scholarly journals The Latest Technique of Ultraprecision Positioning. New Stage System for Steo-and-Repeat Scanning Steocer.

1995 ◽  
Vol 61 (12) ◽  
pp. 1676-1680 ◽  
Author(s):  
Susumu MAKINOUCHI ◽  
Yutaka HAYASHI ◽  
Saburo KAMIYA
Keyword(s):  
Stage System ◽  
Repeat Scanning

Russian Education in the Mirror of Demography

2003 ◽  
pp. 4-25 ◽  
Author(s):  
L. Grebnev
Keyword(s):  
Higher Education ◽  
High School ◽  
High School Graduates ◽  
Educational Institutions ◽  
Level Of Education ◽  
Demographic Indicators ◽  
Federal Districts ◽  
Stage System ◽  
Migration Flows ◽  
Russian Education

The dynamics of several demographic indicators of Russia - child and teenage cohorts in 1970-2000, life expectancy in 1995-2000, migration flows among federal districts in the period between two censuses of 1989 and 2002 - are considered in the article. The author puts forward the hypothesis about the influence of these indicators on the level of education in narrow and broad senses - in educational institutions and the society as a whole. He estimates the perspectives of regional higher educational institutions under conditions of absence of plan distribution of graduates and the double cyclical fall in the number of high school graduates. The agenda for the development of a two-stage system of higher education corresponding with international integration processes is formulated.

Danish Experience with Emergent Hydrophyte Treatment Systems (EHTS) and Prospects in the Light of Future Requirements on Outlet Water Quality

1990 ◽  
Vol 22 (3-4) ◽  
pp. 65-72 ◽  
Author(s):  
H.-H. Schierup ◽  
H. Brix
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Reed Beds ◽  
Effluent Quality ◽  
Multi Stage ◽  
Run Off ◽  
Stage System

Since 1983 approximately 150 full-scale emergent hydrophyte based wastewater treatment plants (reed beds) have been constructed in Denmark to serve small wastewater producers. The development of purification performance for 21 plants representing different soil types, vegetation, and hydraulic loading rates has been recorded. Cleaning efficiencies were typically in the range of 60-80% reduction for BOD, 25-50% reduction for total nitrogen, and 20-40% reduction for total phosphorus. The mean effluent BOD, total nitrogen and total phosphorus concentrations of the reed beds were 19 ± 10, 22 ± 9 and 6.7 ± 3.2 mg/l (mean ± SD), respectively. Thus, the general Danish effluent standards of 8 mg/l for N and 1.5 mg/l for P for sewage plants greater than 5,000 PE cannot be met by the present realised design of EHTS. The main problem observed in most systems is a poor development of horizontal hydraulic conductivity in the soil which results in surface run-off. Since the political demands for effluent quality will be more strict in the future, it is important to improve the performance of small decentral sewage treatment plants. On the basis of experiences from different types of macrophyte based and conventional low-technology wastewater treatment systems, a multi-stage system is suggested, consisting of sedimentation and sand filtration facilities followed by basins planted with emergent and submergent species of macrophytes and algal ponds.

The application of the root zone method for the treatment and reuse of high-strength abattoir waste in Mexico

1997 ◽  
Vol 35 (5) ◽  
pp. 271-278 ◽  
Author(s):  
Fermin Rivera ◽  
Alan Warren ◽  
Colin R. Curds ◽  
Esperanza Robles ◽  
Alejandro Gutierrez ◽  
...  
Keyword(s):  
Treatment Process ◽  
Root Zone ◽  
Ornamental Plants ◽  
High Strength ◽  
Faecal Coliforms ◽  
Treatment Efficiency ◽  
Zone Method ◽  
Stage System ◽  
Flow Through ◽  
Two Stages

A two-stage system for treating high-strength wastewater from an abattoir at Pachuca, Mexico is described. The system consists of an anaerobic digester followed by an artificially-constructed wetland which employs horizontal subsurface flow through the root zone of emergent hydrophytes planted in a gravel substrate. The main goals of this study were to monitor the treatment efficiency of the system for the first twelve months of operation and to assess the suitability of the effluent for irrigation purposes. The treatment efficiency during the twelve month period was generally good with mean removal efficiencies of 88.5% for BOD5, 87.4% COD, 89% suspended solids, 73.6% organic nitrogen and >99% faecal coliforms. Removal rates were generally poor for orthophosphates, NH3-nitrogen and NO3-nitrogen. The differing roles of the two stages in the treatment process are discussed. Although not suitable for irrigating crops, the effluent is being successfully used for the irrigation of ornamental plants and recreational lands.

