Engineering Science and Materials Commons^™

Oxidative Efficiency Of Ozonation Coupled With Electrolysis For Treatment Of Acid Wastewater, Ze-You Hu, Feng-Yun Xiang, Ji-Qiang Mao, Ya-Lei Ding, Shao-Ping Tong

Journal of Electrochemistry

Establishment of an ozone-based advanced oxidation process (AOPs-O₃) for effective treatment of acid wastewater is an important and difficult task. The process of ozonation coupled with electrolysis (electrolysis-ozonation, E-O₃) has been reported to effectively degrade pollutants in neutral solution. We studied the efficiency of E-O₃ for degradation of acetic acid (HAc, an ozone inert chemical) in acid solution and found that E-O₃ had high oxidative efficiency at pH less than 3. For example, 52.2% of 100 mg·L-1 HAc could be removed by E-O₃ in 120 min at pH 1.0, but only 2.2% and …

Mathematical Model Of The Efficiency Of Investments Aimed In The Implementation Of Water-Saving Technologies

Irrigation and Melioration

In Uzbekistan, research work is being carried out aimed at improving the economic mechanisms for the introduction of water-saving technologies for irrigating agricultural crops. At the same time, the issues related to the analysis of the effectiveness of the use of water-saving technologies when irrigating cotton, the development of mathematical methods for assessing the effectiveness of investments, as well as their introduction into practice have not been sufficiently studied. This article provides a mathematical model of the efficiency of investments aimed at introducing water-saving technologies. The results of a numerical experiment of a mathematical model show that the introduction of …

Empirical Assessment Of Climate Change Impacts On Agriculture In Samarkand Region, Sh.B. Babakholov

Irrigation and Melioration

Agricultural production is highly sensitive to climate factors like other endogenous factors, and the expected climate change projections may have a negative impact on the efficiency and income of agricultural producers. Therefore, this study aims to analyze the impact of changes in climatic factors (average air temperature and precipitation) on the technical efficiency of cotton growing farmers as its determinants in Samarkand region. Empirical analyzes were performed on the cases of 1141 cotton-growing farms using panel-based Time-Invariant Inefficiency model. According to the results of the analysis, cotton farms in the region have an average technical efficiency of 76%, which in …

Equivalent Numerical Algorithm For The Strip-Rolling Process Of A Continuous Variable Crown Mill Using The Coupled Rigid-Plastic Finite Element Method, Tao Wang, Zhong-Kai Ren, Dong-Ping He

Journal of Marine Science and Technology

For the accurate simulation of the rolling process of a wide strip and plates, highly sophisticated algorithms must be developed to couple material flow behavior with the elastic deformation of rolls. A coupling simulation system based on a three-dimensional rigid-plastic finite element method (RPFEM), elastic-plastic finite element method, and influential function method was developed in this study. Calculation of the continuous variable crown (CVC) mill was more complex than that of the normal 4-high rolling mill. According to the point symmetry of the roll gap profile, the CVC curves of work rolls at various shifting positions were equal to various …

Comparative Study Of Power Semiconductor Devices In A Multilevel Cascaded H-Bridge Inverter, Kenneth Mordi

Graduate Theses and Dissertations

This thesis compares the performance of a nine-level transformerless cascaded H-bridge (CHB) inverter with integrated battery energy storage system (BESS) using SiC power MOSFETs and Si IGBTs. Two crucial performance drivers for inverter applications are power loss and efficiency. Both of these are investigated in this thesis. Power devices with similar voltage and current ratings are used in the same inverter topology, and the performance of each device is analyzed with respect to switching frequency and operating temperature. The loss measurements and characteristics within the inverter are discussed. The Saber® simulation software was used for the comparisons. The power MOSFET …

Towards The Scalability And Hybrid Parallelization Of A Spatially Variant Lattice Algorithm, Henry Roger Moncada Lopez

Open Access Theses & Dissertations

The purpose of this research is to design a faster implementation of the spatially variant algorithm that improves its performance when it is running on a parallel computer system.

The spatially variant algorithm is used to synthesize a spatially variant lattice for a periodic electromagnetic structure. The algorithm has the ability to spatially vary the unit cell orientation and exploit its directional dependencies. The algorithm produces a lattice that is smooth, continuous and free of defects. The lattice spacing remains strikingly uniform when the unit cell orientation, lattice spacing, fill fraction and more are spatially varied. This is important for …

Waste Heat Reclamation For Commercial Use, Andrew Webber

Liberal Arts and Engineering Studies

The purpose of this project was to capture waste heat to raise the temperature of groundwater for commercial applications.

Quantum Dot Deposition Into Pdms And Application Onto A Solar Cell, Christopher Marcus Botros, Richard N. Savage

Master's Theses

Research to increase the efficiency of conventional solar cells is constantly underway. The goal of this work is to increase the efficiency of conventional solar cells by incorporating quantum dot (QD) nanoparticles in the absorption mechanism. The strategy is to have the QDs absorb UV and fluoresce photons in the visible region that are more readily absorbed by the cells. The outcome is that the cells have more visible photons to absorb and have increased power output. The QDs, having a CdSe core and a ZnS shell, were applied to the solar cells as follows. First, the QDs were synthesized …