Low temperature magnetic properties of Cr0.25Co0.25Zn0.5Fe2O4 nano particles

Low temperature Mössbauer and AC susceptibility have been used to study relaxation phenomena in nano-sized particles of Cr_0.25Co_0.25Zn_0.5Fe₂O₄. From these studies, the energy density constant for this system has been estimated to be 4 x 10⁶ erg/cm³. Cation distribution has also been determined and the observed results are correlated to calculated relaxation times.     

A review on <Superscript>90</Superscript>Y-labeled compounds and biomolecules

The field of therapeutic nuclear medicine is emerging rapidly as choice of treatment in oncology and other cellular malignancies. The growth of this branch of nuclear medicine is greatly facilitated by the introduction of a number of new radiopharmaceuticals and radionuclides. ⁹⁰Y-radiopharmaceuticals have confirmed their worth in medical and clinical areas in a very short span of time. The ⁹⁰Y is a radioisotope widely used for therapeutic purposes and considerable perfection has been made to understand the chemistry of ⁹⁰Y-labeled radiopharmaceuticals. The development of these radiopharmaceuticals can be made favorable by using appropriate buffer, incubation period, optimal pH, specific activity and reaction temperature. In this review, we have discussed the preparation of range of ⁹⁰Y transporting biological molecules such as antibodies radiolabeled peptides, antigens and microsphere with their clinical applications.     

Biological entities as chemical reactors for synthesis of nanomaterials: Progress,challenges and future perspective

Synthesis of nanomaterials is being gained extensive attention in the fields of chemistry, applied physics, catalysis, drug delivery and the most important in diagnosis and therapeutic applications. Recently, many reports have been published on physical and chemical synthesis of magnetic as well as metallic nanoparticles (NPs) with viable surface functionalization, but still there is a dire need of such strategies that can combine synthetic methodology with stable surface modification found in nature. Synthesis of NPs via biological methods is the possible way to solve these barriers. However, systematized summary and outlooks of NPs synthesis via biological entities with various influencing factors e.g. temperature, pH, concentration of reactants and reaction time has rarely been reported. This review will present the distinct advantages of biological synthesis of NPs over physical and chemical methods. It will also highlight the recent progress on synthesis of NPs via various biological systems i.e. plant, fungus, bacteria, and yeast. Furthermore, it will explain various factors that control the size, shape, and morphology of these NPs. Finally, it would present the future perspectives of green chemistry for the development of nano-science and -biotechnology.     

Efficient User Based Authentication Protocol for Location Based Services Discovery Over Road Networks

In road network, the decision accuracy of event message under location privacy-enhanced scheme, fast forwarding falsification message, and collusion attacks are all knotty problems that arise in event trust management. In this paper, we proposed protocol verification to check vehicles activity in privacy manner. We proposed a new method to adjusted vehicles speed which reduces the vehicle delay suffers from network gap problem. We established privacy preserving authentication protocol to verify vehicle activities in the term of privacy preserving manner. Vehicles moving trend, velocity differences, and distance differences are taken into consideration so, to maintain as many common users as possible to reduce the cost. The cost analysis and performance evaluation indicate that our frame-work can reduced cost factor and achieve good performance. The proposed model achieved reliably and efficiently with packet rate information. The evaluation experiments based on NS-3 to our improve user’s authenticated key establishment protocol has comparatively shorter time response, reduce cost, less packet lost information and enhanced privacy preservation compared with existing methods.     

Centralized dynamic frequency allocation for cell-edge demand satisfaction in fractional frequency reuse networks

Fractional frequency reuse (FFR) has emerged as a well-suited remedy for inter-cell interference reduction in the next-generation networks by allocating frequency reuse factor (FRF) of unity for the cell-center (CC) and higher FRF for the cell-edge (CE) users. However, this strict FFR comes at a cost of equal partitioning of frequency resources to the CE which most likely has varying demands in current networks. In order to mitigate this, we propose a centralized dynamic resource allocation scheme which allocates demand-dependent resources to CE users. The proposed scheme therefore outperforms the fixed allocation scheme of strict FFR for both CC and CE users. Complexity analysis provides a fair means of analyzing the suitability of proposed algorithm. We have also compared the proposed methodology with a reference dynamic fractional frequency reuse (DFFR) scheme. Results show maximum performance gain of up to 30% for 3 reference cells employing Rayleigh fading—through normalized area spectral efficiency (ASE) analysis for both fixed allocation and DFFR. Spectral efficiency analysis also indicates per-cell performance gain for both CC and CE users. Further, detailed three-dimensional ASE plots give insights into the affects to other cells. Due to dynamic nature of traffic loads, the proposed scheme is a candidate solution for satisfying the demands of individual cells.