challenge for orthopedics, especially considering the high incidence of re‐rupture of injured tendons. Our aim was to evaluate the pharmacological potential of Aloe vera on the content and arrangement of glycosaminoglycans (GAGs) during tendon healing, which was based on the effectiveness of A. vera on collagen organization previously observed by our group. In rats, a partial calcaneal tendon transection was performed with subsequent topical A. vera application at the injury site. The tendons were treated with A. vera ointment for 7 days and excised on the 7^th, 14^th, or 21^st day post‐surgery. Control rats received ointment without A. vera. A higher content of GAGs and a lower amount of dermatan sulfate were detected in the A. vera‐treated group on the 14^th day compared with the control. Also at 14 days post‐surgery, a lower dichroic ratio in toluidine blue stained sections was observed in A. vera‐treated tendons compared with the control. No differences were observed in the chondroitin‐6‐sulfate and TGF‐β1 levels between the groups, and higher amount of non‐collagenous proteins was detected in the A. vera‐treated group on the 21^st day, compared with the control group. No differences were observed in the number of fibroblasts, inflammatory cells and blood vessels between the groups. The application of A. vera during tendon healing modified the arrangement of GAGs and increased the content of GAGs and non‐collagenous proteins. Microsc. Res. Tech. 77:964–973, 2014. © 2014 Wiley Periodicals, Inc.     

Temperature during conservation in laboratory silos affects fermentation profile and aerobic stability of corn silage treated with Lactobacillus buchneri,Lactobacillus hilgardii,and their combination

The environment temperature and its effect on the temperature of silage is very important for the fermentation and subsequent quality of a silage. Obligate heterofermentative lactic acid bacteria (LAB) inocula, because of their ability to inhibit yeasts, have been developed to prevent the aerobic deterioration of silages. The temperature during silage conservation may also play an important role in the fermentation profile of silages. This study has evaluated the effect of temperature, during the conservation of whole crop corn silage, untreated or treated with different LAB inocula, on the fermentation profile and on the aerobic stability of the silage. Corn was harvested at 42% dry matter and either not treated (control) or treated with Lactobacillus buchneri NCIMB 40788 (LB) at 300,000 cfu/g fresh matter (FM); Lactobacillus hilgardii CNCM I-4785 at 150,000 cfu/g FM (LH₁₅₀); L. hilgardii CNCM I-4785 at 300,000 cfu/g FM (LH₃₀₀); or LB+LH at 150,000 cfu/g FM each. In an attempt to experimentally simulate temperature fluctuations in the mass or at the periphery of a silage bunker, corn was conserved in laboratory silos at a constant temperature (20 ± 1°C; MASS) or at lower and variable outdoor temperatures (PERIPH; ranging from 0.5 to 19°C), and the silos were opened after 15, 30, and 100 d of conservation. Lactic acid, acetic acid, and ethanol contents increased in all the silages over the conservation period. The lactic acid content was higher (+10%) in the silages kept at a constant temperature than those conserved at the lower and variable outdoor temperatures. The acetic acid was higher in the treated silages than in the control ones conserved at a constant temperature for 100 d. Moreover, 1,2-propanediol was only detected in the treated silages after at least 30 d at a constant temperature, whereas only traces were detected in the LB+LH treatment for the other temperature conditions. The yeast count decreased during conservation at a slower rate in PERIPH than in MASS and on average reached 2.96 and 4.71 log cfu/g for MASS and PERIPH, respectively, after 100 d of conservation. The highest aerobic stability values were observed for LH₃₀₀ (191 h) in the MASS silage after 100 d of conservation, whereas the highest aerobic stability was observed in LB+LH (150 h) in the PERIPH silages. After 7 d of air exposure, a pH higher than 4.5 and a higher yeast than 8.0 log cfu/g were detected in all the silages opened after 15 and 30 d of conservation. A pH value close to that of silo opening was detected in the LB, LH₁₅₀, and LH₃₀₀ silages conserved under MASS conditions after 100 d, whereas LB+LH was the most effective under PERIPH conditions. The temperature and its fluctuation during conservation of silage in laboratory silos influenced the fermentation, which in turn had an effect on the quality of silage and on the extent of the effect of LAB inocula.     

