CONTROL OF MEAN DROPLET DIAMETER ISSUED FROM Y-JET-TYPE AIRBLAST ATOMIZER BY USING FLUID AMPLIFIER

1995 ◽  
Vol 5 (3) ◽  
pp. 243-260 ◽  
Author(s):  
Takao Inamura ◽  
Nobuki Nagai
Keyword(s):  
Droplet Diameter

Theoretical Post-Dryout Heat Transfer Model

2018 ◽  
Vol 1 (1) ◽  
pp. 142-150
Author(s):  
Murat Tunc ◽  
Ayse Nur Esen ◽  
Doruk Sen ◽  
Ahmet Karakas
Keyword(s):  
Heat Transfer ◽  
Droplet Diameter ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Operating Pressure ◽  
Vertical Pipe ◽  
Two Phase ◽  
Experimental Values ◽  
Reactor Operating ◽  
Coolant System

A theoretical post-dryout heat transfer model is developed for two-phase dispersed flow, one-dimensional vertical pipe in a post-CHF regime. Because of the presence of average droplet diameter lower bound in a two-phase sparse flow. Droplet diameter is also calculated. Obtained results are compared with experimental values. Experimental data is used two-phase flow steam-water in VVER-1200, reactor coolant system, reactor operating pressure is 16.2 MPa. On heater rod surface, dryout was detected as a result of jumping increase of the heater rod surface temperature. Results obtained display lower droplet dimensions than the experimentally obtained values.

Development and Oral Bioavailability of Self-Emulsifying Formulation of Ketoconazole

2013 ◽  
Vol 5 (4) ◽  
pp. 1858-1865
Author(s):  
Arundhati Bhattacharyya ◽  
M Bajpai
Keyword(s):  
Oral Bioavailability ◽  
Oral Delivery ◽  
Oral Absorption ◽  
Aqueous Suspension ◽  
Droplet Diameter ◽  
Tween 80 ◽  
Concurrent Administration ◽  
System Maintenance ◽  
Pure Drug ◽  
Ph Dependent

Ketoconazole is an imidazole antifungal drug belonging to the class II of Biopharmaceutic Classification System. Maintenance of gastric acidity is essential for adequate dissolution and absorption of ketoconazole. Concurrent administration of antacid and antiulcer preparations decreases the oral absorption of ketoconazole often causing therapeutic failure.  The aim of this study was to evaluate whether a self-emulsifying formulation of ketoconazole would be able to overcome the pH dependent dissolution and oral bioavailability. Self-emulsifying drug delivery system (SEDDS) was prepared after selecting the oil, surfactant and co-surfactant by solubility analysis. Optimum ratio of the components was finalized on the basis of drug content, self-emulsification and mean droplet diameter. The effect of pH on dissolution was studied in comparison to the pure drug. Oral bioavailability was determined in comparison to aqueous suspension in rats and the effect of co-administration of ranitidine hydrochloride solution and a commercially available liquid antacid preparation was studied. The optimized formulation containing 20% Capryol 90 and 40% each of Carbitol and Tween 80, exhibited 100% drug release regardless of the pH whereas the pure drug exhibited a highly pH dependent dissolution. The AUC0-24 resulted with oral administration of the SEDDS formulation was about 34%, 43% and 60% higher compared to the aqueous suspension when administered alone, administered with ranitidine and administered with antacid respectively. The results of the present study demonstrate that self-emulsifying formulations can be utilized for oral delivery of weakly basic drugs like ketoconazole which exhibit pH dependent dissolution.

scholarly journals Development and Evaluation of an Ultrasonic Humidifier to Control Humidity in a Cold Storage Room for Postharvest Quality Management of Dates

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 949
Author(s):  
Maged Mohammed ◽  
Nashi Alqahtani ◽  
Hamadttu El-Shafie
Keyword(s):  
Quality Management ◽  
Cold Storage ◽  
Cooling System ◽  
Positive Impact ◽  
Droplet Diameter ◽  
Postharvest Quality ◽  
Main Element ◽  
Small Scale ◽  
Storage Room ◽  
Ultrasonic Humidifier

