The engine emission characteristics of Mahua biodiesel (Mahua oil Methyl Ester) and petro-diesel are presented. The thermo-physical properties of all the fuel blends have been measured and presented. The engine tests are conducted on a 4Stroke Tangentially Vertical (TV) single cylinder kirloskar 1500 rpm water cooled direct injection diesel engine with eddy current dynamometer at different static injection timings of 22°, 23° (standard) and 24°bTDC under standard nozzle opening pressure of 240 bar maintained as constant throughout the experiment under steady state conditions at full load condition of the engine. From the test results, it could be observed that the lower static injection timing (22° bTDC) for B0 fuel and B100 fuel give lower Carbon Monoxide, Smoke Density and Oxides of Nitrogen in the case of emissions.

 

Keywords: - Petro-Diesel; Biodiesel; Static Injection Timings; Engine Emissions

[1] A S Ramadhas, S. Jayaraj and C. Muraleedharan, Use of vegetable oils as IC engine fuels: A review, Renewable Energy, 29, 2003, 27-742.
[2] P Srinivasa Rao and K.V Goplalakrishna. Esterified oils as fuels in diesel engine, 11th National Conference on IC Engines, IIT Madras, 1983, India.
[3] Canakci and Vam Geroen, 2003, A pilot plant to produce biodiesel form high free fatty acid feedstock, American society of agricultural engineers, 46 (4), 2003, 945-954.
[4] M A Fangrui and A. Milford, Hanna biodiesel production: a review, Bioresource Technology, 70, 1993, 1-15.
[5] Suresh Kumar, A.K. Gupta and S.N. Naik, Conversion of non-edible oil into biodiesel, Journal of Scientific and Industrial Research, 62, 2003, 124-132.

An algorithm based on Fourier series approximation is proposed for separating touching grain kernels. The algorithm starts with image acquisition of wheat grain samples in group of two, three, and four as a first step. Then pre-processing techniques are applied to threshold the required region and make the image smoother, and also to find the boundary points. Pre-processing is followed by chain coding where freeman coding is used to get the connected components and given to Fourier approximation for getting boundary contours. Curvature analysis is done to get the corner points. Then possible potential node pairs are found by using radical critical distance. Nearest neighbors among corner point is calculated by finding pair-wise distance among all possible nodal points. From potential pairs, true pairs are selected based on nearest neighbor distance criteria. Finally Bresenham's line drawing algorithm is used to draw segmentation line. The algorithm is successful in separating most of touching grain kernels.

 

Index terms: - Fourier series, Grain separation, Curvature analysis, nearest neighbor

An algorithm to separate touching grains based on Fourier series Approximation

An algorithm based on Fourier series approximation is proposed for separating touching grain kernels. The algorithm starts with image acquisition of wheat grain samples in group of two, three, and four as a

This study aimed to compare the Varian portal dosimetry system and the ImatriXX 2-D array system of IBA dosimetry for IMRT and Rapid arc patient specific quality assurance (QA). Fifteen cases of IMRT and fifteen cases of Rapid arc plans were selected for the patient specific QA study using portal dosimetry and ImatriXX 2-D array system. Planar dose comparison was carried out with gamma criteria of 3% -3 mm {dose difference and distance-to-agreement (DTA)}. For portal dosimetry system area gamma, average gamma and maximum gamma were analyzed and for the ImatriXX 2-D array system, the % of pixels passing the 3%-3mm gamma was chosen. In case of IMRT, the portal dosimetry mean values of area gamma, average gamma and maximum gamma were 1.01, 0.48 and 1.72 with standard deviation values of 0.38, 0.05 and 0.20 and for Rapid arc the corresponding values were 2.01, 0.48 and 1.72 with standard deviation of 0.54, 0.07 and 0.29. With the ImatriXX 2-D array system, on an average 99.22% of the pixels passed the criteria of 3%-3 mm with standard deviation of 0.58 for IMRT. For rapid arc, the average value was 97.14% with a standard deviation of 1.26. The results showed that both the systems can be use for patient specific QA measurements for IMRT and rapid arc. Portal dosimetry as well as ImatriXX measurements showed significant difference in gamma results of IMRT vs. rapid arc with p-value less than 0.05. Compared to ImatriXX 2-D array system, the portal dosimetry values were more consistent. The portal dosimetry QA is less time consuming and in case of IMRT individual field verification is easier compared to ImatriXX 2-D array system.

