eChapters

Introduction

Definition of ‘urban’ areas varies from country to country. Consequently, it is difficult to provide a universally acceptable meaning of the term. The difficulty has been summarised by UN (1998) as follows: “because of national differences in the characteristics that distinguish urban from rural areas, the distinction between urban and rural population is not amenable to a single definition that would be applicable to all countries” (UN, 1998). In many cases the divide between a rural and an urban area is based on the minimum population, but the number varies widely between the countries, e.g., 200 in Iceland, 2000 in some countries of West Asia, 5000 in India, and 10000 in Italy! Despite this challenge, most towns and cities are historical phenomena and have their defined administrative boundaries for services and other purposes, including municipalities. These places straight away qualify as the urban centres.

In India, the word has been defined by the Census of India (2001) as: “(a) All statutory places with a municipality, corporation, cantonment board or notified town area committee, etc.; (b) A place satisfying the following three criteria simultaneously: (i) a minimum population of 5,000; (ii) at least 75 per cent of male working population engaged in non-agricultural pursuits; and (iii) a density of population of at least 400 per sq. km (1,000 per sq. mile).” This definition was adopted for the 2011 Census.

Introduction 
Jatropha, a genus belonging to the Euphorbiaceae family, comprises 175 species and has its origins in tropical America and Mexico, later spreading to the tropics and subtropics of Asia and Africa (Divakara et al., 2010). In Asian countries, India, China, and Myanmar account for more than 85% of Jatropha cultivation, while Africa and Latin American countries like Brazil and Mexico make up 12% and 2%, respectively. India stands as the largest cultivator of Jatropha (Kumar and Sharma, 2008). Historically, Jatropha has been utilized for various purposes, including storm protection, soil erosion control, firewood, hedges, and traditional medicines (Openshaw, 2000; Gubitz et al., 1999; Heller, 1996; Kaushik and Kaushik, 2011). The seed oil of Jatropha has also been used as lamp fuel, soap manufacturing ingredient, paints, and lubricant (Gubitz et al., 1999; Achten et al., 2007; Brittaine and Lutaladio, 2010). The characteristics of Jatropha seed oil closely resemble those of diesel (Pramanik, 2003; Foidl et al., 1996; Augustus et al., 2002), earning it the title of a biodiesel plant (Pandey et al., 2012). Jatropha thrives on diverse wastelands without requiring agricultural inputs like irrigation and fertilization and its seeds contain 40 to 60% oil content (Pandey et al., 2012; Achten et al., 2007). The plant’s easy propagation, rapid growth, drought tolerance, pest resistance, higher oil content compared to other oil crops, adaptation to a wide range of environmental conditions, short gestation period and optimal plant size and architecture which facilitate seed collection (Divakara et al., 2010), make it a promising crop for biofuel production (Abou Kheira and Atta, 2009; Fairless, 2007). The oil extracted from Jatropha curcas L. is primarily converted into biodiesel for use in diesel engines. The protein-rich cake resulting from oil extraction can be used as fish or animal feed after detoxification. Additionally, it serves as a biomass feedstock for electricity generation or biogas production and is a high-quality organic fertilizer (Gubitz et al., 1999). Crop improvement in Jatropha curcas L. focuses on enhancing its potential as a biodiesel feedstock by addressing challenges like low yield, variable oil content and narrow adaptability. Efforts in selection and breeding aim to identify highyielding genotypes with desirable traits such as high oil content, early maturity and resistance to pests and diseases. Hybridization and mutation breeding are used to introduce genetic diversity and develop improved varieties suited to diverse environmental conditions. Biotechnological approaches, including genetic engineering and marker-assisted selection are employed to accelerate

The exile of Rama and his journey to the forests (vanvasa) for 14 years was started from Ayodhya (Uttar Pradesh, India) and ended to Lanka (Sri Lanka), through different forests, territorial regions, lands, hills, lakes of old India. The whole journey to those places was candidly portrayed in Ramayana with vivid descriptions, from narrations of the night sky, the position of different stars to descriptions of the flora, fauna and landscape. In this chapter, a retrospection of the places, forests, Rama passed through during his entire journey has been documented. The present status of those forests and places has been considered to evaluate a comparison over the thousands of years and the changes taken place besides significance they hold till date (Anonymous, 2024; Iyer, 2014).