Dates are subjected to postharvest losses in quality and quantity caused by water loss, fermentation, insect infestation, and microbial spoilage during storage. Cold storage is the main element in the postharvest quality management used for fruit preservation. Although cold storage is used for dates, precision control of the relative humidity (RH) using ultrasonic applications is not used thus far, or it is applied to other fruits on a small scale. Therefore, we designed and constructed an ultrasonic humidifier (DUH) for RH control in the cold storage room (CSR) of dates. The optimum air velocity of 3 m s−1 at the outlets of the DUH ducts produced a mist amount of 6.8 kg h-1 with an average droplet diameter of 4.26 ± 1.43 µm at the applied voltage of 48 V and frequency of 2600 kHz of the transducers. The experimental validation was carried out by comparing a CSR controlled with the DUH with two conventional CSRs. The three tested CSRs were similar in dimensions, cooling system, and amount of stored dates. The time required for cooling 800 kg of dates in the controlled CSR from 25 °C to the target temperature of 5 °C was approximately 48 h. The DUH precisely controlled the RH at the maximum RH set point of 80% in the tested CSR at 5 °C. The controlled RH at 80% has a positive impact on the physicochemical characteristics of the stored dates. It significantly reduced the weight loss of the fruits and preserved fruit mass, moisture content, water activity, firmness, and color parameters. However, no significant effect was observed on fruit dimensions, sphericity, and aspect ratio. The microbial loads of mesophilic aerobic bacteria, molds, and yeasts fell within the acceptable limits in all tested CSRs. Both stored date fruits and artificially infested dates showed no signs of insect activity in the controlled CSR at the temperature of 5 °C and RH of 80%. The DUH proved to be a promising technology for postharvest quality management for dates during cold storage.

Evaluation on the performance fluctuation after water ingestion for a turbofan engine compressor during flight descent

2020 ◽  
pp. 095441002097798
Author(s):  
Lu Yang ◽  
Qun Zheng ◽  
Aqiang Lin
Keyword(s):  
Droplet Diameter ◽  
Pressure Ratio ◽  
Critical Role ◽  
Water Film ◽  
Heavy Rain ◽  
Diameter Distribution ◽  
Turbofan Engine ◽  
Water Ingestion ◽  
The Core ◽  
Engine Compressor

Turbofan engine compressor is most severely threatened by the entry of liquid water during flight descent. This study aims to deeply understand the fluctuations of compressor performance parameters caused by water ingestion through frequency spectrum analysis. The water content and droplet diameter distribution are determined based on the real heavy rain environment. Results reveal that most of the droplets actually entering the core compressor have a particle size of less than 100 μm. In addition, the formation and motion of water film plays a critical role in affecting the fluctuation characteristics. Water ingestion deteriorates the compression performance and aggravates the unsteady fluctuations of the fan. However, the performance of the core compressor is less affected by water ingestion, but their fluctuations are still exacerbated. For some important parameters, such as inlet mass flow rate, total pressure ratio, total temperature ratio, compression work and efficiency, their main frequency of fluctuation are switched from the original blade passing frequency to the rotor passing frequency, and their amplitudes are correspondingly amplified to varying degrees. These phenomena can be observed in both the fluctuations of the fan and core compressor. Moreover, the operating point of them will be in the long-period and large-amplitude fluctuations, which leads them experiences the non-optimal state for a long time and threatens their operating stability.

Influence of Water Droplet Size and Temperature on Wet Compression

2007 ◽  
Author(s):  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto ◽  
P. R. Spina ◽  
S. Ingistov
Keyword(s):  
Gas Turbine ◽  
Water Droplet ◽  
Droplet Diameter ◽  
Axial Compressor ◽  
Combined Cycle ◽  
Water Evaporation ◽  
Air Cooling ◽  
Compression Process ◽  
Two Phase ◽  
Wet Compression

In the last years, among all different gas turbine inlet air cooling techniques, an increasing attention to fogging approach is dedicated. The various fogging strategies seem to be a good solution to improve gas turbine or combined cycle produced power with low initial investment cost and less installation downtime. In particular, overspray fogging and interstage injection involve two-phase flow consideration and water evaporation during compression process (also known as wet compression). According to the Author’s knowledge, the field of wet compression is not completely studied and understood. In the present paper, all the principal aspects of wet compression and in particular the influence of injected water droplet diameter and surface temperature, and their effect on gas turbine performance and on the behavior of the axial compressor (change in axial compressor performance map due to the water injection, redistribution of stage load, etc.) are analyzed by using a calculation code, named IN.FO.G.T.E. (INterstage FOgging Gas Turbine Evaluation), developed and validated by the Authors.

The toxicity of some insecticidal sprays to adult locusts

1962 ◽  
Vol 53 (3) ◽  
pp. 597-608 ◽  
Author(s):  
R. D. MacCuaig
Keyword(s):  
Schistocerca Gregaria ◽  
Droplet Diameter ◽  
Flight Activity ◽  
Spray Application ◽  
Single Drop ◽  
Flying Insects ◽  
Spray Droplets ◽  
Tentative Explanation

The toxicities of sprays of some insecticides used against locusts have been determined. The LD50's of γ BHC, diazinon, and dieldrin to both flying and settled adults of Schistocerca gregaria (Forsk.) were between 0·9 and 1·5 times those of the same formulations when applied as a single drop to the abdomen. The toxicity of these insecticides was not affected by the size of the spray droplets when these ranged from about 60 to 250 µ in diameter. The toxicity of DNC, however, was always less by spray application than when applied by micro-drop syringe and was affected by the droplet diameter (droplets of 100 µ being 1·5 times as toxic as those of 200–230 µ) and by whether the locusts were sprayed in flight or when tethered on a card (those in flight being about 1·6 times as susceptible to 100 µ droplets as those at rest). A tentative explanation of this effect is given.The speed of action of the insecticides was compared and the effects of flight activity on susceptibility to the insecticides when sprayed over the flying insects was examined, but none could be detected by the technique used.

scholarly journals Mass transfer volumetric coefficient and droplet diameter in liquid-liquid dispersions stirred with a paddle impeller with wire gauze.

