Application of Emerging Cell Disintegration Techniques for the Accelerated Recovery of Curcuminoids from Curcuma longa

Curcuminoids, the bioactive compounds with many beneficial effects on human health, exist in Curcuma longa (turmeric). In the present study, the impact of different cell disintegration techniques to enhance total curcuminoid recovery (TC) from fresh and dried turmeric was investigated. The impact of thermal pretreatment (TP), ultrasound pretreatment (UP), enzyme pretreatment (EP), and pulsed electric field pretreatment (PEF) on the recovery of curcumin (CUR), demethoxycurcumin (DMC), and bis-demethoxycurcumin (BDMC) from fresh and dried turmeric were studied. The cell disintegration index (Zp) and high-performance liquid chromatography (HPLC) analysis of curcuminoids were performed to evaluate the efficiency of the applied techniques. With fresh turmeric, the highest curcuminoid recovery was 83.6 mg/g dry basis with EP. The highest structural tissue damage was obtained with UP achieving a cell disintegration level of 92.5%. The technology with the highest time-saving and low specific energy input was PEF with a total curcuminoid recovery of 80.9 mg/g dry basis. Working with dried turmeric, the drying required high specific energy input for 72 h at 50 °C; however, the untreated dried sample reached 125.3 mg/g dry basis of TC without further pretreatment after drying.

Effect of CO2 Laser Fluence on Cladding Geometrical Dimensions Alternations

Geometrical dimensions could play a potential role in the function of laser cladding of nickel-base powder on the cold-rolled carbon steel substrate. The geometrical dimensions and their impact on the efficiency of the process of laser cladding of nickel-base powder (Ni -10wt% Al) on cold rolled 0.2% carbon steel substrate was investigated. This work focused on the effect of laser-specific energy input of CO2laser. The geometrical dimensions of cladding regions are including cladding width, cladding height, depth of dilution, contact angle, dilution area, cladding area, and heat-affected zone dimensions determinations. The laser power (1.8 kW) was used at different traverse speeds (1.5, 3.6, 5, 7.1, 8.6, 12.5 mm/s) with (3mm) laser beam diameter. The feed rate was kept constant after many preliminary claddings at approximately 11 g/min. Fluence values ranged from (48-400J/mm2), and the power density value was (255W/mm2). A minimum dilution percentage (25%) was obtained at the highest fluence value (400 J/mm2). Observations were measured using an optical microscope, scanning electron microscopy, and Image software. Obtained results indicated that the increase in the fluence leads to an increase in height of cladding, HAZ region but lower depth of dilution

Grinding Media Motion and Collisions in Different Zones of Stirred Media Mills

Product fineness during grinding in stirred media mills is mainly influenced by the specific energy input, the stress energy transferred by the colliding grinding media and the stress frequency. The stress energy from grinding media collisions is heterogeneously distributed in stirred media mills. Herein, in order to characterize the stress energy distribution and the local grinding media collision frequencies, the grinding media motion was calculated using discrete element method (DEM) simulations coupled with computational fluid dynamics (CFD). The local grinding media concentration, velocity profiles, grinding media collisions and stress energies were compared for varied total grinding media fillings and stirrer speeds. It was confirmed that the normalized grinding media velocity profile can be used to divide the grinding chamber into four types of zones that allow the modeling of the stress energy distribution. However, the collision frequency showed very different distributions for varied stirrer velocities and grinding media fillings.

