eChapters

ABSTRACT

Minerals are important raw materials for the economic development of any nation. However, unscientific mining for minerals poses a serious threat to the environment. Mine spoils from outer Uttaranchal Himalaya are highly variable from loose to hard and compact at places. Rehabilitation technology for degraded mine sites consist of several steps, each of them playing an important role. Rehabilitation of these spoils is imperative to meet our demand of fuel, fodder, timber, reduce soil erosion and improve environmental pollution. The paper presents the efforts of rehabilitation of mine spoils in Uttaranchal Himalayas both mechanical as well as vegetative measures. Agroforestry techniques used in rehabilitation of mine spoils has been given in this paper.

INTRODUCTION

Himalayan region which constitute about 54 million ha (16.5%) area of the country is characterized by marginality, inaccessibility and fragility, compounded by high intensity erratic rainfall, steep slopes, large scale deforestation and faulty management practices. Natural resources in the region are under great stress due to mounting human and livestock populations. The increasing frequency of natural disasters, e.g. landslides, floods, droughts and deterioration of water bodies due to accelerated deforestation, conversion of marginal/forest land into agriculture and unscientific developmental activities e.g. mining, roads etc. further aggravate the problem. Soil erosion is the major constraint in crop production. High intensity rains in the monsoon season cause excessive runoff and soil loss. On erosion-prone steep slopes, about 50 per cent of the rainfall is lost as runoff, carrying with it 20 t ha-l soil.

ABSTRACT

In agroforestry and forestry sectors, little efforts have been made for tree improvement research in India. Planting of genetically poor quality of seedlings/propagules is one of the major reasons of low level impact of agroforestry systems in Indian Agriculture. Most of the agroforestry tree species have not been even gone through simple selection for superior types (plus trees). Exploration, collection and conservation of germplasm of woody agroforestry species, selection for fast growing trees, clonal propagation, seed orchards and other advances in tree breeding are still in fancy stage. At present, all the woody agroforestry species are propagated through collected seeds and/or propagules by unskilled labourers. It is well known that through tree breeding and establishment of seed orchards of improved genotypes, significant achievements towards the improvement of productivity of economic tree products is possible as happened in agricultural crops in India and industrial trees in USA and Europe. Even by small efforts of tree improvement, productivity of economic tree products can be raised by 20-30 per cent. In this paper breeding methodology, limitations, status and strategy of various agroforestry species has been discussed in special reference to Leucaena leucocephala (Subabul), Prosopis cinereria (Khejri), Azadirachta indica (Neem), Populus spp., Dalbergia sissoo (Shisham), Acacia nilotica (Desi babul), Eucalyptus spp. Casuarina equisetifolia (Casuarina), Albizia lebbek (Desi siris) and Jatropha curcus (Ratanjot).

ABSTRACT

Contour hedgerow technology has different names in different regions. Sloping Agriculture Land Technology (SALT) has alley farming with hedgerow barrier technology. It is basically an agroforestry system in which nitrogen - fixing trees or shrubs are planted very closely in rows and cash crops grown in between the alleys. The SALT has been considered as an alernative to shifting cultivation. Forest dwellers are mostly tribals and shifting cultivation have been their practice for food production. The slash and burn has caused enormous damage to the forest composition. The forests on the hills and on the mountains have suffered a lot due to “Podhu” cultivation. The similar situations have been observed also in most of the Asian country. The hilly area has been considered under the hedgerow system for soil and water conservation. The introduction of the agroforestry systems in the farmers fields and in the wastelands have brought potential forest farming. The young leaves of some hedge row plants provide good fodder for livestock. Hedgerows can also be managed to provide fuelwood, if necessary. The hedgerows and their trimming provide mechanical and biological barriers and help minimise soil erosion by reducing surface runoff velocities, leading to higher deposition of soil sediments and living source of nutrient cycling. The food and cash production has been observed to be the most essential components in four types of SALT models.

What is Nanotechnology? Answers differ depending on who you ask, and their background. Broadly speaking however, nanotechnology is the act of purposefully manipulating matter at the atomic scale, otherwise known as the “nanoscale.” Coined as “nano-technology” in a 1974 paper by Norio Taniguchi at the University of Tokyo, and encompassing a multitude of rapidly emerging technologies, based upon the scaling down of existing technologies to the next level of precision and miniaturization. Taniguchi approached nanotechnology from the ‘top-down’ standpoint, from the viewpoint of a precision engineer.

Foresight Nanotech Institute Founder K. Eric Drexler introduced the term “nanotechnology” to the world in 1986, using it to describe a ‘bottom-up’ approach. Drexler approaches nanotechnology from the point-of-view of a physicist, and defines the term as “large-scale mechano synthesis based on positional control of chemically reactive molecules.” In the future,“ nanotechnology” will likely include building machines and mechanisms with nanoscale dimensions, referred to these days as Molecular Nanotechnology (MNT).

Nanomaterials are a field which takes a materials science-based approach to nanotechnology. It studies materials with morphological features on the nanoscale, and especially those which have special properties stemming from their nanoscale dimensions. Nanoscale is usually defined as smaller than a one tenth of a micrometer in at least one dimension, though this term is sometimes also used for materials smaller than one micrometer.

An aspect of nanotechnology is the vastly increased ratio of surface area to volume present in many nanoscale materials which makes possible new quantum mechanical effects, for example the “quantum size effect” where the electronic properties of solids are altered with great reductions in particle size. This effect does not come into play by going from macro to micro dimensions. However, it becomes pronounced when the nanometer size range is reached. A certain number of physical properties also alter with the change from macroscopic systems. Novel mechanical properties of nanomaterials are a subject of nanomechanics research. Catalytic activities also reveal new behaviour in the interaction with biomaterials.

