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Radiation injury occurs when living tissues are exposed to harmful ionizing radiation. This radiation can damage cellular structures and genetic material, leading to acute and chronic health issues. Sources of ionizing radiation include nuclear accidents, radiation therapy, industrial exposure, and environmental contaminants. Radiation injury can have devastating effects on livestock and wildlife health, necessitating effective veterinary treatment and nutritional management to mitigate its consequences.
Mechanism of radiation injury
Radiation injury occurs when high-energy particles or electromagnetic waves interact with biological tissues. The mechanisms involved include:
1. Ionization of molecules:Ionizing radiation removes electrons from atoms, forming free radicals such as hydroxyl radicals (OH) that damage cellular components.
2. DNA damage: Radiation causes single- or double-strand breaks in DNA, leading to mutations, impaired replication, or cell death.
3. Lipid peroxidation: Free radicals attack lipid membranes, disrupting cellular integrity and causing oxidative stress.
4. Protein denaturation: Radiation alters the structure and function of proteins, affecting enzymatic activities and cell signalling.
5. Inflammatory response: Damaged cells release inflammatory cytokines, leading to tissue inflammation and fibrosis.

1. Introduction

Food is processed for its preservation, hygienization or value addition. To date, the food preservation technologies such as canning, dehydration, freezing, pasteurization and controlled atmosphere and modified atmosphere packaging have been the main processes employed to preserve foods, with the use of antimicrobials and microwaves also being employed more recently. In future, however, technologies such as exposure to ionizing radiation, high pressure processing, ohmic heating and pulsed electric field processing, could potentially be the new alternatives to the above food preservation technologies.

Irradiation of food involves the exposing of food, either in prepacked form or as such to controlled doses of ionizing radiation being generated either by electrically driven machines such as electron beam accelerators, x-rays or gamma rays produced by radioactive isotopes such as CS-137,CO-60, to achieve certain desirable objectives. The process of exposing a range of food stuffs to specific doses of ionizing radiation is being used to extend the shelf life of food stuffs, to improve their overall safety and quality by eliminating pathogenic bacteria, by reducing number of food spoilage organisms, to reduce the bacterial load on herbs and spices and thereby making them safe to incorporate into food stuffs, to inhibit sprouting in stored tuber and bulb crops such as potatoes, onions and garlic, to disinfest grains, grain products and tropical fruits to prevent damage to the commodity and to meet the quarantine regulations(Arun Sharma, 2004, Farkas, 2006).

Need to Preserve Food

Food is vital for human existence. Conservation and preservation of food is a prerequisite for food security and it provides economic stability and self reliance to a nation. The need to preserve food has been felt by mankind since time immemorial. The seasonal nature of production, long distances between production and consumption centers and rising gap between demand and supply have made this need even more relevant today. The hot and humid climate of a country like India is quite favorable for the growth of numerous insects and microorganisms that destroy stored crops and cause spoilage of food every year. Spoilage can also occur due to chemical and physiological changes in stored foods. Sea-foods, meat and poultry may carry harmful microbes and parasitic organisms that cause illnesses associated with their consumption. As in other parts of the world, India has also practiced various methods of food preservation such as sun drying, pickling and fermentation which were supplemented with more energy consuming techniques such as refrigeration, freezing and canning. Each of these methods has its merits and limitations. Man has always been on the search for newer methods to preserve foods with least change in sensory qualities. Radiation processing of food is one of the latest methods developed for this purpose.

1. Introduction The chapter aims to bring out the potential benefits of radiation processing technology for value-addition of millets. How the radiation processing technology can be exploited for making millets as a popular staple food would be the central theme. The key focus is to establish if irradiation (the term generally used for radiation processing of any material) can be employed for making millets for different purposes relevant to farmers and consumers. In order to understand and prove, we would list out the challenges involved in developing the market for millets. The key points that need to be considered for this go-to-market strategy for millets are : a) Millet grains have a long shelf-life, much better than the popular grains e.g., rice and wheat, consumed worldwide, but millet flour shelf life is significantly much shorter.

