eChapters

7.1 Introduction

Evaporation is an unit operation which converts a liquid into a vapour, leaving behind a concentrated solution or a higher boiling liquid. In other words, the goal of evaporation is to vaporize most of the water from a solution containing a desired product. Heat is the main tool in evaporation, and the process occurs more readily at high temperature and low pressures. Removal of water from foods provides microbiological stability, reduces deteriorative chemical reactions, and reduces transportation and storage costs. Evaporation can be distinguished from some other drying methods in that the final product of evaporation is a concentrated liquid, not a solid. It also differs from distillation, since the vapours produced in the evaporator are not further divided into fractions.

10.1 Evapotranspiration (ET = Evaporation + Transpiration)

Evaporation is a diffusive process by which water from natural surfaces, such as free water surface, bare soil, from live or dead vegetation foliage (intercepted water, dewfall, guttation etc) is lost in the form of vapour to the atmosphere. It is one of the basic components of hydrologic cycle.

Likewise transpiration is a process by which water is lost in the form of vapour through plant surfaces, particularly leaves. In this process water is essentially absorbed by the plant roots due to water potential gradients and it moves upward through the stem and is ultimately lost into the atmosphere through numerous minute stomata in the plant leaves. It is basically an evaporation process. However, unlike evaporation from a water or soil surface, plant structure and stomatal behaviour operating in conjunction with the physical principles governing evaporation modify transpiration.

Thus, evapotranspiration is a combined loss of water from the soil (evaporation) and plant (transpiration) surfaces to the atmosphere through vaporization of liquid water, and is expressed in depth per unit time (for example mm/ day). Quantification of evapotranspiration is required in the context of many issues:

In cropped soils, evaporation refers to evaporation of water from the soil and transpiration refers to evaporation of water from plant canopies (Fig.6.1). Evaporation and transpiration play very significant role in mass and energy transfer. The latent heat of vaporization is defined as amount of heat required to evaporate 1 gm of water at a temperature of 100°C; i.e. the boiling point of water is 540 cal/gm. The amount of heat required for evaporation of water at ordinary temperature of about say 30°C is 610 cal/gm.
Fig. 6.1: Process of evapotranspiration
The evapotranspiration from crop depends upon several factors as indicated below:
• The evapotranspiration increases with increase in air temperature.
• The evapotranspiration increases with increase in wind speed up to a certain limit.
• The evapotranspiration decreases with increase in relative humidity
• The evapotranspiration increases with increase in Saturation Vapor Pressure Deficit (SVPD). SVPD = es – ea

Evapotranspiration is the combination of two separate processes named evaporation and transpiration. Evaporation accounts for the movement of water to the air from sources such as the waterbodies and soil. Transpiration accounts for the movement of water within a plant and the subsequent loss of water as vapour through stomata in its leaves. So evapotranspiration is a bio-physical process.

Evaporation

The change of state of water from liquid to the vapour and its diffusion into the atmosphere is referred to as evaporation. During evaporation, water molecules absorb energy which gives them the motion required to escape from the surface of liquid and become a gas. Since a certain amount of energy is consumed in the process of evaporation, the remaining liquid is cooled by an equivalent amount. Thus, the process of evaporation is always accompanied by a cooling effect.

As evaporation proceeds, the surrounding air becomes gradually saturated with water vapour and the process will slow down and might stop if the wet air is not transferred to the atmosphere. The replacement of the saturated air with drier air depends greatly on wind speed. Hence, solar radiation, air temperature, air humidity and wind speed are meteorological parameters to be considered when assessing the evaporation process.

In agrometeorology, evaporation is defined as the maximum possible loss of moisture from a wet, horizontal, flat surface exposed to weather parameters, which exist in the vicinity of plants. Evaporation is an essential part of the water cycle. It is the primary pathway through which water moves from the liquid state back into the water cycle as atmospheric water vapour. The oceans, seas, lakes and rivers provide nearly 90 per cent of the moisture in the atmosphere via evaporation, with the remaining 10 per cent being contributed by plant transpiration. A very small amount of water vapour enters the atmosphere through sublimation, the process by which water changes from a solid (ice or snow) state to a gaseous one, bypassing the liquid phase.

