Do as I say or as I do? Food handler's knowledge on good handling practices and evaluation of hygienic–sanitary conditions in hospital foodservices

The aim of the study was to evaluate the overall hygienic–sanitary conditions of university hospitals foodservices and assess food safety knowledge and self‐reported practices of food handlers. A self‐administered questionnaire based on sanitary standards for foodservices was given to 123 food handlers from three public hospitals. Microbiological analysis of food handling surfaces and food hygiene inspections were also performed. Food handlers' self‐reported knowledge and practices reached satisfactory levels (77.2% and 78.1%, respectively), and showed a significant positive intercorrelation (p < .05). Food hygiene inspections in the hospitals foodservices presented a 60.9% average of adequacy and microbiological analysis results showed that 66.7% of the evaluated surfaces presented significant contamination by mesophilic bacteria. The presence of coliforms at 45°C above the safety limit was identified in 47.9% of the surfaces. The results showed a need for motivating hospital food handlers to practice the safe handling knowledge that they have demonstrated in theory.     

Continuous-discontinuous formulation for ductile fracture

In this contribution, a continuum-discontinuum model for ductile failure is presented. The degradation of material properties through deformation is described by a Continuum Damage Mechanics model, which uses a non-local integral formulation to avoid mesh dependence. In the final stage of failure, the damaged zone is replaced by a macro crack for a more realistic representation of the phenomenon. The inclusion of the discontinuity surfaces is performed by the XFEM and Level Set Method to avoid the spurious damage growth typical of this class of models.     

Rayleigh mixture model for plaque characterization in intravascular ultrasound

Vulnerable plaques are the major cause of carotid and coronary vascular problems, such as heart attack or stroke. A correct modeling of plaque echomorphology and composition can help the identification of such lesions. The Rayleigh distribution is widely used to describe (nearly) homogeneous areas in ultrasound images. Since plaques may contain tissues with heterogeneous regions, more complex distributions depending on multiple parameters are usually needed, such as Rice, K or Nakagami distributions. In such cases, the problem formulation becomes more complex, and the optimization procedure to estimate the plaque echomorphology is more difficult. Here, we propose to model the tissue echomorphology by means of a mixture of Rayleigh distributions, known as the Rayleigh mixture model (RMM). The problem formulation is still simple, but its ability to describe complex textural patterns is very powerful. In this paper, we present a method for the automatic estimation of the RMM mixture parameters by means of the expectation maximization algorithm, which aims at characterizing tissue echomorphology in ultrasound (US). The performance of the proposed model is evaluated with a database of in vitro intravascular US cases. We show that the mixture coefficients and Rayleigh parameters explicitly derived from the mixture model are able to accurately describe different plaque types and to significantly improve the characterization performance of an already existing methodology.     

Adsorbent Derived from Pinus pinaster Tannin for Cationic Surfactant Removal

Abstract

Pinus tannin gel (PTG) has proven to be an effective adsorbent for removing various cationic pollutants including heavy metals, dyes, and surfactants. The form of obtaining these condensed tannins from Pinus pinaster bark was conventional aqueous extraction using 5.0% ethanol as additive. The present study focused on the removal of the surfactant hexadecyltrimethylammonium bromide (CTAB) from aqueous solutions using PTG. Kinetic studies showed that the Lagergren, Ho, and Elovich models all adequately explained the kinetics of CTAB adsorption onto PTG, with r² correlation coefficients of around 0.98. The influences of pH and temperature were found not to be critical, and the CTAB-PTG system was modeled theoretically according to the Langmuir hypothesis using linear, nonlinear, and multiparametric forms, obtaining the values of the activation energies and such system constants as k _l .     

Torque loss in a gearbox lubricated with wind turbine gear oils

In this study, four different fully formulated ISO VG 320 wind turbine gear oils were select: a mineral oil‐based, a polyalphaolefin‐based, an ester‐based and a polyalkyleneglycol‐based fluids. Their physical properties (viscosity, thermoviscosity, piezoviscosity etc.) were characterised for a wide range of operating temperatures. A two‐stage multiplying gearbox, with helical gears, was selected to evaluate the influence of the wind turbine gear oil formulation on torque loss with the gearbox operating at low speed (130–230 rpm) and high torque (500–1000 Nm). The results obtained showed that each wind turbine gear oil formulation generated very different torque losses, evacuated heat flows and operating temperatures, with differences above 20 °C under the most severe operating conditions. A numerical model was developed, simulating all power loss mechanisms inside the gearbox, in particular the churning and friction losses. The coefficients of friction, between gear teeth and between rolling elements and bearing raceways, were calculated for all the tested oils. Copyright © 2013 John Wiley & Sons, Ltd.     

