QoE-Oriented Cooperative Broadcast Optimization for Vehicular Video Streaming

The popularity of online vehicular video has caused enormous information requests in Internet of vehicles (IoV), which brings huge challenges to cellular networks. To alleviate the pressure of base station (BS), Roadside Units (RSUs) and vehicle peers are introduced to collaboratively provide broadcast services to vehicle requesters where vehicles act as both service providers and service requesters. In this paper, we propose an efficient framework leveraging scalable video coding (SVC) technique to improve quality of experience (QoE) from two perspectives: (1) maximizing the data volume received by all requesters and (2) determining buffer action based on playback fluency and average playback quality. For (1), potential providers cooperate to determine the precached video content and delivery policy with the consideration of vehicular mobility and wireless channel status. If one provider fails, other sources will complement to provide requested content delivery. Therefore, their cooperation can improve the QoE and enhance the service reliability. For (2), according to buffer occupancy status, vehicle requesters manage buffer action whether to buffer new segments or upgrade the enhancement level of unplayed segment. Furthermore, the optimization of the data volume is formulated as an integer nonlinear programming (INLP) problem, which can be converted into some linear integer programming subproblems through McCormick envelope method and Lagrange relaxation. Numerical simulation results show that our algorithm is effective in improving total data throughput and QoE.

AMINOMETHANSULFONIC AND ALKYLAMINOMETHANSULFONIC BUFFER SYSTEMS

The investigations of acid-base interactions in aminomethanesulfonic acid (AMSA)–potassium aminomethanesulfonate–water and alkylaminomethanesulfonic acid–potassium alkylaminomethane-sulfonate–water systems, where alkyl are methyl (MeAMSA), N-(2-hydroxyethyl) (HEAMSA), n-propyl (n-PrAMSA), n-butyl (n-BuAMSA), tert-butyl (t-BuAMSA), n-heptyl (n-HpAMSA) and benzyl (BzAMSA) were performed in temperature range 293–313 К. Buffer action pH limits were determined and the buffer capacity of these systems was estimated.Based on the evaluation of buffer action pH limits of aminomethansulfonic acids, it has been found that with the help of n-PrAMSA and n-BuAMSA, it was possible to maintain the medium acidity in the range of physiological pH values throughout the range of investigated temperatures.As the temperature rises, the pH of the lower buffer limit increases for AMSA and n-BuAMSA systems, while for HEAMSA, t-BuAMSA, n-HpA-MSA and BzAMSA decreases. The value of the pH of the upper buffer threshold for all tested systems decreases during their heating. With the increase of the electron-donor properties of the N-substituent in the AMSA–MeAMSA–HEAMSA–t-BuAMSA series, the value of their electronegativity decreases to result in lowering of the pH values of the lower buf-fering action limit of these systems. For the more lipophilic N-substituents (n-C4H9, n-C7H15 and C6H5CH2), this regularity is not typical.It has been established that with increasing the CYAMSK/CYAMSA concentration ratio, the buffer capacity of YNHCH2SO3H–YNHCH2SO3K–H2O systems with hydrophilic aminomethansulfonic acids (Y = H, CH3 and HOCH2CH2) increases. For systems with lipophilic n-PrAMSA and t-BuAMSA, their buffer capacity doesn’t change at 0.4 ≤ QKOH/QYAMSA ≤ 1.0.The obtained data on the buffer capacity of the investigated systems is recommended for use in chemical analysis, microbiological and biochemical studies.

Acidity Study of Donor-Acceptor Complexes of Boric Acid with Polyols for Oil Displacing Compositions

The results of theoretical and experimental studies of the acidity of donor-acceptor complexes of boric acid with polyols – glycerol and sorbitol, which were used in the development of oil-displacing compositions, are presented. A model of donor-acceptor acid-base equilibria in coordinating polyol solvents has been created, due to which the constants of polyolboric acids formation and ionization were determined by pH-meter and electrical conductivity methods. The obtained constant values were used to calculate the compositions buffer capacity. Due to the using a mixture of polyolboric acids in the compositions at various ratios it was possible to regulate the range of the buffer action

Supercharged ceria quantum dots with exceptionally high oxygen buffer action

Supercharged ceria nanoparticles with excellent oxygen storage capacity.

Experimental Research for SO2 Absorption in Bubbling Stirring Reactor

The effect of different parameters on SO2 absorption was investigated in a semi-batchwise bubbling stirring reactor. From the experimental results, an increase of the gas flow, which substantially decreased the residence time of the gas in liquid, led to a quick reduce of the time of 100% removal efficiency of SO2. The addition of CaCO3 increased the removal efficiency of SO2 significantly. With increasing the concentration of CaCO3, the time of SO2=100% was almost increased linearly. The increase of the stirring speed prolonged the time of SO2=100% at first, but when beyond a certain value, no further effect of the stirring speed was observed, which showed that the mass transfer of SO2 in slurry was controlled by both gas and liquid mass transfer. Citric acid displays a good buffer action on SO2 absorption. The addition of citrate prolonged the time in which the SO2 removal efficiency remained high valves.