13.1. INTRODUCTION

Photosynthetically active radiation is a primary energy resource for terrestrial plants, necessary for the plant growth. Plants receives this photosynthetically active radiation from sunlight as a consequence, plants are also exposed to the ultraviolet (UV)-radiation. Seven percent of the electromagnetic radiation emitted by the sun is the UV range (200-400 nm). Though representing only a small portion of the total solar electromagnetic spectrum, UV-B has a disproportionately large photobiological effect. As it passes through the atmosphere, the flux transmitted is greatly reduced, and the composition of the UV-radiation is modified. This UV-radiation is mainly divided into three classes, namely UV-A, UV-B and UV-C. The UV-A region of the spectrum (wavelengths from 320 to 400 nm) are not attenuated by ozone, so their influence will be unaffected by ozone layer reduction. This portion of the UV radiation is less damaging and important for photomorphogenic signal in plant development (Bjorn, 1994). The wavelength of UV-B portion ranges from 280 to 320 nm. This region of UV is very energetic and effectively absorbed by ozone in the stratosphere. Thus, only a very small portion, approximately 4% is transmitted to the earths. Shortwave UV-C radiation (200-280 nm) is highly energetic and strongly absorbed by atmospheric oxygen and ozone. Thus, none of this sterilizing radiation is present in terrestrial sunlight.

Radio Pharmaceuticals
Radiopharmaceuticals are a specialized class of drugs that contain radioactive isotopes and are used primarily in the fields of diagnostic imaging and therapeutic interventions in medicine. These agents can either emit radiation themselves or be used to deliver radiation to specific tissues, making them invaluable in diagnosing and treating various medical conditions, particularly cancer.
Definition and Composition
Radiopharmaceuticals consist of three main components: a radioactive molecule, a targeting molecule that selectively binds to specific cells or tissues, and a linker that connects these two components. The radioactive isotopes used in these compounds can emit different types of radiation, including gamma rays, positrons, or alpha particles, depending on their intended use—diagnostic or therapeutic. For instance, diagnostic radiopharmaceuticals are typically designed to emit low-level gamma rays that can be detected by imaging equipment such as positron emission tomography (PET) or single-photon emission computed tomography (SPECT) scanners. Therapeutic radiopharmaceuticals, on the other hand, deliver targeted radiation to destroy cancer cells while minimizing damage to surrounding healthy tissues.
Radiopharmaceuticals: Storage Guidelines
Radiopharmaceuticals are unique medicinal formulations containing radioisotopes that are used for both diagnostic and therapeutic purposes in nuclear medicine. Proper storage of these compounds is essential to ensure safety, maintain their effectiveness, and comply with stringent regulatory requirements. Storage protocols are designed to prevent contamination, minimize radiation exposure, and preserve the chemical stability of the radiopharmaceuticals.

Although a number of radioactive isotopes are found in nature, most of the isotopes used as radioactive tracers are produced artificially. Methods for producing radioactive isotopes include nuclear fission and the bombardment of selected materials by neutrons or positively charged particles.

6.1 Production of Radioactive Nuclides

Nuclear Reactors

In a nuclear reactor, a fissionable nuclear fuel such as ²³⁵U or ²³⁹Pu is placed in a defined geometry within the reactor core. Fast moving neutrons released as the ²³⁵U or ²³⁹Pu nuclei fission are slowed to thermal energy (0.025 eV) by a low-Z moderator such as water, heavy water, beryllium, or graphite surrounding or mixed intimately with the nuclear fuel. The slowly moving neutrons are absorbed by addition of ²³⁵U or ²³⁹Pu nuclei, and a chain reaction is maintained. The rate of absorption of slow neutrons by fissionable nuclei determines the fission rate for the reactor and is controlled by placing inert neutron absorbers in the reactor core. Typical neutron absorbers, usually termed control roads include boron and calcium. Heat generated in the reactor is removed by a coolant such as water or one of a variety of gases or liquid materials.

Radioactive pollution is largely attributable to radioactivity, a natural property of certain elements, such as radium, uranium, thorium, etc. of spontaneously emitting protons (alpha particles), electrons (beta particles), and gamma rays (short-wave electromagnetic waves) through the disintegration of their atomic nuclei (nuclides).

