Use Of Evaporation Research Articles

Effect of gamma irradiation and evaporation on physicochemical, antibacterial, and antioxidant activity of selected high-quality herbal honey

This study was conducted to evaluate the influence of evaporation and gamma irradiation on physicochemical characteristics, antibacterial properties, and antioxidant activity of selected high-quality herbal honey (SH3), an Indonesian traditional herbal medicine recipe. Treatments consisted of untreated sample, evaporated SH3, irradiated SH3, and evaporated-irradiated SH3. Gamma irradiation dose of 10 kGy was applied in this study. Evaporation-irradiation treatments significantly decreased water activity (p < 0.01), moisture content (p < 0.01), and pH value (p < 0.001). Evaporated-irradiated samples also had the lowest total bacteria count (p < 0.05). Moreover, according to the prediction of Accelerated Shelf Life Testing (ASLT), shelf life increased from 180 d in untreated samples to 371, 335, and 419 d in the samples treated with evaporation, irradiation, or both, respectively. Antioxidant activity in irradiated and evaporated-irradiated samples was higher (p < 0.05) than untreated samples. Evaporation treatment increased antibacterial properties of SH3 (p < 0.05). The antibacterial characteristics of SH3 for Bacillus subtilis were observed to be similar among treatments. Except for evaporation treatment, similar findings were demonstrated for Escherichia coli antibacterial activity. The results of the present study suggest that the use of evaporation, combined with irradiation, may increase physicochemical characteristics, shelf life and antioxidant activity of SH3.

A Review on Dry Deposition Techniques: Pathways to Enhanced Perovskite Solar Cells

This review discusses the use of evaporation, chemical vapor deposition, and sputtering as the three main dry deposition techniques currently available for fabricating perovskite solar cells. We outline the distinct advantages that each method offers in terms of film quality, control, and scalability. Additionally, recent advancements in process optimization and the integration of dry deposition with other fabrication techniques are highlighted. Thus, this review provides valuable insights into the potential of dry deposition processes to produce high-performance perovskite solar cells and aids researchers and industry professionals in selecting the most suitable technique for the fabrication of efficient and stable devices.

Combination of different preservation techniques as low-cost strategies inhibiting sugar degradation in liquid feedstock used for bioethanol fermentation

Just like for the food supply chain, sugar-based feedstock used in the bioethanol industry might be affected by biological contamination, resulting in important economic losses. Therefore, it is necessary to develop cost-effective storage techniques capable of preserving feedstock over several months. In this study, three different techniques (ozonation, acidification, and addition of a corn oil layer) were investigated individually as well as combined for the long-term storage of sugars dedicated to fermentation. After 300 days of storage, up to 100% of the initial fermentable sugars were preserved with acidification (pH 2.0), independently or in conjunction with other conservation techniques. However, in terms of fermentation potential, the groups treated with acid had a lower ethanol yield than the groups maintained at pH 6.0. When the solution was treated with ozone combined with acidification, it yielded 55.71% of bioethanol efficiency, whereas when treated only with ozonation at pH 6.0, fermentation reached a 67.20% yield. Ozonation was found to be efficient to preserve fermentable sugars, either with the use of an oil layer (80% conservation) or at lower pH (100% ethanol efficiency). Finally, the combination of ozonation and an oil layer presented the highest total ethanol production, reaching 101g L−1 after 96h of incubation using Saccharomyces cerevisiae. Thus, the combined use of ozonation and an oil layer has the potential to be used in the bioethanol sector as a system to preserve liquid feedstock without the use of evaporation to increase sugar concentration.

PDA Laser Measurements of Droplet-Laden Flows in a Four-Stage Axial Compressor

Abstract Droplet-laden flows play a significant role in the development of turbomachinery. For example, fine water droplets are injected into the flow path of axial compressors to increase the power output of gas turbines by making use of evaporation cooling, often referred to as wet compression. Another example is the ingestion of rain droplets in aircraft engines. Therefore, thermodynamic and aerodynamic measurements of air and liquid are indispensable to better predict the following behavior of the droplets in the gas flow. This article presents a new PDA measurement setup for a droplet-laden four-stage axial compressor to analyze the droplet behavior in swirled flows. To reduce optical disturbances of the laser beam path, liquid films at the casing are suppressed by a boundary layer air injection. Supplementary investigations with this treatment show a negligible influence on the compressor behavior. To minimize refraction effects of the laser beams at the casing window, the laser device with the optical probes can be translated and rotated, thus having 4 degrees-of-freedom. Furthermore, the collected droplet data are compared with a mathematical description of velocity slip in superimposed air flows. For the first time, it can be shown experimentally that droplets smaller than 10 μm attain the velocity of air one stage after injection. For larger droplets, however, deviations from the air Mach number of up to 0.05 remain. In addition, detached liquid films behind the trailing edge of the stator blades with low velocities can be clearly detected.