A semiconductor is a material that has an electrical resistivity between that of a conductor and an insulator.

A semiconductor is a substance, usually a solid chemical element or compound that can conduct electricity under some conditions but not others, making it a good medium for the control of electrical current. Its conductance varies depending on the current or voltage applied to a control electrode, or on the intensity of irradiation by infrared (IR), visible light, ultraviolet (UV), or X rays.

An external electrical field changes a semiconductor’s resistivity. Devices made from semiconductor materials are the foundation of modern electronics, including radio, computers, telephones, and many other devices. Semiconductor devices include the transistor, solar cells, many kinds of diodes including the light–emitting diode, the silicon controlled rectifier, and digital and analog integrated circuits. Solar photovoltaic panels are large semiconductor devices that directly convert light energy into electrical energy. In a metallic conductor, current is carried by the flow of electrons. In semiconductors, current can be carried either by the flow of electrons or by the flow of positively–charged “holes” in the electron structure of the material.

Polymeric nanoparticles are nanoparticles which are prepared from polymers. The drug is dissolved, entrapped, encapsulated or attached to nanoparticles and depending upon the method of preparation, nanoparticles, nanospheres or nanocapsules can be obtained. Nanocapsules are vesicular systems in which the drug is confined to a cavity surrounded by a polymer membrane, while nanospheres are matrix systems in which the drug is physically and uniformly dispersed.

In recent years, biodegradable polymeric nanoparticles have attracted considerable attention as potential drug delivery devices in view of their applications in drug targeting to particular organs/tissues, as carriers of DNA in gene therapy, and in their ability to deliver proteins, peptides and genes through oral route of administration.

In spite of development of various synthetic and semi synthetic polymers, natural polymers still enjoy their popularity in drug delivery, some of them are: gums (Eg. Acacia, Guar, etc.,) chitosan, gelatin, sodium alginate, and albumin. A range of materials have been employed to delivery of bioactive agents. A polymer used in controlled drug delivery formulation, must be chemically inert, non-toxic and free of leachable impurities. It must also have an appropriate physical structure, with minimal undesired aging, and be readily processable. Some of the polymeric materials are: cellulosics., poly(2-hydroxyethyl methacrylate), poly(N-vinyl pyrrolidone), poly(methyl methacrylate), poly(vinyl alcohol), poly(acrylic acid), polyacrylamide, poly(ethylene-co-vinyl acetate), poly(ethylene glycol), poly(methacrylic acid).

“Small is beautiful”, today we know that small is not only beautiful but also powerful. With the range of applications that nanoparticles find in varied fields of engineering and science, nanoparticles seem a promising option when compared to the conventional materials used. Nanoparticles are particles that have at least one dimension in less than 100nm range. They have a high surface to volume ratio and thus mass transfer and heat transfer properties are better than bulk materials. Recently; core/shell nanoparticles are finding widespread application. There is a class of core/shell nanoparticle that has its entire constituent in the nanometer range. Core/shell nanoparticles are nanostructures that have core made of a material coated with another material. They are in the size range of 20nm-200nm. Also, composite structures with these core/shell particles embedded in a matrix material are in use. The necessity to shift to core/shell nanoparticles is the improvement in the properties. Taking into consideration the size of the nanoparticles, the shell material can be chosen such that the agglomeration of particle can be prevented. This implies that the monodispersity of the particles can be improved. The core/shell structure enhances the thermal and chemical stability of the nanoparticles, improves solubility, makes them less cytotoxic and allows conjugation of other molecules to these particles. The shell can also prevent the oxidation of the core material. “When a core nanoparticle is coated with a polymeric layer or an inorganic layer like silicabecausethe polymeric orinorganiclayerwould endow the hybrid structure with an additional function/property on top of the function/property of the core hence synergistically emerged functions can be envisioned”.

A fullerene is any molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube. Spherical fullerenes are also called buckyballs, and cylindrical ones are called carbon nanotubes or buckytubes. Fullerenes are similar in structure to graphite, which is composed of stacked graphene sheets of linked hexagonal rings; but they may also contain pentagonal (or sometimes heptagonal) rings.

The first fullerene to be discovered, and the family’s namesake, was buckminsterfullerene C₆₀, made in 1985 by Robert Curl, Harold Kroto and Richard Smalley. The name was homage to Richard Buckminster Fuller, whose geodesic domesit resembles. Fullereneshave since been found to occur (if rarely) in nature.

The discovery of fullerenes greatly expandedthe numberof known carbon allotropes, which until recently were limited to graphite, diamond, and amorphous carbon such as soot and charcoal. Buckyballs and buckytubes have been the subject of intense research, both for their unique chemistry and for their technological applications, especially in materials science, electronics, and nanotechnology.

There aremany different points of view aboutthe nanotechnology. These differences start with the definition of nanotechnology. Some define it as any activity that involves manipulating materials between one nanometer and 100 nanometers. However the original definition of nanotechnology involved building machines at the molecular scale and involves the manipulation of materials on an atomic (about two-tenths of a nanometer) scale.

The debate continues with varying opinions about exactly what nanotechnology can achieve. Some researchers believe nanotechnology can be used to significantly extend the human lifespan or produce replicator-like devices that can create almost anything from simple raw materials. Others see nanotechnology only as a tool to help us do what we do now, but faster or better.

The third major area of debate concerns the timeframe of nanotechnology-related advances. Will nanotechnology have a significant impact on our day-to-day lives in a decade or two, or will many of these promised advances take considerably longer to become realities?

