eChapters

Introduction

At the very outset, the varied aspects which govern the agricultural scenario in India have been taken up. Basically, India is a land of diversity and Indian climate defies an easy generalization. It comprises a wide range of weather conditions prevailing across a large geographic scale existing in the midst of varied topography. A systematic analysis reveals that Indian climate can be partitioned into six major climatic subtypes, ranging from deserts in the west, to the alpine tundra and glaciers in the north, to humid tropical regions supporting rainforests in the southwest and the island territories. The landform pattern is also found to be widely varying over places. Interestingly, tIndian soils can be divided into six categories, namely, alluvial soils, regular soils, red soils, laterite soils, mountain soils as well as the desert soils. Being a populous country whose sixty percent of the population earns its livelihood on agro-based incomes, directly or indirectly, it is important to review the robustness of the system followed in the actual practice in the Indian scenario towards the process of raising crops which ultimately feed more than hundred crores population. The review reveals that the agricultural production and farm incomes in India are frequently affected by the natural disasters such as droughts, floods, cyclones, storms, landslides as well as the earthquakes, and, indeed, the susceptibility of Indian agriculture to these disasters is compounded by the outbreak of epidemics and man-made disasters such as fire, sale of spurious seeds, fertilizers and pesticides, price crashes etc. As a sequel, the farmers are severely affected through the loss of production of agricultural crops and consequently, the loss of farm income due to occurrence of such events, and it is no denying that the management of or coping with such factors remains beyond the control of the farmers.

Scientists rely on a variety of endocrine, behavioral, autonomic nervous system and immunological end points to measure stress. Unfortunately, none of these measures has proved to be a litmus test for stress. Increased secretion of the adrenal glucocorticoids and cortisol has been found to be associated with stress and investigators frequently cite an increase in circulating cortisol as a proof of stress. Colborn et al., (1991) found that stallions secreted similar amounts of cortisol whether the stallions were restrained, exercised or permitted to mate with a mare. Serum cortisol concentrations are often used to evaluate stress, but due to the marked variability, faecal corticosterone has been used to evaluate stress in cattle (Morrow et al., 2002). Dairy cattle secrets cortisol during restrained and when approached by strangers. So it is difficult to simply use secretion of cortisol or any other hormone to differentiate between non threatening stress and distress. Further, complicating is inter animal variability in stress response. Even among the same breed some cows may produce more cortisol to the same amounts of thermal stressors.

ABSTRACT

A watershed is a topographically delineated area that is drained by a stream system, i.e. the total land area above some point on a stream or river that drains past that point. The watershed is a hydrologic unit that often is used as a physical – biological unit and a social – economic political unit for the planning and management of natural resources. Remote Sensing (RS) and Geographic Information System (GIS) techniques can be used effectively to generate the land use/land cover for evaluating the changes in an area. Conventional methods of runoff measurements are not easy for inaccessible terrain of Tamilnadu. Remote sensing technology can augment the conventional method to a great extent in rainfall-runoff studies. In this study, SCS Curve Number technique modified for Indian condition has been used for generation of CN for an ungauged watershed. A sub watershed of Manimuktha watershed is considered as study area. The daily rainfall data of Virudhachalam rain gauge station is collected and used to predict the daily runoff from the watershed using GIS based Soil Conservation Service -Curve Number (SCS – CN) method (USDA, 1972). Monthly and annual runoff values are obtained from the daily runoff values of the watershed. Base map, Soil map and Land use map of the study area are prepared by using Remote Sensing data and Survey of India (SOI) toposheets. PC Arc/Info GIS software is used for analysis.

Availability of genetic variability and exploitation of this variability are two basic requirements of successful crop breeding programmes. The presence of genetic variation in a character is a must for any improvement in that character. If all the individuals in a population are identical i.e. no variation is there, selection cannot be done, so no improvement will be done. In case of crops, if variation is not present or variation is very small, variations are created through hybridization, mutation, polyploidy etc. Selection is identification and isolation of desirable plants from a variable population. A population consists of large number of heterogenous individuals with different morphological expressions. This variability is contributed by three factors: 1. Genetic constitution of individual, 2. Environmental effect on the individual and 3. Interaction effect between gene and environment. These three factors contribute towards the phenotypic variability among the individuals of the population. Assessment of magnitude of variability present in a crop species is of utmost importance as it provides the evidence for effective selection. Phenotypic variation in a population arises due to genotypic and environmental effects.

Introduction

Agriculture is the main sector of the Odisha economy and contributes approximately 42% to the gross domestic product (GDP) and employs over 80% of the population. Despite its role, agricultural production is constrained by high climate variability where rainfall distribution is extremely uneven and this has negative implications for the livelihoods of people .Drought frequently results in crop failure, while high rainfall intensities result in low infiltration and high runoff causing enhanced soil erosion and land degradation. Land degradation in the form of soil erosion and declining land fertility is a serious challenge to agricultural productivity and economic growth (Lemenih, 2004).Studies indicate that the tribal district of Odisha have experienced high rates of soil erosion and deforestation, resulting in sediment accumulation in downstream reservoirs and rivers.

