Engineering

Search by keywords:
Total Articles 82 - 90 of 15834 | |

Differences between SCIG and DFIG Inertia Response

Author(s):Sajede Darvishi-Niafenderi
Journal: Technical Journal of Engineering and Applied Sciences
Publisher:Science Explorer Publications
Abstract
| Pages: 812-818
In this paper we studied the inertia response of SCIG and DFIG. With increased production capacity in wind farms, their role in power system stability has become important. SCIG and DFIG are used in wind turbin. DFIGs are variable speed generators and SCIGs are fixed speed generators. At first we simulated SCIG and DFIG in MATLAB simulink and compare them. The inertia response of a generator is influenced by the sensitivity of the generator’s electromagnetic torque to changes in the power system frequency. DFIG has low inertia response, we improved the inertia response of DFIG by adding feedback parameter as a function of the rate of the change of the grid frequency to reference electromagnetic torque.

The Application of Remote Sensing and Geographic Information System in Environmental Changes Studies (Case Study: The East of Mazandaran)

Author(s):V. Gholami
Journal: Studies in Surveying and Mapping Science
Publisher:
Abstract
| Pages: 37-42
Cartography is applied in providing different kinds of maps such as landuse, slope and DEM and so on, which is very time consuming. Today, many maps are provided using Remote Sensing (RS) in a short time with in an acceptable accuracy. In this study, ASTER and ETM+ (LANDSAT) images have been used to provide landuse, DEM and drainage density maps. Kasilian Watershed (northern Iran) landuse has been provided using supervised classification technique and ETM+ image. Then ETM+ image ability was investigated in terms of different land uses separation. Also, Digital Elevation Model (DEM) was generated using ASTER image in the south of Gorgan Gulf and then DEM accuracy was investigated. Channels network map was extracted analyzing topographic conditions using DEM in GIS (ArcView) and the results for accuracy were controlled and confirmed comparing these results with those of topography maps. The results proved the capability of RS in environmental studies and in providing different maps.

Urban Municipal Growth and Landuse Change Monitoring Using High Resolution Satellite Imageries and Secondary Data-A Geospatial Study on Kolkata Municipal Corporation, India

Author(s):Biswajit Nath, Shukla Acharjee
Journal: Studies in Surveying and Mapping Science
Publisher:
Abstract
| Pages: 43-54
The Kolkata Municipal Corporation (KMC) formerly renowned as Calcutta Municipal Corporation, established in 1876, is responsible for the civic maintenance and infrastructure of Kolkata. The KMC serves an area of 187.33 sq. km. The city is divided into 141 administrative wards that are grouped into 15 boroughs. The geographical extent of the KMC area falls between north latitudes of 22028/00// and 22037/30// and east longitudes 88017/30// and 88025/00//. Kolkata becomes a place to initiate improvements in several fields such as electric trams (1902), imtroduction of aeroplane (1910), Victoria Memorial(1929), Bengali Film (1931) and Howra Bridge (1941) and the maps prepared by National Atlas and Thematic Mapping Organization (NATMO) in 1982 and 1984 clearly reflect the multifold increase of the population of the city. Land use mapping of KMC carried out using NASA-GLCF provided free Landsat TM (GeoTIFF) imageries from 1990-2004. And landuse change in the KMC area has been detected using geospatial techniques and presented in the paper. The industrial growth was limited in the period between 1990-2004 due to political and other problems. The data indicates a negative trend but recently due to government initiatives industries have been set up and therefore the overall change shows an increasing trend (+) 0.34%. The overall change of the residential area (+) 27.89% and waterbodis (+) 1.01% as well shows positive increasing trend. The Multi-temporal Land use map of Kolkata Municipal Corporation prepared for this research work will be definitely helpful in generating tax property map in future as well as for the fruitful decision making in the development of Municipal Corporation.

Using of Artificial Intelligence and Image Texture to Estimate Desiccation Rate of Quince Fruit

Author(s):Adel Bakhshipour, Abdolabbas Jafari, Farahmand Babellahi
Journal: Technical Journal of Engineering and Applied Sciences
Publisher:Science Explorer Publications
Abstract
| Pages: 641-646
Image processing can quantitatively define the visual properties of foods. Textural properties provide lots of information from a captured image which can be used for further system design. The combination of artificial neural networks (ANN) and machine vision can provide simple solutions to problems associated with agricultural products processing. In this research, the effect of drying on the parameters related to the image texture of sliced quinces was investigated dried at constant temperature level of 40 in an oven dryer. Images were captured from samples at several intervals during drying period. Co-occurrence matrix was computed separately for L*, a*, b* color components as well as grey-level images. Five textural features were extracted from each matrix. Dehydration causes contraction on quince slices which in turn produce special texture look on the dried sample. A feed-forward back-propagation artificial neural network (ANN) with three hidden layers and different transfer functions was developed and trained for instantaneous prediction of moisture content of fruit being dried. The ANN with tangent sigmoid transfer function and Levenberg-Marquardt learning algorithm was the most efficient networks for prediction of drying behaviors of quince slices with an R2 of 0.994 and uncertainty of 0.12%.