The movement of water from soil to the crop canopy and leaves to provide water for transpiration and the effect of weather factors on transpiration is most important area of study. When the crop is just sown, there will be an only evaporation of water from the soil. After germination of seeds there will be emergence of seedlings. After the emergence of seedlings there will be formation of leaves. The small leaves start intercepting the incoming solar radiation and absorb some portion of solar energy, get heated and there will be evaporation turn off water from the stomata of the leaf. When water vapour escapes into the atmosphere through the stomata of leaf, the plant absorbs carbon dioxide which results in photosynthetic activity. During night time, there will not be any photosynthesis due to absence of sunlight. The plants use parts of the photosynthetic accumulate for its metabolic activity and the process is called maintenance respiration. The balance of the photosynthetic accumulate contributes to the expansion of leaves and increased dry matter accumulation in crop plans. The process of dry matter accumulation in plants is called crop growth. When the seedlings start growing, there will be formation of tillers or branches. When the leaves grow it reaches a stage when the crop will be completely shading the ground and the soil evaporation will be minimum and maximum amount of water is lost only through evapotranspiration (Fig.6.1).

19.1 Introduction

The combination of two separate processes whereby water is lost on the one hand from the soil surface by evaporation and on the other hand from the tree by transpiration is referred to as evapotranspiration (ET).

19.2 Evaporation

Evaporation is the process whereby liquid water is converted into water vapour (vaporization) and removed from the evaporating surface (vapour removal). Water evaporates from a variety of surfaces, such as lakes, rivers, pavements, soils and wet vegetation. (Penman, 1963).

Energy is required to change the state of the molecules of water from liquid to vapour. Direct solar radiation and, to a lesser extent, the ambient temperature of the air provide this energy. The driving force to remove water vapour from the evaporating surface is the difference between the water vapour pressure at the evaporating surface and that of the surrounding atmosphere. As evaporation proceeds, the surrounding air becomes gradually saturated and the process will slow down and might stop if the wet air is not transferred to the atmosphere. The replacement of the saturated air with drier air depends greatly on wind speed. Hence, solar radiation, air temperature, air humidity and wind speed are climatological parameters to consider when assessing the evaporation process.

Where the evaporating surface is the soil surface, the degree of shading of the tree canopy and the amount of water available at the evaporating surface are other factors that affect the evaporation process. Frequent rains, irrigation and water transported upwards in a soil from a shallow water table wet the soil surface. Where the soil is able to supply water fast enough to satisfy the evaporation demand, the evaporation from the soil is determined only by the meteorological conditions. However, where the interval between rains and irrigation becomes large and the ability of the soil to conduct moisture to pear the surface is small, the water content in the topsoil drops and the soil surface dries out. Under these circumstances the limited availability of water exerts a controlling influence on soil evaporation. In the absence of any supply of water to the soil surface, evaporation decreases rapidly and may cease almost completely within a few days.

Humans possess an innate tendency to preserve their experiences and knowledge. Throughout evolution, this inclination led to the recording of text and images on materials such as stone, rock, leaves, bark, and eventually paper. The desire to preserve not only written and visual content but also sound culminated in the invention of sound recording in the late 19th century. This innovation enabled humanity to capture and reproduce auditory experiences.

In 1924, Western Electric in the United States developed the first electromagnetic sound recording machine. This device marked a significant advancement, as it allowed for the conversion of acoustic waves into electrical signals that could drive a stylus to inscribe the sounds onto a medium, such as wax records. Over time, the technology evolved, leading to the widespread adoption of electromagnetic recording on plastic tapes coated with materials like ferrous oxide and ferric oxide. The late 20th century saw the introduction of Compact Discs (CDs), followed by DVDs and Blu-ray discs. Today, sound recordings are commonly stored on hard drives, flash drives, and memory cards.

The geologists of the Indian subcontinent have all along been of the opinion, that, the southern part of the Indian Peninsula is a stable shield area. But, the recently acquired IRS-1A image of June, 1988 vividly displays spectacular geomorphic anomalies suggesting that this part of the Indian subcontinent is prone to earth movements. In order to unearth more evidences on such earth movements / neotectonism in Tamil Nadu, the IRS-1A image of Coromandel coast of Tamil Nadu was analysed ( Fig. 1).

OBSERVATIONS

• The IRS-1A image conspicuously displays three contrasting morphotectonic domains in the study area marked by the western undissected Tertiary upland (Vallam upland), central highly dissected Tertiary upland (Pattukottai -Mannargudi upland) and the eastern Cauvery delta (Fig 1 and 2). These three domains are separated by two conspicuous N-S trending lineaments (E and F, Fig.1 and 2) namely the Tanjavur - Avadaiyarkovil lineament in the west and Kumbakonam -Muttupet lineament in the east.
• In addition, two more E-W trending lineaments (G and H, Fig.1 and 2) are also observed trifurcating the undissected Vallam upland into three blocks.
• Along these lineaments, especially the Tanjavur -Avadaiyarkovil and Kumbakonam -Muttupet lineaments, the rivers show conspicuous drainage anomalies in the form of drainage deflection, drainage compression etc., wherever they transect the lineaments.

