Synchrotron Radiation

In this book, the readers will find chapters exposing them to different, useful applications of synchrotron radiation in various fields of physics, archeology, and biosciences. Different research has been carried out in this field and has conveyed a novel approach to the applications of synchrotron radiation.The chapters are crisp and precise and will motivate students, young researchers, and professionals to carry out research with novel ideas. The authors have successfully tried to convey their ideas in a very simple text. It will be useful for both the novice and those who are currently doing research in this field. I hope it will complete my task of enriching researcher into synchrotron radiation with better applications and also giving students a better platform for understanding the subject

Emerging technologies for the non-invasive characterization of physical-mechanical properties of tablets

The density, porosity, breaking force, viscoelastic properties, and the presence or absence of any structural defects or irregularities are important physical-mechanical quality attributes of popular solid dosage forms like tablets. The irregularities associated with these attributes may influence the drug product functionality. Thus, an accurate and efficient characterization of these properties is critical for successful development and manufacturing of a robust tablets. These properties are mainly analyzed and monitored with traditional pharmacopeial and non-pharmacopeial methods. Such methods are associated with several challenges such as lack of spatial resolution, efficiency, or sample-sparing attributes. Recent advances in technology, design, instrumentation, and software have led to the emergence of newer techniques for non-invasive characterization of physical-mechanical properties of tablets. These techniques include near infrared spectroscopy, Raman spectroscopy, X-ray microtomography, nuclear magnetic resonance (NMR) imaging, terahertz pulsed imaging, laser-induced breakdown spectroscopy, and various acoustic- and thermal-based techniques. Such state-of-the-art techniques are currently applied at various stages of development and manufacturing of tablets at industrial scale. Each technique has specific advantages or challenges with respect to operational efficiency and cost, compared to traditional analytical methods. Currently, most of these techniques are used as secondary analytical tools to support the traditional methods in characterizing or monitoring tablet quality attributes. Therefore, further development in the instrumentation and software, and studies on the applications are necessary for their adoption in routine analysis and monitoring of tablet physical-mechanical properties

Remote sensing in the coastal and marine environment. Proceedings of the US North Atlantic Regional Workshop

Presentations were grouped in the following categories: (1) a technical orientation of Earth resources remote sensing including data sources and processing; (2) a review of the present status of remote sensing technology applicable to the coastal and marine environment; (3) a description of data and information needs of selected coastal and marine activities; and (4) an outline of plans for marine monitoring systems for the east coast and a concept for an east coast remote sensing facility. Also discussed were user needs and remote sensing potentials in the areas of coastal processes and management, commercial and recreational fisheries, and marine physical processes

Spectral Properties of Accretion Disks Around Galactic and Extragalactic Black Holes

We study the spectral properties of a very general class of accretion disks which can be decomposed into three distinct components apart from a shock at $r=r_s$: (1) An optically thick Keplerian disk on the equatorial plane ($r>r_s$), (2) A sub-Keplerian optically thin halo above and below this Keplerian disk $r>r_s$ and (3) A hot, optically slim, $\tau\sim 1$ postshock region $r<r_s\sim 5-10 r_g$ where $r_g$ is the Schwarzschild radius. The postshock region intercepts soft photons from the Keplerian component and reradiates them as hard X-rays and $\gamma$ rays after Comptonization. We solve two-temperature equations in the postshock region with Coulomb energy exchange between protons and electrons, and incorporating radiative processes such as bremsstrahlung and Comptonization. We also present the exact prescription to compute the reflection of the hard X-rays from the cool disk. We produce radiated spectra from both the disk components as functions of the accretion rates and compare them with the spectra of galactic and extragalactic black hole candidates. We find that the transition from hard state to soft state is smoothly initiated by a single parameter, namely, the mass accretion rate of the disk. In the soft state, when the postshock region is very optically thick and cooled down, bulk motion of the converging flow determines the spectral index to be about $1.5$ in agreement with observations.Comment: 45 pages of Latex file + 10 figures (Misprints in Description and Caption of Figure 2 are corrected

Skylab experiments. Volume 5: Astronomy and space physics

The astronomy and space physics investigations conducted in the Skylab program include over 20 experiments in four categories to explore space phenomena that cannot be observed from earth. The categories of space research are as follows: (1) phenomena within the solar system, such as the effect of solar energy on Earth's atmosphere, the composition of interplanetary space, the possibility of an inner planet, and the X-ray radiation from Jupiter, (2) analysis of energetic particles such as cosmic rays and neutrons in the near-earth space, (3) stellar and galactic astronomy, and (4) self-induced environment surrounding the Skylab spacecraft