Abstract

Information and Communication Technology (ICT) played and continue to play pivotal role in better decision making of farmers for plant health management under the climate change scenario. For judicious plant health management by farmers through the use of ICT tools (viz. interactive Kiosk, Mobile Apps, Whatsapp, Webportal), information need and information access network to be assessed. Based on farmers’ information need and network, information delivery tree should be designed in ICT tools. Under this backdrop this research work was carried out among the farmers of Bhagalpur district of Bihar. The sample size was 120. From the study it was noted that the major information needs of the farmers were seed availability, crop disease management, insect pest management, weed management and weather information and pesticide application. Farmers were enthusiastic to improve their knowledge on insect pests and disease identification and management. Specifically, farmers need information on insect pest management of wheat (aphid), maize (stem borer), vegetables (fruit borer), pulses (pod borer) and oilseeds (aphid) and also disease management of wheat (leaf blight and spot blotch disease), maize (Turcicum leaf blight), vegetables (wilt and leaf spot) and pulses (wilt disease). Farmers decision making was positively and significantly correlated with crop disease management(0.196*),insect pest management of crop(0.208*) and weed management(0.239**). Through the Path Analysis it was noted that farmers decision making on disease management was mediated by the variables - Bihar Agricultural University-Kisan Diary, Mobile Apps(Bihar Krishi Apps) and Kisan Salahkar. So, it can be concluded that these much needed information should be provided to the farmers though different ICT tools and extension personnel should be trained to operate these ICT tools for accelerated use of ICT tools by the farmers.

In any work environment the managers, facilitators are equipped with some specific type of skills to perform their activity effectively. In this study, multi stakeholders were involved in the process of Precision Farming from land preparation to marketing. Every stakeholder has a specific task to be performed so as to lead the client in the direction desired. In order to achieve this, the skill components viz., Management and Facilitating skills possessed by them and their own perception on those skills were assessed.

The main objective of cropping system is to utilize the available resources in an efficient manner. There are several indices to evaluate the yield advantage of cropping system and also to compare the efficiency of different cropping system in terms of land use.

Assessment is a fundamental component of education because it provides evidence of learning, identifies gaps, and guides instructional improvement. Generative AI is creating new possibilities for making assessment more adaptive, personalized, responsive, and scalable. This chapter examines the transformation of assessment, evaluation, and feedback through generative AI technologies. It explores AI-supported generation of multiple-choice questions, essay prompts, programming tasks, case studies, simulations, rubrics, and other assessment resources. Generative AI can also provide rapid formative feedback, explanations, hints, and personalized learning activities based on individual student performance. These capabilities can reduce repetitive assessment tasks for educators while increasing the variety and flexibility of learning evaluations. The chapter considers applications across school education, higher education, vocational learning, and professional training. At the same time, it addresses concerns surrounding validity, reliability, fairness, transparency, academic integrity, bias, and inappropriate dependence on automated evaluation. Effective implementation therefore requires human oversight, appropriate assessment design, and continuous evaluation of AI-generated outputs. The chapter presents GenAI as both a disruptive force and a powerful enabler of contemporary educational assessment.

Introduction
Assisted reproductive technology (ART) refers to treatments and procedures in the field of reproductive biology that are utilised to achieve pregnancy by artificial or partially artificial means.
Artificial insemination
Artificial insemination (AI) is the earliest form of assisted reproductive technology. The technology has been of immense relevance in enhancing production and health features through the appropriate use of better male animals, as well as in eliminating certain venereal illnesses.
• Semen collection: The man is typically allowed to mount a phantom during the process. In cattle, an artificial vagina is used)
• Semen evaluation: Evaluating semen is crucial before processing. The most basic semen evaluation involves examining the concentration, progressive motility, and morphological normality of the spermatozoa)
• Semen dilution, packaging and freezing: Following examination, the semen is ready for dilution and packaging. Spermatozoa require storage mediums that are particular to each species. After packaging, the semen dosages must be properly maintained until insemination. Cryopreservation is typically used for cattle.
• Insemination: Insemination should occur during the female’s oestrus, when she is receptive to copulation.
Multiple Ovulation and Embryo Transfer (MOET)
The main processes are to stimulate a donor female to create suitable embryos, then remove the embryos from her and transfer them to unmated recipient females at equivalent post-ovulatory reproductive phases, ensuring that the donor’s embryos are carried to term in the recipients’ uteri. Multiple ovulations are caused by superovulation or superstimulation, a procedure that increases the number of ovulations in a donor beyond what is normal for a given species. Embryos are recovered 6-8 days following the start of oestrus. Most embryos are transferred during the late morula or blastocyst stage.

Introduction

Among the rice growing countries, India has the largest area (448 lakh ha) followed by china and Bangladesh. Total food grain production in India is estimated at 2813l.7 lakh tonnes. Rice production is estimated at 1156 lakh tonnes (Anonymous, 2010). In India, rice is grown in the state of Kerala, Andhra Pradesh, Orissa, Bihar, Uttar Pradesh, Madhya Pradesh, Punjab and West Bengal lead in the area, while West Bengal harvest highest rice production. The average yield per hectare is highest i.e., 5970 kg/ha in the Punjab during 2018-19.

Rice is grown throughout the state except Kachchh and Saurashtra. Some part of the state is growing rice as a drilled, while transplanted rice is taken in south and middle Gujarat. In Gujarat rice occupies about 10.61 per cent of the gross cropped area of the state and accounts for around 25.5 per cent of the food grain production. It is grown on an average about 7.5 to 8.5 lakh hector of land comprising nearly 70 to 80 per cent low land (transplanted) and 15 to 20 per cent of upland (drilled) rice (Anonymous, 2020). During the 2018-19, the yield of kharif rice in Gujarat was around 2247.75 kg/ha. Yield of summer rice was 3130.96 kg/ha and total production of rice in the year of 2018-19 was 1911 tonnes (Anonymous, 2020). During the 2019-20, the yield of kharif rice was 2117.81 kg/ha and yield of summer paddy was 2996.36 kg/ha and total production of rice in the year of 2019-20 was 1929.98 tonnes (Anonymous, 2020).

In Gujarat some districts like Chhotaudepur, Tapi, Navsari have highest rice productivity which covered 1.279 lakh hector area with production and productivity respectively of 3.338 lakh tonne and 2582 kg/ha and some district like Mehsana, Narmada, Panchmahal, North Gujarat etc. have medium to low productivity of paddy. But in some part of North Gujarat like Gandhinagar and Sabarkantha have low productivity of rice.

