A hybrid approach to differentiated services multicast

Internet, the largest network of networks has evolved from a research-oriented network to one with a myriad number of commercial applications. Over the last several years, there has been an explosion in the introduction of new Internet technologies with high-end workstations being engaged in real-time and multimedia communications like video conferencing, IP telephony, streaming video broadcast, online gaming etc. Supporting both the legacy services like email, file transfer and real-time multimedia like video conferencing requires service differentiation of Internet traffic. Moreover, multipoint communication requires implementation of multicast services. Two of the emerging technologies for service differentiation in multipoint communication are Differentiated Services (DiffServ) and multicasting. Although the two technologies share complementary goals, the integration of the two technologies is a non-trivial issue due to three fundamental problems. The problems are the scalability of per-group state information, sender- versus receiver-driven QoS, and resource management. The issues surrounding how to solve these problems provide the basis for this thesis. Edge Based Multicast (EdgeCast)--has been proposed here to satisfy the requirements for scalable DiffServ multicasting architectures. In addition it also presents a new join/leave protocol to support the EdgeCast architecture. Performance simulation has been done and compared with some already developed techniques. Finally, the whole work has been summarized and comments have been made on future applications of the architecture and several potential areas for future research

A rare case of ulnar nerve calcification in a patient without Hansen’s disease

Ulnar nerve calcification is rarely seen without association with Hansen’s disease. Ulnar nerve arises from brachial plexus within the axilla and is a major peripheral nerve of the upper limb. Its root value is C8-T1. It is one of the superficial nerves and is the most commonly affected nerve in leprosy. Our patient 52 years old female, came to Dr. D. Y. Patil hospital, Nerul casualty with a history of fall in bathroom and complaining of pain in right elbow with no neurological deficit. The radiological investigations confirmed a severely comminuted intra-articular humeral condylar fracture of the right side with a linear calcification seen in soft tissues near the ulnar nerve. It is an idiopathic ulnar nerve calcification of the right side. Hence, ulnar nerve calcification can also be seen in patients without Hansen’s disease

Self-Assembly and Catalytic Activity of Metal Nanoparticles Immobilized in Polymer Membrane Prepared via Layer-by-Layer Approach

Densely packed nanoparticles distributed in a stable and robust thin film is a highly preferred system for utilizing the various applications of nanoparticles. Here, we report covalent bond mediated layer-by-layer (LbL) self-assembled thin films of nanoparticles embedded in polymer membrane. Polymer with complementary functional group is utilized for fabrication of thin film via covalent bonding. UV-visible spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to monitor the growth of LbL thin film. Subsequently, the composite thin film is used for catalysis of an organic electron transfer reaction of p-nitrophenol to p-aminophenol by sodium borohydride. The catalytic activity of these composite films is assayed multiple times, proving its applicability as a catalyst. The kinetic data obtained by monitoring reduction of p-nitrophenol suggest that the reaction rates are directly related to the sizes of the nanoparticle and porosity of the membrane

Herringbone to cofacial solid state packing via H-bonding in diketopyrrolopyrrole (DPP) based molecular crystals: influence on charge transport

Themono-alkylation of DPP derivatives leads to cofacial pi-pi stacking via H-bonding unlike their di-alkylated counterparts, which exhibit a classical herringbone packing pattern. Single crystal organic field-effect transistor (OFET) measurements reveal a significant enhancement of charge carrier mobility for mono-hexyl DPP derivatives

Self-Assembly and Catalytic Activity of Metal Nanoparticles Immobilized in Polymer Membrane Prepared via Layer-by-Layer Approach

Densely packed nanoparticles distributed in a stable and robust thin film is a highly preferred system for utilizing the various applications of nanoparticles. Here, we report covalent bond mediated layer-by-layer (LbL) self-assembled thin films of nanoparticles embedded in polymer membrane. Polymer with complementary functional group is utilized for fabrication of thin film via covalent bonding. UV–visible spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to monitor the growth of LbL thin film. Subsequently, the composite thin film is used for catalysis of an organic electron transfer reaction of <i>p</i>-nitrophenol to <i>p</i>-aminophenol by sodium borohydride. The catalytic activity of these composite films is assayed multiple times, proving its applicability as a catalyst. The kinetic data obtained by monitoring reduction of <i>p</i>-nitrophenol suggest that the reaction rates are directly related to the sizes of the nanoparticle and porosity of the membrane

Correlation between Optical Properties and Nanomorphology of Fluoranthene-Based Conjugated Copolymer

Nanoparticles of conjugated polymers are receiving attention due to their interesting optical properties. Here we report nanoparticles of fluoranthene-based conjugated copolymer prepared by the Suzuki coupling reaction. The copolymer forms nanoparticles by the spontaneous self-assembly after evaporation of organic solvent. The mean diameter of the nanoparticles can be manipulated by varying solvent composition. We investigated the parameters that govern the nanostructured morphology of polymer by systematic variation of good and poor solvent. The UV vis and time-resolved fluorescence spectroscopy measurement reveal the use of poor solvent in the organization of nanostructures. Furthermore, transmission electron microscopy highlights the importance of rigidity of the polymer backbone in morphological development

Photophysical, electrochemical and solid state properties of diketopyrrolopyrrole based molecular materials: importance of the donor group

Diketopyrrolopyrrole (DPP) based molecular semiconductors have emerged as promising materials for high performance active layers in organic solar cells. It is imperative to comprehend the origin of such a property by investigating the fundamental structure property correlation. In this report we have investigated the role of the donor group in DPP based donor-acceptor- donor (D-A-D) structure to govern the solid state, photophysical and electrochemical properties. We have prepared three derivatives of DPP with varying strengths of the donor groups, such as phenyl (PDPP-Hex), thiophene (TDPP-Hex) and selenophene (SeDPP-Hex). The influence of the donor units on the solid state packing was studied by single crystal X-ray diffraction. The photophysical, electrochemical and density functional theory ( DFT) results were combined to elucidate the structural and electronic properties of three DPP derivatives. We found that these DPP derivatives crystallized in the monoclinic space group P21/c and show herringbone packing in the crystal lattice. The derivatives exhibit weak p-p stacking interactions as two neighboring molecules slip away from each other with varied torsional angles at the donor units. The high torsional angle of 32 degrees ( PDPP-Hex) between the phenyl and lactam ring results in weak intramolecular interactions between the donor and acceptor, while TDPP-Hex and SeDPP-Hex show lower torsional angles of 9 degrees and 12 degrees with a strong overlap between the donor and acceptor units. The photophysical properties reveal that PDPP-Hex exhibits a high Stokes shift of 0.32 eV and SeDPP- Hex shows a high molar absorption co-efficient of 33 600 L mol -1 1 cm -1 1 with a low band gap of similar to 2.2 eV. The electrochemical studies of SeDPP- Hex indicate the pronounced effect of selenium in stabilizing the LUMO energy levels and this further emphasizes the importance of chalcogens in developing new n-type organic semiconductors for optoelectronic devices