An alpha particle consists of two protons and two neutrons, which is akin to a helium nucleus. Alpha particles travel at a very slow speed, whereas gamma rays propagate at the speed of light. The alpha particles have less penetration power than the beta and gamma rays. In human tissues, alpha particles can penetrate up to a depth of about 0.005 to 0.008 cm. The gamma rays, on the other hand, are the most penetrating and can easily pass through a human body without striking anything in between. The high penetration power of gamma rays is because they have no charge; therefore, they do not interact with anything as the charged alpha particles would do

Ionization Chambers for Gases

Generally these type of instruments are known as dose-rate meter (e.g., the so called “cutie-pie”). Radiation intensity (i.e., a constant stream of particles or photons) gives rise to a continuous series of pulses, and if these are allowed to merge, they form a weak electric current, which may be amplified and registered by an electronic circuit. The final scale reading will then be a measure of the energy dissipated in the following chamber per unit of time by the ionizing particles or photons. In gas-flow counters, the radioactive samples are placed inside the detector which will be transfused by a gas at atmospheric pressure. This instrument counts particles of low energy, such as the b particles from 14C, effectively (Window-less counting).

Radioactivity

The discovery of radioactivity, in general, actually came about on a few different fonts. First was the discovery of x-ray radiation that was artificially generated in a laboratory, followed by the discovery of several elements that naturally emit radiation when the nucleus of the atoms disintegrates or decay. These are the elements that today are called radioactive elements and are said to have unstable nuclei.

Abstract

The dating of fluvial landforms by archaeological, epigraphical, historical, thermo-luminescence, radiocarbon, etc. are of greater significance because it not only provides information on the date of origin of such fluvial landforms but also isostatic, eustatic, climatic histories of the Quaternary period. Hence, the Geoscientists have always been giving greater importance to the dating of the fluvial landforms. In India, the Cauvery is one such river studied for its migratory melodrama with the help of satellite data and inferred that the river Cauvery has earlier flowed along the Hogenekkal-Chennai tract (PCS-1-Palaeo Channel System-1) during 500 thousand to 3000 YBP (years Before Present), then migrated towards southerly and flowed along the present day paths of Thoppurar, Vaniyar and Ponnaiyar rivers (PCS-2) during 2700-2300 YBP and further migrated southerly and entered into Tiruchirappalli-Thanjavur plains after 2300 YBP and finally anticlockwisely migrated in different parts of the present day Cauvery delta and stabilized as river Coleroon during 2100-750 YBP. Such broad chronological history was brought out on the basis of archaeological, epigraphical, historical, literature and few radiocarbon dating. In the present study, more number of radiocarbon dating was done in various palaeochannels of river Cauvery which has over all coincided with above observations and further provided discrete information on (1) the southerly migration of river Cauvery from PCS-1 to PCS-2 after 8000 YBP, (2) tectonic arching and splitting up of channels in Chennai region during above period, (3) gradual younging nature of palaeochannels from PCS-1 of Chennai region to PCS-3 of Tiruchirappalli – Thanjavur region, etc.

In 1896, French physicist Becquerel observed that uranium compounds affected a photographic plate that was wrapped inside a black paper. He found that all uranium compounds gave off penetrating rays. He called the production of radiation by uranium compounds “radioactivity”. Madame and Pierre Curie later identified thorium, polonium, and radium as the other radioactive elements.

Radiofrequency (RF) pasteurization is an emerging thermal processing technology that uses electromagnetic energy to generate rapid and volumetric heating within food materials. This chapter introduces the principles underlying RF heating and explains how alternating electric fields interact with polar molecules and ions to produce heat. It examines RF system configuration, electrode arrangements, packaging considerations and the operational workflow from raw-material preparation to post-treatment cooling and quality evaluation. Particular attention is given to microbial inactivation, enzyme control, uniform heating, nutrient and bioactive-compound retention, colour and structural preservation. The chapter also discusses technical limitations, hotspot formation, packaging challenges, nutritional considerations and current industrial constraints associated with RF processing.

