Part III of the series on cooking systems presents a qualitative description of cooking methods such as open pan cooking, pressure cooking, steam cooking, solar energy-based cooking, microwave cooking, etc. A large number of chemical and physical changes occur during the process of cooking. These changes have been comprehensively covered in published literature including some textbooks. An attempt has been made to discuss a brief coherent description regarding the changes occurring in starches, proteins, fats, etc. The kinetics of the cooking reaction has also been investigated. This information can be advantageously employed for developing a protocol for an optimum temperature–time program. Because the cooking process is practically thermally neutral, a good scope is available for the optimization of energy supply. It was also thought desirable to understand the kinetics of degradation of proteins, vitamins, anti-nutrients, and flavors in different cooking practices, including microwave ovens and pressure cookers. The mechanism of cooking of rice and lentils has been described. The cooking process involves first the transfer of water from bulk to the particle surface, where the resistance for transfer is provided by a thin film in the vicinity of grain (rice and lentils) surfaces. Second, water has to transfer from the external surface to swollen cooked mass to uncooked core. Finally, on the surface of the uncooked core, the cooking reaction occurs. All published literature regarding this mechanism has been systematically analyzed, and the procedure has been given regarding the rate controlling step(s) and the estimation of the overall rate of cooking. For this purpose, the mathematical models have been given and methods have been described for the quantitative evaluation of the model parameters. A substantial amount of additional work is needed on the mechanism of cooking and suggestions have been made for future research.

Sections 2–6 of Part I were devoted to the analysis of heat transfer characteristics of cookers. In all the experiments, only water was employed as a working medium. Now, we extend such an analysis to the actual cooking process in order to arrive at an improved cooking device. The major strategies for the optimization of energy utilization is to design appropriate insulation that has been obtained by two cover vessels. In order to select an air gap, the flow and temperature patterns in the air gap have been extensively analyzed using computational fluid dynamics (CFD). The flow pattern and heat transfer in cooking pots have also been analyzed by CFD. This has enabled us to design suitable internals for minimizing the stratification of temperature. The understanding of fluid mechanics has also given basis for selection of heat flux, gap between burner tip and cooker bottom, and temperature of flue gases leaving the cooker. Chemical engineering principles have been used for modeling and optimization. Kinetics have been obtained in batch cookers. The knowledge of kinetics, thermal mixing, axial mixing, and optimum selection of insulation have been employed for the development of continuous cookers. The continuous mode of operation also helps in saving of energy. Systematic data have been collected for the design and scale up of continuous cookers.

In the conventional cooking practice, where a pot or a pan is directly placed on a flame, the thermal energy efficiency is in the range of 10–25%. It was thought desirable to increase this efficiency up to 60% or more. The cooking systems can be of various sizes. In the developing world (85% of the world’s population), open pan cooking is largely still practiced at the family level (4–10 people) or at the community level (50–2000 people or more). The latter requirement is encountered in schools, homes for senior citizens, jails, social and/or religious centers (temples, mosques, churches), social and/or educational functions (conferences, marriages, celebrations, etc.), remand homes, etc. For these different types of final application, in the present work, cooking systems have been developed. A systematic work has has been reported regarding the effect of several parameters on thermal efficiency. The parameters include the cooker size, number of pots, size and aspect ratio of the pots, heat flux, flame size, flux–time relationship, insulating alternatives, etc. Local and global optima of the parameters have been obtained, resulting in thermal efficiency of about 70%.

The purpose of this paper is to present a new form of chart, which clarifies the inter-relationships between six fundamental urban design parameters that affect the quality and character of any urban layout. These parameters are: built-up area per capita; public ground area per capita (which includes streets and parks); plot factor (the ratio of land area given over to private development to land area available for public use, including that needed for circulation and area available for sport, recreation and public amenities (schools, hospitals, public toilets); floor space index (ratio of built-up area to buildable plot area); net density (population divided by the sum of all buildable plot areas); and gross density (population divided by total area). Mapping these six parameters in a chart shows the complicated trade-offs between one desirable feature and another, including combinations that show that higher densities do not necessarily mean small accommodation and inadequate public space -but they do mean high-rise, and there are severe limits on how high densities can go. The paper also plots diagrams that show the values of these parameters for existing localities in New York, Mumbai (including Dharavi) and Delhi. These diagrams are examples. With more data and more diagrams we might reach a better understanding of what particular values or combinations of values for these parameters we should aim for when designing a new development or modifying an old one. We might also understand the values or combinations of values that we should avoid.

This paper describes a proposal for affordable housing across all income groups on urbanizable mostly greenfield peri-urban sites served by a suburban railway station. Connecting to this arterial transit node, a bus rapid transit system (BRTS) of high frequency would provide a feeder service that penetrates areas too far to be otherwise easily reached from the station. Starting with an income profile of the city's residents, we estimate what households can afford to pay for housing. Then, assuming cross-subsidized differential pricing of land for different income groups, we determine the financial viability of any particular site. Two specific sites in northern Mumbai are studied for their implementation problems. But the proposal is generic, and with altered assumptions could be applied internationally wherever the context allows. Keywords affordable housing / cross-subsidy / feeder rapid transit system / inaccessible peri-urban land parcels / interconnected transit system / land pooling / town planning scheme shirish b Patel is a civil engineer and urban planner, one of three original authors who first suggested the idea of new bombay (now navi Mumbai). He was in charge of planning, design and execution of the new city during its first five years. Address: nanda deep,