119 research outputs found
COLOR AND COD REMOVAL OF DYEING WASTEWATER BY COMBINATION TREATMENT OF COAGULATION AND FENTON OXIDATION
Joint Research on Environmental Science and Technology for the Eart
Estimating Disturbance Torque Effects on the Stability and Control Performance of Two-Axis Gimbal Systems
Introduction. Two-axis gimbal systems are applied for stabilizing and controlling the line of sight (LOS) of an optical or imaging system mounted on a moving vehicle. Gimbal systems are intended to isolate various disturbance torques and control the LOS toward the direction of a target. Two-axis gimbals can be of two main types, namely Yaw-Pitch and Swing-Roll type. In this article, we focus on investigating mathematical models of two-axis gimbals, which describe the impact of cross-disturbance torques on their stability and control performance. Simulations were conducted to compare advantages and disadvantages of the two types of two-axis gimbals.Aim. To study mathematical models describing the impact of cross-disturbance torques on the stability and control performance of two-axis gimbals.Materials and methods. Mathematical models of two-axis gimbal systems were synthesized by the Lagrange method. The operation of two-axis gimbal systems was simulated in the Matlab-Simulink environment. Results. Mathematical models and structural diagrams of the synthesized Yaw-Pitch and Swing-Roll gimbals were obtained. The conducted simulations of typical cases revealed different cross-disturbance effects.Conclusion. Motion equations for Swing-Roll and Yaw-Pitch gimbals were derived using similar methodology. The impact of cross-disturbance torques on gimbal systems was evaluated. The obtained results form a basis for selecting an optimal structure of tracking systems meeting the desired characteristics.Introduction. Two-axis gimbal systems are applied for stabilizing and controlling the line of sight (LOS) of an optical or imaging system mounted on a moving vehicle. Gimbal systems are intended to isolate various disturbance torques and control the LOS toward the direction of a target. Two-axis gimbals can be of two main types, namely Yaw-Pitch and Swing-Roll type. In this article, we focus on investigating mathematical models of two-axis gimbals, which describe the impact of cross-disturbance torques on their stability and control performance. Simulations were conducted to compare advantages and disadvantages of the two types of two-axis gimbals.Aim. To study mathematical models describing the impact of cross-disturbance torques on the stability and control performance of two-axis gimbals.Materials and methods. Mathematical models of two-axis gimbal systems were synthesized by the Lagrange method. The operation of two-axis gimbal systems was simulated in the Matlab-Simulink environment. Results. Mathematical models and structural diagrams of the synthesized Yaw-Pitch and Swing-Roll gimbals were obtained. The conducted simulations of typical cases revealed different cross-disturbance effects.Conclusion. Motion equations for Swing-Roll and Yaw-Pitch gimbals were derived using similar methodology. The impact of cross-disturbance torques on gimbal systems was evaluated. The obtained results form a basis for selecting an optimal structure of tracking systems meeting the desired characteristics
Ammonia oxidation capacity of bacillus bacteria in swine wastewater after biogas treatment
Nitrogen removal with biological methods plays a crucial role in wastewater treatment technology. The treatment begins with the oxidation of ammonia to nitrite to facilitate the subsequent nitrification and denitrification. Various strains of ammonia-oxidising bacteria have been reported. In this study, we use three Bacillus bacteria isolated from swine wastewater to oxidise ammonia. Different initial densities (103, 104, 105, and 106 CFU·mL–1) of each strain were examined. The results show that the combination of all the bacteria at a ratio of 1:1:1 and a density of 105 CFU·mL–1 exhibits the most effect. The findings contribute to the diversity of ammonia-oxidising bacterial species and pose a great potential for applying these strains in wastewater treatment
STUDY ON APPLICABILITY OF THE CONTACT OXIDATION PROCESS IN REMOVAL OF ORGANIC POLLUTANTS FROM TEXTILE WASTEWATER
Joint Research on Environmental Science and Technology for the Eart
A Deep Learning-Based Aesthetic Surgery Recommendation System
We propose in this chapter a deep learning-based recommendation system for aesthetic surgery, composing of a mobile application and a deep learning model. The deep learning model built based on the dataset of before- and after-surgery facial images can estimate the probability of the perfection of some parts of a face. In this study, we focus on the most two popular treatments: rejuvenation treatment and eye double-fold surgery. It is assumed that the outcomes of our history surgeries are perfect. Firstly a convolutional autoencoder is trained by eye images before and after surgery captured from various angles. The trained encoder is utilized to extract learned generic eye features. Secondly, the encoder is further trained by pairs of image samples, captured before and after surgery, to predict the probability of perfection, so-called perfection score. Based on this score, the system would suggest whether some sorts of specific aesthetic surgeries should be performed. We preliminarily achieve 88.9 and 93.1% accuracy on rejuvenation treatment and eye double-fold surgery, respectively