The survey of qualitative and economic analysis of the penetration level of FACTS device installation on network congestion management

Author(s):Mohammad Daliri, Amin Beiranvand, Mohammad H.Moradi
Journal: Technical Journal of Engineering and Applied Sciences
Publisher:Science Explorer Publications
Abstract
| Pages: 647-653
In a deregulated electricity market, it may alwaysnot be possible to dispatch all of the contracted powertransactions due to congestion of the transmission corridors.The ongoing power system restructuring requires an openingof unused potentials of transmission system due toenvironmental, right-of-way and cost problems which aremajor hurdles in the expansion of power transmissionnetwork. Flexible AC transmission system (FACTS) devicescan be an alternative to reduce the flows in heavily loadedlines, resulting in an increased loadability, low system loss,improved stability of the network, reduced cost of productionand fulfilled contractual requirement by controlling the powerflows in the network. In this paper, TCPST has been used in the congestionmanagement. For optimal setting of TCPST and determining theappropriate location for the management and reduction of thetransmission lines congestion in the restructured environment, amethod based on the locational marginal price (LMP) andoptimal power flow (OPF) in combination withThyristorControlled PhaseShiftingTransformer(TCPST) is used.This method is applied on IEEE 30 bus system.Simulation results show the effect of TCPST appropriatelocating on the reduction of the total restructured power systemcosts.

Application Effect of Domestic Sewage on Available Iron Concentration in Different Soil Depths

Author(s):Ali Gholami, Robabeh Abdi Dezfuli
Journal: Technical Journal of Engineering and Applied Sciences
Publisher:Science Explorer Publications
Abstract
| Pages: 654-657
As more than 90 percent of water is used in agriculture, experts were made to turn to non-conventional waters, among which sewage is of significant importance due to having high amounts of plants required elements. The study was conducted with the objective of reviewing the impact of the application of raw and treated sewage on the trend of changes of iron in different soil depths. An experiment was performed three times to this end in the form of a CRD (Completely Randomized Design) with three treatments including tap water, treated sewage, and raw sewage. Soil sampling was done as composites at the soil depths of 0-30 and 30-60 cm. The available iron was determined in soil by DTPA method. The data experimented was analyzed at two probability levels of 1 and 5 percent by SPSS statistical software to determine the level of significance, and the Duncan test was used to compare the averages. The results from the statistical analysis showed that the use of raw and treated domestic sewage has stimulated an increasing trend in available iron concentration.

The Impact of Domestic Sewage Sludge on the Changes of Manganese and Zinc Concentrations in Soil

Author(s):Ali Gholami, Robabeh Abdi Dezfuli
Journal: Technical Journal of Engineering and Applied Sciences
Publisher:Science Explorer Publications
Abstract
| Pages: 658-661
An experiment was performed three times to this end in the form of a completely randomized design with three treatments including tap water, treated sewage, and raw sewage. Soil sampling was done as composites at the soil depths of 0-30 and 30-60 centimeters. Analyzing the samples was done by common experimental methods to determine some of the soil chemical properties and micronutrients, and the data was saved in Excel software database. The data experimented was analyzed at two probability levels of 1 and 5 percent by SPSS statistical software to determine the level of significance, and the Duncan test was used to compare the averages. The results from the statistical analysis showed that the use of raw and treated sewage has stimulated an increasing trend in parameters including, Manganese and Zinc.

Analyzing the Rate of Rural Women’s benefiting Various Radio and Television Programs

Author(s):Masoumeh Taghibaygi, Amirhossein Alibaygi, Seyed Alireza Ghadimi
Journal: Technical Journal of Engineering and Applied Sciences
Publisher:Science Explorer Publications
Abstract
| Pages: 662-668
The existence of capable women is one of the most important factors to develop rural communities.one way to improve rural women’s conditions is education through mass media. Among the mass media, radio and Tv have an effective role to empower the rural women with amount of different skills and abilities. This article analyzs the women’s benefit from various radio and Tv programs. The statistical population included 15000 rural women in west Islam Abad township(375 women were selected as samples). The results show women are interested in news(27/6), educational programs(23/6), movies and serials(18/3). The results also indicated that married women spent more time listening to. level of significance of the distance between village and city and listening to radio programs duration was 0/01. There was no significant relationship between the women age, the family earning, the number of children and the time spending watching Tv and listening to radio programs. However, there is a significant relationship between the women’s level of education, morital status, age and their interest in different programs. Most women agreed that the best time to broadcast these programs was night and evening. They stated that biggest problems of radio and Tv programs were the large number of commercials, and repetitive programs.

Investigation of Karoon River Self-Refinement Capacity Exposed to Khorramshahr‘s Soup Factory Based on EC, BOD, COD and DO Parameters Using River Sediments

Author(s):Ebrahim Panahpour, Soudabeh Asadi, Ali Gholami
Journal: Technical Journal of Engineering and Applied Sciences
Publisher:Science Explorer Publications
Abstract
| Pages: 669-672
Khorramshahr’s soup factory daily producing 1000 tons of soup chips and 14 tons of glycerin as well as other kinds of soup is situated near Karoon River which discharges 144000 m3 wastewater in to this river annually. The aim of this research is to study the effect of the wastewater on river water quality and the capacity of its self-refinement. For this purpose, the samples were taken from river sediments and outlet wastewater in 10 months ( from September 2006 to July 2007) in the 3 stations include 50 meters far from upstream as control (×0) , 50 and 500 meters from downstream (×1 and ×2) where the wastewater is discharged. In this study, the physico- chemical parameters of both water and wastewater from the factory such as temperature ,BOD,COD,DO as well as their properties such as bicarbonate, sulfate, calcium, magnesium, sodium, potassium, organic matter percentage and percentage of particle size were investigated. The statistical analysis showed that in the second station the BOD and COD increased 31%, 57% relatively compared to control station that was an indication of wastewater contamination. In the third station, these parameters decreased 42%, 47% compared to second one, suggesting that the river refines itself through oxygen-taking over route and contaminants’ adsorption by bed sediments in different ways such as electrostatic and proton- taking mechanism and hydrogen bond through water bridge. These differences were significant at level 5% of the Dunned test.
Page:12345678910Next