Oil and fungal biomass dispersion in a stirred tank containing a simulated fermentation broth

The production of γ‐decalactone by the filamentous fungus Trichoderma harzianum involves four phases (oil–water–air–mycelium) and its dispersion is crucial during fermentation. Oil and biomass (when present) dispersion, as a function of the volumetric power drawn (P/V), was characterized, in two; three‐ and four‐phase systems agitated with Rushton turbines. Trichoderma harzianum mycelium was used as the solid phase in the four‐phase system. Two stages of the fermentation were simulated: the beginning (15% oil and 1.4 kgm^?3 of mycelium) and the end (2% oil and 10.6 kg m^?3 of mycelium). In the two‐phase system, the use of exhausted broth achieved higher oil dispersions at low P/V values as compared with distilled water. Aeration decreased the oil dispersion for the high‐oil system, but enhanced oil dispersion for the low‐oil system. Compared with the P/V used in the actual fermentation (0.2 kW m^?3), a high segregation of the system was observed for the high‐oil/low‐biomass system, due to the difficulty of mixing the thick oil–air emulsion present at the top of the tank. The system simulating the end of the fermentation reached almost complete homogeneity of oil and biomass, a phenomenon due to the high biomass/oil ratio and the biomass acting as an oil carrier. © 2001 Society of Chemical Industry     

Multihierarchical interactive task planning: application to mobile robotics.

To date, no solution has been proposed to human-machine interactive task planning that deals simultaneously with two important issues: 1) the capability of processing large amounts of information in planning (as it is needed in any real application) and 2) being efficient in human-machine communication (a proper set of symbols for human-machine interaction may not be suitable for efficient automatic planning and vice versa). In this paper, we formalize a symbolic model of the environment to solve these issues in a natural form through a human-inspired mechanism that structures knowledge in multiple hierarchies. Planning with a hierarchical model may be efficient even in cases where the lack of hierarchical information would make it intractable. However, in addition, our multihierarchical model is able to use the symbols that are most familiar to each human user for interaction, thus achieving efficiency in human-machine communication without compromising the task-planning performance. We formalize here a general interactive task-planning process which is then particularized to be applied to a mobile robotic application. The suitability of our approach has been demonstrated with examples and experiments.     

Write–Read–Erase Molecular‐Switching System Trapped in a Polymer Hydrogel Matrix

In this paper we report the encapsulation of the compound 4′,7‐dihydroxyflavylium in a water‐permeable crosslinked poly(2‐hydroxyethyl methacrylate) matrix. The water permeability of the polymer and its transparency allow the use of pH and light stimuli to attain different states on the network defined by the various chemical reactions (multistate/multifunctional system). Unlike in water, in the polymer the compound 4′,7‐dihydroxyflavylium encapsulated exhibits a thermal barrier between the cis‐ and trans‐chalcones, a necessary requirement to define a write–read–erase cycle.     

Investigation of Enhancement Band Using Double Screen Frequency Selective Surfaces with Koch Fractal Geometry at Millimeter Wave Range

Numerical and theoretical investigations are presented for a double screen frequency selective surface (DSFSS) with perfectly conducting Koch fractal patch elements. The work was developed in two steps, in the first step two Koch fractal FSS screens were designed using the commercial software Ansoft Designer^TM. In the second these FSS were cascaded and separated by an air gap layer, forming the so-called DSFSS, to improve the bandwidth behavior. Thereafter, a numerical cascading technique is used to analyze the effect of the air gap on the DSFSS. The results were compared and a good agreement was observed.     

Temperature Control of a Thermal Plasma Torch with Inductive Coupling Using the Arduino Board

Plasma torch is a device that transforms electrical energy into heat carried by a gas and its safe operation is necessary to control her temperature. This paper presents the use of the Arduino board in temperature control of a plasma torch through fuzzy control. The plasma torch of this project was built so that a flow of water can circulate through your body, allowing its cooling. The cooling system mounted consists of one radiator, one expansion vase, one water pump and one temperature sensor. The heated water coming the plasma torch is passed by the temperature sensor. This is converted in a voltage and read by an analog input port of the Arduino. This processes the information received and makes the decision to turn on/off the radiator fan and/or powered the frequency inverter water pump to control the temperature. The graph of the fuzzy control showed an oscillation between 104 °F to 122 °F around the chosen reference 113 °F. The results show that it is possible to control the temperature of a plasma torch using the Arduino board and fuzzy logic.     

Mosquito bite hypersensitivity

Incidence of gastrointestinal tuberculosis increases in the western world. Exact epidemiological data about this rare extrapulmonological disease are not available in Hungary. Three advanced cases with intestinal tuberculosis have been reported, all of them recognised during surgery due to complications. The clinicopathological correlations are briefly reviewed, and the importance of early diagnosis is emphasized.     

