558 research outputs found
Mobile Based Stock Exchange (MBSE)
Most stock exchanges provide stock price quotation through market watch service. Since stock prices change every second; investors have to observe the change throughout the
trading session in order to make the right decision at the appropriate moment. However, accessing this service has limitation, where it is only available through the brokerage
firms' screens as well as online computer. Since there is a tremendous need to access information regarding the stock prices, an alternative way of accessing the information is
required. This arises when the investors are not able to be at the brokerage firm, or contact their brokers or access the information about the stock through online computer.
Mobile technology and wireless communication have been identified as potential alternatives since they are able to fulfill the need of the investors through ubiquitous
service. This study discusses a prototype Mobile-Based Stock Exchange (MBSE) and simplifies ubiquitously accessing online stock exchange through mobile devices. MBSEwas developed for stock exchange market watch. The results of user evaluation on the MBSE indicate that it has been rated highly in terms of The Usefulness, Ease of Use, Information Quality, Functionality, Interface Quality, Design/Layout and Outcome/Future Use. Moreover, the results also indicate that there is no significant difference between novices and experts for MBSE users in most measured dimensions
Remediation of NORM and TENORM Contaminated Sites—Review Article
Naturally Occurring Radioactive Materials (NORM) present in many natural resources, human activities that exploit these resources enhance the concentrations, solubility, and subsequently the exposure to these materials. NORM and Technically Enhanced NORM (TENORM) dispersion in soil, groundwater, and surface water has induced different contamination problems. Dealing with such problems differs from site to site depending on the associated risk. The development of green and sustainable remediation project aims to restore the contaminated sites to productive use and conserves undeveloped areas, minimize or eliminate the pollution source, reduce waste generation, and reduce the associated costs. This work is intended to highlight recent advances in remediation activities for NORM contaminated sites. The main aim is to identify difficulties that affect the application of different remediation technology. This will be achieved by reviewing advances in regulating NORM and TENORM, and site contamination assessment. Then different remediation technologies, their applicability and factors that affect the efficiency of the remediation process will be identified
Optimal relay coordination of an adaptive protection scheme using modified PSO algorithm.
Recently, future smart grids are described by a dominantly fluctuating character due to the power consumption change from peak to off-peak loading conditions, the operation of micro-grids in grid-connected or islanded mode and other possible network topologies resulting in an effective change in network impedances and short circuit current level. Therefore, the situation from protection sensitivity, selectivity and speed may become more and more challenging. In this paper, Adaptive protection scheme is proposed to respond to structural variations occurred in interconnected power systems. A designed software based on Modified Particle Swarm Optimization (MPSO) algorithm is suggested to solve the relay coordination problem in modern distribution networks. In this study, the 14 IEEE bus system is tested via three power system scenarios showing the effect of adding and disconnecting of DG units and the occurrence of sudden line outages on the system. The obtained results show that the proposed algorithm has achieved optimum relay settings for each existing network topology
Developing an adaptive protection scheme towards promoting the deployment of distributed renewable sources in modern distribution networks: operational simulation phase.
The large-scale integration of renewables into the electricity grid as distributed generation sources for providing clean energy supply together with the recent introduction of the smart grid concept, have accelerated the need to modernize the existing protection schemes to accommodate the challenges originated from distributed generation. This paper presents an adaptive protection scheme that has been developed to allow automatic adjustment of optimal relay settings in response to multiple network topologies and unexpected variations arising from renewable energy systems integration towards promoting their deployment in modern distribution networks. A Simulink model is developed to simulate the operation of the adaptive protection scheme, being interlinked to a linear-programming technique to allow optimizing the relay settings in response to dynamic changes of network topology associated with the integration of distributed generation sources. The performance of the developed adaptive protection scheme in accommodating the dynamic changes of network topology has been assessed under two proposed network topologies using a small-scale network that has been built in the lab as part of experimental work for the purpose of implementing the adaptive control unit. Results have demonstrated the effectiveness of the developed approach in optimizing the relay settings in response to the subjected topology changes, achieving minimum relay trip times while ensuring a suitable relay coordination is satisfied in each of the tested network topologies
Towards digitalized and automated substations: implementation of adaptive protection control unit and monitoring system for modern distribution networks under increased hosting capacity of distributed renewable sources.
