Realization of a Scanning Photoacoustic Technique: Thermal properties of Bulk and Film Samples

Among the large number of photothcrmal techniques available, photoacoustics assumes a very significant place because of its essential simplicity and the variety of applications it finds in science and technology. The photoacoustic (PA) effect is the generation of an acoustic signal when a sample, kept inside an enclosed volume, is irradiated by an intensity modulated beam of radiation. The radiation absorbed by the sample is converted into thermal waves by nonradiative de-excitation processes. The propagating thermal waves cause a corresponding expansion and contraction of the gas medium surrounding the sample, which in tum can be detected as sound waves by a sensitive microphone. These sound waves have the same frequency as the initial modulation frequency of light. Lock-in detection method enables one to have a sufficiently high signal to noise ratio for the detected signal. The PA signal amplitude depends on the optical absorption coefficient of the sample and its thermal properties. The PA signal phase is a function of the thermal diffusivity of the sample.Measurement of the PA amplitude and phase enables one to get valuable information about the thermal and optical properties of the sample. Since the PA signal depends on the optical and thennal properties of the sample, their variation will get reflected in the PA signal. Therefore, if the PA signal is collected from various points on a sample surface it will give a profile of the variations in the optical/thennal properties across the sample surface. Since the optical and thermal properties are affected by the presence of defects, interfaces, change of material etc. these will get reflected in the PA signal. By varying the modulation frequency, we can get information about the subsurface features also. This is the basic principle of PA imaging or PA depth profiling. It is a quickly expanding field with potential applications in thin film technology, chemical engineering, biology, medical diagnosis etc. Since it is a non-destructive method, PA imaging has added advantages over some of the other imaging techniques. A major part of the work presented in this thesis is concemed with the development of a PA imaging setup that can be used to detect the presence of surface and subsmface defects in solid samples.Determination of thermal transport properties such as thermal diffusivity, effusivity, conductivity and heat capacity of materials is another application of photothennal effect. There are various methods, depending on the nature of the sample, to determine these properties. However, there are only a few methods developed to determine all these properties simultaneously. Even though a few techniques to determine the above thermal properties individually for a coating can be found in literature, no technique is available for the simultaneous measurement of these parameters for a coating. We have developed a scanning photoacoustic technique that can be used to determine all the above thermal transport properties simultaneously in the case of opaque coatings such as paints. Another work that we have presented in this thesis is the determination of thermal effusivity of many bulk solids by a scanning photoacoustic technique. This is one of the very few methods developed to determine thermal effiisivity directly.

International Human Rights Movements and Protection of Women's Rights

This thesis is an attempt to explore the problems faced by Indian Women and to examine the ways in which the human rights of women could be better protected in the light of international movements with special reference to national legislation and judicial decisions.The evolution of human rights from early period to Universal Declaration of Human Rights, 1948 is traced in the first chapter. The second chapter deals with the evolution of human rights in India. The evolution of fundamental rights and directive principles and the role played by the Indian Judiciary in enforcing the human rights enumerated in various international instruments dealing with human rights are also dealt with in this chapter. The rights guaranteed to women under the various international documents have been dealt with in the third chapter.It is noticed that the international documents have had their impact in India leading to creation of machinery for protection of human rights. Organised violations of women's rights such as prostitution, devadasi system, domestic violence, sexual harassment at workplaces, the evil of dowry, female infanticide etc. have been analysed in the light of existing laws and decisional jurisprudence in the fourth chapter. The fifth chapter analyses the decisions and consensus that emerged from the world conferences on women and their impact on the Indian Society and Judiciary. The constitutional provisions and legislative provisions protecting the rights of women have been critically examined in the sixth chapter. Chapter seven deals with various mechanisms evolved to protect the human rights of women. The eighth chapter contains conclusions and suggestions.

Fractal based techniques for classification of mammograms and identification of microcalcifications

After skin cancer, breast cancer accounts for the second greatest number of cancer diagnoses in women. Currently the etiologies of breast cancer are unknown, and there is no generally accepted therapy for preventing it. Therefore, the best way to improve the prognosis for breast cancer is early detection and treatment. Computer aided detection systems (CAD) for detecting masses or micro-calcifications in mammograms have already been used and proven to be a potentially powerful tool , so the radiologists are attracted by the effectiveness of clinical application of CAD systems. Fractal geometry is well suited for describing the complex physiological structures that defy the traditional Euclidean geometry, which is based on smooth shapes. The major contribution of this research include the development of • A new fractal feature to accurately classify mammograms into normal and normal (i)With masses (benign or malignant) (ii) with microcalcifications (benign or malignant) • A novel fast fractal modeling method to identify the presence of microcalcifications by fractal modeling of mammograms and then subtracting the modeled image from the original mammogram. The performances of these methods were evaluated using different standard statistical analysis methods. The results obtained indicate that the developed methods are highly beneficial for assisting radiologists in making diagnostic decisions. The mammograms for the study were obtained from the two online databases namely, MIAS (Mammographic Image Analysis Society) and DDSM (Digital Database for Screening Mammography.