Journey to the Forest and Route Map

Ayodhya, the capital city, kingdom of Kosala, was situated on the banks of holy river Saryu and was the birthplace of Rama. To fulfill the wish of his father, king Dasharatha, Rama left Ayodhya for 14 years of exile to the forest, along with Sita and Lakshmana. Their journey started from Ayodhya and passed through different places / forests.

The Resource of Land
One limited natural resource is land. The resource-generating regions found in terrain forms such as hills, valleys, plains, river basins, and wetlands are essential to the livelihood of the inhabitants. An ordered combination of minerals, organic matter, living things, air, and water is called soil. The soil is bound together by grass and tree roots. Land becomes unproductive and turns into wasteland when trees are reduced in size or grasslands are overgrazed.
Land is a valuable resource because it supplies the necessary substrate for the growth of vegetation, forestry, agriculture, and other industries. Approximately 54% of India’s land is used for agriculture. Land is necessary for man to construct dwellings, cultivate food, maintain pastures for domesticated animals, create towns and cities to support industries, and develop industries to produce things.
Degradation of Land
It can be characterized as any alteration to the land that lowers its quality or condition and, consequently, its capacity for yield. It happens anytime human activity alters the natural equilibrium of the environment through abuse or overuse. The main issues with land degradation are:
• Erosion by wind
• Water erosion including large-scale hillside movement
• Salinity of dry terrain
• The salinity caused by irrigation
• Surface scorching of soil
• Logging using water

Abstract

Continental erosion and fluvial transport play an important role enhancing mobilization of organic carbon from soils and transferring this pool to the ocean through downstream rivers and streams. The Ganges-Brahmaputra river system represents one of the largest transporters of terrestrial carbon to ocean. Intensive agriculture in the Ganges basin coupled with atmospheric deposition (AD) of nitrogen may render the soil more prone to erosion loss of carbon and nutrients. The aims of this study were to quantify atmospheric deposition of nitrogen (AD-N) in the watershed and to assess the influence of land use and AD-N on carbon and nitrogen transport in Ganga River. We collected samples in summer low flow along a 1595 km long transect of the river to assess the status of DOC under variable land use and AD-N input and, at monthly intervals along a 35 km long transect to understand seasonal patterns and the influence of local control. Our study shows average deposition of reactive-N (NO₃^- + NH₄⁺) range from 19.7 kg ha^-1yr-1 in upper stretch to 38.6 kg ha-1yr-1 in the middle stretch. The AD-N in lower stretch was almost similar to the values recorded in the middle stretch of the watershed. The average concentrations of dissolved organic carbon (DOC) and dissolved inorganic nitrogen (DIN) in the river range from 0.62 to 5.3 mg L-1 and 52.0 to 385.6 µg L-1 respectively. The land-derived carbon and nitrogen emerging in surface runoff showed positive correlation with AD-N and the river DOC showed synchrony with land use, AD-N and autochthonous carbon pool. Our data indicate that DOC in Ganga River is rising and the land use together with AD-N is an important driver of rising DOC. We suggest that future climate model should consider large scale regional time series data on changing state of atmosphere-land-water coupling and associated shifts in carbon and nutrient transport of major rivers. This has relevance predicting region specific climate change drivers and preparing action plan for integrated river basin management (IRBM).

4.1. Introduction

Presently, in the world, there are 195 countries according to the United Nations, and the number would even go up to 247 if we consider the disputed territories like Isle of Man, Hong Kong, etc. (United Nations, 2016) (Kershner, 2020). But the majority of the countries are still struggling to provide basic life-supporting amenities like nutrition, shelter, and employment. Conjointly, termed as emerging and developing countries such as India, Vietnam, Venezuela, Utopia, etc. (Ahmed and Shimada, 2019). Most of the developing countries are situated mainly in the continent of Africa, Asia and South America. They have got independence for the European countries like England, France, Portugal and Spain in the mid and late 20th century. 