Finally, all the opinions about what nanotechnology can help us achieve echo with ethical challenges. If nanotechnology helps us to increase ourlifespans orproduce manufactured goodsfrom inexpensive raw materials, what is the moral imperative about making such technology available to all? Is there sufficient understanding or regulation of nanotech based materials to minimize possible harm to us or ourenvironment? Only timewill tell how nanotechnology will affect our lives.

Atoms and molecules are the essential building blocks of every object. The manner in which things are constructed with these basic units is vitally important to understand their properties and their reciprocal interactions. An efficient control of the synthetic pathways is essential during the preparation of nanobuilding blocks with different sizes and shapes that can lead to the creation of new devices and technologies with improved performances. Traditionally nanoparticles were produced only by physical and chemical methods. Some of the commonly used physical and chemical methods are ion sputtering, solvothermal synthesis, reduction and sol gel technique

Basically there are two approaches for nanoparticle synthesis namely the Bottom up approach and the Top down approach. In the Top down approach, scientists try to formulate nanoparticles using larger ones to direct their assembly. The Bottom up approach is a process that builds towards larger and more complex systems by starting at the molecular level and maintaining precise control of molecular structure.

These two different methods highlight the organization level of nanosystems as the crossing point hanging between the worlds of molecular objects and bulk materials.

The top-down approach has been advanced by Richard Feynman in his often-cited 1959 lecture stating that “there is plenty of room at the bottom” and it is ideal for obtaining structures with long-range order and for making connections with macroscopic world. Conversely, the bottom-up approach was pioneered by Jean-Marie Lehn (revealing that “there is plenty of room at the top”) and it is best suited for assembly and establishing short-range order at the nanoscale. The integration of the two techniques is expected to provide, atleast in principle, thewidest combination of tools for nanofabrication.

It is classified asbottom-up manufacturing which involves building up of the atomor molecular constituents asagainstthetop methodwhich involves making smaller and smaller structures through etching from the bulk material as exemplified by the semiconductor industry.

Chemical synthesis is spontaneous organization of molecules into stable, structurally well-defined aggregates at the nanometer length scale. Chemical synthesis is largely an art form (i.e., theory often does not quantitatively predict how to make new materials from molecules).Yet, chemical synthesis can be quite powerful (e.g., proteins and complex organic molecules can be made from simple reagents) Semiconductor nanocrystals have been synthesized via “natural self-assembly” in two steps:

1.Capped cluster molecule forms spontaneously from molecular reagents in solution

2.Cluster molecules crystallize out of solution

Nanoparticles synthesis is done by two major routes, which include classical synthesis and green synthesis. The green synthesis techniques generally utilize relatively non-toxic chemicals non-toxic solvents, biological extracts and systems. Biological methods are considered safe and ecologically sound forthe nanomaterial fabrication asan alternative to conventional physical and chemical methods

Nanoparticles

Gold, silver, and copper have been used mostly for the synthesis of stable dispersions of nanoparticles, which are useful in areas of photography, catalysis, biological labeling, photonics, optoelectronics and surface-enhanced Raman scattering (SERS) detection

The need for biosynthesis of nanoparticles rose as the physical and chemical processes were costly. So in the search of cheaper pathways for nanoparticle synthesis, scientists used microorganisms and then plant extracts for synthesis. Nature has devised various processes for the synthesis of nano- and micro- length scaled inorganic materials which have contributed tothedevelopment of relatively newandlargely unexplored area of research based on the biosynthesis of nanomaterials.

The most commonly used technique has been discussed and we have tried to generalize the type of particle that can be synthesized by each of these methods. Though it is not a rule that is applicable to all cases but it can be applied to most cases.

Polymerization Radical Polymerization

The polymerization could be a free radical polymerization or an atom transfer radical polymerization. The process of atom transfer radical polymerization (ATRP) is better than the free radical polymerization as control of molecular weight and size of the particle can be achieved. The coating of polymer on silica nanoparticles is generally done by ATRP. The surface of the silica particle is modified with a suitable initiator.

Techniques have been developed to produce nanotubes in sizeable quantities, including arc discharge, laser ablation, high pressure carbon monoxide (HiPCO),andchemicalvapor deposition (CVD).Mostof these processes take place in vacuum or with process gases. CVD growth of CNTs can occur in vacuum or at atmospheric pressure. Large quantities of nanotubes can be synthesized by these methods; advances incatalysis and continuous growthprocessesare making CNTs more commercially viable.

1. Mechanical Properties of Nanomaterials

Scientific challenges in nanoscience and nanotechnology include the development of nanomaterials with novel mechanical properties. The need for scratch, mar and/or abrasion resistance is well established in various markets, including fingernail polishes, flooring, plastic glazing, headlamp covers and other automotive parts, transportation windows and optical lenses, where clear scratch-resistant coatings are used. Because the nanosize, many of their mechanical properties of the materials is modified, among others, hardness and elastic modulus, fracture toughness, scratch resistance, fatigue strength, and hardness. Energy dissipation, mechanical coupling within arrays of components, and mechanical nonlinearities are influenced by structuring components at the nanometer scale. This includes also the interpretation of unusual mechanical behavior (e.g., strengths approaching the theoretical limit) and the exploration of new ways to integrate diverse classes of mechanically functional materials on the nano-size.

Strength

Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively. This strength results from the covalent sp² bonds formed between the individual carbon atoms. In 2000, a multi-walled carbon nanotube was tested to have a tensile strength of 63 gigapascals (GPa). (This, for illustration, translates into the ability to endure tension of 6300 kg on a cable with cross-section of 1 mm².) Since carbon nanotubes have a low density for a solid of 1.3 to 1.4 g·cm”³, its specific strength of up to 48,000 kN·m·kg”¹ is the best of known materials, compared to high-carbon steel’s 154 kN·m·kg”¹. Under excessive tensile strain, the tubes will undergo plastic deformation, which means the deformation is permanent. This deformation begins at strains of approximately 5% and can increase the maximum strain the tubes undergo before fracture by releasing strain energy.