1993 ◽  
Vol 26 (2) ◽  
pp. 227-229 ◽  
Author(s):  
Setsuro Hiraoka ◽  
Noboru Kamei ◽  
Yoshihito Kato ◽  
Yutaka Tada ◽  
Katsuya Asai ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Droplet Diameter ◽  
Wire Gauze

Study on Spray on Degradation of TNT-RDX Explosives Wastewater by Synergetic Ozonation

2013 ◽  
Vol 726-731 ◽  
pp. 2316-2319
Author(s):  
Hai Xia Duan
Keyword(s):  
Gas Phase ◽  
Removal Rate ◽  
Droplet Diameter ◽  
Cod Removal ◽  
The Self ◽  
Cod Removal Rate

TNT-RDX wastewater is hard to biodegrade and highly toxic. The self-made reactor was used to degrade the wastewater, spray and the conditions of droplet diameter, number of nozzle, spray height were clearly observed. The results show that the average COD removal rate of TNT-RDX wastewater was 69.6%.The spray conditions can improve the dispersion of the wastewater and increase the use of the residual ozone in gas phase. Keywords: Spray; TNT-RDX wastewater; ozone; UV; GAC

Investigation of Droplet Impinging on a Heated Porous Surface Under Various Working Conditions; A Mathematical Modeling

2021 ◽  
pp. 2150015
Author(s):  
Mohammad Azadeh ◽  
Hamidreza Khakrah
Keyword(s):  
Droplet Diameter ◽  
High Surface ◽  
Adaptive Method ◽  
Porous Surface ◽  
Droplet Temperature ◽  
Surface Porosity ◽  
Two Phase ◽  
Air Interface ◽  
Accuracy Of Results ◽  
The Impact

This study numerically investigated the behavior of a Newtonian droplet impacting a heated porous surface. In this regard, a two-phase finite volume code was used for laminar flow. The time adaptive method was applied to enhance the accuracy of results and better convergence of the solving process. Also, the dynamic grid adaptation technique was adopted to predict the liquid-air interface precisely. The results were first validated against experimental data at different Weber numbers. Then the effect of variations in the droplet temperature was investigated on the spreading factor. The obtained results revealed that the rise in droplet temperature led to an increase in the maximum spreading diameter due to the reduction in the effects of viscosity, density, and surface tension. In the next step, the effects of droplet impact on the hydrophilic and superhydrophobic surfaces with the porosities of 20–80% were evaluated. The obtained results revealed that the increase in the surface porosity caused a decrease in the droplet diameter during the impact time. Also, at high surface porosity values, the decline in the contact angle influence on the droplet dynamic behavior was observed.

Energy and exergy analysis of a downstream single-row air washer at different droplet diameters for air cooling application

2022 ◽  
pp. 095440622110645
Author(s):  
Minhua Huang ◽  
Haiqiao Wang ◽  
Feng Tian ◽  
Junxin Huang ◽  
Shiqiang Chen ◽  
...  
Keyword(s):  
Performance Indicator ◽  
Droplet Diameter ◽  
Exergy Efficiency ◽  
Air Cooling ◽  
Design Calculation ◽  
Outlet Temperature ◽  
Single Row ◽  
Energy And Exergy ◽  
Water Gas ◽  
Gas Ratio

This study proposes a downstream single-row air washer for air cooling. The theoretical energy and exergy balance models were established at different droplet diameters and verified by the experimental data. Based on the abovementioned theoretical relationship, the single performance indicator of heat exchange efficiency (HEE) and exergy efficiency was quantitatively analyzed; a comprehensive analysis method of two indicators was proposed, combining HEE and exergy efficiency, and a numerical simulation was carried out. Results show that the smaller the droplet diameter and the larger the water–air ratio, the lower the dry-bulb temperature of the outlet air and the higher the HEE and exergy flux destruction. When the droplet diameter is less than 440 μm, the droplet diameter does not affect exergy efficiency and dry-bulb temperature. When the droplet diameter is larger than 440 μm, the droplet diameter is positively correlated with the air outlet dry-bulb temperature and exergy efficiency; in contrast, the water–gas ratio is negatively correlated with the air outlet dry-bulb temperature. An engineering case reveals that when the air outlet temperature is less than 34°C, the critical water–gas ratio can be set as 2.6 (mass ratio). At this time, the HEE is more than 90%, the exergy efficiency is more than 60%, and the critical value of droplet diameter is 440 μm. The research results provide an essential theoretical basis for the optimization of engineering design calculation.

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