Design and evaluation of a refractance window lab-scale dryer

Purpose Refractance window drying (RWD) has been identified as the method that can give high-quality products at a relatively low production cost. However, knowledge about its use and adoption remains lacking both in academic curricula and industry in the developing world. Design/methodology/approach A lab-scale batch RWD of a closed-loop control system was designed, fabricated and evaluated for drying rates, evaporation rate, the energy of evaporation, energy efficiency and throughput. Testing was done using mango and tomato pulps. Findings Drying rates at 95°C of 1.32 gg−1min−1 and 0.854 gg−1min−1 at 2 and 3 mm, respectively, for tomato, 0.6 gg−1min−1 and 0.33 gg−1min−1 at 2 and 3 mm for mango pulp were obtained. The dryer had an evaporation rate of 4.63 × 10–4 kg/s and 4.25 × 10–4 kg/s, the energy of evaporation of 1.05 kW and 0.96 kW and thermal energy efficiency of 25.64% and 21.73% while drying tomato and mango pulps, respectively. Dryer throughput of 0.6 kg/h of dried mango Pulp and 0.47 kg/h of dried tomato pulp was obtained. Originality/value The designed RWD can be adequately used in laboratory experiments on different products to produce powders. This will enable the transfer of knowledge about RWD technology in developing countries.

Co-Crystal Structures of Furosemide:Urea and Carbamazepine:Indomethacin Determined from Powder X-Ray Diffraction Data

Co-crystallization is a promising approach to improving both the solubility and the dissolution rate of active pharmaceutical ingredients. Crystal structure determination from powder diffraction data plays an important role in determining co-crystal structures, especially those generated by mechanochemical means. Here, two new structures of pharmaceutical interest are reported: a 1:1 co‑crystal of furosemide with urea formed by liquid-assisted grinding and a second polymorphic form of a 1:1 co‑crystal of carbamazepine with indomethacin, formed by solvent evaporation. Energy minimization using dispersion-corrected density functional theory was used in finalizing both structures. In the case of carbamazepine:indomethacin, this energy minimization step was essential in obtaining a satisfactory final Rietveld refinement.

Predicted real solubility (– log x2) and the level of hydrophilic-lipophilic balance (HLBRequ.) of phytochemicals contained in extracts isolated from linden inflorescence (Tiliae flos) with solvents of diversified polarity (εM)

Summary Introduction: The broad spectrum of pharmacological properties of linden inflorescence extracts results from polarity and the level of hydrophilic-lipophilic balance of solvents (medium) used to separate compatible phytochemical structures with the expected pharmacotherapeutic profile. Objective: The use of the general Hildebrand-Scatchard-Fedors theory of solubility to calculate the predicted solubility of classes of phytochemicals contained in linden inflorescences (Tiliae flos) and the indication of those structures which, due to their high solubility in the medium, are responsible for the profile of pharmacological activity. Material and methods: The Hildebrand, Scatchard equation, supported with computational technique proposed by Fedors, allows calculation of the solubility parameters of the extraction medium. Despite application reservations, it is a fundamental tool for estimating the predictable solubility of phytochemicals in real solution. Results: The structure of phytochemicals isolated from linden inflorescences (Tiliae flos) owing to the use of solvents of significantly diversified polarity (–dielectric constant – εM) was the basis for calculating the molar evaporation energy – ΣΔEi (cal/mol) and molar volume – ΣΔVi (cm3/mol) by Fedors method, which are fundamental quantities necessary to estimate the solubility parameter – δ1/2 and required solubility level of hydrophilic-lipophilic balance – HLBRequ. Conclusions: Results of the presented research indicate that basing on the parameters characterizing the structure of phytochemicals and the calculated ideal (–logxi2) and predicted real (– log x2) solubility, it is possible – using the general Hildebrand-Scatchard-Fedors theory of solubility – to choose selectively the cascade of extraction media in order to distinguish in the plant material chemical and structural individuals of different polarity.

Spacetime Continuity and Quantum Information Loss

Continuity across the shock wave of two regions in the metric during the formation of a black hole can be relaxed in order to achieve information preservation. A Planck scale sized spacetime discontinuity leads to unitarity (a constant asymptotic entanglement entropy) by restricting the origin of coordinates (moving mirror) to be timelike. Moreover, thermal equilibration occurs and total evaporation energy emitted is finite.

Nanofluid Al2O3–H2O evaporation: energy and deposition patterns

This study experimentally investigated the deposition patterns of Al2O3–H2O nanofluid droplets with mass concentration of 0.05%, 0.2%, 1% and 3% after evaporating on transparent glass substrate with temperature of 30 °C, 40 °C, 50 °C and 60 °C, obtaining three typical kinds of patterns: the peripheral ring, the thin uniform layer with a thicker ring at the periphery and the concentric circular respectively. With the increase of concentration, the uniform pattern embedded in the peripheral ring changes into a concentric circular pattern gradually. The flow velocities corresponding to the three typical forces were solved and the results are 10−3 < Vma/Vrad − a < 10−2 and 10−28 < VDLVO+/Vrad − a < 10−5 (Marangoni, Vma, the integral mean value of the entire radius Vrad − a and the velocity caused by DLVO force VDLDO+). This indicated that the radial flow played a dominant role in the formation of the deposition pattern.

PENGARUH UKURAN ATOMISASI BAHAN BAKAR TERHADAP UNJUK KERJA MOTOR BAKAR

The size of droplet affects the evaporation of the fuel. The greater the size of droplet is also the energy of fuel evaporation. The evaporation energy is directly proportional to the size of the droplet and oxidation must be mixed homogeneously. Mixing conditions in the combustion process affect the rate of combustion. One of the conditions of combustion is the droplet to the vapor. The more perfect the evaporation process the better the combustion process. This study saw the success of combustion due to the size of droplet on the performance. The droplet produced by atomization in the form of liquid granules. The size of atomization is the determinant of burning success. The four-stroke Otto engine performance depends on the size of the atomization in order to mix well with the oxidant during combustion process. The results of the research characteristic of the machine are due to the influence of the size of the droplet seen from the generated power, torque and thermal efficiency. Characteristic features increase with decreasing the size of the droplet. Torque increased 7.9%, power generated increased 7%, and thermal efficiency increased up to 7.3%. The results of this study show size of the droplet can improve the performance of engine.

Research on Energy-Saving Technology for Salt Solution Heat Pump Evaporators

Aiming at increasing the energy-saving efficiency of salt solution evaporation, the effect of several factors on heat pump energy-saving efficiency is studied through theoretical analyses and calculation. The factors include boiling point elevation caused by solution static pressure, superheat loss of surface evaporation, temperature difference loss caused by fouling. The conclusions are that falling-film evaporator helps improve heat pump evaporation energy-saving the most and forms the fluctuating flow of the falling film which can be used to remove fouling automatically. The Φ38mm×2mm single-tube dynamics experiment results show that the flow can produce stable 3D vibration of the cleaning spiral when the nominal flow velocity is more than 0.25m/s. The axial reciprocating motion distance is longer than one spiral pitch and reciprocating periodicity is 3-6 seconds. The sodium carbonate solution fouling removal experiment results show that the salt fouling decreases the overall heat transfer coefficient by 30% in one hour when there is no the 3D vibrating spiral-insert; and the insert can enhance heat transfer by 59% comparing to that during stable operation without this technology. Key Words: Falling-film Evaporator, Heat Pump Evaporate, Energy saving, Automatic cleaning, Heat transfer