The combined effect of melt stirring and ultrasonic agitation on the degassing efficiency of AlSi9Cu3 alloy

The combined effect of high intensity ultrasound and melt stirring on the degassing of AlSi₉Cu₃ using simultaneously the novel MMM (Multi-frequency Multimode Modulated) ultrasonic technology to promote cavitation, and low frequency mechanical vibration to induce melt stirring, was studied. On a first stage single low frequency mechanical vibration experiments were carried out in water in order to visualize and characterize its individual effect on the liquid dynamics. On a second stage ultrasonic vibration combined with different mechanical vibration frequencies, melt temperatures and processing times were tested in liquid AlSi₉Cu₃ alloy and their influence on the degassing efficiency was evaluated and compared with the results of the single MMM ultrasonic degassing technique. Fixed ultrasonic parameters (frequency and electric power) were used, according to the best results obtained in former experimental works developed by the authors. For the experimental conditions used in this research, it was found that melt stirring significantly improves degassing efficiency, and such improvement depends on the metal temperature and the mechanical vibration frequency. The experimental results suggest that combining melt agitation and ultrasonic vibration it is possible to achieve almost the aluminum alloy theoretical density without increasing the processing time.     

Small hydropower dam alters the taxonomic composition of benthic macroinvertebrate assemblages in a neotropical river

Hydropower dams substantially modify lotic ecosystems. Most studies regarding their ecological impacts are based on large dams and provide little information about the far more abundant effects of small hydropower dams. Our aim was to characterize the ecological effects of a small hydropower dam and run‐of‐the‐river reservoir on the structure of benthic macroinvertebrate assemblages in the Pandeiros River located in the neotropical savanna of Brazil. We tested the hypothesis that benthic macroinvertebrate assemblages in sites directly affected by the dam and reservoir would show a different taxonomic structure compared with those in free‐flowing sites. We expected to find sensitive native species associated with the free‐flowing sites, whereas resistant and non‐native invasive taxa were expected in impounded sites. We also explored associations between the presence of native and non‐native invasive taxa to each habitat type. We found that the structure of benthic macroinvertebrate assemblages was significantly different between free‐flowing and impounded sites. Also, we found that the dam and reservoir facilitated colonization of non‐native invasive species (Corbicula fluminea and Melanoides tuberculata) because only in those sites they were found in high abundance, in contrast to the free‐flowing sites. Although the environmental conditions imposed by the impoundment altered the structure of benthic macroinvertebrate assemblages, the effects were limited to sites closest to the dam. Our results highlight the necessity of understanding physical habitat changes caused by the presence and management of run‐of‐the‐river dams and reservoirs.     

Use of industrial wastes in the formulation of olivine green pigments

This work describes the formulation and synthesis of Ni-olivine green pigments from industrial wastes, namely foundry sand and a sludge resulting from the wastewater treatment of the Ni/Cr galvanising process. This second one is considered as hazardous waste since the leached levels of nickel and chromium are above legal concentrations. Pigments were prepared by the solid state reaction method and Ni₂SiO₄ is formed at only 1050 °C. SiO₂ (in excess) and NiCr₂O₄ are present as secondary phases. By using pure reagents and following similar processing conditions, the Ni-olivine phase is only observed at 1200 °C. The green colour of the pigments is due to spin-allowed transitions of Ni²⁺ in octahedral M1 and M2 positions. The sample prepared from wastes shows a stronger and darker green hue. The colouring performance of ceramic glazes and bodies is also optimal, confirming the potential of the use of such wastes for ceramic pigments production.     

Inflorescences of Brassicacea species as source of bioactive compounds: A comparative study

Two Brassica oleracea varieties (B. oleracea L. var. costata DC and B. oleracea L. var. acephala) and Brassica rapa L. var. rapa inflorescences were studied for their chemical composition and antioxidant capacity. Phenolic compounds and organic acids profiles were determined by HPLC–DAD and HPLC–UV, respectively. B. oleracea var. costata and B. oleracea L. var. acephala inflorescences presented a similar qualitative phenolic composition, exhibiting several complex kaempferol derivatives and 3-p-coumaroylquinic acid, while B. rapa var. rapa was characterized by kaempferol and isorhamnetin glycosides and several phenolic acids derivatives. B. oleracea L. var. costata and B. rapa var. rapa showed the highest phenolics content. The three Brassica exhibited the same six organic acids (aconitic, citric, pyruvic, malic, shikimic and fumaric acids), but B. oleracea L. var. acephala presented a considerably higher amount. Each inflorescence was investigated for its capacity to act as a scavenger of DPPH radical and reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid), exhibiting antioxidant capacity in a concentration dependent manner against all radicals. These samples were also studied for its antimicrobial potential against Gram-positive and Gram-negative bacteria and fungi, displaying antimicrobial capacity only against Gram-positive bacteria.