Synthesis and structure activity studies of novel H3-receptor histamine antagonists

This thesis describes various approaches to the design and synthesis of potential H3- receptor histamine antagonists. The ultimate aim is to provide the basis for the design of a non-toxic, brain-penetrating compound which could be used as a prototype drug for investigative clinical studies in humans. Novel compounds were synthesized and submitted for testing as potential antagonists in vitro on rat cerebral cortex. The more active compounds were tested further, in vivo. The results, in terms of Kj or EC50 values were used as a guide in making further modifications of structures derived from compounds existing in the literature. The published selective H3 antagonist, N-cyclohexyl-4-(4 -imidazolyl)-!-piperidine carbothioamide (thioperamide) was used as a lead. In order to try to improve brain penetration, it was desirable to remove the imidazole group altogether, or replace it with a less hydrogen-bonding group. To this end the imidazole group was removed and the 4- piperidine position substituted with functional groups of differing polarities. The imidazole group was replaced with 2-pyridine, and the 3-(2-piperidinyl)pyridine isomer was also prepared. A significant loss of activity was observed for all these compounds. Another approach was to open up the piperidine ring in thioperamide, thus investigating the effect of increased flexibility on the molecule. This led to a drop in activity which was restored by methylating the sulphur atom. The potential toxicity of the thiocarbonyl group in thioperamide, was avoided by the synthesis of some esters and amides of urocanic acid. The p-nitrophenyl ester seemed to indicate a direction dependent dipolar interaction with the receptor. A set of amines was also prepared, one following up the p-nitro effect, and two exploring the omission of the imidazole group, this time with the retention of antagonistic activity. A number of ethyl-imidazol-4-yl isothioureas, with a range of n-alkyl and a cyclohexyl group substituted on the isothiourea nitrogen atoms, showed a progression from an antagonist as potent as thioperamide through to an agonist. Omitting the imidazole group from the most potent isothiourea antagonist, resulted in loss of activity. S-(2-(2-Pyridinyl)ethyl)isothiourea proved to be a partial agonist, while the propyl side chain analogue was an antagonist. Some analogous isoureas were prepared. Two novel synthetic schemes were developed, for the starting materials 2-(4- piperidinyl)pyridine and 3-(imidazol-4-yl)propylamine. Thus, an indication of the structure activity behaviour of antagonists at the H3 receptor has been established

A Review of Information Security from Consumer’s Perspective Especially in Online Transactions

In the current internet technology, most of the transactions to banking system are effective through online transaction. Predominantly all these e-transactions are done through e-commerce web sites with the help of credit/debit cards, net banking and lot of other payable apps. So, every online transaction is prone to vulnerable attacks by the fraudulent websites and intruders in the network. As there are many security measures incorporated against security vulnerabilities, network thieves are smart enough to retrieve the passwords and break other security mechanisms. At present situation of digital world, we need to design a secured online transaction system for banking using multilevel encryption of blowfish and AES algorithms incorporated with dual OTP technique. The performance of the proposed methodology is analyzed with respect to number of bytes encrypted per unit time and we conclude that the multilevel encryption provides better security system with faster encryption standards than the ones that are currently in use

Storage Minimization of Marine Energy Grids Using Polyphase Power

Multiple wave energy converter (WEC) buoys can be used to establish a WEC array-powered microgrid collectively forming a Marine Energy Grid (MEG). An oceanic domain with gravity waves will have significant spatial variability in phase, causing the power produced by a WEC array to have high peak-to-average ratios. Minimizing these power fluctuations reduces the demand for large energy storage by WEC array-powered DC microgrids while also reducing losses in the undersea cable to the shore. Designs that reduce energy storage requirements are desirable to reduce deployment and maintenance costs. This work demonstrates that polyphase power in conjunction with an energy storage system can be used to maintain constant power. This work shows that an N WEC array geometry can be designed to reduce the energy storage requirements needed to mitigate the power fluctuations if the WEC array produces constant, polyphase power. Additionally, the conditions that identify the wave frequencies and control the effort needed to produce polyphase power are developed. This paper also shows that increasing the number of WECs in an array reduces aggregate power fluctuations. Finally, WEC array power profiles are investigated using simulation results to verify the mathematical conditions developed for the three and six WEC cases

Finite Element Modeling of a Reinforced Concrete Column Strengthened with Steel Jacket

The reinforced concrete column is designed to have a nominal axial resistance. Under different conditions like errors in design, and changing the use of the building from residential to public or storage (extra live loads), the reinforced concrete column will not be able to sustain the desired applied load, and the strengthening is required. This paper presents a finite element model to simulate and investigate the behavior of adding steel jacket to a preloaded and non-damaged reinforced concrete column. Depending on the loading state of the non-strengthened reinforced concrete column and the purpose of adding the steel jacket, two possible cases have been studied. In the first case, which is suitable to investigate the reinforced concrete column with design errors, the steel jacket has been added to the unloaded reinforced concrete column; while the second case is suitable for adding steel jacket to the pre-loaded non-damaged reinforced concrete column. The finite element model was carried out using the ABAQUS/standard v. 6.13 software. The results obtained by the proposed finite element model showed fairly good agreement with the existing experimental and analytical results