General Introduction 
Growing populations and industrialisation around the world are driving up energy demand, which increases reliance on fossil fuels. The World Energy Forum projects that global stocks of fossil fuels like coal, natural gas, and oil will run out in less than ten years and decades [1]. Fossil fuels account for 88.1% of total energy consumption; they include coal (43%), oil and other liquids (23%), waste (6%), natural gas (6%), and biomass (24%). Hydroelectricity, and nuclear energy, on the other hand, share relatively small percentages of energy (1% and 2%, respectively) [2]. Petro-diesel, also known as petroleum diesel, is currently utilized as a fossil fuel and is created when crude oil is fractionally distilled at temperatures between 250°C and 350°C under atmospheric pressure. Once heated to a certain degree, the different types of diesel fuel are formed via the vaporization of hydrocarbon chains and the isolation and blending of constituents in a prescribed ratio. Typically, 25% of the petrodiesel’s composition consists of aromatic hydrocarbons and 75% of saturated hydrocarbons. The combustion of diesel fuel releases sulfur, nitrogen, and particulate matter into the environment, which are all present in significant concentrations in petro-diesel. Moreover, burning fossil fuels has resulted in several environmental problems, such as greenhouse gas emissions (GHG), which have a major impact on global warming, climate change, and a host of other chronic illnesses [3]. India is ranked as the fourth-biggest importer and user of petroleum products and crude oil. With demand for oil reaching about 4.1 million gallons per day in 2015, there is a growing disparity between India’s oil supplies and supply. The IEA analysis predicts that beyond 2050, there won’t be any oil reserves and that India’s oil consumption will increase by 6.0 million barrels per day to 9.8 mg/d in 2040 [4]. Two-thirds of the growth in oil demand and 16% of the increase in

Introduction 
A major challenge facing the world today is making the transition to a sustainable and resource-efficient economy, especially considering climate change, resource depletion, and rising waste production. The idea of a circular economy has drawn a lot of attention in this setting. In contrast to the conventional linear economic paradigm of “take-make-dispose,” the circular economy prioritizes closed-loop solutions that reduce waste and environmental impact by reusing, recycling, and regenerating resources. The efficient use of biomass as a plentiful and renewable resource to produce biofuels, biochemicals, and bio-based products is a crucial part of this circular framework. The combination of cellulose, hemicellulose, and lignin, known as lignocellulosic biomass, is one of the most widely available and sustainable types of feedstocks for biomass. Originating from forestry byproducts, specific energy crops, and agricultural residues like corn stover and wheat straw, lignocellulosic biomass is a feasible substitute for raw materials derived from fossil fuels [1]. By minimizing reliance on non-renewable resources and supporting sustainable waste management, its conversion through biorefineries into a wide range of bio-based goods is fully in line with the concepts of the circular economy [2]. Integrated systems known as lignocellulosic biorefineries maximize resource efficiency and reduce environmental impact by converting all the components of biomass into marketable products. The production of biofuels (such as bioethanol and biodiesel), platform chemicals, bioplastics, and energy by these biorefineries greatly aids in the creation of renewable energy and sustainable industrial processes [3]. Biorefineries can maximize the utilization of biomass feedstocks by converting them into high-value products while upholding zero-waste principles by utilizing a variety of biochemical and thermochemical conversion processes [4]. A summation of the function of lignocellulosic biorefineries in promoting the circular economy is given in this chapter. The first section covers the current developments in pretreatment and conversion methods as well as the composition of lignocellulosic biomass. By incorporating these technologies into biorefinery systems, waste valorization and energy efficiency issues can be resolved, and biobased goods can be produced more effectively. This chapter also examines the prospects and problems faced by lignocellulosic biorefineries, looking at their technological, economic, and regulatory elements as well as how they might help with the worldwide transition to a circular bioeconomy.

