scholarly journals Influence of Selected Parameters and Different Methods of Implementing Vacuum Impregnation of Apple Tissue on Its Effectiveness

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 428
Author(s):  
Tomasz Guz ◽  
Leszek Rydzak ◽  
Marek Domin

The study provides comprehensive information on the vacuum impregnation process applied to plant materials. It aims (in traditional applications) to ensure impermeability and elimination of porosity of various materials. The process substantially accelerates mass transfer in the liquid–solid system. The study describes the course of the process and accompanying phenomena as well its effects on plant tissues. The aim of the investigations was to determine the impact of some impregnation parameters (pressure, pressure change rate, vacuum maintenance time, relaxation time, and the coefficient of impregnating liquid viscosity) and the mode of impregnation (wet, dry, cyclic wet) on the degree of filling the plant tissue with the impregnating solution. Jonagold apples were used as the study material. The investigations have revealed that changes in the vacuum impregnation parameters (vacuum maintenance time, relaxation time, pressure change rate in the system) and the impregnation method do not exert a significant impact on the effectiveness of the process as expressed by the degree of permeation of the impregnating solution into the tissue. The pressure value and the viscosity coefficient were the only parameters that had a significant effect on the impregnation yield.

2012 ◽  
Vol 209-211 ◽  
pp. 2094-2099
Author(s):  
Xiu Yuan Xing ◽  
Ze Chang Sun ◽  
Meng Wang

Based on a new type of electro-hydraulic brake system of electric vehicle, the operating principle was studied. A model of hydraulic brake system and corresponding control strategy were built with the co-simulation platform of AMESim and MATLAB. The impact factors of brake pressure change rate were analyzed theoretically. The influences of the main hydraulic parameters were analyzed through simulation, such as volume of brake fluid, type of pipe, ABS valve and brake clearance. The results provide a theoretical basis for the accurate control of wheel cylinder pressure.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 938
Author(s):  
Hanwei Bao ◽  
Zaiyu Wang ◽  
Zihao Liu ◽  
Gangyan Li

In contrast to the traditional pneumatic braking system, the electronic-controlled pneumatic braking system of commercial vehicles is a new system and can remedy the defects of the conventional braking system, such as long response time and low control accuracy. Additionally, it can adapt to the needs and development of autonomous driving. As the key pressure regulating component in electronic-controlled pneumatic braking system of commercial vehicles, automatic pressure regulating valves can quickly and accurately control the braking pressure in real time through an electronic control method. By aiming at improving driving comfort on the premise of ensuring braking security, this paper took the automatic pressure regulating valve as the research object and studied the pressure change rate during the braking process. First, the characteristics of the automatic pressure regulating valve and the concept of the pressure change rate were elaborated. Then, with the volume change of automatic pressure regulating valve in consideration, the mathematical model based on gas dynamics and the association model between pressure change rate and vehicle dynamic model was established in MATLAB/Simulink and analyzed. Next, through the experimental test of a sample product, the mathematical models have been verified. Finally, the key structure parameters affecting the pressure change rate of the automatic pressure regulating valve and the influence law have been identified; therefore, appropriate design advice and theoretical support have been provided to improve driving comfort.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Marcelo Silveira ◽  
Flavio Teles ◽  
Erica Melo ◽  
Valeria Borges ◽  
Filipe Miranda ◽  
...  

Abstract Background and Aims End-stage chronic kidney disease is associated with the condition of chronic inflammation, impacting increased cardiovascular mortality in this specific population. Patients on hemodialysis are known to be predisposed to several factors that predispose to inflammation: dialysis membranes, central venous catheters, oxidative stress, fluid overload, sodium overload, uraemic toxins. Propolis, a natural resin produced by bees from plant materials, has anti-inflammatory, immunomodulatory, and anti-oxidant properties. The aim of this study was to evaluate the impact of Brazilian green propolis extract on inflammation in hemodialysis patients. Here we present preliminary results of the trial NCT04072341. Method We performed a prospective trial, open-label 9-week crossover study examining the effect of Brazilian green propolis (250mg/day, in capsules) on inflammation in hemodialysis patients. We included patients over 18 years, under intermittent hemodialysis (thrice per week), on hemodialysis for at least 1 month and until now 37 patients were included. We excluded pregnant women, cancer carried and patients who developed infection or underwent any surgical procedure during the study period. Each period was 4 weeks in duration with a 1-week washout period in between. The primary end point was change in serum level of high-sensitivity c-reactive protein (HsCRP). Secondary end point evaluated the safety of propolis use in hemodialysis patients. Results Their mean age was 58.6 ± 15.2 years (mean ± SD), and 22 (59.4%) were men. The proportion of patients with hypertension was 14 (37.8%) and diabetes was 9 (24.3%). The number of patients using arteriovenous fistula were 26 (70.2%). The HsCRP presented (mean ± SE) 5.31 ± 1.02 mg/L at baseline, 4.26 ± 0.76 mg/L after propolis period and 4.56 ± 1.32 mg/L in control period, p = 0.0042. Safety parameters were analyzed such as amylase, aspartate aminotransferase (AST) and creatine phosphokinase (CPK); there was no difference between them before and after the use of propolis. None of the participants reported any adverse effects or allergic reactions during the treatment. Conclusion Patients on hemodialysis have an increased inflammatory state. For the best of our knowledge it was the first clinical trial who demonstrated the safety of propolis in hemodialysis patients. Brazilian green propolis demonstrated a tendency to reduce inflammation in these patients.


1977 ◽  
Vol 32 (1) ◽  
pp. 57-60 ◽  
Author(s):  
H. E. Gunilla Knape ◽  
Lena M. Torell

Abstract Brillouin spectra of molten CSNO3 were investigated for scattering angles between 40 and 140° and in a temperature interval of 420-520 °C. An Ar+ singlemode laser was used for excitation and the total instrumental width was ~265 MHz. The measured frequency shifts and linewidths of the Brillouin components were used to determine velocities and attenuations of thermal sound waves in the frequency range 2.3-7.0 GHz. A dispersion of 4-5% was found between the present hyper­ sonic velocities and reported ultrasonic velocities. A considerable decrease in attenuation with frequency was observed in the investigated frequency range, with the value at high frequency ap­ proaching the classical attenuation. The results are in good agreement with Mountain's theory of a single relaxation time. The relaxation time of the bulk viscosity coefficient was calculated to 1.2×10-10S.


2016 ◽  
Vol 43 (10) ◽  
pp. 865-874 ◽  
Author(s):  
Sheng-lin Wang ◽  
Qing-feng Lv ◽  
Hassan Baaj ◽  
Xiao-yuan Li ◽  
Yan-xu Zhao

Freeze–thaw action is considered to be one of the most destructive actions that can induce significant damage in stabilized subgrades in seasonally frozen loess areas. Laboratory tests including frost heave – thaw shrinkage and microstructure change during freeze–thaw cycles were conducted to evaluate the volume change rate of loess stabilized with cement, lime, and fly ash under the impact of cyclic freeze–thaw conditions. The loess specimens collapsed after eight freeze–thaw cycles (192 h), but most stabilized loess specimens had no visible damage after all freeze–thaw cycles were completed. All of the stabilized loess samples underwent a much smaller volume change than the loess alone after the freeze–thaw cycles. Although surface porosity and equivalent diameter of stabilized loess samples increased, the stabilized loess can retain its microstructure during freeze–thaw cycles when the cement content was less than 6%. To ensure freeze–thaw resistance of stabilized loess subgrades, the mix proportions of the three additives was recommended to be 4 to 5% cement, 6% lime, and 10% fly ash.


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