scholarly journals The influence of temperature and TMGa flow rate on the quality of p-GaN

AIP Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 035109
Author(s):  
Zikun Cao ◽  
Xiaowei Wang ◽  
Degang Zhao ◽  
Feng Liang ◽  
Zongshun Liu
Keyword(s):  
Flow Rate ◽  
Influence Of Temperature

Radon removal by aeration: observations on testing, installation and maintenance of domestic treatment units

2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen
Keyword(s):  
Water Quality ◽  
Water Flow ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Test Protocol ◽  
Household Water ◽  
Medium Flow ◽  
Removal Efficiencies ◽  
Frequent Sampling

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.

Effect of working pressure, travel speed and nozzle wear rate on spray quality of different flat fan nozzles

2011 ◽  
Vol 7 (1) ◽  
pp. 17-31
Author(s):  
Eleonóra Kecskés-Nagy ◽  
Milan Koszel ◽  
István Sztachó-Pekáry
Keyword(s):  
Wear Rate ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Travel Speed ◽  
Coverage Rate ◽  
Working Pressure ◽  
Nozzle Wear ◽  
Mean Diameter

The objective of the work was to determine the influence of working pressure and working speed on drop tracks size and changes in flow rate of flat fan nozzles. New nozzles and nozzles after laboratory wear were tested. The influence of nozzles wear on drop tracks size was tested. It was found that the increase in liquid flow rate resulted in higher values of mean diameter of the droplet track. The increase in working pressure or working speed causes decrease in drop tracks size and reduction in merging of droplets on sprayed surface. The increase of the wear was followed by increased coverage rate. This phenomenon is especially dangerous when using nozzles with a considerable wear for agricultural spraying since this causes ecological threat to environment.

scholarly journals A novel method for the codecs’ performance analysis in mobile telephony systems

2020 ◽  
Vol 33 (2) ◽  
pp. 243-259
Author(s):  
Aleksandar Lebl ◽  
Dragan Mitic ◽  
Vladimir Matic ◽  
Mladen Mileusnic ◽  
Zarko Markov
Keyword(s):  
Quality Of Service ◽  
Flow Rate ◽  
Mobile Communications ◽  
Voice Quality ◽  
Mobile Telephony ◽  
Mobile Telecommunication ◽  
Telecommunication System ◽  
Full Rate ◽  
Novel Method

This paper presents a novel method of expressing the quality of service in a mobile telecommunication system when its performance depends on several factors including applied codecs? characteristics (voice quality and data flow rate) and telecommunications traffic service possibilities. The influence of these factors is unified in one variable - quality of service measure. The proposed method is especially applicable in the cases when two-dimensional systems are analyzed - for example when two codecs with different flow rate and different achievable connection quality are used in a system. As an example, we also studied system with full-rate or mixed full-rate and half-rate codec implementation depending on the offered traffic. The system performances - mean dataflow and mean connection quality as a function of offered traffic are presented graphically and also expressed quantitatively by the novel quality of service measure. The systems with different number of available traffic channels may be compared on the base of this novel evaluation value such that the system with the highest value is the most suitable one for the concrete situation. In this way mobile system design is simplified to the great extent. The developed model is applicable generally for mobile telephony systems defining, but in this paper we studied its implementation for Global System for Mobile communications.

scholarly journals Preservatives Stability: Stability Study of Parabens under Different Conditions of Stress Degradation

2020 ◽  
Vol 11 (3) ◽  
pp. 4187-4194
Author(s):  
Ismail Bennani ◽  
Madiha Alami Chentoufi ◽  
Miloud El Karbane ◽  
Ibrahim Sbai El Otmani ◽  
Amine Cheikh ◽  
...  
Keyword(s):  
Extreme Values ◽  
Stability Study ◽  
Wide Field ◽  
Direct Influence ◽  
Light Conditions ◽  
Influence Of Temperature ◽  
Stress Degradation ◽  
Quality Of Products ◽  
The Stability

Preservatives are used in a wide field of application to maintain the quality of products. They are used to deal with the chemical, physical and microbiological problems and the constraints of the development of several formulations. In this work, we tested the stability of antimicrobial preservatives which are the parabens under different stress degradation conditions to evaluate their degree of effectiveness. The tested parabens were incubated in different solutions at different pH, Temperatures, light conditions, and presence or absence of sucrose in solution (create a medium similar of syrups). The HPLC was used for the assay, by a validated method for the parabens assay and the statistical analysis of the data is carried out by JMP software. The results show a direct influence of temperature and pH on the level of parabens, while the influence of light remains negligible. The increase in temperature gives a degree of immunity of parabens levels, especially with the extreme values of pH. This study is one of the first studies of forced decomposition of parabens carried out under the various conditions suggested. The results give an idea of the stability profile of the tested parabens and suggest a model of the conditions of conservation and use of these products in different domains and under different conditions.

