Biosurfactant Production by Pseudomonas aeruginosa and Yarrowia lipolytica and Its Use for Detergent Formulations

This work reports detergents production using biological surfactants, microbiologically synthesized, and compares its foaming power and emulsification capacity to those presented by a petroleum based surfactant. Both used microorganisms were capable to produce surfactants, been able to emulsify oil/water mixtures and cause decrease of surface tension of water. The biosurfactant produced from Yarrowia lipolytica has a critical micelle concentration lower than that obtained from Pseudomonas aeruginosa （10 and 30 mg·Lt, respectively）, but the later showed better results in foaming power and emulsification experiments, similar to the synthetic detergent.     

Capture and reversible storage of volatile iodine by porous carbon with high capacity

The capture of iodine using porous materials has attracted considerable interest. In this work, porous carbon with a special surface area of 1973 m² g^?1 was prepared by simple activation method. As an adsorbent, the adsorption capacity of the resulting porous carbon could reach up to 376 wt% for iodine vapor and 460 mg g^?1 for iodine uptake in cyclohexane, which both are among the highest values reported up to now. Taking advantages of its high special surface area, easy preparation, low cost, as well as good regeneration, the resulting porous carbon shows great potential in the removal of radioactive iodine at different states.     

Study of different nectarine cultivars and their suitability for fresh‐cut processing

Nectarine [Prunus persica (L.) Batsch] is a sought‐after fruit due to its properties. In addition, minimally processed produces are more and more accepted by consumers. Four nectarine cultivars (‘Early Top’, ‘Nectaprima’, ‘Big Top’ and ‘Venus’) were selected to study their suitability for minimal processing. Samples were processed in a clean room at 8 °C, washed them in water (4 °C) and stored at 4 °C in modified atmosphere packaging. The samples were analysed at 0, 3, 6 and 9 days of storage, and quality parameters as well as functional compounds (polyphenols and polyphenol oxidase activity) were studied. Principal component analysis (PCA) was carried out to assess the relationship between nectarine cultivars and determined parameters. In conclusion, ‘Early Top’ and ‘Nectaprima’ cultivars showed the best quality results and therefore a promising suitability for fresh‐cut processing. Nevertheless, the remaining cultivars should not be ruled out due to their functional content, advising additional conservation treatments for them.     

Extended kinetic theory applied to dense,granular, simple shear flows

We apply the extended kinetic theory (EKT) to the dense, simple shear flow of inelastic hard spheres. EKT is a phenomenological extension of kinetic theory which aims at incorporating in the simplest possible way the role of pre-collisional velocity correlations which are likely to occur at a concentration larger than the freezing point. The main effect of that correlation is the decrease in the rate at which fluctuating energy is dissipated in inelastic collisions. We use previously published results of numerical simulations performed using an event-driven algorithm to obtain analytical expressions for the radial distribution function at contact (which diverges at a concentration lower than the value at random close packing for sheared inelastic spheres) and the correlation length (i.e., the decreasing factor of the dissipation rate) at different values of the coefficient of restitution. With those, we show that when the diffusion of fluctuating energy of the particles is negligible, EKT implies that three branches of the analytical relation between the ratio of the shear stress to the pressure and the concentration (granular rheology) exist. Hence, for a certain value of the stress ratio, up to three corresponding values of the concentration are possible, with direct implications on the existence of multiple solutions to steady granular flows.     

Temperature dependence of the viscoelastic response of In, Sn and In–Sn alloys

The elastic modulus and the internal friction of Sn and the γ-In–Sn phase are measured with a two-component piezoelectric oscillator at 50 kHz in the temperature range from 296 to 390 K. For both materials the viscoelastic responses at strains below 10⁻⁶ are described in terms of a Debye peak characterized by an effective activation enthalpy of 54.8 and 20.4 kJ/mol, for Sn and the γ-In–Sn phase, respectively. Due to their higher damping, the dynamic mechanical responses of In and the eutectic In–Sn were measured with a three-components piezoelectric resonator between 296 and 390 K at 50 kHz. The temperature dependence of the internal friction of the eutectic can be well described in terms of a single relaxation time with an effective activation enthalpy of 38 kJ/mol. Indium is not only amplitude dependent but also exhibits thermal hysteresis.     

