Two-parameter differential calculus on the h-superplane

We introduce a noncommutative differential calculus on the two-parameter $h$-superplane via a contraction of the (p,q)-superplane. We manifestly show that the differential calculus is covariant under $GL_{h_1,h_2}(1| 1)$ transformations. We also give a two-parameter deformation of the (1+1)-dimensional phase space algebra.Comment: 14 page

Cartan calculi on the quantum superplane

Cartan calculi on the extended quantum superplane are given. To this end, the noncommutative differential calculus on the extended quantum superplane is extended by introducing inner derivations and Lie derivatives

STUDY THE SUSTAIN RELEASE EFFECT OF DIFFERENT POLYMERS USED IN THE FORMULATION OF ASPIRIN-ROSUVASTATIN TABLETS

Objective: Low permeability of rosuvastatin calcium faces a problem of low bioavailability (absolute bioavailability 20%) as its permeation is the rate limiting factor. Rosuvastatin calcium is a selective competitive inhibitor of HMG-CoA reductase and it lowers plasma cholesterol level. Aspirin is an anti-platelet agent with half-life of 6-7 h. Frequency of dosing of both drugs is high to maintain the desired plasma drug concentration so it is selected to formulate a sustained release tablet of aspirin and rosuvastatin calcium, which release the drug in a sustained manner over a period of time by using various polymers and study the effect of polymers on the release pattern of both drugs. This approach will also enhance the residence time of rosuvastatin calcium at the absorption site and enhance permeation by the effect of the polymers used and this in turn will enhance bioavailability. Methods: Tablets contain aspirin plus rosuvastatin calcium were prepared by direct compression method. The sustained release of the tablets was obtained by using different polymers (xanthan gum, microcrystalline cellulose, HPMC K4M and chitosan) incorporated in the tablet and responsible for the release of both drugs from each tablet. Tablets were evaluated for weight variation, drug content, friability, hardness and thickness for all batches (F1 to F12). In-vitro dissolution was studied for all batches (F1 to F12) according to the type and ratio of each polymer used within these formulas i.e. (10 mg, 20 mg and 30 mg) respectively. Results: The release of aspirin and rosuvastatin calcium from sustained release tablets varied according to the type and amount (ratio) of each polymer used. After the 7 h release study; (F1, F2, F3) that uses xanthan gum as the sustain release polymer showed the most sustained formulations than other polymers. The sustained release of drugs from tablet enhanced by increasing the amount of polymer, so F3 for example, which contain 30 mg xanthan gum had most sustained release than F1 and F2 which contain (10 mg and 20 mg) of the polymer respectively, this due to polymer related viscosity, swelling and binding mechanisms.Conclusion: Using suitable polymer for sustained release will enhance the pharmacokinetics and efficacy of drugs and increase patient complains about combination therapy.Â

Error models for digital channels and applications to wireless communication systems

Digital wireless channels are extremely prone to errors that appear in bursts or clusters. Error models characterise the statistical behaviour of bursty profiles derived from digital wireless channels. Generative error models also utilise those bursty profiles in order to create alternatives, which are more efficient for experimental purposes. Error models have a tremendous value for wireless systems. They are useful for the design and performance evaluation of error control schemes, in addition to higher layer protocols in which the statistical properties of the bursty profiles are greatly functional. Furthermore, underlying wireless digital channels can be substituted by generated error profiles. Consequently, computational load and simulation time can be significantly reduced when executing experiments and performing evaluation simulations for higher layer communications protocols and error control strategies. The burst error statistics are the characterisation metrics of error models. These statistics include: error-free run distribution; error-free burst distribution; error burst distribution; error cluster distribution; gap distribution; block error probability distribution; block burst probability distribution; bit error correlation function; normalised covariance function; gap correlation function; and multigap distribution. These burst error statistics scrutinise the error models and differentiate between them, with regards to accuracy. Moreover, some of them are advantageous for the design of digital components in wireless communication systems. This PhD thesis aims to develop accurate and efficient error models and to find applications for them. A thorough investigation has been conducted on the burst error statistics. A breakdown of this thesis is presented as follows. Firstly, an understanding of the different types of generative error models, namely, Markovian based generative models, context-free grammars based generative models, chaotic models, and deterministic process based generative models, has been presented. The most widely used models amongst the generative models have been compared with each other consulting the majority of burst error statistics. In order to study generative error models, error burst profiles were obtained mainly from the Enhanced General Packet Radio Service (EGPRS) system and also the Long Term Evolution (LTE) system. Secondly, more accurate and efficient generative error models have been proposed. Double embedded processes based hidden Markov model and three-layered processes based hidden Markov model have been developed. The two types of error profiles, particularly the bit-level and packet-level error profiles were considered. Thirdly, the deterministic process based generative models’ parameters have been tuned or modified in order to generate packet error sequences rather than only bit error sequences. Moreover, a modification procedure has been introduced to the same models to enhance their generation process and to make them more desirable. Fourthly, adaptive generative error models have been built in order to accommodate widely used generative error models to different digital wireless channels with different channel conditions. Only a few reference error profiles have been required in order to produce additional error profiles in various conditions that are beneficial for the design and performance evaluation of error control schemes and higher layer protocols. Finally, the impact of the Hybrid Automatic Repeat reQuest (HARQ) on the burst error statistics of physical layer error profiles has been studied. Moreover, a model that can generate predicted error sequences with burst error statistics similar to those of error profiles when HARQ is included has been proposed. This model is constructive in predicting the behaviour of the HARQ in terms of a set of higher order statistics rather than only predicting a first order statistic. Moreover, the whole physical layer is replaced by adaptively generated error profiles in order to check the performance of the HARQ protocol. The developed generative error models as well as the developed adaptive generative error models are expected to benefit future research towards the testing of many digital components in the physical layer as well as the wireless protocols of the link and transport layers for many existing and emerging systems in the field of wireless communications