Dynamic modelling of a two-phase thermofluidic oscillator for efficient low grade heat utilization: Effect of fluid inertia

In this paper, a promising heat engine technology capable of utilizing low grade heat is examined. Based on a two-phase thermofluidic oscillator concept, the novelty and advantage of this particular system lie in its use of phase change and its lack of reliance on inertia to sustain oscillations, though it is recognized that inertia will always be present in any physical manifestation of the engine. The system is analysed using lumped linearized one-dimensional network models, both with and without inertia, based on thermoacoustic principles and extending these to account for phase change. The gain (temperature difference between source and sink heat exchangers) and frequency at which marginal stability (desirable continuous oscillations) can be achieved is calculated. The effects of the load resistance (fluid drag) and fluid inertia, as well as of the flow resistance due the feedback valve on the marginal stability gain, frequency and exergetic efficiency of the system are investigated. It is found that an increase in feedback resistance leads to a need for a higher gain for oscillatory behaviour to be achieved. In addition, even though an increase in either the resistance or inertia in the load, or the feedback resistance at low values of these variables has almost no effect on the required gain and the oscillation frequency of the system, an increase in these variables can lead at higher values to increased gains and reduced frequencies. A reduced feedback resistance and greater load inertia can also lead to considerably higher efficiencies, while increasing the load resistance allows for an increase in efficiency until a maximum is reached, after which the efficiency decreases again. The validity of certain approximations made previously is considered, and it is shown that these must be made with care. The results from this study can be used for the improved design and optimization of such oscillators, and similar systems.     

Mild Muscle Mitochondrial Fusion Distress Extends Drosophila Lifespan through an Early and Systemic Metabolome Reorganization

In a global aging population, it is important to understand the factors affecting systemic aging and lifespan. Mitohormesis, an adaptive response caused by different insults affecting the mitochondrial network, triggers a response from the nuclear genome inducing several pathways that promote longevity and metabolic health. Understanding the role of mitochondrial function during the aging process could help biomarker identification and the development of novel strategies for healthy aging. Herein, we interfered the muscle expression of the Drosophila genes Marf and Opa1, two genes that encode for proteins promoting mitochondrial fusion, orthologues of human MFN2 and OPA1. Silencing of Marf and Opa1 in muscle increases lifespan, improves locomotor capacities in the long term, and maintains muscular integrity. A metabolomic analysis revealed that muscle down-regulation of Marf and Opa1 promotes a non-autonomous systemic metabolome reorganization, mainly affecting metabolites involved in the energetic homeostasis: carbohydrates, lipids and aminoacids. Interestingly, the differences are consistently more evident in younger flies, implying that there may exist an anticipative adaptation mediating the protective changes at the older age. We demonstrate that mild mitochondrial muscle disturbance plays an important role in Drosophila fitness and reveals metabolic connections between tissues. This study opens new avenues to explore the link of mitochondrial dynamics and inter-organ communication, as well as their relationship with muscle-related pathologies, or in which muscle aging is a risk factor for their appearance. Our results suggest that early intervention in muscle may prevent sarcopenia and promote healthy aging.     

Description of the thermodynamic properties and fluid-phase behavior of aqueous solutions of linear,branched, and cyclic amines

The SAFT-γ Mie group-contribution equation of state is used to represent the fluid-phase behavior of aqueous solutions of a variety of linear, branched, and cyclic amines. New group interactions are developed in order to model the mixtures of interest, including the like and unlike interactions between alkyl primary, secondary, and tertiary amine groups (NH₂, NH, N), cyclic secondary and tertiary amine groups (cNH, cN), and cyclic methine-amine groups (cCHNH, cCHN) with water (H₂O). The group-interaction parameters are estimated from appropriate experimental thermodynamic data for pure amines and selected mixtures. By taking advantage of the group-contribution nature of the method, one can describe the fluid-phase behavior of mixtures of molecules comprising those groups over broad ranges of temperature, pressure, and composition. A number of aqueous solutions of amines are studied including linear, branched aliphatic, and cyclic amines. Liquid–liquid equilibria (LLE) bounded by lower critical solution temperatures (LCSTs) have been reported experimentally and are reproduced here with the SAFT-γ Mie approach. The main feature of the approach is the ability not only to represent accurately the experimental data employed in the parameter estimation, but also to predict the vapor–liquid, liquid–liquid, and vapor–liquid–liquid equilibria, and LCSTs with the same set of parameters. Pure compound and binary phase diagrams of diverse types of amines and their aqueous solutions are assessed in order to demonstrate the main features of the thermodynamic and fluid-phase behavior.