1. Introduction
Increasing population, industrialization, and change in the human lifestyle have become the reason for the exhaustion of non-renewable energy sources, our prime energy resource. The combustion of non-renewable energy sources produces toxic pollutants such as CO2, CO, NOx, SO2, etc., and greenhouse gases CH4, CO2, and N2O which significantly contribute to global warming, environmental pollution, and health hazards. In the current scenario, we need a green energy source that does not generate toxic gases and is eco-friendly. Hence, the research is triggered towards finding alternative solutions to overcome the energy crisis. The various green energy sources are solar, wind, tidal, geothermal, hydropower, biomass, hydrogen fuel cells, etc. The major drawback of these sources is the geographical location to install the plants. In the present context, identifying an alternate energy source that is sustainable, renewable, and eco-friendly to overcome the ever-growing energy demands is crucial. Hence, bioenergy is an eco-friendly, economical, and sustainable source of energy that gratifies the contemporary development environment by utilizing the potential of renewable organic energy resources (Yin and Wang et al., 2022).
2. Biomass
The sources of biomass are agro wastes, wood wastes, aquatic wastes, municipal wastes, wet wastes, industrial wastes, forest residues, etc. Figure 1.1 illustrates various sources of biomass, such as agricultural leftovers, forestry waste, energy crops, and organic municipal waste, showcasing their potential as renewable energy resources. Biomass is the product of photosynthesis and is also a versatile renewable energy source that can be utilized for sustainable biohydrogen generation. Biomass absorbs atmospheric CO2 during its growth, leading to relatively a lower net carbon impact as compared to fossil fuels. Renewable organic resources (biomass) can be in a solid, liquid, or gaseous phase. Energy generation through the incineration of biomass has been a longstanding practice. Since the energy potential of the biomass is not extracted effectively, it leads to environmental pollution (Kumar and Fiori et al., 2024). Biomass can be converted to liquid and gaseous fuels called biofuels with significant calorific value through thermochemical and biochemical processes (Gautam et al., 2020). Biofuels are superior to fossil fuels in the context of sustainability and reduced emissions of greenhouse gases. A variety of biofuels and chemicals such as bio-ethanol, biodiesel, acetic acid, formaldehyde, etc., can be manufactured from biomass (Gautam et al., 2020). Globally, research is advancing towards replacing non-renewable fuels with biofuels. However, the transition to biofuel technique presents a challenge due to the huge space requirement for biomass. Table 1.1 illustrates the categories of biomass employed for hydrogen generation, categorized into lignocellulosic materials, algal biomass, organic waste, and energy crops.

Despite the meticulous methodology and extensive analysis employed throughout this research project, it is crucial to acknowledge and address the limitations that arose during the study. By recognizing these limitations, we not only ensure a transparent evaluation of the research process but also shed light on potential areas for future investigations to refine and expand upon the findings.

In this section of the chapter, the limitations encountered in this thesis are highlighted as follows:

1. Due to the complexity of the concept, obtaining quantitative responses proved to be exceedingly challenging.

2. The development of improved scales for scoring could have enhanced the research if implemented.

3. The inclusion of a greater number of relevant variables could have provided a more comprehensive and in-depth understanding of the research topic.

4. Deploying mathematical optimization and simulations could have effectively integrated and co-integrated the seemingly disparate aspects of climate change perception, uncertainty perception, and perception of agricultural dynamics.

5. Presently, farmers are hesitant to engage in conversations and provide data to individuals outside their close social circles.

9.1 Introduction

Biomass conversion is a transformative process that harnesses the energy and chemical potential of organic materials derived from living organisms. It encompasses various methods of converting biomass, including agricultural residues, forestry by-products, algae, and even waste materials, into valuable products such as biofuels, chemicals, and energy. This process is a cornerstone of sustainable resource utilization and plays a critical role in addressing environmental concerns, reducing reliance on fossil fuels, and promoting a circular economy. Biomass conversion methods range from biochemical processes like fermentation and anaerobic digestion to thermochemical processes such as combustion, pyrolysis, gasification, and liquefaction. Each method employs distinct conditions, catalysts, and technologies to break down complex biomass structures and convert them into desired products.