Iron Nanoparticle Production by the Method of Electric Explosion of Wire

Background: The widespread use of the iron nanopowders connected with widely range of characteristics such as size, magnetic characteristics and high surface area and that is why in the literature are present many researches of its different applications. Objective: The work studies the influence of the conditions of the iron wire electrical explosion on the course of the explosion process and the dispersed composition of the resulting metal nanopoweder. Method: Experiments on electrical explosion of iron wires were carried out in the laboratory setup with the different initial conditions of electrical explosion of the iron wire. Results: The influence of the initial wire electrical explosion conditions on the explosion regime, the specific energy input into the conductor, and the specific energy released in the arc stage of discharge are definitely determined. The empirical equations for calculation of the initial wire electrical explosion conditions for providing the critical explosion in the argon medium at a pressure of 2·105 Pa were defined. It has been established that for synthesis of iron nanopowders with a narrow particle size distribution, it is preferable to use modes with a high level of the energy released in the arc stage of the discharge. Conclusion: It was found that disabling the arc stage of the discharge during EEW leads to the decreasing of the average surface particle size by 50%.

Perspectives of pulsed electric field application for larvae biomass drying

The perspectives of pulsed electric field (PEF) application for larvae biomass drying are considered. Drying process optimization was carried out using two-way analysis of variance in the range of applied specific energy input of from 0 up to 20 kJ/kg and drying temperature of from 50 up to 90°С. It was found out that application of pulsed electric field treatment allowed marked decreasing of larvae biomass drying time from 183 to 124 minutes for the samples treated with electric filed intensity of E = 2 kV/cm and specific energy of 20 kJ/kg. Based on the obtained experimental data the optimal drying and PEF treatment parameters for larvae biomass were determined for the ranges of drying temperature – 82–85℃ and specific energy input – 4.1–6.6 kJ/kg.

STUDYING CO₂ CONVERSION IN DC GLOW DISCHARGE

We have registered the mass-spectra of the gas mixture leaving the chamber and the discharge current-voltage characteristics and determined the specific energy input (SEI), the absolute conversion coefficient χ and the conversion energy efficiency η in the CO₂ pressure range of 0.05...5 Torr. Converting CO₂ molecules was performed in the glow discharge in a chamber with distributed same-side gas supply and pumping. As a result the conversion coefficient χ equaling 70% was achieved, but the conversion energy efficiency η did not exceed 1...3 % because of considerable power loss due to acceleration of positive ions, gas and electrode heating as well as to inelastic collisions between electrons and gas molecules not leading to CO₂ conversion.

Improving biogas production performance of dairy activated sludge via ultrasound disruption prior to microwave disintegration

In this study, ultrasound disruption was employed to enhance the efficiency of microwave disintegration of dairy sludge. Results revealed that ultrasound specific energy input of 1,500 kJ/kg TS was found to be optimum with limited cell lysis at the end of the disruption phase. Biodegradability study suggested an enhancement in suspended solids reduction (16%) and biogas production (180 mL/gVS) in floc disrupted (deflocculated) samples when compared to sole microwave pretreatment (8.3% and 140 mL/gVS, respectively). Energy assessment to attain the 15% optimum solubilization revealed a positive net production of 26 kWh per kg sludge in deflocculated samples compared to 18 kWh in flocculated (sole microwave) samples. Thus, ultrasound disruption prior to microwave disintegration of dairy sludge was considered to be a feasible pretreatment technique.

Use of pulsed electric fields to induce breakage of glandular trichome cells in leaves of fresh patchouli (Pogostemon cablin Benth.): Specific energy input consumption

Research has been performed using a pulsed electric field (PEF) to damage plant cells to obtain bioactive compounds before extraction. However, research into the use of PEF to break down the glandular trichome (GT) cells of patchouli for essential oil extraction is still limited. The purpose of this study was to determine the specific energy input needed to break patchouli leaf GT cells by PEF treatment. Patchouli leaves were harvested at 7 months of age, then treated with PEF. GT cell changes were analyzed using scanning electron microscopy. The results show that treatment with variable frequencies caused GT cell wrinkling and treatments with a variable electric field caused GT cell rupture. Electric field treatment at E=133.33 V/cm and a PEF exposure time of 2 seconds or E=116.66 V/cm and 3 seconds of PEF exposure resulted in consistent rupture of GT cells. Energy consumption of 0.049 kJ/cm3 promoted GT cell wall shrinkage and consumption of 0.59 kJ/cm3 broke GT cell walls.