Introduction

Food safety and quality assumes paramount significance in any food industry. Globalization has driven both the food and agricultural firms to adopt systems that functions in a way to interlink food standards and international trade so as to achieve superior food quality and safety. Food industries follow several regional and international food safety procedures to procure certification from the government and other agencies in order to survive in both domestic and international markets (Ryan, 2014). The essential components in the food safety include handling, preparation and storing of the food products to ensure the food quality and to avoid food-borne diseases. The unwanted substances in a food product included by an accident is known as contaminants and the unwanted substance added to the food product to reduce the cost or to improve the other properties are known as adulterants. Contaminants and adulterants may lead to pathogens and toxins that pose serious concerns over the health of the consumer (Jha, 2016). The adulterants and contaminants are classified as physical adulterants and contaminants, chemical adulterants and residues, microbiological and pathogenic contaminants and toxins.

Hazards in food can be categorized into physical, chemical and biological.

Physical Hazards: Physical hazards are foreign organic or inorganic objects or extraneous materials in the food products. Hard and sharp physical hazards are of particular concern. Examples of physical hazards are broken glass, plastics, metal pieces, wood pieces, stones etc.

Botanically aster belongs to the family Asteraceae and scientifically known as Callistephus chinesnsis which is basically native to China aster and annual aster. It is native to China and Japan and it is cultivated worldwide as cut flower, loose flower, bedding plant, for flower decoration and for making floral ornaments. It can easily cultivate in the open fields and green houses for the production of cut-flowers. The genus Callistephus derives from two Greek words that is ‘Kalistos’ and ‘Stephos’ meaning ‘most beautiful’ and ‘a crown’, respectively. The name Aster comes from the Ancient Greek word acx^p (aster),, meaning “star”;, referring to the shape of the flower head (Janakiram, 2006).Among various flowering annuals, China aster is having an important position in Indian floriculture industry. It holds the position next to chrysanthemum and marigold among the traditional flowers. In fact, it has widely replaced an already grown annual Chrysanthemum up to greater extent in Indian floriculture industry.

This flower is most preferred for wide cultivation by virtue of its wide variation in attractive color and longer vase life. It is also very much used for beautification in landscape gardening which create mass effect. In India it is cultivated in about 1,020 ha with a production of flower 800 million tonnes. It is commercially cultivated in Karnataka, Tamil Nadu, West Bengal and Maharashtra. In Karnataka it account for 6 % of the total area and 8.8 % of the total flower production.

Asteraceae or Compositae is one of the largest families of flowering plants, represented by about 1,707 genera and over 23,600 species which are worldwide in distribution. Radford (1986) has mentioned the number of genera to be ‘One thousand to 2000’. About 140 of its genera and over 700 species have been reported from India. Some of the largely represented genera include Senecio (2,000+), Eupatorium (1,200), Vernonia (1,000), Hieracium (1,000), Centaurea (600), Aster (500), Helichrysum (500), Cousinia (400), Artemisia (400), Baccharis (400), Mikania (250), Bidens (230), Crepis (200), Inula (200), Erigron (200), Chrysanthemum (160), Cirsium (150), Ligularia (150), Helianthus (110), Lactuca (100), Hypochoeris (100) and Carduus (100).
In the Chrysanthemum genus, the modern autumn flowering perennial Chrysanthemum morifolium Ramat is most important. The name of C. morifolium Ramat has been changed to Dendranthema grandiflora Tzvelev (Anderson, 1987; Heywood and Humphries, 1977 and Kitamura, 1978). Chrysanthemum (D.x grandiflora) is an internationally recognized floriculture crop. It ranks second among commercial flowers in the international market. It is known as ‘Queen of East’ in Japan while in USA, it is considered as the ‘Queen of the fall flowers’. Flowers are in great demand in landascape, for making garland, wreath, veni and religious offerings. Pot chrysanthemums are
commonly known as ‘mums’ and large flowered cultivars are used as potted plants.

Asthma is a condition of sudden paroxysmal, expiratory, wheezing dyspnoea caused by an abnormal response of the respiratory center to stimulus causing hyperactivity of the vagal endings in the broncho-constricting muscles resulting in bronchial spasm; with it, hyperaemia oftlte mucous membrane followed by excessive bronchial secretion is associated.

This is true spasmodic asthma and in this other conditions of periodic expiratory dyspnoea with a different primary factor should not be included.

The disease has in most a family history and is more common in males; sometimes found in young children but more frequently begins in early adult life. Some of these have definite bronchitis also but in the most, the main is paroxysmal bronchospasm no physical sign obtained in the lungs.

The factors concerned in asthma are (i) bronchospasm from causes central and peripheral, (ii) oedema of the bronchial mucous membrane from allergy. Neuropathic predisposition.

The more immediate causes are (i) allergy, (ii) peripheral stimuli from their site of production, grouped as (a) naso-pharyngeal, (b) alimentary, (c) endocrine (d) broncho-pulmonary (iii) constitutional disturbances.

Astro-meteorology is considered as one of the branches of Astronomy along with Astrophysics, Astrobiology and Astrometry. Astronomy is the science that deals with the material universe beyond the earth’s atmosphere. It studies the nature and constitution of Celestial (heavenly) bodies and the laws which govern them including the effect they produce upon one another. It seeks to unravel the probable past history of heavenly bodies and their development. There exists a confusion between the branches of Astronomy viz., Astrophysics and Astro-meteorology with the term Astrology. Astrophysics uses principles and laws of physics to explain how Celestial bodies form and function or in other words it will help to ascertain the nature of the astronomical objects, rather than their positions or motions in space. However, the Astrology and Astro-meteorology are the subjects deal in future prediction and often considered as pseudo-science which uses position and movement of stars and planets for that purpose. Astrology links these to predict the human behaviour, while that of Astro-meteorology links the same to predict the future weather.

