Excitation wavelength dependent fluorescence behaviour of nano colloids of ZnO

In this paper, the fluorescence behaviour of nano colloids of ZnO has been studied as a function of the excitation wavelength. We have found that excitation at the tail of the absorption band gives rise to an emission that shifts with the change of the excitation wavelength. The excitation wavelength dependent shift of the fluorescence maximum is measured to be between 60 and 100 nm. This kind of excitation wavelength dependent fluorescence behaviour, which may appear to be in violation of Kasha’s rule of excitation wavelength independence of the emission spectrum, has been observed for nano ZnO colloids prepared by two different chemical routes and different capping agents. It is shown that the existence of a distribution of energetically different molecules in the ground state coupled with a low rate of the excited state relaxation processes, namely, solvation and energy transfer, are responsible for the excitation wavelength dependent fluorescence behaviour of the systems.

Excitation wavelength dependent fluorescence behaviour of nano colloids of ZnO

In this paper, the fluorescence behaviour of nano colloids of ZnO has been studied as a function of the excitation wavelength. We have found that excitation at the tail of the absorption band gives rise to an emission that shifts with the change of the excitation wavelength. The excitation wavelength dependent shift of the fluorescence maximum is measured to be between 60 and 100 nm. This kind of excitation wavelength dependent fluorescence behaviour, which may appear to be in violation of Kasha’s rule of excitation wavelength independence of the emission spectrum, has been observed for nano ZnO colloids prepared by two different chemical routes and different capping agents. It is shown that the existence of a distribution of energetically different molecules in the ground state coupled with a low rate of the excited state relaxation processes, namely, solvation and energy transfer, are responsible for the excitation wavelength dependent fluorescence behaviour of the systems.

Judicial Creativity in Constitutional Interpretation

The focus of study in this thesis is on the necessity and extent of judicial creativity in interpreting provisions in certain crucial areas in the Constitution of India. Judicial innovation was essential to adapt the constitutional provisions to modern changed context. Creativity of the Court has been mainly in the creation and introduction of certain new concepts not found in any specific provision of the Constitution which, but were essential for its meaningful interpretation.Independence of the judiciary, basic structure and certain elements of social justice cherished as ideal by the makers of the Constitution are some such concepts infused into the Constitution by the judiciary. The second aspect of creativity lies in the attempt of the Court to construe provisions in the Constitution with a view to upholding and maintaining the concepts so infused into the Constitution. Introduction of those concepts into the Constitution was necessary and is justified. all important features of the Constitution like democratic form of government, federal structure, judicial review, independence of judiciary and rule of law were thus included in the doctrine to prevent their alteration by amendments.As a result of such a construction, the nature of those directive principles itself has changed. They ceased to be mere directives for state action but became mandate for it. If left to legislative or executive will for their implementation, the directives would have remained enforceable as ordinary right.To conclude, notwithstanding the errors committed by the Supreme Court in construing the provisions in the above areas, they stand testimony to its creative and innovative response in interpreting the Constitution. If this trend is continued, it will be possible to achieve through the judicial process, maintenance of independence of the judiciary, avoidance of destruction of the Constitution through the process of amendment and realisation of social justice envisaged in the directive principles. It can be hoped that the Court would maintain its energetic and vibrant mind and rise up to the occasions and extend the same to other areas in future.

A Generic Software Architecture for a Domain Specific Distributed Embedded System

In this paper, we have evolved a generic software architecture for a domain specific distributed embedded system. The system under consideration belongs to the Command, Control and Communication systems domain. The systems in such domain have very long operational lifetime. The quality attributes of these systems are equally important as the functional requirements. The main guiding principle followed in this paper for evolving the software architecture has been functional independence of the modules. The quality attributes considered most important for the system are maintainability and modifiability. Architectural styles best suited for the functionally independent modules are proposed with focus on these quality attributes. The software architecture for the system is envisioned as a collection of architecture styles of the functionally independent modules identified