Nanoparticle characterization is necessary to establish understanding and control of nanoparticle synthesis and applications. Characterization is done by using a variety of different techniques, mainly drawn from materials science. Common techniques are electron microscopy (TEM, SEM), atomic force microscopy (AFM), dynamic light scattering (DLS), x-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF),ultraviolet-visible spectroscopy and dual polarisation interferometry.

Whilst the theory has been known for over a century (see Robert Brown), the technologyfor Nanoparticle trackinganalysis (NTA) allows direct tracking of the Brownian motion and thismethodtherefore allows the sizing of individual nanoparticles in solution.

X-ray scattering techniquesarea family of non-destructive analytical techniques which reveal information about the crystallographic structure, chemical composition, and physical properties of materials and thin films. These techniques are based on observing the scattered intensity of an X-ray beam hitting a sample as a function of incident and scattered angle, polarization, and wavelength or energy.

Electron Microscope

An electron microscope is a type of microscope that uses a particle beamof electronstoilluminate a specimen and createa highly-magnified image. Electron microscopes have much greater resolving power than light microscopes that use electromagnetic radiation and can obtain much higher magnifications of up to 1 million times, while the best light microscopes are limited to magnifications of 1000 times. Both electron and light microscopes have resolution limitations, imposed by the wavelength of the radiation they use. The greater resolution and magnification of the electron microscope is because the de Broglie wavelength of an electron is much smallerthan that of a photon of visible light.

The electron microscope uses electrostatic and electromagnetic lenses in forming the image by controlling the electron beam to focus it at a specific plane relative to the specimen. This manner is similar to how a light microscope uses glass lenses to focus light on or through a specimen to form an image.

A Scanning electron microscope (SEM) is a type of electron microscope that images a sample by scanning it with a high-energy beam of electrons in a raster scan pattern. The electrons interact with the atoms that make up the sample producing signals that contain information about the sample’s surface topography, composition, and other properties such as electrical conductivity.

The types of signals produced by an SEM include secondary electrons, back-scattered electrons (BSE), characteristic X-rays, light (cathodoluminescence), specimen current and transmitted electrons. Secondary electron detectors are common in all SEMs, but it is rare that a singlemachine would havedetectors for allpossiblesignals. The signals result from interactions of the electron beam with atoms at or near the surface of the sample. In the most common or standard detection mode, secondary electron imaging or SEI, the SEM can produce very high-resolution images of a sample surface, revealing details less than 1 nm in size. Due to the very narrow electron beam, SEM micrographs have a large depth of field yielding a characteristic three dimensional appearance useful for understanding the surface structure of a sample.

Infrared spectroscopy (IRspectroscopy) is the spectros copy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light. It covers a range of techniques, mostly based on absorption spectroscopy. As with all spectroscopic techniques, it can be used to identifyand study chemicals. A common laboratory instrument that uses this technique is a Fourier transform infrared (FTIR) spectrometer.

The infrared portion of the electromagnetic spectrum is usually divided into three regions; the near-, mid- and far- infrared, named for their relation to the visible spectrum. The higher energy near-IR, approximately 14000–4000 cm^–1 (0.8–2.5 μm wavelength) can excite overtone orharmonic vibrations. Themid-infrared, approximately 4000– 400 cm^–1 (2.5–25 μm) may be used to study the fundamental vibrations and associated rotational-vibrational structure. The far-infrared, approximately 400–10 cm^–1 (25–1000 μm), lying adjacent to the microwave region, has low energy and may be used for rotational spectroscopy. The names and classifications of these sub regions are conventions, and are only loosely based on the relative molecular or electromagnetic properties.

Infrared spectroscopy exploits the fact that molecules absorb specific frequencies that are characteristic of their structure. These absorptions are resonant frequencies, i.e. the frequency of the absorbed radiation matches the frequency of the bond or group that vibrates. The energies are determined by the shape of the molecular potential energy surfaces, the masses of the atoms, and the associated vibronic coupling.

Nanotechnology has the potential to revolutionizethe agricultural andfood industry with newtools forthemoleculartreatmentof diseases, rapid disease detection, enhancing the ability of plants to absorb nutrients etc. Smart sensors and smart delivery systems will help the agricultural industry combat viruses and other crop pathogens. In the near futurenanostructured catalysts will beavailable which will increase the efficiency of pesticides and herbicides, allowing lower doses to be used. Nanotechnology will also protect the environment indirectly through the use of alternative (renewable) energy supplies, and filters or catalysts to reduce pollution and clean-up existing pollutants.

Nanomedicine is the medical application of nanotechnology. The approaches to nanomedicine range from the medical use of nanomaterials, to nanoelectronic biosensors, and even possible future applications of molecular nanotechnology. Current problems for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials.

Nanomedicine research is receiving funding from the US National Institute of Health. Of note is the funding in 2005 of a five-year plan to set up four nanomedicine centers. In April 2006, the journal Nature Materials estimated that130 nanotech-based drugsanddeliverysystems were being developed worldwide.