From ancient days, these predictions are based on one’s wisdom and knowledge in astronomy and often these astrologers are astronomers who keenly watch the stars and planets movement and guide their rulers and farmers with their guesstimates. Till date it is being lore, mainly passed to followers of this group and the methodology is not documented clearly and properly. There are many incidences of falsified predictions of astrology as reported by many reviewers elsewhere and we are not discussing the same here, owing to our interest in weather prediction i.e., astro-meteorology only. However, we have to recognize the works of the ancient astrologers who helped in developing the astronomical science.

Basically, there are two approaches in astrology viz., geocentric and heliocentric as used by the practitioner of astrology worldwide. As the name implies the Geocentric astrology is based on the calculation of planetary position as seen by the observer from the earth and thus earth is centre, while Heliocentric astrology bases its interpretation upon position within solar system with reference to the sun as centre. Though in true sense, the sun is the centre, the effect of motion as manifest on the earth is the basis of most astrological interpretation. Hence, vast majority of astrologers employs the geocentric calculations of the planetary positions for their predictions.

Withania somnifera, also known as Ashwagandha, Indian ginseng, Winter cherry, Ajagandha, Kan-aje Hindi, Amukkara in Tamil and Samm Al Ferakh, is a plant in the Solanaceae or nightshade family.

Grasshoppers : Trilophida an- nulata : Acrididae

The nymphs and adults of this grasshopper feed on the margins of leaves of Aswagandha. It is only a minor pest, nibbling on the leaves.

There are several bacteria which fix atmospheric nitrogen and do not have a symbiotic partner such as a plant. There are conclusive evidences regarding nitrogen gains due to free living bacteria (Dart and Day, 1975) The diazotrophic bacteria have been classified based on the mode of nutrition and oxygen requirement (Alexander, 1977, Knowles, 1977). Free living nitrogen fixing bacteria fix nitrogen in soil and their population in rhizosphere of plants are significantly higher than in non-rhizosphere soils

Although the economic and ecological significance of many of these bacteria have yet to be established, the most promising diazotrophs are Azotobacter, Azospirillum, Beijerinckia and Clostridium. Azotobacter and Beijerinckia are some of the most preponderant, non-symbiotic nitrogen fixing bacteria. Studies on these organisms in Indian soils have been done earlier by Rangaswamy and Sadasivam (1964) Sen and Barooah (1964) and Jagtap and Bhide (1971). Among the free living bacteria, Azotobacter is the most intensively investigated. Several species viz., A. chroococcum, A. vinelandii, A. macrocytogenes, A. agilis and A. insignis were reported but A. chroococcum is the most common specie encountered in arable soils.

This vertebra is decidedly atypical in form and structure. The body and spineous process are absent. It has the form of a strong ring, from which two curved plates, the wings, project laterally. The ring incloses a very large vertebral foramen and consistis of two lateral masses connected by dorsal and ventral arches.

The lateral masses (Massae laterales) present two deep oval anterior articular cavities (Foveae articulares craniales) which receive the occipital condyles; they are separated by a wide notch above and a narrow one below. The lateral margin is also notched, and a triangular non-articular depression cuts into the medial part of each cavity. The posterior articular surfaces (Facies articulares caudales) are somewhat saddle-shaped; they are confluent on the ventral arch, but are widely separated dorsally, and do not conform in shape to the corresponding surfaces of the axis.

The dorsal arch (Arcus dorsali,) presents a median dorsal tubercle (Tuberculum dorsale) and is concave ventrally. It is perforated on either side near its anterior margin by the inter vertebral foramen (Foramen invertebrale). The anterior border is deeply notched, and the posterior border is thin and concave.

The ventral arch (Arcus ventralis) is thicker, narrower, and less curved than the dorsal. In its lower surface is the ventral tubercle (Tuberculum ventrale), into which the terminal tendon of the longus colli muscle is inserted. The upper face has posteriorly a transversely- concave articular surface, the fovea dentis, on which the dens or odontoid process of the axis rests.

In front of this is a transverse rough excavation and a ridge for the attachment of the ligamentirm dentis.

Atmosphere can be defined as the gaseous envelope surrounding the earth. It is retained by earth’s gravity. The atmosphere has a mass of about 5.15 × 10¹⁸ kg, three quarters of which is within about 11 km of the surface. The imaginary ‘Karman line’ lies at an altitude of 100 km above the earth’s sea level, and commonly represents the boundary between the earth’s atmosphere and outer space. The study of earth’s atmosphere and its processes is called atmospheric science or ‘aerology’.

Geological evidence suggests that the age of the earth is about 4,50,00,00,000 (4.5 billion) years and life began on earth between 0.6 to 1.0 billion years after earth has formed. That is life began on earth some where 4 to 3.5 billion years ago.
The plant kingdom over the globe produce oxygen about 30,00,00,000 (3 million) kg per second which is consumed by the living beings on the earth. Air which is present in the atmosphere is a mechanical mixture of gases. The various gases, solid and liquid particles in the air that envelope the earth are bound to it by the gravitational attraction. This complex content of gases, solid and liquid particles is called atmosphere. The atmosphere extends above the surface of the earth to great heights. There is no sharp boundary between the atmosphere and the outer space. For our convenience, the height of the atmosphere is taken as 1000 km. The lowest one km which is called planetary boundary layer, contains 10 per cent of the mass of the atmosphere. All biological and human activities are confined to this planetary boundary level. The mass of the atmosphere is about 5.6 x 1018 kg (mass of earth is 6 x 1024 kg). The mass of the oceans water is about 1.4 x 1021 kg. This shows that the mass of the oceans is more than 250 times the mass of the atmosphere. The density of the dry air at the earth surface is 1.225 kg/m3 and at an altitude of 5.5 km this drops to 0.66 kg/m3 and at 30 km altitude it is about 0.013 kg/m3.