Effect of the stage of growth,wilting and inoculation in field pea (Pisum sativum L.) silages. II. Nitrogen fractions and amino acid compositions of herbage and silage

The aim of the study was to investigate the effects of stage of maturity, wilting and inoculant application on proteolysis in field pea herbage and silage in northern Italy. Semi‐leafless field peas were harvested at four progressive morphological stages (end of flowering, I; beginning of pod filling, II; advanced pod filling, III; beginning of ripening, IV). For each stage of growth, the herbage was field wilted to a dry matter (DM) content around 330 g kg^?1. The unwilted and wilted herbages were ensiled with (I) and without (C) a lactic acid bacteria (LAB) inoculant. The stage of growth significantly affected all the nitrogen fraction concentrations both in herbage and in silage. Extensive proteolysis took place in silages made at early morphological stages and characterised by a high crude protein content (around 240 g kg^?1 DM), as shown by the non‐protein nitrogen (NPN) value (around 700 g kg^?1 total N or higher). Neither inoculum nor wilting helped to reduce the protein degradation in these silages. The level of proteolysis was reduced in silages made from the pod filling stage onwards where most of the protein was localised in the seed and a better fermentation pattern was observed. The amino acid (AA) composition of silages made at stage IV was close to that of fresh herbage, with minimal losses of nutritionally essential amino acids for ruminants. Copyright © 2006 Society of Chemical Industry     

Influence of walls on the migration of non-Brownian spherical particles in creeping flow: a lattice Boltzmann study

The influence of walls on binary encounters of spherical particles under creeping flow is studied by means of the lattice Boltzmann method. Depending on the initial particle displacement different behaviours can be observed, including the 'swapping' trajectories. The domain of the swapping trajectories is identified for interacting spheres with the same diameter; some preliminary results are given for the case of two spheres with different diameters. Finally, the influence of particle swapping on the dynamics of monodisperse suspensions is also described.     

Incidence of Listeria monocytogenes in cheese manufacturing plants from the northeast region of São Paulo, Brazil

The incidence of Listeria monocytogenes in three cheese manufacturing plants from the northeastern region of S?o Paulo, Brazil, was evaluated from October 2008 to September 2009. L. monocytogenes was found in samples from two plants, at percentages of 13.3% (n = 128) and 9.6% (n = 114). Samples of raw and pasteurized milk, water, and Minas Frescal cheese were negative for L. monocytogenes, although the pathogen was isolated from the surface of Prato cheese and in brine from one of the plants evaluated. L. monocytogenes was also isolated from different sites of the facilities, mainly in non-food contact surfaces such as drains, floors, and platforms. Serotype 4b was the most predominant in the plants studied. The results of this study indicate the need for control strategies to prevent the dispersion of L. monocytogenes in the environment of cheese manufacturing plants.     

Aflatoxin accumulation in whole crop maize silage as a result of aerobic exposure