Development of Toxic Degradation Products during Heat Sterilization of Glucose-Containing Fluids for Peritoneal Dialysis: Influence of Time and Temperature

1995 ◽  
Vol 15 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Per Kjellstrand ◽  
Evi Martinson ◽  
Anders Wieslander ◽  
Björn Holmquist
Keyword(s):  
Peritoneal Dialysis ◽  
Glucose Solution ◽  
Degradation Products ◽  
General Pattern ◽  
Low Ph ◽  
Uv Absorbance ◽  
Influence Of Temperature ◽  
In Vitro Systems

Objective Fluids for peritoneal dialysis (PD) cause cytotoxic reactions in many different in vitro systems. The low pH, the high osmolality of the fluids, and the glucose degradation products formed during heat sterilization have been considered responsible. In the present study, we investigate the influence of temperature and time during heat sterilization of PD fluids and glucose solutions on glucose degradation and cytotoxicity of the solutions. Design Ampoules containing PD-fluid or glucose solution were heated in an oil bath to predetermined F o values (combinations of time and temperature giving equal energy/bacteriallethality). Cytotoxicity of the solutions was measured as groWth inhibition of cultured L-929 fibroblasts. Glucose degradation was measured as UV absorbance at 228 and 284 nm. Results The same general pattern was seen in both PD fluid and glucose solution. Cytotoxicity decreased from 90% to 15% when the sterilization temperature was increased from 115° to 140°C and concomitantly the length of time shortened in order to maintain equal bacteriallethality. Under the same conditions, degradation products, measured as UV absorbance at 284 nm, decreased from 0.2 to 0.02. Conclusion To minimizethe development of cytotoxic breakdown products, high temperatures over short periods of time should be used to heat-sterilize PD fluids. Even as small an increase as 5°C at around 120°C will improve the quality of the solutions.

scholarly journals A drug-coated balloon treatment for urethral stricture disease: Two-year results from the ROBUST I study

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Rachel A. Mann ◽  
Ramon Virasoro ◽  
Jessica M. DeLong ◽  
Rafael E. Estrella ◽  
Merycarla Pichardo ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Adverse Events ◽  
Urethral Stricture ◽  
Flow Rate ◽  
Erectile Function ◽  
Urine Volume ◽  
Urethral Stricture Disease ◽  
Residual Urine ◽  
Drug Coated Balloon

Introduction: Mechanical balloon dilation and direct visualization internal urethrotomy (DVIU) are the most widely used treatments for urethral stricture disease in the U.S., but recurrence rates are high, especially after re-treatment. This study investigates the safety and efficacy of the Optilume™ paclitaxel-coated balloon for the treatment of recurrent strictures. Methods: Men with recurrent bulbar strictures ≤2 cm with 1–4 prior endoscopic treatments were treated with the Optilume™ drug-coated balloon. Patients were evaluated within 14 days, three, six, 12, and 24 months post-treatment. The primary safety endpoint was serious urinary adverse events. The primary efficacy endpoint was ≥50% improvement in International Prostate Symptom Score (IPSS) at 24 months. Secondary outcomes included quality of life, erectile function, flow rate, and post-void residual urine volume. Results: A total of 53 subjects were enrolled and treated; 46 completed the 24-month followup. Forty-three percent of men had undergone >1 previous dilations, with a mean of 1.7 prior dilations. There were no serious adverse events related to treatment at two years. Success was achieved in 32/46 (70%), and baseline IPSS improved from a mean of 25.2 to 6.9 at 24 months (p<0.0001). Quality of life, flow rate, and post-void residual urine volumes improved significantly from baseline. There was no impact on erectile function. Conclusions: Two-year data indicates the Optilume™ paclitaxel-coated balloon is safe for the treatment of recurrent bulbar urethral strictures. Early efficacy results are encouraging and support further followup of these men through five years, as well as further investigation with a randomized trial.

FLOW RATE QUALITY OF NEW FLAT FAN NOZZLES

2001 ◽  
Vol 44 (4) ◽  
Author(s):  
B. Huyghebaert ◽  
C. Debouche ◽  
O. Mostade
Keyword(s):  
Flow Rate
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