The gaseous envelope surrounding the earth is called atmosphere. Thus, atmosphere can be defined as the dynamic layer surrounding the earth above its surface containing various gases, moisture, aerosols, etc. The atmosphere is retained by earth’s gravity.

The atmosphere protects life on earth by absorbing ultraviolet solar radiation, warming the earth’s surface through heat retention and reducing temperature extremes between day and night. The common name given to the atmospheric gases used in breathing and photosynthesis is air. The atmosphere has a mass of about 5.15 × 10¹⁸ kg, three quarters of which is within about 11 km from the surface. The atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. The imaginary ‘Karman line’ lies at an altitude of 100 km above the mean sea level, and commonly represents the boundary between the earth’s atmosphere and outer space. The study of earth’s atmosphere and its processes is called atmospheric science or ‘aerology’. The atmosphere serves the life-system on the earth by the following activities.

1. Introduction

In recent years, consumers have been demanding convenient, healthy and safe foods which have ’fresh-like’ characteristics with a long shelf-life. These demands include important food quality such as appearance, texture, taste and nutritional content which are strongly impacted by the way it is processed. Another major concern among the consumers is food safety and quality. The shelf-life of the food products are mostly influenced due to the action of various harmful microorganisms and enzymes. The conventional food processing technologies, such as thermal treatments (pasteurisation and high temperature sterilisation), evaporation, drying, frying and baking can assure the microbiological safety and/or stability of processed food products, but affects the food quality and nutrients (heat sensitive vitamins, flavour and other bioactive compounds) (Zhang et al., 2019)

Abstract

Drying is one of the most important industrial operations for preservation of food material. Due to the major limitations posed by convective drying methods, there is always a need for novel drying techniques which are technically, economically and environmentally sustainable. Based on the principle of moisture diffusion due to vapor pressure gradient, atmospheric freeze drying (AFD) offers a promising alternative to conventional drying systems. A cold gas with low water vapor pressure is used as drying medium to sublimate moisture directly from the frozen material at atmospheric pressure conditions. As a result the product gets dried at much lower temperature unlike convective drying. Thus, products dried with AFD retain better nutrition, texture and color and the process is also considerably cost effective. Major limitation of the AFD process is longer drying time, which can however be accelerated by using heat pump drying or new ultrasound technology. This chapter focuses on mechanism, benefits, limitations and comparative study of AFD with other drying methods such as hot air drying and vacuum freeze drying. It provides an insight regarding effect of AFD on properties of food material based on various studies reported in literature.

Moisture present in the atmosphere plays a significant role in weather and climate of the region. There are three major components in the atmospheric moisture.

  I. Humidity

 II. Precipitation

III. Evaporation.

Humidity: The terminology related to humidity and concerned with gaseous form of water i.e. water vapour, several expressions of the amount of water vapour in the air is used. They are as follows.

Water is the only substance that exists in the atmosphere in all the three phases, i.e., solid, liquid and gas. The moisture on the earth’s surface is in a constant phase change. The moisture content of the atmosphere is about 0.035% of all fresh water. The atmosphere receives its supply of moisture from the earth’s surface through evaporation from oceans, lakes, rivers, damp soil, etc. and through transpiration from vegetation. Water vapour is the gaseous state of water and is invisible.

The amount of water vapour present in the atmosphere is called atmospheric moisture or humidity. It is a measure of the amount of water vapour dissolved in the air, not including any liquid water or ice falling through the air. While humidity itself is a climate variable, it also interacts strongly with other climate variables. The humidity is affected by winds and by rainfall. Moisture content is determined by the local rate of evaporation, air temperature and the horizontal transport of moisture. Humidity indicates the likelihood of precipitation, dew or fog. It also plays a major role in the heat budget and the weather phenomenon of the atmosphere.

Water is the only substance that exists in the atmosphere in all the three phases, i.e., solid, liquid and gas. The moisture on the earth's surface is in a constant phase change. The moisture content of the atmosphere is about 0.035% of all fresh water. The atmosphere receives its supply of moisture from the earth's surface through evaporation from oceans, lakes, rivers, damp soil, etc. and through transpiration from vegetation. Water vapour is the gaseous state of water and is invisible. The amount of water vapour present in the atmosphere is called atmospheric moisture or humidity. It is a measure of the amount of water vapour dissolved in the air, not including any liquid water or ice falling through the air.

Water vapour is constantly being cycled between the atmosphere and the earth's surface. The input rate (the rate at which water vapour enters the atmosphere from the ground through evaporation) and output rate (the rate at which water moves from the atmosphere to ground through precipitation) are equal. The average length of time that individual molecules of water remain in the atmosphere is called the residence time. It can be found by dividing the mass of the substance in the atmosphere (in kilograms) by the rate (in kg per year) at which the substance enters to and exists in the atmosphere. The total volume of atmospheric water vapour at any instance over the globe is about 14000 km³, which is 0.001% of the hydrosphere.

Although water vapour is lighter than air, the combination of higher temperatures and the ocean source tends to restrict it to the lower atmosphere. The decrease of water vapour with elevation is quite important in many meteorological processes. Infact, most of the water vapour is contained within the lower 5 km of the atmosphere (> 90%) and more than half is actually contained within the lowest 1.5 to 2 km. Less than 5 - 6% of the water is above 5 km, and less than 1% is in the stratosphere.

Water is the only substance that exists in the atmosphere in all the three phases, i.e., solid, liquid and gas. The moisture on the earth’s surface is in a constant phase change. The moisture content of the atmosphere is about 0.035% of all fresh water. The atmosphere receives its supply of moisture from the earth’s surface through evaporation from oceans, lakes, rivers, damp soil, etc. and through transpiration from vegetation. Water vapour is the gaseous state of water and is invisible.