The fourth house: the design of a bioclimatic house in Venezuela

A new prototype, bioclimatic terraced (or row) house for Tamare, Venezuela is being developed to address contemporary Venezuelan urban problems of lot size, urban sprawl, urban dispersion and high energy consumption. The design is based upon principles from three previous vernacular house types in the Maracaibo Lake basin. The design of the high density bioclimate house is proposed with narrow frontage, two or three floors and an innovative interior space which is integrated into the building as a vertical patio to generate a ‘detached row building’. The resulting prototype is predicted to consume less energy and land resources while exploiting bioclimatic principles.

Un nouveau prototype: la maison à terrasses (ou rangées) bioclimatiques pour Tamare, au Venezuela a été développé pour faire face aux problèmes urbains vénézuéliens actuels que sont la dimension des parcelles, l'étendue et la dispersion des zones urbaines et la consommation élevée d'énergie. Le concept de base repose sur un principe de trois types de maisons anciennes de style régional typique du lac Maracaibo. Le projet de la maison à haute densité bioclimatique prévoit une façade étroite, deux ou trois étages et un espace innovateur intérieur qui est intégré dans le bâtiment comme une sorte de patio vertical afin de former un ‘bâtiment à rangée séparée’. Le prototype en résultant est prévu pour consommer moins d'énergie et de ressources naturelles grâce à l'exploitation des principes bioclimatiques.     

Iterative decoding in Factor Graph representation using Particle Filtering

In this paper, we study iterative decoding over channels with phase noise in Digital Communications. A Factor Graph representation is used for the system under study and a message-passing algorithm is derived. To reduce the complexity of such an algorithm, several methods have been proposed in the literature. One consists of a discretization of the phase space using a fixed number of equally spaced values. In this paper, we propose a Particle-Filtering approach that reduces the complexity and performs better than does the Equally Spaced Discretization.     

The High Temperature Annular Shear Cell: A modified ring shear tester to measure the flow properties of powders at high temperature

Although changes of cohesive behaviour of powders is observed at high temperature in several industrial process units, conventional testers and procedures are still not suited for testing powder flow properties at high temperature. In this work a High Temperature Annular Shear Cell was designed, built and set-up in order to directly measure the flow properties of powders up to 500 °C. A temperature control system was also developed to establish a uniform temperature inside the powder sample.Yield loci at room temperature and 500 °C were measured for samples of fluid catalytic cracking catalyst (FCC powder), fly ashes, natural corundum, synthetic porous α-alumina and glass beads. Experimental evidences did not reveal a univocal effect of temperature in the tested range.Finally, shear tests on glass beads mixed to with some high-density polyethylene (HDPE) (1% of the total weight) confirmed that a significant increase of the cohesive behaviour occurs at high temperature when liquid bridges form due to the melting of one of the solid phases.     

Effect of SDS on Casein Micelles: SDS-Induced Milk Gel Formation

ABSTRACT: The addition of sodium dodecyl sulfate (SDS) during skim-milk reconstitution contributed to a modification of hydrophobic interactions and, consequently, to change in the micellar structure. SDS-induced modifications in casein micelles were investigated by biochemical measurements (soluble mineral and protein analyses, granulometric and electrokinetic potential measurements, and casein micelle solvation). SDS induced micellar κ-casein dissociation and caused a decrease in steric, hydration, and electrostatic repulsive forces between casein micelles and as a result altered micellar stability. Consequently, SDS-modified micelle aggregation occurred. Mineral analysis indicated that Ca, PO₄^3- and Mg partitioning between aqueous phase and curd is similar, suggesting a possible bridging mechanism via minerals and SDS molecules.