The impact of nanotechnology in the food industry has become more apparent over the last few years with the organization of various conferences dedicated to the topic, initiation of consortia for better and safefood, along with increased coveragein themedia. Several companies which were hesitant about revealing their research programmes in nanofood, have now gone public announcing plans to improve existing products and develop new ones to maintain market dominance. The typesof application include:smartpackaging, on demand preservatives, and interactive foods. Building on the concept of “on-demand” food, the idea of interactive food is to allow consumers to modify food depending on their own nutritional needs or tastes. The concept is that thousands of nanocapsules containing flavour or colour enhancers, or added nutritional elements (such as vitamins), would remain dormant in the food and only be released when triggered by the consumer.24 Most of the food giants including Nestle, Kraft, Heinz, and Unilever supportspecific research programmes tocapturea share of the nanofood market in the next decade.

The definition of nanofood is that nanotechnology techniques or tools are used during cultivation, production, processing, or packaging of the food. It does not mean atomically modified foodor foodproduced by nanomachines. Although there are ambitious thoughts of creating molecularfood using nanomachines, this is unrealistic in the foreseeable future. Instead nanotechnologists are moreoptimisticabout thepotential to changethe existing systemof food processingand to ensure the safety of food products, creating a healthy food culture. They are also hopeful of enhancing the nutritional quality of food through selected additives and improvements to the way the body digests and absorbs food. Although some of these goals are further away, the food packaging industry already incorporates nanotechnology in products.

Nanosensors are any biological, chemical, or sugery sensory points used to convey information about nanoparticles to the macroscopic world. Their use mainly include various medicinal purposes and as gateways to building other nanoproducts, such as computer chips that work at the nanoscaleand nanorobots. Presently, there are several ways proposed to make nanosensors, including Top-down and bottom-up design, top-downlithography, bottom-upassembly, and molecular self-assembly.

Predicted applications

Medicinal uses of nanosensors mainly revolve aroundthe potential of nanosensors to accurately identify particular cells or places in the body in need. By measuring changes in volume, concentration, displacement and velocity, gravitational,electrical, and magneticforces, pressure, or temperature of cells in a body, nanosensors may be able to distinguish between and recognize certain cells, most notably those of cancer, at the molecular level in order to deliver medicine or monitor development to specific places in the body. In addition, they may be able to detect macroscopic variations from outside the body and communicate these changes to other nanoproducts working within the body.

Over the past few decades, the fields of science and engineering have been seeking to develop new and improved types of energy technologies that havethe capability of improvinglifeall over the world. In order to make the next leap forward from the current generation of technology, scientists and engineers have been developing Energy Applications of Nanotechnology. Nanotechnology, a new field in science, is any technology that contains components smaller than 100 nanometers. For scale, a single virus particle is about 100 nanometers in width.

An important subfield of nanotechnology related to energy is nanofabrication. Nanofabrication is the process of designing and creating devices on the nanoscale. Creating devices smaller than 100 nanometers opens many doors for the development of new ways to capture, store, and transfer energy. The inherent level of control that nanofabrication could give scientists and engineers would be critical in providing the capability of solving many of the problems that the world is facing today related to the current generation of energy technologies.

People in the fields of science and engineering have already begun developing ways of utilizing nanotechnology for the development of consumer products. Benefits already observed from the design of these products are an increased efficiency of lighting and heating, increased electrical storage capacity, and a decrease in the amount of pollution from the use of energy. Benefits such as these make the investment of capital in the research and development of nanotechnology a top priority.

The societal implications of nanotechnology are the potential benefits and challenges that the introduction of novelnanotechnological devices and materials may hold for society and human interaction. The term is sometimes expanded to also include nanotechnology’s health and environmental implications, but this article will only consider the social and political implications of nanotechnology.

As nanotechnology is an emerging field andmostof its applications are still speculative, there is much debate about what positive and negative effects that nanotechnology might have.

Beyond the toxicity risks to human health and the environment which are associated with first-generation nanomaterials, nanotechnology has broader societal implications and poses broader social challenges. Social scientistshave suggestedthatnanotechnology’s social issues should be understood and assessed not simply as “downstream” risks or impacts. Rather, the challenges should be factored into “upstream” research and decision making in order to ensure technology development that meets social objectives.

Nanotoxicology is the study of the toxicity of nanomaterials. Because of quantum size effects and large surface area, nanomaterials have unique properties compared with their larger counterparts

Nanotoxicology is that branch of bionanoscience, which deals with the study and application of toxicity of nanomaterials. The nanomaterials, even when they are made of inert elements like gold, become very active at a nanometer range. Nanotoxicological studies are intended to determine whether and to what extent these may pose a threat to the environment and to human beings. For instance, Diesel nanoparticles have been found to damage the cardiovascular system in a mouse model.

Human health and safety

Calls for tighter regulation of nanotechnology have occurred alongside a growing debate related to the human health and safety risks associated with nanotechnology. The Royal Society identifies the potential for nanoparticles to penetrate the skin, and recommend that the use of nanoparticles in cosmetics be conditional upon a favorable assessment by the relevant European Commission safety advisory committee. Andrew Maynard also reports that ‘certain nanoparticles may move easily into sensitive lung tissues after inhalation, and cause damage that can lead to chronic breathing problems’.

Nanotechnology, which deals with understanding and control of matter at dimension of roughly 100 nm and below, has a cross sectoral application and an interdisciplinary orientation. At this scale, the physical, chemical and biological properties of materials differ from the properties of individual atoms and molecules or bulk matter, which enable novel applications. Nanotechnology research and development is directed towards understanding and creating improved materials, devices and systems that exploit these properties as they are discovered and characterized

There are many applications of nanotechnology such as in the area of medicine, chemistry and environment, energy, agriculture, information and communication, heavy industry and consumer goods. The alleged potential of this technology has garnered the attention of both developed and developing countries across the globe. The US National Science Foundation (NSF) has listed it as one of six priority areas; it is one of the themesin the EU Framework Program for Research and Technological Development in Europe; and it has been the focus of research in countries worldwide.