Maximizing the hosting capacity of modern distribution networks to accommodate more distributed renewable sources is key driver to realise energy system security and Net-Zero carbon goals. Protection systems under increased share of renewable sources became more challenging with diverse topology changes originated from the addition, disconnection, or islanding of distributed generation to secure increasing energy demands. This paper aims to implement an adaptive protection control unit interlinked with an interactive monitoring system to enable the real-world application of smart adaptive protection schemes for modern distribution networks under increased hosting capacity of distributed renewable sources. An adaptive protection control kit is experimentally developed to enable the automatic adjustment of optimal relay settings in response to network topology changes arising from the integration of distributed generation. A set of relay settings are pre-optimized within a small-scale meshed network under possible network topologies and stored offline via a master microcontroller which then uses the online breaker status to identify the corresponding network topology and accordingly adjust the pre-optimized relay settings. A human machine interface is further designed and interlinked with the experimentally developed control kit via a slave microcontroller, providing real-time data of actual current measurements and waveforms together with topological changes and self-adaptation of pre-optimized relay settings. Experimental results showed successful adjustment of pre-optimized relay settings in response to topological changes while achieving coordination time intervals within acceptable limits under the tested network topologies
Occurrence of intestinal parasites and hygiene characters among food handlers in Gaza strip, Palestine
Noise Effects on a Proposed Algorithm for Signal Reconstruction and Bandwidth Optimization
The development of wireless technology in recent years has increased the demand for channel resources within a limited spectrum. The system\u27s performance can be improved through bandwidth optimization, as the spectrum is a scarce resource. To reconstruct the signal, given incomplete knowledge about the original signal, signal reconstruction algorithms are needed. In this paper, we propose a new scheme for reducing the effect of adding additive white Gaussian noise (AWGN) using a noise reject filter (NRF) on a previously discussed algorithm for baseband signal transmission and reconstruction that can reconstruct most of the signal’s energy without any need to send most of the signal’s concentrated power like the conventional methods, thus achieving bandwidth optimization. The proposed scheme for noise reduction was tested for a pulse signal and stream of pulses with different rates (2, 4, 6, and 8 Mbps) and showed good reconstruction performance in terms of the normalized mean squared error (NMSE) and achieved an average enhancement of around 48%. The proposed schemes for signal reconstruction and noise reduction can be applied to different applications, such as ultra-wideband (UWB) communications, radio frequency identification (RFID) systems, mobile communication networks, and radar systems
Modified technique for sacrospinous-sacrotuberous ligament complex colpopexy in apical prolapse: preliminary results of a pilot randomized study
Background: Apical prolapse is frequently encountered following vaginal hysterectomy either or as a primary finding in patients with pelvic organ prolapse. This pilot comparative study introduces a modified sacrospinous sacrotuberous ligament fixation with biologic mesh augmentation which necessitates no special kits to be performed.Methods: This study was conducted at Department of Obstetrics and gynecology, Ain Shams University, Cairo, Egypt, and Department of Women Health of Bethanien Hospital, Iserlöhn, Germany from March 2018 to May 2020. 40 women with either utero-vaginal or vaginal vault prolapse were randomized to either; group (A): 20 women scheduled for modified sacrospinous-sacrotuberous fixation procedure, or group (B): 20 women scheduled for conventional sacrospinous-sacrotuberous fixation procedure.Results: Improvement of the Pelvic organ prolapse quantification system (POP-Q) stage from the base line pre-operative stage was 1 stage higher in the modified SS/ST-F group compared to the conventional SSF group (3 stage improvement from baseline in SS/ST-F group versus 2 stage improvement only in conventional SSF group).Conclusions: This pilot study provides a modified sacrospinous sacrotuberous ligament colpopexy technique which is easier to be performed and mastered, does not need the use of special devices, provides better improvement of grade of prolapse and less complications compared to the conventional technique.
Adsorption of toxic dye using red seaweeds from synthetic aqueous solution and its application to industrial wastewater effluents
This study investigated the potential application of dried powder from red seaweed Pterocladia capillacea as an eco-friendly adsorbent for removing Crystal Violet Dye (CV dye) from a synthetic solution. The adsorption conditions for the adsorbent were determined, in batch conditions, by changing different experimental parameters such as initial CV dye concentrations (5, 10, 20, 30, and 40 mg L–1), contact time (15, 30, 60, 120, and 180 min.), adsorbent doses (0.025, 0.05, 0.1, 0.2, and 0.3 g), temperature (25, 35, 45, and 55°C), and pH (3, 5, 7, 9, and 11). The adsorption mechanisms of CV dye onto the P. capillacea biomass were examined using various analytical techniques such as FTIR, BET, UV–Visible, and SEM. These characterizations suggest the average BET surface area of P. capillacea was 87.17 m2 g–1 and a pore volume of 0.10368 cc g−1. Moreover, according to the FTIR study, the dye has been deposited inside the adsorbent’s pores after adsorption. The adsorption behavior of the adsorbent was investigated by performing both kinetic and equilibrium isothermal studies in batch conditions at 25°C. Also, the thermodynamic factors showed the exothermic nature and physisorption of the adsorption process, which tends to be spontaneous at lower temperatures. In addition, Langmuir, Dubinin-Radushkevich, Freundlich, and Tempkin isotherm models were selected to evaluate the adsorption of CV dye on P. capillacea. The equilibrium adsorption data were best represented by the Freundlich, indicating multilayer adsorption on the heterogeneous surface. The qe experiment and calculation values for the Pseudo-Second-Order and interparticle diffusion kinetic models were determined. The results showed that, under optimum conditions P. capillacea exhibited 98% removal of CV dye from synthetic wastewater. Moreover, it will help to regenerate the adsorbents that can be reused to adsorb CV dye ions and develop a successful adsorption process. Finally, this study concluded that the dried powdered form of P. capillacea is an attractive source for adsorbing CV dye from aqueous solution
Biochemical Studies on Albino Rats after Administration of Nitrosamine and the Therapeutic Actions of Vitamin C, Honey Bee or Crushed Citrus Seeds
The current investigation was carried out to study the effect of administration of dibutyl nitrosamine (DBNA) precursors namely: dibutylamine (DBA) and sodium nitrite for eight weeks on some biochemical blood indices of albino rats and the therapeutic action of vitamin C (150 mg/L), honey bee (100 mg/L) or crushed citrus seeds (100 g/Kg diet) against toxicity induced by DBNA. Nitrosamine administration elevated the concentrations of serum glucose, triglycerides, total cholesterol and nonprotein nitrogenous constituents. Activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were increased also significantly following DBNA treatment to rats for eight weeks, but total protein were decreased. However, honey bee, Vitamin C and crushed citrus seeds were able to modulate the affected values of the previous biochemical parameters, approximately, near to the control values. Our findings suggested that honey bee, Vitamin C and crushed citrus seeds suppresses DBNA induced hepato-renalo-carcinogenesis, maybe, by modulating the antioxidant defense status
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