 

Keywords: - Intensity modulated radiotherapy, Rapid arc, ImatriXX, Portal dosimetry, QA

[1] T. Wiezorek, M. Banz Nschwedas, D. Georg and T. G. Wendt, "Dosimetric quality assurance for intensity-modulated radiotherapy feasibility study for a filmless approach," Strahlenther. Oncol. , 181: 468-74, 2005.
[2] F. Branci Buonamici, L. Marrazzo and S. Russo, "An inter comparison between film dosimetry and diode matrix for IMRT quality assurance," Med. Phys., 34: 1372-1379, 2007.
[3] G. J. Budgell, Q. Zhang, R. J. Trouncer and R. I. Mackay, "Improving IMRT quality control efficiency using an amorphous silicon electronic portal imager," Med. Phys., 32: 3267-78, 2005.
[4] P. Winkler, A. Hefner and D. Georg, "Dose- response characteristics of an amorphous silicon EPID," Med. Phys., 32: 3095-105, 2005.
[5] E. E. Grein, R. Lee and K. Luchka, "An investigation of a new amorphous silicon electronic portal imaging device for transit dosimetry," Med. Phys., 29: 2262-8, 2002.

Nitrite compound exerts environmental stress on fish. High levels of nitrite in water results in high stress levels leading to hyperventilation, elevated heart rate, increased blood pressure in fish. The present study was to evaluate the histopathological changes in liver exposed to nitrite toxicity during 7th, 14th, 21st , 28th , and 35th , days respectively. Morphological structure of liver of Cirrhinus mrigala was presented in (Ph. m. 8). In the control fish, the liver showed hepatic cells located with central nucleus and homogenous cytoplasm. During acute treatment the liver exhibit disintegration of parenchymal cells, extensive vacuolation of parenchymal hepatocytes, degenerative cell and organelles and lumen with necrotic cells (Ph. m. 9). During sublethal treatment liver showed enlargements of hepatocytes, disintegration of cell boundaries of intercellular spaces, nuclear degeneration with pyknotic nucleus were noticed at the end of 7th day (Ph. m. 10). At the end of 14th day, disintegration of hepatocytes and necrosis of parenchymatous tissue noticed. The cell undergo necrosis or apoptosis. It is followed by karyorrhexis or fragmentation of the nucleus (Ph. m. 11). The above said structural changes were severe at the end of 21st and 28th , exposure period (Ph. m. 12, 13). Complete rupture of hepatic cells, vacuolar degeneration, intercellular edema, were observed at the end of the treatment period (Ph. m. 14).

 

Keywords: - Cirrhinus mrigala, Nitrite, Fish liver

[1] Au, D.W.T., 2004. The application of histo-cytopathological biomarkers in marine pollution monitoring: a review. Mar. pollut. Bull., 48: 817-834.
[2] Ayas, Z., Ekmekci, G., Ozmen, M., Yerli, S.V., 2007. Histopathological changes in the livers and kidneys of fish in Sariyar Reservoir, Turkey. Environ Toxicol. Pharmacol., 23, 242-249.
[3] Benli, A.C.K., Koksal, G., Ozkul, A., 2008. Sublethal ammonia exposure of Nile tilapia (Oreochromis niloticus L). Effects on gill, liver, kidney histology. Chemosphere. 72, 1355-1358.
[4] Bernet. D., Schmidt, H., Meier, W., Burkhardt-holm, P., Wahli, T., 1999. Histopathology in fish: proposal for a protocol to assess aquatic pollution. J. Fish. Dis., 22, 25-34.
[5] Bhattacharya, S., Mukherjee, S., Bhayyacharya, S., 1975. Toxic effects of endrin on hepatopancreas on the teleost fish, Clarias batrachus (Linn.). Indian J. Exp. Biol., 13, 185-186.

Several methods of realization of floating inductance with current conveyors, current feedback amplifier has been reported. The methods for the realization of inductance simulation with electronically tunable properties using current controlled conveyors required well matching of transistors. These devices have limited performance due to component matching. Simulation of inductance is also obtained from second generation current conveyors with excessive number of components. The simulated inductance is varied through passive elements and the approach is based on the use of current differencing buffer amplifier realized with CMOS technology and is unavailable in integrated form. Operational transconductance amplifier has an attractive feature of transconductance gain which is linearly controlled over more than 4 decades from the bias current. The OTA is a commercial low cost device and also easy to implement in monolithic integrated form. The realization of floating inductance simulation is more attractive. A commercial OTA with least number of active and passive elements exhibit an attractive method to simulate a floating inductance. A review on floating inductance using number of OTAs with resistor and single capacitor is reported in terms of searching for the best method of simulating the floating inductance in the design of low pass filter.

 

Keywords: - Floating inductance, LPF-low pass filter, OTA- Operational Transconductance Amplifier.

[1] A.U. Keskin and E. Hangeioglu, CDBA based synthetic floating inductance circuits with electronic
tuning properties, ETR J, Vol 27, No-2, 2005, 239-242
[2] Abdullah Ferikoglu, Toner Topal, Inductor Simulation With Operational Devices", G.U. Journal of
Sciences , Vol. 18(1),2005,143-151
[3] Khanittha Kaewdang, K. Kumwachara and W.Surakampontorn, Electronically Tunable Floating CMOS
Resistor Using OTA,IEEE ISCIT,2005, 705-708
[4] Shahram Minaei, Erkan Yuce, Oguzhan Cicekoblu, Lossless active floating inductance simulator, Third
IEEE International workshop on electronic design, tests and applications, 2005
[5] H. Kuntman, M Gulsoy,O. Cicekoglu, Actively Simulated Grounded Lossy Inductors Using Third
Generation Current Conveyors, Elsevier, Microelectronics Journal 31, 2000 , 245-250.