Evaluation Of Voice Trunking Performance Using AA2 Over ATM Networks

The urgent market needs for an efficient transport mechanism to carry voice traffic over Broadband Integrated Service Digital Networks (B-ISDN). Asynchronous Transfer Mode (A TM) network has been developed to integrate all types of traffic (e.g. voice, data and video) over B-ISDN networks. ATM Adaptation Layer 2 (AAL2) has been designed for efficient transport of voice, fax, and voice-band data traffic over an A TM virtual circuit. AAL2 allows the VBR sources to generate different packet sizes to be packed in an A TM cell, which increases the number of voice channels and decreases the packetization delay. The growing trend of using A TM has also given great impetus to the use of AAL2 in wire-line trunking (e.g. PBX), which provides a good opportunity for multiplexing many voice channels over a single A TM virtual connection. Voice trunking over A TM using AAL2 is the main subject of this thesis. The efficiency of AAL2 for voice transport in ATM networks is evaluated using a simulation approach. Additionally, the performance and capacity of an ATM multiplexer are analysed based on AAL2 technique. The power of AAL2 trunking and multiplexing high number of voice channels over a single ATM virtual connection makes it an efficient layer to support voice traffic with low delay and high efficiency using low bit rate as a reliable compression technique. In this thesis, the comparison between AAL2 and AAL 1 is made in terms of the number of users that can be carried over Tl AThI trunk. Then the focus is shifted to the use of AAL2 to support Voice and Telephony Over ATM (VTOA) networks. The effect of Timer-Composite Unit (Timer-CD) parameter, number of voice channels and voice coding rate on the packing density and link efficiency is further discussed. The results show that ATM cell packetization delay decreases when the number of users increases. Also, the Timer-CD affects the generation of partially filled cells when it is not set properly. Finally, the use of low coding bit rates to support high number of voice channels makes AAL2 a very efficient layer to carry VTOA networks

Transfer functions of the 2-phase servomotor

One of the most common electromechanical positioning devices for low-power applications is the 2-phase servomotor, several different . constructional forms being available. When used in a control application, various transfer functions of the machine are important and these have been investigated by previous workers using analyses of varying validity. For example, in early studies, it was common to regard the speed-torque characteristics of the machine as straight lines, and also to neglect the electrical energy storage elements in comparison with those of the mechanical system. Quite sophisticated mathematical studies using, for example, symmetrical components, were based on these assumptions, but the results obtained are obviously highly suspect in view of the doubtful basis from which they are established. Experimental verification of the results of the analyses were confined to steady-state. measurements, attention being devoted to establishing an equivalent circuit to provide steady-state characteristics. Recently, with the increasing use of powerful mathematical tools in engineering situations, several workers have attempted to obtain direct solutions of the nonlinear equations characterising the -operation of the servomotor. Thus, simulation and state transition methods, involving a step-by-step numerical solution, have attracted considerable interest. Although these approaches may provide useful numerical answers, they do not help in forming any understanding of the main factors affecting the transient performance of the machine. A recent paper used the complex convolution approach to provide analytical transfer functions, but unfortunately this paper contains a fundamental error which completely invalidates the work. The same formal approach is followed in this thesis, with the complex convolution technique being used to find time-domain expressions for the variations in speed which follow step changes in either the torque or the magnitude or phase of the control-winding voltage. As in the previous work, attention is confined to the practically important range of speed much lower than synchronous speed, Results obtained from the analysis are compared with experimentally obtained results and with results provided by earlier analyses, and an assessment is made of the usefulness and limitations of the various techniques

