New Simulated Corrugated Scaltering Surface Giving Widebandcharacter I Sti Cs

Simultaneous elimination of specular reflection and backscattered power from a plane metallic surface by simulated corrugated surfaces of constant period and variable strip width for TM polarisation is reported. This new configuration offers almost a ten-fold frequency bandwidth compared with a regularly spaced strip grating of the same size.

Aircraft down-range profiles formed from simulated and compact-range radar backscatter

Compact-range radar backscatter measurements are taken of aircraft scale models. In addition, computer software is used to predict the RCS of the aircraft. Synthetic down-range profiles formed from the two sources of backscatter data are compared and visualized in an innovative manner. Similar discrimination rates between the two aircraft are obtained on data from both source

Development of a new type of simulated scalar feed

This thesis presents the results of an investigation conducted for the development of a new type of feed horn antenna called "Simulated Scalar Feed". A schematic presentation of the work is given below. A review of the past important work done in the field of conventional/multimode electromagnetic horn antennas is presented in the first part of the second chapter. The work carried out on corrugated horns and surfaces are included in the second part of the review. In the third part, work on dielectric and dielectric loaded metal horns are reviewed. In all the parts of the review, special emphasis is given to theoretical design considerations. The methodology adopted for the experimental investigations is presented in the third chapter. The instrumentation utilized and thThis thesis presents the results of an investigation conducted for the development of a new type of feed horn antenna called "Simulated Scalar Feed". A schematic presentation of the work is given below. A review of the past important work done in the field of conventional/multimode electromagnetic horn antennas is presented in the first part of the second chapter. The work carried out on corrugated horns and surfaces are included in the second part of the review. In the third part, work on dielectric and dielectric loaded metal horns are reviewed. In all the parts of the review, special emphasis is given to theoretical design considerations. The methodology adopted for the experimental investigations is presented in the third chapter. The instrumentation utilized and the details of fabrication ofe details of fabrication of the new simulated scalar feed are described. The method of measurements of radiation characteristics of the antenna are also explained in this chapter. In the fourth chapter the outcome of the experimental results of the investigations carried out on horn antennas fabricated with different physical dimensions and different parameters for the E—plane boundary walls are highlighted. The theoretical explanation used to explain the experimental results is given in the fifth chapter of the thesis. A comparison between the experimental and the theoretical results is also presented in this chapter. In chapter six, the conclusions drawn from the experimental as well as the theoretical investigations are discussed. The advantages and features of the newly developed simulated scalar feed is examined in this chapter. Scope of further investigations in this field is also discussed at the end of this chapter.

Comparative efficacy of MS-222 and benzocaine as anaesthetics under simulated transport conditions of a tropical ornamental fish Puntius filamentosus(Valenciennes)

There is a growing commercial interest in the ¢sh, Puntius ¢lamentosus, in the ornamental ¢sh trade in India and elsewhere.The trade is, however, hampered by severe mortalities during transport of the ¢sh owing to insu⁄cient data available on the use of anaesthetics. To resolve this problem, we evaluated the e⁄cacy of two anaesthetics, MS-222 and benzocaine, in sedating P. ¢lamentosus in simulated transportation experiments and used stress response parameters such as cortisol and blood glucose levels to perform assessments. We observed that MS-222 at 40 mg L 1 and benzocaine at 20mg L 1 were su⁄- cient to induce sedation for 48 h. Above these concentrations, both the anaesthetics adversely a¡ected the ¢sh and resulted inmortalities. Both anaesthetics signi¢cantly lowered the blood cortisol and glucose levels compared with the unsedated controls. Importantly, the anaesthetics treatment signi¢cantly lowered the post-transport mortality in the ¢sh. The results of the study show that MS-222 and benzocaine could be used as sedatives to alleviate transport- related stress in P. ¢lamentosus to improve their post-transport survival and hence reduce economic loss.