The amount of water vapour present in the atmosphere is called atmospheric moisture or humidity. It is a measure of the amount of water vapour dissolved in the air, not including any liquid water or ice falling through the air. While humidity itself is a climate variable, it also interacts strongly with other climate variables. The humidity is affected by winds and by rainfall. Moisture content is determined by the local rate of evaporation, air temperature and the horizontal transport of moisture. Humidity indicates the likelihood of precipitation, dew or fog. It also plays a major role in the heat budget and the weather phenomenon of the atmosphere.

A big layer of air called the atmosphere surrounds the earth. The air within this layer moves from place to place when it warms up or cools down. This moving air is known as wind. In other words, air in motion is called wind. Winds move moisture and heat around the world and also produce much of our weather.

The strength of the wind can vary enormously. Sometimes air moves slowly and the wind is barely noticeable. When the weather is clear there may be a gentle breeze. When the wind is still very light, but it can be felt and there may be rustlings by leaves. At other times, the air can move very quickly and become a gale or hurricane, blowing down trees and damaging electric poles and buildings.

Winds are part of a global air circulation system that acts to balance temperature and pressure around the world. Different parts of the world receive different amounts of heat from the sun. This differential heating in turn results in differences in temperature and air pressure around the world, which drives the world’s winds.

As equatorial areas are heated most, the air above them warms and rises as it becomes lighter than the surrounding air, causing an area of low pressure. In cooler areas, the air sinks because it is heavier and results in an area of high pressure. Winds will blow as air is squashed out by the sinking cold air and drawn in under the rising warm air. Any difference in temperature like this will always cause a difference in air pressure, and therefore winds will blow. These movements result in a global wind pattern, with air moving between different areas around the world and also at different heights in the atmosphere. Colder air from the poles tends to sink and move towards the equator closer to the surface of the earth. In contrast, warm air from the equator rises and moves towards the poles high in the atmosphere because it is lighter.

2.1 Introduction
Building upon the foundational understanding of meteorology and data science established in Chapter 1, we now turn our focus to the fundamental physical processes that govern our atmosphere and the essential principles behind how we measure them. The Earth’s atmosphere is a dynamic fluid system, and its behavior is dictated by a complex interplay of physical laws. To truly comprehend weather phenomena, from the smallest updraft to the largest global circulation patterns, one must grasp the underlying atmospheric physics. This includes understanding how energy is transferred, how gases and
water vapor behave, and how forces shape atmospheric motion.
This chapter will delve into these core physical concepts, providing the theoretical bedrock necessary for a deeper appreciation of meteorological processes. Furthermore, accurate and reliable data is the lifeblood of modern meteorology and, by extension, data science applications within the field. Therefore, we will also explore the fundamental principles that underpin the measurement of key atmospheric variables.

16.1. Global Warming
The industrial revolution from mid 18th century is recognized as the primary cause of atmospheric pollution. Some of the gases like CO2, Chlorofluorocarbons, methane, nitrous oxide etc. are getting released into the atmosphere in greater volumes by combustion of fossil fuels. These gases can absorb the heat radiation leading to increase in air temperature and are called as greenhouse gases. When there is no vertical movement of air, these gases can accumulate near the ground and causes serious health hazards (Fig.16.2). Fig. 16.2: Global warming Under unstable conditions, there will be more convection and vertical movement of air that can prevent pollution near ground level. These air pollutants can be transmitted and carried away to long distance by strong winds. So, the air pollution which defies local, regional or even continental boundaries can cause atmospheric pollution and global warming. Therefore, air pollution control is not an issue for just one location or region and is now a matter of global concern.
16.2. Climate Change
As the greenhouse gases are spreading into the atmosphere, there is gradual increase in the air temperature and if no control measures are uniformly adopted

Atmospheric pressure is the force per unit area exerted on a surface by the weight of air above that surface in the atmosphere of earth. The gas molecules of the atmosphere are pulled towards the earth by the force of gravity and hence exert a force on earth surface. Atmospheric pressure can be calculated as the summed weight of all gas molecules between a horizontal plane and top of the atmosphere and divided by the area of the plane. Low pressure areas have less atmospheric mass above their location, whereas high pressure areas have more atmospheric mass above their location.

Imagine the air around us. Even though we can’t see it, air has weight. Atmospheric pressure is essentially the force exerted by the weight of the air molecules above a particular point on the Earth’s surface.
Think of it like this: Imagine you’re at the bottom of a swimming pool. The water above presses you down, and you feel that pressure. Similarly, the atmosphere, a giant ocean of air, has layers of air molecules, and their weight presses down on everything below, including us.
• Atmospheric pressure is defined as the force per unit area exerted by the weight of the air column extending from the surface of the earth ,to the top of the atmosphere above that area
• It can be explain in simple terms like:
• Air has weight: Just like water or a pile of books, the air surrounding the Earth has mass, and thus, weight due to gravity.
• Weight creates pressure: This weight of the air presses down on the surface. The more air there is above a certain point, the greater the pressure.
• Like a stack: Imagine a stack of blankets. The blanket at the bottom has to support the weight of all the blankets above it, so it experiences more pressure. Similarly, the air at lower altitudes has the weight of all the air above pressing down on it.

Imagine the air around us. Even though we can’t see it, air has weight. Atmospheric pressure is essentially the force exerted by the weight of the air molecules above a particular point on the Earth’s surface.
Think of it like this: Imagine you’re at the bottom of a swimming pool. The water above presses you down, and you feel that pressure. Similarly, the atmosphere, a giant ocean of air, has layers of air molecules, and their weight presses down on everything below, including us.
• Atmospheric pressure is defined as the force per unit area exerted by the weight of the air column extending from the surface of the earth to the top of the atmosphere above that area (Fig. 3.1).