Multi modes coupling galloping of slender structures
The paper presents a general theoretical framework for galloping analysis of slender structures, taking into account the coupling among modes, the modes shapes, and the variation along the structure of mass per unit length and mean wind velocity. The theory is then applied to a real structure. In the galloping analysis, aerodynamic coefficients are obtained from wind tunnel tests. The results of the analysis show crucial points different from conventional analysis
Nitrite metabolism of several bacterial strains isolated from abattoir and swine wastewater after biogas treatment
In nitrogen treatment with biological methods, nitrite metabolism is an intermediate process that facilitates other processes involving different bacteria strains. In this study, we isolated two nitrite-oxidising bacteria strains from abattoir wastewater and wastewater from biogas tanks of an industrial pig farm in Ha Tinh province. The bacteria strains grow, develop, and metabolise nitrite at pH 6–8 and 30–37 °C. The samples with the nitrite concentration up to 750 mg·L–1 were oxidised within four days of incubation, and the nitrite metabolism rate was proportional to the concentration of nitrite tested. Under severe conditions (salinity up to 3% NaCl, a low dissolved oxygen level of 0.1 mg·L–1), the two isolated bacterial strains exhibited their effective growth and nitrite metabolism capacity. The results enrich the database of nitrite-oxidising bacteria and are prospective in wastewater treatment
EFFECTS OF COD/TN RATIO AND LOADING RATES ON PERFORMANCE OF MODIFIED SBRs IN SIMULTANEOUS REMOVAL OF ORGANIC MATTER AND NITROGEN FROM RUBBER LATEX PROCESSING WASTEWATER
Two modified sequencing batch reactors (SBRs) specially configured to consist of both oxic and anoxic zones, and be operated with only a single simultaneous oxic/anoxic phase in each treatment batch were tested to evaluate their applicability in treatment of rubber latex processing (RLP) wastewater. The former, R1 was operated with constant aeration, whereas the latter, R2 was operated with air flow varied from lower rate in the early period of the reaction phase to higher rate in the later one. Effects of the chemical oxygen demand (COD) to total nitrogen (TN) ratio and their loading rates on performance of the modified SBRs in simultaneous removal of organic matter and nitrogen from RLP wastewater were investigated. It was observed that performance of the two reactors in removal of COD and ammonium nitrogen was similar, and did not remarkably change when varying COD/TN ratio, as well as COD and TN loading rates in the ranges of 3.4 – 6.0 gCOD/gN, 0.8 – 1.7 kgCOD×m-3×d-1 and 0.15 – 0.34 kgN×m-3×d-1, respectively. The average COD removal efficiencies were over 95%. Ammonium nitrogen was almost completely eliminated in both reactors with effluent concentrations lower than 1.0 mg/L. Nevertheless, TN removal efficiencies of both reactors were significantly increased with increasing the COD/TN ratio from 3.4 to 6.0, and slightly decreased when increasing the TN loading rate from 0.15 to 0.34 kgN×m-3×d-1. The most effective COD/TN ratios were in the range of 5 – 6, at which the maximal TN removal efficiencies of R1 and R2 were 92% and 97%, respectively
Impact of PLA/PEG ratios on Curcumin solubility and encapsulation efficiency, size and release behavior of Curcumin loaded poly(lactide)-poly(ethylenglycol) polymeric micelles
Curcumin, a natural compound isolated from rhizomes of the herb Curcuma longa, is suggested as a potential therapeutic agent thanks to its multiple biological and pharmaceutical activities including anti-inflammatory, anti-oxidant, wound healing, anti-microbial and anti-cancer activities. Particularly, Curcumin has demonstrated efficacy as an anticancer agent for various kinds of cancer. However, its low aqueous solubility and bioavailability hamper its clinical application. Therefore, many drug delivery systems have been developed to overcome these limitations. In this study, by using polymeric micelles composed by poly (lactide)-poly (ethylenglycol) (PLA-PEG) copolymers, the aqueous solubility of Curcumin was increased to 0.73 mg.mL-1 compared to 0.11×10-4 mg.mL-1 of pure Curcumin. In addition, we found that the ratio of PLA/PEG has large impact on Curcumin solubility, Curcumin encapsulation efficiency, size and Curcumin release behavior of polymeric micelles. The increase in Curcumin solubility, Curcumin encapsulation efficacy and particle size but decrease in Curcumin release rate were observed when increasing the PLA/PEG ratio
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