Stable and Salt-Resistant Janus Evaporator Based on Cellulose Composite Aerogels from Waste Cotton Fabric.

Solar steam generation has been considered a promising approach for using renewable solar energy to produce clean water from seawater and wastewater. It shows great potential for alleviating water shortages. However, salt accumulation and system longevity are challenges which impede the widespread use of evaporators. This paper reports a stable Janus evaporator with thickness controllable hydrophilic and hydrophobic layers based on cellulose composite aerogels, which were extracted from waste cotton fabric by a two-step freeze-drying process. The obtained glutaraldehyde cross-linked carbon nanotubes/cellulose Janus aerogel exhibited an attractive solar steam generation rate of 1.81 kg·m-2·h-1 and a light-to-vapor efficiency of up to 92.5% in 1 sun illumination. Moreover, the Janus solar steam generator could pledge stable and sustainable solar-driven water evaporation performance within a 10 h test, showing a high salt-resistant property in simulated seawater. In addition, the developed solar evaporator also had a good purification effect on dye wastewater. These findings suggest its potential ability for seawater desalination and wastewater purification.

Vertical porous MoS2/hectorite double-layered aerogel as superior salt resistant and highly efficient solar steam generators

Solar desalination which can produce freshwater by using green and renewable solar energy is considered as a promising strategy to mitigate water scarcity. However, in practical application, the crystallization and accumulation of salt will cause adverse impact on the water transportation, vapor generation efficiency, and long-term sustainable use of evaporator. Herein, we proposed a vertical porous MoS2/hectorite bi-layered aerogel for efficient solar steam generation with superior salt redissolution performances, excellent light absorption and outstanding local thermal effect. The top MoS2 layer functioned as efficient solar absorbers with excellent light absorption and photo-thermal conversion performances. For the bottom layer, the vertical water transport path and natural strong hydrophilicity of hectorite aerogel ensure stable water supply to the evaporation layer and prevent the accumulation of salt at the evaporation interface. The results show that the constructed superhydrophilic MoS2/hectorite bilayer aerogel has excellent self-driven salt removal performance, and can achieve self-cleaning within 30 min under extreme conditions simulating salt crystallization. In addition, the aerogels exhibited a steam generation rate of 1.32 kg m−2 h−1 and an evaporation efficiency of 85.99% under a light intensity of only 1 kW m−2. The superior performances of MoS2/hectorite double-layer aerogel, such as low cost, simple preparation, high strength and good salt resistance, make it suitable as portable evaporator for efficient solar interface desalination.

Zinc Oxide Superstructures in Colloidal Polymer Nanocomposite Films: Enhanced Antibacterial Activity through Slow Drying

Achieving control over the distribution of biocides across the thickness of polymer nanocomposite films is one of the largest challenges to develop efficient antibacterial surfaces. In such applications, it is key to maximize the biocide presence at the film top surface to ensure contact with bacteria. Here, we make use of evaporation driven colloidal self-assembly to control the vertical distribution of biocides in polymer composite films cast from colloidal blends of polymer and zinc oxide (ZnO) nanoparticles. We present a thorough study which shows that the evaporation rate and ZnO volume fraction have a strong impact on the final film architecture and on its wetting and antibacterial properties. For high enough ZnO volume fraction, the ZnO nanoparticles assemble in superstructures on top of the film, which are higher the slower the evaporation rate used, and maximum ZnO surface coverage achieved through slow film drying. At high ZnO volume fraction (ϕ=0.29), the zone of inhibition diameter against E. ...

