Effects Of Treatment Pressure Research Articles

Instant Controlled Pressure Drop (DIC) Treatment for Improving Process Performance and Milled Rice Quality

In this study, instant controlled pressure drop (DIC) treatment was applied for enhancing both process and IR-20 rice quality. This treatment was integrated with soaking and hot air drying (soaking–DIC–hot air drying) in order to improve process performance and quality attributes of the rice. For the optimization, the effect of treatment pressure (TP), treatment time (TT) and decompressed state duration (DD) was investigated on hot air drying time (DT) and head rice yield (HRY). Optimized results were obtained by applying an integrated approach of artificial neural network (ANN) and particle swarm optimization (PSO). With values of TP, TT and DD as the inputs, 3-6-2 was found as the best ANN architecture in order to predict DT and HRY of the DIC-treated parboiled rice. Optimum process conditions as obtained from hybrid ANN–PSO approach were TP of 0.6 MPa, TT of 39 s and DD of 14 s with maximum HRY and minimum DT. The results reveal that IR-20 milled rice produced by DIC-treated parboiling method stands better than conventional method in terms of shorter drying time (DT of 200 min against 1140 min for conventional method), higher degree of gelatinization, higher percent of HRY (70% against 55% of total paddy rice for conventional method), lower broken ratio, ease of cooking and improved pasting and texture properties.

Wettability of nano-treated calcite/CO2/brine systems: Implication for enhanced CO2 storage potential

Nanofluids are proven to be efficient agents for wettability alteration in subsurface applications including enhanced oil recovery (EOR). Nanofluids can also be used for CO2-storage applications where the CO2-wet rocks can be rendered strongly water-wet, however no attention has been given to this aspect in the past. Thus in this work we presents contact angle (θ) measurements for CO2/brine/calcite system as function of pressure (0.1MPa, 5MPa, 10MPa, 15MPa, and 20MPa), temperature (23°C, 50°C and 70°C), and salinity (0, 5, 10, 15, and 20% NaCl) before and after nano-treatment to address the wettability alteration efficiency. Moreover, the effect of treatment pressure and temperature, treatment fluid concentration (SiO2 wt%) and the period of nano-treatment on the wettability of calcite is examined. We find that nano-treatment alters the wettability significantly i.e. intermediate-wet calcite turns strongly water-wet after treatment (e.g. at 20MPa and 50°C, θ=64° for intermediate-wet calcite, and θ=28° for nano-treated calcite). Consequently, pre-injection of nanofluids will significantly enhanced the storage potential. It was also found that the permanent shift in wettability after nano-treatment is a function of treatment conditions including temperature, pressure, and treatment duration time and that surfaces treated under high pressure and low temperature yield better wettability alteration efficiency. We point out that the change in wettability is attributed to the changes in surface properties of the nano-treated sample. The results of the study thus depict that nanoparticles can significantly enhance storage potential and de-risk storage projects.

Effect of treatment pressure on structures and properties of PMIA fiber in supercritical carbon dioxide fluid

ABSTRACTThe effects of treatment pressure on the structures and properties of PMIA fiber were investigated by Scanning electron microscopy, Dynamic wetting measurements, Fourier transform infrared spectrometry, X‐ray diffraction, thermogravimetric analysis, and mechanical properties test technology in supercritical carbon dioxide. The results indicated that the surface morphology, the water contact angle, the interaction of macromolecules, the crystal structure, the thermal property, and tensile strength of PMIA fibers were changed during supercritical carbon dioxide treatment, particularly the surface morphology and the wettability of fiber changed the most obviously with the increase of treatment pressure. Furthermore, the thermal property and tensile strength of treated PMIA fiber sample were improved in comparison with those of untreated sample. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41756.

Effect of treatment pressure on wool fiber in supercritical carbon dioxide fluid

The treatment of wool in supercritical carbon dioxide fluid is an environmentally friendly and advantageous solution for cleaner production of wool textiles with water free and energy preserving, as well as avoiding a large amount of effluent discharge and serious environment pollution in conventional wet chemical processes. In the present work, some basic supports for the applications of supercritical carbon dioxide fluid in the cleaner production of wool were developed at different system pressures. The effects of treatment pressures on the crystal and chemical structures, macrochain conformations, thermal property and surface morphology of wool were investigated by employing Wide-angle X-ray diffraction (WAXD), Fourier transform infrared spectrometry (FT-IR), thermogravimetric (TG)/differential thermogravimetric analysis (DTG) and scanning electron microscopy (SEM). The WAXD analysis indicates that an improvement of crystallization both in α-helix and β-sheet structures was obtained for wool treated at different pressures in supercritical CO2 fluid, although the improvement tendency was decreased with pressures. Moreover, a re-crystallization and a swelling of crystals in wool fiber were also occurred during the supercritical treatment. FT-IR analysis shows that more powerful interactions of hydrogen bonds between the macromolecular chains of wool were formed during the supercritical treatment, accompanying with a significant transformation of α-helix to β-sheet structure and an oxidation or acidic hydrolysis of disulfide bonds in wool scales. The TG-DTG analysis shows that an enhanced thermal stability of wool was obtained after a treatment in supercritical CO2 fluid. Moreover, a notable etching effect or dilapidation on the scales of wool was observed in SEM analysis with a decrease in scale height, thickness and coating density on fiber.

Effect of high-pressure treatment on normal rice and waxy rice starch-in-water suspensions

The effects of treatment pressure (⩽700 MPa), temperature at treatment (10–60 °C), and treatment duration (0–30 min) on the gelatinization of normal and waxy rice starches were investigated. Pressure-treated starch suspensions were examined for pasting behaviour, initial apparent viscosity ( η initial), degree of swelling, birefringence changes, and leaching of starch and amylose. The η initial measurements provided an objective and analytical means of determining the degree of pressure-induced gelatinization of starch. Both normal and waxy rice starches exhibited sigmoidal-shaped pressure-induced gelatinization curves. The degree of gelatinization was dependent on the type of starch, the pressure, the temperature, and the duration of treatment. Different combinations of these factors could result in the same degree of gelatinization. There was a linear correlation between the degree of swelling and η initial. After treatments at ⩾500 MPa, both starches lost all birefringence although they experienced different extents of change in η initial and the degree of swelling.

Effects of treatment pressure, holding time, and starch content on gelatinization and retrogradation properties of potato starch–water mixtures treated with high hydrostatic pressure

Potato starch–water mixtures (10–70% w/w) were treated with high hydrostatic pressure (HHP) at 600, 800, and 1000 MPa at 40 °C for 18 and 66 h, and enthalpy change for gelatinization (Δ H gel), gelatinization temperature ( T gel), and enthalpy change for re-gelatinization of retrograded starch (Δ H retro) were investigated by differential scanning calorimetry. Furthermore, the results were compared with those of samples HHP-treated for 1 h reported in our previous study. The Δ H gel values of 10–50% (w/w) mixtures decreased with increased treatment pressure and with decreased starch content. The 30–60% (w/w) mixtures retrograded, and the Δ H retro values increased with decreased Δ H gel values and with increased starch content. There was little effect of holding time on the values of Δ H gel and Δ H retro. The T gel values of the 10–50% (w/w) mixtures increased with decreased Δ H gel values and with prolonged holding time.