The anaerobic treatment of a ligno-cellulosic substrate offering little natural pH buffering capacity

1998 ◽  
Vol 38 (4-5) ◽  
pp. 29-35 ◽  
Author(s):  
C. J. Banks ◽  
P. N. Humphreys
Keyword(s):  
Ph Control ◽  
Anaerobic Treatment ◽  
Buffering Capacity ◽  
Single Stage ◽  
Stable Operation ◽  
Reactor Performance ◽  
Two Stage ◽  
Ph Buffering ◽  
Stage System ◽  
The Stability

The stability and operational performance of single stage digestion with and without liquor recycle and two stage digestion were assessed using a mixture of paper and wood as the digestion substrate. Attempts to maintain stable digestion in both single stage reactors were unsuccessful due to the inherently low natural buffering capacity exhibited; this resulted in a rapid souring of the reactor due to unbuffered volatile fatty acid (VFA) accumulation. The use of lime to control pH was unsatisfactory due to interference with the carbonate/bicarbonate equilibrium resulting in wide oscillations in the control parameter. The two stage system overcame the pH stability problems allowing stable operation for a period of 200 days without any requirement for pH control; this was attributed to the rapid flushing of VFA from the first stage reactor into the second stage, where efficient conversion to methane was established. Reactor performance was judged to be satisfactory with the breakdown of 53% of influent volatile solids. It was concluded that the reactor configuration of the two stage system offers the potential for the treatment of cellulosic wastes with a sub-optimal carbon to nitrogen ratio for conventional digestion.

scholarly journals Research on Double-Stage and Multi-Stage Capacitive Deionization Absorption Air-Conditioning System

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 395
Author(s):  
Feng Cheng ◽  
Boqing Ding ◽  
Xiuwei Li
Keyword(s):  
Air Conditioning ◽  
Pure Water ◽  
Good Choice ◽  
Coefficient Of Performance ◽  
Capacitive Deionization ◽  
Joint Work ◽  
Thermal Regeneration ◽  
Air Conditioning System ◽  
Multi Stage ◽  
Stage System

An absorption air-conditioning system is a good choice for green buildings. It has the superiority in the utilization of renewable energy and the refrigerant is environment-friendly. However, the performance of the traditional absorption system has been restricted by the energy waste in the thermal regeneration process. Capacitive deionization (CDI) regeneration is proposed as a potential method to improve system efficiency. In the new method-based air-conditioning system, strong absorbent solutions and pure water are acquired with the joint work of two CDI units. Nevertheless, the practical CDI device is composed of a lot of CDI units, which is quite different from the theoretical model. To reveal the performance of multiple CDI units, the model of the double/multi-stage CDI system has been developed. Analysis has been made to expose the influence of some key parameters. The results show the double-stage system has better performance than the single-stage system under certain conditions. The coefficient of performance (COP) could exceed 4.5, which is higher than the traditional thermal energy-driven system, or even as competitive as the vapor compression system. More stages with proper voltage distribution better the performance. It also provides the optimization method for the multi-stage CDI system.

scholarly journals Data-Driven Tuning of PID Controlled Piezoelectric Ultrasonic Motor

Actuators ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 148
Author(s):  
Sarah Makarem ◽  
Bülent Delibas ◽  
Burhanettin Koc
Keyword(s):  
Genetic Algorithm ◽  
Pid Controller ◽  
Good Alternative ◽  
Data Driven ◽  
Grid Search ◽  
Single Source ◽  
Dual Frequency ◽  
Dual Source ◽  
Stage System ◽  
Piezoelectric Ultrasonic Motor

Ultrasonic motors employ resonance to amplify the vibrations of piezoelectric actuator, offering precise positioning and relatively long travel distances and making them ideal for robotic, optical, metrology and medical applications. As operating in resonance and force transfer through friction lead to nonlinear characteristics like creep and hysteresis, it is difficult to apply model-based control, so data-driven control offers a good alternative. Data-driven techniques are used here for iterative feedback tuning of a proportional integral derivative (PID) controller parameters and comparing between different motor driving techniques, single source and dual source dual frequency (DSDF). The controller and stage system used are both produced by the company Physik Instrumente GmbH, where a PID controller is tuned with the help of four search methods: grid search, Luus–Jaakola method, genetic algorithm, and a new hybrid method developed that combines elements of grid search and Luus–Jaakola method. The latter method was found to be quick to converge and produced consistent result, similar to the Luus–Jaakola method. Genetic Algorithm was much slower and produced sub optimal results. The grid search has also proven the DSDF driving method to be robust, less parameter dependent, and produces far less integral position error than the single source driving method.

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