Algae are organisms that grow in an aquatic environment and use light and carbon dioxide (CO2) to produce biomass. There are two categories of algae: macroalgae and microalgae. Macroalgae, measured in inches, are large multicellular algae that often grow in ponds. Macroalgae refers to thousands of macroscopic and multicellular seaweed species. The term includes some species of macroalgae such as Rhodophyta (red), Phaeophyta (brown), and Chlorophyta (green). Algae species such as kelp provide important breeding habitats for fisheries and other marine species, thereby protecting food sources; Other species such as plankton algae play an essential role in carbon sequestration and produce up to 90% of the Earth’s oxygen. Macroalgae, or large seaweeds, grow very rapidly and can reach extraordinary lengths up to 60 meters (McHugh, 2003). Their growth rates are much higher compared to many land plants. For example, wild brown algae can yield between 3.3 and 11.3 kg of dry biomass per square meter each year, and cultivated varieties can produce up to 13.1 kg in just seven months. In contrast, sugarcane, which is known for its high productivity, typically produces 6.1 to 9.5 kg of fresh biomass per square meter per year (Kraan. 2010). Additionally, macroalgae are available naturally in water bodies on a seasonal basis, and farming them in the ocean does not require traditional farming land or fertilizers. This makes them a promising option for addressing energy needs, as they are not only used for food and hydrocolloid extraction but also have potential for ethanol production. Humans have a long history of growing algae for uses such as food, food additives, feed, textiles and papers, bio-plastics. In recent years, seaweed farming has become a worldwide agricultural practice, providing food and feedstock for various chemical uses such as carrageenan, animal feed, biofertilizers and growth promoters. Due to its importance in marine ecology and carbon uptake, recent attention has focused on kelp farming as a potential climate change mitigation strategy for carbon dioxide biocapture, along with other benefits, such as reduced nutrient loads and increased habitat for coastal aquatic species, and reduced local ocean acidification in addition to biofuel opportunities. The seven most commonly cultivated algal taxa are Eucheuma spp., Kappaphycus alvarezii, Gracilaria spp., Saccharina japonica, Undaria pinnatifida, Pyropia spp. and Sargassum fusiform. Eucheuma and K. alvarezii are cultivated for carrageenan (a gelling agent); Gracilaria is grown for agar; while the rest is grown for food. Macroalgae production has become a cornerstone of global aquaculture, serving diverse industries such as food, biofuels, and pharmaceuticals

12.1 Introduction

A magneto hydrodynamic energy conversion system or MHD system converts heat energy directly into electricity. An MHD generator produces electricity via the interaction of a moving fluid with a magnetic field and ionized gas. MHD conversion does not involve any mechanical conversion intermediary. As a result, this process offers substantial fuel savings because the process of producing mechanical energy and then converting it to electrical energy is eliminated. It is possible to generate electricity in large quantities using MHD power plants while reducing the impact on the environment. During his Bakerian lecture in 1832 to the Royal Society, Michael Faraday presented the concept of MHD power generation for the very first time. 

Introduction 
Maize (Zea mays L.) which belongs to the Poaceae family, has its roots in the American continent where it was once grown by ancient cultures like the Indians, Magyars, and Aztecs. Today, maize is one of the most widely cultivated crops globally, with the largest productions in countries such as the US, China, India, and Brazil. As a monocotyledonous and cross-pollinated annual plant, maize is an angiosperm with seeds enclosed in a fruit or shell. The root system of maize is fibrous, reaching up to 60 cm. in soil depth. Maize is a warm-season crop with specific agro climatic requirements for successful cultivation. It thrives in warm temperatures and requires a minimum temperature of around 10°C (50°F) for germination. The ideal temperature range for its growth is between 20°C and 30°C (68°F to 86°F). However, maize is sensitive to frost, and exposure to freezing temperatures can damage or kill the crop. Adequate and well-distributed rainfall is crucial during its growing season, as maize needs about 500 to 1000 mm. (20 to 40 inches) of rainfall to support its development, with higher water requirements during flowering and grain-filling stages. While the crop is moderately droughttolerant, moisture stress at critical growth stages can significantly impact yield. Maize is a sun-loving crop and requires long daylight hours with ample sunshine for efficient photosynthesis and plant growth. The soil should be well-drained, loamy or sandy, rich in organic matter, and have a pH ranging from 5.8 to 7.0 (Greaves et al., 1996). Avoiding waterlogged or compacted soils is crucial, as they can impede root development and nutrient uptake. Maize can be cultivated at varying altitudes, but its suitability is generally limited to elevations below 2,500 meters (8,200 feet) above sea level. The crop typically requires 90 to 120 days from planting to maturity, although some varieties with shorter growing seasons are available for regions with limited frost-free periods. High salinity can result in decreased plant leaves, green weight, fresh weight, shorter shoots, and root length but salt-tolerant varieties have been developed.