Elecrical conduction and dielectric behaviour of thin films of vacuum evaporated amorphous silicon, hydrogenated amorphous silicon and chemically deposited cadmium sulphide

A brief account of the several methods used for the production of thin films is presented in this Chapter. The discussions stress on the important methods used for the fabrication of a-si:H thin films. This review' also reveals ‘that almost all the general methods, like vacuum evaporation, sputtering, glow discharge and even chemical methods are currently employed for the production of a-Si:H thin films. Each method has its own advantages and disadvantages. However, certain methods are generally preferred. Subsequently a detailed account of the method used here for the preparation of amorphous silicon thin films and their hydrogenation is presented. The metal chamber used for the electrical and dielectric measurements is also described. A brief mention is made-on the electrode structure, film area and film geometry.

"Profile of Industrial workers in Kerala - A Comparative Study of the Socioeconomic Profile of Workers in Traditional and Modern Industries

The objective of this study is to assess the changes that have been taking place in the socio-economic profile of organized industrial workers of Kerala in the context of the changes that have been taking place in the state's industrial structure. with this object in view, the study seeks to find out the similarities and differences in the profile of workers belonging to two Segments of factory sector industries in Kerala viz., modern and traditional segments. It also seeks to examine the factors leading to the differences in profile, if any, and their consequences. As noted earlier, the profile of workers may be influenced both by external societal factors and by internal factors like the difference in industrial structure and the technologies used. It is proposed to assess the relative importance of these two groups of factors. In drawing up the profile, we seek to find out whether the workers belonging to the organised sector of industry in Kerala particularly the more modern sector have begun to form a ‘select group‘ in the Kerala society and the total work force. Wherever possible, it is proposed to compare the profile of the Kerala workers with those of workers in other states of India. As an incidental objective, it is also proposed to find out to the extent possible, whether trends towards labour embourgeoisement and class shifting have begun to set in among the industrial workers of Kerala, particularly among the workers in the modern industries as a result of their relative affluence and their middle class socioeconomic background. besides, the study seeks to find out whether there is any difference in the class consciousness of workers belonging to these two segments of organized industry, arising from the differences in their economic status and social background.

Impact of Quality on Ethics and Social Responsibility in Marketing, in Industries in Kerala in the present Indian Scenario

The paper ‘Impact of Quality on Ethics and Social Responsibility in Marketing in Industries in Kerala in the present Indian scenario’ highlights the observations, based on a descriptive research carried out in five leading industries in Kerala, in the private and public sector. Ethics and social responsibilities, practiced in these industries, are reflected in the results of the survey conducted on specific queries like awareness of products/services provided by them, total understanding of the requirements of the customer, open discussion on technical matters, accountability of employees to the society and social needs, consumer ethics vis a vis business ethics etc. Team working goes a long way, in building relations, which in turn, results in a progressive and effective marketing strategy. This assumes paramount importance, considering the severe competition we are facing in the light of liberalization, privatization and globalization, which encompasses the globe. The prediction of India becoming a lead nation, along with USA, China and Japan, in this decade, can get fructified only if we follow a very high standards of ethics and social responsibility, in all domains including marketing. Organizations like TRW.Rane, Sundaram Fasteners, TVS Motors, in Chennai are a few among others in India, who have achieved the highest distinction in quality viz Deming Prize, and these demonstrate their commitment to quality, society and humanity at large. Cost effectiveness, without jeopardizing quality has become the need of the hour and MRTP has become history. This trait is being brought out through the survey and the results speak for themselves. Unethical practices like switch and bait, not only brings shame to the organization, and country but also results in the company getting wiped out from the market. Adherence to standards like ISO 14000 helps to maintain the minimum level of social responsibility and environmental friendliness. Like quality audit, safety audit etc, social audit is being insisted in all progressive countries to ensure that the organization comply with the minimum statutory requirements. The paper also touches upon Corporate Social Responsibility practiced in the industries and this becomes crystal clear through their commitment to improve the community. Green Marketing lays a lot of importance on the three Rs of environmentalism viz Reduce, Reuse and Recycle. The objective of any business is to achieve optimal profit and this is possible only by reducing the cost as well as waste. In this context, management tools like brainstorming, suggestion schemes, benchmarking etc becomes helpful. These characteristics are brought out through the analysis of survey results. The conclusions drawn throw a lot of information on the desirable practices with respect to Ethics and Social Responsibility in Marketing