A Novel Low‐Pressure Device for Production of Nanoemulsions

A novel device is applied to produce emulsions of methyl methacrylate in water with a controllable size in the range of 30–100 nm. The process is based on the reciprocating flow of the material through an abrupt contraction which generates a strong elongational flow. This results in highly efficient dispersive mixing even at moderate pressures, thus reducing viscous dissipation and improving temperature control. The original design of the device also allows easy feeding and sampling, easy adjusting of the total volume of the emulsion, and processing volatile components owing to the liquid‐ and gas‐tightness of the device. The influence of process parameters (like pressure drop and mixing time) and composition of the system (volume ratio of the dispersed and continuous phases, surfactant and hydrophobic agent weight percentages) on the droplet size and stability of the emulsions is investigated and discussed.     

Long-Term Effects of Ionizing Radiation on the Hippocampus: Linking Effects of the Sonic Hedgehog Pathway Activation with Radiation Response

Radiation therapy represents one of the primary treatment modalities for primary and metastatic brain tumors. Although recent advances in radiation techniques, that allow the delivery of higher radiation doses to the target volume, reduce the toxicity to normal tissues, long-term neurocognitive decline is still a detrimental factor significantly affecting quality of life, particularly in pediatric patients. This imposes the need for the development of prevention strategies. Based on recent evidence, showing that manipulation of the Shh pathway carries therapeutic potential for brain repair and functional recovery after injury, here we evaluate how radiation-induced hippocampal alterations are modulated by the constitutive activation of the Shh signaling pathway in Patched 1 heterozygous mice (Ptch1^+/−). Our results show, for the first time, an overall protective effect of constitutive Shh pathway activation on hippocampal radiation injury. This activation, through modulation of the proneural gene network, leads to a long-term reduction of hippocampal deficits in the stem cell and new neuron compartments and to the mitigation of radio-induced astrogliosis, despite some behavioral alterations still being detected in Ptch1^+/− mice. A better understanding of the pathogenic mechanisms responsible for the neural decline following irradiation is essential for identifying prevention measures to contain the harmful consequences of irradiation. Our data have important translational implications as they suggest a role for Shh pathway manipulation to provide the therapeutic possibility of improving brain repair and functional recovery after radio-induced injury.     

Study of CO2 stability and electrochemical oxygen activation of mixed conductors with low thermal expansion coefficient based on the TbBaCo3ZnO7+δ system

The influence of different application-oriented factors on the electrochemical activity and stability of TbBaCo₃ZnO_7+δ when used as a solid oxide fuel cell cathode has been studied. Calcination at temperatures above 900 °C (e.g. 1000 °C) leads to a significant increase in the electrode polarization resistance. The effect of the sintering temperature of the TbBaCo₃ZnO_7+δ cathode seems to be more important than the effect produced by the Tb substitution as observed when compared with 900 °C-sintered YBaCo₃ZnO_7+δ; and ErBaCo₃ZnO_7+δ electrode performances. The presence of CO₂ in the air flow leads to an increase of roughly 10% in the polarization resistance for the whole studied temperature range (500-850 °C) while this effect is reversible. Analysis of the impedance spectroscopy measurements shows that the exchange rate constant (k_G from Gerischer element) is significantly affected by CO₂ at temperatures below 700 °C, while the diffusion coefficient related parameter is slightly influenced at low temperatures. Electrode degrades with a low constant rate of 1 mΩ cm² h⁻¹ after 60 h. This cathode material exhibits high CO₂ tolerance, as shown by temperature programmed treatment under a continuous gas flow of air with 5% CO₂, and a relatively low thermal expansion coefficient.     

A chemical study of the protein fractions of Tarragona hazelnuts (Corylus avellana)

The protein contents of six Tarragona hazelnuts varieties were determined. The protein contents (g protein per 100 g hazelnuts) were between 12.1g/100 g and 18.8 g/100 g, according to variety; a mean discrepancy of 2.3 g/100 g was detected between data from the same variety grown with irrigation and using a dry-farming method. Percentages of albumins, globulins, glutelins and prolamines were also determined. In all varieties albumins and globulins were the major fractions, averaging about 86.58 % of the total protein content.     

ADC characterization by using the histogram test stimulated by Gaussian noise: Theory and experimental results

This paper presents results relating to the measurement of differential and integral nonlinearity of ADCs using the histogram method with white Gaussian noise as the stimulus signal. We specify the optimum noise power of the generator, in the sense of number of samples minimisation, as a function of the converter range and resolution. An expression of tolerance interval as a function of the number of samples acquired given a certain confidence level is presented both for the determination of transition levels (INL) and quantization intervals (DNL). Experimental and simulation results concerning the characterization of a 12-bit PC acquisition board are shown.     

The use of matrix converters in direct torque control of inductionmachines

In this paper, a new control method for matrix converters is proposed which allows, under the constraint of unity input power factor, the generation of the voltage vectors required to implement the direct torque control (DTC) of induction machines. Using this control method, it is possible to combine the advantages of matrix converters with the advantages of the DTC schemes. Some numerical simulations are carried out, showing the effectiveness of the proposed method in steady-state and transient conditions. Some experimental tests were also carried out demonstrating the practical feasibility of this control scheme     

Development of quality matrix to measure the effectiveness of quality management systems in Turkish construction industry

Quality Management Systems (QMS) are being operated in some sectors in Turkey but it is rare to meet these systems in construction industry. There are many hinderances that make it difficult to apply these systems effectively due to the nature of construction and therefore, no objective way of measuring the effectiveness of these systems exists in construction industry.