Introduction

Accumulation of excess soluble salts in the root zone of soils resulting in partial or complete loss of soil productivity is a worldwide phenomenon. The problems of soil salinity are widespread in the arid and semi-arid areas but salt-affected soils also occur extensively in the sub-humid and humid climates particularly in the coastal regions where the ingress of sea water through estuaries and rivers and through ground water movement causes large scale soil and water salinisation. Soil salinity is also a serious problem in areas where ground waters of high salt content are the only source of water available for irrigation. By far the most serious problems of salinity are being faced in the irrigated, arid and semi-arid regions of the world. Our ability to manage salt-affected soils and waters both in the irrigated and in the unirrigated regions will constitute a major effort in meeting potential food requirements. The magnitude of the problem can be appreciated from the following.

Expression of genetic potential for growth and yield of a crop variety is directly dependent upon the environment comprising both climate (weather) and soil components. As discussed in the preceding chapter, the term ‘salt-affected soils’ encompasses a broad group of adverse but distinct soil conditions, namely, saline, alkali (sodic) and acid soils with further variations such as coastal and inland locations as well as arid and water-logged situations (Swaminathan 1977; Bresler et al. 1982). Factors limiting growth and yield of crop plants in various categories of problem soils are different and specific. Likewise, adaptive strategies evolved by plants to cope with the prevailing edaphic stresses, such as salt stress, also vary a great deal as indicated in Table 1. It is not unexpected therefore, that even varieties within a crop often show notable differences regarding tolerance to adverse soil conditions (Epstein et al. 1980; Devine 1982; Shannon 1984; Sayed 1985). Hence, it is essential that the breeder must understand the inherent charaderistics of the problem soil with which he is concerned and should also simultaneously appreciate that basically it is the sensitivity of crop variety, rather than the soil parameters per se, that essentially determines the occurrence as well as the magnitude of actual soil problem (Rana 1977). Since the degree of tolerance (adaptation) of crop varieties to different kinds of salt affected soils is genetically controlled, it is axiomatic that it can be improved through genetic manipulations by adopting suitable breeding procedures.

Introduction

Drought is the most common adverse environmental factor which limits crop production in different parts of the world. Often drought is accompanied by relatively high temperatures, which promote evapotranspiration, and hence could accentuate the effects of drought and thereby further reduce crop yields. Since these events occur more frequently in tropical and semitropical regions where most of the developing countries are situated, droughts are often associated with food shortages and an overall setback to developmental activities. Therefore, raising of drought-resistant crops is common sense to achieve stability in production and to enhance the possibility of self-suficiency in food. Consequently, breeding for drought resistance is a major objective of many research programmes in the international and national institutions. This has been so for the past several decades. But, it is disappointing that, there has not been any measurable success in these programmes compared with the success achieved in breeding for yield; or breeding for disease resistance or breeding for quality attributes. In fact, this was amply expressed by Arnon (1980) when he stated “Breeding for drought resistance has been a consistent theme for as long as I remember and probably the greatest source of wasted breeding efforts in the whole field of plant breeding.” However, the fact remains that we do hear of drought resistant varieties in many crops. For example, C-306 in wheat, Lalnakanda in rice and M 35-1 in Sorghum are some of the better known examples in India. It is also claimed that a large number of cultures among the Assam Rice Collection exhibit a considerably high degree of drought tolerance. Many land races and wild relatives of several crop species are said to contain drought resistant traits, which could be profitably utilised in breeding programmes. This situation is not unique to India alone but is a common experience in different parts of the world. However, to afirm a conviction a short questionnaire to assess the current state-of-art on breeding for drought resistance was distributed to 75 distinguished plant breeders and plant physiologists all over the world. The questionnaire and a summary based on the responses is as follows:

Introduction

Man’s intervention in the evolution of plants, to adapt them to suit his needs, constitutes the practice of plant breeding. Historically regarded as an art and still too empirical to be accepted universally as a science, it has recently been described as a technology (Riley 1978). Whether art, science or technology, it certainly draws on a wide range of disciplines and embodies all those principles of organisation and management that determine success in any production-oriented programme.

Perhaps the biggest contribution that the plant breeder has made to increased production during the past 50 years has been in helping to alleviate the effects of natural hazards such as lodging, pests and diseases on crop production. While most of this progress has been through the manipulation of biotic stresses, much is still to be achieved under non-biotic stresses such as drought, salinity, temperature, etc. This argument is strengthened by the fact that in spite of the spectacular achievements made possible by the ‘Green Revolution’, the productivity level of most crop plants, including wheat and rice, has remained both low and static under stress conditions. Concerted efforts are needed through an approach of interdisciplinary research, since not much has been done to define criteria for stress assessment and evolving breeding approaches for incorporating stress tolerance in crop plants.

Introduction

Drought is one of the primary factors responsible for depressing rice yield in chronic areas and in destabilising rice production in drought-prone areas. It is a production constraint common to all rainfed rice cultures: wetland, upland, and deepwater (O’Toole and Chang 1979). Breeding for drought resistance, a major component of the International Rice Research Institute’s (IRRI) Genetic Evaluation and Utilization (GEU) Program since the early 1970s, aims at countering the adverse effects of drought in unfavoured rice production areas.

Rice germplasm has such remarkably rich diversity that a continuous spectrum of genotypes differing in the various physiological mechanisms can be found and is available for genetic manipulation (Chang et al. 1982a). However, effective evaluation methods are essential for unravelling the specific mechanism(s) involved and for devising eficient selection criteria in a breeding program. Moreover, the broad spread in growth duration among rice cultivars makes it impractical to obtain uniform evaluation of a large number of cultivars when they differ in physiological responses that are specific to certain growth stages. Methods that can accommodate large numbers are essential to breeding program.