Imagine the air around us. Even though we can’t see it, air has weight. Atmospheric pressure is essentially the force exerted by the weight of the air molecules above a particular point on the Earth’s surface. Think of it like this: Imagine you’re at the bottom of a swimming pool. The water above you presses down, and you feel that pressure. Similarly, the atmosphere, a giant ocean of air, has layers of air molecules, and their weight presses down on everything below, including us.
• Definition: Atmospheric pressure is defined as the force per unit area exerted by the weight of the air column extending from the surface of the earth to the top of the atmosphere above that area (Fig.8.1).
• How to Explain It Simply
• Air has weight: Just like water or a pile of books, the air surrounding the Earth has mass, and thus, weight due to gravity.
• Weight creates pressure: This weight of the air presses down on the surface. The more air there is above a certain point, the greater the pressure.
• Like a stack: Imagine a stack of blankets. The blanket at the bottom has to support the weight of all the blankets above it, so it experiences more pressure. Similarly, the air at lower altitudes has the weight of all the air above pressing down on it.

The atmospheric pressure is weight of the air which lies vertically above an unit area centered at a point. Normal pressure of air is 1.034/cm².

Pressure is defined as the force per unit area.
At the surface of the earth the atmosphere air exerts a pressure of about 10⁵ Newtons/m² or 10⁵ Pascals, which is called one bar or one atmosphere. Evangelista Torricelli (1608-1647) devised a method for measuring the atmospheric pressure by mercury (Hg) barameter in 1643.

Atmospheric pressure is the force per unit area exerted on a surface by the weight of air above that surface in the atmosphere of earth. The gas molecules of the atmosphere are pulled towards the earth by the force of gravity and hence exert a force on earth surface. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. Atmospheric pressure influences other weather elements in a significant way. Small changes in air pressure may not be felt, but they are important for bringing a change in weather. Atmospheric pressure can be calculated as the summed weight of all gas molecules between a horizontal plane and top of the atmosphere and divided by the area of the plane. Low pressure areas have less atmospheric mass above their location, whereas high pressure areas have more atmospheric mass above their location.

Measurement of atmospheric pressure

The standard unit of pressure in the SI system is the Pascal which is the name given to one Newton per square metre (N/m²). For meteorological purposes, standard sea-level pressure is 101325 pascal (Pa). To simplify this large number, the millibar unit (mb) has been adopted, which is equal to 100 pascals. Units like kiloPascal (kPa) or hectoPascal (hPa) are also used to measure pressure. 1 kiloPascal is equal to 10 millibars and 1 hPa is 1 millibar. The standard sea-level pressure is represented as 1013.2 mb or hPa.

Atmospheric pressure is the force per unit area exerted on a surface by the weight of air above that surface in the atmosphere of earth. The gas molecules of the atmosphere are pulled towards the earth by the force of gravity and hence exert a force on earth surface. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. Atmospheric pressure inf luences other weather elements in a significant way. Small changes in air pressure may not be felt, but they are important for bringing a change in weather. Atmospheric pressure can be calculated as the summed weight of all gas molecules between a horizontal plane and top of the atmosphere and divided by the area of the plane. Low pressure areas have less atmospheric mass above their location, whereas high pressure areas have more atmospheric mass above their location.

FACTORS AFFECTING ATMOSPHERIC PRESSURE

Air pressure never remains constant. Air pressure is greatly influenced by air temperature, altitude, water vapour presence in the air, rotation of earth, etc. However, these factors are not independent of each other in affecting the atmospheric pressure.

Temperature: Hot air expands and exerts low pressure. Cold air contracts and exerts high pressure. Thus, increase in temperature decreases the air pressure. Places nearer to equator experience low pressure due to prevalence of high temperature. The air being cold and heavy throughout the year a high pressure belt is created in both polar regions.

Altitude: Pressure varies smoothly from the earth’s surface to the top of the mesosphere. The pressure depends on the density or mass of the air. The density of air depends on its temperature. The density of air decreases with increase in height so the pressure also decreases with increase in height. At low altitudes above the sea level, the pressure decreases by about 1.2 kPa for every 100 metres.

Water vapour: Water vapour content of air is low in cold areas than that in dry areas. Hence, moist air of high temperature in dry areas exerts less pressure compared to cold air.

The mass of a body is usually defined as the material content of the body whereas the weight of the body is defined as the force with which the body is attracted towards the earth due to gravity. Therefore, the weight of a body is the product of its mass and acceleration due to gravity. The air in the atmosphere, which is a mixture of several gases has certain mass and although not very dense, will acquire some weight due to gravitational force of attraction when the entire column of the atmosphere from the ground level to the top of it is considered. Pressure is defined as the force for unit area. Therefore, the atmospheric pressure is defined as the force exerted by an air column of units area of cross section extending from earth’s surface to the top of atmosphere. As we go up in the atmosphere the height of the air column decreases, the air also become rarer and the atmospheric pressure decreases with increase in height.

Temperature is the physical property of an object that quantitatively expresses the hotness or coldness. Most of the weather parameters are dependent on temperature, directly or indirectly. It has important role to play in the development and growth of all living organisms in all stages of their growth. Atmosphere receives the heat energy from the sun and its temperature increases. Due to different amount of heat energy receipt at different places, the air temperatures at different places also vary. The variation in air temperature basically results into air motion, so as to equalize the energy content of the different regions of the earth. Thus, atmospheric temperature is one of the basic elements of weather and climate.

The temperature at a given location and time is affected by energy transfer processes including conduction, convection, advection and radiation. The controls of temperature include those factors that bring about spatial variations in temperature. The important factors that determine the temperature of a particular place on the earth’s surface are latitude, altitude, distribution of land and water, topography, ocean currents, prevailing wind, cloudiness, precipitation, nature of the surface, and turbulence.