In his classic book ‘The Ascent of Man’, Bronowski has written, “When I was a young man, we all thought that mastery came from man’s domination of his physical environment. Now we have learned that real mastery comes from understanding and moulding the living environment.” Our Biosphere, the living environment that supports us all, has problems and we humans are mainly responsible. We do not live ‘gently’ on the earth. The seven billion of us require air, water, food, energy, housing and amenities and we have developed the earth to provide them and have also created problems. That the problems exist are serious is the bad news. That we are recognizing them and that man has shown ability to organize and grow in ascending order from time to time is the good news.

Introduction
Marine Pollution
The pollution of the sea substances that humans have directly or indirectly introducedinto the marine environment, which can have negative impacts on the ecosystem, including health risks to people, obstructions to marine activities, and a decline in the quality of seawater.
It happens when invading species or chemicals or particles or garbage from industry, agriculture, or residential sources find their way into the ocean and can have detrimental impacts.
The majority of maritime pollution originates on land. Nonpoint causes of pollution include wind-blown debris and agricultural runoff.
A great deal of potentially harmful substances stick to small particles, which plankton and benthos animals (most of which are deposit or filter feeders) then consume.
Pesticides swiftly find their way into marine food webs after entering the marine ecology. These pesticides can induce diseases and mutations once they enter food webs, which can be dangerous for both humans and the entire food chain.
Marine food webs may also be exposed to toxic metals. These have the power to alter biochemistry, behavior, reproduction, tissue composition, and growth inhibition in marine organisms. Additionally, a lot of animal diets contain a lot of fish meal or fish hydrolysate. Toxins from the sea can thus spread to land animals and then show up in meat and dairy products.

The research methodology constitutes a comprehensive and well-structured plan of action for conducting the investigation and serves as a blueprint for the research process. Its purpose is to gain an understanding of the underlying concepts, methods, and techniques employed to define the study, gather relevant information, analyse data, and interpret the findings, thereby revealing concrete evidence and formulating theories.

In this chapter, an in-depth exploration of the research methodology is undertaken to comprehend the concepts, methods, and techniques employed for designing the study, gathering data, conducting data analysis, and interpreting the results. To facilitate clarity and ease of comprehension, the chapter has been divided into the following sub-headings:

1. Research Design

2. Locale of research

3. Pilot study

4. Sampling Design

5. Variables and their Empirical measurement 6. Methods of Data collection

7. Preparation of Interview Schedule

8. Item analysis and Expert’s rating for devising scoring technique for variables

9. Pre-testing of Interview Schedule

10. Data Processing and Analysis for FCM

11. Statistical Tools used for Data Analysis

12. Software used for Data Analysis

Introduction

Flat plate collector is the heart of a solar heat collection system designed for delivery of heated fluid in the low to medium temperature range (5o70oC above ambient temperature) for applications, such as water heating, space heating, drying and similar industrial applications. The flat plate collectors absorb both beam and diffuse radiation. The absorbed radiation is converted into heat which is transferred to water or air flowing through the collector tubes or duct, respectively. Such collectors do not require tracking of the sun and little maintenance is required.

The conventional flat plate solar air heater, shown in Fig. 7.1, consists of a flat blackened absorber plate, a transparent cover (such as a glass cover) at the top and insulation at the bottom and on the sides. The air to be heated flows through the rectangular duct below the absorber plate. The glass cover transmits a major part of solar radiation incident upon it to the absorber plate where it is converted into heat. The glass is, however, opaque to longwavelength radiation and thus it does not allow the infrared radiation from the heated absorber plate to escape.

Karwa et al. (2002) have presented the following deductions of heat collection rate and pumping power equations for the flat plate solar air heater.

Surface-Enhanced Raman Spectroscopy (SERS) may detect and identify chemical and biological species ultrasensitively. Through localized surface plasmon resonance (LSPR) effects, metal nanostructures boost analyte Raman signals. This chapter covers current advances and essential principles in metal nanostructures for SERS chemical detection. It discusses SERS fundamentals and enhancing processes, such as metal nanostructure size, shape, and composition. Top-down and bottom-up processes including lithography, chemical synthesis, and self-assembly are used to create repeatable and controllable metal nanostructures. The complex interactions between light, metal nanostructures, and analyte molecules are best understood by combining theoretical modeling and experimental observations.