Experimental Study to Performance Improvement of Vapor Compression Cooling System Integrated Direct Evaporative Cooler and Condenser

For areas with very hot and humid weather condition increased latent and sensible load are a major problem in cooling systems that will increase compressor work so that electricity consumption will also increase. Combined condenser with direct evaporate cooling will increase the heat removal process by using an evaporative cooler effect that will increase the efficiency of energy use. This paper presents the study of the use of evaporator cooling and condenser. This paper mainly calculated energy consumption in steam compression cooling systems and related problems. From the results of this study, the use of condensers with evaporative cooling, power consumption can be reduced to 46% and performance coefficient (COP) can be increased by about 12%, with 1,2 kW cooling capacity.

Manufacturing cost and market potential analysis of demonstrated roll-to-roll perovskite photovoltaic cell processes

Perovskite photovoltaic solar cells and modules can be manufactured using roll-to-roll (R2R) techniques, which have the potential for very low cost production. Understanding cost barriers and drivers that will impact its future commercial viability can beneficially guide research directions. Because processes, materials and equipment for manufacturing are still under development, it is difficult to estimate these costs accurately. We use a cost method developed to allow for uncertainty in the input assumptions to analyse three demonstrated R2R compatible manufacturing sequences and two potential optimised sequences. Using these novel methods, we have identified and quantified key cost barriers; high cost materials P3HT and PCBM, the use of evaporation for the rear metal deposition, and the transparent ITO coating. We project that technology developments in these key areas would halve the expected manufacturing cost to US$37/m±30%. With 68% GFF, 10% PCE and a 3 year lifetime, such R2R perovskite modules would be competitive with existing flexible PV products in the market on a $/W and power to weight basis. To compete with Si and CdTe in the flat plate PV market, PCE and lifetimes in excess of 15% and 15 years respectively would be required.

Strategies for Inorganic Incorporation using Neat Block Copolymer Thin Films for Etch Mask Function and Nanotechnological Application.

Block copolymers (BCPs) and their directed self-assembly (DSA) has emerged as a realizable complementary tool to aid optical patterning of device elements for future integrated circuit advancements. Methods to enhance BCP etch contrast for DSA application and further potential applications of inorganic nanomaterial features (e.g., semiconductor, dielectric, metal and metal oxide) are examined. Strategies to modify, infiltrate and controllably deposit inorganic materials by utilizing neat self-assembled BCP thin films open a rich design space to fabricate functional features in the nanoscale regime. An understanding and overview on innovative ways for the selective inclusion/infiltration or deposition of inorganic moieties in microphase separated BCP nanopatterns is provided. Early initial inclusion methods in the field and exciting contemporary reports to further augment etch contrast in BCPs for pattern transfer application are described. Specifically, the use of evaporation and sputtering methods, atomic layer deposition, sequential infiltration synthesis, metal-salt inclusion and aqueous metal reduction methodologies forming isolated nanofeatures are highlighted in di-BCP systems. Functionalities and newly reported uses for electronic and non-electronic technologies based on the inherent properties of incorporated inorganic nanostructures using di-BCP templates are highlighted. We outline the potential for extension of incorporation methods to triblock copolymer features for more diverse applications. Challenges and emerging areas of interest for inorganic infiltration of BCPs are also discussed.

Initial dissolution kinetics of cocrystal of carbamazepine with nicotinamide.

Objectives of this study are investigating the initial dissolution kinetics of the cocrystal of carbamazepine (CBZ) with nicotinamide (NIC) and understanding its initial dissolution process. Cocrystal solids of CBZ with NIC were prepared by co-milling and solvent evaporation methods. The formation of cocrystal solid was verified via X-ray diffraction measurement. Dissolution tests of the solids were performed using an original flow cell and ultraviolet-visible spectroscopic detector. The spectra monitored in situ were analyzed to determine the dissolved compounds separately using the classical least squares regression method. The initial dissolution profiles were interpreted using simultaneous model of dissolution and phase changes. In the initial dissolution, CBZ in the cocrystal structure dissolved in water and it was suggested that CBZ reached a metastable intermediate state simultaneously with dissolution. The cocrystal solid prepared by solvent evaporation provided a higher rate constant of the phase change than that prepared by co-milling. Our results thus support the use of evaporation as the method of choice to produce ordered cocrystal structures. We suggest that CBZ forms dihydrate during the dissolution process; however, during the initial phase of dissolution, CBZ changes to a metastable intermediate phase.