The Khaprabhanga Chapalir Don River (Mohipur channel), an important navigation route, is situated in the Upazilla Kalapara under the administrative district of Patuakhali. The sea going engine boats used to take shelter in this river during cyclone. The river has been experiencing siltation over the years. Boat cannot enter from Rabnabad and Andarmanik Channel to the Mohipur channel during the ebb tide. A comprehensive mathematical modelling study has been carried out to assess the capital dredging volume, resiltation rate, maintenance dredging, and dredge spoil locations. In the existing condition the navigation depth in the channel varies from 1.25m to 2.00m in the western stretch and in the eastern it is 0.50 m to 1.25m, which implies 4.00 m dredging is required to improve the navigability of the channel for movement of ships and engine boats. Model result shows that, for option-2 tidal flow/prism in the channel is increased by 21% during high tide compared to existing condition which indicates sustainable deeper channel compared to present condition. Navigable depth 3.60m to 4.60m can be achieved in this option. The capital dredging is about 3.40 million m3 and re-siltation rate is the least compared to the other options. However, the annual maintenance dredging is about 60% of the capital dredging. If high tide followed then maintenance dredging may be required after 6 months.

 

Keywords: - Navigability, Capital and Maintenance Dredging, Dredged Volume, Tidal prism, Siltation.

[1] AIT, Nguten Huong Thuy Phan (1998), "Field Application of 2D Morphological Modelling for Estuarine and Coastal Areas"
[2] DHV Consultants BV (2001). Hydro-morphological Dynamics of the Meghna Estuary (MES II)
[3] IWM (2010), Updating of Hydrodynamic & Morphological Models to Investigate Land Accretion & Erosion in the Estuary Development Program (EDP) Area.
[4] IWM (2009), "Survey and Modelling Study of Sandwip-Urirchar-Noakhali Cross-Dam(s)", Final Report submitted to Char Development and Settlement Project-III (CDSP-III) by IWM.
[5] O' Brien, M.P. (1969). "Equilibrium Flow Areas of Inlets on Sandy Coast", Journal of the Water Ways and Harbours, DIV, Proc. ASCE.

The Meghna Estuary region of Bangladesh is a unique environment where the constant process of land formation and erosion takes place due to the complex interactions between large river discharge, enormous sediment load, strong tidal forces, wind actions, wave, salinity & cyclonic storm surge and estuarine circulation. These hydrodynamic factors and their interactions shape the morphology of the Meghna Estuary. During dry season upland fresh water flow into the Bay through the estuary is very much lower than that of monsoon season. Tidal action becomes stronger and dominates water flow pattern in the Meghna estuary. The distribution of flow and water level in the different channels of the Meghna estuary are governed by river discharge, the tide and the wind speed. Velocity is higher during ebb tide than that of flood tide due to combined effect of upstream flow and downward tidal current. Velocity in monsoon is much higher compare to dry period because upstream discharge is higher in monsoon. Most of the accretion and erosion mainly occurs during monsoon and post monsoon period. In pre-monsoon and post monsoon, wave height is less compared to monsoon as wind speed is less during these periods. Along the left Bank of this estuary, significant wave is considerable. As a result, tremendous whirl action due to tidal effects and whirl action due to enormous drainage flow during monsoon, wave action, tidal surge of the lower Meghna causes breaching of the major parts of the embankments of polder 59/2 and adjacent area. The main purpose of this research paper is to understand the hydrodynamic features of the Meghna estuary.

 

Keywords: - Bay of Bengal Model (BoBM), Flexible Mesh (FM), Ganges-Brahmaputra-Meghna (GBM), Hydrodynamic, Meghna Estuary Study (MES)

[1] J.D. Milliman, Flux and fate of fluvial sediment and water in coastal seas, Mantoura, R.F.C., Martin, J.-M. & Wollast, R. (Ed.), Ocean Margin Processes in Global Change, John Willey and Sons Ltd., Chichester,1991, 69-89.
[2] J.M. Coleman, Brahmaputra River: Channel processes and sedimentation, Journal of Sedimentary Geology, vol. 3, issue 2-3, 1969, 129-239.
[3] MES, Year 2000 update of trends and processes; addendum to morphological processes, Volume 2 of Draft Masterplan for Meghna Estuary, Technical Note MES-029 , Ministry of Water Resources, Bangladesh Water Development Board, DHV Consultants BV and associates, 2001.
[4] MES, Morphological Processes, Draft Masterplan, Volume 2, Ministry of Water Resources, Bangladesh Water Development Board, DHV Consultants BV and associates,1998.
[5] MES, Tidal volume and sediment transport patterns, Technical Note MES-001, Ministry of Water Resources, Bangladesh Water Development Board, DHV Consultants BV and associates, 1997.6