On the Development and Performance Test of Combined Packing Integrated Device for Treating Domestic Sewage Aboard Ships

2011 ◽  
Vol 66-68 ◽  
pp. 2153-2157
Author(s):  
Zhi Li Chen ◽  
Kai Sheng Xiong ◽  
Wan Tu Zhang ◽  
Wen Biao Wang ◽  
Wen Ping Chen ◽  
...  

This paper elaborates on the development of elastic combined packing and an integrated device for treating domestic sewage aboard ships, analyzes the growth of combined packing microorganisms, the speed of membrane forming as well as the impact of raw water quality on membrane forming, and conducts a simulation experiment of treating domestic sewage by membrane bio-reactors. Researches show that elastic combined packing features high specific surface area and high speed of membrane forming and that this integrated domestic sewage treatment device performs well and can be widely applied.

2013 ◽  
Vol 779-780 ◽  
pp. 1500-1504
Author(s):  
Fu Jun Liu ◽  
Fan Yang

Pulsed SBR process is a new type of SBR operation mode proposed against the traditional SBR process with poorer denitrification effect. This experiment is carried out at laboratory of sewage treatment, Beijing University of Technology, using real sewage for study, to study denitrification efficiency of pulsed SBR in nitration add raw water - denitrification this repeated and cycled process (with the same amount of water). The experimental results show that the effluent TN is less than 2 mg/L, removal efficiency is more than 96%.Keywords: pulsed SBR; domestic sewage; denitrification; experimental study


2019 ◽  
Vol 11 (8) ◽  
pp. 179 ◽  
Author(s):  
Veronika Kirova ◽  
Kirill Karpov ◽  
Eduard Siemens ◽  
Irina Zander ◽  
Oksana Vasylenko ◽  
...  

The presented work is a result of extended research and analysis on timing methods precision, their efficiency in different virtual environments and the impact of timing precision on the performance of high-speed networks applications. We investigated how timer hardware is shared among heavily CPU- and I/O-bound tasks on a virtualized OS as well as on bare OS. By replacing the invoked timing methods within a well-known application for estimation of available path bandwidth, we provide the analysis of their impact on estimation accuracy. We show that timer overhead and precision are crucial for high-performance network applications, and low-precision timing methods usage, e.g., the delays and overheads issued by virtualization result in the degradation of the virtual environment. Furthermore, in this paper, we provide confirmation that, by using the methods we intentionally developed for both precise timing operations and AvB estimation, it is possible to overcome the inefficiency of standard time-related operations and overhead that comes with the virtualization. The impacts of negative virtualization factors were investigated in five different environments to define the most optimal virtual environment for high-speed network applications.


2019 ◽  
Vol 9 (24) ◽  
pp. 5309 ◽  
Author(s):  
Jiaojiao Zhang ◽  
Lin Yang ◽  
Haisong Chen ◽  
Chengcheng Ma ◽  
Xinmin Shen ◽  
...  

Nowadays, piezoelectric actuators are widely used, but are rarely applied in high overload environments due to th difficulty implementing them. Traveling wave rotary ultrasonic motors (TRUMs) have the characteristics of variable structure and are insensitive to overload, endowing them with the potential ability of high overload resistance. In this study, four TRUMs with different rotor structures are designed to work under the high-impact acceleration of 10,000 g through modifying the rotors with a designed slotted disc spring. The dynamics model is established, the impact process is simulated, and the results are analyzed successively. The high-impact test, deformation measurement and performance test of the motors are carried out to verify the modification. The results show that performance of the TRUMs with a disc spring declines much less than those without a disc spring after the high-impact test. The TRUM-4 with the modified rotor and disc spring has the best performance, the speed of which decreased only 1.6% at the torque of 0.15 N m, and it is considered to be capable of withstanding the high acceleration of 10,000 g. This work is significance for guiding the ultrasonic motors’ optimization to expand their application in high-overload environments.