The modern commercial poultry production in India is barely 50 years old, although backyard poultry keeping dates back to pre-historic period. In between 1955 to 1965, some Christian Missionaries had imported White Leghorn, Rhode Island Red and White Rock breeds, to upgrade the local chicken, having very high disease resistance power; but highly broody. Later, hybrid broiler (Arbor Acres) and layer (Babcock) strains were brought to India in early seventies, to start modern poultry industry. Among the two, the layer industry took wings early and registered a spectacular growth rate between 1970 and 1985. The broiler industry came to existence five years later and showed 25 -100% annual growth rate initially and 10-20% growth rate subsequently; between 1975 – 2005. The growth indicators of poultry development in India are presented

The modern breeds of chicken have known to be descended from the wild jungle fowl. India, Nepal, Bangladesh, Myanmar, Thailand, Sri Lanka and Malaysia are the homeland to these jungle fowls. There are four known species of jungle fowl viz. Gallus gallus (Red jungle fowl), Gallus lafayetti (Ceylon jungle fowl), Gallus sonnerati (Grey jungle fowl) and Gallus varius (Java jungle fowl). The domestic breeds of chicken/fowl have originated from Gallus gallus.

The word indigenous, originates from the Latin work, indigena, implies that the individual and its ancestors originated from a specified country or continent. Presently, certain synonymous words used for indigenous chicken are: ‘native’, ‘local’ or ‘village chicken’. The indigenous fowls are well adapted to the local climate, need less input and produce tasty egg and meat at the least possible cost through scavenging. The birds require no scientific feeding, health care, housing and management and thus make the indigenous birds suitable for backyard poultry farming. Indigenous birds are normally handled by women, can significantly contribute to farmers’ livelihoods through increased food security and cash income. These breeds are self-propagating; contribute to poultry diversity and cultural heritage. Because of their local origin they are less prone to disease or predator attacks, and their cultural and sporting values secure additional income. The prices of egg and meat of local birds are 100- 150 percent higher than that of commercial counterpart. Some of these fowls are described in brief, as below.

Male Reproductive System

Male reproductive system (Fig. 15) consists of testes, epididymis, vas deferens and papillae.

Cocks have two ovoid creamy white testes, of which the left one is slightly larger than the right. Testes are located in the fore end of the kidneys in the abdominal cavity. Closely attached to the testes is short epididymis that continues as vas deferens which ends in the cloaca. The copulatory apparatus consists of two papillae and a rudimentary copulatory organ, the phallus which is located on the median ventral portion of one of the transverse folds of cloaca. Accessory reproductive organs like seminal vesicles, prostrate and Cowper’s glands are absent in the cocks. The phallus is small and has associated lymph glands that produce a fluid which is added to the semen.

The spermatozoa pass through the epididymis and are stored in the distal end of the vas deferens. The sperm after mating is stored in the folds in the oviduct of the hen to effect fertility up to six days. The spermatozoa of the cock have a long cylindrical head with a pointed acrosome, a short mid-piece and a long tail. Cocks produce about 0.5 -1 ml of whitish semen per ejaculate with a sperm concentration of 2- 4 billion.

A hen can produce eggs without mating by a cock. Such an egg is edible but infertile and will not hatch. If the hen is naturally or artificially inseminated with poultry semen, the spermatozoon unites with the ovum to form a fertile egg that will hatch after incubation. Unlike mammals, the embryo of birds grows independently within an enclosed hard structure called shell and thus, all nutrients required for embryonic development are contained in the egg. The yolk, albumen, shell membrane and shell protect the developing embryo apart from providing well balanced nutrients.

In modern poultry farming, successful management relies on accurate and complete daily record keeping. Some of the traits may influence the profit of farm, thereby affecting the economics of the farm than the other traits, and hence they are called economic traits. Economic traits can be defined as those traits which are economically important and improvement in these traits would increase the profit of the farm. These traits are generally assumed to be controlled by the genes at larger number of loci. Some of the economic traits in egg and meat type chickens are as follows:

Importance of Backyard Poultry Farming in India

Commercial chicken production in India has undergone a remarkable change in the last three decades. While India is among the top five chicken producing and top seven duck producing countries in the world, the gap between the demand and production is still alarming. Average per capita availability of eggs in big cities is 170 while it stands at 9 eggs per annum in the rural areas. Though the commercial poultry sector has made a stupendous progress over the years, the conventional free and backyard poultry farming remain neglected. Backyard poultry farming contributes around 11% to the national production while in certain states like U.P. around 60% of the poultry population is indigenous fowls reared under backyard system. The backyard sector contributed to 23 per cent of the total egg production in 2005-06.

Commercial chicken production is capital intensive and is generally concentrated in and around urban areas. There is a wide disparity in consumption of the poultry products between urban and rural population. Around 75% of country’s population living in the rural areas has limited access to the protein rich poultry products. Protein deficiency is quite common in the diets of rural people. Adoption of rural poultry farming may ameliorate the high incidence of protein hunger in growing children and pregnant women.

It has been seen that the commercial birds have poor immunity against common poultry diseases. As production is inversely proportional to the viability traits, the nutrients absorbed are mostly diverted for growth in commercial chicken. On the other hand, indigenous birds reared in rural areas are resistant to many diseases and pests. Unlike the local breeds maintained in villages, the commercial breeds require high level of input pertaining to feed and health care to maintain production and check mortality.