Introduction

Advertising is an integral component of modern commerce and communication. It has evolved from primitive oral traditions to sophisticated digital marketing strategies. This chapter explores the historical evolution of advertising, from ancient civilizations to the digital age, and provides a scholarly analysis supported by bibliographic references.

Early Forms of Advertising

The earliest forms of advertising date back to ancient civilizations. Merchants in Mesopotamia and Egypt used papyrus posters and inscriptions to announce products and services (Presbrey, 1929). Ancient Greek and Roman societies

Introduction Agricultural extension plays a pivotal role in the advancement of agriculture in any nation. It encompasses the dissemination of knowledge, guidance, and assistance to farmers, rural communities, and various stakeholders involved in the agricultural domain. The primary objective of agricultural extension is to empower farmers to enhance their productivity, income, and overall quality of life. The concept of agricultural extension has undergone significant transformations across various countries, including India. This article will delve into the historical progression of agricultural extension both internationally and within the Indian context.

Agricultural extension plays a critical role in bridging the gap between research and farmers by disseminating knowledge, improving skills and enabling farmers to adopt new practices that can boost productivity and sustainability. Over the years, the role of extension has evolved from a focus on productivity to a more holistic approach, which now includes market orientation, environmental sustainability and rural development. Evaluating the role of extension involves examining its contributions to rural livelihoods, food security and the broader agricultural ecosystem.
Impact on Productivity and Food Security: Extension services have traditionally aimed to increase agricultural productivity through technology dissemination and best practices, contributing significantly to food security in countries like India.
Market and Value Chain Linkages: Modern extension efforts emphasize connecting farmers to markets, enhancing income potential, and promoting value addition, especially through initiatives like FPOs and ICT-based tools.
Environmental Sustainability: With a rising focus on climate resilience, extension has expanded to educate farmers on sustainable practices, water conservation, soil health, and organic farming.
Empowerment and Community Development: Extension now goes beyond agriculture, aiming to empower rural communities by encouraging selfreliance, entrepreneurship, and participatory decision-making.
The evolution of agricultural extension in India reflects a dynamic journey shaped by various agricultural challenges, government policies, and the changing needs of rural communities. The main stages in the development of agricultural extension in India are as follows:
A. Pre-Independence Period (Before 1947)
Here’s a brief overview of each pre-independence rural development program along with their objectives and significance:

Agriculture has progressed from labour-intensive traditional practices through mechanization and the Green Revolution to precision agriculture and Agriculture 5.0. This chapter traces that historical development and identifies limitations associated with conventional farming, including inefficient resource use, environmental degradation and weak adaptability. It explains how GPS-guided machinery, sensors and precision technologies prepared the foundation for intelligent systems. Artificial neural networks, deep learning and fuzzy logic now process data from IoT devices, UAVs and satellites to support automated irrigation, crop monitoring and soil analysis. The chapter emphasizes that integrating human knowledge with computational power is increasingly essential for global food security, sustainability and climate resilience.

Introduction

Baking is not a new concept to us. Baking process dates thousand years back since the Paleolithic age. During those days, the baking was done by simply grinding the grains, mixed with water and baked on the hot rocks. The bread produced that time was not leavened but flat. Ancient Egyptians have the credit for development of baking between 2600-1200 BC. Roman Empire also had the popularity of the art of baking and bakeries were in existence in Europe too during Middle Age. Baking was considered a highly respected profession under the Roman Empire. The art of baking has travelled a long journey since then. The bakery and confectionary has undergone a gradual evolution with time. Great technical progress stared in the nineteenth century. Development of automatic machines reduced the task of the manual labour and because of this development the bakers could perform many more tasks with the machines. Today’s baking has a dependency on the machines. All the work is performed by the automated machines whereas the bakers only control the machine operations. The baking process has become easier, the efficiency has increased and the quality of the products has improved because of these high-tech machines. The preparation of bakery products using traditional methods has also improved over the time to minimize the energy and time consumption. Today’s consumer is very much concerned about his/her health and look for the healthy options in baked products. The trend has led to various innovative formulations for the baked products so that the health benefits may also be provided not only the calories. This chapter will discuss various advancements and trends in different types of bakery and confectionary products.

The Rochdale Society of Equitable Pioneers was founded in Rochdale, England, in 1844 and soon became a prototype for cooperatives worldwide. Its governance structure, known as the Rochdale Principles, is still a key guideline for the design of cooperatives. The social dislocations of the Industrial Revolution inspired workers and enlightened entrepreneurs to establish cooperative societies since the beginning of the nineteenth century.