2013 ◽  
Vol 842 ◽  
pp. 367-373
Author(s):  
Yao Ting Wang ◽  
Qiu Ju Zhang ◽  
Jin Sai Cheng

A key issue of the machining for the small line block is to improve the machining feedrate while keeping the machining precision and satisfying the acceleration constraints. In this paper, a new approach for continuous small line blocks high speed machining is proposed to avoid the impact of Computer Numerical Control (CNC) equipments caused by acceleration gust. This approach uses the small line flag to distinguish whether the path is small line block. While the paths are continuous small line blocks, this approach can automatically adjust the number of look-ahead segments, and predigest the velocity calculation method of the connection point. We first define what a path is small line block. Then we analyze the restrictions for velocity linking of adjacent processing paths, and propose the approach for continuous small line blocks machining. Finally we design a simulation experiment on 30 points processing of the spline track. The result of the simulation shows that this algorithm can obviously shorten the processing time and make control system more harmonious in high speed machining.


Author(s):  
Michael D. Hathaway

A state-of-the-art CFD code (APNASA) was employed in a computationally based investigation of the impact of casing bleed and injection on the stability and performance of a moderate speed fan rotor wherein the stalling mass flow is controlled by tip flow field breakdown. The investigation was guided by observed trends in endwall flow characteristics (e.g., increasing endwall aerodynamic blockage) as stall is approached, and based on the hypothesis that application of bleed or injection can mitigate these trends. The “best” bleed and injection configurations were then combined to yield a self-recirculating casing treatment concept. The results of this investigation yielded: 1) identification of the fluid mechanisms which precipitate stall of tip critical blade rows, and 2) an approach to recirculated casing treatment which results in increased compressor stall range with minimal or no loss in efficiency. Subsequent application of this approach to a high speed transonic rotor successfully yielded significant improvements in stall range with no loss in compressor efficiency.


2018 ◽  
Vol 15 (30) ◽  
pp. 160-176
Author(s):  
J. L. SATELLES ◽  
H. E. BEZERRA DA SILVA ◽  
L. R. FARIAS ◽  
F. S. PANERO

The water body, object of this study, Grande igarapé, is located in the Municipality of Boa Vista, State of Roraima, in the northern region of Brazil. The present study aims to evaluate the environmental impact caused by the contribution of substances in the igarapé and possibly in the Branco River after receiving the ETE Boa Vista-RR effluent through the determination of physical-chemical and biological parameters (chlorophyll-a). In the accomplishment of this study six points of collections considered strategic to the attainment of the proposed objectives were selected. The parameters were analyzed: color, turbidity, conductivity, pH, temperature, dissolved oxygen, nitrite, ammonia, total phosphorus, chloride, BOD5, COD, chlorophyll a. The igarapé suffers the human impact through the withdrawal of the vegetal cover, waterproofing of the ground by the occupation of the surroundings and launches of polluting agents. Through the results it was possible to confirm the impact of the discharge of the effluent on Great stream. Parameters such as phosphorus, ammonia, nitrite and chlorophyll-a have shown that the Grande stream does not have assimilation capacity, especially during periods of drought, of nutrients and contaminating species during the journey to its mouth in the Branco river. The analysis of the data obtained in its environmental amplitude shows the need to plan actions to reverse the environmental damage caused to the Great stream and its biodiversity.


2017 ◽  
Vol 48 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Shadi Houshyar ◽  
Rajiv Padhye ◽  
Sandip Ranjan ◽  
Steve Tew ◽  
Rajkishore Nayak

This study evaluated the deterioration in thermo-mechanical and performance properties of the polyaramid and polybenzidimazole fabric used in firefighters’ protective clothing after exposure to ultraviolet irradiation, and the effect of weathering. The performance of firefighters’ protective clothing plays an important role in protection against heat and physical threats to firefighters. However, frequent exposure to heat and ultraviolet irradiation can deteriorate performance. Test results demonstrated a 79% drop in the residual strength of polybenzidimazole/Kevlar® fabric and a 51% drop in the residual strength of polyaramid (Nomex® IIIA). The results confirmed that heat accelerates the degradation of PBI, resulting in lower performance, an important consideration for firefighters’ protective clothing. In this study, a new ‘UVPro-Tex’ sensor was developed, with the capability to record the amount of ultraviolet irradiation absorbed by the fabric. When the amount of the absorbed ultraviolet irradiation reaches a critical value, the sensor warns the wearer of the end-of-life of the garment.


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