Parasitic Flux Analysis of Cooled Infrared Detectors for Space Applications

An infrared imager measures radiations emitted by an object in specified spectral bands to determine change in object’s characteristics over a period of time. A typical infrared imager consists of focusing optics and a cryogenically cooled two-dimensional infrared detector array mounted on the cold tip of an active micro-cooler vacuum sealed with an optical window, typically known as integrated detector cooler assembly (IDCA). Detection of feeble radiant flux from the intended target in a narrow spectral band requires a highly sensitive low noise sensor array with high well capacity. However, in practical applications the performance of an infrared imager is limited by the parasitic thermal emissions from optical elements and emissions from IDCA components like vacuum window, Dewar walls which are generally kept at ambient temperature. To optimise the performance of imager it becomes imperative to estimate these parasitic fluxes and take corrective actions to minimise their effects. This paper explains an analytical model developed to estimate parasitic fluxes generated from different components of a long wave infrared imager. Validation of the developed model was carried out by simulations in ZEMAX optical design software using ray trace method after analytical computations in MATLAB

Lunar surface exploration by satellite. An integrated experiment package to perform measurements of the composition of the lunar surface Final report

Integrated experiment package to measure lunar surface composition - gamma ray, alpha particle, X ray fluorescence, and neutron albedo experiment

Airglow emissions : fundamentals of theory and experiment

In this article, discovery of airglow and ionosphere has been discussed briefly in the historical and scientific perspectives. Mentioning about all significant atmospheric parameters, different areas of research in airglow and different ionospheric layers of importance have been briefly described. Different types of airglow emissions, related chemical kinetics, different excitation mechanisms of the involved atomic, molecular or ionic species have been discussed giving stress specially to four main airglow emissions. Different layers of ionosphere, their characteristic material content and specific ranges of responses to different kinds of interacting fields etc. have also been briefly discussesd. The Sun has been described as the main source of all kinds of energetic interactions with the terrestrial ionosphere. Specific solar parameters, that are representatives of various solar activity, have been discussed briefly in relation with the corresponding covariation of various ionospheric parameters involved in the calculations of airglow intensity. Different solar activity periodicities that have been discovered upto date are mentioned. Relations of different airglow emissions with ionospheric activities and specific ionospheric parameters have been briefly described. The important role of ozone in the stratosphere and lower thermosphere in the production of some airglow emissions has been discussed with exemplary works. Different wellknown features of airglow intensity variations such as altitudinal variation, latitudinal variation etc have also been mentioned. Different atmospheric models have been briefly described along with their usefulness. Descriptions of different missions and campaigns with which a number of airglow experiment sets are involved , have been presented in a tabular form. Discovery of some new airglow lines, some newly proposed excitation mechanisms and related kinetics, and some remeasured or reevaluated constants and coefficients have been reported too. Effect of different types of solar activity, of different kinds of lunar influences and of various terrestrial atmospheric features, such as, geomagnetic field alignment, geomagnetic storm, lightning, earthquake, dynamical coupling between layers of thermosphere, E x B drift and ring current etc on terrestrial airglow emissions have also been briefly discussed. Some interesting airglow related features which have been discovered in recent past are discussed. Applications of different airglow features have been reported. Lastly, facts and speculation about ionospheric compositions, activities and possible airglow emission features of other inner and outer planets, satellites, comets and meteors have been discussed very briefly.Author Affiliation: R Chattopadhyay and S K Midya 1.Haripal G.D. Institution, Khamarchandi, Hooghly-712 405, West Bengal, India 2.Department of Physics, Serampore College, Serampore, Hooghly-712 201, West Bengal, India 3.Centre for Space Physics, 43 Chalantika, Garia Station Road, Kolkata-700 084, India E-mail : [email protected] G.D. Institution, Khamarchandi, Hooghly-712 405, West Bengal, India 2Department of Physics, Serampore College, Serampore, Hooghly-712 201, West Bengal, India 3Centre for Space Physics, 43 Chalantika, Garia Station Road, Kolkata-700 084, Indi

Terahertz Detectors (THzDs): Bridging the Gap for Energy Harvesting

It is indispensable to integrate electronics with environment for better lives. Huge amount of solar energy, dark energy, and unused microwave energy is untapped till now due to insufficient availability of high frequency THz detectors. The difference between THz wave detection and THz electric field detection must be clear. THz wave detection connects the detection of explosives, drugs, astronomy, metals, and imaging applications, etc. On the other hand, THz electric field detection involves the conversion of electromagnetic (EM) radiations to usable DC power. The optimum choice of detectors for energy harvesting is a highly diverse area. The latter part is concentrated on the nonlinear behavior of the incoming radiations and has been highlighted also. In this chapter, metal‐insulator‐metal (MIM) diode detectors have been explored to become a best choice for high frequency detectors