29 research outputs found
SMOKE AND VAPOR PLUME MERGENCE
Observations at power plants have indicated that vapor plumes emitted from cooling
towers frequently merge with smoke plumes released from stacks. Mergence of cooling tower
and stack plume leads to formation of acidic compounds which have adverse effects on the en-
vironment. Wind speed and direction play an important role in merging smoke and vapor
plume. This paper lists some arguments to verify that studies have not sufficiently addressed
stack and cooling tower plume mergence. In conclusion, the present authors hope to find more
information in the future with regard to vapor and smoke plume mergence
SMOKE AND VAPOR PLUME MERGENCE
Observations at power plants have indicated that vapor plumes emitted from cooling
towers frequently merge with smoke plumes released from stacks. Mergence of cooling tower
and stack plume leads to formation of acidic compounds which have adverse effects on the en-
vironment. Wind speed and direction play an important role in merging smoke and vapor
plume. This paper lists some arguments to verify that studies have not sufficiently addressed
stack and cooling tower plume mergence. In conclusion, the present authors hope to find more
information in the future with regard to vapor and smoke plume mergence
A novel genetic programming approach to the design of engine control systems for the voltage stabilisation of hybrid electric vehicle generator outputs
This paper describes a Genetic Programming based automatic design methodology applied to the maintenance of a stable generated electrical output from a series-hybrid vehi- cle generator set. The generator set comprises a 3-phase AC generator whose output is subsequently rectified to DC.The engine/generator combination receives its control input via an electronically actuated throttle, whose control integration is made more complex due to the significant system time delay. This time delay problem is usually addressed by model predictive design methods, which add computational complexity and rely as a necessity on accurate system and delay models. In order to eliminate this reliance, and achieve stable operation with disturbance rejection, a controller is designed via a Genetic Programming framework implemented directly in Matlab, and particularly, Simulink. the principal objective is to obtain a relatively simple controller for the time-delay system which doesn’t rely on computationally expensive structures, yet retains inherent disturabance rejection properties. A methodology is presented to automatically design control systems directly upon the block libraries available in Simulink to automatically evolve robust control structures
Mineralization and decolorization of fermentation industry wastewater by catalyticmechanismozonation process: Kinetics and mechanism
Background and purpose: Molasses is colored, toxic and non-biodegradable compound which is found in the wastewater of fermentation industries. This study investigated the kinetic and efficiency of molass dye removal and mineralization in the yeast wastewater using nanocomposite catalysts in ozonation process. Materials and methods: The catalytic ozonation process (COP) of colored effluent of biological treatment of yeast production factory was carried out using semi-continuous flow cylindrical reactor and the effects of operational parameters such as initial pH value (4-10) and reaction time (5-60 min) on removal efficiency of dye and mineralization were investigated. After determining the kinetic parameters of reaction, the effects of some other parameters such as adsorption and reuse of the catalyst were calculated and the efficiency was compared with single ozonation process (SOP) and granular carbon as catalyst. Results: The removal efficiency of dye of molass factories effluent and its kinetic, at the condition of initial dye concentration 4521 ADMI, catalyst concentration 2 g/L and 60 min reaction time were 95 and 0.045 min-1, respectively; while these parameters in SOP and granular activated carbon as catalyst were 71 with 0.018 min-1and 86 with 0.028 min-1, respectively. But, the mineralization and its kinetic in COP were 74 and 0.023 min-1, respectively, in which initial TOC was decreased from 510 mg/L to 132 mg/L. Conclusion: The nanocomposite was found to have the best efficiency in dye degradation and TOC removal and it is easy to recover and reuse over and over by magnet. The main mechanism of dye degradation in COP was chemical oxidation and less occurred by adsorption. © 2016, Mazandaran University of Medical Sciences. All rights reserved
Assessment of variations in benzene concentration produced from vehicles and gas stations in Tehran using GIS
This study investigates the variations of benzene concentration levels
in district 1, situated in the north part of Tehran, capital of Iran.
Thirty-three stations in five categories, namely roadsides, busy roads,
residential areas, traffic intersections, and the vicinity of gas
stations, were monitored during the rush hours in the afternoon once a
week over a period of 1 year. Accordingly, benzene concentration levels
were measured and predicted by inverse distance weight model. The
recorded benzene concentration levels were then compared with those
reported in other parts of the world. According to the results, the
annual concentration levels of benzene was 13.85 ppb for roads with
heavy traffic flow, 14.98 ppb for traffic intersections, 29.01 ppb for
the vicinity of the gas stations, 3.26 ppb for residential areas, and
9.97 ppb for roadsides. The concentration of benzene in the vicinity of
the gas station sampling point was higher than in the other stations,
and at all locations was found to be so much more than the standard
concentration levels (1.56 ppb) prescribed by Environmental Protection
Agency for the ambient air quality. The results of the study revealed
that the benzene concentration levels in Tehran are distinctly more
than its standard level. This is mainly attributed to the poor quality
of fuel and lack of a standard system for controlling petrol vapors in
the gas stations
Providing interoperability for air quality in-situ sensors observations using GML technology
Geographic information provides the basis for many types of decisions
ranging from simple path finding, to the sustainable management of
environmental conditions. Producing such information is a time
consuming and costly endeavor. Data sharing on the web is an avenue to
increase the efficiency of the practices. This paper scientifically
examines the new emerging technologies namely, internet, geographic
markup language (GML), and observation and measurement models, to
construct an interoperable repository for air quality sensors
measurements. The paper also elaborates on the design and
implementation of a web-based air quality information system (AQIS) for
the city of Tehran. In-situ sensors measure ozone (O3), carbon monoxide
(CO), sulfur dioxide (SO2), nitrogen dioxide (NO2) and particulate
matters (PM) in polluted metropolitans. Providing real-time air quality
information can improve the decisions of the pertinent environmental
organizations. Using GML for encoding sensors observations makes it
possible to build an interoperable repository that is independent of
platforms and vendors. Providing query possibilities based on
monitoring stations, sensor names (pollutants), date and time
intervals, and spatial query on the AQIS interfaces are the major
functions of this system. Although standardized, it was concluded that
the use of GML as data format increases the size of GML document. In
addition, the developed system provides no map based results for the
clients. Therefore, it is required to be improved by adding more GIS
functions
Porosity, characterization and structural properties of natural zeolite - clinoptilolite - as a sorbent
The characterization and porous structure of raw and modified clinoptilolite as a sorbent has been investigated by nitrogen adsorption, X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy, differential thermal analysis, scanning electron microscopy and atomic force microscopy methods. The nitrogen adsorption data revealed that the total pore volume and specific surface area were increased after modification. The nitrogen adsorption was used to determine percent of mesoporosity. The TG data show that 14 wt. % of clinoptilolite is lost after heating up to 1200 °C. Two types of porosities - primary porosity (microporosity) and secondary one (meso- and macroporosity) have been observed