Abstract

Camelids across the world are reared for milk, meat, draught, race and tourism. Camelids are also the source of world’s finest natural fibre. They are distributed in the South American, African, Arabian and Asian countries. Apart from this a feral population exists in Australia and recent reports indicate that a few animals of the species are also being reared in Europe. Camel (Camelus dromedarius) is the predominant species of the camelids. The world camel population shows an increasing trend with 12.92 m in 1961 to 26.63 m in 2011 producing 0.42 m tonnes of meat and 2.11 m tonnes of milk per annum. The top 20 camel rearing countries produce both milk and meat with the exception of India and Pakistan as per FAO data. There are about 83 populations of the dromedary camels in the world spread mainly across African and Asian countries. There are about 3.04 m Alpacas in world with Huacaya and Suri as the two main populations and 3.24 m Llamas with Chaku and Kara as the two main populations. The Guanaco population in the world is about 0.5 m and that of Vicuna is 0.35 m. The wild Bactrian camels are around a thousand but the domesticated Bactrian camels are about 0.6 m. The Alpaca and Bactrian camel genome has been sequenced whereas the expressed sequence tags of the Dromedary are available in the public domain. A brief account of evolution, present status and conservation of camelids is discussed.

Modern farm planning involves nonlinear, discontinuous and multi-objective problems that conventional optimization methods may not solve effectively. This chapter examines Genetic Algorithms, Particle Swarm Optimization and Differential Evolution for improving agricultural resource allocation. These nature-inspired techniques can simultaneously address crop yield, water use, fertilizer application, environmental effects and financial viability. Their integration with deep-learning forecasts and crop-simulation systems enables more realistic optimization. Multi-objective evolutionary algorithms identify Pareto-optimal alternatives, allowing decision-makers to balance productivity and ecological sustainability. The chapter also emphasizes explainable artificial intelligence, economical implementation and farmer usability as necessary conditions for transferring evolutionary optimization methods from experimental research to practical farm management.

Origin of Species

A biological species is a group of reproductively isolated individuals

Speciation usually occurs via a branching process called cladogenesis

Divergent evolution can be allopatric, parapatric, or sympatric

Müntzing was able to re-create an allotetraploid species

Evolution can proceed gradually or be punctuated by periods of rapid change

Introduction

Agriculture is vital to the Indian economy in terms of job creation, with nearly half of the Indian population relying on agriculture and related activities for a living. A large proportion of the population, particularly in rural areas, is illiterate. The rural population, which is illiterate and ignorant, is unable to cope with the complexities of agricultural technology management. As a result, vocational training and technology dissemination are few viable options for increasing production efficiency and achieving rapid and sustainable agricultural development. The State of Odisha derives more than a quarter of its revenue from agriculture. More than 40% of the people in the state of Odisha depend on farming as their primary source of income and way of life, making up more than 53% of the state’s workforce. whereas agricultural technology has developed into a logical extension of the traditions, conventions, knowledge, and skills that date back to the early days of human civilization and have continued to evolve over time. It was not just agriculture that produced food or other biological means; rather, it essentially presented a wide range of traditional values to make it abundantly evident that “TECHNOLOGY and TECHNIQUE” are the cultural means to satisfy the biological as well as social demand for life. To provide the necessary acceleration to the agricultural development, Agricultural Technology Management Agency (ATMA) Scheme was launched during 2005-06 in order to enrich farmer’s skills, knowledge and competency several developmental programmes/projects, in agriculture and allied sectors. In the state Odisha, a district level autonomous institute has taken the main responsibility of all technology dissemination activities at district level for development of farmers and farm women through its bottom –up approach. During 2010 the reforms made in ATMA project and farm persons were given due importance to its multifarious activities like training, demonstration, information support, input supply, market-oriented facilities, linking credit and exposure visit etc. These multi-purpose activities provide ample opportunities for the farm communities and makes the resources accessible for them. Additionally, ATMA served as a link between individuals in need and those with the means necessary for undergoing rapid technological change. It is also critical to evaluate various stakeholders of ATMA in order to enhance both its organisational and functional approach. This includes various parameters such as efficiency of skilled professionals of ATMA, availability of resources and feedback from farmer beneficiaries among other factors.

In case of Allahabad, it is evident that a major thrust catapulting the city to an invincible position was experienced immediately after 1857. These changes in the character of Allahabad along its journey which witnessed the resurgence of the pilgrim town into a front ranking educational and cultural node also saw the shades of capital center and finally its transition into a low profile city which today has lost its vitality and seem to be comparable to a non functioning muffossil town of Uttar Pradesh. The facts and figures representing the key events and a survey of the city enable us to establish a direct relationship between the functions and performance of the city.

The first part of the chapter is based on the inferences from the study on Allahabad covered earlier. The second part deals with testing these facts on ground by conducting interviews with eminent individuals who had been deeply associated with education and cultural status of Allahabad. The third part consists of the final inferences. Some critical conclusions are also borne out reflecting a clearer understanding of the phenomenon of decline of Allahabad.