Optical absorption studies in ion implanted and amorphous semiconductors - Investigations in some tetrahedrally co-ordinated and chalcogenide materials

The thesis provides an overall review and introduction to amorphous semiconductors, followed by a brief discussion on the important structural models proposed for chalcogenide glasses and their electrical, optional and thermal properties. It also gives a brief description of the Physics of thin films, ion implantation and Photothermal Deflection Spectroscopy. A brief description of the experimental setup of a photothermal deflection spectrometer and the details of the preparation and optical characterization of the thin film samples. It deals with the employment of the subgap optional absorption measurement by PDS to characterize the defects, amorphization and annealing behavior in silicon implanted with B+ ions and the profiles of ion range and vacancy distribution obtained by the TRIM simulation. It reports the results of all absorption measurements by PDS in nitrogen implanted thin film samples of Ge-Se and As-Se systems

Transition Metal Complexes of Schiff Bases with Azide and Thiocyanate as Coligands:Spectral and Structural Investigations

Metallo-organic chemistry,incorporating the frontiers of both inorganic and organic chemical aspects,is a topic of utility concern.The first exploration of coordinated metal complexes dates back to the ninettenth century,during the days of Alfred Werner.Thereafter,inorganic chemistry witnessed a great outflow of coordination compounds,with unique structural characteristics and diverse applicatons.The diversity in structures exhibited by the coordination complexes of multidentate ligands have led to their usage as sensors,models for enzyme mimetic centers,medicines etc.The liganda chosen are of prime importance in determining the properties of coordination compounds.Schiff bases are compounds obtained by the condensation of an aidehyde or ketone with an amine.The chemical properties of Schiff bases and their complexes are widely explored in recent years owing to their pharmacological activity,their catalytic activities and so on.On the other hand pseudohalides like azide and thiocyanate are versatile candidates for the construction of dimeric or polymeric complexes having excellent properties and diverse applications.So a combination of the Schiff bases and the pseudohalogens for the synthesis of metal complexes can bring about interesting results.An attempt into this area is the besis of this Ph.D theis.

An Analysis of Work Related Stress Factor in Selected Industries in Kerala ,India

Occupational stress is becoming a major issue in both corporate and social agenda .In industrialized countries, there have been quite dramatic changes in the conditions at work, during the last decade ,caused by economic, social and technical development. As a consequence, the people today at work are exposed to high quantitative and qualitative demands as well as hard competition caused by global economy. A recent report says that ailments due to work related stress is likely to cost India’s exchequer around 72000 crores between 2009 and 2015. Though India is a fast developing country, it is yet to create facilities to mitigate the adverse effects of work stress, more over only little efforts have been made to assess the work related stress.In the absence of well defined standards to assess the work related stress in India, an attempt is made in this direction to develop the factors for the evaluation of work stress. Accordingly, with the help of existing literature and in consultation with the safety experts, seven factors for the evaluation of work stress is developed. An instrument ( Questionnaire) was developed using these seven factors for the evaluation of work stress .The validity , and unidimensionality of the questionnaire was ensured by confirmatory factor analysis. The reliability of the questionnaire was ensured before administration. While analyzing the relation ship between the variables, it is noted that no relationship exists between them, and hence the above factors are treated as independent factors/ variables for the purpose of research .Initially five profit making manufacturing industries, under public sector in the state of Kerala, were selected for the study. The influence of factors responsible for work stress is analyzed in these industries. These industries were classified in to two types, namely chemical and heavy engineering ,based on the product manufactured and work environment and the analysis is further carried out for these two categories.The variation of work stress with different age , designation and experience of the employees are analyzed by means of one-way ANOVA. Further three different type of modelling of work stress, namely factor modelling, structural equation modelling and multinomial logistic regression modelling was done to analyze the association of factors responsible for work stress. All these models are found equally good in predicting the work stress.The present study indicates that work stress exists among the employees in public sector industries in Kerala. Employees belonging to age group 40-45yrs and experience groups 15-20yrs had relatively higher work demand ,low job control, and low support at work. Low job control was noted among lower designation levels, particularly at the worker level in these industries. Hence the instrument developed using the seven factors namely demand, control, manager support, peer support, relationship, role and change can be effectively used for the evaluation of work stress in industries.

Investigation of structural, optical and electrical properties and valence band splitting in cu-ln-se compounds

Investigations on thin films that started decades back due to scientific curiosity in the properties of a two-dimensional solid, has developed into a leading research field in recent years due to the ever expanding applications of the thin films in the fann of a variety of active and passive microminiaturized components and devices, solar cells, radiation sowces and detectors, magnetic memory devices, interference filters, refection and antireflection coatings etc. [1]. The recent environment and energy resource concerns have aroused an enonnous interest in the study of materials in thin film form suitable for renewable energy sources such as photovoltaic devices. Recognition of the immense potential applications of the chalcopyrites that can fonn homojunctions or heterojunctions for solar cell fabrication has attracted many researchers to extensive and intense research on them. In this thesis, we have started with studies performed on CuInSe, thin films, a technologically well recognized compound belonging to the l•ill-VI family of semiconductors and have riveted on investigations on the preparation and characterization of compoWlds Culn3Se5. Culn5Seg and CuIn7Se12, an interesting group of compounds related to CuInSe2 called Ordered Vacancy Compounds, having promising applications in photovoltaic devices. A pioneering work attempted on preparing and characterizing the compound Culn7Sel2 is detailed in the chapters on OVC's. Investigation on valence band splitting in avc's have also been attempted for the first time and included as the last chapter in the thesis. Some of the salient features of the chalcopyrite c.ompounds are given in the next section .of this introductory chapter.

A framework for translating English text into Malayalam using statistical models

A methodology for translating text from English into the Dravidian language, Malayalam using statistical models is discussed in this paper. The translator utilizes a monolingual Malayalam corpus and a bilingual English/Malayalam corpus in the training phase and generates automatically the Malayalam translation of an unseen English sentence. Various techniques to improve the alignment model by incorporating the morphological inputs into the bilingual corpus are discussed. Removing the insignificant alignments from the sentence pairs by this approach has ensured better training results. Pre-processing techniques like suffix separation from the Malayalam corpus and stop word elimination from the bilingual corpus also proved to be effective in producing better alignments. Difficulties in translation process that arise due to the structural difference between the English Malayalam pair is resolved in the decoding phase by applying the order conversion rules. The handcrafted rules designed for the suffix separation process which can be used as a guideline in implementing suffix separation in Malayalam language are also presented in this paper. Experiments conducted on a sample corpus have generated reasonably good Malayalam translations and the results are verified with F measure, BLEU and WER evaluation metrics