BACKGROUND: Most of the maize silage stored in horizontal silos is exposed to air and can be spoiled by fungi. Potentially toxigenic fungi have been found in maize silage, and about 300 mycotoxins have been detected. Among these mycotoxins, the most harmful for feed and food safety are aflatoxins. The aim of the study was to set up a specific method to detect aflatoxins in maize silage, and to investigate whether aflatoxin contamination in maize silage depends on the level of field contamination of the crop, and whether the occurrence of aerobic spoilage during ensiling has any effect on the final contamination of the silage. RESULTS: A method for the determination of aflatoxin B₁, B₂, G₁ and G₂ in maize silage using high‐performance liquid chromagraphy with fluorescence detection has been developed and validated. Recoveries of aflatoxin B₁, B₂, G₁, and G₂ spiked over the 0.25 to 5 µg kg^?1 range averaged 74–94%. The results of laboratory scale and farm scale ensiling experiments indicated that aflatoxins could increase when silage is exposed to air during conservation or during the feed‐out phase. CONCLUSIONS: The method here proposed to detect aflatoxins in silages has proved to be sensitive and is able to detect levels of 0.1 and 0.5 ng mL^?1 for AFB₁ and AFG₁, and between 0.025 and 0.125 ng mL^?1 for AFB₂ and AFG₂. This study also provides evidence of aflatoxin accumulation in whole crop maize silage as a result of aerobic exposure. Copyright © 2011 Society of Chemical Industry     

Ethanol oxidation on a high temperature PBI-based DEFC using Pt/C, PtRu/C and Pt3Sn/C as catalysts

A high temperature ethanol-fed polymer electrolyte membrane fuel cell has been implemented by using H₃PO₄-doped m-polybenzimidazole as polymeric electrolyte. Commercial Pt/C, PtRu/C and Pt₃Sn/C catalysts are used in the anode. The performance was assessed in terms of polarization curves at different temperatures, feeding the cell with a high concentration ethanol solution (water/ethanol mass ratio of 2). The product distribution was measured with the support of a gas chromatograph. The use of bimetallic catalysts increased the current density. PtRu/C showed the best performance up to 175 °C, but it is outperformed by Pt₃Sn/C at 200 °C. In terms of oxidation products, higher temperatures and current densities favour the oxidation of ethanol. However, Pt₃Sn/C promoted the generation of more oxidized products compared to PtRu/C (in which most of the ethanol is oxidized to acetaldehyde), especially at high temperature. This accounts for the large current density. In terms of complete oxidation of ethanol to CO₂, Pt/C was by far the most efficient catalyst for C–C scission, achieving percentages of 56 % of CO₂, although operating above 175 °C dramatically boosted an undesirable methanation process that slashed the efficiency. The combination of fuel cell results and product distribution helped to suggest the different oxidation routes on the surface of the different catalysts.     

Measurement of the Energy Spectrum of the Neutrons inside the Neutron Flux Trap Assembled in the Center of the Reactor Core IPEN/MB-01

This paper presents the neutron energy spectrum in the central position of a neutron flux trap assembled in the core center of the research nuclear reactor IPEN/MB-01, obtained by an unfolding method. To this end, we have used several different types of activation foils （Au, Sc, Ti, Ni, and plates） which have been irradiated in the central position of the reactor core （setting number 203） at a reactor power level （64.57±2.91 watts）. The activation foils were counted by solid-state detector HPGe （high pure germanium detector） （gamma spectrometry）. The experimental data of nuclear reaction rates （saturated activity per target nucleus） and a neutron spectrum estimated by a reactor physics computer code are the main input data to get the most suitable neutron spectrum in the irradiation position obtained through SANDBP （spectrum analysis neutron detection code-version Budapest University） code： a neutron spectra unfolding code that uses an iterative adjustment method. the integral neutron flux, （2.41 ± 0.01） × 10^9 n·cm^-2·s^-1 for the thermal The adjustment resulted in （3.85 ± 0.14） × 10^9 n·cm^-2·s^-1 for neutron flux, （1.09 ±0.02） × 10^9n·cm^-2·s^-1 for intermediate neutron flux and （3.41 ± 0.02） × 10^8 n·cm^-2·s^-1 for the fast neutrons flux. These results can be used to verify and validate the nuclear reactor codes and its associated nuclear data libraries, besides, show how much effective it can be that the use of a neutron flux trap in the nuclear reactor core to increase the thermal neutron flux without increase the operation reactor power level. The thermal neutral flux increased 4.04 ± 0.21 times compared with the standard configuration of the reactor core.