A Study of Single Stage Semi‐Dry Anaerobic Digestion of Organic Fraction of Municipal Solid Waste

Solid waste generation is a natural consequence of human activity and is increasing along with population growth, urbanization and industrialization. Improper disposal of the huge amount of solid waste seriously affects the environment and contributes to climate change by the release of greenhouse gases. Practicing anaerobic digestion (AD) for the organic fraction of municipal solid waste (OFMSW) can reduce emissions to environment and thereby alleviate the environmental problems together with production of biogas, an energy source, and digestate, a soil amendment. The amenability of substrate for biogasification varies from substrate to substrate and different environmental and operating conditions such as pH, temperature, type and quality of substrate, mixing, retention time etc. Therefore, the purpose of this research work is to develop feasible semi-dry anaerobic digestion process for the treatment of OFMSW from Kerala, India for potential energy recovery and sustainable waste management. This study was carried out in three phases in order to reach the research purpose. In the first phase, batch study of anaerobic digestion of OFMSW was carried out for 100 days at 32°C (mesophilic digestion) for varying substrate concentrations. The aim of this study was to obtain the optimal conditions for biogas production using response surface methodology (RSM). The parameters studied were initial pH, substrate concentration and total organic carbon (TOC). The experimental results showed that the linear model terms of initial pH and substrate concentration and the quadratic model terms of the substrate concentration and TOC had significant individual effect (p < 0.05) on biogas yield. However, there was no interactive effect between these variables (p > 0.05). The optimum conditions for maximizing the biogas yield were a substrate concentration of 99 g/l, an initial pH of 6.5 and TOC of 20.32 g/l. AD of OFMSW with optimized substrate concentration of 99 g/l [Total Solid (TS)-10.5%] is a semi-dry digestion system .Under the optimized condition, the maximum biogas yield was 53.4 L/kg VS (volatile solid).. In the second phase, semi-dry anaerobic digestion of organic solid wastes was conducted for 45 days in a lab-scale batch experiment for substrate concentration of 100 g/l (TS-11.2%) for investigating the start-up performances under thermophilic condition (50°C). The performance of the reactor was evaluated by measuring the daily biogas production and calculating the degradation of total solids and the total volatile solids. The biogas yield at the end of the digestion was 52.9 L/kg VS for the substrate concentration of 100 g/l. About 66.7% of volatile solid degradation was obtained during the digestion. A first order model based on the availability of substrate as the limiting factor was used to perform the kinetic studies of batch anaerobic digestion system. The value of reaction rate constant, k, obtained was 0.0249 day-1. A laboratory bench scale reactor with a capacity of 36.8 litres was designed and fabricated to carry out the continuous anaerobic digestion of OFMSW in the third phase. The purpose of this study was to evaluate the performance of the digester at total solid concentration of 12% (semi-dry) under mesophlic condition (32°C). The digester was operated with different organic loading rates (OLRs) and constant retention time. The performance of the reactor was evaluated using parameters such as pH, volatile fatty acid (VFA), alkalinity, chemical oxygen demand (COD), TOC and ammonia-N as well as biogas yield. During the reactor’s start-up period, the process is stable and there is no inhibition occurred and the average biogas production was 14.7 L/day. The reactor was fed in continuous mode with different OLRs (3.1,4.2 and 5.65 kg VS/m3/d) at constant retention time of 30 days. The highest volatile solid degradation of 65.9%, with specific biogas production of 368 L/kg VS fed was achieved with OLR of 3.1 kg VS/m3/d. Modelling and simulation of anaerobic digestion of OFMSW in continuous operation is done using adapted Anaerobic Digestion Model No 1 (ADM1).The proposed model, which has 34 dynamic state variables, considers both biochemical and physicochemical processes and contains several inhibition factors including three gas components. The number of processes considered is 28. The model is implemented in Matlab® version 7.11.0.584(R2010b). The model based on adapted ADM1 was tested to simulate the behaviour of a bioreactor for the mesophilic anaerobic digestion of OFMSW at OLR of 3.1 kg VS/m3/d. ADM1 showed acceptable simulating results.