Managing evaporation for more robust microscale assays. Part 1. Volume loss in high throughput assays.

Evaporation is a well known issue when handling small liquid volumes. Here we present a review of microscale assays prone to evaporation and methods to make them more robust. Applications for these assays span from combinatorial chemistry to cell-biology where the stability of concentrations and osmolarity can be critical. A dimensionless evaporation number Ev is presented and used to characterize volume loss in short term and long term microscale assays. Ev can be used both as a design tool and as an analysis parameter. The advantageous use of evaporation in some applications is also discussed.

Experimental comparison of electronic and thermostatic expansion valves performances in an air conditioning plant

Adopting electronic expansion valves in air conditioners enables an appreciable energy saving with respect to the same installations equipped with traditional thermostatic expansion valves. This is due to the fact that electronic valves allow a lower condensation pressure in systems equipped with air cooled condensers, which is adjusted to variations in outside air temperature. Furthermore, PID (Proportional–Integral–Derivative) control over the superheating leads to the best use of evaporator under every condition (lower superheating level of the vapour refrigerant), thus increasing the refrigerating capacity. This paper reports on the results of a set of measurements that were carried out from March to November 2006 on the operation of eight direct expansion air conditioners having a total cooling capacity of 120 kW installed at a telephone control room near Bologna (North Italy). Air conditioners are equipped with both thermostatic and electronic expansion valves, alternatively activated by solenoid valves on a daily basis, in order to compare the two systems in the same environment and at similar load conditions. The annual analysis is supplemented by a transient simulation program to simulate the behaviour of the system in the two different operating modes in different European climates, in order to evaluate the energetic and economic advantages of electronic valve.

A method for measuring the surface impedance of superconductors in the temperature range 0.4–120 K

A method and a setup for making precision measurements of the temperature dependences of components of surface impedance Z(T) = R(T) + iX(T) of small superconductor crystals in the temperature range 0.4–120 K have been developed. The setup combines a high-quality-factor resonance system for measuring the microwave response of a sample at a frequency of 28 GHz and a refrigerating unit with the use of evaporation of 3He vapors. Measurements of Z(T) of optimally doped YBa2Cu3O6.93 single crystals in the superconducting and normal states were performed to illustrate the operation of the setup.

Simulating a multiphase reactor with continuous phase transition

A novel multiphase fixed-bed reactor with continuous phase transition for benzene hydrogenation to cyclohexane has been presented by Cheng et al. (A.I.Ch.E. J. 47 (2001a) 1185; Chem. Eng. Sci. 56 (2001b) 6025; 57 (2002) 3407; A.I.Ch.E. J. 49 (2003) 225) which makes use of evaporation of volatile components to remove the reaction heat. This paper investigates issues related to the numerical simulation of the model for this novel fixed-bed reactor. The reactor is supposed to be divided into two parts subject to the phase transition point on the bed level, that is, the liquid-contacted zone at the lower part and the gas-contacted zone at the upper part. A steady-state mathematical model for the reactor is developed. All external mass and heat transfer resistances can be neglected in the case investigated, as well as temperature differences in the particles. The effects of feed inlet temperature, inlet benzene concentration, gas flow rate and liquid flow rate on the reactor performance are theoretically studied. Reliability of the model is verified by bench-scale experiments. The results show that dryout phenomena will occur in the reactor both on the bed-scale and on the pellet-scale under certain conditions.

