The performance of resilient layers made from cork granulates mixed with resins for impact noise reduction

This paper analyses the impact noise reduction of resilient layers made from cork granulates with eight different sizes, mixed with polyurethane and epoxy resins. The predicted impact sound improvement index and dynamic stiffness are compared with some commercially available underlays. According to the type of binder and particle size, the acoustical cork based layers present values of the impact sound improvement index and dynamic stiffness similar to the commercial layers used in buildings.     

Assessment of Bread Dough Expansion during Fermentation

The aim of this work was to investigate different methods of measuring the expansion of bread dough during fermentation and to develop a mathematical model to describe the variation of dough volume. Dough was prepared with wheat flour, salt, yeast, and selected amount of water (56%, 58%, and 60% w/w flour basis). Proving time was 1 h and proving temperature investigated were 25, 30, and 35°C. Dough volume was measured with three methods: (1) vertical expansion in a flask, (2) horizontal expansion between two plates, and (3) free expansion method. Volume was measured either using displacement transducer or from image analysis of pictures taken during expansion. All the methods allowed monitoring the increase in dough volume as a function of proving time. Small differences were observed between the three methods. Free expansion shows a faster start of expansion in comparison with the two other methods. Expansion curves have been fitted with a modified Gompertz model (Romano et al., J Food Eng 83:142–148, 2007). They exhibited three phases: a lag phase, followed by a linear phase (constant expansion rate), and finally a phase with a decreasing expansion rate. Statistical analysis of the set of data showed that the proving temperature had a significant effect on the different parameters calculated (volume expansion ratio, expansion rate), while the water content had no significant effect.     

Effect of environmental parameters on growth kinetics of Bacillus cereus (ATCC 7004) after mild heat treatment

The influence of temperature (10 to 50 degrees C), initial pH (4.0 to 6.0) and sodium chloride concentration (0.5 to 3.0%) on the growth in nutrient broth and in meat extract of Bacillus cereus after mild heat treatment (90 degrees C--10 min) was determined. B. cereus spores survived after heating and they were able to germinate and grow in both media when post-treatment conditions were favourable. Heated B. cereus did not grow at 10 and 50 degrees C or in a medium with pH 4.0. Decreasing pH values and increasing levels of sodium chloride decreased growth rate and increased the lag phase of B. cereus. pH 4.5 was unable to prevent the growth of heated spores in a meat substrate with 0.5% NaCl at 12 degrees C. The combination of pH /=1.0% and temperatures /=60 degrees C could control heated B. cereus ATCC 7004 growth.     

Conical receiver for a paraboloidal concentrator with large rim angle

The design and optimization of novel type of receiver for a paraboloidal concentrator with 90° rim angle is carried out by means of detailed ray tracing simulations. Cylindrical, conical, and spherical geometries are compared and their dimensions optimized. The chosen design is based on a conical cavity, which differs from similar receivers developed for concentrators with smaller rim angles. In particular, the receiver is able to catch concentrated solar energy both on its outer side and on the inner walls. Water flows inside the receiver along the conical geometry, in a double layer configuration. The receiver was built and implemented in a 90° rim angle paraboloidal concentrator. Thermal efficiency of the system is evaluated for different flow rates and inlet temperatures, both in stationary and in transient regimes, and results for fluid temperatures are compared with the results predicted by a thermal model. The time constant is evaluated.     

Aggregation and Phase Separation Phenomenon of Amitriptyline Hydrochloride Under the Influence of Pharmaceutical Excipients

The interaction between the amphiphilic drug amitriptyline hydrochloride (AMT) and the nonionic surfactants used in drug delivery has been investigated. Herein, we report the micellization behavior of AMT in presence of ethoxylated alkyl phenols in aqueous medium and the clouding phenomenon in the absence and presence of different nonionic surfactants in buffer solution. The values of critical micelle concentration (CMC) of AMT obtained using the conductivity method, decrease as nonionic surfactant concentration increases. With an increase in temperature, the CMC first increases and then decreases. At 303.15 K, the maximum CMC values were obtained with or without nonionic surfactant. The results obtained indicate attractive interactions (synergism) between the two mixing amphiphiles in solution. The experimentally obtained critical micelle concentration (CMC) values are always lower than ideal CMC values. Micellar mole fraction (X₁) values, calculated by different proposed models, show the contribution of nonionic surfactant concentration. At a fixed drug concentration (50 mmol kg^?1) and pH (=6.7) nonionic surfactants show continuous increase in cloud point (CP). Increase in drug concentration and pH, in the presence of fixed amounts of nonionic surfactant, increases and decreases the CP, respectively.