A diagnostic radiograph is defined as one showing the tissues adequately penetrated, sharply outlined, and the variations in tissue opacity sufficiently demonstrated. An ideal diagnostic radiograph should have excellent detail, correct density and proper scale of contrast. The sharpness of the image determines the detail or definition of an image. There are two factors in radiographic quality control, viz: photographic and the geometric effect.  Density, contrast and detail are photographic aspects of radiographic quality. Detail and distortion are geometric aspects of radiographic quality. Because a radiograph is a two-dimensional (2-D) image of a three-dimensional (3-D) object, the appearance of a radiographic image varies with the patient’s orientation in relation to the primary X-ray beam. 

The radiographic appearance of various tissues is influenced by a number of factors which determine the character of X-rays.  Various exposure factors control the radiographic dentsity, detail and contrast: milliamperage (mA), time (sec), kilovoltage (kV), focal spot/film distance (FFD) and object-film distance (OFD), thickness and nature of the part radiogaphed, speed and type of film and intensifying screens, temperature and time of developing, grid type, incoming line voltage, make and type of X-ray machine. Of these, first five exposure factors (milliamperage (mA), time (sec), kilovoltage (kV), focal spot/film distance (FFD) and object-film distance (OFD) are very important as radiographic technique chart may be worked out by varying one or more of the five factors.  These exposure factors are integral to image quality and should, therefore, to be adjusted appropriately in order to achieve a diagnostic radiograph of optimal quality (image contrast, brightness and clarity).

Artifacts are any unwanted radiographic densities in the form of blemishes arising from improper handling x-ray film, exposure, processing, housekeeping or setting up a technique for an examination. Artifacts will reduce the overall quality of the radiograph and in certain cases may nullify its diagnostic outcome. An idea about the possible errors is desirable in order to adopt corrective measures.

One of the most important pieces of information in the field of  X-rays is a radiographic technique chart. If one select exposure factors from a good rating chart, consistent radiographic examinations of diagnostic quality will be obtained. In addition, there will be a saving of X-ray films because waste from repeated exposures will be avoided.

There are several types of techniques chart that can be formulated, each type must be formulated with the goat of maximum potential of a particular X-ray machine. Perhaps the most popular type of technique chart used by veterinarians is a variable kilovoltage technique chart. A variable mA second chart is probably more appropriate for the most powerful X-ray machine. However, combination of variable kilovoltage and mAs technique chart is best. Such charts take into consideration the need to adopt a technique chart for different body systems, such as a thoracic and abdominal study, as well as examination involving the musculoskeletal system. The principle of how to prepare a variable kilovoltage technique chart along with an example of such a chart is given.

Radiology has been an important diagnostic modality in exotic animals and birds (includes rodents, reptiles and fish). The radiographic equipment needed for radiography of exotic animals and birds is basically the same to that used for domestic animals. A high-milliamperage (mA) X-ray machine, having 200- or 300 mA unit is recommended to allow the use of a short exposure time (1/40 seconds) or less are preferred. Maximum kilovoltage (kVp, 40-75) is less important for avian and exotic radiography than for domestic animal radiography. As with other species, at least two radiographic views at 900 angles to each other are recommended. However, restraining and knowledge of radiographic anatomy of different species of exotic animals and birds are the prerequisite for the modality. Restrain and immobilization:

Radiographic examination of mammary tumour patients should be done prior to any treatment to detect the chances of lung metastasis. Radiographs of the thorax helped to provide information pertaining to the extent of organs involved and the presence of metastasis in the lungs. Lateral radiograph of thorax revealed absence of pulmonary metastasis in normal cases. Lung metastasis may observe in animal characterized by radioopaque soft tissue scattered in the lungs indicating pulmonary metastasis.

Sensors onboard the satellite records the intensity of emitted or reflected electromagnetic radiations in the form of digital number (DN) for each pixel. These digital numbers can be transformed to more meaningful intensity units like radiance or reflectance. This process of conversion of digital numbers to radiance or reflectance is known as radiometric calibration. Sensor specific information is required to conduct radiometric calibration.