Construction of N-M Interaction Diagram for Reinforced Concrete Columns Strengthened with Steel Jackets Using Plastic Stress Distribution Method

No attempts have been made in developing the N-M interaction diagram for reinforced concrete columns strengthened with steel jackets using the plastic stress distribution method. Therefore, this paper presents an analytical model to construct the N-M interaction diagram for reinforced concrete columns strengthened with steel jackets using the plastic stress distribution method after assuming the behavior of strengthened column to be like composite column and including the effects of confinement on concrete compressive strength. The proposed model was compared with experimental results. The comparisons showed that the model is conservative and it reveals the ultimate strength of the strengthened column. A parametric study has been also carried out to investigate the influence of various parameters on the N-M interaction diagram of the strengthened column. These parameters were: dimensions of steel angle, yield stress of the steel angles, concrete compressive strength and the size of the reinforcement bars used in RC columns. The results made clear the effects of these parameters on the N-M interaction diagram, and encouraged the use of the model in preliminary strengthening studies

Facebook Brand Communities and Social Capital

This study examines the role of social media-based marketing in generating social capital by analyzing wall posts and comments on Facebook pages of a for-profit social enterprise (TOMS) and a conventional for-profit company (Sperry Top-Sider). Our content analysis shows that compared to the Sperry Facebook page, the TOMS Facebook page featured a higher proportion of wall posts involving community engagement and social issues. While aspects of bonding social capital were most prominent in both Facebook pages, the TOMS online community was more likely to generate bridging social capital than the Sperry online community. These results suggest that the social entrepreneurship aspect of TOMS contributes to information exchanges between weak ties and forging of new ties via its brand community on Facebook. This research enhances our understanding of differences and similarities between for-profit social enterprises and conventional for-profit companies in use of social media for public relations and their implications for creating a dialogic space essential for facilitating development of social capital

Radiation Force Modeling for a Wave Energy Converter Array

The motivation and focus of this work is to generate passive transfer function matrices that model the radiation forces for an array of WECs. Multivariable control design is often based on linear time-invariant (LTI) systems such as state-space or transfer function matrix models. The intended use is for designing real-time control strategies where knowledge of the model’s poles and zeros is helpful. This work presents a passivity-based approach to estimate radiation force transfer functions that accurately replace the convolution operation in the Cummins equation while preserving the physical properties of the radiation function. A two-stage numerical optimization approach is used, the first stage uses readily available algorithms for fitting a radiation damping transfer function matrix to the system’s radiation frequency response. The second stage enforces additional constraints on the form of the transfer function matrix to increase its passivity index. After introducing the passivity-based algorithm to estimate radiation force transfer functions for a single WEC, the algorithm was extended to a WEC array. The proposed approach ensures a high degree of match with the radiation function without degrading its passivity characteristics. The figures of merit that will be assessed are (i) the accuracy of the LTI systems in approximating the radiation function, as measured by the normalized root mean squared error (NRMSE), and (ii) the stability of the overall system, quantified by the input passivity index, , of the radiation force transfer function matrix

Image Compression Based on 2D Dual Tree Complex Wavelet Transform (2D DT-CWT)

By removing the redundant data, the image can be represented in a smallernumber of bits and hence can be compressed. There are many different methods ofimage compression. This paper investigates a proposed form of compression based on2D Dual Tree complex wavelet transform (2D DT-CWT). Many wavelet coefficientsare closed to zero. Thresholding can modify the coefficients to produce more zerosthat are allowed a higher compression rate. The wavelet analysis does not actuallycompress a signal. Therefore Huffman coding is used with a signal processed by thewavelet analysis in order to compress data. Wide range of threshold values is used inthe proposed form. From the results the proposed form give higher rate ofcompression and lower RMS error compared with that forms based on DiscreteWavelet Transform (DWT), Dual Tree Real Wavelet Transform (DT-RWT) and thewell known method based Discrete Cosine Transform (DCT)

Development Of National Legal Political Strategy In Indonesia

In the development of the political situation entering the era of the third millennium, in various countries, it turned out that they were leaving political autocracies that were more dynamic toward legal reform, including Indonesia, which had implications for amendments to the 1945 Constitution. The study aimed to analyze the problem, how to correlate legal reform with the development of national legal politics in Indonesia. The study method used was descriptive analysis approach. The discussion of these problems that correlate legal reform in the development of national legal politics in Indonesia, in essence, has a philosophical content to achieve legal goals within the framework of realizing the goals of the Indonesian state, namely achieving a just and prosperous society. It can be concluded that the development of national legal politics is one of the important areas of development, which also requires intensive attention and handling like other development fields. In the transitional era of the New Order era to the Reformation era, national law reforms provided accommodation to resolve various problems. The political development of the national law seems rather difficult to implement so that in some ways the politics of national law development seems to be somewhat sloganistic. Keywords: development of national, legal political, Indonesi