Бактерицидный эффект He-Ne лазера (632,8 нм) на колонии Staphylococcus aureus

The bactericidal effect of 632.8 nm low level laser has been studied in order to point out both the effective power and laser exposure time on Staphylococcus aureus, which is reported to be involved in several dermatology problems. Low level laser has been reported to be useful for infected wounds, tissue necrosis, nerve injury, osteoarthritis or other chronic pain syndromes. Numerous studies have been conducted to quantify the effective laser parameters, i.e. dose, power, and exposure time, which ultimately leads toward clinical implementation. Staphylococcus aureus bacteria colonies were exposed to laser doses with powers of both 1 and 3 mW at different exposure times varies between 3 to 30 minutes. The bacterial colonies were isolated from a patient with inflamed wounds. Two sets of bacterial colonies were prepared to be exposed to laser beam. Next, the bacterial colonies were compared before and after exposing them to laser doses. The results showed that laser sessions have reduced the number of the bacterial colonies for both doses; 1 and 3 mw at the different exposure times and concentrations. The results revealed significant dose dependent bactericidal effects of He-Ne laser on Staphylococcus aureus at 3 mW for 30 minutes, which was found to be more effective in reducing the amount of bacteria to the less than 2% of its initial count. The results exhibited the reduction of the number of colonies as a function of exposure time. Appropriate doses of 632.8 nm can kill Staphylococcus aureus, suggesting that a similar effect may be used in clinical cases of bacterial infection.Нами был изучен бактерицидный эффект низкочастотного лазера с длиной волны 632,8 нм с целью определения эффективной мощности и времени воздействия лазера на бактерии Staphylococcus aureus, участвующие в патогенезе ряда дерматологических заболеваний. Ранее проведены многочисленные исследования количественной оценки эффективных параметров лазера: световой дозы, плотности мощности и времени воздействия. В настоящем исследовании на колонии бактерий Staphylococcus aureus воздействовали лазерным излучением мощностью 1 и 3 мВт при разном времени воздействия (от 3 до 30 мин). Колонии бактерий были выделены у больного с воспаленными ранами. Воздействие лазером уменьшило количество бактериальных колоний во всех экспериментах. Результаты выявили значительное дозозависимое бактерицидное воздействие гелий-неонового лазера на Staphylococcus aureus. При мощности 3 мВт при воздействии в течение 30 мин количество бактерий снизилось до уровня менее 2% от его первоначального количества. Результаты показали уменьшение количества колоний в зависимости от времени воздействия. Лазерное излучение на длине волны 632,8 нм обладает бактерицидным действием в отношении Staphylococcus aureus

Study of Optical OFDM System for Wireless LAN Applications

The advantages of optical fiber make it possible to extend the data rate transmission and propagation distance. Orthogonal frequency division multiplexing (OFDM) as a multicarrier technique (MC) is used in hybrid optical-wireless system designs because it has the best spectral efficiency to radio frequency (RF) interference and lower multipath distortion. In this dissertation, a study and evaluation of optical OFDM based wireless local area network (W-LAN) systems are presented. The baseband of the OFDM signal is fully transmitted and up-converted to a radio frequency signal. Also, to reduce system costs, simple base stations (BSs) are interconnected to a central office (CO) via an optical fiber. All the required operations are achieved in the CO. The directly modulated laser (DML) and continuous wave (CW) laser are used in the system simulations as optical laser sources. Identical rectangular microstrip patch antennas have been used at the transmitter and the receiver as well. The simulations were carried out for different SMF and MMF lengths, and the variable wireless distance between the transmitting and receiving antennas was in a range of 40 dB to 80 dB. The purpose of this work is to provide a framework for integrating wireless and optical technologies in one system with the presence of OFDM technology. The required microstrip patch antenna parameters for the system are analyzed and designed. The microstrip patch antenna (S-parameters) is loaded into the Optisystem communication software tool in Touchstone format. As a result, this achievement gives a greater impetus to design an integrated optical-wireless system, and simulation results validate the proposed technique. Then, the integration of the microstrip patch antenna and optical OFDM system is achieved, and the performance is intensely studied. The entire system has been presented by developing analytical models and simulations. The system performance results are obtained regarding EIRP, SNR, signal constellations and BER. The results show that this integrated optical wireless link is very robust for carrying OFDM based wireless LAN signals over an optical fiber. Moreover, using an active patch antenna in the system helps to increase the coverage service to more than 30 meters when an SMF of 80 km length is utilized