Use of Evaporation for Heavy Oil Produced Water Treatment

Abstract Heavy oil recovery processes have traditionally used "once through" steam generators (OTSG) to produce high pressure steam for injection into geological formations containing heavy oil. The heat given up by the condensing steam fluidizes the heavy oil and allows the oil/water mixture to be brought to the surface. The oil is recovered as product and the water, referred to as produced water, is de-oiled and treated for feedwater to the OTSG. The typical treatment method for produced water is warm or hot lime softening (WLS or HLS), filtration, and weak acid cation exchange (WAC). An alternative method of produced water treatment is vertical tube, falling film, vapour compression evaporation. This method:eliminates physical-chemical produced water treatment;results in lower life cycle costs;does not produce any softener sludge for disposal;minimizes the number and volume of waste streams requiring disposal;requires fewer maintenance materials and less maintenance labour;reduces the required amount of produced water de-oiling equipment;dramatically increases OTSG feed water quality, improving OTSG reliability; and,provides increased system availability and reliability. For steam assisted gravity drainage (SAGD) processes, which require 100% quality steam, it has the added advantage of producing water of sufficient quality for use in standard packaged boilers in lieu of OTSG. Packaged boilers are less expensive than OTSG, produce a much smaller liquid blowdown stream, and result in a boiler feed system which is 20% smaller than that of an OTSG. Introduction Heavy oil recovery requires large volumes of water commensurate in volume to the production of oil that it yields. Water is used in the form of steam to heat the geological formations that hold the oil. The oil is fluidized by the condensing steam and the oil/water mixture is pumped to the surface. The oil and water are separated. The oil is recovered as product and the water, referred to as produced water, is de-oiled and treated for reuse in the steam generator. Traditionally, "once-through" steam generators (OTSG) have been used to produce 80% quality steam (80% vapour, 20% liquid) for injection into the well. A relatively new heavy oil recovery process, steam assisted gravity drainage (SAGD), requires 100% quality steam to be injected into the well (i.e., no liquid water). To produce 100% quality steam using OTSG, a series of vapour-liquid separators are required to separate the liquid water from the steam. The 100% quality steam is then injected into the well. For both SAGD and non-SAGD applications, the produced water can generally be characterized as predominantly sodium chloride brine with high silica and minimal calcium and magnesium. High alkalinity, or carbonate, is present as well. The produced water generally contains about 4,000 mg/l total dissolved solids but can be much higher depending on the geological contribution. Dissolved and emulsified organics (oil) are present at a variety of levels, depending on the oil separation processes used.

Design and Control for Energy Integration in a Bio-Process

This paper presents an industrial viewpoint on designing for energy integration in processes with substantial water removal (e.g. bio-processes) to ensure dynamic controllability. The use of evaporation and distillation for water removal and product purification in a bio-process is energy intensive, since the concentration of desired product leaving the fermenter is often quite low. The nature of a fermentation process causes inherent variation in the feed composition to downstream units. Potential opportunities for energy integration can be exploited, but must be done in a way that ensures the process is controllable. An example is presented of a multi-effect evaporator system combined with two distillation columns, describing how the design of energy integration between them requires some mechanism or manipulator to prevent disturbances from propagating around the material and energy loops.

Micro-evaporation electrolyte concentrator

The sensitivity of miniaturized chemical analysis systems depends most of the time on the obtainable detection limit. Concentrating the analyte prior to the detection system can enhance the detection limit. In this writing an analyte concentrator is presented that makes use of evaporation to increase the ion concentration of an electrolyte. The evaporation rate can be enhanced using forced convection. In order to control the evaporation rate a nitrogen flow is fed over a liquid channel covered with a hydrophobic vapor permeable membrane. Water vapor can pass through this membrane in contrast to water itself because of the hydrophobic nature of the membrane surface. An electrolyte conductivity detector is used to measure directly the concentration effect as a function of the nitrogen flow velocity. The influence of the convective nitrogen flow and the residence time of the analyte inside the concentrator are investigated in this paper. It is shown that the evaporation rate is enlarged with an increase in convective flow. The concentration effect is also enhanced when the residence time of the analyte inside the concentrator is increased. The higher concentration enhancement due to the longer residence time, however, results in an increase in water vapor present in the nitrogen flow. This results in a lower normalized evaporation rate when the available evaporation time is enlarged.

The Use of Evaporation in Vacuum for Purification and Analysis of Zinc

The method for matrix distilling off was used for concentration of impurities in zinc to decrease (lower) their detection limits and to purify zinc thoroughly. Thermodynamic approximation was used in the modeling of the process. The results of the modeling are compared with those of the experiment.

The Use of Spiral Wound Ultrafiltration Technology in Gelatin Processing – an Overview

Since the first commercial system was installed in the early 1980s, the use of spiral wound ultrafiltration technology has become an accepted unit operation in gelatin processing. Ultrafiltration (UF) replaces or reduces the use of evaporators, which are energy intensive and expensive to run. Other benefits of UF are increased product quality, improved environmental impact and reduced operating costs.