Temperature is the physical property of an object that quantitatively expresses the hotness or coldness. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot. When a heat transfer path between them is open, heat spontaneously flows from bodies of a higher temperature to bodies of lower temperature. If no net heat flow occurs between two objects, the objects have the same temperature which are then said to be in ‘thermal equilibrium’. Temperature plays an important role in all fields of natural and applied sciences. Most of the weather parameters are dependent on it, directly or indirectly. It has important role to play in the development and growth of all living organisms in all stages of their growth.

Atmosphere receives the heat energy from the sun and its temperature increases. Due to different amount of heat energy receipt at different places, the air temperatures at different places also vary. The variation in air temperature basically results into air motion, so as to equalise the energy content of the different regions of the earth. Thus, atmospheric temperature is one of the basic elements of weather and climate.

Temperature is the physical property of an object that quantitatively expresses the hotness or coldness. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot. When a heat transfer path between them is open, heat spontaneously flows from bodies of a higher temperature to bodies of lower temperature. If no net heat flow occurs between two objects, the objects have the same temperature which are then said to be in ‘thermal equilibrium’. Temperature plays an important role in all fields of natural and applied sciences. Most of the weather parameters are dependent on it, directly or indirectly. It has important role to play in the development and growth of all living organisms in all stages of their growth.

Atmosphere receives the heat energy from the sun and its temperature increases. Due to different amount of heat energy receipt at different places, the air temperatures at different places also vary. The variation in air temperature basically results into air motion, so as to equalise the energy content of the different regions of the earth. Thus, atmospheric temperature is one of the basic elements of weather and climate.

Atmospheric temperature refers to the measure of the warmth or coldness of the air at different levels within the Earth’s atmosphere. It’s not a uniform value but varies significantly with altitude and location. More detailed descrption of atmospheric temperature is as follows:
• Different Layers, Different Temperatures: The Earth’s atmosphere is divided into several layers (troposphere, stratosphere, mesosphere, thermosphere, and exosphere), and each layer has a distinct temperature profile. For example, the troposphere (where we live and where weather occurs) generally gets colder with increasing altitude, while the stratosphere above it gets warmer due to the absorption of ultraviolet radiation by the ozone layer.
• Surface Temperature: When people talk about the “temperature” in daily life, they usually refer to the temperature of the air near the Earth’s surface, which is measured at meteorological stations.
• Global Average: Climatologists also use the concept of a “global temperature,” which is an average of temperature measurements taken at the surface, near-surface, or in the troposphere across the entire planet.

Atmospheric temperature refers to the measure of the warmth or coldness of the air at different levels within the Earth’s atmosphere. It’s not a uniform value but varies significantly with altitude and location.
More detailed descrption of atmospheric temperature is as follows:
• Different Layers, Different Temperatures: The Earth’s atmosphere is divided into several layers (troposphere, stratosphere, mesosphere, thermosphere, and exosphere), and each layer has a distinct temperature profile. For example, the troposphere (where we live and where weather occurs) generally gets colder with increasing altitude, while the stratosphere above it gets warmer due to the absorption of ultraviolet radiation by the ozone layer.
• Surface Temperature: When people talk about the “temperature” in daily life, they usually refer to the temperature of the air near the Earth’s surface, which is measured at meteorological stations.
• Global Average: Climatologists also use the concept of a “global temperature,” which is an average of temperature measurements taken at the surface, near-surface, or in the troposphere across the entire planet.

The potential of atomic absorption spectrometry/spectrophotometry/ spectroscopy for determination of metallic elements was first realized by Alan Walsh during 1950. The standard equipment termed as atomic absorption spectrometer/ spectrophotometer (AAS) has now gained a reputation in the field of analytical chemistry for determination of very small concentrations of metallic elements and metalloids. As little as 0.01 ppm of many elements can be determined through this tool. Recently, the Zeeman background correction technique has further enhanced the quality of the results obtained from the flame-less graphite furnace atomizer. Combining the very latest in AA technology with the most powerful computing and software available many manufacturers have developed several designs/models of AAS based on flame or flame-less technique.

Introduction

The first application of atomic absorption spectra to chemical analysis was made just over 100 years ago by Kirchoff (1860), who demonstrated the presence of various elements in the solar atmosphere. He and Bunsen, demonstrated shortly afterwards that atomic spectra, whether in emission or absorpiton, could be the basis of a powerful method of chemical analysis. Walsh (1955) recognized the potential advantages of the absorption method over emission method and devised simple and versatile apparatus applicable to the routine analysis of solutions of a wide range of elements. Alkemade and Milatz (1955) published papers describing the application of atomic absorption  techniques to chemical analysis.

Introduction

Biological systems are complex and are full of mysteries. Understanding function in relation to structure is crucial in many biological systems. A microscope is used to magnify, resolve and visualize a substance that is impossible to see by naked eyes and plays a vital role in various biological studies. We can visualize macroscopic organisms like animals, plants, and insects by the unaided eye but not bacteria, viruses or individual proteins. Biological structures have sizes variable over such a wide range that is not possible for a single microscopic technique to analyze all of them. Therefore, different types of microscopes with varying magnification and resolving abilities were developed to unveil the structural complexities of biomolecules (Fig. 1). Over the last 100 years, several types of microscopes have been designed and used in various fields. The microscopes work on different principles, and have a broad range of applications.

Atomic-absorption (AA) spectroscopy uses the absorption of light to measure the concentration of gas-phase atoms. Since samples are usually liquids or solids, the analyte atoms or ions must be vaporized in a flame or graphite furnace. The atoms absorb ultraviolet or visible light and make transitions to higher electronic energy levels. The analyte concentration is determined from the amount of absorption. Applying the Beer-Lambert law directly in AA spectroscopy is difficult due to variations in the atomization efficiency from the sample matrix, and non-uniformity of concentration and path length of analyte atoms (in graphite furnace of AA). Concentration measurements are usually determined from a working curve after calibrating the instrument with standards of known concentration.