Poultry industry in India has registered a phenomenal growth during the last four decades making it one among the world leaders in poultry production. The development of organized poultry has in fact masked the contribution of backyard poultry or house-hold poultry of rural sector. Backyard poultry production in India is characterized by small flock size consisting of 5-10 predominantly non-descript birds maintained in extensive system under zero input conditions but fetch the owners much needed animal protein and supplementary income. Importance of backyard poultry is well recognized by Government of India and special programmes are formulated for its promotion.

Non-descript Chicken

Maintaining small flocks of local non-descript fowls under free range condition by landless poor, small and marginal farmers are a common sight in rural areas. These birds are very popular due to their adaptability to local agro climatic conditions and management practices with prominent brooding behaviour and mothering ability. But these birds are small in size, poor layers (40-50 eggs/ annum), with small clutch size and intense brooding behavior, thus making them not suitable for commercial exploitation.

Mixed farming exists in many forms depending on external and internal factors. External factors are weather patterns, market prices, technological developments, etc. Internal factors relate to local soil characteristics, composition of the family and farmers’ ingenuity. Farmers can decide to opt for mixed enterprises when they want to save resources by interchanging them on the farm - because these permit wider crop rotations and thus reduce dependence on chemicals, because they consider mixed systems closer to nature, or because they allow diversification for better risk management. There is wide variation in mixed systems. Even pastoralists practice a form of mixed farming since their livelihood depends on the management of different feed resources and animal species. Mixed farms are systems that consist of different parts, which together should act as a whole. They thus need to be studied in their entirety and not as separate parts in order to understand the system and the factors that drive farmers and influence their decisions. It may be the most important principle to achieve increased production in mixed systems, together with the awareness that crops and animals have multiple functions.

Brooding and Rearing Practices Used for Chicken

What is Brooding?

Rearing of young ones immediately after hatching for at least 2-3 weeks, either by natural means or by artificial method is called brooding. Brooding is done by two ways i.e., Natural or Artificial ways.

Natural Brooding

In the natural method a desi fowl which acts both as incubator and brooder is used to raise only a small number of chicks. She sits on eggs (chicken) for 21 days to produce chicks from fertile eggs and broods thereafter.

Among various animal husbandry enterprises, poultry production has emerged as number one position and attained industrial status in many countries, including India.

This tremendous growth in poultry production is due to the following reasons:

There is no religious taboo towards poultry and poultry products.

Egg is the most nutritious, natural, unadulterated and easily digestible food with the highest biological value.

Eggs can be consumed by all age groups and economic classes, since it is the cheapest among all the nutritious natural foods on the earth.

Among various meats, poultry meat has the highest protein, lowest fat and cholesterol content.

Poultry is the best converter of feed into meat and eggs. A hen needs only 1.5 kg feed to produce 1 dozen eggs. Similarly a broiler needs less than 2 kg of feed to produce one kg broiler meat whereas other species need more than 3 kg of feed to produce 1kg of meat.

Poultry has the shortest generation interval among various livestocks.

Poultry meat and eggs have high nutritive value. Egg is used as a standard for measuring the quality of other food proteins. It is a well balanced source of nutrients. Similarly poultry meat is easily digestible, high in protein and low in fat content. It contains all the essential amino acids. Though the poultry meat and egg production have tremendously increased in India during last few decades however due to lack of organized marketing channels poultry producers are not getting reasonable returns. Indian broiler and egg markets are in a disorganized state. In last few decades various efforts have been made so as to organize and co-ordinate marketing channel of poultry meat and eggs. Through these efforts producers are also benefited but only in some particular areas. Therefore, there is need to expand it further covering the country.

What is Marketing?

Marketing may be defined as exchange of a produce for an agreed sum of money. It is a commercial process involved in promoting, selling and distributing a product. In simple words marketing is finding out what customers want and supplying it at a profit. Marketing is a business in terms of customer needs and their satisfaction. As per P. Taylor, marketing is not simply providing products or services; it is essentially about providing changing benefits to the changing needs and demands of the customer.

Selection of site for a poultry farm: The following points should be considered while selecting site or location for a poultry farm.

The farm should be located at an elevated area with proper facilities for drainage.

To protect the farm against strong wind, tall trees may be planted surrounding the farm complex.

The farm should be located not too far from city to bring in and take out materials.

The commercial farm should be located near to marketing centres.

The breeder farm should be located in an isolated area away from commercial farm to ensure biosecurity.

The farm should have an easy access to connecting roads.

The site should have provision of electricity.

The desirable soil type for a poultry farm is loamy or sandy loam.

There should be provision of abundant potable water at the site. The water should be tested for various impurities like total solids, microbiological contamination, high percentage of salts of Na, K and Chlorine, nitrite, nitrate etc. Total bacterial count and Coliform count should be 0/ml.

Organic Farming

The FAO/WHO Codex Alimentarius Commission defines organic farming as “a unique production management system which promotes and enhances agro- ecosystem health, including biodiversity, biological cycles and soil biological activity, and this is accomplished by using on-farm agronomic, biological and mechanical methods in exclusion of all synthetic off-farm inputs”. It is a certification of a production system as opposed to the certification of a product. For a product to be certified organic, all operators in the product chain, including farmers, processors, manufacturers, exporters, importers, wholesalers and retailers must be certified organic. The establishment of organic animal/poultry husbandry requires a specific period called as “conversion period”. This period is the time taken between the start of the organic management on farm and certification of livestock farm and its product. Changing from conventional to organic management system for livestock enterprises requires a careful and gradual approach. It is learnt that global organic product has increased 20% annually over the past 10 years. Though Australia, European Union and USA are leading organic producers, a recent study indicated that developing countries including India are also adopting the system and marching ahead.